Macro-micro numerical analysis of granular materials considering principal stress rotation based on DEM simulation of dynamic hollow cylinder test

Abstract

The granular materials were subjected to the principal stress rotation effect induced by traffic loads, wave loads, and earthquake loads in geotechnical engineering practice. In order to reveal the influence of principal stress rotation on the macro-micro dynamic characteristics, this study proposed a numerical simulation method modeling physical dynamic hollow cylinder tests. Taking the dynamic stress state induced by traffic loading as an example, the numerical test model of the dynamic hollow cylinder was conducted on the subgrade soil, and the influence of principal stress rotation on the macro-micro evolution of dynamic characteristics was analyzed.The results showed that the principal stress rotation accelerated the development of vertical accumulative plastic strain and particle displacement, which aggravated micro-structure destruction of granular material. Moreover, the increase of confining stress declined the variations of normal contact numbers in each direction, which resisted the shear stress induced by principal stress rotation. This study provided a novel method to investigate the macro-micro dynamic characteristics of granular materials subjected to principal stress rotation, which made up for the inability of physical hollow cylinder tests to study microscopic evolution.