Study on advance treatment technology and engineering practice of faults in coal mining face
ZHANG Dunxi,YANG Zhangjie,WANG Qingniu,LI Shihui
淮南矿区地质条件复杂,断层构造多,为了解决采煤工作面过断层期间大尺度顶板岩块超前抽冒、煤壁片帮、支架失稳、护帮护顶困难及压架等问题,研发了一种用于工作面过断层的超前预加固无机复合注浆材料,优选了“两堵一注”耐高压囊袋封孔方法及注浆机具,结合长距离钻孔测斜验证,提出了采煤工作面断层超前预注浆治理技术。依据采煤工作面中断层的产状特征及赋存条件,按照断层加固区注浆钻孔全覆盖和提高注浆钻孔利用率的思路,将工作面断层超前治理预注浆钻孔布置分为如下3种方式:①对于断层组或断层走向与工作面回采巷道走向夹角较小(小于45°)的单一断层构造带,可在回采巷道内垂直采煤帮布置平行递进式预注浆钻孔;②对于断层走向与工作面回采巷道走向夹角较大(大于45°)的单一断层构造带,可在工作面回采巷道巷帮钻场内集中布置扇形预注浆钻孔;③对于煤层厚、落差大的断层构造带,可采用巷钻结合方式布置预注浆钻孔。工程实践表明:采用采煤工作面断层超前预注浆治理技术能够提高过断层期间顶板强度及稳定性,可有效避免顶板岩块超前抽冒,煤壁片帮及支架失稳等问题,有利于工作面快速通过断层构造带,为采煤工作面的安全生产提供了技术支撑。
Huainan Mining Area has complex geological conditions and many fault structures. In order to solve the problems of advanced mining of large-scale roof rock blocks, coal wall slabs, support instability, difficulties in protecting the roof and supporting during the coal mining face passing through the fault, an advanced pre-reinforced inorganic composite grouting material was developed for the working face to cross the fault. The sealing method of “two plugs and one injection”high pressure resistant bag and grouting machine were optimized, combined with long-distance drilling and inclination measurement verification, this paper put forward the technology of pre-grouting treatment technology for faults in coal working face. According to the occurrence characteristics and occurrence conditions of the fault layer in the coal mining face, the principle of full coverage of grouting borehole in fault reinforcement area and the improvement of utilization rate of grouting borehole are adopted, the layout of pre-grouting boreholes for advanced treatment of fault in the working face is divided into the following three ways:①for a single fault structural zone with a small angle (less than 45°)between fault strike and mining roadway strike, parallel progressive pre-grouting drilling holes can be arranged vertically in the mining roadway; ②for a single fault structural belt with larger angle (more than 45°)between the fault strike and mining roadway strike, it can be concentrated in the roadway side drilling field of working face. The fan-shaped pre-grouting boreholes can be centrally arranged in the drilling yard of the mining roadway at the working face; ③for the fault structural zone with thick coal seam and large drop, the combination of roadway excavation and drilling can be used to arrange pre-grouting boreholes. Engineering practice shows that the use of advanced pre-grouting treatment technology for faults in coal mining face can improve the strength and stability of the roof during the fault crossing period, and effectively avoid the problems such as advanced roof caving, rib spalling and support instability, which is conducive to the working face passing through the fault quickly and provides technical support for the safety production of the coal mining face.
fault; advanced roof fall; grouting material; parallel drilling; fan-shaped drilling; pre-grouting
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会