饱水格栅加筋土挡墙结构特性数值分析

Numerical analysis on structural characteristics of saturated geogrid reinforced soil retaining wall

格栅加筋土挡墙由面板、格栅和土体组成。本文根据加筋土挡墙筋土相互作用的特点,将格栅与其上下表面一定厚度的土层视为具有应变相容条件的筋土复合材料。引入饱和多孔介质模型来模拟土体和筋土复合材料,由此建立了饱水格栅加筋土挡墙结构特性数值分析的数学模型。采用Galerkin加权残值法推导出有限元平衡方程,求解该方程,得到饱水格栅加筋土挡墙的动力响应。算例分析表明,格栅加筋土挡墙在饱水状态下的变形和塑性区分布有明显增大,且呈现外倾变形特征,挡墙的承载力也有较大幅度的降低。

The geogrid reinforced soil retaining wall is composed of panel, geogrid and soil. According to the characteristics of the interaction between reinforcement and soil, the geogrid and its surrounding soils with definite thickness were regarded as a kind of composite material with strain-consistency condition. A saturated porous media model was introduced to simulate the soil and reinforcement-soil composite material and a mathematical model for numerical analysis of structural characteristics of water-saturated geogrid reinforced soil retaining wall was established. Subsequently, the penalty finite element equations were deduced from the standard Galerkin procedure. By solving theses equations the dynamic response of the retaining wall can be obtained. The calculation results of examples show that deformation and plastic zone of this kind of retaining wall is larger than that under the condition of unsaturated. The retaining wall exhibits a tendency of inclining to outside and the bearing capacity is greatly reduced.