深井复合顶板条件下沿空留巷充填体水平方向稳定性分析

Backfill horizontal stability analysis of gob-side entry retaining with compound roof in deep mine

针对深井沿空留巷充填体常向巷道空间发生移动,分析深井复合顶板条件下充填体水平位移特征,计算顶底板对充填体的摩擦力和基于弹性地基梁理论下的采空区冒落矸石对充填体的水平挤压力。基于淮南矿区顾桥矿1115(1)工作面轨道顺槽典型深井复合顶板条件下沿空留巷工程地质条件,建立充填体力学计算模型,得到深井复合顶板条件下沿空留巷充填体内移表达式。结果表明,(1)由于复合顶板裂隙发育,垮落后具有较好的流动性,在关键块旋转下沉过程中容易对充填体产生水平挤压力,且复合顶板能够较大程度吸收关键块旋转下沉施加的给定变形,底板不易插底,充填体更易发生内移;(2)理论计算充填体位移量为0.38 m,实测位移量为0.5 m,二者能够吻合,验证了研究成果的正确性。根据充填体内移特点,提出抗剪锚杆等措施增加充填体和顶底板摩擦因数和在靠近充填体的采空区侧设置隔离桩的控制技术。

For the backfill horizontal movement of gob-side entry retaining in deep mine, the characteristics of horizontal movement of backfill in deep mine with compound roof are analyzed; the horizontal pressure of backfill suffered from gob caving gangue based on elastic foundation beam theory and friction force between backfill and roof(floor) are calculated; based on the condition of 1115(1) working face tail entry in Guqiao mine of Huainan mining area which is typical condition of gob-side entry retaining with compound roof in deep mine; and then the mechanical model of backfill is established; the backfill horizontal movement expression of gob-side entry retaining with compound roof in deep mine is obtained. The results show that:(1) Due to the development of the compound roof fissure, it has a good flow ability after the collapse; it is easy to produce horizontal squeezing force on the filling during the rotation of the key block, and the given deformation of key block can be absorbed by compound roof which leads to the backfill is not easy to insert the bottom; therefore, the backfill is more prone to shift to roadway under the condition of gob-side entry retaining with compound roof in deep mine.(2) Theoretical calculation displacement of backfill is 0.536 m; the field measured displacement is 0.55 m; the results verify the correction of researches. According to the characteristics of backfill horizontal movement, the supporting scheme that increasing the friction factor by using shear bolts between backfill and roof(bottom) and setting isolation piles near the backfill in gob to isolate the backfill and gangue are proposed.