瑶渠煤矿大巷间煤柱尺寸确定及支护优化

Determination of coal pillar size and support optimization between large roadways in Yaoqu Coal Mine

为研究大巷过剥蚀区时大巷间煤柱合理尺寸及围岩稳定性,以瑶渠煤矿西采区Ⅱ回风大巷为研究对象,采用理论分析、数值模拟等研究方法,建立了煤柱尺寸计算模型,揭示了煤柱在8 m、10 m、12 m、14 m条件下巷道围岩应力、位移及塑性区的分布规律,确定了过剥蚀区大巷间煤柱的合理尺寸,并优化了西采区Ⅱ回风大巷的支护参数。研究结果表明,瑶渠煤矿西采区Ⅱ回风大巷与辅运大巷之间煤柱尺寸由14 m减小至8 m时,巷道围岩内的垂直应力由1.381 MPa增加至1.465 MPa、最大位移量增加了12.52%,塑性区逐渐贯通煤柱。当煤柱尺寸为10 m时,煤柱塑性区处于贯通的临界区域,煤柱内部具有一定的弹性核区域,且煤柱尺寸大于理论计算的9.23 m,能够满足巷道围岩的稳定性。综合考虑,确定煤柱最小合理尺寸为10 m。对10 m煤柱尺寸下西采区Ⅱ回风大巷进行支护优化,采用帮部3根锚杆支护后巷道围岩应力、位移和塑性区均显著改善,保证了巷道围岩的稳定性。

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 support 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.