To reduce seismic vulnerability and the economic impact of seismic structural damage, it is important to protect structures using supplemental energy dissipation devices. Several types of supplemental damping systems can limit loads transferred to structures and absorb significant response energy without sacrificial structural damage. Lead extrusion dampers are one type of supplemental energy dissipation devices. A smaller volumetric size with high force capacities, called high force to volume (HF2V) devices, have been employed in a large series of scaled and full-scaled experiments, as well as in three new structures in Christchurch and San Francisco. HF2V devices have previously been designed using very simple models with limited precision. They are then manufactured, and tested to ensure force capacities match design goals, potentially necessitating reassembly or redesign if there is large error. In particular, devices with a force capacity well above or below a design range can require more testing and redesign, leading to increased economic and time cost. Thus, there is a major need for a modelling methodology to accurately estimate the range of possible device force capacity values in the design phase – upper and lower bounds. Upper and lower bound force capacity estimates are developed from equations in the metal extrusion literature. These equations consider both friction and extrusion forces between the lead and the bulged shaft in HF2V devices. The equations for the lower and upper bounds are strictly functions of device design parameters ensuring easy use in the design phase. Two different sets of estimates are created, leading to estimates for the lower and upper bounds denoted FLB,1, FUB,1, FUB,2, respectively. The models are validated by comparing the bounds with experimental force capacity data from 15 experimental HF2V device tests. All lower bound estimates are below or almost equal to the experimental device forces, and all upper bound estimates are above. Per the derivation, the (FLB,1, FUB,1) pair provide narrower bounds. The (FLB,1, FUB,1) pair also had a mean lower bound gap of -34%, meaning the lower bound was 74% of device force on average, while the mean upper bound gap for FUB,1 was +23%. These are relatively tight bounds, within ~±2 SE of device manufacture, and can be used as a guide to ensure device forces are in range for the actual design use when manufactured. Therefore, they provide a useful design tool.
The University of Canterbury’s RECOVER project (Reef Ecology and Coastal Values, Earthquake Recovery) is a research programme funded by the Ministry of Business, Innovation and Employment (MBIE), and supported by the Ministry of Primary Industries (MPI). It has been evaluating recovery from the 7.8 Mw Kaikōura earthquake in the coastal environment between Oaro in the south and Marfells Beach in the north. The project has documented a wide range of biological and physical impacts in the coastal environment over the past four years. These include the widespread mortality of habitat-forming species that support characteristic ecosystems and natural resources on the coast (Alestra et al. 2021; Schiel et al. 2019; Tait et al. 2021). Due to the popularity of the coast for recreational use, interactions between people and the recovering environment are an important influence on recovery processes. These interactions may include threats to the natural environment but also the potential for positive interventions that could help to restore natural ecosystems and resources – including those that have been degraded in the past. Physical effects of uplift at the coastline include the seaward movement of shorelines and creation of new land above the reach of the tide, leading to a widening of beaches (Orchard et al. 2020; Orchard et al. in press). This has also provided a greater opportunity for off-road vehicle access to sections of the coast previously protected by headlands that were impassable at high tide (Marlborough District Council 2019; Orchard 2020). MDC management responses have included the development of a proposed bylaw to reduce the impacts of motor vehicle use in the area (Marlborough District Council 2021). Changes in the position of the sea-level on the landscape also affect the location of characteristic ecosystems such as sand dunes and storm beaches as they recover to a new norm. Notable changes include the establishment of new dunes closer to the sea which could potentially lead to the degradation of old dune systems that may experience reduced sand supply as a result. Wildlife habitat has also been affected by these uplift and re-assembly effects although the specific impacts remain largely unknown. This report contributes to a collaborative project between the Marlborough District Council (MDC) and University of Canterbury (UC) which aims to help protect and promote the recovery of native dune systems on the Marlborough coast. It is centred around the mapping of dune vegetation and identification of dune protection zones for old-growth seed sources of the native sand-binders spinifex (Spinifex sericeus) and pīngao (Ficinia spiralis). Both are key habitat-formers associated with nationally threatened dune ecosystems (Holdaway et al. 2012), and pīngao is an important weaving resource and Ngāi Tahu taonga species. The primary goal is to protect existing seed sources that are vital for natural regeneration following major disturbances such as the earthquake event. Several additional protection zones are also identified for areas where new dunes are successfully regenerating, including areas being actively restored in the Beach Aid project that is assisting new native dunes to become established where there is available space.
Welcome to the Recover newsletter Issue 6 from the Marine Ecology Research Group (MERG) of the University of Canterbury. Recover is designed to keep you updated on our MBIE-funded earthquake recovery project called RECOVER (Reef Ecology, Coastal Values & Earthquake Recovery). This 6th instalment features the ‘new land’ created by the earthquake uplift of the coastline, recreational uses of beaches in Marlborough, and pāua survey work and hatchery projects with our partners in Kaikōura
The Manchester Courts building was a heritage building located in central Christchurch (New Zealand) that was damaged in the Mw 7.1 Darfield earthquake on 4 September 2010 and subsequently demolished as a risk reduction exercise. Because the building was heritage listed, the decision to demolish the building resulted in strong objections from heritage supporters who were of the opinion that the building had sufficient residual strength to survive possible aftershock earthquakes. On 22 February 2011 Christchurch was struck by a severe aftershock, leading to the question of whether building demolition had proven to be the correct risk reduction strategy. Finite element analysis was used to undertake a performance-based assessment, validating the accuracy of the model using the damage observed in the building before its collapse. In addition, soil-structure interaction was introduced into the research due to the comparatively low shear wave velocity of the soil. The demolition of a landmark heritage building was a tragedy that Christchurch will never recover from, but the decision was made considering safety, societal, economic and psychological aspects in order to protect the city and its citizens. The analytical results suggest that the Manchester Courts building would have collapsed during the 2011 Christchurch earthquake, and that the collapse of the building would have resulted in significant fatalities.
While societal messages can encourage an unhealthy strive for perfection, the notion of embracing individual flaws and openly displaying vulnerabilities can appear foreign and outlandish. However, when fallibility is acknowledged and imperfection embraced, intimate relationships built on foundations of acceptance, trust and understanding can be established. In an architectural context, similar deep-rooted connections can be formed between a people and a place through the retention of layers of historical identity. When a building is allowed to age with blemishes laid bare for all to see, an architectural work can exhibit a sense of 'humanising vulnerability' where the bruises and scars it bears are able to visually communicate its contextual narrative. This thesis explores the notion of designing to capitalise on past decay through revitalisation of the former Wood Brothers Flour Mill in Addington, Christchurch (1891). Known as one of the city's last great industrial buildings, the 130-year-old structure remains hugely impressive due to its sheer size and scale despite being abandoned and subject to vandalism for a number of years. Its condition of obsolescence ensured the retention of visible signs of wear and tear in addition to the extensive damage caused by the 2010-12 Canterbury earthquakes. In offering a challenge to renovation and reconstruction as a means of conservation, this thesis asks if 'doing less' has the potential to 'do more'. How can an understanding of architecture as an ongoing process inform a design approach to celebrate ageing and patina? While the complex is undergoing redevelopment at the time of writing, the design project embraces the condition of the historic buildings in the immediate aftermath of the earthquakes and builds upon the patina of the mill and adjacent flour and grain store in developing a design for their adaptation as a micro-distillery. Research into the traditional Japanese ideology of wabi-sabi and its practical applications form the basis for a regenerative design approach which finds value in imperfection, impermanence and incompleteness. The thesis combines a literature review, precedent review and site analysis together with a design proposal. This thesis shows that adaptive reuse projects can benefit from an active collaboration with the processes of decay. Instead of a mindset where an architectural work is considered the finished article upon completion of construction, an empathetic and sensitive design philosophy is employed in which careful thought is given to the continued preservation and evolution of a structure with the recognition that evidence of past wear, tear, patina and weathering can all contribute positively to a building's future. In this fashion, rather than simply remaining as relics of the past, buildings can allow the landscape of their urban context to shape and mould them to ensure that their architectural experience can continue to be enjoyed by generations to come.
A city’s planted trees, the great majority of which are in private gardens, play a fundamental role in shaping a city’s wild ecology, ecosystem functioning, and ecosystem services. However, studying tree diversity across a city’s many thousands of separate private gardens is logistically challenging. After the disastrous 2010–2011 earthquakes in Christchurch, New Zealand, over 7,000 homes were abandoned and a botanical survey of these gardens was contracted by the Government’s Canterbury Earthquake Recovery Authority (CERA) prior to buildings being demolished. This unprecedented access to private gardens across the 443.9 hectares ‘Residential Red Zone’ area of eastern Christchurch is a unique opportunity to explore the composition of trees in private gardens across a large area of a New Zealand city. We analysed these survey data to describe the effects of housing age, socio-economics, human population density, and general soil quality, on tree abundance, species richness, and the proportion of indigenous and exotic species. We found that while most of the tree species were exotic, about half of the individual trees were local native species. There is an increasing realisation of the native tree species values among Christchurch citizens and gardens in more recent areas of housing had a higher proportion of smaller/younger native trees. However, the same sites had proportionately more exotic trees, by species and individuals, amongst their larger planted trees than older areas of housing. The majority of the species, and individuals, of the larger (≥10 cm DBH) trees planted in gardens still tend to be exotic species. In newer suburbs, gardens in wealthy areas had more native trees than gardens from poorer areas, while in older suburbs, poorer areas had more native big trees than wealthy areas. In combination, these describe, in detail unparalleled for at least in New Zealand, how the tree infrastructure of the city varies in space and time. This lays the groundwork for better understanding of how wildlife distribution and abundance, wild plant regeneration, and ecosystem services, are affected by the city’s trees.
Brooklands Lagoon / Te Riu o Te Aika Kawa (‘Brooklands’) is an important wetland and estuarine ecosystem in Canterbury. It is a site of cultural significance to Ngāi Tūāhuriri, and is also valued by the wider community. Home to an array of life, it is connected to the Pūharakekenui/Styx and Waimakariri rivers, and is part of a wetland landscape complex that includes the Avon-Heathcote / Ihutai estuary to the south and the Ashley / Rakahuri estuary to the north. Notionally situated within the territorial boundary of Christchurch City Council and jurisdictionally encompassed by the regional council Environment Canterbury, it has been legally determined to be part of the coastal marine area. The complicated administrative arrangements for the lagoon mirror the biophysical and human challenges to this surprisingly young ecosystem since its formation in 1940. Here we present a synthesis of the historical events and environmental influences that have shaped Brooklands Lagoon. Before existing as an intertidal ecosystem, the Waimakariri river mouth was situated in what is now the southern end of the lagoon. A summary timeline of key events is set out in the table below. These included the diversion of the Waimakariri River mouth via the construction of Wrights Cut in the 1930s, which influenced the way that the lower reaches of the river interacted with the land and sea. A large flood in 1940 shifted the river mouth ~2 to 3 kilometres north, that created the landscape that we see today. However, this has not remained stable, as the earthquake sequence in 2010 and 2011 subsided the bed of the estuary. The changes are ongoing, as sea level rise and coastal inundation will place ongoing pressure on the aquatic ecosystem and surrounding land. How to provide accommodation space for Brooklands as an estuary will be a key planning and community challenge, as Environment Canterbury begins the engagement for the review of its Regional Coastal Plan. There is also a requirement to safeguard its ecological health under the 2020 National Policy Statement on Freshwater Management. This will necessitate an integrated mountains to sea (ki uta ki tai) management approach as the lagoon is affected by wider catchment activities. We hope that this report will contribute to, and inform these processes by providing a comprehensive historical synthesis, and by identifying considerations for the future collaborative management of Brooklands Lagoon, and protection of its values. In essence, we suggest that Te Riu o Te Aika Kawa deserves some sustained aroha.
On November 14, 2016 an earthquake struck the rural districts of Kaikōura and Hurunui on New Zealand’s South Island. The region—characterized by small dispersed communities, a local economy based on tourism and agriculture, and limited transportation connections—was severely impacted. Following the quake, road and rail networks essential to maintaining steady flows of goods, visitors, and services were extensively damaged, leaving agrifood producers with significant logistical challenges, resulting in reduced productivity and problematic market access. Regional tourism destinations also suffered with changes to the number, characteristics, and travel patterns of visitors. As the region recovers, there is renewed interest in the development and promotion of agrifood tourism and trails as a pathway for enhancing rural resilience, and a growing awareness of the importance of local networks. Drawing on empirical evidence and insights from a range of affected stakeholders, including food producers, tourism operators, and local government, we explore the significance of emerging agrifood tourism initiatives for fostering diversity, enhancing connectivity, and building resilience in the context of rural recovery. We highlight the motivation to diversify distribution channels for agrifood producers, and strengthen the region’s tourism place identity. Enhancing product offerings and establishing better links between different destinations within the region are seen as essential. While such trends are common in rural regions globally, we suggest that stakeholders’ shared experience with the earthquake and its aftermath has opened up new opportunities for regeneration and reimagination, and has influenced current agrifood tourism trajectories. In particular, additional funding for tourism recovery marketing and product development after the earthquake, and an emphasis on greater connectivity between the residents and communities through strengthening rural networks and building social capital within and between regions, is enabling more resilient and sustainable futures.
There is growing expectation that local volunteers will play a more integrated role in disaster response, yet emergent groups are often ‘outsiders’ to crisis management, prompting questions of the conditions and processes by which these groups can forge relationships with established response agencies, and the tensions which can arise those interactions. This article analyses how student-led volunteers, as an emergent group, nevertheless gained “authority to operate” in the aftermath of the 2010-2011 earthquakes in Canterbury, New Zealand. Our study demonstrates how established response agencies and emergent groups can form hugely impactful and mutually supportive relationships. However, our analysis also points to two interrelated tensions that can arise, regarding the terms by which emergent groups are recognised, and the ‘distance’ considered necessary between emergent groups and established response agencies. The discussion considers implications for inclusiveness, risk and responsibility if emergent volunteers are to be further integrated into disaster response.
