An overview of surface water hazards in China coal mines and disaster-causing mechanism

Surface water is not only an important water supply to mining region but also the cause of severe water burst accidents in coal mines. In China, surface water is categorized as a major water hazard that has inflicted serious property losses and casualties not seen in the rest of the world. Based on the analysis of the distribution and characteristics of 47 major mining accidents caused by surface water in China coal mines, this paper summarizes the disaster-causing mechanism of surface water hazards in coal mines. Main research results are as follows: (1) coal mine accidents caused by surface water mainly occur in spring and summer with large rainfall; particularly in summer when 70% of such coal mine accidents took place, (2) natural water channels include valleys and gullies, surface tension fissures, water-conducting faults, and karst collapse caves in mountain areas; (3) artificial water channels include underground structures in abandoned mines (such as shafts and roadways), water-conducting cracks resulted from mining activities, and illegal mining of water and sand-resistant coal (rock) pillars. Through the analysis of engineering cases, this paper puts forward prevention and control measures of surface water hazards of coal mines. The results of this paper can be of reference to other countries tasked to treat surface water hazard while protecting surface water resources.