单调荷载下砂土变形过程数值模拟及细观机制研究  

Numerical simulation of sand deformation under monotonic loading and mesomechanical analysis

作　　者：刘洋[1] 吴顺川[1] 周健[2] 

机构地区：[1]北京科技大学土木与环境工程学院土木系,北京100083 [2]同济大学地下建筑与工程系,上海200092

出　　处：《岩土力学》2008年第12期3199-3204,3216,共7页Rock and Soil Mechanics

基　　金：教育部新世纪优秀人才支持计划资助项目(No.NCET-06-0084);国家自然科学基金资助项目(No.50808016)

摘　　要：采用离散单元法的颗粒流理论,模拟了松砂和密砂在单调荷载作用下的变形过程,研究了砂土渐进破坏过程中的宏观力学行为和细观组构参量的演化规律。采用PFC的FISH语言开发了细观组构统计程序,通过记录加载不同时刻试样的细观参量,如配位数、接触法向分布、粒间法向接触力、切向接触力等的演化,分析了砂土变形过程中细观组构变化与宏观力学响应之间的内在联系。应用表征上述量的组构参数研究了砂土的诱发各向异性,探讨了松砂剪缩、密砂剪胀的细观机制。研究成果对于揭示砂土变形的细观机制以及建立砂土的细观力学模型具有重要意义。Based on the biaxial test by PFC^2D, the behavior of sand with different densities under monotonic loading is simulated by discrete element method. The evolution law of macromechanism behaviors and mesofabric parameters is studied during sand soil progressive failure process. A statistic code is developed by fish language in PFC to study the evolution of microscopic fabric parameters including coordination number distribution, contact normal, normal contact force and shear contact force. The relationship between mesoparameters and macromechanical response can be achieved. The mechanism of induced anisotropy, compaction of loose sand and dilatancy of dense sand are discussed by using the mesofabric parameters. The results are valuable for the studying of mesomechanism of sand deformation and the construction of mesomodel for sand.

关 键 词：砂土 细观组构 颗粒流 诱发各向异性 

分 类 号：TU441[建筑科学—岩土工程]