ABSTRACT

Coal mines in China have extremely complex geological conditions, including extremely lowpermeability coal bed, high gas content, high gas pressure, and low gas extraction rate. Because of this gas accidents are the number one killer of coal mine disasters in China, with gas accidents accounting for 20% and number of fatality accounting for 71%. There are more than 30 mechanisms used by the international community to explain coal and gas outburst at present, such as ground stress effect hypothesis [1], gas pressure effect hypothesis [2], and combined effect hypothesis [3]. The combined effect hypothesis is accepted by most scholars.