Study On Instability Law Of Soft Rock Slope In Zhundong Open-pit Mine And Safety Control Technology Of High Inner-dump Slope

Xinjiang is the pivot of the “Belt and Road” construction line and has always played an important role in energy security and technology output.As the third largest coal field in Xinjiang,Zhundong Coalfield has 40% of its reserves suitable for open pit mining.Many open pit mines in Zhundong Coalfield are now approaching the turning phase.A series of similar engineering and safety issues have emerged in this area.The research on the typical safety technology issues in the production process of the Zhundong Opencast Mine has been carried out,which results has a good promotion in Zhundong Coalfield.The geological survey and data analysis were used to determine the three main factors affecting the stability of the Zhundong open pit mine slope.It identified the geological structure is simple,and the rock mass belongs to easily disintegrated soft rock.The loss of the stop slope is clarified as the slope of stope slope is dominated by bedding landslides,the slope of the dumping site is dominated by circular landslides,and the composite slope is dominated by arc-bed landslides.According to the tectonic stress graphic method,the horizontal principal stress direction of the Zhundong mining area is determined to be N21°E,which has little effect on the slope stability.The causes of vibration liquefaction formation and the physical and mechanical characteristics after liquefaction are theoretically analyzed.The vibration conditions of the Zhundong open-pit mine are combined with the vibration conditions of different working conditions to explore the dynamic stability of the sand slope.The time-dependent changes of the ultra-hydrostatic pore water pressure and the excess pore pressure ratio of the sand slope under different vibration acceleration and vibration frequency are tested.The results show that the vibration acceleration or vibration frequency is larger,the ultra-hydrostatic pore water is higher,and the shorter the time to peak.The geometry and mechanical model of the slope formed by the dumping on the inclined base are established,which reveals that the slope stability of the dump slope decreases with the increase of the height.Based on the three factors of stability of slope foundation,slope stability and maximum slope angle,a linear programming model of internal and external dumping stability is constructed,which provides a method to determine the maximum safety angle of the slope.A three-dimensional force model of asymmetric dumping field is established,and the supporting force of the basement on both sides of the dumping field is introduced,and the stability calculation method of the asymmetric soft rock dumping site is modified.According to the calculation method of gravity stress and lateral pressure,the calculation formulas of effective shear strength and normal stress of the end rock mass during the steep mining process are derived,which reveals that the effective shear strength decreases with the increase of the slope angle.The normal stress is negatively correlated with the angle of the end slope.The asymmetric weak layer extrusion model under the inclined condition is established,and the minimum thickness that needs to be satisfied by the overlying carrier during the extrusion of the weak side layer is determined.Aiming at the characteristics of the weak base weak layer in the Zhundong Open-pit Mine,a weak layer extrusion control method is proposed.The mechanical model of the concave slope of the dumping site is established.Based on the limit equilibrium principle and the strip method,the calculation method of the slope stability coefficient of the concave dump is derived.The maximum safe heights of bench for the straight and concave inner dump of-Zhundong Open pit mine were determined by simulation analysis to be 64 m and 80 m respectively.As the inner dump rapid follow to the mining bench,the optimum angle for western slope in the first mining area is 38°.By analyzing the problem of the downward transportation of the stripping material currently faced by the Zhundong Open-pit Mine,the technical and economical characteristics of the downward transport of the inclined end and the downstream transport of the dumping site are demonstrated,and the end-help road is optimized to solve the heavy-duty vehicle down-plan and the ?430 level is cancelled.The end of the road,set the ?414 horizontal end of the road,the internal dumping step and the formation of the ?414 horizontal step and the new ?462 horizontal step,providing a follow-up production process in the end of the section and the dumping section of the project implementation plan.This dissertation includes 75 figures,9 tables,and 124 pieces of reference.