Cohesionless soil anisotropic mechanical property microcosmic mechanism numerical simulation method

Abstract

The invention provides a soil anisotropic mechanical property research idea and method from the microscopic point of view by developing a horizontal loading program and a micro-mechanical parameter monitoring program through a particle discrete element unit method. The method includes the steps of (1) obtaining stress-strain curves and related mechanical parameters of cohesionless soil according to laboratory tests; (2) establishing a plane biaxial specimen to simulate soil original anisotropy according to micromechanics parameters determined in a particle flow biaxial test in step (1); (3) establishing a plane biaxial specimen to simulate soil stress anisotropy according to the micromechanics parameters determined in the particle flow biaxial test in step (1); (4) comparing and analyzing expression rules of soil original anisotropy and the soil stress anisotropy to obtain the difference and relation between the two kinds of anisotropy and finding out microscopic mechanisms of the production of the two kinds of soil anisotropy. The soil anisotropic mechanical property research idea and method provides a new idea for the cohesionless soil anisotropic mechanical property numerical simulation by using the advantages of the particle flow discrete element method in the research of the particulate material microstructure.

Description

technical field [0001] The invention belongs to the field of rock and soil mechanics research, and is based on the particle flow discrete element method in the research of microstructure and micromechanics mechanism. [0002] The numerical simulation method to explore the microcosmic mechanism of the anisotropy of the macroscopic mechanical properties of the cohesionless soil is based on the advantage of this method. Background technique [0003] On the one hand, in engineering practice, the stress path of the soil is complex and changeable, and there are a large number of anisotropic engineering problems caused by the loading method, such as the stress state caused by the excavation and support of deep and large foundation pits. change of the small principal stress caused by the vacuum preloading method; the change of the small principal stress caused by the vacuum preloading method; the change of the stress state of the internal unit caused by the water storage of the high...

AI Technical Summary

Problems solved by technology

[0003] On the one hand, in engineering practice, the stress path of the soil is complex and changeable, and there are a large number of anisotropic engineering problems caused by the loading method, such as the stress state caused by the excavation and support of deep and large foundation pits. change of the small principal stress caused by the vacuum preloading method; the change of the small principal stress caused by the vacuum preloading method; the change of the stress state of the internal unit caused by the water storage of the high earth-rock dam. The calculation method of heterogeneity is not perfect; on the other hand, the existing indoor test methods are limited, although the indoor true triaxial test can also realize loading from different directions, but considering the high cost of the indoor test, the repeatability is difficult , and more importantly, the indoor true triaxial test cannot obtain the macroscopic anisotropic mechanical properties of the soil, and at the same time give the change law of the microstructure and micromechanical mechanism of the granular material such as cohesionless soil, and cannot find out the macroscopic anisotropic mechanical properties of the soil. relationship with the micro

[0004] Although many experts and scholars have simulated and studied the mechanical properties of soil through the particle flow discrete element method, they rarely focus on the research of soil stress anisotropy, and there are a few existing studies on soil stress anisotropy. The research on volume anisotropy mostly cuts samples according to different angles to the sample deposition surface (for example, 0° represents vertical, 90° represents horizontal), which leads to changes in the particle units that make up the sample after cutting. The compositions of samples loaded from different directions are not exactly the same, and these studies are mainly aimed at the simulation of native anisotropy

Images