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The use of discrete damping devices in New Zealand buildings is increasing as designers seek to limit damage to both architectural and structural building elements in moderate earthquakes. The overall damping of the structure becomes a combination of inherent material damping, hysteretic damping from yielding of building elements at specific locations and damping from discrete devices. For over 60 years, engineers have used simplified analysis procedures (e.g., modal response spectrum analysis) to predict building response under seismic actions. The design of structures incorporating viscous dampers requires a paradigm shift in approach as the force each damper resists is a function of the relative velocity between its ends. Popular pseudo-static design methodologies promote the use of a viscous strut in the analysis model to represent them. However, it is incorrect to use elastic, mode-based analysis for a structure incorporating damping devices and relying on significant inelastic behaviour. This paper elucidates the complex mechanics of damper-structure interaction by reviewing some of the established classical, modal-based, simplified analysis techniques used in seismic design. A series of numerical investigations demonstrate how these techniques are usually invalid for structures that incorporate viscous dampers because they violate the laws of physics. The reason why mode-based techniques are invalid is explored with reference to the imaginary components of the natural modes of vibration and the effect on them of significant inelasticity within the structure. The dynamic characteristics of viscous dampers challenge conventional design approaches such as displacement-based design. This paper establishes that nonlinear time-history analysis is the only meaningful way of predicting the dynamic response of a structure incorporating viscous dampers when significant inelastic behaviour of the structure is expected. [ABSTRACT FROM AUTHOR]

'Planning Emergency Levels of Service' (PELOS) are goals for the delivery of infrastructure services following a major hazard event, such as an earthquake or flood. This paper presents an operationalised PELOS framework for the Wellington region based on interviews with emergency and critical infrastructure managers and discusses important changes from the preliminary to the operationalised framework. A shared understanding of these PELOS will help Wellington region infrastructure providers, emergency management professionals and the potentially impacted communities plan for major events. PELOS for the energy, telecommunications, transport, and water sectors have been developed, and high-level interdependencies considered. The PELOS framework can be updated for other regions, by the critical infrastructure entities and emergency managers, using locally relevant hazard scenarios. In turn, this approach can inform the endusers (communities) of the goals of the critical infrastructure providers following a major hazard event. [ABSTRACT FROM AUTHOR]

Infrastructure networks (e.g. transport, water, energy, telecommunications) support life and the economy of communities of all sizes. New Zealand has witnessed several damaging earthquakes in the last decade that provide a compelling case to accelerate building resilient infrastructures in the country, so we can minimize any adverse impacts from future earthquakes. One of the regions that is highly vulnerable to earthquakes is Wellington. With the region's population continually expanding and placing increasing demand on its ageing infrastructures, with limited redundancy in the networks, and with many of its assets close to and / or intersecting fault lines, a large earthquake in the region could be highly disruptive, potentially resulting in serious social and economic consequences. While it may not be possible to completely avoid the impacts, they can be reduced. This paper provides an overview of the process taken in delivering a Wellington Lifelines Group report that demonstrates how impacts from a future major earthquake can be reduced through integrated and targeted infrastructure resilience investments. To quantify the benefits that can be achieved by making the proposed investments, impact modelling on nine different lifeline utilities in the Wellington metropolitan area were conducted; the assessment approach taken, and results derived and their use to prioritise resilience investments, are shown in this paper for selected key networks. The time-stamped service outage maps and tables produced from this work formed an essential input to evaluate and demonstrate the impact of the proposed resilience initiatives on the regional and national economies. [ABSTRACT FROM AUTHOR]

Nonlinear response history analysis (NLRHA), or so-called "nonlinear time history analysis", is adopted by practicing structural engineers who implement performance-based seismic design and/or assessment procedures. One important aspect in obtaining reliable output from the NLRHA procedure is the input ground motion records. The underlying intention of ground motion selection and amplitude-scaling procedures is to ensure the input for NLRHA is representative of the ground shaking hazard level, for a given site and structure. The purpose of this paper is to highlight the salient limitations of the ground motion selection and scaling requirements in Sections 5.5 and 6.4 of the New Zealand (NZ) loading standard NZS 1170.5 (2004). From a NZ regulatory perspective; there is no specific framework for seismic hazard analysis and ground motion selection (thus self-regulation is the current norm). In contrast, NZS 1170.5 contains many prescriptive requirements for scaling and applying records which are challenging to satisfy in practice. Also discussed within, there are implications for more modern guidance documents in NZ, such as the 2017 "Assessment Guidelines" for existing buildings, which cite NZS 1170.5, a standard which is at least 16 years old (draft issued in 2002). To emphasize the above issues with NZS 1170.5, this paper presents a summary of the more contemporary approaches in the US standards ASCE 7-16 (new buildings) and ASCE 41-17 (existing buildings), along with some examples of the more stringent US requirements for Tall Buildings. [ABSTRACT FROM AUTHOR]

This paper identifies the inherent strengths/weaknesses of rigid timber-framed partitions and quantifies the onset drifts for different damage thresholds under a unidirectional quasi-static cyclic loading. It reports construction and testing of a multi-winged timber-framed partition wall specimen, with details typical of New Zealand construction practice. As the tested subassembly included four partition wall wings oriented along four different directions, bi-directional performance of the tested wall system could be assessed despite the loading being unidirectional. Furthermore, the tested rigid timber-framed partition wall's cyclic performance is also compared with that of similar partition walls incorporating "partly-sliding" connection details and "seismic gaps", previously tested under the same test setup. Theoretical equations proposed/derived in the literature to predict the ultimate strength, initial stiffness, and onset drifts of different damage states are scrutinized based on the experimentally recorded cyclic performance measures. Some equations are updated in order to alleviate identified possible shortcomings. These theoretical estimates are then validated with the experimental results. It is found that the equations can reasonably predict the initial stiffness and ultimate shear strength of the partitions, as well as the onset-drifts corresponding to the screw damage and diagonal buckling failure mode of the plasterboard. [ABSTRACT FROM AUTHOR]

Buckling-restrained braces (BRBs) form a bracing system that provides lateral strength and stiffness to a building. These systems have been shown to provide larger energy dissipation in severe earthquake events compared to concentrically and eccentrically braced frames (CBFs and EBFs). However, unlike CBFs and EBFs there is no guidance document or specific instructions in regulatory standards for the design of buckling-restrained braced frames (BRBFs) in New Zealand. This makes it difficult for structural engineers to be aware of all the strength and stability considerations required for the safe design of BRBFs. Currently, structural designs that include BRBFs require a peer-review to gain building compliance. The American standard ANSI/AISC 341-16 is the adopted document used in New Zealand for guidance in how to collect evidence showing a BRBF system will perform as intended. However, as ANSI/AISC 341-16 is not a governing document in New Zealand, instructions within the document are not enforced and can be made to fit within the constraints of a building project. By way of example, this paper presents the experimental test process and results acquired from pre-qualification testing of three different commercially available BRB architypes. Of the three BRB designs investigated, one failed prematurely due to global buckling. A manufacturing error was the likely cause of this premature failure. This failure highlights the need for strict quality control during fabrication. All remaining BRBs performed well, meeting the acceptance criteria set out in ANSI/AISC 341-16. Positive pre-qualification results meant the BRBs were installed in medium to high-rise buildings throughout New Zealand. The importance of sub-assemblage testing to assess the performance of a BRB and its frame components is also discussed. Finally, the capability of high fidelity modelling to supplemental physical testing is also presented. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The paper uses two geospatial liquefaction models based on (1) global and (2) New Zealand specific variables such as Vs30, precipitation and water table depth to estimate liquefaction probability and spatial extent for the 2016 Kaikōoura earthquake. Results are compared to observational data, indicating that the model based on global variables underestimates liquefaction manifestation in the Blenheim area due to the low resolution of the input datasets. Furthermore, a tendency for underprediction is evident in both models for sites located in areas with rapidly changing elevation (mountainous terrain), which is likely caused by the low resolution of the elevation-dependent variables Vs30 and water table depth leading to incorrect estimates. The New Zealand specific model appears to be less sensitive to this effect as the variables provide a higher resolution and a better representation of region specific characteristics. However, the results suggest that the modification might lead to an overestimation of liquefaction manifestation along rivers (e. g. Kaikōura). An adjustment of the model coefficients and / or the integration of other resources such as geotechnical methods can be considered to improve the model performance. The evaluation of the geospatial liquefaction models demonstrates the importance of high-resolution input data and leads to the conclusion that the New Zealand specific model should be preferred over the original model due to better prediction performance. The findings provide an overall better understanding on the models' applicability and potential as a tool to predict liquefaction manifestation for future hazard assessments. [ABSTRACT FROM AUTHOR]

Post-Tensioned Timber (PTT) frames have significant advantages over traditional timber frame systems especially where a low damage design and fast construction are desired. New Zealand practitioners designing timber structures for fire are accustomed to applying ambient design methods to an element cross-section reduced by a char depth based on a duration of Standard Fire exposure following NZS 3603 or AS/NZS 1720.4. The behaviour of PTT frames in fire remains a concern because this approach does not account for the actual mechanics of PTT connection and frame response under natural fires that will occur in the structure. This paper examines the individual and interdependent response of PTT connection components (tendon, dissipater, fasteners, etc) to fire. It is shown that the ambient analysis tool for PTT connections, the Modified Monolithic Beam Analogy, cannot be applied to the fire case by only using char reduced cross-sections of timber elements. This approach of combining ambient methodologies with reduced cross-sections does not account for the specific connection detailing, which result in unique damage in fire that may govern the structural response. The responses of two seismically detailed PTT connections are predicted using this approach and compared to a first principles assessment of connection behaviour to demonstrate that failure will occur earlier than otherwise predicted. Numerical thermal analyses of these two connections also qualitatively corroborate the damage that occurs. This investigation establishes that additional studies are required to understand the complex behaviour of these connections when exposed to fire before a design methodology can be developed. [ABSTRACT FROM AUTHOR]

An editorial is presented on the NZSEE Bulletin presents four papers covering diverse topics spanning into seismic performance of nonstructural elements (SPONSE) and learning from earthquakes (LFE). It mentions that this method enables improved prediction of floor acceleration demands for acceleration sensitive non-structural components and contents provided the building period is known.

Fire sprinkler systems damaged during earthquakes can compromise the functionality of a building facility either by loss of fire protection and/or by damage due to flooding. Shake table tests were conducted on a sprinkler piping specimen, with features representative of actual practices in New Zealand, to characterize its dynamic behavior under seismic floor excitation. The aim of the testing was to signify the need for a reliable procedure in the relevant New Zealand Standard (NZS 4541) for the estimation of seismic demands on these systems. The specimen was subjected to a set of motions including recorded floor acceleration response histories of an instrumented building in New Zealand. This paper first describes the test setup and the piping specimen and then discusses the seismic response of the specimen to multiple floor motions for different bracing variations. The testing showed that bracing segments of piping other than the distribution pipe modifies the dynamic characteristics of the system and consequently the seismic demands. The test results further confirm that seismic demands on pipes can be considerably greater if the system is in resonance with the floor excitation. Recommendations are provided for necessary improvements to NZS 4541 (2020) for a reliable estimation of seismic demands. [ABSTRACT FROM AUTHOR]

Recent earthquakes in New Zealand not only highlighted the vulnerabilities of the existing building stock but also the need for: (i) a better understanding of the building inventory, and (ii) easy access to information for quicker response after an event. In the case of Wellington, efforts over the years by the City Council and other stakeholders have produced a number of useful datasets about the building inventory. These available datasets when put together are critical in understanding the composition and characteristics of the building inventory in Wellington. This paper describes the available information, and the process to combine the different strands of data possessed by multiple stakeholders into an effective and usable multi-disciplinary building inventory database for Wellington's CBD. The uses and future directions for this collated database are also discussed. [ABSTRACT FROM AUTHOR]

This paper describes the shaking intensity levels caused by the M7.8 Kaikōura earthquake of 14/11/2016 according to the information from the two current GeoNet online questionnaires, 'Felt Detailed' and 'Felt RAPID'. A recently developed method to extract intensity levels at a community scale using 'Felt Detailed' data is used. These are compared with individual intensities from 'Felt RAPID' survey, instrumental intensities from two recent ground motion to intensity conversion equations, and traditional intensity assignments. While maximum Modified Mercalli instrumental, traditional, 'Felt RAPID' and individual 'Felt Detailed' intensities go up to 8, community intensities using 'Felt Detailed' mostly only go up to 5, with only four communities with MM 6-7. Reasons for this discrepancy include a) lack of data around the epicentre; b) few reports from this event compared to other smaller recent earthquakes; and c) lack of public awareness of 'Felt Detailed" surveys, released shortly after the earthquake. In addition, only 47% of reports were used to calculate community intensities, based on a minimum requirement for robust calculation of 5 reports. Although 'Felt RAPID' provided a much larger number of reports (more than 15,000) for this earthquake compared to 'Felt Detailed' (3500), the reliability of the former may be compromised by their lack of detail. Results from this paper suggest that, when enough reports are submitted, 'Felt Detailed' can provide good quality data that can be used in tools such as the near-real time shaking intensity maps provided in ShakeMapNZ. [ABSTRACT FROM AUTHOR]

This paper describes the damage to non-structural elements in buildings following the 14th November 2016 Kaikōura earthquake. As has been observed in recent earthquakes in New Zealand and around the world, damage to non-structural elements is a major contributor to overall building damage. This paper focusses on damage to non-structural elements in multi-storey commercial buildings, in particular damage to the following: suspended ceilings, suspended services, glazing, precast panels, internal linings, seismic gaps and contents. The nature and extent of damage to each of these components is discussed in this paper with the help of typical damage photos taken after the earthquake. The paper also presents observations on the seismic performance of non-structural elements where seismic bracing was present. These observations suggest that seismic bracing is an effective means to improve seismic performance of non-structural elements. [ABSTRACT FROM AUTHOR]

QuakeCoRE is one of 10 Centres of Research Excellence funded by the New Zealand Tertiary Education Commission. With a focus on earthquake resilience of communities and societies, it has played a major role in addressing needs identified following the Christchurch Earthquake and other major events over the last decade. QuakeCoRE comprises a number of Flagship Programmes, including Flagship 4, which is entitled "Next-generation infrastructure: Low-damage and repairable solutions." This paper aims to support turning research into practice by identifying the key areas of Flagship 4 that are likely to have an impact on the industry. Five key areas of impact were identified, based on a review of the published research, engagement with Flagship 4 leadership and the authors' experience in the industry. For each area identified, summaries of the major research outcomes are provided, along with views as to how these can support the engineering practice. [ABSTRACT FROM AUTHOR]

This paper presents site-specific probabilistic seismic hazard analysis (PSHA) results at 24 locations throughout New Zealand (NZ). Specifically, peak ground acceleration (PGA) hazard curves for two generic soft soil conditions are considered. For specific return periods of interest, seismic hazard disaggregation is used to obtain the percentage contributions of various seismic sources to the hazard, including metrics such as mean earthquake magnitude used for simplified geotechnical calculations. The seismic hazard analyses utilise concensus models for seismic source and ground-motion characterisation, including consideration of alternative ground-motion models. The analyses therefore represent an appreciable improvement relative to the science that underpin current loading standards [e.g., 1,2]. Consequently, we advocate the use of these results as a scientific basis for potential revisions to standards and guidance documents that characterise seismic hazard via PGA. [ABSTRACT FROM AUTHOR]

Acceleration-sensitive non-structural elements not only constitute a significant portion of a building's component inventory, but also comprise components and systems that are indispensable to the operational continuity of essential facilities. In New Zealand, Section 08 of the seismic loadings standard, NZS 1170.5: Earthquake Actions, and a dedicated standard, NZS 4219: Seismic Performance of Engineering Systems in Buildings, address the seismic design of non-structural elements. This paper scrutinizes the design provisions for acceleration-sensitive non-structural elements in NZS 1170.5 and NZS 4219, and provides an international perspective by comparing with the design provisions for non-structural elements specified in ASCE 7-16, the latest ATC approach and Eurocode 8. This is followed by a detailed discussion on the improvements required for component demand estimation, the need for design criteria that are consistent with performance objectives, definition of realistic ductility factors, and recommendations for the future way forward in the form of an improved design procedure and its application through a new seismic rating framework. [ABSTRACT FROM AUTHOR]

In an effort to provide practicing engineers with simple means of limiting earthquake-induced losses to buildings, this paper extends a simplified damage-state loss vs. intensity approach for estimation of expected annual losses in two ways. Firstly, modifications to allow consideration of a threshold replacement limit state are provided. Secondly, an equation for simplified loss assessment of buildings characterised with a three-damage state loss-intensity model is presented. Furthermore, recommendations are provided for the simplified models associated parameters’ values. The proposed approach is trialled for three New Zealand code compliant eccentrically braced frame buildings, and the results compared against those obtained through the PEER framework. It is found that the expected annual loss can be predicted to within 10% of the values obtained via rigorous approaches and opportunities for further research are discussed. [ABSTRACT FROM AUTHOR]

There are many applications in buildings in which precast pre-stressed hollow-core (HC) slabs are subjected to shear, torsion, or combined shear and torsion. Nonetheless, extruded HC units contain no transverse reinforcement, being inherently vulnerable to brittle failure modes due to shear and torsional actions. In previous work by the authors, a finite element (FE) modelling approach for HC units failing in shear was developed and validated against experimental test data. This paper aims to extend the applicability of the proposed FE approach to help improve the understanding of the torsional behavior of HC units. For this purpose, the developed model is further validated against experimental data available in the literature and then used to predict the torsional capacity of New Zealand-specific 200 mm deep HC units. Results suggest that the FE model is capable of predicting the capacity of HC slabs with and without eccentricity of the applied vertical load. Finally, the numerical results are used to evaluate the performance of available simplified analysis approaches for assessing the torsional capacity of HC units, which are found to be nonconservative if used with expected material properties. [ABSTRACT FROM AUTHOR]

In the context of infrastructure and natural hazard planning, a new agenda for applied research is emerging which, focused on resilience, integrates government, hazard science, engineering and economics. This paper sets out the context and key tenets guiding the direction of this topic of enquiry, including the New Zealand legislative and policy context under which infrastructure decisions are made, core principles implied by the resilience objective, current norms and challenges in the practice of infrastructure planning, and key criteria for decision-support tools. While decision-making processes strongly informed by cost-benefit analysis (CBA) continue to be common in the New Zealand policy process, this paper demonstrates that there are certain distinguishing features of infrastructure networks that make it challenging to effectively and validly apply standard CBA approaches, particularly when resilience values are at stake. To help address this challenge, a new conceptual framework is presented to assist in the critical review and selection of decisionmaking tools to support infrastructure planning. This framework provides a synthesis of the ways through which contextual uncertainties influence the relative advantages and appropriateness of different decision support tools. Ultimately, we seek to promote a diverse but also nuanced approach to analysis supporting infrastructure planning under seismic and other natural hazard risk. [ABSTRACT FROM AUTHOR]

This paper provides an overview on the physical and functional performance of the New Zealand telecommunication network following the 14 November 2016 Kaikōura earthquake (Mw 7.8). Firstly, the paper provides an overview of the New Zealand telecommunications infrastructure. Secondly, the paper presents preliminary information on the impacts of the Kaikōura earthquake on the telecommunication network following the format proposed by [1] for post-earthquake assessment and resilience analysis of infrastructure systems, namely: extent of earthquake-induced physical impacts on the components of the telecommunication networks, identified according to a proposed taxonomy; main observed dependency issues; identification of resilience attributes and strategies that allowed an effective and rapid reinstatement of the telecommunication service. Finally lessons learned and research needs are discussed. [ABSTRACT FROM AUTHOR]

The transport infrastructure was majorly affected by the 14th November 2016 Kaikōura Earthquake. Severe vertical and horizontal peak ground accelerations generated high inertial forces, land-slides, and liquefaction. Most of the bridges in the Hurunui, Malborough and Kaikōura districts were critical nodes to the railway and road networks. In total, 904 road bridges across those districts were affected. Two reached the life safety limit state, suffering severe damage, however, most of the affected bridges experienced only minor to moderate damage. This paper describes the structural performance of the most severely damaged bridges based on observations made from site inspections. In addition to this, several performance issues have arisen from this event and are posed in this paper, hopefully to be addressed in the near future. [ABSTRACT FROM AUTHOR]

The 2016 Mw7.8 Kaikōura earthquake struck the north-eastern region of the South Island of New Zealand on November 13th 11:02 (UTM). The damaging earthquake generated extreme surface displacements, land deformations and surface ground motions (Figure 1), as well as a regional tsunami and triggered major slow slip events on the Hikurangi subduction zone interface. This special issue of the Bulletin for the New Zealand Society for Earthquake Engineering presents a compilation of papers focussing on reconnaissance observations and preliminary analysis of a range of extensive datasets collected following the Kaikōura earthquake. [ABSTRACT FROM AUTHOR]

Professional engineers have provided a range of inputs into the responses to the Canterbury Earthquake Sequence and the recovery process that has followed. This earthquake sequence has been unique in many respects, including the intensity of shaking produced in the Christchurch CBD by each of the major aftershocks in February, June and December 2011. For engineers, the heavy workload has been continuous from the response to the original 4 September 2010 Darfield earthquake, and will extend for several years to come. There have been many post-earthquake challenges for seismologists and geotechnical and structural engineers, commencing with urban search and rescue responses and rapid building evaluations, and extending through the more detailed assessments and repair specifications during the recovery phase. Engineers are required to interface with owners, regulatory authorities and insurers, and face many challenges in meeting the objectives of these different sectors, which are rarely aligned. Adding to the technical demands has been the requirement for many scientists and engineers to provide input into the Canterbury Earthquakes Royal Commission of Inquiry and other investigations. The Royal Commission was set up to investigate the failure of buildings that led to the loss of 185 lives in the 22 February 2011 aftershock, and has placed close scrutiny on many aspects of engineering activities, particularly those undertaken following the 4 September 2010 earthquake. The prominent public reporting of the Royal Commission hearings has placed additional pressure on many engineers, including those who volunteered their services following the original earthquake into a role for which they had received only limited prior training. Interpreting and communicating 'safety' in relation to the re-occupancy (or continued occupancy) of commercial buildings continues to be a challenge in the face of liability concerns. A more comprehensive understanding of the technical and process guidance required by engineers and authorities has resulted from the work undertaken in response to this earthquake sequence. Much of this guidance has now been produced, and will be of considerable benefit for future major earthquake events. This paper reflects on the range of work undertaken by scientists and engineers during the response and recovery stages. The scope and implications of the various official inquiries are summarised, and the potential impacts on engineers involved in the response to and recovery from future major earthquakes are briefly discussed. [ABSTRACT FROM AUTHOR]

Probabilistic Seismic Hazard Analysis (PSHA) is widely accepted as the most robust approach for evaluating the seismic hazard at a given site and provides the basis for seismic loads in most design codes. To obtain more detailed information on the specific earthquake scenarios contributing to the hazard at a site, it is common to include seismic hazard disaggregation results within a PSHA. This is mostly done in terms of exceedance of the intensity level of interest, but for many applications a disaggregation in terms of occurrence of the intensity level of interest is more appropriate. A number of researchers have examined the theoretical differences between the exceedance and occurrence approaches; however, few have provided extensive application examples. This paper therefore compares the approaches for 24 sites across New Zealand. It is shown that the two different approaches can result in moderate differences in the mean magnitudes and siteto-source distances, as well as differences in the relative contributions from different Tectonic Region Types. Whilst some weak trends are identified, it is concluded that generally it is not possible to know a priori whether the difference between occurrence or exceedance approaches would have a tangible impact on disaggregation results or the results of subsequent applications. It is therefore recommended that developers of seismic hazard analysis software and providers of seismic hazard data products make both approaches readily available. [ABSTRACT FROM AUTHOR]

Good seismic performance of glazing systems is essential to maintaining building functionality and limiting repair costs in a post-earthquake scenario. This paper reports on experimental research into the seismic performance of a standard commercial glazing system used in New Zealand. The focus of the research is to provide information not only on the life-safety performance of glazing but also on the serviceability of glazing systems, considering post-earthquake weather-tightness. This paper first describes the experimental testing set-up developed at the University of Canterbury to achieve this, then details the damage observed and finally, fragility functions for different damage states are reported. Leakage of the glazing is seen to initiate at a median storey drift demand of only 0.35%, whereas glass breakage did not occur until a median drift storey demand of 5.0%. The results obtained from this research demonstrate that the life-safety risk posed by modern commercial glazing in earthquakes will typically be low but the serviceability performance, and in particular weather-tightness post-earthquake, should be improved. [ABSTRACT FROM AUTHOR]

A practice-oriented modal superposition method for setting elastic floor acceleration response spectra is proposed in this paper. The approach builds on previous contributions in the literature, making specific recommendations to explicitly consider floor displacement response spectra and accounts for uncertainty in modal characteristics. The method aims to provide reliable predictions which improve on existing code methods but maintain simplicity to enable adoption in practical design. This work is motivated by recent seismic events which have illustrated the significant costs that can be incurred following damage to secondary and nonstructural components within buildings, even where the structural system has performed well. This has prompted increased attention to the seismic performance of nonstructural components with questions being raised about the accuracy of design floor acceleration response spectra used in practice. By comparing floor acceleration response spectra predicted by the proposed method with those recorded from instrumented buildings in New Zealand, it is shown that the proposed approach performs well, particularly if a good estimate of the building's fundamental period of vibration is available. [ABSTRACT FROM AUTHOR]

This paper examines ground motions for a major potential Mw7:51 rupture of the Hope Fault using a physicsbased simulation methodology and a 3D crustal velocity model of New Zealand. The simulation methodology was validated for use in the region through comparison with observations for a suite of historic small magnitude earthquakes located proximal to the Hope Fault. Simulations are compared with conventionally utilised empirical ground motion models, with simulated peak ground velocities being notably higher in regions with modelled sedimentary basins. A sensitivity analysis was undertaken where the source characteristics of magnitude, stress parameter, hypocentre location and kinematic slip distribution were varied and an analysis of their effect on ground motion intensities is presented. It was found that the magnitude and stress parameter strongly influenced long and short period ground motion amplitudes, respectively. Ground motion intensities for the Hope Fault scenario are compared with the 2016 Kaikoura Mw7:8 earthquake, it was found that the Kaikoura earthquake produced stronger motions along the eastern South Island, while the Hope Fault scenario resulted in stronger motions immediately West of the near-fault region and similar levels of ground motion in Canterbury. The simulated ground motions for this scenario complement prior empirically-based estimates and are informative for mitigation and emergency planning purposes. [ABSTRACT FROM AUTHOR]

The recent earthquakes in New Zealand have raised awareness of the seismic vulnerability of non-structural elements and the costly consequences when non-structural elements perform poorly. Impacts on business continuity due to the damage of non-structural elements has been identified as a major cost and disruption issue in recent earthquakes in New Zealand, as well as worldwide. Clearly improvements in performance of non-structural elements under earthquake loads will yield benefits to society. This paper explores the intended and expected performance objectives for non-structural elements. Possible historic differences in performance objective expectations for non-structural elements between building services engineers, fire engineers and structural engineers are discussed. Wider construction industry expectations are explored along with our experience of client and regulatory authority views. The paper discusses the application and interpretation of the New Zealand earthquake loadings Standard NZS1170.5:2004 for the design of non-structural elements including possible differences in interpretation between building services, structural and fire engineers leading to confusion around the expected performance of non-structural elements under different limit states. It is based on the experience of several of the authors as members of the Standards committee for NZS1170.5:2004. The paper concludes by discussing changes to NZS1170.5:2004 the authors have proposed as members of the NZS1170.5 Standards committee to clarify and address the identified issues. These changes clarify the classification of parts, requirements for consideration earthquake imposed deformations, parts supported on ledges, potential falling of parts, the combination of fire and earthquake loads, and the requirement for parts to be designed for both serviceability and ultimate limit states along with the effective introduction of a serviceability limit state for parts for occupational continuity. [ABSTRACT FROM AUTHOR]

The recent Canterbury earthquake sequence and the more recent Seddon, Lake Grassmere and Castlepoint earthquakes have raised awareness of the vulnerability of non-structural elements of buildings (e.g. ceilings, cladding, building services equipment and piping, etc.). With architectural and building services components comprising up to 70% of a building's value, significant damage to these elements resulted in some buildings being declared economic losses, even when the structure itself was not badly damaged. Impacts on business continuity due to the damage of non-structural elements have also been identified as a major issue in recent earthquakes in New Zealand, as well as worldwide. It appears a step change is required in the seismic performance of non-structural elements in New Zealand. This paper explores whether the current approach being used in New Zealand for non-structural contractor designed elements is appropriate in meeting society's expectations. It contrasts the approach that has historically been taken in New Zealand, with that followed overseas. The paper goes on to explore a pragmatic "best bang for the buck" approach to upgrading non-structural elements in existing buildings. The approach is presented through illustrated examples of issues and solutions that have been adopted. It also discusses the challenges with trying to upgrade non-structural elements within existing operational buildings including for example, congestion issues and practicalities of access. The paper concludes with ideas on possible ways to improve the seismic performance of non-structural elements within the New Zealand environment and regulatory regimen from both design and construction perspectives. [ABSTRACT FROM AUTHOR]

This paper presents an overview of the soil profile characteristics at strong motion station (SMS) locations in the Christchurch Central Business District (CBD) based on recently completed geotechnical site investigations. Given the variability of Christchurch soils, detailed investigations were needed in close vicinity to each SMS. In this regard, CPT, SPT and borehole data, and shear wave velocity (Vs) profiles from surface wave dispersion data in close vicinity to the SMSs have been used to develop detailed representative soil profiles at each site and to determine site classes according to the New Zealand standard NZS1170.5. A disparity between the NZS1170.5 site classes based on Vs and SPT N60 investigation techniques is highlighted, and additional studies are needed to harmonize site classification based on these techniques. The short period mode of vibration of soft deposits above gravels, which are found throughout Christchurch, are compared to the long period mode of vibration of the entire soil profile to bedrock. These two distinct modes of vibration require further investigation to determine their impact on the site response. According to current American and European approaches to seismic site classification, all SMSs were classified as problematic soil sites due to the presence of liquefiable strata, soils which are not directly accounted for by the NZS1170.5 approach. [ABSTRACT FROM AUTHOR]

This paper summarizes the role site-specific seismic hazard analyses can play in seismic design and assessment in New Zealand. The additional insights and potential improvements in the seismic design and assessment process through a better understanding of the ground motion hazard are examined through a comparative examination with prescriptive design guidelines. Benefits include the utilization of state-of-the-art knowledge, improved representation of site response, reduced conservatism, and the determination of dominant seismic source properties, among others. The paper concludes with a discussion of these relative benefits so that the efficacy of site-specific hazard analysis for a particular project can be better judged by the engineer. [ABSTRACT FROM AUTHOR]

This paper presents the development of representative shear wave velocity profiles for the prominent geologic formations in the Nelson-Tasman region of New Zealand. Shear wave velocity (VS) profiles to depths of up to 100 m were developed at over 50 sites using a combination of active source and passive source surface wave testing. Using this data and regional geologic information, VS-depth models were developed for six of the prominent geologic formations. Comparison with existing VS-depth models from New Zealand and international studies highlighted the significantly higher shear wave velocities of the deposits in this region. VS exceeded 750 m/s for the Moutere Gravels and Port Hills Gravels at relatively shallow depths, representative of rock deposits. However, while the Port Hills Gravels transition to a conglomerate rock below depths of 30 m or less, the Moutere Gravel formation is an uncemented clay-bound gravel. The young gravel and sand deposits have VS higher than those from other regions. As the region is thought to have undergone cycles of geologic uplift, the resulting over-consolidation of these deposits could explain the high VS. Horizontal-to-vertical spectral ratio testing was not able to characterise the fundamental site period across the region, likely due to the weak impedance contrast that would exist at the gravel-rock interface at depth. These outcomes highlight the importance of regional geotechnical and geophysical characterisation to constrain the salient features that can control potential seismic site amplification and site classification. [ABSTRACT FROM AUTHOR]

This paper scrutinises the seismic hazard of New Zealand (NZ) from a geotechnical engineering perspective. The two codified versions of the seismic hazard in NZS1170.5 (structural loading standard) and NZTA Bridge Manual (NZTA-BM) are shown to yield consistently different peak ground acceleration (PGA) hazards throughout NZ. Results from site-specific PSHA for 24 locations in NZ are used to examine key hazard characteristics, including earthquake magnitude and the effects of site conditions (classes) on the PGA hazard. The comparative evaluations show that for most of the locations considered, NZS1170.5 and NZTA-BM overestimate the PGA hazard. However, NZS1170.5, and NZTA-BM in particular, significantly underestimate the PGA hazard for locations that are at a short source-to-site distance from the Hikurangi Subduction Zone (HSZ), and for which HSZ significantly contributes to their hazard. Using the results from this study, an interim PGA hazard is recommended for geotechnical assessment and design in support of the NZ guidelines for geotechnical earthquake engineering practice. The recommended interim PGA hazard is applicable to all site classes without any modification or use of site amplification factors. [ABSTRACT FROM AUTHOR]

This paper provides a near-term reconnaissance of the economic and social impacts of the November 14th, 2016 Kaikōura earthquakes and tsunami. The effect of this event on the national economy is relatively minimal. The main impacts at the national scale include short-term falls in tax revenues from the affected regions and the Government's NZ$1 billion spending increase for reconstruction activities. Disruptions at the regional and industry-level are far more significant. Approximately 11 per cent of office space in the nation's capital of Wellington was closed in the week following the event and cordons were erected around several city blocks due to safety concerns. Damage to transport infrastructure is having the most significant economic impact, both in terms of the direct cost of repair and the indirect impacts on businesses whose supply chains have been disrupted. The Kaikōura District's two largest industries, tourism and primary production, lost important infrastructure and essential functions were hampered by transport disruptions. In the tourism industry, ongoing safety concerns and reduced amenities for tourists will reduce trade in the coming season. Primary production businesses face increased transportation and land remediation costs and the closure of fisheries while affected shellfish habitats recover. Communities in the districts most affected by the Kaikōura earthquakes experienced the loss of critical utility services, the loss of homes, and temporary isolation. The Kaikōura earthquake has starkly highlighted the vulnerability of key infrastructure and transportation routes to natural hazards. It is also a timely reminder of the need for New Zealand to be prepared and to continue efforts to build resilience. [ABSTRACT FROM AUTHOR]

This paper describes the performance of log houses in the 2016 Kaikoura earthquake. Most of these houses are in the Mt Lyford village 45 km south-east of Kaikoura. Typical log houses at Mt Lyford were built using 200mm diameter machined logs. A smaller number of log houses were built with much larger hand-hewn logs of less regular shapes, in traditional log house construction. Most houses were constructed on a concrete slab incorporating the foundations. A small number, especially those on steep sites, had timber poles supporting a timber ground floor platform. Most of the log houses suffered some lateral movement and subsequent damage. Very few of the houses were damaged beyond repair, and the overall performance was excellent considering the nature of the quake. One house close to Waiau suffered extreme near-fault shaking, leading to extensive damage, but this is considered to be the result of exceptional ground movement rather than any deficiencies in the design or construction. [ABSTRACT FROM AUTHOR]

The M7.8 Kaikōura Earthquake in 2016 presented a number of challenges to science agencies and institutions throughout New Zealand. The earthquake was complex, with 21 faults rupturing throughout the North Canterbury and Marlborough landscape, generating a localised seven metre tsunami and triggering thousands of landslides. With many areas isolated as a result, it presented science teams with logistical challenges as well as the need to coordinate efforts across institutional and disciplinary boundaries. Many research disciplines, from engineering and geophysics to social science, were heavily involved in the response. Coordinating these disciplines and institutions required significant effort to assist New Zealand during its most complex earthquake yet recorded. This paper explores that effort and acknowledges the successes and lessons learned by the teams involved. [ABSTRACT FROM AUTHOR]

The 14 November 2016 Kaikōura earthquake resulted in long duration shaking in excess of the code demand for many buildings with fundamental periods between 1 and 2 seconds in Wellington, particularly in those parts of the city where shaking has been amplified due to basin effects and deeper deposits, notably in the port area or Thorndon basin. This paper outlines the initial response of engineers and the engineering assessment processes undertaken in Wellington in the weeks following the Kaikōura Earthquake, along with the technical support provided to Wellington City Council through the establishment of the Critical Buildings Team and the Wellington Engineering Leadership Group. An overview is provided of the Targeted Assessment Programme subsequently undertaken by Wellington City Council to look more closely at the buildings most likely to be affected. Background is provided to the key elements of the Targeted Damage Evaluation Guidelines that were developed in support of this programme, including the relationship with the Detailed Engineering (Damage) Evaluation process used following the Canterbury Earthquake Sequence. [ABSTRACT FROM AUTHOR]

This paper summarizes the impact the 2016 Kaikōura earthquakes have had on electrical transmission and distribution infrastructure performance. It also provides background context to the distribution network operator's (i.e. MainPower's) prior earthquake preparedness following the 2010 earthquakes in the region. [ABSTRACT FROM AUTHOR]

This paper provides a brief discussion of observed strong ground motions from the 14 November 2016 Mw7:8 Kaikō ura earthquake. Specific attention is given to examining observations in the near-source region where several ground motions exceeding 1.0g horizontal are recorded, as well as up to 2.7g in the vertical direction at one location. Ground motion response spectra in the near-source, North Canterbury, Marlborough and Wellington regions are also examined and compared with design levels. Observed spectral amplitudes are also compared with predictions from empirical and physics-based ground motion modelling. [ABSTRACT FROM AUTHOR]

At 00:02 on 14th November 2016, a Mw 7.8 earthquake occurred in and offshore of the northeast of the South Island of New Zealand. Fault rupture, ground shaking, liquefaction, and co-seismic landslides caused severe damage to distributed infrastructure, and particularly transportation networks; large segments of the country's main highway, State Highway 1 (SH1), and the Main North Line (MNL) railway line, were damaged between Picton and Christchurch. The damage caused direct local impacts, including isolation of communities, and wider regional impacts, including disruption of supply chains. Adaptive measures have ensured immediate continued regional transport of goods and people. Air and sea transport increased quickly, both for emergency response and to ensure routine transport of goods. Road diversions have also allowed critical connections to remain operable. This effective response to regional transport challenges allowed Civil Defence Emergency Management to quickly prioritise access to isolated settlements, all of which had road access 23 days after the earthquake. However, 100 days after the earthquake, critical segments of SH1 and the MNL remain closed and their ongoing repairs are a serious national strategic, as well as local, concern. This paper presents the impacts on South Island transport infrastructure, and subsequent management through the emergency response and early recovery phases, during the first 100 days following the initial earthquake, and highlights lessons for transportation system resilience. [ABSTRACT FROM AUTHOR]

The magnitude Mw7.8 'Kaikōura' earthquake occurred shortly after midnight on 14 November 2016. This paper presents an overview of the geotechnical impacts on the South Island of New Zealand recorded during the post-event reconnaissance. Despite the large moment magnitude of this earthquake, relatively little liquefaction was observed across the South Island, with the only severe manifestation occurring in the young, loose alluvial deposits in the floodplains of the Wairau and Opaoa Rivers near Blenheim. The spatial extent and volume of liquefaction ejecta across South Island is significantly less than that observed in Christchurch during the 2010-2011 Canterbury Earthquake Sequence, and the impact of its occurrence to the built environment was largely negligible on account of the severe manifestations occurring away from the areas of major development. Large localised lateral displacements occurred in Kaikōura around Lyell Creek. The soft fine-grained material in the upper portions of the soil profile and the free face at the creek channel were responsible for the accumulation of displacement during the ground shaking. These movements had severely impacted the houses which were built close (within the zone of large displacement) to Lyell Creek. The wastewater treatment facility located just north of Kaikōura also suffered tears in the liners of the oxidation ponds and distortions in the aeration system due to ground movements. Ground failures on the Amuri and Emu Plains (within the Waiau Valley) were small considering the large peak accelerations (in excess of 1g) experienced in the area. Minor to moderate lateral spreading and ejecta was observed at some bridge crossings in the area. However, most of the structural damage sustained by the bridges was a result of the inertial loading, and the damage resulting from geotechnical issues were secondary. [ABSTRACT FROM AUTHOR]

Although located about 200 km away from the epicentre of the 2016 Kaikōura Earthquake, the waterfront areas of Wellington City suffered varying degrees of damage as a result of soil liquefaction and associated ground deformations. This paper presents a summary of the major observations made following reconnaissance inspections of the geotechnical effects caused by the earthquake, with emphasis on the ground performance in the affected areas near the waterfront. Except for CentrePort, summarised elsewhere in this Special Issue, the inspections concentrated mostly on the waterfront areas and the impact to buildings built on reclaimed lands. Cracks and minor ground subsidence were observed in many parts of the waterfront, but the damage was less than that in CentrePort where significant liquefaction-induced damage was evident. The age of reclamation appears to have significant effect on the distribution of liquefactioninduced damage, while reclaimed areas where improvement techniques have been implemented performed well. [ABSTRACT FROM AUTHOR]

Base isolation is arguably the most reliable method for providing enhanced protection of buildings against earthquake-induced actions, by virtue of a physical separation between the structure and the ground through elements/devices with controlled force capacity, significant lateral deformation capacity and (often) enhanced energy dissipation. Such a design solution has shown its effectiveness in protecting both structural and non-structural components, hence preserving their functionality even in the aftermath of a major seismic event. Despite lead rubber bearings being invented in New Zealand almost forty years ago, the Christchurch Women's hospital was the only isolated building in Christchurch when the Canterbury earthquake sequence struck in 2010/11. Furthermore, a reference code for designing base-isolated buildings in New Zealand is still missing. The absence of a design standard or at least of a consensus on design guidelines is a potential source for a lack of uniformity in terms of performance criteria and compliance design approaches. It may also limit more widespread use of the technology in New Zealand. The present paper provides an overview of the major international codes (American, Japanese and European) for the design of base-isolated buildings. The design performance requirements, the analysis procedures, the design review process and approval/quality control of devices outlined in each code are discussed and their respective pros and cons are compared through a design application on a benchmark building in New Zealand. The results gathered from this comparison are intended to set the basis for the development of guidelines specific for the New Zealand environment. [ABSTRACT FROM AUTHOR]

A wide range of reinforced concrete (RC) wall performance was observed following the 2010/2011 Canterbury earthquakes, with most walls performing as expected, but some exhibiting undesirable and unexpected damage and failure characteristics. A comprehensive research programme, funded by the Building Performance Branch of the New Zealand Ministry of Business, Innovation and Employment, and involving both numerical and experimental studies, was developed to investigate the unexpected damage observed in the earthquakes and provide recommendations for the design and assessment procedures for RC walls. In particular, the studies focused on the performance of lightly reinforced walls; precast walls and connections; ductile walls; walls subjected to bi-directional loading; and walls prone to out-of-plane instability. This paper summarises each research programme and provides practical recommendations for the design and assessment of RC walls based on key findings, including recommended changes to NZS 3101 and the NZ Seismic Assessment Guidelines. [ABSTRACT FROM AUTHOR]

This paper provides a comparison of four different seismic performance metrics which relate to the determination of design seismic demands from seismic response history analyses. The considered metrics include those implemented in New Zealand and international codes of practice, as well as emerging metrics which are well established in related research and state-of-the-art practice, but have yet to find their way into conventional guidelines. The metrics are directly compared and contrasted based on a central example. It is illustrated that the use of the "maximum demand" metric in the NZ loadings standard, and the "mean demand" in international codes of practice are notably conservative and unconservative, respectively. Either of the two emerging metrics provide a significant improvement, and given that they require the same information from an analyst's perspective, are recommended as replacements. [ABSTRACT FROM AUTHOR]

The fundamental site period, T, is a key parameter for site classification in NZS 1170.5:2004. Many sites in New Zealand will fall into site classes C and D, where the boundary between the site classes is T = 0.6 seconds. NZS 1170.5 offers several methods of determining site classification. The intent of this paper is to expand on NZS 1170.5 and guide practising engineers towards more accurate and efficient methods for determining site period. We review methods to calculate the shear-wave velocity, then give specific examples for calculating the site period for five types of soil profile (uniform layer, shear-wave velocity increasing as a power of depth, shear modulus increasing linearly with depth, two-layer profile and three-layer profile). We find that NZS 1170.5 clause 3.1.3.7 for calculating site period at layered sites is unconservative and inconsistent with two other well-accepted methods for calculating site period. We consider the most accurate and efficient method of calculating site period for layered sites is to represent the profile as a lumped mass system, then calculate the fundamental frequency from the eigenvalues of the system. The successive application of the two-layer closed form solution is also considered an acceptable method. [ABSTRACT FROM AUTHOR]

In April 2011, 27 processed seismic acceleration records at 27 seismic stations whose epicental distances were less than 50 km in Feb. 22 Christchurch, New Zealand earthquake (Mw6.3), were collected from GeoNet strong motion data centre. Applying Sun-Yuan liquefaction detection method on the selected records, 9 liquefied sites and 18 non-liquefied sites were blindly identified thereof in May 2011, prior to the real liquefaction reports (papers) been published. Up to present, liquefaction detection results of 11 sites, i.e., 8 liquefied sites CBGS, CCCC, CHHC, CMHS, HPSC, PRPC, REHS and SHLC and 3 non-liquefied sites PPHS, HVSC and LPCC, were confirmed by publications which were consistent with the detections. New approaches and proof (or evidence) need to be pursued to demonstrate the detected results on other sites, i.e., liquefied site LINC and 15 non-liquefied sites. [ABSTRACT FROM AUTHOR]

This paper investigates the validity of the soil class dependent spectral shape factors used to calculate seismic design actions in the New Zealand seismic design standard NZS1170.5, which currently specifies seismic design spectra corresponding to five different soil classes. According to the current provisions stipulated in NZS1170.5, for all natural periods, the seismic demand for structures on soft soil is either equal to or greater than that for structures on hard soil. This is opposite to the basic structural dynamics theory which suggests that an increase in stiffness of a system results in an increase in the acceleration response. In this pretext, a numerical parametric study is undertaken using a nonlinear site response analysis tool in order to capture the effect of soil characteristics on structural seismic demand and to scrutinize the validity of the current site specific seismic design spectra. It is identified that the level of input ground motion intensity and shear stiffness of the soil deposit (represented by its shear wave velocity Vs) greatly affect the maximum acceleration and frequency content of the surface motion. The study found some shortfalls in the way the current code defines seismic design demand, in particular the hierarchy of soil stiffness at low structural periods. It was found that stiff soils generally tend to have a higher spectral acceleration response in comparison to soft soils although this trend is less prominent for high intensity bed rock motions. It was also found that for medium to hard soils the spectral acceleration response at short period is grossly underestimated by the current NZS 1170.5 provisions. Based on the outcomes of the parametric numerical analyses, a revised strategy to determine structural seismic demand for different soil classes is proposed and its application is demonstrated through an example. [ABSTRACT FROM AUTHOR]

The Christchurch earthquakes have highlighted the mismatch in expectations between the engineering profession and society regarding the seismic performance of buildings. While most modern buildings performed as expected, many buildings have been, or are to be, demolished. The ownership, occupancy, and societal costs of only targeting life-safety as the accepted performance standard for building design are now apparent in New Zealand. While the structural system has a significant effect on the seismic performance of the entire building, including the contents, it is only about 20% of the total building cost. Hence, structural engineers should view the seismic performance in a wider context, looking at all the systems of the building rather than just the damage to structural items and life-safety. The next generation of performance-based seismic design procedures, outlined in the FEMA P-58 document, provide engineers with the tools to express the seismic performance of the entire building in terms of the future life loss, facility repair cost and repair time. This paper will outline the FEMA P-58 procedure and present the results of a comparative study of six different structural systems for a three storey commercial and laboratory building: moment frame; buckling restrained braced frame; viscously damped moment frame; Pres-Lam timber coupled-walls; cast-in-place reinforced concrete shear wall; and base isolated braced frame. Each system was analysed as a fully non-linear structure and the calculated drifts and floor accelerations were input into the FEMA P-58 PACT tool to evaluate the overall building performance. The PACT tool performs loss calculations for the expected casualties, repair cost; and repair time from which a QuakeStar or SEAONC rating for the building can be obtained. [ABSTRACT FROM AUTHOR]