Research On Steep Slope Mining Technology In North End Of Pingshuo East Open-pit Mine

The static rigid body limit equilibrium method is usually used in the initial design of the openpit mine end slope,and the final slope shape of the open-pit mine is designed based on the safety of the end slope serving the entire mining life of the open-pit mine.Since the three-dimensional effect of the internal dumping field on the end slope during the development of the open-pit mine stripping project is not considered,the final designed slope angle is gentler than the actual stable slope angle,resulting in A large amount of coal resources overwhelmed by end-slope cannot be recovered,resulting in waste of resources.In this paper,the mining technology of steep slope in the north end of Pingshuo East Openpit Mine is studied.After the engineering geological investigation and analysis of the north end of the East Open-pit Mine,the main factors affecting the stability of the north slope are analyzed theoretically,and the potential landslide mode is determined.The feasibility of steep slope mining in the northern end slope is analyzed by using the rigid body limit equilibrium method,and two steep slope shape schemes are further designed to determine the slope shape parameters.The numerical simulation method is used to optimize the tracking pressure side distance of the inner dump,and the double retaining effect of the working side and the inner dump is fully utilized to ensure the stability of the northern slope.Finally,the transportation system is optimized to determine the specific mining scheme of steep slope mining in the north end.The research shows that the potential landslide mode of the northern slope is a slice-bedding sliding with arc as the side interface and weak layer of wind oxidized coal as the bottom interface.Through the stability analysis of the current slope of the northern slope,the results show that the stability coefficient is greater than the safety reserve coefficient,and it is feasible to implement the steep slope mining.Through the scheme comparison,it is determined that the morphological design scheme of the steep slope in the north end is to remove 4 coal roof transportation flats,retain 4 coal bottom transportation flats,4 coals,9 coals and 11 coals are not combined,and the transportation flats are 40 m wide.The security flat is 5m wide.When the tracking and pressing distance is 50 m,the north end slope is more stable.Through the steep slope mining of the northern end,an additional coal volume of 1.006 million tons was mined,and the stripping volume was increased by 2.26 million m3,which improved the economic benefits of the mine and extended the service life.The paper has 41 pictures,12 tables,and 45 references.