Abstract: Utilizing the finite element method, the mechanical responses of base cracking in semi-rigid pavement are analyzed. The research believed that the road surface deflection cannot accurately reflect the destruction condition of the semi-rigid pavement structure. After the crosswise cracking of the base, the bituminous pavement destruction is mainly controlled by the shearing stress. The longitudinal tensile stresses, shearing stress of the two sides of the base cracking rapidly increase; and cause the two sides of the cross-oint base to form the serious destruction. It has left behind the serious hidden danger, which will form the water damage to escape spatially in the board bottom of the cross joint place, then cause cracking and settlement of the surface layer along the two sides of the cross-joint. In the base, the longitudinal cracking of each level, not only causes the cracking further to expand to the upper formation, then causes the overall longitudinal cracking of the pavement structure, but also creates the condition for the crosswise weary fracture. When the size of the base tectonic plate is bigger than the critical dimension 1 m×1 m, the structure still belongs to the semi-rigid pavement. When the size of the base tectonic plate is smaller than this value, the stress and strain conditions of the pavement structure tend to belong in the flexible pavement.

Key words: semi-rigid pavement, crack, deflection, stress