The Stability Analysis Of The Fracturing And Deformation Body At The Right Bank Of Head Area In Pubugou Hydropower Station

With the continuous development of science and technology, human's ability to reform natural became more and more powerful, especially the development of infrastructure such as hydropower project, slope instability seriously threat the state property and people's lives, therefore, related research on slope stability analysis and evaluation of control effect has attracted worldwide attention.This paper studied on the fracturing and deformation body at the right bank of head area in Pubugou Hydropower Station, combined with the basic geological conditions of dam area and the rock structure of the fracturing and deformation body, have judged failure modes of the body, and have summarized causes and mechanisms of the body by analyzing the deformation phenomena and the development and distribution of deep cracks of the slope on the other side. Based on the geological qualitative analysis on the body, by monitoring data analysis, rigid body limit equilibrium calculation and FEA numerical simulation, etc, have comprehensively analyzed and evaluated the stability of the fracturing and deformation body's bank slop.Monitoring achievements analysis consist of outside deformation,inside deformation and stress measurement support system. In the analysis of monitoring results, it discusses the relationship between displacement of each measuring point and space and time.It also discusses variation of the supporting structure of anchoring force when anchor and prestressed steel rope are in different time. It analyses physical stability of the banks crack in the light of location. Monitoring achievements analysis mainly shows that:Crack edge slope after the main body is mainly on the deformation of the boundary cracks. Deformation occurres in the slope of 20m ~ 45m depth and is sliding - dumping of deformation mode mainly by the concentration of rainfall,which local micro-slip surface is in upgrowth and posterior slope is shallow loose with the basic creep deformation. Stress measurement support system shows that: Rock slope in the absence of support easily occurs deformation failure.It is anchor cable and prestressed steel rope effectively prevent the slope to increase deformation to the empty direction. Support measures for the overall strengthening effect is obvious.By limit equilibrium calculation for rigid block, and through the generalization of geological model, calculated the safety factor on account of potential sliding surface, for instance, bedrock-overlay boundary line, Loose deformation bottom boundary, highly unloading bottom boundary, and weak unloading bottom boundary, besides that, rechecked the calculation according to the strengthened bank slop. The results of analysis of limit equilibrium for rigid block shows that: Loose deformation rock mass located in the surface layer of bank slop is the most dangerous area, in the state of no strengthening, the bank slop is in danger, but after strengthened, the stability of bank slop improved significantly, the support effect can meet design requirement .By two-dimensional numerical simulation, analysis of crack rock slope body deformation and stress feature, respectively on the nature state and state of power station after the normal storage. The results shows that: The main deformation of slope is settlement deformation along the direction of gravity, after storage, by the water pressure action, the deformations of the front slope increased. The relationship between the stress of rock slope and the depth of rock is approximation linear, in other words, the depth greater, the stress also greater. At the foot of the slope and near the slope point, very easy to appear stress suddenly change, form the stress Concentration Area.