The Vibration Response Of Bedding Structure Of Track In Frozen Soil Region

Frozen soil is sensitive to climate change,and small climate change will have a big impact on its status and physical parameters.In recent years,the damage to the original state of permafrost subgrade construction leads adverse geological disasters of permafrost to be aggravating and cost of late maintenance subgrade to be incresing,so that researching the dynamic response of frozen subgrade-foundation under dynamic load and analysising the settlement of frozen soil and attenuation regularity of frozen soil under different working conditions have important guiding significance for the design and construction of the railway and highway in permafrost regions.Firstly,based on the vehicle-track coupling dynamics theory,this paper establish vehicle-track coupling dynamics equations by the dynamic analysis of vehicle-track coupling,and get the dynamic wheel-rail force of rail through the Matlab programming.Secondly,using ANSYS finite element software establishes a track-subgrade-foundation model and calculates the vibration responses of track,subgrade and foundation.Finally,compared with the different condition,such as different train speed,frozen soil under the condition of different temperature,embankmentheigh,analysis the acceleration and displacement response of track bed,subgrade and foundation and the attenuation of the lateral and depth of the line.The main conclusions are as follows:(1)With the increase of the train speed,the acceleration and displacement response become gradually larger;in the attenuation trend,with the increase of the train speed,the attenuation speed is faster in both the horizontal and vertical directions;compared with acceleration,the increase of velocity is not sensitive to the attenuation velocity of displacement(2)Under different temperature conditions,on the track bed,subgrade and foundation,the acceleration and displacement increase obviously at 0?;among-5??-7??-10?,with the decrease of temperature,the peak value of acceleration and displacement decreases gradually,but the change is not large.Under different temperature conditions,with the decrease of temperature,the attenuation speed is slower in both the horizontal and vertical directions;when the temperature is below-5?,the change of attenuation rate begins to decrease.(3)Numerical simulation of train under dynamic loadingshows that subgrade structure contributes greatly to the attenuation of vibration;With the increase of subgrade height,the attenuation rate of acceleration and displacement response in transverse and depth directions is smaller,It shows that the attenuation of vibration response of silty clay foundation is more obvious than that of filling subgrade.