Study On The Influence Of Train Load On Railway Subgrade In The Yellow River Sedimentary Region

In recent years,with the vigorous development of China’s infrastructure industry,the construction of railways and the development and utilization of underground space are also continuing.The combination of the two forms of engineering is not uncommon.At the same time,the problems faced and the lack of security guarantees have become increasingly prominent.Silt and silt are widely distributed in the impingement plain area of the Yellow River.The filling capacity of the soil subgrade filling and foundation is not enough.It is liable to liquefy under the action of vibration,and many unpredictable problems will occur under the repeated load of the train.There will also be a lot of settlement problems when the shield underpasses the foundation under such geological conditions when constructing the subway.In this paper,a railway is taken as the engineering background in the Yellow River sedimentary area,and there is subway shield construction under the railway.The influence of the railway dynamic load on the roadbed is studied.The distribution law of railway roadbed dynamic stress caused by the vehicle load under this background is analyzed.In order to study the influence of train load on the subgrade,the additional stress in the soil under the upper load is theoretically analyzed,and the Boussinesq analytical solution and the Framan solution derived from the elastic theory are introduced to further explain the moving load.Distribution and calculation of foundation dynamic stress.The relevant theories of soil mechanics are analyzed,including some yield criteria and soil model.ABAQUS finite element software is used to establish a corresponding numerical analysis model to study the dynamic characteristics of subgrade dynamic stress,the results show that the dynamic stress caused by the moving load of the train is random,complex and repetitive,and it mainly presents as vertical compressive stress.The dynamic stress distribution in the roadbed changes dynamically;the vertical dynamic stress gradually decreases with the increase of the roadbed depth,and the curve will tend to relax after reaching a certain depth;the lateral distribution curve of the dynamic stress in the roadbed increases with depth and its peak value From 2 to 1,and gradually reduced to a uniform distribution at the bottom of the bed;when the front and rear wheels of the same bogie pass in the direction of the rail,there is an additive effect of the vertical dynamic stress below the bottom of the track plate.In order to verify the accuracy of the model,on-site stress testing and comparative analysis were further conducted.Finally,the design control and reinforcement methods of the railway subgrade are discussed by explaining the deformation composition of the railway subgrade,which provides a reference for areas with similar geological conditions and engineering background.