Research On The Stability And Treatment Of High-Steep Slope In Open Pit Mine Based On Strength Reduction Method

Open-pit mining is one of the main mining methods in modern society,and the stability analysis and treatment of open-pit mining high and steep slope have became one of the important research fields of open-pit mining.Sandaozhuang open-pit mine in henan province is an extremely large open-pit mine in China.In recent years,the annually total amount of exploitation and stripping reached 40 million tons.At the end of 2016,the south slope of the mine suffered from a landslide,which seriously threatened the safety of mine production and operation.Therefore,it has great practical significance to treat the landslide and carry on the relevant stability analysis and research.Based on the field investigation and data collection,the stability and failure mode of the slope before treatment are analyzed by limit equilibrium method and strength reduction method.After adding the supporting measures,the stability of the slope after treatment is analyzed to verify the effect of the treatment project,and analyze the stress situation of the supporting structure and its influence on the stability of the slope.Get the main conclusions:1.Before the treatment,the horizontal displacement and plastic strain of the slope are mainly concentrated in the loose accumulation body in the upper part of the slope,and the horizontal displacement and plastic strain in the loose accumulation are much larger than the sheet rock in the lower part of the slope.The safety factor of the slip zone along the interface of the loose accumulation body is much smaller than that of the whole slope slip zone.The main failure mode of the slope is the local failure caused by the loose accumulation on the upper part of the slope.2.Under the condition of rainfall,the horizontal displacement and plastic strain in the body of the loose accumulation at the top of the slope rise significantly,and the slope safety factor decreased from 1.175 to 1.078.lt is proved that under rainfall condition,the slope is unstable and may be destroyed.3.After treatment,the slope displacement area and plastic strain area are no longer concentrated in the loose accumulation,but distributed along the slope as a whole.The overall horizontal displacement is uniform,and the horizontal displacement and plastic strain in the loose accumulation are reduced.lt is proved that the possibility of local failure of the slope at the upper part of the loose accumulation body tends to disappear,and the integrity of the slope is significantly improved.The slope safety coefficient increases from 1.175 to 1.478 in natural working condition and from 1.078 to 1.350 in rainfall working condition,both of which were in stable state,and the slope stability get substantially improved.4.The simulation results show that the prestressed anchor cable and anti-slide pile bear a large force at the interface of the loose accumulation body,which proves that they can effectively resist the sliding force of the loose accumulation body along the interface and play a supporting role.At the same time,the grey correlation method shows that,among the components of prestressed anchor cables,the number of anchor cables has a great influence on the slope stability.