Study of Prevention and Control Technology for Roadway Excavation under the Soft and Extra-Thick Coal Roof in Luling Coal Mine

In view of the problems associated with poor stability coal walls, slide and leakage top-coal at tunnel excavation working face under a soft extra-thick roof, surrounding rock must be strengthened. The theoretical analysis pressure, numerical simulation other methods were comprehensively used to study coal-wall-slicing mechanism. Given characteristics combined supporting technology “coal wall water injection + metal roof frame” is proposed. findings show that in process roadway excavation, coal–rock junctions middle part are weak areas prone spalling therefore need Laboratory tests determined moisture content body during tunneling provide data for parameter design injection. Safe efficient was ensured by injecting into combination protection skeleton. application this not only effectively prevents rib but improves control deformation rock. During 40 days field observation, maximum 24.8 mm, distance between two walls 21.5 mm. controlled within safety zone. reduced repair rate improved efficiency excavation. It brought significant economic benefits provides an important reference similar mines.