Collapse probability of soft-storey building in Australia and implications for risk-based seismic design

ABSTRACT

Collapse prevention is the primary objective of earthquake-resistant design of structures; hence, the probability of collapse should be taken as a crucial performance indicator for risk-based design of new structures or assessment of existing structures. One major challenge in collapse risk assessment is to reliably model the non-linear structural response behaviour. This study features the rocking response behaviour of precast reinforced concrete (RC) columns based on results from previous field testing on parts of a real building and supplemented with a study of their rocking behaviours through a series of shake-table tests. The effects of bidirectional earthquake actions on failure drift capacity of columns have also been incorporated, such that realistic estimates of displacement capacity were made for constructing collapse fragility functions, which were then combined with the ground motion recurrence relationships of Melbourne, Australia for the computation of collapse probability. A suite of typical soft-storey buildings was adopted, with considerations given to a diversity of site conditions. Deaggregation of the results reveals the range of return periods that controls the collapse risk, which could have important implications for the choice of earthquake scenarios for seismic analysis and design in regions of lower seismicity.

KEYWORDS:

• Risk-based Seismic Design
• Collapse Probability
• Soft-storey Building
• Drift Capacity
• Return Period

Acknowledgments

The long-term research partnership with Professor Nelson Lam and Dr Elisa Lumantarna from the University of Melbourne on related projects is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Australian Research Council [LE110100052]; Australian Research Council [DP140103350]; Australian Research Council [DP1096753]; Bushfire and Natural Hazards Cooperative Research Centre [Project A9].

Notes on contributors

Hing-Ho Tsang

Hing-Ho Tsang is an Associate Professor at Swinburne University of Technology, Australia. He received his BEng (Hons) and PhD from the University of Hong Kong. He is a Chartered Professional Engineer (CPEng) and serves in advisory roles to governments, industry and professional bodies, leading to the development of design standards and guidelines globally. His research interests include structural design and protective technology for extreme events.

John L. Wilson

John L. Wilson is a Professor, Deputy Vice-Chancellor and Chief Executive Officer of Swinburne Sarawak, Malaysia. He received his BEng (Hons) from Monash University; MSc from the University of California, Berkeley; and PhD from the University of Melbourne. John is the chairman of BD6/11, the committee responsible for AS 1170.4. John’s research interests are focused on earthquake engineering with a particular emphasis on the seismic performance of limited ductile RC columns and walls.

Emad F. Gad

Emad F. Gad is a Professor and Dean of School of Engineering at Swinburne University of Technology, Australia. He received his BEng (Hons) from Monash University; and PhD from the University of Melbourne. He is chairman of the Board of the Australian Engineered Fasteners and Anchors Council (AEFAC) and a Fellow of Engineers Australia. His research interests include structural dynamics, light-framed steel construction and connections.