Search

found 10 results

Research papers, University of Canterbury Library

Paper 132 Recent advances in timber design at the University of Canterbury have led to new structural systems that are appropriate for a wide range of building types, including multi-storey commercial office structures. These buildings are competitive with more traditional construction materials in terms of cost, sustainability and structural performance. This paper provides seismic design recommendations and analytical modelling approaches, appropriate for the seismic design of post-tensioned coupled timber wall systems. The models are based on existing seismic design theory for precast post-tensioned concrete, modified to more accurately account for elastic deformation of the timber wall systems and the influence of the floor system. Experimental test data from a two storey post-tensioned timber building, designed, constructed and tested at the University of Canterbury is used to validate the analytical models.

Images, UC QuakeStudies

A view down Cashel Street from the Bridge of Remembrance, showing earthquake damage to several buildings along Cashel Mall. In the background the Hotel Grand Chancellor can be seen, a Christchurch hotel that was badly damaged in the February 2011 earthquake. The collapse of a key supporting shear wall caused the building to visibly lean to one side.

Research papers, University of Canterbury Library

Paper 090 The NMIT Arts & Media Building is the first in a new generation of multistorey timber structures. It employs an advanced damage avoidance earthquake design that is a world first for a timber building. Aurecon structural engineers are the first to use this revolutionary Pres-Lam technology developed at the University of Canterbury. This technology marks a fundamental change in design philosophy. Conventional seismic design of multi-storey structures typically depends on member ductility and the acceptance of a certain amount of damage to beams, columns and walls. The NMIT seismic system relies on pairs of coupled LVL shear walls that incorporate high strength steel tendons post-tensioned through a central duct. The walls are centrally fixed allowing them to rock during a seismic event. A series of U-shaped steel plates placed between the walls form a coupling mechanism, and act as dissipators to absorb seismic energy. The design allows the primary structure to remain essentially undamaged while readily replaceable connections act as plastic fuses. In this era where sustainability is becoming a key focus, the extensive use of timber and engineered-wood products such as LVL make use of a natural resource all grown and manufactured within a 100km radius of Nelson. This project demonstrates that there are now cost effective, sustainable and innovative solutions for multi-story timber buildings with potential applications for building owners in seismic areas around the world.

Research papers, University of Canterbury Library

An extensive research program is on-going at the University of Canterbury, New Zealand to develop new technologies to permit the construction of multi-storey timber buildings in earthquake prone areas. The system combines engineered timber beams, columns and walls with ductile moment resisting connections using post-tensioned tendons and eventually energy dissipaters. The extensive experimental testing on post-tensioned timber building systems has proved a remarkable lateral response of the proposed solutions. A wide number of post-tensioned timber subassemblies, including beam-column connections, single or coupled walls and column-foundation connections, have been analysed in static or quasi-static tests. This contribution presents the results of the first dynamic tests carried out with a shake-table. Model frame buildings (3-storey and 5-storey) on one-quarter scale were tested on the shake-table to quantify the response of post-tensioned timber frames during real-time earthquake loading. Equivalent viscous damping values were computed for post-tensioned timber frames in order to properly predict their response using numerical models. The dynamic tests were then complemented with quasi-static push and pull tests performed to a 3-storey post-tensioned timber frame. Numerical models were included to compare empirical estimations versus dynamic and quasi-static experimental results. Different techniques to model the dynamic behaviour of post-tensioned timber frames were explored. A sensitivity analysis of alternative damping models and an examination of the influence of designer choices for the post-tensioning force and utilization of column armouring were made. The design procedure for post-tensioned timber frames was summarized and it was applied to two examples. Inter-storey drift, base shear and overturning moments were compared between numerical modelling and predicted/targeted design values.

Audio, Radio New Zealand

Questions to Ministers 1. Hon PHIL GOFF to the Prime Minister: Does he have confidence in all his Ministers? 2. METIRIA TUREI to the Acting Minister of Energy and Resources: What emergency response, safety, and environmental protection provisions, if any, were included in the permit granted to Anadarko Petroleum Corporation to undertake deepwater oil exploration and drilling in the Canterbury Basin? 3. SIMON BRIDGES to the Minister of Finance: What signs are there that New Zealanders are saving more? 4. GRANT ROBERTSON to the Prime Minister: Does he have confidence in his Minister of Health? 5. JOHN HAYES to the Minister for Communications and Information Technology: What benefit will rural communities receive from the Rural Broadband Initiative signed last month? 6. SUE MORONEY to the Prime Minister: Does he have confidence in his Minister of Education? 7. MELISSA LEE to the Minister of Corrections: How are Corrections Department staff showing support for their Christchurch colleagues following the earthquake? 8. DAVID SHEARER to the Minister of Defence: Does he agree with all of the statements made by the Minister of Foreign Affairs on that Minister's use of RNZAF aircraft to travel to Vanuatu in February of this year? 9. KANWALJIT SINGH BAKSHI to the Minister of Customs: What recent reports has he received on the success of SmartGate? 10. CLARE CURRAN to the Prime Minister: Does he have confidence in the Minister for Communications and Information Technology? 11. KEITH LOCKE to the Minister of Defence: Did the New Zealand Defence Force, when preparing their response dated 2 May 2011, talk to any of the Afghan civilians interviewed by Jon Stephenson in the Metro article "Eyes Wide Shut" and seen on the subsequent 60 Minutes TV special; if so, who? 12. HONE HARAWIRA to the Acting Minister of Energy and Resources: Does the survey and drilling arrangement between the Government and Petrobras have the prior and informed consent of Te-Whanau-a-Apanui; if not, will this lack of consent breach the United Nations Declaration on the Rights of Indigenous Peoples?

Audio, Radio New Zealand

Questions to Ministers 1. AMY ADAMS to the Minister of Finance: What will be the focus of the Budget on 19 May? 2. Hon PHIL GOFF to the Prime Minister: Does he stand by all his statements on the sale of State-owned assets? 3. SHANE ARDERN to the Minister of Customs: What recent reports has he received regarding interceptions of methamphetamine by Customs officers at the border? 4. Hon ANNETTE KING to the Prime Minister: Does he stand by his statement that "we've done as good a job as we can in the conditions we've got to try and help low-income New Zealanders"? 5. KEITH LOCKE to the Minister of Defence: Has New Zealand's SAS detained anyone during its operations or joint operations with other forces, since being redeployed to Afghanistan in 2009? 6. Hon DAVID CUNLIFFE to the Minister of Finance: Does he stand by his statement that "I have seen almost no criticism of the Government's plan to rebalance the economy" given the statement from the Chair of the 2025 Taskforce, Don Brash, that "There is certainly no evidence yet that current policies will deliver the kind of accelerated growth we need"? 7. NICKY WAGNER to the Minister for Canterbury Earthquake Recovery: What process will the Government use to rebuild and restore damaged infrastructure in Canterbury? 8. Hon CLAYTON COSGROVE to the Minister for Canterbury Earthquake Recovery: Is he satisfied that the Canterbury Earthquake Recovery Act 2011 provides him with all the powers necessary to facilitate the recovery of Canterbury? 9. Hon JOHN BOSCAWEN to the Minister of Finance: By how much has Government expenditure increased as a percentage of GDP since he became Minister of Finance? 10. DAVID SHEARER to the Prime Minister: Does he have confidence in his Minister of Foreign Affairs? 11. KATRINA SHANKS to the Minister for Social Development and Employment: Why has the Government announced a Green Paper on how we value, nurture and protect children? 12. Hon TREVOR MALLARD to the Prime Minister: Does he have confidence in all his Ministers?

Audio, Radio New Zealand

Questions to Ministers 1. Hon DAVID PARKER to the Minister of Finance: What was the combined increase in the value of the Crown's equity in Meridian, Mighty River Power, Solid Energy, Genesis and Air New Zealand for each of the last five years? 2. SIMON BRIDGES to the Minister of Finance: How did Budget 2011 continue the Government's programme to build faster growth, higher incomes and more jobs? 3. Hon MARYAN STREET to the Minister of Foreign Affairs: Have all recent actions of New Zealand's diplomats been consistent with Government policy? 4. Hon TAU HENARE to the Minister of Health: What reports has he received about improved access to dialysis for patients in Auckland and Waitemata? 5. Dr RUSSEL NORMAN to the Minister of Finance: Will the Government have to borrow further to pay for the latest Christchurch earthquakes? 6. GRANT ROBERTSON to the Minister of Health: Does he agree with the statement of the Auditor-General, "Despite the encouraging improvements made in the last 10 years, we do not yet have a system for scheduled services that can demonstrate national consistency and equitable treatment for all"? 7. AMY ADAMS to the Minister for the Environment: What steps has the Government taken to facilitate resource consents for work required at the Lyttelton Port to ensure it is able to recover quickly from earthquake damage? 8. JACINDA ARDERN to the Prime Minister: Does he stand by the statement made on his behalf that "this Government is focused on improvements within the economy in order to create the platform on which business and New Zealanders can invest and grow jobs"? 9. TE URUROA FLAVELL to the Minister of Health: Does he agree that under section 118 of the Health Practitioners Competence Assurance Act 2003, the Medical Council has a responsibility to ensure the cultural competence of doctors, and what support has the Government provided to the health sector to ensure cultural competence is achieved across the health sector? 10. DAVID SHEARER to the Minister of Science and Innovation: Does he agree with Professor Sir Paul Callaghan's statement on science and innovation "it's clear that the Minister of Finance and the Prime Minister have not really seen this as a top priority"? 11. CHESTER BORROWS to the Minister of Justice: What progress is being made on preparations for the referendum on the electoral system to be held in conjunction with this year's general election? 12. Hon RICK BARKER to the Minister of Veterans' Affairs: When can veterans expect to have a full response from the Government in response to the Law Commission's report "A New Support Scheme for Veterans"?

Research papers, University of Canterbury Library

Currently there is a worldwide renaissance in timber building design. At the University of Canterbury, new structural systems for commercial multistorey timber buildings have been under development since 2005. These systems incorporate large timber sections connected by high strength post-tensioning tendons, and timber-concrete composite floor systems, and aim to compete with existing structural systems in terms of cost, constructability, operational and seismic performance. The development of post-tensioned timber systems has created a need for improved lateral force design approaches for timber buildings. Current code provisions for seismic design are based on the strength of the structure, and do not adequately account for its deformation. Because timber buildings are often governed by deflection, rather than strength, this can lead to the exceedence of design displacement limitations imposed by New Zealand codes. Therefore, accurate modeling approaches which define both the strength and deformation of post-tensioned timber buildings are required. Furthermore, experimental testing is required to verify the accuracy of these models. This thesis focuses on the development and experimental verification of modeling approaches for the lateral force design of post-tensioned timber frame and wall buildings. The experimentation consisted of uni-direcitonal and bi-directional quasi-static earthquake simulation on a two-thirds scale, two-storey post-tensioned timber frame and wall building with timber-concrete composite floors. The building was subjected to lateral drifts of up to 3% and demonstrated excellent seismic performance, exhibiting little damage. The building was instrumented and analyzed, providing data for the calibration of analytical and numerical models. Analytical and numerical models were developed for frame, wall and floor systems that account for significant deformation components. The models predicted the strength of the structural systems for a given design performance level. The static responses predicted by the models were compared with both experimental data and finite element models to evaluate their accuracy. The frame, wall and floor models were then incorporated into an existing lateral force design procedure known as displacement-based design and used to design several frame and wall structural systems. Predictions of key engineering demand parameters, such as displacement, drift, interstorey shear, interstorey moment and floor accelerations, were compared with the results of dynamic time-history analysis. It was concluded that the numerical and analytical models, presented in this thesis, are a sound basis for determining the lateral response of post-tensioned timber buildings. However, future research is required to further verify and improve these prediction models.