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Images, UC QuakeStudies

A photograph of administrators and technicians from the Department of Civil and Natural Resources Engineering at the University of Canterbury enjoying a barbeque outside the Avonhead Baptist Church. The students and staff from this department used the church as a base after the 22 February 2011 earthquake, until their building on campus was deemed safe to enter.

Images, UC QuakeStudies

A photograph of administrators and technicians from the Department of Civil and Natural Resources Engineering at the University of Canterbury enjoying a barbeque outside the Avonhead Baptist Church. The students and staff from this department used the church as a base after the 22 February 2011 earthquake, until their building on campus was deemed safe to enter.

Images, UC QuakeStudies

A photograph of administrators and technicians from the Department of Civil and Natural Resources Engineering at the University of Canterbury enjoying a barbeque outside the Avonhead Baptist Church. The students and staff from this department used the church as a base after the 22 February 2011 earthquake, until their building on campus was deemed safe to enter.

Images, UC QuakeStudies

A photograph of administrators and technicians from the Department of Civil and Natural Resources Engineering at the University of Canterbury enjoying a barbeque outside the Avonhead Baptist Church. The students and staff from this department used the church as a base after the 22 February 2011 earthquake, until their building on campus was deemed safe to enter.

Images, UC QuakeStudies

A photograph of administrators and technicians from the Department of Civil and Natural Resources Engineering at the University of Canterbury enjoying a barbeque outside the Avonhead Baptist Church. The students and staff from this department used the church as a base after the 22 February 2011 earthquake, until their building on campus was deemed safe to enter.

Images, UC QuakeStudies

A photograph of administrators and technicians from the Department of Civil and Natural Resources Engineering at the University of Canterbury enjoying a barbeque outside the Avonhead Baptist Church. The students and staff from this department used the church as a base after the 22 February 2011 earthquake, until their building on campus was deemed safe to enter.

Images, UC QuakeStudies

A photograph of administrators and technicians from the Department of Civil and Natural Resources Engineering at the University of Canterbury enjoying a barbeque outside the Avonhead Baptist Church. The students and staff from this department used the church as a base after the 22 February 2011 earthquake, until their building on campus was deemed safe to enter.

Images, UC QuakeStudies

A photograph of administrators and technicians from the Department of Civil and Natural Resources Engineering at the University of Canterbury enjoying a barbeque outside the Avonhead Baptist Church. The students and staff from this department used the church as a base after the 22 February 2011 earthquake, until their building on campus was deemed safe to enter.

Images, UC QuakeStudies

A photograph of a man cooking sausages outside the Avonhead Baptist Church for the administrators and technicians from the Department of Civil and Natural Resources Engineering at the University of Canterbury. The students and staff from this department used the church as a base after the 22 February 2011 earthquake, until their building on campus was deemed safe to enter.

Images, UC QuakeStudies

Quin Henderson, South Island Manager, Hawkins Construction, part of the McConnell Group of companies, has donated $100,000 to the UC Business Partnerships Campaign for a three-year PhD scholarship in Engineering.

Audio, Radio New Zealand

The first of Christchurch's high-rise buildings to close after the February earthquake has reopened. All the tenants of the12-storey HSBC Tower are now back in the building which has been extensively checked by engineering experts.

Images, UC QuakeStudies

Structural Engineers from the New Zealand and Los Angeles County Fire Department Urban Search and Rescue teams performing an assessment of the Kenton Chambers Building on Hereford Street.

Images, UC QuakeStudies

Structural Engineers from the New Zealand and Los Angeles County Fire Department Urban Search and Rescue teams performing an assessment of the Kenton Chambers Building on Hereford Street.

Images, UC QuakeStudies

Structural Engineers from the New Zealand and Los Angeles County Fire Department Urban Search and Rescue teams performing assessments of buildings on High Street near Manchester Street.

Research papers, Lincoln University

Implementing seismic risk mitigation is a major challenge in many earthquake prone regions. The objective of this research is to investigate how property investment market practices can be used to enhance building owners’ decisions to improve seismic performance of earthquake prone buildings (EPBs). A case study method adopted, revealed the impacts of the property market stakeholders’ practices on seismic retrofit decisions. The findings from this research provide significant new insights on how property market-based incentives such as such as mandatory disclosure of seismic risks in all transactions in the property market, effective awareness seismic risk program and a unified earthquake safety assessment information system, can be used to enhance EPBs owners seismic retrofit decisions. These market-based incentives offer compelling reasons for the different property market stakeholders and the public at large to retain, care, invest, and act responsibly to rehabilitate EPBs. The findings suggest need for stakeholders involved in property investment and retrofit decisions to work together to foster seismic rehabilitation of EPBs.

Images, Alexander Turnbull Library

The EQC (Earthquake Commission) has developed new standards and designs to help rebuild Christchurch after the earthquakes of 2010 and 2011. The Department of Building and Housing have produced some generic building foundation and floor designs that can be used for residential homes being built or repaired on liquefied, tilting, unsettled and/or damaged land. (RebuildChristchurch.co.nz) Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

Two people crawl across a desert littered with animal bones and skulls towards the words 'Land reports' in the distance. The woman says 'Don't get your hopes up! It's probably a mirage!' Context - On Thursday 23 June Prime Minister John Key, Canterbury Earthquake Recovery Minister Gerry Brownlee and representatives from engineering consultants Tonkin & Taylor announced the first part of the Government's long-awaited land report that revealed the fate of up to 5000 quake-damaged homes. Quantity: 1 digital cartoon(s).

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.

Research papers, University of Canterbury Library

Timber has experienced renewed interests as a sustainable building material in recent times. Although traditionally it has been the prime choice for residential construction in New Zealand and some other parts of the world, its use can be increased significantly in the future through a wider range of applications, particularly when adopting engineered wood material, Research has been started on the development of innovative solutions for multi-storey non-residential timber buildings in recent years and this study is part of that initiative. Application of timber in commercial and office spaces posed some challenges with requirements of large column-free spaces. The current construction practice with timber is not properly suited for structures with the aforementioned required characteristics and new type of structures has to be developed for this type of applications. Any new structural system has to have adequate capacity for carry the gravity and lateral loads due to occupancy and the environmental effects. Along with wind loading, one of the major sources of lateral loads is earthquakes. New Zealand, being located in a seismically active region, has significant risk of earthquake hazard specially in the central region of the country and any structure has be designed for the seismic loading appropriate for the locality. There have been some significant developments in precast concrete in terms of solutions for earthquake resistant structures in the last decade. The “Hybrid” concept combining post-tensioning and energy dissipating elements with structural members has been introduced in the late 1990s by the precast concrete industry to achieve moment-resistant connections based on dry jointed ductile connections. Recent research at the University of Canterbury has shown that the concept can be adopted for timber for similar applications. Hybrid timber frames using post-tensioned beams and dissipaters have the potential to allow longer spans and smaller cross sections than other forms of solid timber frames. Buildings with post-tensioned frames and walls can have larger column-free spaces which is a particular advantage for non-residential applications. While other researchers are focusing on whole structural systems, this research concentrated on the analysis and design of individual members and connections between members or between member and foundation. This thesis extends existing knowledge on the seismic behaviour and response of post-tensioned single walls, columns under uni-direction loads and small scale beam-column joint connections into the response and design of post-tensioned coupled walls, columns under bi-directional loading and full-scale beam-column joints, as well as to generate further insight into practical applications of the design concept for subassemblies. Extensive experimental investigation of walls, column and beam-column joints provided valuable confirmation of the satisfactory performance of these systems. In general, they all exhibited almost complete re-centering capacity and significant energy dissipation, without resulting into structural damage. The different configurations tested also demonstrated the flexibility in design and possibilities for applications in practical structures. Based on the experimental results, numerical models were developed and refined from previous literature in precast concrete jointed ductile connections to predict the behaviour of post-tensioned timber subassemblies. The calibrated models also suggest the values of relevant parameters for applications in further analysis and design. Section analyses involving those parameters are performed to develop procedures to calculate moment capacities of the subassemblies. The typical features and geometric configurations the different types of subassemblies are similar with the only major difference in the connection interfaces. With adoption of appropriate values representing the corresponding connection interface and incorporation of the details of geometry and configurations, moment capacities of all the subassemblies can be calculated with the same scheme. That is found to be true for both post-tensioned-only and hybrid specimens and also applied for both uni-directional and bi-directional loading. The common section analysis and moment capacity calculation procedure is applied in the general design approach for subassemblies.

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.

Research papers, University of Canterbury Library

This manuscript provides a critical examination of the ground motions recorded in the near-source region resulting from the 22 February 2011 Christchurch earthquake. Particular attention is given to reconciling the observed spatial distribution of ground motions in terms of physical phenomena related to source, path and site effects. The large number of near-source observed strong ground motions show clear evidence of: forward-directivity, basin generated surface waves, liquefaction and other significant nonlinear site response. The pseudo-acceleration response spectra (SA) amplitudes and significant duration of strong motions agree well with empirical prediction models, except at long vibration periods where the influence of basin-generated surface waves and nonlinear site response are significant and not adequately accounted for in empirical SA models. Pseudo-acceleration response spectra are also compared with those observed in the 4 September 2010 Darfield earthquake and routine design response spectra used in order to emphasise the amplitude of ground shaking and elucidate the importance of local geotechnical characteristics on surface ground motions. The characteristics of the observed vertical component accelerations are shown to be strongly dependent on source-to-site distance and are comparable with those from the 4 September 2010 Darfield earthquake, implying the large amplitudes observed are simply a result of many observations at close distances rather than a peculiar source effect.

Images, Alexander Turnbull Library

Two skeletal people sit in armchairs waist-deep in silt. The man is reading the newspaper and says 'The wait's over! The Land Report's due out dear!... DEAR?' He realises that his wife, whose bony hand clutches 'EQC update No. 37', is dead. Context - On Thursday 23 June Prime Minister John Key, Canterbury Earthquake Recovery Minister Gerry Brownlee and representatives from engineering consultants Tonkin & Taylor announced the first part of the Government's long-awaited land report that revealed the fate of up to 5000 quake-damaged homes. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

Text at the top of the cartoon reads 'NZ city strengthening?' A whole city enclosed in a glass dome and balanced on huge springs intended to make it earthquake resistant rocks as another aftershock hits. Context - Two earthquakes and hundreds of aftershocks have hit Christchurch, the first on 4 September 2010 and a second more devastating one on 22 February 2011. There has been great emphasis on making heritage buildings that are rebuilt and all new buildings earthquake resistant. The example in the cartoon is perhaps a Springs-with-damper base isolator. Quantity: 1 digital cartoon(s).

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.

Research papers, University of Canterbury Library

Surface rupture of the previously unrecognised Greendale Fault extended west-east for ~30 km across alluvial plains west of Christchurch, New Zealand, during the Mw 7.1 Darfield (Canterbury) earthquake of September 2010. Surface rupture displacement was predominantly dextral strike-slip, averaging ~2.5 m, with maxima of ~5 m. Vertical displacement was generally less than 0.75 m. The surface rupture deformation zone ranged in width from ~30 to 300 m, and comprised discrete shears, localised bulges and, primarily, horizontal dextral flexure. About a dozen buildings, mainly single-storey houses and farm sheds, were affected by surface rupture, but none collapsed, largely because most of the buildings were relatively flexible and resilient timber-framed structures and also because deformation was distributed over a relatively wide zone. There were, however, notable differences in the respective performances of the buildings. Houses with only lightly-reinforced concrete slab foundations suffered moderate to severe structural and non-structural damage. Three other buildings performed more favourably: one had a robust concrete slab foundation, another had a shallow-seated pile foundation that isolated ground deformation from the superstructure, and the third had a structural system that enabled the house to tilt and rotate as a rigid body. Roads, power lines, underground pipes, and fences were also deformed by surface fault rupture and suffered damage commensurate with the type of feature, its orientation to the fault, and the amount, sense and width of surface rupture deformation.

Images, Alexander Turnbull Library

Someone in a car full of passengers who represent '10,000 residents' says 'For Pete's sake... Are they ever going to change?' Spider webs have been spun between the car and the road as the car waits at a traffic light that represents the 'land report' and is stuck on orange. Context - Context - On Thursday 23 June Prime Minister John Key, Canterbury Earthquake Recovery Minister Gerry Brownlee and representatives from engineering consultants Tonkin & Taylor announced the first part of the Government's long-awaited land report that revealed the fate of up to 5000 quake-damaged homes. These homes were in the 'red zone'. But 10,500 owners in the orange zone were left in limbo, with their properties requiring further assessment. The areas included Kaiapoi, Pines Beach, Brooklands, Spencerville, Parklands and Queenspark (www.rebuildchristchurch.co.nz 6 July 2011)) Quantity: 1 digital cartoon(s).