厚层坚硬顶板工作面沿空留巷技术

Gateway Retained Technology Along Goaf of Coal Mining Face with Thick and Hard Roof

针对凤凰山煤矿厚层坚硬顶板条件下工作面沿空留巷难度大,留巷变形严重的情况,结合顶板移动规律,采用顶板预裂爆破技术,利用采场周期来压沿空切顶,形成上覆基本顶岩梁的支撑结构,控制基本顶的回转和下沉变形,实现卸压作用。结合154307工作面沿空留巷工艺特征,分析了坚硬顶板条件下沿空留巷充填系统工艺流程、顶板预处理手段、留巷内辅助加强支护方式,并对留巷期间围岩移近速度等活动规律进行观测分析。留巷后巷道断面8 m2以上,巷道顶板完整稳定。

According to the high difficulty and gateway retained serious deformation conditions of the gateway retained along goaf in the coal mining face under conditions of thick and hard roof in Fenghuangshan Mine, in combination with the roof movement law, a blasting technology was applied to pre-fracture the roof and periodical roof weighting of the coal mining face was applied to cut the roof along the goaf. Thus a support structure of the basic roof in the overburden strata was formed, the rotary and subsidence deformation of the basic roof was controlled and a pressure releasing role was realized.In combination with the technical features of the gateway retained along the goaf in No. 154307 coal mining face of Fenghuangshan Mine, a plane layout mode of the coal mining face with the gateway retained along the goaf under the hard roof condition, the backfill material width, an auxiliary enhanced support method and the roof pre-treatment means were analyzed and designed.An observation and analysis were conducted on the convergence speed between the roof and floor as well as the two sides of the gateway and the surrounding rock activity law.After the gateway retained along the goaf, the cross section area of the gateway was over 8 m^2 and the roof of the gateway was completed and stable.