The paper discussed a comprehensive numerical simulation and field work by the usage of waterjet slotting tech- nique to prevent the occurrence of outbursts in soft and outburst prone coal seams. This was based on the...The paper discussed a comprehensive numerical simulation and field work by the usage of waterjet slotting tech- nique to prevent the occurrence of outbursts in soft and outburst prone coal seams. This was based on the geological and ge- omechanical conditions of Jinjiachong Colliery, Guizhou Province, associated with varied waterjet slotting parameters such as slotting penetration, slotting thickness and slotting distance along the length of borehole. Also, to understand the variation of internal stress of coal seams after waterjet slotting application, the internal stress levels were compared with and without slot- ting application, and the results indicate that the internal effective stress levels can be reduced to 70% and 45% for the vertical and horizontal stresses, respectively, and the gas concentration can be increased up to 5 times when the waterjet slotting is ap- plied.展开更多
文摘The paper discussed a comprehensive numerical simulation and field work by the usage of waterjet slotting tech- nique to prevent the occurrence of outbursts in soft and outburst prone coal seams. This was based on the geological and ge- omechanical conditions of Jinjiachong Colliery, Guizhou Province, associated with varied waterjet slotting parameters such as slotting penetration, slotting thickness and slotting distance along the length of borehole. Also, to understand the variation of internal stress of coal seams after waterjet slotting application, the internal stress levels were compared with and without slot- ting application, and the results indicate that the internal effective stress levels can be reduced to 70% and 45% for the vertical and horizontal stresses, respectively, and the gas concentration can be increased up to 5 times when the waterjet slotting is ap- plied.
