Christchurch's Cathedral
Re:START Mall, Cashel Street, Christchurch. Monday 23 April 2012. File reference: CCL-2012-04-23IMG_2025 From the collection of Christchurch City Libraries.
Re:START Mall, Cashel Street, Christchurch. Monday 23 April 2012. File reference: CCL-2012-04-23IMG_2027 From the collection of Christchurch City Libraries.
In the last century, seismic design has undergone significant advancements. Starting from the initial concept of designing structures to perform elastically during an earthquake, the modern seismic design philosophy allows structures to respond to ground excitations in an inelastic manner, thereby allowing damage in earthquakes that are significantly less intense than the largest possible ground motion at the site of the structure. Current performance-based multi-objective seismic design methods aim to ensure life-safety in large and rare earthquakes, and to limit structural damage in frequent and moderate earthquakes. As a result, not many recently built buildings have collapsed and very few people have been killed in 21st century buildings even in large earthquakes. Nevertheless, the financial losses to the community arising from damage and downtime in these earthquakes have been unacceptably high (for example; reported to be in excess of 40 billion dollars in the recent Canterbury earthquakes). In the aftermath of the huge financial losses incurred in recent earthquakes, public has unabashedly shown their dissatisfaction over the seismic performance of the built infrastructure. As the current capacity design based seismic design approach relies on inelastic response (i.e. ductility) in pre-identified plastic hinges, it encourages structures to damage (and inadvertently to incur loss in the form of repair and downtime). It has now been widely accepted that while designing ductile structural systems according to the modern seismic design concept can largely ensure life-safety during earthquakes, this also causes buildings to undergo substantial damage (and significant financial loss) in moderate earthquakes. In a quest to match the seismic design objectives with public expectations, researchers are exploring how financial loss can be brought into the decision making process of seismic design. This has facilitated conceptual development of loss optimisation seismic design (LOSD), which involves estimating likely financial losses in design level earthquakes and comparing against acceptable levels of loss to make design decisions (Dhakal 2010a). Adoption of loss based approach in seismic design standards will be a big paradigm shift in earthquake engineering, but it is still a long term dream as the quantification of the interrelationships between earthquake intensity, engineering demand parameters, damage measures, and different forms of losses for different types of buildings (and more importantly the simplification of the interrelationship into design friendly forms) will require a long time. Dissecting the cost of modern buildings suggests that the structural components constitute only a minor portion of the total building cost (Taghavi and Miranda 2003). Moreover, recent research on seismic loss assessment has shown that the damage to non-structural elements and building contents contribute dominantly to the total building loss (Bradley et. al. 2009). In an earthquake, buildings can incur losses of three different forms (damage, downtime, and death/injury commonly referred as 3Ds); but all three forms of seismic loss can be expressed in terms of dollars. It is also obvious that the latter two loss forms (i.e. downtime and death/injury) are related to the extent of damage; which, in a building, will not just be constrained to the load bearing (i.e. structural) elements. As observed in recent earthquakes, even the secondary building components (such as ceilings, partitions, facades, windows parapets, chimneys, canopies) and contents can undergo substantial damage, which can lead to all three forms of loss (Dhakal 2010b). Hence, if financial losses are to be minimised during earthquakes, not only the structural systems, but also the non-structural elements (such as partitions, ceilings, glazing, windows etc.) should be designed for earthquake resistance, and valuable contents should be protected against damage during earthquakes. Several innovative building technologies have been (and are being) developed to reduce building damage during earthquakes (Buchanan et. al. 2011). Most of these developments are aimed at reducing damage to the buildings’ structural systems without due attention to their effects on non-structural systems and building contents. For example, the PRESSS system or Damage Avoidance Design concept aims to enable a building’s structural system to meet the required displacement demand by rocking without the structural elements having to deform inelastically; thereby avoiding damage to these elements. However, as this concept does not necessarily reduce the interstory drift or floor acceleration demands, the damage to non-structural elements and contents can still be high. Similarly, the concept of externally bracing/damping building frames reduces the drift demand (and consequently reduces the structural damage and drift sensitive non-structural damage). Nevertheless, the acceleration sensitive non-structural elements and contents will still be very vulnerable to damage as the floor accelerations are not reduced (arguably increased). Therefore, these concepts may not be able to substantially reduce the total financial losses in all types of buildings. Among the emerging building technologies, base isolation looks very promising as it seems to reduce both inter-storey drifts and floor accelerations, thereby reducing the damage to the structural/non-structural components of a building and its contents. Undoubtedly, a base isolated building will incur substantially reduced loss of all three forms (dollars, downtime, death/injury), even during severe earthquakes. However, base isolating a building or applying any other beneficial technology may incur additional initial costs. In order to provide incentives for builders/owners to adopt these loss-minimising technologies, real-estate and insurance industries will have to acknowledge the reduced risk posed by (and enhanced resilience of) such buildings in setting their rental/sale prices and insurance premiums.
A photograph of emergency management personnel examining a Stonehurst Accommodation building on Gloucester Street. There is liquefaction in the car park in front of the building.
This paper discusses the seismic performance of the standard RC office building in Christchurch that is given as a structural design example in NZS3101, the concrete structures seismic standard in New Zealand. Firstly the push-over analysis was carried out to evaluate the lateral load carrying capacity of the RC building and then to compare that carrying capacity with the Japanese standard law. The estimated figures showed that the carrying capacity of the New Zealand standard RC office building of NZS3101:2006 was about one third of Japanese demanded carrying capacity. Secondly, time history analysis of the multi-mass system was performed to estimate the maximum response story drift angle using recorded ground motions. Finally, a three-dimensional analysis was carried out to estimate the response of the building to the 22nd February, 2011 Canterbury earthquake. The following outcomes were obtained. 1) The fundamental period of the example RC building is more than twice that of Japanese simplified calculation, 2) The example building’s maximum storey drift angle reached 2.5% under the recorded ground motions. The main purpose of this work is to provide background information of seismic design practice for the reconstruction of Christchurch.
The Canterbury Earthquake Sequence (CES), induced extensive damage in residential buildings and led to over NZ$40 billion in total economic losses. Due to the unique insurance setting in New Zealand, up to 80% of the financial losses were insured. Over the CES, the Earthquake Commission (EQC) received more than 412,000 insurance claims for residential buildings. The 4 September 2010 earthquake is the event for which most of the claims have been lodged with more than 138,000 residential claims for this event only. This research project uses EQC claim database to develop a seismic loss prediction model for residential buildings in Christchurch. It uses machine learning to create a procedure capable of highlighting critical features that affected the most buildings loss. A future study of those features enables the generation of insights that can be used by various stakeholders, for example, to better understand the influence of a structural system on the building loss or to select appropriate risk mitigation measures. Previous to the training of the machine learning model, the claim dataset was supplemented with additional data sourced from private and open access databases giving complementary information related to the building characteristics, seismic demand, liquefaction occurrence and soil conditions. This poster presents results of a machine learning model trained on a merged dataset using residential claims from the 4 September 2010.
The Catholic Cathedral is classified as a category 1 listed heritage building constructed largely of unreinforced stone masonry, and was significantly damaged in the recent Canterbury earthquakes of 2010 and 2011. In the 2010 event the building presented slight to moderta damage, meanwhile in the 2011 one experienced ground shaking in excess of its capacity leading to block failures and partial collapse of parts of the building, which left the building standing but still posing a significant hazard. In this paper we discuss the approach to develop the earthquake analysis of the building by 3D numerical simulations, and the results are compared/calibrated with the observed damage of the 2010 earthquake. Very accurate records were obtained during both earthquakes due to a record station located least than 80 m of distance from the building and used in the simulations. Moreover it is included in the model the soil structure interaction because it was observed that the ground and foundation played an important role on the seismic behavior of the structure. A very good agreement was found between the real observed damage and the nonlinear dynamic simulations described trough inelastic deformation (cracking) and building´s performance.
The earthquake swarm that has struck Canterbury, New Zealand from September 2010 has led to widespread destruction and loss of life in the city of Christchurch. In response to this the New Zealand government convened a Royal Commission under the Commissions of Inquiry Act 1908. The terms of reference for this enquiry were wide ranging, and included inquiry into legal and best-practice requirements for earthquake-prone buildings and associated risk management strategies. The Commission produced a final report on earthquake-prone buildings and recommendations which was made public on the 7th December 2012. Also on the 7th of December 2012 the Ministry of Business, Innovation and Employment (MBIE) released a Consultation Document that includes many of the recommendations put forward by the Royal Commission. This paper examines the evidence presented to the Royal Commission and reviews their recommendations and those of MBIE in relation to the management of earthquake-prone buildings. An analysis of the likely impacts of the recommendations and proposals on both the property market and society in general is also undertaken.
A new office building in central Christchurch has multiple flaws in its earthquake design that the city council was warned about almost two years ago. Construction of the seven-storey building above the busy shopping precinct at 230 High Street, continued even after those warnings in December 2017. Three leading engineering firms have found critical faults - the latest are detailed in a Government-ordered report that's been leaked to RNZ. Phil Pennington joins Corin Dann with the details.
A photograph of an earthquake-damaged building on the corner of Tuam and Colombo Streets. The brick wall on the top storey of the building has crumbled onto the footpath below and the windows on the bottom storey have been boarded up with plywood. Workers in a cherry picker and a crane-raised platform are working on the second storey. Wire fencing surrounds the building.
Damage to the church hall of St John the Baptist Church in Latimer Square. Masonry has fallen from one of the building's gables and has been piled against its base. The site has been enclosed in a safety fence. A spray-painted sign can be seen at the base of the building reading, "Danger! Wall unstable, stay clear". A piece of plywood is also visible weather proofing the building's roof.
A photograph of an earthquake-damaged building on the corner of Tuam and Colombo Streets. The brick wall on the top storey of the building has crumbled onto the footpath below and the windows on the bottom storey have been boarded up with plywood. Workers in a cherry picker and a crane-raised platform are working on the second storey. Wire fencing surrounds the building.
Photograph captioned by BeckerFraserPhotos, "Aerial view of the centre of the city, with the cathedral in the centre, and the art gallery in the foreground".
An aerial photograph of the Copthorne Hotel on Colombo Street. The photograph has been captioned by BeckerFraserPhotos, "When the PricewaterhouseCoopers building is demolished, the Copthorne Central Hotel will be alone on the block".
A video of an interview with Mayor Bob Parker about the building consent crisis at the Christchurch City Council. The council received a letter from International Accreditation New Zealand (IANZ) on 30 May 2013. The letter says that the Council has until 28 June 2013 to improve its processes or it will be stripped of its accreditation as a building consent authority.
A photograph of the rubble from the demolished Domo furniture store on Tuam Street. In the background is the earthquake-damaged McKenzie & Willis store. The closest wall of the building has collapsed, exposing the inside of the building. Scaffolding has been constructed on the top floor in order to brace the ceiling. Shipping containers have been placed on the street in front of the building.
A photograph of a map used by emergency management personnel to inspect buildings after the 22 February 2011 earthquake. The map is of the block bordered by Barbadoes Street, Worcester Street, Gloucester Street, and Fitzgerald Avenue. Many of the buildings have been highlighted in blue, with some smaller buildings highlighted in orange. Numbers and messages have been written on the map with biro.
A photograph of members of the Clandeboye Emergency Response Team and the Red Cross working on High Street near the intersection of Manchester Street. A digger is parked on the street in front of the workers. Behind the digger is a large pile of rubble from the ANZ Bank building.
A photograph of the entrance to the Brannigan's building on the corner of Gloucester Street and Oxford Terrace. Many of the windows down the centre of the building have broken, and the glass has fallen onto the footpath below. USAR codes have been spray painted on one of the front windows. A red sticker in the door indicates that the building is unsafe to enter.
A panoramic photograph looking south out of a window of the PricewaterhouseCoopers Building. Notable landmarks include: New Regent Street and the Rendezvous Hotel on the left side of the photograph; the Novotel in the centre; the Lyttelton Times building and the Forsyth Barr building to the right; and the Hotel Grand Chancellor in the distance.
A photograph of a building on the corner of Victoria Street and Bealey Avenue. Large sections of the building have collapsed and the bricks have spilled onto the footpath below. Scaffolding has been constructed around the rest of the building, blocking it from view. In the foreground steel fencing and road cones have been placed across Victoria Street as a cordon.
An interior view of the Cranmer Court building's octagonal corner section, which housed Plato Creative from March 2008 to November 2009. The photograph showcases the building's high windows and intricate wooden ceiling. Although designed as a book depot, this room was used as the principal's office while Christchurch Normal School was operating from the building. A table with chairs set around it can be seen in the lower part of the photograph.
A information board on the fence around the Homestead at Mona Vale. It says 'This hertiage building is managed by the Christchurch City Council on behalf of the city's residents. Until recently it served as a restaurant and function centre. This building was damaged in the 2010/2011 Canterbury earthquakes and ongoing aftershocks. Propping walls and other support is designed to keep the building weather-proof until a decision about its future can be made'.
A photograph of street art on the side of the Manchester Street parking building, seen from Hereford Street. The artists are Chris Finlayson and Dean Blundell. The art work depicts a tram, an aeroplane, a helicopter, a boat and other unusual vehicles parked in the parking building.
A photograph of a volunteer from the Wellington Emergency Management Office inspecting The Painted Room on Colombo Street. The roof of the building has caved in and can be seen inside the building through the smashed windows. The front facade has begun to peel away at the right. Wire fencing and tape has been used to create a cordon around the building.
A photograph of the earthquake damage to the Asko Design building on Victoria Street. Mod's Hair can be seen to the right. The top of the facade of Asko Design has crumbled and fallen into the street, taking the awning with it. The side wall has also collapsed, exposing the inside of the building. Wire fencing and tape have been used to cordon the buildings off.
A photograph of an earthquake-damaged building on the corner of Colombo Street and St Asaph Street. The walls of the top storey of the building have crumbled, and bricks and other rubble have fallen onto the footpath and road below. In the background are many other earthquake-damaged buildings. Wire fencing and police tape have been placed across the street as a cordon.
A photograph of a member of an emergency management team in front of a earthquake-damaged building next to Calendar Girls on Hereford Street. The outer wall of the second storey of the building has collapsed, the bricks spilling onto the footpath below. USAR codes have been spray-painted on a window and a column of the building. Codes have also been spray-painted on the front of Calendar Girls.
A video about a fire which broke out in an earthquake-damaged building on High Street. The video includes an interview with Steve Kennedy, Canterbury Fire Service Assistant Area Manager, Brigid Fayle, who worked in the building prior to the 22 February 2011 earthquake, and Anne MacKenzie, a structural engineer who worked on strengthening the building.