宏细观结合各向异性砂土的变形特性模拟

Deformation Analysis of Anisotropic Sand Using the Method of Macromeso Incorporation

摘要:

采用宏细观结合的方法建立本构模型对各向异性砂土的变形特性进行模拟.该方法用组构张量定义了一新的各向异性状态变量，考虑该变量对临界状态线的影响建立各向异性模型.引入状态变量后，模型的临界状态面和其他状态面都随各向异性程度的不同而偏离静水压力轴，临界状态方程、硬化准则和剪胀方程都是孔隙比、围压、加载模式和各向异性变量的函数，模型用一组参数可以描述不同围压和密度的砂土各向异性强度变形的力学响应.通过对各向异性砂的强度和含细观特性分析的试验变形模拟，初步验证了模型的合理性.

Abstract:

The deformation analysis of anisotropic sand was conducted by employing the constitutive model with the method of macromeso incorporation. A novel anisotropy state variable which is properly defined in the term of fabric tensor was imployed and a constitutive model for anisotropic sand was proposed with incorporation of the novel anisotropy state into the critical state line（CSL）. After the introduction of the novel anisotropy state, the critical state surface and other state surfaces of the model offset from the axes of hydrostatic pressure for the degree of anisotropy. The CSL, the harding rule and the dilatancy equation of model are the function of void ratio, confining pressure, shearmode and anisotropy variable. One set of model constants can simulate well the strengthdeformation responses of sand under different confining pressures and different densities. The simulation of strength experimental data and the simulation of the deformation results for Toyoura sand contained analysis of microstructure verify the proposed method can be validated from the verification.