The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

315 / 2018-05-04 10:41:31

Research on the width of fault waterproof coal pillar based on underground pressure control theory

underground pressure; distribution characteristics; water inrush from floor; destroyed floor depth; fault waterproof coal pillar

Mine Dynamics Disaster > Water inrush

Abstract: The paper expounds the distribution characteristics of underground pressure and its damage to a coal seam in front of working face based on underground pressure control theory, and the distribution and propagation characteristics of vertical underground pressure in floor with simulation results of 2D-σ finite element analysis software. Numerical simulation reveals that the peak stress line of the vertical underground pressure inclines to the advancing direction of the working face. Based on the establishment of mechanics model for water inrush from floor through a fault in stope, a formula for calculating the distance between the bottom of coal seam and the intersection point of the peak stress line with the fault is derived. The condition of water inrush from floor aquifer through a fault is obtained, that is, the destroyed floor depth caused by underground pressure is not less than the distance between the bottom of coal seam and the intersection point of the peak stress line with the fault. The water inrush pathway is composed of the fault and the destroyed floor strata by underground pressure. The formula for calculating destroyed floor depth based on grey multivariate nonlinear regression analysis is derived by four main factors taken into consideration, which are mining depth, dip angle of coal seam, inclination width of working face, floor strata Platts coefficient, the calculation formula of a fault waterproof coal pillar in stope is put forward and the rationality of the formula is proved by a case history of water inflow in Suncun Coal Mine, China.