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Monday, February 01, 2010Last Update: 9:43 AM PT

Formaldehyde-Laden FEMA Trailers May Be Headed to Haiti

By SABRINA CANFIELD

NEW ORLEANS (CN) – The trailer industry and lawmakers have asked FEMA to send thousands of empty, Katrina-era trailers to Haiti. Opponents of the idea say sending the formaldehyde-emitting trailers is a self-serving attempt to dump shoddy U.S. products on the poor. U.S. citizens made homeless by hurricanes have filed thousands of lawsuits, and multiple class actions, claiming the trailers made them sick.
Days after Haiti’s 7.0 earthquake left up to 200,000 dead and hundreds of thousands homeless, Mississippi state Senator Billy Hewes III, R-Gulfport, was among the first to say the 100,000 trailers, bought by the government after hurricanes Katrina and Rita, could be shipped to Haiti for shelter.
If the trailers are “being staged in Mississippi and there is no apparent use for them,” Hewes told the Biloxi-Gulfport Sun Herald, “there’s a great need for them down in Haiti and there’s no need for them to sit here in Mississippi.”
“If I had the choice between no shelter and having the opportunity of living in a shelter that might have some fumes, I know what I’d choose,” Hewe told The Associated Press.
“If these trailers were good enough for Mississippians, I would think they were good enough for folks down in Haiti as well.”
The trailers were bought by the government to house hundreds of thousands of Gulf Coast hurricane refugees in 2005, but after people got sick – and by some accounts, died – tests found the trailers contained high levels of formaldehyde, a chemical found in building materials that can cause respiratory problems and cancer. Many of the trailers have sat empty for years, and many are damaged.
Opponents of the idea say that formaldehyde-laden particle board inside the trailers poses higher risks of toxicity in hot, humid climates – such as in the American South and Haiti. The wood swells with heat and sweats with moisture, increasing emissions of toxic formaldehyde fumes.
“Just go ahead and sign their death certificate,” Paul Nelson of Coden, Ala., whose mother allegedly died because of formaldehyde fumes in her FEMA trailer, told The Associated Press.
The U.S. Agency for International Development, which is coordinating U.S. assistance in Haiti, has expressed no interest in sending the trailers to the earthquake-stricken country, the AP reported. FEMA spokesman Clark Stevens declined to comment on the idea.
Haitian Culture and Communications Minister Marie Laurence Jocelyn Lassegue said she hadn’t heard of the idea and added: “I don’t think we would use them. I don’t think we would accept them.”
In a Jan. 15 letter to FEMA, U.S. Rep. Bennie Thompson, D-Miss., chairman of the House Committee on Homeland Security, said the trailers could be used as temporary shelter or emergency clinics.
“While I continue to believe that these units should not be used for human habitation, I do believe that they could be of some benefit on a short-term, limited basis if the appropriate safeguards are provided,” he wrote.
For the recreational and travel trailer industry, which has lost thousands of jobs during the recession, the push to send the trailers to Haiti is motivated by more than charity. Thousands of lawsuits have been filed in the South against the largest trailer manufacturers – among them, Indiana-based Gulf Stream Coach – by people who lived in the trailers and say they have suffered illnesses as the result of toxic gases.
Bidding is under way in an online government-run auction to sell the trailers in large lots at bargain prices. The RV industry fears the sales will reduce demand for new products. Some of the bids so far work out to less than $500 for trailers that ordinarily sell for about $20,000 new.
Lobbyists for the industry, much of which is based in Indiana and includes major manufactures such as Gulf Stream, have been talking to members of Congress and disaster relief agencies to see if it would be possible to send the trailers to Haiti.
“This isn’t really the best time for the RV Industry to have very low-priced trailers put out onto the market,” the group’s spokesman Kevin Broom told AP.
How much, if any, formaldehyde remains in the trailers is unknown. The auction site warns that the trailers may not have been tested for the chemical, and FEMA says buyers are required to sign an agreement not to use the auctioned trailers for housing. Broom maintains that most are “perfectly safe,” and “the handful of trailers that might have a problem” can be removed.
Lindsay Huckabee, who lived in a FEMA trailer in Mississippi for two years with her husband and five children, blames a series of illnesses on the trailer.
“While some shelter is better than no shelter,” she said, “sending FEMA trailers is a bad idea without tight controls and warnings.”
“I think it’s very self-serving to hand off a product that’s not good for Americans and say, ‘Hey, we’re doing a good thing here,'” she said.
In Haiti, Ermite Bellande said she has had no shelter since losing her three-story house. Still, she doesn’t want one of the trailers.
“We have nothing,” she lamented. “But I would rather sleep outside than be in a metal box full of chemicals.”
Joseph Pacious, who was hoping to find shelter at a tent city near the Port-au-Prince airport, disagreed. “The trailers may be hot, and they may make us sick,” he said. “But look at how we are living already. How bad can it be?”
Myriam Bellevu, who is sleeping in a tent because she does not feel safe in her damaged home, said: “If the trailers are not good, the Americans must keep them for themselves. It’s true that we are poor, but if they want to help, they must help in a good way.”
Officials with the Mississippi Emergency Management Agency said Mississippi does not have authority on the matter because the trailers belong to FEMA.
Hewes told the Sun Herald that he spoke with officials from the Port of Gulfport who are planning to send supplies to Haiti. In case the trailers are released by FEMA, the officials have looked into transportation. One container company at the Port of Gulfport, Crowley, has facilities in Haiti, although Haiti’s main port has been severely damaged.
Hewes said it might be possible to ship a few trailers in military cargo planes.

http://www.courthousenews.com/2010/02/01/24241.htm

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From my notes – 08 – 21 – 09

National Geographic

“The Science of Brick”

Broadcast 08-21-09, (Atlanta 2 – 4 am)

Has shown at end about – earthquake resistant polymer and polymer/fiberglass fabrics to retrofit on brick to prevent earthquake damage to them.

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Science of Brick | National Geographic Channel

Science of Brick. Explore one of the world’s first building materials. See how brick is made and how is was used to form such time-tested structures as the
channel.nationalgeographic.com/episode/science-of-brick…/Overview – Cached

Science of Brick | Video | | National Geographic Channel
Science of Brick , Science of Brick , No other building material is so
channel.nationalgeographic.com/episode/science-of-brick-2665/Videos

Science of Brick | Photos | Image: A mason builds a wall in a …
Science of Brick,The Markets of Trajan in the Roman Forum is a brick
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More results from channel.nationalgeographic.com »

http://channel.nationalgeographic.com/episode/science-of-brick-2665/Overview#tab-Videos/02325_00

Near the end of the show – Science of Brick by Nat Geo – there was a segment about earthquake resistant brick retrofit fabrics made of polymers and polymer / fiberglass which were wrapped or incorporated into the building structure. Good explanation of what happens to a building during an earthquake or other extreme event. –  cricketdiane (facebook note)

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Link –

http://channel.nationalgeographic.com/episode/science-of-brick-2665/Videos/02325_00

Embed –

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Science of Brick

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Special Thanks
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Read more: http://channel.nationalgeographic.com/channel/tout/2665-show-credits#ixzz0gI0xrYHP

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**

http://books.google.com/books?id=FN-C9ns0rQcC&pg=PA49&lpg=PA49&dq=polymer+earthquake+retrofit+brick+structures&source=bl&ots=3tqk-ltHNs&sig=WJQ1r3Jbelz3excPqW6Q2RNvYog&hl=en&ei=IMmCS6u3IY60tgfHnYDWBg&sa=X&oi=book_result&ct=result&resnum=10&ved=0CDIQ6AEwCQ#v=onepage&q=&f=false

pp, 54 and pp.57

Developments in mechanics of structures and materials: proceedings …, Volume 2

edited by Andrew Deeks, Hong Hao

2005

pp. 71

Comparative study of failure mechanisms in steel and concrete members strengthened with CFRP composites

S. Fawzia, R. Al-Mahaidi & X.L. Zhao

Department of Civil Engineering, Monash University, Clayton, Victoria, Australia

S. Rizkalla

North Carolina State University, Raleigh, North Carolina, USA

ABSTRACT:  Over the last decade, advanced composite materials, like carbon fibre reinforced polymer (CFRP), have increasingly been used in civil engineering infrastructure. The benefits of advanced composites are rapidly becoming evident. This paper focuses on the comparative performance of steel and concrete members retrofitted by carbon reinforced polymers. The objective of this work is a systematic assessment and evaluation of the performance of CFRP for both the concrete and steel members available in the technical literature. Existing empirical and analytical models were studied. Comparison is made with respect to failure mode, bond characteristics, fatigue behavior, durability, corrosion, load carrying capacity and force transfer. It is concluded that empirical expressions for the concrete-CFRP composite are not readily suited for direct use in the steel-CFRP composite. The paper identifies some of the major issues that need further investigation.

I     INTRODUCTION

Modern advanced composites have been in use since World War II. The ability to design the materials, coupled with high strength-to-weight ratio, allow engineers to maximize material usage for specific applications. While many studies have been conducted on the repair and strengthening of concrete structures using advance composites [Teng et al. 2002, Hollaway & Lemming 1999], only a very limited amount of research has been conducted on the application of these materials to steel structures [Moy 2001, Hollaway & Caidei 2002]. This paper evaluates the performance differences of CFRP for the concrete and steel members which have been reported in the technical literature. Further, the paper discusses the non-applicability of the existing knowledge of the CFRP-concrete systems to the CFRP-steel systems.

2     COMPOSITES IN STEEL AND CONCRETE STRENGTHENING

The common FRP composites, namely GFRP, CFRP, and Aramid composites, have been used for strengthening RC structures in both practical application and research. These three FRP materials have comparable stress-strain behavior:  linear elastic up to final brittle rupture when subjected to tension. This is a very important property in terms of structural use of FRP composites. Typical stress strain curves for CFRP, GFRP, concrete and steel show the brittle behavior of FRP composites and concrete and the ductile behavior of steel. This has two major structural consequences. First, these materials do not possess the ductility of steel, and second, owing to this lack of ductility, the redistribution of stresses in FRP composite is restricted. Consequently, the methods used to strengthen steel structures with CFRP composite cannot be the same as existing methods for strengthening RC structures.

The upgrading or retrofitting of steel structures is not as widespread as the upgrading or retrofitting of RC structures, as it poses a different and more complex set of problems [Mertz & Gillespie 1996, Mertz et al. 2001]. First, the likelihood of lateral buckling makes it necessary to fabricate composite steel sections where the compression flange is continuously supported by a reinforced concrete slab. Second, the high strength and stiffness of steel make it a more difficult material to strengthen, especially with high-strength carbon-fiber-reinforced polymers (CFRP). For a given allowable strain, CFRP reinforcement will work at a lower stress than steel, unless the steel is allowed to yield under certain load and geometry conditions. Finally, the CFRP/adhesive bond is generally the weakest link and is likely to control the mode of failure. Epoxy adhesive is much weaker than steel, and nonlinear finite element analyses have indicated [Sen et al. 2001], that the epoxy adhesive may fail at the ends of the CFRP plates, owing to high peeling stresses.

3     DIFFERENCES BETWEEN CONCRETE AND STEEL STRUCTURES STRENGTHENED WITH CFRP

Technically it is possible to compare CFRP strengthened concrete structures with CFRP strengthened steel structures, as some of the aspects are common to both although there are many differences. However, CFRP with steel bonding should not be thought of as simple as CFRP with concrete bonding since the two materials, concrete and steel, are completely different, their strengthening process with CFRP is somewhat different. A brief comparison is made below.

3.1     Material properties

The Young’s modulus of CFRP is about 6 times that of concrete whereas the Young’s modulus of CFRP is up to 2 or 3 times that of steel. Ohelers (2000) compared the material properties of steel with FRPs. It is evident that the peeling mechanism of RC structures strengthened by FRP plates and by steel plates is the same but the load at which peeling occurs differs due to the difference in the material properties.

For the same reason, the composite action between CFRP and steel would be different compared to that of CFRP and concrete structures. In concrete structures, the CFRP can be kept thin because of the very favorable stiffness of CFRP compared to concrete and also because the bond strength between CFRP and concrete is limited by the concrete rather than the adhesive.

In steel structures, the CFRP strips have to be thicker because the stiffness of CFRP will be high and the stiffness has to be transmitted across the adhesive. Another concern is in regard to Poisson’s ratio. Poisson’s ratio for the CFRP and the steel structures are different which can cause edge failures [Mertz & Gillespie 1996].

3.2     Surface preparation

Previous studies have shown that for an effective adhesive bonding process either with a concrete or steel surface, a fresh, chemically active surface is essential [Laura et al. 2001, Hollaway & Caidei 2002]. Surface preparation may be achieved chemically by etching or by abrasion. There are three types of abrasion, namely hand abrasion, grinding with stone and mechanical abrading. Hand abrasion is less efficient than other abrasion. In the case of concrete structures, usually abrasion pad is used which can trap contaminants and moisture. However, in case of steel tubes, mechanical abrasion is used and found to be more effective [Fawzia et al. 2004], because of the non-contact process.

Surface preparation of the steel substrate is very important if a good bond is to be achieved between the steel and the CFRP. The choice of bonding method is also important. The obvious approach is to use a suitable adhesive applied to the bonding surfaces. The choice of glue is more critical for steel structures than for the concrete structures.

3.3     Force transfer

It is evident from the literature that how the force transfer takes place between adhesive and adherends is a very wide subject. It is important because the rate of force transfer and the corresponding development length affect the length and position of the CFRP.

Many investigations have been carried out to evaluate the bond force transfer in the case of the concrete structure strengthened with CFRP [Chajes et al. 1996]. The test results concluded that strain distribution in the composite plate along the bonded length decreases at a fairly linear rate, which means that the force transfer is largely uniform. This leads to a constant value of bond resistance.

In the case of bond force transfer in steel members, Miller (2000) have discussed experimental and analytical studies to quantify force transfer. The test result concluded that 98% or more of the force transfer between the steel and CFRP plates occurs within 100 mm. They also showed that the force transfer across bonded plate-to-plate interface may reduce the required force transfer distance.

An analytical model of the bonded joint was also used to investigate the adhesive shear stress and CFRP strain distribution. This research only focused on the sustained loads. More research is needed under varying environmental conditions subjected to static and cyclic loads.

3.4     Environmental effects

The effect of environmental conditions on debonding failure is different for CFRP-steel system [Stehn & Hedman 2001], compared to that for CFRP-concrete system [Malvar et al. 2003, Karbhari 2002]. Concrete tends to creep and shrink, while steel does not.

CFRP is the largest class of materials with mechanical properties that have characteristics of both elastic solids and viscous fluids, and hence they are classified as viscoelastic materials. For this reason, creep becomes a significant consideration in assessing their long-term carrying capacity. Thus, when CFRP is used to strengthen a concrete structure, it is easier to design the bonding process because creep is the common characteristic of both of these materials.

The incompatibility of thermal coefficients for CFRP and concrete may cause significant stresses to develop at the bond line during large swings in temperature [Hamilton & Dolan 2000]. The thermal coefficient for concrete is 1.0 x 10-5 ⁰C while that of CFRP is near zero.

The difference in thermal coefficients is even larger between steel and CFRP. There is a potential galvanic corrosion problem associated with the strengthening of steel members using CFRP [Karbhari & Shulley 1995, Tavakkolizadeh & Saadatmanesh 2001, Torres-Acosta 2002]. Corrosion is more likely to happen in steel structures than in concrete structures. However, in the case of direct contact between carbon fibers and steel in the presence of an electrolyte, the wet corrosion cell could accelerate the corrosion of steel and create possible blistering and subsequent delamination or debonding.

In order to prevent the formation of such and electric circuit, it is necessary to insulate the two materials from one another. In theory, the adhesive alone should be sufficient to isolate the two constituents. However, material discontinuities or installation defects could result in local galvanic couples. In order to safeguard against this possibility, a fiberglass scrim may be used in the bond line [West 2001]. It was demonstrated that the current flow through the composite was eliminated through the presence of the fiberglass scrim and that the corrosion resistance was significantly improved,

Thermal exposure may be an advantage up to a certain temperature, as it can result in a post-cure for the CFRP composite and adhesive. However, at an elevated temperature, adhesive can soften and cause an increase in viscoelastic response, a reduction in mechanical performance and an increase in the susceptibility to moisture absorption.

The effect of elevated temperatures on bond strength is different for the CFRP-concrete system and for the CFRP-steel system. Concrete and steel behave differently at elevated temperatures because they have very different thermal conductivity and thermal expansion properties. Tests indicated that at 350⁰C CFRP retains 35% of its normal temperature breaking load and 40% of its normal temperature tensile elastic modulus [Alsayed et al. 2000]. Research work on CFRP strengthened concrete beams at elevated temperatures [Sakashita et al. 1997], found that the capacity and ductility of such beams depend on the types of CFRP used.

Recent fire resistance tests at EMPA – Swiss Federal Laboratories for Materials Testing and Research [Busel & Barno 1996], conducted on reinforced concrete beams show that CFRP has demonstrated excellent fire resistance when a protective coating is applied to the composite layer. Vermitex, a Vermiculite-Cement blend plus trace chemical additives and lightweight polymer beads, is now available to provide passive fire protection to CFRP strips used to reinforce concrete beams, slabs and columns [LAF group 2003]. The impact of Vermitex on the debonding failure of CFRP strengthened steel members is unknown.

Concrete itself is more susceptible to the effects of moisture than steel [Hollaway & Leeming 1999]. Of greater significance at this stage is that the properties of the matrix resin in CFRP materials, together with the properties of adhesives, are susceptible to the effects of heat and moisture. The result of moisture absorption, which is reversible, is to lower the glass transition temperature of these materials, leading to a change in their mechanical properties. If water is trapped behind the CFRP bonding, the insulating properties of the composite materials reduce the risk of disruption of the concrete due to freeze/thaw [Hamilton & Dolan 2000]. However, this problem would be more difficult to detect with steel structures.

The effect of cyclic loading on bond strength is different for the CFRP-concrete system and for the CFRP-steel system. There are two types of cyclic loads, namely low-amplitude cyclic load related to fatigue and high-amplitude cyclic load related to earthquakes. Research has been conducted on CFRP strengthened RC bridges [Barnes & Mays 1999, Shahawy & Beitelman 1999, Masoud et al. 2001, Tavakkolizadeh & Saadatmanesh 2003a, Bassetti et al. 2000, Sean & Scott 2003], under low-amplitude fatigue load.

For CFRP-strengthened RC beams, fatigue fracture of the internal reinforcement steel bar was found to be the dominant failure mode, whereas for CFRP-strengthened steel girders, fatigue crack initiates in the steel followed by debonding failure. The CFRP reduces the crack growth rate in the steel.

On the other hand, the performance of the CFRP strengthened concrete or a steel system under high-amplitude cyclic load is almost unknown as pointed out in the latest review article on this topic [Buyukozturk et al. 2004]. The Precast Seismic Structural Systems (PRESS) program has taken the lead on research and design recommendations for precast concrete structures in areas of high seismicity [Priestly 1996].

One of the vulnerable structural elements observed in an earthquake [Earthquake 1995], is the connection between precast concrete shear wall panels. The lack of available repair techniques for these welded connections led to the investigation by Volnyy & Pantelides (1999). It is well known that steel and concrete behave very differently under high-amplitude cyclic loads. A completely new debonding model is expected for CFRP-steel system under such loading.

4     BOND CHARACTERISTICS AND FAILURE MODES OF CFRP LAMINATES

The bond of the CFRP reinforcement to the concrete and steel is of critical importance since it is the means for the transfer of stresses between the CFRP composite and the substrates. Many studies were carried out to investigate CFRP bonding. The findings of these studies are presented in the following sections.

4.1     Concrete structures

Chajes et al. (1996) conducted tests investigating bond strength and force transfer. Their results show that the use of ductile adhesives (i.e.  those having a low stiffness and a large strain to failure) leads to a less effective bond. Concrete itself does not have ductile behaviour like steel. Two types of failure mechanisms were observed:  direct concrete shearing beneath the bond surface and cohesive type failure. The results presented are based on single lap shear tests. The effect of double lap shear test as well as the plate width is unknown.

Brosens  & Van Gemert (1997) showed that an increase in bonded length increases the failure load. This is contrary to the findings of other researchers. However, they found that the influence of bonded length decreased beyond a certain threshold.

In another study by Lee and Al-Mahaidi (2003), advanced photogrammetry measurement technique was used to study the deformation mechanism of shear deficient reinforce concrete T-beams post strengthened with web bonded L-shaped CFRP laminate strips. (the pdf I saw on the T-beams with CFRP, my note). A maximum increase in the shear capacity of 81% was achieved in one of the T-beams strengthened with the external CFRP reinforcement.

The study conducted by Horiguchi and Saeki (1997) showed that there is high correlation between the bond strength and the compressive strength. The bond strength decreases with the decrease of the compressive strength. The combined effect of varying compressive strength, adhesive ductility and composite-material properties is still unknown. Four types of failure mechanism were observed in this study. They are concrete fracture, delamination of CFRP, CFRP rupture, and concrete Aggregate/matrix interfacial fracture.

(My Note – in the concrete slab construction that has been pan-caking the slabs one on top of the other, how is it possible if the steel reinforcing re-bar was embedded and extended from the columns to the slab for some length and the rebar within the concrete slab was extended into the columns for some length? Wouldn’t the failure of that system leave the areas surrounding the columns with the embedded rebar and the columns in place with only the middle sections of the slab dropping in chunks, maybe pulling over the columns or leaving them standing? How is it possible that these slab constructions have dropped like pancake layers into more or less unbroken or partially broken slabs of concrete with rebar sticking out sheared off at some point? Why would the columns and reinforcement in use at that point of support, have served no vertical support purpose whatsoever and consistently, in all these building collapses appeared to have behaved identically regardless of extreme or fatigue event that caused them? How is that possible?)

An analytical model based on shear lag theory has been developed by Bizindavyi & Neale (1999). This theory is valid only in the elastic range. There is a significant difference between the analytical model for determining shear stress distribution of the CFRP bonded concrete member and the CFRP bonded steel member [Miller 2000]. The observed modes of failure were shearing of the concrete beneath the glue line and rupture of the composite coupon. With regard to transfer lengths, empirical expressions by Bizindavyi & Neale (1999), are not readily suited for direct use for composite-to-steel joints, unless appropriate correction factors based on experimental investigations are applied.

Karbhari and Engineer (1996) developed a peel test for bond and also developed a methodology for understanding the different mechanisms and modes of interfacial fracture.

The investigation by Pham and Al-Mahaidi (2004) attempted to assess all available theoretical models. Their assessment is based on failure mechanisms and verification against a database comprised of 154 simply supported retrofitted RC beams. They found that for simple and conservative design, midspan debond can be avoided by limiting FRP stress level. End debond (or anchorage failure) can be avoided by limiting the interfacial bond stress between FRP and concrete to a concrete shear stress of 0.4fct.

It has been shown in the literature [Hassan and Rizkala 2003, Pham and Al-Mahaidi 2001], that the debonding failure in CFRP-concrete system depends on many factors such as concrete properties (strength, modulus and thermal conductivity), quality of surface preparation, creep and shrinkage of concrete, CFRP modulus and types of resins or adhesives, stiffness, bonded length, number of plies, CFRP width.

4.2     Steel structures

Unlike RC structures, the bond characteristics of steel structures strengthened by CFRP has not been widely reported in the literature. The principles of CFRP bonding to steel structures are not similar to those used for CFRP reinforced concrete structures because of the more complex nature of the steel with CFRP strengthening, particularly with aging steel structures [Miller 2000]. Some of the problems have already been discussed in this paper. In addition, researchers have verified the durability of the CFRP-steel bond under few environmental conditions. However, there is a need to understand bond characteristics and durability of the bond between steel CFRP bonded structure under varying environmental conditions subjected to static, cyclic and sustained loads.

From the study by Miller (2000), it is evident that effective parameters for CFRP bonded steel member are the geometric and material properties of the steel substrate, CFRP reinforcement, and adhesive. More experimental and analytical research is needed for steel CFRP bonded structure to find an effective parameter for the debonding failure.

Jiao and Zhao (2004) investigated the behaviour of CFRP strengthened butt-welded very high strength circular steel tubes. A significant strength increase was achieved using the CFRP-epoxy strengthening technique. Failure modes observed were the adhesive failure mode, fiber-tear failure mode, and mixed failure mode (combination of fiber-tear and adhesive failure). This research was restricted to very high strength steel tube, so that behaviour of normal strength steel tube bonded with CFRP needs to be investigated.

pp. 74

Sen et al. (2001) conducted experiments on damaged specimens repaired by using CFRP laminates bonded to the tension flange and tested to failure. Test results showed significant increases in ultimate capacity of steel composite bridge members strengthened by CFRP laminates. The failure mode of the strengthened sections was generally ductile and accompanied by considerable deformation.

Tavakkolizadeh and Saadatmanesh (2003b) found that the stress in the CFRP laminate for the one-layer system was 75% of its ultimate strength while in the five-layer system, it dropped to 42%. This indicates that a balanced design should be considered to effectively utilize the strength of CFRP laminates. Several distinct failure modes observed in this test, namely:  concrete crushing; CFRP debonding; CFRP rupture; web crippling; and shear stud failure.

Brent et al. (2003) tested two existing, structurally deficient steel girder bridges strengthened utilizing CFRP composite materials. They concluded that there is a significant increase of live load carrying capacity of these bridges.

Nikouka et al. (2002) establish the effects on bond strength of the adhesive during the curing period when it is subjected to cyclic loading similar to that experience in real bridges not closed to rail traffic during the strengthening process. It has concluded that adhesive cure under cyclic loading can affect the bending stiffness and failure load of the reinforced beam.

5     CONCLUSIONS

The existing knowledge of CFRP-concrete debonding may not be applicable to CFRP-steel system because of the reasons stated in section 3. There is a distinct difference between the debonding mechanism of the CFRP-steel system and the CFRP-concrete system even under normal conditions, i.e.  without the effects of environment, elevated temperature and cyclic loading. It is well known that concrete tends to fracture under tension or shear force while steel tends to yield under tension and buckle under shear force. The debonding in CFRP-concrete is mainly caused by concrete fracture whereas the debonding in CFRP-steel tends to be an interface one.

Empirical expressions for the concrete-CFRP composite are not readily suited for direct use for the steel-CFRP composite. Less research work has been conducted on the steel CFRP composite structures. Although they provide good results, some test methods seem to be completely dedicated to one type of material or to one bonded surface per specimen. CFRP steel composite members require many more tests in order to obtain more definite information regarding the behaviour at the interface.

pp. 75

REFERENCES

Alsayed, S.H., Al-Salloum, Y.A. & Almusallam, T.H.  2000. Fibre-reinforced polymer repair materials – some facts. Proceedings of the Institution of Civil Engineers, Civil Engineering, 138(3):  131– 134.

Barnes, R.A. & Mays, G.C.  1999. Fatigue performance of concrete beams strengthened with CFRP plates. Journal of Composites for Construction. ASCE, 3 (2):  63 – 72.

Bassetti, A., Nussbaumer, A. & Hirt, M.A.  2000. Crack repair and fatigue extension of riveted bridge members using composite materials, Bridge Engineering Conference, ESE-IABSE-FIB, 26 – 30 March, Sharm El Sheikh:  Egypt.  227 – 238.

Bizindavyi, L. & Neale, K.W.  1999. Transfer lengths and bond strengths for composites bonded to concrete, Journal of Composites for Construction. ASCE, 3 (4):  153 – 160.

Brent, M.P., Terry, J.W., Wayne, F.K., Hawash, A.A. & Lee, Y.S.  2003. Strengthening of steel girder bridges using FRP. Proceedings of the 2003 Mid-Continent Transportation Research Symposium. Iowa State University, August.

Brosens, K. & Van Gemert, D.  1997. Anchoring stresses between concrete and carbon fiber reinforced laminates. Non-Metallic (FRP) Reinforcement for Concrete Structures, Japan Concrete Institutes, Japan, 1:  271 – 278.

Busel, J.P. & Barno, D.  1996. Composites extend the life of concrete structures, Composites Design & Application. Winter, 12 – 14.

Buyukozturk, O., Gunes, O. & Karaca, E.  2004. Progress on understanding debonding problems in reinforced concrete and steel members strengthened using FRP composites, Construction and Building Materials, 18:  9 – 19.

Chajes, M.J., Finch, W.W. Jr., Januszha, T.F. & Thomson, T.A.  1996. Bond and force transfer of composite material plates bonded to concrete. ACI Structural Journal, 93(2):  295 – 303.

Earthquake Engineering Research Institute,  1995. Guam earthquake reconnaissance report. Earthquake Spectra, Supplement to volume 11, 95(20:  63 – 137.

El-Tawil., Ognuc, S., Okeil, C.A. & Shahawy, M.  2001. Static and Fatigue analysis of RC beams strengthened with CFRP laminates, Journal of Composites for Construction, ASCE, 5(4):  258 – 267.

Fawzia, S., Zhao, X.L., Al-Mahaidi, R. & Rizkalla, S.  2004. Investigation into the bond between CFRP and steel tubes. The Second International Conference on FRP Composites in Civil Engineering, December, Adelaide, submitted.

Hamilton, H.R. & Dolan, C.W.  2000. Durability of FRP reinforcements for concrete. Prog. Struct Eng Mat., 2:  139 – 145.

Hassan, T. & Rizkalla, S.  2003. Investigation of bond in concrete structures strengthened with near surface mounted carbon fiber reinforced polymer strips. J. of Comp. for Construction, August 1.7(3):  248 – 257.

Hollaway, L.C. & Caidei, J.  2002. Progress in the technique of upgrading metallic structures with advanced polymer composites. Progress in Structural Engineering, 131 – 148.

Hollaway, L.C. & Leeming, M.B.  1999. Strengthening of reinforced concrete structures. Woodhead Publishing Limited. Cambridge, England.

Horiguchi, T. & Saeki, N.  1997. Effect of test methods and quality of concrete on bond strength of CFRP sheet.  (incomplete entry – lookup on internet elsewhere.)

(incomplete references because of google book preview exclusion of pp,s 76 – 77)

From –

http://books.google.com/books?id=FN-C9ns0rQcC&pg=PA49&lpg=PA49&dq=polymer+earthquake+retrofit+brick+structures&source=bl&ots=3tqk-ltHNs&sig=WJQ1r3Jbelz3excPqW6Q2RNvYog&hl=en&ei=IMmCS6u3IY60tgfHnYDWBg&sa=X&oi=book_result&ct=result&resnum=10&ved=0CDIQ6AEwCQ#v=onepage&q=&f=true

**

http://www.newcastle.edu.au/research-centre/cipar/research/earthquake-protection.html

Centre for Infrastructure and Reliability – Australia

Project – Earthquake Protection of Masonry Buildings Using Fibre Reinforced Polymer Strengthening

Investigators
Michael Griffith, Mark Masia, Adrian Page and Jason Ingham

Project Description
Unreinforced masonry construction is vulnerable to damage during earthquake loading as a result of its high mass and relatively low tensile strength and ductility. Much of the built infrastructure in Australia and other parts of the world uses unreinforced masonry construction. The overall aim of this project is to develop new methods for earthquake protection of brick masonry buildings using fibre reinforced polymer (FRP) strips and other forms of reinforcement which can be applied (retrofitted) to existing construction. The methods developed in this project will be able to be applied so that the aesthetic appearance of the masonry construction is not destroyed while still providing the additional strength and ductility needed to safely withstand earthquake shaking. In order to accomplish this, the fundamental bond-slip behaviour between reinforcement and brickwork under cyclic loading must first be fully understood and quantified. Design methodology based on this cyclic bond behaviour will be validated with full scale tests on actual buildings. The project involves collaboration between researchers at The University of Newcastle, The University of Adelaide and Auckland University. In addition to the investigators named above, The project involves numerous RHD students and postdoctoral researchers.

Above Left: Pull test specimen used to quantify the bond behaviour between FRP reinforcement and masonry
Above Right: FRP retrofitted masonry panel subjected to large displacement under shear loading

Selected Publications

  • Petersen, R.B., M.J. Masia and R. Seracino. Bond behavior of NSM FRP strips bonded to modern clay brick masonry prisms: Influence of strip orientation and compression perpendicular to the strip. Journal of Composites for Construction (ASCE), Submitted April 2008. Reviewed and resubmitted Oct 2008. Accepted 23 Oct 2008.
  • Petersen, R.B., M.J. Masia and R. Seracino (2008). Experimental verification of finite element model to predict the shear behaviour of NSM FRP strengthened masonry walls. Proceedings of the 14th International Brick and Block Masonry Conference, Sydney, Australia, February 17-20, 2008.
  • Petersen, R.B., M.J. Masia and R. Seracino (2007). Influence of plate orientation and amount of precompression on the bond strength between NSM CFRP strips and masonry. Proceedings of the 10th North American Masonry Conference, St. Louis, Missouri, USA, June 3-6, 2007, pp. 62-73.
  • Petersen, R. B., Seracino, R., and Masia, M. J. (2007). Development of a finite element model to simulate near-surface mounted fiber reinforced polymer strengthened unreinforced masonry walls. In Ninth U.S. National Congress on Computational Mechanics, San Francisco, California, U.S.A. July 2007.
    (extended abstract and presentation only – no paper)
  • Shrive, N.G., M.M. Reda Taha and M.J. Masia (2004). Restoration and Strengthening with Fibre Reinforced Polymers: Issues to Consider. Proceedings of The Fourth International Seminar On Structural Analysis of Historical Constructions, Padova, Italy, Nov 10 – 13, 2004, pp. 829-835.
  • Masia, M.J. and N.G. Shrive (2003). Carbon fibre reinforced polymer wrapping for the rehabilitation of masonry columns. Canadian Journal of Civil Engineering Vol. 30, No. 4, Aug 2003, pp. 734-744.
  • Shrive, N.G., M.J. Masia and S.L. Lissel (2001). Strengthening rehabilitation of masonry using fibre reinforced polymers. Proc. 3rd International Seminar on Structural Analysis of Historical Constructions, Guimaraes, Portugal, November 7-9, 2001, pp. 1047-1056.
  • Masia, M.J., N.G. Shrive and D. Tilleman (2001). Rehabilitation of masonry columns using carbon fibre wraps. Proc. 9th Canadian Masonry Symposium, Fredericton, New Brunswick, Canada, 4-6 June, 2001.
  • Last Updated: Friday, 5 February 2010 10:26 AM ADST

http://www.newcastle.edu.au/research-centre/cipar/research/earthquake-protection.html

**

Reinforced concrete column burst

Jacketed and grouted column on left, unmodified on right

Reinforced concrete columns typically contain large diameter vertical rebar (reinforcing bars) arranged in a ring, surrounded by lighter-gauge hoops of rebar. Upon analysis of failures due to earthquakes, it has been realized that the weakness was not in the vertical bars, but rather in inadequate strength and quantity of hoops. Once the integrity of the hoops is breached, the vertical rebar can flex outward, stressing the central column of concrete. The concrete then simply crumbles into small pieces, now unconstrained by the surrounding rebar. In new construction a greater amount of hoop-like structures is used.

One simple retrofit is to surround the column with a jacket of steel plates formed and welded into a single cylinder. The space between the jacket and the column is then filled with concrete, a process called grouting. Where soil or structure conditions require such additional modification, additional pilings may be driven near the column base and concrete pads linking the pilings to the pylon are fabricated at or below ground level. In the example shown not all columns needed to be modified to gain sufficient seismic resistance for the conditions expected. (This location is about a mile from the Hayward Fault Zone.)

http://en.wikipedia.org/wiki/Seismic_retrofit

**

Lift

Where moist or poorly consolidated alluvial soil interfaces in a “beach like” structure against underlying firm material, seismic waves traveling through the alluvium can be amplified, just as are water waves against a sloping beach. In these special conditions, vertical accelerations up to twice the force of gravity have been measured. If a building is not secured to a well-embedded foundation it is possible for the building to be thrust from (or with) its foundations into the air, usually with severe damage upon landing. Even if it is well-founded, higher portions such as upper stories or roof structures or attached structures such as canopies and porches may become detached from the primary structure.

Good practices in modern, earthquake-resistant structures dictate that there be good vertical connections throughout every component of the building, from undisturbed or engineered earth to foundation to sill plate to vertical studs to plate cap through each floor and continuing to the roof structure. Above the foundation and sill plate the connections are typically made using steel strap or sheet stampings, nailed to wood members using special hardened high-shear strength nails, and heavy angle stampings secured with through bolts, using large washers to prevent pull-through. Where inadequate bolts are provided between the sill plates and a foundation in existing construction (or are not trusted due to possible corrosion), special clamp plates may be added, each of which is secured to the foundation using expansion bolts inserted into holes drilled in an exposed face of concrete. Other members must then be secured to the sill plates with additional fittings.

[edit] Soil

One of the most difficult retrofits is that required to prevent damage due to soil failure. Soil failure can occur on a slope, a slope failure or landslide, or in a flat area due to liquefaction of water-saturated sand and/or mud. Generally, deep pilings must be driven into stable soil (typically hard mud or sand) or to underlying bedrock or the slope must be stabilized. For buildings built atop previous landslides the practicality of retrofit may be limited by economic factors, as it is not practical to stabilize a large, deep landslide. The likelihood of landslide or soil failure may also depend upon seasonal factors, as the soil may be more stable at the beginning of a wet season than at the beginning of the dry season. Such a “two season” Mediterranean climate is seen throughout California.

In some cases, the best that can be done is to reduce the entrance of water runoff from higher, stable elevations by capturing and bypassing through channels or pipes, and to drain water infiltrated directly and from subsurface springs by inserting horizontal perforated tubes. There are numerous locations in California where extensive developments have been built atop archaic landslides, which have not moved in historic times but which (if both water-saturated and shaken by an earthquake) have a high probability of moving en masse, carrying entire sections of suburban development to new locations. While the most modern of house structures (well tied to monolithic concrete foundation slabs reinforced with post tensioning cables) may survive such movement largely intact, the building will no longer be in its proper location.

http://en.wikipedia.org/wiki/Seismic_retrofit

**

Utility pipes and cables: risks

Natural gas and propane supply pipes to structures often prove especially dangerous during and after earthquakes. Should a building move from its foundation or fall due to cripple wall collapse, the ductile iron pipes transporting the gas within the structure may be broken, typically at the location of threaded joints. The gas may then still be provided to the pressure regulator from higher pressure lines and so continue to flow in substantial quantities; it may then be ignited by a nearby source such as a lit pilot light or arcing electrical connection.

There are two primary methods of automatically restraining the flow of gas after an earthquake, installed on the low pressure side of the regulator, and usually downstream of the gas meter.

  • A caged metal ball may be arranged at the edge of an orifice. Upon seismic shock, the ball will roll into the orifice, sealing it to prevent gas flow. The ball may later be reset by the use of an external magnet. This device will respond only to ground motion.
  • A flow-sensitive device may be used to close a valve if the flow of gas exceeds a set threshold (very much like an electrical circuit breaker). This device will operate independently of seismic motion, but will not respond to minor leaks which may be caused by an earthquake.

It appears that the most secure configuration would be to use one of each of these devices in series.

**

BART tube

For current BART information concerning various seismic retrofits see[10].

A tube of particular structural, seismic, economic, and political interest is the BART (Bay Area Rapid Transit) trans-bay tube. This tube was constructed at the bottom of San Francisco Bay through an innovative process. Rather than pushing a shield through the soft bay mud, the tube was constructed on land in sections. Each section consisted of two inner train tunnels of circular cross section, a central access tunnel of rectangular cross section, and an outer oval shell encompassing the three inner tubes. The intervening space was filled with concrete. At the bottom of the bay a trench was excavated and a flat bed of crushed stone prepared to receive the tube sections. The sections were then floated into place and sunk, then joined with bolted connections to previously-placed sections. An overfill was then placed atop the tube to hold it down. Once completed from San Francisco to Oakland, the tracks and electrical components were installed. The predicted response of the tube during a major earthquake was likened to be as that of a string of (cooked) spaghetti in a bowl of gelatin dessert. To avoid overstressing the tube due to differential movements at each end, a sliding slip joint was included at the San Francisco terminus under the landmark Ferry Building.

The engineers of the construction consortium PBTB (Parsons-Brinkerhoff-Tudor-Bechtel) used the best estimates of ground motion available at the time, now known to be insufficient given modern computational analysis methods and geotechnical knowledge. Unexpected settlement of the tube has reduced the amount of slip that can be accommodated without failure. These factors have resulted in the slip joint being designed too short to ensure survival of the tube under possible (perhaps even likely) large earthquakes in the region. To correct this deficiency the slip joint must be extended to allow for additional movement, a modification expected to be both expensive and technically and logistically difficult. Other retrofits to the BART tube include vibratory consolidation of the tube’s overfill to avoid potential liquefying of the overfill, which has now been completed. (Should the overfill fail there is a danger of portions of the tube rising from the bottom, an event which could potentially cause failure of the section connections.)

022srUSGSCyprusVia

022srUSGSCyprusVia.jpg

USGS photo from 1989 en:Loma Prieta earthquake.

Caption: Side view of support-column failure and collapsed upper deck, en:Cypress Viaduct. [H.G. Wilshire, U.S. Geological Survey]

Original image: USGS page – Oakland

A related image

Date

Not dated. Probably late 1989.

Source

USGS page – Oakland

Author

H.G. Wilshire, U.S. Geological Survey

Permission
(Reusing this file)

PD-USGOV-INTERIOR-USGS.

http://en.wikipedia.org/wiki/File:022srUSGSCyprusVia.jpg

800px-Cypress_structure

Cypress structure.jpeg

USGS photo from 1989 Loma Prieta earthquake.

Caption: Aerial view of collapsed sections of the en:Cypress Viaduct of en:Interstate 880. [H.G. Wilshire, U.S. Geological Survey]

Date 1989(1989)
Source Photo by H. G. Wilshire for U.S. Geological Survey.

High res version on line at : [1]

Lower resolution version: Original image here: http://pubs.usgs.gov/dds/dds-29/web_pages/oakland.html

Author H.G. Wilshire, U.S. Geological Survey
Permission
(Reusing this file)
PD-USGOV-INTERIOR-USGS.

http://commons.wikimedia.org/wiki/File:Cypress_structure.jpeg

**

Seismic retrofit

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Main article: Earthquake engineering

Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with our recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. Prior to the introduction of modern seismic codes in the late 1960s for developed countries (US, Japan etc) and late 1970s for many other parts of the world (Turkey, China etc), [1], many structures were designed without adequate detailing and reinforcement for seismic protection. In view of the imminent problem, various research work has been carried out. Furthermore, state-of-the-art technical guidelines for seismic assessment, retrofit and rehabilitation have been published around the world – such as the ASCE-SEI 41 [2] and the New Zealand Society for Earthquake Engineering (NZSEE)’s guidelines [3].

The retrofit techniques outlined here are also applicable for other natural hazards such as tropical cyclones, tornadoes, and severe winds from thunderstorms. Whilst current practice of seismic retrofitting is predominantly concerned with structural improvements to reduce the seismic hazard of using the structures, it is similarly essential to reduce the hazards and losses from non-structural elements. It is also important to keep in mind that there is no such thing as an earthquake-proof structure, although seismic performance can be greatly enhanced through proper initial design or subsequent modifications.

Infill shear trusses — University of California dormitory, Berkeley, California

External bracing of an existing reinforced concrete parking garage (Berkeley) Note the pleasing use of detail with “waist” effect and integrated bench in base. Pedestrians exiting shops are protected from collision with bench by railings behind original footing

Contents

[hide]

[edit] Strategies

Many seismic retrofit (or rehabilitation) strategies have been developed in the past few decades following the introduction of new seismic provisions and the availability of advanced materials (e.g. fiber-reinforced polymers, FRP, fiber reinforced concrete and high strength steel)[4]. Retrofit strategies are different from retrofit techniques, where the former is the basic approach to achieve an overall retrofit performance objective, such as increasing strength, increasing deformability, reducing deformation demands while the latter is the technical methods to achieve that strategy, for example FRP jacketing (see Figure 2a).

  • Increasing the global capacity (strengthening). This is typically done by the addition of cross braces or new structural walls.
  • Reduction of the seismic demand by means of supplementary damping and/or use of base isolation systems [5].
  • Increasing the local capacity of structural elements. This strategy recognises the inherent capacity within the existing structures, and therefore adopt a more cost-effective approach to selectively upgrade local capacity (deformation/ductility , strength or stiffness) of individual structural components.
  • Selective weakening retrofit. This is a counter intuitive strategy to change the inelastic mechanism of the structure, whilst recognising the inherent capacity of the structure. [6]

[edit] Performance objectives

In the past, seismic retrofit was primarily applied to achieve public safety, with engineering solutions limited by economic and political considerations. However, with the development of Performance based earthquake engineering (PBEE), several levels of performance objectives are gradually recognised:

  • Public safety only. The goal is to protect human life, ensuring that the structure will not collapse upon its occupants or passersby, and that the structure can be safely exited. Under severe seismic conditions the structure may be a total economic write-off, requiring tear-down and replacement.
  • Structure survivability. The goal is that the structure, while remaining safe for exit, may require extensive repair (but not replacement) before it is generally useful or considered safe for occupation. This is typically the lowest level of retrofit applied to bridges.
  • Structure functionality. Primary structure undamaged and the structure is undiminished in utility for its primary application. A high level of retrofit, this ensures that any required repairs are only “cosmetic” – for example, minor cracks in plaster, drywall and stucco. This is the minimum acceptable level of retrofit for hospitals.
  • Structure unaffected. This level of retrofit is preferred for historic structures of high cultural significance.

[edit] Techniques

Common seismic retrofitting techniques fall into several categories:

One of many “earthquake bolts” found throughout period houses in the city of Charleston subsequent to the Charleston earthquake of 1886. They could be tightened and loosened to support the house without having to otherwise demolish the house due to instability. The bolts were directly loosely connected to the supporting frame of the house.

[edit] External post-tensioning

The use of external post-tensioning for new structural systems have been developed in the past decade. Under the PRESS (Precast Seismic Structural Systems)[7], a large-scale U.S./Japan joint research program, unbonded post-tensioning high strength steel tendons have been used to achieve a moment-resisting system that has self-centering capacity. An extension of the same idea for seismic retrofitting has been experimentally tested for seismic retrofit of California bridges under a Caltrans research project [8] and for seismic retrofit of non-ductile reinforced concrete frames [9]. Pre-stressing can increase the capacity of structural elements such as beam, column and beam-column joints. It should be noted that external pre-stressing has been used for structural upgrade for gravity/live loading since 1970s [10]

[edit] Base isolators

Base isolation is a collection of structural elements of a building that should substantially decouple the building’s structure from the shaking ground thus protecting the building’s integrity and enhancing its seismic performance. This earthquake engineering technology, which is a kind of seismic vibration control, can be applied both to a newly designed building and to seismic upgrading of existing structures[11][12]. Normally, excavations are made around the building and the building is separated from the foundations. Steel or reinforced concrete beams replace the connections to the foundations, while under these, the isolating pads, or base isolators, replace the material removed. While the base isolation tends to restrict transmission of the ground motion to the building, it also keeps the building positioned properly over the foundation. Careful attention to detail is required where the building interfaces with the ground, especially at entrances, stairways and ramps, to ensure sufficient relative motion of those structural elements.

[edit] Supplementary dampers

Supplementary dampers absorb the energy of motion and convert it to heat, thus “damping” resonant effects in structures that are rigidly attached to the ground. In addition to adding energy dissipation capacity to the structure, supplementary damping can reduce the displacement and acceleration demand within the structures. In some cases, the threat of damage does not come from the initial shock itself, but rather from the periodic resonant motion of the structure that repeated ground motion induces. In partical sense, supplementary dampers act similarly to Shock absorbers used in automotive suspensions.

[edit] Tuned mass dampers

Tuned mass dampers (TMD) employ movable weights on some sort of springs. These are typically employed to reduce wind sway in very tall, light buildings. Similar designs may be employed to impart earthquake resistance in eight to ten story buildings that are prone to destructive earthquake induced resonances [13].

[edit] Slosh tank

A slosh tank is a large tank of fluid placed on an upper floor. During a seismic event, the fluid in this tank will slosh back and forth, but is directed by baffles – partitions that prevent the tank itself becoming resonant; through its mass the water may change or counter the resonant period of the building. Additional kinetic energy can be converted to heat by the baffles and is dissipated through the water – any temperature rise will be insignificant.

[edit] Active control system

Very tall buildings (“skyscrapers“), when built using modern lightweight materials, might sway uncomfortably (but not dangerously) in certain wind conditions. A solution to this problem is to include at some upper story a large mass, constrained, but free to move within a limited range, and moving on some sort of bearing system such as an air cushion or hydraulic film. Hydraulic pistons, powered by electric pumps and accumulators, are actively driven to counter the wind forces and natural resonances. These may also, if properly designed, be effective in controlling excessive motion – with or without applied power – in an earthquake. In general, though, modern steel frame high rise buildings are not as subject to dangerous motion as are medium rise (eight to ten story) buildings, as the resonant period of a tall and massive building is longer than the approximately one second shocks applied by an earthquake.

[edit] Adhoc addition of structural support/reinforcement

The most common form of seismic retrofit to lower buildings is adding strength to the existing structure to resist seismic forces. The strengthening may be limited to connections between existing building elements or it may involve adding primary resisting elements such as walls or frames, particularly in the lower stories.

[edit] Connections between buildings and their expansion additions

Frequently, building additions will not be strongly connected to the existing structure, but simply placed adjacent to it, with only minor continuity in flooring, siding, and roofing. As a result, the addition may have a different resonant period than the original structure, and they may easily detach from one another. The relative motion will then cause the two parts to collide, causing severe structural damage. Proper construction will tie the two building components rigidly together so that they behave as a single mass or employ dampers to expend the energy from relative motion, with appropriate allowance for this motion.

[edit] Exterior reinforcement of building
[edit] Exterior concrete columns

Historic buildings, made of unreinforced masonry, may have culturally important interior detailing or murals that should not be disturbed. In this case, the solution may be to add a number of steel, reinforced concrete, or poststressed concrete columns to the exterior. Careful attention must be paid to the connections with other members such as footings, top plates, and roof trusses.

[edit] Infill shear trusses

Shown here is an exterior shear reinforcement of a conventional reinforced concrete dormitory building. In this case, there was sufficient vertical strength in the building columns and sufficient shear strength in the lower stories that only limited shear reinforcement was required to make it earthquake resistant for this location, near the Hayward fault.

[edit] Massive exterior structure

In other circumstances, far greater reinforcement is required. In the structure shown at right — a parking garage over shops — the placement, detailing, and painting of the reinforcement becomes itself an architectural embellishment.

[edit] Typical Retrofit Scenario & Solution

[edit] Soft-story failure

Main article: Soft story building

Partial failure due to inadequate shear structure at garage level. Damage in San Francisco due to the Loma Prieta event.

This collapse mode is known as soft story collapse. In many buildings the ground level is designed for different uses than the upper levels. Low rise residential structures may be built over a parking garage which have large doors on one side. Hotels may have a tall ground floors to allow for a grand entrance or ballrooms. Office buildings may have stores in the ground floor which desire continuous windows for display.

Traditional seismic design assumes that the lower stories of a building are stronger than the upper stories and where this is not the case –if the lower story is less strong than the upper structure–the structure will not respond to earthquakes in the expected fashion. Using modern design methods, it is possible to take a weak story into account. Several failures of this type in one large apartment complex caused most of the fatalities in the 1994 Northridge earthquake.

Typically, where this type of problem is found, the weak story is reinforced to make it stronger than the floors above by adding shear walls or moment frames. Moment frames consisting of inverted U bents are useful in preserving lower story garage access, while a lower cost solution may be to use shear walls or trusses in several locations, which partially reduce the usefulness for automobile parking but still allow the space to be used for other storage.

[edit] Beam-column joint connections

Corner joint steel reinforcement and high tensile strength rods with grouted anti-burst jacket below

Beam-column joint connections are a common structural weakness in dealing with seismic retrofitting. Prior to the introduction of modern seismic codes in early 1970s, beam-column joints were typically non-engineered or designed. Laboratory testings have confirmed the seismic vulnerability of these poorly detailed and under-designed connections [14][15][16][17]. Failure of beam-column joint connections can typically lead to catastrophic collapse of a frame-building, as often observed in recent earthquakes [18] [19]

For reinforced concrete beam-column joints – various retrofit solutions have been proposed and tested in the past 20 years. Philosophically, the various seismic retrofit strategies discussed above can be implemented for reinforced concrete joints. Concrete or steel jacketing have been a popular retrofit technique until the advent of composite materials such as Carbon fiber-reinforced polymer (FRP). Composite materials such as carbon FRP and aramic FRP have been extensively tested for use in seismic retrofit with some success [20][21] [22]. One novel technique includes the use of selective weakening of the beam and added external post-tensioning to the joint [23] in order to achieve flexural hinging in the beam, which is more desirable in terms of seismic design.

Widespread weld failures at beam-column joints of low-to-medium rise steel buildings during the Northridge 1994 earthquake for example, have shown the structural defiencies of these ‘modern-designed’ post-1970s welded moment-resisting connections [24]. A subsequent SAC research project [9] has documented, tested and proposed several retrofit solutions for these welded steel moment-resisting connections. Various retrofit solutions have been developed for these welded joints – such as a) weld strengthening and b) addition of steel haunch or ‘dog-bone’ shape flange [25].

[edit] Shear failure within floor diaphragm

Floors in wooden buildings are usually constructed upon relatively deep spans of wood, called joists, covered with a diagonal wood planking or plywood to form a subfloor upon which the finish floor surface is laid. In many structures these are all aligned in the same direction. To prevent the beams from tipping over onto their side, blocking is used at each end, and for additional stiffness, blocking or diagonal wood or metal bracing may be placed between beams at one or more points in their spans. At the outer edge it is typical to use a single depth of blocking and a perimeter beam overall.

If the blocking or nailing is inadequate, each beam can be laid flat by the shear forces applied to the building. In this position they lack most of their original strength and the structure may further collapse. As part of a retrofit the blocking may be doubled, especially at the outer edges of the building. It may be appropriate to add additional nails between the sill plate of the perimeter wall erected upon the floor diaphragm, although this will require exposing the sill plate by removing interior plaster or exterior siding. As the sill plate may be quite old and dry and substantial nails must be used, it may be necessary to pre-drill a hole for the nail in the old wood to avoid splitting. When the wall is opened for this purpose it may also be appropriate to tie vertical wall elements into the foundation using specialty connectors and bolts glued with epoxy cement into holes drilled in the foundation.

[edit] Sliding off foundation and “cripple wall” failure

House slid off of foundation

Low cripple wall collapse and detachment of structure from concrete stairway

Single or two story wood-frame domestic structures built on a perimeter or slab foundation are relatively safe in an earthquake, but in many structures built before 1950 the sill plate that sits between the concrete foundation and the floor diaphragm (perimeter foundation) or studwall (slab foundation) may not be sufficiently bolted in. Additionally, older attachments (without substantial corrosion-proofing) may have corroded to a point of weakness. A sideways shock can slide the building entirely off of the foundations or slab.

Often such buildings, especially if constructed on a moderate slope, are erected on a platform connected to a perimeter foundation through low stud-walls called “cripple wall” or pin-up. This low wall structure itself may fail in shear or in its connections to itself at the corners, leading to the building moving diagonally and collapsing the low walls. The likelihood of failure of the pin-up can be reduced by ensuring that the corners are well reinforced in shear and that the shear panels are well connected to each other through the corner posts. This requires structural grade sheet plywood, often treated for rot resistance. This grade of plywood is made without interior unfilled knots and with more, thinner layers than common plywood. New buildings designed to resist earthquakes will typically use OSB (oriented strand board), sometimes with metal joins between panels, and with well attached stucco covering to enhance its performance. In many modern tract homes, especially those built upon expansive (clay) soil the building is constructed upon a single and relatively thick monolithic slab, kept in one piece by high tensile rods that are stressed after the slab has set. This poststressing places the concrete under compression – a condition under which it is extremely strong in bending and so will not crack under adverse soil conditions.

[edit] Multiple piers in shallow pits

Some older low-cost structures are elevated on tapered concrete pylons set into shallow pits, a method frequently used to attach outdoor decks to existing buildings. This is seen in conditions of damp soil, especially in tropical conditions, as it leaves a dry ventilated space under the house, and in far northern conditions of permafrost (frozen mud) as it keeps the building’s warmth from destabilizing the ground beneath. During an earthquake, the pylons may tip, spilling the building to the ground. This can be overcome by using deep-bored holes to contain cast-in-place reinforced pylons, which are then secured to the floor panel at the corners of the building. Another technique is to add sufficient diagonal bracing or sections of concrete shear wall between pylons.

[edit] Reinforced concrete column burst

Jacketed and grouted column on left, unmodified on right

Reinforced concrete columns typically contain large diameter vertical rebar (reinforcing bars) arranged in a ring, surrounded by lighter-gauge hoops of rebar. Upon analysis of failures due to earthquakes, it has been realized that the weakness was not in the vertical bars, but rather in inadequate strength and quantity of hoops. Once the integrity of the hoops is breached, the vertical rebar can flex outward, stressing the central column of concrete. The concrete then simply crumbles into small pieces, now unconstrained by the surrounding rebar. In new construction a greater amount of hoop-like structures is used.

One simple retrofit is to surround the column with a jacket of steel plates formed and welded into a single cylinder. The space between the jacket and the column is then filled with concrete, a process called grouting. Where soil or structure conditions require such additional modification, additional pilings may be driven near the column base and concrete pads linking the pilings to the pylon are fabricated at or below ground level. In the example shown not all columns needed to be modified to gain sufficient seismic resistance for the conditions expected. (This location is about a mile from the Hayward Fault Zone.)

[edit] Reinforced concrete wall burst

Concrete walls are often used at the transition between elevated road fill and overpass structures. The wall is used both to retain the soil and so enable the use of a shorter span and also to transfer the weight of the span directly downward to footings in undisturbed soil. If these walls are inadequate they may crumble under the stress of an earthquake’s induced ground motion.

One form of retrofit is to drill numerous holes into the surface of the wall, and secure short L-shaped sections of rebar to the surface of each hole with epoxy adhesive. Additional vertical and horizontal rebar is then secured to the new elements, a form is erected, and an additional layer of concrete is poured. This modification may be combined with additional footings in excavated trenches and additional support ledgers and tie-backs to retain the span on the bounding walls.

[edit] Brick wall resin and glass fiber reinforcement

Brick building structures have been reinforced with coatings of glass fiber and appropriate resin (epoxy or polyester). In lower floors these may be applied over entire exposed surfaces, while in upper floors this may be confined to narrow areas around window and door openings. This application provides tensile strength that stiffens the wall against bending away from the side with the application. The efficient protection of an entire building requires extensive analysis and engineering to determine the appropriate locations to be treated.

[edit] Lift

Where moist or poorly consolidated alluvial soil interfaces in a “beach like” structure against underlying firm material, seismic waves traveling through the alluvium can be amplified, just as are water waves against a sloping beach. In these special conditions, vertical accelerations up to twice the force of gravity have been measured. If a building is not secured to a well-embedded foundation it is possible for the building to be thrust from (or with) its foundations into the air, usually with severe damage upon landing. Even if it is well-founded, higher portions such as upper stories or roof structures or attached structures such as canopies and porches may become detached from the primary structure.

Good practices in modern, earthquake-resistant structures dictate that there be good vertical connections throughout every component of the building, from undisturbed or engineered earth to foundation to sill plate to vertical studs to plate cap through each floor and continuing to the roof structure. Above the foundation and sill plate the connections are typically made using steel strap or sheet stampings, nailed to wood members using special hardened high-shear strength nails, and heavy angle stampings secured with through bolts, using large washers to prevent pull-through. Where inadequate bolts are provided between the sill plates and a foundation in existing construction (or are not trusted due to possible corrosion), special clamp plates may be added, each of which is secured to the foundation using expansion bolts inserted into holes drilled in an exposed face of concrete. Other members must then be secured to the sill plates with additional fittings.

[edit] Soil

One of the most difficult retrofits is that required to prevent damage due to soil failure. Soil failure can occur on a slope, a slope failure or landslide, or in a flat area due to liquefaction of water-saturated sand and/or mud. Generally, deep pilings must be driven into stable soil (typically hard mud or sand) or to underlying bedrock or the slope must be stabilized. For buildings built atop previous landslides the practicality of retrofit may be limited by economic factors, as it is not practical to stabilize a large, deep landslide. The likelihood of landslide or soil failure may also depend upon seasonal factors, as the soil may be more stable at the beginning of a wet season than at the beginning of the dry season. Such a “two season” Mediterranean climate is seen throughout California.

In some cases, the best that can be done is to reduce the entrance of water runoff from higher, stable elevations by capturing and bypassing through channels or pipes, and to drain water infiltrated directly and from subsurface springs by inserting horizontal perforated tubes. There are numerous locations in California where extensive developments have been built atop archaic landslides, which have not moved in historic times but which (if both water-saturated and shaken by an earthquake) have a high probability of moving en masse, carrying entire sections of suburban development to new locations. While the most modern of house structures (well tied to monolithic concrete foundation slabs reinforced with post tensioning cables) may survive such movement largely intact, the building will no longer be in its proper location.

[edit] Utility pipes and cables: risks

Natural gas and propane supply pipes to structures often prove especially dangerous during and after earthquakes. Should a building move from its foundation or fall due to cripple wall collapse, the ductile iron pipes transporting the gas within the structure may be broken, typically at the location of threaded joints. The gas may then still be provided to the pressure regulator from higher pressure lines and so continue to flow in substantial quantities; it may then be ignited by a nearby source such as a lit pilot light or arcing electrical connection.

There are two primary methods of automatically restraining the flow of gas after an earthquake, installed on the low pressure side of the regulator, and usually downstream of the gas meter.

  • A caged metal ball may be arranged at the edge of an orifice. Upon seismic shock, the ball will roll into the orifice, sealing it to prevent gas flow. The ball may later be reset by the use of an external magnet. This device will respond only to ground motion.
  • A flow-sensitive device may be used to close a valve if the flow of gas exceeds a set threshold (very much like an electrical circuit breaker). This device will operate independently of seismic motion, but will not respond to minor leaks which may be caused by an earthquake.

It appears that the most secure configuration would be to use one of each of these devices in series.

[edit] Tunnels

Unless the tunnel penetrates a fault likely to slip, the greatest danger to tunnels is a landslide blocking an entrance. Additional protection around the entrance may be applied to divert any falling material (similar as is done to divert snow avalanches) or the slope above the tunnel may be stabilized in some way. Where only small- to medium-sized rocks and boulders are expected to fall, the entire slope may be covered with wire mesh, pinned down to the slope with metal rods. This is also a common modification to highway cuts where appropriate conditions exist.

[edit] Underwater tubes

The safety of underwater tubes is highly dependent upon the soil conditions through which the tunnel was constructed, the materials and reinforcements used, and the maximum predicted earthquake expected, and other factors, some of which may remain unknown under current knowledge.

[edit] BART tube

For current BART information concerning various seismic retrofits see[10].

A tube of particular structural, seismic, economic, and political interest is the BART (Bay Area Rapid Transit) trans-bay tube. This tube was constructed at the bottom of San Francisco Bay through an innovative process. Rather than pushing a shield through the soft bay mud, the tube was constructed on land in sections. Each section consisted of two inner train tunnels of circular cross section, a central access tunnel of rectangular cross section, and an outer oval shell encompassing the three inner tubes. The intervening space was filled with concrete. At the bottom of the bay a trench was excavated and a flat bed of crushed stone prepared to receive the tube sections. The sections were then floated into place and sunk, then joined with bolted connections to previously-placed sections. An overfill was then placed atop the tube to hold it down. Once completed from San Francisco to Oakland, the tracks and electrical components were installed. The predicted response of the tube during a major earthquake was likened to be as that of a string of (cooked) spaghetti in a bowl of gelatin dessert. To avoid overstressing the tube due to differential movements at each end, a sliding slip joint was included at the San Francisco terminus under the landmark Ferry Building.

The engineers of the construction consortium PBTB (Parsons-Brinkerhoff-Tudor-Bechtel) used the best estimates of ground motion available at the time, now known to be insufficient given modern computational analysis methods and geotechnical knowledge. Unexpected settlement of the tube has reduced the amount of slip that can be accommodated without failure. These factors have resulted in the slip joint being designed too short to ensure survival of the tube under possible (perhaps even likely) large earthquakes in the region. To correct this deficiency the slip joint must be extended to allow for additional movement, a modification expected to be both expensive and technically and logistically difficult. Other retrofits to the BART tube include vibratory consolidation of the tube’s overfill to avoid potential liquefying of the overfill, which has now been completed. (Should the overfill fail there is a danger of portions of the tube rising from the bottom, an event which could potentially cause failure of the section connections.)

[edit] Bridge retrofit

Bridges have several failure modes.

[edit] Expansion rockers

Many short bridge spans are statically anchored at one end and attached to rockers at the other. This rocker gives vertical and transverse support while allowing the bridge span to expand and contract with temperature changes. The change in the length of the span is accommodated over a gap in the roadway by comb-like expansion joints. During severe ground motion the rockers may jump from their tracks or be moved beyond their design limits, causing the bridge to unship from its resting point and then either become misaligned or fall completely. Motion can be constrained by adding ductile or high-strength steel restraints that are friction-clamped to beams and designed to slide under extreme stress while still limiting the motion relative to the anchorage.

[edit] Deck rigidity

Additional diagonals were inserted under both decks of this bridge

Suspension bridges may respond to earthquakes with a side-to-side motion exceeding that which was designed for wind gust response. Such motion can cause fragmentation of the road surface, damage to bearings, and plastic deformation or breakage of components. Devices such as hydraulic dampers or clamped sliding connections and additional diagonal reenforcement may be added.

[edit] Lattice girders, beams, and ties

Obsolete riveted lattice members

Lattice girders consist of two “I”-beams connected with a criss-cross lattice of flat strap or angle stock. These can be greatly strengthened by replacing the open lattice with plate members. This is usually done in concert with the replacement of hot rivets with bolts.

Bolted plate lattice replacement, forming box members

[edit] Hot rivets

Many older structures were fabricated by inserting red-hot rivets into pre-drilled holes; the soft rivets are then peened using an air hammer on one side and a bucking bar (an inertial mass) on the head end. As these cool slowly, they are left in an annealed (soft) condition, while the plate, having been hot rolled and quenched during manufacture, remains relatively hard. Under extreme stress the hard plates can shear the soft rivets, resulting in failure of the joint.

The solution is to burn out each rivet with an oxygen torch. The hole is then prepared to a precise diameter with a reamer. A special locator bolt, consisting of a head, a shaft matching the reamed hole, and a threaded end is inserted and retained with a nut, then tightened with a wrench. As the bolt has been formed from an appropriate high-strength alloy and has also been heat-treated, it is not subject to either the plastic shear failure typical of hot rivets nor the brittle fracture of ordinary bolts. Any partial failure will be in the plastic flow of the metal secured by the bolt; with proper engineering any such failure should be non-catastrophic.

[edit] Fill and overpass

Elevated roadways are typically built on sections of elevated earth fill connected with bridge-like segments, often supported with vertical columns.If the soil fails where a bridge terminates, the bridge may become disconnected from the rest of the roadway and break away. The retrofit for this is to add additional reinforcement to any supporting wall, or to add deep caissons adjacent to the edge at each end and connect them with a supporting beam under the bridge.

Another failure occurs when the fill at each end moves (through resonant effects) in bulk, in opposite directions. If there is an insufficient founding shelf for the overpass it may then fall. Additional shelf and ductile stays may be added to attach the overpass to the footings at one or both ends. The stays, rather than being fixed to the beams may instead be clamped to them. Under moderate loading these keep the overpass centered in the gap so that it is less likely to slide off its founding shelf at one end. The ability for the fixed ends to slide, rather than break, will prevent the complete drop of the structure If it should fail to remain on the footings.

[edit] Viaducts

Large sections of roadway may consist entirely of viaduct, sections with no connection to the earth other than through vertical columns. When concrete columns are used, the detailing is critical. Typical failure may be in the toppling of a row of columns due either to soil connection failure or to insufficient cylindrical wrapping with rebar. Both failures were seen in the 1995 Great Hanshin earthquake in Kobe, Japan, where an entire viaduct, centrally supported by a single row of large columns, was laid down to one side. Such columns are reinforced by excavating to the foundation pad, driving additional pilings, and adding a new, larger pad, well connected with rebar along side of or into the column. A column with insufficient wrapping bar, which is prone to burst and then hinge at the bursting point, may be completely encased in a circular or elliptical jacket of welded steel sheet and grouted as described above.

Cypress Freeway viaduct collapse. Note failure of inadequate anti-burst wrapping and lack of connection between upper and lower vertical elements.

Sometimes viaducts may fail in the connections between components. This was seen in the failure of the Cypress Freeway in Oakland, California, during the Loma Prieta earthquake. This viaduct was a two-level structure, and the upper portions of the columns were not well connected to the lower portions that supported the lower level; this caused the upper deck to collapse upon the lower deck. Weak connections such as these require additional external jacketing – either through external steel components or by a complete jacket of reinforced concrete, often using stub connections that are glued (using epoxy adhesive) into numerous drilled holes. These stubs are then connected to additional wrappings, external forms (which may be temporary or permanent) are erected, and additional concrete is poured into the space. Large connected structures similar to the Cypress Viaduct must also be properly analyzed in their entirety using dynamic computer simulations.

[edit] Residential retrofit

For detailed information concerning retrofit of certain types common wood frame structures not exceeding two stories, see this web page (Association of Bay Area Governments). For specific “permit ready” details as recommended by a public agency for simple low-rise construction see this PDF document (by the City of San Leandro).

[edit] Wood frame structure

Predominantly residential/dwelling in North America consisted of wood-frame structure. Wood is one of the best materials for anti-seismic construction since it is of low mass and is relatively less brittle than masonry. It is easy to work with and very cheap compared to other modern material as steel and reinforced concrete. This is only resistant if the structure is properly connected to its foundation and has adequate shear resistance, in modern construction obtained by well connected surfacing of panels with plywood or oriented strand board in combination with exterior stucco. Steel strapping and sheet forms are also used to connect elements securely.

Retrofit methods in older woodframe structures may consist of the following, and other methods not described here.

  • The lowest plate rails of walls are bolted to a continuous foundation, or held down with rigid metal clips bolted to the foundation.
  • Selected vertical elements, especially at wall junctures and window and door openings are attached securely to the sill plate.
  • In two story buildings using “western” style construction (walls are progressively erected upon the lower story’s upper diaphragm, unlike “eastern” balloon framing), the upper walls are connected to the lower walls with tension elements. In some case connections may be extended vertically to include retention of certain roof elements.
  • Low cripple walls are made shear resistant by adding plywood at the corners and by securing corners from opening with metal strapping or fixtures.
  • Vertical posts may be restrained from jumping off of their footings.

Wooden frame is efficient with masonry if properly designed. In Turkey, the traditional houses (bagdadi) are made with this technology. In El Salvador wood and bamboo are used to build

[edit] Reinforced and unreinforced masonry

In many parts of developing countries such as Pakistan, Iran and China, unreinforced or in some cases reinforced masonry is the predominantly form of structures for rural residential and dwelling. Masonry was also a common construction form in the early part of 20th centuries, which implies significant number of these at-risk masonry structures would have significant heritage value. Masonry walls that are not reinforced are especially hazardous. Such structures may be more appropriate for replacement than retrofit, but if the walls are the principal load bearing elements in structures of modest size they may be appropriately reinforced. It is especially important that floor and ceiling beams be securely attached to the walls. Additional vertical supports in the form of steel or reinforced concrete may be added.

In the western United States, much of what is seen as masonry is actually brick or stone veneer. Current construction rules dictate the amount of tie–back required, which consist of metal straps secured to vertical structural elements. These straps extend into mortar courses, securing the veneer to the primary structure. Older structures may not secure this sufficiently for seismic safety. A weakly secured veneer in a house interior (sometimes used to face a fireplace from floor to ceiling) can be especially dangerous to occupants. Older masonry chimneys are also dangerous if they have substantial vertical extension above the roof. These are prone to breakage at the roofline and may fall into the house in a single large piece. For retrofit, additional supports may be added or it may be better to simply remove the extension and replace it with lighter materials, with special piping replacing the flue tile and a wood structure replacing the masonry. This may be matched against existing brickwork by using very thin veneer (similar to a tile, but with the appearance of a brick).

[edit] See also

[edit] Related Journals

Journal of Earthquake Engineering[11]

Earthquake Engineering & Structural Dynamics [12]

Journal of Structural Engineering [13]

Earthquake Spectra [14]

International Journal of Structural Stability and Dynamics [15]

Soil Dynamics and Earthquake Engineering [16]

[edit] External links

[edit] References

  1. ^ NZSEE Bulletin 39(2)-June 2006
  2. ^ ASCE-SEI 41
  3. ^ NZSEE 2006
  4. ^ Moehle, J. (2000) State of Research on Seismic Retrofit[1]
  5. ^ Filiatrault & Cherry (1986) [2]
  6. ^ e.g. Kam & Pampanin (2008)- Selective weakening retrofit for RC frames [3]
  7. ^ 1994 Building Publications – Status of the U.S. Precast Seismic Structural Systems (PRESSS) Program
  8. ^ Lowes & Moehle (1998) – ACI Structural Journal Vol 96(4) – pp 519-532 [4]
  9. ^ Experimental testing of external post-tensioning for retrofit of RC beam-column joint [5]
  10. ^ VSL Repair/Strengthening Page [6]
  11. ^ Clark Construction Group, LLC
  12. ^ Projects
  13. ^ Slide 2
  14. ^ Beres, A., Pessiki, S., White, R., and Gergely, P. (1996).
  15. ^ Implications of experimental on the seismic behaviour of gravity load designed RC beam-column connections. Earthquake Spectra, 12(2), 185-198.
  16. ^ Calvi, G. M., Moratti, M., and Pampanin, S. (2002). Relevance of beam-column damage and collapse in RC frame assessment. Journal of Earthquake Engineering, 6(1), 75-100.
  17. ^ Park, R. (2002). A Summary of Result of Simulated Seismic Load Tests on Reinforced Concrete Beam-Column Joints, Beams and Columns with Substandard Reinforcing Details. Journal of Earthquake Engineering, 6(2), 147-174.
  18. ^ Park R, Billings IJ, Clifton GC, Cousins J, Filiatrault A, Jennings DN, et al. The Hyogo-ken Nanbu Earthquake of 17 January 1995. Bull of New Zealand Soc of Earthquake Eng. 1995;28(1):1 -99.
  19. ^ Holmes WT, Somers P. Northridge Earthquake Reconnaissance Report. Supplement C, vol. 2.Earthquake Spectra. 1996(11):1-278.
  20. ^ Pampanin, S., Bolognini, D., Pavese, A. (2007) Performance-based Seismic Retrofit Strategy for Existing Reinforced Concrete Frame Systems using FRP composites. ASCE Journal of Composites for Construction, 11(2), pp. 211-226. [7]
  21. ^ A. Ghobarah and A. Said. 2002. Shear strengthening of beam-column joints. Engineering Structures, Vol. 24, No. 7, pp. 881- 888.
  22. ^ A. Ghobarah and A. Said 2001 Seismic rehabilitation of beam-column joints using FRP laminates. Journal of Earthquake Engineering, Vol. 5, No. 1, pp. 113-129.
  23. ^ Selective weakening and post-tensioning for seismic retrofit of RC beam-column joint [8]
  24. ^ Bertero VV, Anderson JC & Krawinkler H. Performance of steel building structures during the Northridge earthquake. Report No UCB/EERC-94/09. Berkeley, California: Earthquake Engineering Research Center, University of California at Berkeley. 1994.
  25. ^ Civjan SA, Engelhardt MD and Gross JD (2000). Retrofit of pre-Northridge Moment Resisting Connections. ASCE J.o.Structural Engineering Vol 126(4) 445-452

Retrieved from “http://en.wikipedia.org/wiki/Seismic_retrofit

Categories: Earthquake and seismic risk mitigation | Earthquake engineering | Construction

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ategory:Earthquake and seismic risk mitigation

From Wikipedia, the free encyclopedia

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Main article: Earthquake engineering

See also: Structural engineering

See also: Disaster preparedness

Pages in category “Earthquake and seismic risk mitigation”

The following 32 pages are in this category, out of 32 total. This list may not reflect recent changes (learn more).

A

C

D

E

E cont.

I

L

M

Q

S

S cont.

U

V

Retrieved from “http://en.wikipedia.org/wiki/Category:Earthquake_and_seismic_risk_mitigation

Categories: Seismology | Disaster preparedness | Structural engineering | Earthquake engineering

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VAN method

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This article does not cite any references or sources.
Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2006)

The VAN method is an experimental method of earthquake prediction, named after the surname initials of each of its inventors, Greek physicists Panayotis Varotsos, Caesar Alexopoulos and Kostas Nomikos.

The method tries to assess electromagnetic emissions that, according to the VAN team, occur several days to hours before the earthquake and can be interpreted as warnings for a forthcoming catastrophe. The method uses a network of metal rods impacted in the ground. Electromagnetic signals picked up by the rods are then processed to filter out noise and the so-called “seismic signals”, thought to result from piezoelectric phenomena as material in the earth’s mantle is subject to changing pressures preceding an earthquake, are identified. One inherent problem of the method is that, in order for any prediction to be useful, it has to predict a forthcoming earthquake with a reasonable accuracy with respect to timeframe, epicenter and magnitude. Otherwise, if the prediction is too vague, no feasible decision (such as to evacuate the population of a certain area for a given period of time) can be made. The VAN team have been arguing that, as the sensor rod network expands and its data processing technique is refined, its predictions will become increasingly useful.

The efficiency of the VAN method in earthquake prediction is a matter of debate, as a number of prominent seismologists have disputed its accuracy. One of the major opponents of VAN is the Greek seismologist Vassilis Papazachos. The debate between Papazachos and the VAN team has repeatedly caused public attention in their home country Greece and has been extensively discussed in the Greek media. As Greece is highly seismogenic and has suffered major disasters by earthquakes, the Greek public is extremely concerned over this debate.

[edit] See also

[edit] External links

This geophysics-related article is a stub. You can help Wikipedia by expanding it.

v • d • e

Retrieved from “http://en.wikipedia.org/wiki/VAN_method

Categories: Earthquake and seismic risk mitigation | Geophysics stubs

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Mitigation of seismic motion

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Main article: Earthquake engineering

Mitigation of seismic motion is an important factor in earthquake engineering and construction in earthquake-prone areas. The destabilizing action of an earthquake on constructions may be direct (seismic motion of the ground) or indirect (earthquake-induced landslides, liquefaction of the foundation soils and waves of tsunami).

Knowledge of local amplification of the seismic motion from the bedrock is very important in order to choose the suitable design solutions. Local amplification can be anticipated from the presence of particular stratigraphic conditions, such as soft soil overlapping the bedrock, or where morphological settings (e.g. crest zones, steep slopes, valleys, or endoreic basins) may produce focalization of the seismic event.

The identification of the areas potentially affected by earthquake-induced landslides and by soil liquefaction can be made by geological survey and by analysis of historical documents. Even quiescent and stabilized landslide areas may be reactivated by severe earthquake. Young soil may be particularly susceptible to liquefaction.

[edit] See also

Retrieved from “http://en.wikipedia.org/wiki/Mitigation_of_seismic_motion

Categories: Construction terminology | Earthquake and seismic risk mitigation

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International Institute of Earthquake Engineering and Seismology

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International Institute of Earthquake Engineering and Seismology (IIEES) is an international earthquake engineering and seismology institute based in Iran. It was established as a result of the 24th UNESCO General Conference Resolution DR/250 under Iranian government approval in 1989. It was founded as an independent institute within the Iran’s Ministry of Science, Research and Technology.[1]

On its establishment, the IIEES drew up a seismic code in an attempt to improve the infrastructural response to earthquakes and seismic activity in the country. Its primary objective is to reduce the risk of seismic activity on buildings and roads and provide mitigation measures both in Iran and the region.[1]

The institute is responsible for much of the research and education in this field by conducting research and providing education and knowledge in seismotectonic studies, seismology and earthquake engineering.[1] In addition conducts research and educates in risk management and generating possibilities for an effective earthquake response strategy.

The IIEES is composed of the following research Centers: Seismology, Geotechnical Earthquake Engineering, Structural Earthquake Engineering, Risk Management; National center for Earthquake Prediction, and Graduate School, Public Education and Information Division.[1]

[edit] See also

[edit] References

  1. ^ a b c d “About Institute”. International Institute of Earthquake Engineering and Seismology. http://www.iiees.ac.ir/English/institute/eng_about.html. Retrieved November 23, 2008.

[edit] External links

Retrieved from “http://en.wikipedia.org/wiki/International_Institute_of_Earthquake_Engineering_and_Seismology

Categories: Earthquake and seismic risk mitigation | Earthquake engineering | Organisations based in Iran | Science and technology in Iran

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220px-Snapshot_of_earthquake-like_crash_testing

Shake-table crash testing of a regular building model (left) and a base-isolated building model (right) [2] at UCSD

The first evidence of earthquake protection by using the principle of base isolation was discovered in Pasargadae, a city in ancient Persia, now Iran: it goes back to VI century BCE. Below, there are some samples of seismic vibration control technologies of today.

Dry-stone walls control

Dry-stone walls of Machu Picchu Temple of the Sun, Peru

People of Inca civilization were masters of the polished dry-stone walls, called ashlar, where blocks of stone were cut to fit together tightly without any mortar. The Incas were among the best stone masons the world has ever seen [10], and many junctions in their masonry were so perfect that even blades of grass could not fit between the stones.

Peru is a highly seismic land, and for centuries the mortar-free construction proved to be apparently more earthquake-resistant than using mortar. The stones of the dry-stone walls built by the Incas could move slightly and resettle without the walls collapsing which should be recognized as an ingenious passive structural control technique employing both the principle of energy dissipation and that of suppressing resonant amplifications [11].

http://en.wikipedia.org/wiki/Earthquake_construction

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7-story reinforced concrete buildings on steep slope collapse due to the following [28]:

  • Poor detailing of the reinforcement (lack of concrete confinement in the columns and at the beam-column joints, inadequate splice length).

http://en.wikipedia.org/wiki/Earthquake_construction

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Earthquake engineering

From Wikipedia, the free encyclopedia

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Earthquake engineering is the study of the behavior of buildings and structures subject to seismic loading. It is a subset of both structural and civil engineering.

The main objectives of earthquake engineering are:

  • Understand the interaction between buildings or civil infrastructure and the ground.
  • Foresee the potential consequences of strong earthquakes on urban areas and civil infrastructure.
  • Design, construct and maintain structures to perform at earthquake exposure up to the expectations and in compliance with building codes[1].

A properly engineered structure does not necessarily have to be extremely strong or expensive.

Shake-table crash testing of a regular building model (left) and a base-isolated building model (right) [2] at UCSD

Taipei 101, equipped with tuned mass damper, is the world’s second tallest skyscraper, after the Burj Khalifa.

The most powerful and budgetary tools of earthquake engineering are vibration control technologies and, in particular, base isolation.

Contents

[hide]

[edit] Seismic loading

Seismic loading means application of an earthquake-generated agitation to a structure. It happens at contact surfaces of a structure either with the ground [9], or with adjacent structures [10], or with gravity waves from tsunami. Seismic loading depends, primarily, on:

The Last Day of Pompeii

Ancient builders believed that earthquakes were a result of wrath of gods (in Greek mythology, e.g., the main “Earth-Shaker” was Poseidon) and, therefore, could not be resisted by humans. Nowadays, the people’s attitude has changed dramatically though the seismic loads, sometimes, exceed ability of a structure to resist them without being broken, partially or completely.

Due to their mutual interaction, seismic loading and seismic performance of a structure are intimately related.

[edit] Seismic performance

Main article: Seismic analysis

Earthquake or seismic performance is an execution of a building’s or structure’s ability to sustain their due functions, such as its safety and serviceability, at and after a particular earthquake exposure. A structure is, normally, considered safe if it does not endanger the lives and wellbeing of those in or around it by partially or completely collapsing. A structure may be considered serviceable if it is able to fulfill its operational functions for which it was designed.

Basic concepts of the earthquake engineering, implemented in the major building codes, assume that a building should survive The Big One (the most powerful anticipated earthquake) though with partial destruction [2].

[edit] Seismic performance evaluation

Engineers need to know the quantified level of an actual or anticipated seismic performance associated with the direct damage to an individual building subject to a specified ground shaking.

The best way to do it is to put the structure on a shake-table that simulates the earth shaking and watch what may happen next [11]. Such kinds of experiments were performed still more than a century ago[3]

Snapshot from shake-table video of a 6-story non-ductile concrete building destructive testing

Another way is to evaluate the earthquake performance analytically.

[edit] Seismic performance analysis

Seismic performance analysis or, simply, seismic analysis is a major intellectual tool of earthquake engineering which breaks the complex topic into smaller parts to gain a better understanding of seismic performance of building and non-building structures. The technique as a formal concept is a relatively recent development.

In general, seismic analysis is based on the methods of structural dynamics[4]. For decades, the most prominent instrument of seismic analysis has been the earthquake response spectrum method which, also, contributed to the proposed building code’s concept of today[5].

However, those spectra are good, mostly, for single-degree-of-freedom systems. Numerical step-by-step integration proved to be a more effective method of analysis for multi-degree-of-freedom structural systems with severe non-linearity under a substantially transient process of kinematic excitation[6].

[edit] Research for earthquake engineering

Shake-table testing of Friction Pendulum Bearings at EERC

Research for earthquake engineering means both field and analytical investigation or experimentation intended for discovery and scientific explanation of earthquake engineering related facts, revision of conventional concepts in the light of new findings, and practical application of the developed theories. The National Science Foundation (NSF) is the main United States government agency that supports fundamental research and education in all fields of earthquake engineering. In particular, it focuses on experimental, analytical, and computational research on design and performance enhancement of structural systems.

E-Defense Shake Table [3]

The Earthquake Engineering Research Institute (EERI) is a leader in dissemination of earthquake engineering research related information both in the U.S. and globally.

A definitive list of earthquake engineering research related shaking tables around the world may be found in Experimental Facilities for Earthquake Engineering Simulation Worldwide. The most prominent of them is now E-Defense Shake Table [7] in Japan.

Major earthquake engineering research centers in the United States and worldwide [show]

All earthquake engineering research activities worldwide are mostly associated with the following centers:

[edit] Major U.S. research programs

The NSF Hazard Mitigation and Structural Engineering program (HMSE) supports research on new technologies for improving the behavior and response of structural systems subject to earthquake hazards; fundamental research on safety and reliability of constructed systems; innovative developments in analysis and model based simulation of structural behavior and response including soil-structure interaction; design concepts that improve structure performance and flexibility; and application of new control techniques for structural systems [12].

Large High Performance Outdoor Shake Table, UCSD, NEES network

NSF also supports George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) [13] that advances knowledge discovery and innovation for earthquakes and tsunami loss reduction of the nation’s civil infrastructure, and new experimental simulation techniques and instrumentation.

NEES@Buffalo testing facility

NEES [14] comprises a network of 15 earthquake engineering experimental equipment sites available for experimentation on-site or in the field and through telepresence. NEES equipment sites include shake-tables, geotechnical centrifuges, a tsunami wave basin, unique large-scale testing laboratory facilities, and mobile and permanently installed field equipment [15].

NEES Cyberinfrastructure Center (NEESit) connects, via Internet2, the equipment sites as well as provides telepresence, a curated central data repository, simulation tools, and collaborative tools for facilitating on-line planning, execution, and post-processing of experiments.

[edit] Earthquake simulation

The very first earthquake simulations were performed by statically applying some horizontal inertia forces based on scaled peak ground accelerations to a mathematical model of a building [8]. With the further development of computational technologies, static approaches began to give way to dynamic ones.

Dynamic experiments on building and non-building structures may be physical, like shake-table testing, or virtual ones. In both cases, to verify a structure’s expected seismic performance, some researchers prefer to deal with so called “real time-histories” though the last cannot be “real” for a hypothetical earthquake specified by either a building code or by some particular research requirements. Therefore, there is a strong incentive to engage an earthquake simulation which is the seismic input that possesses only essential features of a real event.

Sometimes, earthquake simulation is understood as a re-creation of local effects of a strong earth shaking.

[edit] Structure simulation

Theoretical or experimental evaluation of anticipated seismic performance mostly requires a structure simulation which is based on the concept of structural likeness or similarity. Similarity is some degree of analogy or resemblance between two or more objects. The notion of similarity rests either on exact or approximate repetitions of patterns in the compared items.

Concurrent experiments with two kinematically equivalent to a real prototype building models [4]

In general, a building model is said to have similarity with the real object if the two share geometric similarity, kinematic similarity and dynamic similarity. The most vivid and effective type of similarity is the kinematic one. Kinematic similarity exists when the paths and velocities of moving particles of a model and its prototype are similar.

The ultimate level of kinematic similarity is kinematic equivalence when, in the case of earthquake engineering, time-histories of each story lateral displacements of the model and its prototype would be the same.

[edit] Seismic vibration control

Seismic vibration control is a set of technical means aimed to mitigate seismic impacts in building and non-building structures. All seismic vibration control devices may be classified as passive, active or hybrid [16] where:

  • passive control devices have no feedback capability between them, structural elements and the ground;
  • active control devices incorporate real-time recoding instrumentation on the ground integrated with earthquake input processing equipment and actuators within the structure;
  • hybrid control devices have combined features of active and passive control systems.[9]

When ground seismic waves reach up and start to penetrate a base of a building, their energy flow density, due to reflections, reduces dramatically: usually, up to 90%. However, the remaining portions of the incident waves during a major earthquake still bear a huge devastating potential.

After the seismic waves enter a superstructure, there are a number of ways to control them in order to soothe their damaging effect and improve the building’s seismic performance, for instance:

  • to disperse the wave energy between a wider range of frequencies;

Mausoleum of Cyrus, the oldest base-isolated structure in the world

Devices of the last kind, abbreviated correspondingly as TMD for the tuned (passive), as AMD for the active, and as HMD for the hybrid mass dampers, have been studied and installed in high-rise buildings, predominantly in Japan, for a quarter of a century [18].

However, there is quite another approach: partial suppression of the seismic energy flow into the superstructure known as seismic or base isolation.

For this, some pads are inserted into or under all major load-carrying elements in the base of the building which should substantially decouple a superstructure from its substructure resting on a shaking ground.

The first evidence of earthquake protection by using the principle of base isolation was discovered in Pasargadae, a city in ancient Persia, now Iran: it goes back to VI century BCE. Below, there are some samples of seismic vibration control technologies of today.

[edit] Dry-stone walls control

Dry-stone walls of Machu Picchu Temple of the Sun, Peru

People of Inca civilization were masters of the polished dry-stone walls, called ashlar, where blocks of stone were cut to fit together tightly without any mortar. The Incas were among the best stone masons the world has ever seen [10], and many junctions in their masonry were so perfect that even blades of grass could not fit between the stones.

Peru is a highly seismic land, and for centuries the mortar-free construction proved to be apparently more earthquake-resistant than using mortar. The stones of the dry-stone walls built by the Incas could move slightly and resettle without the walls collapsing which should be recognized as an ingenious passive structural control technique employing both the principle of energy dissipation and that of suppressing resonant amplifications [11].

[edit] Lead Rubber Bearing

LRB being tested at the UCSD Caltrans-SRMD facility

Lead Rubber Bearing or LRB is a type of base isolation employing a heavy damping.

Heavy damping mechanism incorporated in vibration control technologies and, particularly, in base isolation devices, is often considered a valuable source of suppressing vibrations thus enhancing a building’s seismic performance. However, for the rather pliant systems such as base isolated structures, with a relatively low bearing stiffness but with a high damping, the so-called “damping force” may turn out the main pushing force at a strong earthquake. The video [19] shows a Lead Rubber Bearing being tested at the UCSD Caltrans-SRMD facility. The bearing is made of rubber with a lead core. It was a uniaxial test in which the bearing was also under a full structure load.

[edit] Tuned mass damper

Tuned mass damper in Taipei 101, the world’s second tallest skyscraper

Typically, the tuned mass dampers are huge concrete blocks mounted in skyscrapers or other structures and moved in opposition to the resonance frequency oscillations of the structures by means of some sort of spring mechanism.

Taipei 101 skyscraper needs to withstand typhoon winds and earthquake tremors common in its area of the Asia-Pacific. For this purpose, a steel pendulum weighing 660 metric tons that serves as a tuned mass damper was designed and installed atop the structure. Suspended from the 92nd to the 88th floor, the pendulums sways to decrease resonant amplifications of lateral displacements in the building caused by earthquakes and strong gusts.

[edit] Friction pendulum bearing

FPB [5] shake-table testing

Friction Pendulum Bearing (FPB) is another name of Friction Pendulum System (FPS). It is based on three pillars[12]:

  • articulated friction slider;
  • spherical concave sliding surface;
  • enclosing cylinder for lateral displacement restraint.

Snapshot with the link to video clip of a shake-table testing of FPB system supporting a rigid building model is presented at the right.

[edit] Building elevation control

Transamerica Pyramid building

Building elevation control is a valuable source of vibration control of seismic loading. Thus, pyramid-shaped skyscrapers continue to attract attention of architects and engineers because such structures promise a better stability against earthquakes and winds.

Besides, the elevation configuration can prevent buildings’ resonant amplifications due to the fact that a properly configured building disperses the shear wave energy between a wide range of frequencies.

Earthquake or wind quieting ability of the elevation configuration is provided by a specific pattern of multiple reflections and transmissions of vertically propagating shear waves, which are generated by breakdowns into homogeneity of story layers, and a taper. Any abrupt changes of the propagating waves velocity result in a considerable dispersion of the wave energy between a wide ranges of frequencies thus preventing the resonant displacement amplifications in the building.

Tapered profile of a building is not a compulsory feature of this method of structural control. A similar resonance preventing effect can be also obtained by a proper tapering of other characteristics of a building structure, namely, its mass and stiffness. As a result, the building elevation configuration techniques permit an architectural design that may be both attractive and functional (see, e.g., Pyramid).

[edit] Simple roller bearing

Simple roller bearing is a base isolation device which is intended for protection of various building and non-building structures against potentially damaging lateral impacts of strong earthquakes.

This metallic bearing support may be adapted, with certain precautions, as a seismic isolator to skyscrapers and buildings on soft ground. Recently, it has been employed under the name of Metallic Roller Bearing for a housing complex (17 stories) in Tokyo, Japan [20].

[edit] Elevated building foundation

Bottom view of the Municipal Services Building [6] sitting on abutments of its elevated building foundation, City of Glendale, CA

Elevated building foundation (EBF) is a kind of seismic vibration control technology which remains an integral part of a building superstructure [13]. It is conceived to shield the building’s superstructure against potentially destructive components of the anticipated earthquakes including both lateral and vertical shaking.

This goal can be achieved by means of a proper choice of building materials, dimensions, and configuration of EBF for the particular construction site and local soil conditions.

As a result of multiple wave reflections and diffractions, as well as energy dissipations of the seismic waves in a process of their vertical propagation through horizontal strata of the EBF, any transmission of seismic wave energy into the building superstructure furnished with EBF will be decreased considerably which will decrease seismic loads and enhance seismic performance of the structure [21].

[edit] Springs-with-damper base isolator

Springs-with-damper close-up

Springs-with-damper base isolator installed under a three-story town-house, Santa Monica, California is shown on the photo taken prior to the 1994 Northridge earthquake exposure. It is a base isolation device conceptually similar to Lead Rubber Bearing.

One of two three-story town-houses like this, which was well instrumented for recording of both vertical and horizontal accelerations on its floors and the ground, has survived a severe shaking during the Northridge earthquake and left valuable information for further learning.

[edit] Hysteretic damper

Hysteretic damper is intended to provide better and more reliable seismic performance than that of a conventional structure at the expense of the seismic input energy dissipation [22]. There are four major groups of hysteretic dampers used for the purpose, namely:

  • Fluid viscous dampers (FVDs)
  • Metallic yielding dampers (MYDs)
  • Viscoelastic dampers (VEDs)
  • Friction dampers (FDs)

Each group of dampers has specific characteristics, advantages and disadvantages for structural applications.

[edit] Seismic design

Seismic design is based on authorized engineering procedures, principles and criteria meant to design or retrofit structures subject to earthquake exposure[8]. Those criteria are consistent just with the contemporary state of the knowledge about earthquake engineering structures[14]. Therefore, the building design which blindly follows some seismic code regulations does not guarantee safety against collapse or serious damage [23].

The price of poor seismic design may be enormous. Nevertheless, seismic design has always been a trial and error process no matter it was based upon physical laws or empirical knowledge of the structural performance of different shapes and materials.

Ruin of the $7,000,000 poorly designed San Francisco City Hall by 1906 earthquake and fire

To practice seismic design, seismic analysis or seismic evaluation of new and existing civil engineering projects, an engineer should, normally, pass examination on Seismic Principles [24] which, e.g. in the State of California, include:

  • Seismic Data and Seismic Design Criteria
  • Seismic Characteristics of Engineered Systems
  • Seismic Forces
  • Seismic Analysis Procedures
  • Seismic Detailing and Construction Quality Control

San Francisco after the 1906 earthquake and fire

To build up complex structural systems[15], seismic design utilizes, mostly, the same relatively small number of basic structural elements (to say nothing of vibration control devices) as any non-seismic design project.

Normally, according to building codes, structures are designed to “withstand” the largest earthquake of a certain probability that is likely to occur at their location. This means the loss of life should be minimized by preventing collapse of the buildings.

Seismic design is carried out by understanding the possible failure modes of a structure and providing the structure with appropriate strength, stiffness, ductility, and configuration[16] to ensure those modes cannot occur.

[edit] Seismic design requirements

Seismic design requirements depend on the type of the structure, locality of the project and its authorities which stipulate applicable seismic design codes and criteria [2]. For instance, California Department of Transportation‘s requirements called The Seismic Design Criteria (SDC) and aimed at the design of new bridges in California [25] incorporate an innovative seismic performance based approach.

Metsamor, Armenia nuclear power plant was closed after the 1988 destructive earthquake [7]

The most significant feature in the SDC design philosophy is a shift from a force-based assessment of seismic demand to a displacement-based assessment of demand and capacity. Thus, the newly adopted displacement approach is based on comparing the elastic displacement demand to the inelastic displacement capacity of the primary structural components while ensuring a minimum level of inelastic capacity at all potential plastic hinge locations.

In addition to the designed structure itself, seismic design requirements may include a ground stabilization underneath the structure: sometimes, heavily shaken ground breaks up which leads to collapse of the structure sitting upon it [26]. The following topics should be of primary concerns: liquefaction; dynamic lateral earth pressures on retaining walls; seismic slope stability; earthquake-induced settlement [17].

Nuclear facilities should not jeopardise their safety in case of earthquakes or other hostile external events. Therefore, their seismic design is based on criteria far more stringent than those applying to non-nuclear facilities [18].

[edit] Failure modes

Failure mode is the manner by which a earthquake induced failure is observed. It, generally, describes the way the failure occurs. Though costly and time consuming, learning from each real earthquake failure remains a routine recipe for advancement in seismic design methods. Below, some typical modes of earthquake-generated failures are presented. For information on the photographer and/or the agency that released corresponding images, usually accompanied with brief comments which were used, with sincere gratitude, here and there in this Section, click on the thumb nearby.

Typical damage to unreinforced masonry buildings at earthquakes

The lack of reinforcement coupled with poor mortar and inadequate roof-to-wall ties can result in substantial damage to a unreinforced masonry building. Severely cracked or leaning walls are some of the most common earthquake damage. Also hazardous is the damage that may occur between the walls and roof or floor diaphragms. Separation between the framing and the walls can jeopardize the vertical support of roof and floor systems.

Soft story collapse due to inadequate shear strength at ground level, Loma Prieta earthquake

Soft story effect. Absence of adequate shear walls on the ground level caused damage to this structure. A close examination of the image reveals that the rough board siding, once covered by a brick veneer, has been completely dismantled from the studwall. Only the rigidity of the floor above combined with the support on the two hidden sides by continuous walls, not penetrated with large doors as on the street sides, is preventing full collapse of the structure.

Effects of soil liquefaction during the 1964 Niigata earthquake

Soil liquefaction. In the cases where the soil consists of loose granular deposited materials with the tendency to develop excessive hydrostatic pore water pressure of sufficient magnitude and compact, liquefaction of those loose saturated deposits may result in non-uniform settlements and tilting of structures. This caused major damage to thousands of buildings in Niigata, Japan during the 1964 earthquake [27].

Car smashed by landslide rock, 2008 Sichuan earthquake

Landslide rock fall. A landslide is a geological phenomenon which includes a wide range of ground movement, including rock falls. Typically, the action of gravity is the primary driving force for a landslide to occur though in this case there was another contributing factor which affected the original slope stability: the landslide required an earthquake trigger before being released.

Effects of pounding against adjacent building, Loma Prieta

Pounding against adjacent building. This is a photograph of the collapsed five-story tower, St. Joseph’s Seminary, Los Altos, California which resulted in one fatality. During Loma Prieta earthquake, the tower pounded against the independently vibrating adjacent building behind. A possibility of pounding depends on both buildings’ lateral displacements which should be accurately estimated and accounted for.

Effects of completely shattered joints of concrete frame, Northridge

At Northridge earthquake, the Kaiser Permanente concrete frame office building had joints completely shattered, revealing inadequate confinement steel, which resulted in the second story collapse. In the transverse direction, composite end shear walls, consisting of two wythes of brick and a layer of shotcrete that carried the lateral load, peeled apart because of inadequate through-ties and failed.

7-story reinforced concrete buildings on steep slope collapse due to the following [28]:

  • Poor detailing of the reinforcement (lack of concrete confinement in the columns and at the beam-column joints, inadequate splice length).

Shifting from foundation, Whittier

Sliding off foundations effect of a relatively rigid residential building structure during 1987 Whittier Narrows earthquake. The magnitude 5.9 earthquake pounded the Garvey West Apartment building in Monterey Park, California and shifted its superstructure about 10 inches to the east on its foundation.

If a superstructure is not mounted on a base isolation system, its shifting on the basement should be prevented.

Insufficient shear reinforcement let main rebars to buckle, Northridge

Reinforced concrete column burst at Northridge earthquake due to insufficient shear reinforcement mode which allows main reinforcement to buckle outwards. The deck unseated at the hinge and failed in shear. As a result, the La Cienega-Venice underpass section of the 10 Freeway collapsed.

Support-columns and upper deck failure, Loma Prieta earthquake

Loma Prieta earthquake: side view of reinforced concrete support-columns failure which trigged the upper deck collapse onto the lower deck of the two-level Cypress viaduct of Interstate Highway 880, Oakland, CA.

Failure of retaining wall due to ground movement, Loma Prieta

Retaining wall failure at Loma Prieta earthquake in Santa Cruz Mountains area: prominent northwest-trending extensional cracks up to 12 cm (4.7 in) wide in the concrete spillway to Austrian Dam, the north abutment.

Lateral spreading mode of ground failure, Loma Prieta

Ground shaking triggered soil liquefaction in a subsurface layer of sand, producing differential lateral and vertical movement in a overlying carapace of unliquified sand and silt. This mode of ground failure, termed lateral spreading, is a principal cause of liquefaction-related earthquake damage [29].

Beams and pier columns diagonal cracking, 2008 Sichuan earthquake

Severely damaged building of Agriculture Development Bank of China after 2008 Sichuan earthquake: most of the beams and pier columns are sheared. Large diagonal cracks in masonry and veneer are due to in-plane loads while abrupt settlement of the right end of the building should be attributed to a landfill which may be hazardous even without any earthquake, see video footage at [30].

Tsunami strikes Ao Nang, [8]

Two-fold tsunami impact: sea waves hydraulic pressure and inundation. Thus, 2004 Indian Ocean earthquake of December 26, 2004, with the epicenter off the west coast of Sumatra, Indonesia, triggered a series of devastating tsunamis, killing more than 225,000 people in eleven countries by inundating surrounding coastal communities with huge waves up to 30 meters (100 feet) high. For a video footage of the tsunami propagation, click on [31].

[edit] Earthquake construction

Earthquake construction means implementation of seismic design to enable building and non-building structures to live through the anticipated earthquake exposure up to the expectations and in compliance with the applicable building codes.

Construction of Pearl River Tower X-bracing to resist lateral forces of earthquakes and winds

Design and construction are intimately related. To achieve a good workmanship, detailing of the members and their connections should be, possibly, simple. As any construction in general, earthquake construction is a process that consists of the building, retrofitting or assembling of infrastructure given the construction materials available [19].

The destabilizing action of an earthquake on constructions may be direct (seismic motion of the ground) or indirect (earthquake-induced landslides, soil liquefaction and waves of tsunami).

A structure might have all the appearances of stability, yet offer nothing but danger when an earthquake occurs [32]. The crucial fact is that, for safety, earthquake-resistant construction techniques are as important as quality control and using correct materials. Earthquake contractor should be registered in the state of the project location, bonded and insured.

To minimize possible losses, construction process should be organized with keeping in mind that earthquake may strike any time prior to the end of construction.

Each construction project requires a qualified team of professionals who understand the basic features of seismic performance of different structures as well as construction management.

[edit] Adobe structures

Partially collapsed adobe building in Westmorland, California

One half of the world’s population lives or works in the buildings made of earth.[20] Adobe type of mud bricks is one of the oldest and most widely used building materials. The use of adobe is very common in some of the world’s most hazard-prone regions, traditionally across Latin America, Africa, Indian subcontinent and other parts of Asia, Middle East and Southern Europe.

Adobe buildings are considered very vulnerable at strong quakes [33]. However, multiple ways of seismic strengthening of new and existing adobe buildings are available, see, e.g., [34].

Key factors for the improved seismic performance of adobe construction are:

  • Quality of construction.
  • Compact, box-type layout.
  • Seismic reinforcement [35].

[edit] Limestone and sandstone structures

Base-isolated City and County Building, Salt Lake City, Utah

Limestone is very common in architecture, especially in North America and Europe. Many landmarks across the world, including the pyramids in Egypt, are made of limestone. Many medieval churches and castles in Europe are made of limestone and sandstone masonry. They are the long-lasting materials but their rather heavy weight is not beneficial for adequate seismic performance.

Application of modern technology to seismic retrofitting can enhance the survivability of unreinforced masonry structures. As an example, from 1973 to 1989, the Salt Lake City and County Building in Utah was exhaustively renovated and repaired with an emphasis on preserving historical accuracy in appearance. This was done in concert with a seismic upgrade that placed the weak sandstone structure on base isolation foundation to better protect it from earthquake damage.

[edit] Timber frame structures

Half-timbered museum buildings, Denmark, date from 1560

Timber framing dates back thousands of years, and has been used in many parts of the world during various periods such as ancient Japan, Europe and medieval England in localities where timber was in good supply and building stone and the skills to work it were not.

The use of timber framing in buildings provides their complete skeletal framing which offers some structural benefits as the timber frame, if properly engineered, lends itself to better seismic survivability [21].

[edit] Light-frame structures

A two-story wooden-frame for a residential building structure

Light-frame structures usually gain seismic resistance from rigid plywood shear walls and wood structural panel diaphragms [36]. Special provisions for seismic load-resisting systems for all engineered wood structures requires consideration of diaphragm ratios, horizontal and vertical diaphragm shears, and connector/fastener values. In addition, collectors, or drag struts, to distribute shear along a diaphragm length are required.

[edit] Reinforced masonry structures

Reinforced hollow masonry wall

A construction system where steel reinforcement is embedded in the mortar joints of masonry or placed in holes and after filled with concrete or grout is called reinforced masonry [37].

Devastating 1933 Long Beach earthquake revealed that masonry construction should be improved immediately. Then, the California State Code made the reinforced masonry mandatory.

There are various practices and techniques to achieve reinforced masonry. The most common type is the reinforced hollow unit masonry. The effectiveness of both vertical and horizontal reinforcement strongly depends on the type and quality of the masonry, i.e. masonry units and mortar.

To achieve a ductile behavior of masonry, it is necessary that the shear strength of the wall is greater than the tensile strength of reinforcement to ensure a kind of bending failure [22].

[edit] Reinforced concrete structures

Stressed Ribbon pedestrian bridge over the Rogue River, Grants Pass, Oregon

Reinforced concrete is concrete in which steel reinforcement bars (rebars) or fibers have been incorporated to strengthen a material that would otherwise be brittle. It can be used to produce beams, columns, floors or bridges.

Prestressed concrete is a kind of reinforced concrete used for overcoming concrete’s natural weakness in tension. It can be applied to beams, floors or bridges with a longer span than is practical with ordinary reinforced concrete. Prestressing tendons (generally of high tensile steel cable or rods) are used to provide a clamping load which produces a compressive stress that offsets the tensile stress that the concrete compression member would, otherwise, experience due to a bending load.

To prevent catastropic collapse in response earth shaking (in the interest of life safety), a traditional reinforced concrete frame should have ductile joints. Depending upon the methods used and the imposed seismic forces, such buildings may be immediately usable, require extensive repair, or may have to be demolished.

[edit] Prestressed structures

Prestressed structure is the one whose overall integrity, stability and security depend, primarily, on a prestressing. Prestressing means the intentional creation of permanent stresses in a structure for the purpose of improving its performance under various service conditions[23].

Naturally pre-compressed exterior wall of Colosseum, Rome

There are the following basic types of prestressing:

  • Pre-compression (mostly, with the own weight of a structure)
  • Pretensioning with high-strength embedded tendons
  • Post-tensioning with high-strength bonded or unbonded tendons

Prestressed concrete cable-stayed bridge over Yangtze river

Today, the concept of prestressed structure is widely engaged in design of buildings, underground structures, TV towers, power stations, floating storage and offshore facilities, nuclear reactor vessels, and numerous kinds of bridge systems[24].

A beneficial idea of prestressing was, apparently, familiar to the ancient Rome architects; look, e.g., at the tall attic wall of Colosseum working as a press for the wall piers beneath.

[edit] Steel structures

Collapsed section of the San Francisco – Oakland Bay Bridge in response to Loma Prieta earthquake

Steel structures are considered mostly earthquake resistant but their resistance should never be taken for granted[citation needed]. A great number of welded steel moment frame buildings, which looked earthquake-proof, surprisingly experienced brittle behavior and were hazardously damaged in the 1994 Northridge earthquake. After that, the Federal Emergency Management Agency (FEMA) initiated development of repair techniques and new design approaches to minimize damage to steel moment frame buildings in future earthquakes.[25]

For structural steel seismic design based on Load and Resistance Factor Design (LRFD) approach, it is very important to assess ability of a structure to develop and maintain its bearing resistance in the inelastic range. A measure of this ability is ductility, which may be observed in a material itself, in a structural element, or to a whole structure.

As a consequence of Northridge earthquake experience, all pre-qualified connection details and design methods contained in the building codes of that time have been rescinded. The new provisions stipulated that new designs be substantiated by testing or by use of test-verified calculations.[citation needed]

[edit] Prediction of earthquake losses

Earthquake loss estimation is usually defined as a Damage Ratio (DR) which is a ratio of the earthquake damage repair cost to the total value of a building[26]. Probable Maximum Loss (PML) is a common term used for earthquake loss estimation, but it lacks a precise definition. In 1999, ASTM E2026 ‘Standard Guide for the Estimation of Building Damageability in Earthquakes’ was produced in order to standardize the nomenclature for seismic loss estimation, as well as establish guidelines as to the review process and qualifications of the reviewer[27].

Earthquake loss estimations are also referred to as Seismic Risk Assessments. The risk assessment process generally involves determining the probability of various ground motions coupled with the vulnerability or damage of the building under those ground motions. The results are defined as a percent of building replacement value.

[edit] See also

Wikimedia Commons has media related to: Earthquake engineering

Structures and Seismic Activity (v)


[edit] References

  1. ^ Berg, Glen V. (1983). Seismic Design Codes and Procedures. EERI. ISBN 0943198259.
  2. ^ a b Seismology Committee (1999). Recommended Lateral Force Requirements and Commentary. Structural Engineers Association of California.
  3. ^ Omori, F. (1900). Seismic Experiments on the Fracturing and Overturning of Columns. Publ. Earthquake Invest. Comm. In Foreign Languages, N.4, Tokyo.
  4. ^ Chopra, Anil K. (1995). Dynamics of Structures. Prentice Hall. ISBN 0138552142.
  5. ^ Newmark, N.M.; Hall, W.J. (1982). Earthquake Spectra and Design. EERI. ISBN 0943198224.
  6. ^ Clough, Ray W.; Penzien, Joseph (1993). Dynamics of Structures. McGraw-Hill. ISBN 0070113947.
  7. ^ “The NIED ‘E-Defence’ Laboratory in Miki City“]. http://www.bosai.go.jp/hyogo/ehyogo/. Retrieved 3 March 2008.
  8. ^ a b Lindeburg, Michael R.; Baradar, Majid (2001). Seismic Design of Building Structures. Professional Publications. ISBN 1888577525.
  9. ^ Chu, S.Y.; Soong, T.T.; Reinhorn, A.M. (2005). Active, Hybrid and Semi-Active Structural Control. John Wiley & Sons. ISBN 0470013524.
  10. ^ Live Event Q&As
  11. ^ Clark,Liesl; First Inhabitants PBS online, Nova; updated Nov. 2000
  12. ^ Zayas, Victor A. et al. (1990). A Simple Pendulum Technique for Achieving Seismic Isolation. Earthquake Spectra. pp. 317, Vol.6, No.2. ISBN 0087552930.
  13. ^ Elevated Foundation for Earthquake Protection of Building Structures
  14. ^ Housner, George W.; Jennings, Paul C. (1982). Earthquake Design Criteria. EERI. ISBN 1888577525.
  15. ^ Edited by Farzad Naeim (1989). Seismic Design Handbook. VNR. ISBN 0442269226.
  16. ^ Arnold, Christopher; Reitherman, Robert (1982). Building Configuration & Seismic Design. A Wiley-Interscience Publication. ISBN 0471861383.
  17. ^ Robert W. Day (2007). Geotechnical Earthquake Engineering Handbook. McGraw Hill. ISBN 0713778294.
  18. ^ Nuclear Power Plants and Earthquakes
  19. ^ Edited by Dr. Robert Lark (2007). Bridge Design, Construction and Maintenance. Thomas Telford. ISBN 0727735934.
  20. ^ “Earth Architecture – the Book, Synopsis”. http://www.eartharchitecture.org/. Retrieved 21 January 2010.
  21. ^ Timber Design & Construction Sourcebook=Gotz, Karl-Heinz et al.. McGraw-Hall. 1989. ISBN 0070238510.
  22. ^ Ekwueme, Chukwuma G.; Uzarski, Joe (2003). Seismic Design of Masonry Using the 1997 UBC. Concrete Masonry Association of California and Nevada.
  23. ^ Nilson, Arthur H. (1987). Design of Prestressed Concrete. John Wiley & Sons. ISBN 0471830720.
  24. ^ Nawy, Edward G. (1989). Prestressed Concrete. Prentice Hall. ISBN 0136983758.
  25. ^ [1]
  26. ^ EERI Endowment Subcommittee (May 2000). Financial Management of Earthquake Risk. EERI Publication. ISBN 0943198216.
  27. ^ Eugene Trahern (1999). “Loss Estimation”. http://www.cccengr.com/cccengerwebpage_lossestimation.html.

[edit] External links

Retrieved from “http://en.wikipedia.org/wiki/Earthquake_engineering

Categories: Civil engineering | Structural engineering | Earthquake engineering | Seismic vibration control | Engineering disciplines | Earthquakes | Seismology

**

http://www.curee.org/

The Consortium of Universities for Research in Earthquake Engineering (CUREE), is a non-profit organization, established in 1988, devoted to the advancement of earthquake engineering research, education and implementation.

The Consortium of Universities for Research in Earthquake Engineering (CUREE) is a non-profit organization, established in 1988, devoted to the advancement of earthquake engineering research, education and implementation.

  • 9th US National & 10th Canadian Conference on Earthquake Engineering –
    July 25-29, 2010 – Toronto [read more]
  • CUREE Newletter : Golden Gate Bridge Outdoor Exhibition Project [read more]
  • Winner of the prestigious 2008 SEAOC Excellence in Engineering Award –
    General Guidelines for the Assessment and Repair of Earthquake Damage in Residential Woodframe Buildings edited by J. Osteraas
  • NEES Research Program Funds Grand Challenge on Ceiling-Piping-Partition Systems – The vision of this Grand Challenge research project is to significantly enhance the seismic resilience of buildings and communities, by providing practicing engineers and architects with verified tools and guidelines for the understanding, prediction and improvement of the seismic response of the ceiling-piping-partition nonstructural system. [read more]
  • The family of Professor Hugh McNiven of the University of California at Berkeley has announced the sad news that he died on December 7, 2009. A memorial service will be held on January 31 at the U.C. Berkeley Faculty Club. [read more]
  • CUREE Education and Outreach Services: [learn more]

  • Information from NSF on NEESR Awards: [see complete listing]
BOOKS by CUREE MEMBERS
Felix Candela – Engineer, Builder, Structural Artist
M. Garlock and D. Billington
Structure and Design
G. G. Schierle
Design of Wood Structures-ASD/LRFD (6th edition)
D. E. Breyer, K. J. Fridley, K. E. Cobeen, and D. G. Pollock
Snow Loads – Guide to the Snow Load Provisions of ASCE 7-05
M. O’Rouke
Displacement-Based Seismic Design of Structures
M. J. N. Priestley, G. M. Calvi, and M. J. Kowalsky
[view entire list]
On this day in history, the February 22, 1981 Loyalty Islands, New Caledonia Earthquake occurred.

NEES Nonstructural
Building Bridges Between Civil Engineers and Science Museums

NEES Cityblock Project

Earthquake Architecture

Earthquake Damage Assessment and Repair Project

CUREE-Kajima
Joint Research Program

[view more]

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Faculty Position Openings : 4
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What is this and how can I get one?

http://www.curee.org/

**

Conference Updates

NSF and CAEE Travel Grants Available for Students, Early Academics, and Early Professionals

The U.S. National Science Foundation (NSF) and Canadian Association for Earthquake Engineering (CAEE) have made US $50,000 and Can $10,000 available to award travel grants to students, early academics, and early professionals to defray travel costs for attending the 9th US National and 10th Canadian Conference on Earthquake Engineering (9USN/10CCEE). Awards made from NSF funds are limited to students and early academics who reside in the U.S., attend a U.S. university, or teach at a U.S. university as of March 1, 2010. Awards made from Canadian funds can be made to students, early academics, and early professionals who reside in Canada as of March 1, 2010. These grants are being coordinated by the Earthquake Engineering Research Institute (EERI). All recipients will be expected to contribute 4 hours of voluntary service during the conference. We anticipate funding up to 50 U.S. participants and up to 20 Canadian participants. The award criteria, application procedure, and deadlines are described in the full article. READ MORE…

800 9USN/10CCEE Papers Received

The Technical Program Committee of the 9th U.S. National and 10th Canadian Conference on Earthquake Engineering (9USN/10CCEE) is pleased to announce that nearly 800 papers have been submitted to the online submission web site. The committee, co-chaired by professors Shamim Sheikh of the University of Toronto and Catherine French of the University of Minnesota, estimate 1,500 attendees from all over the world. They are planning for approximately 100 technical sessions, including several panel discussions, augmented by two plenary sessions and six special sessions with invited speakers, as well as poster sessions.

Authors will be notified of paper acceptance (or tentative acceptance if revisions are required) by January 31, 2010, with final papers due by March 20, 2010. All accepted papers, whether presented orally or as posters, will be published in the conference proceedings CD-ROM provided as part of the registration package.

Dates for Conference and Excursions

With the theme of “Reaching Beyond Borders,” the 9USN/10CCEE is scheduled for July 25-29, 2010, in Toronto, Ontario, Canada. Technical tours are planned for the SkyDome on Sunday and the CN Tower Monday evening, immediately after sessions end. An all-day field trip on Friday will tour Niagara Power Plant and Niagara Falls in the morning, followed by lunch at Queens Landing and a visit to Niagara-on-the-Lake in the afternoon.

Co-sponsors

So far, 30 organizations are co-sponsoring the conference, and more are expected to sign on. Members of co-sponsoring organizations will receive the EERI-CAEE member rate for the conference registration fee.

The Tsunami Society will hold its Fourth International Tsunami Symposium, July 25 – 29, 2010 in conjunction with the 9USN/10CCEE.


FINANCIAL CO-SPONSORS:

Degenkolb Engineers
DOE
FEMA / DHS
MCEER
NSF
USGS
US NRC

Click here to see a list of our other co-sponsors.

Paper formatting instructions

Paper template, and

Paper submission instructions

·         Conference Organizers

Earthquake Engineering Research Institute
499 14th Street, Suite 320
Oakland, CA 94612

Canadian Association for Earthquake Engineering
c/o Department of Civil Engineering
The University of Ottawa
161 Louis Pasteur St.
Ottawa, ON., K1N 6N5 Canada

·         Boost Your Visibility

Thinking about becoming a sponsor or exhibitor? Just download our brochure for sponsors & exhibitors to get started.

·         Paper Submission Materials

Paper formatting instructions
Paper template
Paper submission instructions

·         Announcements

Text of Second Announcement

Download 2nd Announcement

Text of First Announcement

© 2006 – 2010 9th US National & 10th Canadian Conference on Earthquake Engineering

http://2010eqconf.org/

**

List of Exhibitors

as of February 8, 2010

Booth# — Occupant Booth# — Occupant
218 ATC
208
and
210
Digitexx Data Systems
220 Dynamic Isolation Systems
109
and
111
EERI
100
and
102
FEMA
123 FYFECO
222 GeoConstruction
112 International Code Council
224 Kamatics
103
and
202
Kinemetrics
222 Layne GeoConstruction
204 MCEER
111 Nanometrics
214
and
216
NEES
110 NICEE
105 PEER Center
114 Reftek
106 R.J.Watson
115
and
117
Schnell SPA
108 Seismic Energy Products
107 SPI Housing
206 Taylor Devices
122
and
124
THK America Inc
300
and
302
USGS
125 Wiss Janney Elstner

map of exhibitor booths
Booths colored grey are already taken.

·         Conference Organizers

Earthquake Engineering Research Institute
499 14th Street, Suite 320
Oakland, CA 94612

Canadian Association for Earthquake Engineering
c/o Department of Civil Engineering
The University of Ottawa
161 Louis Pasteur St.
Ottawa, ON., K1N 6N5 Canada

·         Boost Your Visibility

Thinking about becoming a sponsor or exhibitor? Just download our brochure for sponsors & exhibitors to get started.

·         Paper Submission Materials

Paper formatting instructions
Paper template
Paper submission instructions

http://2010eqconf.org/exhibitors-sponsors/list-exhibitors/

**

Seismic Energy Products, L.P. (SEP) provides custom fabricated structural bearings for buildings, bridges and infrastructure world wide.

Since 1957 when SEP produced the first US Elastomeric Bridge Bearing, SEP has maintained its leadership in bearing technology, quality and on time delivery. That’s why SEP produces more Seismic Bearings, Teflon® Slide Bearings and Elastomeric Bearings and is the #1 structural bearing supplier in the US.

Please see the attached Design Template under ‘Contact Us/ Seismic Bearings’ if you have a current project under design. Just fax it to 903.677.4980 or email it to steve.bowman@sepbearings.com.

SEISMIC ENERGY PRODUCTS, LP
518 PROGRESS WAY | ATHENS, TX 75751
TEL: 903.675.8571

http://www.sepbearings.com/

**

As the major initiative of the International Polar Year (IPY) 2007 – 2009, Antarctica’s Gamburtsev Province Project (AGAP) investigates the Gamburtsev subglacial mountain range in the East Antarctic. Aerogeophysical surveys and ground-based seismological studies are being conducted by scientists from the United States, Germany, China, United Kingdom, Australia and Japan to better understand why a mountain system the size of the Alps is located in the middle of the continent. The mountain range is completely covered by 600m of ice and snow.

As part of AGAP, the Department of Earth and Planetary Sciences at Washington University in St. Louis, designed GAMSEIS (Gamburtsev Antarctic Mountains Seismic Experiment) to determine what is driving the mountains upward and how they may have contributed to the formation of the East Antarctic Ice sheet.

Read more…
Trillium Compact Carrying/Insulating Case
Products

Trillium Compact is available with an optional transport/installation case. The unique design provides space for the sensor and tripod deployment cradle (included with the case) which can be set securely into soil or onto an irregular rocky surface. The Trillium Compact is then set into the bowl-shaped arms of the cradle and leveled in seconds. Optional tripod cradle spike kits are also available for use in unconsolidated soil and sand deployments.

Read more…
Welcome Trillium Compact
News

Nanometrics is pleased to announce a new generation in broadband seismometry.

Standing at just 128 mm (5.04”) tall with a diameter of only 90 mm (3.54”), Trillium Compact combines the superior performance of a broadband seismometer with the installation convenience of a rugged geophone. The instrument incorporates a symmetric triaxial force feedback sensor with a response flat to velocity from 120 seconds to 100Hz. Scientists no longer need to compromise on performance in applications demanding small, highly portable seismometers.

  • Bandwidth -3 dB points at 120 s and 100Hz
  • Clip level 26 mm/s fom 0.1 Hz to 10 Hz
  • Extremely low power consumption of just 160 mW
  • No mass lock, no mass centering required
Nanometrics
About Nanometrics
Earthquakes. Volcanoes. Tsunamis. Global Warming. Nuclear Proliferation. Nanometrics is a world leader in the development of seismological instruments and networks used to monitor, investigate and help understand these global events.

An award-winning Canadian exporter, Nanometrics was the first company to produce a fully-integrated satellite system specially designed for studying and monitoring earthquakes.

Customers

Nanometrics has customers on every continent in more than 100 different countries.  Our customers have used our technology to establish and grow research networks across every environment in the world from the frozen tundra of Canada’s north to the arid deserts of the Middle East to the jungles of South America.  Many of these include mission-critical national and regional networks that demand the highest possible data quality and availability.
History

Nanometrics was founded by Robin Hayman, and has since grown to more than 100 full-time staff with a head office and production facility located in Ottawa in the Kanata North Business Park, the high-tech heart of Canada’s capital region.

Read more…
The Caribbean Tsunami Warning Network Set in Motion
News
The Seismic Research Unit (SRU) of the University of the West Indies selected the Nanometrics Inc. Libra VSAT telemetry seismic systems to establish a sustainable and robust seismic network to rapidly provide accurate detection of tsunamigenic events and issue early warnings for the region. This organization is responsible for monitoring earthquakes and volcanoes for islands of the Eastern Caribbean, in addition to the Dutch islands of Saba, St. Eustatius and St. Martin.
Read more…

More…

http://www.nanometrics.ca/

**

13th US – Japan Workshop on the Improvement of Structural Design and Construction Practices

April 20-22, 2010 Big Island, Hawaii

ATC site – Applied Technology Council – Structural engineering applications for earthquake, wind, flood, and man-made hazard mitigation

Welcome!

What’s New in 2010? The new ATC website you are viewing provides an updated, streamlined information resource and improved functionality, particularly in the speed of the online store.  ATC is also pleased to announce one important upcoming event: the 13th U.S.-Japan Workshop on Improvement of Structural Design and Construction Practices (April 20-22, 2010, on the Big Island in Hawaii).

Available Products. The library of completed ATC products includes more than 100 publications on key issues in structural, earthquake, wind, and coastal engineering.  Some are available as free down loads and others can be purchased through ATC’s online store.   More…

Projects. With funding from various government agencies and the ATC Endowment Fund, ATC is actively engaged in a broad range of funded technical projects to mitigate the effects of natural and other hazards on the built environment.  More…

Events. Periodically ATC conducts seminars, conferences, workshops and other meetings to document and advance the state of structural engineering practice and to identify research needs.  Registration for these events can be made through the “Events” section of this web site.  More…

ATC-15-12

April 20-22, 2010

Big Island, Hawaii

Call for Abstracts and Registration Information

ATC Publications in Highest Demand

1. ATC-20-1, Field Manual:
Postearthquake Safety
Evaluation of Buildings
(Second Edition
)
2. ATC-45, Field Manual:
Safety Evaluation of
Buildings after Wind
Storms and Floods
3. ATC-20 Set,
Postearthquake Safety
Evaluation of Buildings
& Companion Addendum
4. ATC-20-3, Case Studies
in Rapid Postearthquake
Safety Evaluation of Buildings
Applied Technology Council • 201 Redwood Shores Parkway, Suite 240 • Redwood City, California 94065 • (650) 595-1542

Contact Us

https://www.atcouncil.org/index.php

**

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Spirex SPIREX is an innovative machine proposed by Schnell, able to realize a continuous cla more…
Multi Assembler Shaped bars assembling plant producing structural meshes, meshes on request, baffles, more…
GTM telescope Machine for the production of round cages with welded spirals and pre-set pitch. The more…
Software
Grafo Boss Production supervision software that shows the job execution stat more…
News
• 3-6 Febbraio 2010
MADE EXPO 2010 – Milano, Italia
MADE Expo Nuovo Quartiere Fiera Mi  more…
• 29/09/2009
Il “Sistema Spirex” al 54° Congresso nazionale degli ingegneri
Da quando è stata presentata a Pari  more…
• 15/09/09
SPIREX, conquista il Belgio
Ancora un grande successo internazi  more…
• 29/05/2009
SPIREX, l’armatura a prova di sisma
Realizzata dal Gruppo Schnell è con  more…
•SAPIENS
This issue of @Schnell focuses espe  more…
Home | The Company | Worldwide | Products | Software | E-Commerce | News | Download | Career Opportunities | Contacts Privacy | Credits
English | Italian | French | Spanish | German | Poland | | Portuguese

http://www.schnell.it/

**

RefTek

Welcome to Refraction Technology, Inc. (REF TEK), your UNSHAKABLE source of digital recording instruments for imaging studies and earthquake research. We strive to give you the most technically advanced range of products available, support your work through top-notch customer service and stay one step ahead of your needs through continuing research. Please feel free to contact a sales person or engineer to answer your questions or help you find the right system for your application.

http://www.reftek.com/

**

RJ Watson, Inc.

R.J. Watson is a world wide designer, manufacturer and supplier of Bridge Bearings, Seismic Isolation Disk Bearings,  Multirotational Disk Bearings, Bridge Expansion Joints, Fiber Composites and Spray Applied Membrane for the Bridge & Highway Industry.

http://www.rjwatson.com/

**

(My note – why aren’t the manufacturers and engineers involved with reinforcing polymer fabrics – not at this show where the designers and engineers for earthquake resistant design are attending who would integrate these products into their menu of options for building constructions and engineering?)

**

NICEE

National Information Centre of Earthquake Engineering, at IIT Kanpur, INDIA

http://www.nicee.org/

National Information Centre of Earthquake Engineering
at IIT Kanpur, INDIA


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Last Updated on 2 January 2010
Latest News
Call for Papers – ISET Journal of Earthquake Technology.
Inter School Quiz on “Earthquake Tips” conducted at IIT Kanpur.
Open House for PG Students/Professionals (Engineers & Architects) conducted successfully.
Earthquake Engineering Literature Survey Workshop for Post Graduate Students, 10-19 July 2010 at IIT Kanpur.
Workshop for Earthquake Resistant Practices for Students of Architecture, 12-17 July 2010 at IIT Kanpur.
IAEE Guidelines for Earthquake Resistant Non-Engineered Construction – Oriya Translation by NICEE.
Publications and Resource Material of NICEE.
National Seminar and a Short Course on Seismic Design of Concrete Gravity Dams 2009 conducted successfully.
Seismic Design Guide For Masonry Buildings – Svetlana Brzev.
Earthquake Tips in Marathi.
Scholarships for the Advanced Masters in Structural Analysis of Monuments and Historical Constructions.
Interesting article on prediction of earthquakes.
3rd International Earthquake Symposium Bangladesh, March 5-6, 2010 at Dhaka, Bangladesh.
MEEES Scholarships to Study in Europe.
9th US National and 10th Canadian Conference on Earthquake Engineering, July 25-29, 2010 at Toronto.
ICIWSE-2010-Interantaional Conference on “Innovative World of Structural Engineering”, September 17-19, 2010 at Aurangabad, Maharashtra.
The National Information Centre of Earthquake Engineering hosted at Indian Institute of Technology Kanpur is intended to collect and maintain information resources on Earthquake Engineering and make these available to the interested professionals, researchers, academicians and others with a view to mitigate earthquake disasters in India.
NICEE has undertaken a range of capacity building activities towards earthquake safety such as organising Literature Review/Curriculum Workshops in Earthquake Engineering for Students and Teachers from Engineering Colleges across India
more….
NICEE helps in publication and wide dissemination of Earthquake Engineering publications. Also, it is equiped with a good collection of study materials and books in earthquake engineering related topics. It helps the resourse material being supplied to in
more…
NICEE also informs its members the latest news of earthquake engineering through the electronic newsletter.
more…

Copyright © 2005 National Information Centre of Earthquake Engineering – Kanpur – INDIA
Item Price (Rs.)
IITK-BMTPC Earthquake Tips: Targeted at stakeholders in the building and construction industry, this very popular series introduces the basics of earthquake resistant design concepts in a simple and easy to understand format. Author: C.V.R. Murty. 56 pages in colour 150

Seismic Conceptual Design of Buildings – Basic principles for engineers, architects, building owners, and authorities: This monograph conveys the concept of earthquake resistant design of buildings in a very simple and pictorial style. Authors: Hugo Bachmann. 84 pages . 200
AT RISK: The Seismic Performance of Reinforced Concrete Frame Buildings with Masonry Infill Walls: A tutorial developed by a committee of the World Housing Encyclopedia, a project of the Earthquake Engineering Research Institute and the International Association for Earthqauke Engineering. Authors: C. V. R. Murty, Svetlana Brzev, Heidi Faison, Craig D. Comartin and Ayhan Irfanoglu. 80 pages . 200
Confined Masonry – A guidebook for technicians and artisans: This manual is meant for artisans, masons, and homeowners engaged in construction of one- and two-storey dwellings in a low-tech environment. It provides clear guidance on the construction aspects as well as do’s and don’ts.
Authors:
Tom Schacher. 20 pages .
100
Seismic Design with Supplemental Energy Dissipation Devices: The purpose of this monograph is to impart basic concepts of the supplemental energy dissipation technology to design engineers, architects, and buildings officials so they can understand its benefits and limitations in structural applications. Authors: Robert D Hanson and TSU T Soong. 135 pages . 200
Earthquake Spectra and Design: This monograph provides an overview of the earthquake design procedure, with particular focus on buildings. It describes the concept of Design Response Spectra, both elastic and inelastic.Authors: N M Newmark and W J Hall. 103 pages . 200
Earthquake-Resistant Confined Masonry Construction: This document presents confined mansonry construction as an alternative form of masonry construction in seismic areas. It contains a review of the international state-of-the-practice as well as guidelines for construction of new structures by this method. Authors: Svetlana Brzev. 81 pages . 100

Guidelines for Earthquake Resistant Non-Engineered Construction: This monograph of the International Association for Earthquake Engineering covers monry, earthen, wooden and reinforced concrete buildings. The simple, presentation style enables the common man to apply these techniques in non-engineered constructions. Available in English and Hindi versions . 114 Pages 100
Guidelines for Earthquake Resistant Non-Engineered Construction: Published in 1986 by International Association for Earthquake Engineering Hindi Translation in June 2004 by National Information Center of Earthquake Engineering, IIT Kanpur 100
Fundamentals of Seismic Protection for Bridges: This EERI monograph discusses the seismic performance of bridges, and current practices in the seismic analysis and design of new bridges as well as retrofit strategies for old bridges. It brings state-of-the-art practices in earthquake resistant design and construction of bridges to the research, teaching and design community of India . Authors: Mark Yashinsky and M.J. Karshenas. 184 pages . 200
Seismic Hazard and Risk Analysis: This EERI monograph introduces methods of seismic hazard and risk analysis that form the basis for development of consensus probabilistic seismic hazard maps, an important prerequisite for responding effectively to earthquake risk. Author: Robin K. McGuire . 221 pages 200
Earthquake Dynamics of Structures, A Primer: This EERI monograph provides a primer on the fundamentals of structural dynamics, with the intention of providing the non-specialist in dynamics with the basic concepts and knowledge needed to understand the response of structures to earthquake motions. Authors: Anil K. Chopra. 131 pages 200
Earthquake Design Criteria: This EERI monograph presents information on the earthquake performance of structures and on important aspects of specifying seismic design criteria. Authors: G. W. Housner and P. C. Jennings. 128 pages 200
Keeping Schools Safe in Earthquakes: This monograph presents a series of papers authored by participants of the 2004 OECD-GHI Meeting at Paris . The articles encompass issues pertaining to new buildings, retrofitting of old buildings as well as enforcement and public policy towards maximizing seismic safety of schools. 200
Earthquake Rebuilding in Gujarat , India: This publication describes the post-earthquake recovery process after the Bhuj 2001 earthquake. It showcases the complex and challenging recovery phase and the strategies employed by the communities towards disaster mitigation that can serve as useful lessons and guidelines for handling future disasters. Authors: C.V.R. Murty, Marjorie Greene, Sudhir K. Jain, N. Purendra Prasad, Vipul V. Mehta . 120 pages 150
The Great Sumatra Earthquake and Andaman Ocean Tsunami of December 26, 2004: A report based on a reconnaissance study coordinated by IIT Kanpur, this publication gives an overview of the effects in Indian territory of the 2004 Sumatra tsunami and the earthquake. Originally published in EERI newsletter. Authors: Sudhir K. Jain, et.al. 16 pages in colour 100
Reconnaissance Report of Sikkim Earthquake of 14 February 2006: This reconnaissance study report by IIT Kanpur summarises the damages caused by the moderate 5.7 magnitude earthquake. Authors: Hemant B. Kaushik, Kaustubh Dasgupta, Dipti R. Sahu and Gayatri Kharel. 20 pages in colour . 100
Annotated Images from the Bhuj, India Earthquake of January 26, 2001 (CD): This CD compiled by EERI contains annotated images from the Bhuj, India Earthquake of January 26, 2001 . Over 300 images illustrate widespread damages of different categories. 200
Bhuj , India Republic Day January 26, 2001 Earthquake Reconnaissance Report (CD): This CD contains full text and images of the 398-page, Reconnaissance Report, published by EERI. Technical editors : Sudhir K. Jain, Wiliam R. Lettis, C.V.R. Murty and Jean-Pierre Bardet 200
Engineering Response to Hazards of Terrorism: This volume contains the articles or power point presentations made during the seminar. The seminar themes included hazard estimations, structural and non-structural mitigaton measures and hazard detection.Authors: Sudhir K. Jain, C.V.R. Murty and D.C. Rai. 398 pages. 450
For More Publications Click Here

Copyright © 2005 National Information Centre of Earthquake Engineering – Kanpur – INDIA
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**

Product Information of THK General Catalog No.500E is available in PDF format. To view the PDF formatted catalog, please read ” Limited Warranty ” carefully. If you would not agree with our ” Limited Warranty ” , we ask you not to use these sources.

Product Categories

Linear Motion


Feed Screw Rotation



Actuator / Custom Assemblies Others


http://www.thk.com/eng/products/index.html

**

The Structural Engineer

A Center for Integrating Information on Structural Engineering

CEngineer Information Center

http://www.thestructuralengineer.info/onlinelibrary/

WELCOME

Welcome to the main entrance of the Online Structural Engineering Library. The online structural engineering library provides links to useful publications such as papers, books, manuals, theses, that are available online for free.

Resources are divided into sections shown to the left. Choose the topic of your interest. Resources may be listed in more categories, if more categories are appropriate to the document’s content.

Contact us to inform us about a resource, donate or make other recommendations.

Please read our Disclaimer before using our service.

Currently the Online Structural Engineering Library includes 1525 documents and 1693 authors in 20 categories.

The Structural Engineer
A Center for Integrating Information on Structural Engineering

WELCOME

Welcome to the main entrance of the Online Structural Engineering Library. The online structural engineering library provides links to useful publications such as papers, books, manuals, theses, that are available online for free.

Resources are divided into sections shown to the left. Choose the topic of your interest. Resources may be listed in more categories, if more categories are appropriate to the document’s content.

Contact us to inform us about a resource, donate or make other recommendations.

Please read our Disclaimer before using our service.

Currently the Online Structural Engineering Library includes 1525 documents and 1693 authors in 20 categories.

Search the Online Structural Engineering Library:

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Show only this author’s papers (ASCE), American Society of Civil Engineers Abdelrazaq, A. Abou-Hanna, J. Abraham, E.J. Abrams, D. Accord, N.B. Adamchack, J.C. Adams, J. Adamson, D. Adan, S.M. Adany, S. Afshar, A. Agrawal, S.K. Agrawal, A.K. Aguiar, B. Aguilar, Z. Ahmad, S. Ahmed, M.S. Ahmed, O. Ahmed, E.U. Ahmed, I. Ahn, I.-S. Ahner, C. Akguzel, U. Aktas, M. Al-Ali, A.A.K. Al-Omaishi, N. Al-Salloum, Y.A. Alam, J.B Alarcon, J. Alavi, B. Alcocer, S.M. Alexander, S.D.B. Alfawakhiri, F. Ali, Q. Ali, S.I. Alimoradi, A. Alkhrdaji, T. Allen, R. Almeida, J.C Almusallam, T.H. Alsayed, S.H. Aluminiumwalla, M. Alva-Hurtado, J. Alves, J.L.D. Alves, T.M.J. Amaris, A. Ameli, M. Amiruddin, A.A. Amrhein, W.A. Anagnos, T. Anderson, R. Anderson, D.L. Anderson, J. Anderson-Wilk, M. Andrade, A. Andre, G.P. Angal, R.D. Ankenman, B.E. Anooshehpoor, R. Antunes, J. Anzani, A. Aquado, P. Aquino, W. Arciszewski, T. Arede, A. Aref, A.J. Arlekar, J.N. Arnold, S. Arora, D. Arslan, M.H. Arslan, G. Arteaga, A. Arulselvan, S. Arya, A.S. Aschheim, M. Ashford, S.A. Ashraf, M. Aslani, H. Assaf, A. Assakkaf, I.A. Atik, L.A. Atis, C.D. Atua, K.I. Aydan, O. Ayoub, A. Ayyub, B.M. Azher, S.A. Azuma, T. Babu, T.S. Babu, R.R. Bachmann, H. Bacinskas, D. Backer, S. Badoux, M. Bae, H.-U. Bai, Y. Bai, J.-W. Bailey, B.M.W. Bailey, C.G. Bailey, K. Bajpai, K. Baker, K.A. Baker, J. Baker, W.F. Balazs, G. Baldo, P. Ballantyne, D.B. Bambach, M.R. Bank, L.C. Banta, T.E. Barker, J. Barnecut, C. Barr, P. Barros, J.A.O. Barroso, L.R. Bartlett, F.M. Basheer, P.A.M. Bashor, R. Basu, D. Baudic, S.F. Bayasi, Z.M. Bazant, Z.P. Bazzurro, P. Beach, J.E. Beason, W.L. Beazley, B.F. Bechtoula, H. Beck, J.L. Beconcini, M.L. Becque, J. Bedrinana, E. Beeldens, A. Begum, M. Behbahanifard, M.R. Belevicius, R. Bell, D.K. Belouar, A. Bendimerad, F. Benediktas, D. Benichou, N. Benipal, G.S. Benmokrane, B. Bennie, S.D. Bentur, A. Bentz, D.P. Bentz, E.C. Benzaid, R. Beque, J. Bergmeister, K. Berman, J. Berneiser, A. Berry, M. Bertero, V. Bertero, R.D. Bessason, B. Betti, M. Bhaskar, N.V.R.C.B. Bhattacharya, S.N. Bhedasgaonkar, B.V. Bike, S.G. Billie, F. Binda, L. Binici, B. Biro, Y. Bisby, L. Bisch, P. Black, C.J. Black, E. Blades, K. Blazevicius, Z. Bodin, P. Bonowitz, D. Booth, E. Boquera, A.M. Borcherdt, R.D. Borgal, C.P. Borja, R.I. Borowicz, D.T. Boshoff, W.P. Bosiljkov, V.B. Bosiljkow, V. Boulfoul, A. Bouscher, J.W. Bousias, S.N. Bousselham, A. Bowers, S.E. Boys, A. Bracci, J.M. Bradford, S.C. Brattland, A. Bremault, D. Brindos, R. Brink, M. Broms, C.E. Brosens, K. Brown, R. Brown, J. Brown, A.W.M. Brown, M.C. Browne, C. Bruckner, M. Brune, J.N. Bruneau, M. Bucker, I. Buffarini, G. Bukowski, R.W. Bull, D.K. Bullard, J.W. Buratti, G. Burdet, O. Burrow, M.C. Burton, P. Bustamante, A.O. Butterworth, J. Buyukozturk, O. Caestecker, C. Cai, M. Cai, Q. Calderone, A.J. Calle, G.D. Callele, L.J. Camoes, A. Camotim, D. Campbell, H. Campos-Costa, A. Cao, L. Cardenas, L. Carino, N.J. Carlson, A.E. Carneiro, J.O. Carol, I. Carpenter, J.A. Carr, A. Castro, R. Castrodale, R.W. Cauley, P. Ceesay, J. Celebi, M. Celep, U. Celik, O.C. Cermak, J.E. Chaallal, O. Chai, Z. Chai, J.-F. Chakkaravarth, K. Chan, E. Chan, O.B. Chana, P.S. Chandler, R.F. Chandrangsu, T. Chang, L. Chang, K.C. Chang, S.-P. Chapman, J.R. Charleson, A. Chau, K. Chaubey, S.K. Chawla, G. Chebili, R. Chen, S.S. Chen, G.D. Chen, D. Chen, Y. Chen, H. Chen, B. Chen, C.S. Chen, X. Cheng, J.J.R. Cheng, C.M. Cheok, G. Chern, J.-C. Chi, W.-M. Chica, E. Chiewanichakorn, M. Chikh, N.E. Chin, J.W. Ching, J. Chintanapakdee, C. Chiroiu, L. Chiu, Y.-H. Cho, C. Choi, K.-K. Chopra, A.K. Chow, H.S.W. Chowdhury, E. Christopoulos, C. Chung, Y.-S. Chung, D. Chung, R.M. Chung, L.L. Cimellaro, G.P. Cimellaroa, G.P. Civjan, S.A. Cladys, C.O. Clancy, C.M. Clark, A.J. Clear, C.A. Clemente, P. Clifton, J.R. Clyde, URS Greiner Woodward Clyde, C. Coburn, A. Coelho, E. Coil, J.M. Collins, M.P. Comeau, E. Comerio, M.C. Conley, J.A. Connolly, J.D. Connor, J. Cook, R. Cooper, M. Cooper, J.D. Cordova, P.P. Cornell, C.A. Coronelli, D. Costa, A. Costa, P. Cotton, S.C. Cox, K.E. Craig, J.I. Crandell, J.H. Crawford, J.E. Cress, M. Crick, D. Crispino, E.D. Croce, P. Crowley, H. Csanyi, E. Csebfalvi, A. Csikos, A. Cunha, V.M.C.F. Curtin, D. Czarnecki, L. D’ Ambrisi, A. D’Andrea, M. D’Ayala, D. da Porto, F. Dadfar, B. Daei, M. Darter, M. Das, N.K. Das, D. Dasgupta, K. Dash, S.R. Datta, A.K. Datta, T.K. Dattatrayam, R.S. Daudeville, L. Davidson, B.J. Dayal, U. De Backer, H. de Felice, G. De Jong, K.A. de Juan, A. De Lange, J.H. de Larrard, F. De Roeck, G. De Rosa, E. De Sortis, A. De Zotti, A. Deaton, S. Debaiky, A.S. Decanini, L. Degrande, G. Dehn, F. Deierlein, G.G. Del Re, D. Delgado, R. DeMatteis, G. Demircioglu, M.B. Denarie, E. Deng, K. Deniaud, C. Der Kiureghian, A. Dereymaeker, J. DesRoches, R. Dettling, J.E. Detwiler, R.J. DeVall, R. Devi, P.R. Dexter, R.J. Di Julio Jr., R.M. Di Sarno, L. Diamantidis, D. DiBattista, J.D. Dietz, J. Dillon, L. Dinu, F. Dolan, J.D. Doneux, C. Donnecke, c. Donze, F. Dooms, D. Dotson, S. Douglas, B.M. Driver, R.G. Drosopoulos, G.A. Dryburgh, R.B. Duan, X. Dudas, A. Duenas-Osorio, L. Dunai, L. Dupont, D. Dura, A.A. Duran, F.C. Durrani, A. Duthinh, D. Dutta, J. Dyke, S. Earls, C.J. Easterlink, W.S. Ebecken, N.F.F. Eberhard, M. Eccher, G. Ehlen, M.A. Eibl, J. Eisner, R. El-Amoury, T. El-Azazy, S. El-Hacha, R. El-Tawil, S. Elezaby, Y.K. Elgawady, M. Elhajj, N. Eligehausen, R. Elkadi, A.S.K. Elkhoraibi, T. Ellery, M. Ellingwood, B.R. Ellobody, E.A. Ellul, F. Elnashai, A.S. Elsanadedy, H.M. Elwi, A.E. Elwood, K.J. Encalada, J. Engelhardt, M. Englehardt, M.D. Erbay, O.O. Erberik, M.A. Erdelyi, L. Erdelyi, S. Erdik, M. Ereckson, N.L. Erwin, C. Esmaeily-Gh., A. Estabrooks, B.G. Estrada, M. Faber, M. Fabio, F. Fairbairn, E.M.R. Fajfar, P. Fallahi, A. Farag, N.O. Fardis, M.N. Farkas, G. Farooq, S.H. Farvashany, F.E. Fattal, S.G. Faust, T. Favre, R. Febrin, I. Fehrenkamp, A. Feldman, L.R. Fenves, G.L. Feritto, J.M. Ferragut, T.R. Ferraris, C.F. Ferreira, M. Ferreira, R.M. Feytons, S. Figeys, W. Filho, R.D.T. Filiatrault, M. Filiatrault, A. Filippou, F.C. Filliben, J.J. Finnigan, T.D. Fischer, G. Fischer, M. Fischinger, M. Fisher, J. Flottmeyer, B.L. Foley, C. Fonseca, G.M. Forney, G.P. Foster, S.J. Fowler, D.W. Frank, K. Franklin, S. Fraser, E.S. Fraser, R. Free, M. Freeborne, W. Friedland, I.M. Fritz, W.A. Frohnsdorff, G. Frost, D. Frost, J.D. Fu, C.C. Fujikura, S. Fujimoto, T. Fujisaki, E. Fujiwara, T. Fukumoto, T. Fukushima, S. G.L., Kulak Gajan, S. Galambos, T.V. Galizia, F. Gallocher, S. Gallt, J.G. Galsworthy, J. Gan, W. Gandhi, P. Ganesh, G.M. Ganev, T. GangaRao, V.S. Ganz, H.R. Garay-Moran, J.de Dios. Garboczi, E.J. Garcia, D.L. Gardoni, P. Geiker, M.R. Genesio, G. Gentry, T.R. Gettu, R. Geubelle, P.H. Gewain, R.G. Ghaffar, A. Ghaffarzadeh, H. Ghobarah, A. Ghosh, S.K. Ghosh Associates Inc., S.K. Gibson, N. Gibson, W. Gibu, P. Giessler, S. Gilani, A. Gilbert, R.I. Gilbert, B.P. Gilbert, M. Giovinazzi, S. Giroldo, F. Gjorv, O.E. GKhalfallah, S. Goel, S. Goel, R.K. Goodno, B.J. Goodson, E. Goodspeed, C. Goretti, A. Gosh, S.K. Goto, H. Govindaraj, K. Goyet, J. Graff, R. Graham, C. Gram, M.M. Gramoll, K. Grauvilardell, J.E. Graybeal, B.A. Green, R. Green, P.S. Green, M. Gribniak, V. Griffith, M.C. Grigoriu, M. Grillo, V.E. Grondin, G.Y. Gross, J.L. Grubbs, A.J. Gu, M. Gubati, A.A.-H.S. Gulay, F.G. Guo, T. Gupta, A.K. Gupta, M. Gupta, S.M. Gurley, K. Guzman, R. Haan J.R., F.L. Haan Jr., F.L. Habel, K. Hacopian, S. Hajirasouliha, I. Hajjar, J.F. Hakam, A. Halamickova, P. Hall, J.F. Hall, G. Hallberg, S. Hamada, T. Hamburger, R.O. Hameed, M.A. Hamilton, J. Hancock, G.J. Hansen, M.R. Hansen, K.K. Haque, M.E. Harden, C. Harding, G. Haroun, M.A. Harries, K.A. Harrington, D. Hartle, R.A. Hartmann, J.L. Hartt, W.H. Harwood, K. Hasegawa, T. Haselton, C.B. Hashash, Y. Hashemi, A. Hashida, T. Hass, C.T. Hassan, M. Hassoun, N.M. Hatzinikolas, M.A. Haukaas, T. Hausner, G.W. Hawkins, N.M. Hayashi, Y. Hayen, R. Hayes, J. Hays, W. He, L. Hearing, B. Heckert, A. Hegarty, D.G. Hegedus, I. Hegemier, G.A. Heidarzadeh, M. Hentz, S. Herroelen, B. Hess, PE. Hewetson, C.G. Hieber, D.G. Higgins, P. Hillier, T.S. Hino, S. Hjiaj, M. Hodhod, O. Hoehler, M.S. Hoffmann, C.M. Holmes, W.T. Holschemacher, K. Holst, J.M.F.G. Holzer, T.L. Hong, K.-J. Horii, H. Horton, S. Hose, Y.D. Hotta, S. Hover, K. Howell, T.D. Hrelja, G. Hsiao, C.P. Hsieh, C.C. Hsu, Y.T. Hu, S.-L. J. Huaco, G. Huang, Y. Huang, Z.-F. Huang, S.N. Hubbard, S. Hueste, M.B.D. Hughes, T.G. Hughes, R. Hung, C. Huns, B.B.S.H. Hunston, D. Hunter, O.K. Husid, R. Hussain, Z. Hussain, M.A. Hutchinson, T. Hutchinson, R.S. Hwang, H. Hwang, J.S. Hwang, S.-J. Iai, S. Iban, A.L. Ibarra, L.F. Ibrahim, R. Ichii, K. Ignoul, S. Iiba, M. Ilyas, M. Imamura, F. Inai, E. Ingham, J.M. Innamorato, D. Iravani, S. Ireland, M.G. Irfanoglu, A. Irwin, R. Ishida, E. Ishizaki, H. Ismail, M. Isoyama, R. Isyumov, N. Itani, A. Ito, S. Ivanyi, M. Iwai, S. Iwankiw, N.R. Iwasaki, T. J., Panda Jackson, H.W. Jacobson, D.A. Jahanshahi, M. Jain, S.K. Jain, A.K. Jaiswal, O.R. Jaiswal, A. Jalali, S. Jansohn, R. Jatulis, D. Javed, M. Jeffs, P.A. Jennings, P.C. Jensen, J.P. Jeong, S.-H. Ji, J. Ji, C. Jin, M. Johansson, J. Johanssons, J. Johnson, L. Johnson, N. Johnston, A. Jones, S.E. Joon, L.S. Joshi, M. Joshi, H.R. Josi, G. Juan, W. Juhas, P. Juozapaitis, A. Juska, T. Juvas, K. Kabat, S. Kabele, P. Kabeyasawa, T. Kaewkulchai, G. Kai, M. Kaklauskas, G. Kala, J. Kala, Z. Kaliszky, S. Kalpakidis, I. Kam, W.Y. Kamat, M.K. Kanda, T. Kanda, K. Kang, T.H.-K. Kanstad, T. Kantor, J.C. Kanvinde, A.M. Kappi, A. Kara, M.E. Karbhari, V.M. Kareem, A. Karim, K.R. Karr, M.E. Kase, B. Kashiryfar, A. Kaufmann, E.J. Kaushik, H.B. Kaushik, S.K. Kaveh, A. Kawano, H. Kawano, A. Kayvani, K. Kazemi, M.T. Keller, C. Kelly, J.M. Kendall, A. Kennedy, D.J.L. Kennedy, S.J. Kennedy, G.D. Kenyon, J.M. Keoleian, G.A. Kerschen, G. Khalfallah, S. Khalil, H.S.E. Khaloo, A.R. Khanzadi, M. Kharel, G. Khaskia, A. Khong, H. Khuntia, M. Kicinger, R. Kihl, D.P. Kijewski, T. Kijewski-Correa, T. Kilar, V. Kilic, A. Kilpatrick, J. Kim, Y.-S. Kim, H. Kim, S.J. Kim, T. Kim, J. Kim, W.S. Kindij, A. King, S.A. Kious, W.J. Kiremidjian, A.S. Kiss, K. Kitahara, A. Kitayama, N. Kitazawa, M. Kitsuse, A. Kiureghian, A. Kline, S. Klingner, R.E. Klotz, S. Klug, Y. Knapen, E. Knight, D.E. Koch, G. Kochly, M. Kodur, v. Koehler, E.P. Koen, D. Koganemaru, K. Kohiyama, M. Komatitsch, D. Konagai, K. Kong, H.-J. Kong, K.H. Konig, G. Kono, S. Konstantinidis, D. Koo, R. Koseki, J. Koshimura, S. Kosmatka, S.H. Kovacs, T. Kovalev, A. Kovler, K. Kozikowski, R.L. Krajewski, J.E. Krauss, P.D. Krawinkler, H. Kren, A. Krishnan, S. Kriviak, G.J. Kroggel, O. Krstulovic-Opara, N. Kruger, G. Krzmarzick, D. Kuchma, D.A. Kudsi, T. Kuklik, P. Kulak, G.L. Kumar, P.R. Kumar, G.R. Kuo, C. Kurian, J.V. Kurtovich, M. Kutas, R. Kuthinh, D. Kutter, B.L. Kuzik, M.D. Kvedaras, A.K. Kwak, H.G. Kwak, Y.K. Kwan, Y.K. Kwon, O.-S. Kwon, D.K. Kyungha, P. LaBelle, J. LaBoube, R.A. Lagomarsino, S. Lai, H.C.J. Lai, W. Lal, R. Lamanna, A.J. Lang, K. Lange, D.A. Langenbach, R. Laplace, P.N. Larmie, E.A. Lawler, J.S. Lecce, M. Ledezma, C. Lee, D. Lee, T.-H. Lee, H.-J. Lee, B.J. Lee, K. Lee, R. Lehman, D.E. Lennon, T. Leon, R. Leon, E. Lepech, M. Lesko, J.J. Lesse, M. Lestuzzi, P. Leung, C.-K. Levesque, A.P. Lew, M. Lew, H.S. Leyendecker, E.V. Li, J. Li, Y.F. Li, V.C. Li, C. Liel, A. Lignola, G.P. Lim, Y.M. Lim, H.S. Limaye, R.G. Lin, C.-C.J. Lin, F.-B. Lindvall, A. Lineham, K. Liroux, V. Little, J. Liu, Z. Liu, H. Liu, Y.K. Liu, C. Liu, J.B. Liu, S.-L. V. Liu, L. Lizundia, B. Loftus, P. Logo, J. Lohrmann, G. Lombaert, G. Longstreth, M. Longworth, J. Lopez, P. Lopez Garcia, D. Lopez-Garcia, D. Losiriluk, T. Lourenco, P.B. Lu, W. Lu, X.Z. Lu, P.-C. Lubell, A.S. Lubkowski, Z.A. Lucien, M.P. Lui, G.K. Luigi, C. Luise, M. Lukowski, P. Lura, P. Lwin, M. Lynch, J. Lysogorski, D.K. Ma, X. Maaddawy, T.E. Maalej, M. MacGregor, J.G. Mackie, K.R. Mackin, T.J. MacPhedran, I.J. Madan, S.K. Madrzykowski, D. Maeck, J. Maes, M. Magued, M.H. Mahamid, M. Mahdi, T. Maheri, M.R. Mahin, S.A. Mahini, S.S. Mahmood, M.Ta. Mahmood, S. Mahmood, H. Mahoney, E.E. Mahoney, M. Main, A. Makoto, K. Makris, N. Malhas, F. Malik, J.N. Malley, J.O. Malone, S. Malvar, L.J. Manafpour, A.R. Mandal, S. Mander, J.B. Manlapig, R. Mannan, M.A. Mansur, M.A. Manzouri, T. Maoai, C. Mar, D. Marchand, K.A. Marino, E.M. Marriott, D. Marsh, M.L. Marshall, R.D. Marshall, T.P. Marson, J. Martin, G.R. Martinez, J.M. Martins, F. Maruyama, Y. Marzahn, G. Masek, J. Masmoudi, R. Mast, R.F. Masud, A. Masullo, A. Mata, L.A. Matchen, B. Materschlager, A. Matsuda, E. Matsumoto, M. Matsuoka, M. Maurenbrecher, A.H.P. Maurer, M.B. Mayes, R.L. Mayorca, P. Mazars, J. McDonald, J.R. McEleney, B. McGinley, W.M. McGrattan, K.B. McMullin, K.M. Meacham, B.J. Medhekar, M.S. Medlock, R. Meguro, K. Megyesi-Jeney, A. Mehanny, S.S. Mei, G. Melcher, J. Mellas, M. Melton, W.M. Memari, A.M. Memon, M.S. Mendes, S. Meneses, J. Mengozzi, M. Menun, C. Mera, M. Mertol, H.C. Mertz, D. Mesbah, H. Meyer, C. Mezghiche, B. Midorikawa, M. Milani, G. Mileto, C. Minami, K. Mingqi, L. Minor, J.E. Miranda, E. Miri, M. Mirmiran, A. Mistakidis, E.S. Mitchell, D.W. Miyajima, M. Miyamoto, H.K. Mizukoshi, K. Moan, T. Mobasher, B. Modena, C. Moehle, J.P. Moghadam, A.S. Moghaddam, H. Mohraz, B. Mollaioli, F. Mondal, G. Moore, M.A. Moran-Yanez, L. Morgan, R. Mori, O. Mori, K. Morino, S. Morril, K.B. Morrish, D. Morrow, G. Mosalam, K.M. Moses, J. Motamed, J. Motlagh, A.Y. Motomura, H. Moxon, D.E. Mu, B. Mukai, A. Mukherjee, A. Mulenga, M.N. Muller, M. Murao, O. Muraoka, N. Murphy, W.P. Murty, C.V.R. Muttoni, A. Naaman, A.E. Nabana, K. Nabhan, F. Nacewicz, R.M. Naeem, A. Naeim, F. Naghipour, M. Nagi, M.A. Nagy, Z.V. Naito, C.J. Nakahara, H. Nakamura, S. Nakane, H. Nakashima, M. Nakayama, W. Nanni, A. Nappi, N. Narang, V.A. Nasab, E.N. Naseer, A. Natarajan, K.R. Navaee, S. Nazir, C.P. Nejati, M. Neuenhofer, A. Newtson, C.M. Ng, A.K.F. Nguyen, H. Ni, S.-D. Nichols, J. Nishijima, K. Nishiyama, I. Nkurunziza, G. Noel, S. Nordenswan, E. Nottis, A. Nowak, A.S. Nozaka, K. Nunziata, V. O’Fallon, J. O’Rourke, T. Oehlers, D.J. Oi, K. Ojard, S.D. Okamoto, P.A. Olasz, Z.J. Olatunji, T.M. Oliva, M.G. Oliveira, D.V. Oliveira, C.S. Olson, R. Ong, S.Y. Orakcal, K. Orban, Z. Orduna, A. Orozco, G.L. Orsini, P. Ospina, C.E. Osterson, T. Ouchenane, M. Ouchi, M. Outtier, A. Ozbolt, J. Pachakis, D. Palacio, K. Palermo, A. Pampanin, P. Pampanin, S. Pannirselvam, N. Pantelides, C.P. Papanikolaou, V.K. Paquette, J. Paramasivam, P. Pareja, J.F. Park, S.-M. Park, J. Parra-Montesinos, G.J. Patel, K. Patel, D. Bhudia Paul, D.K. Peacock, R.D. Pedersen, B.M. Peeters, B. Peiris, N. Pekoz, T. Pellegrino, C. Pellicer, F. Pereira, E.B. Pessiki, S. Petal, M. Petrangeli, M.P. Pezeshk, S. Phalen, J. Pham, C.H. Phan, L.T. Phillips, J.J. Pierce, M.J. Pimenta, F. Pina-Henriques, J. Pindoria, K. Pineda, O. Pinho, R. Pinto, L. Pla-Rucki, G. Platt, B.S. Plesha, M.E. Plumier, A. Pluta, G. Pollino, J. Pollino, M. Pomonis, A. Pong, W.S. Popescu, V. Popov, E.P. Porter, K.A. Poveromo, S. Powers, R.G. Preston, J. Price, T.E. Prickett, B.S. Priestley, M.J.N. Prieto, F. Prion, H.G.L. Proenca, J. Pulido, N.E. Punch, S. Qian, S. Qu, B. Radic, L. Radke, A.S. Rafiee, S. Raghunath, P.N. Rahal, K.N. Rahman, A. Rahnama, M. Rai, D.C. Rajan, S.D. Ramakrishnan, V. Ramamoorthy, S.K. Ramezanianpour, A.A. Ramos, L. Ranf, T. Ranf, R.T. Rao, K.B. Rao, M.V.K. Rashad, A.M. Rashed, A.A. Rashid, M.A. Rasmussen, K.J.R. Rasmussen, R. Rasulo, A. Rauch, A.F. Ray, J.C. Razak, H.A. Razik, M.M. Reaveley, L.D. Reig, I.B. Reineck, K.-H. Reinhorn, A. Reinhornb, A.M. Resemini, S. Restrepo, J.I. Revathi, P. Reynaud, D. Reynders, E. Ribeiro, A. Ricles, J. Rizkalla, S.H. Roberts, J.W. Roca, P. Roder, C.W. Rodgers, J.E Rogers, J.D. Rogowsky, D.M. Rojas, H.A. Roke, D.A. Ronagh, H.R. Rosa, M.A. Roselund, N. Rosen, P. Rosseto, T. Rossetto, T. Rostam, S. Rots, J.G. Rotter, J.M. Rousseau, M.Z. Roussos, Y. Ruiz, M.F. Ruiz-Garcia, J. Runjic, A. Russell, A.P. Russell, J.S. Saatcioglu, M. Saaticioglu, M. Sackman, J.L. Sadek, F. Sadr, A. Sahoo, D.R. Saiidi, S.M. Saiidi, M.”S”. Sain, T. Sakamoto, T. Sakashita, M. Sakino, K. Saleh, H. Salo, K. Sameer, S. Sanchez, I.B. Sanders, D.H. Sanli, A.K. Santhosh, K.R. Santhosh, G. Santos, S.P.F. Sanyal, S. Saouma, V. Sarabandi, P. Sarkar, C.K. Sarraf, M. Sasani, M. Sathre, R. Sato, H. Satta, A. Sause, R. Scanlon, A. Scawthorn, C. Schaad, J. Schacher, A.T. Schafer, B.W. Scherzer, J. Schevenels, M. Schickert, M. Schiff, A.J. Schinler, D. Schnapp, J. Schneider, H. Schoettler, M.J. Schueremans, L. Schultz, A.E. Schuster, R.M. Schwartz, J. Seagren, D. Seguirant, S.J. Sehgal, V.K. Seible, F. Selvaduray, G.S. Seo, J.-W. Seracino, R. Serrette, R. Sesetyan, K. Seshu, D.R. Sesok, D. Sexsmith, R.G. Sezen, H. Shaalan, M.K.A. Shah, A.A. Shah, S.A.A. Shah, H.S. Shahawy, M. Shanmugasundaram, K. Shao, D. Sharafi, P. Sharifian, M. Sharma, V.P. Shatarat, N. Shaw, P. Sheikh, S.A. Shek, P.N. Sheng, L.-H. Shenton, H.W. Sheth, A.R. Shield, C.K. Shima, H. Shimizu, Y. Shing, P.B. Shirole, A. Shishkin, J.J. Shock, B.T. Shoghli, O.R. Shrikhande, M. Shukla, A. Shustov, V. Sidarta, D. Sieve, M.W. Sigfusson, T. Sikora, J.P. Silva, P.F. Silva, R.M. Silvoso, M.M. Simiu, E. Simmonds, S.H. Singh, A.K. Singh, M.P. Singh, S.P. Sinn, R.C. Sitar, N. Sivagnanam, B. Skaloud, M. Skolicki, Z. Slak, T. Smilowitz, R. Smith, M.J. Smith, C.A.S. Smith, B.G. Smith, V.M. Smith, H.A. Snyder, K.A. So, E. Sobhani, J. Soderstrom, J.L. Sodhi, J.S. Sofronie, R.A. Sohanghpurwala, A.A. Solari, G. Sondipon, A. Song, J. Soong, T.T. Sorathia, U. Soudki, K. Soundararajan, A. Spacone, E. Spence, R. Spencer, Jr. Sputo, T. Stallmeyer, J.C. Stander, H. Stang, H. Stankevicius, J. Stanton, J.F. Starnes, M. Starossek, U. Stavroulakis, G.E. Stearns, C. Stepanishen, P. Stevenson, C. Stewart, J. Stojadinovic, B. Stokes, T. Stone, W. Strasky, J. Struik, J.H.A. Stull, C.J. Stutzman, P.E. Su, R.K.L. Subercaseaux, M.I. Subramanian, N. Subramanian, K. Sucuoglu, H. Suetomi, I. Suguna, K. Suhardjo, J. Sullivan, S. Sultana, P. Sun, W.-J. Sun, Y. Suter, G.T. Suthar, K.N. Suzuki, Y. Suzuki, T. Suzuki, S. Svadbik, P. Swamy, R.N. Swinnen, L. Szabo, Z.K. Szakats, G.A.J. Szatmari, I. Szekely, E. Szerszen, M.M. Szewczyk, A.A. Szwed, A. Tabbara, M.R. Tack, J. Tadros, M.K. Taghdi, M. Takacs, P.F. Takada, T. Takhirov, S.M. Tam, K.S.S. Tamura, Y. Tan, C.S. Tan, K.H. Tan, H. Tanaka, H. Tanakai, H. Tang, Y. Tangorra, F.M. Taniguichi, H. Tanner, P. Tanner, J.E. Tanouye, A. Taucer, F. Tavarez, F.A. Taylor, P.C. Taylor, A.W. Taylor, M. Taylor, S.E. Teixeira, V. Teo, D.C.L. Teran, J.M.G. Teughels, A. Thanh, N.H. Thomas, J. Thompson, B.P. Thong, C.M. Tian, Y. Tiecheng, W. Tilling, R.I. Timler, P. Tobriner, S. Todd, D.R. Tognarelli, M.A. Tokinoya, H. Tomas, M. Tomaselli, F. Tonks, G.M. Topper, T. Torres, T. Toumbakari, E.E. Towashiraporn, P. Towhata, I. Tracy, S.L. Trahair, N.S. Tralli, A. Tremblay, R. Trent, J.D. Trischuk, K. Trochalakis, P. Tromp, J. Troup, E.W.J. Tsai, C.S. Tsai, K.C. Tsai, H.-C. Tso, W.K. Tu, K.-C. Tue, N.V. Tureyen, A.K. Tuttle, M. Uang, C.M. Uchikoshi, M. Uckan, E. Uddin, N. Uemura, A. Ulusay, R. Uma, S.R. Unay, A.I. Uno, N. Upadhyay, A. Uttrachi, J. Uzuoka, R. Vagh, S. Valipour, H.R. Valluzzi, M.R. Vamvatsikos, D. Van Balen, K. Van Bogaert, Ph. van Breugel, K. Van Gemert, D. van Rensburg, B.W.J. Van Rickstal, F. van Zijl, G.P.A.G. Vanikar, S. Vargas, R. Vasarhelyi, A. Vasconcelos, G. Vegas, F. Velazquez, G.I. Veltri, P. Venture, ATC/MCEER Joint Verdure, M. Verma, K. Vermeltfoort, A.T. Verrucci, E. Vertes, K. Vian, D. Vickery, P. Vidal, P. Vijay, P.V. Villaverde, R. Vinnakota, S. Vinnakota, M. Virmani, Y.P. Voigt, G.F. Volle, L.E. von Winterfeldt, D. Vong, S. Wacker, J.M. Wadekar, M.K. Wahab, M.M.A. Wahyu, Y. Waisman, F. Wallace, J.A. Waller, V. Walton, W.D. Wang, J.-F. Wang, K. Wang, R. Wang, E.C.L. Wang, M. Wang, S. Wang, Y. Wang, Q. Warner, R.F. Warwaruk, J. Wassef, W.G. Watanabe, F. Wee, T.H. Weibe, B. Weibe, D. Wellenius, K. Whalen, T.M. White, P.M. White, D.W. White, C.D. Whitney, M. Whittaker, A. Wilcoski, J. Wilkinson, T. Wilkinson, S. Williams, A. Williams, B. Williams, M. Williamson, E.B. Wilson, A. Wilson, K.E. Wilson, J.C. Winpigler, J.A. Withers, M. Wittmann, F. Woldegiorgis, B. Wong, H.S. Wong, K.W. Wood, G.S. Wright, W. Wu, Z. Wu, L. Wu, Y.F. Wu, H.-C. Xiang, Y.-Q. Xiao, J.-Z. Xiao, Y. Xiaoqin, S. Yajiang, L. Yalla, S. Yamada, M. Yamaguchi, N. Yamaguchi, K. Yamamoto, T. Yamanouchi, H. Yamashita, T. Yamauchi, A. Yamazaki, F. Yan, Z. Yang, Y. Yang, K.-H. Yap, D.C.Y. Yasar, E. Yasuda, S. Ye, Y. Ye, L.P. Yen, W.P. Yeo, M.F. Ying, F.J. Yonezawa, K. Yoo, S.-W. Yoo, J.H. Yoshimura, K. Yoshioka, K. You, C.-.M. Young, B.S. Youssef, N. Youssef & Associates, N. Yu, D. Yu, Z. Yu, Q.S. Yun, G.J. Zadeh, H.A. Zahrai, S.M. Zallen, R.M. Zang, S.D. Zare, A. Zavala, C. Zderic, Z. Zeghichi, L. Zhang, Y. Zhang, Z. Zhang, H. Zhang, J. Zhao, J. Zhao, B. Zheng, J.-J. Zhou, X.-Z. Zhou, K.J.H. Zhou, Y. Zhu, Y. Zink, M.


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TNO DIANA BV is a renowned International Software Company for FEA applications in civil and geotechnical engineering, with one of the strongest and most advanced solver capabilities in the world.

Course Announcement: Non-linear Analysis using DIANA: Applications to Structural and Geotechnical Engineering

Dates: 29 March – 1 April 2010

Place: Istanbul Kültür University, Istanbul, Turkey

TNO DIANA BV and its official DIANA distributor in Turkey, GEOgrup (www.geogrup.com.tr) are pleased to invite you to the training course Non-linear Analysis using DIANA:  Applications to Structural and Geotechnical Engineering.  The training course consists of a balanced mixture of lectures and hands-on computer analyses with DIANA finite element software, release 9.4.

Further Information & Registration

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TNO DIANA BV is pleased to announce that CSP Fea have been appointed DIANA reseller in Italy. For more information, please see their website www.cspfea.net

7th International DIANA Users Meeting

TNO DIANA BV and the DIANA Users Association are honoured to announce the 7th International DIANA Users Meeting, which will be held in Brescia, Italy, from 17 -18 June 2010. The event will be hosted by University of Brescia.

The aim of this meeting is to provide a forum for exchanging experiences with DIANA and for discussing users’ needs. The meeting also offers the possibility to learn more about current and future developments in the program.

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Dates: 4-5 March 2010

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TNO DIANA BV is pleased to invite you to its promotional training course on 3D Finite Element Analysis for Geotechnical & Tunnel Engineering. The course will be held on 4-5 March 2010. The training course consists of a balanced mixture of lectures and hands-on computer analyses with midas GTS finite element software.

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TNO DIANA BV is pleased to announce the International Geotechnical Seminar “Geotechnical Advances in Urban Renewal: Analysis & Design”.

This will be in held at Imperial College, London on 20 April 2010, the Seminar is free of charge to delegates and therefore there are only a limited number of places available, these will be awarded on a first come, first serve basis.

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plane strain vs plane stress


By salahqudah – Posted on 13 February 2010

where can I use plane strain and plane stress?
if I have a portal frame : column 600×600 mm and beam 600x800mm, which element type is suitable?

‹ 3D Interface Element Unable to use graphic input ›

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Re: plane strain vs plane stress

Submitted by Kesio Palacio on Fri, 02/19/2010 – 08:42.

Dear Salahqudah,
Plane strain and Plane stress are two simplification structural models for the modeling of 3D problems, in which:
– Plane strain modelling: strain in Z-direction is neglectible
– Plane stress modelling: stress in Z-direction is neglectible
For a beam, plane stress is normally used, assuming that the stress in Z-direction can be neglected;
otherwise 3D modelling is advisable.
With reference to the element types, for 2D models, quadrilateral elements with quadratic interpolation is recommended.
For 3D models, brick solid elements with quadratic interpolation is recommended.
Kesio Palacio
TNO DIANA support team

http://tnodiana.com/content/plane-strain-vs-plane-stress

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define confined concrete behavior


By Yihai – Posted on 18 February 2010

I was using total strain crack model with predefined compressive curve (THOREN) and lateral influence option (CNFCRV: VECCHI). However, compared with the increase of compressive strength, the increase of ultimate strain is very limited. The residual strength is also not presented. I tried with user defined curve but it can not work with the lateral influence option. Any idea will be appreciated.

‹ Staggered Heat and stability analysis 3D Interface Element ›

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Re: define confined concrete behavior

Submitted by Kesio Palacio on Fri, 02/19/2010 – 09:53.

Dear Yihai,
It seems that you are using the correct syntax to include the confinement behavior of concrete in DIANA.
You complain about the limited increase of the ultimate strain for an increase of compressive strength. Do you refer to the ultimate compressive or tensile strain? To take into account the the lateral cracking effects, degration of concrete compressive strength due to cracking, you have to specify REDCRV with VC1993, see Section 6.2.5 of DIANA 9.4 Material Library manual for details. For the same level of loading, comparing with non-confined concrete response, if the compressive strength of concrete increases due to confinement, the strain field in the concrete body will decrease.
I hope it to be helpful,
Kesio Palacio
TNO DIANA support

Thank you Kesio. I am

Submitted by Yihai on Mon, 02/22/2010 – 15:06.

Thank you Kesio. I am refering to the concrete ultimate compressive strain. I have some difficulty to understand the last sentence “For the same level of loading, comparing with non-confined concrete response, if the compressive strength of concrete increases due to confinement, the strain field in the concrete body will decrease.” My understanding is confinement will not only increase compressive strength but also concrete ductility (ultimate strain, higher stress at ultimate strain). I am trying to validate FE model with experimental test, and I found softening behavior (post-peak) of simulated result shows sharper slope than test results which is caused by less-ducitile compressive softening behavior of concrete. I don’t know if REDCRV option will change anything. Correct me if I am wrong. Appreciated for the timely reply to my question.

http://tnodiana.com/content/define-confined-concrete-behavior

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Assessing the seismic collapse risk of reinforced concrete frame structures, including effects of modeling uncertainties
A. Liel, C.B. Haselton, G.G. Deierlein, J. Baker.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University. Available from Joint Committee on Structural Safety. Go

Reliability Analysis for Eccentrically Loaded Columns
M.M. Szerszen, A. Szwed, A.S. Nowak.
2005. ACI Structural Journal. Go

Background Paper On Consequences Of Localised Failure From An Undefined Cause
G. Harding.
2005. Workshop on Robustness of Structures, November, 28-29, 2005, Watford, UK. Available from Joint Committee on Structural Safety. Go


A risk managed framework for ensuring robustness
J.A. Carpenter.
2005. Paper for BRE Workshop on Robustness of Structures, November, 28-29, 2005, Watford, UK. Available from Joint Committee on Structural Safety. Go

Workshop on Reliability Based Code Calibration, Papers and Presentations
2002. Swiss Federal Institute of Technology, ETH Zurich, Switzerland. Available from Joint Committee on Structural Safety (JCSS). Go

Reliability Analysis in Structural Masonry Engineering
L. Schueremans, D. Van Gemert.
1998. IABSE Colloquium “Saving Buildings in Central and Eastern Europe”, Berlin. Go

http://www.thestructuralengineer.info/onlinelibrary/index.php?classification=4

Reliability Analysis of Concentrically Loaded Fillet Welded Joints
C. Li, G.Y. Grondin, R.G. Driver.
2007. Structural Engineering Report 271, Department of Civil and Environmental Engineering, University of Alberta. Go


Slip Critical Bolted Connections – A Reliability Analysis for Design at the Ultimate Limit State
G.Y. Grondin, M. Jin, G. Josi.
2007. Structural Engineering Report 270, Department of Civil and Environmental Engineering, University of Alberta. Go


Quantifying and communicating uncertainty in seismic risk assessment
B.R. Ellingwood.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University, Stanford. Available from Joint Committee on Structural Safety. Go


Safety acceptance criteria for existing structures
D. Diamantidis, P. Bazzurro.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University. Available from Joint Committee on Structural Safety. Go


Structural safety requirements based on notional risks associated with current practice
P. Tanner, A. Arteaga.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University. Available from Joint Committee on Structural Safety. Go


Development of accidental collapse limit state criteria for offshore structures
T. Moan.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University. Available from Joint Committee on Structural Safety. Go


Using risk as a basis for establishing tolerable performance: an approach for building regulation
B.J. Meacham.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University. Available from Joint Committee on Structural Safety. Go


Assessing the seismic collapse risk of reinforced concrete frame structures, including effects of modeling uncertainties
A. Liel, C.B. Haselton, G.G. Deierlein, J. Baker.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University. Available from Joint Committee on Structural Safety. Go


Optimal Reliability of Components of Complex Systems Using Hierarchical System Models
K. Nishijima, M. Maes, J. Goyet, M. Faber.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University. Available from Joint Committee on Structural Safety. Go


Unified Reliability and Design Optimization in Earthquake Engineering
T. Haukaas.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University. Available from Joint Committee on Structural Safety. Go


Probabilistic comparison of seismic design response spectra
S. Fukushima, T. Takada.
2007. Special Workshop on Risk Acceptance and Risk Communication, March 26-27, 2007, Stanford University. Available from Joint Committee on Structural Safety. Go


Seismic Response and Reliability of Electrical Substation Equipment and Systems
J. Song, A. Kiureghian, J.L. Sackman.
2006. PEER Report 2005/16. Pacific Earthquake Engineering Research Center, College of Engineering, University of California, Berkeley. Go


Reliability Analysis for Eccentrically Loaded Columns
M.M. Szerszen, A. Szwed, A.S. Nowak.
2005. ACI Structural Journal. Go


Background Paper On Consequences Of Localised Failure From An Undefined Cause
G. Harding.
2005. Workshop on Robustness of Structures, November, 28-29, 2005, Watford, UK. Available from Joint Committee on Structural Safety. Go


A risk managed framework for ensuring robustness
J.A. Carpenter.
2005. Paper for BRE Workshop on Robustness of Structures, November, 28-29, 2005, Watford, UK. Available from Joint Committee on Structural Safety. Go


System Reliability Methods Using Advanced Sampling Techniques
L. Schueremans, D. Van Gemert.
2003. ESREL 2003, Maastricht. Go


Reliability-Based Design Guidelines for Fatigue of Ship Structures
B.M. Ayyub, I.A. Assakkaf, D.P. Kihl, M.W. Sieve.
2002. Naval Engineers Journal, ASNE. Go


Redundancy Analysis of Existing Truss Bridges: A System Reliability-based Approach
T. Kudsi, C.C. Fu.
2002. 1st International Conference on Bridge Maintenance, Safety and Management 2002 (IABMAS’02), Barcelona, Spain. Go


Workshop on Reliability Based Code Calibration, Papers and Presentations
2002. Swiss Federal Institute of Technology, ETH Zurich, Switzerland. Available from Joint Committee on Structural Safety (JCSS). Go


Reliability-Based Load and Resistance Factor Design (LRFD) Guidelines for Stiffened Panels and Grillages of Ship Structures
B.M. Ayyub, I.A. Assakkaf, PE. Hess, K.I. Atua.
2002. Naval Engineers Journal, ASNE. Go


Methodology for Developing Reliability-Based Load and Resistance Factor Design (LRFD) Guidelines for Ship Structures
B.M. Ayyub, I.A. Assakkaf, J.E. Beach, W.M. Melton, N. Nappi, J.A. Conley.
2001. Naval Engineers Journal, ASNE. Go


Reliability-Based Load and Resistance Factor Design (LRFD) Guidelines for Hull Girder Bending
B.M. Ayyub, I.A. Assakkaf, J.P. Sikora, J.C. Adamchack, K.I. Atua, W.M. Melton, PE. Hess.
2001. Naval Engineers Journal, ASNE. Go


Reliability-Based Load and Resistance Factor Design (LRFD) Guidelines for Unstiffened Panels of Ship Structures
B.M. Ayyub, I.A. Assakkaf, PE. Hess, D.E. Knight.
2001. Naval Engineers Journal, ASNE. Go


Reliability-Based Load and Resistance Factor Design (LRFD) of Hull Girders for Surface Ships
B.M. Ayyub, I.A. Assakkaf, K.I. Atua.
2000. ASNE Day 2000. American Society of Naval Engineers, Alexandria. Go


Reliability Analysis in Structural Masonry Engineering
L. Schueremans, D. Van Gemert.
1998. IABSE Colloquium “Saving Buildings in Central and Eastern Europe”, Berlin. Go


Evaluation of System-Reliability Methods for Cable-Stayed Bridge Design
M. Bruneau.
1992. ASCE Journal of Structural Engineering, Vol.118, No.4, pp.1106-1120. Available from Michel Bruneau Webpage, State University of New York at Buffalo. Go


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Behaviour of Square Concrete Column Confined with GFRP Composite Warp
R. Benzaid, N.E. Chikh, H. Mesbah.
2008. Journal of Civil Engineering and Management, International Research and Achievements. Vilnius: Technika, 2008, Vol. 14, No. 2, pp. 115-120. Go

Time-Dependant Behaviour of Engineered Cement-Based Composites
W.P. Boshoff.
2007. PhD Thesis, Department of Civil Engineering, Stellenbosch University. Go

Cement Concrete and Concrete-Polymer Composites: Two Merging Worlds: A report from 11th ICPIC Congress in Berlin, 2004
D. Van Gemert, L. Czarnecki, P. Lukowski, E. Knapen.
2006. Proceedings of ISPIC International Symposium Polymers in Concrete, Guimaraes, Portugal, pp. 1-12. Go

Recent Development of Concrete Polymer Composites in Belgium
D. Van Gemert, E. Knapen.
2006. 5th Asian Symposium on Polymers in Concrete, Chennai, India. Go


Concrete-Polymer Composites: Synergies and Prospects
D. Van Gemert, E. Knapen.
2006. Tagung Bauchemie, Karlsruhe, Germany. Go


The Experimental Behavior of Steel Fiber Reinforced Polymer Retrofit Measures
M.P. Lucien.
2006. MSc Thesis, Civil and Environmental Engineering, University of Pittsburgh. Go


Durability and Long Term Performance of Engineered Cementitious Composites
M. Lepech, V.C. Li.
2005. International RILEM Workshop on High Performance Fiber Reinforced Cementitious Composites (HPFRCC) in Structural Applications, Honolulu, Hawaii. Go


Water Permeability of Cracked Cementitious Composites
M. Lepech, V.C. Li.
2005. Paper 4539 of Compendium of Papers CD ROM, ICF 11, Turin, Italy. Go


Punching Shear Capacity of Double Layer FRP Grid Reinforced Slabs
D.A. Jacobson, L.C. Bank, M.G. Oliva, J.S. Russell.
2005. Proceedings of the 7th Symposium on FRP in Reinforced Concrete Structures- FRPRCS7, SP-230, American Concrete Institute, Farmington Hills, MI, pp. 857-876. Go

Behaviour Of A New Type Of Composite Connection
S. Erdelyi, L. Dunai.
2004. Periodica Polytechnica, Civil Engineering, 48/1, pp. 89-100. Available from Budapest University of Technology and Economics. Go

Analysis and Modelling of the Seismic Behaviour of High Ductility Steel-Concrete Composite Structures
F. Fabio.
2004. PhD Thesis, University of Trento, Department of Mechanical and Structural Engineering, Italy. Go

Analysis of Fiber-Reinforced Polymer Composite Grid Reinforced Concrete Beams
F.A. Tavarez, L.C. Bank, M.E. Plesha.
2003. ACI Structural Journal, Title no. 100-S27, Vol. 100, No. 2, pp. 250-258. Go

Rapid Strengthening of Reinforced Concrete Beams with Mechanically Fastened, Fiber Reinforced Polymeric Composites Materials
L.C. Bank, A.J. Lamanna, J.C. Ray, G.I. Velazquez.
2002. Report ERDC/GSL TR-02-4. Geotechnical and Structures Laboratory, US Army Corps of Engineers, Engineer Research and Development Center. Go


Rapid Strengthening of Full-Sized Concrete Beams with Powder-Actuated Fastening Systems and Fiber-Reinforced Polymer (FRP) Composite Materials
L.C. Bank, A.J. Lamanna, J.C. Ray, G.I. Velazquez, D.T. Borowicz.
2002. Report ERDC/GSL TR-02-12. Geotechnical and Structures Laboratory, US Army Corps of Engineers, Engineer Research and Development Center. Go


Simplified Inverse Method for Determining the Tensile Properties of Strain Hardening Cementitious Composites (SHCC)
S. Qian, V.C. Li.
2008. Journal of Advanced Concrete Technology, Vol.6, No.2, pp. 353-363. Japan Concrete Institute. Go

Behaviour of Square Concrete Column Confined with GFRP Composite Warp
R. Benzaid, N.E. Chikh, H. Mesbah.
2008. Journal of Civil Engineering and Management, International Research and Achievements. Vilnius: Technika, 2008, Vol. 14, No. 2, pp. 115-120. Go

http://www.thestructuralengineer.info/onlinelibrary/index.php?classification=13

Simplified Inverse Method for Determining the Tensile Properties of Strain Hardening Cementitious Composites (SHCC)
S. Qian, V.C. Li.
2008. Journal of Advanced Concrete Technology, Vol.6, No.2, pp. 353-363. Japan Concrete Institute. Go


Flexural Behaviour of Concrete-Filled Steel Hollow Sections Beams
A. Soundararajan, K. Shanmugasundaram.
2008. Journal of Civil Engineering and Management, International Research and Achievements. Vilnius: Technika, 2008, Vol. 14, No. 2, pp. 107-114. Go


Behaviour of Square Concrete Column Confined with GFRP Composite Warp
R. Benzaid, N.E. Chikh, H. Mesbah.
2008. Journal of Civil Engineering and Management, International Research and Achievements. Vilnius: Technika, 2008, Vol. 14, No. 2, pp. 115-120. Go


Fatigue of Steel Plate – Elastomer Composite Beams
G.K. Lui, S.D.B. Alexander.
2007. Structural Engineering Report 274. Department of Civil and Environmental Engineering, University of Alberta. Go


Numerical Simulations of the Behaviour of Partially Encased Composite Columns
M. Begum, R.G. Driver, A.E. Elwi.
2007. Structural Engineering Report 269, Department of Civil and Environmental Engineering, University of Alberta. Go


Sandwich Plate System Under In-Plane Load and Uniform Lateral Pressure
J. Little, G.Y. Grondin, S.D.B. Alexander.
2007. Structural Engineering Report 267, Department of Civil and Environmental Engineering, University of Alberta. Go


Time-Dependant Behaviour of Engineered Cement-Based Composites
W.P. Boshoff.
2007. PhD Thesis, Department of Civil Engineering, Stellenbosch University. Go


Interfacial bond properties for ECC overlay systems
H. Stander.
2007. Msc Thesis, Department of Civil Engineering, Stellenbosch University. Go


Engineered Cementitious Composites with High-Volume Fly Ash
S. Wang, V.C. Li.
2007. ACI Materials Journal, Title No. 104-M25, Technical Paper, Vol. 104, No. 3, pp. 233-241. Go


FRP Stay-in-Place Formwork and Reinforcing for Concrete Highway Bridge Decks
M.G. Oliva, L.C. Bank, H.-U. Bae, J. Barker, S.-W. Yoo.
2007. Proceedings of FRPRCS8, 8th International Symposium on FRP in Reinforced Concrete Structures, July 16-18, Patras, GREECE, pp. 602- 603. Go


On the adaptability of concrete-filled steel tubular columns in the light of the post-fire testing results
Z. Blazevicius.
2007. Technological and Economic Development of Economy, Research Journal of Vilnius Gediminas Technical University, No. 2, pp. 100-108. Go


Load Rating of Composite Steel Curved I-Girder Bridges through Load Testing with Heavy Trucks
D. Krzmarzick, J.F. Hajjar.
2006. Report No. MN/RC-2006-40, Minnesota Department of Transportation, St. Paul, Minnesota, October, 546 pp. Go


Assessment of longitudinal shear strength parameters of composite slab by artificial neural network
G.M. Ganesh, A. Upadhyay, S.K. Kaushik.
2006. Asian Journal of Civil Engineering (Building and Housing), Vol. 7, No. 3, pages 287-300. Go


Effect of Nonlinear Interface Debonding on the Constitutive Model of Composite Materials
H. Tan, Y. Huang, C. Liu, P.H. Geubelle.
2006. International Journal for Multiscale Computational Engieering, 4(1), pp. 147-167. Begell House, Inc. Go


Cement Concrete and Concrete-Polymer Composites: Two Merging Worlds: A report from 11th ICPIC Congress in Berlin, 2004
D. Van Gemert, L. Czarnecki, P. Lukowski, E. Knapen.
2006. Proceedings of ISPIC International Symposium Polymers in Concrete, Guimaraes, Portugal, pp. 1-12. Go


Recent Development of Concrete Polymer Composites in Belgium
D. Van Gemert, E. Knapen.
2006. 5th Asian Symposium on Polymers in Concrete, Chennai, India. Go


Concrete-Polymer Composites: Synergies and Prospects
D. Van Gemert, E. Knapen.
2006. Tagung Bauchemie, Karlsruhe, Germany. Go


The Experimental Behavior of Steel Fiber Reinforced Polymer Retrofit Measures
M.P. Lucien.
2006. MSc Thesis, Civil and Environmental Engineering, University of Pittsburgh. Go


Behaviour of Partially Encased Composite Columns Made with High Performance Concrete
B.S. Prickett, R.G. Driver.
2006. Structural Engineering Report No. 262, Department of Civil and Environmental Engineering, University of Alberta, Canada. Go


Durability and Long Term Performance of Engineered Cementitious Composites
M. Lepech, V.C. Li.
2005. International RILEM Workshop on High Performance Fiber Reinforced Cementitious Composites (HPFRCC) in Structural Applications, Honolulu, Hawaii. Go


Water Permeability of Cracked Cementitious Composites
M. Lepech, V.C. Li.
2005. Paper 4539 of Compendium of Papers CD ROM, ICF 11, Turin, Italy. Go


Punching Shear Capacity of Double Layer FRP Grid Reinforced Slabs
D.A. Jacobson, L.C. Bank, M.G. Oliva, J.S. Russell.
2005. Proceedings of the 7th Symposium on FRP in Reinforced Concrete Structures- FRPRCS7, SP-230, American Concrete Institute, Farmington Hills, MI, pp. 857-876. Go


Validation of the Seismic Performance of Composite RCS Frames: Full-Scale Testing, Analytical Modeling, and Seismic Design
P.P. Cordova, G.G. Deierlein.
2005. Report TR155. The John A. Blume Earthquake Engineering Center. Department of Civil and Environmental Engineering Stanford University. Go


Effective Slab Width for Composite Steel Bridge Members
S.S. Chen, A.J. Aref, I.-S. Ahn, M. Chiewanichakorn, J.A. Carpenter, A. Nottis, I. Kalpakidis.
2005. NCHRP Report 543. Transportation Research Board. National Cooperative Highway Research Program. Washington. Go


Experimental Study Of The Behavior Of Fiber Reinforced Polymer Deck System
Y. Wahyu.
2005. PhD Thesis, Civil and Environmental Engineering, University of Pittsburgh. Go


Nonlinear analysis of smart composite plate and shell structures
L.S. Joon.
2005. PhD Thesis, Civil Engineering, Texas A&M University. Go


Behaviour Of A New Type Of Composite Connection
S. Erdelyi, L. Dunai.
2004. Periodica Polytechnica, Civil Engineering, 48/1, pp. 89-100. Available from Budapest University of Technology and Economics. Go


Analysis and Modelling of the Seismic Behaviour of High Ductility Steel-Concrete Composite Structures
F. Fabio.
2004. PhD Thesis, University of Trento, Department of Mechanical and Structural Engineering, Italy. Go


Accelerated Test-Based Material Specifications for Fiber Reinforced Plastics for Highway Structures
L.C. Bank, M.G. Oliva, D. Arora, D.T. Borowicz.
2003. Rapid Strengthening of Reinforced Concrete Bridges. Report WHRP 03-06. Wisconsin Highway Research Program. Go


Image Processing Applications for the Study of Displacements and Cracking in Composite Materials
B. Mobasher, S.D. Rajan.
2003. The 16th ASCE Engineering Mechanics Conference, July 16 – 18, 2003, University of Washington, Seattle. Go


Durability Gap Analysis for Fiber-Reinforced Polymer Composites in Civil Infrastructure
V.M. Karbhari, J.W. Chin, D. Hunston, B. Benmokrane, T. Juska, R. Morgan, J.J. Lesko, U. Sorathia, D. Reynaud.
2003. Building and Fire Research Laboratory, National Institute of Standards and Technology (NIST), Journal of Composites for Construction, 7(3), pp. 238-247. Go


Analysis of Fiber-Reinforced Polymer Composite Grid Reinforced Concrete Beams
F.A. Tavarez, L.C. Bank, M.E. Plesha.
2003. ACI Structural Journal, Title no. 100-S27, Vol. 100, No. 2, pp. 250-258. Go


Summary of Research on Concrete-Filled Structural Steel Tube Column System Carried Out Under The US-JAPAN Cooperative Research Program on Composite and Hybrid Structures
I. Nishiyama, S. Morino, K. Sakino, H. Nakahara, T. Fujimoto, A. Mukai, E. Inai, M. Kai, H. Tokinoya, T. Fukumoto, K. Mori, K. Yoshioka, O. Mori, K. Yonezawa, M. Uchikoshi, Y. Hayashi.
2002. BRI Research Paper, Report No. 147. Go


Effect of Matrix Ductility on Deformation Behavior of Steel Reinforced ECC Flexural Members under Reversed Cyclic Loading Conditions
G. Fischer, V.C. Li.
2002. ACI Structural Journal, Technical Paper, Title No. 99-S79, Vol. 99, No. 6, pp. 781-790. Go


Rapid Strengthening of Reinforced Concrete Beams with Mechanically Fastened, Fiber Reinforced Polymeric Composites Materials
L.C. Bank, A.J. Lamanna, J.C. Ray, G.I. Velazquez.
2002. Report ERDC/GSL TR-02-4. Geotechnical and Structures Laboratory, US Army Corps of Engineers, Engineer Research and Development Center. Go


Rapid Strengthening of Full-Sized Concrete Beams with Powder-Actuated Fastening Systems and Fiber-Reinforced Polymer (FRP) Composite Materials
L.C. Bank, A.J. Lamanna, J.C. Ray, G.I. Velazquez, D.T. Borowicz.
2002. Report ERDC/GSL TR-02-12. Geotechnical and Structures Laboratory, US Army Corps of Engineers, Engineer Research and Development Center. Go


Accelerated Test-Based Material Specifications for Fiber Reinforced Plastics for Highway Structures
L.C. Bank, J.S. Russell, T.R. Gentry, B.P. Thompson.
2002. Final Report, Contract No. DTFH61-00-C-00021. FHWA. Go


Summary of Research on Concrete-Filled Structural Steel Tube Column System Carried Out Under The US-JAPAN Cooperative Research Program on Composite and Hybrid Structures
I. Nishiyama, S. Morino, K. Sakino, H. Nakahara, T. Fujimoto, A. Mukai, E. Inai, K. Makoto, H. Tokinoya, T. Fukumoto, K. Mori, K. Yoshioka, O. Mori, K. Yonezawa, M. Uchikoshi, Y. Hayashi.
2002. BRI Research Paper No. 147, 176p. Available from BRI. Go


Shear Strength of Steel-Fiber Reinforced Concrete Beams Without Stirrups
Y.K. Kwak, M. Eberhard, W.S. Kim, J. Kim.
2002. ACI Structural Journal, Jul.-Aug. 2002, Vol. 99(4), pp. 530-538. Available from Marc O. Eberhard homepage, Department of Civil and Environmental Engineering, University of Washington. Go


European Development of Seismic Design Guidelines for Composite Steel Concrete Structures
A. Plumier, C. Doneux.
2001. University of Liege, Belgium. Go


Numerical Simulation of Composite Plated Columns
Y.F. Wu, D.J. Oehlers, M.C. Griffith.
2001. Research Report No. R172. Department of Civil and Environmental Engineering, The University of Adelaide, Australia. Go


Modeling of Assessment of Seismic Performance of Composite Frames with Reinforced Concrete Columns and Steel Beams
S.S. Mehanny, G.G. Deierlein.
2000. Report TR135. The John A. Blume Earthquake Engineering Center. Department of Civil and Environmental Engineering Stanford University. Go


Interface Property and Apparent Strength of a High Strength Hydrophilic Fiber in Cement Matrix
T. Kanda, V.C. Li.
1998. Journal of Materials in Civil Engineering, Vol. 10, No. 1, pp. 5-13. Go


Composite Slab Design
Z.V. Nagy, I. Szatmari.
1998. 2nd International PhD Symposium in Civil Engineering at the Technical University of Budapest. Go


Reinforced and Prestressed Concrete using HPFRCC Matrices
A.E. Naaman, P. Paramasivam, G. Balazs, Z.M. Bayasi, J. Eibl, L. Erdelyi, N.M. Hassoun, N. Krstulovic-Opara, V.C. Li, G. Lohrmann.
1996. High Performance Fiber Reinforced Cementitious Composites, RILEM Proc. 31, A.E. Naaman and H.W. Reinhardt (eds.), pages 291-344. Go


Effect of Fiber Volume Fraction on the Off-Crack-Plane Fracture Energy in Strain-Hardening Engineered Cementitious Composites
M. Maalej, T. Hashida, V.C. Li.
1995. Journal of the American Ceramics Society, Vol. 78, No. 12, pp. 3369-3375. Go


Shrinkage and Flexural Tests of a Full-Scale Composite Truss
M.B. Maurer, D.J.L. Kennedy.
1994. Structural Engineering Report No. 206, Department of Civil and Environmental Engineering, University of Alberta, Canada. Go


Some Behavioural Aspects of Composite Trusses
B. Woldegiorgis, D.J.L. Kennedy.
1994. Structural Engineering Report No. 195, Department of Civil and Environmental Engineering, University of Alberta, Canada. Go


Experimental Determination of Tensile Behavior of Fiber Reinforced Concrete
Y. Wang, V.C. Li, S. Backer.
1990. ACI Materials Journal, Technical Paper, Title No. 87-M48, Vol. 87, No. 5, pp. 461-468. Go


Design of Partially or Fully Composite Beams, with Ribbed Metal Deck, Using LRFD Specifications
S. Vinnakota, C. Foley, M. Vinnakota.
1988. Engineering Journal Second Quarter, pp. 60-78. Available from Christopher M. Foley, Department of Civil and Environmental Engineering, College of Engineering, Marquette University. Go


Behaviour of Transversely Loaded Continuous Steel-Concrete Composite Plates
S.J. Kennedy, J.J.R. Cheng.
1987. Structural Engineering Report No. 150, Department of Civil and Environmental Engineering, University of Alberta, Canada. Go


Shrinkage and Flexural Tests of Two Full-Scale Composite Trusses
A. Brattland, D.J.L. Kennedy.
1986. Structural Engineering Report No. 143, Department of Civil and Environmental Engineering, University of Alberta, Canada. Go

http://www.thestructuralengineer.info/onlinelibrary/index.php?classification=13

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We are a team of structural engineers and construction professionals focused on providing customized solutions for repair, retrofit and strengthening of structures using Carbon Fiber Reinforced Polymer (FRP) products.  Pioneered since the 1980s by QuakeWrap President, Professor Mo Ehsani, FRP is applied similar to wallpaper and becomes 2-3 times stronger than steel in 24 hours.

QuakeWrap

Latest News …..
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TRAINING Click here to register for our Contractors Training & Certification Course on March 4 & 5 2010
We had a very successful webinar with over 440 individuals from 18 countries registered. Click here to view archived webinar and presentation material.
QuakeWrap completes a 1.1 miles long by 7 ft diameter pipeline in Costa Rica, the largest reported FRP pipeline retrofit job to date
PipeMedic™ – The Future in Pipe Renovation! An innovative product that can reduce pipe repair time by up to 80%!
QuakeWrap Blast Protection – Blast Retrofit of Buildings with Carbon Fiber Reinforced Polymer (CFRP)
Buildings Pipes Bridges Mines
FRP can be used in many ways in existing buildings to:

  • Strengthen floors and walls for larger live loads
  • Increase strength and ductility of columns
  • Correct excessive deflections
  • Increase shear capacity of beams
  • Convert unreinforced masonry (URM) walls into shear walls
  • Repair and strengthen corrosion damage

Click here to see many of these applications in the McKinley Tower.

PileMedic™ – A new technology for pile repair and underwater applications.
QuakeWrap Inc. wins the 2008 Award of Excellence for Restoration of Large Diameter Prestressed Concrete Pipelines from the International Concrete Repair Institute (ICRI)
QuakeWrap President, Professor Ehsani’s Live interview on CNN within hours following collapse of the I-35W Bridge in Minnesota
Prof. Ehsani gave a 1 hour webinar to HDR employees on Dec 10, 2008 on Retrofit of Structures with FRP. One hundred twenty eight engineers from 25 offices nationwide attended the seminar.
Browse all QuakeWrap projects on the map…
For upcoming trade shows and current projects, click here…
QuakeWrap products are certified by NSF for application in potable water pipes and tanks.
FRP Construction completes Seismic Retrofit of Anchorage International Airport
.…more news

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Advantages of QuakeWrap®

Fiber Composites offer a number of advantages compared to conventional repair and retrofit systems. These advantages have resulted in exponential increase in the use of these materials since the early 1990s.

Some of the salient features of QuakeWrap® are listed here:

  • High tensile strength
  • Low weight (little change to the mass of structure means no foundation adjustments required)
  • Corrosion resistance
  • Thermal compatibility with common construction materials, e.g. concrete
  • Excellent fatigue behavior
  • Fast speed of construction
  • Products are light and can be handled without the need for any lifting equipment on job site
  • Versatility to be applied to non-flat surfaces
  • Odorless (extremely important when the structure is occupied)
  • Low cost

While the cost for FRP materials is higher than conventional construction materials, the savings resulting from shorter construction time, and minimal disturbance of occupants, generally result in lower overall construction cost.

Seismic Repair and Strengthening of Concrete Columns with Glass or Carbon FRP

Reinforced Concrete columns or bridge piers can be efficiently strengthened with Glass FRP (GFRP) or Carbon FRP (CFRP). Older (pre-1970s) columns have two major shortcomings; they are inadequately confined (usually a No. 3 or 4 tie placed at a spacing of 12 inches) and the ends of the ties are not properly anchored in the core region. During an earthquake, the ties open and allow the longitudinal steel to buckle, leading to failure of the column.


Glass FRP and Carbon FRP can provide significant lateral confinement for concrete columns or bridge piers. While spiral columns have in general performed well in past earthquakes, the above shortcomings have resulted in failure of many tied columns such as the one shown on the right.


The solution is to externally confine the column. External confinement increases the strength of the concrete, but more importantly for seismic applications, the strain at failure of the concrete (i.e. ductility) increases significantly. Among the advantages of retrofitting columns with Fiber Reinforced Polymer (FRP) are:

  • Increases Ductility
  • Increases Shear Strength
  • Improves Bond in Starter Bars
  • Conforms to Various Cross Sections
  • Requires Minimum Access
  • Costs Less than Conventional Methods

Research and Development

QuakeWrap principals were the first research team in the U.S. to receive a 3-year grant from the National Science Foundation in 1991 to study the behavior of columns retrofitted with fiber composite jackets. Both repair and retrofit of circular and rectangular columns with active and passive confinement were examined. The findings of this extensive study have been published in several journal articles dealing with such topics as confinement effects on circular and rectangular columns and repair of earthquake-damaged columns. A number of other researchers have also studied this problems and a sample of those technical papers is also available.


Columns were subjected to an axial load of 100 kips that remained constant throughout the test while the top of the columns were subjected to reversed cyclic loading, simulating earthquake motions. Retrofitted specimens continued to resist additional lateral loads during consecutive loading cycles and testing usually had to be stopped because the maximum displacement of the testing equipment was reached.


Case Studies

A sample of projects where Fiber Reinforced Polymer (FRP) have been used to strengthen reinforced concrete columns are listed below. By clicking on each project, you will be able to view specific information on each project.

For detailed field installation procedures click here.

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**

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Editor’s Note

Timber Beams Strengthened with GFRP Bars: Development and Applications
Repair and rehabilitation of infrastructure is becoming increasingly important for bridges due to material deterioration and limited capacity to accommodate current load levels. An experimental progra…

J. Compos. for Constr. / Volume 6 / Issue 1 / TECHNICAL PAPERS

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Ductile Anchorage for Connecting FRP Strengthening of Under-Reinforced Masonry Buildings

J. Compos. for Constr. Volume 6, Issue 1, pp. 3-10 (February 2002)

Issue Date: February 2002

ABSTRACT

REFERENCES (5)

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J. D. Hall,1 P. M. Schuman,2 and H. R. Hamilton III3
1Graduate Research Assistant, Univ. of Texas, Austin, TX 78712.
2Graduate Research Assistant, Univ. of California at San Diego, San Diego, CA 92093.
3Associate Professor of Civil Engineering, Univ. of Florida, Gainesville, FL 32611.

Fiber-reinforced polymer (FRP) composites have been examined as a convenient and cost-effective means of strengthening unreinforced masonry structures. Seismic design in the United States is almost entirely based on the assumption that the structural system provides a ductile failure mode. FRP strengthened masonry walls inherently have brittle failure modes due to the nature of the strengthening system. The concept explored in this article is the introduction of ductility using a hybrid strengthening system. This involves the placement of structural steel or reinforcing steel at critical locations in the lateral force resisting system. This article presents the testing and analysis of a ductile structural steel connection that can be used to strengthen the connection of FRP strengthened shear walls to the foundation. The connection also increases energy dissipation. Results indicate that a ductile failure mode can be attained when the connection is designed to yield prior to the failure of the FRP strengthening.

©2002 American Society of Civil Engineers

History: Submitted December 20, 1999; accepted January 17, 2001
Permalink: http://dx.doi.org/10.1061/(ASCE)1090-0268(2002)6:1(3)

ASCE SUBJECT HEADINGS

civil engineering, building, polymers, fibre reinforced composites

http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JCCOF2000006000001000003000001&idtype=cvips&gifs=yes&ref=no

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When Dots-On-Plots Just Don’t Cut It Any More – How to Use Interactive 3-D Visualizations to Explore the Fine-Scale Fault Structure of Southern California (Based on Focal Mechanism Catalog Data)
Kilb, Debi (IGPP/SIO), Jeanne Hardebeck (USGS), and Kristoffer T. Walker (IGPP/SIO)

Fed up with GMT but just can’t seem to break free of the 2-D flat-map world? Too intimidated by the large learning curve for software required to manipulate and view your data in 3D? Resigned to the idea that whatever you need to do, you can do in MATLAB? An intermediate solution is to use the iView3D freeware (http://www.ivs.unb.ca/products/iview3d; runs on multiple platforms) to interactively explore geo-referenced 3D data, to easily toggle on/off different data from view, and to set topography and bathymetry maps transparent for aiding in correlation of surface and sub-surface features. With (HASH) focal mechanism catalogs, we have used the iview3D associated Fledermaus software to create 3-D visualizations of the fine-scale fault structure in southern California. The end products are 3-D visualizations that, for each of the >6000 individual earthquakes, include: (1) a sphere in 3-D space representing the earthquake’s latitude, longitude and depth, (2) a rectangle oriented with respect to the strike and dip of the fault (both nodal planes can be included), and (3) color coding to highlight differences among the data such as rake, dip, method used to compute the focal mechanisms (FPFIT or HASH), or temporal behavior. In this way, our initial results show that the fine-scale fault structure in southern California is extremely heterogeneous in comparison with the simple fault structure of the San Andreas Fault near Parkfield and the Hayward fault in the Bay area. Future plans are to scale the sub-faults by magnitude and extend our study region so we can compare and contrast fine-scale fault complexity in different tectonic settings and incorporate the larger-scale results from the SCEC Community Fault Model (CFM) project (http://structure.harvard.edu/cfm/). These visualizations will be distributed through the visual objects library at the SIO Visualization Center (http://www.siovizcenter.ucsd.edu/library/objects).

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Deep Bay

Crater Name Location Latitude Longitude Diameter (km) Age (Ma)* Exposed Drilled Target Rock** Bolide Type***
Deep Bay Saskatchewan, Canada N 56° 24′ W 102° 59′ 13 99 ± 4 N Y C

SIR-B (Shuttle) image; Vertical view
Space Shuttle Image STS59-L08-63
***

DEM (High Resolution image available)

References

1. Beals, C. S., Halliday, I., Impact craters of the Earth and Moon. Journal of the Royal Astronomical Society of Canada, v. 59, p. 208. 1965.

2. Beals, C. S., Innes, M.J.S. and Rottenberg,J.A., Fossil meteorite craters. Middlehurst, B.M. and Kuiper, G.P., eds., The Moon, Meteorites and Comets, University of Chicago Press, Chicago, v. IV, pp. 235-284. 1963.

3. Beals, C. S., Innes, M.J.S. and Rottenberg,J.A., The search for fossil meteorite craters. Ottawa Dominion Observatory Contributions, v. 4, pp. 1-31. 1960.

4. Bertaud, C., The Deep Bay fossil meteorite crater (in French). Astronomie, v. 79, pp. 329-331. 1965.

5. Clark, J. F., Magnetic survey data at meteoritic impact sites in North America. Geomagnetic Service of Canada, Earth Physics Branch Open File # 83-5, 30 p. 1983.

6. Cockell, C. S., Lee, P., The Biology of Impact Craters – a review. Biol. Rev., 77, P. 279 – 310. 2002.

7. Currie, K. L., Analogues of lunar craters on the Canadian shield. New York Academy of Sciences, Annals, v. 123, pp. 915-940. 1965.

8. Dabizha, A. I., Ivanov, B. A., A geophysical model of the structure of meteorite craters and some problems of the mechanics of crater formation (in Russian). Meteoritika, v. 37, pp. 160-167. 1978.

9. Dabizha, A. I., A new interpretation of the structure of meteorite craters (in Russian). Astronomicheskii Vestnik, v. 11, pp. 73-77. 1977.

10. Dabizha, A. I., Fedynsky, V. V., Features of the gravitational field of astroblemes (in Russian). Meteoritika, v. 36, pp. 113-120. 1977.

11. Dabizha, A. I., Fedynsky, V. V., The Earth’s “star wounds” and their diagnosis by geophysical methods (in Russian). “Zemlya i Vselennaya”, v. 3, pp. 56-64. 1975.

12. Dence, M. R., Innes, M.J.S. and Robertson,P.B., Recent geological and geophysical studies of Canadian craters. in Shock Metamorphism of Natural Materials, eds. B. M. French and N. M. Short, Mono Book Corp., Baltimore, MD, pp. 339-362. 1968.

13. Dence, M. R., A comparative structural and petrographic study of probable Canadian meteorite craters. Meteoritics, v. 2, pp. 249-270. 1964.

14. Dent, B. E., Gravity model of the Deep Bay, Saskatchewan impact crater. Thesis, Department of Geophysics, Stanford University, California, 36 p. 1973.

15. Dent, B. E., Three dimensional gravity model of the Deep Bay, Saskatchewan impact crater (abstract). EOS, v. 53, p. 1036. 1972.

16. Grieve, R. A. F., The record of impact on Earth: Implications for a major Cretaceous/Tertiary impact event. Geological Society of America, Special Paper 190, pp. 25-37. 1982.

17. Grieve, R. A. F., Robertson, P. B., The terrestrial cratering record. 1. Current status of observations. Icarus, v. 38, pp. 212-229. 1979.

18. Gurov, E. P., Gurova, E. P., Impact structures on the Earth’s surface (in Russian). Geologicheskii Zhurnal, v. 47, pp. 117-124. 1987.

19. Innes, M. J. S., Recent advances in meteorite crater research at the Dominion Observatory, Ottawa, Canada. Meteoritics, v. 2, pp. 6-12. 1964.

20. Innes, M. J. S., Pearson, W.J. and Geuer,J.W., The Deep Bay crater. Ottawa Dominion Observatory Publications, v. 31, pp. 19-52. 1964.

21. Innes, M. J. S., The use of gravity methods to study the underground structure and impact energy of meteorite craters. Journal of Geophysical Research, v. 66, pp. 2225-2239. 1961.

22. Innes, M. J. S., A possible meteorite crater at Deep Bay, Saskatchewan. Royal Astronomical Society of Canada Journal, v. 51, pp. 235-240. 1957.

23. Krinov, E. L., Meteorite craters on the surface of the Earth. Beynon, M.M., ed., Giant Meteorites, Pergamon Press, New York, pp. 75-76. 1966.

24. Krinov, E. L., Meteorite craters on the Earth’s surface. Middlehurst, B.M. and Kuiper, G.P., eds., The Moon, Meteorites and Comets, University of Chicago Press, Chicago, v. IV, pp. 183-207. 1963.

25. Masaitis, V. L., Danilin, A.N., Maschak, M.S., Raykhlin, A.I., Selivanovskaya, T.V. and Shadenkov,Ye.M., The Geology of Astroblemes (in Russian). Leningrad, Nedra, 231 p. 1980.

26. Ogilvie, B. Y., Robertson, B. and Grieve,R.A.F., Meteorite impact features in Canada: An inventory and an evaluation. Unpublished Report, 180 p. 1984.

27. Pilkington, M., Grieve, R. A. F., The geophysical signature of terrestrial impact craters (abstract). Lunar and Planetary Science XXIII, pp.1073-1074. 1992.

28. Robertson, P. B., Dence, M. and Vos,M.A., Deformation in rock-forming minerals from Canadian craters. French, B.M. and Short, N.M., eds., Shock Metamorphism of Natural Materials, Mono Book Corp., Baltimore, MD, pp. 433-452. 1968.

29. Sander, G. W., Overton, A. and Bataille,R., Seismic and magnetic investigation of the Deep Bay crater. Ottawa Dominion Observatory Contributions, v. 5, 15 p. 1964.

30. Scott, R. G., Pilkington, M., Tanczyk, E.I. and Grieve,R.A.F., Magnetic properties of three impact structures in Canada (abstract). Meteoritics, v. 30, pp. 576-577. 1995.

31. Sweet, A. R., Applied research report on 4 mid Cretaceous samples from boreholes in the Deep Bay crater, Northern Saskatshewan, Paleontological Report, Department of Natural Resources Canada 3-ARS-1999. 1999.

32. Zotkin, I. T., Dabizha, A. I., Evolution of a meteorite crater as a process of random displacements (in Russian). Meteoritika, v. 40, pp. 82-90. 1982.

33. Zotkin, I. T., “Moon” craters on the Earth (in Russian). Priroda, v. 9, pp. 95-105. 1969.

* pre-1977 K-Ar, Ar-Ar and Rb-Sr ages recalculated using the decay constants of Steiger and Jager (1977) Ages in millions of years (Ma) before present.

** Abbreviations: C – Crystalline Target; C-Ms – Metasedimetary Target; M – Mixed Target (i.e.sedimentary strata overlying crystalline basement); S – sedimentary target (i.e. no crystalline rocks affected by the impact event). From Osinski. G. R., Spray J. G., and Grieve R. A. F. 2007. Impact melting in sedimentary target rocks: A synthesis. In The Sedimentary Record of Meteorite Impacts, Geological Society of America Special Paper. Editors: Evans K. Horton W., King D., Morrow J., and Warme J. Geological Society of America: Boulder, in press.

*** From Koeberl,C. Identification of meteoritic components in impactites. 1998, Koeberl, C. The Geochemistry and Cosmochemistry of Impacts. 2007 and PASSC Files. (IAB, IIIAB, IIIB, IIID – Iron Meteorite)


| Africa | Asia | Australia | Europe | North America | South America |

Earth Impact Database Sorted by : | Age | Diameter | Name |

Impact Cratering Essay

Earth Impact Database Frequently Asked Questions

PASSC Director: John Spray
Data Manager

Last updated January 30, 2009

Site developed and maintained by
Planetary and Space Science Centre
University of New Brunswick
Fredericton, New Brunswick, Canada
Queries to:
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http://www.unb.ca/passc/ImpactDatabase/images/deep-bay.htm

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Page 1

Interactive Visualization Systems

Description

Fledermaus is a powerful interactive 3D data

visualization system that is used for a variety of

applications including swath bathymetry editing and

quality control, environmental impact assessment,

mining, geology, cable laying and dredge planning. A

wide variety of industry standard formats are

supported for direct import of data to the 3D scene.

Innovative data exploration features including the Bat

(“flying mouse”), allow for intuitive 3D exploration of

spatial data. Fledermaus also allows data from

remotely operated vehicles, ships or other entities, to

be visualized in real-time. Due to its flexible object

oriented software design, Fledermaus can be easily

tailored to support many additional visualization

modules.

Features

Multiple data sets and types can be visualized and

interactively explored at the same time.

Integrated support for very large data sets.

All data sets can be geo-referenced in the

3D scene.

Users can interactively query data sets to select

coordinates for profiles and measurements.

Advanced object oriented architecture allows

easy integration of new data types into the system.

Explorations can be recorded and used to

create movies of data exploration sessions.

Visualizations can be displayed in 3D stereo.

Tel: (506) 454-4487

Fax: (506) 453-4510

email: info@www.ivs.unb.ca

Web: www.ivs.unb.ca

2 Garland Court

P. O. Box 69000

Fredericton, NB. Canada

E3B 6C2


Page 2

Interactive Visualization Systems

Tel: (506) 454-4487

Fax: (506) 453-4510

email: info@www.ivs.unb.ca

Web: www.ivs.unb.ca

2 Garland Court

P. O. Box 69000

Fredericton, NB. Canada

E3B 6C2

Applications

• Swath Bathymetry Editing and Quality Control

View massive data sets to allow quick and

accurate discrimination of features and artifacts.

• Cable and Pipeline Route Planning

Plan cable or pipeline routes. View route

in 3D with route draped on surface.

• Project Planning

Import many data types for project overview and

work in a team environment.

• Analysis of Seafloor and Sub-Surface Data

Combined visualization of bathymetry, seabed

type and sub-surface data enhances analysis.

Specifications

Data Types

• Digital elevation models, 3D surface plots.

• Gridded and un-gridded spatial data

• Pipelines and cables.

• Seismic sub-surface data.

• Imagery such as satellite imagery, maps,

and aerial photos.

• Measurement planes and grids.

• DXF CAD format and solid models.

• ArcView data (shape files, grids, and imagery).

• Real time tracked objects/ROV module.

• Sounding class for area based edit and

quality control.

Data Capacity

• Integrated support for very large data sets.

• Data set size not limited by software.

Data Processing

• Software allows for the importing of numerous

data formats including ASCII xyz/gridded,

GMT GRD/NetCDF, Etopo5, NOAA Gravity

database, Grass, binary raster data, DTED,

Arcview, ERMapper, and many others.

• No need to resample to a single resolution.

• New data formats are easily added.

• Surfaces are colour coded by height, depth or

any other attribute (such as imagery) that

can be draped over a DTM.

3D Visualization

• Multiple hierarchical data sets can be visualized

and explored at the same time.

• All data sets can be geo-referenced.

• Users can interactively select data points to get

geo-referenced 3D co-ordinates and

perform profiling.

• Advanced object oriented architecture allows easy

integration of new data types into the software.

2D Visualization

• Color-coding can be interactively designed or

modified by the user.

• Surfaces are illuminated with an artificial lighting

and have cast shadows.

• Allows exploration of the data with continuous

zoom and translation abilities.

• Provides profiling, histogram and other tools to

analyze the surface data.

• Users can interactively select data points

to get geo-referenced 3D co-ordinates

and perform profiling.

Movie Making Tools

• Exploration flights recorded to make movies.

Computer Platforms

• SGI and Sun workstations.

• Linux and Windows NT/2000 PCs.

Note: Cover image from USGS Data of Crater Lake

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River Watch Home | Français

Cooperating Agencies

This recent addition to the River Watch program is the result of a cooperative partnership between New Brunswick Emergency Measures Organization, the University of New Brunswick, CARIS and the Government of Canada through the GeoConnections program. This application has been developed to provide the public with current and forecast information for the area along the lower Saint John River Valley which has been most frequently subjected to open water flooding.


NB Emergency Measures Organization

Protecting People, Property and the Environment

We provided project management and river watch expertise.

For more information: http://www.gnb.ca/cnb/emo-omu/index-e.asp


CARIS

Geospatial Software Solutions

We provided web design, data processing, and the mapping product, Spatial Fusion. We also host these pages.

For more information: http://www.caris.com


University of New Brunswick

Faculty of Computer Science

We designed and implemented web cameras at the following bridges: Princes Margaret, Lakeville Corner Bridge and Burton. We also designed Your Observations.

For more information: http://www.cs.unb.ca


Interactive Visualization Systems (IVS 3D)

We designed the 3D fly through at the 1973 flood levels of the St. John River from the Mactaquac Dam to Oak Point.

For more information: http://www.ivs3d.com

Co-operating Agencies

Communications New Brunswick

Email |   Contacts |   Disclaimer |   Privacy Statement

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http://www.ivs.unb.ca/products/iview3d

In this way, our initial results show that the fine-scale fault structure in southern California is extremely heterogeneous in comparison with the simple fault structure of the San Andreas Fault near Parkfield and the Hayward fault in the Bay area. Future plans are to scale the sub-faults by magnitude and extend our study region so we can compare and contrast fine-scale fault complexity in different tectonic settings and incorporate the larger-scale results from the SCEC Community Fault Model (CFM) project (http://structure.harvard.edu/cfm/). These visualizations will be distributed through the visual objects library at the SIO Visualization Center (http://www.siovizcenter.ucsd.edu/library/objects).

**

LIBRARY

The Library is designed to be an open-source database for images, software tips, development skills and code snippets that help users of the SIO Visualization Center to manipulate and display their data in the best way. The following sections are available for browsing:

VISUAL OBJECTS

This is a place to download visual objects for the classroom, whether you are a high school teacher, college lecturer, professor, or researcher (who needs some material for a talk!). Files are in various flavors, including Quicktime, Flash .SWF, Inventor, Fledermaus SD, MPEG, WAV, AIFF, MP-3, Windows Media Player and VRML1 & 2.

Scene Files

Explore earthquakes, bathymetry, topography and many other datasets in 3D! These scene files were created using the Fledermaus toolkit. You can view these files in Fledermaus or with the free player iView3d.

Movies

Download Quicktime movies, video podcasts, mpeg files. You will need Apple’s Quicktime player to view these.

Online Tools

This section of the library has many Flash tools that you can use to estimate earthquake magnitude or to listen to what an earthquake sounds like! You need a web browser and the Flash plugin to interact with these tools.

Presentations

You just saw a great professional talk or class lecture and you think to yourself that it would be great to incorporate some of that material in your own work. In the presentations portion of our visual objects library, we catalog a collection of PowerPoint and KeyNote presentations that can be used to supplement research talks, classroom lectures or outreach activities.

TUTORIALS

Tutorials

Want to know how to plot lines in a Fledermaus .sd file? Or maybe create a QuickTime movie on the SGI? How about SGI shortcut keys to reduce the amount of finger-tapping?

LINKS

Links

Can’t find what you’re looking for in our archives?

http://www.siovizcenter.ucsd.edu/library.php

**

LIBRARY / LINKS

ASSOCIATED RESEARCH PROJECTS

HARDWARE AND SOFTWARE DEVELOPERS

GRAPHICS CARDS

DISCUSSION FORUMS

TUTORIALS

GEOPHYSICAL INFORMATION & FREEWARE PROGRAMS

http://www.siovizcenter.ucsd.edu/library/links.php

**

iView4 – viewer download 02-24-10, 3.02 pmET

win64_iview4D.exe

from –

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**

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