Seismic performance of suspended ceilings

Research papers, University of Canterbury Library

Non-structural elements (NSEs) have frequently proven to contribute to significant losses sustained from earthquakes in the form of damage, downtime, injury and death. In New Zealand (NZ), the 2010 and 2011 Canterbury Earthquake Sequence (CES), the 2013 Seddon and Cook Strait earthquake sequence and the 2016 Kaikoura earthquake were major milestones in this regard as significant damage to building NSEs both highlighted and further reinforced the importance of NSE seismic performance to the resilience of urban centres. Extensive damage in suspended ceilings, partition walls, façades and building services following the CES was reported to be partly due to erroneous seismic design or installation or caused by intervening elements. Moreover, the low-damage solutions developed for structural systems sometimes allow for relatively large inter-story drifts -compared to conventional designs- which may not have been considered in the seismic design of NSEs. Having observed these shortcomings, this study on suspended ceilings was carried out with five main goals: i) Understanding the seismic performance of the system commonly used in NZ; ii) Understanding the transfer of seismic design actions through different suspended ceiling components, iii) Investigating potential low-damage solutions; iii) Evaluating the compatibility of the current ceiling system with other low-damage NSEs; and iv) Investigating the application of numerical analysis to simulate the response of ceiling systems. The first phase of the study followed a joint research work between the University of Canterbury (UC) in NZ, and the Politecnico Di Milano, in Italy. The experimental ceiling component fragility curves obtained in this existing study were employed to produce analytical fragility curves for a perimeter-fixed ceiling of a given size and weight, with grid acceleration as the intensity measure. The validity of the method was proven through comparisons between this proposed analytical approach with the recommended procedures in proprietary products design guidelines, as well as experimental fragility curves from other studies. For application to engineering design practice, and using fragility curves for a range of ceiling lengths and weights, design curves were produced for estimating the allowable grid lengths for a given demand level. In the second phase of this study, three specimens of perimeter-fixed ceilings were tested on a shake table under both sinusoidal and random floor motion input. The experiments considered the relationship between the floor acceleration, acceleration of the ceiling grid, the axial force induced in the grid members, and the effect of boundary conditions on the transfer of these axial forces. A direct correlation was observed between the axial force (recorded via load cells) and the horizontal acceleration measured on the ceiling grid. Moreover, the amplification of floor acceleration, as transferred through ceiling components, was examined and found (in several tests) to be greater than the recommended factor for the design of ceilings provided in the NZ earthquake loadings standard NZS1170.5. However, this amplification was found to be influenced by the pounding interactions between the ceiling grid members and the tiles, and this amplification diminished considerably when the high frequency content was filtered out from the output time histories. The experiments ended with damage in the ceiling grid connection at an axial force similar to the capacity of these joints previously measured through static tests in phase one. The observation of common forms of damage in ceilings in earthquakes triggered the monotonic experiments carried out in the third phase of this research with the objective of investigating a simple and easily applicable mitigation strategy for existing or new suspended ceilings. The tests focused on the possibility of using proprietary cross-shaped clip elements ordinarily used to provide seismic gap as a strengthening solution for the weak components of a ceiling. The results showed that the solution was effective under both tension and compression loads through increasing load bearing capacity and ductility in grid connections. The feasibility of a novel type of suspended ceiling called fully-floating ceiling system was investigated through shaking table tests in the next phase of this study with the main goal of isolating the ceiling from the surrounding structure; thereby arresting the transfer of associated seismic forces from the structure to the ceiling. The fully-floating ceiling specimen was freely hung from the floor above lacking any lateral bracing and connections with the perimeter. Throughout different tests, a satisfactory agreement between the fully-floating ceiling response and simple pendulum theory was demonstrated. The addition of isolation material in perimeter gaps was found effective in inducing extra damping and protecting the ceiling from pounding impact; resulting in much reduced ceiling displacements and accelerations. The only form of damage observed throughout the random floor motion tests and the sinusoidal tests was a panel dislodgement observed in a test due to successive poundings between the ceiling specimen and the surrounding beams at resonant frequencies. Partition walls as the first effective NSE in direct interaction with ceilings were the topic of the final experimental phase. Low-damage drywall partitions proposed in a previous study in the UC were tested with two common forms of suspended ceiling: braced and perimeter-fixed. The experiments investigated the in-plane and out-of-plane performance of the low-damage drywall partitions, as well as displacement compatibility between these walls and the suspended ceilings. In the braced ceiling experiment, where no connection was made between ceiling grids and surrounding walls no damage in the grid system or partitions was observed. However, at high drift values panel dislodgement was observed on corners of the ceiling where the free ends of grids were not restrained against spreading. This could be prevented by framing the grid ends using a perimeter angle that is riveted only to the grid members while keeping sufficient clearance from the perimeter walls. In the next set of tests with the perimeter-fixed ceiling, no damage was observed in the ceiling system or the drywalls. Based on the results of the experiments it was concluded that the tested ceiling had enough flexibility to accommodate the relative displacement between two perpendicular walls up to the inter-storey drifts achieved. The experiments on perimeter-fixed ceilings were followed by numerical simulations of the performance of these ceilings in a finite element model developed in the structural analysis software, SAP2000. This model was relatively simple and easy to develop and was able to replicate the experimental results to a reasonable degree. Filtering was applied to the experimental output to exclude the effect of high frequency noise and tile-grid impact. The developed model generally simulated the acceleration responses well but underestimated the peak ceiling grid accelerations. This was possibly because the peak values in time histories were affected by impact occurring at very short periods. The model overestimated the axial forces in ceiling grids which was assumed to be caused by the initial assumptions made about the tributary area or constant acceleration associated with each grid line in the direction of excitation. Otherwise, the overall success of the numerical modelling in replicating the experimental results implies that numerical modelling using conventional structural analysis software could be used in engineering practice to analyse alternative ceiling geometries proposed for application to varying structural systems. This however, needs to be confirmed through similar analyses on other ceiling examples from existing instrumented buildings during real earthquakes. As the concluding part of this research the final phase addressed the issues raised following the review of existing ceiling standards and guidelines. The applicability of the research findings to current practice and their implications were discussed. Finally, an example was provided for the design of a suspended ceiling utilising the new knowledge acquired in this research.

Fine grained sediment clean-up in a modern urban environment

Research papers, University of Canterbury Library

Fine grained sediment deposition in urban environments during natural hazard events can impact critical infrastructure and properties (urban terrain) leading to reduced social and economic function and potentially adverse public health effects. Therefore, clean-up of the sediments is required to minimise impacts and restore social and economic functionality as soon as possible. The strategies employed to manage and coordinate the clean-up significantly influence the speed, cost and quality of the clean-up operation. Additionally, the physical properties of the fine grained sediment affects the clean-up, transport, storage and future usage of the sediment. The goals of the research are to assess the resources, time and cost required for fine grained sediment clean-up in an urban environment following a disaster and to determine how the geotechnical properties of sediment will affect urban clean-up strategies. The thesis focuses on the impact of fine grained sediment (<1 mm) deposition from three liquefaction events during the Canterbury earthquake sequence (2010-2011) on residential suburbs and transport networks in Christchurch. It also presents how geotechnical properties of the material may affect clean-up strategies and methods by presenting geotechnical analysis of tephra material from the North Island of New Zealand. Finally, lessons for disaster response planning and decision making for clean-up of sediment in urban environments are presented. A series of semi-structured interviews of key stakeholders supported by relevant academic literature and media reports were used to record the clean-up operation coordination and management and to make a preliminary qualification of the Christchurch liquefaction ejecta clean-up (costs breakdown, time, volume, resources, coordination, planning and priorities). Further analysis of the costs and resources involved for better accuracy was required and so the analysis of Christchurch City Council road management database (RAMM) was done. In order to make a transition from general fine sediment clean-up to specific types of fine disaster sediment clean-up, adequate information about the material properties is required as they will define how the material will be handled, transported and stored. Laboratory analysis of young volcanic tephra from the New Zealand’s North Island was performed to identify their geotechnical properties (density, granulometry, plasticity, composition and angle of repose). The major findings of this research were that emergency planning and the use of the coordinated incident management system (CIMS) system during the emergency were important to facilitate rapid clean-up tasking, management of resources and ultimately recovery from widespread and voluminous liquefaction ejecta deposition in eastern Christchurch. A total estimated cost of approximately $NZ 40 million was calculated for the Christchurch City clean-up following the 2010-2011 Canterbury earthquake sequence with a partial cost of $NZ 12 million for the Southern part of the city, where up to 33% (418 km) of the road network was impacted by liquefaction ejecta and required clearing of the material following the 22 February 2011 earthquake. Over 500,000 tonnes of ejecta has been stockpiled at Burwood landfill for all three liquefaction inducing earthquake events. The average cost per kilometre for the event clean-up was $NZ 5,500/km (4 September 2010), $NZ 11,650/km (22 February 2011) and $NZ 11,185/km (13 June 2011). The duration of clean-up time of residential properties and the road network was approximately two to three months for each of the three liquefaction ejecta events; despite events volumes and spatial distribution of ejecta. Interviews and quantitative analysis of RAMM data revealed that the experience and knowledge gained from the Darfield earthquake (4 September 2010) clean-up increased the efficiency of the following Christchurch earthquake induced liquefaction ejecta clean-up events. Density, particle size, particle shape, clay content and moisture content, are the important geotechnical properties that need to be considered when planning for a clean-up method that incorporates collection, transport and disposal or storage. The geotechnical properties for the tephra samples were analysed to increase preparedness and reaction response of potentially affected North Island cities from possible product from the active volcanoes in their region. The geotechnical results from this study show that volcanic tephra could be used in road or construction material but the properties would have to be further investigated for a New Zealand context. Using fresh volcanic material in road, building or flood control construction requires good understanding of the material properties and precaution during design and construction to extra care, but if well planned, it can be economically beneficial.

Engineering geological investigation of the Lake Coleridge rock avalanche …

Research papers, University of Canterbury Library

The Lake Coleridge Rock Avalanche Deposits (LCRADs) are located on Ryton Station in the middle Rakaia Valley, approximately 80 km west of Christchurch. Torlesse Supergroup greywacke is the basement material and has been significantly influenced by both active tectonics and glaciation. Both glacial and post-glacial processes have produced large volumes of material which blanket the bedrock on slopes and in the valley floors. The LCRADs were part of a regional study of rock avalanches by WHITEHOUSE (1981, 1983) and WHITEHOUSE and GRIFFITHS (1983), and a single rock avalanche event was recognised with a weathering rind age of 120 years B.P. that was later modified to 150 ± 40 years B.P. The present study has refined details of both the age and the sequence of events at the site, by identifying three separate rock avalanche deposits (termed the LCRA1, LCRA2 and LCRA3 deposits), which are all sourced from near the summit of Carriage Drive. The LCRA1 deposit is lobate in shape and had an estimated original deposit volume of 12.5 x 10⁶ m³, although erosion by the Ryton River has reduced the present day debris volume to 5.1 x 10⁶ m³. An optically stimulated luminescence date taken from sandy loess immediately beneath the LCRA1 deposit provided a maximum age for the rock avalanche event of 9,720 ± 750 years B.P., which is believed to be realistic given that this is shortly after the retreat of Acheron 3 ice from this part of the valley. Emplacement of rock avalanche material into an ancestral Ryton riverbed created a natural dam with a ~17 M m³ lake upstream. The river is thought to have created a natural spillway over the dam structure at ~557 m (a.s.l), and to have existed for a number of years before any significant downcutting occurred. Although a triggering mechanism for the LCRA1 deposit was poorly constrained, it is thought that stress rebound after glacial ice removal may have initiated failure. Due to the event occurring c.10,000 years ago, there was a lack of definition for a possible earthquake trigger, though the possibility is obvious. The LCRA₂ event had an original deposit volume of 0.66 x 10⁶ m³, and was constrained to the low-lying area adjacent to the Ryton River that had been created by river erosion of the LCRA1 deposit. Further erosion by the Ryton River has reduced the deposit volume to 0.4 x 10⁶ m³. A radiocarbon date from a piece of mānuka found within the LCRA2 deposit provided an age of 668 ± 36 years B.P., and this is thought to reliably date the event. The LCRA2 event also dammed the Ryton River, and the preservation of dam-break outwash terraces downstream from the deposit provides clear evidence of rapid dam erosion and flooding after overtopping, and breaching by the Ryton River. Based on the mean annual flow of the Ryton River, the LCRA2 lake would have taken approximately two weeks to fill assuming that there were no preferred breach paths and the material was relatively impermeable. The LCRA2 event is thought to have been coseismic with a fault rupture along the western segment of the PPAFZ, which has been dated at 600 ± 100 years B.P. by SMITH (2003). The small LCRA3 event was not able to be dated, but it is believed to have failed shortly after the LCRA2 event and it may in fact be a lag deposit of the second rock avalanche event possibly triggered by an aftershock. The deposit is only visible at one locality within the cliffs that line the Ryton River, and its lack of geomorphic expression is attributed to it occurring closely after the LCRA2 event, while the Ryton River was still dammed from the second rock avalanche event. A wedge-block of some 35,000 m³ of source material for a future rock avalanche was identified at the summit of Carriage Drive. The dilation of the rock mass, combined with unfavourably oriented sub-vertical bedding in the Torlesse Supergroup bedrock, has allowed toppling-style failure on both of the main ridge lines around the source area for the LCRADs. In the event of a future rock avalanche occurring within the Ryton riverbed an emergency response plan has been developed to provide a staged response, especially in relation to the camping ground located at the mouth of the Ryton River. A long-term management plan has also been developed for mitigation measures for the Ryton riverbed and adjacent floodplain areas downstream of a future rock avalanche at the LCRAD site.

Geologic and anthropogenic influences on rockfall and liquefaction in the …

Research papers, University of Canterbury Library

Geologic phenomena produced by earthquake shaking, including rockfalls and liquefaction features, provide important information on the intensity and spatiotemporal distribution of earthquake ground motions. The study of rockfall and liquefaction features produced in contemporary well- instrumented earthquakes increases our knowledge of how natural and anthropogenic environments respond to earthquakes and improves our ability to deduce seismologic information from analogous pre-contemporary (paleo-) geologic features. The study of contemporary and paleo- rockfall and liquefaction features enables improved forecasting of environmental responses to future earthquakes. In this thesis I utilize a combination of field and imagery-based mapping, trenching, stratigraphy, and numerical dating techniques to understand the nature and timing of rockfalls (and hillslope sedimentation) and liquefaction in the eastern South Island of New Zealand, and to examine the influence that anthropogenic activity has had on the geologic expressions of earthquake phenomena. At Rapaki (Banks Peninsula, NZ), field and imagery-based mapping, statistical analysis and numerical modeling was conducted on rockfall boulders triggered by the fatal 2011 Christchurch earthquakes (n=285) and compared with newly identified prehistoric (Holocene and Pleistocene) boulders (n=1049) deposited on the same hillslope. A significant population of modern boulders (n=26) travelled farther downslope (>150 m) than their most-travelled prehistoric counterparts, causing extensive damage to residential dwellings at the foot of the hillslope. Replication of prehistoric boulder distributions using 3-dimensional rigid body numerical models requires the application of a drag-coefficient, attributed to moderate to dense slope vegetation, to account for their spatial distribution. Radiocarbon dating provides evidence for 17th to early 20th century deforestation at the study site during Polynesian and European colonization and after emplacement of prehistoric rockfalls. Anthropocene deforestation enabled modern rockfalls to exceed the limits of their prehistoric predecessors, highlighting a shift in the geologic expression of rockfalls due to anthropogenic activity. Optical and radiocarbon dating of loessic hillslope sediments in New Zealand’s South Island is used to constrain the timing of prehistoric rockfalls and associated seismic events, and quantify spatial and temporal patterns of hillslope sedimentation including responses to seismic and anthropogenic forcing. Luminescence ages from loessic sediments constrain timing of boulder emplacement to between ~3.0 and ~12.5 ka, well before the arrival of Polynesians (ca AD 1280) and Europeans (ca AD 1800) in New Zealand, and suggest loess accumulation was continuing at the study site until 12-13 ka. Large (>5 m3) prehistoric rockfall boulders preserve an important record of Holocene hillslope sedimentation by creating local traps for sediment aggradation and upbuilding soil formation. Sediment accumulation rates increased considerably (>~10 factor increase) following human arrival and associated anthropogenic burning of hillslope vegetation. New numerical ages are presented to place the evolution of loess-mantled hillslopes in New Zealand’s South Island into a longer temporal framework and highlight the roles of earthquakes and humans on hillslope surface process. Extensive field mapping and characterization for 1733 individual prehistoric rockfall boulders was conducted at Rapaki and another Banks Peninsula site, Purau, to understand their origin, frequency, and spatial and volumetric distributions. Boulder characteristics and distributions were compared to 421 boulders deposited at the same sites during the 2010-2011 Canterbury earthquake sequence. Prehistoric boulders at Rapaki and Purau are comprised of two dominant lithofacies types: volcanic breccia and massive (coherent) lava basalt. Volcanic breccia boulders are found in greatest abundance (64-73% of total mapped rockfall) and volume (~90-96% of total rockfall) at both locations and exclusively comprise the largest boulders with the longest runout distances that pose the greatest hazard to life and property. This study highlights the primary influence that volcanic lithofacies architecture has on rockfall hazard. The influence of anthropogenic modifications on the surface and subsurface geologic expression of contemporary liquefaction created during the 2010-2011 Canterbury earthquake sequence (CES) in eastern Christchurch is examined. Trench observations indicate that anthropogenic fill layer boundaries and the composition/texture of discretely placed fill layers play an important role in absorbing fluidized sand/silt and controlling the subsurface architecture of preserved liquefaction features. Surface liquefaction morphologies (i.e. sand blows and linear sand blow arrays) display alignment with existing utility lines and utility excavations (and perforated pipes) provided conduits for liquefaction ejecta during the CES. No evidence of pre-CES liquefaction was identified within the anthropogenic fill layers or underlying native sediment. Radiocarbon dating of charcoal within the youngest native sediment suggests liquefaction has not occurred at the study site for at least the past 750-800 years. The importance of systematically examining the impact of buried infrastructure on channelizing and influencing surface and subsurface liquefaction morphologies is demonstrated. This thesis highlights the importance of using a multi-technique approach for understanding prehistoric and contemporary earthquake phenomena and emphasizes the critical role that humans play in shaping the geologic record and Earth’s surface processes.

Question Time for 27 June 2019

Audio, Radio New Zealand

Hon RUTH DYSON to the Minister for Greater Christchurch Regeneration: What progress has been made on the Crown’s Global Settlement with the Christchurch City Council for costs flowing from the Canterbury earthquake sequence? Hon PAUL GOLDSMITH to the Minister of Finance: Does he stand by all of his policies, statements, and actions? Hon JUDITH COLLINS to the Minister of Housing and Urban Development: Does he stand by his statement in response to a question on if he would meet his commitment to be a keynote speaker at the KiwiBuild summit on 24 June, “No, because I have two papers at Cabinet”, and did he take two papers to Cabinet on 24 June? GARETH HUGHES to the Minister of State Services: Does he support measuring and improving the energy efficiency of Government buildings, both leased and owned? Hon MICHAEL WOODHOUSE to the Minister of Health: Does he stand by his statement yesterday that “Yes, that will mean that we will have deficits that we wouldn’t want to see. That member and his Government under-invested in health for nine long years, and we will be investing ourselves for quite a period to set that right”; if so, when will he “set that right”? Dr DUNCAN WEBB to the Minister of Justice: What recent announcements has he made regarding community law centres? CHRIS BISHOP to the Minister of Transport: What will the percentage increase in the fuel excise duty and accompanying road-user charges be on Monday, 1 July, and what will be the total revenue raised from this increase? Hon TIM MACINDOE to the Minister for ACC: Does he stand by all of his answers during the Vote Labour Market Estimates hearing at the Education and Workforce Committee meeting on 12 June? Dr LIZ CRAIG to the Minister of Health: What, if anything, is the Government doing to better support the wellbeing of parents with mental health and addiction needs? Hon LOUISE UPSTON to the Minister for Women: How can she be responsible for eliminating the gender pay gap when the Ministry for Women’s gender pay gap has gone from 5.6 percent in favour of women to 6 percent in favour of men? JONATHAN YOUNG to the Minister of Energy and Resources: Does she stand by all her statements, policies, and actions? ANAHILA KANONGATA'A-SUISUIKI to the Minister for Pacific Peoples: How does Budget 2019 support Pacific peoples in Aotearoa New Zealand?

Question Time for 11 December 2012

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DAVID SHEARER to the Prime Minister: Does he stand by his statement &quot;I am deeply concerned about every child in New Zealand who is in poverty&quot;; if so, why has the number of children living in material hardship grown under his watch? TODD McCLAY to the Minister of Finance: What measures has the Government taken to support vulnerable New Zealanders through the aftermath of the domestic recession and global financial crisis? METIRIA TUREI to the Prime Minister: When he said &quot;we don't want to see any New Zealand child suffer &hellip; children don't get to make choices, they're often the victim of circumstance&quot; does that mean he will take tangible steps to ensure children don't suffer because of circumstances beyond their control? Rt Hon WINSTON PETERS to the Prime Minister: Does he have confidence in the Minister of Immigration? Hon DAVID PARKER to the Minister of Finance: Compared to 2012, does the Reserve Bank forecast the New Zealand dollar (as measured by the Trade Weighted Index) to strengthen or weaken in the next two years, and does he believe this will make New Zealand exporters more competitive or less competitive? DAVID BENNETT to the Minister for Economic Development: How is the Government encouraging the sustainable use of natural resources to support jobs and grow the economy? Hon MARYAN STREET to the Minister of Health: Is he satisfied with the state of children's health in New Zealand; if not, why not? COLIN KING to the Minister of Energy and Resources: What recent announcement has he made about Block Offer 2012? EUGENIE SAGE to the Minister for the Environment: Does she agree with the New Zealand Freshwater Sciences Society in relation to freshwater that &quot;failure to act with decisiveness and urgency risks further environmental degradation and erosion of our international environmental reputation&quot;; if not, why not? Hon LIANNE DALZIEL to the Minister for Building and Construction: How quickly will he respond to the building performance, assessment and construction recommendations of the Royal Commission of Inquiry into Building Failure caused by the Canterbury Earthquakes? NICKY WAGNER to the Minister for Building and Construction: What is the Government doing in response to the Canterbury Earthquakes Royal Commission's full report? CLARE CURRAN to the Prime Minister: Does he stand by all his statements?

Question Time for 25 October 2012

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Hon DAVID PARKER to the Minister of Finance: Does he stand by his answer on Tuesday regarding jobs &quot;I think that the number of 170,000 may come from the initial Budget forecast for 2009, perhaps. I cannot remember the year exactly.&quot;? Dr KENNEDY GRAHAM to the Minister for Climate Change Issues: Given the recent loss of Māori Party support for his Climate Change Response (Emissions Trading and Other Matters) Amendment Bill, will he consider working with opposition parties on amendments to improve it? LOUISE UPSTON to the Minister of Finance: How is the Government's infrastructure programme contributing to building a more competitive economy? Hon DAVID CUNLIFFE to the Minister for Economic Development: Does he agree with the NZIER shadow board that &quot;the growth outlook for the second half of 2012 looks weak and unemployment remains stubbornly high.&quot;? IAN McKELVIE to the Minister for Social Development: What announcements has she made to review Child Youth and Family's complaints process? Hon MARYAN STREET to the Minister of Health: What progress has been made in the delivery of the Prime Minister's Youth Mental Health Project announced in April of this year with an extra $11.3 million provided to support it? JACQUI DEAN to the Minister for the Environment: What reports has she received on the time taken for decisions on notified consents issued under the Resource Management Act 1991? GARETH HUGHES to the Minister of Foreign Affairs: Why did New Zealand pull out of a joint proposal with the United States to create a marine reserve in Antarctica's Ross Sea? Rt Hon WINSTON PETERS to the Prime Minister: Does he stand by the answers he gave yesterday to supplementary question 5 on Oral Question No 7 and supplementary question 3 on Oral Question No 12? NICKY WAGNER to the Minister for Canterbury Earthquake Recovery: What progress has the Government made to support repairing damaged houses and infrastructure following the Canterbury earthquakes? SUE MORONEY to the Prime Minister: Does he stand by his statement on 3News last night, on the subject of Business New Zealand's assertion that women need retraining when returning to employment after extended parental leave that &quot;no. It wouldn't be my view&quot;? JAMI-LEE ROSS to the Minister of Immigration: What is the Government doing to ensure that New Zealanders have first priority for jobs in the Canterbury rebuild?

Question Time for 14 September 2010

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Questions to Ministers 1. AARON GILMORE to the Minister of Finance: What steps are the Government and the Earthquake Commission taking to streamline the Canterbury earthquake claims process? 2. Hon PHIL GOFF to the Prime Minister: Does he stand by his statement that "the vast majority" of people will be "better off" as a result of his tax switch on 1 October 2010? 3. KEVIN HAGUE to the Minister of Conservation: Does she agree with Forest and Bird that "many endangered species will meet a watery death, or be rudely shunted from their homes", if the Mōkihinui dam is given the green light? 4. Hon ANNETTE KING to the Minister for ACC: Is he satisfied with the performance of ACC? 5. NICKY WAGNER to the Minister for Economic Development: What steps will the Government take to aid the recovery of the Canterbury region from the recent major earthquake? 6. Hon DAVID CUNLIFFE to the Minister of Finance: What advice, if any, did Treasury receive from KordaMentha in relation to South Canterbury Finance's financial condition prior to approving the extension of the Crown Retail Deposit Guarantee Scheme, and did this advice question whether such an extension was appropriate? 7. COLIN KING to the Minister of Transport: What is the Government doing to address challenges in delivering supplies into the area affected by the Canterbury earthquake? 8. Hon RUTH DYSON to the Minister of Health: When will all the District Health Board Annual Plans for 2010/11 be publicly available? 9. JO GOODHEW to the Minister of Education: How were Canterbury schools affected by last Saturday's earthquake, and what is the current situation for schools in the region? 10. Hon DAVID PARKER to the Attorney-General: Is his objective under the new foreshore and seabed bill to settle the protracted controversy around foreshore and seabed? 11. AMY ADAMS to the Minister of Agriculture: What is the Government doing to support the rural Canterbury community through the earthquake recovery? 12. DARIEN FENTON to the Minister of Labour: Does she stand by all of the statements made on her behalf in response to question for oral answer No. 11 on 9 September 2010? Questions to Members 1. DARIEN FENTON to the Chairperson of the Transport and Industrial Relations Committee: How many submissions were received on the Employment Relations Amendment Bill (No. 2) as at 5pm Monday, 13 September 2010?

Question Time for 14 June 2011

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Questions to Ministers 1. Hon ANNETTE KING to the Prime Minister: What recent reports has he received on the impact of rising prices on families in light of his statement that "no one is worse off"? 2. AARON GILMORE to the Minister of Finance: How is the Government supporting the earthquake recovery effort in Canterbury? 3. Hon DAVID CUNLIFFE to the Prime Minister: Does he stand by his statement that his plan to sell public assets would give "New Zealanders a fantastic opportunity to invest in this country's future"? 4. KANWALJIT SINGH BAKSHI to the Minister of Corrections: What progress has been made in using technology to improve public safety and reduce costs in the criminal justice system? 5. Hon DAVID PARKER to the Prime Minister: Does he stand by his statement "each of us can do something that could save someone's job, create a new job for another person or help someone else find a new job as soon as possible"? 6. LOUISE UPSTON to the Minister for Communications and Information Technology: What benefits will ultra-fast broadband services bring to education in New Zealand? 7. GRANT ROBERTSON to the Minister of Health: Is it correct that there is a $156 million gap between the amount the Ministry of Health has advised was necessary to meet population and demographic growth in Vote Health for 2011/12 and the amount of new spending allocated for Vote Health in the 2011 Budget? 8. KEVIN HAGUE to the Prime Minister: Does he stand by his statement on Breakfast yesterday that "we're constantly changing aquaculture laws, or fishing laws, or whatever it might be. I mean in the case of Sky City, that particular licence is site specific"? 9. JACINDA ARDERN to the Prime Minister: Does he stand by his statement that "it is New Zealanders … that create new jobs and opportunities - not the Government"? 10. KATRINA SHANKS to the Minister of Housing: What recent announcement has he made about the Government's response to the Housing Shareholders' Advisory Group report? 11. DARIEN FENTON to the Prime Minister: Does he stand by his statement on proposed labour law changes "we are not talking dramatic changes"? 12. JONATHAN YOUNG to the Acting Minister of Energy and Resources: What recent initiatives has the Government undertaken to help New Zealanders control the cost of their power bills?

A line of best fit: Re-stitching earthquake prone buildings and re-connect…

Research papers, Victoria University of Wellington

A Line of Best Fit explores weakness and disconnection in the city. Weakness: There are over 600 earthquake prone buildings in Wellington. The urgency to strengthen buildings risks compromising the aesthetic integrity of the city through abrasive strengthening techniques, or losing a large portion of our built environment to demolition. The need for extensive earthquake strengthening in Wellington, Christchurch and other New Zealand cities provides an exciting opportunity for architecture. Disconnection: In Wellington pedestrian activity is focused around three main routes: Cuba Street, Lambton Quay and Courtney Place. The adjacent areas are often disconnected and lack vibrancy due to large building footprints, no-exit laneways and lack of public spaces. The Design proposes a strategy for earthquake strengthening, preserving and upgrading the built environment, and expanding and connecting the pedestrian realm. The site is two earthquake prone buildings on the block between Marion Street and Taranaki Street in central Wellington. A cut through the centre of the Aspro and Cathie Buildings ties the buildings together to strengthen and create a new arcade as public space. The cut aligns with existing pedestrian routes connecting the block with the city. The Design is divided into three components: Void, Curve, and Pattern and Structure. Void investigates the implications of cutting a portion out the existing buildings and the opportunities this provides for connection, urban interaction, and light. Curve discusses the unusual form of The Design in terms of scale, the human response and the surrounding spaces. Pattern and Structure considers the structural requirements of the project and how a void enveloped in perforated screens can strengthen the earthquake prone buildings. The importance of connection, providing strength in the city, a dialogue between old and new, and engagement with the unexpected are evaluated. Opportunities for further development and research are discussed, with particular reference to how the principles of The Design could be implemented on a larger scale throughout our cities. A Line of Best Fit is an architectural proposal that creates strength and connection.

"Ko Wai te Ingoa o Tenei Whare?" Architecture and Māori Identity

Research papers, Victoria University of Wellington

The whare whakairo or traditional Māori meeting house plays an important part in Māori society and identity. These whare tell the tale of their origin, and in so doing, the origins of their people. The analysis of the meeting house, the histories expressed in its decorative carvings and structural elements are inextricably linked with and dependent upon the structure of the world created by myth and the Māori worldview. However, due to the deleterious effects of colonisation, the art of wood carving and associated architectural practices - central to Māori identity, suffered decline in many parts of the country, leading to the decline of Māori culture and identity. Sir Apirana Ngata instigated the National Institute of Māori Arts and Crafts to resurrect the dying art of Māori carving and carved houses would be a catalyst for the restoration of Māori culture throughout the country. Ngata saw these whare whakairo as being the heart of Māori communities by establishing a renewed sense of belonging and identification with space for Māori, through the telling of tribal histories and emphasising key geographical features. New threats in the form of global hegemony and urbanisation have further impacted on Māori notions of identity, creating a generation of displaced urban Māori youth. This research proposes to establish an architectural response to capture displaced Māori youth through the resurrection of the Māori carving school and return to them the lost stories of their cultural history and identity. This program will be developed within the complex challenges that exist within post-earthquake Ōtautahi/Christchurch, where many have lost homes and livelihoods, especially Māori youth in the Eastern Suburbs. The building elements of the proposed Māori carving school give reference to the historio-cultural features of the original Ōtautahi/Christchurch landscape that are situated in tribal song and myth. It is envisioned that the development of a Māori carving school will help restore Māori identity and a renewed sense of belonging, and allow for the telling of this generations stories through traditional narratives.

Question Time for 29 June 2017

Audio, Radio New Zealand

PHIL TWYFORD to the Minister for Building and Construction: Does he agree with Mainfreight founder and Chairman Bruce Plested that housing is a &ldquo;social disgrace&rdquo;, that the market cannot sort out this problem, and that real leadership and intestinal fortitude is needed now? JONATHAN YOUNG to the Minister of Finance: What reports has he received on real after-tax wages rising in New Zealand? CHRIS HIPKINS to the Minister of Education: Will she apologise on behalf of the Government for the flawed handling of the Canterbury school mergers and closures after the 2011 earthquakes; if not, why not? ANDREW BAYLY to the Minister for Building and Construction: What progress has the Government made in improving the tenancy laws and guidance for dealing with the problem of methamphetamine testing and contamination? CARMEL SEPULONI to the Associate Minister for Social Housing: What motels has the Government purchased in response to the increased emergency housing demand, and how much has this cost? RON MARK to the Prime Minister: Does he stand by all his statements on the Clutha-Southland electorate office issue even if facts known to him make doing so extraordinarily difficult? MAUREEN PUGH to the Minister of Corrections: How is Budget 2017 investing in rehabilitation and reintegration outcomes for offenders? Hon DAVID PARKER to the Minister of Local Government: Does she agree with the Prime Minister&rsquo;s answer yesterday that drinking-water contamination in Havelock North was &ldquo;about local government performance and overseeing ratepayer-funded assets whose purpose is to deliver clean and healthy water to its local people. The extensive inquiry into that incident was warranted by widespread illness in the area ... it is about local body performance in overseeing their clean water system&rdquo;? BRETT HUDSON to the Minister of Local Government: What recent announcements has she made regarding Wellington&rsquo;s resilience to natural hazards? JULIE ANNE GENTER to the Minister of Transport: Will the Government start building rail to the airport sooner if Auckland hosts the next America&rsquo;s Cup regatta or will Aucklanders still have to wait 30 years? STUART NASH to the Minister of Police: Does she have any concerns about any of the results of the New Zealand Police Workplace Survey 2017; if so, what in particular? ALASTAIR SCOTT to the Associate Minister of Education: What recent announcements has he made to improve school infrastructure in the Wairarapa?

Effects of Member Overstrength and Initial Residual Stresses on the Behavi…

Research papers, University of Canterbury Library

Extended Direct Analysis (EDA), developed at the University of Canterbury, is an advance on the AISC Direct Analysis method for the analysis of frames subjected to static forces. EDA provides a faster, simple and more rational way to properly consider the second-order effects, initial residual stresses (IRS) and the initial imperfections or steel structures under one directional loading than conventional analysis methods. This research applied the EDA method to quantify the effect of member overstrength on frame behaviour for a single storey frame. Also, the effects of IRS, which were included in the EDA static analysis, but which are not considered explicitly in non-linear seismic analysis, were evaluated in two ways. Firstly, they were considered for simple structures subject to increasing cyclic displacement in different directions. Secondly, incremental dynamic analysis with realistic ground motion was used to quantify the likely effect of IRS in earthquakes. It was found that, contrary to traditional wisdom and practice, greater member strengths can result in lower frame strengths for frames under monotonic lateral loading. The structural lateral capacity of the overstrength case was reduced by 6% compared to the case using the dependable member strengths. Also, it resulted significantly different in member demands. Therefore, it is recommended that when either plastic analysis or EDA is used, that both upper and lower bounds on the likely member strength should be considered to determine the total frame strength and the member demands. Results of push-pull analysis under displacement control showed that for IRS ratio, gamma < 0.5 and axial compressive force ratio, N*/Ns, up to 0.5, IRS did affect the structural behaviour in the first half cycle. However, the behavior in the later cycles was not significantly affected. It also showed that the effect of initial residual stresses in the frame was less significant than for the column alone when the column was subjected to similar axial compressive force. The incremental dynamic analysis results from both cantilever column and the three-storey steel frame showed that by increasing gamma = 0 to 0.5, the effect of IRS on seismic responses, based on the 50% confidence level, was less than 3% for N*/Ns, up to 0.5.

How important is the CERA recovery strategy to Canterbury refugees?

Research papers, University of Canterbury Library

For the people of Christchurch and its wider environs of Canterbury in New Zealand, the 4th of September 2010 earthquake and the subsequent aftershocks were daunting. To then experience a more deadly earthquake five months later on the 22nd of February 2011 was, for the majority, overwhelming. A total of 185 people were killed and the earthquake and continuing aftershocks caused widespread damage to properties, especially in the central city and eastern suburbs. A growing body of literature consistently documents the negative impact of experiencing natural disasters on existing psychological disorders. As well, several studies have identified positive coping strategies which can be used in response to adversities, including reliance on spiritual and cultural beliefs as well as developing resilience and social support. The lifetime prevalence of severe mental health disorders such as posttraumatic stress disorder (PTSD) occurring as a result of experiencing natural disasters in the general population is low. However, members of refugee communities who were among those affected by these earthquakes, as well as having a past history of experiencing traumatic events, were likely to have an increased vulnerability. The current study was undertaken to investigate the relevance to Canterbury refugee communities of the recent Canterbury Earthquake Recovery Authority (CERA) draft recovery strategy for Christchurch post-earthquakes. This was accomplished by interviewing key informants who worked closely with refugee communities. These participants were drawn from different agencies in Christchurch including Refugee Resettlement Services, the Canterbury Refugee Council, CERA, and health promotion and primary healthcare organisations, in order to obtain the views of people who have comprehensive knowledge of refugee communities as well as expertise in local mainstream services. The findings from the semi-structured interviews were analysed using qualitative thematic analysis to identify common themes raised by the participants. The key informants described CERA’s draft recovery strategy as a significant document which highlighted the key aspects of recovery post disaster. Many key informants identified concerns regarding the practicality of the draft recovery strategy. For the refugee communities, some of those concerns included the short consultation period for the implementation phase of the draft recovery strategy, and issues surrounding communication and collaboration between refugee agencies involved in the recovery. This study draws attention to the importance of communication and collaboration during recovery, especially in the social reconstruction phase following a disaster, for all citizens but most especially for refugee communities.

The Hope Fault at Hossack Station east of Hanmer Basin, North Canterbury

Research papers, University of Canterbury Library

Oblique convergence of the Pacific and Australian Plates is accommodated in the northern South Island by the Marlborough Fault System. The Hope Fault is the southern of four major dextral strike-slip faults of this system. Hanmer Basin is a probable segment boundary between the Hope River and Conway segments of the Hope Fault. The Conway segment is transpressional and shows increasing structural complexity near the segment boundary at Hanmer Basin, with multiple Late Quaternary traces, and fault-parallel folding in response to across-fault shortening. Between Hossack Station and Hanmer Basin a crush zone in excess of one kilometre wide is exposed in incised streams and rivers. The crush zone has an asymmetrical geometry about the active trace of the Hope Fault, being only 100-300 metres wide south of the fault, and more than 500 metres wide north of the fault. The most intense deformation of Torlesse bedrock occurs at the south side of the fault zone, indicating that strain is accommodated against the fault footwall. North of the fault deformation is less intense, but occurs over a wider area. The wide fault zone at Hossack Station may reflect divergence of the Hanmer Fault, a major splay of the Hope Fault. At Hossack Station, the Hope Fault has accommodated at least 260 metres of dextral displacement during the Holocene. Dating of abandoned stream channels, offset by the Hope Fault, indicated a Late Holocene dextral slip-rate of 18±8 mm-¹ for the west end of the Conway segment. Using empirical formulae and inferred fault parameters, the expected magnitude of an earthquake generated by the Conway segment is M6.9 to M7.4; for an exceedence probability of 10%, the magnitude is M7.7 to M7.9. Effects associated with coseismic rupture of the Conway segment include shaking of up to MMIX along the ruptured fault and at Hanmer Basin. Uplift at the east end of Hanmer Basin, in conjunction with subsidence at the southwest margin of the basin, is resulting in the development of onlapping stratigraphy. Seismic reflection profiles support this theory. Possible along-fault migration of the basin is inferred to be a consequence of non-parallelism of the master faults.

An evaluation of the late Quaternary displacements and seismic hazard asso…

Research papers, University of Canterbury Library

The Amuri Earthquake of September 1, 1888 (magnitude M = 6.5 to 6.8) occurred on the Hope River Segment of the Hope Fault west of Hanmer Plains. The earthquake was felt strongly in North Canterbury and North Westland and caused considerable property damage and landsliding in the Lower Hope Valley. However, damage reports and the spatial distribution of felt intensities emphasize extreme variations in seismic effects over short distances, probably due to topographic focusing and local ground conditions. Significant variations in lateral fault displacement occurred at secondary fault segment boundaries (side-steps and bends in the fault trace) during the 1888 earthquake. This historical spatial variation in lateral slip is matched by the Late Quaternary geomorphic distribution of slip on the Hope River Segment of the Hope Fault. Trenching studies at two sites on the Hope Fault have also identified evidence for five pre-historic earthquakes of similar magnitude to the 1888 earthquake and an average recurrence interval of 134 ± 27 years between events. Magnitude estimates for the 1888 earthquake are combined with a. strong ground motion attenuation expression to provide an estimate of potential ground accelerations in Amuri District during-future earthquakes on the Hope River Segment of the Hope Fault. The predicted acceleration response on bedrock sites within 20 km of the epicentral region is between 0.23 g and 0.34 g. The close match between the historic, inferred pre-historic and geomorphic distribution of lateral slip indicates that secondary fault segmentation exerts a strong structural control on rupture propagation and the expression of fault displacement at the surface. In basement rocks at depth the spatial variations in slip are inferred to be distributed within zones of pervasive cataclastic shear, on either side of the fault segment boundaries. The large variations in surface displacement across fault segment boundaries means that one must know the geometry of the fault in order to evaluate slip-rates calculated from individual locations. The average Late Quaternary slip-rate on the Hope Fault at Glynn Wye Station is between 15.5 mm/yr and 18.25 mm/yr and the rate on the subsidiary Kakapo Fault is between 5.0 mm/yr and 7.5 mm/yr. These rates have been determined from sites which are relatively free of structural complication.

Planning for resilient communities: and every other day: learning from the…

Research papers, University of Canterbury Library

After a disaster, cities experience profound social and environmental upheaval. Current research on disasters describes this social disruption along with collective community action to provide support. Pre-existing social capital is recognised as fundamental to this observed support. This research examines the relationship between sense of place for neighbourhood, social connectedness and resilience. Canterbury residents experienced considerable and continued disruption following a large and protracted sequence of earthquakes starting in September 2010. A major aftershock on 22 February 2011 caused significant loss of life, destruction of buildings and infrastructure. Following this earthquake some suburbs of Christchurch showed strong collective action. This research examines the features of the built environment that helped to form this cooperative support. Data were collected through semi-structured interviews with 20 key informants followed by 38 participants from four case study suburbs. The objectives were to describe the community response of suburbs, to identify the key features of the built environment and the role of social infrastructure in fostering social connectedness. The last objective was to contribute to future planning for community resilience. The findings from this research indicated that social capital and community competence are significant resources to be called upon after a disaster. Features of the local environment facilitated the formation of neighbourhood connections that enabled participants to cope, manage and to collectively solve problems. These features also strengthened a sense of belonging and attachment to the home territory. Propinquity was important; the bumping and gathering places such as schools, small local shops and parks provided the common ground for meaningful pre-existing local interaction. Well-defined geography, intimate street typology, access to quality natural space and social infrastructure helped to build the local social connections and develop a sense of place. Resourceful individuals and groups were also a factor, and many are drawn to live near the inner city or more natural places. The features are the same well understood attributes that contribute to health and wellbeing. The policy and planning framework needs to consider broader social outcomes, including resilience in new and existing urban developments. The socio-political structures that provide access to secure and stable housing and local education should also be recognised and incorporated into local planning for resilience and the everyday.

Critical infrastructure impacts and adaptations in small rural towns follo…

Research papers, University of Canterbury Library

On 14 November 2016, the Mw 7.8 Kaikōura earthquake caused widespread damage along the east coast of the South Island, New Zealand. Kaikōura town itself was isolated from the rest of the country by landslides blocking off major roads. While impacts from the Kaikōura earthquake on large, urban population centres have been generally well documented, this thesis aims to fill gaps in academic knowledge regarding small rural towns. This thesis investigates what, where and when critical infrastructure and lifeline service disruption occurred following the 2016 Kaikōura earthquake in a selection of small towns, and how the communities in these areas adapted to disruption. Following a robust review of literature and news media, four small rural towns were selected from North Canterbury (Culverden & Waiau) and Marlborough (Seddon & Ward) in the South Island, New Zealand. Semi-structured interview sessions with a special focus on these towns were held with infrastructure managers, emergency response and recovery officials, and organisation leaders with experience or expertise in the 2016 Kaikōura earthquake. Findings were supplemented with emergency management situation reports to produce hazard maps and infrastructure exposure maps. A more detailed analysis was conducted for Waiau involving interdependence analyses and a level of service timeline for select lifeline services. The earthquake impacted roads by blocking them with landslides, debris and surface rupture. Bridges where shaken off their abutments, breaking infrastructure links such as fibre landlines as they went. Water supplies and other forms of infrastructure relied heavily on the level of service of roads, as rough rural terrain left few alternatives. Adapting to an artificial loss of road service, some Waiau locals created their own detour around a road cordon in order to get home to family and farms. Performance of dwellings was tied to socioeconomic factors as much as proximity to the epicentre. Farmers who lost water access pulled out fences to allow stock to drink from rivers. Socioeconomic differences between farmland and township residents also contributed to resilience variations between the towns assessed in this study. Understanding how small rural towns respond and adapt to disaster allows emergency management officials and policy to be well informed and flexible with planning for multiple size classes of towns.

Investigating the compressive toe of post-tensioned CLT core-walls using p…

Research papers, University of Canterbury Library

Post-tensioned timber technology was originally developed and researched at the University of Canterbury (UC) in New Zealand in 2005. It can provide a low-damage seismic design solution for multi-storey mass timber buildings. Since mass timber products, such as cross-laminated timber (CLT), have high in-plane stiffness, a post-tensioned timber shear wall will deform mainly in a rocking mechanism. The moment capacity of the wall at the base is commonly determined using the elastic form of the Modified Monolithic Beam Analogy (MMBA). In the calculation of the moment capacity at the wall base, it is critical to accurately predict the location of the neutral axis and the timber compressive stress distribution. Three 2/3 scale 8.6m tall post-tensioned CLT walls were experimentally tested under quasi-static cyclic loading – both uni-directional and bi-directional- in this study. These specimens included a single wall, a coupled wall, and a C-shaped core-wall. The main objective was to develop post-tensioned C-shaped timber core-walls for tall timber buildings with enhanced lateral strength and stiffness. To better understand the timber compressive stress distributions at the wall base, particle tracking technology (PTT) technology was applied for the first time to investigate the behaviour of the compression toe. Previous post-tensioned timber testing primarily used the displacement measurements to determine the timber compressive behavior at the wall base or rocking interfaces. However, by using PTT technology, the timber strain measurements in the compression zone can be much more accurate as PTT is able to track the movement of many particles on the timber surface. This paper presents experimental testing results of post-tensioned CLT walls with a focus on capturing timber compressive behavior using PTT. The PTT measurements were able to better capture small base rotations which occurred at the onset of gap opening and capture unexpected phenomena in core-wall tests. The single wall test result herein presented indicates that while the MMBA could predict the moment rotation behavior with reasonable accuracy, the peak strain response was under predicted in the compression toe. Further detailed study is required to better understand the complex strain fields generated reflective of the inherent cross-thickness inhomogeneity and material variability of CLT.

Ki uta ki tai/From land to sea : Māori forms of organising and responding …

Research papers, University of Canterbury Library

When researchers seek to understand community resilience, it often centres on individual agents and actors. They look at the traits individuals have in order to help recover from adverse events, as well as the decisionmaking processes required to plan and adapt. In Aotearoa New Zealand, Māori forms of organising can challenge these. This research was about uncovering Māori forms organising and practices in the context of resilience. The methodology I used was He Awa Whiria/Braided Rivers and storytelling analysis in kanohi ki te kanohi/semi-structured interviews to understand how Māori communities responded to and recovered from the 2010 Darfield (Canterbury), 2011 Ōtautahi/Christchurch, and 2016 Kaikōura earthquakes. Five themes emerged from the project: (i) the importance of marae as a powerful physical location, (ii) the value in building strong reciprocal connections and cultural relationships, (iii) the stronghold that kai/food has in helping to heal communities, (iv) the exchange and trading of resources, and (v) being practical when move forward after a disaster event. As a non-Māori researcher, I have been an outsider to te Ao Māori and to Aotearoa. In using this blended methodology, it became apparent that there are many socio-cultural and historical contentions from the effects of colonisation, assimilation, to grappling with Western norms. Notably, the findings pointed to more similarities than differences, such as taking care of family and communities, being community-driven, and ways of coping with adverse events. This revealed that there are similar ways of doing things regardless of having different customs. This research makes several contributions. It contributes to the field of management studies by addressing gaps in how the concept of resilience is viewed from a practical Māori perspective. The research presents emergency management professionals with similar blended and practical strategies to co-design approaches for collaborative readiness, response, and recovery plans and programmes. The study further demonstrates the localised and tangible benefits that can be gained from utilising a blended methodology and storying method. Ultimately, the purpose of the thesis was to start bridging the gap between agencies and communities, to shift to more Indigenous-led approaches, integrating local Indigenous practices and knowledges that lead to more prepared communities in managing, responding to, and recovering from earthquake hazard events.

Vegetation change and native forest restoration in urban environments: Man…

Research papers, Lincoln University

Global biodiversity is threatened by human actions, including in urban areas. Urbanisation has removed and fragmented indigenous habitats. As one of the 25 biodiversity ’hot spots’, New Zealand is facing the problems of habitat loss and indigenous species extinction. In New Zealand cities, as a result of the land clearance and imported urban planning precepts, many urban areas have little or no original native forest remaining. Urbanisation has also been associated with the introduction of multitudes of species from around the world. Two large earthquakes shook Christchurch in 2010 and 2011 and caused a lot of damage. Parts of the city suffered from soil liquefaction after the earthquakes. In the most damaged parts of Christchurch, particularly in the east, whole neighbourhoods were abandoned and later demolished except for larger trees. Christchurch offers an excellent opportunity to study the biodiversity responses to an urban area with less intensive management, and to learn more about the conditions in urban environments that are most conducive to indigenous plant biodiversity. This study focuses on natural woody plant regeneration of forested sites in Christchurch city, many of which were also surveyed prior to the earthquakes. By repeating the pre-earthquake surveys, I am able to describe the natural regeneration occurring in Christchurch forested areas. By combining this with the regeneration that has occurred in the Residential Red Zone, successional trajectories can be described under a range of management scenarios. Using a comprehensive tree map of the Residential Red Zone, I was also able to document minimum dispersal distances of a range of indigenous trees in Christchurch. This is important for planning reserve connectivity. Moreover, I expand and improve on a previous analysis of the habitat connectivity of Christchurch (made before the earthquakes) to incorporate the Residential Red Zone, to assess the importance for habitat connectivity of restoring the indigenous forest in this area. In combination, these data sets are used to provide patch scenarios and some management options for biodiversity restoration in the Ōtākaro-Avon Red Zone post-earthquake.

Diversity and public engagement in planning: A case study of Chinese migra…

Research papers, Lincoln University

Aotearoa New Zealand’s population has grown rapidly from 3.85 million in 2000, to 5 million in 2020. Ethnic diversity has consequently increased. Territorial Authorities (TAs) undertaking statutory consultation and wider public engagement processes need to respond to increased diversity and foster inclusivity. Inclusivity is necessary to facilitate a greater understanding of TA statutory functions, as well as to encourage awareness and participation in annual planning processes, and resource management plans and consents. We examined perceptions, and experiences, of planning within the ethnic Chinese immigrant population of Christchurch. The Chinese ethnic group is a significant part of the city’s population and is in itself derived from diverse cultural and language backgrounds. We surveyed 111 members of this community, via social media and in person, to identify environmental and planning issues of concern to them. We sought to ascertain their previous engagement with planning processes and to gauge their willingness for future involvement. We also undertook a small number of semi-structured interviews with Chinese immigrants to explore their experiences with planning in more detail. Results showed only 6% of respondents had been engaged in any planning processes, despite only 20% being unwilling to participate. We analysed these responses by gender, age, visa category, and length of time resident in Christchurch. Notwithstanding the low level of reported engagement, earthquake recovery (70% of respondents) along with water quality, transport, and air quality were the most important issues of concern. However, there was a general lack of awareness of the ability to make public submissions on these and other issues, and of the statutory responsibilities of TAs. We discuss possible explanations and provide several suggestions for TAs to increase awareness and to improve engagement. This includes further research to assist in identifying the nature of barriers as well as the effectiveness of trialling different solutions.

Low-damage gravity rocking connection for multi-storey moment frame buildi…

Research papers, The University of Auckland Library

A review of the literature showed the lack of a truly effective damage avoidance solution for timber or hybrid timber moment resisting frames (MRFs). Full system damage avoidance selfcentring behaviour is difficult to achieve with existing systems due to damage to the floor slab caused by beam-elongation. A novel gravity rocking, self-centring beam-column joint with inherent and supplemental friction energy dissipation is proposed for low-medium rise buildings in all seismic zones where earthquake actions are greater than wind. Steel columns and timber beams are used in the hybrid MRF such that both the beam and column are continuous thus avoiding beam-elongation altogether. Corbels on the columns support the beams and generate resistance and self-centring through rocking under the influence of gravity. Supplemental friction sliders at the top of the beams resist sliding of the floor whilst dissipating energy as the floor lifts on the corbels and returns. 1:20 scale tests of 3-storey one-by-two bay building based on an earlier iteration of the proposed concept served as proof-of-concept and highlighted areas for improvement. A 1:5 scale 3-storey one-by-one bay building was subsequently designed. Sub-assembly tests of the beam-top asymmetric friction sliders demonstrated repeatable hysteresis. Quasi-static tests of the full building demonstrated a ‘flat bottomed’ flag-shaped hysteresis. Shake table tests to a suite of seven earthquakes scaled for Wellington with site soil type D to the serviceability limit state (SLS), ultimate limit state (ULS) and maximum credible event (MCE) intensity corresponding to an average return period of 25, 500 and 2500 years respectively were conducted. Additional earthquake records from the 22 February 2011 Christchurch earthquakes we included. A peak drift of 0.6%, 2.5% and 3.8% was reached for the worst SLS, ULS and MCE earthquake respectively whereas a peak drift of 4.5% was reached for the worst Christchurch record for tests in the plane of the MRF. Bi-directional tests were also conducted with the building oriented at 45 degrees on the shake table and the excitation factored by 1.41 to maintain the component in the direction of the MRF. Shear walls with friction slider hold-downs which reached similar drifts to the MRF were provided in the orthogonal direction. Similar peak drifts were reached by the MRF in the bi-directional tests, when the excitation was amplified as intended. The building self-centred with a maximum residual drift of 0.06% in the dynamic tests and demonstrated no significant damage. The member actions were magnified by up to 100% due to impact upon return of the floor after uplift when the peak drift reached 4.5%. Nonetheless, all of the members and connections remained essentially linearelastic. The shake table was able to produce a limited peak velocity of 0.275 m/s and this limited the severity of several of the ULS, MCE and Christchurch earthquakes, especially the near-field records with a large velocity pulse. The full earthquakes with uncapped velocity were simulated in a numerical model developed in SAP2000. The corbel supports were modelled with the friction isolator link element and the top sliders were modelled with a multi-linear plastic link element in parallel with a friction spring damper. The friction spring damper simulated the increase in resistance with increasing joint rotation and a near zero return stiffness, as exhibited by the 1:5 scale test building. A good match was achieved between the test quasi-static global force-displacement response and the numerical model, except a less flat unloading curve in the numerical model. The peak drift from the shake table tests also matched well. Simulations were also run for the full velocity earthquakes, including vertical ground acceleration and different floor imposed load scenarios. Excessive drift was predicted by the numerical model for the full velocity near-field earthquakes at the MCE intensity and a rubber stiffener for increasing the post joint-opening stiffness was found to limit the drift to 4.8%. Vertical ground acceleration had little effect on the global response. The system generates most of its lateral resistance from the floor weight, therefore increasing the floor imposed load increased the peak drift, but less than it would if the resistance of the system did not increase due to the additional floor load. A seismic design procedure was discussed under the framework of the existing direct displacement-based design method. An expression for calculating the area-based equivalent viscous damping (EVD) was derived and a conservative correction factor of 0.8 was suggested. A high EVD of up to about 15% can be achieved with the proposed system at high displacement ductility levels if the resistance of the top friction sliders is maximised without compromising reliable return of the floor after uplift. Uniform strength joints with an equal corbel length up the height of the building and similar inter-storey drifts result in minimal relative inter-floor uplift, except between the first floor and ground. Guidelines for detailing the joint for damage avoidance including bi-directional movement were also developed.

First Responders to Cataclysmic Upheaval: Earthquake–Driven Effects on Mic…

Research papers, University of Canterbury Library

The Avon-Heathcote Estuary is of significant value to Christchurch due to its high productivity, biotic diversity, proximity to the city, and its cultural, recreational and aesthetic qualities. Nonetheless, it has been subjected to decades of degradation from sewage wastewater discharges and encroaching urban development. The result was a eutrophied estuary, high in nitrogen, affected by large blooms of nuisance macroalgae and covered by degraded sediments. In March 2010, treated wastewater was diverted from the estuary to a site 3 km offshore. This quickly reduced water nitrogen by 90% within the estuary and, within months, there was reduced production of macroalgae. However, a series of earthquakes beginning in September 2010 brought massive changes: tilting of the estuary, changes in channels and water flow, and a huge influx of liquefied sediments that covered up to 65% of the estuary floor. Water nitrogen increased due to damage to sewage infrastructure and the diversion pipeline being turned off. Together, these drastically altered the estuarine ecosystem. My study involves three laboratory and five in situ experiments that investigate the base of the food chain and responses of benthic microalgae to earthquake-driven sediment and nutrient changes. It was predicted that the new sediments would be coarser and less contaminated with organic matter and nutrients than the old sediments, would have decreased microalgal biomass, and would prevent invertebrate grazing and bioturbation activities. It was believed that microalgal biomass would become similar across new and old sediments types as the unstable new sediments were resuspended and distributed over the old sediments. Contact cores of the sediment were taken at three sites, across a eutrophication gradient, monthly from September 2011 to March 2012. Extracted chlorophyll a pigments showed that microalgal biomass was generally lower on new liquefied sediments compared to old sediments, although there was considerable site to site variation, with the highly eutrophic sites being the most affected by the emergence of the new sediments. Grazer experiments showed that invertebrates had both positive and negative site-specific effects on microalgal biomass depending on their identity. At one site, new sediments facilitated grazing by Amphibola crenata, whereas at another site, new sediments did not alter the direct and indirect effects of invertebrates (Nicon aestuariensis, Macropthalmus hirtipes, and A. crenata) on microalgae. From nutrient addition experiments it was clear that benthic microalgae were able to use nutrients from within both old and new sediments equally. This implied that microalgae were reducing legacy nutrients in both sediments, and that they are an important buffer against eutrophication. Therefore, in tandem with the wastewater diversion, they could underpin much of the recovery of the estuary. Overall, the new sediments were less favourable for benthic microalgal growth and recolonisation, but were less contaminated than old sediments at highly eutrophic sites. Because the new sediments were less contaminated than the old sediments, they could help return the estuary to a noneutrophic state. However, if the new sediments, which are less favourable for microalgal growth, disperse over the old sediments at highly eutrophic sites, they could become contaminated and interfere with estuarine recovery. Therefore, recovery of microalgal communities and the estuary was expected to be generally long, but variable and site-specific, with the least eutrophic sites recovering quickly, and the most eutrophic sites taking years to return to a pre-earthquake and non-eutrophied state. changes in channels and water flow, and a huge influx of liquefied sediments that covered up to 65% of the estuary floor. Water nitrogen increased due to damage to sewage infrastructure and the diversion pipeline being turned off. Together, these drastically altered the estuarine ecosystem. My study involves three laboratory and five in situ experiments that investigate the base of the food chain and responses of benthic microalgae to earthquake-driven sedimen tand nutrient changes. It was predicted that the new sediments would be coarser and less contaminated with organic matter and nutrients than the old sediments, would have decreased microalgal biomass, and would prevent invertebrate grazing and bioturbation activities. It was believed that microalgal biomass would become similar across new and old sediments types as the unstable new sediments were resuspended and distributed over the old sediments. Contact cores of the sediment were taken at three sites, across a eutrophication gradient, monthly from September 2011 to March 2012. Extracted chlorophyll a pigments showed that microalgal biomass was generally lower on new liquefied sediments compared to old sediments, although there was considerable site to site variation, with the highly eutrophic sites being the most affected by the emergence of the new sediments. Grazer experiments showed that invertebrates had both positive and negative site-specific effects on microalgal biomass depending on their identity. At one site, new sediments facilitated grazing by Amphibola crenata, whereas at another site, new sediments did not alter the direct and indirect effects of invertebrates (Nicon aestuariensis, Macropthalmus hirtipes, and A. crenata) on microalgae. From nutrient addition experiments it was clear that benthic microalgae were able to use nutrients from within both old and new sediments equally. This implied that microalgae were reducing legacy nutrients in both sediments, and that they are

The geotechnical characterisation of Christchurch sands for advanced soil …

Research papers, University of Canterbury Library

In 2010 and 2011 Christchurch, New Zealand experienced a series of earthquakes that caused extensive damage across the city, but primarily to the Central Business District (CBD) and eastern suburbs. A major feature of the observed damage was extensive and severe soil liquefaction and associated ground damage, affecting buildings and infrastructure. The behaviour of soil during earthquake loading is a complex phenomena that can be most comprehensively analysed through advanced numerical simulations to aid engineers in the design of important buildings and critical facilities. These numerical simulations are highly dependent on the capabilities of the constitutive soil model to replicate the salient features of sand behaviour during cyclic loading, including liquefaction and cyclic mobility, such as the Stress-Density model. For robust analyses advanced soil models require extensive testing to derive engineering parameters under varying loading conditions for calibration. Prior to this research project little testing on Christchurch sands had been completed, and none from natural samples containing important features such as fabric and structure of the sand that may be influenced by the unique stress-history of the deposit. This research programme is focussed on the characterisation of Christchurch sands, as typically found in the CBD, to facilitate advanced soil modelling in both res earch and engineering practice - to simulate earthquake loading on proposed foundation design solutions including expensive ground improvement treatments. This has involved the use of a new Gel Push (GP) sampler to obtain undisturbed samples from below the ground-water table. Due to the variable nature of fluvial deposition, samples with a wide range of soil gradations, and accordingly soil index properties, were obtained from the sampling sites. The quality of the samples is comprehensively examined using available data from the ground investigation and laboratory testing. A meta-quality assessment was considered whereby a each method of evaluation contributed to the final quality index assigned to the specimen. The sampling sites were characterised with available geotechnical field-based test data, primarily the Cone Penetrometer Test (CPT), supported by borehole sampling and shear-wave velocity testing. This characterisation provides a geo- logical context to the sampling sites and samples obtained for element testing. It also facilitated the evaluation of sample quality. The sampling sites were evaluated for liquefaction hazard using the industry standard empirical procedures, and showed good correlation to observations made following the 22 February 2011 earthquake. However, the empirical method over-predicted liquefaction occurrence during the preceding 4 September 2010 event, and under-predicted for the subsequent 13 June 2011 event. The reasons for these discrepancies are discussed. The response of the GP samples to monotonic and cyclic loading was measured in the laboratory through triaxial testing at the University of Canterbury geomechanics laboratory. The undisturbed samples were compared to reconstituted specimens formed in the lab in an attempt to quantify the effect of fabric and structure in the Christchurch sands. Further testing of moist tamped re- constituted specimens (MT) was conducted to define important state parameters and state-dependent properties including the Critical State Line (CSL), and the stress-strain curve for varying state index. To account for the wide-ranging soil gradations, selected representative specimens were used to define four distinct CSL. The input parameters for the Stress-Density Model (S-D) were derived from a suite of tests performed on each representative soil, and with reference to available GP sample data. The results of testing were scrutinised by comparing the data against expected trends. The influence of fabric and structure of the GP samples was observed to result in similar cyclic strength curves at 5 % Double Amplitude (DA) strain criteria, however on close inspection of the test data, clear differences emerged. The natural samples exhibited higher compressibility during initial loading cycles, but thereafter typically exhibited steady growth of plastic strain and excess pore water pressure towards and beyond the strain criteria and initial liquefaction, and no flow was observed. By contrast the reconstituted specimens exhibited a stiffer response during initial loading cycles, but exponential growth in strains and associated excess pore water pressure beyond phase-transformation, and particularly after initial liquefaction where large strains were mobilised in subsequent cycles. These behavioural differences were not well characterised by the cyclic strength curve at 5 % DA strain level, which showed a similar strength for both GP samples and MT specimens. A preliminary calibration of the S-D model for a range of soil gradations is derived from the suite of laboratory test data. Issues encountered include the influence of natural structure on the peak-strength–state index relationship, resulting in much higher peak strengths than typically observed for sands in the literature. For the S-D model this resulted in excessive stiffness to be modelled during cyclic mobility, when the state index becomes large momentarily, causing strain development to halt. This behaviour prevented modelling the observed re- sponse of silty sands to large strains, synonymous with “liquefaction”. Efforts to reduce this effect within the current formulation are proposed as well as future research to address this issue.

Question Time for 18 May 2011

Audio, Radio New Zealand

Questions to Ministers 1. Hon PHIL GOFF to the Prime Minister: In stating that "this Government introduced a balanced package of tax cuts" was he saying that his tax changes and the tax system are fair to all New Zealanders? 2. LOUISE UPSTON to the Minister of Finance: What will be the main objectives of Budget 2011 tomorrow? 3. Hon ANNETTE KING to the Prime Minister: When he said "in most cases the tax switch more than compensated people for the increase in GST", in which cases hadn't people been fully compensated? 4. JOHN BOSCAWEN to the Prime Minister: Does he stand by the statement he made in his post-Cabinet press conference on Monday that "Everyone needs to understand that what Don Brash is talking about is hardcore"; if so why? 5. Hon DAVID CUNLIFFE to the Minister of Finance: What is the total impact on the operating balance, over the forecast period, of the fiscal impact of the tax changes in Budget 2010 according to page 70 of the 2010 Budget and Economic Fiscal Update, and how does he reconcile that with the Prime Minister's statement in the House yesterday that "National's tax plan 2010…was fiscally neutral"? 6. ALLAN PEACHEY to the Minister of Corrections: What reports has she received about the first year of container units being used in New Zealand prisons? 7. RAHUI KATENE to the Minister for Communications and Information Technology: What was the motivation behind the decision to remove regulatory forbearance from the Telecommunications (TSO, Broadband, and Other Matters) Amendment Bill? 8. JACINDA ARDERN to the Minister for Canterbury Earthquake Recovery: Does he stand by the Prime Minister's statement in relation to Christchurch that "it looks like the residential rebuild alone will require up to 12,500 full-time workers", if not, how many full-time workers does he believe will now be needed? 9. Hon TAU HENARE to the Minister for Social Development and Employment: What recent announcements has she made to support community social services? 10. CLARE CURRAN to the Minister for Communications and Information Technology: What is the best estimate of the additional cost to the Crown of the change he announced to the ultrafast broadband network this morning? 11. TIM MACINDOE to the Minister of Housing: What recent announcements has he made regarding the Government's Housing Innovation Fund? 12. GARETH HUGHES to the Acting Minister of Energy and Resources: What is her response to the statement of leading scientist and NASA director Dr James Hansen, currently touring New Zealand, that "coal is the single greatest threat to civilisation and all life on our planet" and we should leave it in the ground?

Question Time for 15 September 2010

Audio, Radio New Zealand

Questions to Ministers 1. Hon ANNETTE KING to the Minister for Canterbury Earthquake Recovery: Does he agree with the Canterbury Employers' Chamber of Commerce chief executive Peter Townsend that the reconstruction of Canterbury following the earthquake requires someone "to co-ordinate and oversee" reconstruction? 2. COLIN KING to the Minister of Finance: What steps is the Government taking to ensure the Earthquake Commission can meet claims arising from the Canterbury earthquake? 3. Hon DAVID CUNLIFFE to the Minister of Finance: What was the earliest date that Treasury formed the conclusion that South Canterbury Finance could fail, and when and by whom was that first raised with him? 4. DAVID GARRETT to the Attorney-General: Does he agree that "tikanga" as it is described in the Marine and Coastal Area (Takutai Moana) Bill will differ in meaning from iwi to iwi and hapū to hapū? 5. Hon RUTH DYSON to the Minister of Health: Are doctors and nurses having more say in how the health system is run? 6. NICKY WAGNER to the Minister for the Environment: What reports has he received on responses to the Canterbury earthquake, particularly with respect to the region's flood and waste management systems? 7. TE URUROA FLAVELL to the Attorney-General: What is the burden of proof under the Marine and Coastal Area (Takutai Moana) Bill in relation to applications for customary interests, and what type of evidence would the Crown be required to produce to prove that a customary interest had been extinguished? 8. Hon DAVID PARKER to the Attorney-General: When he answered yesterday that "hopefully" the new foreshore and seabed bill "will settle the protracted controversy around the issues of the foreshore and seabed", was he aware that the Government's confidence and supply partner Hon Pita Sharples told TV3 that he was "not entirely happy" with the new bill? 9. JO GOODHEW to the Minister for Social Development and Employment: How have Government social services been supporting the people of Canterbury? 10. PHIL TWYFORD to the Minister of Local Government: Why did the Auckland Transition Agency award the $53.8 million contract for the Auckland Council's Enterprise Resource Planning computer system without a competitive tender? 11. Dr JACKIE BLUE to the Minister of Women's Affairs: Why is the Ministry of Women's Affairs celebrating Suffrage Day? 12. CATHERINE DELAHUNTY to the Minister of Women's Affairs: How will New Zealand's forthcoming report to the UN under the Convention on the Elimination of All Forms of Discrimination Against Women explain the Government's decision to axe the Pay and Employment Equity Unit?

Question time for 2 August 2012

Audio, Radio New Zealand

PAUL GOLDSMITH to the Minister of Finance: What reports has he received on progress in lifting New Zealand&rsquo;s household savings and reducing household debt? EUGENIE SAGE to the Minister for Canterbury Earthquake Recovery: Did the advice he has received on Christchurch City Council assets contemplate a sell off or sell down of shares in companies supervised by Christchurch City Holdings Ltd or of other council assets; if so, which ones? Hon DAVID PARKER to the Minister of Finance: Does he stand by his answer to yesterday&rsquo;s primary question &ldquo;as I understand it, there are no regional statistics that specifically isolate the number of people leaving any particular region to move overseas&rdquo; and has the Treasury reported to him the existence of official statistics on permanent and long-term migration compiled by local council area and region? SCOTT SIMPSON to the Minister for Tertiary Education, Skills and Employment: What changes is the Government making to improve results from industry training? Hon LIANNE DALZIEL to the Minister for Canterbury Earthquake Recovery: Which of the assets identified by CERA in response to his request has he ruled out asking Christchurch City Council to sell? KATRINA SHANKS to the Minister of Justice: What changes is she making to improve the Family Court? Le'aufa'amulia ASENATI LOLE-TAYLOR to the Minister for Whānau Ora: Does she stand by her statement that &ldquo;I don&rsquo;t object to any vulnerable family receiving Whānau Ora support, because that&rsquo;s what the money is for&rdquo;? Hon ANNETTE KING to the Minister of Housing: Does he stand by all his comments on housing; if not, why not? Dr KENNEDY GRAHAM to the Minister of Foreign Affairs: What is the total number and cost of uncontested contracts given by the Ministry of Foreign Affairs and Trade to external consultants in the last two financial years? MARK MITCHELL to the Minister for Communications and Information Technology: Has she received any reports on the progress of the Government&rsquo;s Ultra-Fast Broadband and Rural Broadband Initiatives? DARIEN FENTON to the Minister of Labour: Does she stand by her statement regarding foreign chartered fishing vessels &ldquo;If breaches of labour law occur &ndash; such as underpayment of wages or illegal deductions or breaches of the Code of Practice, the Department of Labour will be able to investigate them and take action&rdquo;? NICKY WAGNER to the Minister for the Environment: What recent announcements has she made in relation to the Waste Minimisation Fund?

Effects of a major disaster on skills shortages in the construction indust…

Research papers, The University of Auckland Library

The purpose of this paper is to empirically investigate the effects of a major disaster on the management of human resources in the construction sector. It sets out to identify the construction skills challenges and the factors that affected skills availability following the 2010/2011 earthquakes in Christchurch. It is hoped that this study will provide insights for on-going reconstruction and future disaster response with respect to the problem of skills shortages. Design/methodology/approach A triangulation method was adopted. The quantitative method, namely, a questionnaire survey, was employed to provide a baseline description. Field observations and interviews were used as a follow-up to ascertain issues and potential shortages over time. Three focus groups in the form of research workshops were convened to gain further insight into the feedback and to investigate the validity and applicability of the research findings. Findings The earthquakes in Christchurch had compounded the pre-existing skills shortages in the country due to heightened demand from reconstruction. Skills shortages primarily existed in seismic assessment and design for land and structures, certain trades, project management and site supervision. The limited technical capability available nationally, shortage of temporary accommodation to house additional workers, time needed for trainees to become skilled workers, lack of information about reconstruction workloads and lack of operational capacity within construction organisations, were critical constraints to the resourcing of disaster recovery projects. Research limitations/implications The research findings contribute to the debate on skills issues in construction. The study provides evidence that contributes to an improved understanding of the industry’s skills vulnerability and emerging issues that would likely exist after a major disaster in a resource-limited country such as New Zealand. Practical implications From this research, decision makers and construction organisations can gain a clear direction for improving the construction capacity and capability for on-going reconstruction. Factors that affected the post-earthquake skills availability can be considered by decision makers and construction organisations in their workforce planning for future disaster events. The recommendations will assist them in addressing skills shortages for on-going reconstruction. Originality/value Although the study is country-specific, the findings show the nature and scale of skills challenges the construction industry is likely to face following a major disaster, and the potential issues that may compound skills shortages. It provides lessons for other disaster-prone countries where the resource pool is small and a large number of additional workers are needed to undertake reconstruction.

Seismic Behaviour of Grouted Connections in Precast Concrete Panels

Research papers, The University of Auckland Library

Following the 2010/2011 Canterbury (New Zealand) earthquakes the seismic design of buildings with precast concrete panels has received significant attention. Although this form of construction generally performed adequately in Christchurch, there were a considerable number of precast concrete panel connection failures. This observation prompted a review of more than 4700 panel details to establish representative details used in both existing and new multi-storey and low rise industrial precast concrete buildings. The detailing and quantity of each reviewed connection type in the sampled data is reported, and advantages and potential deficiencies of each connection type are discussed. Following the Canterbury earthquakes, it was observed that brittle failure had occurred in some grouted metal duct connections used for precast concrete wall panels, resulting in recommendations for more robust detailing of this connection type. A set of experimental tests was subsequently performed to investigate the in-plane seismic behaviour of precast concrete wall panel connections. This testing comprised of seven reversed cyclic in-plane tests of fullscale precast concrete wall panels having wall-to-foundation grouted metal duct connections. Walls with existing connection detailing were found to perform adequately when carrying low axial loads, but performance was found to be less satisfactory as the axial load and wall panel length increased. The use of new recommended detailing was observed to prevent brittle connection response and to improve the robustness of the reinforcement splice. A parametric investigation was conducted using the finite element method to predict the failure mode of metal duct connections. From the results of the parametric study on metal duct connections it was identified that there were three possible failure modes, being reinforcement fracture, concrete spalling without metal duct pull out, and concrete spalling with metal duct pull-out. An alternative simple analytical method was proposed in order to determine the type of connection failure without using a time-consuming finite element method. Grouted sleeves inserts are an alternative connector that is widely used to connect wall panels to the foundations. The two full-scale wall panels were subjected to reversed cyclic in-plane demands until failure of either the connection or the wall panel. Wall panel failure was due to a combination of connection reinforcement pulling-out from the coupler and reinforcement fracture. In addition, non-embedded grouted sleeve tests filled with different quality of grout were conducted by subjecting these coupler assemblages to cyclic and monotonic forces.