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Research papers, The University of Auckland Library

The progressive damage and subsequent demolition of unreinforced masonry (URM) buildings arising from the Canterbury earthquake sequence is reported. A dataset was compiled of all URM buildings located within the Christchurch CBD, including information on location, building characteristics, and damage levels after each major earthquake in this sequence. A general description of the overall damage and the hazard to both building occupants and to nearby pedestrians due to debris falling from URM buildings is presented with several case study buildings used to describe the accumulation of damage over the earthquake sequence. The benefit of seismic improvement techniques that had been installed to URM buildings is shown by the reduced damage ratios reported for increased levels of retrofit. Demolition statistics for URM buildings in the Christchurch CBD are also reported and discussed. VoR - Version of Record

Research papers, The University of Auckland Library

During the Christchurch earthquake of February 2011, several midrise reinforced concrete masonry (RCM) buildings showed performance levels that fall in the range of life safety to near collapse. A case study of one of these buildings, a six-story RCM building deemed to have reached the near collapse performance level, is presented in this paper. The RCM walls on the second floor failed due to toe crushing, reducing the building's lateral resistance in the east–west direction. A three-dimensional (3-D) nonlinear dynamic analysis was conducted to simulate the development of the governing failure mechanism. Analysis results showed that the walls that were damaged were subjected to large compression loads during the earthquake, which caused an increase in their in-plane lateral strength but reduced their ductility capacity. After toe crushing failure, axial instability of the model was prevented by a redistribution of gravity loads. VoR - Version of Record

Research papers, The University of Auckland Library

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.

Research papers, The University of Auckland Library

Following the devastation of the Canterbury earthquake sequence a unique opportunity exists to rebuild and restructure the city of Christchurch, ensuring that its infrastructure is constructed better than before and is innovative. By installing an integrated grid of modern sensor technologies into concrete structures during the rebuild of the Christchurch CBD, the aim is to develop a network of self-monitored ‘digital buildings’. A diverse range of data will be recorded, potentially including parameters such as concrete stresses, strains, thermal deformations, acoustics and the monitoring of corrosion of reinforcement bars. This procedure will allow an on-going complete assessment of the structure’s performance and service life, both before and after seismic activity. The data generated from the embedded and surface mounted sensors will be analysed to allow an innovative and real-time health monitoring solution where structural integrity is continuously known. This indication of building performance will allow the structure to alert owners, engineers and asset managers of developing problems prior to failure thresholds being reached. A range of potential sensor technologies for monitoring the performance of existing and newly constructed concrete buildings is discussed. A description of monitoring work conducted on existing buildings during the July 2013 Cook Strait earthquake sequence is included, along with details of current work that investigates the performance of sensing technologies for detecting crack formation in concrete specimens. The potential market for managing the real-time health of installed infrastructure is huge. Civil structures all over the world require regular visual inspections in order to determine their structural integrity. The information recorded during the Christchurch rebuild will generate crucial data sets that will be beneficial in understanding the behaviour of concrete over the complete life cycle of the structure, from construction through to operation and building repairs until the time of failure. VoR - Version of Record

Research papers, The University of Auckland Library

The 2011, 6.3 magnitude Christchurch earthquake in New Zealand caused considerable structural damage. It is believed that this event has now resulted in demolition of about 65-70% of the building stock in the Central Business District (CBD), significantly crippling economic activities in the city of Christchurch. A major concern raised from this event was adequacy of the current seismic design practice adopted for reinforced concrete walls due to their poor performance in modern buildings. The relatively short-duration earthquake motion implied that the observed wall damage occurred in a brittle manner despite adopting a ductile design philosophy. This paper presents the lessons learned from the observed wall damage in the context of current state of knowledge in the following areas: concentrating longitudinal reinforcement in wall end regions; determining wall thickness to prevent out-of-plane wall buckling; avoiding lap splices in plastic hinge zones; and quantifying minimum vertical reinforcement. http://www.2eceesistanbul.org/

Research papers, The University of Auckland Library

The current seismic design practice for reinforced concrete (RC) walls has been drawn into question following the unsatisfactory performance of several RC wall buildings during the Canterbury earthquakes. An overview of current research being undertaken at the University of Auckland into the seismic behaviour of RC walls is presented. The main objectives of this research project are to understand the observed performance of RC walls in Christchurch, quantify the seismic loads on RC walls, and developed improved design procedures for RC walls that will assist in revisions to the New Zealand Concrete Structures Standard. A database summarising the performance of RC wall buildings in the Christchurch CBD was collated to identify damage modes and case-study buildings. A detailed investigation is underway to verify the seismic performance of lightly reinforced concrete walls and initial numerical modeling and small-scale tests are presented in addition to details of planned experimental tests of RC walls. Numerical modelling is being used to understand the potential influence that interactions between walls and other structural elements have on the seismic response of buildings and the loads generated on RC walls. The results from finite element analysis of a severely damaged RC wall in Christchurch highlighted the effect that the floor diaphragms have on the distribution of shear stains in the wall.

Research papers, The University of Auckland Library

The Christchurch earthquakes have highlighted the importance of low-damage structural systems for minimising the economic impacts caused by destructive earthquakes. Post-tensioned precast concrete walls have been shown to provide superior seismic resistance to conventional concrete construction by minimising structural damage and residual drifts through the use of a controlled rocking mechanism. The structural response of unbonded post-tensioned precast concrete wall systems, with and without additional energy dissipating elements, were investigated by means of pseudo-static cyclic, snap back and forced vibration testing with shake table testing to be completed. Two types of post-tensioned rocking wall system were investigated; a single unbonded post-tensioned precast concrete wall or Single Rocking Wall (SRW) and a system consisting of a Precast Wall with End Columns (PreWEC). The equivalent viscous damping (EVD) was evaluated using both the pseudo-static cyclic and snap back test data for all wall configurations. The PreWEC configurations showed an increase in EVD during the snap back tests in comparison to the cyclic test response. In contrast the SRW showed lower EVD during the snap back tests in comparison to the SRW cyclic test response. Despite residual drifts measured during the pseudo-static cyclic tests, negligible residual drift was measured following the snap back tests, highlighting the dynamic shake-down that occurs during the free vibration decay. Overall, the experimental tests provided definitive examples of the behaviour of posttensioned wall systems and validated their superior performance compared to reinforced concrete construction when subjected to large lateral drifts.

Research papers, The University of Auckland Library

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

Research papers, The University of Auckland Library

Axial elongation of reinforced concrete (RC) plastic hinges has previously been observed in a range of laboratory experiments, and more recently was observed in several Christchurch buildings following the 2010/2011 Canterbury earthquakes. Axial restraint to plastic hinges is provided by adjacent structural components such as floors as the plastic hinges elongate, which can significantly alter the performance of the plastic hinge and potentially invalidate the capacity design strength hierarchy of the building. Coupling beams in coupled wall systems are particularly susceptible to axial restraint effects due to their importance in the strength hierarchy, the high ductility demands that they experience, and the large stiffness of bounding walls. From computational modelling it has been found that ignoring axial restraint effects when designing coupled walls can result in significantly increased strength, reduced ductility and reduced energy dissipation capacity. The complexity of the topic merits further research to better account for realistic restraint effects when designing coupled walls.

Research papers, The University of Auckland Library

Between September 4, 2010 and December 23, 2011, a series of earthquakes struck the South Island of New Zealand including the city of Christchurch producing heavy damage. During the strongest shaking, the unreinforced masonry (URM) building stock in Christchurch was subjected to seismic loading equal to approximately 150-200% of code values. Post-earthquake reconnaissance suggested numerous failures of adhesive anchors used for retrofit connection of roof and floor diaphragms to masonry walls. A team of researchers from the Universities of Auckland (NZ) and Minnesota (USA) conducted a field investigation on the performance of new adhesive anchors installed in existing masonry walls. Variables included adhesive type, anchor diameter, embedment length, anchor inclination, and masonry quality. Buildings were selected that had been slated for demolition but which featured exterior walls that had not been damaged. A summary of the deformation response measured during the field tests are presented. AM - Accepted Manuscript

Research papers, The University of Auckland Library

The Evaluating Maternity Units (EMU) study is a mixed method project involving a prospective cohort study, surveys (two postnatal questionnaires) and focus groups. It is an Australasian project funded by the Australian Health and Medical Research Council. Its primary aim was to compare the birth outcomes of two groups of well women – one group who planned to give birth at a primary maternity unit, and a second group who planned to give birth at a tertiary hospital. The secondary aim was to learn about women’s views and experiences regarding their birthplace decision-making, transfer, maternity care and experiences, and any other issues they raised. The New Zealand arm of the study was carried out in Christchurch, and was seriously affected by the earthquakes, halting recruitment at 702 participants. Comprehensive details were collected from both midwives and women regarding antenatal and early labour changes of birthplace plans and perinatal transfers from the primary units to the tertiary hospital. Women were asked about how they felt about plan changes and transfers in the first survey, and they were discussed in some focus groups. The transfer findings are still being analysed and will be presented. This study is set within the local maternity context, is recent, relevant and robust. It provides midwives with contemporary information about transfers from New Zealand primary maternity units and women’s views and experiences. It may help inform the conversations midwives have with each other, and with women and their families/whānau, regarding the choices of birthplace for well childbearing women.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside his favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of visitors to the 'Present Tense' project which was held in Gap Filler's Inconvenience Store. The project consisted of ten paintings which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of Nikki Wallace at Gap Filler's Inconvenience Store, standing beside her favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of Catherine Morganti at Gap Filler's Inconvenience store, standing beside her favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of Jeni Reveley at Gap Filler's Inconvenience Store, standing beside her favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside his favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside her favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside his favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside his favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of visitors to the 'Present Tense' project which was held in Gap Filler's Inconvenience Store. The project consisted of ten paintings which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of visitors to the 'Present Tense' project which was held in Gap Filler's Inconvenience Store. The project consisted of ten paintings which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside her favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside her favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of visitors to Gap Filler's Inconvenience Store standing beside their favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of visitors to the 'Present Tense' project which was held in Gap Filler's Inconvenience Store. The project consisted of ten paintings which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside his favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside his favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside his favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.

Images, UC QuakeStudies

A photograph of a visitor to Gap Filler's Inconvenience Store standing beside her favourite painting. The painting was part of the 'Present Tense' project which sought to highlight the inconvenience of the city in the present day. Visitors to the store were asked to choose five paintings they would like to see presented as a billboard installation in Auckland.