非饱和膨胀土/岩持水与渗透特性试验研究  

Experimental study of water-holding and permeability characteristics of unsaturated expansive soils and rocks

作　　者：戴张俊[1] 陈善雄[1] 罗红明[1] 陆定杰[1] 

机构地区：[1]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,武汉430071

出　　处：《岩土力学》2013年第S1期134-141,共8页Rock and Soil Mechanics

基　　金："十二五"国家科技支撑计划项目课题资助(No.2011BAB10B02)

摘　　要：以南水北调中线工程原状强、中膨胀土/岩为研究对象,开展压力板试验与双环注水试验,结合试验结果与土-水特征曲线(SWCC),对比研究不同性质膨胀土和膨胀岩的持水性能及影响因素,计算并分析水体积变化系数的变化规律,在该基础上重点探讨渗透系数的变化特征及其与基质吸力的非线性关系,总结出膨胀土/岩的渗透特性及其规律。结果表明,膨胀土/岩的持水特性受岩土的物理性质、矿物成分与结构特征的影响,膨胀潜势强、细颗粒含量大、孔隙结构小的试样有着较低的脱水速率;渗透系数和水体积变化系数均随含水率的减小而减小,变化特征受到膨胀潜势与干密度的共同影响,并与基质吸力呈幂函数关系。研究成果可为工程建设提供计算参数及理论依据。Pressure plate tests and double-ring infiltration tests are carried out for typical undisturbed strong and medium expansive soil and rock of the middle-route of South-to-North Water Transfer Project.According to the soil water characteristic curve and test results,the water-holding characteristics and its influence factors of different expansive soils and rocks are comparativly studied;and the variation of water volume change coefficients are calculated and analyzed.On that basis,the change characteristics of permeability coefficient and its nonlinear relationship with matric suction are discussed;and the infiltration characteristics and rules of expansive soils and rocks are summarized.The results show that,water-holding characteristics are influenced by the physical properties,mineral composition and structure characteristics of expansive soils and rocks.The sample with stronger expansion potential,higher fine grain content and smaller pore structure has lower dehydrated rate.Permeability coefficient and water volume change coefficient decrease with the decrease of the moisture content;and these parameters are influenced by dry density and expansion potential,which also have power function relationship with matric suction.The research results can provide calculation parameters and theoretical basis for the engineering construction.

关 键 词：膨胀土 膨胀岩 土-水特征曲线 持水特性 渗透性 

分 类 号：TU443[建筑科学—岩土工程]