外置耗能角钢的摇摆-自复位桥梁双柱墩地震易损性分析

Seismic vulnerability analysis of rocking self-centering double column bridge bents using external angles

为评估设置耗能角钢的摇摆-自复位桥梁双柱墩的抗震能力,本文建立该结构的有限元分析模型,分别定义和量化双柱墩不同损伤状态和损伤指标。本文从太平洋地震工程研究中心选取16条近断层地震动,基于增量动力分析,得到该结构的地震响应。基于最小二乘法,对得到的增量动力分析曲线进行对数回归分析,计算结构不同损伤状态的超越概率及易损性曲线。研究表明:当地面峰值加速度为0.1 g时,外置耗能角钢与耗能钢筋屈服的超越概率分别为34%和22%;当峰值加速度为0.4 g时,外置耗能角钢与耗能钢筋失效的超越概率分别为6%和11%,而预应力筋未屈服;当峰值加速度为1.0 g时,外置耗能角钢和耗能钢筋失效的概率分别达到85%和91%,桥墩发生倒塌的概率为46%。

In order to evaluate the seismic behavior of rocking self-centering(RSC)double column bridge bents with energy dissipation steel angle,a finite element analysis model of one RSC double column bent was proposed.Different damage states and damage indexes of the bent components were defined and quantified.Sixteen near-fault ground motions were selected from the pacific earthquake engineering research center(PEER),and incremental dynamic analysis(IDA)was conducted to obtain the seismic response of the bent.Based on the least square method,the obtained IDA curves were analyzed by logarithmic regression method,and the exceedance probability of different damage states and the vulnerability curves of the bent were obtained.The results show that,under the near-fault ground motions with peak ground acceleration(PGA)of 0.1g,the exceedance probability of external steel angle and energy dissipation bar yielding reaches 34%and 22%,respectively.Under the near-fault ground motions with PGA of 0.4g,the failure probability of the steel angle and energy dissipation bar is 6%and 11%,respectively.And the prestressing tendon would not yield.Under the near-fault ground motions with PGA of 1.0g,the failure probability of the external steel angle and energy dissipation bar is 85%and 91%,respectively.And the probability of collapse failure of the bridge bent is about 46%.