MicroBlast: Experimental assessment of charge shape effects on blast loading in urban environments

Rigorous and accurate quantification of blast loading in urban environments is a topic of increasing importance. This work discusses the ongoing development of a new experimental facility, MicroBlast, to study urban blasts at small-scale; typically 1-10g PE10 explosives. In this paper in particular, the effects of charge shape on the form and magnitude of loading within a complex array of reduced-scale building forms are investigated. Experiments are performed using three different charge shapes (hemispheres, cubes, and rotated cubes) and three different environments (free-air and two urban layouts: regular and irregular). A significant finding from this work is that whilst charge shape has a significant influence on free-field blast parameters, loading in an urban environment is largely dependent on the urban layout only, and charge shape effects are secondary.