On the seismic loss estimation of integrated performance-based designed buildings

Performance-based earthquake engineering (PBEE) is a probabilistic framework developed to improve seismic risk decision-making, characterising building performance in terms of metrics such as casualties, economic losses and anticipated downtime. Building upon PBEE, expected annual loss (EAL) and collapse safety expressed in terms of mean annual frequency of collapse (MAFC) have been recently proposed as fundamental objectives within an integrated performance-based seismic design (IPBSD) framework. This article, following the parametric investigations conducted, proposes a refined design loss curve and demonstrates the capabilities of IPBSD to target a certain MAFC and limit EAL through its application to several reinforced concrete case-study buildings. The performance was evaluated using both incremental dynamic analysis and a storey-based loss assessment procedure to estimate MAFC and EAL of risk-targeted designs, respectively. The agreement and consistency of design solutions and intended performance objectives were then checked to demonstrate the validity of the IPBSD framework, with MAFC being effectively targeted and the EAL limited as initially foreseen by the method. Further scrutiny of the results highlighted the validity of the assumptions made in the IPBSD framework and shed further light on the pertinent sources of economic losses, namely the ones deriving from structural and non-structural elements, when designing buildings, in addition to influential parameters like initial period range and the influence of design engineering demand parameter profiles. This is seen as part of the next-generation risk-targeted and loss-driven design approaches in line with modern PBEE requirements.