场地条件对桥梁结构体系抗震性能影响的研究

Performance-based earthquake analysis of 2-span bridge system using BridgePBEE

桥梁结构的振动特性受场地条件及土—结相互作用影响显著,为提高桥梁结构的抗震性能,减少因结构破坏而产生的经济损失,进一步开展考虑场地土体非线性以及土—结相互作用对桥梁结构地震反应影响的研究工作十分必要。本文以一典型桥梁结构为例,着重介绍了美国太平洋地震工程研究中心基于性能的桥梁有限元模拟平台BridgePBEE应用中所涉及的地震动选取、桥梁结构建模、土体本构选择以及基于构件的桩—土—桥梁结构体系损伤评估方法,为研究震后桥梁结构经济损失分析方法提供可行性方案。

This study aims to introduce a graphical user interface（BridgePBEE） to assess the seismic performance of coupled soil-structure systems under the Performance-Based Earthquake Engineering（PBEE） framework. A three-dimensional（3D） Finite-Element（FE） model for a typical simple bridge configuration is developed using Bridge PBEE to conduct time history analysis of the bridge-ground system. The nonlinear dynamic response of the bridge during multiple suites of earthquake excitations is studied. Seismic loss in terms of repair cost for pre-defined performance groups is derived thereafter. This study shows that the local site soil profile affects the seismic response of the bridge considerably and should be considered in design procedures.