This paper presents an overview of the soil profile characteristics at strong motion station (SMS) locations in the Christchurch Central Business District (CBD) based on recently completed geotechnical site investigations. Given the variability of Christchurch soils, detailed investigations were needed in close vicinity to each SMS. In this regard, CPT, SPT and borehole data, and shear wave velocity (Vs) profiles from surface wave dispersion data in close vicinity to the SMSs have been used to develop detailed representative soil profiles at each site and to determine site classes according to the New Zealand standard NZS1170.5. A disparity between the NZS1170.5 site classes based on Vs and SPT N60 investigation techniques is highlighted, and additional studies are needed to harmonize site classification based on these techniques. The short period mode of vibration of soft deposits above gravels, which are found throughout Christchurch, are compared to the long period mode of vibration of the entire soil profile to bedrock. These two distinct modes of vibration require further investigation to determine their impact on the site response. According to current American and European approaches to seismic site classification, all SMSs were classified as problematic soil sites due to the presence of liquefiable strata, soils which are not directly accounted for by the NZS1170.5 approach.
The Canterbury Earthquake Sequence (CES), induced extensive damage in residential buildings and led to over NZ$40 billion in total economic losses. Due to the unique insurance setting in New Zealand, up to 80% of the financial losses were insured. Over the CES, the Earthquake Commission (EQC) received more than 412,000 insurance claims for residential buildings. The 4 September 2010 earthquake is the event for which most of the claims have been lodged with more than 138,000 residential claims for this event only. This research project uses EQC claim database to develop a seismic loss prediction model for residential buildings in Christchurch. It uses machine learning to create a procedure capable of highlighting critical features that affected the most buildings loss. A future study of those features enables the generation of insights that can be used by various stakeholders, for example, to better understand the influence of a structural system on the building loss or to select appropriate risk mitigation measures. Previous to the training of the machine learning model, the claim dataset was supplemented with additional data sourced from private and open access databases giving complementary information related to the building characteristics, seismic demand, liquefaction occurrence and soil conditions. This poster presents results of a machine learning model trained on a merged dataset using residential claims from the 4 September 2010.
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.
This article examines the representation of Christchurch, New Zealand, student radio station RDU in the exhibition Alternative Radio at the Canterbury Museum in 2016. With the intention of ‘making visible what is invisible’ about radio broadcasting, the exhibition articulated RDU as a point of interconnection between the technical elements of broadcasting, the social and musical culture of station staff and volunteers, and the broader local and national music scenes. This paper is grounded in observations of the exhibitions and associated public programmes, and interviews with the key participants in the exhibition including the museum's exhibition designer and staff from RDU, who acted as independent practitioners in collaboration with the museum. Alternative Radio also addressed the aftermath of the major earthquake of 22 February 2011, when RDU moved into a customised horse truck after losing its broadcast studio. The exhibition came about because of the cultural resonance of the post-quake story, but also emphasised the long history of the station before that event, and located this small student radio station in the broader heritage discourse of the Canterbury museum, activating the historical, cultural, and personal memories of the station's participants and audiences.
Home address-based school zoning regulations are widely used in many countries as one means of selecting pupils and estimating future enrolment. However, there is little research regarding an alternative system of zoning for parents’ place of employment. Previous research has failed to analyse potential impacts from workplace-based zoning, including negating the effects of chain migration theory and settlement patterns to facilitate cultural integration, promoting the physical and mental wellbeing of families by enabling their close proximity during the day, as well as positive results concerning a volatile real estate market. As the modern family more often consists of one or both parents working full-time, the requirement of children to attend school near their home may not be as reasonably convenient as near their parents’ workplace. A case study was performed on one primary school in Christchurch, consisting of surveys and interviews of school stakeholders, including parents and staff, along with GIS mapping of school locations. This found deeper motivations for choosing a primary school, including a preference for cultural integration and the desire to school children under 14 years near their parents’ place of employment in case of illness or earthquake. These data suggest that the advantages of workplace-based zoning may be worth considering, and this thesis creates a framework for the Ministry of Education to implement this initiative in a pilot programme for primary schools in Christchurch.
The New Zealand city of Christchurch suffered a series of devastating earthquakes in 2010-11 that changed the urban landscape forever. A new rebuilt city is now underway, largely based on the expressed wishes of the populace to see Christchurch return to being a more people-oriented, cycle-friendly city that it was known for in decades past. Currently 7% of commuters cycle to work, supported by a 200km network of mostly conventional on-road painted cycle lanes and off-road shared paths. The new "Major Cycleways" plan aims to develop approximately 100km of high-quality cycling routes throughout the city in 5-7 years. The target audience is an unaccompanied 10-year-old cycling, which requires more separated cycleways and low-volume/speed "neighbourhood greenways" to meet this standard. This presentation summarises the steps undertaken to date to start delivering this network. Various pieces of research have helped to identify the types of infrastructure preferred by those currently not regularly cycling, as well as helping to assess the merits of different route choices. Conceptual cycleway guidelines have now been translated into detailed design principles for the different types of infrastructure being planned. While much of this work is based on successful designs from overseas, including professional advice from Dutch practitioners, an interesting challenge has been to adapt these designs as required to suit local road environments and road user expectations. The first parts of the new network are being rolled out now, with the hope that this will produce an attractive and resilient network for the future population that leads to cycling being a major part of the local way of life.
We examined changes in psychological distress experienced by residents of Christchurch following two catastrophic earthquakes in late 2010 and early 2011, using data from the New Zealand Attitudes and Values Study (NZAVS), a national probability panel study of New Zealand adults. Analyses focused on the 267 participants (172 women, 95 men) who were living in central Christchurch in 2009 (i.e., before the Christchurch earthquakes), and who also provided complete responses to our yearly panel questionnaire conducted in late 2010 (largely between the two major earthquakes), late 2011, and late 2012. Levels of psychological distress were similar across the different regions of central Christchurch immediately following the September 2010 earthquake, and remained comparable across regions in 2011. By late 2012, however, average levels of psychological distress in the regions had diverged as a function of the amount of property damage experienced within each given region. Specifically, participants in the least damaged region (i.e., the Fendalton-Waimairi and Riccarton-Wigram wards) experienced greater drops in psychological distress than did those in the moderately damaged region (i.e., across the Spreydon-Heathcote and Hagley- Ferrymead wards). However, the level of psychological distress reported by participants in the most damaged region (i.e., across Shirley-Papanui and Burwood-Pegasus) were not significantly different to those in the least damaged region of central Christchurch. These findings suggest that different patterns of psychological recovery emerged across the different regions of Christchurch, with the moderately damaged region faring the worst, but only after the initial shock of the destruction had passed.
On 22 February 2011，a magnitude Mw 6.3 earthquake occurred with an epicenter located near Lyttelton at about 10km from Christchurch in Canterbury region on the South Island of New Zealand (Figure 1). Since this earthquake occurred in the midst of the aftershock activity which had continued since the 4 September 2010 Darfield Earthquake occurrence, it was considered to be an aftershock of the initial earthquake. Because of the short distance to the city and the shallower depth of the epicenter, this earthquake caused more significant damage to pipelines, traffic facilities, residential houses/properties and multi-story buildings in the central business district than the September 2010 Darfield Earthquake in spite of its smaller earthquake magnitude. Unfortunately, this earthquake resulted in significant number of casualties due to the collapse of multi-story buildings and unreinforced masonry structures in the city center of Christchurch. As of 4 April, 172 casualties were reported and the final death toll is expected to be 181. While it is extremely regrettable that Christchurch suffered a terrible number of victims, civil and geotechnical engineers have this hard-to-find opportunity to learn the response of real ground from two gigantic earthquakes which occurred in less than six months from each other. From geotechnical engineering point of view, it is interesting to discuss the widespread liquefaction in natural sediments, repeated liquefaction within short period and further damage to earth structures which have been damaged in the previous earthquake. Following the earthquake, an intensive geotechnical reconnaissance was conducted to capture evidence and perishable data from this event. The team included the following members: Misko Cubrinovski (University of Canterbury, NZ, Team Leader), Susumu Yasuda (Tokyo Denki University, Japan, JGS Team Leader), Rolando Orense (University of Auckland, NZ), Kohji Tokimatsu (Tokyo Institute of Technology, Japan), Ryosuke Uzuoka (Tokushima University, Japan), Takashi Kiyota (University of Tokyo, Japan), Yasuyo Hosono (Toyohashi University of Technology, Japan) and Suguru Yamada (University of Tokyo, Japan).
The Avon and Heathcote Rivers, located in the city of Christchurch, New Zealand, are lowland spring-fed rivers linked with the Christchurch Groundwater System. At present, the flow paths and recharge sources to the Christchurch Groundwater System are not fully understood. Study of both the Avon and Heathcote Rivers can provide greater insight into this system. In addition, during the period 2010-2012, Christchurch has experienced large amounts of seismic activity, including a devastating Mw 6.2 aftershock on February 22nd, 2011, which caused widespread damage and loss of life. Associated with these earthquakes was the release of large amounts of water through liquefaction and temporary springs throughout the city. This provided a unique opportunity to study groundwater surface water interactions following a large scale seismic event. Presented herein is the first major geochemical study on the Avon and Heathcote Rivers and the hydrological impact of the February 22, 2011 Christchurch Earthquake. The Avon, Heathcote, and Waimakariri Rivers were sampled in quarterly periods starting in July 2011 and analyzed for stable Isotopes δ¹⁸O, δD, and δ¹³C and major anion composition. In addition, post -earthquake samples were collected over the days immediately following the February 22, 2011 earthquake and analyzed for stable isotopes δ¹⁸O and δD and major anion composition. A variety of analytical methods were used identify the source of the waters in the Avon-Heathcote System and evaluate the effectiveness of stable isotopes as geochemical tracers in the Christchurch Groundwater System. The results of this thesis found that the waters from the Avon and Heathcote Rivers are geochemically the same, originating from groundwater, and exhibit a strong tidal influence within 5km of the Avon-Heathcote Estuary. The surface waters released following the February 22nd, 2011 earthquake were indistinguishable from quarterly samples taken from the Avon and Heathcote Rivers when comparing stable isotopic composition. The anion data suggests the waters released following the February 22nd, 2011 Christchurch Earthquake were sourced primarily from shallow groundwater, and also suggests a presence of urban sewage at some sites. Attempts to estimate recharge sources for the Avon-Heathcote Rivers using published models for the Christchurch Groundwater System yielded results that were not consistent between models. In evaluating the use of geochemical constituents as tracers in the Christchurch Groundwater System, no one isotope could provide a clear resolution, but when used in conjunction, δ¹⁸O, δ¹³C, and DIC, seem to be the most effective tracers. Sample sizes for δ¹³C were too small for a robust evaluation. Variability on the Waimakariri River appears to be greater than previously estimated, which could have significant impacts on geochemical models for the Christchurch Groundwater System. This research demonstrates the value of using multiple geochemical constituents to enrich our understanding of the groundwater surfaces-water interactions and the Christchurch Groundwater System as a whole.
This thesis explores the discussions and perspectives of Christchurch secondary school students in regards to their particular experiences and engagement with Anzac. In this thesis I seek to rigorously and robustly examine these viewpoints through semi-structured focus group interviews and thematic analysis. I seek to situate these youth perspectives within wider debates around Anzac mythology and Anzac resurgence in New Zealand which often do not represent the youth outlook. These debates are seen, on the one hand, to present a resurgence of youth engagement with Anzac and, on the other hand, to present the idea that Anzac has become an exclusionary myth which distorts Australians’ and New Zealanders’ understanding of wider Anzac experiences and educates them in a narrow, militarised way. Youth engagement with Anzac was not something which could be solely situated under either of these debates and, instead, it was seen to be multifaceted and made up of unique ideas and elements. The youth in my study acknowledged that their Anzac education did have mythic elements which made it hard for them to engage with Anzac despite the fact that they were actually interested in learning and understanding it. These mythic elements were the idea that Anzac is taught as a ‘simple narrative’ which does not allow room for critique, that it emphasises a link between Anzac and national identity, that it disregards many alternative Anzac experiences and that it presents a particular New Zealand identity to internalise. These students responded to their mythic Anzac education in a very active way, and instead of accepting it as truth, they were able to have constructive and critical conversations about their education and push against parts of it which they found to be too narrow or skewed in particular directions based on gender, ethnicity and national identity. The students were not passive vessels which internalised their Anzac education as fact; instead, they were able to acknowledge the mythic elements of their education and its negative influence in the classroom. This thesis went further in exploring what factors were seen to enhance this active process of critique and provide students with alternative knowledge and perspectives about Anzac. These factors were ancestral ties to Anzac, research into personal Anzac stories and experiences, unassessed educational units, centenary discussions, an understanding of hardship through the earthquakes and alternative perspectives of the Anzac experience through access to the internet. These factors presented a broader understanding of Anzac perspectives and experiences and students believed that if the mythic elements of their education could be revised and these elements encouraged then their engagement with Anzac would continue long into the future.
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OPINION: Associate Professor MARK QUIGLEY, from the University of Canterbury's department of geological sciences, and Dr MATTHEW HUGHES, from its department of civil and natural resources engineering, survey the changing landscape of post-quake Christchurch.
Liquefaction of sandy soil has been observed to cause significant damage to infrastructure during major earthquakes. Historical cases of liquefaction have typically occurred in sands containing some portion of fines particles, which are defined as 75μm or smaller in diameter. The effects of fines on the undrained behaviour of sand are not however fully understood, and this study therefore attempts to quantify these effects through the undrained testing of sand mixed with non-plastic fines sourced from Christchurch, New Zealand. The experimental program carried out during this study consisted of undrained monotonic and cyclic triaxial tests performed on three different mixtures of sand and fines: the Fitzgerald Bridge mixture (FBM), and two Pinnacles Sand mixtures (PSM1 and PSM2). The fines content of each host sand was systematically varied up to a maximum of 30%, with all test specimens being reconstituted using moist tamping deposition. The undrained test results from the FBM soils were interpreted using a range of different measures of initial state. When using void ratio and relative density, the addition of fines to the FBM sand caused more contractive behaviour for both monotonic and cyclic loadings. This resulted in lower strengths at the steady state of deformation, and lower liquefaction resistances. When the intergranular void ratio was used for the interpretation, the effect of additional fines was to cause less contractive response in the sand. The state parameter and state index were also used to interpret the undrained cyclic test results – these measures suggested that additional fines caused less contractive sand behaviour, the opposite to that observed when using the void ratio. This highlighted the dependency on the parameter chosen as a basis for the response comparison when determining the effects of fines, and pointed out a need to identify a measure that normalizes such effects. Based on the FBM undrained test results and interpretations, the equivalent granular void ratio, e*, was identified from the literature as a measure of initial state that normalizes the effects of fines on the undrained behaviour of sand up to a fines content of 30%. This is done through a parameter within the e* definition termed the fines influence factor, b, which quantifies the effects of fines from a value of zero (no effect) to one (same effect as sand particles). The value of b was also determined to be different when interpreting the steady state lines (bSSL) and cyclic resistance curves (bCR) respectively for a given mixture of sand and fines. The steady state lines and cyclic resistance curves of the FBM soils and a number of other sand-fines mixtures sourced from the literature were subsequently interpreted using the equivalent granular void ratio concept, with bSSL and bCR values being back-calculated from the respective test data sets. Based on these interpretations, it was concluded that e* was conceptually a useful parameter for characterizing and quantifying the effects of fines on the undrained behaviour of sand, assuming the fines influence factor value could be derived. To allow prediction of the fines influence factor values, bSSL and bCR were correlated with material and depositional properties of the presented sand-fines mixtures. It was found that as the size of the fines particles relative to the sand particles became smaller, the values of bSSL and bCR reduced, indicating lower effect of fines. The same trend was also observed as the angularity of the sand particles increased. The depositional method was found to influence the value of bCR, due to the sensitivity of cyclic loading to initial soil fabric. This led to bSSL being used as a reference for the effect of fines, with specimens prepared by moist tamping having bCR > bSSL, and specimens prepared by slurry deposition having bCR < bSSL. Finally the correlations of the fines influence factor values with material and depositional properties were used to define the simplified estimation method – a procedure capable of predicting the approximate steady state lines and cyclic resistance curves of a sand as the non-plastic fines content is increased up to 30%. The method was critically reviewed based on the undrained test results of the PSM1 and PSM2 soils. This review suggested the method could accurately predict undrained response curves as the fines content was raised, based on the PSM1 test results. It also however identified some key issues with the method, such as the inability to accurately predict the responses of highly non-uniform soils, a lack of consideration for the entire particle size distribution of a soil, and the fact the errors in the prediction of bSSL carry through into the prediction of bCR. Lastly some areas of further investigation relating to the method were highlighted, including the need to verify the method through testing of sandy soils sourced from outside the Christchurch area, and the need to correlate the value of bCR with additional soil fabrics / depositional methods.
An overview of the 22 February 2011 Christchurch earthquake is presented in the context of characterization of extreme/rare events. Focus is given to the earthquake source, observed near-source strong ground motions, and effects of site response, while structural response and consequences are mentioned for completeness. For each of the above topics comparisons and discussions are made with predictive models for each of phenomena considered. In light of the observations and predictive model comparisons, the author’s opinion on improving the characterization of such extreme/rare events, and their appropriate consideration in seismic design is presented
Using greater Christchurch as a case study, this research seeks to understand the key drivers of residential choice of families with children who live in recently developed, low-density greenfield subdivisions. In particular, the research examines the role that transport-related implications play in families’ choice of residence and location. It also explores the lived experience of the quotidian travel of these households, and the intrinsic value of their time in the car. While the research is situated in one particular location, it is designed to gain an understanding of urban processes and residents’ experiences of these as applicable to broader settings. Concerns about the pernicious environmental, fiscal, and wellbeing effects of sprawling urban form have been growing over the past few decades, inciting many cities including Christchurch to start shifting planning policies to try and achieve greater intensification and a denser development pattern. The 2010/2011 Christchurch earthquake sequence and its destruction of thousands of homes however created huge pressure for housing development, the bulk of which is now occurring on greenfield sites on the peripheries of Christchurch City and its neighbouring towns. Drawing on the insights provided by a wide body of both qualitative and quantitative literature on residential choice, transport and urban form, and mobilities literature as a basis, this research is interested in the attraction of these growing neighbourhoods to families, and puts the focus firmly on the attitudes, values, motivations, decisions, and lived experience of those who live in the growing suburbs of Christchurch.
The 22 February 2011, Mw6.2 Christchurch earthquake is the most costly earthquake to affect New Zealand, causing an estimated 181 fatalities and severely damaging thousands of residential and commercial buildings. This paper presents a summary of some of the observations made by the NSF-sponsored GEER Team regarding the geotechnical/geologic aspects of this earthquake. The Team focused on documenting the occurrence and severity of liquefaction and lateral spreading, performance of building and bridge foundations, buried pipelines and levees, and significant rockfalls and landslides. Liquefaction was pervasive and caused extensive damage to residential properties, water and wastewater networks, high-rise buildings, and bridges. Entire neighborhoods subsided, resulting in flooding that caused further damage. Additionally, liquefaction and lateral spreading resulted in damage to bridges and to stretches of levees along the Waimakariri and Kaiapoi Rivers. Rockfalls and landslides in the Port Hills damaged several homes and caused several fatalities.
This paper presents preliminary field observations on the performance of selected steel structures in Christchurch during the earthquake series of 2010 to 2011. This comprises 6 damaging earthquakes, on 4 September and 26 December 2010, February 22, June 6 and two on June 13, 2011. Most notable of these was the 4 September event, at Ms7.1 and MM7 (MM as observed in the Christchurch CBD) and most intense was the 22 February event at Ms6.3 and MM9-10 within the CBD. Focus is on performance of concentrically braced frames, eccentrically braced frames, moment resisting frames and industrial storage racks. With a few notable exceptions, steel structures performed well during this earthquake series, to the extent that inelastic deformations were less than what would have been expected given the severity of the recorded strong motions. Some hypotheses are formulated to explain this satisfactory performance. http://db.nzsee.org.nz/SpecialIssue/44%284%290297.pdf
Test results are presented for wall-diaphragm plate anchor connections that were axially loaded to rupture. These connection samples were extracted post-earthquake by sorting through the demolition debris from unreinforced masonry (URM) buildings damaged in the Christchurch earthquakes. Unfortunately the number of samples available for testing was small due to the difficulties associated with sample collection in an environment of continuing aftershocks and extensive demolition activity, when personal safety combined with commercial activity involving large demolition machinery were imperatives that inhibited more extensive sample collection for research purposes. Nevertheless, the presented data is expected to be of assistance to structural engineers undertaking seismic assessment of URM buildings that have existing wall-diaphragm anchor plate connections installed, where it may be necessary to estimate the capacity of the existing connection as an important parameter linked with determining the current seismic capacity of the building and therefore influencing the decision regarding whether supplementary connections should be installed.
Ingham and Biggs were in Christchurch during the M6.3, 22 February 2011 earthquake and Moon arrived the next day. They were enlisted by officials to provide rapid assessment of buildings within the Central Business District (CBD). In addition, they were asked to: 1) provide a rapid assessment of the numbers and types of buildings that had been damaged, and 2) identify indicator buildings that represent classes of structures that can be used to monitor changing conditions for each class following continuing aftershocks and subsequent damage. This paper explains how transect methodology was incorporated into the rapid damage assessment that was performed 48 hours after the earthquake. Approximately 300 buildings were assessed using exterior Level 1 reporting techniques. That data was used to draw conclusions on the condition of the entire CBD of approximately 4400 buildings. In the context of a disaster investigation, a transect involves traveling a selected path assessing the condition of the buildings and documenting the class of each building, and using the results in conjunction with prior knowledge relating to the overall population of buildings affected in the area of the study. Read More: http://ascelibrary.org/doi/abs/10.1061/9780784412640.033
In the aftermath of the 22 February 2011 earthquake, the Natural Hazards Research Platform (NHRP) initiated a series of Short Term Recovery Projects (STRP) aimed at facilitating and supporting the recovery of Christchurch from the earthquake impacts. This report presents the outcomes of STRP 6: Impacts of Liquefaction on Pipe Networks, which focused on the impacts of liquefaction on the potable water and wastewater systems of Christchurch. The project was a collaborative effort of NHRP researchers with expertise in liquefaction, CCC personnel managing and designing the systems and a geotechnical practitioner with experience/expertise in Christchurch soils and seismic geotechnics.
This paper summarizes the development of a high-resolution surficial shear wave velocity model based on the combination of the large high-spatial-density database of cone penetration test (CPT) logs in and around Christchurch, New Zealand and a recently-developed Christchurch-specific empirical correlation between soil shear wave velocity and CPT. This near-surface shear wave velocity model has applications for site characterization efforts via the development of maps of time-averaged shear wave velocities over specific depths, as well as use in site response analysis and ground motion simulation.
This paper shows an understanding of the availability of resources in post-disaster reconstruction and recovery in Christchurch, New Zealand following its September 4, 2010 and February 22, 2011 earthquakes. Overseas experience in recovery demonstrates how delays and additional costs may incur if the availability of resources is not aligned with the reconstruction needs. In the case of reconstruction following Christchurch earthquakes, access to normal resource levels will be insufficient. An on-line questionnaire survey, combined with in-depth interviews was used to collect data from the construction professionals that had been participated in the post-earthquake reconstruction. The study identified the resources that are subject to short supply and resourcing challenges that are currently faced by the construction industry. There was a varied degree of impacts felt by the surveyed organisations from resource shortages. Resource pressures were primarily concentrated on human resources associated with structural, architectural and land issues. The challenges that may continue playing out in the longer-term reconstruction of Christchurch include limited capacity of the construction industry, competition for skills among residential, infrastructure and commercial sectors, and uncertainties with respect to decision making. Findings provide implications informing the ongoing recovery and rebuild in New Zealand. http://www.iiirr.ucalgary.ca/Conference-2012
The 22nd February 2011, Mw 6.3 Christchurch earthquake in New Zealand caused major damage to critical infrastructure, including the healthcare system. The Natural Hazard Platform of NZ funded a short-term project called “Hospital Functions and Services” to support the Canterbury District Health Board’s (CDHB) efforts in capturing standardized data that describe the effects of the earthquake on the Canterbury region’s main hospital system. The project utilised a survey tool originally developed by researchers at Johns Hopkins University (JHU) to assess the loss of function of hospitals in the Maule and Bío-Bío regions following the 27th February 2010, Mw 8.8 Maule earthquake in Chile. This paper describes the application of the JHU tool for surveying the impact of Christchurch earthquake on the CDHB Hospital System, including the system’s residual capacity to deliver emergency response and health care. A short summary of the impact of the Christchurch earthquake on other CDHB public and private hospitals is also provided. This study demonstrates that, as was observed in other earthquakes around the world, the effects of damage to non-structural building components, equipment, utility lifelines, and transportation were far more disruptive than the minor structural damage observed in buildings (FEMA 2007). Earthquake related complications with re-supply and other organizational aspects also impacted the emergency response and the healthcare facilities’ residual capacity to deliver services in the short and long terms.
The Canterbury earthquake sequence in New Zealand’s South Island induced widespread liquefaction phenomena across the Christchurch urban area on four occasions (4 Sept 2010; 22 Feb; 13 June; 23 Dec 2011), that resulted in widespread ejection of silt and fine sand. This impacted transport networks as well as infiltrated and contaminated the damaged storm water system, making rapid clean-up an immediate post-earthquake priority. In some places the ejecta was contaminated by raw sewage and was readily remobilised in dry windy conditions, creating a long-term health risk to the population. Thousands of residential properties were inundated with liquefaction ejecta, however residents typically lacked the capacity (time or resources) to clean-up without external assistance. The liquefaction silt clean-up response was co-ordinated by the Christchurch City Council and executed by a network of contractors and volunteer groups, including the ‘Farmy-Army’ and the ‘Student-Army’. The duration of clean-up time of residential properties and the road network was approximately 2 months for each of the 3 main liquefaction inducing earthquakes; despite each event producing different volumes of ejecta. Preliminary cost estimates indicate total clean-up costs will be over NZ$25 million. Over 500,000 tonnes of ejecta has been stockpiled at Burwood landfill since the beginning of the Canterbury earthquakes sequence. The liquefaction clean-up experience in Christchurch following the 2010-2011 earthquake sequence has emerged as a valuable case study to support further analysis and research on the coordination, management and costs of large volume deposition of fine grained sediment in urban areas.
This thesis is about many things, not least of all the September 4th 2010 and February 22nd 2011 earthquakes that shook Christchurch, New Zealand. A city was shaken, events which worked to lay open the normally invisible yet vital objects, processes and technologies which are the focus of inquiry: the sewers, pipes, pumps, the digital technologies, the land and politics which constitute the Christchurch wastewater networks. The thesis is an eclectic mix drawing together methods and concepts from Bruno Latour, John Law, Giles Deleuze and Felix Guattari, Nigel Thrift, Donna Haraway and Patrick Joyce. It is an exploration of how the technologies and objects of sanitation perform the city, and how such things which are normally hidden and obscured, are made visible. The question of visibility is also turned toward the research itself: how does one observe, and describe? How are sociological visibilities constructed? Through the research, the encountering of objects in the field, the processes of method, the pedagogy of concepts, and the construction of risk, the thesis comes to be understood as a particular kind of social scientific artefact which assembles four different accounts: the first regards the construction of visibility; the second explores Christchurch city from the control room where the urban sanitary infrastructures are monitored; the third chapter looks at the formatted and embodied practices which emerge with the correlation of the city and sanitation; the fourth looks at the changing politics of a city grappling with severely damaged essential services, land and structures. The final chapter considers how the differences between romantic and baroque sensibilities mean that these four accounts elicit knowing not through smoothness or uniformity, but in partiality and non-coherence. This thesis is about pipes, pump stations, and treatment plants; about the effluent of a city; about the messiness of social science when confronted by the equally messy world of wastewater.
This study followed two similarly affected, but socio-economically disparate suburbs as residents responded to and attempted to recover from the devastating 6.3 magnitude earthquake that struck Christchurch, New Zealand, on February 22, 2011. More specifically, it focuses on the role of local churches, community-based organisations (CBOs) and non-governmental organisations (NGOs), here referred to broadly as civil society, in meeting the immediate needs of local residents and assisting with the longer-term recovery of each neighbourhood. Despite considerable socioeconomic differences between the two neighbourhoods, civil society in both suburbs has been vital in addressing the needs of locals in the short and long term following the earthquake. Institutions were able to utilise local knowledge of both residents and the extent of damage in the area to a) provide a swifter local response than government or civil defence and then help direct the relief these agencies provided locally; b) set up central points for distribution of supplies and information where locals would naturally gather; c) take action on what were perceived to be unmet needs; and d) act as a way of bridging locals to a variety of material, informational, and emotional resources. However the findings also support literature which indicates that other factors are also important in understanding neighbourhood recovery and the role of civil society, including: local leadership; a shared, place-based identity; the type and form of civil society organizations; social capital; and neighbourhood- and household-level indicators of relative vulnerability and inequality. The intertwining of these various factors seems to influence how these neighbourhoods have coped with and taken steps in recovering from this disaster. It is recommended that future research be directed at developing a better understanding of how this occurs. It is suggested that a model similar to Yasui’s (2007) Community Vulnerability and Capacity model be developed as a useful way to approach future research in this area.
Damage distribution maps from strong earthquakes and recorded data from field experiments have repeatedly shown that the ground surface topography and subsurface stratigraphy play a decisive role in shaping the ground motion characteristics at a site. Published theoretical studies qualitatively agree with observations from past seismic events and experiments; quantitatively, however, they systematically underestimate the absolute level of topographic amplification up to an order of magnitude or more in some cases. We have hypothesized in previous work that this discrepancy stems from idealizations of the geometry, material properties, and incident motion characteristics that most theoretical studies make. In this study, we perform numerical simulations of seismic wave propagation in heterogeneous media with arbitrary ground surface geometry, and compare results with high quality field recordings from a site with strong surface topography. Our goal is to explore whether high-fidelity simulations and realistic numerical models can – contrary to theoretical models – capture quantitatively the frequency and amplitude characteristics of topographic effects. For validation, we use field data from a linear array of nine portable seismometers that we deployed on Mount Pleasant and Heathcote Valley, Christchurch, New Zealand, and we compute empirical standard spectral ratios (SSR) and single-station horizontal-to-vertical spectral ratios (HVSR). The instruments recorded ambient vibrations and remote earthquakes for a period of two months (March-April 2017). We next perform two-dimensional wave propagation simulations using the explicit finite difference code FLAC. We construct our numerical model using a high-resolution (8m) Digital Elevation Map (DEM) available for the site, an estimated subsurface stratigraphy consistent with the geomorphology of the site, and soil properties estimated from in-situ and non-destructive tests. We subject the model to in-plane and out-of-plane incident motions that span a broadband frequency range (0.1-20Hz). Numerical and empirical spectral ratios from our blind prediction are found in very good quantitative agreement for stations on the slope of Mount Pleasant and on the surface of Heathcote Valley, across a wide range of frequencies that reveal the role of topography, soil amplification and basin edge focusing on the distribution of ground surface motion.
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Results from cyclic undrained direct simple shear tests on reconstituted specimens of two sands from Christchurch are compared against the liquefaction resistance inferred from CPT-based empirical liquefaction triggering methods. Limitations in existing empirical triggering relationships to capture important effects related to processes which originated test soils are highlighted and discussed.
Tsunami have the potential to cause significant disruptions to society, including damage to infrastructure, critical to the every-day operation of society. Effective risk management is required to reduce the potential tsunami impacts to them. Christchurch city, situated on the eastern coast of New Zealand’s South Island, is exposed to a number of far-field tsunami hazards. Although the tsunami hazard has been well identified for Christchurch city infrastructure, the likely impacts have not been well constrained. To support effective risk management a credible and realistic infrastructure impact model is required to inform risk management planning. The objectives of this thesis are to assess the impacts on Christchurch city infrastructure from a credible, hypothetical far-field tsunami scenario. To achieve this an impact assessment process is adopted, using tsunami hazard and exposure measures to determine asset vulnerability and subsequent impacts. However, the thesis identified a number of knowledge gaps in infrastructure vulnerability to tsunami. The thesis addresses this by using two approaches: a tsunami damage matrix; and the development of tsunami fragility functions. The tsunami damage matrix pools together tsunami impacts on infrastructure literature, and post-event field observations. It represents the most comprehensive ‘look-up’ resource for tsunami impacts to infrastructure to date. This damage matrix can inform the assessment of tsunami impacts on Christchurch city infrastructure by providing a measure of damage likelihood at various hazard intensities. A more robust approach to tsunami vulnerability of infrastructure are fragility functions, which are also developed in this thesis. These were based on post-event tsunami surveys of the 2011 ‘Tohoku’ earthquake tsunami in Japan. The fragility functions are limited to road and bridge infrastructure, but represent the highest resolution measure of vulnerability for the given assets. As well as providing a measure of damage likelihood for a given tsunami hazard intensity, these also indicate a level of asset damage. The impact assessment process, and synthesized vulnerability measures, are used to run tsunami impact models for Christchurch infrastructure to determine the probability of asset damage occurring and to determine if impact will reach or exceed a given damage state. The models suggest that infrastructure damage is likely to occur in areas exposed to tsunami inundation in this scenario, with significant damage identified for low elevation roads and bridges. The results are presented and discussed in the context of the risk management framework, with emphasis on using risk assessment to inform risk treatment, monitoring and review. In summary, this thesis A) advances tsunami vulnerability and impact assessment methodologies for infrastructure and B) provides a tsunami impact assessment framework for Christchurch city infrastructure which will inform infrastructure tsunami risk management for planners, emergency managers and lifelines groups.
