Reliability Analysis For Asphalt Pavement Under Traffic Load

Asphalt pavement is more and more widely used in the highway, which has become one of the main structures of highway in China. But then, the phenomenon of seriously overload vehicles is more and more, that lead to asphalt pavement structure early fatigue in the design life. For the above problem, the paper on the asphalt pavement structure as the research object, simplify the model of pavement structure and establish the load stress of asphalt pavement structure of3D finite element model using ANSYS software. Establish the functions on deflection value index and every pavement structure layer stress’s considering the random variables of traffic parameters with pavement structure parameters, and further analysis vehicle loads and accumulative equivalent axles on reliability influence taking Liaoning province highway traffic volume data as example. Finally, summarize the asphalt pavement structure displacement, dynamic stress, dynamic strain, shear stress response on traffic load, thinking about the variation law of pavement structure maximum mechanics in load and speed influence.Result are as follows:(1) The reliability on the vehicle load’s sensitivity is maximum,which derived from various layers of asphalt pavement structure deflection functions as the bottom of layers stress functions;(2) Asphalt pavement structure reliability as the road surface deflection, pavement and subgrade bottom tensile stress index decreased rapidly with increasing of vehicle load stress and the accumulative equivalent axle;(3)Under the action of traffic load, on the top of asphalt pavement layer produce maximum vertical displacement, the largest vertical compressive stress. The maximum horizontal tensile stress and the transverse tensile stress consist in the subbase and subgrade combining part.The maximum shear stress is at the bottom of asphalt pavement surface layer.Asphalt pavement structure of alternating-compressive and tensile strain variation is the main cause for the reflective crack fatigue with slip of asphalt pavement structure(4) Vehicle load and speed will have varying degrees of impact on max vertical displacement,max dynamic stress,max dynamic strain.