@article {bnh-7464, title = {Collapse probability of soft-storey building in Australia and implications for risk-based seismic design}, journal = {Australian Journal of Structural Engineering}, year = {2020}, month = {10/2020}, pages = {1-13}, 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 = {Collapse Probability, drift capacity, Return Period, Risk-based Seismic Design, soft-storey building}, doi = {https://doi.org/10.1080/13287982.2020.1835157}, url = {https://www.tandfonline.com/doi/abs/10.1080/13287982.2020.1835157}, author = {Hing-Ho Tsang and John Wilson and Emad F Gad} } @article {bnh-6781, title = {Final report on vulnerability of as-built and retrofitted LDRC buildings}, number = {551}, year = {2020}, month = {03/2020}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Previous Bushfire and Natural Hazard CRC (BNH CRC) reports have presented the fragility curves for reinforced concrete buildings that are supported by reinforced concrete walls and moment resisting frames, and the fragility curves for this type of buildings with four retrofitting options. This study presents the vulnerability curves for these buildings presented in terms of damage factor, which is the ratio of the repair cost to the replacement cost for the buildings. This report contributes to the project {\textquotedblleft}Cost-effective mitigation strategy development for building related earthquake risk{\textquotedblright} which is aimed to develop knowledge to facilitate evidence-based informed decision making in relation to the need for seismic retrofitting, revision of codified design requirement, and insurance policy.

}, keywords = {as-built, buildings, retrofit, Vulnerability}, issn = {551}, author = {Elisa Lumantarna and Nelson Lam and Hing-Ho Tsang and Emad F Gad and John Wilson} } @article {bnh-7687, title = {Performance of geotechnical seismic isolation system using rubber-soil mixtures in centrifuge testing}, journal = {Earthquake Engineering and Structural Dynamics}, year = {2020}, month = {11/2020}, abstract = {

Geotechnical seismic isolation (GSI) system involves the dynamic interaction between structure and low-modulus foundation material, such as rubber-soil mixtures (RSM). Whilst numerical studies have been carried out to demonstrate the potential benefits of GSI-RSM system, experimental research is indispensable for confirming its isolation mechanism and effectiveness in reducing structural demand. In this regard, centrifuge modelling with an earthquake shaker under an acceleration field of 50\ g adopted in this study can mimic the actual nonlinear dynamic response characteristics of RSM and subsoil in a coupled soil-foundation-structure system. This is the first time the performance of GSI-RSM system was examined in a geotechnical centrifuge. It was found that an average of 40-50\% reduction of structural demand can be achieved. The increase in both the horizontal and rotation responses of the foundation was also evidenced. The unique augmented rocking mechanism with reversible foundation rotation was highlighted.

}, keywords = {augmented rocking mechanism, centrifuge, geotechnical seismic isolation, rubber-soil mixtures, waste tyre}, doi = {https://doi.org/10.1002/eqe.3398}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/eqe.3398}, author = {Hing-Ho Tsang and Duc-Phu Tran and Wen-Yi Hung and Kyriazis Pitilakis and Emad F Gad} } @article {bnh-6011, title = {Design procedure for seismic retrofit of RC beam-column joint using single diagonal haunch}, journal = {Structural Engineering and Mechanics}, volume = {71}, year = {2019}, month = {08/2019}, pages = {341-350}, abstract = {

Exterior beam-column joint is typically the weakest link in a limited-ductile reinforced concrete (RC) frame structure. The use of diagonal haunch element has been considered as a desirable seismic retrofit option for reducing the seismic demand at the joint. Previous research globally has focused on implementing double haunches, while the use of single haunch element as a less-invasive and more architecturally favorable retrofit option has not been investigated. In this paper, the key formulations and a design procedure for the single haunch system for retrofitting RC exterior beam-column joint are developed. An application of the proposed design procedure is then illustrated through a case study.

}, keywords = {limited-ductile; RC frame; exterior beam-column joint; seismic retrofit; single diagonal haunch}, doi = {https://doi.org/10.12989/sem.2019.71.4.341}, url = {http://koreascience.or.kr/article/JAKO201924750736475.page}, author = {Zabihi, Alireza and Hing-Ho Tsang and Emad F Gad and John Wilson} } @article {bnh-6043, title = {Framework for seismic vulnerability assessment of reinforced concrete buildings in Australia}, journal = {Australian Journal of Structural Engineering}, volume = {20}, year = {2019}, month = {05/2019}, pages = {143-158}, abstract = {

The project {\textquoteleft}Cost-Effective Mitigation Strategy Development for Building Related Earthquake Risk{\textquoteright} under the Bushfire and Natural Hazards Cooperative Research Centre (BNHCRC) aims to develop knowledge to facilitate evidence-based informed decision-making in relation to the need for seismic retrofitting, revision of codified design requirements and insurance policy. Seismic vulnerability assessment is an essential component in the project. The objective of this paper is to present the framework for carrying out vulnerability assessment of limited-ductile reinforced concrete (RC) buildings in Australia. This paper is organised into four parts: (i) overview of typical building construction in Australia and description of the three broad categories of vulnerable RC buildings identified by the authors; (ii) identification and overview of case study buildings for seismic vulnerability assessment; (iii) definition and description for each performance level and damage state, including recommended material strain limits and drift limits for RC buildings; and (iv) hazard-consistent ground motion inputs for dynamic analyses.

}, keywords = {RC buildings, regions of lower seismicity, Seismic vulnerability assessment, seismic vulnerability of RC buildings}, doi = {https://doi.org/10.1080/13287982.2019.1611034}, url = {https://www.tandfonline.com/doi/abs/10.1080/13287982.2019.1611034}, author = {Scott Menegon and Hing-Ho Tsang and Elisa Lumantarna and Nelson Lam and John Wilson and Emad F Gad} } @article {bnh-6129, title = {Progress report on costing of limited ductile reinforced concrete buildings}, number = {520}, year = {2019}, month = {10/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

{\textquotedblleft}Cost-effective mitigation strategy development for building related earthquake risk{\textquotedblright} under the Bushfire and Natural Hazards Cooperative Research Centre (BNHCRC) aims to develop knowledge to facilitate evidence-based informed decision making in relation to the need for seismic retrofitting, revision of codified design requirement, and insurance policy. Previous report has presented vulnerability assessment of two types of reinforced concrete (RC) buildings, RC buildings that are mainly supported laterally by limited ductile RC walls and buildings that are supported jointly by limited ductile RC walls and RC frames. The analyses demonstrate buildings that are jointly supported by RC walls and frames to be more vulnerable. This report presents summary findings of the vulnerability analyses along with descriptions for the types of damage observed for each performance levels with the aim of estimating cost of repair for this type of buildings.\ 

}, keywords = {buildings, concrete, emergency recovery, engineering, risk and safety}, issn = {520}, author = {Elisa Lumantarna and Nelson Lam and Hing-Ho Tsang and Emad F Gad and John Wilson} } @article {bnh-5198, title = {Report on fragility curves for limited ductile reinforced concrete buildings}, year = {2018}, month = {12/2018}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Reinforced concrete buildings make up the majority of Australian building stocks.\ Structural elements of these buildings are often designed with limited to\ nonductile detailing. With a very low building replacement rate many of the\ Australian buildings are vulnerable to major earthquakes and pose significant risk\ to lives, properties and economic activities.

"Cost-effective mitigation strategies for building-related earthquake risk{\textquotedblright} under the Bushfire and Natural Hazards Cooperative\ Research Centre (BNHCRC) aims to develop knowledge to facilitate evidencebased\ informed\ decision\ making\ in\ relation\ to\ the\ need\ for\ seismic\ retrofitting,\ revision\ of codified design requirement, and insurance policy. Seismic\ vulnerability assessment is an essential component in the project.\ 

This report presents sets of fragility curves that have been developed for two types of reinforced concrete buildings, buildings that are mainly supported by shear or core walls and buildings that are supported by walls and moment resisting frames. The seismic assessment frameworks, the approach for selection of ground motions and the development of archetype building models will be discussed. The fragility curves for low-rise, mid-rise and high-rise buildings for both types of limited ductile reinforced concrete buildings will be presented in the forms of PGV, MMI and RSDmax as intensity measures.

}, issn = {433}, author = {Elisa Lumantarna and Helen M. Goldsworthy and Nelson Lam and Hing-Ho Tsang and Emad F Gad and John Wilson} } @article {bnh-4692, title = {Seismic retrofit of exterior RC beam-column joint using diagonal haunch}, journal = {Engineering Structures}, volume = {174}, year = {2018}, month = {01/2018}, abstract = {

Exterior beam-column joint is typically the weakest link in a limited-ductile RC frame structure. The use of diagonal haunch element has been considered as a desirable seismic retrofit option for reducing the seismic demand at the joint. Previous research globally has focused on implementing double haunches, whilst the performance of using single haunch element as a less-invasive and more architecturally favourable retrofit option has not been investigated. In this study, the feasibility of using a single haunch system for retrofitting RC exterior beam-column joint is explored. This paper presents the derivation of the key formulations for the implementation of a single diagonal haunch as well as the generalization of the formulations for all three systems: the non-retrofitted subassembly, the double haunch retrofitting system, and the single haunch retrofitting system. The formulations have then been validated by available experimental data for non-retrofitted subassembly and double haunch retrofitting system. Finally, the effectiveness of the single haunch retrofitting system is compared with that of the double haunch retrofitting system through a parametric study.

}, keywords = {Exterior beam-column joint, limited-ductile, RC frame, Seismic retrofit, Single diagonal haunch.}, doi = {10.1016}, url = {https://www.sciencedirect.com/science/article/pii/S0141029617328857}, author = {Zabihi, Alireza and Hing-Ho Tsang and Emad F Gad and John Wilson} } @conference {bnh-6026, title = {Analytical Model for Seismic Retrofit of Concrete Beam-Column Joint using Diagonal Metallic Haunch}, booktitle = {World Congress on Advances in Structural Engineering and Mechanics}, year = {2017}, month = {01/09/2017}, publisher = {Swinburne University of Technology}, organization = {Swinburne University of Technology}, address = {Korea}, abstract = {

Exterior beam-column joint is typically the weakest link in a limited-ductile concrete frame structure. The use of diagonal haunch element has been considered as a desirable seismic retrofit option for reducing the seismic demand at the joint. Previous research globally has focused on implementing double haunches, whilst the performance of using single haunch element as a less-invasive and more architecturally favourable retrofit option has not been investigated. In this study, the feasibility of using a single haunch system for retrofitting RC exterior beam-column joint is explored. This paper presents the key formulations and illustrates its effectiveness by investigating the changes in the shear demand at the joint through a case study.

}, keywords = {building, building disaster proof, construction, Emergency management, engineering, hazards, risk management}, author = {Hing-Ho Tsang and Zabihi, Alireza and Emad F Gad and John Wilson} } @article {bnh-5092, title = {RC walls in Australia: reconnaissance survey of industry and literature review of experimental testing}, journal = {Australian Journal of Structural Engineering}, volume = {18}, year = {2017}, month = {04/2017}, abstract = {

This paper presents the findings of a recent reconnaissance survey of the reinforced concrete (RC) construction industry in Australia. The survey involved the review of the structural documentation of a set of case study buildings constructed in Australia. The types of walls and observed methods of detailing are documented. Upper and lower bound values for typical wall attributes have been presented which researchers can utilise to design laboratory test specimens or perform parametric computer studies, to ensure their study accurately represents real-world conditions. A literature review of experimental testing of the lateral in-plane capacity of RC walls is included. The literature review identified 81 experimental studies, in which 501 RC wall test specimens have been tested worldwide. It is shown that very little experimental studies have been performed on RC walls that match what is being constructed in Australia.

}, doi = {https://doi.org/10.1080/13287982.2017.1315207}, url = {https://www.tandfonline.com/doi/abs/10.1080/13287982.2017.1315207}, author = {Scott Menegon and John Wilson and Nelson Lam and Emad F Gad} } @conference {bnh-6028, title = {Analytical development of seismic retrofit technique for RC beam-column joint using single diagonal haunch}, booktitle = {24th Australian Conference on the Mechanics of Structures and Materials}, year = {2016}, month = {12/2016}, publisher = {Swinburne University of Technology}, organization = {Swinburne University of Technology}, address = {Perth, Australia}, abstract = {

Exterior beam-column joint is typically the weakest link in a limited-ductile RC frame structure. The use of diagonal haunch element has been considered as a desirable seismic retrofit option for preventing brittle failure of the joint. Previous research has been focused on implementing double haunches, whilst the performance of using single haunch element as a less-invasive and more architecturally favourable retrofit option has not been investigated. Hence, the feasibility of using single haunch system for retrofitting RC beam-column joint is explored in this study. This paper presents the analytical development of the technique and illustrates its effectiveness by showing the changes in the shear demand at the joint.

}, keywords = {building, construction, earthquake, engineering, retrofitting, risk management}, author = {Zabihi, Alireza and Hing-Ho Tsang and Emad F Gad and John Wilson} } @conference {bnh-6008, title = {Retrofitting RC Beam-Column Joint in Australia using Single Diagonal Haunch}, booktitle = {Australian Earthquake Engineering Society 2016 Conference}, year = {2016}, month = {11/2016}, publisher = {Australian Earthquake Engineering Society}, organization = {Australian Earthquake Engineering Society}, address = {Melbourne}, abstract = {

Exterior beam-column joint is potentially the weakest link in a limited-ductile RC frame structure in Australia. The use of diagonal haunch element has been considered as a desirable seismic retrofit option for preventing brittle failure of the joint. Previous research globally has focused on implementing double haunches, whilst the performance of using single haunch element as a less-invasive and more architecturally favourable retrofit option has not been investigated. In this study, the feasibility of using a single haunch system for retrofitting RC beam-column joint in Australia is explored. This paper presents the key formulations of the technique and illustrates its effectiveness by showing analytically the changes in the shear demand at the joint.

}, keywords = {Exterior beam-column joint, limited-ductile, RC frame, seismic retrofitting, single haunch}, author = {Zabihi, Alireza and Hing-Ho Tsang and Emad F Gad and John Wilson} } @article {bnh-4667, title = {Seismic Vulnerability Assessment of Asymmetrical Reinforced Concrete Buildings in Australia}, journal = {Australian Earthquake Engineering Society }, year = {2016}, month = {11/2016}, abstract = {

Many reinforced concrete buildings in Australia are laterally supported by reinforced concrete cores/shear walls that are eccentrically located in the buildings. The structural elements at the edges of the asymmetrical buildings can be subjected to a significant displacement demand, making this type of buildings highly vulnerable in an earthquake. Seismic assessment methods for asymmetrical buildings commonly involve three-dimensional dynamic analyses that can be computationally expensive. This paper presents a simplified analysis method for multi-storey buildings featuring plan asymmetry. The method has been used to assess the seismic vulnerability of asymmetrical reinforced concrete buildings in Australia.

}, keywords = {Aymmetrical buildings, fragility curves, reinforced concrete., simplified analysis method}, url = {https://www.aees.org.au/wp-content/uploads/2018/06/379-Lumantarna-et-al.pdf}, author = {Elisa Lumantarna and Alireza Mehdipanah and Nelson Lam and Hing-Ho Tsang and John Wilson and Emad F Gad and Helen M. Goldsworthy} } @article {bnh-3456, title = {Drift capacity of lightly reinforced concrete columns}, journal = {Australian Journal of Structural Engineering}, volume = {15}, year = {2015}, month = {11/2015}, pages = {131-150}, chapter = {131}, abstract = {

This paper presents the findings of a research project investigating the lateral load drift behaviour of lightly reinforced concrete columns. Such columns of limited ductility are common in regions of low-moderate seismicity, and although their strength properties are well defined, the drift performance is less understood. The paper presents the results of an experimental study undertaken and the development of a theoretical model for predicting the lateral load-drift behaviour of lightly reinforced concrete columns together with a simplified bi-linear model for checking purposes. The test results are presented and clearly indicate the dramatic impact that the axial load ratio has on the drift performance of columns of limited ductility, particularly the significantly lower drift capacities that are available in compression dominated columns.

}, doi = {10.7158/S13-002.2014.15.2}, url = {http://www.tandfonline.com/doi/pdf/10.7158/13287982.2014.11465154}, author = {Ari Wibowo and John Wilson and Nelson Lam and Emad F Gad} } @article {bnh-3454, title = {Overturning of precast RC columns in conditions of moderate ground shaking}, journal = {Earthquakes and Structures}, volume = {8}, year = {2015}, month = {2015}, pages = {1-18}, chapter = {1}, abstract = {

A simple method of assessing the risk of overturning of precast reinforced concrete columns is presented in this paper. The displacement-based methodology introduced herein is distinguished from conventional force-based codified methods of aseismic design of structures. As evidenced by results from field tests precast reinforced concrete columns can be displaced to a generous limit without sustaining damage and then fully recover from most of the displacement afterwards. Realistic predictions of the displacement demand of such (rocking) system in conjunction with the displacement capacity estimates enable fragility curves for overturning to be constructed. The interesting observation from the developed fragility curves is that the probability of failure of the precast soft-storey column decreases with increasing size of the column importantly illustrating the "size effect" phenomenon.

}, doi = {10.12989/eas.2015.8.1.001}, url = {http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=TPTPJW_2015_v8n1_1}, author = {Bidur Kafle and Nelson Lam and Elisa Lumantarna and Emad F Gad and John Wilson} } @article {bnh-3457, title = {Drift performance of lightly reinforced concrete columns}, journal = {Engineering Structures}, volume = {59}, year = {2014}, month = {02/2014}, pages = {522-535}, chapter = {522}, abstract = {

This paper presents the findings of a research project investigating the lateral load drift behaviour of lightly reinforced concrete columns. Such columns are common in regions of low{\textendash}moderate seismicity, and although their strength properties are well defined, the drift performance is less understood. The paper presents the results of an experimental study undertaken and the development of a theoretical model for predicting the lateral load{\textendash}drift behaviour of lightly reinforced concrete columns. The model includes a study undertaken to estimate the drift capacity of lightly reinforced columns at lateral load failure and axial load failure based on a large database of previous experimental tests. The results of a case study example are presented and clearly indicate the dramatic impact that the axial load ratio has on the drift performance of lightly reinforced columns, particularly the significantly lower drift capacities that are available in compression dominated columns.

}, doi = {http://dx.doi.org/10.1016/j.engstruct.2013.11.016}, url = {http://www.sciencedirect.com/science/article/pii/S0141029613005701}, author = {Ari Wibowo and John Wilson and Nelson Lam and Emad F Gad} } @article {bnh-5181, title = {Drift performance of lightly reinforced concrete columns}, journal = {Engineering Structures}, volume = {59}, year = {2014}, month = {02/2014}, pages = {522-535}, chapter = {522}, abstract = {

This paper presents the findings of a research project investigating the lateral load drift behaviour of lightly reinforced concrete columns. Such columns are common in regions of low{\textendash}moderate seismicity, and although their strength properties are well defined, the drift performance is less understood. The paper presents the results of an experimental study undertaken and the development of a theoretical model for predicting the lateral load{\textendash}drift behaviour of lightly reinforced concrete columns. The model includes a study undertaken to estimate the drift capacity of lightly reinforced columns at lateral load failure and axial load failure based on a large database of previous experimental tests. The results of a case study example are presented and clearly indicate the dramatic impact that the axial load ratio has on the drift performance of lightly reinforced columns, particularly the significantly lower drift capacities that are available in compression dominated columns.

}, doi = {https://doi.org/10.1016/j.engstruct.2013.11.016}, url = {https://www.sciencedirect.com/science/article/pii/S0141029613005701?via\%3Dihub}, author = {Ari Wibowo and John Wilson and Nelson Lam and Emad F Gad} } @article {bnh-3455, title = {Drift Performance of Point Fixed Glass Fa{\c c}ade Systems}, journal = {Advances in Structural Engineering}, volume = {17}, year = {2014}, month = {11/2014}, pages = {1481-1495}, chapter = {1481}, abstract = {

Glass fa{\c c}ade systems in buildings are subject to racking actions caused by inter storey drifts from earthquakes and wind action. The performance of fa{\c c}ade systems is dependent on the amount of imposed drift and the interaction of the glass panels with the fa{\c c}ade structural support frames. There are two major concerns related to the glass fa{\c c}ade system performance during and immediately after a seismic event; hazards to people from falling glass and the cost associated with building down time and repair. It was observed that earthquake damage to glass fa{\c c}ade systems resulting from in-plane racking actions is increasingly common and yet there has been limited research published in this field. The research completed to date has mainly focused on traditional framed glass fa{\c c}ade systems; however, the racking performance of point fixed glass fa{\c c}ade system (PFGFS) is likely to be quite different. Therefore, the aim of the research presented in this paper is to assess the in-plane racking performance of PFGFS which is a fa{\c c}ade system gaining popularity worldwide.

Two unique full scale in-plane racking laboratory tests on typical PFGFS with different types of connections were conducted and specific racking mechanisms were identified. Sophisticated non-linear finite element models (FE models) were developed and benchmarked against experimental results with excellent correlation. Further detailed FE analyses were conducted to evaluate the individual drift contributions of each racking mechanism such as rigid body translation of the glass panels at the oversize holes for construction tolerance, spider arm rotation and spider arm deformation. It was found that most of the drift capacity is attributed to the rigid body translation at the oversize holes. In this paper, the laboratory test setup and the experimental results are discussed together with the confirmatory FE analysis results to assess the in-plane racking performance of the PFGFS.

}, doi = {https://doi.org/10.1260/1369-4332.17.10.1481}, url = {http://journals.sagepub.com/doi/abs/10.1260/1369-4332.17.10.1481}, author = {S Sivanerupan and John Wilson and Emad F Gad and Nelson Lam} }