Study On Seepage Factors And Slope Stability Of Earth Rock Dam

The study of seepage and dam slope stability has always been a hot topic in geotechnical engineering.In particular,the seepage problem of dam body is closely related to the safe operation of earth dams.Many earth dam failures result from the presence of seepage problems in the dam body.Therefore,reasonable analysis of the seepage problem of earth-rock dams and the stability change law of dam slope under seepage conditions is the key precondition for guaranteeing safe operation of earth-rock dams.In this paper,based on Geo Studio software simulation of the dam in the water level changes and changes in soil parameters of the dam seepage field and stability of the impact,and finally with the case calculation and analysis of the Dasigou reservoir in Qinghai,verifying the stability of the seepage of the dam under the water level changes.The conclusions drawn provide a reference for similar dam construction design.(1)The finite element software was used to simulate the seepage stability of the dam under rising and falling conditions.The change of the infiltration line within the dam is directly related to the rate of water level rise and fall.As the water level rises,the infiltration line rises.The larger the rate of rise,the more obvious the hysteresis is.The safety factor of the upstream dam slope increases as the water level rises,and then slowly decreases until The time required for the maximum rise rate to reach the maximum value is shorter;the rate of decline in the water level is greater at the initial stage of the saturation line,the greater the rate of water level decline,the more obvious the hysteresis phenomenon,and the lowering of the reservoir water level for the upstream slope.The safety factor has a greater influence.The faster the water level declines in the early stage,the faster the safety factor of the slope declines.The greater the rate of decline in the water level,the less time it takes for the safety factor to decrease to the minimum value;The safety factor of a dam slope always declines rapidly at the initial stage and slowly rises after falling to the minimum value of the safety factor.The greater the water level decline rate,the slower the slope safety factor rises from the lowest value,but eventually tends to be stable.(2)The effect of soil permeability and strength parameters on the seepage stability of the dam slope is simulated and analyzed.The results show that the larger the soil permeability coefficient is,the more obvious the change of the seepage field of the dam body is,and the safety factor of the slope has a slight decrease,but it is not obvious;the internal friction angle and the cohesion of the soil fill parameter increase.There is a positive effect on the stability of the dam slope,and an increase in the weight of the soil will reduce the safety factor of the dam slope.(3)Based on the case of Dasigou Reservoir in Qinghai Province,the seepage stability of the dam body under the change of water level was analyzed.The results show that the change law of seepage field and stability of the dam slope is consistent with the previous one.The engineering example is used to verify the effect of water level change on seepage stability of the dam body.