Study on form optimization of open-pit mine slope based on section and spatial form effect

Reasonable design of the slope form of mining field is an important prerequisite for optimizing open-pit mining boundary, ensuring safe production and improving economic benefits of open-pit mines. Taking an open-pit mine in Thar coalfield of Pakistan as the research background. Based on the section form effect of slope stability and the occurrence characteristics of coal seam and weak layer, the section form of slope was optimized step by step from two-dimensional angle by using the rigid body limit equilibrium method. The three-dimensional numerical simulation method was used to revealed the influence of slope spatial geometry on slope stability, that based on the three-dimensional spatial effect of slope stability. At the same time, the three-dimensional numerical simulation method was used to optimize the spatial form of the slope, thus revealed the evolution mechanism of slope instability. By comparing the optimized slope form with the preliminary design and the slope form of the the straight slope with equal flat plate, the economic benefits were further analyzed. The results showed that under the premise of meeting the safety reserve coefficient, compared with the preliminary design and the design of equal plate. The slope angle of the optimized section form was increased by 1 ° and 3 ° respectively, and the coal resource recovery was increased by 332m 2 and 1790m 2 respectively, and the economic benefits were $ 18065859 and $ 54408251 respectively. And the slope angle of the optimized spatial form was increased by 3 ° and 5 ° respectively, and the coal resource recovery was increased by 1188m 2 and 2726m 2 respectively, and the economic benefits were $ 72082808 and $ 108417368 respectively.