魏家沟滑坡滑带土非饱和蠕变特性试验研究  

Experimental Research on Unsaturated Creep Characteristics of Slip Soils in Weijiagou Landslide

作　　者：黄志全[1] 李小慧[1] 孙怡[1] 李磊[1] 

机构地区：[1]华北水利水电大学资源与环境学院,河南郑州450045

出　　处：《华北水利水电大学学报（自然科学版）》2015年第1期47-50,共4页Journal of North China University of Water Resources and Electric Power：Natural Science Edition

基　　金：国家自然科学基金资助项目(41140030);河南省科技创新人才计划

摘　　要：滑带是滑坡的一个重要结构要素,滑带土则是滑坡滑动过程中形成的特殊岩土体,其蠕变特性是滑坡动态演化过程的直接反映.降雨是滑坡失稳的重要诱因,在降雨入渗的条件下会导致滑带土常年处于非饱和状态,研究降雨条件下的滑坡滑带土非饱和蠕变特性具有很重要的意义.以栾川魏家沟滑坡滑带土为研究对象,开展了一系列非饱和土蠕变试验.采用陈氏加载法,得到了相同净围压、不同基质吸力、不同应力水平下的蠕变试验曲线.采用Boltzmann叠加原理对数据进行处理,分析滑带土非饱和蠕变特性,发现同一偏应力水平下,蠕变变形及变形速率均随着偏应力的增大而增大,且随着基质吸力的减小而增大;建立了一种包含基质吸力的Singh-Mitchell蠕变模型,即剪应力-应变关系采用指数函数表示,应变-时间关系采用幂函数表示.Sliding zone is the most important structural factor of a landslide. Slip soils are peculiar geotechnical soils formed in the sliding process of landslides,and their creep characteristics directly reflect the dynamic developing process of landslides. Rainfall is a main cause of instability for landslides,the slip soils are perennial in unsaturated state under the conditions of rainfall infiltration,thus researching unsaturated creep characteristics of slip soils of landslide under the condition of rainfall has very important significance.Taking slip soils in Weijiagou landslide in Luanchuan as a research object,a series of creep experiments of unsaturated soils were performed. Using Chen＇s loading method,the creep experimental curves were obtained under same net confining pressures,different matric suctions and different stress levels. The datum were dealed with by Bolzmann superposition principle,the unsaturated creep characteristics of slip soils were analyzed,and some results were obtained. The results indicate that under the same deviatoric stress level,the creep deformation and the deformation velocity increase with the increase of the deviatoric stresses,and decrease with the increase of matric suction. Then Singh-Mitchell creep model containing a matric suction was established,that is,the relation between shear stresses and strains adopted exponential functions,and the relation between strains and time adopted power functions.

关 键 词：滑带土 非饱和三轴蠕变试验 基质吸力 Singh-Mitchell蠕变模型 

分 类 号：TU441[建筑科学—岩土工程]