复杂山区不规则桥上无缝线路地震损伤机理及行车安全性研究

随着我国西南山区铁路大规模修建，山区局部场地空间变异地震波以及多联不规则桥梁间不同地震响应导致的桥上无缝线路损伤变形将更为显著，并严重危及桥上行车安全性。本项目拟针对山区不规则桥上无缝线路地震损伤机理和行车安全性问题开展研究。首先，基于地震波动理论，建立考虑局部山区复杂地形和土层参数的地震波动数值模型，提出复杂山区空间变异地震动描述方法；其次，开展山区空间变异地震作用下不规则桥梁-无缝线路系统三维非线性分析和振动台试验，研究无缝线路的稳定性、变形特征和损伤机理；最后，建立列车-轨道-桥梁系统非线性动力学模型，结合桥上行车安全试验，研究地震下轨道损伤变形与行车安全性指标之间的关系，提出复杂山区不规则桥梁相对变形限值、控制措施和桥上无缝线路设计建议。本课题是衔接地震工程学与山区铁路桥梁-无缝线路系统抗震计算脱节状态的应用基础研究，对完善我国山区不规则铁路桥梁抗震设计具有重要理论意义。

With the rapid development of the high-speed railway construction in mountainous areas of Southwest China, the damage and deformation of continuous welded rail track (CWRT) is more evident due to the spatially varying ground motions induced by local topography of mountain areas and the different seismic responses of adjacent irregular bridges, and further endanger the running safety of train. This project is aimed to investigate the seismic damage mechanism of the CWRT and the running safety of train passing over irregular bridges in mountainous areas. Firstly, based on seismic wave theory, the numerical model of seismic wave propagation is established considering the local topography and subsoil in mountainous areas, and the simulation method of the spatially varying ground motion in mountain areas will be proposed. Then, 3D nonlinear numerical analyses and shaking table tests of the irregular bridge-CWRT system under spatially varying ground motion are performed, and the stability, deformation behavior, and damage mechanism of the CWRT are analyzed. At last, the nonlinear dynamic model of the train-track-bridge coupled system is established, combining the running safety tests of train passing over bridges, to investigate the relationship between the damage deformation of track and the running safety indices. The relative deformation limits of multiple irregular bridges in mountainous areas, the corresponding control measures, and the design suggestions of CWRT on irregular bridges are put forward. This project is the applied basic research to combine the earthquake engineering and the seismic analyses of railway bridge-CWRT system in mountainous areas. Research achievements will improve the seismic design of irregular railway bridges in mountainous areas of China.