@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} } @conference {bnh-6389, title = {Development of Cost-effective Mitigation Strategy for Limited Ductile Reinforced Concrete Buildings}, booktitle = {Australian Earthquake Engineering Society 2019 Conference}, year = {2019}, month = {12/2019}, address = {Newcastle}, abstract = {

With the new awareness that most Australian reinforced concrete (RC) buildings have not been designed to withstand seismic actions, and are considered to have limited ductility, it is essential to consider retrofitting options. This study aims to evaluate the seismic performance of an archetypal Australian RC building, and then implement various retrofit techniques to find the most suitable retrofit. The structural performance of the buildings before and after various retrofitting were compared to study the effectiveness of the proposed methods as well as the effect on the seismic hazard design factor. SeismoStruct software was used to perform the nonlinear analysis of the structures. This paper contributes to a research with the overall aim of assessing the seismic performance of existing buildings and their expected failure modes, impact of retrofitting measures, and the associated costs.

}, keywords = {earthquake, existing structures, limited ductility buildings, performance validation, seismic evaluation and retrofitting}, url = {https://aees.org.au/wp-content/uploads/2019/12/55-Raneem-Alazem.pdf}, author = {Raneem Alazem and Elisa Lumantarna and Nelson Lam and Scott Menegon} } @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-6390, title = {Prioritisation strategy for seismic retrofitting of reinforced concrete buildings in Australia}, booktitle = {Australian Earthquake Engineering Society 2019 Conference}, year = {2019}, month = {12/2019}, address = {Newcastle}, abstract = {

This paper presents a study on the seismic evaluation and retrofit of limited ductile reinforced concrete (RC) buildings, which make up the bulk of built infrastructure in the central building districts and high-density residential areas in Australian cities. In low to moderate seismicity regions such as Australia, RC buildings will have structural elements that have been designed with limited to no ductility. The individual building needs to be assessed and ranked for their retrofitting priority. An assessment for retrofitting methodology involving a three-tiered approach will be introduced in this paper. The assessment framework including a tiered approach was developed to evaluate the potential vulnerability of Australian RC buildings and to facilitate decision making in relation to the need for seismic retrofitting. Structural threshold values related to the vulnerable features introduced in the framework were also investigated to support the identification process of the method. It is expected that the developed three-tiered methodology will provide a significant contribution to the seismic evaluation and retrofit of existing RC buildings in Australia.

}, keywords = {reinforced concrete building, seismic evaluation and retrofitting, tiered methodology}, url = {https://aees.org.au/wp-content/uploads/2019/12/21-Bin-Xing.pdf}, author = {Bin Xing and Elisa Lumantarna and Nelson Lam and Scott Menegon} } @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-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} }