Blast waves caused by internal explosion in ammunition and explosive facility: vulnerability and protection alternatives

Internal explosion in an ammunition and explosive (A&E) facility might cause the most dangerous consequences. The blast can spread to all parts of the facility harming personnel in different levels. High pressure can cause lethality due to lung damage. It might also cause building collapse mainly of the structure’s elements right aside the explosion that might turn into debris and rubbels. The secondary fragments of nearby equipment (connected or unconnected) might fly with high velocity. Shock wave moving through the structure and the ground might cause people to be overturned or to fall down with possible injuries or fatalities. Analytical-numerical research for the Israeli Ministry of economy analyzed a typical A&E facility. In one of the rooms in the facility a TNT explosive charge was detonated. The TNT charge weights were 1, 10, and 50 kg. The charges were lying on the floor (hemispherical) and at 1 m above the floor (spherical). The blast wave generated from the explosions was calculated by BLASTX software under a few conditions: all openings are closed, all openings are opened, and additional venting opening in the room where the explosion took place. The 1 kg explosion caused only minor structural damage, the 10 kg explosion caused moderate structural damage, while the 50 kg explosion caused severe structural damage. The blast leakage in all the rooms was calculated for the various cases. In order to provide protection and prevent fatalities in the rooms adjacent to the explosion, a few upgrading protection measures are suggested: addition of steel plate, polymer sheets, or reinforced concrete layer to the existing reinforced concrete (RC) walls that will enhance the flexure and shear capacity of the structure; installing blast doors between the rooms that will be closed when dangerous activities are done, and addition of venting openings in the dangerous places. The internal shock can be lowered by absorption technics layers, dampers, and springs.