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Videos, UC QuakeStudies

A video of a press conference with Bishop Victoria Matthews in the Botanic Gardens about the plans for the earthquake-damaged ChristChurch Cathedral. Matthews announces that the cathedral will be deconstructed, allowing the safe retrieval of taonga and heritage items within the building.

Images, UC QuakeStudies

People gather in a fenced-off area of Cathedral Square to view the damage to the cathedral and surrounding buildings. In the centre is the plinth which formerly held the statue of John Robert Godley. Taken on a day when a walkway was opened up between Re:Start Mall and Cathedral Square to allow temporary public access.

Audio, Radio New Zealand

A huge milestone in the rebuild of the Christchurch Cathedral. Twelves years since the Canterbury earthquakes caused extensive damage to the building, community leaders and project managers have gathered inside the cathedral this morning for the first time since the quakes. It also marks the completion of stablisation phase of the project. Our reporter Adam Burns went along.

Images, eqnz.chch.2010

A magnitude 7.1 earthquake occurred at 4:35 am on September 4, 2010 here in Christchurch. There was damage and destruction to buildings but no loss of life. Five months later (22nd Feb, 2011) the city was struck by another quake. This time we weren't so lucky. 185 people lost their lives. Many people lost homes and businesses. The central b...

Images, UC QuakeStudies

People walk and drive along Manchester Street shortly after the 22 February earthquake. Bricks from collapsed buildings litter the road. The photographer comments, "Just after the aftershock settled on Tuesday afternoon, myself and colleagues fled our Tuam Street office to absolute devastation outside. We couldn't see more than a block in either direction due to the clouds of dust that had arisen from buildings that had just collapsed ... From here, we picked up our vehicles from the CCC car park and headed out to get out of the chaos to a position where we could check on loved ones. Heading first along Manchester Street, buildings that were already heavily damaged were now completely written off".

Research papers, University of Canterbury Library

On 22 February 2011,a magnitude Mw 6.3 earthquake occurred with an epicenter located near Lyttelton at about 10km from Christchurch in Canterbury region on the South Island of New Zealand (Figure 1). Since this earthquake occurred in the midst of the aftershock activity which had continued since the 4 September 2010 Darfield Earthquake occurrence, it was considered to be an aftershock of the initial earthquake. Because of the short distance to the city and the shallower depth of the epicenter, this earthquake caused more significant damage to pipelines, traffic facilities, residential houses/properties and multi-story buildings in the central business district than the September 2010 Darfield Earthquake in spite of its smaller earthquake magnitude. Unfortunately, this earthquake resulted in significant number of casualties due to the collapse of multi-story buildings and unreinforced masonry structures in the city center of Christchurch. As of 4 April, 172 casualties were reported and the final death toll is expected to be 181. While it is extremely regrettable that Christchurch suffered a terrible number of victims, civil and geotechnical engineers have this hard-to-find opportunity to learn the response of real ground from two gigantic earthquakes which occurred in less than six months from each other. From geotechnical engineering point of view, it is interesting to discuss the widespread liquefaction in natural sediments, repeated liquefaction within short period and further damage to earth structures which have been damaged in the previous earthquake. Following the earthquake, an intensive geotechnical reconnaissance was conducted to capture evidence and perishable data from this event. The team included the following members: Misko Cubrinovski (University of Canterbury, NZ, Team Leader), Susumu Yasuda (Tokyo Denki University, Japan, JGS Team Leader), Rolando Orense (University of Auckland, NZ), Kohji Tokimatsu (Tokyo Institute of Technology, Japan), Ryosuke Uzuoka (Tokushima University, Japan), Takashi Kiyota (University of Tokyo, Japan), Yasuyo Hosono (Toyohashi University of Technology, Japan) and Suguru Yamada (University of Tokyo, Japan).

Research papers, University of Canterbury Library

Despite their good performance in terms of their design objectives, many modern code-prescriptive buildings built in Christchurch, New Zealand had to be razed after the 2010-2011 Canterbury earthquakes because repairs were deemed too costly due to widespread sacrificial damage. Clearly a more effective design paradigm is needed to create more resilient structures. Rocking, post-tensioned connections with supplemental energy dissipation can contribute to a damage avoidance designs (DAD). However, few have achieved all three key design objectives of damage-resistant rocking, inherent recentering ability, and repeatable, damage-free energy dissipation for all cycles, which together offer a response which is independent of loading history. Results of experimental tests are presented for a near full-scale rocking beam-column sub-assemblage. A matrix of test results is presented for the system under varying levels of posttensioning, with and without supplemental dampers. Importantly, this parametric study delineates each contribution to response. Practical limitations on posttensioning are identified: a minimum to ensure static structural re-centering, and a maximum to ensure deformability without threadbar yielding. Good agreement between a mechanistic model and experimental results over all parameters and inputs indicates the model is robust and accurate for design. The overall results indicate that it is possible to create a DAD connection where the non-linear force-deformation response is loading history independent and repeatable over numerous loading cycles, without damage, creating the opportunity for the design and implementation of highly resilient structures.

Research papers, University of Canterbury Library

Impact between structures of bridge sections can play a major, unexpected role in seismic structural damage. Linear and non-linear models are developed to analyze structural impact and response of two single-degree-of-freedom structures, representing adjacent buildings or bridge sections. The analyses presented assess probability of impact, displacement change due to impact, and the probability of increased displacement due to impact. These are assessed over a matrix of structural periods for each degree-of-freedom, different impact coefficients of restitution, and a probabilistically scaled suite of earthquake events. Linear versus non-linear effects are assessed using a Ramberg-Osgood non-linear model for column inelasticity. The normalized distance, or gap-ratio (GR), defined as a percentage of the summed spectral displacements, is used to create probabilistic design requirements. Increasing GR and structural periods that are similar (T2/T1~0.8-1.25) significantly decrease the likelihood of impact, and vice-versa. Including column inelasticity and decreasing coefficient of restitution decrease displacement increases due to impact and thus reduce potential damage. A minimum GR~0.5-0.9 ensures that any displacement increases will be less than 10% for 90% of ground motions over all structural period combinations (0.2-5.0sec). These results enable probabilistic design guidelines to manage undesirable effects of impact– an important factor during the recent Canterbury, New Zealand Earthquakes.

Research papers, University of Canterbury Library

This thesis studies the behaviour of diaphragms in multi-storey timber buildings by providing methods for the estimation of the diaphragm force demand, developing an Equivalent Truss Method for the analysis of timber diaphragms, and experimentally investigating the effects of displacement incompatibilities between the diaphragm and the lateral load resisting system and developing methods for their mitigation. The need to better understand the behaviour of diaphragms in timber buildings was highlighted by the recent 2010-2011 Canterbury Earthquake series, where a number of diaphragms in traditional concrete buildings performed poorly, compromising the lateral load resistance of the structure. Although shortcomings in the estimation of force demand, and in the analysis and design of concrete floor diaphragms have already been partially addressed by other researchers, the behaviour of diaphragms in modern multi-storey timber buildings in general, and in low damage Pres-Lam buildings (consisting of post-tensioned timber members) in particular is still unknown. The recent demand of mid-rise commercial timber buildings of ten storeys and beyond has further highlighted the lack of appropriate methods to analyse timber diaphragms with irregular floor geometries and large spans made of both light timber framing and massive timber panels. Due to the lower stiffness of timber lateral load resisting systems, compared with traditional construction materials, and the addition of in-plane flexible diaphragms, the effect of higher modes on the global dynamic behaviour of a structure becomes more critical. The results from a parametric non-linear time-history analysis on a series of timber frame and wall structures showed increased storey shear and moment demands even for four storey structures when compared to simplistic equivalent static analysis. This effect could successfully be predicted with methods available in literature. The presence of diaphragm flexibility increased diaphragm inter-storey drifts and the peak diaphragm demand in stiff wall structures, but had less influence on the storey shears and moments. Diaphragm force demands proved to be significantly higher than the forces derived from equivalent static analysis, leading to potentially unsafe designs. It is suggested to design all diaphragms for the same peak demand; a simplified approach to estimate these diaphragm forces is proposed for both frame and wall structures. Modern architecture often requires complex floor geometries with long spans leading to stress concentrations, high force demands and potentially large deformations in the diaphragms. There is a lack of guidance and regulation regarding the analysis and design of timber diaphragms and a practical alternative to the simplistic equivalent deep beam analysis or costly finite element modelling is required. An Equivalent Truss Method for the analysis of both light timber framed and massive timber diaphragms is proposed, based on analytical formulations and verified against finite element models. With this method the panel unit shear forces (shear flow) and therefore the fastener demand, chord forces and reaction forces can be evaluated. Because the panel stiffness and fastener stiffness are accounted for, diaphragm deflection, torsional effects and transfer forces can also be assessed. The proposed analysis method is intuitive and can be used with basic analysis software. If required, it can easily be adapted for the use with diaphragms working in the non-linear range. Damage to floor diaphragms resulting from displacement incompatibilities due to frame elongation or out-of plane deformation of walls can compromise the transfer of inertial forces to the lateral load resisting system as well as the stability of other structural elements. Two post-tensioned timber frame structures under quasi-static cyclic and dynamic load, respectively, were tested with different diaphragm panel layouts and connections investigating their ability to accommodate frame elongations. Additionally, a post-tensioned timber wall was loaded under horizontal cyclic loads through two pairs of collector beams. Several different connection details between the wall and the beams were tested, and no damage to the collector beams or connections was observed in any of the tests. To evaluate the increased strength and stiffness due to the wall-beam interaction an analytical procedure is presented. Finally, a timber staircase core was tested under bi-directional loading. Different connection details were used to study the effect of displacement incompatibilities between the orthogonal collector beams. These experiments showed that floor damage due to displacement incompatibilities can be prevented, even with high levels of lateral drift, by the flexibility of well-designed connections and the flexibility of the timber elements. It can be concluded that the flexibility of timber members and the flexibility of their connections play a major role in the behaviour of timber buildings in general and of diaphragms specifically under seismic loads. The increased flexibility enhances higher mode effects and alters the diaphragm force demand. Simple methods are provided to account for this effect on the storey shear, moment and drift demands as well as the diaphragm force demands. The analysis of light timber framing and massive timber diaphragms can be successfully analysed with an Equivalent Truss Method, which is calibrated by accounting for the panel shear and fastener stiffnesses. Finally, displacement incompatibilities in frame and wall structures can be accommodated by the flexibilities of the diaphragm panels and relative connections. A design recommendations chapter summarizes all findings and allows a designer to estimate diaphragm forces, to analyse the force path in timber diaphragms and to detail the connections to allow for displacement incompatibilities in multi-storey timber buildings.

Images, UC QuakeStudies

A photograph of the earthquake damage to the Country Theme store on the corner of Manchester and St Asaph Streets. Sections of the second storey walls have crumbled, and the bricks have fallen onto the footpath below. Wire fences have been placed around the building as a cordon. Red stickers on the front door and the wire fence indicate that the building is not safe to enter.

Images, UC QuakeStudies

Detail of damage to the former Princess Cinema in New Brighton. Bricks have fallen from the wall, exposing the interior. The photographer comments, "This is the back of the old Princess Cinema in New Brighton after the earthquake in Christchurch, New Zealand on 22 February. The bricks seem to be just on the edge of falling. This building has now been knocked down as it was so dangerous".

Images, UC QuakeStudies

A photograph of the earthquake-damaged buildings and rubble on Colombo Street near the intersection of St Asaph Street. The walls of the top storey of the buildings to the left have crumbled, and bricks and other rubble have fallen onto the footpath and road below. Wire fencing and police tape have been placed across the street as a cordon. An excavator from Daniel Smith Industries Ltd is parked in front of the fence.

Research papers, University of Canterbury Library

Recently developed performance-based earthquake engineering framework, such as one provided by PEER (Deierlein et al. 2003), assist in the quantification in terms of performance such as casualty, monetary losses and downtime. This opens up the opportunity to identify cost-effective retrofit/rehabilitation strategies by comparing upfront costs associated with retrofit with the repair costs that can be expected over time. This loss assessment can be strengthened by learning from recent earthquakes, such as the 2010 Canterbury and 2016 Kaikoura earthquakes. In order to investigate which types of retrofit/rehabilitation strategies may be most cost-effective, a case study building was chosen for this research. The Pacific Tower, a 22-storey EBF apartment located within the Christchurch central business district (CBD), was damaged and repaired during the 2010 Canterbury earthquake series. As such, by taking hazard levels accordingly (i.e. to correspond to the Christchurch CBD), modelling and analysing the structure, and considering the vulnerability and repair costs of its different components, it is possible to predict the expected losses of the aforementioned building. Using this information, cost-effective retrofit/rehabilitation strategy can be determined. This research found that more often than not, it would be beneficial to improve the performance of valuable non-structural components, such as partitions. Although it is true that improving such elements will increase the initial costs, over time, the benefits gained from reduced losses should be expected to overcome the initial costs. Aftershocks do increase the predicted losses of a building even in lower intensities due to the fact that non-structural components can get damaged at such low intensities. By comparing losses computed with and without consideration of aftershocks for a range of historical earthquakes, it was found that the ratio between losses due to main shock with aftershocks to the losses due to the main shock only tended to increase with increasing main shock magnitude. This may be due to the fact that larger magnitude earthquakes tend to generate larger magnitude aftershocks and as those aftershocks happen within a region around the main shock, they are more likely to cause intense shaking and additional damage. In addition to this observation, it was observed that the most significant component of loss of the case study building was the non-structural partition walls.

Images, UC QuakeStudies

A view down Manchester Street, looking south. The road is noticably buckled, and rubble from damaged buildings can be seen beyond the cordon fence. The photographer comments, "Today I ... went for a walk along the cordon to the north of Christchurch CBD which runs about one street back from Bealey Avenue. The soldiers manning the cordon seemed happy for me to take photos but I couldn't see much of the city from the barrier ... what you can see shows there's obviously a lot of damage. The roads are swollen and raised in many place. The once flat CBD will now feature plenty of hills as well as natural traffic calming features".

Images, UC QuakeStudies

A photograph captioned by BeckerFraserPhotos, "The Octagon Live Restaurant, formerly Trinity Congregational Church, on the corner of Manchester and Worcester Street. This was further damaged in the 23 December 2011 earthquake when a big piece of the rose window fell out".

Images, UC QuakeStudies

A photograph looking north-west down High Street towards the intersection with Manchester Street. Rubble from several earthquake-damaged buildings lines both sides of the street. In the distance members of the Wellington Emergency Management Office Emergency Response Team and several excavators are working.

Images, UC QuakeStudies

A photograph of the earthquake damage to the Knox Church on the corner of Bealey Avenue and Victoria Street. The gable walls have crumbled, exposing the wooden structure inside. Wire fencing, road cones and cordon tape have been placed around the building as a cordon.

Images, UC QuakeStudies

A photograph looking west down Lichfield Street towards the intersection of Manchester Street. Bricks and other rubble from the earthquake-damaged buildings on either side of the road have scattered on the footpath and street. Road cones and plastic fencing has been used as cordons.

Images, UC QuakeStudies

A photograph of the Wellington Emergency Management Office Emergency Response Team standing in a car park on Lichfield Street. The team are wearing face and gas masks, hard hats, safety glasses, knee pads, and rubber gloves. In the background are several earthquake-damaged buildings.

Images, UC QuakeStudies

A photograph of the earthquake damage to South of the Border and Denis Moore the Auto Electrician on Colombo Street. The top storey of South of the Border has crumbled. Fencing, road cones and tape have been placed around the buildings as a cordon.

Research papers, University of Canterbury Library

The effects of soil-foundation-structure interaction (SFSI) have been a topic of discussion amongst the structural and geotechnical community for many decades. The complexity of the mechanisms, as well as the need for inter-disciplinary knowledge of geotechnical and structural dynamics has plagued the advancement and the consequent inclusion of SFSI effects in design. A rigorous performance-based design methodology should not just consider the performance of the superstructure but the supporting foundation system as well. Case studies throughout history (eg. Kobe 1995, Kocaeli 1999 and Christchurch earthquakes 2010-2011) have demonstrated that a poor performance at the foundation level can result in a full demolition of the structure and, in general terms, that the extent of damage to, and repairability of, the building system as a whole, is given by the combination of the damage to the soil, foundation and superstructure. The lack of consideration of the modifying factors of SFSI and an absence of intuitive performance levels for controlling foundation and soil behaviour under seismic loads has resulted in inadequate designs for buildings sited on soft soil. For engineers to be satisfied that their designs meet the given performance levels they must first, understand how SFSI affects the overall system performance and secondly have tools available to adequately account for it in their design/assessment. This dissertation presents an integrated performance-based design procedure for buildingfoundation systems that considers all of the major mechanisms of SFSI. A new soil-foundation macro-element model was implemented into a nonlinear finite element software and validated against several experimental tests. The numerical model was used to provide insights in to the mechanisms of SFSI and statistical analysis on the results yielded simple expressions that allow the behaviour to be quantified. Particular attention was paid to the effects of shear force on the foundation response and the quantification of the rocking mode of response. The residual deformations of the superstructure and distribution of forces up the structure were also investigated. All of the major SFSI mechanisms are discussed in detail and targeted numerical studies are used to explain and demonstrate concepts. The design procedure was validated through the design and assessment of a series of concrete buildings that were designed to account for the effects of SFSI.

Images, Alexander Turnbull Library

Passengers use the baggage carousel at the Christchurch Airport to sleep on as they are swept around. 'Such a unique concept... a revolving motel!' Shortage of accommodation in Christchurch, because of earthquake-damaged hotels and motels and workers coming in for the Rebuild, was a serious problem for travellers to Christchurch, leading many to sleep in the airport overnight. Quantity: 1 digital cartoon(s).

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, eqnz.chch.2010

The back of the old Odeon movie theatre, that was for about 15-20 years a New Life Christian Centre. This is earthquake damage, although the roof was lifted off in 2011. I don't know whether this is a building that they want to save or still awaiting demolition. The smaller building to the immediate left was restored a few years ago and for a...

Images, eqnz.chch.2010

The September Canterbury earthquake. These pictures were taken of The New Zealand Army, along with Police, minding the cordons. This was beside The Press building, and behind the Christchurch Cathedral. Note: these photos were taken on a cellphone; mind the quality.

Research papers, Victoria University of Wellington

<b>In the late 1960s the Wellington City Council surveyed all the commercial buildings in the city and marked nearly 200 as earthquake prone. The owners were given 15 years to either strengthen or demolish their buildings. The end result was mass demolition throughout the seventies and eighties.¹ Prompted by the Christchurch earthquakes, once again the council has published a list of over 630 earthquake prone buildings that need to be strengthened or demolished by 2030.²Of these earthquake prone buildings, the majority were built between 1880 and 1930, with 125 buildings appearing on the Wellington City Council Heritage Building List.³ This list accounts for a significant proportion of character buildings in the city. There is a danger that the aesthetic integrity of our city will be further damaged due to the urgent need to strengthen these buildings. Many of the building owners are resistant because of the high cost. By adapting these buildings to house co-workspaces, we can gain more than just the retention of the building’s heritage. The seismic upgrade provides the opportunity for the office space to be redesigned to suit changes in the ways we work. Through a design-based research approach this thesis proposes a framework that clarifies the process of adapting Wellington’s earthquake prone heritage buildings to accommodate co-working. This framework deals with the key concepts of program, structure and heritage. The framework is tested on one of Wellington’s earthquake prone heritage buildings, the Wellington Working Men’s Club, in order to demonstrate what can be gained from this strengthening process. ¹ Reid, J., “Hometown Boomtown,” in NZ On Screen (Wellington, 1983).</b> ² Wellington City Council, List of Earthquake Prone Buildings as at 06/03/2017. (Wellington: Absolutely Positively Wellington. 2017). ³ ibid. 

Images, UC QuakeStudies

Members of the public take photographs of the damaged Christ Church Cathedral. A walkway from Gloucester Street to the Square was opened up for a few days to allow the public a closer look at the cathedral. The tower and the front wall of the building have partially collapsed. Steel bracing has been added to the front wall for support.