Probabilistic pounding analysis of high-pier continuousrigid frame bridge with actual site conditions
Probabilistic pounding analysis of high-pier continuousrigid frame bridge with actual site conditions
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发表时间：
2018-08
影响因子：
1.5
通讯作者：
Hong-yu Jia;Jingang Zhao;Xi Li;Lanping Li;Shixiong Zheng
中科院分区：
文献类型：
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作者：
Hong-yu Jia;Jingang Zhao;Xi Li;Lanping Li;Shixiong Zheng
本文研究了大跨度高墩连续刚构桥在考虑局部土效应的地震作用下桥面与桥台发生碰撞的概率。提出了一种以基岩峰值加速度为烈度指标的多点地震作用下的碰撞概率分析方法。建立了四种不同间距的桥梁非线性有限元模型。模拟了实际场地条件和非均匀空间土层剖面对地震波从基岩到地表传播的影响。基于非线性增量动力分析法（n-IDA），对高墩桥梁在多点地震激励下的碰撞概率进行了分析。比较了均匀激励下无实际场地效应和MSSE下有场地效应的碰撞概率计算结果。研究表明，随着基岩峰值加速度的增加，一致激励下桥面与桥台的设计间距比MSSE下的设计间距要大。随着桥面与桥台间距和加速度峰值的增大，MSSE工况下单桥台或双桥台同时发生碰撞的概率均小于UE工况。通过对MSSE作用下高墩桥梁的概率碰撞分析，考虑实际的局部场地效应，确定桥面与桥台的分离距离具有重要意义。
This paper studied the probability of pounding occurred between decks and abutments of a long span high-pier continuous rigid fame bridge subjected to ground motions with local soil effect. A pounding probability analysis methodology has been proposed using peak acceleration at bedrock as intensity measure (IM) for multi-support seismic analysis. The bridge nonlinear finite element (FE) models was built with four different separation distances. Effect of actual site condition and nonuniform spatial soil profiles on seismic wave propagating from bedrock to ground surface is modelled. Pounding probability of the high-pier bridge under multi-support seismic excitations (MSSE) is analyzed based on the nonlinear incremental dynamic analysis (n-IDA). Pounding probability results under uniform excitations (UE) without actual local site effect are compared with that under MSSE with site effect. The study indicates that the required design separation length between deck and abutment under uniform excitations is larger than that under MSSE as the peak acceleration at bedrock increases. As the increase of both separation distance between deck and abutment and the peak acceleration, the probability of pounding occurred at a single abutment or at two abutments simultaneously under MSSE is less than that under UE. It is of great significance considering actual local site effect for determining the separation distance between deck and abutment through the probability pounding analysis of the high-pier bridge under MSSE.