河流下综放工作面覆岩破坏特征和陷落柱防水煤柱留设研究OA北大核心CSTPCD

Objectives The Ⅲ 2317 working face of Changping Cole Mine exposed the SX20 collapse column at the open-off cut.The surface Dan River flows in the same direction as the advancement of the working face.Affected by mining,the water in the collapse column and the river may flow into the working space through the mining fissures,potentially causing water inrushes in the working face.Methods This study in-vestigated the"two-zone"height of the overburden,overburden failure characteristics,and the width of the collapse column coal pillar using theoretical analysis,numerical simulation,and field observation.Results The results showed that the maximum development heights of the roof caving zone and the water-conducting fissure zone were 18.38,93.85 m,respectively.The Dan River water did not pose a water inrush threat to the working face.When mining without coal pillars,roof damage on the collapse column side developed up-wards along the cemented face of the collapse column.Combining theoretical calculations and numerical simulations,the coal pillar width was determined to be 35 m.The working face was safely mined with a 35 m coal pillar left in place.Surface deformation characteristics met expectations,with a maximum subsidence of 4 000 mm.No water inrush incidents occurred during the recovery process.Conclusions The research re-sults could provide theoretical and empirical support for the safe mining of coal seams under similar condi-tions.