Seismic response study of ordinary and isolated bridges crossing strike‐slip fault rupture zones

Abstract

This article presents a comprehensive parametric study of ordinary and seismically isolated bridges crossing strike‐slip faults by performing nonlinear response history analysis using actual near‐fault ground‐motion records and by varying the fault crossing angle, fault crossing location, pier height, span length, seismic excitation polarity, and number of ground‐motion components. The considered ground motions include three records from major earthquakes with their peak ground displacements and pulse periods being considerably larger in the fault‐parallel component than in the fault‐normal component and one record from a strong earthquake with comparable peak ground displacements and pulse periods in both components. The analysis results indicate that fault crossing angle and fault crossing location significantly affect the displacement demands, the distributions of peak displacement responses at piers and abutments, and the deformed shapes of both ordinary and seismically isolated bridges. The most advantageous scenario is generally obtained at a fault crossing angle of 90° and a fault crossing location at the middle span of the bridge. In addition, the variation trends of isolation displacement demands and pier drift demands of seismically isolated bridges with fault crossing angle and fault crossing location appear to depend primarily on earthquake magnitude. Based on the limited number of considered records, it is also observed that utilizing only the fault‐parallel ground‐motion component is generally sufficient for the seismic analysis of bridges crossing strike‐slip faults, with the exception of seismically isolated bridges subjected to records from smaller earthquakes. Furthermore, the effect of seismic excitation polarity on the displacement demands of ordinary and seismically isolated bridges may be significant depending on the fault crossing angle. Finally, pier height and span length are found to have an insignificant effect on the displacement demands of bridges crossing strike‐slip faults.

Seismic response characteristics and whiplash effect mechanism of continuous rigid-frame bridges subjected to near-fault ground motions

“…Qiao et al (2022) conducted an in-depth parametric study of topographic effect on the seismic response and running safety of a train-bridge coupled system on a CRFB. Park et al (2004), Ucak et al (2014) and Yang et al (2021) presented seismic response study of ordinary and isolated bridges crossing strikeslip fault rupture zones by utilizing finite element models of the 10-span Bolu Viaduct.…”

Dynamic Analysis of Train–Bridge Coupling System for a Long-Span Railway Suspension Bridge Subjected to Strike–Slip Fault

“…Moreover, the results indicated that, among the various FCAs analyzed, a 90 • angle resulted in smaller pylon displacement and longitudinal bearing displacement while leading to larger transverse bearing displacement. Lin et al [6], Yang et al [7], and Zeng et al [8] examined both ordinary and seismically isolated bridges crossing strike-slip faults. Their study systematically explored various factors, including FCA and fault-crossing location.…”

Seismic Response Characteristics and Performance Improvement of Near-Fault Continuous Rigid-Frame Bridges

“…Researchers evaluated the seismic fragility of multi-span CRFBs (Jung and Andrawes 2018;Abbasi and Moustafa 2019;Liang et al 2020;Shan et al 2020), conducted a parametric analysis of trainbridge interactions (Qiao et al 2023). Additionally, researchers have developed novel structural systems (Peng and Zhang 2020;Lin et al 2020c) and assessed the seismic response of ordinary and isolated CRFBs crossing strike-slip fault rupture zones (Ucak et al 2014;Yang et al 2021). However, existing studies have the following limitations: (1) the influence of different spans and pier heights on the seismic response of CRFBs has not been investigated; (2) the transverse whiplash effect and spatial torsion effect of CRFBs have not been investigated in detail; (3) few seismic control methods have been able to improve the seismic performance of CRFBs under near-fault ground motions (Xu et al 2017;Zhang and Xu 2022;Li and Xu 2023a).…”