Study On Dynamic Testing Technology Of Pavement Bearing Capacity Under Moving Vehile Load

Highway as the most important infrastructure in transportation,its health status directly affects the normal passage of the vehicle.At present,testing of pavement bearing capacity is mainly using Benkelman beam,automatic deflecting instrument and the falling weight deflectometer.The Benkelman beam is measured by the static deflection of the road,which can not reflect the real working condition of the pavement structure,and the test efficiency is low.The automatic deflection test technology is expensive,the accuracy of test results is questionable.The falling weight deflectometer(FWD)by applying dynamic load to simulate the driving single wheel load on the pavement,by simulation loading mode to test the pavement bearing capacity,can not represent the real driving load,and the parking sampling,has certain security risk in the testing process.Therefore,how to carry out the scientific and effective detection of pavement bearing capacity,has been a technical problem to be resolved for the highway management departments.Based on National Supercomputing Center(NSCC)in Tianjin and the strong support of Anshi Asia Pacific Company,through a large number of finite element simulation and theoretical analysis,proposed under normal traffic conditions to dynamic testing theory and technology of pavement bearing capacity.Specific research work and the main contents are as follows:1.Because of the influence of pavement roughness and other factors,so that the vehicle in the normal traffic situation,will produce dynamic random force on pavement structure,so as to establish the vehicle road coupling vibration differential equation,combined with the vehicle model and loading situation,established analysis model of pavement dynamic action in the process of vehicle passing.2.Based on the large finite element software ANSYS to establish the three-dimensional finite element model of pavement structure,and the accuracy of finite element model is verified by using the analytical solution.According to the vibration characteristic of pavement structure under vehicle load,the application of dynamic modulus in pavement evaluation thoughts is discussed,and the arrangement of sensors on the spot suggestions are given.3.Through a large number of finite element simulation calculations,the control variable method is used to study the dynamic displacement and dynamic strain variation of the testarea.The key control parameters in the process of inversion of the pavement structure strength are determined and established.And the mathematical model is established between the dynamic displacement and dynamic strain peak value of the test area and the main influencing factors,Provide the basis for pavement bearing capacity programming calculation.4.Nondestructive testing of bearing capacity of the pavement in the normal vehicle traffic conditions,which is a new technology of detection method,the new techniques are applied in Xingtai City,Hebei Province,State Road 107 lines,it proves that the detecting means and theories are feasible and achieve good results.