Canterbury Earthquakes Research Articles

Impact of post-disaster government policy on reconstruction: A case study of post-earthquake Christchurch, New Zealand

The New Zealand government, following the Canterbury earthquakes 2010-2011, adopted new ways to rebuild the city. Given an opportunity to find solutions to pre-existing issues in the city, the government was keen to rebuild faster and better. The blueprint that was finalised mid-2012, had 17 anchor projects to lead its rebuilding efforts along with governance and legislative changes to facilitate rebuilding. Drawing on past literature using the case study of Canterbury earthquakes 2010-2011, this paper first reviews the rebuilding process in Christchurch. 14 face to face interviews were held with those involved in and subjected to these governance and structural changes. The study suggests the complex post-disaster environment limit the effectiveness of the imposed changes. Rebuilding efforts were hindered by the absence of a proper legislative framework, the ambiguity in defining roles and responsibilities of recovery agents, the time-pressure to rebuild resulting in hasty planning, limited public involvement in rebuilding and the lack of strategic relevance to ensure the outcomes are accepted by the public and fit with the city’s image in the long run. It is recommended that future research focuses on implications of post-disaster rebuilding practices on the wider community, businesses, and the government.

Can artesian groundwater and earthquake-induced aquifer leakage exacerbate the manifestation of liquefaction?

Vast quantities of liquefaction ejecta repeatedly inundated properties during the 2010-2011 Canterbury earthquake sequence in New Zealand, resulting in differential ground surface subsidence and significant damage to buildings and urban infrastructure. There are strong spatial correlations between the occurrence of ejected sediment with groundwater pressure in deep aquifers. When geotechnical testing sites are grouped according to liquefaction vulnerability indices (to control variance relating to shaking strength, water table depth, and soil profile strength), places where ‘minor’ and ‘moderate-severe’ liquefaction occurred during the Mw6.2 Christchurch earthquake had distinctly higher aquifer pressure than sites where liquefaction was not observed. Together with observations of earthquake-induced pressure changes and inferred transfer of groundwater from deep aquifers to shallower levels, an interpretation is that leakage from aquifers with artesian (above ground) pressure provided an additional driving mechanism for surface manifestation of water and sediment. It is surmised that above-ground aquifer pressures further promoted suffusion and piping along fractures, flow-pathways and liquefied horizons. The Mw6.2 Christchurch earthquake is presented as an example where leakage of artesian groundwater likely contributed to the near-surface liquefaction-induced ground damage. The process can result in underprediction of liquefaction vulnerability so needs to be considered when evaluating potential for earthquake-induced liquefaction and ground damage wherever groundwater is confined.

“It’s about the most needy children”: A Foucauldian analysis of school social workers’ responses to need in post-earthquake Canterbury

INTRODUCTION: After the 2011 Canterbury earthquake, the provision of school social work was extended into a larger number of schools in the greater Christchurch region to support discussions of their practice priorities and responses in post-earthquake schools.FINDINGS: Two main interpretations of need are reflected in the school social workers’ accounts of their work with children and families. Firstly, hardship-focused need, which represented children as adversely influenced by their home circumstances; the interventions were primarily with parents. These families were mainly from schools in low socioeconomic areas. Secondly, anxiety-based need, a newer practice response, which emphasised children who were considered particularly susceptible to the impacts of the disaster event. This article considers how these practitioners conceptualised and responded to the needs of the children and their families in this context.METHOD: A qualitative study examining recovery policy and school social work practice following the earthquakes including 12 semi-structured interviews with school social workers. This article provides a Foucauldian analysis of the social worker participants’ perspectives on emotional and psychological issues for children, particularly those from middle-class families; the main interventions were direct therapeutic work with children themselves. Embedded within these practice accounts are moments in which the social workers contested the predominant, individualising conceptualisations of need to enable more open-ended, negotiable, interconnected relationships in post-earthquake schools.IMPLICATIONS: In the aftermath of disasters, school social workers can reflect on their preferred practice responses and institutional influences in schools to offer children and families opportunities to reject the prevalent norms of risk and vulnerability.

Beliefs about Memory Questionnaire: psychometric properties in a natural disaster sample

ABSTRACT Several theories exist regarding the role of memory in the development of PTSD. The metacognitive model of PTSD contends beliefs about trauma memory are pivotal in the development and maintenance of PTSD. The Beliefs About Memory Questionnaire (BAMQ) was developed to measure metacognitive beliefs about trauma memory. This study aimed to test the psychometric properties of the BAMQ and its relationship to PTSD in a community sample of 674 adults exposed to the 2010–2011 Canterbury earthquakes and Queensland floods. Participants completed a series of online, self-report questionnaires between October and December 2012, exploring thinking and memory processes related to their experience of a natural disaster. Factor analysis validated the two-factor, positive and negative structure of the BAMQ. Convergent, concurrent, and discriminant validity was established through positive relationships with relevant metacognitive beliefs, thought control variables, and risk factors related to PTSD. Logistic regression revealed scores on the BAMQ predicted clinically significant symptoms of PTSD. The psychometric properties of the BAMQ suggest the instrument is a valuable addition to the assessment of metacognitive beliefs about trauma memory, and the utility of the BAMQ in the prediction of clinically significant symptoms of PTSD.

The utility of earth science information in post-earthquake land-use decision-making: the 2010–2011 Canterbury earthquake sequence in Aotearoa New Zealand

Abstract. Earth science information (data, knowledge, advice) can enhance the evidence base for land-use decision-making. The utility of this information depends on factors including the context and objectives of land-use decisions, the timeliness and efficiency with which earth science information is delivered, and the strength, relevance, uncertainties, and risks assigned to earth science information relative to other inputs. We investigate land-use decision-making practices in Christchurch, New Zealand, and the surrounding region in response to mass movement (e.g., rockfall, cliff collapses) and ground-surface fault rupture hazards incurred during the 2010–2011 Canterbury earthquake sequence (CES). Rockfall fatality risk models combining hazard, exposure, and vulnerability data were co-produced by earth scientists and decision makers and formed primary evidence for risk-based land-use decision-making with adaptive capacity. A public consultation and submission process enabled consideration of additional earth science information primarily via stakeholder requests. For fault rupture hazards, pre-disaster geotechnical guidelines and collaboration networks enhanced the ability of earth scientists to rapidly acquire relevant observational data to meet the demands of decision makers. Expeditious decision-making granted permissive consent for rebuilding in the fault rupture zone based on preliminary scientific advice that was subsequently supported by more comprehensive geological investigations. Rapidly fluctuating and diverse demands for post-disaster earth science information may be best met through the prior establishment of (i) land-use policies and technical guidelines tailored for a variety of diverse disaster scenarios, (ii) hazard and risk analyses in land-use plans, including acquisition of geospatial and other earth science data, and (iii) coordinated scientific networks that may comprise subgroups with diverse goals, operational perspectives, and protocols which allow the many facets of scientific information acquisition and delivery to be successfully addressed. Despite the collective knowledge shared here, some recent land-use practices in New Zealand continue to prioritize other (e.g., socioeconomic) factors above earth science information, even in areas of extreme disaster risk.

‘Spontaneous’ volunteers? Factors enabling the Student Volunteer Army mobilisation following the Canterbury earthquakes, 2010–2011

‘Spontaneous’ volunteers have long been recognized for the distinct and important contribution they can have within disaster response and recovery. The emergence of the Student Volunteer Army (SVA) has featured as a success story of crisis volunteerism in international disaster response literature and as a potential blueprint for youth-centred post-disaster civic action. Drawing on in-depth interviews with people involved in the SVA, we provide a framework for understanding the factors that helped enable its mobilisation. In outlining these factors, many of which pre-date the emergence of the SVA, the paper demonstrates that the successful mobilisation of ‘spontaneous’ volunteers is not necessarily as spontaneous as the term suggests. Our analysis furthers understanding of the diversity of crisis volunteerism and has implications for disaster response practitioners, particularly in recognising the importance of networks of support which exist before and beyond disaster.

Improving human resource mobilisation for post-disaster recovery: A New Zealand case study

New Zealand is a hazard-prone country and experiences one of the highest rates of seismic activity in the world. While a wide range of tools have been developed in previous decades to support strategic and tactical decisions for post-disaster recovery, a challenge exists in identifying critical human resources to meet the demand of post-disaster infrastructure rebuild. Based on two case studies of the 2010–2011 Canterbury earthquakes and 2016 Kaikōura earthquake, this paper aims to explore whether relevant professionals involved in the infrastructure recovery from 2010 to 2011 earthquakes were mobilised to the 2016 earthquake and what mechanisms employed and challenges faced to utilise their expertise in a systematic way. This research highlights that a gap remains in incorporating expertise and advisory capacities from the former event to the latter one due to rapid staff turnover in recovery organisations and lack of information regarding infrastructure recovery experts. Addressing these issues is important, as such expertise and advisory capacities may set the tone for disaster management and significantly impact the quality of infrastructure rebuild in New Zealand and many other countries.

Structural Damage Evaluation of Multistory Timber–Steel Hybrid Structures through Shake Table Tests

Timber-based hybrid structures provide a prospective solution for utilizing environmentally friendly timber material in the construction of midrise or high-rise structures. This study mainly focuses on structural damage evaluation for a type of timber–steel hybrid structure that incorporates prefabricated light wood-frame shear walls into steel moment-resisting frames (SMRFs). The structural damage of such a hybrid structure was evaluated through shake table tests on a 4-story large-scale timber–steel hybrid structure. Four ground motion records (i.e., Wenchuan earthquake, Canterbury earthquake, El-Centro earthquake, and Kobe earthquake) were chosen for the tests, with the consideration of three different probability levels (i.e., minor, moderate, and major earthquakes) for each record. During the shake table tests, the hybrid structure performed quite well with visual damage only to wood shear walls. No visual damage in SMRFs and the frame-to-wall connections was observed. The correlation of visual damage to seismic intensity, modal-based damage index, and interstory drift is discussed. The reported work provides a basis of knowledge for performance-based seismic design (PBSD) for such timber-based hybrid structures.

Burning the buffer: New Zealand's budgetary response to COVID-19

PurposeThe New Zealand Government has progressively strengthened its balance sheet position since the mid-1990s, other than for the four years immediately following the global financial crisis and the Canterbury earthquakes. This paper describes the nature and the forecast and actual fiscal impacts of the COVID-19 response, and identifies the transparency mechanisms which reveal these impacts. It also expresses a viewpoint on the implications of the COVID-19 response for the future resilience of the Government's fiscal position.Design/methodology/approachThe paper draws on the suite of official budgetary documents to demonstrate both the transparency of the disclosures on the COVID-19 impact and the substance of the forecast and actual fiscal impacts.FindingsThe paper reveals the change in the long-term fiscal aspirations of the New Zealand Government from one of achieving and maintaining a significant net worth buffer, to one which accommodates in the long-term a markedly smaller buffer and lower level of net worth.Originality/valueThe public financial management system in New Zealand is notable for its transparency. The Government's response to the pandemic is used to illustrate the nature and extent of that transparency.

Structural Adjustment and Community Resilience: The Case of Postdisaster Housing Recovery After the Canterbury Earthquakes of 2010 and 2011.

This project is a case study of postdisaster housing recovery in Christchurch, New Zealand, after the Canterbury earthquakes of 2010 and 2011. In this qualitative study, we analyzed the statutory framework governing the process of postdisaster housing recovery and its impact on local democracy. We also explored the role of communities and the third sector in housing and urban renewal. This aim was to contribute to the development of a critical theoretical understanding of community resilience as an inherently political concept. Community resilience is influenced by causal factors or generative mechanisms that affect the relations between people in a particular social context. We completed a narrative synthesis of textual data from the thematic analysis of in-depth interviews with key informants, related policies, media, and fieldwork. A centralization of government authority over housing recovery resulted in an erosion of democracy and representative government at a local level. This centralization had major impacts on communities and their voice in the process of postdisaster housing recovery. Communities, however, never relented and worked tirelessly among themselves and with other social sectors to make a positive impact on postdisaster housing and urban recovery against difficult odds and stretched resources. This immense social capital and inspiring sense of community must be fostered and given the opportunity to democratically participate in the development of recovery policy as a key element of community resilience.

Facing adversity together: the biopolitics of the community-focussed recovery policies in post-earthquake Canterbury, New Zealand

ABSTRACT Community building was a feature of the recovery policies implemented to respond to the 2010 and 2011 Canterbury earthquakes in New Zealand. This strategy aimed for survivors to manage the disruption of the events by activating and enhancing their community networks. Drawing on Foucault’s and Esposito’s theorizing of biopolitics, community, and immunity, this article provides a close reading of the policies and tools implemented to manage the post-earthquake context. I outline the unacknowledged effects of two intertwined forms of governance. First, populational governance through which communities were guided to take care of themselves within a recovery framework, which prized resilience. Second, therapeutic governance in which vulnerable individuals and groups were offered specialized, therapeutic assistance. I argue, whilst operating at different levels, both forms of governance functioned to re-value the desires, motivations, and actions of survivors in terms of their capacity to contribute to post-earthquake life in Canterbury.

Field testing of vintage masonry: Mechanical properties and anchorage strengths

Investigations of damage sustained following the 2010–2011 Canterbury earthquake sequence highlighted premature failure of anchorages in previously strengthened masonry. These failures suggest that a lack of understanding surrounding anchorage design is limiting the ability to seismically retrofit masonry structures. In order to provide experimental observations for use in developing and calibrating anchorage models a series of in-situ tests have been undertaken on three masonry structures to quantify in-situ mechanical properties and corresponding anchor pull-out loads and failure modes. Importantly, the outcomes of this field testing show poor correlation with the outcomes predicted by current design standards and approaches – that is, that the failure of anchorages by splitting of the masonry units rather than cone/wedge type failure or masonry unit extraction was the predominant observation. Additionally, due to difficulties with common test procedures, interpretation of standardised tests such as the “shove” test and the bond wrench test have been difficult. Alternative material tests and statistical distributions are proposed and a new anchorage failure model is suggested.

Numerical evaluation of a non-ductile RCFMI building subjected to the Canterbury, New Zealand Earthquakes: A case study of the St Elmo Courts building

The 2010/2011 Canterbury, NewZealand earthquakes resulted in minor to severe levels of damage to a number of high-rise Reinforced Concrete Frame with Masonry Infill (RCFMI) buildings that were constructed before the establishment of the first New Zealand seismic code in 1935. Because a ductile design philosophy was not adopted in the NewZealand structural seismic design process until the release of the 1976 NewZealand Seismic Code, these high-rise RCFMI buildings can be considered to be non-ductile and potentially earthquake-vulnerable buildings. The seismic performance of these NewZealand non-ductile high-rise RCFMI buildings has received little research attention previously, and the reported study was consequently conducted to investigate the appropriateness of employing a macro-modelling approach using commercial software. The level of modelling accuracy was first established by correlation against previously reported experimental studies and the adopted numerical model was then applied to numerically assess a case study non-ductile high-rise RCFMI building that was severely damaged during the Canterbury earthquakes. It was shown that the numerical modelling results were well-matched with the observed earthquake damage. As a result, it was concluded that the adopted numerical modelling approach can be implemented for the seismic assessment of existing non-ductile RCFMI buildings across NewZealand.

Mortality salience and meaning in life for residents visiting dark tourism sites

Reflections on meanings of life and death are rarely comfortable or linear, and can be triggered by crises and disasters. This study explores the meanings of dark tourism sites for residents, including their visitation motives, and subsequent reflections on death and life. Semi-structured in-depth interviews were conducted with 37 residents of Christchurch in Aotearoa New Zealand, following the Canterbury earthquakes of 2010 and 2011. Our findings suggest that visits to disaster sites that have dark tourism connotations trigger mortality salience, prompting residents to reflect on memories of the disaster, which are often accompanied by deep and meaningful reflections on death and meaning in life, nostalgia for the past, and the significance of the sites themselves. We argue that dark tourism sites provide spaces for residents to assess and address socio-emotional distress caused by disasters. We suggest that interpretations of disaster-related dark tourism sites should memorialise death and disaster, but should also celebrate the lives of survivors. In this way, dark tourism sites can take on a more productive role in facilitating individual and community coping with post-disaster recovery.

The effects of earthquake exposure on preparedness in the short and long term: a difference-in-differences estimation

Emergency support is often delayed after a disaster. Despite the importance of being prepared to deal with the immediate aftermath of disasters, not everyone prepares effectively. While exposure to disasters improves people’s preparedness in the short term, it is yet to be determined whether this improvement is long lasting. In this paper, we use a difference-in-differences method to estimate the causal effects of the 2010 and 2011 Canterbury earthquakes on people’s preparedness in the short-term (1 month after the second earthquake) and long-term (up to 25 months after the second earthquake). Our results show that people who experienced the earthquakes increase their preparedness by 0.67 standard deviations in the short term. This impact stays positive, but declines to 0.42 standard deviations in the long term.

Enacting “accountability in collaborative governance”: lessons in emergency management and earthquake recovery from the 2010–2011 Canterbury Earthquakes

PurposeThe paper illustrates how accountability of collaborative governance was constituted in the context of disaster managerial work carried out by the Government, local authorities, and Maori community organisations, after the 2010–2011 Canterbury earthquakes in New Zealand.Design/methodology/approachA case study detailing the communitarian approach to disaster recovery management by a nationalised Maori earthquake response network is contrasted with the formal emergency management infrastructure's response to the Canterbury earthquakes.FindingsCritical analysis of the effectiveness and failures of these approaches highlights the institutional and cultural political issues that hinder the institutionalization of collaborative and accountable governance in the fields of disaster risk reduction and emergency management.Research limitations/implicationsThe paper contributes to the accountability research and practice in general and disaster accountability in particular by addressing a more multifaceted model of ‘accountability combined with collaborative governance’ as a way to build on and critique some of the seemingly more narrow views of accountability.Originality/valueThe study presents rare insights on the interactions between formal and community level accountability and collaborative governance in the context of New Public Governance (NPG).

RESEARCH PROGRAMME ON SEISMIC PERFORMANCE OF REINFORCED CONCRETE WALLS: KEY RECOMMENDATIONS

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

A case study of liquefaction: demonstrating the application of an advanced model and understanding the pitfalls of the simplified procedure

The complexity of advanced constitutive models often dictates that their capabilities are only demonstrated in the context of model testing under controlled conditions. In the case of earthquake engineering and liquefaction in particular, this restriction is magnified by the difficulties in measuring field behaviour under seismic loading. In this paper, the well-documented case of the Canterbury earthquake sequence in New Zealand, for which extensive field and laboratory data are available, is utilised to demonstrate the accuracy of a bounding surface plasticity model in fully coupled finite-element analyses. A strong motion station with manifestation of liquefaction and the second highest peak vertical ground acceleration during the 22 February 2011 Mw6·2 seismic event is modelled. An empirical assessment predicted no liquefaction for this station, making this an interesting case for rigorous numerical modelling. The calibration of the model aims at capturing both the laboratory tests and the field measurements in a consistent manner. The characterisation of the ground conditions is presented, while, to specify the bedrock motion, the records of two stations without liquefaction are de-convolved and scaled to account for wave attenuation with distance. The numerical predictions are compared to both the horizontal and vertical acceleration records and other field observations, showing a remarkable agreement, also demonstrating that the high vertical accelerations can be attributed to compressional resonance. The results provide further insights into the underperformance of the simplified procedure.

Vulnerability assessment of RC buildings to lateral spreading

Large magnitude earthquakes have historically caused devastating damage to engineered structures as a result of permanent ground deformations induced by soil liquefaction (e.g. 1964 Niigata earthquake, 1995 Kobe earthquake, 2010–2011 Christchurch earthquakes). A relevant amount of such damages is directly connected to liquefaction induced lateral spreading. This paper deals with the capacity of concrete framed structures with shallow foundations to handle lateral spreading demands. A simplified force–displacement compatible model was developed to capture the loads on the shallow foundations and estimate the performance of the building. The key parameters of foundation embedment, foundation width and shear length of the pillar, as well as soil friction angle were identified as having a strong influence on the expected performance. The developed model was used to develop probabilistic fragility curves for a class of buildings representing two to five storeys reinforced concrete buildings. Field measurements from existing literature of the liquefaction induced lateral displacement demand from the the September 4, 2010 (Mw 7.1) and the February 22, 2011 (Mw 6.2) Canterbury (New Zealand) earthquakes along the Avon River were probabilistically quantified in relation to the distance from the river. Finally, the displacement demand and fragility curves were used to estimate the probability of exceeding the considered limit states as a function of the distance from the river.

A liquefaction potential integral index based on pore pressure build-up

The increased attention paid to the effects of liquefaction on the built environment has led over time to the introduction of vulnerability integral parameters that somehow quantify for a given site and a given seismic shaking the severity of the potential liquefaction damage induced at ground level. If the vulnerability parameter is properly calibrated and effective, it should somehow correlate to the observed damage datasets, increasing as the severity of liquefaction effects increase.In some cases, as for instance for the Canterbury earthquakes (New Zealand, 2010–2011) and for the 2012 Emilia Romagna seismic sequence, the existing vulnerability parameters for the assessment of liquefaction potential were not able to capture the observed damages induced by liquefaction, highlighting that further progress remains to be made in the current state-of-practice. The potentiality of a new index (Induced dAmage paraMeter- IAM), strictly related to the free-field post-volumetric consolidation settlement and therefore based on the estimate of liquefaction induced excess pore pressure, has been verified for a reference site located in the area struck by the 2012 Emilia seismic sequence by means of simplified and 1D effective stress dynamic analyses. The results were compared with those obtained by using one of the most convincing parameters existing in literature (Liquefaction Severity Number, LSN), showing the robustness of IAM, as well as the possibility to calculate it at different levels of complexity (via either coupled, simplified or super simplified and conservative analyses). The outcomes of the analyses allowed to define a simplified procedure for defining liquefaction microzonation maps, then representing a step forward towards the definition of a sound but easy-to-implement procedure to assess the resilience to liquefaction of urban centres.