Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10518-025-02142-9

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Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.engstruct.2025.119643

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Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

Displacement response is critical data for post‐earthquake fast building assessment. However, directly measuring building displacement response remains a great challenge in practice. Therefore, it is practically common to estimate displacement response from acceleration response using double integration. Unfortunately, the low‐frequency component of displacement obtained by double integrating acceleration often contains noise that is indistinguishable from low‐frequency displacement components. Consequently, the maximum displacement estimated from acceleration is commonly underestimated in comparison to its true value due to the removal of the low‐frequency components. This can potentially lead to an underestimation of post‐earthquake building damage state, especially when a building undergoes significant nonlinear deformation. This study develops a framework to improve the accuracy of the maximum displacement obtained from floor acceleration data by fusing it with the low‐frequency displacement component estimated from an equivalent SDOF analysis for both reinforced concrete (RC) and steel structures. Procedures for constructing the equivalent SDOF model of a building and a procedure for extracting the low‐frequency component from the analysis displacement were developed. The proposed method was verified using a diverse range of case studies from numerical simulation and experimental studies under different seismic records for both RC and steel structures. The results showed that the proposed method was effective with a range of seismic characteristics and damage levels. A significant reduction in maximum displacement errors was observed for cases with significant nonlinear deformation, which may contribute to a more accurate post‐earthquake building assessment.

DOI： 10.1002/eqe.4141

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Publishing type：Research paper (scientific journal)   Publisher：New Zealand Society for Earthquake Engineering  

Quantitative seismic loss assessment has become an increasingly popular tool for evaluating the seismic performance of structures. The growth in popularity is largely in response to a desire to look beyond the traditional life safety performance objective and instead consider also economic losses and downtime due to earthquakes. A key step in the loss assessment calculation process is relating damage in both structural and nonstructural components to appropriate repair strategies and subsequently repair costs and repair times. This is achieved through the use of so-called consequence functions, which in this paper are derived specifically for the New Zealand context. Furthermore, a framework is established for other researchers and professional engineers to continue to build on and improve the initial dataset. It is shown that using New Zealand specific consequence functions can have a noticeable effect on estimates of expected annual loss when compared to a benchmark case using consequence functions from FEMA P-58. The opportunity is also taken to evaluate the impact of recent updates to the New Zealand National Seismic Hazard Model, with the results for a case-study building in Wellington indicating that the change in hazard has a far more significant effect on estimates of loss when compared to the choice of different consequence functions.

DOI： 10.5459/bnzsee.1642

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.soildyn.2023.108061

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Publishing type：Research paper (scientific journal)   Publisher：New Zealand Society for Earthquake Engineering  

<jats:p>Major seismic events occurring around urban centres often cause widespread damage to the building stock. Engineers are then required to perform safety inspections of these buildings. This process may be time-consuming and can cause residents or businesses to be displaced for a considerable duration even if the building is safe to occupy. Furthermore, other post-earthquake recovery phases, such as repair and demolition/reconstruction works, may not even initiate until the building inspection phase is complete. As such, the disruptions caused by post-earthquake inspection need to be considered when modelling building occupancy/functionality downtime.
This study uses the data obtained from the 2011 Christchurch earthquake to develop a post-earthquake inspection duration quantification model. Firstly, the duration of the rapid assessment phase is estimated from the number of damaged buildings to be assessed, the total number of available engineers, and the median time needed for assessing each building. Secondly, the probability of a building being assigned a certain colour tag (White, Yellow or Red) is derived based on the extent of damage. Finally, both sets of information are combined to quantify the post-earthquake inspection duration. A case study is examined to demonstrate the application of the proposed model.</jats:p>

DOI： 10.5459/bnzsee.1568

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Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

Structures may predominantly inelastically deform in a single direction during earthquakes and incur greater damage. This behavior is known as seismic ratcheting and can be caused by eccentric gravity loads. Code clauses were introduced in Canada and New Zealand to amplify displacements obtained from static analysis methods to consider seismic ratcheting effects. However, such clauses are based on analyses of reinforced concrete (RC) wall or single‐degree‐of‐freedom (SDOF) structures, and methods to mitigate seismic ratcheting behavior were not explicitly provided. In this study, parametric analyses of steel and RC moment resisting frame buildings were performed to evaluate the adequacy of code clauses, identify parameters which influence seismic ratcheting behavior, and propose methods to mitigate such behavior. It was found that the New Zealand code underestimated the displacement increase for RC buildings, though it was able to envelope the displacement increase for steel buildings while the Canadian code was conservative. Additionally, the displacement increase was found to be sensitive to the building's post‐yield behavior and ground motion properties. However, assumptions of these properties during design may not be reflective of the actual building and seismic conditions, indicating that a reliable estimate of the increase in displacement is difficult to obtain. Instead, employing mitigation measures to reduce seismic ratcheting effects, such as designing to higher seismic demands, adding a secondary structural system to increase the building's post‐elastic stiffness, or providing more balanced lateral strengths after adjusting for eccentric gravity load effects are better measures to counter seismic ratcheting effects caused by eccentric gravity loads.

DOI： 10.1002/eqe.3790

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/eqe.3790

Publishing type：Research paper (scientific journal)   Publisher：New Zealand Society for Earthquake Engineering  

Fire sprinkler systems damaged during earthquakes can compromise building functionality either by loss of fire protection and/or flooding damage. To characterize the seismic behavior of fire sprinkler piping systems, shake table tests were conducted on a piping specimen with features representative of actual practices in New Zealand. The specimen was subjected to a set of motions including recorded floor acceleration response histories of an instrumented building in New Zealand. This paper describes the test setup and the piping specimen, and discusses the seismic response of the specimen to multiple floor motions for different bracing variations. Based on the test results reported in this paper, it can be concluded that bracing segments of piping other than the distribution pipe, such as the branch and arm-over pipes, can considerably affect the seismic demand on the system. Further, the test results confirm that the seismic demands on pipes can be considerably greater if the piping system is in resonance with the input excitation motion.

DOI： 10.5459/bnzsee.55.3.167-182

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Publishing type：Research paper (scientific journal)   Publisher：New Zealand Society for Earthquake Engineering  

During seismic events, some structures have a tendency to ratchet and displace more in one direction than in the opposite direction after yielding, resulting in larger peak and residual displacements. Provisions to define the tendency for seismic ratcheting and the resulting displacement amplification are provided in the 2016 amendments of NZS1170.5. This paper presents some insight into the factors causing ratcheting, along with interpretation and evaluation of the proposed provisions. Firstly, the mechanics of seismic ratcheting due to dynamic stability, eccentric gravity loads, and unbalanced structural strengths in the back-and-forth directions are discussed. Afterwards, the new provisions were detailed and demonstrated by working through the NZS1170.5 commentary examples. The authors’ interpretation of the provisions is then presented, potential areas of confusion are identified, and wording changes to provide consistency and clarity are proposed. Finally, the displacement amplification factors provided in the 2016 amendments were evaluated using results of an independent study on single-degree-of-freedom reinforced concrete bridge columns subjected to eccentric gravity loading. It was found that the displacement amplification method proposed was reasonable, except when columns designed with a high ductility factor or which exhibit inelastic bilinear response had a significant tendency for ratcheting.

DOI： 10.5459/bnzsee.55.3.183-198

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Society of Civil Engineers ({ASCE})  

DOI： 10.1061/(asce)st.1943-541x.0003391

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Language：English   Publisher：Architectural Institute of Japan  

DOI： 10.3130/aijt.28.585

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Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

DOI： 10.1080/13632469.2021.1988764

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Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/eqe.3577

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/eqe.3577

Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s10518-021-01181-2

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Other Link： https://link.springer.com/article/10.1007/s10518-021-01181-2/fulltext.html

Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

DOI： 10.1080/13632469.2020.1865219

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Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1177/8755293019901311

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DOI： 10.1177/8755293019900775

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1680/jencm.18.00001

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DOI： 10.5459/bnzsee.52.1.23-43

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Publishing type：Research paper (scientific journal)  

DOI： 10.5459/bnzsee.51.1.1-11

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s10518-018-0421-x

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Publishing type：Research paper (scientific journal)  

DOI： 10.5459/bnzsee.51.3.127-144

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/eqe.2843

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11803-016-0301-9

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1061/(ASCE)AE.1943-5568.0000193

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/eqe.2598

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.engstruct.2015.01.004

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1080/13632469.2013.771591

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Publishing type：Research paper (scientific journal)   Publisher：RILEM Bookseries  

DOI： 10.1007/978-94-007-4566-7_79

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