Study On Stability Analysis And Control Measures Of Gangue Dump In Gushuyuan Coal Mine

The coal gangue dump is bound to be unstable when it is piled up for a long time under the natural state,which poses a threat to the surrounding residential areas and ecological environment.Therefore,it is necessary to analyze the stability of coal gangue dump.Based on the engineering background of the treatment of the coal gangue dump in Gushuyuan Coal Mine,the stability analysis and treatment measures of the coal gangue dump are analyzed by combining theoretical analysis,numerical simulation and field measurement.The main conclusions of the study are as follows:(1)Through the study on the instability mode of coal gangue dump,it is concluded that the instability of coal gangue dump mainly includes three modes:internal sliding,sliding along the contact surface and collapse caused by the failure of soft foundation;the factors influencing the stability of coal gangue dump mainly include the physical and mechanical properties of gangue dump,pile structure,rainfall infiltration and accumulation mode.Among them,the physical and mechanical properties of gangue bulk is one of the most important factors affecting the stability of gangue dump.(2)The physical and mechanical parameters of coal gangue dump are obtained through field test and relevant mechanical test,which provides basis for theoretical formula and numerical simulation to solve stability coefficient.Based on the theory of upper bound method of limit analysis and unbalanced thrust principle,we add strength reduction method theory to study the dynamic mechanical characteristics and stress state of slope sliding body,derive the calculation formula of coal gangue dump stability coefficient,and establish the evaluation standard of slope stability of gangue dump in Gushuyuan Coal Mine.According to the engineering characteristics and test parameters of gangue dump,we get the corresponding stability coefficient.(3)The stability coefficient obtained by FLAC numerical simulation and theoretical solution is used to evaluate the stability of the coal gangue dump in Gushuyuan Coal Mine.The results of stability evaluation show that many areas of the gangue dump are under stable state and need to be reinforced,which provides a theoretical basis for the treatment of gangue dump.(4)The paper puts forward the treatment scheme of the coal gangue dump in the ancient academy:drilling and grouting reinforcement at the top platform of the slope.The purpose of the treatment scheme is to reinforce the loose coal gangue accumulation area of the slope to form a gravity-like retaining wall structure,and greening the slope surface of the treatment area after reinforcement.(5)Based on the in-situ test,the grouting effect is tested by means of heavy cone dynamic penetration test,wave velocity test in hole,water injection(seepage)test in hole,laboratory test of grouting stone body,slope stability evaluation and grouting technical data inspection.The results show that the shear wave velocity of the gangue layer in the treatment area is significantly improved,the drilling core strength is high,and the gangue slope is in a stable state.The comprehensive evaluation of the quality of the grouting project for the treatment of gangue dump in Gushuyuan Coal Mine is qualified.The grouting treatment scheme adopted in this project is reasonable and effective,and the theoretical derivation and numerical simulation calculation method in the paper are reasonable.