Optimization Analysis of Roadway Layout of Close Coal Seam Based on Energy Releasing Method

In order to ensure the safe and efficient mining of the multi coal seam face in Xinliu Coal Mine, due to the coal losses caused by roadway layout with 20-metre-wide alternate interior distance in lower coal seam, both laboratory experiment for energy surge and failure mechanism in the pressing process of coal sheet, and energy analysis for internal energy change of sectional coal pillar and its damage to the floor were conducted to determine the reasonable size of sectional coal pillar. The conclusions are as follows: the energy will cause to coal damage while the energy load of coal surged to a maximum, and the sharp release of energy was the essential reason for its sudden failure; according to the internal strain energy of sectional coal pillar obtained by the stress-strain monitoring point, the 15-metre-wide alternate interior distance of roadway layout was the minimum value. In such a circumstance, both the residual pillar in the upper coal seam and section pillar in the alternate interior area of the lower coal seam（W）maintain remarkably stable; the site measurement results show that the surrounding rock of roadway maintains greatly stability while 1117 working face in Jiaozili mining area takes 15 m inner stagger distance to layout the roadway.