综放工作面过硐室围岩破坏机理及卸压技术研究

Research on Surrounding Rock Failure Mechanism and Pressure Relief Technology of Fully-mechanized Caving Face Crossing Chamber

以小庄煤矿40309综放工作面过设备硐室为工程背景,理论推导了围岩破坏机理,揭示了工作面与硐室间煤体的弹性区和塑性区范围之比是煤体发生失稳的主要影响因素,采用数值模拟对钻孔卸压技术煤体应力变化进行分析,工作面与硐室间煤体从30 m减小到5 m,工作面前方的煤体一直处于应力升高状态,钻孔卸压后,煤体中的应力集中现象逐渐消失,高应力向实体煤转移。工程实践表明:采用帮部长钻孔施工+合理推采联合技术措施,支架压力由22 MPa增加至26 MPa,增幅平缓,确保了综放工作面回采过程中安全平稳通过设备硐室。

Based on the engineering background of 40309 fully mechanized caving face crossing the equipment chamber in Xiaozhuang coal mine. The research shows that the elastic zone and plastic zone of the coal body between the working face and the chamber are the main factors of coal body instability. The pressure relief technology of drilling can effectively adjust the stress change, and the coal body between the working face and the chamber is reduced from 30 m to 5 m, the coal body in front of the working face has been in a state of increasing stress. After the borehole pressure relief, the stress concentration phenomenon in the coal body gradually disappears, and the high stress is transferred to the solid coal. The numerical simulation shows that the borehole pressure relief can weaken the coal body and transfer the high stress in the coal body, which is one of the most commonly used methods to prevent and control the coal body rockburst between the working face and the chamber. In the engineering practice, the combined technical measures of drilling construction and reasonable mining are adopted to ensure the safe and stable crossing the equipment chamber in the mining process of the fully mechanized caving face. The increase of support pressure is gentle from 22 MPa to 26 MPa.