The Effect of Scaling Building Configuration Blast Experiments on Positive Phase Blast Wave Parameters

Explosions in an urban setting can have a significant negative impact. There is a need to further understand the loading effects caused by the blast's interaction with structures. In conjunction with this, the effects of scaling and understanding the limitations of laboratory experiments are equally important given the cost incurred for full-scale experiments. The aim of this study was to determine the scaling effects on blast wave parameters found for reduced-scale urban blast scenario laboratory experiments. This paper presents the results of numerical modelling and physical experiments on detonating cuboidal PE-4 charges and measuring the pressure in direct line of sight and at three distinct positions around the corner of a small-scale "building" parallel to the rear wall. Two scales were used, namely 75% and 100%. Inter-scaling between 75% and 100% worked fairly well for positions shielded by the corner of the wall. Additionally, the lab-scale results were compared to similar (but not identical) field trials at an equivalent scale of 250%. The comparison between lab-scale idealised testing and the larger-scale field trials published by Gajewksi and Sielicki in 2020, indicated sensitivity to factors such as detonator positioning, explosive material, charge confinement/mounting, building surface roughness, and environment.