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Research papers, University of Canterbury Library

Heathcote Valley school strong motion station (HVSC) consistently recorded ground motions with higher intensities than nearby stations during the 2010-2011 Canterbury earthquakes. For example, as shown in Figure 1, for the 22 February 2011 Christchurch earthquake, peak ground acceleration at HVSC reached 1.4 g (horizontal) and 2 g (vertical), the largest ever recorded in New Zealand. Strong amplification of ground motions is expected at Heathcote Valley due to: 1) the high impedance contrast at the soil-rock interface, and 2) the interference of incident and surface waves within the valley. However, both conventional empirical ground motion prediction equations (GMPE) and the physics-based large scale ground motions simulations (with empirical site response) are ineffective in predicting such amplification due to their respective inherent limitations.

Research papers, University of Canterbury Library

We present ground motion simulations of the Porters Pass (PP) fault in the Canterbury region of New Zealand; a major active source near Christchurch city. The active segment of the PP fault has an inferred length of 82 km and a mostly strike-slip sense of movement. The PP fault slip makes up approximately 10% of the total 37 mm/yr margin-parallel plate motion and also comprises a significant proportion of the total strain budget in regional tectonics. Given that the closest segment of the fault is less than 45 km from Christchurch city, the PP fault is crucial for accurate earthquake hazard assessment for this major population centre. We have employed the hybrid simulation methodology of Graves and Pitarka (2010, 2015), which combines low (f<1 Hz) and high (f>1 Hz) frequencies into a broadband spectrum. We have used validations from three moderate magnitude events (𝑀𝑤4.6 Sept 04, 2010; 𝑀𝑤4.6 Nov 06, 2010; 𝑀𝑤4.9 Apr 29, 2011) to build confidence for the 𝑀𝑤 > 7 PP simulations. Thus far, our simulations include multiple rupture scenarios which test the impacts of hypocentre location and the finite-fault stochastic rupture representation of the source itself. In particular, we have identified the need to use location-specific 1D 𝑉𝑠/𝑉𝑝 models for the high frequency part of the simulations to better match observations.

Videos, UC QuakeStudies

A video of a presentation by Professor David Johnston during the fourth plenary of the 2016 People in Disasters Conference. Johnston is a Senior Scientist at GNS Science and Director of the Joint Centre for Disaster Research in the School of Psychology at Massey University. The presentation is titled, "Understanding Immediate Human Behaviour to the 2010-2011 Canterbury Earthquake Sequence, Implications for injury prevention and risk communication".The abstract for the presentation reads as follows: The 2010 and 2011 Canterbury earthquake sequences have given us a unique opportunity to better understand human behaviour during and immediately after an earthquake. On 4 September 2010, a magnitude 7.1 earthquake occurred near Darfield in the Canterbury region of New Zealand. There were no deaths, but several thousand people sustained injuries and sought medical assistance. Less than 6 months later, a magnitude 6.2 earthquake occurred under Christchurch City at 12:51 p.m. on 22 February 2011. A total of 182 people were killed in the first 24 hours and over 7,000 people injured overall. To reduce earthquake casualties in future events, it is important to understand how people behaved during and immediately after the shaking, and how their behaviour exposed them to risk of death or injury. Most previous studies have relied on an analysis of medical records and/or reflective interviews and questionnaire studies. In Canterbury we were able to combine a range of methods to explore earthquake shaking behaviours and the causes of injuries. In New Zealand, the Accident Compensation Corporation (a national health payment scheme run by the government) allowed researchers to access injury data from over 9,500 people from the Darfield (4 September 2010) and Christchurch (22 February 2011 ) earthquakes. The total injury burden was analysed for demography, context of injury, causes of injury, and injury type. From the injury data inferences into human behaviour were derived. We were able to classify the injury context as direct (immediate shaking of the primary earthquake or aftershocks causing unavoidable injuries), and secondary (cause of injury after shaking ceased). A second study examined people's immediate responses to earthquakes in Christchurch New Zealand and compared responses to the 2011 earthquake in Hitachi, Japan. A further study has developed a systematic process and coding scheme to analyse earthquake video footage of human behaviour during strong earthquake shaking. From these studies a number of recommendations for injury prevention and risk communication can be made. In general, improved building codes, strengthening buildings, and securing fittings will reduce future earthquake deaths and injuries. However, the high rate of injuries incurred from undertaking an inappropriate action (e.g. moving around) during or immediately after an earthquake suggests that further education is needed to promote appropriate actions during and after earthquakes. In New Zealand - as in US and worldwide - public education efforts such as the 'Shakeout' exercise are trying to address the behavioural aspects of injury prevention.

Research papers, University of Canterbury Library

As a result of the Canterbury earthquakes, over 60% of the concrete buildings in the Christchurch Central Business District have been demolished. This experience has highlighted the need to provide guidance on the residual capacity and repairability of earthquake-damaged concrete buildings. Experience from 2010 Chile indicates that it is possible to repair severely damaged concrete elements (see photo at right), although limited testing has been performed on such repaired components. The first phase of this project is focused on the performance of two lightly-reinforced concrete walls that are being repaired and re-tested after damage sustained during previous testing.

Research papers, University of Canterbury Library

This poster discusses several possible approaches by which the nonlinear response of surficial soils can be explicitly modelled in physics-based ground motion simulations, focusing on the relative advantages and limitations of the various methodologies. These methods include fully-coupled 3D simulation models that directly allow soil nonlinearity in surficial soils, the domain reduction method for decomposing the physical domain into multiple subdomains for separate simulation, conventional site response analysis uncoupled from the simulations, and finally, the use of simple empirically based site amplification factors We provide the methodology for an ongoing study to explicitly incorporate soil nonlinearity into hybrid broadband simulations of the 2010-2011 Canterbury, New Zealand earthquakes.

Research papers, University of Canterbury Library

Liquefaction-induced lateral spreading during earthquakes poses a significant hazard to the built environment, as observed in Christchurch during the 2010 to 2011 Canterbury Earthquake Sequence (CES). It is critical that geotechnical earthquake engineers are able to adequately predict both the spatial extent of lateral spreads and magnitudes of associated ground movements for design purposes. Published empirical and semi-empirical models for predicting lateral spread displacements have been shown to vary by a factor of <0.5 to >2 from those measured in parts of Christchurch during CES. Comprehensive post- CES lateral spreading studies have clearly indicated that the spatial distribution of the horizontal displacements and extent of lateral spreading along the Avon River in eastern Christchurch were strongly influenced by geologic, stratigraphic and topographic features.

Research papers, University of Canterbury Library

In 2010 and 2011 a series of earthquakes hit the central region of Canterbury, New Zealand, triggering widespread and damaging liquefaction in the area of Christchurch. Liquefaction occurred in natural clean sand deposits, but also in silty (fines-containing) sand deposits of fluvial origin. Comprehensive research efforts have been subsequently undertaken to identify key factors that influenced liquefaction triggering and severity of its manifestation. This research aims at evaluating the effects of fines content, fabric and layered structure on the cyclic undrained response of silty soils from Christchurch using Direct Simple Shear (DSS) tests. This poster outlines preliminary calibration and verification DSS tests performed on a clean sand to ensure reliability of testing procedures before these are applied to Christchurch soils.

Research papers, University of Canterbury Library

The operation of telecommunication networks is critical during business as usual times, and becomes most vital in post-disaster scenarios, when the services are most needed for restoring other critical lifelines, due to inherent interdependencies, and for supporting emergency and relief management tasks. In spite of the recognized critical importance, the assessment of the seismic performance for the telecommunication infrastructure appears to be underrepresented in the literature. The FP6 QuakeCoRE project “Performance of the Telecommunication Network during the Canterbury Earthquake Sequence” will provide a critical contribution to bridge this gap. Thanks to an unprecedented collaboration between national and international researchers and highly experienced asset managers from Chorus, data and evidences on the physical and functional performance of the telecommunication network after the Canterbury Earthquakes 2010-2011 have been collected and collated. The data will be processed and interpreted aiming to reveal fragilities and resilience of the telecommunication networks to seismic events

Research papers, University of Canterbury Library

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.

Videos, UC QuakeStudies

A video of the keynote presentation by Sir John Holmes, during the first plenary of the 2016 People in Disasters Conference. Holmes is the former United Nations Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, the current Director of Ditchley Foundation, and the chair of the Board of the International Rescue Committee in the UK. The presentation is titled, "The Politics of Humanity: Reflections on international aid in disasters".The abstract for this presentation reads as follows: As United Nations Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinate from 2007-2010, Sir John Holmes was heavily involved in the coordination of air provision to countries struck by natural and man-made disasters, raising the necessary funds, and the elaboration of humanitarian policy. The international humanitarian system is fragmented and struggling to cope with rising demands from both conflicts such as that in Syria, and the growing effects of climate change. Sir John will talk about what humanitarian aid can and cannot achieve, the frustrations of getting aid through when access may be difficult or denied, and the need to ensure that assistance encompasses protection of civilians and efforts to get them back on their feet, as well as the delivery of essential short term items such as food, water, medical care and shelter. He will discuss the challenges involved in trying to make the different agencies - UN United Nations, non-government organisations and the International Red Cross/Crescent movement - work together effectively. He will reveal some of the problems in dealing with donor and recipient governments who often have their own political and security agendas, and may be little interested in the necessary neutrality and independence of humanitarian aid. He will illustrate these points by practical examples of political and other dilemmas from aid provision in natural disasters such as Cyclone Nargis in Myanmar in 2009, and the Haiti earthquake of 2010, and in conflict situations such as Darfur, Afghanistan and Sri Lanka in the past, and Syria today. He will also draw conclusions and make recommendations about how humanitarian aid might work better, and why politicians and others need to understand more clearly the impartial space required by humanitarian agencies to operate properly.

Videos, UC QuakeStudies

A video of the keynote-presentation by Dr Jeanne LeBlanc, Registered Psychologist, during the second plenary of the 2016 People in Disasters Conference. LeBlanc is a Registered Psychologist, specialising in Clinical Neuropsychology and Rehabilitation. She is the British Columbia Psychological Association (BCPA) Representative for the American Psychological Associate State, Territorial and Provincial Disaster Response Network, and has also been appointed as the Behavioural Health Liaison to the American Board of Disaster Medicine. The presentation is titled, "Machetes and Breadfruit: Medical disaster response challenges in unstable settings".The abstract for this presentation reads as follows: The January 2010 earthquake in Haiti resulted in a massive response to a setting which was already fraught with danger, causing a number of personal, logistical, and safety challenges to responding medical teams. This presentation will provide a first-person account of this experience from the perspective of a behavioural health professional, whose responsibility was both the overall emotional wellbeing of the medical responders, as well as those impacted by the quake. Unique 'lessons learned' by these response teams will be highlighted, and recommendations will be provided for responders considering deploying to future events in highly unstable areas.

Research papers, The University of Auckland Library

Predictive modelling provides an efficient means to analyse the coastal environment and generate knowledge for long term urban planning. In this study, the numerical models SWAN and XBeach were incorporated into the ESRI ArcGIS interface by means of the BeachMMtool. This was applied to the Greater Christchurch coastal environment to simulate geomorphological evolution through hydrodynamic forcing. Simulations were performed using the recent sea level rise predictions by the Intergovernmental Panel on Climate Change (2013) to determine whether the statutory requirements outlined in the New Zealand Coastal Policy Statement 2010 are consistent with central, regional and district designations. Our results indicate that current land use zoning in Greater Christchurch is not consistent with these predictions. This is because coastal hazard risk has not been thoroughly quantified during the process of installing the Canterbury Earthquake Recovery Authority residential red zone. However, the Christchurch City Council’s flood management area does provide an extent to which managed coastal retreat is a real option. The results of this research suggest that progradation will continue to occur along the Christchurch foreshore due to the net sediment flux retaining an onshore direction and the current hydrodynamic activity not being strong enough to move sediment offshore. However, inundation during periods of storm surge poses a risk to human habitation on low lying areas around the Avon-Heathcote Estuary and the Brooklands lagoon.

Videos, UC QuakeStudies

A video of a presentation by Dr Scott Miles during the Community Resilience Stream of the 2016 People in Disasters Conference. The presentation is titled, "A Community Wellbeing Centric Approach to Disaster Resilience".The abstract for this presentation reads as follows: A higher bar for advancing community disaster resilience can be set by conducting research and developing capacity-building initiatives that are based on understanding and monitoring community wellbeing. This presentation jumps off from this view, arguing that wellbeing is the most important concept for improving the disaster resilience of communities. The presentation uses examples from the 2010 and 2011 Canterbury earthquakes to illustrate the need and effectiveness of a wellbeing-centric approach. While wellbeing has been integrated in the Canterbury recovery process, community wellbeing and resilience need to guide research and planning. The presentation unpacks wellbeing in order to synthesize it with other concepts that are relevant to community disaster resilience. Conceptualizing wellbeing as either the opportunity for or achievement of affiliation, autonomy, health, material needs, satisfaction, and security is common and relatively accepted across non-disaster fields. These six variables can be systematically linked to fundamental elements of resilience. The wellbeing variables are subject to potential loss, recovery, and adaptation based on the empirically established ties to community identity, such as sense of place. Variables of community identity are what translate the disruption, damage, restoration, reconstruction, and reconfiguration of a community's different critical services and capital resources to different states of wellbeing across a community that has been impacted by a hazard event. With reference to empirical research and the Canterbury case study, the presentation integrates these insights into a robust framework to facilitate meeting the challenge of raising the standard of community disaster resilience research and capacity building through development of wellbeing-centric approaches.

Videos, UC QuakeStudies

A video of a presentation by Dr Duncan Webb, Partner at Lane Neave, during the third plenary of the 2016 People in Disasters Conference. The presentation is titled, "Loss of Trust and other Earthquake Damage".The abstract for this presentation reads as follows: It was predictable that the earthquakes which hit the Canterbury region in 2010 and 2011 caused trauma. However, it was assumed that recovery would be significantly assisted by governmental agencies and private insurers. The expectation was that these organisations would relieve the financial pressures and associated anxiety caused by damage to property. Some initiatives did exactly that. However, there are many instances where difficulties with insurance and related issues have exacerbated the adverse effects of the earthquakes on people's wellness. In some cases, stresses around property issues have become and independent source of extreme anxiety and have had significant impacts on the quality of people's lives. Underlying this problem is a breakdown in trust between citizen and state, and insurer and insured. This has led to a pervading concern that entitlements are being denied. While such concerns are sometimes well founded, an approach which is premised on mistrust is frequently highly conflicted, costly, and often leads to worse outcomes. Professor Webb will discuss the nature and causes of these difficulties including: the complexity of insurance and repair issues, the organisational ethos of the relevant agencies, the hopes of homeowners and the practical gap which commonly arises between homeowner expectation and agency response. Observations will be offered on how the adverse effects of these issues can be overcome in dealing with claimants, and how such matters can be managed in a way which promotes the wellness of individuals.

Videos, UC QuakeStudies

A video of a presentation by Associate Professor John Vargo during the fifth plenary of the 2016 People in Disasters Conference. Vargo is a senior researcher and co-leader of the Resilient Organisations Research Programme at the University of Canterbury. The presentation is titled, "Organisational Resilience is more than just Business Continuity".The abstract for this presentation reads as follows: Business Continuity Management is well-established process in many larger organisations and a key element in their emergency planning. Research carried out by resilient organisations follow the 2010 and 2011 Canterbury Earthquakes show that most small organisations did not have a business continuity plan (BCP), yet many of these organisations did survive the massive disruptions following the earthquakes. They were resilient to these catastrophic events, but in the absence of a BCP. This research also found that many of the organisations with BCP's, struggled to use them effectively when facing real events that did not align with the BCP. Although the BCPs did a good job of preparing organisations to deal with technology and operational disruptions, there was virtually no coverage for the continuity of people. Issues surrounding staff welfare and engagement were amongst the most crucial issues faced by Canterbury organisations, yet impacts of societal and personal disruption did not feature in BCPs. Resilience is a systematic way of looking at how an organization can survive a crisis and thrive in an uncertain world. Business continuity is an important aspect for surviving the crisis, but it is only part of the bigger picture addressed by organisational resilience. This presentation will show how organizational experiences in the Canterbury earthquakes support the need to move to a 'Business Continuity' for the '21st Century', one that incorporates more aspects of resilience, especially the 'people' areas of leadership, culture, staff welfare, and engagement.

Videos, UC QuakeStudies

A video of a presentation by Richard Conlin during the Community Resilience Stream of the 2016 People in Disasters Conference. The presentation is titled, "Resilience, Poverty, and Seismic Culture".The abstract for this presentation reads as follows: A strategy of resilience is built around the recognition that effective emergency response requires community involvement and mobilization. It further recognizes that many of the characteristics that equip communities to respond most effectively to short term emergencies are also characteristics that build strong communities over the long term. Building resilient communities means integrating our approaches to poverty, community engagement, economic development, and housing into a coherent strategy that empowers community members to engage with each other and with other communities. In this way, resilience becomes a complementary concept to sustainability. This requires an asset-based change strategy where external agencies meet communities where they are, in their own space, and use collective impact approaches to work in partnership. This also requires understanding and assessing poverty, including physical, financial, and social capital in their myriad manifestations. Poverty is not exclusively a matter of class. It is a complex subject, and different communities manifest multiple versions of poverty, which must be respected and understood through the asset-based lens. Resilience is a quality of a community and a system, and develops over time as a result of careful analysis of strengths and vulnerabilities and taking actions to increase competencies and reduce risk situations. Resilience requires maintenance and must be developed in a way that includes practicing continuous improvement and adaptation. The characteristics of a resilient community include both physical qualities and 'soft infrastructure', such as community knowledge, resourcefulness, and overall health. This presentation reviews the experience of some earlier disasters, outlines a working model of how emergency response, resilience, and poverty interact and can be addressed in concert, and concludes with a summary of what the 2010 Chilean earthquake tells us about how a 'seismic culture' can function effectively in communities even when government suffers from unexpected shortcomings.

Research papers, University of Canterbury Library

This poster presents work to date on ground motion simulation validation and inversion for the Canterbury, New Zealand region. Recent developments have focused on the collection of different earthquake sources and the verification of the SPECFEM3D software package in forward and inverse simulations. SPECFEM3D is an open source software package which simulates seismic wave propagation and performs adjoint tomography based upon the spectral-element method. Figure 2: Fence diagrams of shear wave velocities highlighting the salient features of the (a) 1D Canterbury velocity model, and (b) 3D Canterbury velocity model. Figure 5: Seismic sources and strong motion stations in the South Island of New Zealand, and corresponding ray paths of observed ground motions. Figure 3: Domain used for the 19th October 2010 Mw 4.8 case study event including the location of the seismic source and strong motion stations. By understanding the predictive and inversion capabilities of SPECFEM3D, the current 3D Canterbury Velocity Model can be iteratively improved to better predict the observed ground motions. This is achieved by minimizing the misfit between observed and simulated ground motions using the built-in optimization algorithm. Figure 1 shows the Canterbury Velocity Model domain considered including the locations of small-to-moderate Mw events [3-4.5], strong motion stations, and ray paths of observed ground motions. The area covered by the ray paths essentially indicates the area of the model which will be most affected by the waveform inversion. The seismic sources used in the ground motion simulations are centroid moment tensor solutions obtained from GeoNet. All earthquake ruptures are modelled as point sources with a Gaussian source time function. The minimum Mw limit is enforced to ensure good signal-to-noise ratio and well constrained source parameters. The maximum Mw limit is enforced to ensure the point source approximation is valid and to minimize off-fault nonlinear effects.

Videos, UC QuakeStudies

A video of a presentation by David Meates, Chief Executive of the Christchurch District Health Board and the West Coast District Health Board, during the first plenary of the 2016 People in Disasters Conference. The presentation is titled, "Local System Perspective".The abstract for this presentation reads as follows: The devastating Canterbury earthquakes of 2010 and 2011 have resulted in challenges for the people of Canterbury and have altered the population's health needs. In the wake of New Zealand's largest natural disaster, the health system needed to respond rapidly to changing needs and damaged infrastructure in the short-term in the context of developing sustainable long-term solutions. Canterbury was undergoing system transformation prior to the quakes, however the horizon of transformation was brought forward post-quake: 'Vision 2020' became the vision for now. Innovation was enabled as people working across the system addressed new constraints such as the loss of 106 acute hospital beds, 635 aged residential care beds, the loss of general practices and pharmacies as well as damaged non-government organisation sector. A number of new integration initiatives (e.g. a shared electronic health record system, community rehabilitation for older people, community falls prevention) and expansion of existing programs (e.g. acute demand management) were focused on supporting people to stay well in their homes and communities. The system working together in an integrated way has resulted in significant reductions in acute health service utilisation in Canterbury. Acute admission rates have not increased and remain significantly below national rates and the number of acute and rehabilitation bed days have fallen since the quakes, with these trends most evident among older people. However, health needs frequently reported in post-disaster literature have created greater pressures on the system. In particular, an escalating number of people facing mental health problems and coping with acute needs of the migrant rebuild population provide new challenges for a workforce also affected by the quakes. The recovery journey for Canterbury is not over.

Research papers, The University of Auckland Library

Eccentrically Braced Frames (EBFs) are a widely used seismic resisting structural steel system. Since their inception in the late 1970s, they have been a viable option with an available stiffness that is between simple braced systems and moment resisting systems. A similar concept, the linked column frame (LCF), uses shear links between two closely spaced columns. In both cases, the key component is the active link or the shear link, and this component is the objective of this study. The performance of high rise EBF buildings in the 2010 and 2011 Christchurch earthquakes was beyond that which was expected, especially considering the very high accelerations recorded. As the concrete high-rises were torn down, two EBF buildings remained standing and only required some structural repair. These events prompted a renewed interest in bolted shear links, as well as their performance. While some research into replaceable shear links had already been done (Mansour, 2011), the objectives of this study were to improve on the shear link itself, with the consideration that links built in the future are likely to be bolted. The main components of this study were to: 1. Reduce or eliminate the requirements for intermediate web stiffeners, as they were suspected of being detrimental to performance. Furthermore, any reduction in stiffening requirements is a direct fabrication cost saving. Links with low web aspect ratios were found to achieve exceptional ductilities when no stiffeners were included, prompting new design equations. 2. Ensure that the stresses in the ends of links are adequately transferred into the endplates without causing fractures. Although most of the experimental links had web doubler plates included, four had varied lengths of such doubler plates from 0.0 in. to 8.0 in. The link without any doubler plates performed to a similar level to its peers, and thus it is likely that links with quality end details may not need web doubler plates at all. 3. Evaluate the performance of a link with double sided stiffeners without the use of web welds, as opposed to conventional single sided, welded stiffeners. This link performed well, and web-weld-less double sided stiffeners may be an economical alternative to conventional stiffeners for deeper sections of links. 4. Evaluate the performance of a link with thin endplates that are made efficient with the use of gusset plates. This link performed to an acceptable level and provides evidence for a cost effective alternative to thick endplates, especially considering the high overstrength end moments in links, typically requiring 16-bolt connections. 5. Examine the potential use of an alternative EBF arrangement where the collector beam is over sized, and the link section is formed by cutting out parts of the beam's web. After running a series of finite element models each with a unique variation, a number of approximate design rules were derived such that future research could develop this idea further experimentally. 6. Ensure that during testing, the secondary elements (members that are not the shear link), do not yield and are not close to yielding. None of the instrumented elements experienced any unexpected yielding, however the concerns for high stresses in the collector beam panel zone during design were warranted. The use of an existing New Zealand design equation is recommended as an extra check for design codes worldwide. The above objectives were mainly conducted experimentally, except: the data set for item 1 was greatly expanded through the use of a calibrated numerical model which was then used in an extensive parametric study; item 5 was purely finite element based; and, a small parametric study was included for item 3 in an attempt to expand on the trends found there.