利用扫描电镜和X射线衍射仪对滑坡滑带土的研究

利用扫描电子显微镜（SEM）和X射衍射仪（XRD）研究了三峡库区，黄河小浪底等地40个滑坡滑带土的结构及物质组合，指出当滑坡处于滑动阶段时，滑带土表居可见粘土矿物定向排列，普遍可见擦痕（弧型，线型，紊乱型），微裂隙和微空隙发育，微生物较多，当斜坡处于稳定阶段时，岩层软弱带可见粘土矿物无定向排列，表面无擦痕，常见树枝状结构。滑带土的物质组合主要为：蒙脱石，蛭石，伊利石，高岭石，绿泥石，方解石，石英，长石和微生物，而蒙脱石，蛭石和微生物含量是滑坡滑动的一个重要因素。据微结构的变化和物质组合可以分析滑坡的活动次数，活动阶段和形成机理，为滑坡治理和稳定性评价提供依据。

STUDY ON THE SOIL OF SLIPPING ZONE IN LANDSLIDES AND ITS SIGNIFICANCE BY SCANNING ELECTRON MICROSCOPE AND X-RAY DIFFRACTOMETER

Soil microtextures and composition in the slipping zone were analyzed by scanning electron microscope(SEM) and X ray diffractometer(XRD).Forty landslides over the reservoir district in the Yangtze Gorges and Xiaolangdi on Yellow River were investigated,and the relationship between deformational landslides and soil microtextures and composition was established.When a landslide is in slipping stage,clay minerals are often found to be distributed in the same direction,scratches (linear,arcuate and chaos),widespread,micro porosity and micro cranny,crowded,and microbes enriched.On the contrary,if a landslide is in a steady stage,there shows no direction in clay minerals and no scratches in the surface microtextures,with the leached clay minerals often taking on branch shapes.The characteristics of soil surface microtextures will enable us to analyse activated times and stages of landslides,give the mechanism of landslide formation,and offer the evidence on the landslide stability analyses and landslide control.Many kinds of minerals and microbe are seen in slipping zone of landslide,including montmorillonite,vermculite,kaolinite,illite,chlorite,calcite,quartz,feldspar and bacteria,with montmorillonite,vermculite and microbe as the main effective factors for landslides.