断层地震动对隔震桥梁地震响应的影响

Response Analysis of Seismic Isolated Bridge Under Influence of Fault Crossing Groundmotions

摘要:

以一跨断层简支桥梁为工程背景，根据已有脉冲模型，生成了模拟断层效应的地面运动.在此基础上，建立了跨断层桥梁空间有限元模型，应用非一致激励的非线性时程分析方法，研究了断层断裂效应对隔震桥梁的影响.还分别针对采用铅芯橡胶支座和盆式橡胶支座两种支座系统，研究了考虑和不考虑断层跨越效应对结构的地震响应影响.研究结果表明，断层效应对结构的地震响应影响非常大，会较大地增加结构地震响应.

Abstract:

This paper was based on the engineering background of a simple bridge across the fault. According to the proposed pulse models, a set of synthetic fault crossing strong ground motions was generated and the finite element model of a simple bridge across the fault was built, utilizing the non uniform excitation nonlinear time history analysis method to investigate the effect of the fault rupture on a seismic isolated bridge. Two different bearing systems, without and with accounting for differential ground movement across the fault rupture, were considered in the analysis to evaluate and compare the performances of the structure. The analysis indicate that the fault crossing is an important factor in the earthquake response of seismically isolated bridges which increases the earthquake response of the structure larger.