Control factors of coal and gas outburst and regional prediction in Hancheng mining area,Shaanxi

Based on a series of geologic investigation and research on gas-geologic features,main geologic controlling factors influencing coal and gas outburst in Hancheng mining area are considered as gas content of coal-bed,structural fractured types of coal-body and sress of geological structures.The quantitative index and its critical value of predicting outbursts are established.The idea of the stacked method which based on same-geological conditions block are put forward.Through dividing the coal-bed into blocks with same-geological condition including gas content,coal-body structural type and geological structure stress,setting up the principle and scheme evaluated on the types of outburst danger,applying the stacked method which based on same-geological conditions blocks,the range of the outburst danger types of No.3 coalbed are predicted.It provides scientific basis for rational preventing and controlling gas-outbursts.