Attenuation of Blast Waves When Detonating Explosives inside Barriers

Noise produced by blast waves can be a problem, especially when an explosion occurs near populated areas. As one means of reducing the blast noise, the explosive is detonated in a pit, a space closed at the bottom and sides, open at the top. A two-dimentional finite difference model was used to simulate such an explosion in a pit and to determine to what extent the blast wave was attenuated. The code used, CSQ, developed by scientists at Sandia National Laboratories, was tailored for our studies. The key results were: (a) the presence of a pit in all cases caused the blast wave to be attenuated; (b) for a cylindrical pit, a pit of a radius which effected maximum blast wave attenuation was found; (c) a useful parameter, dE,-&dt, the energy loss rate from the pit, was shown to be a good indicator of relative pit effectiveness.