Study On Slope Stability Of Open Pit Mine Under High Dump

This paper focuses on the stability of the stope slope under the action of the waste dump of an open pit mine in Inner Mongolia.The waste dump of the mining area is located in the northwest of the open pit,and the nearest distance is 270 meters.The stacking height of the dump is 60 meters,and the designed dumping height is 100 meters.At present,the mining depth of the stope is 170 meters,and the designed final mining depth is 290 meters The waste dump is close to the stope,and the effect on the upper slope of the stope increases with the accumulation of waste dump.Therefore,it is of great practical significance to analyze the influence of waste dump on stope slopeThrough the laboratory test of rock mechanics and FLAC3D numerical simulation,the stability of the high and steep slope in the north side of Pit 2 and the influence of waste dump on the high and steep slope are analyzed.Firstly,the rock samples are taken from the slope in the field,and the mechanical parameters of the rock are obtained through the rock test in the laboratory,and the mechanical parameters of the rock are transformed into the mechanical parameters of the rock.Secondly,according to the rock mechanics test data,the geological data of the mining area,as well as the current situation of the waste dump and the stope,the FLAC3D numerical software is used to establish the slope model under different mining depth and different height waste dump conditions,and the numerical calculation is carried out to analyze the stability of the slope under different working conditionsBy calculating the slope stress,displacement,safety factor and other parameters under different mining conditions.The results show that at the depth of 170m,the maximum safety factor is 1.89,the maximum displacement and stress in the z-axis direction are 0.107m and 4.46mpa respectively,and there is no plastic zone.At a depth of 230m,the safety factor is 1.74,the maximum displacement is 0.150m from z-axis,the maximum stress is 5.560mpa from Z-axis,and there is no plastic zone.When the mining depth is 290m,the safety factor is 1.35,the z-axis maximum displacement is 0.207m,the maximum principal stress is 7.068mpa,and a minimum part of the plastic zone occurs.The mining depth is 170m,230m and 290m are in a stable state.However,the stability coefficient decreases obviously at the depth of 290mBy calculating the stability parameters of the stope slope under different working conditions.The final results show that when the mining depth is 170m and the height of the dump is 60m,the slope is the most stable and the safety factor of the slope is the largest,which is 1.89.The dump has only a minimal influence on the displacement,stress and shear strain increment of z-axis,but almost no influence on others.When the mining depth is 230m and the dump height is 80m,the safety factor of the slope is also 1.74.The dump begins to have a certain influence on the displacement and stress of the slope in all directions of the open-pit mine,and a plastic zone appears in the dump.When the mining depth is 290m and the dump height is 100m,the safety factor drops to 1.34.The plastic zone mainly appears on the dump and only a small amount of plastic zone appears on the open-pit slope.The dump not only affects the displacement,stress,shear strain increment and plastic zone of the open-pit slope.It also begins to affect the safety factor of open pit slope.Therefore,when the dump height is 100m,the dump starts to affect the safety factor of the open-pit slope,and the safety of the open-pit slope decreases.Therefore,it is not recommended to increase the dump heightThe research results of this paper can provide reference for similar open pit mining technology.