厚硬顶板水力压裂弱化和精准控制技术研究

Research on Hydraulic Fracturing Weakening and Precise Control Technology of Thick Hard Roof

针对厚硬顶板易悬顶难破断导致工作面矿压显现剧烈问题,以神辉煤业灰岩顶板为对象,采用理论分析、数值模拟和现场应用方法,研究厚硬顶板水力弱化机理和效果模拟、高压水小孔径预裂关键参数和技术。研究结论如下:高压水沿预割导向裂缝扩展将厚硬岩层裂化为分层和小块体,及时垮落充填于采空区,切断应力传递路径、减小作用载荷,从而实现精准控制;确定了致裂高度、层位、泵站压力和钻孔参数等关键参数和工艺,工业性应用后顶板悬顶长度由10~30 m减为5 m、出现及时垮落充填,成功实现了神辉煤业厚硬顶板的有效控制。

Aiming at the problem that the heavy hard roof is easy to overhang and difficult to break,the hydraulic weakening mechanism and effect simulation of the heavy hard roof and the key parameters and technologies of the pre-cracking of high pressure water with small aperture are studied by theoretical analysis,numerical simulation and field application methods.The research conclusions are as follows:the high pressure water spreads along the pre-cut guided fracture to crack the thick hard rock into layers and small blocks,timely caving and filling in the goaf,cutting off the stress transfer path,reducing the load,so as to achieve accurate control.The key parameters and processes such as cracking height,bedding,pumping station pressure and drilling parameters are determined.After the industrial application,the roof suspended length is reduced from 10~30 m to 5 m,and timely caving and filling occurs,which successfully realizes the effective control of thick hard roof in Shenhui Mining Industry.