Analysing explosive damage in an urban environment

Abstract

This paper describes the determination of the mass of explosive and the location of the source of the explosion in a terrorist attack in a congested urban environment. A computational dynamic analysis was carried out for a real congested urban environment that corresponds to opposite rows of blocks of buildings in the same street. Many combinations corresponding to different locations and explosive masses were simulated, and the corresponding distributions of pressure and impulse on the building façades were obtained. Additionally, conclusions about the applicability of empirical expressions for evaluating incident and reflected pressure and associated impulses in a congested urban environment arise from a comparison with the numerical results, and are discussed in the paper. The structural damage produced by an explosion can be assessed with the use of isodamage curves, which approximately relate pressures and impulses to the damage produced in different types of building and parts of them. In general, isodamage curves have been obtained from a vast compilation of damage produced in masonry houses and other buildings and structural members, in both experimental and actual explosions. Damage contours were defined and used in order to compare the real damage with that obtained by the numerical simulation over a wide zone around the origin of the explosion. Additionally, conclusions that lead to the ability to discard many combinations of mass of explosive and location of the source of the explosion arise from the comparison of real and simulated damages, and are discussed in the paper.