高墩大跨铁路桥梁构件三维地震易损性分析

Three-dimensional seismic vulnerability analysis of long-span railway bridge components with high pier

针对目前桥梁易损性分析方法大多仅适用于一维地震作用下的分析局限性,构建了桥梁危险部位的三维地震损伤指标函数,运用结构可靠度理论和概率统计分析法,推导了三维地震下桥梁损伤破坏发生概率计算理论,建立了三维地震桥梁易损性分析方法.以西部地区某典型铁路刚构-连续梁桥为研究对象,基于云图法的计算结果,验证了三维易损性分析方法的正确性,并建立了桥梁构件全视角极坐标空间易损性云图,全面评估了桥梁构件三维抗震性能.分析结果表明:只进行桥梁结构纵、横向地震易损性分析,已无法真实有效地评估桥梁的实际抗震能力,应开展典型桥梁三维易损性分析.建立的桥梁构件全视角易损性云图可用于评估桥梁的抗震性能,为桥梁三维地震下的抗震设计提供依据.

Since most current vulnerability analysis methods are only applicable for one-dimensional seismic analysis, we established three-dimensional (3D) seismic damage index functions of bridge risk components. Based on the reliability theory of engineering structure and the method of probability and statistics, a general 3D seismic vulnerability calculation theory of bridge structure was derived and the corresponding analysis method was developed. A typical rigid frame continuous beam combined railway bridge from the Western region was selected as the research object and the vulnerability analysis of the bridge was carried out. Based on the results of the cloud method, the correctness of the 3D seismic vulnerability analysis method was verified and full-view vulnerability cloud pictures of each bridge risk component were established to evaluate the general seismic performance of the bridge structure in 3D earthquakes. Results show that only analysis of the distribution characteristics of the longitudinal and transverse vulnerability of the bridge is not effective for reflecting its actual seismic capacity, so it is necessary to conduct the 3D vulnerability analysis. The full-view vulnerability cloud pictures of the bridge can be applied to evaluate the seismic performance of the bridge, which provides evidence for 3D bridge seismic design.