不同荷载作用下半刚性沥青路面力学响应规律

基于半刚性基层路面典型结构建立三维力学模型,综合考虑常载、常载+刹车、超载和超载+刹车4种组合荷载,采用双轮最不利矩形接触面形式,并运用特征路径分析方式,数值模拟了路表及深层内力学响应规律。结果表明:刹车对路表弯沉和路基顶面压应变影响较小,超载影响显著;刹车主要对面层弯拉应力影响较大,并使上面层出现较大拉应力,对基层基本无影响,超载使基层弯拉应力增大显著;超载和刹车对剪应力峰值增大明显,特别是刹车使剪应力增大极其显著;在不同荷载作用下,从路表沿深度方向力学响应峰值位置会发生变化,在进行沥青路面结构设计和力学分析时应取相应位置处的值作为力学控制指标。

Mechanical Response Law of Semi-Rigid Asphalt Pavement under Different Loads

Based on typical construction of semi-rigid asphalt pavement,the three-dimensional dynamic model was built up.Considering four combined load types of standard load,standard load+brake,overload,overload+brake,taking the worst two-wheel contact surface pattern of rectangular section,the analysis method of characteristic path and the numerical simulation method were to analyze the mechanical response law of the surface and the deeper part of the road.The results show that the brake has little impact on the road deflection and compressive strain on top layer,but the effect in the condition of overload is significant.Brake has great influence on the flexural stress on the surface course,and the large tensile force appears in the upper layer.But the brake almost have no influence on the base course,overload greatly increase the flexural stress.Peak of shear stress increases significantly in the condition of overload and brake,especially when brake appears.The place where peak of mechanical response appears changes along the depth of the road surface.We shall choose the corresponding peak as the mechanical index when we design the asphalt pavement and do the mechanical analysis.