Research On The Ground Vibration Caused By The Small Radius Curve Operation Of Zhengzhou Metro

In recent years,with the rapid growth of my country’s economy,my country’s rail transit infrastructure has also entered a stage of rapid development.While the increasingly dense rail transit network brings convenience to the people,it will inevitably bring a certain degree of The micro-vibration problem affects the people.At the same time,in order to meet the city’s requirements for the layout of rail transit lines,more and more curved rail sections have been designed.Therefore,studying the surface vibration response caused by the operation of subway trains in small radius curved tunnels is of great significance to the subsequent track route design.In this paper,the two methods of field measurement and finite element numerical simulation are combined to study and analyze the impact of surface vibration caused by the operation of subway trains in small radius curve tunnels.The tunnel depth,vibration center distance,train speed,etc.are discussed in detail.The influence law of factors on the ground surface vibration,and the difference between the ground surface vibration when the train runs in a curved tunnel and a straight tunnel is compared.The main research work and conclusions of this paper are as follows:(1)The environmental vibration was measured on the curve tunnel section from Greentown Square Station to Bishagang Station of Zhengzhou Metro Line 1,and the environmental vibration characteristics caused by subway operation in the curved tunnel were analyzed,and the environmental vibration was evaluated.The measured data shows that the ground surface vibration caused by the subway train running in the curved tunnel is mainly the vibration in the horizontal direction;the ground surface vibration of this section meets the environmental vibration limit requirements of commercial and civil buildings.(2)The tunnel-soil model was established using ABAQUS finite element software,and the size,soil parameters,artificial boundary,damping,incremental step size and other parameters of the finite element model were determined;the simulation method and curve of the moving load of the train were given Semi-refined tunnel modeling method;DLOAD and UTRACLOAD programs are used to control the movement of the moving load on the track,which simulates the movement of the train inside the tunnel more realistically;the reliability of the model is verified by the comparison and analysis of the simulation calculation results and the measured data Sex.(3)Using the established curved tunnel finite element model to simulate and analyze the influence of tunnel depth,train speed and other factors on the surface vibration caused by the operation of subway trains in small radius curved tunnels under the change of the vibration center distance.The main conclusions are as follows: When the speed per hour and the buried depth of the tunnel are constant,as the vibration center distance increases,the surface vibration speed gradually decreases,high frequency vibration is filtered,and low frequency vibration is gradually active;when the vibration center distance and the subway train speed are constant,the tunnel buried depth becomes larger,The lower the surface vibration speed and when the buried depth reaches 20 m,the surface vibration rate decays faster,but the main vibration frequency of the surface is basically not affected by the buried depth of the tunnel;when the vibration center distance and the buried depth of the tunnel are constant,as the speed of the subway train The increase in the speed of the surface vibration is faster,and the main vibration frequency of the surface will also increase with the increase in the speed of the train.(4)The difference between the surface vibration caused by the train running in the straight tunnel and the curved tunnel is analyzed.The results show that the horizontal vibration is dominant in the curved tunnel,and the vertical vibration is basically the main vibration in the linear tunnel,with vibration characteristics.The difference is large,so the same evaluation standard cannot be used for evaluation.