A new technology for coal and gas control based on the in situ stress distribution and the roadway layout

An auxiliary gas control technology is described that can reduce coal and gas outburst accidents when there is no existing protective coal seam and gas pre-draining is not effective. Numerical simulation methods were used to study the stress distribution ahead of the roadway face for different in situ stresses. The results from the simulation can then provide a new gas control technology. The results show that a high stress concentration, high stresses, and high displacement gradients appear ahead of the roadway face when the maximum in situ stress is aligned perpendicular to the roadway axis. The risk of gas outburst is higher when the stresses decrease rapidly over distance and when the release of more energy occurs immediately after driving the roadway. The gas outburst risk is much smaller when the in situ stress is aligned parallel to the roadway axis. During design of the coal mine most of the coal roadways should be arranged to parallel the maximum in situ stress. This will decrease the outburst risk in general and may be considered a new gas outburst prevention method. (C) 2012 Published by Elsevier B.V. on behalf of China University of Mining & Technology.