考虑颗粒抗转动的砂土双轴试验离散元模拟  

Discrete element simulation of biaxial compression test considering rolling resistance

作　　者：蒋明镜[1,2] 李秀梅[1,2] 孙渝刚[1,2] 胡海军[1,2] 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土力学》2009年第S2期514-517,共4页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.50679057);国家自然科学基金项目(No.40534021)

摘　　要：颗粒间抗转动作用是影响砂土力学行为的重要因素。将蒋明镜等(2005年)提出的考虑颗粒抗转动作用的颗粒接触模型植入PFC2D中,对砂土双轴试验进行了模拟,研究颗粒抗转动作用对砂土力学行为的影响。研究显示:颗粒抗转动对砂土力学行为影响显著。抗转作用越强,砂土强度越高;抗转系数为0.4时,松砂亦出现软化及剪胀现象。抗转动作用对孔隙比及配位数变化趋势影响也很显著。A novel contact model incorporating rolling resistance proposed by Jiang et al.(2005)is implemented into PFC2D.The behavior of sand with rolling resistance is simulated by PFC2D with the novel contact model.Based on the biaxial compression test,the effect of rolling resistance on the behavior of sand is studied.And some microscopic parameters including the average coordination number and force chains are studied too.The results show that the rolling resistant is very important in controlling the peak strength and leading to extensive dilatancy of sand.With rolling resistance the loose sand can also have a strain-softening and shear-dilantant behavior.With the increasing of the rolling resistance,the average coordination number reduces.

关 键 词：砂土 离散元法 抗转动 双轴试验 

分 类 号：TU411.3[建筑科学—岩土工程]