PCC+AC (Portland Cement Concrete and Asphalt Concrete) composite pavement has been more and more widely applied in road engineering, especially in the sections of tollgate. However, due to the special traffic load condition in tollgate and the differences of material properties between PCC and AC, the composite pavement is prone to serious rutting problems. In order to analyze the potential rutting and its structural affecting factors of PCC+AC composite pavement, 3D finite element models were established under the combined action of vertical and horizontal load in tollgate. Main considerations are asphalt layer thickness and modulus ratio. The results show that for the PCC+AC composite pavement of tollgate, the rutting depth increases with the increase of asphalt surface thickness. Through the study of deformation ratio of PCC+AC composite pavement, the change rule and economy of the bottom tensile stress of the base course, it is determined that the reasonable overlay thickness of the asphalt pavements for the reconstruction and expansion of the rigid base is 22-24cm.

CICTP