切槽形式及位置对夹矸煤巷卸压效果的影响

Influence of pressure relief effect of groove form and position on gangue coal roadway

为研究夹矸煤巷的卸压效果,以城子河矿二水平中部采区3B号煤层右一面回采巷道为背景,依据夹矸位置制定切槽方案,采用FLAC^(3D)数值模拟软件建立了切槽卸压数值模型。研究结果表明:切槽卸压后,巷帮移近量降低了50.7%,侧向支承压力峰值点和蝶形塑性破坏区明显向围岩深部移动,有利于巷道围岩稳定;切槽形式不同,巷道侧向支承压力峰值和巷帮移近量变化均小于5.0%,而水平切槽使应力峰值向围岩深部移动1.52 m,卸压效果较好;切槽位置不同,下部煤层切槽侧向支承压力峰值及位置均居中,其巷帮移近量降低了62.1%,降幅分别为上部煤层切槽和夹矸切槽的近8倍、2倍,能更好的维持巷道稳定。在巷帮下部煤层中布设水平切槽对巷道围岩卸压效果最优。

This paper aims to study the pressure relief effects in the gangue alley.The study building on the right mining roadway of No.3B coal seam in the middle mining area of Level 2 of Chengzihe Mine as the background,consists of the formulation of grooving schemes with the position of gangue,the development of a numerical model of grooving pressure relief using FLAC3D numerical simulation software.The results show that:the pressure relief by cutting the groove is followed a decrease by 50.7%in the roadway wall displacement,and the obvious movement of the peak value of lateral abutment pressure and the butterfly plastic failure zone move towards the depth of surrounding rock,which is beneficial to the stability of surrounding rock;different forms of grooves see less than 5.0%of the variations in lateral abutment pressure peak value and side movement of roadway and the stress peak movement by 1.52 m to the depth of surrounding rock due to the horizontal grooves,contributing to a better relief effect;among the grooves at different positions,the peak value and position of lateral abutment pressure of the grooves at the lower coal seam are both in the middle,but the amount of roadway side movement decreases by 62.1%,which is nearly 8 times and 2 times what are the grooves at the upper coal seam and gangue grooves,respectively,with a better ability to maintain roadway stability.The arrangement of horizontal grooves in the coal seam at the bottom of roadway wall could have the optimal pressure relief effect on roadway surrounding rock.