列车作用下双隧道轨枕与衬砌的动力响应分析

Analysis of the Dynamic Response of Twin-tunnel Rail Sleepers and Lining under the Action of Trains

为研究近间距地铁双隧道在列车振动作用下的动力响应,基于颗粒流程序(PFC)建立双隧道离散元模型。该模型通过对地铁运营期间的三种工况进行模拟,分析了单列列车(6节车厢)通过对相邻隧道和自身隧道的影响以及两列列车同时通过对隧道的影响。结果表明:列车驶入隧道后(1~3节),隧道的竖向动力响应大致在波动中逐渐增强,之后(4~6节)隧道竖向动力响应峰值逐渐平稳,且自身隧道衬砌的竖向振动幅度比相邻隧道平均小23%;两列列车同时通过时隧道衬砌的动力响应最大,最大振动位移达6.4 mm,发生在靠近双隧道中间区域的位置;近间距双隧道应对中间区域附近的衬砌振动重点监测以防微裂纹产生。

To study the dynamic response of closely-spaced subway twin tunnels under the action of train vibration,this paper establishes a discrete element model of twin tunnels based on particle flow code(PFC).The model simulates three scenarios during subway operation to analyze the impact of a single passing train(with 6 carriages)on the adjacent tunnel and its own tunnel,as well as the impact of two simultaneously passing trains on the twin tunnels.The results show that after the train enters the tunnel(1-3 carriages),there is a gradual increase with fluctuations in the vertical dynamic response of the tunnel,and then(4-6 carriages),the peak vertical dynamic response of the tunnel gradually stabilizes,and the vertical vibration amplitude of the lining of its own tunnel is,on average,23%smaller than that of the adjacent tunnel.The dynamic response of the tunnel lining reaches its maximum value when the two trains are passing simultaneously with a maximum vibration displacement of 6.4 mm,which occurs near the middle of the twin tunnels.This indicates that closely-spaced twin tunnels should be monitored for lining vibrations near the middle area with a focus on preventing microcracking.