多煤层开采下伏巷道零内错布置及支护设计研究

Zero-inboard-type Layout and Supporting Design in Underlying Roadways of Multiple Seams Mining

为了解决多煤层开采下伏工作面煤柱逐渐增大的问题,以四台矿14号煤层311盘区81105面为对象,利用极限平衡理论,计算得12号煤层开采对底板的最大破坏深度2.74 m,距巷帮水平距离1.85 m,使14号煤层51105巷顶板保留了足够岩层,且释放顶板上部分应力,保障了14号煤层81105面的零内错布置实施;通过钢带锚杆的支护,14号煤层51105巷顶板表面最大拉应力承载能力达到51.7 MPa,远大于超前支承压力时的拉应力承受值,验证了巷道支护的可靠性。工程结果表明,掘进中巷道顶板没有发现明显变形,最大下沉量仅18.3 mm,并因采用零内错布置,仅81105面就可多采原煤20 592 t,取得了较大的经济效益和社会效益。

To solve the gradual increase of coal pillars in underlying roadways of multiple seams mining, on the mining face 81105, panel 311, seam 14 in Sitai Mine, limit equilibrium theory was used to work out the maximum damage depth of 2.74m on floor in seam 12 mining and horizontal distance of 1.85m to roadway walls. Sufficient rock stratum was retained for the roof of roadway 51105 of seam 14 and the stress above the roof was released, so that zero-inboard-type layout was ensured for the mining face 81105 of seam 14. With steel belt anchor supporting, the maximum bearing capacity of tensile stress reached to 51.7MPa, which was far more than the value of advanced abutment pressure. This proved the reliability of the roadway support. The engineering results showed that there was no obvious deformation of the roof in the driving roadway with the maximum subsidence 18.3mm. In addition, the zero-inboard-type layout led to mine out 20 592 t more coal only on the 81155 mining face, which has achieved ideal economic and social benefits.