Abstract: Along with the increasing of mining depth, crustal stress is playing more and more important role in coal and gas outburst By using theoretical analysis, numerical simulation and field investigation, the influence of fault strike on gas outburst under the modern tectonic stress field is discussed in this paper. The results show that the risk of coal and gas outburst is mainly controlled by the tectonic evolution and the relationship between fault strike and maximum principal stress direction in the modern tectonic stress field. When the fault strike is parallel to the maximum principal stress, it contributes to stress re-lief featuring, better gas permeability of coal seam, and small risk of outburst. But at the end of fault, especially at the lower end of fault, stress concentration may occur and gas occurrence conditions are relatively good, it needs to to pay attention to gas accidents.Along with the increase of angle between fault strike and principal stress direction, the scope of extruding shear stress concentration increases, and outburst risk scope increases. When fault strike is vertical to maximum principal stress, the extruding shear stress concentrates in a large scope, the coal seam permeability is low, which contributes to the formation of large gas concentration zone, and the outburst risk is largest.

Key words: gas outburst, modern tectonic stress field, fault strike, numerical simulation