摘要
以软土平均接触面积率Rca作为评价标准,结合常规三轴固结排水试验以及电镜扫描试验,对排水剪切状态下软黏土微观接触面积演化规律进行定量分析。研究结果表明:在排水剪切过程中,软土微观颗粒会逐渐凝聚形成大尺寸团粒,孔隙尺寸显著减小,结构变密实。这一过程中微观接触面积显著增加,平均接触面积率Rca可达20%甚至30%左右,Rca在剪切过程中随孔隙率n均匀变化,二者呈线性关系;在弹塑性变形阶段,土体变形模量Et与平均接触面积率Rca之间也近似呈线性关系,可见采用微观物理参数来定量表征软土宏观力学性能是可行的。
Microscopic assessment index Rca(soft clay average contact area ratio)was introduced to quantitatively investigate the variation of soft soil microscopic contact area during shear process with drainage,in combination with the conventional triaxial test and SEM test.The results show that microparticles of soft soil gradually coagulate to form large-sized aggregates during shear process,while the pore size is significantly reduced and the soil becomes denser.During this process,the microscopic contact area also increases significantly with the increase of deformation,and the average contact area ratio Rca reaches 20%or even 30%.As deformation develops,Rca varies uniformly with porosity n,and a good linear relationship is observed between them.Furthermore,an approximate linear relationship between average contact area ratio Rca and tangential modulus Et is presented as elastoplastic deformation occurs.Therefore,it is feasible to quantitatively characterize the macroscopic mechanical properties of soft soil using microscopic physical parameters.
作者
徐日庆
蒋佳琪
董梅
徐丽阳
XU Riqing;JIANG Jiaqi;DONG Mei;XU Liyang(Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China;Engineering Research Center of Urban Underground Development of Zhejiang Province,Hangzhou 310058,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第2期411-419,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(41672264)
浙江省重点研发计划项目(2019C03103)~~
关键词
软土
微观接触面积
三轴试验
SEM图像
宏观力学性能
soft soil
microscopic contact area
triaxial test
SEM image
macroscopic mechanical property
