恒昇煤业9304工作面顶板存在13m的坚硬厚层K2石灰岩,岩石的普氏系数f>7,工作面推采过后顶板不易垮落。针对端头位置容易存在十几米的悬顶,造成一定的安全隐患问题,以恒昇煤业9304工作面为工程背景,分析端头悬顶问题的形成原因及水力压裂消除机理,模拟不同影响因素下水压裂缝在坚硬厚层顶板中的扩展规律,确定9304回风顺槽坚硬厚层顶板的水力压裂技术参数,提出了9304回风顺槽坚硬厚层顶板分段水力压裂技术。结果表明:9304回风顺槽进行压裂的过程中出现锚杆孔、锚索孔出水现象,压裂之后伴随着工作面的推进,坚硬顶板能够及时垮落,悬顶区域可控制在4m以内,分段水力压裂技术能够解决坚硬顶板端头悬顶问题。

There is a hard thick layer K2 limestone of 13 m existing in the roof of the 9304 working face of Hengsheng Coal Industry. The Proctor's coefficient f of the rock is greater than 7, and the roof is not easy to collapse after the pushing mining of the working face. In response to the certain safety hidden dangers caused by the easily presence of a hanging roof over ten meters at the end position, taking the 9304 working face of Hengsheng Coal Industry as the engineering background, the formation reasons of the end hanging roof problem and the elimination mechanism of hydraulic fracturing are analyzed, the propagation law of water pressure cracks in hard thick layer roof under different influencing factors are simulated, determines the hydraulic fracturing technical parameters of the hard thick layer roof in the 9304 return air channel, and proposes a segmented hydraulic fracturing technology for the hard thick layer roof of the 9304 return air channel. The results show that during the fracturing process of the 9304 return air channel, water out phenomenon of the anchor rod holes and anchor cable holes is happened. With the advancement of the working face after fracturing, the hard roof can collapse in a timely manner, and the hanging roof area can be controlled within 4 m. Segmented hydraulic fracturing technology can solve the problem of end hanging roof of the hard roof.