粒料类基层材料非线性特征对应变响应的影响

Influence of nonlinear characteristics of granular base material on strain response

为了分析粒料类基层材料非线性特征对应变响应的影响、提高分析的准确性,采用密实级配、设计级配、连续级配3种类型的粒料类材料,开发轮胎移动载荷的DLOAD子程序以及材料非线性的UMAT子程序,与基层材料线性时的应变响应分析比较。结果表明:基层材料非线性特征对面层底部、土基顶部的应变响应要大于线性时的应变响应。连续级配材料非线性对路面应变响应影响最大,面层底部的横向拉应变、纵向拉应变、竖向压应变比线性材料分别增大了44%、46%、29%。但3种粒料类材料非线性特征对土基顶部压应变的影响并不明显,说明基层材料非线性对土基顶部压应变的影响有限。

In order to analyze the nonlinear strain response of granular base material and improve the accuracy of analysis,three types(dense grading,design grading,and continuous grading)of pellet materials were used.The DLOAD subroutine for tire moving loads and the UMAT subroutine for material nonlinearity were developed,which were compared with the strain response analysis of the linear base material.The results show that the strain response of the nonlinear characteristics of the base material to the bottom of the surface layer and the top of the subgrde are greater than the strain response of the linear material.The nonlinearity of the continuous grading material has the largest response to the pavement strain.The transverse tensile strain,longitudinal tensile strain and vertical compressive strain at the bottom of the surface layer are 44%,46%,29%higher than those of the linear material respectively.However,the nonlinearity of the three types of granular materials is not obvious to the compressive strain at the top of the subgrade,which indicates that the nonlinearity of the base material has a limited influence on the compressive strain of the subgrade.