为研究桥梁动力响应对列车脱轨风险的影响，基于有限元软件ANSYS/LS-DYNA建立三维数值研究模型，对船舶撞击整桥过程进行了数值模拟，研究不同撞击速度对撞击力作用下桥梁动力响应的影响，并依据数值模拟结果，以桥面1 m/s²的横向加速度作为外部激励限值，对行驶在桥上的列车进行脱轨概率评估。结果表明：随着撞击速度的提高，撞击力峰值、主塔横向位移及桥梁横向加速度相应增大，撞击速度对船撞动力响应及列车脱轨概率具有较大影响；当撞击速度为2.5 m/s时，桥面上最大横向加速度为0.942 m/s²，未超过列车脱轨加速度临界限值1 m/s²，不存在脱轨风险。当撞击速度为3.5 m/s，4.5 m/s时，列车脱轨概率分别为1.371 × 10^-6、1.920 × 10^-6、研究结论可为桥梁船撞动力响应分析及桥上列车脱轨风险评估提供参考。

In order to investigate the impact of bridge dynamic response on train derailment risk, the three-dimensional numerical models were established using finite element software ANSYS/LS-DYNA to numerically simulate the entire process of ship collision on the bridge. The influence of different impact velocities on the dynamic response of the bridge under impact force was studied. Based on the numerical simulation results, a lateral acceleration of 1 m/s² on the bridge deck was used as the external excitation limit, to evaluate the derailment probability of trains traveling on the bridge. The results indicate that as the impact speed increases, the peak impact force, lateral displacement of the smain tower, and lateral acceleration of the bridge increase accordingly. The impact speed has a significant impact on the ship collision dynamic response and the probability of train derailment; When the impact speed is 2.5 m/s, the maximum lateral acceleration on the bridge deck is 0.942 m/s², which does not exceed the critical limit of train derailment acceleration by 1 m/s², and there is no risk of derailment. When the impact speed is 3.5 m/s and 4.5 m/s, the probability of train derailment is 1.371 × 10^-6 and 1.920 × 10^-6. The research conclusion of this study can provide reference for the analysis of bridge ship collision dynamic response and the risk assessment of train derailment on the bridge.