Study On Stability Of Bank Slope Of Binary Structure Reservoir Under Water Level Change Conditions

We know that water has an important effect on slope stability.The occurrence of large landslides in the world is almost related to water,and the effect of water on slope stability is mainly water level change and rainfall.The influence of water level change on slope stability is complicated.With the change of reservoir water level,the geological environment and stress state of the slope will change.On the one hand,with the rise of reservoir water level,Strength decreases,the pore water pressure increases,on the other hand,with the decline of reservoir water level,the seepage force in the slope is larger and the hydrostatic pressure cdecreases.The double-decked slopes is the most common kind of slope in the bank slope.Based on the practical problems,this paper studies the influence of the reservoir water level on the seepage and stability of the reservoir bank slope.Stability of the study and the operation of hydropower engineering safety is of great significance.In this paper,the new slope of Ahai reservoir is taken as the research object,from the two aspects of qualitative and quantitative research and discussion on the change of reservoir water level on slope stability.First,theoretically,the mechanism of deformation and failure of slope is analyzed,and then the influence of water level change on the stability of bank slope is analyzed from the qualitative point of view.Finally,quantitative analysis is carried out,mainly from the change of reservoir water level and the change of permeability coefficient and the change of water level.The influence of the slope on the stability of the bank double-decked slopes is studied and compared with the monitoring data of the new landslide since the Ahai reservoir.The results are as follows:(1)As the reservoir water level rises,the pore water pressure increases gradually.As the reservoir water level decreases,the pore water pressure decreases gradually.And the higher the rate of reservoir water level changes,the greater the change of pore water pressure.(2)The change of the whole and local stability of the bank double-decked slope in the process of rapid rise of the reservoir water level shows the change law of increasing first and then increasing and then increasing.In the process of slowly changing the reservoir water level,The change of local stability shows the change rule of first increase and then increases,and the faster the reservoir water level rises,the faster the safety factor of slope stability is improved;In general,as the reservoir water level rises,the slope stability is reduced.(3)The safety factor of the stability of the whole and local stability of the bank double-decked slopes is decreasing first and then increased,and the faster the reservoir water level descends,the slope stability is safe The greater the change in the coefficient.(4)Under the effect of water level rise and fall repeatedly,There are two potential failure modes in the bank double-decked slopes,that is,the local slip of the slope front and the sliding along the slope.When the slope of the slope before the local sliding body damage,the trailing edge due to loss of support the occurrence of the overall traction landslide.