Risk assessment of re-mining the residual slice of thick seam under unconsolidated aquifers

摘要

The characterization of overburden hydrogeology and investigation on overburden re-fracture due to the re-mining of the residual slices are very important for preventing panels from groundwater and sand inrush and ensuring mining safety.Moreover, the research results will be an important reference for safe recovery of coal seams with the similar geological conditions.The overburden caving and fractures due to mining the thick coal seam in the Yangzhuang Coalmine, Shandong province have been compacted and closed for more than 12 years after excavation.The variations of crack closure, water-bearing capacity of caving zone and fractured zone, structure and specific capacity of the Quaternary bottom aquifer and goaf water will significantly influence the recovery of the residual coal seams.