Seismic Vulnerability Evaluation of a Three‐Span Continuous Beam Railway Bridge

Abstract

In order to evaluate the seismic vulnerability of a railway bridge, a nonlinear finite element model of typical three-span continuous beam bridge on the Sichuan-Tibet railway in China was built. It further aimed at performing a probabilistic seismic demand analysis based on the seismic performance of the above-mentioned bridge. Firstly, the uncertainties of bridge parameters were analyzed while a set of finite element model samples were formulated with Latin hypercube sampling method. Secondly, under Wenchuan earthquake ground motions, an incremental dynamic method (IDA) analysis was performed, and the seismic peak responses of bridge components were recorded. Thirdly, the probabilistic seismic demand model for the bridge principal components under the prerequisite of two different kinds of bearing, with and without seismic isolation, was generated. Finally, comparison was drawn to further ascertain the effect of two different kinds of bearings on the fragility components. Based on the reliability theory, results were presented concerning the seismic fragility curves.

Effects of friction-based fixed bearings on seismic performance of high-speed railway simply supported girder bridges and experimental validation

“…And the damage of bearings and piers, defined using those displacement-based indexes, were classified into five states: basically intact, slight damage, moderate damage, severe damage, and complete destruction. The damage states of bearings for the scaled model were defined based on the relative displacement between girders and piers (Jiang et al, 2017). The displacement capacities of friction-based fixed bearings in this study were designed the same as those in Jiang et al (2017), although their bearings were different from each other.…”

“…The damage states of bearings for the scaled model were defined based on the relative displacement between girders and piers (Jiang et al, 2017). The displacement capacities of friction-based fixed bearings in this study were designed the same as those in Jiang et al (2017), although their bearings were different from each other.…”

“…The damage states of bearings for the scaled model were defined based on the relative displacement between girders and piers (Jiang et al, 2017). The displacement capacities of friction-based fixed bearings in this study were designed the same as those in Jiang et al (2017), although their bearings were different from each other. When the displacement reached 12.5, 18.75, 31.25, and 62.50 mm, the bearings exceeded the basically intact state, slight damage state, moderate damage state, severe damage state, respectively, into the complete destruction state.…”

Definition and Quantified Research of Track Structural Damage Index of High-speed Railway Girder Bridge

“…In practical terms, a large number of damage assessments are currently carried out only for bridge structures in HRBs. Jiang et al (2017) calculated the damage exceedance probability of the piers and bearings of a HRB arranged as the continuous beam bridge in terms of the incremental dynamic analysis method. Park and Towashiraporn (2014) established a response surface model for seismic damage assessment of HRBs, but the assessment objects are also limited to piers and bearings.…”

Assessment of an optimal intensity measure for isolated bridges based on the geometric mean of the response spectrum

“…Some researchers further put forward an IM called Sa(T1) that can consider both structural and ground motion information, here T1 means the fundamental period. Sa(T1) can better quantify the elastic structural response of single-degree-of-freedom and multi-degree-of-freedom structures dominated by the first mode; therefore, it is widely used in probabilistic seismic demand models (Chen et al 2020;Jiang et al 2017;Mackie et al 2003;Wei et al 2019). However, for structures involving higher-order mode shapes, Sa(T1), which considers only the value of the response spectrum at a single point, is not an optimal IM (Baker et al 2005;Bojórquez et al 2011;Bojórquez et al 2012;Tothong et al 2007;Zhang et al 2018).…”