半刚性路面基层开裂的力学响应

采用有限元的方法，研究了半刚性路面基层开裂后路面结构的力学响应。研究认为，路表弯沉不能准确反映半刚性路面结构的破坏状态。基层横向开裂后，沥青面层的破坏主要受控于剪应力；基层底部裂缝两侧的纵向拉应力、剪应力迅速增加，将使横缝底部两侧形成严重破坏，这为水损坏后基层形成横缝处板底脱空，进而引起面层沿横缝两侧的开裂、沉陷留下了严重隐患。基层中各层的纵向开裂，不仅使得裂缝向上层进一步扩展，导致路面结构的总体纵向开裂，而且为横向的疲劳开裂创造了条件。当基层板块大于1 m×1 m的临界尺寸时，结构仍属于半刚性路面，当基层板块的尺寸小于此值时，路面结构的应力应变状态趋向于柔性路面。

Mechanical responses of base cracking in semi-rigid pavement

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.