Perimeter Moment resisting steel frames (PMRSFs) are a commonly used seismic resisting system, placed around the perimeter of the building for maximum torsional stiffness. They are typically designed as “strong column weak beam” systems with fixed column bases. When subjected to severe earthquake demand, sufficient to push the beams into the inelastic range, it is expected that plastic hinging at the column bases will occur. However, the response of PMRSF systems to the severe 2010/2011 Christchurch earthquake series did not generate column base hinging in systems which exhibited beam yielding.
Unrestrained unreinforced clay brick masonry (URM) parapets are found atop a large number of vintage URM buildings. Parapets are typically non-structural cantilevered wall elements that form a fire barrier and in most cases form decorative and ornamental features of vintage URM buildings. Parapets are considered to be one of the most vulnerable elements that are prone to out-of-plane collapse when subjected to earthquake induced shaking. An in-depth analysis of the damage database collected following the 2010/2011 Canterbury earthquakes was performed to obtain information about the distribution, characteristics and observed performance of both the as-built and retrofitted parapets in the Christchurch region. Results, statistical interpretation and implications are presented herein. http://www.aees.org.au/downloads/conference-papers/2015-2/
Description: Observations of RC building performance in recent earthquakes with a special focus on the devastating events in Christchurch, New Zealand. These events have highlighted the complexity of post-earthquake decisions for damaged buildings and the impacts on communities. The presentation will reflect on factors influencing demolition decisions and emerging challenges for the earthquake engineering community. http://atc-sei.org/
The Canterbury earthquakes in New Zealand caused significant damage to a number of reinforced concrete (RC) walls and subsequent research that has been conducted to investigate the design provisions for lightly reinforced RC walls and precast concrete wall connection details is presented. A combination of numerical modelling and large-scale tests were conducted to investigate the seismic behaviour of lightly RC walls. The model and test results confirmed the observed behaviour of an RC wall building in Christchurch that exhibited a single flexural crack and also raised questions regarding the ability of current minimum reinforcement requirements to prevent the concentration of inelastic deformation at a small number of flexural cracks. These findings have led to changes to the minimum vertical reinforcement limits for RC walls in in the Concrete Structures Standard (NZS 3101:2006), with increased vertical reinforcement required in the end region of ductile RC walls. An additional series of wall tests were conducted to investigate the seismic behaviour of panel-to-foundation connections in singly reinforced precast concrete panels that often lack robustness. Both in-plane and out-of-plane panel tests were conducted to assess both grouted connections and dowel connections that use shallow embedded inserts. The initial test results have confirmed some of the previously identified vulnerabilities and tests are ongoing to refine the connection designs. http://www.aees.org.au/downloads/conference-papers/2015-2/
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The Canterbury earthquakes of 2010-2012 have been generation shaping. People living and working in and around the city during this time have had their lives and social landscapes changed forever. The earthquake response, recovery and rebuild efforts have highlighted unheralded social strengths and vulnerabilities within individuals, organisations, communities and country writ large. It is imperative that the social sciences stand up to be counted amongst the myriad of academic research, commentary and analysis.
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During the recent devastating earthquakes in Christchurch, many residential houses were damaged due to widespread liquefaction of the ground. In-situ testing is widely used as a convenient method for evaluating liquefaction potential of soils. Cone penetration test (CPT) and standard penetration test (SPT) are the two popular in situ tests which are widely used in New Zealand for site characterization. The Screw Driving Sounding (SDS) method is a relatively new operating system developed in Japan consisting of a machine that drills a rod into the ground by applying torque at seven steps of axial loading. This machine can continuously measure the required torque, load, speed of penetration and rod friction during the test, and therefore can give a clear overview of the soil profile along the depth of penetration. In this paper, based on a number of SDS tests conducted in Christchurch, a correlation was developed between tip resistance of CPT test and SDS parameters for layers consisting of different fines contents. Moreover, using the obtained correlation, a chart was proposed which relates the cyclic resistance ratio to the appropriate SDS parameter. Using the proposed chart, liquefaction potential of soil can be estimated directly using SDS data. As SDS method is simpler, faster and more economical test than CPT and SPT, it can be a reliable alternative in-situ test for soil characterization, especially in residential house constructions.
This paper explores the responses by a group of children to an art project that was undertaken by a small school in New Zealand after the September 2010 and February 2011 Christchurch earthquakes. Undertaken over a period of two years, the project aimed to find a suitable form of memorialising this significant event in a way that was appropriate and meaningful to the community. Alongside images that related directly to the event of the earthquakes, the art form of a mosaic was chosen, and consisted of images and symbols that clearly drew on the hopes and dreams of a school community who were refusing to be defined by the disaster. The paper 'writes' the mosaic by placing fragments of speech spoken by the children involved in relation to ideas about memory, affect, and the 'sublime', through the work of Jean-Francois Lyotard. The paper explores the mosaic as constituted by the literal and metaphorical 'broken pieces' of the city of Christchurch in ways that confer pedagogic value inscribed through the creation of a public art space by children. AM - Accepted Manuscript
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There is very little research on total house strength that includes contributions of non-structural elements. This testing programme provides inclusive stiffness and response data for five houses of varying ages. These light timber framed houses in Christchurch, New Zealand had minor earthquake damage from the 2011 earthquakes and were lateral load tested on site to determine their strength and/or stiffness, and to identify damage thresholds. Dynamic characteristics including natural periods, which ranged from 0.14 to 0.29s were also investigated. Two houses were quasi-statically loaded up to approximately 130kN above the foundation in one direction. Another unidirectional test was undertaken on a slab-on-grade two-storey house, which was also snapback tested. Two other houses were tested using cyclic quasi-static loading, and between cycles snapback tests were undertaken to identify the natural period of each house, including foundation and damage effects. A more detailed dynamic analysis on one of the houses provided important information on seismic safety levels of post-quake houses with respect to different hazard levels in the Christchurch area. While compared to New Zealand Building Standards all tested houses had an excess of strength, damage is a significant consideration in earthquake resilience and was observed in all of the houses. http://www.aees.org.au/downloads/conference-papers/2015-2/
The role of belonging in post-disaster environments remains an under-theorised concept, particularly regarding refugee populations. This paper presents a qualitative study with 101 refugee-background participants from varying communities living in Christchurch, New Zealand, about their perspectives and responses to the Canterbury earthquakes of 2010–11. Participants spoke of how a sense of belonging as individuals and as a wider community was important in the recovery effort, and highlighted the multiple ways in which they understood this concept. Their comments demonstrate how belonging can have contextual, chronological and gendered dimensions that can help inform effective and resonant disaster responses with culturally and linguistically diverse populations. This analysis also illustrates how the participants' perspectives of belonging shifted over time, and discusses the corresponding role of social work in supporting post-disaster recovery through the concepts of civic, ethno and ethnic-based belonging. AM - Accepted Manuscript
The objective of the study presented herein is to assess three commonly used CPT-based liquefaction evaluation procedures and three liquefaction severity index frameworks using data from the 2010–2011 Canterbury earthquake sequence. Specifically, post-event field observations, ground motion recordings, and results from a recently completed extensive geotechnical site investigation programme at selected strong motion stations (SMSs) in the city of Christchurch and surrounding towns are used herein. Unlike similar studies that used data from free-field sites, accelerogram characteristics at the SMS locations can be used to assess the performance of liquefaction evaluation procedures prior to their use in the computation of surficial manifestation severity indices. Results from this study indicate that for cases with evidence of liquefaction triggering in the accelerograms, the majority of liquefaction evaluation procedures yielded correct predictions, regardless of whether surficial manifestation of liquefaction was evident or not. For cases with no evidence of liquefaction in the accelerograms (and no observed surficial evidence of liquefaction triggering), the majority of liquefaction evaluation procedures predicted liquefaction was triggered. When all cases are used to assess the performance of liquefaction severity index frameworks, a poor correlation is shown between the observed severity of liquefaction surface manifestation and the calculated severity indices. However, only using those cases where the liquefaction evaluation procedures yielded correct predictions, there is an improvement in the correlation, with the Liquefaction Severity Number (LSN) being the best performing of the frameworks investigated herein. However scatter in the relationship between the observed and calculated surficial manifestation still remains for all liquefaction severity index frameworks.
The Canterbury region experienced widespread damage due to liquefaction induced by seismic shaking during the 4 September 2010 earthquake and the large aftershocks that followed, notably those that occurred on 22 February, 13 June and 23 December 2011. Following the 2010 earthquake, the Earthquake Commission directed a thorough investigation of the ground profile in Christchurch, and to date, more than 7500 cone penetration tests (CPT) have been performed in the region. This paper presents the results of analyses which use a subset of the geotechnical database to evaluate the liquefaction process as well as the re-liquefaction that occurred following some of the major events in Christchurch. First, the applicability of existing CPT-based methods for evaluating liquefaction potential of Christchurch soils was investigated using three methods currently available. Next, the results of liquefaction potential evaluation were compared with the severity of observed damage, categorised in terms of the land damage grade developed from Tonkin & Taylor property inspections as well as from observed severity of liquefaction from aerial photography. For this purpose, the Liquefaction Potential Index (LPI) was used to represent the damage potential at each site. In addition, a comparison of the CPT-based strength profiles obtained before each of the major aftershocks was performed. The results suggest that the analysis of spatial and temporal variations of strength profiles gives a clear indication of the resulting liquefaction and re-liquefaction observed in Christchurch. The comparison of a limited number of CPT strength profiles before and after the earthquakes seems to indicate that no noticeable strengthening has occurred in Christchurch, making the area vulnerable to liquefaction induced land damage in future large-scale earthquakes.
This article argues that teachers deserve more recognition for their roles as first responders in the immediate aftermath of a disaster and for the significant role they play in supporting students and their families through post-disaster recovery. The data are drawn from a larger study, 'Christchurch Schools Tell Their Earthquake Stories' funded by the United Nations Educational, Scientific and Cultural Organisation and the University of Auckland, in which schools were invited to record their earthquake stories for themselves and for historical archives. Data were gathered from five primary schools between 2012 and 2014. Methods concerned mainly semi-structured individual or group interviews and which were analysed thematically. The approach was sensitive, flexible and participatory with each school being able to choose its focus, participants and outcome. Participants from each school generally included the principal and a selection of teachers, students and parents. In this study, the data relating to the roles of teachers were separated out for closer analysis. The findings are presented as four themes: immediate response; returning to (new) normal; care and support; and long term effects.
Churches are an important part of New Zealand's historical and architectural heritage. Various earthquakes around the world have highlighted the significant seismic vulnerability of religious buildings, with the extensive damage that occurred to stone and clay-brick unreinforced masonry churches after the 2010-2011 Canterbury earthquakes emphasising the necessity to better understand this structural type. Consequently, a country-wide inventory of unreinforced masonry churches is here identified. After a bibliographic and archival investigation, and a 10 000 km field trip, it is estimated that currently 297 unreinforced masonry churches are present throughout New Zealand, excluding 12 churches demolished in Christchurch because of heavy damage sustained during the Canterbury earthquake sequence. The compiled database includes general information about the buildings, their architectural features and structural characteristics, and any architectural and structural transformations that have occurred in the past. Statistics about the occurrence of each feature are provided and preliminary interpretations of their role on seismic vulnerability are discussed. The list of identified churches is reported in annexes, supporting their identification and providing their address.
Following a damaging earthquake, the immediate emergency response is focused on individual collapsed buildings or other "hotspots" rather than the overall state of damage. This lack of attention to the global damage condition of the affected region can lead to the reporting of misinformation and generate confusion, causing difficulties when attempting to determine the level of postdisaster resources required. A pre-planned building damage survey based on the transect method is recommended as a simple tool to generate an estimate of the overall level of building damage in a city or region. A methodology for such a transect survey is suggested, and an example of a similar survey conducted in Christchurch, New Zealand, following the 22 February 2011 earthquake is presented. The transect was found to give suitably accurate estimates of building damage at a time when information was keenly sought by government authorities and the general public. VoR - Version of Record
The Sendai Framework for Disaster Risk Reduction 2015-2030 finds that, despite progress in disaster risk reduction over the last decade “evidence indicates that exposure of persons and assets in all countries has increased faster than vulnerability has decreased, thus generating new risk and a steady rise in disaster losses” (p.4, UNISDR 2015). Fostering cooperation among relevant stakeholders and policy makers to “facilitate a science-policy interface for effective decisionmaking in disaster risk management” is required to achieve two priority areas for action, understanding disaster risk and enhancing disaster preparedness (p. 13, p. 23, UNISDR 2015). In other topic areas, the term science-policy interface is used interchangeably with the term boundary organisation. Both terms are usually used refer to systematic collaborative arrangements used to manage the intersection, or boundary, between science and policy domains, with the aim of facilitating the joint construction of knowledge to inform decision-making. Informed by complexity theory, and a constructivist focus on the functions and processes that minimize inevitable tensions between domains, this conceptual framework has become well established in fields where large complex issues have significant economic and political consequences, including environmental management, biodiversity, sustainable development, climate change and public health. To date, however, there has been little application of this framework in the disaster risk reduction field. In this doctoral project the boundary management framework informs an analysis of the research response to the 2010-2011 Canterbury Earthquake Sequence, focusing on the coordination role of New Zealand’s national Natural Hazards Research Platform. The project has two aims. It uses this framework to tell the nuanced story of the way this research coordination role evolved in response to both the complexity of the unfolding post-disaster environment, and to national policy and research developments. Lessons are drawn from this analysis for those planning and implementing arrangements across the science-policy boundary to manage research support for disaster risk reduction decision-making, particularly after disasters. The second aim is to use this case study to test the utility of the boundary management framework in the disaster risk reduction context. This requires that terminology and concepts are explained and translated in terms that make this analysis as accessible as possible across the disciplines, domains and sectors involved in disaster risk reduction. Key findings are that the focus on balance, both within organisations, and between organisations and domains, and the emphasis on systemic effects, patterns and trends, offer an effective and productive alternative to the more traditional focus on individual or organisational performance. Lessons are drawn concerning the application of this framework when planning and implementing boundary organisations in the hazard and disaster risk management context.
Improving community resilience requires a way of thinking about the nature of a community. Two complementary aspects are proposed: the flows connecting the community with its surrounding environment and the resources the community needs for its ongoing life. The body of necessary resources is complex, with many interactions between its elements. A systems approach is required to understand the issues adequately. Community resilience is discussed in general terms together with strategies for improving it. The ideas are then illustrated and amplified by an extended case study addressing means of improving the resilience of a community on the West Coast of New Zealand to natural disasters. The case study is in two phases. The first relies on a mix of on-the-ground observations and constructed scenarios to provide recommendations for enhancing community resilience, while the second complements the first by developing a set of general lessons and issues to be addressed from observations of the Christchurch earthquakes of 2010 and 2011.
The sequence of earthquakes that has affected Christchurch and Canterbury since September 2010 has caused damage to a great number of buildings of all construction types. Following post-event damage surveys performed between April 2011 and June 2011, an inventory of the stone masonry buildings in Christchurch and surrounding areas was carried out in order to assemble a database containing the characteristic features of the building stock, as a basis for studying the vulnerability factors that might have influenced the seismic performance of the stone masonry building stock during the Canterbury earthquake sequence. The damage suffered by unreinforced stone masonry buildings is reported and different types of observed failures are described using a specific survey procedure currently in use in Italy. The observed performance of seismic retrofit interventions applied to stone masonry buildings is also described, as an understanding of the seismic response of these interventions is of fundamental importance for assessing the utility of such strengthening techniques when applied to unreinforced stone masonry structures. AM - Accepted Manuscript
Recent earthquakes have shown that liquefaction and associated ground deformations are major geotechnical hazards to civil engineering infrastructures, such as pipelines. In particular, sewer pipes have been damaged in many areas in Christchurch as a result of liquefaction-induced lateral spreading near waterways and ground oscillation induced by seismic shaking. In this paper, the addition of a flexible AM liner as a potential countermeasure to increase sewer pipe capacity was investigated. Physical testing through 4-point loading test was undertaken to characterise material properties and the response of both unlined pipe and its lined counterpart. Next, numerical models were created using SAP2000 and ABAQUS to analyse buried pipeline response to transverse permanent ground displacement and to quantify, over a range of pipe segment lengths and soil parameters, the effectiveness of the AM liner in increasing displacement capacity. The numerical results suggest that the addition of the AM liner increases the deformation capacity of the unlined sewer pipe by as much as 50 times. The results confirmed that AM liner is an effective countermeasure for sewer pipes in liquefied ground not only in terms of increased deformation capacity but also the fact that AM-Liner can prevent influx of sand and water through broken pipes, making sewer pipes with liner remaining serviceable even under severe liquefaction condition.
The empirical liquefaction triggering chart of Idriss and Boulanger (2008) is compared to direct measurements of the cyclic resistance of Christchurch silty sands via undisturbed and reconstituted lab specimens. Comparisons suggest that overall there is a reasonable agreement between the empirical triggering curve and the interpreted test data. However, the influence of fines on cyclic resistance appears to be over-predicted by the empirical method, particularly for non-plastic silty sands that are commonly encountered in flood over-bank deposits in Christchurch and nearby settlements
This literature review uses research informed by disasters including the Christchurch Earthquakes, Hurricane Katrina, Red River floods, War in Israel and natural disasters in Indonesia to identify key aspects within teacher-student relationships which result in an increase in the emotional stability of our students. These aspects include prior knowledge of students and their development, psycho-social interventions and incorporation of the disaster into the curriculum. Teacher-student relationships are highlighted as vital to a child’s healing and resilience after experiencing disaster trauma.
Following the 2010–2011 Canterbury earthquakes, a renewed focus has been directed across New Zealand to the hazard posed by the country‘s earthquake-vulnerable buildings, namely unreinforced masonry (URM) and reinforced concrete (RC) buildings with potentially nonductile components that have historically performed poorly in large earthquakes. The research reported herein was pursued with the intention of addressing several recommendations made by the Canterbury Earthquakes Royal Commission of Inquiry which were classified into the following general categories: Identification and provisional vulnerability assessment of URM and RC buildings and building components; Testing, assessment, and retrofitting of URM walls loaded out-of-plane, with a particular focus on highly vulnerable URM cavity walls; Testing and assessment of RC frame components, especially those with presumably non-ductile reinforcement detailing; Portfolio management considering risks, regulations, and potential costs for a portfolio that includes several potentially earthquake-vulnerable buildings; and Ongoing investigations and proposed research needs. While the findings from the reported research have implications for seismic assessments of buildings across New Zealand and elsewhere, an emphasis was placed on Auckland given this research program‘s partnership with the Auckland Council, the Auckland region accounting for about a third each of the country‘s population and economic production, and the number and variety of buildings within the Auckland building stock. An additional evaluation of a historic building stock was carried out for select buildings located in Hawke‘s Bay, and additional experimental testing was carried out for select buildings located in Hawke‘s Bay and Christchurch.
In this paper we outline the process and outcomes of a multi-agency, multi-sector research collaboration, led by the Canterbury Earthquake Research Authority (CERA). The CERA Wellbeing Survey (CWS) is a serial, cross-sectional survey that is to be repeated six-monthly (in April and September) until the end of the CERA Act, in April 2016. The survey gathers self-reported wellbeing data to supplement the monitoring of the social recovery undertaken through CERA's Canterbury Wellbeing Index. Thereby informing a range of relevant agency decision-making, the CWS was also intended to provide the community and other sectors with a broad indication of how the population is tracking in the recovery. The primary objective was to ensure that decision-making was appropriately informed, with the concurrent aim of compiling a robust dataset that is of value to future researchers, and to the wider, global hazard and disaster research endeavor. The paper begins with an outline of both the Canterbury earthquake sequence, and the research context informing this collaborative project, before reporting on the methodology and significant results to date. It concludes with a discussion of both the survey results, and the collaborative process through which it was developed.
On 22 February 2011, the second day of the first semester, a devastating magnitude 6.2 earthquake struck the city of Christchurch forcing the campus of the University of Canterbury to close for several weeks. Here, we report on the sudden curriculum and assessment overhaul that needed to be implemented using two large, first-year introductory courses as case studies. We discuss the reasoning and justifications behind these changes, as well as the logistics of this process. We draw conclusions based on student feedback and assessments and formulate lessons learnt.
There is a now a rich literature on the connections between digital media, networked computing, and the shaping of urban material cultures. Much less has addressed the post-disaster context, like we face in Christchurch, where it is more a case of re-build rather than re-new. In what follows I suggest that Lev Manovich’s well-known distinction between narrative and database as distinct but related cultural forms is a useful framework for thinking about the Christchurch rebuild, and perhaps urbanism more generally.
