Comprehensive governance technology for fully-mechanized mining face across abandoned roadways in thick coal seam

In order to address impacts of various types of abandoned roadways on normal mining of working face in thick coal seamꎬ field surveysꎬ theoretical analysis and other methods were used to summarize occurrence characteristics and hazards of abandoned roadways which were divided into complete types along bottomꎬ complete types along topꎬ and fallen onesꎬ and different treatment methods for them were proposed. Meanwhileꎬ in order to meet needs of various construction schemesꎬ sulfoaluminate ̄based multifunctional grouting materials were developedꎬ and comprehensive governance technology for fully ̄ mechanized mining face passing abandoned roadways in thick coal seam was proposed. Finallyꎬ with Sihe 中 国 安 全 科 学 学 报 China Safety Science Journal 第30卷 2020年 coal mineꎬ Chengzhuang coal mine and Guozhuang coal mine taken as engineering backgroundsꎬ filling pillar supportꎬ high water filling and deep ̄hole grouting methods were applied respectively to treat abandoned roadwaysꎬ and their governance effectiveness was investigated. The results show that after specific treatment of empty roadwaysꎬ there will be no sloughing and roof accidentsꎬ and roof pressure becomes normalꎬ thus ensuring safe mining of working faces.