描述砂性土宏细观力学关系的数学模型

Mathematical Model Describing the Macro-and Micro-stress Relationship of Sandy Soil

土体等颗粒材料在外力作用下的细观颗粒层面的力学行为决定着其宏观力学性质。然而,目前已经提出的宏细观本构关系多基于对某一种试验数据的唯象总结,缺乏普适性。根据已有的理论研究成果,基于Hertz接触理论,采用颗粒流离散元程序(particle flow code,PFC^(3D))模拟了粒状砂性土的单轴压缩试验,推导了一种更具普适性的描述砂性土宏细观力学关系的数学模型。建立宏观力学响应与细观力学行为的联系,为构建土的本构关系提供了新的途径。

Under the action of external force,the mechanical behavior of granular materials(soil etc.)at the meso-grain level determines their macroscopic mechanical properties.For sandy soil,the macroscopic stress tensor can be determined by the magnitude of contact force and the distance between the centroids of the adjacent particles,and the structural characteristics of the contact force network can be quantified by fabric tensor.However,the macro and meso constitutive relations that have been proposed are mostly based on the phenomenological summary of a certain kind of experimental data,which lacks universality.According to the existed theoretical research results,based on the Hertz contact theory,the particle flow code(PFC^(3D))was used to simulate the uniaxial compression test of granular sandy soil,and a more general mathematical model describing the macro-and meso-mechanical relationship of sandy soil was derived.Establishing the relationship between the macro-mechanical response and the meso-mechanical behavior provides a new way to construct the constitutive law of soil.