沿空-煤柱型孤岛工作面接续开采覆岩结构及能量聚散演化特征OA

In order to optimize the continuous mining method of isolated island working face and clarify the key areas for disaster prevention and control,taking the 12405 gob side-coal pillar isolated island working face of Selian No.2 Coal Mine as the research object,the overburden structure and energy accumulation and dispersion evolution characteristics during continuous mining of this isolated island working face were studied by means of similar simulation,theoretical analysis,numerical simulation,and engineering practice.The results show that the bending deformation energy and gravitational potential energy accumulated by the high T-shaped beam and the low main roof strata are instantaneously converted into kinetic energy after goaf connection on the non-pillar side of the isolated island working face,which is the main reason for the periodic mine seismicity disturbance in the stope.Before the mining of the isolated island working face,the energy is mainly accumulated in the two road-ways of the coal seam and the overlying roof strata up to 40 m above them.The accumulated energy at the end of the non-coal pillar side and the coal pillar is higher than that in the middle,extending to the floor in an arc shape.After the mining of this working face,the energy is transferred to the remaining coal pillar and the key strata,and the energy level of the remaining coal pillar rises significantly,which is easy to induce the coal pillar spalling and slip hazards.The engineering practice shows that the pre-splitting blasting roof cutting and pressure relief can ef-fectively reduce the risk of large-scale roof weighting,improve the stress state of surrounding rock of roadways,eliminate the isolated coal pillar,and achieve the purpose of safe and efficient non-coal pillar continuous mining.