基于结构强度指数的沥青路面裂缝区域承载力特性

Bearing Capacity of Asphalt Pavement Crack Area based on PavementStructural Strength Index (PSSI)

针对广东云罗高速(一期工程)路面结构与典型裂缝,构建了含横向单道裂缝、横向平行裂缝、纵向裂缝与网状裂缝四类裂缝的沥青路面有限元模型,模拟含上述裂缝沥青路面的弯沉盆,计算包括不同裂缝路面模型的路面结构强度指数(PSSI),以评价裂缝区域的结构承载力。结果表明,与无裂缝沥青路面的弯沉相比,含横向单道或平行裂缝路面的弯沉盆各点弯沉均增大,而含纵向或网状裂缝路面距荷载中心900mm以内和以外的各点弯沉分别增大和减小;横向单道裂缝对路面结构承载力的影响范围基本在1m以内,且其宽度对路面PSSI值影响较小;横向平行裂缝对路面结构承载力的影响范围超过2m,且其间距对路面PSSI值有明显影响;纵向裂缝对路面结构承载力较小,其宽度对路面PSSI值影响较小。网状裂缝严重影响路面结构承载力,且其间距对对路面PSSI值有较大影响。

For the pavement structure and typical cracks of Guangdong Yunluo Expressway(Phase I), finite element models of asphalt pavement with four types of cracks, that is, transverse single crack, transverse parallel crack, longitudinal crack and mesh crack have been built. The deflection basins of asphalt pavement with the cracks have been simulated and the corresponding pavement structural strength index(PSSI) have been calculated to evaluate the structural bearing capacity of the crack area. The results have shown that being compared with the deflection of non-cracked asphalt pavement, the deflections in the deflection basin of the pavement with transverse single or parallel cracks increase, while the deflections of pavement with longitudinal or mesh cracks within and outside 900 mm from the load center increase and decrease respectively. The width of transverse single crack has little influence on the PSSI value, and the influence of the transverse single crack on the bearing capacity of pavement structure is basically within 1 m. The transverse parallel crack spacing has obvious influence on the PSSI value, and the influence of the transverse parallel crack on the bearing capacity of pavement structure exceeds 2 m. The width of longitudinal crack has little influence on the PSSI value, and the longitudinal crack has little influence on the bearing capacity of pavement structure. The spacing of mesh cracks has a great influence on the PSSI value, and the mesh cracks seriously affect the structural bearing capacity of the pavement structure.