Design criteria essential for an uncontrolled demolition (explosion)

In the case of an uncontrolled demolition or a terrorist attack no prior knowledge is usually available as to what the exact explosives is and what the exact charge weight is. As well, in most cases the authorities have no idea what the target is to be in advance of an attack. For a designer to design a structure to minimize the damage in such cases is somewhat difficult if not impossible but, nevertheless, it must be done. Once the explosive, either as an improvised explosive device or vehicle improvised explosive device, has detonated the normal aftermath of such events such as fragmentation, primary and secondary fires, ground cratering and building collapse are all obvious. From a designers’ point of view, the starting point is to understand in detail all building collapse mechanisms to be able to design for such events and so allow time, if possible, for all those caught inside a building to escape and for structural damage to be minimized. To obtain such design parameters the designer must refer to past uncontrolled demolitions on Australian soil or in countries close by to gauge the most likely threat. Prior to design commencing one also must have clear criteria and strategy in mind to be able to complete a suitable design to ensure his obligation to allow time for people to escape from its collapse is met and damage is minimized. Designers not only have to address new building designs to withstand blast and ballistic loadings but also how to retrofit existing buildings cost effectively against such blast and ballistic loadings. Detailed lists of required criteria and strategies that are necessary so at to arrive at a suitable design for any blast or ballistic loadings likely to being applied to a structure are provided within the paper based on all aspects of an uncontrolled demolition (explosion) that may confront a designer.