高应力复合顶板沿空掘巷煤柱留设研究

Study on Coal Pillar Retaining of Compound Roof with High Stress Gob-side Entry Driving

以某矿沿空掘巷为背景,采用FLAC^(3D)数值模拟软件对巷道围岩稳定机理深入剖析,基于煤柱尺寸留设原则,分别模拟煤柱在不同宽度下的应力分布特征和变形规律,确定该矿地质条件下煤柱的合理尺寸。结果表明:二_(1)煤层的顶底板属于软岩类,巷道围岩塑性区呈现蝶形分布特征,垂直应力和水平应力主要影响巷道浅部的围岩,其中侧压系数主要影响水平应力的大小,对垂直应力的影响主要表现在应力增速。煤柱的尺寸在满足原有原则下,还需考虑现有的工程地质条件和不同尺寸煤柱的应力分布和位移变化,结合巷道围岩的变形量,确定巷道和煤柱能够保持长期稳定的合理宽度,并利于采取支护措施。

Take the gob-side entry driving in a coal mine as background,the FLAC^(3D) software was used to in-depth analysis the stability mechanism of roadway surrounding rock.Based on the principle of retaining coal pillar size,the stress distribution characteristics and deformation law of coal pillar under different widths are simulated respectively,and determine the reasonable size of coal pillar under geological conditions.The results show that the roof and floor of the coal seam belong to soft rock,the plastic zone of roadway surrounding rock presents butterfly distribution,and the vertical and horizonta stress mainly affect the shallow surrounding rock of the roadway,in addition,the lateral pressure coefficient mainly affects the horizontal stress,and the vertical stress is mainly affected as the stress growth rate.Under the condition of satisfying the original principle,the existing engineering geologica conditions and the stress distribution and displacement variation of coal pillars with different sizes should be considered,and combined with the deformation of roadway surrounding rock,the reasonable width of roadway and coal pillar can be maintained for a long time,which is conducive to taking support measures.