Determination of coal pillar size and support optimization between large roadways in Yaoqu Coal Mine
In order to study the reasonable size of coal pillars between roadways and the stability of surrounding rock when the roadway passes through the denudation area,the Ⅱ return air roadway in the west mining area of Yaoqu Coal Mine was taken as the research object.The calculation model of coal pillar size was established by theoretical analysis and numerical simulation.The distribution law of stress,displacement and plastic zone of roadway surrounding rock under the conditions of 8 m,10 m,12 m and 14 m were revealed.The reasonable size of coal pillars between roadways in the denudation area was determined,and the support parameters of Ⅱ return air roadway in the west mining area were optimized.The results show that when the size of the coal pillar between the Ⅱ return air roadway and the auxiliary transportation roadway in the western mining area of the mine is reduced from 14 m to 8 m,the vertical stress in the surrounding rock of the roadway is increased from 1.381 MPa to 1.465 MPa,and the maximum displacement is increased by 12.52%.When the size of coal pillar is 10 m,the plastic zone of coal pillar is in the critical area of penetration,and there is a certain elastic core area in the coal pillar,and the size of coal pillar is larger than theoretically calculated 9.23 m,which can meet the stability of roadway surrounding rock.Considering comprehensively,the reaso-nable size of coal pillar is determined to be 10 m.The sup-port optimization of the Ⅱ return air roadway in the west mining area under the size of 10 m coal pillar is carried out.The stress,displacement and plastic zone of the surrounding rock of the roadway are significantly improved after the support of three bolts in the side,so as to ensure the stability of the surrounding rock.
denudation arealarge roadwaycoal pillar sizesurrounding rock supportplastic zonevertical stress