Behavior of bridge piers during vehicular impacts
Item
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Title
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Behavior of bridge piers during vehicular impacts
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Identifier
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d_2009_2013:4d62f355bc93:11254
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identifier
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11526
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Creator
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Liu, Guangyong,
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Contributor
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Anil Kumar Agrawal
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Date
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2012
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Language
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English
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Publisher
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City University of New York.
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Subject
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Civil engineering | Bridge | Impact | Pier | Vehicular
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Abstract
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Accidental collision of vehicle with highway bridges is the third leading cause of bridge failures in USA. Recent studies show that the dynamic forces because of truck impacts may be significantly higher than the 400kips force recommended by the AASHTO. Because of the highly cost of the vehicular impact tests on bridge piers, this dissertation extensively investigated the behavior of a three-span bridge with reinforced concrete piers impacted by trucks using finite element models in LS-DYNA.;An appropriate material model to describe the high nonlinear deformation of concrete elements under impact loads is crucial for numerical simulation. For simulation of vehicular impact on bridge structures, the CSCM model demonstrates a more reasonable damage mode than the JHC model. Various numerical parameters have been verified through comparisons between simulations and impact tests on reinforced concrete beams. A high fidelity numerical model of highway bridge has been developed. With low, medium and high velocities of truck impacts on the bridge piers, the failure modes are indentified. The profiles of impact force and the mid-height displacement are captured during the simulation.;In order to study the correlation between seismic detailing and vehicle impact effects, four seismic bridge models have been developed. With twelve numerical cases of vehicle collision, the framework of seismic-impact correlations has been built for the further safety assessment. The ductility and shear strength can be taken as key parameters to evaluate impact-resistance capacities of bridge piers.;Numerical simulation using the whole bridge models requires significant capability. A simplified Pier-bent model is proposed based on the simulations of whole bridge model. Under the condition of 95% impulse from the vehicle impact, simulation results show that the simplified Pier-Bent model can be a reliable replacement of whole bridge model for future research.;Traditional seismic steel/FRP jacketing can be used to strengthen bridge piers vulnerable to vehicular impacts. Numerical simulations have been carried out to evaluate the efficiency of this rehabilitation approach. It is observed that both steel jacket and FRP wrapping can be effective in reducing damages to bridge piers during vehicular impacts.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Engineering
