Stress of Pavement Structure with Surface Cracking under Non-uniform Moving Load

Adopted the moving load model and the non-uniform tire load mode,based on the tire footprint,a 3D finite element model of pavement structure was established to analyse the stress response of the pavement structure with either longitudinal cracks or transverse cracks under non-uniform moving load to search for the mechanism of surface-initiated cracking under moving load.Time difference was combined with space analysis in 3D finite element with the crack tip meshing densely during the calculation,and the stress intensity factor(SIF) of the crack tip was calculated by displacement method.It can be drawn the conclusion that(1) with the load moving,the value of the SIF KⅠ at the position of crack tip right under the moving load reaches maximum;(2) the point of longitudinal cracks right below the moving load gets the larger value of KI than that below static load,indicating the moving traffic load can speed up the development of the cracks;(3) to transverse cracks,the load has stronger effect on the cracks when the load get close to the cracks,but the moving load has stronger effect on the longitudinal cracks than the transverse cracks.Therefore,more attention must be paid for precaution and maintenance of surface longitudinal cracks in pavement structure.