The University of Canterbury has initialized a research program focusing on the seismic sustainability of structures. As part of this program, the relative seismic sustainability of various structures will be assessed to identify those with the highest sustainability for the Christchurch rebuild and general use in New Zealand. This preliminary case study assesses one reinforced concrete (RC) frame structure and one RC wall structure. The scenario loss is evaluated for two earthquake records considering direct losses only in order to explain and illustrate the methodology.
A preliminary case study assessing the seismic sustainability of two reinforced concrete structures, a frame structure and a wall structure, was conducted to determine which structural system is more seismically sustainable. The two structures were designed to the same standards and were assumed to be located in Christchurch, New Zealand. A component-based probabilistic seismic loss assessment, considering direct losses only, was conducted for two ground motion records, regarded to approximately represent a 1 in 500 year earthquake event and a 1 in 2500 year earthquake event, respectively. It is shown that the wall structure results in lower direct losses than the frame structure in the less severe ground motion scenario. However, in the more severe ground motion scenario, the frame structure results in lower direct losses. Hence, this study demonstrates that which structural system has the lower direct losses depends on the ground motion intensity level.
This report reviews the literature on regeneration requirements of main canopy
tree species in Westland. Forests managed for production purposes have to be
harvested in an ecologically sustainable way; to maintain their natural character, harvesting should facilitate regeneration of target species and ensure that their recruitment is in proportion to the extent of extraction. The reasons for species establishing at any point in time are unclear; however, they are probably related to the availability of suitable microsites for establishment, the size of the canopy openings formed by disturbance, and whether or not seeds are available at or around the time of the disturbance. Age structures from
throughout Westland show that extensive, similar-aged, post-earthquake cohorts of trees are a feature of the region. This suggests that infrequent, massive earthquakes are the dominant coarse-scale disturbance agent, triggering episodes of major erosion and sedimentation and leaving a strong imprint in the forest structure. In other forests, flooding and catastrophic
windthrow are major forms of disturbance. The findings suggest that, in general, large disturbances are required for conifer regeneration. This has implications for any sustained yield management of these forests if conifers are to remain an important component. Any harvesting should recognise the importance for tree establishment of: forest floor microsites, such as fallen logs
and tree tip-up mounds; and the variable way in which canopy gaps are formed. Harvesting should maintain the 'patchy' nature of the natural forest—large patches of dense conifers interspersed with more heterogeneous patches of mixed species.This is a client report commissioned by West Coast Conservancy and funded from the Unprogrammed Science Advice fund.
In recent Canterbury earthquakes, structures have performed well in terms of life safety but the estimated total cost of the rebuild was as high as $40 billion. The major contributors to this cost are repair/demolition/rebuild cost, the resulting downtime and business interruption. For this reason, the authors are exploring alternate building systems that can minimize the downtime and business interruption due to building damage in an earthquake; thereby greatly reducing the financial implications of seismic events. In this paper, a sustainable and demountable precast reinforced concrete (RC) frame system in which the precast members are connected via steel tubes/plates or steel angles/plates and high strength friction grip (HSFG) bolts is introduced. In the proposed system, damaged structural elements in seismic frames can be easily replaced with new ones; thereby making it an easily and quickly repairable and a low-loss system. The column to foundation connection in the proposed system can be designed either as fixed or pinned depending on the requirement of strength and stiffness. In a fixed base frame system, ground storey columns will also be damaged along with beams in seismic events, which are to be replaced after seismic events; whereas in a pin base frame only beams (which are easy to replace) will be damaged. Low to medium rise (3-6 storey) precast RC frame buildings with fixed and pin bases are analyzed in this paper; and their lateral capacity, lateral stiffness and natural period are scrutinized to better understand the pros and cons of the demountable precast frame system with fixed and pin base connections.
Purpose - The purpose of this paper is to identify through the application of Actor Network Theory (ANT) the issues and impediments to the implementation of mandatory seismic retrofitting policies proposed by the New Zealand Government. In particular the tension between the heritage protection objectives contained in the Resource Management Act 1991 and the earthquake mitigation measures contained in the Building Act 2004 are examined.
Design/methodology/approach - The paper uses a case study approach based on the Harcourts Building in Wellington New Zealand and the case law relating to attempts to demolish this particular building. Use is made of ANT as a 'lens' to identify and study the controversies around mandatory seismic retrofitting of heritage buildings. The concept of translation is used to draw network diagrams.
The NMIT Arts & Media Building is the first in a new generation of multistorey timber structures. It employs an advanced damage avoidance earthquake design that is a world first for a timber building. Aurecon structural engineers are the first to use this revolutionary Pres-Lam technology developed at the University of Canterbury. This technology marks a fundamental change in design philosophy. Conventional seismic design of multi-storey structures typically depends on member ductility and the acceptance of a certain amount of damage to beams, columns and walls. The NMIT seismic system relies on pairs of coupled LVL shear walls that incorporate high strength steel tendons post-tensioned through a central duct. The walls are centrally fixed allowing them to rock during a seismic event. A series of U-shaped steel plates placed between the walls form a coupling mechanism, and act as dissipators to absorb seismic energy. The design allows the primary structure to remain essentially undamaged while readily replaceable connections act as plastic fuses. In this era where sustainability is becoming a key focus, the extensive use of timber and engineered-wood products such as LVL make use of a natural resource all grown and manufactured within a 100km radius of Nelson. This project demonstrates that there are now cost effective, sustainable and innovative solutions for multi-story timber buildings with potential applications for building owners in seismic areas around the world.
Geographically isolated communities around the world are dependent upon the limited assets in local subsistence economies to generate livelihoods. Locally available resources shape and give identity to unique cultural activities that guarantee individual, family and community livelihood sustainability. The social structure provides community relationship networks, which ensure access to, and availability of, resources over long periods. Resources are utilised in ways that reduces vulnerability, stresses and shocks while ensuring long-term resilience. Preparedness and adaptation are embedded into cultural memory, enabling communities to survive in isolated, remote and harsh conditions. Communities’ cultural memories, storytelling, traditional knowledge, interdependence and unwritten cultural norms that build resilience to sustain cultures that have limited interactions with the outside world.
This thesis aims to investigate the consequences of transport infrastructure development, mainly of roads, on livelihood strategies of isolated communities in a tourism context in Gilgit-Baltistan, Pakistan. The thesis incorporates a review of literature of transport infrastructure development and livelihood security in reference to vulnerability, resilience and sustainability. Research gaps are identified in terms of transport infrastructure development and tourism, the Sustainable Livelihood Approach, resilience and sustainability. The fieldwork was undertaken using qualitative research methods. Ninety-eight participants were interviewed using open-ended semi-structured interview questions to get an in-depth understanding of livelihood systems, livelihood activities and transport infrastructure development within the tourism context.
Gilgit-Baltistan is a disputed mountainous territory in the Asia Subcontinent whose ancient trade routes (silk routes) were severed during the geopolitical upheaval of the partition of the Indian Subcontinent in 1947. An alliance between Pakistan and China resulted in transport infrastructure development of the Karakorum Highway between 1958 and 1978, providing the only road access to the regions isolated communities. Karakoram Highway connects China with Pakistan through Gilgit-Baltistan. Gilgit-Baltistan is going through immense transport infrastructure development, including the China Pakistan Economic Corridor. The road infrastructure is expected to link China and other South Asian and Central Asian countries to the world and provide a direct link for Chinese goods to reach the Persian Gulf. China Pakistan Economic Corridor is part of China’s Belt and Road Initiative project, which aims to improve connectivity and cooperation between 69 Eurasian countries by investing in infrastructure development. Such an immense infrastructural development is expected to enhance the mobility of people, goods and services.
In order to understand the impacts of transport infrastructure development, this thesis has analysed livelihood capital status at macro, and micro levels are examined over two time periods (pre-road and post-road). Results show that sustainable farming practices provided long-term resilience to these geographically isolated communities. Transport infrastructure development has been a significant factor to ensure access and has resulted in changes to social inclusion, socio-political structures and livelihood opportunities with a subsequent dependence upon tourism, imported consumer goods and a monetary economy as people divert valuable farmland to building developments and cash crop monocultures. Gilgit-Baltistan is vulnerable to frequent manmade and natural disasters, such as terrorism, earthquakes and landslides. Shocks impact upon the livelihoods of those affiliated with tourism who are forced to revert to subsistence farming practices and alternative livelihood choices. The dependency on external resources and subsequent loss of the cultural memory and farming techniques has created a vulnerability to the unpredictable shocks and disasters that frequently close the singular access road.
The thesis finally presents the ‘Livelihood Framework for Transport Infrastructure Development and Tourism (LF-TIDT)’ a guiding tool to understand the impacts of transport infrastructure development at micro and macro levels for tourism planning, policy formulation and implementation and management. Attention is drawn to the newly introduced ‘Location: a Meta Capital’ and its importance in terms of geographically isolated communities. The research also highlights that livelihood capitals are not equally essential to achieve sustainable and resilient livelihood outcomes.
Structures of the Lowry Peaks Range - Waikari Valley district are complex. The majority comprise three members of a predominantly WSW -ENE striking major northwards-directed, leading edge imbricate thrust system, with associated angular, asymmetric fault-propagation folds. This system forms anomalously within a large NESW trending belt of structures characterising the entire east coast of north Canterbury, both onshore and offshore and terminates westwards against N-S striking, east facing fold-fault zone. The objectives of this study address the origin, geometry and kinematics of the interaction between these diversely trending systems. Stratigraphy and small-scale structures denote three periods of deformation, namely: i) Middle Cretaceous deformation of the basement rocks, ii) weak Middle Oligocene deformation associated with the inception of the plate boundary through the South Island, and iii) major Pliocene - Recent deformation that formed the majority of the above-mentioned structures. Stress tensor analyses within competent basement and limestone cover rocks suggest two sets of sub-horizontal compression, NE-SW and NW-SE, the former likely to relate to a localised earlier period of deformation, now overprinted by the latter. NW-SE oriented sub-horizontal compression correlates well with results from other parts of north Canterbury. The result of NW-SE compression on the W-E to WSW-ENE striking structures is a large component of oblique motion, which is manifest in four ways: i) movement on two, differently oriented splays rather than a single fault strand, ii) the development of a sinuous trace for a number of the major folds, whereby the ends are oriented normal to the compression direction, the centres parallel to the strike of the faults, iii) the development of a number of cross-folds, striking NNE-SSW and iv) the apparently recent development of a strike-slip component on at least one of the major thrust faults. The origin of the W-E, or WSW-ENE striking structures may be reactivation of Late Cretaceous faults, stratigraphic evidence for the existence of a "structural high" (the Hurunui High) over the majority of the area in the Late Cretaceous to Early Eocene times suggests the formation of a W-E trending horst structure, with a corresponding asymmetric graben to the south. The junction of WSW-ENE trending structures with N-S trending structures to the west centres on an alluvial-filled depression, Waikari Flat, into which the structures of the WSW-ENE trending imbricate thrust system plunge, locally curling to the SW at their ends to link with N-S trending structures to the south. Roof thrusting on two orientations, W-E and N-S, towards to SE is currently occurring above these structures. Currently the area is not highly seismically active, although a magnitude ~6.4 Ms earthquake in historic times has been recorded. The effects of tectonics on the drainage of the area does suggest that the majority of the systems, are still potentially active, albeit moving at a comparatively slow rate. The majority of the recent motion appears to be concentrated on the roof-thrusting occurring in Waikari Flat, and uplift along the Lowry Peaks Fault System. Increasing amounts of secondary movement on back-thrusts and cross fractures is also implied for western ends of the major imbricate thrust system. In contrast, the southern-most fault system appears to be largely sustaining dextral strike-slip motion, with some local folding in central portions.
Group case study report prepared for lecturers Ton Buhrs and Roy Montgomery by students of ERST 635 at Lincoln University, 2013.The New Zealand Government’s decision to establish a unitary authority in the Auckland Region has provided much of the context and impetus for this review of current governance arrangements in the Canterbury region, to determine whether or not they are optimal for taking the communities of greater Christchurch into the future. A number of local governance academics, as well as several respected political pundits, have prophesised that the Auckland ‘Super City’ reforms of 2009 will have serious implications and ramifications for local governance arrangements in other major cities, particularly Wellington and Christchurch. Wellington councils have already responded to the possibility of change by undertaking a series of reports on local governance arrangements, as well as a major review led by Sir Geoffrey Palmer, to investigate options for governance reform. Alongside these developments, the Christchurch earthquakes beginning in September 2010 have raised a myriad of new and complex governance issues, which may or may not be able to be addressed under the status quo, while the replacement of Regional Councillors’ with centrally-appointed Commissioners is suggestive of government dissatisfaction with current arrangements. With these things in mind, the research group has considered local government in Canterbury and the greater Christchurch area in the wider governance context. It does not limit discussion to only the structure of local government in Canterbury but rather, as the brief (Appendix 1) indicates, considers more broadly the relationship between central, regional, and local tiers of government, as well as the relationship between local government and local communities.
The 22 February 2011, Mw6.2-6.3 Christchurch earthquake is the most costly earthquake to affect New Zealand, causing 181 fatalities and severely damaging thousands of residential and commercial buildings, and most of the city lifelines and infrastructure. This manuscript presents an overview of observed geotechnical aspects of this earthquake as well as some of the completed and on-going research investigations. A unique aspect, which is particularly emphasized, is the severity and spatial extent of liquefaction occurring in native soils. Overall, both the spatial extent and severity of liquefaction in the city was greater than in the preceding 4th September 2010 Darfield earthquake, including numerous areas that liquefied in both events. Liquefaction and lateral spreading, variable over both large and short spatial scales, affected commercial structures in the Central Business District (CBD) in a variety of ways including: total and differential settlements and tilting; punching settlements of structures with shallow foundations; differential movements of components of complex structures; and interaction of adjacent structures via common foundation soils. Liquefaction was most severe in residential areas located to the east of the CBD as a result of stronger ground shaking due to the proximity to the causative fault, a high water table approximately 1m from the surface, and soils with composition and states of high susceptibility and potential for liquefaction. Total and differential settlements, and lateral movements, due to liquefaction and lateral spreading is estimated to have severely compromised 15,000 residential structures, the majority of which otherwise sustained only minor to moderate damage directly due to inertial loading from ground shaking. Liquefaction also had a profound effect on lifelines and other infrastructure, particularly bridge structures, and underground services. Minor damage was also observed at flood stop banks to the north of the city, which were more severely impacted in the 4th September 2010 Darfield earthquake. Due to the large high-frequency ground motion in the Port hills numerous rock falls and landslides also occurred, resulting in several fatalities and rendering some residential areas uninhabitable.
As a result of the Christchurch Earthquake that occurred on 22nd February 2011 and the resultant loss of life and widespread damage, a Royal Commission of Enquiry was convened in April 2011. The Royal Commission recommended a number of significant changes to the regulation of earthquake prone building in New Zealand. Earthquake prone buildings are buildings that are deemed to be of insufficient strength to perform adequately in a moderate earthquake. In response to the Royal Commission recommendations the New Zealand Government carried out a consultative process before announcing proposed changes to the building regulations in August 2013. One of the most significant changes is the imposition of mandatory strengthening requirements for earthquake prone buildings on a national basis. This will have a significant impact on the urban fabric of most New Zealand towns and cities. The type of traditional cost benefit study carried out to date fails to measure these impacts and this paper proposes an alternative methodology based on the analysis of land use data and rating valuations. This methodology was developed and applied to a small provincial town in the form of a case study. The results of this case study and the methodology used are discussed in this paper.
Saltwater Forest is a Dacrydium cupressinum-dominated lowland forest covering 9000 ha in south Westland, South Island, New Zealand. Four thousand hectares is managed for sustainable production of indigenous timber. The aim of this study was to provide an integrated analysis of soils, soil-landform relationships, and soil-vegetation relationships at broad and detailed scales. The broad scale understandings provide a framework in which existing or future studies can be placed and the detailed studies elucidate sources of soil and forest variability.
Glacial landforms dominate. They include late Pleistocene lateral, terminal and ablation moraines, and outwash aggradation and degradation terraces. Deposits and landforms from six glacial advances have been recognised ranging from latest Last (Otira) Glaciation to Penultimate (Waimea) Glaciation. The absolute ages of landforms were established by analysis of the thickness and soil stratigraphy of loess coverbeds, augmented with radiocarbon dating and phytolith and pollen analysis.
In the prevailing high rainfall of Westland soil formation is rapid. The rate of loess accretion in Saltwater
Forest (ca. 30 mm ka⁻¹) has been low enough that soil formation and loess accretion took place contemporaneously. Soils formed in this manner are known as upbuilding soils. The significant difference between upbuilding pedogenesis and pedogenesis in a topdown sense into an existing sediment body is that each subsoil increment of an upbuilding soil has experienced processes of all horizons above. In Saltwater Forest subsoils of upbuilding soils are strongly altered because they have experienced the extremely acid environment of the soil surface at some earlier time. Some soil chronosequence studies in Westland have included upbuilding soils formed in loess as the older members of the sequence. Rates and types of processes inferred from these soils should be reviewed because upbuilding is a different pedogenic pathway to topdown pedogenesis.
Landform age and morphology were used as a primary stratification for a study of the soil pattern and nature of soil variability in the 4000 ha production area of Saltwater Forest. The age of landforms (> 14 ka) and rapid soil formation mean that soils are uniformly strongly weathered and leached. Soils include Humic Organic Soils, Perch-gley Podzols, Acid Gley Soils, Allophanic Brown Soils, and Orthic or Pan Podzols. The major influence on the nature of soils is site hydrology which is determined by macroscale features of landforms (slope, relief, drainage density), mesoscale effects related to position on landforms, and microscale influences determined by microtopography and individual tree effects. Much of the soil variability arises at microscales so that it is not possible to map areas of uniform soils at practical map scales. The distribution of soil variability across spatial scales, in relation to the intensity of forest management, dictates that it is most appropriate to map soil complexes with boundaries coinciding with landforms.
Disturbance of canopy trees is an important agent in forest dynamics. The frequency of forest disturbance in the production area of Saltwater Forest varies in a systematic way among landforms in accord with changes in abundance of different soils. The frequency of forest turnover is highest on landforms with the greatest abundance of extremely poorly-drained Organic Soils. As the abundance of better-drained soils increases the frequency of forest turnover declines. Changes in turnover frequency are reflected in the mean size and density of canopy trees (Dacrydium cupressinum) among landforms. Terrace and ablation moraine landforms with the greatest abundance of extremely poorly-drained soils have on average the smallest trees growing most densely. The steep lateral moraines, characterised by well drained soils, have fewer, larger trees. The changes manifested at the landform scale are an integration of processes operating over much shorter range as a result of short-range soil variability. The systematic changes in forest structure and turnover frequency among landforms and soils have important implications for sustainable forest management.
Christchurch Ōtautahi, New Zealand, is a city of myriad waterways and springs. Māori, the indigenous people of New Zealand, have water quality at the core of their cultural values. The city’s rivers include the Avon/Ōtākaro, central to the city centre’s aesthetic appeal since early settlement, and the Heathcote/Ōpāwaho. Both have been degraded with increasing urbanisation. The destructive earthquake sequence that occurred during 2010/11 presented an opportunity to rebuild significant areas of the city. Public consultation identified enthusiasm to rebuild a sustainable city. A sustainable water sensitive city is one where development is constructed with the water environment in mind. Water sensitive urban design applies at all scales and is a holistic concept. In Christchurch larger-scale multi-value stormwater management solutions were incorporated into rapidly developed greenfield sites on the city’s outskirts and in satellite towns, as they had been pre-earthquake. Individual properties on greenfield sites and within the city, however, continued to be constructed without water sensitive features such as rainwater tanks or living roofs. This research uses semi-structured interviews, policy analysis, and findings from local and international studies to investigate the benefits of building-scale WSUD and the barriers that have resulted in their absence. Although several inter-related barriers became apparent, cost, commonly cited as a barrier to sustainable development in general, was strongly represented. However, it is argued that the issue is one of mindset rather than cost. Solutions are proposed, based on international and national experience, that will demonstrate the benefits of adopting water sensitive urban design principles including at the building scale, and thereby build public and political support. The research is timely - there is still much development to occur, and increasing pressures from urban densification, population growth and climate change to mitigate.
This paper outlines the deconstruction, redesign and reconstruction of a 2 storey timber building at the University of Canterbury, in Christchurch, New Zealand. The building consists of post tensioned timber frames and walls for lateral and gravity resistance, and timber concrete composite flooring. Originally a test specimen, the structure was subjected to extreme lateral displacements in the University structural testing laboratory. This large scale test of the structural form showed that post tensioned timber can withstand high levels of drift with little to no structural damage in addition to displaying full recentering characteristics with no residual displacements, a significant contributor to post earthquake cost. The building subsequently has been dismantled and reconstructed as offices for the Structural Timber Innovation Company (STIC). In doing this over 90% of the materials have been recycled which further enhances the sustainability of this construction system. The paper outlines the necessary steps to convert the structure from a test specimen into a functioning office building with minimal wastage and sufficient seismic resistance. The feasibility of recycling the structural system is examined using the key indicators of cost and time.
Recent advances in timber design at the University of Canterbury have led to new structural systems that are appropriate for a wide range of building types, including multi-storey commercial office structures. These buildings are competitive with more traditional construction materials in terms of cost, sustainability and structural performance. This paper provides seismic design recommendations and analytical modelling approaches, appropriate for the seismic design of post-tensioned coupled timber wall systems. The models are based on existing seismic design theory for precast post-tensioned concrete, modified to more accurately account for elastic deformation of the timber wall systems and the influence of the floor system. Experimental test data from a two storey post-tensioned timber building, designed, constructed and tested at the University of Canterbury is used to validate the analytical models.
Earthquake Engineering is facing an extraordinarily challenging era, the ultimate target being set at increasingly higher levels by the demanding expectations of our modern society. The renewed challenge is to be able to provide low-cost, thus more widely affordable, high-seismic-performance structures capable of sustaining a design level earthquake with limited or negligible damage, minimum disruption of business (downtime) or, in more general terms, controllable socio-economical losses. The Canterbury earthquakes sequence in 2010-2011 has represented a tough reality check, confirming the current mismatch between societal expectations over the reality of seismic performance of modern buildings. In general, albeit with some unfortunate exceptions, modern multi-storey buildings performed as expected from a technical point of view, in particular when considering the intensity of the shaking (higher than new code design) they were subjected to. As per capacity design principles, plastic hinges formed in discrete regions, allowing the buildings to sway and stand and people to evacuate. Nevertheless, in many cases, these buildings were deemed too expensive to be repaired and were consequently demolished. Targeting life-safety is arguably not enough for our modern society, at least when dealing with new building construction. A paradigm shift towards damage-control design philosophy and technologies is urgently required. This paper and the associated presentation will discuss motivations, issues and, more importantly, cost-effective engineering solutions to design buildings capable of sustaining low-level of damage and thus limited business interruption after a design level earthquake. Focus will be given to the extensive research and developments in jointed ductile connections based upon controlled rocking & dissipating mechanisms for either reinforced concrete and, more recently, laminated timber structures. An overview of recent on-site applications of such systems, featuring some of the latest technical solutions developed in the laboratory and including proposals for the rebuild of Christchurch, will be provided as successful examples of practical implementation of performance-based seismic design theory and technology.
“One of the most basic and fundamental questions in urban master planning and building regulations is ‘how to secure common access to sun, light and fresh air?” (Stromann-Andersen & Sattrup, 2011). Daylighting and natural ventilation can have significant benefits in office buildings. Both of these ‘passive’ strategies have been found to reduce artificial lighting and air-conditioning energy consumption by as much as 80% (Ministry for the Environment, 2008); (Brager, et al., 2007). Access to daylight and fresh air can also be credited with improved occupant comfort and health, which can lead to a reduction of employee absenteeism and an increase of productivity (Sustainability Victoria, 2008). In the rebuild of Christchurch central city, following the earthquakes of 2010 and 2011, Cantabrians have expressed a desire for a low-rise, sustainable city, with open spaces and high performance buildings (Christchurch City Council, 2011). With over 80% of the central city being demolished, a unique opportunity to readdress urban form and create a city that provides all buildings with access to daylight and fresh air exists. But a major barrier to wide-spread adoption of passive buildings in New Zealand is their dependence on void space to deliver daylight and fresh air – void space which could otherwise be valuable built floor space. Currently, urban planning regulations in Christchurch prioritize density, allowing and even encouraging low performance compact buildings. Considering this issue of density, this thesis aimed to determine which urban form and building design changes would have the greatest effect on building performance in Central City Christchurch. The research proposed and parametrically tested modifications of the current compact urban form model, as well as passive building design elements. Proposed changes were assessed in three areas: energy consumption, indoor comfort and density. Three computer programs were used: EnergyPlus was the primary tool, simulating energy consumption and thermal comfort. Radiance/Daysim was used to provide robust daylighting calculations and analysis. UrbaWind enabled detailed consideration of the urban wind environment for reliable natural ventilation predictions. Results found that, through a porous urban form and utilization of daylight and fresh air via simple windows, energy consumption could be reduced as much as 50% in buildings. With automatic modulation of windows and lighting, thermal and visual comfort could be maintained naturally for the majority of the occupied year. Separation of buildings by as little as 2m enabled significant energy improvements while having only minimal impact on individual property and city densities. Findings indicated that with minor alterations to current urban planning laws, all buildings could have common access to daylight and fresh air, enabling them to operate naturally, increasing energy efficiency and resilience.
It is fast becoming common practice for civil engineering infrastructure and building structures to be designed to achieve a set of performance objectives. To do so, consideration is now being given to systems capable of sustaining minimal damage after an earthquake while still being cost competitive. This has led to the development of high performance seismic resisting systems, followed by advances in design methodologies. The paper presents the experimental response of four pre-cast, post-tensioned rocking walls with high-performing dissipating solutions tested on the shake-table at the University of Canterbury. The wall systems were designed as a retrofit solution for an existing frame building however, can also be used for the design of new, high-performance structures. The use of externally mounted dampers allowed numerous dissipation schemes to be explored including mild-steel dampers (hysteretic dampers), viscous dampers, a combination of both or no dampers. The advantages of both velocity and displacement dependant dissipation was investigated for protection against strong ground motions with differing rupture characteristics i.e. far-field and near-field events. The experimental results are used to verify a proposed design procedure for post-tensioned rocking systems with supplementary hysteretic and viscous dissipation. The predicted response compared well with the measured shake-table response.
There are many swaths of land that are deemed unsuitable to build on and occupy. These places, however, are rarely within an established city. The Canterbury earthquakes of 2010 and 2011 left areas in central Christchurch with such significant land damage that it is unlikely to be re-inhabited for a considerable period of time. These areas are commonly known as the ‘Red Zone’.This thesis explores redevelop in on volatile land through innovative solutions found and adapted from the traditional Indonesian construction techniques. Currently, Indonesia’s vernacular architecture sits on the verge of extinction after a cultural shift towards the masonry bungalow forced a rapid decline in their occupation and construction. The 2004 Indian Ocean earthquake and tsunami illustrated the bungalows’ poor performance in the face of catastrophic seismic activity, being outperformed by the traditional structures. This has been particularly evident in the Rumah Aceh construction of the Aceh province in Northern Sumatra. Within a New Zealand context an adaptation and modernisation of the Rumah Aceh construction will generate an architectural response not currently accepted under the scope of NZS 3604:2011; the standards most recent revision following the Canterbury earthquake of 2010 concerning timber-based seismic performance. This architectural exploration will further address light timber structures, their components, sustainability and seismic resilience. Improving new builds’ durability as New Zealand moves away from the previously promoted bungalow model that extends beyond residential and into all aspects of New Zealand built environment.
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
<b>Aotearoa has undoubtedly some of the most beautiful landscapes in the world, a privilege for its inhabitants. However, as our cities have developed post-colonisation, the connection between the natural environment and its occupants has diminished. Designers play a vital role within an ever evolving world to progress the built environment in a way that reflects and restores vital values that have been deprioritised. Future practice should prioritise diversity, care for the land, enhancement of community space, and sustainable practices.</b>
This research sets out to demonstrate that new design methodologies can encourage kaitiakitanga, whilst meeting the needs of urban public space. Initially through critical analysis and literature based research, a study of Ōtautahi Christchurch, the South Island’s largest city, was undertaken. The principles of a ‘15 minute city’ were also explored and applied to the city, establishing issues within the built environment that drove the overall research direction.
Through the tools of critical reflection and a research through design methodology, a design toolkit was constructed. This toolkit sets out to provide designers with a simple streamlined method of developing urban interventions that are sustainable and beneficial for human well-being. The toolkit incorporates an abstraction of the ‘15 minute city’ ideology and introduces the concepts of evolving green transportation routes within cities. Ōtautahi Christchurch, a city with a significant history of earthquake-caused damage, was chosen as the primary site for the application of this research’s proposed toolkit. The city becomes a canvas for an urban rebuild that explores and aims to set a precedent for a progressive 21st-century city.
A key finding as the toolkit research developed was the idea of a ‘temporary’ phase or intervention, being added to traditional design methodologies prior to permanent building. The research explains how this temporary phase could more actively engage diverse user groups and create active conversations between communities and designers.
The refined toolkit sets outs proposed timeline phases, methods of site analysis and development of design drivers. Alongside this, a modular architectural system establishes a design proposal for the temporary phase of an individual site within an evolving green route. This outcome provides further opportunity for realistic testing, which would actively involve communities and aims to shift our priorities within urban development. The introduction of the ‘temporary’ phase is beneficial in mitigating psychological implications on people and limiting physical impacts on the landscape.
The final design stage of the thesis applied the toolkit process to three sites in Ōtautahi Christchurch. Through a holistic lens, the toolkit framework set out methods to collate information that provides guidance for development on the sites. While some layers are initiated simply by recognising site characteristics, others are informed through software such as GIS.
Connected by a proposed green transport route, the three initial sites are developed with temporary interventions that utilise the modular design set out previously in the research. Contextualising the interventions on real world sites tested the flexibility of the system and allowed for critical reflection on the applicability of the toolkit to Aotearoa.
The research concludes by identifying future research opportunities and speculates on possible applications of its findings within the real world. Temporary Permanence highlights the significant role that we, as designers, have in shifting urban priorities to create more holistic, sustainable, and inclusive cities for people and the planet.
In the aftermath of the 2010-2011 Canterbury earthquakes in New Zealand, the residual capacity and reparability of damaged reinforced concrete (RC) structures was an issue pertinent to building owners, insurers, and structural engineers. Three precast RC moment-resisting frame specimens were extracted during the demolition of the Clarendon Tower in Christchurch after sustaining earthquake damage. These specimens were subjected to quasi-static cyclic testing as part of a research program to determine the reparability of the building. It was concluded that the precast RC frames were able to be repaired and retrofitted to an enhanced strength capacity with no observed reduction in displacement capacity, although the frames with “shear-ductile” detailing exhibited less displacement ductility capacity and energy dissipation capacity than the more conventionally detailed RC frames. Furthermore, the cyclic test results from the earthquake-damaged RC frames were used to verify the predicted inelastic demands applied to the specimens during the 2010-2011 Canterbury earthquakes. https://www.concrete.org/publications/acistructuraljournal.aspx
The Canterbury earthquakes of 2010 and 2011 caused significant damage and disruption to the city of Christchurch, New Zealand. A Royal Commission was established to report on the causes of building failure as a result of the earthquakes as well as look at the legal and best-practice requirements for buildings in New Zealand Central Business Districts. The Royal Commission made 189 recommendations on a variety of matters including managing damaged buildings after an earthquake, the adequacy of building codes and standards, and the processes of seismic assessments of existing buildings to determine their earthquake vulnerability. In response the Ministry of Business, Innovation and Employment, the agency responsible for administering building regulation in New Zealand, established a work programme to assist with the Canterbury rebuild and to implement the lessons learned throughout New Zealand. The five primary work streams in the programme are: • Facilitating the Canterbury Rebuild • Structural Performance and Design Standards • Geotechnical and structural guidance • Existing Building Resilience • Post Disaster Building Management This paper provides more detail on each of the work streams. There has been significant collaboration between the New Zealand Government and the research community, technical societies, and engineering consultants, both within New Zealand and internationally, to deliver the programme and improve the resilience of the New Zealand built environment. This has presented major challenges for an extremely busy industry in the aftermath of the Canterbury earthquakes. The paper identifies the items of work that have been completed and the work that is still in progress at the time of writing.
Timber has experienced renewed interests as a sustainable building material in recent times. Although traditionally it has been the prime choice for residential construction in New Zealand and some other parts of the world, its use can be increased significantly in the future through a wider range of applications, particularly when adopting engineered wood material, Research has been started on the development of innovative solutions for multi-storey non-residential timber buildings in recent years and this study is part of that initiative. Application of timber in commercial and office spaces posed some challenges with requirements of large column-free spaces. The current construction practice with timber is not properly suited for structures with the aforementioned required characteristics and new type of structures has to be developed for this type of applications. Any new structural system has to have adequate capacity for carry the gravity and lateral loads due to occupancy and the environmental effects. Along with wind loading, one of the major sources of lateral loads is earthquakes. New Zealand, being located in a seismically active region, has significant risk of earthquake hazard specially in the central region of the country and any structure has be designed for the seismic loading appropriate for the locality. There have been some significant developments in precast concrete in terms of solutions for earthquake resistant structures in the last decade. The “Hybrid” concept combining post-tensioning and energy dissipating elements with structural members has been introduced in the late 1990s by the precast concrete industry to achieve moment-resistant connections based on dry jointed ductile connections. Recent research at the University of Canterbury has shown that the concept can be adopted for timber for similar applications. Hybrid timber frames using post-tensioned beams and dissipaters have the potential to allow longer spans and smaller cross sections than other forms of solid timber frames. Buildings with post-tensioned frames and walls can have larger column-free spaces which is a particular advantage for non-residential applications. While other researchers are focusing on whole structural systems, this research concentrated on the analysis and design of individual members and connections between members or between member and foundation. This thesis extends existing knowledge on the seismic behaviour and response of post-tensioned single walls, columns under uni-direction loads and small scale beam-column joint connections into the response and design of post-tensioned coupled walls, columns under bi-directional loading and full-scale beam-column joints, as well as to generate further insight into practical applications of the design concept for subassemblies. Extensive experimental investigation of walls, column and beam-column joints provided valuable confirmation of the satisfactory performance of these systems. In general, they all exhibited almost complete re-centering capacity and significant energy dissipation, without resulting into structural damage. The different configurations tested also demonstrated the flexibility in design and possibilities for applications in practical structures. Based on the experimental results, numerical models were developed and refined from previous literature in precast concrete jointed ductile connections to predict the behaviour of post-tensioned timber subassemblies. The calibrated models also suggest the values of relevant parameters for applications in further analysis and design. Section analyses involving those parameters are performed to develop procedures to calculate moment capacities of the subassemblies. The typical features and geometric configurations the different types of subassemblies are similar with the only major difference in the connection interfaces. With adoption of appropriate values representing the corresponding connection interface and incorporation of the details of geometry and configurations, moment capacities of all the subassemblies can be calculated with the same scheme. That is found to be true for both post-tensioned-only and hybrid specimens and also applied for both uni-directional and bi-directional loading. The common section analysis and moment capacity calculation procedure is applied in the general design approach for subassemblies.
Bulk rock strength is greatly dependent on fracture density, so that reductions in rock strength associated with faulting and fracturing should be reflected by reduced shear coupling and hence S-wave velocity. This study is carried out along the Canterbury rangefront and in Otago. Both lie within the broader plate boundary deformation zone in the South Island of New Zealand. Therefore built structures are often, , located in areas where there are undetected or poorly defined faults with associated rock strength reduction. Where structures are sited near to, or across, such faults or fault-zones, they may sustain both shaking and ground deformation damage during an earthquake. Within this zone, management of seismic hazards needs to be based on accurate identification of the potential fault damage zone including the likely width of off-plane deformation. Lateral S-wave velocity variability provides one method of imaging and locating damage zones and off-plane deformation. This research demonstrates the utility of Multi-Channel Analysis of Surface Waves (MASW) to aid land-use planning in such fault-prone settings. Fundamentally, MASW uses surface wave dispersive characteristics to model a near surface profile of S-wave velocity variability as a proxy for bulk rock strength. The technique can aid fault-zone planning not only by locating and defining the extent of fault-zones, but also by defining within-zone variability that is readily correlated with measurable rock properties applicable to both foundation design and the distribution of surface deformation. The calibration sites presented here have well defined field relationships and known fault-zone exposure close to potential MASW survey sites. They were selected to represent a range of progressively softer lithologies from intact and fractured Torlesse Group basement hard rock (Dalethorpe) through softer Tertiary cover sediments (Boby’s Creek) and Quaternary gravels. This facilitated initial calibration of fracture intensity at a high-velocity-contrast site followed by exploration of the limits of shear zone resolution at lower velocity contrasts. Site models were constructed in AutoCAD in order to demonstrate spatial correlations between S-wave velocity and fault zone features. Site geology was incorporated in the models, along with geomorphology, river profiles, scanline locations and crosshole velocity measurement locations. Spatial data were recorded using a total-station survey. The interpreted MASW survey results are presented as two dimensional snapshot cross-sections of the three dimensional calibration-site models. These show strong correlations between MASW survey velocities and site geology, geomorphology, fluvial profiles and geotechnical parameters and observations. Correlations are particularly pronounced where high velocity contrasts exist, whilst weaker correlations are demonstrated in softer lithologies. Geomorphic correlations suggest that off-plane deformation can be imaged and interpreted in the presence of suitable topographic survey data. A promising new approach to in situ and laboratory soft-rock material and mass characterisation is also presented using a Ramset nail gun. Geotechnical investigations typically involve outcrop and laboratory scale determination of rock mass and material properties such as fracture density and unconfined compressive strength (UCS). This multi-scale approach is espoused by this study, with geotechnical and S-wave velocity data presented at multiple scales, from survey scale sonic velocity measurements, through outcrop scale scanline and crosshole sonic velocity measurements to laboratory scale property determination and sonic velocity measurements. S-wave velocities invariably increased with decreasing scale. These scaling relationships and strategies for dealing with them are investigated and presented. Finally, the MASW technique is applied to a concealed fault on the Taieri Ridge in Macraes Flat, Central Otago. Here, high velocity Otago Schist is faulted against low velocity sheared Tertiary and Quaternary sediments. This site highlights the structural sensitivity of the technique by apparently constraining the location of the principal fault, which had been ambiguous after standard processing of the seismic reflection data. Processing of the Taieri Ridge dataset has further led to the proposal of a novel surface wave imaging technique termed Swept Frequency Imaging (SFI). This inchoate technique apparently images the detailed structure of the fault-zone, and is in agreement with the conventionally-determined fault location and an existing partial trench. Overall, the results are promising and are expected to be supported by further trenching in the near future.
In the early morning of 4th September 2010 the region of Canterbury, New Zealand, was subjected to a magnitude 7.1 earthquake. The epicentre was located near the town of Darfield, 40 km west of the city of Christchurch. This was the country’s most damaging earthquake since the 1931 Hawke’s Bay earthquake (GeoNet, 2010). Since 4th September 2010 the region has been subjected to thousands of aftershocks, including several more damaging events such as a magnitude 6.3 aftershock on 22nd February 2011. Although of a smaller magnitude, the earthquake on 22nd February produced peak ground accelerations in the Christchurch region three times greater than the 4th September earthquake and in some cases shaking intensities greater than twice the design level (GeoNet, 2011; IPENZ, 2011). While in September 2010 most earthquake shaking damage was limited to unreinforced masonry (URM) buildings, in February all types of buildings sustained damage. Temporary shoring and strengthening techniques applied to buildings following the Darfield earthquake were tested in February 2011. In addition, two large aftershocks occurred on 13th June 2011 (magnitudes 5.7 and 6.2), further damaging many already weakened structures. The damage to unreinforced and retrofitted clay brick masonry buildings in the 4th September 2010 Darfield earthquake has already been reported by Ingham and Griffith (2011) and Dizhur et al. (2010b). A brief review of damage from the 22nd February 2011 earthquake is presented here
This thesis revisits the topic of earthquake recovery in Christchurch City more than a decade after the Canterbury earthquakes. Despite promising visions of a community reconnected and a sustainable and liveable city, significant portions of the city’s core – the Red Zone – remain dilapidated and “eerily empty”. At the same time, new developments in other areas have proven to be alienated or underutilised. Currently, the Canterbury Earthquake Recovery Authority’s plans for the rebuilding highlight the delivery of more residential housing to re-populate the city centre. However, prevalent approaches to housing development in Christchurch are ineffective for building an inclusive and active community. Hence, the central inquiry of the thesis is how the development of housing complexes can revitalise the Red Zone within the Christchurch city centre. The inquiry has been carried out through a research-through-design methodology, recognising the importance of an in-depth investigation that is contextualised and combined with the intuition and embodied knowledge of the designer. The investigation focuses on a neglected site in the Red Zone in the heart of Christchurch city, with significant Victorian and Edwardian Baroque heritage buildings, including Odeon Theatre, Lawrie & Wilson Auctioneers, and Sol Square, owned by The Regional Council Environment Canterbury. The design inquiry argues, develops, and is carried through a place-assemblage lens to housing development for city recovery, which recognizes the significance of socially responsive architecture that explores urban renewal by forging connections within the social network. Therefore, place-assemblage criteria and methods for developing socially active and meaningful housing developments are identified. Firstly, this thesis argues that co-living housing models are more focused on people relations and collective identity than the dominant developer-driven housing rebuilds, as they prioritise conduits for interaction and shared social meaning and practices. Secondly, the adaptive reuse of derelict heritage structures is proposed to reinvigorate the urban fabric, as heritage is seen to be conceived as and from a social assemblage of people. The design is realised by the principles outlined in the ICOMOS charter, which involves incorporating the material histories of existing structures and preserving the intangible heritage of the site by ensuring the continuity of cultural practices. Lastly, design processes and methods are also vital for place-sensitive results, which pay attention to the site’s unique characteristics to engage with local stakeholders and communities. The research explores place-assemblage methods of photographic extraction, the drawing of story maps, precedent studies, assemblage maps, bricolages, and paper models, which show an assembly of layers that piece together the existing heritage, social conduits, urban commons and housing to conceptualise the social network within its place.
Livelihood holds the key to a rapid recovery following a large-scale devastating disaster, building its resilience is of paramount importance. While much attention has been given to how to help people who are displaced from their jobs to regain employment, little research on livelihood resilience has been undertaken for those relocated communities following a disaster event. By studying five re-located villages post-2004 Indian Ocean Tsunami in Banda Aceh and Aceh Besar, Indonesia, this research has identified the indicators of livelihood resilience and the critical factors driving it for post-disaster relocated communities. A mixed approach, combining questionnaire surveys, semistructured interviews, and field observations, was used for the collection of data. Housing entitlement, the physical and mental health of residents, access to external livelihood support and the provision of infrastructure and basic services were identified as amongst the most critical indicators that represent the level of livelihood resilience. Early recovery income support, physical and mental health, availability and timeliness of livelihood support, together with cultural sensitivity and governance structure, are amongst the most important factors. Given the nature of resettlement, access to infrastructure, location of relocated sites, the safety of the neighbourhood and the ability to transfer to other jobs/skills also play an important role in establishing sustained employment for relocated communities in Indonesia. Those indicators and factors were synthesised into a framework which was further tested in the recovery of Christchurch, and Kaikoura, New Zealand during their recovery from devastating earthquakes. It is suggested that the framework can be used by government agencies and aid organisations to assess the livelihood resilience of post-disaster relocated communities. This will help better them plan support policies and/or prioritise resilience investment strategies to ensure that the recovery needs of those relocated are best met.
“much of what we know about leadership is today redundant because it is literally designed for a different operating model, a different context, a different time” (Pascale, Sternin, & Sternin, p. 4). This thesis describes a project that was designed with a focus on exploring ways to enhance leadership capacity in non-government organisations operating in Christchurch, New Zealand. It included 20 CEOs, directors and managers from organisations that cover a range of settings, including education, recreation, and residential and community therapeutic support; all working with adolescents. The project involved the creation of a peer-supported professional learning community that operated for 14 months; the design and facilitation of which was informed by the Appreciative Inquiry principles of positive focus and collaboration. At the completion of the research project in February 2010, the leaders decided to continue their collective processes as a self-managing and sustaining professional network that has grown and in 2014 is still flourishing under the title LYNGO (Leaders of Youth focussed NGOs). Two compelling findings emerged from this research project. The first of these relates to efficacy of a complexity thinking framework to inform the actions of these leaders. The leaders in this project described the complexity thinking framework as the most relevant, resonant and dynamic approach that they encountered throughout the research project. As such this thesis explores this complexity thinking informed leadership in detail as the leaders participating in this project believed it offers an opportune alternative to more traditional forms of positional leadership and organisational approaches. This exploration is more than simply a rationale for complexity thinking but an iterative in-depth exploration of ‘complexity leadership in action’ which in Chapter 6 elaborates on detailed leadership tools and frameworks for creating the conditions for self-organisation and emergence. The second compelling finding relates to efficacy of Appreciative Inquiry as an emergent research and development process for leadership learning. In particular the adoption of two key principles; positive focus and inclusivity were beneficial in guiding the responsive leadership learning process that resulted in a professional learning community that exhibited high engagement and sustainability. Additionally, the findings suggest that complexity thinking not only acts as a contemporary framework for adaptive leadership of organisations as stated above; but that complexity thinking has much to offer as a framework for understanding leadership development processes through the application of Appreciative Inquiry (AI)-based principles. A consideration of the components associated with complexity thinking has promise for innovation and creativity in the development of leaders and also in the creation of networks of learning. This thesis concludes by suggesting that leaders focus on creating hybrid organisations, ones which leverage the strengths (and minimise the limitations) of self-organising complexity-informed organisational processes, while at the same time retaining many of the strengths of more traditional organisational management structures. This approach is applied anecdotally to the place where this study was situated: the post-earthquake recovery of Christchurch, New Zealand.
Capacity design and hierarchy of strength philosophies at the base of modern seismic codes allow inelastic response in case of severe earthquakes and thus, in most traditional systems, damage develops at well-defined locations of reinforced concrete (RC) structures, known as plastic hinges. The 2010 and 2011 Christchurch earthquakes have demonstrated that this philosophy worked as expected. Plastic hinges formed in beams, in coupling beams and at the base of columns and walls. Structures were damaged permanently, but did not collapse. The 2010 and 2011 Christchurch earthquakes also highlighted a critical issue: the reparability of damaged buildings. No methodologies or techniques were available to estimate the level of subsequent earthquakes that RC buildings could still sustain before collapse. No repair techniques capable of restoring the initial condition of buildings were known. Finally, the cost-effectiveness of an eventual repair intervention, when compared with a new building, was unknown. These aspects, added to nuances of New Zealand building owners’ insurance coverage, encouraged the demolition of many buildings. Moreover, there was a perceived strong demand from government and industry to develop techniques for assessing damage to steel reinforcement bars embedded in cracked structural concrete elements. The most common questions were: “Have the steel bars been damaged in correspondence to the concrete cracks?”, “How much plastic deformation have the steel bars undergone?”, and “What is the residual strain capacity of the damaged bars?” Minimally invasive techniques capable of quantifying the level and extent of plastic deformation and residual strain capacity are not yet available. Although some studies had been recently conducted, a validated method is yet to be widely accepted. In this thesis, a least-invasive method for the damage-assessment of steel reinforcement is developed. Based on the information obtained from hardness testing and a single tensile test, it is possible to estimate the mechanical properties of earthquake-damaged rebars. The reduction in the low-cycle fatigue life due to strain ageing is also quantified. The proposed damage assessment methodology is based on empirical relationships between hardness and strain and residual strain capacity. If damage is suspected from in situ measurements, visual inspection or computer analysis, a bar may be removed and more accurate hardness measurements can be obtained using the lab-based Vickers hardness methodology. The Vickers hardness profile of damaged bars is then compared with calibration curves (Vickers hardness versus strain and residual strain capacity) previously developed for similar steel reinforcement bars extracted from undamaged locations. Experimental tests demonstrated that the time- and temperature-dependent strain-ageing phenomenon causes changes in the mechanical properties of plastically deformed steels. In particular, yield strength and hardness increases, whereas ductility decreases. The changes in mechanical properties are quantified and their implications on the hardness method are highlighted. Low-cycle fatigue (LCF) failures of steel reinforcing bars have been observed in laboratory testing and post-earthquake damage inspections. Often, failure might not occur during a first seismic event. However, damage is accumulated and the remaining fatigue life is reduced. Failure might therefore occur in a subsequent seismic event. Although numerous studies exist on the LCF behaviour of steel rebars, no studies had been conducted on the strain-ageing effects on the remaining fatigue life. In this thesis, the reduction in fatigue life due to this phenomenon is determined through a number of experimental tests.
