目前,通常采用确定性方法对桥梁隔震效果进行分析,即通过隔震与非隔震地震响应进行对比得到隔震效果;而概率方法对隔震桥梁进行分析时又大多仅分析其失效概率,很少从失效概率的角度开展隔震与非隔震桥梁对比研究。本文利用概率性地震需求分析模型分别对隔震与非隔震连续梁桥进行了地震易损性分析。在考虑桥梁结构及地震动参数随机性的基础上,以墩柱位移延性比和支座相对位移比作为破坏指标,定义并量化了隔震与非隔震桥梁桥墩和支座的五种极限破坏状态。利用传统可靠度概率分析方法通过非线性时程分析生成了桥墩和支座的易损性曲线,对比分析了隔震与非隔震桥梁墩柱和支座在不同破坏状态下的超越概率。研究结果表明:从易损性对比的角度分析,相比于非隔震连续梁桥,隔震连续梁桥在地震动作用下表现出了较好的抗震性能,各破坏状态下构件的超越概率较小。
Nowadays, definitive method is adopted to analyze the bridge isolation effect by the comparison between isolated and non-isolated earthquake response;the comparison between isolated and non-isolated bridge analysis is rarely researched from the scale of failure probability, which is analyzed when probability method is used to analyze the isolated bridge. The seismic vulnerability analysis of the isolated and non-isolated continuous girder bridge are developed by using probabilistic seismic demand models. Considering the random of bridge structure and ground motion parameter, five different kinds of ultimate which the displacement ductility ratio of pier and damage states of pier and bearing are defined and quantified, in relative displacement ratio of bearing are the damage indexes. The vulnerability curves are generated by the use of the traditional reliability probability method throughout nonlinear transient analysis, and the exceeding probability of pier and bearing in isolated and non-isolated bridge under dif- ferent damage states is analyzed. The result shows that compared with the non-isolated bridge, the isolated bridge has better anti-seismic property under earthquake effect and the exceeding probability of the components is smaller under different damage conditions from the perspective of vulnerability.