Study and practice of water filling mode and water control mining technology in typical coal mine area under roof water body

For water hazard prevention and control as well as water resource protection in typical mining areas with thick and extremely thick coal seams under water-bearing strata, nearly 30 years of practical experience in mining under water-bearing strata were summarized and refined. This has led to the development of a water control (protection) technology model suitable for typical mining areas in China. Based on the occurrence characteristics of water-bearing roof in typical mining areas and the spatial relationship with the main coal seam, five water filling models were proposed, that is, weakly consolidated water sand collapse, high pressure progressive water filling, high-positioned thick water-bearing strata permeation, upward and downward cracks progressive conduction water filling, and lateral large channel strong recharge water filling. Based on the dual control of disturbance range and water filling volume, an integrated theory and technical system for controlled (protecting) water in coal mine roof water-bearing strata were established, including precise detection of water-bearing strata, precise control of overburden damage, controllable reduction of water filling volume, and coordinated monitoring and early warning of hydro logical conditions. Key technologies were proposed, such as precise detection using transient electromagnetic methods considering shutdown time effects, height estimation of high-intensity mining-induced conductive fracture zones in thick and extremely thick coal seams, pre-mining precise pre-reduction of roof water-bearing strata based on drainage capacity constraints, weakening hard main control overburden to guide the height of conductive fracture zones, and hydrological monitoring and early warning involving three parameters of absolute value, change rate and trend of water level in water-bearing strata. For the water control practice of roof water-bearing strata in some typical mining areas in China, corresponding water control mining models have been proposed, achieving sucess in water control for mining under different types of water-bearing strata. The research findings provide scientific reference for coal mining under water-bearing strata, realizing safe, efficient and green mining.