The Canterbury earthquakes, which involved widespread damage in the February 2011 event and ongoing aftershocks near the Christchurch central business district (CBD), presented decision-makers with many recovery challenges. This paper identifies major government decisions, challenges, and lessons in the early recovery of Christchurch based on 23 key-informant interviews conducted 15 months after the February 2011 earthquake. It then focuses on one of the most important decisions – maintaining the cordon around the heavily damaged CBD – and investigates its impacts. The cordon displaced 50,000 central city jobs, raised questions about (and provided new opportunities for) the long-term viability of downtown, influenced the number and practice of building demolitions, and affected debris management; despite being associated with substantial losses, the cordon was commonly viewed as necessary, and provided some benefits in facilitating recovery. Management of the cordon poses important lessons for planning for catastrophic urban earthquakes around the world.
This paper develops representative ground motion ensembles for several major earthquake scenarios in New Zealand. Cases considered include representative ground motions for the occurrence of Alpine, Hope, and Porters Pass earthquakes in Christchurch, and the occurrence of Wellington, Wairarapa, and Ohariu, fault ruptures in Wellington. Challenges in the development of ground motion ensembles for subduction zone earthquakes are also highlighted. The ground motions are selected based on the generalized conditional intensity measure (GCIM) approach, ensuring that the ground motion ensembles represent both the mean, and distribution of ground motion intensity which such scenarios could impose. These scenario-based ground motion sets can be used to complement ground motions which are often selected in conjunction with probabilistic seismic hazard analysis, in order to understand the performance of structures for the question “what if this fault ruptures?”
This paper presents a qualitative study with multiple refugee background communities living in Christchurch, New Zealand about their perspectives and responses to the Canterbury earthquakes of 2010-2011 (32 semi-structured interviews and 11 focus group discussions comprising 112 participants). Whilst the Canterbury earthquakes created significant challenges for the entire region, several refugee background communities found multiple ways to effectively respond to such adversity. Central to this response were their experiences of belonging which were comprised of both ‘civic’ and ‘ethno’ conceptualisations. This discussion includes an analysis on the intersectionality of identity to highlight the gendered, contextual and chronological influences that impact people’s perspectives of and responses to a disaster. As the study was conducted over 18 months, the paper discusses how social capital resources and experiences of belonging can help inform urban disaster risk reduction (DRR) with refugee groups. http://3icudr.org/program
Using case studies from the 2010-2011 Canterbury, New Zealand earthquake sequence, this study assesses the accuracies of paleoliquefaction back-analysis methods and explores the challenges, techniques, and uncertainties associated with their application. While liquefaction-based back-analyses have been widely used to estimate the magnitudes of paleoearthquakes, their uncertain efficacies continue to significantly affect the computed seismic hazard in regions where they are relied upon. Accordingly, their performance is evaluated herein using liquefaction data from modern earthquakes with known magnitudes. It is shown that when the earthquake source location and mechanism are known, back-analysis methods are capable of accurately deriving seismic parameters from liquefaction evidence. However, because the source location and mechanism are often unknown in paleoseismic studies, and because accurate interpretation is shown to be more difficult in such cases, new analysis techniques are proposed herein. An objective parameter is proposed to geospatially assess the likelihood of any provisional source location, enabling an analyst to more accurately estimate the magnitude of a liquefaction-inducing paleoearthquake. This study demonstrates the application of back-analysis methods, provides insight into their potential accuracies, and provides a framework for performing paleoliquefaction analyses worldwide.
This paper presents the preliminary findings of a study on the resilience and recovery of organisations following the Darfield earthquake in New Zealand on 4 September 2010. Sampling included organisations proximal and distal to the fault trace, organisations located within central business districts, and organisations from seven diverse industry sectors. The research captured information on the challenges to, the impacts on, and the reflections of the organisations in the first months of recovery. Organisations in central business districts and in the hospitality sector were most likely to close while organisations that had perishable stock and livestock were more heavily reliant on critical services. Staff well-being, cash flow, and customer loss were major concerns for organisations across all sectors. For all organisations, the most helpful factors in mitigating the effects of the earthquake to be their relationship with staff, the design and type of buildings, and critical service continuity or swift reinstatement of services.
Generalized conditional intensity measure (GCIM) method is extended to ground motion selection for scenario ruptures. Using different rupture scenarios and site conditions, various aspects of the GCIM methodology are scrutinized, including: (i) implementation of different weight vectors and the composition of the IM vector; (ii) quantifying the importance of replicate selections for different number of desired ground motions; and (iii) the effect of considering bounds on the implicit causal parameters of the prospective ground motions. Using the extended methodology, representative ground motion ensembles for several major earthquake scenarios in New Zealand are developed. Cases considered include representative ground motions for the occurrence of Alpine, Hope, and Porters Pass earthquakes in Christchurch city, and the occurrence of Wellington, Wairarapa, and Ohariu fault ruptures in Wellington city. Challenges in the development of ground motion ensembles for subduction zone earthquakes are also highlighted. The selected scenario-based ground motion sets can be used to complement ground motions which are often selected in conjunction with probabilistic seismic hazard analysis, in order to understand the performance of structures for the question “what if this fault ruptures?”
Generalized conditional intensity measure (GCIM) method is extended to ground motion selection for scenario ruptures. Using different rupture scenarios and site conditions, various aspects of the GCIM methodology are scrutinized, including: (i) implementation of different weight vectors and the composition of the IM vector; (ii) quantifying the importance of replicate selections for different number of desired ground motions; and (iii) the effect of considering bounds on the implicit causal parameters of the prospective ground motions. Using the extended methodology, representative ground motion ensembles for several major earthquake scenarios in New Zealand are developed. Cases considered include representative ground motions for the occurrence of Alpine, Hope, and Porters Pass earthquakes in Christchurch city, and the occurrence of Wellington, Wairarapa, and Ohariu fault ruptures in Wellington city. Challenges in the development of ground motion ensembles for subduction zone earthquakes are also highlighted. The selected scenario-based ground motion sets can be used to complement ground motions which are often selected in conjunction with probabilistic seismic hazard analysis, in order to understand the performance of structures for the question “what if this fault ruptures?”
Urban Ensembles explores the way in which landscape and architecture can be employed together within the design of a steep, urban site. Lyttelton is a small port town on the border of Christchurch, settled in the foothills of a harbour formed by a major volcanic eruption. This rugged setting, with steeply sloping urban terrain, presents an interesting challenge when designing an urban development. The site was badly damaged in a series of earthquakes in 2010-2011, and many of the town’s oldest buildings, heritage structures dating back to the colonial settlement era, were destroyed. This has left a void in the heart of Lyttelton, and caused the loss of much of the tourism business that the town relies upon for its income. This thesis takes a methodological approach to the design of landscape architecture on such a challenging site. A range of techniques are explored, drawing from both landscape and architecture to explore the roles that each discipline plays in the design of urban spaces. The frequent imbalance between disciplines is addressed both through the literature review and design method, as this landscape architecture thesis draws on architectural design as a tool for generating spaces which fall somewhere in between the two ideals of interior and exterior. The final design proposal is an alternative rebuild plan for the central business area to the south of London St, and also addresses the relationships between that site and the surrounding context, both urban and environmental. The aim of this design is to create a series of interconnected spaces which have a strong relationship to the surrounding harbour setting, and also to facilitate development of the pedestrian spaces throughout the block and encouraging the development of activity at the street level, through the interface between buildings and landscape.
The quality of multi-owned residential buildings and the capability to maintain that quality into the future is important in preserving not only the monetary value of such housing (Lujanen, 2010) but also the quality of life for its residents. The aim of this paper is to examine the governance and decision-making rules and regulations as they relate to the undertaking of major repairs in multi-owned residential buildings in Finland and New Zealand with particular regard to the Finnish Limited Liability Housing Companies Act 2010 (LLHCA 2010) and the New Zealand Unit Titles Act 2010 (UTA 2010). Currently, major building repairs are topical issues in both countries; in Finland as a result of ageing buildings requiring major re-fitting of pipes and other infrastructure, and in New Zealand as a result of earthquake damage in Christchurch and Leaky Building Syndrome nationwide. Major repairs can be a significant financial burden to unit owners and collective decisions can be difficult to achieve. Interestingly, new legislation that governs multi-owned housing was enacted in both countries in 2010. The recent enactment of this legislation provides an opportunity to examine the UTA 2010 and LLHCA 2010 with regard to how they address major repairs, improvements in housing stock and the financing possibilities associated with these undertakings. More specifically this paper explores housing intensification (i.e. building up, out or alongside existing multi-owned residential buildings on commonly owned land) as a means of financing major repairs. The comparison of governance and decision-making in two different shared ownership systems with different histories and cultural contexts provides a chance to explore the possibilities and challenges that each country faces, and the potential to learn from each other’s practices and develop these further. In this regard the findings from this paper contribute to the academic literature (Bugden 2005; Easthope & Randolph 2009; Dupuis & Dixon 2010; Lujanen 2010; Easthope, Hudson & Randolph 2013) concerning to the governance of multi-owned housing as it relates to intensive housing development and its wider social and economic implications.
Following the 2010-2011 earthquakes in Canterbury, New Zealand, the University of Canterbury (UC) was faced with the need to respond to major challenges in its teaching and learning environment. With the recognition of education as a key component to the recovery of the Canterbury region, UC developed a plan for the transformation and renewal of the campus. Central to this renewal is human capital – graduates who are distinctly resilient and broadly skilled, owing in part to their living and rebuilding through a disaster. Six desired graduate attributes have been articulated through this process: knowledge and skills of a recognized subject, critical thinking skills, the ability to interpret information from a range of sources, the ability to self-direct learning, cultural competence, and the recognition of global connections through social, ethical, and environmental values. All of these attributes may readily be identified in undergraduate geoscience field education and graduate field-based studies, and this is particularly important to highlight in a climate where the logistical and financial requirements of fieldwork are becoming a barrier to its inclusion in undergraduate curricula. Fieldwork develops discipline-specific knowledge and skills and fosters independent and critical thought. It encourages students to recognize and elaborate upon relevant information, plan ways to solve complicated problems, execute and re-evaluate these plans. These decisions are largely made by the learners, who often direct their own field experience. The latter two key graduate attributes, cultural competence and global recognition of socio-environmental values, have been explicitly addressed in field education elsewhere and there is potential to do so within the New Zealand context. These concepts are inherent to the sense of place of geoscience undergraduates and are particularly important when the field experience is viewed through the lens of landscape heritage. This work highlights the need to understand how geoscience students interact with field places, with unique implications for their cultural and socio-environmental awareness as global citizens, as well as the influence that field pedagogy has on these factors.
Christchurch was struck by a 6.3 magnitude earthquake on the 22 February 2011. The quake devastated the city, taking lives and causing widespread damage to the inner city and suburban homes. The central city lost over half its buildings and over 7000 homes were condemned throughout Christchurch. The loss of such a great number of homes has created the requirement for new housing to replace those that were lost. Many of which were located in the eastern, less affluent, suburbs. The response to the housing shortage is the planned creation of large scale subdivisions on the outskirts of the city. Whilst this provides the required housing it creates additional sprawl to a city that does not need it. The extension of Christchurch’s existing suburban sprawl puts pressure on roading and pushes residents further out of the city, creating a disconnection between them. Christchurch’s central city had a very small residential population prior to the earthquakes with very few options for dense inner city living. The proposed rebuild of the inner city calls for a new ‘dense, vibrant and diverse central hub’. Proposing the introduction of new residential units within the central city. However the placement of the low-rise housing in a key attribute of the rebuild, the eastern green ‘Frame’, diminishes its value as open green space. The proposed housing will also be restrictive in its target market and therefore the idea of a ‘vibrant’ inner city is difficult to achieve. This thesis acts as response to the planned rebuild of inner Christchurch. Proposing the creation of a model for inner city housing which provides an alternative option to the proposed housing and existing and ongoing suburban sprawl. The design options were explored through a design-led process were the options were critiqued and developed. The ‘final’ proposal is comprises of three tall towers, aptly named the Triple Towers, which condense the proposed low-rise housing from an 11000 square metre footprint to combined footprint of 1500 square metres. The result is an expansion of the publicly available green space along the proposed eastern frame of the city. The height of the project challenges the height restrictions and is provocative in its proposal and placement. The design explores the relationships between the occupants, the building, the ‘Frame’ and the central city. The project is discussed through an exploration of the architecture of Rem Koolhaas, Renzo Piano and Oscar Niemeyer. Rather than their architecture being taken as a direct influence on which the design is based the discussion revolves around how and why each piece of comparative architecture is relevant to the designs desired outcome.
Structural engineering is facing an extraordinarily challenging era. These challenges are driven by the increasing expectations of modern society to provide low-cost, architecturally appealing structures which can withstand large earthquakes. However, being able to avoid collapse in a large earthquake is no longer enough. A building must now be able to withstand a major seismic event with negligible damage so that it is immediately occupiable following such an event. As recent earthquakes have shown, the economic consequences of not achieving this level of performance are not acceptable. Technological solutions for low-damage structural systems are emerging. However, the goal of developing a low-damage building requires improving the performance of both the structural skeleton and the non-structural components. These non-structural components include items such as the claddings, partitions, ceilings and contents. Previous research has shown that damage to such items contributes a disproportionate amount to the overall economic losses in an earthquake. One such non-structural element that has a history of poor performance is the external cladding system, and this forms the focus of this research. Cladding systems are invariably complicated and provide a number of architectural functions. Therefore, it is important than when seeking to improve their seismic performance that these functions are not neglected. The seismic vulnerability of cladding systems are determined in this research through a desktop background study, literature review, and postearthquake reconnaissance survey of their performance in the 2010 – 2011 Canterbury earthquake sequence. This study identified that precast concrete claddings present a significant life-safety risk to pedestrians, and that the effect they have upon the primary structure is not well understood. The main objective of this research is consequently to better understand the performance of precast concrete cladding systems in earthquakes. This is achieved through an experimental campaign and numerical modelling of a range of precast concrete cladding systems. The experimental campaign consists of uni-directional, quasi static cyclic earthquake simulation on a test frame which represents a single-storey, single-bay portion of a reinforced concrete building. The test frame is clad with various precast concrete cladding panel configurations. A major focus is placed upon the influence the connection between the cladding panel and structural frame has upon seismic performance. A combination of experimental component testing, finite element modelling and analytical derivation is used to develop cladding models of the cladding systems investigated. The cyclic responses of the models are compared with the experimental data to evaluate their accuracy and validity. The comparison shows that the cladding models developed provide an excellent representation of real-world cladding behaviour. The cladding models are subsequently applied to a ten-storey case-study building. The expected seismic performance is examined with and without the cladding taken into consideration. The numerical analyses of the case-study building include modal analyses, nonlinear adaptive pushover analyses, and non-linear dynamic seismic response (time history) analyses to different levels of seismic hazard. The clad frame models are compared to the bare frame model to investigate the effect the cladding has upon the structural behaviour. Both the structural performance and cladding performance are also assessed using qualitative damage states. The results show a poor performance of precast concrete cladding systems is expected when traditional connection typologies are used. This result confirms the misalignment of structural and cladding damage observed in recent earthquake events. Consequently, this research explores the potential of an innovative cladding connection. The outcomes from this research shows that the innovative cladding connection proposed here is able to achieve low-damage performance whilst also being cost comparable to a traditional cladding connection. It is also theoretically possible that the connection can provide a positive value to the seismic performance of the structure by adding addition strength, stiffness and damping. Finally, the losses associated with both the traditional and innovative cladding systems are compared in terms of tangible outcomes, namely: repair costs, repair time and casualties. The results confirm that the use of innovative cladding technology can substantially reduce the overall losses that result from cladding damage.
