Study On Failure Mechanism And Stability Of Anti-dumping Layered Slope

Toppling failure often occurred in the area of water conservancy and hydropower projectand mine engineering. Since toppling failure is very complicated and uncertain, takingwhether toppling deformation occurred in slope under the condition is very important.Takingthe number VI slope on the left bank of Cihaxia hydroelectric station as research object, thispaper analyzes the development and evolution of the toppling deformation and study thefailure mechanism of the toppling deformation. Using the mechanical-numerical model,discrete element method and the finite element numerical simulation technology, the paperstudy how different geometrical characteristics of the slope (such as different dips, slopeangles, slope heights and the mechanical parameters of rock) impact on the toppling failure.According to the result of study, we can forecast the development trend of the topplingdeformation under different conditions and evaluate the stability of the number VI slope.(1) Study on the toppling deformation of the anti-dip layered slope, through itstheoretical formula, this paper concluded a result: the river down-cut the slope which makesthe toe of the slope meet the air and the beam-plate in the toe of the slope lose holdingpower, under this circumstance, toppling failure occurred in slope. It is called the model ofacceleration.（2）Analyze the model of the original slope, this paper summarized the stage oftoppling failure of the slope. There are four stages during the toppling failure of the slope:stage one, toppling deformation occurred in the toe of the slope; stage two, topplingdeformation occurred in slope body, collapse occurred in toe of the slope; stage three,bending deformation on the slope; stage four, toppling failure occurred in slope.（3）This paper simulate the evolution of the number VI slope failure. Study on theresult, we know that the toppling deformation on the surface of the slope are on the stage twoor stage three. Since the failure surfaces weren’t linking, the toppling failure was not occurredin slope eventually. For the deformation in deep position of the slope, the trailing edge of theslope is on the stage of tension crack deformation, the whole slope will be stable for a longtime, but it will slides for a new balance at last.（4）Applying model, this paper studies the influencing factor of the toppling deformation and come to the conclusion that compared with the geometrical characteristics ofthe slope, the structure of the rock mass and mechanical parameters of rock, the thick ness ofthe rock mass has the largest influence on the toppling deformation.5）Establishing a model,a finite element software, this paper works out the relationshipof stress and strain under different conditions. The results show that under various conditionsthe slope of the maximum principal stress and minimum principal stress is approximately thesame, there is no obvious difference. The stress concentration of the shear stress occurred onthe toe of the slope and loosen rock mass. The rock mass approach the surface is stable.Counting the safe factor, the number VI slope is stable under natural condition; but under therainfall and earthquake condition, the slope may slide easily, because the safe facture is closeto1.