Published works

This report forms part of the output to a research project titled ‘Cost effective mitigation strategy development for flood prone buildings’ within the Bushfire and Natural Hazards Cooperative Research Centre. The motivation for this project arises from the experience and observations during the recent flooding in Australia in 2011, 2013 and 2015, which caused widespread devastation in Queensland. A fundamental reason for this damage was inappropriate development in floodplains and a legacy of high risk building stock in flood prone areas. The BNHCRC project aims to address this issue and is targeted at assessing mitigation strategies to reduce the vulnerability of existing residential building stock in Australian floodplains.

As a first step to achieving this goal this project has developed a building schema to categorise the Australian residential building stock. The next step was to conduct a literature review of mitigation strategies developed nationally and internationally. The review categorises the strategies into elevation, relocation, dry floodproofing, wet floodproofing and the use of flood barriers. The review helps to evaluate the strategies that suit Australian building types and typical catchment behaviours and, hence, may be adopted in Australia.

Five typical storey types have been selected to evaluate the above mentioned mitigation strategies which represent the most common residential buildings in Australia. The selected storey types are:

• Timber frame (raised floor)
• Cavity masonry - Victorian terrace (raised floor)
• Cavity masonry (raised floor)
• Brick veneer (raised floor)
• Brick veneer (slab-on-grade)

A floodproofing matrix has been developed to assess appropriate strategies for the selected storey types. This report discusses the application of these strategies to the five selected storey types during two construction regimes i.e. existing state before any event and a substantial renovation or reconstruction after an event. Each mitigation strategy has been evaluated and has been costed through engagement of professional quantity surveyor.

In future years (2016-2020) of this project, strength degradation of common building components (materials, structural systems) due to wetting and subsequent drying will be assessed through experimental testing. Vulnerability of selected storey types will also be assessed along with the factors affecting vulnerability. Cost benefit analyses will be conducted to determine optimum retrofit strategies for selected residential building types within a range of catchment behaviours. The result will be an evidence base to inform decision making by government and property owners on the mitigation of flood risk by providing information on the cost effectiveness of different mitigation strategies and an optimal solution for different cases of building and catchment types.t