Numerical and analytical study of overpressures and impulses inside a masonry box subjected to external blast loading

Abstract

Blast loads have attracted considerable attention in recent years due to accidental or intentional events involving important structures, which have occurred around the world. The activities related to terrorist attacks have increased and, unfortunately, the current trend suggests that they will continue to rise in the future. In relation to the design of structures subjected to blast loadings, there are still many uncertainties in the specialized technical literature. Particularly, the overpressures and impulses inside constructions are difficult to estimate due to many reflections of the shock wave. The main objective of this work is to study the propagation of the blast wave inside constructions subjected to external loadings. An experimental study was performed using a masonry box with reinforced concrete beams and columns and a typical window. The results were previously presented. In this article, numerical models are developed in order to compare results and to obtain design guidelines. Explosive charges of equivalent 1–5 kg of TNT and elevated 1 m above the ground were detonated at different distances from the window, and overpressures and impulses were obtained at five points inside and outside the room. However, empirical–analytical results using a well-known technical manual are also obtained and compared. The obtained results are useful to evaluate numerical codes and empirical formulas.