Optimization Research on Slope Parameters of Mining Area Steering Shaft Section in Pingshuo East Open-pit Mine

In order to solve the slope stability problem of the steering shaft sections in the first and second mining areas of Pingshuo East Open-pit Mine, considering the existing influence of thick red clay layers and fault broken zones in this area, the limit equilibrium method is adopted to conduct analysis of slope stabilities at different profiles of the original design scheme in the area: the stability coefficients in profiles 1 and 3 of steering shaft sections of the first and second mining areas are ≥ 1.2, which meets the safety specification requirements, and the slope design scheme remains unchanged; The slope at the profile 2 section is influenced by faults and has relatively low rock mechanics indicator, the slope stability coefficient is less than 1.2, which is in an unstable state, and the profile 2 slope design scheme needs to be optimized. The optimized slope design scheme for the profile 2: The width of the 1260 m horizontal security guard flat plate of No. 4 coal floor is reserved at 10 m, and the width of each security guard flat plate below 1245 m of No. 4 coal floor is increased from 10 m to 15 m, the slope stability coefficient is improved from 0.96 to 1.21, which improve the slope stability and meet the safety specification requirements.