“三软”厚煤层回采巷道围岩整体强度低，且岩层结构组合普遍变化较大，造成掘进工作面悬露顶板稳定性差异明显，部分顶板稳定性较差区域无法直接采用掘锚一体机及配套施工工艺，造成掘进工作面频繁停工，整体掘进效率下降。针对此类问题，以沙吉海煤矿“三软”厚煤层回采巷道为工程背景，采用现场调研、理论分析、数值模拟等综合研究方法，阐明了掘进工作面悬露顶板漏冒、掘锚一体机陷入底板或跑偏、煤壁片帮是制约掘锚一体机在“三软”厚煤层回采巷道中应用的关键制约因素；考虑悬露顶板厚度、扰动影响系数、顶板各岩层强度及各岩层完整性等参量的影响，建立和推导了掘进工作面悬露顶板极限跨距计算公式；形成了以掘进工作面悬露顶板极限跨距计算为主导的巷道围岩稳定性分级方法，将“三软”厚煤层回采巷道围岩划分为极稳定、稳定、中等稳定、不稳定、极不稳定5个级别；提出了不同稳定性级别围岩条件下掘锚一体机装备及施工工艺分类优化方案，并从截割滚筒位态调整、底板接地处理、巷帮作业平台增设等方面给出了困难作业环境下掘锚一体机应用对策。研究成果在沙吉海煤矿B1003W05工作面巷道进行了工程应用，其分类优化方案可有效保障掘锚一体机在“三软”厚煤层中的正常运行，相比邻近巷道采用悬臂式掘进机综掘工艺，掘进速度提升了1.0～1.8倍。

The overall strength of the surrounding rock of “three-soft” thick coal seam mining roadway is low, and the combination of rock structure generally changes greatly, resulting in obvious differences in the stability of hanging roof of driving face, and some areas with poor roof stability cannot directly adopt bolter miners and supporting construction technology, resulting in frequent stoppage of driving face and a decrease in the overall driving efficiency. In view of such problems, taking “three-soft” thick coal seam mining roadway of Shajihai Coal Mine as engineering background, and using comprehensive research methods such as on-site research, theoretical analysis and numerical simulation, it was clarified that roof leakage of driving face, bolter miner falling into the floor or mistracking, and rib spalling are the key constraints restricting the application of the bolter miner in “three-soft” thick coal seam roadway. Considering the influence of parameters such as the thickness of the hanging roof, the influence coefficient of disturbance, the strength of each rock layer of the roof and the integrity of each rock layer, the calculation formula of the limit span of hanging roof of driving face was established and derived. A stability grading method for surrounding rocks of roadway was formed dominated by the calculation of the limit span of hanging roof of driving face, and surrounding rocks of “three-soft” thick coal seam roadway is divided into 5 grades: extremely stable, stable, moderately stable, unstable and extremely unstable. Classification and optimization scheme of bolter miner equipment and construction process under different stability levels of surrounding rock is proposed, and the application countermeasures of bolter miner under difficult operating conditions are given from the aspects of cutting drum position adjustment, floor grounding treatment, and addition of roadway operation platform. The research results were applied in the roadway of Shajihai Coal Mine No.B1003W05 working face, and its classification optimization scheme can effectively ensure the normal operation of the bolter miner in “three-soft” thick coal seams, and the driving speed is increased by 1.0−1.8 times compared with fully-mechanized driving of boom-type roadheader.