Influence Factors Analysis for Deflection Measurement Under Traffic Speed Deflectometer on Semi-rigid Asphalt Pavement
The influence of environmental factors,such as temperature,speed and thickness,on the deflection measurement results of traffic speed deflectometer(TSD)was studied.The dynamic deflec-tion analysis model of road was established by COMSOL,and the viscoelastic mechanical properties of asphalt mixture on pavement were characterized by generalized Maxwell model,and the dynamic load of TSD was simulated based on uneven wheel tracks and simple harmonic motion model.The finite el-ement results show that the position of the maximum deflection does not coincide with the loading cen-ter,and the higher the temperature and speed,the more obvious the hysteresis effect is.The deflec-tion basin parameters such as Do and D0-D20 all increase with the increase of temperature and decrease with the increase of moving speed.The increase of pavement thickness and base thickness will reduce the pavement deflection,and the change of base thickness has less influence on pavement deflection.There is a power function relationship between the modulus of surface,base and foundation and the corresponding deflection basin parameters,and the sensitivity of deflection index to the modulus of base is relatively low.Based on 2 401 groups of data obtained by COMSOL parametric scanning,the decision tree algorithm is applied to data mining,and it is found that the influence of surface layer thickness,temperature and speed on TSD measurement results decreases in turn.Taking the simula-tion result of falling weight deflectometer(FWD)as the standard value of deflection detection,a cor-rection model of TSD deflection measurement result is established by using the method of multiple re-gression,which can better correct the influence of pavement thickness,temperature and vehicle speed.
road engineeringfactor analysisfinite element modelingtraffic speed deflectometerbearing capacitydynamic deflection
万方数据
维普
