坚硬顶板工作面回采巷道底鼓诱因分析及控制技术

为了解决坚硬顶板工作面回风平巷回采期间巷道底鼓严重问题,通过现场观测、数值模拟及工业性实验,确定了造成底鼓的主要原因是: 巷道回采期间受工作面动压影响、两帮支护强度低及底板岩性差。针对该回采巷道特点,提出了采用“顶板超前预裂爆破+两帮锚杆补强+安装底角锚杆”的底鼓控制方案,并进行了工业性试验。工程实践表明:巷道最大底鼓量为258 mm,最大底鼓速率为12.3 mm/d,变形速率及底鼓量在巷道正常使用允许范围之内,动压影响期间巷道底鼓得到有效控制。该控制技术的应用可为地质条件类似的巷道底鼓控制提供一定技术借鉴。

Causes Analysis and Control Technology for Floor Heave in Mining Roadway with Hard Roof

In order to solve the problems of floor heave in return tunnel to the working face with hard roof, the main causes for floor heave were determined based on field observation, numerical simulation and industrial experiment research, including that the influence of dynamic pressure of working face during stoping, and the low support strength of coal wall, as well as the poor lithology of floor. Aiming at these reasons, a floor heave controlling scheme was proposed, including three steps: presplitting blasting of roof, bolt reinforcement of two sides, as well as installation of floor anchor bolt. This scheme was applied in an industrial experiment, and the engineering practice showed that the maximum displacement and the maximum rate of floor heave were 258 mm and 12.3 mm/d, respectively, which were all within the allowable range of normal operation of roadway. It is shown that the floor heave in the roadway can be effectively controlled under the impact of dynamic pressure. The application of this scheme can be of technical reference for controlling those floor heave in the roadway with similar geological conditions.