摘要
为了研究粗粒土填料在荷载及降雨入渗作用下的力学特性变化规律,采用Autotriax全自动三轴试验系统对粗粒土填料进行静三轴试验。基于试验所得力学参数,结合颗粒流软件PFC3D对试验进行细观模拟研究,通过自编程序引入接触黏结模型,对比分析粗粒土在不同围压、含水率和压实度下的力学特性及变形规律。研究结果表明:运用PFC3D软件进行静三轴试验模拟,通过数值分析得到的应力-应变曲线变化趋势与室内试验结果变化趋势较一致;试件的体应变在高围压时表现为整体剪缩,低围压时表现为先剪缩后剪胀;随着应变增加,黏结断裂点快速发展,试件由单一的中间部位挤压呈现出多个潜在的剪切面,且颗粒间的黏结破坏具有滞后性,试件内部演变规律与应力-应变曲线变化规律相一致。
In order to study the variation of mechanical properties of coarse-grained soil under load and rainfall infiltration,Autotriax fully automatic triaxial test system was used to conduct static triaxial test on coarse-grained soil filler.Based on the parameter of test,the mesoscopic simulation of triaxial test was carried out with particle flow software PFC3 D.Contact bond model was introduced by self-programming,the mechanical properties and variation of coarse-grained soil under different confining pressures,moisture contents and degrees of compaction were compared and analyzed.The results show that using the PFC3 Dsoftware for simulation of static triaxial,the trend of stress-strain curves are consistent with the experimental curves.The body strain of specimens appear shear contraction under high confining pressure,and display shear contraction first and then dilatation under low confining pressure.As the strain increases,the bond fracture point develops rapidly in the sample.The sample is extruded from a single intermediate part to multiple potential shear planes,and the bond failure between the particles has hysteresis,and the law of internal evolution is consistent with the law of variation of stress-strain curve.
作者
何忠明
黄超
刘雅欣
范电华
杨煜
HE Zhongming;HUANG Chao;LIU Yaxin;FAN Dianhua;YANG Yu(School of Traffic and Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China;Engineering Research Center of Catastrophic Prophylaxis and Treatment of Road&Traffic Safety of Ministry of Education,Changsha University of Science&Technology,Changsha 410114,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第4期1116-1124,共9页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51978084,51678073)
湖南省自然科学基金资助项目(2015JJ6004)。
关键词
道路工程
力学特性
静荷载
粗粒土
离散元
road engineering
mechanical properties
static load
coarse soil
discrete element
