纯黏土与砂-黏土混合物渗透特性差异及机理分析  

Difference and mechanism analysis on percolation behavior of pure clay and sand-clay mixtures

作　　者：吴子龙[1] 朱向阳 江舜武 刘华山 邓永锋[1] 

机构地区：[1]东南大学岩土工程研究所,南京210096 [2]连云港赣榆港区建设现场指挥部,连云港222100 [3]江苏新苏港投资发展有限公司,连云港222042

出　　处：《东南大学学报（自然科学版）》2015年第2期376-381,共6页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51378117);教育部留学回国人员科研启动基金资助项目(2012-1707);江苏省交通运输科技与成果转化计划资助项目(2012Y01-2)

摘　　要：根据重塑纯黏土和砂-黏土混合物试样的室内固结试验结果,反演了渗透系数,探讨了纯黏土和砂-黏土混合物的渗透特性差异.试验结果表明:常用于评价纯黏土渗透性状的归一化指标e/eL(孔隙比与液限状态孔隙比的比值)能拓展运用于砂-黏土混合物中,但e/eL与渗透系数之间呈现非线性关系,这显著不同于纯黏土的线性关系,其本质原因在于混合物在压缩过程中形成了砂骨架.骨架形成前,纯黏土和砂-黏土混合物的e/eL与渗透系数的2条关系曲线吻合良好,而在骨架形成后,两者的关系曲线存在明显的差异;引入砂-黏土混合物四相体系,从黏土孔隙比和砂孔隙比的角度阐述了砂骨架的形成机制,且对两者渗透性状的差异性进行了详细的机理解释;最后给出了一种可以预测纯黏土和砂-黏土混合物渗透系数的经验公式.To investigate the difference of percolation behavior betw een pure clay and sand-clay mixtures,the oedometer consolidation experiments were performed using artificially remolded samples and the permeability was back analyzed. The results show that the normalized index e / eL（ the ratio of void ratio to that at liquid limit） commonly used can be extended to the sand-clay mixtures,while the nonlinear relationship betw een permeability and this index is observed,which is different from a linear relationship is pure clay. This obvious difference is attributed to the formation of the sand skeleton in sand-clay mixtures. Percolation behavior of pure clay and sand-clay mixtures is the same before the formation of the sand skeleton,while the difference occurs after the formation. The fourphase analysis system of clay-sand mixtures is adopted to clarify the formation of the sand skeleton and the difference of percolation behavior betw een the pure clay and sand-clay mixtures in the view of the sand void ratio and clay void ratio. Finally,an empirical formula to predict the permeability coefficient of pure clay and sand-clay mixtures is proposed.

关 键 词：纯黏土 砂-黏土混合物 归一化指标 渗透特性 砂骨架 

分 类 号：TU43[建筑科学—岩土工程]