Evaluation of goaf water hazard and its prevention and control technology of abandoned coal mines in Zhahe mining area of Huaibei

With the depletion of shallow coal resources and the implementation of the national coal production capacity reduction policy, the number of closed mines has increased year by year. Groundwater will not be drained any more after the coal mine is closed, and this will threaten the adjacent active coal mine. The abandoned coal mines in Zhahe mining area of Huaibei were taken as the research targets, and the recovery of the water level in the closed mines was predicted, and the tensile strength of the main coal seam was evaluated comprehensively. Finally, the safety of the mine was evaluated. The results show that the coal pillar width could not meet the safety requirements at present. So, the comprehensive prevention and control system of water hazard in closed mines were established. The system includes:water accumulation process monitoring of abandoned coal mines, borehole exploration and pre drainage of goaf water, advance drainage of draining laneway, setting of gate wall for over water tunnel, dynamic monitoring of downhole open channel flow, shaft filling and reinforcement and comprehensive exploration and governance of old and small coal mine boundary. Finally, the safe mining of adjacent mines threatened by the water hazard of closed mines has been realized, and significant economic and social ben-efits have been achieved. The research results can provide a basis and method for preventing similar water disasters in closed mines in China.