基于结构力学响应的水泥路面碎石化破碎程度确定

Fragmentation degree determination of cement pavement based on structural mechanical response

采用ABAQUS进行计算,以荷载中线及荷载边缘下部路面结构层的径向应力、剪应力、土基顶面压应变、加铺层表面弯沉等为评价指标,分析在荷载作用下碎石化层模量、沥青层模量及厚度的变化对加铺层结构稳定性的影响及结构层内部受力状态。结果表明,碎石化层的模量对沥青加铺层的层底拉应力和弯沉值有显著影响。当碎石化层的模量较小时,沥青加铺层的层底拉应力、竖向剪应力及土基顶面压应变均较大;当碎石化层弹性模量小于1000MPa时,计算弯沉值随碎石化模量的增大而减小,当碎石化模量大于1000MPa时,碎石化层弹性模量对计算弯沉值的影响较小。鉴于碎石化层的弹性模量与破碎程度密切相关,建议旧水泥路面碎石化层弹性模量控制在800~1000MPa。

This paper uses ABAQUS for calculation,with the radial stress,shear stress,compressive strain on the top surface of the soil foundation,and surface deflection of the overlay as evaluation indicators.It analyzes the impact of changes in the modulus of crushed stone layer,modulus and thickness of asphalt layer on the stability of the overlay structure under load,as well as the internal stress state of the structural layer.The results show that the modulus of crushed stone layer has a significant impact on the bottom tensile stress and deflection of asphalt overlay.When the modulus of crushed layer is small,the tensile stress,vertical shear stress,and compressive strain of the top surface of the asphalt overlay are all large.When the elastic modulus of crushed stone layer is below 1000MPa,increasing its modulus has a significant contribution to reducing the calculated deflection.When the crushed stone modulus is above 1000MPa,increasing its modulus has little contribution to reducing the deflection.Considering that the elastic modulus of crushed stone layer is closely related to the degree of fragmentation,it is recommended to control the elastic modulus of crushed stone layer on the old cement pavement between 800MPa and 1000MPa.