标题：Micro-analysis of sub-ballast direct shearing under normal stress
作者：Guoqing, Jing ;Guixian, Liu ;Yang, Xu ;Jiong, Zhang
作者机构：[Guoqing, Jing ;Guixian, Liu ;Yang, Xu ] Civil Engineering School, Beijing JiaoTong University, Beijing, P.R. 100044, China;[Jiong, Zhang ] School of 更多
来源：Computer Modelling and New Technologies
摘要：This paper presents sub-ballast material analysis through Discrete Element Modelling (DEM) method to investigate its direct shear tests behaviour. Laboratory direct shear box tests were conducted on granite sub-ballast aggregate samples under different normal stress. The size, particle size distribution (PSD) properties of the sub-ballast particles were considered in the analysis. Simultaneously, direct shear box DEM simulations were conducted for different normal stress conditions, the sub-ballast micro-characteristics of the direct shearing tests were analysed, the contact force, displacement etc. index variation interrelated with the direct shearing tests conditions. The shear stress-shear displacement curves predicted from the DEM simulations were in reasonably good agreement with laboratory test results at all normal stress levels that shear box tests were conducted at. The results of discrete element modelling and tests of direct shear test for sub-ballast were presented. Such analysis may provide useful information on the understanding of sub-ballast with discrete element models. The micro-analysis and the direct shear tests were of importance to investigate the sub-ballast behaviour under the track system.