Studies On Formation Mechanism And Stability On The Left Abutment Of The Deformation Body Of Thecertain Hydropower Station In Xinjiang Province

A hydropower station in Xinjiang province Located in theXinjiang changji hui autonomous prefecture.the total designed capacity is 1200 MW,project size is the second largest(2)type.The deformable rock was located inthe left bank abutment and the downstream area.Through field investigation,Its geological conditions is complex,the deformation is diversity.The present situation and the excavation stability under the condition of deformation,and will directly influence the selection of dam site.The deformable rock of left bank abutment was discussed in this paper.It analysis the rock mass structure characteristic,the boundary condition and the mechanism of deformation of the slope on the base of inside investigation of geoengingeering conditions and signs of deformation.The physical simulation and the discrete element numerical simulation method for the cause of the left dam abutment deformation mechanism is simulated.And applied to the rigid body limit equilibrium method and finite element strength subtraction to the deformation under different conditions of stability under various working conditions to make the evaluation.The key contents and conclusions are as follows:(1)The left abutment deformation in overall is not obvious signs of deformation on the surface of the earth,The main deformation performance in along the unloading structure surface cracking and shallow loose rock mass.Surface of adit in slope support overhead phenomenon more obvious,the local did not support the adit of adit roof collapsed.Slope surface of layered rock mass structure is better,interlayer extrusion rupture zone development,individual in the adit slope development outside the structure of the surface cracking overhead.Slope foot development change body deformation failure formation of loose debris.(2)Through the investigation and analysis,this paper thinks that the cause of the deformation mechanism is divided into stages of stress redistribution,slow deformation,earthquake induced phase.And finally,the slope along the flat level,weak structural plane slip,tracking steep dip outside the fissure,weak structure surface cracking,produce large deformation,forming the existing deformation..(3)Combined with the actual survey data,using physical simulation and discrete element numerical simulation of the hydropower station in xinjiang in the library the whole left dam abutment genetic mechanism are well validated.(4)Using rigid body limit equilibrium method and finite element strength subtraction,respectively,to calculate the deformation under the condition of present situation,construction,water’s stability of the working condition of the other natural,heavy rain,earthquake.Come to the conclusion,the deformation body’s area overall Ⅰstability in Ⅱarea.But under heavy rain and earthquake conditions,stability decreases that have can not meet the requirement of the specification,the safety factor of the possibility of control standard.Therefore,it is necessary to take corresponding measures.