武隆鸡尾山滑坡滑带软岩微观结构与流变特性  

The Microscopic Structure and Rheological Characteristics of the Slip Zone Soft Rock of Jiweishan Landslide in Wulong of Chongqing,China

作　　者：邓茂林[1] 许强[1] 韩蓓[1] 朱星[1] 蔡国军[1] 郑光[1] 

机构地区：[1]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),四川成都610059

出　　处：《山地学报》2014年第2期233-240,共8页Mountain Research

基　　金：国家重点基础研究发展计划(2013CB733200);国家杰出青年科学基金(41225011);教育部长江学者特聘教授岗位资助~~

摘　　要：利用理学DMAX-3C衍射仪(CuKa,Ni滤光)、偏光显微镜、扫描电镜(SEM)、岩石直接剪切蠕变试验系统等对武隆鸡尾山滑坡滑带软岩进行矿物成分、岩性鉴定并分析构造和组分,自然风干和饱水后两种状况的显微结构观察,并对其流变特性进行试验研究。其结果为:软弱带方解石含量占68%、有机质13%、滑石9%、蒙脱石5%、石英4%、白云石1%,滑动面的镜面物质没有变化。显微结构测试结果表明:自然风干后在扫描电镜下,样品中出现大量的线型擦痕、微孔隙和微裂隙,粘土矿物呈定向排列。充分饱水后试样出现新的微裂纹,并有扩张现象,孔隙明显增大,也较好的吻合了该滑坡滑动的一些基本事实。对直剪流变试验与快剪试验获得的抗剪强度参数相比较发现,前者的长期抗剪强度有显著降低,摩擦系数降低31.53%,凝聚力降低37.61%,且凝聚力对剪切流变特性的影响高于内摩擦系数。这些试验结果与野外对滑坡的调查结果相吻合,促进了对滑坡的机理研究;滑带软岩的微观结构及流变力学性质是该滑坡发生蠕滑效应的重要因素。The stress state and the intensity which would affect the activities of a landslide are determined by the type,material composition,microstructural features and formation mechanism and others of the slip zone.So the research of the landslide is promoted by the research of the slip zone.For this reason,the mineral composition and lithology of the slip zone soft rock of Jiweishan landslide in Wulong of Chongqing,China are identified by using of DMAX- 3C diffractometer（light filtering by CuKa,Ni）,polarizing microscope,scanning electron microscope（SEM）,the rock direct shearing and creeping test system and etc.,and the structures,components and the microscopic structure of the natural dried or saturated water are analyzed,then the rheological properties are studied according to the experiments.The result shows the composition in weak slip zone：the content of calcite reaches- 68%,the organic matter- 13%,the talcum- 9%,the montmorillonite- 5%,the quartz- 4% and the dolomite- 1%.The mirror material composition of the sliding surface is not changed.The microstructure test shows that there are a large number of linear scratches,micropore,microfissure and the clay mineral directional arrangement in the natural dried samples in the scanning electron microscope.Besides,there are some micro-cracks and expansion in the slip surface of the fully saturated water sample,the porosity increases significantly,and new microcracks emerge,and also coincide with the basic facts of landslide movements.The rheological test results show that the long-term shear strength of the direct shear rheological test significantly decreases by compared to the parameters of the shear strength of the rapid shear tests,the friction coefficient decreases to 31.53%,the cohesion decreases to 37.61%,and also the influence of rock cohesion on shear rheological properties is greater than its internal friction coefficient.These test results are consistent with the understanding results of the field landslide survey,and promoted the study of the landsl

关 键 词：滑带软岩 微观结构 矿物组成 流变特征 长期强度 

分 类 号：P642[天文地球—工程地质学]