基于形变监测成果探讨万州枇杷坪古滑坡稳定性

枇杷坪古滑坡位于重庆市万州区东缘,是三峡库区重点勘察的滑坡之一。近年来滑体部分地区出现蠕滑变形,存在局部复活的可能。枇杷坪古滑坡及移民房屋稳定性监测预警系统始建于2004年初,主要监测手段为GPS及精密水准测量。2a多的监测成果表明,枇杷坪古滑坡局部出现较大的顺坡向位移变形及不均匀沉降。滑体出现蠕滑变形的主要原因:①库水位的升高使地下水位升高;②频繁的人类工程活动。文章依据监测成果,运用Winsurf软件绘制出滑体水平形变场及垂直形变场,综合分析位移监测信息,并运用Mapinfo地理信息系统平台,依据滑体的形变场,试勾描出枇杷坪的强变形区域,该区域对应在滑体中段的中前部,区域内监测点均一致朝向长江方向滑移及倾斜。文章拟通过滑坡变形区的划分,探讨滑体的稳定性区划、变形特征及发展趋势。

Discussion on the stability of the Pipaping Ancient Landslide in Wanzhou based on monitoring data of deformation

The Pipaping Paleo-Landslide locates in the east edge of Wanzhou District,Chongqing City,that is one of the priority investigation and control landslides in the Three Gorge Reservoir area.Creep deformation appears on part of this landslide recently,and there is probability of reactivation locally.Stability monitoring and forecasting system of Pipaping Paleo-Landslide and immigrant houses was established in early 2004,its main methods are GPS geodesic survey and accurate leveling control survey.The result from monitoring data of two years shows that there are big displacements along the slope direction and irregular settlement on part of this landslide.The main reason of creep deformation may be following: the rise of water table resulting from the rising of reservoir water table;frequent human engineering activity.Based on the result from monitoring and forecasting system since two years,protracted horizontal deformation field and vertical deformation field with winsurf software,integrated the displacement monitoring information,taken Mapinfo,a GIS software,as a working flat,we draw the outline of the big deformation area of Pipaping,which is corresponding to middle and front of this landslide volume,there are unanimous slips and dip towards the Yaungtze River for the monitoring sites.By partition of landslide deformation filed,this paper discussed the stability partition,characteristics of deformation and development trend of this landslide.