中文摘要：

瓦斯预抽钻孔在抽放过程中经常出现塌孔、堵孔等现象。针对这一问题,提出采用自进式旋转钻头修复失效钻孔的新方法。其利用自进式旋转钻头后置喷嘴的喷射反冲力作为动力,自行至钻孔堵塞段处,前置喷嘴形成的高压水射流对堵孔煤渣进行破碎,将其与水混合返出孔外,实现清孔排渣、钻孔修复的目的。对自进式旋转钻头钻孔破煤清渣的临界射流压力及流量进行分析,基于摩擦动力学计算钻头自驱的临界射流压力,在此基础上设计钻头结构及优化喷嘴布置,数值分析不同喷嘴组合情况下射流速度分布,得出最优喷嘴布置方式。并应用于鹤煤八矿-655轨道石门揭煤瓦斯预抽,实验结果表明：该方法能够实现失效钻孔的修复,并有效的提高了瓦斯抽采效果,缩短了瓦斯抽放时间。

英文摘要：

The phenomena of hole collapse and plugging have always occur for gas pre - drainage borehole in the drainage process. Aiming at this problem, a new method of failed borehole restoration by using the self - propelling and rotating drill was put forward. It uses the recoil force of jet flow from the rear nozzles of self - propelling and rotating drill as power to reach the plugging position of borehole by itself. The high pressure water jet from the front nozzles is applied to break the coal cinder plugging the borehole and make it flow out the borehole after mixing with water, so as to realize the goals of borehole cleaning, cinder discharge and borehole restoration. The critical jet pressure and critical flow for coal breaking and cinder discharge of borehole by self- propelling and rotating drill were analyzed, and the critical jet pressure of drill self - propel- ling was calculated based on the friction dynamics. On this basis, the structure of drill was designed, and the nozzle colloca- tion was optimized. The distribution of jet velocity under different nozzle combinations were analyzed with numerical simulation, and the optimal mode of nozzle collocation was obtained. The method was applied in gas pre - drainage of the - 655 horizontal roadway rock cross - cut coal uncovering in the 8th Mine of Hebi. The results showed that it can realize the restoration of failed borehole, enhance the gas drainage effect efficiently and shorten the time of gas drainage.