Numerical Simulation And Analysis Of Non-working Helping Landslide In Baoqing Chaoyang Open-pit Coal Mine

The status of non-work in the first mining area of Baoqing Chaoyang open-pit coal mine,the non-work-assisted slope starts from the occurrence of cracks to the end of the landslide for about half a year.After the landslide occurs,the open-pit mine is shut down for 32 days.The landslide body buryes the coal seam exposed in the western part of the bottom of the pit.The landslide amount is 4.944 Mm~3.In order to safely recover the coal resources of the landslide body and to ensure the normal and orderly progress of the stripping project after the open pit mine resumes production,the research is carried out.Through geological surveys,the main lithology of non-working strata was identified.The engineering geological drilling and geophysical and mechanical test sampling were carried out for the non-working landslide research area.The on-site and indoor geotechnical tests were carried out,and the limit equilibrium method was used to carry out landslide back analysis.A total of ten monitoring holes have been established,and the monitoring points are basically lined up for surface and under-ground displacement monitoring.Combined with the results of engineering geology,hydrogeological conditions and geophysical and mechanical properties,the 3DEC discrete element method simulation method was used to analyze the landslide mode and mechanism of non-working gangs in open pit mines.The stability analysis of the slope was carried out using STAB software.The limit equilibrium theory is used to analyze and calculate the stability of the non-working sloping front and the back slope.The calculation results show that the non-working gangs and the western landslides all have graded sliding characteristics,and the west is at the water level of the P-2 section.The stability coefficient of the slope before is only 0.954.Although the stability coefficient of the slope at the P-2section is slightly higher,it is 1.234.However,due to the large unstable slope at the P-2 position,the unstable slope is deformed.Under the action of moving traction,at the same time,the non-working side of the west side of the western landslide body becomes steeper,and the slope of the P-1 section also undergoes deformation and movement.The stability of the overall slope before the eastern slip meets the safety reserve coefficient of the slope.However,the stability coefficient of the local slope of+55m is less one,so the deformation of the local slope below+55m is first stage landslide.After the slope is moved,the rock and soil behind the slope is lost.Front support,+55m flat plate to the surface of this part of the slope stability coefficient is only 0.896,will inevitably follow the deformation movement of the first stage landslide body and gradually lose stability.The analysis results corroborate the previous analysis of non-work to help the eastern slope to be divided into two stages.The whole process of slope landslide instability is inferred,and the correctness of numerical calculation is verified,which provides reference for the stability analysis of similar open slopes.According to the geological conditions of soft rock slope and water-rich slope in the Chaoyang open-pit mine non-work,some suggestions for landslide prevention are proposed.