Hundreds of Christchurch homeowners have discovered extensive damage to the on-sold properties they purchased after the 2010/2011 earthquakes. Licenced Building Practictioner Dan Paltridge talks to Logan Church about what people need to look out for, and what they need to do before buying a home in the city.
A video of a press conference with Anglican Bishop Victoria Matthews and Dean Peter Beck, about the interim plans for the earthquake-damaged ChristChurch Cathedral. In the press conference Matthews announces that the Cathedral will be deconsecrated, that parts of it will be demolished, and that the rest will be made safe. These measures will allow the recovery of artefacts and heritage items from the building.
A video of a public forum being held to discuss the Anglican Church's three options for the restoration of the ChristChurch Cathedral. The three options are restoring the original cathedral, reinterpreting the original cathedral in modern materials, or building a contemporary cathedral. The video includes footage of speeches by Bishop Victoria Matthews and RCP project manager Marcus Read. It also includes footage of Matthews, Read, and Warren and Mahoney architect Bill Gregory answering questions from the public.
A video about the Christchurch City Council housing complex on Conference Street in the Christchurch central city. The housing complex was unoccupied after the 22 February 2011 earthquake despite the housing shortage. Christchurch City Council said that the vacant units could not be lived in because of structural damage or damage to services. However, the building has been checked by structural engineers and many of the rooms have been deemed safe to occupy.
A video of a helicopter using a monsoon bucket to wash loose debris off a cliff in Redcliffs. The debris is from an earthquake-damaged building on the edge of the cliff which has had to be urgently demolished after wet weather and aftershocks made it unstable. The video also includes an interview with Brenden Winder, Red Zone Cordon and Access Manager at CERA, about the removal of the debris and the need to check other properties.
A video of a tour of the historic Canterbury Club building on Cambridge Terrace. The club will reopen on 9 June 2012, after an intensive rebuild and restoration process which has fixed the damage from the 22 February 2011 earthquake. The video also includes an interview with Dr Brent Stanley, the Canterbury Club President. Stanley talks about the strengthening work that was done in 2009, as well as the history of the club.
A video of an interview with Prime Minister John Key about several topical issues. One of these issues is the housing crisis in Christchurch. Key talks about fast tracking the release of land in Christchurch, making sure there are enough resources in the city for building, and working with the Christchurch City Council around consenting. He also talks about the possibility of the National Party winning the Christchurch East by-election.
A video of interviews with members of the public about which option they prefer for the restoration of the ChristChurch Cathedral. The options considered are those unveiled by the Anglican Church: the restoration option which would restore the current cathedral; the traditional option which would reinterpret the original cathedral in modern materials; and the contemporary option which would create a new building featuring a lightweight timber frame, more glazing, and modern interiors.
A video of an interview with Tom Thomson, Managing Director of Elastomer Products, about the experiences of businesses in the aftermath of the 2010 and 2011 Canterbury earthquakes. Thomson talks about the importance of focussing on people, diversifying infrastructure, and informing customers after the earthquakes. He also talks about the need for businesses to understand their insurance policies and to have building and service fall-back plans. This video is part of a series about businesses in Christchurch after the earthquakes.
Base isolation has generally been considered an expensive system used mainly in commercial buildings to make them more earthquake resilient. Katy Gosset meets the University of Canterbury engineers who've developed a safe, low cost model that could work in our homes.
In major seismic events, a number of plan-asymmetric buildings which experienced element failure or structural collapse had twisted significantly about their vertical axis during the earthquake shaking. This twist, known as “building torsion”, results in greater demands on one side of a structure than on the other side. The Canterbury Earthquakes Royal Commission’s reports describe the response of a number of buildings in the February 2011 Christchurch earthquakes. As a result of the catastrophic collapse of one multi-storey building with significant torsional irregularity, and significant torsional effects also in other buildings, the Royal Commission recommended that further studies be undertaken to develop improved simple and effective guides to consider torsional effects in buildings which respond inelastically during earthquake shaking. Separately from this, as building owners, the government, and other stakeholders, are planning for possible earthquake scenarios, they need good estimates of the likely performance of both new and existing buildings. These estimates, often made using performance based earthquake engineering considerations and loss estimation techniques, inform decision making. Since all buildings may experience torsion to some extent, and torsional effects can influence demands on building structural and non-structural elements, it is crucial that demand estimates consider torsion. Building seismic response considering torsion can be evaluated with nonlinear time history analysis. However, such analysis involves significant computational effort, expertise and cost. Therefore, from an engineers’ point of view, simpler analysis methods, with reasonable accuracy, are beneficial. The consideration of torsion in simple analysis methods has been investigated by many researchers. However, many studies are theoretical without direct relevance to structural design/assessment. Some existing methods also have limited applicability, or they are difficult to use in routine design office practice. In addition, there has been no consensus about which method is best. As a result, there is a notable lack of recommendations in current building design codes for torsion of buildings that respond inelastically. There is a need for building torsion to be considered in yielding structures, and for simple guidance to be developed and adopted into building design standards. This study aims to undertaken to address this need for plan-asymmetric structures which are regular over their height. Time history analyses are first conducted to quantify the effects of building plan irregularity, that lead to torsional response, on the seismic response of building structures. Effects of some key structural and ground motion characteristics (e.g. hysteretic model, ground motion duration, etc.) are considered. Mass eccentricity is found to result in rather smaller torsional response compared to stiffness/strength eccentricity. Mass rotational inertia generally decreases the torsional response; however, the trend is not clearly defined for torsionally restrained systems (i.e. large λty). Systems with EPP and bilinear models have close displacements and systems with Takeda, SINA, and flag-shaped models yield almost the same displacements. Damping has no specific effect on the torsional response for the single-storey systems with the unidirectional eccentricity and excitation. Displacements of the single-storey systems subject to long duration ground motion records are smaller than those for short duration records. A method to consider torsional response of ductile building structures under earthquake shaking is then developed based on structural dynamics for a wide range of structural systems and configurations, including those with low and high torsional restraint. The method is then simplified for use in engineering practice. A novel method is also proposed to simply account for the effects of strength eccentricity on response of highly inelastic systems. A comparison of the accuracy of some existing methods (including code-base equivalent static method and model response spectrum analysis method), and the proposed method, is conducted for single-storey structures. It is shown that the proposed method generally provides better accuracy over a wide range of parameters. In general, the equivalent static method is not adequate in capturing the torsional effects and the elastic modal response spectrum analysis method is generally adequate for some common parameters. Record-to-record variation in maximum displacement demand on the structures with different degrees of torsional response is considered in a simple way. Bidirectional torsional response is then considered. Bidirectional eccentricity and excitation has varying effects on the torsional response; however, it generally increases the weak and strong edges displacements. The proposed method is then generalized to consider the bidirectional torsion due to bidirectional stiffness/strength eccentricity and bidirectional seismic excitation. The method is shown to predict displacements conservatively; however, the conservatism decreases slightly for cases with bidirectional excitation compared to those subject to unidirectional excitation. In is shown that the roof displacement of multi-storey structures with torsional response can be predicted by considering the first mode of vibration. The method is then further generalized to estimate torsional effects on multi-storey structure displacement demands. The proposed procedure is tested multi-storey structures and shown to predict the displacements with a good accuracy and conservatively. For buildings which twist in plan during earthquake shaking, the effect of P-Δλ action is evaluated and recommendations for design are made. P-Δλ has more significant effects on systems with small post- yield stiffness. Therefore, system stability coefficient is shown not to be the best indicator of the importance of P-Δλ and it is recommended to use post-yield stiffness of system computed with allowance for P-Δλ effects. For systems with torsional response, the global system stability coefficient and post- yield stiffness ration do not reflect the significance of P-Δλ effects properly. Therefore, for torsional systems individual seismic force resisting systems should be considered. Accuracy of MRSA is investigated and it is found that the MRSA is not always conservative for estimating the centre of mass and strong edge displacements as well as displacements of ductile systems with strength eccentricity larger than stiffness eccentricity. Some modifications are proposed to get the MRSA yields a conservative estimation of displacement demands for all cases.
Construction delays and cost over-runs are prolonging the earthquake risks facing patients and staff at Christchurch hospital. Six major hospital buildings at the central city site have been listed as earthquake prone since May, but there is no safer space to shift patients into. Phil Pennington reports.
Three time capsules recovered from the ruins of Christchurch in the days following the February earthquake have been opened. Two came from the John Robert Godley statue plinth in front of the Christchurch Cathedral, while the other came from the old civic building on Manchester Street.
Kaikoura and Wellington businesses operating adjacent to quake damaged buildings may face disruption for years to come as owners drag their feet on repair or demolition work. A Christchurch property owner has been unable to completely re-open for business since the February 2011 earthquake.
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.
A digitally manipulated image of a broken window on Spicer House. The photographer comments, "One of the office blocks in Christchurch City, New Zealand. As the window has not been fixed I am presuming that this building will be slowly demolished at a later date".
Here's Prarie, outside our flat, the day after the 7.1 earthquake hit Christchurch. You see the damage to the street, which continued through our flat. We were forced to move out once an engineer examined the cracks in our balcony, walls, floors, and ceilings, and told us the building was unsafe for living. One crack ran from the street, pres...
A sign outside the Chinwag Eathai restaurant on Victoria Street reads "To all our valued customers. We are sorry to inform you as of Tuesday 17th January 2012 our building has been red stickered. Don't worry we will be back at a new location!! Yet to be confirmed".
The 2010 and 2011 earthquakes have had a devastating impact on the city of Christchurch, New Zealand. The level of destruction has been especially evident in the central business district where it has been estimated over 1000 buildings have already been or will eventually require demolition. Although, contrary to expectations, most of the fatalities were in relatively modern buildings, the Victorian and Edwardian era building stock was especially hard hit in terms of property damage. Unfortunately this era and style of building were also the focus of the most successful inner city revitalisation projects to date. A major research project is now underway examining the impact on the earthquakes on one of these revitalisation areas. The first step is to examine the international literature on similar inner city revitalisation or gentrification areas and in particular the characteristics of owners and occupiers attracted to this type of environment. This is the focus of this paper.
College of Engineering staff stand beside a sign pointing through a fern garden to the temporary new entrance to the School of Engineering office. Asbestos is currently being removed from areas within the building. Pictured: Lisa Carter, Arran Yuill, Cecillia King, Karen Carthew, Janet Butcher, Cheryl McNickel and Vicki O'Sullivan.
John Key wants inquiry into collapse of buildings; Police update on latest from Christchurch emergency; Cordon update; More budget cuts in store after Christchurch earthquake; Attention turns to shape of new Christchurch CBD; Clifton Hills residents able to go home after evacuations; Quake Minister says ten thousand homes may be written off.
College of Engineering staff stand beside a sign pointing through a fern garden to the temporary new entrance to the School of Engineering office. Asbestos is currently being removed from areas within the building. Pictured: Lisa Carter, Arran Yuill, Cecillia King, Karen Carthew, Janet Butcher, Cheryl McNickel and Vicki O'Sullivan.
A digitally manipulated image of light sculptures on Gloucester Street during the LuxCity event. The photographer comments, "This was part of the LuxCity event in Christchurch, New Zealand. It was a way of creating a city of lights on the sites of demolished buildings in the earthquake devastated red zone. 350 architecture and design students from all around New Zealand created and constructed 16 pop up spaces".
Topics - The Earthquake Recovery Minister, Gerry Brownlee, says it is important to be realistic about the demolition of Christchurch's heritage buildings following the powerful earthquake there last month. Motorists should prepare themselves for more increases in the price of petrol which, the AA warns, is likely to reach a new high.
University of Canterbury geologist Mark Quigley has earned a reputation for being a great science communicator on the subject of earthquakes. But when he's not in the media spotlight, he's out and about around Canterbury building a picture of the region's tectonic history, and trying to understand what might happen in the future.
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.
In recent Canterbury earthquakes, structures have performed well in terms of life safety but the estimated total cost of the rebuild was as high as $40 billion. The major contributors to this cost are repair/demolition/rebuild cost, the resulting downtime and business interruption. For this reason, the authors are exploring alternate building systems that can minimize the downtime and business interruption due to building damage in an earthquake; thereby greatly reducing the financial implications of seismic events. In this paper, a sustainable and demountable precast reinforced concrete (RC) frame system in which the precast members are connected via steel tubes/plates or steel angles/plates and high strength friction grip (HSFG) bolts is introduced. In the proposed system, damaged structural elements in seismic frames can be easily replaced with new ones; thereby making it an easily and quickly repairable and a low-loss system. The column to foundation connection in the proposed system can be designed either as fixed or pinned depending on the requirement of strength and stiffness. In a fixed base frame system, ground storey columns will also be damaged along with beams in seismic events, which are to be replaced after seismic events; whereas in a pin base frame only beams (which are easy to replace) will be damaged. Low to medium rise (3-6 storey) precast RC frame buildings with fixed and pin bases are analyzed in this paper; and their lateral capacity, lateral stiffness and natural period are scrutinized to better understand the pros and cons of the demountable precast frame system with fixed and pin base connections.
A video of a tour of Gloucester Street from Dallington to Rolleston Avenue, a five kilometre journey which can be seen as a cross-section of the Canterbury rebuild. The video includes footage of the site of the demolished St George's Presbyterian Church in Linwood, New Regent Street, the Rendezvous Hotel, the Isaac Theatre Royal, the Press building, the Christchurch Art Gallery, and Christ's College.
There's been widespread dismay at the decision not to prosecute anyone for the deaths of 115 people in the CTV building collapse during the 2011 Canterbury earthquake. Police say it was a tough decision - they wanted to hold someone to account but there simply wasn't the evidence to warrant a prosecution.
Survivors are gathering in Christchurch today to remember those who died in the devastating Christchurch earthquake of 2011. Of the 185 people who were killed, 115 died when the CTV building collapsed. Former CTV employee Tom Hawker watched his workplace collapse in front of him. He speaks to Susie Ferguson.