A numerical study of the evolution of the blast wave shape in tunnels.

When the explosion of condensed materials occurs in a tunnel, the subsequent blast wave reveals two patterns. The region close to the explosive charge exhibits a free-field overpressure decay pattern and the region far from the explosion, which undergoes much less overpressure decay, exhibits a quasi-one-dimensional pattern. Well-known overpressure decay laws that are applicable in each region already exist.