Railway vehicles frequently have derailed during major earthquakes. Although a probabilistic approach based on fragility analysis was established in structural engineering, it has never been applied to railway vehicles. Thus, the aim of this study was to select optimal intensity measures (IMs) and develop fragility curves for the derailment of vehicles. Eight commonly seen IMs were examined to determine their suitability for use in analyzing the derailment of vehicles. The railway vehicle response was analyzed using a nonlinear vehicle-track simulation, and 22 far-field and 28 near-field ground motion records were used as input. Based on the results of the simulation, the correlations of these IMs with the responses of vehicles were evaluated in terms of commonly accepted criteria in the literature, such as efficiency, practicality and sufficiency. It was found that spectral IMs were superior to peak-type IMs. In addition, the acceleration spectral intensity (ASI) and the velocity spectral intensity (SI) were shown to be optimal IMs for the evaluation of derailments. Using the selected IM (ASI), derailment fragility curves were developed for three levels of vehicle performance, which facilitated the probabilistic assessment of vehicle derailment in a performance-based manner.

铁路车辆经常在大地震中脱轨。尽管在结构工程中建立了基于脆性分析的概率方法，但从未应用于铁路车辆。因此，本研究的目的是选择最佳强度测量 (IM) 并开发车辆脱轨的脆性曲线。检查了八种常见的 IM，以确定它们是否适用于分析车辆脱轨。使用非线性车辆轨道模拟分析铁路车辆响应，并使用 22 个远场和 28 个近场地面运动记录作为输入。根据模拟结果，根据文献中普遍接受的标准，如效率、实用性和充分性，评估了这些 IM 与车辆响应的相关性。发现光谱 IM 优于峰型 IM。此外，加速度谱强度 (ASI) 和速度谱强度 (SI) 被证明是评估脱轨的最佳 IM。使用选定的 IM (ASI)，针对三个级别的车辆性能开发了脱轨脆弱性曲线，这有助于以基于性能的方式对车辆脱轨进行概率评估。