Christchurch earthquake events have raised questions on the adequacy of performance-based provisions in the current national building code. At present, in the building code the performance objectives are expressed in terms of safety and health criteria that could affect building occupants. In general, under the high intensity Christchurch events, buildings performed well in terms of life-safety (with a few exceptions) and it proved that the design practices adopted for those buildings could meet the performance objectives set by the building code. However, the damage incurred in those buildings resulted in unacceptably high economic loss. It is timely and necessary to revisit the objectives towards building performance in the building code and to include provisions for reducing economic implications in addition to the current requirements. Based on the observed performance of some buildings, a few specific issues in the current design practices that could have contributed to extensive damage have been identified and recommended for further research leading towards improved performance of structures. In particular, efforts towards innovative design/construction solutions with low-damage concepts are encouraged. New Zealand has been one of the leading countries in developing many innovative technologies. However, such technically advanced research findings usually face challenges towards implementation. Some of the reasons include: (i) lack of policy requirements; (iii) absence of demonstrated performance of new innovations to convince stakeholders; and (iv) non-existence of design guidelines. Such barriers significantly affect implementation of low damage construction and possible strategies to overcome those issues are discussed in this paper.
Earthquakes rupture not only the objective realm of the physical landscape, but also the subjective landscape of emotions. Using the concepts of topophilia and topophobia developed by Yi-Fu Tuan as theories of love and fear of place, this paper investigates the impact of
Christchurch’s earthquakes of 2010 and 2011 on relationships with the city’s landscape.
Published accounts of the earthquakes in newspapers from around New Zealand are examined for evidence of how people responded to the situation, in particular their shifting relationship with familiar landscapes. The reports illustrate how residents and visitors reacted to the actual
and perceived changes to their surroundings, grappling with how a familiar place had become alien and often startling. The extreme nature of the event and the death toll of 185 heightened perceptions of the landscape, and even the most taken-for-granted elements of the landscape became amplified in significance. Enhanced understanding of the landscape of emotions is a vital component of wellbeing. Through recognising that the impact of disasters and perceived threats to familiar places has a profound emotional effect, the significance of sense of place to wellbeing can be appreciated.
The objective of this study is to examine the influence of near-fault motions on liquefaction triggering in Christchurch and neighboring towns during the 2010-2011 Canterbury earthquake sequence (CES). The CES began with the 4 September 2010, Mw7.1 Darfield earthquake and included up to ten events that triggered liquefaction. However, most notably, widespread liquefaction was induced by the Darfield earthquake and the Mw6.2, 22 February 2011 Christchurch earthquake. Of particular relevance to this study is the forward directivity effects that were prevalent in the motions recorded during the Darfield earthquake, and to a much lesser extent, during the Christchurch earthquake. A 2D variant of the Richart-Newmark fatigue theory was used to compute the equivalent number of cycles (neq) for the ground motions, where volumetric strain was used as the damage metric. This study is unique because it considers the contribution and phasing of both the fault-normal and fault-parallel components of motion on neq and the magnitude scaling factor (MSF). It was found that when the fault-normal and fault-parallel motions were treated individually, the former yielded a lower neq than the latter. Additionally, when the combined effects of fault-normal and fault-parallel components were considered, it was found that the MSF were higher than those commonly used. This implies that motions containing near-fault effects are less demanding on the soil than motions that do not. This may be one of several factors that resulted in less severe liquefaction occurring during the Darfield earthquake than the Christchurch earthquake.
In 2010 Neil Challenger, Head of the School of Landscape Architecture at Lincoln University, stated that the malls surrounding Christchurch drove the life out of the inner city of Christchurch. His economic and sociological concerns were expressed even before the earthquake occurred, and this forms the current hesitation on the rebuilding of Christchurch’s inner city. The position of this research proposal is to establish whether an urban architectural intervention can address these economic and sociological concerns and the potentially devastating effects the suburban mall has had on urban life within Christchurch. The thesis specifically asks whether establishing a mall typology as a landmark building within the inner city can strategically engage the damaged historic buildings of post-earthquake Christchurch in ways that actively preserve these historic remnants. The main intention of this research is to engage the damaged historic buildings of post-earthquake Christchurch in ways that actively preserve these remnants and are also economically viable. By preserving the remnants as active, working elements of the urban fabric, they act as historic reminders or memorials of the event and associated loss, while also actively participating in the regrowth of the city. The thesis argues that contemporary architecture can play a strategic role in these imperatives. Overall this research argues that there exists a distinct requirement for large-scale retail in the inner city urban environment that recognises and responds to the damaged cultural and historic architecture of inner city Christchurch. The objective of the thesis is to propose means to rejuvenate not only the economic vitality of central Christchurch,but also its historic character.
The Mѡ=7.1 Darfield (Canterbury) earthquake struck on 4 September 2010, approximately 45 km west of Christchurch, New Zealand. It revealed a previously unknown fault (the Greendale fault) and caused billions of dollars of damage due to high peak ground velocities and extensive liquefaction. It also triggered the Mw=6.3 Christchurch earthquake on 22 February 2011, which caused further damage and the loss of 185 lives. The objective of this research was to determine the relationship between stress and seismic properties in a seismically active region using manually-picked P and S wave arrival times from the aftershock sequence between 8 September 2010-13 January 2011 to estimate shear-wave splitting (SWS) parameters, VP =VS-ratios, anisotropy (delay-time tomography), focal mechanisms, and tectonic stress on the Canterbury plains. The maximum horizontal stress direction was highly consistent in the plains, with an average value of SHmax=116 18 . However, the estimates showed variation in SHmax near the fault, with one estimate rotating by as much as 30° counter-clockwise. This suggests heterogeneity of stress at the fault, though the cause remains unclear. Orientations of the principal stresses predominantly indicate a strike-slip regime, but there are possible thrust regimes to the west and north/east of the fault. The SWS fast directions (ø) on the plains show alignment with SHmax at the majority of stations, indicating stress controlled anisotropy. However, structural effects appear more dominant in the neighbouring regions of the Southern Alps and Banks Peninsula.
The aim of this thesis was to examine the spatial and the temporal patterns of anxiety and chest pain resulting from the Canterbury, New Zealand earthquaeks. Three research objectives were identified: examine any spatial or termporal clusters of anxiety and chest pain; examine the associations between anxiety, chest pain and damage to neighbourhood; and determine any statistically significant difference in counts of anxiety and chest pain after each earthquake or aftershock which resulted in severe damage. Measures of the extent of liquefaction the location of CERA red-zones were used as proxy measures for earthquake damage. Cases of those who presented to Christchurch Public Hospital Emergency Department with either anxiety or chest pain between May 2010 and April 2012 were aggregated to census area unit (CAU) level for analysis. This thesis has taken a unique approach to examining the spatial and spatio-temporal variations of anxiety and chest pain after an earthquake and offers unique results. This is the first study of its kind to use a GIS approach when examining Canterbury specific earthquake damage and health variables at a CAU level after the earthquakes. Through the use of spatio-termporal scan modelling, negative and linear regression modelling and temporal linear modelling with dummy variables this research was able to conclude there are significant spatial and temporal variations in anxiety and chest pain resulting from the earthquakes. The spatio-termporal scan modelling identified a hot cluster of both anxiety and chest pain within Christchurch at the same time the earthquakes occurred. The negative binomial model found liquefaction to be a stronger predictor of anxiety than the Canterbury Earthquake Recovery Authority's (CERA) land zones. The linear regression model foun chest pain to be positively associated with all measures of earthquake damage with the exception of being in the red-zone. The temporal modelling identified a significant increase in anxiety cases one month after a major earthquake, and chest pain cases spiked two weeks after an earthquake and gradually decreased over the following five weeks. This research was limited by lack of control period data, limited measures of earthquake damage, ethical restrictions, and the need for population tracking data. The findings of this research will be useful in the planning and allocation of mental wellbeing resources should another similar event like the Canterbury Earthquakes occur in New Zealand.
Christchurch has experienced a series of over 13,500 earthquakes between September 2010 and January 2012. Some children who have been exposed to earthquakes may experience post-traumatic stress disorder symptoms (PTSD) including difficulty concentrating, feeling anxious, restlessness and confusion. Other children may be resilient to the effects of disaster. Western models of resilience relate to a child’s social support and their capacity to cope. The Māori model of wellbeing relates to whanau (family), wairua (spiritual connections), tinana (the physical body) and hinengaro (the mind and emotions). Children’s concepts of helping, caring and learning may provide insight into resilience without introducing the topic of earthquakes into the conversation, which in itself may provoke an episode of stress. Many researchers have studied the effects of earthquakes on children. However, few studies have examined positive outcomes and resilience or listened to the children’s voices. The objective of this study was to listen to the voices of children who experienced the Canterbury earthquake period in order to gain a deeper understanding of the ideas associated resilience. Individual interviews were conducted with 17 five-year-old participants during their first term of primary school. After the interviews, the teacher shared demographic information and reports on the children’s stress and coping. Six children were identified as New Zealand European and eleven children identified as New Zealand Māori. Children had different views of helping, caring and learning. Themes of resilience from Western and Kaupapa Māori models were identified in transcripts of the children's voices and drawings. Māori children voiced more themes of resilience associated with the Western model, and in the Tapa Whā model, Māori children's transcripts were more likely to be inclusive of all four components of well-being. How five-year-old children, having experienced an earthquake disaster during their preschool years, talk or draw pictures about helping, caring and learning can provide insight into resilience, especially in situations where it is not advisable to re-traumatise children by discussing the disaster event. Future research should interview parents/caregivers and whānau to gain further insights. Considering information from both a Western and a Tapa Whā perspective can also provide new insights into resilience in young children. A limitation of this study is that qualitative studies are not always free from a researcher’s interpretation and are, therefore, subjective.
