基于双地震动强度指标的桥墩地震易损性模型研究
Study on seismic fragility models of piers based on double ground motion intensity measures

基于双地震动强度指标，开展典型桥墩的地震易损性模型研究. 采用OpenSees软件建立桥墩的有限元分析模型，通过增量动力分析方法计算得到桥墩的地震响应. 根据受试者工作特性分析方法对地震动强度指标进行评价，选择出有效性较好的地震动强度指标组合，基于线性组合的方法分别建立双地震动强度指标桥墩易损性模型，并和单地震动强度指标模型进行对比. 结果表明： 双地震动强度指标的有效性普遍优于单一地震动强度指标；桥墩发生相同损伤状态时，基于双地震动强度指标建立的易损性曲面的中位值小于基于单一地震动强度指标得到的中位值. 研究结果可为桥梁结构的后续风险评估及加固决策提供参考.
Based on the double ground motion intensity measures，the research of seismic fragility models for piers is carried out in this study. By adopting the OpenSees platform，finite element models of the piers were established，and the seismic response is obtained with the method of incremental dynamic analysis (IDA). The selected ground motion intensity measures (IM) were evaluated through the approach of receiver operating characteristic (ROC). The seismic fragility models with double ground motion intensity measures were established based on linear combination method，which compared with the results of single ground motion intensity measures. The analyses results show that the efficiency of the double ground motion intensity measures is generally superior to that of the single ground motion intensity measures. For an equal damage state，the median values obtained from the seismic fragility surface based on the double ground motion intensity measures are less than those based on the single ground motion intensity measures. The results can be used for the further seismic risk assessment and bridge retrofit prioritization