考虑软土软化特性的软基加筋道路动力响应

为了研究交通荷载作用下考虑软土软化效应的低路堤软基加筋道路的动力响应问题,以室内动三轴试验为基础,研究了循环荷载作用下初始偏应力以及荷载作用次数对软土刚度软化的影响,通过回归分析得到了软土在循环荷载作用下刚度软化的经验公式;然后编制了用户子程序将经验公式导入有限元分析软件ABAQUS中,采用ABAQUS对软基加筋与不加筋道路在交通荷载作用下的动力特性进行对比分析.结果表明,软土的软化特性对软基加筋道路的动力响应有重要影响.同时,加筋可以提高道路的整体强度,使土体应力均化,约束土体的水平变形,减少道路的整体沉降,并降低道路的不均匀沉降.

Dynamic response of reinforced pavement considering softening of clay

In order to study the dynamic response of reinforced pavement on soft clay under traffic loading,cyclic triaxial tests were conducted to investigate the effects of initial deviator stress and load cycles on the softening behavior of clay.The empirical equation for softening of clay was proposed by using regression analysis method.Then the equation was imported into ABAQUS through compiled subroutine.Contact interface elements were used between geogrid and soil.Dynamic response of unreinforced and geogrid reinforced pavement was studied by FEM program ABAQUS in order to investigate the reinforcement effect.FEA results indicate that softening behavior of clay has important effect on the performance of reinforced pavement.Geogrid reinforcement can provide lateral confinement at the bottom of the base layer by improving the interface shear resistance,and improve the stress distribution on subgrade layer.The geogrid reinforcement can reduce the surface deformation and nonuniform settlement.