三孔小净距隧洞下穿既有铁路列车振动荷载动力响应研究

Dynamic Response of Three Pipes Small Spacing Tunnels Under Train-induced Dynamic Load

以下穿既有铁路的三孔小净距隧洞为工程背景,采用数值方法建立动力计算模型,分别研究初始正常行车工况、初期支护正常行车工况和初期支护慢行工况条件下,列车动荷载作用下路基、围岩和初期支护的应力和位移响应。研究结果表明:列车振动不可避免地对正在施工的隧洞产生不利影响,使初期支护产生一定的附加沉降和附加应力,采取加固措施和限速慢行可有效地减小动荷载产生的不利影响。

Based on three pipes small spacing tunnels underneath existing railway,the dynamic response of roadbed and ground and primary support is studied by numerical method.The calculated work conditions of dynamic analysis model include initial normal driving speed condition,primary-support normal and driving-speed condition and primary-support slow driving-speed condition.The results show that the train vibration inevitably brings adverse effect to construction tunnel,and causes additional displacement and stress to the primary support.The adverse effect can be reduced by adopting reinforcement measures of ground and slow driving speed of train.