Modelling the vulnerability of old URM buildings and the benefit of retrofit

The Shire of York is partnering with the WA Department of Fire and Emergency Services (DFES), the University of Adelaide and Geoscience Australia in a collaborative project that will examine the opportunities for reducing the vulnerability of the township of York to a major earthquake. The project forms part of the Bushfire and Natural Hazards Collaborative Research Centre project “Cost-effective Mitigation Strategy Development for Building related Earthquake Risk”. The township of York has a number of valuable historical buildings that contribute greatly to the town’s economic prosperity and, at the same time, are vulnerable to earthquakes. One of the benefits of retrofitting old buildings is the reduction in physical building repair required following a damaging earthquake. To evaluate this benefit it is necessary to know the vulnerability of the unmitigated building and how this changes following retrofit. This paper describes the approach taken to quantitatively estimate the vulnerability of unmitigated and retrofitted pre-WW1 URM buildings typical of the buildings found in York. Challenges in estimating vulnerability are discussed. Vulnerability curves are presented for one of six generic building types subjected to a range of retrofit scenarios and the economic benefit of each retrofit scenario is discussed.