滑体的运动变形及观测要点

滑体运动变形特征是建立滑坡观测系统的主要依据。前者受控于滑面类型。1.直线型滑面上的滑体作整体运动,运动具等效效应;内部变形微弱,观测重点在地表位移;2.折线型滑面上的滑体亦作整体运动,变形较强,观测重点在深部位移和变形;3.凹弧型滑面上的滑体作整体旋转运动,变形较弱,观测重点在后缘和前缘;4.凸弧型滑面上的滑体作破碎旋转运动,变形较明显,观测重点在地表(尤其是剪出口处);5.复合型滑面上的滑体作分级分块运动,变形强烈,宜作综合观测。

MOTION DEFORMATION OF LANDSLIDE BODY AND ITS OBSERVED FOCAL POINTS

The motion deformation character of landslide body is one of main basises to set up the landslide observational system and it varies with different types of sliding plane.1.The rectilinear sliding plane-it is of a integral landslide body. The motion velocities and displaced volume are equal in each part. The landslide motion is of equivalency and its internal deformation is not obvious in the initial term as well as the middle term. The focal point of observation should be laid on the end section of landslide body.2.The mansard sliding plane:the motion deformation of this landslide body is complex, and the gradient of the sliding plane is different in each section. In the motion courses,crack,fault and buckling would arise in the landslide body. The focal point of observation should be laid on the end and front sections.3.The concave sliding plane:the motion of this landslide body is mainly rotation ones and it keeps as integral mass. The motion velocities of sliding plane are faster than ground surface. The sliding planes arise at the tension crack of end edge and shear fracture of front edge. Thus the two positions are the main observed focal points.4.The convex sliding plane:the motion of this landslide body is also mainly rotational. The displaced volume of the broken ground surface almost is more than sliding plane. The relative height of the sliding plane is equal at 2/3 of the curve radius. The landslide bodies are easy to break away from sliding bed and arise a punching and overlaping phenomenon. This place should be observed focal point.5.The composite sliding plane: the motion deformation of landslide body is very complex, and make a integral motion. The internal deformation is strong so as to cause crack,fault,buckling and even to form new groundwater net. Therefore,it should carry out a integrated observation.