@conference {bnh-6388, title = {How Safe is Safe Enough? Melbourne Case Study}, booktitle = {Australian Earthquake Engineering Society 2019 Conference}, year = {2019}, month = {12/2019}, address = {Newcastle}, abstract = {

Residual risk exists in our buildings even if they were designed in conformance with modern codes of practice. The risk of being killed by earthquakes in Melbourne was discussed in the AEES 2018 Conference (Tsang et al. 2018a). This follow-up paper attempts to address a fundamental question in seismic design: {\textquotedblleft}How Safe is Safe Enough?{\textquotedblright} Various approaches have been implemented or proposed in the last decade for setting risk-targeted performance requirements for seismic design. A target collapse risk limit for a single building may be considered very low by some; however, the aggregated risk for society could become significant, especially for a metropolitan city like Melbourne. This paper introduces an approach proposed by the authors (refer Tsang et al. 2019for full details and discussion)for evaluating the adequacy of existing code level for collapse prevention and life safety by comparing societal risk functions based on regional earthquake loss modelling with a proposed regulatory requirement that aims to limit the earthquake mortality rate to {\textquotedblleft}as low as reasonably practicable (ALARP){\textquotedblright}. The proposed approach is then applied to Melbourne in a case study. The results show that the earthquake fatality risk for society appears to be unacceptable.

}, keywords = {building, Collapse, earthquake, Earthquake fatality, F-N function, Societal risk}, url = {https://aees.org.au/wp-content/uploads/2019/12/66-Hing-Ho-Tsang.pdf}, author = {Hing-Ho Tsang and James Daniell and Friedemann Wenzel and John Wilson} } @article {bnh-6141, title = {A universal approach for evaluating earthquake safety level based on societal fatality risk}, journal = {Bulletin of Earthquake Engineering}, year = {2019}, month = {10/2019}, pages = {1-24}, abstract = {

Residual risk exists in our buildings even if they were designed in conformance with modern codes of practice. Various approaches have been implemented or proposed in the last decade for setting risk-based performance requirements for seismic design of building structures. However, there is insufficient consideration about the aggregated risk for society, which could be significant especially for a densely populated metropolitan city. This paper introduces a rational and universal approach for evaluating the adequacy of structural safety requirements by comparing societal risk functions based on probabilistic loss assessment with a proposed regulatory requirement that aims to limit the mortality rate to {\textquotedblleft}as low as reasonably practicable\ (ALARP){\textquotedblright}. The proposed approach is then applied to Melbourne, Australia, in a case study, which shows that the earthquake fatality risk for the society appears to be unacceptable. The outcome can be used for justification of a seismic retrofitting policy or a required change of the design code level. The proposed scheme is also applicable to other natural hazards and for safety engineering applications generally.

}, keywords = {Building structure, Collapse, Earthquake fatality, F{\textendash}N, Seismic safety, Societal risk}, doi = {https://doi.org/10.1007/s10518-019-00727-9}, url = {https://link.springer.com/article/10.1007/s10518-019-00727-9}, author = {Hing-Ho Tsang and James Daniell and Friedemann Wenzel and John Wilson} }