Mining plan for the western steep slope of Hongshaquan Open-pit Coal Mine

XU Chen; MA Long; MA Ning; MA Li

doi:10.11799/ce202505003

Abstract：In order to improve the recovery rate of coal resources covered by the end slope of Hongshaquan Open-pit Coal Mine,we employed the Morgenstern-Price limit equilibrium method and finite element strength reduction method to analyze the ultimate angle and sliding mode of the western slope.The feasibility of steep slope mining to improve the end slope angle was validated.Using three-dimensional numerical simulations,the influence of tracking distances and working slope angles on end slope stability and deformation under the impact of internal dumping sites and working slopes was investigated.Three end slope and steep slope mining schemes were compared.The results demonstrate that the western slope can achieve a maximum angle of 36°,making it suitable for steep slope mining to optimize the end slope angle.Tracking distance significantly affects slope deformation and stability,with deformation magnitude and range increasing gradually as tracking distance increases,albeit at a diminishing rate.In contrast,changes in working slope angle have a relatively minor impact on end slope stability;However,increasing the working slope angle reduces the exposed area of the end slope surface,thereby enhancing stability.Considering the influence of the crushing station on the western slope,an optimized steep slope mining plan was proposed,combining reduced bench floor width and step merging.This optimization resulted in an overall slope angle of 18°,an annual increase of 800000 tons of raw coal recovery,a stripping ratio of 1.5 m3/t,and economic benefits of 96.7 million yuan.