Experimental Study On The Railway And Subgrade Under Special Load

With the integration of Chinese economic construction and national defense development,more military large-scale equipments have shifted from the highway maneuver to the railway maneuver.This kind of railway trains in working has the characteristics of large axle load and short wheelbase,which posed a new challenge to the mechanical property(force performance)of railway track subgrade.In this paper,the mechanical property(force performance and load capacity)of railway track subgrade under special load are studied by full-scale model test and ANSYS simulation,and the experimental data and simulation results are compared,which offers better engineering significance and theoretical value.Firstly,in this paper the research methods of the track subgrade mechanical properties are systematically analyzed.The track subgrade full-scale test scheme under the special load is designed.The 50m standard gauge straight line Grade I heavy test section is constructed.The strain gauge,displacement meter,accelerometer,earth pressure box,sink plate and other components are buried.The calibration method of earth pressure box and strain gauge bridge are discussed.The calibration tool suitable for the test of the earth pressure box are developed,which meets the requirements of spot testing of the track subgrade under special load.Secondly,based on the finite element software ANSYS,the track subgrade model under the special load is established.The sharing ratio of the sleeper under the uniaxial action is calculated,and the dynamic stress attenuation law of the subgrade is analyzed.Combined with the calculation results of the railway track strength checking method,the correctness of the model is verified.Finally,aiming at the full-scale model test of the railway track subgrade under the special load,the wheel-rail force and displacement,the vertical displacement on the top of subgrade and the each layer stress of the ballasted bed and foundation bed are analyzed and verified by consulting related specifications.Compared with the simulation data obtained by large finite element software ANSYS.The most unfavorable position,mechanical properties and influence factors of railway track subgrade under special load are further studied by simulation model.