Numerical Analysis of Train Impact Load with Finite Element Method
YAN Qixiang1, LI Bin1, ZHANG Meng2, HE Chuan1, YANG Wenbo1, GENG Ping1
1. Key Laboratory of Transportation Tunnel Engineering of Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China;
2. China Railway Engineering Consultants Group Co., Ltd., Beijing 100020, China
In order to obtain the train impact load on shield tunnel to investigate the dynamic responses of shield tunnel segment under train impact load, a 3D numerical analysis model for train formation was established to obtain the time-history curves of train impact force at different impact velocities, train formations and oblique impact angles. The maximum train impact force and impact duration as functions of impact velocity and impact angle were researched. Based on the representative time-history curves, the dynamic responses of shield tunnel with different thickness double lining caused by train impact load were investigated. The research result shows that when train formation is certain, the maximum train impact force increases with the increases of impact velocity and impact angle; when impact angle is larger than 7.5°, impact duration extends with the increase of impact velocity. From different times at which the maximum train impact force appears, the time-history curves of train impact force can be divided into two kinds of characteristic curve, and the first kind of characteristic curve with the maximum impact force appearing at the impact moment is in accordance with the Gauss multiple peak fitting formula, and 10 parameters can be used to achieve its approximate fitting. To increase secondary lining thickness can effectively reduce the dynamic responses of external segment lining under train impact load such as stress, velocity and acceleration as well as tension and compression damage zones.