局部薄弱煤柱影响下临近煤柱应力分布规律研究

Study on adjacent stress distribution of coal pillars under influence of local weak coal pillars

为了研究采空区煤柱—顶板结构安全稳定性,以白羊岭煤矿留煤柱开采为例,借助前期研究已建立多煤柱—顶板结构简化为连续梁力学模型,根据煤柱与顶板变形协调关系进一步建立了局部薄弱煤柱影响下相邻煤柱竖向应力分布函数,推导了局部煤柱承载力衰减影响下临近煤柱竖向应力分布计算公式,研究了煤柱—顶板结构荷载传递规律。结果表明:煤柱内部竖向应力分布理论计算结果和数值模拟结果较为吻合,但在煤柱外侧竖向应力相差较大;3#煤柱承载力由q0l衰减为q0l/2时,两侧相邻煤柱承载力增加了11q0/32,顶板和围岩共同分担了剩余的竖向荷载21q0/32;煤柱承载力的衰减,不但对临近其他煤柱形成了应力传递效应,同时转移的荷载增量对顶板稳定性威胁更大。

To study the safety and stability of coal pillar-roof structure in goaf, taking coal pillar mining in a mine of Baiyangling city as an ex ample ,the coal pillar-roof structure is simplified to a continuous beam. According to the deformation relationship between coal pillars and roof, the vertical stress distribution is establ ished. Fin ally, the formula for the vertical stress distribution of coal pillars under the bearing capacity decay of the adjacent coal pillars is derived ,and the load transfer of coal pillar-roof structure is studied. The results show that the theoretical calculation of the vertical stress distribution in coal pillars is coincide with the result of numerical simulation,but there is a big difference in the lateral vertical stress of the coal pillars ; that ,when the bearing capacity of 3# coal pillar attenuates from q01 to q01/ 2, the vertical load o n adjacent coal pillars is increased by 11 q0/32 , and roof and surrounding rock share the rest of 21 q0/32. The attenuation of the bearing capacity of coal pillar not only forms a stress transfer effect o n other coal pillars but also threatens the stability of the roof.