@article {bnh-7961, title = {Generalized Loading Protocols for Experimentally Simulating Multidirectional Earthquake Actions on Building Columns in Regions of Low-to-Moderate Seismicity }, journal = {Journal of Structural Engineering}, volume = {147}, year = {2021}, month = {04/2021}, abstract = {

This study aimed to quantitatively develop realistic quasi-static loading protocols for simulating bidirectional cyclic actions and axial load variation on building columns in a way that is representative of an actual response during earthquake ground excitation. A case-study building was subjected to a suite of 15 ground motions that were scaled to design basis earthquake (DBE) and maximum considered earthquake (MCE) levels of a typical region of low-to-moderate seismicity. The results showed that the displacement path of a building column under earthquake actions is generally in the form of elliptical loops of various orientations due to the phase difference in the sinusoidal displacements in the two orthogonal axes of the column. Accordingly, this work proposes a bidirectional lateral loading protocol that simplifies and generalizes the displacement path of the column in the form of elliptical loops of four different orientations. Similarly, the patterns of axial load variation in columns were also studied in detail, which led to the development of separate axial load variation protocols for external and internal columns of a building, which can be applied in tandem with the bidirectional lateral loading protocol. The paper concludes with a brief overview of the results of two reinforced concrete (RC) column specimens, which were experimentally tested using the proposed bidirectional loading protocol.

}, keywords = {earthquakes, engineering, reinforced concrete structures}, doi = {https://doi.org/10.1061/(ASCE)ST.1943-541X.0003056}, url = {https://ascelibrary.org/doi/abs/10.1061/\%28ASCE\%29ST.1943-541X.0003056}, author = {Saim Raza and Hing-Ho Tsang and Scott Menegon and John Wilson} } @article {bnh-7971, title = {The Selection and Scaling of Ground Motion Accelerograms for Use in Stable Continental Regions}, journal = {Journal of Earthquake Engineering}, year = {2021}, month = {04/2021}, abstract = {

This paper presents an application of the Conditional Mean Spectrum (CMS) methodology for sourcing accelerogram records for use in dynamic analyses of structures in intraplate regions of lower seismicity. The main challenges with deriving CMS for selecting and scaling accelerograms in regions of lower seismicity stem from the paucity of representative strong motion data and event recurrence data. A step-by-step illustration of the methodology is presented using the south-eastern Australia (SEA) region as an example. The study involves making use of a diversity of Ground Motion Prediction Expressions (GMPEs) including a recently developed regionally adjustable Component Attenuation Model (CAM). Three different schemes using a weighted averaging of candidate GMPEs were adopted and a comparison of predictions demonstrated only minor differences confirming the robustness of the modelling. The CMS constructed in this study have been used to develop a proposed suite of scaled accelerograms for SEA.

}, keywords = {Component attenuation model, Conditional mean spectra, earthquake, engineering, ground motion selection, stable continental region}, doi = {https://doi.org/10.1080/13632469.2021.1913456}, url = {https://www.tandfonline.com/doi/abs/10.1080/13632469.2021.1913456?journalCode=ueqe20}, author = {Yiwei Hu and Nelson Lam and Scott Menegon and John Wilson} } @article {bnh-7017, title = {Axial Load Variation of Columns in Symmetrical RC Buildings Subject to Bidirectional Lateral Actions in Regions of Low to Moderate Seismicity}, journal = {Journal of Earthquake Engineering}, year = {2020}, month = {06/2020}, pages = {1-29}, abstract = {

Columns in building frame systems are subjected to the combined action of bidirectional horizontal loading and axial load variation during an earthquake. Whilst the behaviour of RC columns under unidirectional and bidirectional lateral loading with constant axial load is understood well, the behaviour under bidirectional lateral loading with axial load variation is rarely studied, especially for limited ductile RC columns prevalent in regions of low to moderate seismicity. This paper begins with a numerical study that aims to obtain the generalised patterns and range of axial load variation in RC building columns. To this end, a case study building is subjected to a suite of 15 ground motions, representative of low to moderate seismic regions, in OpenSees. This is followed by an experimental study in which limited ductile high-strength RC columns are tested under bidirectional lateral loading and two different axial load variation protocols, namely synchronous and nonsynchronous variable axial loading protocols. The results of the numerical study demonstrated that axial load variation of the columns in an RC building is primarily dependent on the response spectral acceleration corresponding to the fundamental period of the structure in the two orthogonal horizontal directions and/or the vertical direction. The results of the experimental testing showed that nonsynchronous axial loading (compared to constant and synchronous axial loading) results in the lowest collapse drift capacity and energy dissipation of the RC columns.

}, keywords = {Axial load variation, bidirectional loading, drift capacity, earthquake, RC columns}, doi = {https://doi.org/10.1080/13632469.2020.1772151}, url = {https://www.tandfonline.com/doi/abs/10.1080/13632469.2020.1772151?journalCode=ueqe20}, author = {Saim Raza and Scott Menegon and Hing-Ho Tsang and John Wilson} } @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-5433, title = {Cost-Effective Mitigation Strategy Development for Building Related Earthquake Risk Annual Report 2017-2018}, number = {464}, year = {2019}, month = {03/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {
This project arose out of the on-going research efforts by the group involving\ structural engineering academics at the Universities of Adelaide, Melbourne and\ Swinburne with Geoscience Australia experts all working towards seismic risk\ reduction in Australia. Most of the research team are actively involved in the\ revision to the Australian Earthquake Loads standard (AS1170.4) as well as being\ members of the Australian Earthquake Engineering Society which is a Technical\ Society of Engineers Australia. The devastating impact of the 2010{\textendash}11\ earthquakes in the Christchurch region on the New Zealand economy and\ society has further motivated this group to contribute to this CRC{\textquoteright}s aims of risk\ reduction for all natural hazards in Australia.\ This project addresses the need for an evidence base to inform decision making\ on the mitigation of the risk posed by the most vulnerable Australian buildings\ subject to earthquakes. While the focus of this project is on buildings, many of\ the project outputs will also be relevant for other Australian infrastructure such as\ bridges, roads and ports, while at the\ same time complementing other {\textquoteleft}Natural\ Hazards{\textquoteright} CRC project proposals for severe wind and flood.
}, keywords = {cost-mitigation, earthquake}, author = {Michael Griffith and Hossein Derakhshan and Elisa Lumantarna and Hing-Ho Tsang and John Wilson and Nelson Lam and Mark Edwards and Martin Wehner} } @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} } @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} } @conference {bnh-6387, title = {Predicting Maximum Displacement Demand of Asymmetric Reinforced Concrete Buildings}, booktitle = {Australian Earthquake Engineering Society 2019 Conference}, year = {2019}, month = {12/2019}, address = {Newcastle}, abstract = {

Reinforced concrete buildings make up the majority of Australian building stocks. The buildings generally consist of core walls and/or shear walls as lateral load carrying elements and moment resisting frames as gravitational load carrying elements. The core and/or shear walls are often eccentrically located in the buildings resulting in a large displacement demand on the moment resisting frames that are located at the edge of the buildings. Seismic assessment methods for asymmetrical buildings commonly involve three-dimensional dynamic analyses that can be computationally expensive. This paper presents a simplified analysis method that has been developed to provide estimates for the maximum displacement demand of multi-storey buildings featuring plan asymmetry. The studies form a part of a collaborative research under the Bushfire and Natural Hazards Cooperative Research Centre (BNHCRC)on {\textquotedblleft}cost-effective mitigation strategy development for building related earthquake risk{\textquotedblright}.

}, keywords = {asymmetrical buildings, reinforced concrete, simplified analysis method, torsion}, url = {https://aees.org.au/wp-content/uploads/2019/12/43-Elisa-Lumantarna.pdf}, author = {Elisa Lumantarna and Nelson Lam and John Wilson} } @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-6050, title = {Strengthening and repair of reinforced concrete columns by jacketing: state-of-the-art review}, journal = {Sustainability}, volume = {11}, year = {2019}, month = {06/2019}, pages = {3208}, abstract = {

Sustainability necessitates the protection of infrastructure from any kind of deterioration over the life cycle of the asset. Deterioration in the capacity of reinforced concrete (RC) infrastructure (e.g., bridges, buildings, etc.) may result from localised damage sustained during extreme loading scenarios, such as earthquakes, hurricanes or tsunamis. In addition, factors such as the corrosion of rebars or ageing may also deteriorate or degrade the capacity of an RC column, thereby necessitating immediate strengthening to either extend or ensure its design life is not limited. The aim of this paper is to provide a state-of-the-art review of various strengthening and repair methods for RC columns proposed by different researchers in the last two decades. The scope of this review paper is limited to jacketing techniques for strengthening and/or repairing both normal- and high-strength RC columns. The paper also identifies potential research gaps and outlines the future direction of research into the strengthening and repair of RC columns.

}, keywords = {Infrastructure, Multi-hazard, sustainability}, doi = {https://doi.org/10.3390/su11113208}, url = {https://www.mdpi.com/2071-1050/11/11/3208}, author = {Saim Raza and Muhammad Khan and Scott Menegon and Hing-Ho Tsang 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} } @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} } @article {bnh-5009, title = {Seismic retrofit of precast soft-storey building using diagonal steel-shape memory alloy bracing device: Numerical investigation}, journal = {Advances in Structural Engineering}, year = {2018}, month = {10/2018}, abstract = {

A diagonal steel-shape memory alloy bracing device is proposed for seismic retrofitting of vulnerable building frame structure. Superelastic shape memory alloy bar is put in series with steel bars in the bracing. The device makes use of the loading plateau of superelastic shape memory alloy to limit the tensile force of diagonal bracing. A precast soft-storey building frame in Australia was selected for a case study. A numerical model of the frame was developed and validated with the results from full-scale pull-down field tests. Nonlinear time history analysis was then conducted to evaluate the seismic performance of the frame with different retrofitting strategies. The result shows that the diagonal steel-shape memory alloy bracing can reduce the displacement demand on the soft-storey frame. Meanwhile, the level of tensile force of steel-shape memory alloy bracing can be controlled by the force plateau of the shape memory alloy bar, which is recommended to be 20\% of the yielding force of the steel bar. The lower tensile force demand could alleviate the force demand at the associated support connections.

}, keywords = {diagonal bracing, retrofit, shape memory alloy, soft-storey building, superelastic}, doi = {10.1177/1369433218800939}, url = {http://journals.sagepub.com/doi/abs/10.1177/1369433218800939}, author = {John Wilson and Hing-Ho Tsang and Xiaoxian Liu} } @article {bnh-5160, title = {Unified models for post-peak failure drifts of normal- and high-strength RC columns}, journal = {Magazine of Concrete Research}, volume = {70}, year = {2018}, month = {11/2018}, pages = {1101}, chapter = {1081}, abstract = {

Displacement-based design of reinforced-concrete (RC) columns requires reliable estimation of the drift capacity beyond the elastic range. Although many post-peak drift models exist for normal-strength RC (NSRC) columns, very limited work has been done in this area on high-strength RC (HSRC) columns. This paper evaluates the capability of existing drift models to predict post-peak drift capacity of both NSRC and HSRC columns. A comparative study is conducted using a comprehensive database of 190 RC columns (79 HSRC and 111 NSRC) from past experimental studies. The results of the comparative study indicate that most of the existing drift models overestimate post-peak drift capacity of HSRC columns, primarily because the influence of concrete strength has been ignored. This paper also proposes a unified set of empirical drift models that have a unique ability to predict post-peak drift capacity of lightly to moderately reinforced NSRC as well as HSRC columns. The new models can serve as tools for structural design engineers to estimate drift capacity of RC columns at an early design stage. Moreover, the models can assess the drift performance of RC columns in existing buildings and hence can also aid in decision-making regarding the need for retrofitting.

}, doi = {https://doi.org/10.1680/jmacr.17.00375}, url = {https://www.icevirtuallibrary.com/doi/10.1680/jmacr.17.00375}, author = {Saim Raza and Hing-Ho Tsang 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-5159, title = {Analytical modelling of podium interference on tower walls in buildings}, journal = {Australian Journal of Structural Engineering}, volume = {18}, year = {2017}, month = {11/2017}, abstract = {

In regions of low-to-moderate seismicity like Australia, a common form of building construction is the one featuring a podium structure that supports a tower with smaller floor plan. This building layout is particularly favoured in metropolitan regions as it can cater for a mix of commercial and residential functionalities. This paper investigates the undesirable effects of podium interferences on the shear demands on the structural walls at and above the interface zone. Shear force redistributions between the connected structural walls were found to be the direct consequence of the differential restraints imposed by the podium structure. The generation of in-plane strutting forces in the slabs and beams connecting the structural walls was also found to be proportional to the extent of the deformation incompatibility between the walls and columns above the podium level. An analytical model is proposed herein for estimating in-plane strutting forces in the connecting slabs (or beams). The model has been verified against results obtained from finite element analyses using 2D, and 3D, sub-assemblages of the building. Deficiencies in the conventional diaphragm modelling approaches have been highlighted, and optimal solutions are proposed.

}, doi = {https://doi.org/10.1080/13287982.2017.1396870}, url = {https://www.tandfonline.com/doi/abs/10.1080/13287982.2017.1396870?journalCode=tsen20}, author = {Mehair Yacoubian and Nelson Lam and Elisa Lumantarna and John Wilson} } @article {bnh-5093, title = {Application of hybrid simulation for collapse assessment of post-earthquake CFRP-repaired RC columns}, journal = {ASCE Journal of Structural Engineering}, volume = {143}, year = {2017}, month = {01/2017}, abstract = {

Hybrid simulation combines the flexibility and cost-effectiveness of computer simulations with the realism of experimental testing to provide a powerful platform for large-scale experimental investigation of the seismic response of structures through collapse. This paper presents applications of hybrid simulation for (1)\ tracing the seismic response of a limited-ductility reinforced-concrete (RC) column through collapse and (2)\ evaluating the capability of carbon fiber reinforced polymer (CFRP) repair on rehabilitating the earthquake-damaged RC column to its initial collapse resistance capacity. A state-of-the-art hybrid testing facility, referred to as the multiaxis substructure testing (MAST) system, was used to simulate complex time-varying six-degrees-of-freedom (6-DOF) boundary effects on the physical specimens using mixed load/deformation modes. Based on the experimental results, a comparative collapse risk assessment of the initial and repaired column was conducted, which illustrates the effectiveness of using CFRP repair to restore and improve the collapse resistance of earthquake-damaged RC columns.

}, doi = {https://doi.org/10.1061/(ASCE)ST.1943-541X.0001629}, url = {https://ascelibrary.org/doi/10.1061/\%28ASCE\%29ST.1943-541X.0001629}, author = {Mojgen Hashemi and Al-Ogaidi, Y and Al-Mahaidi, R and Robin Kalfat and Hing-Ho Tsang and John Wilson} } @article {bnh-5087, title = {Collapse assessment of reinforced concrete building columns through multi-axis hybrid simulation}, journal = {ACI Structural Journal}, volume = {114}, year = {2017}, month = {01/2017}, abstract = {

One of the major challenges in collapse assessment of reinforced concrete (RC) structures has been the lack of realistic data obtained from reliable experimental loading protocols that are capable of accurately quantifying the reserve capacity of RC structures beyond the design level to the state of complete collapse. Until now, quasi-static (QS) symmetrically cyclic or monotonic tests with constant axial load have been commonly used, which are not adequate to accurately capture the actual response of a collapsing RC structure in real earthquake events. Hybrid simulation (HS) can be considered an attractive alternative to realistically simulate more complex boundary conditions and improve response prediction of a structure from elastic range to collapse. This paper presents a comparative experimental study on two identical, large-scale, limited-ductility RC columns that are tested to collapse through QS and HS, respectively. The RC columns serve as the first-story corner-column of a half-scale symmetrical five-byfive-bay five-story RC ordinary moment frame building structure. A state-of-the-art facility, referred to as a multi-axis substructure testing (MAST) system, is used that is capable of controlling all six-degrees-of-freedom (6-DOF) boundary conditions in mixed load and deformation modes. The load protocol in the QS test includes constant axial load combined with bidirectional lateral deformation reversals, while in the HS, more realistic boundary effects including fluctuation in axial load and the ratcheting behavior (that is, asymmetrical lateral deformation prior to collapse) are simulated. The hysteretic response behaviors obtained from the QS and HS tests are then used for calibrating the analytical models employed in a comparative collapse risk assessment. The results show that the improved interface boundary effects lead to significant changes in hysteretic response and the calibration parameters and, as a result, estimating the probability of collapse. This highlights that the credibility of collapse assessment results relies to a great extent on the application of correct boundary interface on RC columns.

}, url = {https://www.concrete.org/publications/internationalconcreteabstractsportal/m/details/id/51689438}, author = {Mojgen Hashemi and Hing-Ho Tsang and Al-Ogaidi, Y and John Wilson and Al-Mahaidi, R} } @article {bnh-4212, title = {Cost-effective mitigation strategy for building related earthquake risk: annual project report 2016-17}, number = {348}, year = {2017}, month = {09/2017}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

The 1989 Newcastle Earthquake caused damage to 70,000 properties, with an associated total economic loss of AU$ 4 billion. Consistently, the insurance industry has estimated the economic risk posed by a moderate earthquake in any of the capital cities in Australia to be of the order of billions of dollars. A major reason for this risk is that Australia has not designed buildings for earthquake-induced forces until 1995 so that a large portion of our building stock is seismically vulnerable.

As demonstrated in Christchurch, New Zealand, in 2010-11, a magnitude 6 earthquake can have a devastating impact on a city and country (damage rebuild estimated at ~ 20\% national GDP!) even though buildings there have been designed for earthquakes for many decades.

This project includes collaborative research from 4 partner institutions to establish:

  1. The relative vulnerabilities to earthquake shaking of the most common forms of building construction in Australia;
  2. What earthquake retrofit techniques worked and what didn{\textquoteright}t as a starting point in developing a {\textquoteleft}menu{\textquoteright} of economically feasible seismic retrofit techniques that could be used in Australian cities;
  3. With industry end-user support, conduct proof of concept tests on some of the most promising seismic retrofit techniques on buildings scheduled for demolition by the SA state government;
  4. Use the new damage and economic loss models developed over the first 3 years of this project to undertake a seismic risk assessment case study of the Melbourne metro area; and
  5. Advance a series of end user focused research utilization projects in the areas of improved building regulation, community risk reduction, design profession guidance and insurance industry engagement with their policy holders. These will include an Earthquake Mitigation Case Study for the historic town of York in Western Australia and Development of a Rapid Visual Screening procedure for Australian buildings

Finally, using the new damage loss models and costings for seismically retrofitting buildings, make recommendations for the development of seismic retrofit guidelines and policy based on the strong evidence base developed.

}, issn = {348}, author = {Michael Griffith and Hossein Derakhshan and Elisa Lumantarna and Hing-Ho Tsang and Helen M. Goldsworthy and John Wilson and Nelson Lam and Mark Edwards} } @article {bnh-5089, title = {A design spectrum model for flexible soil sites in regions of low-to-moderate seismicity}, journal = {Soil Dynamics and Earthquake Engineering}, volume = {92}, year = {2017}, month = {2017}, pages = {36-45}, chapter = {36}, abstract = {

Design spectrum (DS) models in major\ codes of practice\ for\ structural designof buildings typically stipulate empirical site factors for each of the five, or six, site classes. Although the phenomenon of resonant like amplification behaviour of the structure caused by multiple\ wave reflections\ is well known, the potentials for such periodic amplification behaviour are not explicitly considered in code models. This is partly because of expert opinion that such effects are very {\textquotedblleft}localised{\textquotedblright} in the frequency domain and can be suppressed readily by damping. However, investigations into the risk of collapse of non-ductile, and irregular structural systems, common in regions of low-to-moderate\ seismicity, revealed the extensive influence of periodic base excitations on flexible soil sites (with initial small-strain natural period\ Ti\>0.5s). In this paper, an alternative DS model which addresses the important phenomenon of soil resonance without the need of computational site\ response analysis\ of the subsurface model of the site is introduced.

}, doi = {https://doi.org/10.1016/j.soildyn.2016.09.035}, url = {https://www.sciencedirect.com/science/article/pii/S0267726116303219}, author = {Hing-Ho Tsang and John Wilson and Nelson Lam and Ray Kai Leng Su} } @article {bnh-5158, title = {Effects of podium interference on shear force distributions in tower walls supporting tall buildings}, journal = {Engineering Structures}, volume = {148}, year = {2017}, month = {10/2017}, abstract = {

High rise constructions featuring a podium surrounding tower walls are often favoured for the versatile functionality of the building. It is shown in this paper that the podium can impose significant differential restraint on coupled tower walls. Incompatible tower wall displacements under lateral loads were found to be the main contributor to the generation of in-plane strutting forces in floors above and below the podium-tower interface level. Shear force localisations in the interior tower wall immediately above the interface was found to be the direct consequence of these actions. Key parameters contributing to this detrimental shear force localisation in a tower wall were analysed by way of parameter studies on representative models of the building and sub-assemblages. It is revealed that the in-plane rigid diaphragm assumption commonly adopted in practice can significantly suppress compatibility forces generated within the building floor leading to unconservative design of the tower walls. Elaborate nonlinear model has been examined to showcase the consequences of understating the shear demands on these walls.

}, doi = {https://doi.org/10.1016/j.engstruct.2017.06.075}, url = {https://www.sciencedirect.com/science/article/pii/S0141029616305454?via\%3Dihub}, author = {Mehair Yacoubian and Nelson Lam and Elisa Lumantarna and John Wilson} } @conference {bnh-4334, title = {Methods of structural analysis of buildings in regions of low to moderate seismicity}, booktitle = {2017 World Congress on Advances in Structural Engineering and Mechanics}, year = {2017}, month = {09/2017}, address = {Seoul, Korea}, abstract = {

The paper introduces simplified methods for the analysis of multi-storey buildings for regions of low to moderate seismicity. Due to functional and architectural requirement most newly designed and existing buildings feature irregularities. The irregularities can be in a form of vertical irregularity (caused by discontinuity in load carrying elements) and plan irregularity (caused by cores that are eccentric ally placed within the buildings). Contemporary earthquake design standards and assessment procedures require dynamic analyses to be performed on such structures. However, dynamic analyses can be computationally expensive and require expert judgment, especially as far as three-dimensionally modelling is involved.

The early part of the paper presents the simplified method for the analysis of torsionally balanced (TB) buildings. Generalised modal displacements that were derived from parametric studies involving multi-storey buildings with vertical irregularities are introduced. The simplified method has been extended to account for the effects of torsion due to plan asymmetry to produce estimates of the maximum displacement demand at the edges of torsionally unbalanced (TU) buildings.

}, author = {Elisa Lumantarna and Alireza Mehdipanah and Nelson Lam 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} } @article {bnh-5090, title = {A refined design spectrum model for regions of lower seismicity}, journal = {Australian Journal of Structural Engineering}, volume = {18}, year = {2017}, month = {03/2017}, abstract = {

This paper presents a refined site classification scheme and a design spectrum (DS) model for different site conditions, with site natural period as the key classification parameter. The refined model has a particular emphasis on the phenomenon of resonant-like amplification behaviour in soil sites, which have not been explicitly considered in any existing code models. The need to address the effects of soil resonance and increased displacement demand is particularly justified in regions of lower seismicity, where structures are typically of limited ductility with low energy dissipation capability. Significantly, the mitigating effects of a very flexible soil site resulting in reduction in the level of seismic demand on low-rise buildings is a distinctive feature of the model which has been well validated by comparison with results obtained from computational site response analysis of soil columns derived from real borehole records, as well as from strong motion data recorded in the 1994 Northridge earthquake.

}, doi = {https://doi.org/10.1080/13287982.2017.1297529}, url = {https://www.tandfonline.com/doi/abs/10.1080/13287982.2017.1297529}, author = {Hing-Ho Tsang and John Wilson and Nelson Lam} } @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} } @article {bnh-5077, title = {Minimum loading requirements for areas of low seismicity}, journal = {Earthquakes and Structures}, volume = {11}, year = {2016}, pages = {539-561}, chapter = {539}, abstract = {

The rate of occurrence of intraplate earthquake events has been surveyed around the globe to ascertain the average level of intraplate seismic activities on land. Elastic response spectra corresponding to various levels of averaged (uniform) seismicity for a return period of 2475 years have then been derived along with modifying factors that can be used to infer ground motion and spectral response parameters for other return period values. Estimates derived from the assumption of uniform seismicity are intended to identify the minimum level of design seismic hazard in intraplate regions. The probabilistic seismic hazard assessment presented in the paper involved the use of ground motion models that have been developed for regions of different tectonic and crustal classifications. The proposed minimum earthquake loading model is illustrated by the case study of Peninsular Malaysia which has been identified with a minimum effective peak ground acceleration (EPGA) of 0.1 g for a return period of 2475 years, or 0.07 g for a notional return period of 475 years.

}, doi = {https://doi.org/10.12989/eas.2016.11.4.539}, url = {http://koreascience.or.kr/article/ArticleFullRecord.jsp?cn=TPTPJW_2016_v11n4_539}, author = {Nelson Lam and Hing-Ho Tsang and Elisa Lumantarna 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-5098, title = {Simplified elastic design checks for torsionally balanced and unbalanced low-medium rise buildings in lower seismicity regions}, journal = {Earthquakes and Structures}, volume = {11}, year = {2016}, pages = {741-777}, chapter = {741}, abstract = {

A simplified approach of assessing torsionally balanced (TB) and torsionally unbalanced (TU) low-medium rise buildings of up to 30 m in height is presented in this paper for regions of low-to-moderate seismicity. The Generalised Force Method of Analysis for TB buildings which is illustrated in the early part of the paper involves calculation of the deflection profile of the building in a 2D analysis in order that a capacity diagram can be constructed to intercept with the acceleration-displacement response spectrum diagram representing seismic actions. This approach of calculation on the planar model of a building which involves applying lateral forces to the building (waiving away the need of a dynamic analysis and yet obtaining similar results) has been adapted for determining the deflection behaviour of a TU building in the later part of the paper. Another key original contribution to knowledge is taking into account the strong dependence of the torsional response behaviour of the building on the periodic properties of the applied excitations in relation to the natural periods of vibration of the building. Many of the trends presented are not reflected in provisions of major codes of practices for the seismic design of buildings. The deflection behaviour of the building in response to displacement controlled (DC) excitations is in stark contrast to behaviour in acceleration controlled (AC), or velocity controlled (VC), conditions, and is much easier to generalise. Although DC conditions are rare with buildings not exceeding 30 m in height displacement estimates based on such conditions can be taken as upper bound estimates in order that a conservative prediction of the displacement profile at the edge of a TU building can be obtained conveniently by the use of a constant amplification factor to scale results from planar analysis.

}, doi = {10.12989/eas.2016.11.5.741}, url = {http://koreascience.or.kr/article/ArticleFullRecord.jsp?cn=TPTPJW_2016_v11n5_741}, author = {Nelson Lam and John Wilson and Elisa Lumantarna} } @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-3464, title = {Local intraplate earthquake considerations for Singapore}, journal = {The IES Journal Part A: Civil \& Structural Engineering}, volume = {8}, year = {2015}, month = {11/2014}, pages = {62-70}, chapter = {62}, abstract = {

The current National Annex for Singapore to Eurocode 8 is primarily to address distant hazards from Sumatra and is not intended to provide coverage for potential local intraplate hazards. The latter type of hazards has safety implications on low-rise structures including many of the aged building construction. It is argued that the absence of local seismic activities in the recorded history within the Malaysian peninsular cannot be used as evidence to justify the assumption that its level of potential local hazards is any lower than other intraplate regions such as Australia, Southern India, and Central and Eastern United States, because of the relative smallness of the landmass of the peninsular. This paper presents a response spectrum model for intraplate earthquakes using relevant data from other regions around the world as opposed to relying on very limited amount of data from regional monitoring. Finally, a response spectrum model that takes into account potential threats from both distant and local seismic sources is recommended for future adoption by Singapore.

}, doi = {http://dx.doi.org/10.1080/19373260.2014.974873}, url = {http://www.tandfonline.com/doi/abs/10.1080/19373260.2014.974873?journalCode=tiea20}, author = {Nelson Lam and Hing-Ho Tsang and Elisa Lumantarna and John Wilson} } @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} } @conference {bnh-2510, title = {Recommended Site Classification Scheme and Design Spectrum Model for Regions of Lower Seismicity}, booktitle = {Tenth Pacific Conference on Earthquake Engineering Building an Earthquake-Resilient Pacific }, year = {2015}, month = {11/2015}, address = {Sydney, Australia}, abstract = {

This paper proposes a site classification scheme and a design spectrum (DS) model for different ground conditions, with site natural period as the key parameter. The proposed model has a particular emphasis on the phenomenon of resonant-like amplification behaviour in soil sites, which have not been explicitly considered in existing code models. The need to address the effects of soil resonance is particularly justified in regions of lower seismicity, where structures are typically of limited ductility with low energy dissipation capability. Significantly, the mitigating effects of a very flexible soil site resulting in reduction in the level of seismic demand on low rise buildings is a distinctive feature of the proposed model which has been well validated by comparison with results obtained from computational site response analysis of soil columns derived from real borehole records, as well as from strong motion data recorded in the 1994 Northridge earthquake.

}, author = {Hing-Ho Tsang and John Wilson and Nelson Lam} } @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} }