地铁隧道列车运行诱发环境二次振动初探

建立了车-线-隧道耦合动力学模型,输入实际的列车、轨道、隧道承力结构参数,获得地铁列车运行时的隧道承力结构动态激励。在此基础上,综合运用有限单元法和无限边界元法,建立了隧道-土体-建筑动力耦合模型,分析隧道周围土体及沿线建筑物的受振特性,探析地铁列车振动对环境的影响规律。结果表明:地铁列车运行引起周围环境的二次振动为低频振动,且主要为竖向振动和横向振动;列车通过时,地面竖向振动最大值出现在距离隧道中心线10 m处,竖向振动加速度除了在距离隧道中心线45 m点出现反弹外,其他各点的振动加速度幅值基本上都是随着距离的增加而逐渐减小;随着传播距离的增加,较高频率的振动成分幅值衰减较快。

Preliminary Study on Secondary Ambient Vibration Induced by Train's Running in Tunnel

The dynamic coupling model of train-track-tunnel was established,and the dynamic excitation of tunnel's load-carrying structure in the process of train's running was acquired by inputting the actual parameters of the train,the track and the tunnel's load-carrying structure.On this basis of the above,by comprehensively using the finite element method and the infinite boundary element method,the dynamic coupling model of tunnel-soil-buildings was established.Afterwards,the characteristics of the vibration responses of both the ambient soils around the tunnel and the buildings along the tunnel were analyzed,so as to analyze the influence of the metro train's vibration on the ambient.The results show that:the secondary ambient vibrations induced by metro train's running generally belong to low-frequency vibrations,which mainly consist of the vertical vibrations and transverse vibrations.When the train passes through,the maximum vertical vibration on the ground will appear at the place of 10 meters away from the tunnel centerline;and except for the rebound phenomena appeared at the point of 45 meters away from the tunnel centerline,the amplitude values of the vertical vibration acceleration at other points basically decrease gradually with the increase of the distance.In addition,with the increase of the propagation distance,the amplitude values of higher-frequency vibration will attenuate relatively rapidly.