The Finite Element Analysis of Ground Vibration Caused by Rail Traffic on Viaduct

The research obtained the vibration propagation law caused by viaduct rail traffic in layered soil,and provided the basis for ambient noise and vibration reduction.Consider the vertical irregularities between the wheel and rail,a train-viaduct-multilayer soil 3D finite element(FE)model in different speed was established,and get the vibration of different distance from the source and the vibration propagation law in layered soil,the vibration can be got by transient analysis.The viaduct have a good attenuation function for vibration caused by train,the vertical vibration acceleration of the end of the pier node is about 1/100 of the midspan node.Compared with 2D model,the vibration acceleration of the calculation results of 3D FE model are smaller,and more close to the actual situation.The vertical acceleration of pier bottom can attenuation 103 times than midspan.The maximum acceleration of piers bottom is 97 times than 23m area.So the attenuation of vibration in viaduct is very large.In this area of soil condition,the vibration decays can reach to a very low level at a distance less than 10m area,so the area without vibration isolation can meet the national standard requirement.