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Research papers, University of Canterbury Library

The 2010 and 2011 earthquakes in the region of Canterbury, New Zealand caused widespread damage and the deaths of 185 people. Suburbs on the eastern side of Christchurch and in the satellite town of Kaiapoi, 20 kilometres north of Christchurch, were badly damaged by liquefaction. The Canterbury Earthquake Recovery Authority (CERA), a government organisation set up in the wake of the earthquakes, began to systematically zone all residential land in 2011. Based on the possibility for land remediation, 7860 houses in Christchurch and Kaiapoi were zoned red. Those who were in this zone were compensated and had to buy or build elsewhere. The other zone examined within this research – that of TC3 – lies within the green zone. Residents, in this zone, were able to stay in their houses but land was moderately damaged and required site-specific geotechnical investigations. This research sought to understand how residents’ senses of home were impacted by a disaster and the response efforts. Focusing on the TC3 and red zone of the eastern suburbs and the satellite town of Kaiapoi, this study interviewed 29 residents within these zones. The concept of home was explored with the respondents at three scales: home as a household; home as a community; and home as a city. There was a large amount of resistance to the zoning process and the handling of claims by insurance companies and the Earthquake Commission (EQC) after the earthquakes. Lack of transparency and communication, as well as extremely slow timelines were all documented as failings of these agencies. This research seeks to understand how participant’s sense of home changed on an individual level and how it was impacted by outside agencies. Homemaking techniques were also focused on showing that a changed sense of home will impact on how a person interacts with a space.

Research papers, University of Canterbury Library

This is an interim report from the research study performed within the NHRP Research Project “Impacts of soil liquefaction on land, buildings and buried pipe networks: geotechnical evaluation and design, Project 3: Seismic assessment and design of pipe networks in liquefiable soils”. The work presented herein is a continuation of the comprehensive study on the impacts of Christchurch earthquakes on the buried pipe networks presented in Cubrinovski et al. (2011). This report summarises the performance of Christchurch City’s potable water, waste water and road networks through the 2010-2011 Canterbury Earthquake Sequence (CES), and particularly focuses on the potable water network. It combines evidence based on comprehensive and well-documented data on the damage to the water network, detailed observations and interpretation of liquefaction-induced land damage, records and interpretations of ground motion characteristics induced by the Canterbury earthquakes, for a network analysis and pipeline performance evaluation using a GIS platform. The study addresses a range of issues relevant in the assessment of buried networks in areas affected by strong earthquakes and soil liquefaction. It discusses performance of different pipe materials (modern flexible pipelines and older brittle pipelines) including effects of pipe diameters, fittings and pipeline components/details, trench backfill characteristics, and severity of liquefaction. Detailed breakdown of key factors contributing to the damage to buried pipes is given with reference to the above and other relevant parameters. Particular attention is given to the interpretation, analysis and modelling of liquefaction effects on the damage and performance of the buried pipe networks. Clear link between liquefaction severity and damage rate for the pipeline has been observed with an increasing damage rate seen with increasing liquefaction severity. The approach taken here was to correlate the pipeline damage to LRI (Liquefaction Resistance Index, newly developed parameter in Cubrinovski et al., 2011) which represents a direct measure for the soil resistance to liquefaction while accounting for the seismic demand through PGA. Key quality of the adopted approach is that it provides a general methodology that in conjunction with conventional methods for liquefaction evaluation can be applied elsewhere in New Zealand and internationally. Preliminary correlations between pipeline damage (breaks km-1), liquefaction resistance (LRI) and seismic demand (PGA) have been developed for AC pipes, as an example. Such correlations can be directly used in the design and assessment of pipes in seismic areas both in liquefiable and non-liquefiable areas. Preliminary findings on the key factors for the damage to the potable water pipe network and established empirical correlations are presented including an overview of the damage to the waste water and road networks but with substantially less detail. A comprehensive summary of the damage data on the buried pipelines is given in a series of appendices.

Research papers, University of Canterbury Library

On February 22, 2011, Christchurch-based journalists were jolted out of their normal work routine by a large 6.3 magnitude earthquake that killed 185 people, wrecked the city and forced reporters to reappraise their journalism. This study considers how the earthquake affected journalists’ relationship to the community, their use of sources and news selection. A theory of collective trauma is used to explain the changes that journalists made to their reporting practice. Specifically, Christchurch journalists had a greater identification and attachment to their audience post-earthquake. Journalists viewed themselves as part of the earthquake story, which prompted them to view sources differently, use those sources differently and see advocacy as a keystone of their news work after the disaster. This study adds to a growing scholarship about journalists and trauma, but focuses on what the event meant for local reporters’ choice of sources and news selection rather than measuring rates of psychological distress.

Research papers, University of Canterbury Library

The Canterbury earthquakes, which involved widespread damage in the February 2011 event and ongoing aftershocks near the Christchurch central business district (CBD), presented decision-makers with many recovery challenges. This paper identifies major government decisions, challenges, and lessons in the early recovery of Christchurch based on 23 key-informant interviews conducted 15 months after the February 2011 earthquake. It then focuses on one of the most important decisions – maintaining the cordon around the heavily damaged CBD – and investigates its impacts. The cordon displaced 50,000 central city jobs, raised questions about (and provided new opportunities for) the long-term viability of downtown, influenced the number and practice of building demolitions, and affected debris management; despite being associated with substantial losses, the cordon was commonly viewed as necessary, and provided some benefits in facilitating recovery. Management of the cordon poses important lessons for planning for catastrophic urban earthquakes around the world.

Research papers, The University of Auckland Library

The 2011, 6.3 magnitude Christchurch earthquake in New Zealand caused considerable structural damage. It is believed that this event has now resulted in demolition of about 65-70% of the building stock in the Central Business District (CBD), significantly crippling economic activities in the city of Christchurch. A major concern raised from this event was adequacy of the current seismic design practice adopted for reinforced concrete walls due to their poor performance in modern buildings. The relatively short-duration earthquake motion implied that the observed wall damage occurred in a brittle manner despite adopting a ductile design philosophy. This paper presents the lessons learned from the observed wall damage in the context of current state of knowledge in the following areas: concentrating longitudinal reinforcement in wall end regions; determining wall thickness to prevent out-of-plane wall buckling; avoiding lap splices in plastic hinge zones; and quantifying minimum vertical reinforcement. http://www.2eceesistanbul.org/

Research papers, The University of Auckland Library

Following the devastation of the Canterbury earthquake sequence a unique opportunity exists to rebuild and restructure the city of Christchurch, ensuring that its infrastructure is constructed better than before and is innovative. By installing an integrated grid of modern sensor technologies into concrete structures during the rebuild of the Christchurch CBD, the aim is to develop a network of self-monitored ‘digital buildings’. A diverse range of data will be recorded, potentially including parameters such as concrete stresses, strains, thermal deformations, acoustics and the monitoring of corrosion of reinforcement bars. This procedure will allow an on-going complete assessment of the structure’s performance and service life, both before and after seismic activity. The data generated from the embedded and surface mounted sensors will be analysed to allow an innovative and real-time health monitoring solution where structural integrity is continuously known. This indication of building performance will allow the structure to alert owners, engineers and asset managers of developing problems prior to failure thresholds being reached. A range of potential sensor technologies for monitoring the performance of existing and newly constructed concrete buildings is discussed. A description of monitoring work conducted on existing buildings during the July 2013 Cook Strait earthquake sequence is included, along with details of current work that investigates the performance of sensing technologies for detecting crack formation in concrete specimens. The potential market for managing the real-time health of installed infrastructure is huge. Civil structures all over the world require regular visual inspections in order to determine their structural integrity. The information recorded during the Christchurch rebuild will generate crucial data sets that will be beneficial in understanding the behaviour of concrete over the complete life cycle of the structure, from construction through to operation and building repairs until the time of failure. VoR - Version of Record

Research papers, The University of Auckland Library

Between September 4, 2010 and December 23, 2011, a series of earthquakes struck the South Island of New Zealand including the city of Christchurch producing heavy damage. During the strongest shaking, the unreinforced masonry (URM) building stock in Christchurch was subjected to seismic loading equal to approximately 150-200% of code values. Post-earthquake reconnaissance suggested numerous failures of adhesive anchors used for retrofit connection of roof and floor diaphragms to masonry walls. A team of researchers from the Universities of Auckland (NZ) and Minnesota (USA) conducted a field investigation on the performance of new adhesive anchors installed in existing masonry walls. Variables included adhesive type, anchor diameter, embedment length, anchor inclination, and masonry quality. Buildings were selected that had been slated for demolition but which featured exterior walls that had not been damaged. A summary of the deformation response measured during the field tests are presented. AM - Accepted Manuscript

Research papers, University of Canterbury Library

Generalized conditional intensity measure (GCIM) method is extended to ground motion selection for scenario ruptures. Using different rupture scenarios and site conditions, various aspects of the GCIM methodology are scrutinized, including: (i) implementation of different weight vectors and the composition of the IM vector; (ii) quantifying the importance of replicate selections for different number of desired ground motions; and (iii) the effect of considering bounds on the implicit causal parameters of the prospective ground motions. Using the extended methodology, representative ground motion ensembles for several major earthquake scenarios in New Zealand are developed. Cases considered include representative ground motions for the occurrence of Alpine, Hope, and Porters Pass earthquakes in Christchurch city, and the occurrence of Wellington, Wairarapa, and Ohariu fault ruptures in Wellington city. Challenges in the development of ground motion ensembles for subduction zone earthquakes are also highlighted. The selected scenario-based ground motion sets can be used to complement ground motions which are often selected in conjunction with probabilistic seismic hazard analysis, in order to understand the performance of structures for the question “what if this fault ruptures?”

Research papers, University of Canterbury Library

Generalized conditional intensity measure (GCIM) method is extended to ground motion selection for scenario ruptures. Using different rupture scenarios and site conditions, various aspects of the GCIM methodology are scrutinized, including: (i) implementation of different weight vectors and the composition of the IM vector; (ii) quantifying the importance of replicate selections for different number of desired ground motions; and (iii) the effect of considering bounds on the implicit causal parameters of the prospective ground motions. Using the extended methodology, representative ground motion ensembles for several major earthquake scenarios in New Zealand are developed. Cases considered include representative ground motions for the occurrence of Alpine, Hope, and Porters Pass earthquakes in Christchurch city, and the occurrence of Wellington, Wairarapa, and Ohariu fault ruptures in Wellington city. Challenges in the development of ground motion ensembles for subduction zone earthquakes are also highlighted. The selected scenario-based ground motion sets can be used to complement ground motions which are often selected in conjunction with probabilistic seismic hazard analysis, in order to understand the performance of structures for the question “what if this fault ruptures?”

Research papers, University of Canterbury Library

The UC CEISMIC Canterbury Earthquakes Digital Archive contains tens of thousands of high value cultural heritage items related to a long series of earthquakes that hit Canterbury, New Zealand, from 2010 - 2012. The archive was built by a Digital Humanities team located at the center of the disaster in New Zealand's second largest city, Christchurch. The project quickly became complex, not only in its technical aspects but in its governance and general management. This talk will provide insight into the national and international management and governance frameworks used to successfully build and deliver the archive into operation. Issues that needed to be managed included human ethics, research ethics, stakeholder management, communications, risk management, curation and ingestion policy, copyright and content licensing, and project governance. The team drew heavily on industry-standard project management methods for the basic approach, but built their ecosystem and stakeholder trust on principles derived directly form the global digital humanities community.

Research papers, University of Canterbury Library

Case study analysis of the 2010-2011 Canterbury Earthquake Sequence (CES), which particularly impacted Christchurch City, New Zealand, has highlighted the value of practical, standardised and coordinated post-earthquake geotechnical response guidelines for earthquake-induced landslides in urban areas. The 22nd February 2011 earthquake, the second largest magnitude event in the CES, initiated a series of rockfall, cliff collapse and loess failures around the Port Hills which severely impacted the south-eastern part of Christchurch. The extensive slope failure induced by the 22nd February 200 earthquake was unprecedented; and ground motions experienced significantly exceeded the probabilistic seismic hazard model for Canterbury. Earthquake-induced landslides initiated by the 22nd February 2011 earthquake posed risk to life safety, and caused widespread damage to dwellings and critical infrastructure. In the immediate aftermath of the 22nd February 2011 earthquake, the geotechnical community responded by deploying into the Port Hills to conduct assessment of slope failure hazards and life safety risk. Coordination within the voluntary geotechnical response group evolved rapidly within the first week post-earthquake. The lack of pre-event planning to guide coordinated geotechnical response hindered the execution of timely and transparent management of life safety risk from coseismic landslides in the initial week after the earthquake. Semi-structured interviews were conducted with municipal, management and operational organisations involved in the geotechnical response during the CES. Analysis of interview dialogue highlighted the temporal evolution of priorities and tasks during emergency response to coseismic slope failure, which was further developed into a phased conceptual model to inform future geotechnical response. Review of geotechnical responses to selected historical earthquakes (Northridge, 1994; Chi-Chi, 1999; Wenchuan, 2008) has enabled comparison between international practice and local response strategies, and has emphasised the value of pre-earthquake preparation, indicating the importance of integration of geotechnical response within national emergency management plans. Furthermore, analysis of the CES and international earthquakes has informed pragmatic recommendations for future response to coseismic slope failure. Recommendations for future response to earthquake-induced landslides presented in this thesis include: the integration of post-earthquake geotechnical response with national Civil Defence and Emergency Management; pre-earthquake development of an adaptive management structure and standard slope assessment format for geotechnical response; and emergency management training for geotechnical professionals. Post-earthquake response recommendations include the development of geographic sectors within the area impacted by coseismic slope failure, and the development of a GIS database for analysis and management of data collected during ground reconnaissance. Recommendations provided in this thesis aim to inform development of national guidelines for geotechnical response to earthquake-induced landslides in New Zealand, and prompt debate concerning international best practice.