处于高烈度区的大跨斜拉桥其地震安全性是设计、审查关注的重点。以迫龙沟斜拉桥为背景,采用Opensees软件建立索塔模型,选取多条地震动数据,在横桥向进行动力增量(Incremental Dynamic Analysis,IDA)分析。采用程序语言提取下塔柱的最大曲率响应,结合塔底截面弯矩曲率曲线,制定出基于性能的损伤指标。通过RambergOsgood函数由众多IDA曲线的上下界及数据拟合得到概率分位数为10%、50%,90%的IDA曲线。运用符合极值Ⅱ型地震动加速度概率分布模型,对大地震和罕遇地震2种风险水平下斜拉桥的结构安全水平进行评估。 The seismic safety of long-span cable-stayed bridges in high-intensity areas is the focus of attention on design and review. Taking Forcedo ditch cable-stayed bridge as a background, the pylon model was established by using Opensees software, multiple ground motion data were selected, and incremental dynamic analysis (IDA) was carried out in transverse bridge. Based on the maximum curvature response of the tower under the program language, the performance-based damage index was developed based on the curvature curve of the moment of the tower bottom section. The IDA curves with 10%, 50%, 90% probability quantiles were obtained by fitting Ramberg Osgood function with the upper and lower bounds of many IDA curves and data fitting. The structure safety level of cable-stayed bridges under two kinds of risk levels of major earthquakes and rare earthquakes is evaluated by using the probability distribution model in accordance with extreme type Ⅱ earthquake acceleration.