Deformation Rule of Protected Coal Seam Exploited by Using the Long-Distance-Lower Protective Seam Method

Abstract

With the help of the similar material simulation experiment,the deformation rule of the protected coal seam exploited by using the long-distance-lower protective-seam method was simulated.The deformation area of the protected coal seam was divided into five regions,which were compressive deformation region,discharging swelling deformation region,discharging swelling stable deformation region,discharging swelling deformation region,and compressive deformation region.The deformation regions showed M-shaped form,symmetrically distributed in two sides.The engineering practice indicates that the discharging swelling deformation of the protected coal seam takes place in a certain range over the goaf,the elastic potential of the coal seam is released,making the permeability be improved and the risk of coal-gas outburst in the protected coal seam eliminated or decreased after the protected coal seam has been exploited out.The research results were applied to the engineering practice and has achieved remarkable economic benefit.