Dynamic Response Of Tunnel And Track Structure Subjected To Metro Load And Vibration Attenuating Methods

With the development of the underpass system in our country, the vibration and noise problem which is aroused by the passing moving metro vehicle become more and more serious. The uneasy and damage brought by the traffic vibration has been considered to be one of the most unbearable public nuisance. So, research on the vibration induced by metro vehicle is urgent and important.The vibration and noise of metro is induced by the unsmooth of track and so the relative movement between the track and wheel. The vibration is transmitted by the track structure to the tunnel structure, inducing the vibration of soil around the tunnel, and is finally transmitted to the overgroud building nearby. Here, based on the existing references, I reviewed the vibration and noise-evaluating methods, and fitted out the moving load to emulate the true vehicle load according to the unsmoothness of track. This paper also introduced different typed of track structures. The dynamic model of these track structure were given precisely and then both theoretical and numerical method are proposed to analysis the dynamic response of track structure subjected to moving vehicle load. Several parameters which influence the dynamic response of track structure were taken into account during the analysis. A conclusion that with the minishing of the stiffness and the increasing of the damping ratio of track structure, the dynamic response of the track structure is reducing is reached .A field test is also conducted to examine the dynamic response of tunnel structure.Data gained from the field test was used to emulate dynamic load the tunnel beard when metro vehicle is passing. The displacement response typical point of the tunnel structure is analyzed at the end of this thesis.In the finality, the problems requiring further studies are discussed.