Depth determination of floor crack zone in coal mining face of Group A in Huainan Mining Area

Abstract

The production mines of Huainan Mining Area have already mined Group A coal, which is seriously threatened by deep high-pressure water, in order to solve the problem of the applicability of the traditional coal seam floor mining failure depth empirical formula, based on the production geological parameters of the Huainan Mining Area, the statistical software SPSS is used to analyze the partial correlation of various parameters, optimize the traditional damage depth calculation formula, and apply the fitting formula to the calculation of the floor damage of the 1612A working face in Zhangji Coal Mine; based on numerical simulation and micro-seismic monitoring are used to verify the accuracy of the formula calculation. The research results show that the coal seam thickness and other parameters are related to the depth of the fissure zone; a new calculation formula is obtained by fitting, and the calculated failure depth of the working face reaches 27.33 m, which is consistent with the fracture zone depth of 28 m measured by water injection test and 30 m calculated by numerical method; the concentration and distribution of micro-seismic events monitored on site are used to obtain a concentration depth of 30-35 m for the micro-fracture of the bottom plate.

Keywords

• group a coal
• failure zone
• numerical simulation
• micro-seismic monitoring
• empirical formula
• floor crack zone