摘要
Abstract
A large amount of water-related old landslides are revived and deformed after the impoundment of the Three Gorges Reservoir,among which Jiuxianping Landslide is one of the typical landslides within the reservoir area,which is continuously deformed since the impoundment and the deformation displacement presents a typical stepped feature.In accordance with the geological investigation and the professional monitoring data concerned,the deformation characteristics of the land slide is deeply analyzed,and then the impacting factors and the deformation mechanism of the landslide deformation are obtained.The result shows that the chair-shaped weak stratum of sand-shale interbed provides the geological condition for the formation of the landslide,while the main impacting factor for the deformation and revival of the landslide is the fluctuation of the reservoir water level;i.e.under the impacts from both the water-saturated loading effect and the hydrodynamic pressure effect during the lowering of the reservoir water level,the downward sliding force is increased,which causes the stability of the slope rapidly lowered,thus induces significant deformation.The result from the calculation made with SEEP/W shows that under the condition of the increase of the lowering of the water level or superimposition of the rainstorm with the recurrence interval of 50 years during the rapid drawdown-period of the reservoir water level,the coefficient of stability of Jiuxianping Landslide is in a range of 1.055 ～ 1.069,even under the most dangerous operation condition,the lanslide is still to be within a basic stable status.The whole body of the landslide is now in a phase of creep-deformation with constant speed,which is possible to be locally damaged under the condition of a continuous rainstorm,thus the local prevention measures must be adopted on those locations with serious deformation damages.The study result provides reference and basis for both the monitoring and early-warning of thelandslide and the actual scheduling of the reservoir water level.关键词
三峡库区/旧县坪滑坡/位移变形/变形机制/成因特征/重庆Key words
Three Gorges Reservoir Area/Jiuxianping Landslide/displacement deformation/genetic characteristics/deformation mechanism/Chongqing分类
天文与地球科学
