三峡库区树坪滑坡变形失稳机制分析  

Analysis of deformation and failure mechanism of Shuping landslide in Three Gorges reservoir area

作　　者：卢书强 易庆林 易武 黄海峰 张国栋 

机构地区：[1]三峡地区地质灾害与生态环境湖北省协同创新中心,湖北宜昌443002 [2]湖北长江三峡滑坡国家野外科学观测研究站,湖北宜昌443002 [3]湖北省地质灾害防治工程技术研究中心,湖北宜昌443002

出　　处：《岩土力学》2014年第4期1123-1130,1202,共9页Rock and Soil Mechanics

基　　金：湖北省自然科学基金(No.2012FFA040;No.2012FFB03804);湖北省教育厅科学技术研究项目(No.D20121304);地质灾害防治与地质环境保护国家重点实验室开放基金(No.SKLGP2012K032)

摘　　要：树坪滑坡自2003年三峡水库蓄水以来,就一直持续变形。为了对其稳定性及变形发展趋势进行评价和预测,有必要对其变形失稳机制进行深入研究。为此,采用现场地质调查和勘探的方法确定了滑坡的形态和性质;充分挖掘变形监测数据,详细分析了滑坡的变形特征。在此基础上,深入研究了变形失稳机制及影响因素,并对滑坡的稳定性进行了计算和预测。结果表明,滑坡区地形、岩性及地质构造等地质因素控制了树坪滑坡的形成和发展;库水位下降和大气降雨进一步激励了滑坡的变形。库水位下降,坡体内地下水位随之下降,但其速度远小于库水位下降速度,导致坡体内水力梯度和渗透力明显增大,从而使滑坡稳定性急剧下降,并且库水位下降速度越快,滑坡的位移速率也越大,是典型的水库下降型滑坡。在库水位下降过程中,若出现明显的降雨过程,更加剧了滑坡的变形,有产生大规模滑动的可能性,须采取防护治理措施。Continuous deformation happened in Shuping landslide, since the impoundment of the Three Gorges reservoir from 2003. It is necessary to study the deformation and failure mechanism of Shuping landslide, in order to evaluate and predict the stability of landslide. The field geological survey and exploration are used to determine the form and property. The deformation characteristics of the landslide are analyzed in detail to make full use of monitoring data. The deformation mechanism and influence factors of landslide are studied based on investigation and monitoring; and the stability of landslide is calculated and predicted. Survey and analysis results show that, the geological factors, included topography, lithology and geological structure, control the deformation. The reservoir water fluctuation and rainfall trigger the deformation of Shuping landslide. Indeed, the relationship between slope groundwater fluctuation and reservoir water fluctuation primarily affected the deformation, especially during the decline process of slope groundwater with the drawdown of reservoir water. Because decline speed of groundwater is much slower than that of reservoir water, it increases the hydraulic gradient and seepage force in the landslide body apparently, and then reduces the slope stability, increases the landslide deformation rate especially when the sharp decline of reservoir water level. In addition, if the long-term or intensive rainfall occurs during the drawdown of reservoir water, more obvious deformation will happen and landslide might be failed. So the engineering control measures should be carried out.

关 键 词：三峡库区 树坪滑坡 变形特征 失稳机制 稳定性预测 

分 类 号：TU443[建筑科学—岩土工程]