The Investigation of Strata Control for Ultrasoft Coal Seam Mining

Strata control of ultrasoft coal seam has been a critical problem for mining and geotechnical engineers in years. In this paper, the No. 66207 longwall panel at Xinzhuangzi mine, Anhui, China, was used as an example study. A systematic approach using laboratory testing, numerical simulation, field validation implemented to investigate influences roadway layout presplit blasting on mechanical properties surrounding rock. Based results, inward-stagger with roof proposed regional strata control. The investigation relationship between angle repose water content showed that first increased then decreased increasing content. peak value observed 17.659% content, suggesting injection into can improve rib stability. “high resistance, integral beam, two-stage rib+roof support system” design replace traditional equipment, which seam. combination system “difference stepping” technique capable preventing from failure, well mitigating rockfall during moving hydraulic support. validation, it found stress concentration coefficient relatively low process. This able effectively manage mining-induced while improving productivity three times than without technique. There also no failure event mining, such safety mine workers improved significantly.