加筋路基边坡筋土界面应变软化模型研究

Study on Reinforced Soil Interface Strain Softening Model in Reinforced Subgrade Slope

土与土工合成材料之间相互作用机理的复杂性,使得通用计算程序中简单的接触面单元模型不能满足模拟界面非连续性变形的要求。为了模拟界面的位移-软化特性,通过ABAQUS中FRIC用户子程序二次开发平台纳入了界面非线性应变-软化本构模型。建立的直剪试验数值模拟验证了界面模型的有效性和可靠性。数值试验与理论计算结果非常吻合,表明该界面模型可以模拟土与土工合成材料界面的非线性位移软化行为。非线性应变软化界面模型在ABAQUS中开发的方法和实现过程为其他界面模型的开发提供了参考。

Due to the complexity of soil-geosynthetics interaction,simple constitutive models typically used for interface elements in general computer programs cannot satisfy the requirements of discontinuous deformation analysis of structures that contain different interfaces.In order to simulate the strain-softening characteristics of interfaces,a nonlinear strain-softening interface constitutive model was incorporated into ABAQUS code through a user subroutine of FRIC.A numerical simulation of a direct shear test for geosynthetic interfaces was conducted to verify that the interface model was implemented correctly.Results of the numerical tests show good agreement with the results obtained from theoretical calculations,indicating that the model incorporated into ABAQUS can simulate the nonlinear strain-softening behavior of interfaces involving geosynthetic materials.The results confirmed the validity and reliability of the improved interface model.The procedure and method of implementing an interface constitutive model into a commercial computer program also provide a reference for implementation of a new interface constitutive model in ABAQUS.