The Analysis Of Right Bank Dam Adutment Slope Stability Of Yellow River Bin Lin Hydropower Station

The deformation and failure of dam abutment slope of hydropower station is a complicated process with many influencing factors.For hydropower prophase of slope excavation,the effect of excavation unloading is universal and important factor of the slope unstability,for has long running operation of hydropower station,deformation of slope is often formed by long-term creep,so the slope excavation unloading and creep under long term stability for the engineering design of slope excavation,supporting measures,etc have important guiding significance.Based on the monitoring data of the right bank slope at the dam site of huanghebingling hydropower station and combined with the field investigation,this paper selects a reasonable section for the creep parameter feedback study,and conducts a detailed study on the stability of the right bank slope at the dam site.The specific research contents and results are as follows:(1)Through the detailed analysis of the characteristics of the structural plane of the dam site area,the classification of the structural plane of the dam site area is completed.Based on the characteristics of rock mass weathering and unloading in dam site area,the characteristics of slope weathering and strong unloading in dam site area are analyzed in detail.Based on the deformation and failure characteristics and monitoring data of dam slope,puts forward the reasonable qualitative evaluation,on the right bank abutment excavation system supporting area(? area)is currently stability is good,not deformation damage,inside of the tailrace system does not support area(? area)is currently the overall stable,but the possibility of partial blocky rock mass is stable.(2)Using rigid body limit equilibrium method on the uncertainty of the right slope of the block stability calculation,calculated ? zone of slope deterministic blocks under different conditions are stable;? slope cracks of block 6 L304 grew up in the working condition of heavy rain and earthquake conditions of stability coefficient is 1.048 and 1.022,for the unstable state;Swedge,the slope block stability analysis software,was used to calculate and analyze the stability of different types of local random blocks under different working conditions,and it was found that most of the random blocks with the combination of hard structure planes were basically stable in the right bank abapment slope.(3)Determine the range of rock creep parameters of the section to be studied,and formulate a reasonable training calculation scheme.the finite difference software is used FLAC3 D calculate the training samples needed for inversion.according to the data requirements of the BP-neural network,the neural network training of the training samples is completed.finally,the monitoring data of the inversion section is substituted into the neural network for regression calculation to obtain the creep parameters of the inversion section.(4)Based on the creep calculation of the slope rock mass in the dam site area,it is concluded that the creep characteristics of the excavated slope are mainly divided into three stages: the rock mass stress is released rapidly at the moment of excavation,and the rock mass near the excavation surface will produce instantaneous deformation with a large deformation rate.In the creep curve,this section is described as the instantaneous elastic strain and instantaneous plastic strain of the rock mass.Then the rock mass deformation of the slope enters the deceleration stage and gradually transitions to the deformation rate stabilization stage.Finally,the rock mass of excavation slope enters the stage of stable creep,and the rock mass deformation rate remains basically unchanged.(5)Using numerical analysis method of dam site area on the right bank slope stability evaluation,can be concluded that the slope at the excavation system supporting area(? area)for a stable state,? slope due to excavation supporting,not after the rainstorm,earthquake conditions although the overall slope is stable,but local grew up by the fissure cutting blocky rock mass is the possibility of instability.(6)Propose rational support measures ? zone of slope,the slope to spray anchor supporting the system,and limit further extension of fracture;Through finite difference numerical simulation supporting the stability of slope under different conditions,is supporting the stability of the slope support front has significantly increased,to verify the ? slope anchor cable system supporting method has certain reliability.