急倾斜近距离下保护层开采岩层移动相似模拟

Similar simulation of strata movement in exploiting steep-inclined,short-distance and under protective layer

针对豫西某矿急倾斜近距离下保护层开采设计,以矿井现场工程概况为基础,通过相似模拟试验及现场考察,对保护层开采过程中岩层移动变形及裂隙发育进行研究,据此分析该矿急倾斜近距离下保护层开采的可行性及预期卸压效果。结果表明:保护层开采过后,顶板以缓慢下沉为主,未出现大规模垮落,岩层移动量最大位置位于倾斜中部略偏上;相似模拟所得倾斜下部卸压角为73°,现场考察倾斜下部卸压角为72°,《防治煤与瓦斯突出规定》中在煤层倾角为50°情况下倾斜下部卸压角参考值为70°,三者高度吻合;岩层移动以及裂隙发育使被保护层得以卸压,也可为卸压瓦斯运移和瓦斯抽采提供通道;被保护层开采条件不会破坏,该矿此类型保护层开采安全可行,可以达到预期防突效果。

According to the design of exploiting steep-inclined,short-distance and underprotective layer in a mine located in the western area of Henan,the strata movement,deformation and fracture development were studied by similar simulation experiments and the site inspection. Then the feasibility and expected pressure relief effect of the close distance of mining steeply inclined lower protective layer mining were analyzed as well. The results show that： after the protective layer mining,the roof is given priority to sink slowly,there is no massive collapse after the mining and the largest rock movement located in the upper middle of the inclined part. The similar simulation shows that the relief angle of the lower part of inclined part is 73° while the site inspection showed that the angle is 72°. The prevention of coal and gas outburst regulations pointed out that the angle should be 70° when the seam pitch was 50°. The pressure of a protected layer could be released by the movement and fracture development,which could also provide a channel for the pressure relief gas migration and drainage. In addition,the mining conditions of a protected layer will not be damaged,this type of protective layer mining is safe and feasible in this mine,and an expected outburst prevention effect can be achieved.