易冒顶板锚索毛石墙联合沿空留巷技术及应用

 为了避免损失优质煤炭资源,缓解接续紧张的状况,鸡西矿业集团公司对稳固顶板推行沿空留巷,对不稳固顶板沿走向布置条带煤柱护巷。实际工作中为了避免资源损失,曾经提出砌毛石墙沿空留巷技术,但当开采深度达到600—800m时几乎一半巷道的断面净空缩小到初期掘进断面的一半以下;为了进一步解决深部开采时沿空留巷的地压难题,又曾提出控制爆破切槽放顶沿空留巷技术。在易冒顶板,顶板随液压支架的移动而冒落,根本无法实施控制爆破切槽放顶。本文在分析上述沿空留巷技术变革的基础上,提出锚索毛石墙联合沿空留巷技术,即先锚索支护软帮顶板,然后毛石墙支护该锚索支护过的软帮顶板,引起部分顶板应力向底板转移,从而避免顶板过度应力集中。邱家矿井的开采实践表明,锚索毛石墙联合沿空留巷技术能经济有效地控制易冒顶板下沿空留巷的地压,但由于向底板转移的应力较大,需要多次挖底而消除底鼓危害。

The Technology and Application of the Gob-side Entry Retaining with Building Mullocks and Anchor Cable in the Roof Liable to Collapse

To relieve the tension of driving behind the mining coal, the gob-side entry retained stage was promoted at stable roof, and the strip pillar along strike was distributed at unstable roof in Jixi Coal-Mining Group Co. Ltd. In order to slow driving behind the mining coal as well as avoid damnifying coal resource, the gob-side entry retained with building mullocks was ever developed, but its headroom had been less than 50% of its initial section when the mining deepness arrived at 600—800m. Further more, to solve the underground pressure problem of the gob-side entry retained stage, the gob-side entry retaining with the local grooving top-caving method was also brought forward, but it wasn't applied at all because the roof collapse was accompanying with the movement of the hydraulic support in the easily falling roof. On the basis of transformation of the gob-side entry retained stage, the gob-side entry retained stage with anchor cable and building the waste rock wall is put forward in this paper, i.e. the mild roof is first supported by anchor cable, and then it is again supported by the waste rock wall, so that cause a part of roof stress transfer to bottom, thereby avoiding roof excessive stress concentration. Qiujia Mine production practice shows that the gob-side entry retained stage with the waste rock wall and anchor cable can economically and effectively control the underground- pressure in the easily falling roof, but due to the transfer of stress is bigger, need many times excavating the bottom to eliminate the harm of the bottom drum.