Dynamic Analysis Of Soils Under Moving Load

With the development of traffic and the increase of vehicle speed in China, people have began to give more and more concern to the influence of vibration induced by traffic load around environment.Therefore,it has very important practical value to analyze and calculate the dynamic response of soil under moving load in road engineering and railway engineering.At first,the current works of dynamic analysis of soils under dynamic load and the characteristics of propagation of Rayleigh Wave in soils are introduced. On the foundation of senior people, this paper investigate the dynamic analysis of soils under moving load and the characteristics of propagation of Rayleigh Wave in soils, based on Elasto Dynamics's theory.The main ideas of this paper can be summarized as follows:(1) Based on coordinate transformation algorithm,a systematic study on dynamic analysis of half-space soil is performed using Fast Fourier Transform(FFT).The results suggested that the effects of the different speeds of the moving loads and the different loading frequency to the dynamic response of soils have been compared and analyzed. The numerical results are compared with those from the existed documents,which verifies the accuracy and efficiency of the spectral element method given in the paper.(2) Based on Elasto Dynamics's theory, this paper analyze the dynamic analysis of layered soils under moving load.Considering the absolutely uninterrupted interlayer state, the effects of different parameters to the dynamic response of soils have been compared and analyzed: first,as to load parameters,the different speeds of the moving loads and the different loading frequency have been considered;second,as to soil models,the different value of the damping parameters,the different depth of soils and the different elastic moduli of soils have been compared.Through these comparison and analyses,some useful proposals have been suggested,which have much practical significance in road engineering and railway engineering.(3) In order to analysis the Rayleigh Wave's property of different model including half-space soil and layered soils,this paper deduced the expression of the characteristics equation of Rayleigh Wave based on the principle of spectral element. Some practical examples can reflect that the disadvantages of the traditional transfer matrix method and the stiffness matrix method can be overcome.In the end,the content of this paper has been ummarized and some problems,which need further study, have been proposed.