高速铁路路桥过渡段动力响应分析

综合考虑不同结构层之间的相互作用，结合无砟板式轨道动力学模型，利用有限元软件建立车辆-轨道-路基耦合系统的动力学空间数值模型，分析了时速350 km/h高速列车在运营时正梯形和倒梯形形式路桥过渡段的动力响应。结果表明:列车荷载作用下，两种路桥过渡段的动力响应基本上一致；倒梯形过渡段的沉降量稍大于正梯形过渡段，而正梯形过渡段比倒梯形过渡段更有利于保持轨道的平顺性；路桥连接处（桥台后5 m范围内）是整个路桥过渡段的薄弱环节，应该单独考虑其设计、施工过程。综合考虑机车的各项动力学指标，建议将路桥过渡段轨面弯折角

Analysis on Dynamic Response in Bridge-Subgrade Transition Section of High-speed Railway

This paper considered interaction between structural layers and, by in combination with the dynamic model of ballastless slab track and by use of finite element software, established the spatial dynamic numerical model of vehicle-track-subgrade coupling system and then analyzed the dynamic response of high- speed train at 350 km/h in the bridge-subgrade transition section in the form of regular and inverted trapezoid. The results show that： Under the action of train load, the dynamic responses in the two kinds of transition section are basically consistent ; The settlement of the section in inverted trapezoid is slightly larger than that of the section in regular trapezoid, while the section in regular trapezoid is more favorable to maintenance of the track regularity, in contrast to the section in inverted trapezoid; The junction between bridge and subgrade （in the range of 5 m behind the abutment） is the weak portion in the whole transition section, and should be designed and constructed separately. By considering the dynamics indices of locomotive, the track deflection angle of the transition section should set the limit value of 0. 5 ‰, K30 ≥210 MPa in the range of 0- 5 m behind the abutment and K30 ≥ 150 MPa out of the range of 5 m.