Hazard Characteristics from Gas Explosion in Underground Constructions

Gas explosion is likely to become a new type of attack aimed at underground spaces by terrorists. In this paper, as an example for methane-air gaseous mixture, distribution characteristics of shock wave, flame, temperature field and toxic gaseous products generated from gas explosion in a long straight laneway were analyzed. Along the increasing axial distance, shock wave overpressure increases in original flammable gas area but decreases beyond the original gas area. Range of flame exceeds the original gas area. Flame accelerates continually in the original gas area but decelerates beyond the original gas area. The temperature attenuates slowly along the increasing distance in the flame area by virtue of flame front, but attenuates quickly along the increasing distance beyond the flame region. High temperature hazard involves farther area beyond the original gas area.