Devices for protecting bridge superstructure from pounding and unseating damages: an overview

Shrestha, Bipin; Hao, Hong; Bi, Kaiming

doi:10.1080/15732479.2016.1170155

Cited by 49 publications

(17 citation statements)

References 58 publications

(60 reference statements)

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“…Unseating prevention devices are effective in maintaining the integrity of a total bridge system, and they prevent an excessive relative displacement between decks and can even prevent a deck that is dislodged from its support from falling, which proved once again that the bridge structure should include measures to prevent falling [38,51]. It was found that combination of seismic measures has received considerable attention in terms of reducing damages as well as improving the serviceability of the bridge; although our study is different from the selection type of seismic measures in Shrestha and DesRoches's study, the result is consistent [33,52]. Figure 9 shows the change of the pier top displacement when different seismic measures are taken for the bridge under earthquakes of different magnitudes.…”

Section: Displacement Of Girders Bearings and Pier Topsupporting

confidence: 82%

“…The sudden changes of stiffness during poundings can be smoothed by using a natural rubber shock absorber, which prevents the acceleration peaks due to impact. Shrestha et al [33] discussed the merits and limitations of various pounding and unseating mitigation devices that have been proposed by multiple researchers, and the application of rubber bumpers with restrainers and the combination of dampers with restrainers has received considerable attention in applications to reduce the damages as well as improve the serviceability of the bridge.…”

Section: Introductionmentioning

confidence: 99%

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Seismic Effectiveness of Multiple Seismic Measures on a Continuous Girder Bridge

Shi

Liu

2020

Applied Sciences

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Seismic hazards, such as bridge pounding, unseating, collapse, etc., cause significant economic losses and affect traffic and safety. Research on seismic measures, such as limiting and unseating prevention devices for the bridge, can effectively prevent damage to the bearings, such as excessive displacement, the pounding of the beam end, etc., in an earthquake. In this paper, the dynamic time-history analysis method was used to study the mechanical behaviors of the bridge structure, such as its seismic performance, structural displacement, pier bending moment, etc. We found that different combinations of seismic measures can effectively reduce the displacement at the bridge expansion joint and bearings. The joint application of an expansion device, restrainer, and unseating prevention devices shows the best limiting effect on bridge displacement and expansion joint displacement. The maximum reduction of bridge expansion joint displacement reaches 48% and is within the allowable deformation range of an expansion device in a large earthquake, and the maximum reduction of bearing displacement reaches 34%, which only slightly exceeds the shear deformation of the bearing. The expansion device, restrainer, and unseating prevention devices have smaller internal forces in this case than other cases, without damage. In contrast to the previous studies on single seismic measures of unseating restrainers, this study investigates the combination of multiple seismic measures and earthquakes of various magnitude. It reveals the catastrophe process of the bridge structure and the cooperation law of seismic measures in an earthquake.

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Section: Displacement Of Girders Bearings and Pier Topsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Seismic Effectiveness of Multiple Seismic Measures on a Continuous Girder Bridge

Shi

Liu

2020

Applied Sciences

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“…However, recent strong earthquakes (e.g. the 2010 Chile, 2008 Wenchuan, 1999 Chi-Chi, 1995 Kobe, and 1994 Northridge) have revealed that such bridges are prone to severe damages and unseating failure due to excessive longitudinal movements at expansion joints and supports (Chen et al, 2012; Kawashima et al, 2011; Shrestha et al, 2017). For example, more than 27 MSSS bridges experienced severe damage or complete collapse in 2008 Wenchuan earthquake (Chen et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Performance-based seismic loss assessment of isolated simply-supported highway bridges retrofitted with different shape memory alloy cable restrainers in a life-cycle context

Dezfuli²,

Wang

et al. 2020

Journal of Intelligent Material Systems and Structures

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Shape memory alloy cables have emerged as an alternative to conventional steel cable restrainers for preventing the bridge spans from unseating during an extreme earthquake. Feasibility of high-cost NiTi shape memory alloy restrainers in retrofitting the bridges has been numerically investigated, and promising results have been published; however, considering the economic impacts, the effect of different types of shape memory alloy such as Cu-based and Fe-based shape memory alloy restrainers has not been discussed yet. The objective of this study is to address this problem in detail in order to propose the most cost-effective shape memory alloy restrainer suitable for bridge engineering applications. Seismic fragility and life-cycle loss (both direct and indirect) assessments are analytically performed on an isolated simply-supported highway bridge retrofitted by four types of shape memory alloy restrainers (i.e. NiTi, FeNiCoAlTaB, CuAlMn, and FeMnAlNi). Results showed that for all retrofitted bridges performed in the range of design displacement, the effect of type of shape memory alloy is significant on the damage probability and long-term seismic loss of the bridges. All the bridges retrofitted with shape memory alloy restrainers have a very low probability of collapse (less than 7%). It is also found that the bridge retrofitted with Fe-based shape memory alloy restrainers (SMA-II and SMA-IV) performed better as compared to the other cases. Compared to the bridge without restrainers and with NiTi shape memory alloy restrainers, Fe-based shape memory alloy restrainers can reduce the long-term loss by about 87% and 11%, respectively, at the design earthquake event specified in CHBDC-2014. The probabilistic risk analysis of highway bridges retrofitted with shape memory alloy restrainers can aid in paving the way toward widespread application of such smart materials in structural applications.

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“…The metal damper [17][18][19] is representative of the former, and the viscous fluid damper [20] is related to the speed of motion, which is the representative of the latter. Restraint devices include anti-fall beam devices such as block, shear tenon, and lock-up devices [21,22].…”

Section: Introductionmentioning

confidence: 99%

Research on Longitudinal Collapse Mode and Control of the Continuous Bridge under Strong Seismic Excitations

Zong

Yang

et al. 2020

Applied Sciences

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Bridge collapse events are common in major earthquakes around the world, among which continuous girder bridges are the most involved. In order to explore the collapse mechanism of a continuous girder bridge in an earthquake, the collapse mode of a two-span continuous girder bridge specimen which had been studied by the shaking table test was analyzed. Then, on the basis of the conventional plate rubber bearing system, the collapse control strategies which were high damping rubber bearing, fluid viscous damper, lock-up clutch control methods were discussed. It is found that high damping rubber bearing can delay the collapse time but the collapse mode remains the same; lock-up clutch has the best displacement control effect for the superstructure, but its energy consumption performance is not as good as that of a fluid viscous damper; high damping rubber bearing is quite suitable for protecting the substructure under short-period ground motion to avoid the bridge collapse caused by the failure of piers; fluid viscous damper and lock-up clutch are suitable for protecting the superstructure under long ground seismic motion to avoid the bridge non-use resulted from girder lowering; three collapse control methods can improve the anti-collapse ability of the bridge specimen, although no matter which control method is used, the bridge specimen may still collapse under strong earthquakes, but the target of postponing collapse time can be realized by means of various effective control methods.

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Devices for protecting bridge superstructure from pounding and unseating damages: an overview

Cited by 49 publications

References 58 publications

Seismic Effectiveness of Multiple Seismic Measures on a Continuous Girder Bridge

Seismic Effectiveness of Multiple Seismic Measures on a Continuous Girder Bridge

Performance-based seismic loss assessment of isolated simply-supported highway bridges retrofitted with different shape memory alloy cable restrainers in a life-cycle context

Research on Longitudinal Collapse Mode and Control of the Continuous Bridge under Strong Seismic Excitations

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