Comprehensive control technology of ultra large section open-off cut surrounding rock

Based on the problems of excavation, support and comprehensive utiliation of large section open-off cut, taking ultra large section open-off cut of 8 m | arge mining height fully-mechanized coal mining face in Bulianta Coal Mine as the study object, the parameters, such as the length, diameter and spacing of the anchor and anchor cable for the large section open-off cut support were determined by the actual geological conditions and the parameters of hydraulic support. The parameter s, such as the diameter of the hydraulic fracturing hole, the depth of the orifice, the angle of the orifice and the hydraulic pressure were adopted in the working face. Th e results showed that the application of the large section open-off cut technology, the cross-section support parameters and the subsequent hydraulic pre-cracking top was safe and reliable .Application of the tunneling technology and support parameters could ensure that the open-cut eye rock stability, to meet the 8 m hydraulic suppo rt installation and initial mining requirements, hydraulic pre-cracking caving effect was obvious, which could provide some references for large-section roadway excavati on and support and subsequent comprehensive utilization under similar geological conditions.