BLAST RESISTANT DESIGN PARAMETERS AGAINST AN UNCONTROLLED DEMOLITION (IMPLOSION) IN AUSTRALIA

Abstract

 Because of the uncertainty that presently exists within the Australian community of a possible
improvised explosive device (IED) or vehicle improvised explosive device (VIED) detonating at some time in
the not too distant future there is uncertainty as to what would happen if an Australian engineer was approached
by a civilian developer to either design a new commercial structure or design a retrofit an existing commercial
structure what explosive charge weights are to be designed for and what type of explosives will be used? With
no Australian Standard or Design Code yet available the engineer could look for overseas examples for design
parameters. Three events were considered in this paper using CONWEP software. A 5kg IED detonated on a
top deck of a London bus with zero detonation distance amongst travelers generating a peak pressure of
32.69MPa, a 1020kg VIED was detonated 3m from a club generating a peak pressure of 10.29MPa and a
massive 2990kg VIED was detonated 6m from a multi-storey RC building generating a peak pressure of 5.83
MPa. Peak pressures in all three events meant all were well above lethality for people and that destruction of
assets they were detonated in or next to was inevitable. As explosive charge weights can’t be controlled the
only parameter a designer can dictate is range. So, any design must be such that it forces a terrorist to detonate
as far away from the intended target as possible thus reducing blast overpressures that impact people or assets.