This final report contains a summary of the research undertaken by the research team from four partner institutions towards the development of an evidence base to inform decision making on the mitigation of the seismic risk posed by the most vulnerable Australian buildings subject to earthquakes. Without this evidence base, it is impossible to make cost-effective and economically justifiable decisions by building owners and government officials on all matters concerning seismic strengthening of existing and design of new buildings. While the focus of this project is on buildings, many of the project outputs will also be relevant for other Australian infrastructure such as bridges, roads and ports, while at the same time complementing other ‘Natural Hazards’ CRC project proposals for severe wind and flood.
In order to achieve the overall project aim, work was undertaken on three complementary fronts to:
- Understand the seismic vulnerabilities of existing unreinforced masonry (URM) and limited ductile reinforced concrete (LDRC) buildings and methods to address them through seismic retrofit;
- Risk assessment of the building stock through development of an economic loss model with trial evaluations for a regional town (York, WA) and a metropolitan area (Melbourne); and
- Advance an end-user focused research utilisation project in the area of community risk reduction. This is done through an Earthquake Mitigation Case Study for the historic town of York in Western Australia.
The first of the above components was researched in the Universities of Adelaide, Melbourne, and Swinburne. This work included investigations of existing building seismic capacities and development of building specific retrofit techniques. The second area was studied by Geoscience Australia and the work includes estimating direct and indirect losses associated with building damage and benefits from seismic retrofit. The delivery date for the Melbourne CBD trial evaluation was delayed due to Covid-19 impacts but the revised delivery date of March 2021 has been agreed by the CRC. The last component was conducted utilizing the research findings in the two other areas in collaboration with the Western Australia Department of Fire and Emergency Services, York Shire Council and its residents.
Finally, using the new damage loss models and costings for seismically retrofitting buildings, recommendations are made for the development of seismic retrofit guidelines and policy based on the strong evidence base being developed by this CRC project team.
As a consequence, the project has been extremely successful with several end-users implementing the research outputs. York Shire Council has embarked on seismic retrofit of up to three buildings in the Shire as demonstrations to other building owners of the cost-effectiveness as well as helping to develop the local expertise amongst the building profession to implement these simple seismic strengthening techniques. The project has also resulted in a follow-on project in Western Australia to expand the building typologies from York to include three additional typologies that are common in the rest of WA. The retrofit strategies for all nine typologies will be made publically available through web sites.