The M7.8 Kaikoura 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.
Hybrid broadband simulation methods typically compute high-frequency portion of ground-motions using a simplified-physics approach (commonly known as “stochastic method”) using the same 1D velocity profile, anelastic attenuation profile and site-attenuation (κ0) value for all sites. However, these parameters relating to Earth structure are known to vary spatially. In this study we modify this conventional approach for high-frequency ground-shaking by using site-specific input parameters (referred to as “site-specific”) and analyze improvements over using same parameters for all sites (referred to as “generic”). First, we theoretically understand how different 1D velocity profiles, anelastic attenuation profiles and site-attenuation (κ0) values affects the Fourier Acceleration Spectrum (FAS). Then, we apply site-specific method to simulate 10 events from the 2010-2011 Canterbury earthquake sequence to assess performance against the generic approach in predicting recorded ground-motions. Our initial results suggest that the site-specific method yields a lower simulation standard deviation than generic case.
New Zealand has a long tradition of using light timber frame for construction of its domestic dwellings. After the most recent earthquakes (e.g. Canterbury earthquakes sequence), wooden residential houses showed satisfactory life safety performance which aligns with New Zealand design codes requirements. However, poor performance was reported in terms of their seismic resilience that can be generally associated with community demands. Future expectations of the seismic performance of wooden-framed houses by homeowners were assessed in this research. Homeowners in the Wellington region were asked in a survey about the levels of safety and expected possible damage in their houses after a seismic event. Findings bring questions about whether New Zealand code requirements are good enough to satisfy community demands. Also, questions whether available information of strengthening techniques to structurally prepare wooden-framed houses to face future major earthquakes can help to make homeowners feel safer at home during major seismic events.
Following the 2010/2011 Canterbury earthquakes, approximately 60% of multi-story buildings with reinforced concrete walls required demolition. Both practitioners and researchers have increasingly realized that low-damage structural systems could be an alternative to improve the seismic behaviour of concrete buildings and to reduce the economic and social impact of structural damage in future earthquakes. To verify the seismic response of a low-damage concrete wall building representing state-of-art design practice, a shake table test on a two-story concrete building was recently conducted as part of an ILEE-QuakeCoRE collaborative research program. The building utilized flexible wall-to-floor connections in the long span direction and isolating wall-to-floor devices in the short span direction to provide a comparison of their respective behaviour. Additionally, the wall-to-floor interaction such as effects of wall uplift on the link slab, and force transfer mechanism from floor to the wall will be discussed in this paper.
The development of Digital City technologies to manage and visualise spatial information has increasingly become a focus of the research community, and application by city authorities. Traditionally, the Geographic Information Systems (GIS) and Building Information Models (BIM) underlying Digital Cities have been used independently. However, integrating GIS and BIM into a single platform provides benefits for project and asset management, and is applicable to a range of issues. One of these benefits is the means to access and analyse large datasets describing the built environment, in order to characterise urban risk from and resilience to natural hazards. The aim of this thesis is to further explore methodologies of integration in two distinct areas. The first, integration through connectivity of heterogeneous datasets where GIS spatial infrastructure data is merged with 3D BIM building data to create a digital twin. Secondly, integration through analysis whereby data from the digital twin are extracted and integrated with computational models. To achieve this, a workflow was developed to identify the required datasets of a digital twin, and develop a process of integrating those datasets through a combination of; semi-autonomous conversion, translation and extension of data; and semantic web and services-based processes. Through use of a designed schema, the data were streamed in a homogenous format in a web-based platform. To demonstrate the value of this workflow with respect to urban risk and resilience, the process was applied to the Taiora: Queen Elizabeth II recreation and sports centre in eastern Christchurch, New Zealand. After integration of as-built GIS and BIM datasets, targeted data extraction was implemented, with outputs tailored for analysis in an infrastructure serviceability loss model, which assessed potable water network performance in the 22nd February 2011 Christchurch Earthquake. Using the same earthquake conditions as the serviceability loss model, performance of infrastructure assets in service at the time of the 22nd February 2011 Christchurch Earthquake was compared to new assets rebuilt at the site, post-earthquake. Due to improved potable water infrastructure resilience resulting from installation of ductile piles, a decrease of 35.5% in the probability of service loss was estimated in the serviceability loss model. To complete the workflow, the results from the external analysis were uploaded to the web-based platform. One of the more significant outcomes from the workflow was the identification of a lack of mandated metadata standards for fittings/valves connecting a building to private laterals. Whilst visually the GIS and BIM data show the building and pipes as connected, the semantic data does not include this connectivity relationship. This has no material impact on the current serviceability loss model as it is not one of the defined parameters. However, a proposed modification to the model would utilise the metadata to further assess the physical connection robustness, and increase the number of variables for estimating probability of service loss. This thesis has made a methodological contribution to urban resilience analysis by demonstrating how readily available up-to-date building and infrastructure data can be integrated, and with tailored extraction from a Digital City platform, be used for disaster impact analysis in an external computational engine, with results in turn imported and visualised in the Digital City platform. The workflow demonstrated that translation and integration of data would be more successful if a regional/national mandate was implemented for the submission of consent documentation in a specified standard BIM format. The results of this thesis have identified that the key to ensuring the success of an integrated tool lies in the initial workflow required to safeguard that all data can be either captured or translated in an interoperable format.
The development of Digital City technologies to manage and visualise spatial information has increasingly become a focus of the research community, and application by city authorities. Traditionally, the Geographic Information Systems (GIS) and Building Information Models (BIM) underlying Digital Cities have been used independently. However, integrating GIS and BIM into a single platform provides benefits for project and asset management, and is applicable to a range of issues. One of these benefits is the means to access and analyse large datasets describing the built environment, in order to characterise urban risk from and resilience to natural hazards. The aim of this thesis is to further explore methodologies of integration in two distinct areas. The first, integration through connectivity of heterogeneous datasets where GIS spatial infrastructure data is merged with 3D BIM building data to create a digital twin. Secondly, integration through analysis whereby data from the digital twin are extracted and integrated with computational models. To achieve this, a workflow was developed to identify the required datasets of a digital twin, and develop a process of integrating those datasets through a combination of; semi-autonomous conversion, translation and extension of data; and semantic web and services-based processes. Through use of a designed schema, the data were streamed in a homogenous format in a web-based platform. To demonstrate the value of this workflow with respect to urban risk and resilience, the process was applied to the Taiora: Queen Elizabeth II recreation and sports centre in eastern Christchurch, New Zealand. After integration of as-built GIS and BIM datasets, targeted data extraction was implemented, with outputs tailored for analysis in an infrastructure serviceability loss model, which assessed potable water network performance in the 22nd February 2011 Christchurch Earthquake. Using the same earthquake conditions as the serviceability loss model, performance of infrastructure assets in service at the time of the 22nd February 2011 Christchurch Earthquake was compared to new assets rebuilt at the site, post-earthquake. Due to improved potable water infrastructure resilience resulting from installation of ductile piles, a decrease of 35.5% in the probability of service loss was estimated in the serviceability loss model. To complete the workflow, the results from the external analysis were uploaded to the web-based platform. One of the more significant outcomes from the workflow was the identification of a lack of mandated metadata standards for fittings/valves connecting a building to private laterals. Whilst visually the GIS and BIM data show the building and pipes as connected, the semantic data does not include this connectivity relationship. This has no material impact on the current serviceability loss model as it is not one of the defined parameters. However, a proposed modification to the model would utilise the metadata to further assess the physical connection robustness, and increase the number of variables for estimating probability of service loss. This thesis has made a methodological contribution to urban resilience analysis by demonstrating how readily available up-to-date building and infrastructure data can be integrated, and with tailored extraction from a Digital City platform, be used for disaster impact analysis in an external computational engine, with results in turn imported and visualised in the Digital City platform. The workflow demonstrated that translation and integration of data would be more successful if a regional/national mandate was implemented for the submission of consent documentation in a specified standard BIM format. The results of this thesis have identified that the key to ensuring the success of an integrated tool lies in the initial workflow required to safeguard that all data can be either captured or translated in an interoperable format.
Abstract The original intention for the Partnership Community Worker (PCW) project in 2006 was for it to be an extension of the Pegasus Health General Practice and furthermore to be a bridge between the community and primary healthcare. It was believed that a close working relationship between the Practice Nurse and the PCW would help the target population of Māori, Pacifica and low income people to address and overcome their perceived barriers to healthcare which included: finance, transport, anxiety, cultural issues, communication, or lack of knowledge. Seven years later although the PCW project has been deemed a success in the Canterbury District Health Board annual reports (2013-14) and community and government agencies, including the Christchurch Resettlement Service (2012), many of the Pegasus Health General Practices have not utilised the project to its full extent, hence the need for this research. I was interested in finding out in the first instance if the model had changed and, if so why, and in the second instance if the promotional material currently distributed by Pegasus Health Primary Health Organisation reflected the daily practice of the PCW. A combination of methods were used including: surveys to the Pegasus Health General Practices, interviews with PCWs, interviews with managers of both the PCW host organisations and referring agencies to the PCW project. All the questions asked of all the participants in this research were focussed on their own perception of the role of the PCW. Results showed that the model has changed and although the publications were not reflecting the original intention of the project they did reflect the daily practice of the PCWs who are now struggling to meet much wider community expectations and needs. Key Results: Partnership Community Worker (PCW) interviews: Seventeen PCWs of the 19 employed were interviewed face to face. A number expressed interest in more culturally specific training and some are pursuing qualifications in social work; for many pay parity is an issue. In addition, many felt overwhelmed by the expectations around clients with mental health issues and housing issues now, post-earthquakes. Medical Practice surveys: Surveys were sent to eighty-two Pegasus Health medical practices and of these twenty five were completed. Results showed the full capacity of the PCW role was not clearly understood by all with many believing it was mostly a transport service. Those who did understand the full complexity of the role were very satisfied with the outcomes. PCW Host Community Manager Interviews: Of the ten out of twelve managers interviewed, some wished for more communication with Pegasus Health management because they felt aspects of both the PCW role and their own role as managers had become blurred over time. Referring organisations: Fifteen of the fifty referring community or government organisations participated. The overall satisfaction of the service was high and some acknowledged the continuing need for PCWs to be placed in communities where they were well known and trusted. Moreover results also showed that both the Canterbury earthquakes 2010-2011 and the amalgamation of Partnership Health PHO and Pegasus Health Charitable Limited in 2013 have contributed to the change of the model. Further future research may also be needed to examine the long term effects on the people of Canterbury involved in community work during the 2011-2014 years.
Recent earthquakes have highlighted the vulnerability of existing structure to seismic loading. Current seismic retrofit strategies generally focus on increasing the strength/stiffness in order to upgrade the seismic performance of a structure or element. A typical drawback of this approach is that the demand on the structural and sub-structural elements can be increased. This is of particular importance when considering the foundation capacity, which may already be insufficient to allow the full capacity of the existing wall to develop (due to early codes being gravity load orientated). In this thesis a counter intuitive but rational seismic retrofit strategy, termed "selective weakening" is introduced and investigated. This is the first stage of an ongoing research project underway at the University of Canterbury which is focusing on developing selective weakening techniques for the seismic retrofit of reinforced concrete structures. In this initial stage the focus is on developing selective weakening for the seismic retrofit of structural walls. This is performed using a series of experimental, analytical and numerical investigations. A procedure for the assessment of existing structural walls is also compiled, based on the suggestions of currently available code provisions. A selective weakening intervention is performed within an overall performance-based retrofit approach with the aim of improving the inelastic behaviour by first reducing the strength/stiffness of specific members within the structural system. This will be performed with the intention of modifying a shear type behaviour towards a flexural type behaviour. As a result the demand on the structural member will be reduced. Once weakening has been implemented the designer can use the wide range of techniques and materials available (e.g. use of FRP, jacketing or shotcrete) to ensure that adequate characteristics are achieved. Whilst performing this it has to be assured that the structure meets specific performance criteria and the principles of capacity design. A target of the retrofit technique is the ability to introduce the characteristics of recently developed high performance seismic resisting systems, consisting of a self centring and dissipative behaviour (commonly referred to as a hybrid system). In this thesis, results of experimental investigations performed on benchmark and selectively weakened walls are discussed. The investigations consisted of quasi-static cyclic uni-directional tests on two benchmark and two retrofitted cantilever walls. The first benchmark wall is detailed as typical of pre-1970's construction practice. An equivalent wall is retrofitted using a selective weakening approach involving a horizontal cut at foundation level to allow for a rocking response. The second benchmark wall represents a more severe scenario where the inelastic behaviour is dominated by shear. A retrofit solution involving vertically segmenting the wall to improve the ductility and retain gravity carrying capacity by inducing a flexural response is implemented. Numerical investigations on a multi-storey wall system are performed using non linear time history analysis on SDOF and MDOF lumped plasticity models, representing an as built and retrofitted prototype structure. Calibration of the hysteretic response to experimental results is carried out (accounting for pinching and strength degradation). The sensitivity of maximum and residual drifts to p-delta and strength degradation is monitored, along with the sensitivity of the peak base shear to higher mode affects. The results of the experimental and analytical investigations confirmed the feasibility and viability of the proposed retrofit technique, towards improving the seismic performance of structural walls.
This dissertation addresses a diverse range of topics in the physics-based broadband ground motion simulation, with a focus on New Zealand applications. In particular the following topics are addressed: the methodology and computational implementation of a New Zealand Velocity Model for broadband ground motion simulation; generalised parametric functions and spatial correlations for seismic velocities in the Canterbury, New Zealand region from surface-wave-based site characterisation; and ground motion simulations of Hope Fault earthquakes. The paragraphs below outline each contribution in more detail. A necessary component in physics-based ground motion simulation is a 3D model which details the seismic velocities in the region of interest. Here a velocity model construction methodology, its computational implementation, and application in the construction of a New Zealand velocity model for use in physics-based broadband ground motion simulation are presented. The methodology utilises multiple datasets spanning different length scales, which is enabled via the use of modular sub-regions, geologic surfaces, and parametric representations of crustal velocity. A number of efficiency-related workflows to decrease the overall computational construction time are employed, while maintaining the flexibility and extensibility to incorporate additional datasets and re- fined velocity parameterizations as they become available. The model comprises explicit representations of the Canterbury, Wellington, Nelson-Tasman, Kaikoura, Marlborough, Waiau, Hanmer and Cheviot sedimentary basins embedded within a regional travel-time tomography-based velocity model for the shallow crust and provides the means to conduct ground motion simulations throughout New Zealand for the first time. Recently developed deep shear-wave velocity profiles in Canterbury enabled models that better characterise the velocity structure within geologic layers of the Canterbury sedimentary basin to be developed. Here the development of depth- and Vs30-dependent para-metric velocity and spatial correlation models to characterise shear-wave velocities within the geologic layers of the Canterbury sedimentary basin are presented. The models utilise data from 22 shear-wave velocity profiles of up to 2.5km depth (derived from surface wave analysis) juxtaposed with models which detail the three-dimensional structure of the geologic formations in the Canterbury sedimentary basin. Parametric velocity equations are presented for Fine Grained Sediments, Gravels, and Tertiary layer groupings. Spatial correlations were developed and applied to generate three-dimensional stochastic velocity perturbations. Collectively, these models enable seismic velocities to be realistically represented for applications such as 3D ground motion and site response simulations. Lastly the New Zealand velocity model is applied to simulate ground motions for a Mw7.51 rupture of the Hope Fault using a physics-based 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. The simulated ground motions for this scenario complement prior empirically-based estimates and are informative for mitigation and emergency planning purposes.
Though rare and unpredictable, earthquakes can and do cause catastrophic destruction when they impact unprepared and vulnerable communities. Extensive damage and failure of vulnerable buildings is a key factor which contributes to seismic-related disasters, making the proactive management of these buildings a necessity to reduce the risk of future disasters arising. The devastating Canterbury earthquakes of 2010 and 2011 brought the urgency of this issue to national importance in New Zealand. The national earthquake-prone building framework came into effect in 2017, obligating authorities to identify existing buildings with the greatest risk of collapse in strong earthquakes and for building owners to strengthen or demolish these buildings within a designated period of time. Though this framework is unique to New Zealand, the challenge of managing the seismic risk of such buildings is common amongst all seismically-active countries. Therefore, looking outward to examine how other jurisdictions legally manage this challenge is useful for reflecting on the approaches taken in New Zealand and understand potential lessons which could be adopted. This research compares the legal framework used to reduce the seismic risk of existing buildings in New Zealand with that of the similarly earthquake-prone countries of Japan and Italy. These legal frameworks are examined with a particular focus on the proactive goal of reducing risk and improving resilience, as is the goal of the international Sendai Framework for Disaster Risk Reduction 2015-2030. The Sendai Framework, which each of the case study countries have committed to and thus have obligations under, forms the legal basis of the need for states to reduce disaster risk in their jurisdictions. In particular, the states’ legal frameworks for existing building risk reduction are examined in the context of the Sendai priorities of understanding disaster risk, strengthening disaster risk governance, and investing in resilience. While this research illustrates that the case study countries have each adopted more proactive risk reduction frameworks in recent years in anticipation of future earthquakes, the frameworks currently focus on a very narrow range of existing buildings and thus are not currently sufficient for promoting the long-term resilience of building stocks. In order to improve resilience, it is argued, legal frameworks need to include a broader range of buildings subject to seismic risk reduction obligations and also to broaden the focus on long-term monitoring of potential risk to buildings.
The Mw 6.2 February 22nd 2011 Christchurch earthquake (and others in the 2010-2011 Canterbury sequence) provided a unique opportunity to study the devastating effects of earthquakes first-hand and learn from them for future engineering applications. All major events in the Canterbury earthquake sequence caused widespread liquefaction throughout Christchurch’s eastern suburbs, particularly extensive and severe during the February 22nd event. Along large stretches of the Avon River banks (and to a lesser extent along the Heathcote) significant lateral spreading occurred, affecting bridges and the infrastructure they support. The first stage of this research involved conducting detailed field reconnaissance to document liquefaction and lateral spreading-induced damage to several case study bridges along the Avon River. The case study bridges cover a range of ages and construction types but all are reinforced concrete structures which have relatively short, stiff decks. These factors combined led to a characteristic deformation mechanism involving deck-pinning and abutment back-rotation with consequent damage to the abutment piles and slumping of the approaches. The second stage of the research involved using pseudo-static analysis, a simplified seismic modelling tool, to analyse two of the bridges. An advantage of pseudo-static analysis over more complicated modelling methods is that it uses conventional geotechnical data in its inputs, such as SPT blowcount and CPT cone resistance and local friction. Pseudo-static analysis can also be applied without excessive computational power or specialised knowledge, yet it has been shown to capture the basic mechanisms of pile behaviour. Single pile and whole bridge models were constructed for each bridge, and both cyclic and lateral spreading phases of loading were investigated. Parametric studies were carried out which varied the values of key parameters to identify their influence on pile response, and computed displacements and damages were compared with observations made in the field. It was shown that pseudo-static analysis was able to capture the characteristic damage mechanisms observed in the field, however the treatment of key parameters affecting pile response is of primary importance. Recommendations were made concerning the treatment of these governing parameters controlling pile response. In this way the future application of pseudo-static analysis as a tool for analysing and designing bridge pile foundations in liquefying and laterally spreading soils is enhanced.
The Amuri Earthquake of September 1, 1888 (magnitude M = 6.5 to 6.8) occurred on the Hope River Segment of the Hope Fault west of Hanmer Plains. The earthquake was felt strongly in North Canterbury and North Westland and caused considerable property damage and landsliding in the Lower Hope Valley. However, damage reports and the spatial distribution of felt intensities emphasize extreme variations in seismic effects over short distances, probably due to topographic focusing and local ground conditions. Significant variations in lateral fault displacement occurred at secondary fault segment boundaries (side-steps and bends in the fault trace) during the 1888 earthquake. This historical spatial variation in lateral slip is matched by the Late Quaternary geomorphic distribution of slip on the Hope River Segment of the Hope Fault. Trenching studies at two sites on the Hope Fault have also identified evidence for five pre-historic earthquakes of similar magnitude to the 1888 earthquake and an average recurrence interval of 134 ± 27 years between events. Magnitude estimates for the 1888 earthquake are combined with a. strong ground motion attenuation expression to provide an estimate of potential ground accelerations in Amuri District during-future earthquakes on the Hope River Segment of the Hope Fault. The predicted acceleration response on bedrock sites within 20 km of the epicentral region is between 0.23 g and 0.34 g. The close match between the historic, inferred pre-historic and geomorphic distribution of lateral slip indicates that secondary fault segmentation exerts a strong structural control on rupture propagation and the expression of fault displacement at the surface. In basement rocks at depth the spatial variations in slip are inferred to be distributed within zones of pervasive cataclastic shear, on either side of the fault segment boundaries. The large variations in surface displacement across fault segment boundaries means that one must know the geometry of the fault in order to evaluate slip-rates calculated from individual locations. The average Late Quaternary slip-rate on the Hope Fault at Glynn Wye Station is between 15.5 mm/yr and 18.25 mm/yr and the rate on the subsidiary Kakapo Fault is between 5.0 mm/yr and 7.5 mm/yr. These rates have been determined from sites which are relatively free of structural complication.
People aged 65 years and older are the fastest growing age group in New Zealand. By the mid-2070s, there are predictions that this age group is likely to comprise approximately one third of the population. Older people are encouraged to stay in their own homes within their community for as long as possible with support to encourage the extension of ageing in place. Currently around 14% of those aged 75 years or older, make the move into retirement villages. This is expected to increase. Little is known by retirement villages about the wellbeing and health of those who decide to live independently in these facilities. Predicting the need for a continuum of care is challenging. This research measured the wellbeing and health of older adults. It was situated in a critical realist paradigm, overlaid with an empathetic axiology. A focused literature review considered the impact on wellbeing from the aspects of living place, age, gender, health status and the 2010/2011 Canterbury earthquakes. Longitudinal studies used the Enlightenment Scale and the interRAI Community Health Assessment (CHA) to measure the wellbeing and health of one group of residents (n=120) living independently in one retirement village in Canterbury, New Zealand. The research was extended to incorporate two cross-section studies when initial results for wellbeing were found to be higher than anticipated. These additional studies included participants living independently from other retirement villages (n=115) and those living independently within the community (n=354). A total of 589 participants, aged 65 – 97 years old, completed the Enlightenment Scale across the four studies. Across the living places, wellbeing continued to significantly improve with age. The Enlightenment Scale was a useful measure of wellbeing with older adults. Participants in the longitudinal studies largely maintained a relatively good health status, showing little change over the study period of 15 months. Predictions for the need for a move to supportive care were not able to be made using the CHA. The health status of participants did not influence their level of wellbeing. The key finding of note is that the wellbeing score of older adults increases by 1.27 points per year, using the Enlightenment Scale, irrespective of where they live.
Natural disasters are highly traumatic for those who experience them, and they can have an immense and often lasting emotional impact (Cox et al., 2008). Emotion has been studied in linguistics through its enactment in language, and this field of research has increased over the past decades. Despite this, the expression of emotion in post-disaster narratives is a largely unexplored field of research. This thesis investigates how emotion is expressed in narratives taken from the QuakeBox corpus (Walsh et al., 2013), recorded, following the Christchurch earthquakes, in 2012 and rerecorded in 2019. I take a mixed methods approach, combining computer-based emotion recognition software and discourse analytic techniques, to explore the expression of emotion at both a broad and narrow level. Two emotion recognition programs, Empath (Fast et al., 2016) and Speechbrain (Ravanelli et al., 2021), are employed to measure the levels of positive and negative emotion detected in a wide dataset of participants, which are investigated in relation to the gender and age of participants, and the temporal difference between the first and second QuakeBox recordings. In a second phase, a subset of these participants’ narratives was analysed qualitatively, exploring the co-construction of emotion and identity through a social constructionist lens and examining the societal Discourses present in the earthquake narratives. The findings highlight the relevance of gender in the expression of emotion. Female speakers have higher levels of positive emotion than non-female speakers in the findings of both emotion recognition programs, and there is a clear gendered difference in the construction of identity in the narratives, influencing the expression of emotion. The expression of emotion also appears to be mediated by New Zealand culture. Within this, a Discourse of the Christchurch earthquakes emerges, with motifs of luck, gratitude, and community, which reflects the values of the people of Christchurch at the time. Findings reinforced in both phases of the analysis also indicate differences between the lexical content and acoustic features in the emotion expressions, supporting previous research that argues that the expression of emotion, as a performative act, does not reflect the speaker’s inner state directly. This research adds a new dimension to (socio)linguistic research on emotion, as well as providing insight into how crisis survivors display emotion in their post-disaster narratives.
On 4 September 2010, a magnitude Mw 7.1 earthquake struck the Canterbury region on the South Island of New Zealand. The epicentre of the earthquake was located in the Darfield area about 40 km west of the city of Christchurch. Extensive damage was inflicted to lifelines and residential houses due to widespread liquefaction and lateral spreading in areas close to major streams, rivers and wetlands throughout Christchurch and Kaiapoi. Unreinforced masonry buildings also suffered extensive damage throughout the region. Despite the severe damage to infrastructure and residential houses, fortunately, no deaths occurred and only two injuries were reported in this earthquake. From an engineering viewpoint, one may argue that the most significant aspects of the 2010 Darfield Earthquake were geotechnical in nature, with liquefaction and lateral spreading being the principal culprits for the inflicted damage. Following the earthquake, an intensive geotechnical reconnaissance was conducted to capture evidence and perishable data from this event. This paper summarizes the observations and preliminary findings from this early reconnaissance work.
This paper examines the consistency of seismicity and ground motion models, used for seismic hazard analysis in New Zealand, with the observations in the Canterbury earthquakes. An overview is first given of seismicity and ground motion modelling as inputs of probabilistic seismic hazard analysis, whose results form the basis for elastic response spectra in NZS1170.5:2004. The magnitude of earthquakes in the Canterbury earthquake sequence are adequately allowed for in the current NZ seismicity model, however the consideration of ‘background’ earthquakes as point sources at a minimum depth of 10km results in up to a 60% underestimation of the ground motions that such events produce. The ground motion model used in conventional NZ seismic hazard analysis is shown to provide biased predictions of response spectra (over-prediction near T=0.2s , and under-predictions at moderate-to-large vibration periods). Improved ground motion prediction can be achieved using more recent NZ-specific models.
This study investigates the uncertainty of simulated earthquake ground motions for smallmagnitude events (Mw 3.5 – 5) in Canterbury, New Zealand. 148 events were simulated with specified uncertainties in: event magnitude, hypocentre location, focal mechanism, high frequency rupture velocity, Brune stress parameter, the site 30-m time-averaged shear wave velocity (Vs30), anelastic attenuation (Q) and high frequency path duration. In order to capture these uncertainties, 25 realisations for each event were generated using the Graves and Pitarka (2015) hybrid broadband simulation approach. Monte-Carlo realisations were drawn from distributions for each uncertainty, to generate a suite of simulation realisations for each event and site. The fit of the multiple simulation realisations to observations were assessed using linear mixed effects regression to generate the systematic source, path and site effects components across all ground motion intensity measure residuals. Findings show that additional uncertainties are required in each of the three source, path, and site components, however the level of output uncertainty is promising considering the input uncertainties included.
The UC CEISMIC Canterbury Earthquakes Digital Archive was built following the devastating earthquakes that hit the Canterbury region in the South Island of New Zealand from 2010 – 2012. 185 people were killed in the 6.3 magnitude earthquake of February 22nd 2011, thousands of homes and businesses were destroyed, and the local community endured over 10,000 aftershocks. The program aims to document and protect the social, cultural, and intellectual legacy of the Canterbury community for the purposes of memorialization and enabling research. The nationally federated archive currently stores 75,000 items, ranging from audio and video interviews to images and official reports. Tens of thousands more items await ingestion. Significant lessons have been learned about data integration in post-disaster contexts, including but not limited to technical architecture, governance, ingestion process, and human ethics. The archive represents a model for future resilience-oriented data integration and preservation products.
The Canterbury earthquakes have generated economic demand and supply volatility, highlighting geographical and structural interdependencies. Post-earthquake reconstruction and new developments have seen skills training, relocation, recruitment and importation of skills becoming crucial for construction companies to meet demand and compete effectively. This report presents 15 case studies from a range of organisations involved in the Canterbury rebuild, exploring the business dynamics and outcomes of their resourcing initiatives. A key finding of this research is that, for many construction organisations, resourcing initiatives have become part of their organisational longer-term development strategies, rather than simply a response to ‘supply and demand’ pressures. Organisations are not relying on any single resourcing solution to drive their growth but use a combination of initiatives to create lasting business benefits, such as cost savings, improved brand and reputation, a stable and productive workforce, enhanced efficiency and staff morale, as well as improved skill levels.
This paper presents an examination of ground motion observations from 20 near-source strong motion stations during the most significant 10 events in the 2010-2011 Canterbury earthquake to examine region-specific systematic effects based on relaxing the conventional ergodic assumption. On the basis of similar site-to-site residuals, surfical geology, and geographical proximity, 15 of the 20 stations are grouped into four sub-regions: the Central Business District; and Western, Eastern, and Northern suburbs. Mean site-to-site residuals for these sub-regions then allows for the possibility of non-ergodic ground motion prediction over these sub-regions of Canterbury, rather than only at strong motion station locations. The ratio of the total non-ergodic vs. ergodic standard deviation is found to be, on average, consistent with previous studies, however it is emphasized that on a site-by-site basis the non-ergodic standard deviation can easily vary by ±20%.
The 2010-2011 Canterbury earthquake sequence, and the resulting extensive data sets on damaged buildings that have been collected, provide a unique opportunity to exercise and evaluate previously published seismic performance assessment procedures. This poster provides an overview of the authors’ methodology to perform evaluations with two such assessment procedures, namely the P-58 guidelines and the REDi Rating System. P-58, produced by the Federal Emergency Management Agency (FEMA) in the United States, aims to facilitate risk assessment and decision-making by quantifying earthquake ground shaking, structural demands, component damage and resulting consequences in a logical framework. The REDi framework, developed by the engineering firm ARUP, aids stakeholders in implementing resilience-based earthquake design. Preliminary results from the evaluations are presented. These have the potential to provide insights on the ability of the assessment procedures to predict impacts using “real-world” data. However, further work remains to critically analyse these results and to broaden the scope of buildings studied and of impacts predicted.
The seismic performance and parameter identification of the base isolated Christchurch Women’s Hospital (CWH) building are investigated using the recorded seismic accelerations during the two large earthquakes in Christchurch. A four degrees of freedom shear model is applied to characterize the dynamic behaviour of the CWH building during these earthquakes. A modified Gauss-Newton method is employed to identify the equivalent stiffness and Rayleigh damping coefficients of the building. The identification method is first validated using a simulated example structure and finally applied to the CWH building using recorded measurements from the Mw 6.0 and Mw 5.8 Christchurch earthquakes on December 23, 2011. The estimated response and recorded response for both earthquakes are compared with the cross correlation coefficients and the mean absolute percentage errors reported. The results indicate that the dynamic behaviour of the superstructure and base isolator was essentially within elastic range and the proposed shear linear model is sufficient for the prediction of the structural response of the CWH Hospital during these events.
In this paper, we perform hybrid broadband (0-10 Hz) ground motion simulations for the ten most significant events (Mw 4.7-7.1) in the 2010-2011 Canterbury earthquake sequence. Taking advantage of having repeated recordings at same stations, we validate our simulations using both recordings and an empirically-developed ground motion prediction equation (GMPE). The simulation clearly captures the sedimentary basin amplification and the rupture directivity effects. Quantitative comparisons of the simulations with both recordings and the GMPE, as well as analyses of the total residuals (indicating model bias) show that simulations perform better than the empirical GMPE, especially for long period. To scrutinize the ground motion variability, we partitioned the total residuals into different components. The total residual appears to be unbiased, and the use of a 3D velocity structure reduces the long period systematic bias particularly for stations located close to the Banks Peninsula volcanic area.
Timber has experienced renewed interests as a sustainable building material in recent times. Although traditionally it has been the prime choice for residential construction in New Zealand and some other parts of the world, its use can be increased significantly in the future through a wider range of applications, particularly when adopting engineered wood material, Research has been started on the development of innovative solutions for multi-storey non-residential timber buildings in recent years and this study is part of that initiative. Application of timber in commercial and office spaces posed some challenges with requirements of large column-free spaces. The current construction practice with timber is not properly suited for structures with the aforementioned required characteristics and new type of structures has to be developed for this type of applications. Any new structural system has to have adequate capacity for carry the gravity and lateral loads due to occupancy and the environmental effects. Along with wind loading, one of the major sources of lateral loads is earthquakes. New Zealand, being located in a seismically active region, has significant risk of earthquake hazard specially in the central region of the country and any structure has be designed for the seismic loading appropriate for the locality. There have been some significant developments in precast concrete in terms of solutions for earthquake resistant structures in the last decade. The “Hybrid” concept combining post-tensioning and energy dissipating elements with structural members has been introduced in the late 1990s by the precast concrete industry to achieve moment-resistant connections based on dry jointed ductile connections. Recent research at the University of Canterbury has shown that the concept can be adopted for timber for similar applications. Hybrid timber frames using post-tensioned beams and dissipaters have the potential to allow longer spans and smaller cross sections than other forms of solid timber frames. Buildings with post-tensioned frames and walls can have larger column-free spaces which is a particular advantage for non-residential applications. While other researchers are focusing on whole structural systems, this research concentrated on the analysis and design of individual members and connections between members or between member and foundation. This thesis extends existing knowledge on the seismic behaviour and response of post-tensioned single walls, columns under uni-direction loads and small scale beam-column joint connections into the response and design of post-tensioned coupled walls, columns under bi-directional loading and full-scale beam-column joints, as well as to generate further insight into practical applications of the design concept for subassemblies. Extensive experimental investigation of walls, column and beam-column joints provided valuable confirmation of the satisfactory performance of these systems. In general, they all exhibited almost complete re-centering capacity and significant energy dissipation, without resulting into structural damage. The different configurations tested also demonstrated the flexibility in design and possibilities for applications in practical structures. Based on the experimental results, numerical models were developed and refined from previous literature in precast concrete jointed ductile connections to predict the behaviour of post-tensioned timber subassemblies. The calibrated models also suggest the values of relevant parameters for applications in further analysis and design. Section analyses involving those parameters are performed to develop procedures to calculate moment capacities of the subassemblies. The typical features and geometric configurations the different types of subassemblies are similar with the only major difference in the connection interfaces. With adoption of appropriate values representing the corresponding connection interface and incorporation of the details of geometry and configurations, moment capacities of all the subassemblies can be calculated with the same scheme. That is found to be true for both post-tensioned-only and hybrid specimens and also applied for both uni-directional and bi-directional loading. The common section analysis and moment capacity calculation procedure is applied in the general design approach for subassemblies.
A series of undrained cyclic direct simple shear (DSS) tests on specimens of sandy silty soils are used to evaluate the effects of fines content, fabric and layered structure on the liquefaction response of sandy soils containing non-plastic fines. Test soils originate from shallow deposits in Christchurch, New Zealand, where severe and damaging manifestations of liquefaction occurred during the 2010-2011 Canterbury earthquakes. A procedure for reconstituting specimens by water sedimentation is employed. This specimen preparation technique involves first pluviation of soil through a water column, and then application of gentle vibrations to the mould (tapping) to prepare specimens with different initial densities. This procedure is applied to prepare uniform specimens, and layered specimens with a silt layer atop a sand layer. Cyclic DSS tests are performed on water-sedimented specimens of two sands, a silt, and sand-silt mixtures with different fines contents. Through this testing program, effects of density, time of vibration during preparation, fines content, and layered structure on cyclic behaviour and liquefaction resistance are investigated. Additional information necessary to characterise soil behaviour is provided by particle size distribution analyses, index void ratio testing, and Scanning Electronic Microscope imaging. The results of cyclic DSS tests show that, for all tested soils, specimens vibrated for longer period of time have lower void ratios, higher relative density, and greater liquefaction resistance. One of the tested sands undergoes significant increase in relative density and liquefaction resistance following prolonged vibration. The other sand exhibits lower increase in relative density and in liquefaction resistance when vibrated for the same period of time. Liquefaction resistance of sand-silt mixtures prepared using this latter sand shows a correlation with relative density irrespective of fines content. In general, however, magnitudes of changes in liquefaction resistance for given variations in vibration time, relative density, or void ratio vary depending on soils under consideration. Characterization based on maximum and minimum void ratios indicates that tested soils develop different structures as fines are added to their respective host sands. These structures influence initial specimen density, strains during consolidation, cyclic liquefaction resistance, and undrained cyclic response of each soil. The different structures are the outcome of differences in particle size distributions, average particle sizes, and particle shapes of the two host sands and of the different relationships between these properties and those of the silt. Fines content alone does not provide an effective characterization of the effects of these factors. Monotonic DSS tests are also performed on specimens prepared by water sedimentation, and on specimens prepared by moist tamping, to identify the critical state lines of tested soils. These critical state lines provide the basis for an alternative interpretation of cyclic DSS tests results within the critical state framework. It is shown that test results imply general consistency between observed cyclic and monotonic DSS soil response. The effects of specimen layering are scrutinised by comparing DSS test results for uniform and layered specimens of the same soils. In this case, only a limited number of tests is performed, and the range of densities considered for the layered specimens is also limited. Caution is therefore required in interpretation of their results. The liquefaction resistance of layered specimens appears to be influenced by the bottom sand layer, irrespective of the global fines content of the specimen. The presence of a layered structure does not result in significant differences in terms of liquefaction response with respect to uniform sand specimens. Cyclic triaxial data for Christchurch sandy silty soils available from previous studies are used to comparatively examine the behaviour observed in the tests of this study. The cyclic DSS liquefaction resistance of water-sedimented specimens is consistent with cyclic triaxial tests on undisturbed specimens performed by other investigators. The two data sets result in similar liquefaction triggering relationships for these soils. However, stress-strain response characteristics for the two types of specimens are different, and undisturbed triaxial specimen exhibit a slower rate of increase in shear strains compared to water-sedimented DSS specimens. This could be due to the greater influence of fabric of the undisturbed specimens.
The Avon-Heathcote Estuary, located in Christchurch, New Zealand, experienced coseismic deformation as a result of the February 22nd 2011 Christchurch Earthquake. The deformation is reflected as subsidence in the northern area and uplift in the southern area of the Estuary, in addition to sand volcanoes which forced up sediment throughout the floor of the Estuary altering estuary bed height and tidal flow. The first part of the research involved quantifying the change in the modern benthic foraminifera distribution as a result of the coseismic deformation caused by the February 22nd 2011 earthquake. By analysing the taxa present immediately post deformation and then the taxa present 2 years post deformation a comparison of the benthic foraminifera distribution can be made of the pre and post deformation. Both the northern and the southern areas of the Estuary were sampled to establish whether foraminifera faunas migrated landward or seaward as a result of subsidence and uplift experienced in different areas. There was no statistical change in overall species distribution in the two year time period since the coseismic deformation occurred, however, there were some noticeable changes in foraminifera distribution at BSNS-Z3 showing a landward migration of taxa. The changes that were predicted to occur as a result of the deformation of the Estuary are taking longer than expected to show up in the foraminiferal record and a longer time period is needed to establish these changes. The second stage involved establishing the modern distribution of foraminifera at Settlers Reserve in the southern area of the Avon-Heathcote Estuary by detailed sampling along a 160 m transect. Foraminifera are sensitive to environmental parameters, tidal height, grainsize, pH and salinity were recorded to evaluate the effect these parameters have on distribution. Bray-Curtis two-way cluster analysis was primarily used to assess the distribution pattern of foraminifera. The modern foraminifera distribution is comparable to that of the modern day New Zealand brackish-water benthic foraminifera distribution and includes species not yet found in other studies of the Avon-Heathcote Estuary. Differences in sampling techniques and the restricted intertidal marshland area where the transect samples were collected account for some of the differences seen between this model and past foraminifera studies. xiii The final stage involved sampling a 2.20 m core collected from Settlers Reserve and using the modern foraminiferal distribution to establish a foraminiferal history of Settlers Reserve. As foraminifera are sensitive to tidal height they may record past coseismic deformation events and the core was used to ascertain whether record of past coseismic deformation is preserved in Settlers Reserve sediments. Sampling the core for foraminifera, grainsize, trace metals and carbon material helped to build a story of estuary development. Using the modern foraminiferal distribution and the tidal height information collected, a down core model of past tidal heights was established to determine past rates of change. Foraminifera are not well preserved throughout the core, however, a sudden relative rise in sea level is recorded between 0.25 m and 0.85 m. Using trace metal and isotope analysis to develop an age profile, this sea level rise is interpreted to record coseismic subsidence associated with a palaeoseismic event in the early 1900’s. Overall, although the Avon-Heathcote Estuary experienced clear coseismic deformation as a result of the 22nd of February 2011 earthquake, modern changes in foraminiferal distribution cannot yet be tracked, however, past seismic deformation is identified in a core. The modern transect describes the foraminifera distribution which identifies species that have not been identified in the Avon-Heathcote Estuary before. This thesis enhances the current knowledge of the Avon-Heathcote Estuary and is a baseline for future studies.
Currently there is a worldwide renaissance in timber building design. At the University of Canterbury, new structural systems for commercial multistorey timber buildings have been under development since 2005. These systems incorporate large timber sections connected by high strength post-tensioning tendons, and timber-concrete composite floor systems, and aim to compete with existing structural systems in terms of cost, constructability, operational and seismic performance. The development of post-tensioned timber systems has created a need for improved lateral force design approaches for timber buildings. Current code provisions for seismic design are based on the strength of the structure, and do not adequately account for its deformation. Because timber buildings are often governed by deflection, rather than strength, this can lead to the exceedence of design displacement limitations imposed by New Zealand codes. Therefore, accurate modeling approaches which define both the strength and deformation of post-tensioned timber buildings are required. Furthermore, experimental testing is required to verify the accuracy of these models. This thesis focuses on the development and experimental verification of modeling approaches for the lateral force design of post-tensioned timber frame and wall buildings. The experimentation consisted of uni-direcitonal and bi-directional quasi-static earthquake simulation on a two-thirds scale, two-storey post-tensioned timber frame and wall building with timber-concrete composite floors. The building was subjected to lateral drifts of up to 3% and demonstrated excellent seismic performance, exhibiting little damage. The building was instrumented and analyzed, providing data for the calibration of analytical and numerical models. Analytical and numerical models were developed for frame, wall and floor systems that account for significant deformation components. The models predicted the strength of the structural systems for a given design performance level. The static responses predicted by the models were compared with both experimental data and finite element models to evaluate their accuracy. The frame, wall and floor models were then incorporated into an existing lateral force design procedure known as displacement-based design and used to design several frame and wall structural systems. Predictions of key engineering demand parameters, such as displacement, drift, interstorey shear, interstorey moment and floor accelerations, were compared with the results of dynamic time-history analysis. It was concluded that the numerical and analytical models, presented in this thesis, are a sound basis for determining the lateral response of post-tensioned timber buildings. However, future research is required to further verify and improve these prediction models.
During 2010 and 2011, a series of major earthquakes caused widespread damage in the city of Christchurch, New Zealand. The magnitude 6.3 quake in February 2011 caused 185 fatalities. In the ensuing months, the government progressively zoned residential land in Christchurch on the basis of its suitability for future occupation (considering damage from these quakes and future earthquake risk). Over 6,000 homes were placed in the ‘red-zone’, meaning that property owners were forced to sell their land to the Crown. This study analysed patterns of residential mobility amongst thirty-one red-zone households from the suburb of Southshore, Christchurch. Drawing on interviews and surveys, the research traced their experience from the zoning announcement until they had moved to a new residence. The research distinguished between short (before the zoning announcement) and long term (post the red zone ‘deadline’) forms of household relocation. The majority of households in the study were highly resistant to short term movement. Amongst those which did relocate before the zoning decision, the desire to maintain a valued social connection with a person outside of the earthquake environment was often an important factor. Some households also moved out of perceived necessity (e.g. due to lack of power or water). In terms of long-term relocation, concepts of affordability and safety were much more highly valued by the sample when purchasing post-quake property. This resulted in a distinct patterning of post-quake housing location choices. Perceived control over the moving process, relationship with government organisations and insurance companies, and time spent in the red-zone before moving all heavily influenced participants’ disaster experience. Contrary to previous studies, households in this study recorded higher levels of subjective well-being after relocating. The study proposed a typology of movers in the Christchurch post-disaster environment. Four mobility behaviours, or types, are identified: the Committed Stayers (CSs), the Environment Re-Creators (ERCs), the Resigned Acceptors (RAs), and the Opportunistic Movers (OMs). The CSs were defined by their immobility rather than their relocation aspirations, whilst the ERCs attempted to recreate or retain aspects of Southshore through their mobility. The RAs expressed a form of apathy towards the post-quake environment, whereas, on the other hand, the OMs moved relative to pre-earthquake plans, or opportunities that arose from the earthquake itself. Possibilities for further research include examining household adaptability to new residential environments and tracking further mobility patterns in the years following relocation from the red- zone.
Recent experiences from the Darfield and Canterbury, New Zealand earthquakes have shown that the soft soil condition of saturated liquefiable sand has a profound effect on seismic response of buildings, bridges and other lifeline infrastructure. For detailed evaluation of seismic response three dimensional integrated analysis comprising structure, foundation and soil is required; such an integrated analysis is referred to as Soil Foundation Structure Interaction (SFSI) in literatures. SFSI is a three-dimensional problem because of three primary reasons: first, foundation systems are three-dimensional in form and geometry; second, ground motions are three-dimensional, producing complex multiaxial stresses in soils, foundations and structure; and third, soils in particular are sensitive to complex stress because of heterogeneity of soils leading to a highly anisotropic constitutive behaviour. In literatures the majority of seismic response analyses are limited to plane strain configuration because of lack of adequate constitutive models both for soils and structures, and computational limitation. Such two-dimensional analyses do not represent a complete view of the problem for the three reasons noted above. In this context, the present research aims to develop a three-dimensional mathematical formulation of an existing plane-strain elasto-plastic constitutive model of sand developed by Cubrinovski and Ishihara (1998b). This model has been specially formulated to simulate liquefaction behaviour of sand under ground motion induced earthquake loading, and has been well-validated and widely implemented in verifcation of shake table and centrifuge tests, as well as conventional ground response analysis and evaluation of case histories. The approach adopted herein is based entirely on the mathematical theory of plasticity and utilises some unique features of the bounding surface plasticity formalised by Dafalias (1986). The principal constitutive parameters, equations, assumptions and empiricism of the existing plane-strain model are adopted in their exact form in the three-dimensional version. Therefore, the original two-dimensional model can be considered as a true subset of the three-dimensional form; the original model can be retrieved when the tensorial quantities of the three dimensional version are reduced to that of the plane-strain configuration. Anisotropic Drucker-Prager type failure surface has been adopted for the three-dimensional version to accommodate triaxial stress path. Accordingly, a new mixed hardening rule based on Mroz’s approach of homogeneous surfaces (Mroz, 1967) has been introduced for the virgin loading surface. The three-dimensional version is validated against experimental data for cyclic torsional and triaxial stress paths.
Objective: The nature of disaster research makes it difficult to adequately measure the impact that significant events have on a population. Large, representative samples are required, ideally with comparable data collected before the event. When Christchurch, New Zealand, was struck by multiple, devastating earthquakes, there presented an opportunity to investigate the effects of dose-related quakes (none, one, two or three over a 9-month period) on the cognition of Canterbury’s elderly population through the New Zealand Brain Research Institute’s (NZBRI’s) cognitive screening study. The related effects of having a concomitant medical condition, sex, age and estimated- full scale IQ (Est-FSIQ) on cognition were also investigated. Method: 609 participants were tested on various neuropsychological tests and a self-rated dementia scale in a one hour interview at the NZBRI. Four groups were established, based on the number of major earthquakes experienced at the time of testing: “EQ-dose: None” (N = 51) had experienced no quakes; “EQ-dose: One” (N = 193) had experienced the initial quake in September 2010; “EQ-dose: Two” (N = 82) also experienced the most devastating February 2011 quake; and “EQ-dose: Three” (N = 265) also the June 2011 quake at testing. Results: Two neuropsychological variables of Trail A and the AD8 were impacted by an EQ-dose effect, while having a medical condition was associated with poorer function on the MoCA, Rey Copy and Recall, Trail A, and AD8. Having a major medical condition led to worse performance on the Rey Copy and Recall following the major February earthquake. Males performed significantly better on Trail A and Rey Planning, while females better on the MoCA. Older participants (>73) had significantly lower scores on the MoCA than younger participants (<74), while those with a higher Est-FSIQ (>111) had better scores on the MoCA and Rey Recall than participants with a lower Est-FSIQ. Finally, predicted variable analysis (based on calculated, sample-specific Z-scores) failed to find a significant earthquake effect when variables of age, sex and Est-FSIQ were controlled for, while there was a significant effect of medical condition on each measure. Conclusion: The current thesis provides evidence suggesting resilience amongst Canterbury’s elderly population in the face of the sequence of significant quakes that struck the region over a year from September 2010. By contrast, having a major medical condition was a ‘more significant life event’ in terms of impact on cognition in this group.
