Study On Engineering Rock Mass Stability And Stope Reasonable Span In Sizhuang Mine

With the increasing value of mineral resources, as well as the national increasing emphasis on engineering safety exploring mining resources in a safety, high efficiency and low cost way is becoming the priority for mine companies and mine operators. Due to the complex geological conditions of the deposit, fast determination of rock mass quality in underground excavation is a prerequisite for safe mining. To realize the aim of economic and efficient mining, the classification of the rock mass quality and stope span are investigated in the paper, and following work has been completed.(1)The geological properties and rock mass and its joints were investigated and measured, and the influencing factors for both quality and stability of rock mass were analyzed.(2)In light of the fractal theory, the inherent properties of rock joints were described and detected the effects of fractal features on rock mass stability. The fractal dimension of both joint spacing and joint distribution were calculated, which was taken as an important indicator to evaluate the rock mass quality.(3)By the means of chaos optimization method of BP neural network, the outcome of rock mass quality classification was obtained after inputting the calculated data of rock mass quality. After this, the rock mass stability intelligent identification model was established. According to this model, a plane graph was drawn to predict the stability conditions of rock mass in2#,1#and IV#veins in Sizhuang mining area, which can provide useful references for the stopes span optimization and roadway supporting design.(4)The mechanical parameters of rock mass with different qualities were determined by the proportional reduction of the mechanical properties of rock specimen obtained in laboratory. According to the rock mass quality, the upward drift stopping process with various stope spans was stimulated by ANSYS, a large FEM software. After summarizing the simulation results, the optimal stope span was determined and applied in2#,7#and IV#veins to ensure the safety, efficiency and low-cost mining in Sizhuang mining area.