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Research papers, University of Canterbury Library

Reinforced concrete structures designed in pre-1970s are vulnerable under earthquakes due to lack of seismic detailing to provide adequate ductility. Typical deficiencies of pre-1970s reinforced concrete structures are (a) use of plain bars as longitudinal reinforcement, (b) inadequate anchorage of beam longitudinal reinforcement in the column (particularly exterior column), (c) lack of joint transverse reinforcement if any, (d) lapped splices located just above joint, and (e) low concrete strength. Furthermore, the use of infill walls is a controversial issue because it can help to provide additional stiffness to the structure on the positive side and on the negative side it can increase the possibility of soft-storey mechanisms if it is distributed irregularly. Experimental research to investigate the possible seismic behaviour of pre-1970s reinforced concrete structures have been carried out in the past. However, there is still an absence of experimental tests on the 3-D response of existing beam-column joints under bi-directional cyclic loading, such as corner joints. As part of the research work herein presented, a series of experimental tests on beam-column subassemblies with typical detailing of pre-1970s buildings has been carried out to investigate the behaviour of existing reinforced concrete structures. Six two-third scale plane frame exterior beam-column joint subassemblies were constructed and tested under quasi-static cyclic loading in the Structural Laboratory of the University of Canterbury. The reinforcement detailing and beam dimension were varied to investigate their effect on the seismic behaviour. Four specimens were conventional deep beam-column joint, with two of them using deformed longitudinal bars and beam bars bent in to the joint and the two others using plain round longitudinal bars and beam bars with end hooks. The other two specimens were shallow beam-column joint, one with deformed longitudinal bars and beam bars bent in to the joint, the other with plain round longitudinal bars and beam bars with end hooks. All units had one transverse reinforcement in the joint. The results of the experimental tests indicated that conventional exterior beam-column joint with typical detailing of pre-1970s building would experience serious diagonal tension cracking in the joint panel under earthquake. The use of plain round bars with end hooks for beam longitudinal reinforcement results in more severe damage in the joint core when compared to the use of deformed bars for beam longitudinal reinforcement bent in to the joint, due to the combination of bar slips and concrete crushing. One interesting outcome is that the use of shallow beam in the exterior beam-column joint could avoid the joint cracking due to the beam size although the strength provided lower when compared with the use of deep beam with equal moment capacity. Therefore, taking into account the low strength and stiffness, shallow beam can be reintroduced as an alternative solution in design process. In addition, the presence of single transverse reinforcement in the joint core can provide additional confinement after the first crack occurred, thus delaying the strength degradation of the structure. Three two-third scale space frame corner beam-column joint subassemblies were also constructed to investigate the biaxial loading effect. Two specimens were deep-deep beam-corner column joint specimens and the other one was deep-shallow beam-corner column joint specimen. One deep-deep beam-corner column joint specimen was not using any transverse reinforcement in the joint core while the two other specimens were using one transverse reinforcement in the joint core. Plain round longitudinal bars were used for all units with hook anchorage for the beam bars. Results from the tests confirmed the evidences from earthquake damage observations with the exterior 3-D (corner) beam-column joint subjected to biaxial loading would have less strength and suffer higher damage in the joint area under earthquake. Furthermore, the joint shear relation in the two directions is calibrated from the results to provide better analysis. An analytical model was used to simulate the seismic behaviour of the joints with the help of Ruaumoko software. Alternative strength degradation curves corresponding to different reinforcement detailing of beam-column joint unit were proposed based on the test results.

Images, UC QuakeStudies

A scanned copy of a handmade poster advertising the University Bookshop (UBS) on campus, and the Book Shop in the Arts Centre. The poster was produced in the 1970s and was sourced from archives held at Macmillan Brown Library.

Research papers, University of Canterbury Library

Reconnaissance reports have highlighted the poor performance of non-ductile reinforced concrete buildings during the 2010-11 Canterbury earthquakes. These buildings are widely expected to result in significant losses under future earthquakes due to their seismic vulnerability and prevalence in densely populated urban areas. Wellington, for example, contains more than 70 pre-1970s multi-storey reinforced concrete buildings, ranging in height from 5 to 18 storeys. This study seeks to characterise the seismic performance and evaluate the likely failure modes of a typical pre-1970s reinforced concrete building in Wellington, by conducting advanced numerical simulations to evaluate its 3D nonlinear dynamic response. A representative 9-storey office building constructed in 1951 is chosen for this study and modelled in the finite element analysis programme DIANA, using a previously developed and validated approach to predict the failure modes of doubly reinforced walls with confined boundary regions. The structure consists of long walls and robust framing elements resulting in a stiff lateral load resisting system. Barbell-shaped walls are flanked by stiff columns with sufficient transverse reinforcement to serve as boundary regions. Curved shell elements are used to model the walls and their boundary columns, for which the steel reinforcement is explicitly modelled. Line elements are used to model the frame elements. The steel reinforcement in each member is explicitly modelled. The floor slabs are modelled using elastic shell elements. The model is analysed under short and long duration ground motions selected to match site specific targets in Wellington at the DBE and MCE intensity levels. The observed response of the building including drift profiles at each intesity level, strain localization effects around wall openings, and the influence of bidirectional loading are discussed.

Images, UC QuakeStudies

A scanned copy of a poster produced by the University of Canterbury Drama Society in the 1970s. The poster is advertising a play titled 'Billy Liar', performed at Ngaio Marsh Theatre in the UCSA building. The poster was sourced from DramaSoc archives held at Macmillan Brown Library.

Images, UC QuakeStudies

A scanned copy of a poster produced by the University of Canterbury Drama Society in the 1970s. The poster is advertising a revue titled 'Bobby Sucks', performed at Ngaio Marsh Theatre in the UCSA building. The poster was sourced from DramaSoc archives held at Macmillan Brown Library.

Images, UC QuakeStudies

A scanned copy of a poster produced by the University of Canterbury Drama Society in the 1970s. The poster is advertising a play titled 'Saved', performed at Ngaio Marsh Theatre in the UCSA building. The poster was sourced from DramaSoc archives held at Macmillan Brown Library.

Images, UC QuakeStudies

A scanned copy of a poster produced by the University of Canterbury Drama Society in the 1970s. The poster is advertising a play titled 'Antigone', performed at Ngaio Marsh Theatre in the UCSA building. The poster was sourced from DramaSoc archives held at Macmillan Brown Library.

Research papers, University of Canterbury Library

The 4th of September 2010 Mw 7.1 Darfield (Canterbury) earthquake had generated significant ground shaking within the Christchurch Central Business District (CBD). Despite the apparently significant shaking, the observed structural damage for pre-1970s reinforced concrete (RC) buildings was indeed limited and lower than what was expected for such typology of buildings. This paper explores analytically and qualitatively the different aspects of the "apparent‟ good seismic performance of the pre-1970s RC buildings in the Christchurch CBD, following the earthquake reconnaissance survey by the authors. Damage and building parameters survey result, based on a previously established inventory of building stock of these non-ductile RC buildings, is briefly reported. From an inventory of 75 buildings, one building was selected as a numerical case-study to correlate the observed damage with the non-linear analyses. The result shows that the pre-1970s RC frame buildings performed as expected given the intensity of the ground motion shaking during the Canterbury earthquake. Given the brittle nature of this type of structure, it was demonstrated that more significant structural damage and higher probability of collapse could occur when the buildings were subjected to alternative input signals with different frequency content and duration characteristics and still compatible to the seismicity hazard for Christchurch CBD.

Images, UC QuakeStudies

A scanned copy of a black and white photograph belonging to University of Canterbury alumnus Colin Lau. Colin describes the photograph as follows: "A view from UCSA towards the (right side of our) Science Building. I am not sure what that target white building behind the lamp standard is. I still remember that little wooden bridge we walked across to the UCSA building & that meandering creek or stream that flows beneath it".

Audio, Radio New Zealand

Conversations between one-time residents of an historic riverside community - in the 1970s the late Elsie Locke and Rod Donald helped to create one of Christchurch's strongest riverside communities. The Avon Loop now subject to post earthquake re-classifation and demolition.

Images, UC QuakeStudies

A scanned copy of a black and white photograph belonging to University of Canterbury alumnus Colin Lau. Colin describes the photograph as follows: "Our science building (where I got my physics degree in 1972) on the left, lecture hall in the middle and engineering school to the right & behind the lecture hall".

Images, UC QuakeStudies

A scanned copy of a black and white photograph belonging to University of Canterbury alumnus Colin Lau. The photograph depicts several University of Canterbury buildings, including the Chemistry and Physics building (now known as the Rutherford building) in the background.

Images, UC QuakeStudies

A scanned copy of a black and white photograph belonging to University of Canterbury alumnus Colin Lau. Colin describes the photograph as follows: "A shot of the float of a parade in the downtown area. I could still recognize some of the faces of my friends on the left taking in the sight and sound of the day. I do not quite recall the date of that parade; it has to be around the early 70's." Colin notes that the photograph may depict the 1971 'University Graduation Day' parade.

Images, UC QuakeStudies

A scanned copy of a black and white photograph belonging to University of Canterbury alumnus Colin Lau. Colin describes the photograph as follows: "A scene of the 1971 parade (procession) that celebrates 'University Graduation Day' according to the note on the back of that photo".

Videos, UC QuakeStudies

A video telling the story of a Dallington house which was built by Bill Cooper in 1957. The house was demolished last month as part of the clearance of the Christchurch residential red zone. The story of the house is used to illustrate what is happening in many Christchurch suburbs. The video also includes the story of a sea elephant that lived in the Avon River in the 1970s and 1980s.

Images, Canterbury Museum

One metal backed plastic sign, circa 1970s, for Cokers Hotel, Manchester Street, Christchurch detailing hotel services and featuring a map of the central city. The Cokers Hotel was located in central Christchurch at 52 Manchester Street. First licensed by John Etherdan (Jack) Coker in 1867, in 1890 the lease was taken over by Captain Popham, wh...

Images, UC QuakeStudies

A scanned copy of a poster produced by the University of Canterbury Drama Society in 1973. The poster is advertising a play titled 'Peer Gynt', performed at James Hay Theatre in the Christchurch Town Hall. The poster was sourced from DramaSoc archives held at Macmillan Brown Library.

Images, eqnz.chch.2010

Known by the locals as the "Manager's House" of the large brick and tile works which was situated nearby. Established by the Austin brothers in 1863 the brickworks were named after the town of Farnley in Yorkshire England, from where the family had come. I remember the brickworks as a child and I think they were demolished in the 1970's. Very sa...

Images, eqnz.chch.2010

Known by the locals as the "Owner's House" of the large Farnley Brick and Tile Works which was situated nearby. Established by the Austin brothers in 1863 the brickworks were named after the town of Farnley in Yorkshire England, from where the family had come. I remember the brickworks as a child and I think they were demolished in the 1970's. V...

Research Papers, Lincoln University

It is no secret that there is a problem with the suburb of Aranui. Developed in the 1950s, Aranui and neighbouring Wainoni are an example of the large-scale, state-funded subdivisions of the time, yet, unlike similar developments in the North Island, they have received little to no attention from researchers. In light of the recent Canterbury earthquakes, this dissertation aims to trace the evolution of these suburbs until the 1970s and act as the first stage of a more comprehensive review of state housing and the Aranui/Wainoni area. By critically reviewing existing literature on state housing and housing policy in New Zealand, as well as undertaking archival research, this dissertation addresses the international influences on state housing in New Zealand generally and the development of the Aranui and Wainoni area more specifically in order to provide a foundation for answering the question, "What went so wrong?"

Research papers, University of Canterbury Library

Existing New Zealand (NZ) building stock contains a significant number of structures designed prior to 1995 with non-ductile reinforced concrete (RC) columns. Recent earthquakes and research show that columns with such details perform poorly when subjected to seismic demand, losing gravity load carrying capacity at drift levels lower than the expected one. Therefore, in order to have a better understanding of existing RC columns in NZ, the history of these elements is investigated in this paper. The evolution of RC column design guidelines in NZ standards since the 1970s is scrutinized. For this purpose, a number of RC columns from Christchurch buildings built prior to 1995 are assessed using the current code of practice.