Abstract: In this paper, to improve the gas extraction efficiency of soft coal seam with high gas content and low air permeability, combining with proper borehole layout, we have developed a static creaking technique to fracture coal mass and improve seam permeability, and applied to the practice in No.7601 Driving Face of Wuyang Coal Mine. The practice results show that the deep-hole directional static cracking technique has higher depressurization and antireflection effect than that of common ways, which will provide reliable technical guarantee for high efficient gas extraction in soft coal seams with high gas and low air permeability.

Key words: low air permeability coal seam, static cracking technology, directional blasting, pressure relief and permeability improvement, gas drainage