Recent advances in the modelling of earthquake hazard in Australia: part 2 – estimating the hazard

Fragility Functions for RC Shear Wall Buildings in Australia

“…The definitions of the LR, MR, and HR, corresponding to the number of stories, have been adopted from FEMA (2010). These definitions have also been adopted in EQRM (Robinson et al 2006) and GAR15 (Maqsood et al 2014). It should also be emphasized that the HR buildings investigated here have a 12-story limit, as buildings taller than this are likely to have higher mode effects not captured by the CS method (Mehdipanah et al 2016).…”

“…In contrast to the values for some parameters selected on the basis of a normal distribution, the axial load ratio ( ALR ), for example, is randomly chosen between a minimum of 0.01 (1%) and a maximum of 0.1 (10%), based on common values used in previous research (Henry 2013) as well as investigations by Albidah et al (2013) for low-to-moderate seismic regions and, more recently, Menegon et al (2017) for Australia. It should be noted that other seismic assessment methodologies, such as Hazus (FEMA 2010) and EQRM (Robinson et al 2006), also incorporate the variability of the building stock through lognormally distributed capacity functions that are calculated based on a chosen, random number. Other parameters given in Table 2 that are varied within the assessment program include the yield, hardening, and ultimate strain values of the reinforcement steel ( ∊ sy , ∊ sh , and ∊ su , respectively), Young's modulus of the reinforcing steel and concrete ( E s and E c , respectively), dead and live load of the building per floor ( G and Q , respectively), interstory height ( h s ), longitudinal reinforcement ratio ( ρ wv ), mean in-situ strength of concrete ( f cmi ), and the concrete age strength enhancement factor ( κ ).…”

“…Fragility functions are useful for risk assessments and are used by insurance companies and implemented in loss estimation software, such as the Earthquake Risk Model (EQRM; Robinson et al 2006) from Geoscience Australia. EQRM uses the methodology based on Hazus [Federal Emergency Management Agency (FEMA) 2010], which typically uses generic building parameters to estimate the capacity of a structure.…”

Exploring Australian hazard map exceedance using an Atlas of historical ShakeMaps

“…Since 1990, four widely cited continental-scale hazard assessments have been developed for Australia, with the two most recent PSHAs being published in the last decade (Allen et al, 2020; Burbidge, 2012). Despite these latter two assessments being rigorously developed on modern computational platforms (Pagani et al, 2014; Robinson et al, 2005) using modern data and models, the 1990s-era seismic hazard map of McCue et al (1993) continues to form the basis for the 2018 amendment to the Australian earthquake loading standard, the AS1170.4–2007 [R2018] (Standards Australia, 2018). This was largely because of concerns that these latter assessments would lead to some cities and regions being exposed to unacceptable risks at the 1/500 annual exceedance probability (AEP), given their low estimated hazard relative to the McCue et al (1993) map (Australian Earthquake Engineering Society, 2021).…”