基于车轨耦合模型下地铁对隧土的振动响应

Vibration Response of Metro to Tunnel Based on Wheel-Rail Coupled Model

为了准确预测列车运行时轮轨间相互作用对隧道和地面的振动影响,利用 ANSYS软件建立某地铁的二维模型,通过车轨耦合模型得到轮轨力,将该力施加在隧道-土层2D有限元模型上,得到道床上某点振动加速度的模拟值,并将其与实测值对比验证模型的可靠性。基于此模型计算隧道地面点的振动响应,分析土层深度及宽度参数对地面点振动的影响。结果表明:双线与单线引起的地面振动规律基本一致;地面点的振动加速度随着拾振点与振源距离的增加而减弱,但会在23 m左右出现振动放大区;选择宽度120 m、深度75 m的模型即可达到计算精度要求。结果可为地铁线路减振、环境振动评价等提供参考。

In order to accurately predict the impact of wheel-rail interaction on the vibration of a tunnel and ground during train operation, the ANSYS software is used to establish the two-dimensional modeling of a subway. The wheel-rail coupled model is used to obtain the wheel-rail interaction force. Applying this force to the 2D tunnel-soil FEM model, the acceleration of vibration at a point on the track bed is obtained. The reliability of the model is verified by comparing the simulated value with the measured value. Based on this model, the vibration responses at points on tunnel ground are calculated, and the influence of soil depth and width parameters on ground vibrations is analyzed. The results show that the rule of vibration caused by double track subway operation is basically the same as the one caused by single track subway operation. The vibration acceleration of the ground decreases as the distance between the pick-up point and the vibration source increases, but there will be a vibration enlarged zone around 23 m;Selecting a model with a width of 120 m and a depth of 75 m can meet the calculation accuracy requirements. The results can provide reference for environmental vibration assessment, vibration reduction and rail transit route planning around the subway line.