土工格栅加筋土挡土墙设计参数的弹塑性有限元研究

Elasto-plastic finite element study for parameters of geogrid-reinforced soil retaining wall

土工格栅加筋土挡土墙在水利、交通及城建等领域的应用越来越广泛。在模拟日本PWRI原型实验墙的基础上 ,应用弹塑性有限元法研究该种结构的各项设计参数 ,包括土的性质、加筋长度、加筋层间隔以及土体与面板的相互作用特性等。为了能够准确的描述加筋土挡土墙结构的性状 ,应用先进的弹塑性模型模拟墙体各个组成部分 ,其中土体用可以描述土体压力相关特性的广义塑性模型模拟 ,土工格栅应用弹塑性边界面模型模拟 ,而土与结构的相互作用应用可模拟滑移、脱开以及闭合的有厚度薄层滑移单元模拟。通过有限元分析 。

The application of geogrid-reinforced soil retaining wall in civil engineering has gained great popularity. The test wall by PWRI of Japan is firstly simulated and a series of parametric studies are conducted using elasto-plastic finite element method. The design parameters studied include soil property, reinforcement length, reinforcement spacing, interaction between soil and facing, and so on. To fully capture the behavior of the soil-structure system, a generalized plastic model which can capture the pressure dependency behavior of soil is used to model the backfill and foundation soils, while an elasto-plastic model with bounding surface is employed to simulate the geogrid reinforcement. The soil structure interaction is modeled using thin slip element which can simulate slip, open and close of interfaces. Some conclusions which are helpful to the design of such structures are drawn based on the results of the finite element analyses.