该文基于向量形式的地震动强度度量参数(Intensity Measure,IM),建立了一种预测钢筋混凝土(RC)桥墩损伤水平的地震易损性分析方法。以某城市桥梁为研究对象,考虑桥梁结构本身的不确定性以及地震动的不确定性,采用基于向量IM的易损性曲面对RC桥墩进行了地震易损性分析,对不同损伤状态下RC桥墩的易损性进行了研究。研究表明:由于地震荷载的复杂性,在进行RC桥墩地震易损性分析时,标量IM往往会忽略地震动的其他重要特性。向量IM因其包含了更多的地震动信息,能够显著地降低对于RC桥墩损伤水平预测的离散性,因而具有重要的研究价值。与传统标量IM形成的易损性曲线相比,该文提出的基于向量IM的易损性曲面可以有效地反映第二个地震动强度度量参数引起的RC桥墩易损性失效概率的变化。因此,采用向量IM进行RC桥墩的地震易损性分析能够更加准确地对RC桥墩的抗震性能做出评估。 Based on the vectorial form of Intensity Measure (IM), a seismic vulnerability analysis method for predicting the damage level of RC pier was established. Taking a city bridge as the research object and considering the uncertainty of the bridge structure itself and the earthquake, the fragility surface based on vector IM is used to analyze the seismic fragility of RC piers. The vulnerability of RC pier was studied. The results show that due to the complexity of seismic load, scalar IM tends to neglect other important characteristics of ground motion during the seismic fragility analysis of RC piers. Because vector IM contains more ground motion information, it can significantly reduce the discreteness of RC pier damage level prediction, which is of great research value. Compared with the vulnerability curve formed by traditional scalar IM, the vulnerability vector surface based on vector IM proposed in this paper can effectively reflect the change of failure probability of RC pier vulnerability caused by the second ground motion strength measurement parameter. Therefore, the seismic fragility analysis of RC piers using vector IM can evaluate the seismic performance of RC piers more accurately.