高岭-蒙脱混合黏土渗透各向异性模型研究  

Study on anisotropic permeability model for mixed kaolin-montmorillonite clays

作　　者：徐杰[1,2] 周建[1,2] 罗凌晖 余良贵 XU Jie;ZHOU Jian;LUO Ling-hui;YU Liang-gui(Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou,Zhejiang 310058,China;Engineering Research Center of Urban Underground Development of Zhejiang Province,Zhejiang University,Hangzhou,Zhejiang 310058,China)

机构地区：[1]浙江大学滨海和城市岩土工程研究中心,浙江杭州310058 [2]浙江大学浙江省城市地下空间开发工程技术研究中心,浙江杭州310058

出　　处：《岩土力学》2020年第2期469-476,共8页Rock and Soil Mechanics

基　　金：国家重点研发计划项目(No.2016YFC0800203);国家自然科学基金(No.51338009)。

摘　　要：完善的渗透各向异性模型有助于指导地下建筑施工期和运营期的排水注浆方案的选定,为了建立完善的渗透各向异性模型,利用三轴渗透仪对高岭-蒙脱混合黏土开展一系列渗透试验,并从宏观和微观两个角度尝试建立渗透各向异性模型。研究结果表明:随着膨润土掺入量增加,混合黏土中小孔隙含量不变,中孔隙含量增多,而大孔隙含量减少;随着固结应力的增大,混合黏土中孔隙均减少,且孔隙最大孔径减小;宏观参数孔隙比和液限孔隙比与渗透各向异性比之间的规律性较弱,说明孔隙比和液限孔隙比不是决定渗透各向异性比的关键参数;用微观参数表述的渗透各向异性模型有较强的规律性,说明从微观角度探究渗透各向异性模型不仅可行,而且更能揭示混合黏土渗透各向异性的本质,且微观参数模型中,用能反映较大孔隙变化的孔径指数D50~D70表述的渗透各向异性模型相关性最好。A perfect anisotropic permeability model is helpful to guide the drainage and grouting scheme of underground buildings during construction and operation period.To study permeability anisotropy model,mixed kaolinite-montmorillonite clays were used in a series of permeation experiments by triaxial permeameter,and the development of anisotropic permeability model was attempted from both macroscopic and microscopic perspectives.The results show that:as the amount of bentonite increases,the small pores increase,but the large pores decrease;as the consolidation stress increases,all pores decrease,and the maximum pore size decreases.Macroscopically there is no correlation between the void ratio considering the liquid limit void ratio and the permeability anisotropic ratio,which indicates that the void ratio e and liquid limit void ratio eL are not the key parameter determining the permeability anisotropy ratio.The permeability anisotropy model expressed by microscopic parameters indicates that it is not only feasible to explore the permeability anisotropy model from the microscopic point,but also to reveal the essence of permeability anisotropy.In all microscopic models,the permeability anisotropy model expressed by pore index D50-D70 is well correlated,which can reflect changes in larger pores.

关 键 词：混合黏土 渗透各向异性模型 宏观参数 微观参数 孔径指数 

分 类 号：TU411[建筑科学—岩土工程]