级配和密实度对粗粒土三轴试验影响离散元分析  

DEM Analysis on Impact of Gradation and Compactness on Coarse-Grained Soil in Tri-axial Test

作　　者：朱俊高[1,2] 郭万里[1,2] 徐佳成[3] 褚福永[4] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学岩土工程科学研究所,江苏南京210098 [3]中国国际工程咨询公司,北京100048 [4]丽水学院土木工程学系,丽水浙江323000

出　　处：《重庆交通大学学报（自然科学版）》2017年第6期70-74,共5页Journal of Chongqing Jiaotong University(Natural Science)

基　　金：国家自然科学基金项目(51479052);江苏省六大人才高峰项目(JZ-011);浙江省自然科学基金项目(LY14E080004)

摘　　要：利用4种级配的颗粒生成了不同的三轴试样,并分别对各试样在相同相对密实度和相同孔隙率下进行了三轴剪切的模拟和分析,同时提出了利用实际土体的相对密实度D_r换算得到模拟时孔隙率的方法。结果表明:PFC^(3D)模拟松填法和振动台法分别求得模拟土体的最大、最小孔隙率,再根据相对密实度D_r换算得到模拟时孔隙率的方法是可行的;相对密实度D_r是影响粗粒土力学行为的重要因素,剪切峰值强度(σ_1-σ_3)和内摩擦角φ与D_r成正相关,颗粒级配不同的试样,处于相同的初始孔隙率时,相对密实度不同,则三轴剪切性状及内摩擦角呈现出显著差异;而颗粒级配不同的试样处于相同的相对密实度时,三轴剪切性状相差不大。The coarse-grained soil with four kinds of gradations generated different tri-axial samples.The tri-axial shear simulation and analysis was carried out on the above samples respectively in the same relative density and porosity.At the same time,a method to get the simulation of porosity through the conversion of the actual soil relative density Dr was proposed.The results show that：the maximum and minimum porosity of the simulated soil are respectively solved by the PFC3D loose filling method and vibration table method.And a method to get the simulation of porosity through the conversion of the actual soil relative density Dr is feasible.The relative density Dr is an important factor influencing the mechanical properties of the coarse-grained soil,and it is positively correlated with the shear peak strength （σ1-σ3） and the internal friction angle φ of soil.For samples with different gradations,when they are in the same initial porosity,the relative density will differ;so the tri-axial shear properties and the internal friction angle will show significant differences;on the opposite,when they are in the same relative density,the tri-axial shear properties have little difference.

关 键 词：岩土工程 粗粒料 三轴试验 PFC3D 级配 

分 类 号：TU43[建筑科学—岩土工程]