放顶煤回采初始阶段沿空留巷矿压分析

Analysis of Mine Pressure in the Initial Stage of Mining in Gob-side Entry Retaining with Top Coal Caving

山西兰花集团东峰煤矿对首个综采放顶煤沿空留巷二次回采的工作面初采进行具体的矿压分析,得出如下结论:(1)3G01沿空留巷二次回采时初次来压步距和周期来压步距均出现不同程度的减小,且矿压现象较为明显;(2)第一次大范围来压时,超前20 m范围,巷道变形主要表现为靠墙体侧的顶板剪切下沉,巷道中部的底鼓以及煤帮侧的帮鼓,靠墙体侧顶板变形最为明显;(3)通过锚杆锚索压力表数据分析,超前20 m范围内顶帮压力存在一个快速增大的时间点;(4)沿空留巷推进过程中,柔模混凝土墙体未出现变形、倾斜、破裂等现象,表明柔模墙体强度足够。利用矿压分析的结果,可及时采取针对加强顶板管理措施。

The paper makes mine pressure analysis on the initial mining of the first fully mechanized top coal caving gob-side entry retaining for secondary stoping in Dongfeng Colliery of Shanxi Lanhua Group,and draws the following conclusions which enables timely measures to be taken to strengthen roof management:firstly,during the second stoping of 3G01 gob-side entry retaining,both the initial step and the periodic step distance decreased to different degrees,and the mine pressure phenomenon was more obvious;secondly,when the first large-scale pressure was applied,ahead of 20 m,the deformation of the roadway was mainly manifested by the shearing and sinking of the roof on the side of the wall,floor heave in the middle of the roadway and heave on the side of the coal bank,roof deformation was the most obvious;thirdly,through the data analysis of the anchor rod and cable pressure gauge,there was a time point of rapid increase in the top pressure within 20 m ahead;fourthly,in the process of gob-side entry retaining,the flexible form concrete wall did not appear to be deformed,tilted,or broken,indicating that the flexible form wall was sufficiently strong.