Analysis And Inversion Of The Influence Of Soil Parameters On Environmental Vibration Caused By High-speed Railway

With the rail transit becoming one of the mainstream of people’s travel mode,the highspeed railway,which is represented by high-efficiency,safety and environmental protection,has become the hot direction of traffic development in the current era.The ground vibration caused by high-speed train is determined by many parameters.In recent years,the development of numerical methods represented by finite element method has made the calculation and analysis of ground vibration more and more convenient.In order to fully analyze the relationship between soil parameters and environmental vibration,the influence of vehicletrack-roadbed-foundation finite element model based on abaqus software on the environmental vibration of foundation soil parameters is analyzed in this paper.The sensitivity of environmental vibration to soil parameters and the inversion of soil parameters are studied.The main results are as follows:(1)The vehicle-track-roadbed-foundation dynamic model established by abaqus finite element software,combined with the idea of control variables,the foundation soil is set up as the dp constitutive model to keep the other parameters unchanged,respectively,to the density,elastic modulus and Poisson’s ratio,respectively.The effects of internal friction angle,cohesion and damping ratio on environmental vibration in time domain and frequency domain are analyzed.It is found that density,modulus of elasticity,Poisson’s ratio and damping ratio have different effects on environmental vibration,while internal friction angle and cohesive force have little effect on environmental vibration.(2)The sensitivity of parameters usually refers to the degree of disturbance to the response of the system when the parameters change slightly,which is usually defined as the partial derivative of the variation of the system to the variation of the parameters,which is of great significance to the practical engineering.The relationship between the response of vehicletrack-roadbed-foundation coupling system and soil parameters can not be expressed analytically.Therefore,the sensitivity of soil parameters is analyzed by using finite element method and neural network method in this paper.The results show that the sensitivity of soil parameters is as follows: modulus of elasticity,damping ratio,Poisson ratio,internal friction angle,cohesion.The sensitivity of environmental vibration to internal friction angle and cohesive force is very small,so the change of internal friction angle and cohesive force of foundation soil has little effect on environmental vibration.(3)Based on the environmental vibration samples calculated by dynamic model under each parameter,a bp neural network model with input as environmental vibration response and output as foundation soil parameter is established.After training to convergence,the inversion of soil parameters is realized.Through the verification of five groups of environmental vibration responses,the results show that the relative error of parameter values based on neural network inversion under all working conditions is smaller than that of actual parameters.The basic control is within the practical acceptable range of engineering,and it is proved that the neural network can invert the foundation parameters by the environmental vibration response caused by high-speed railway.