南阳重塑非饱和膨胀土的变形和含水率变化特性  

Variation characteristics of deformation and water content of remolded unsaturated expansive soils in Nanyang

作　　者：牛庚 孙德安[3] 陈盼[2] 邵龙潭[4] 孔亮[1] 吴迪 缪玉松 陈凡秀[1] NIU Geng;SUN De'an;CHEN Pan;SHAO Longtan;KONG Liang;WU Di;MIAO Yusong;CHEN Fanxiu(School of Science,Qingdao University of Technology,Qingdao 266520,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;School of Mechanics and Engineering,Shanghai University,Shanghai 200444,China;Department of Engineering Mechanics,Dalian University of Technology,Dalian 116085,China)

机构地区：[1]青岛理工大学理学院,山东青岛266520 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [3]上海大学力学与工程科学学院,上海200444 [4]大连理工大学力学系,辽宁大连116085

出　　处：《岩土工程学报》2024年第2期426-435,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(12172187,12072170,52008225);岩土力学与工程国家重点实验室开放基金课题(SKLGME021019)。

摘　　要：为研究水-力作用下非饱和土变形和含水率变化特性,采用非饱和土三轴仪,对非饱和膨胀土开展了吸力平衡、等向固结和三轴剪切试验,实时监测土的变形和含水率变化,综合分析了水-力作用下土的变形和含水率随时间的变化规律,并以“双孔”模型为基础框架,揭示了水-力作用下土的变形和含水率变化机制。研究表明:在吸力平衡和等向固结过程,非饱和土的变形和含水率随时间变化规律不同,变形在相对较短时间内达到平衡,而含水率达到平衡耗时更长;在三轴剪切过程,剪缩变形量与孔隙水排出量随时间基本上呈线性变化。随着吸力增大,含水率达到平衡所需时间增长,但对变形达到稳定耗时影响不大。净围压增大会增长含水率达到平衡的时间,然而对变形达到稳定的耗时影响不大。改进“双孔”模型,外力基本上只影响集聚体间孔隙;含水率变化会引起土颗粒重新排列,进而影响集聚体间孔隙;集聚体间孔隙水迁移速率相对较大,颗粒间孔隙水迁移速率相对较小。In order to study the variation characteristics of the deformation and water content of unsaturated soils under hydro-mechanical effects,the unsaturated soil triaxial apparatus is used to carry out suction equilibrium,isotropic consolidation and triaxial shear tests on unsaturated clay.The variation of deformation and water content of expansive soils is real-time monitored,and that with time under hydro-mechanical action is comprehensive analyzed.Based on the“double-pore structure”model,the mechanisms of soil deformation and water content variation under hydro-mechanical action are revealed.The results show that in the process of suction equilibrium and isotropic consolidation,the deformation and water content of unsaturated soils vary with time.The deformation reaches the equilibrium in a relatively short time,but the water content reaches the equilibrium in a longer time.In the triaxial shear process,the amount of shear deformation and the discharge of pore water are basically linear with time.With the increase of suction,the time for the moisture content to reach the equilibrium increases,which has few effects on the time for the deformation to reach stability.The increase of the net confining pressure increases the time for water content to reach the equilibrium,but it has few effects on the time for deformation to reach stability.The“double-pore structure”model is modified,and the external force basically only affects the inter-aggregate pores.The variation of water content causes the rearrangement of soil particles,and then affect the macropores in the soil.The migration rate of pore water between aggregates is relatively large,and the migration rate of pore water between particles is relatively small.

关 键 词：非饱和土 变形 含水率 三轴试验 双孔模型 

分 类 号：TU443[建筑科学—岩土工程]