In the period between September 2010 and December 2011, Christchurch (New Zealand) and its surroundings were hit by a series of strong earthquakes including six significant events, all generated by local faults in proximity to the city: 4 September 2010 (Mw=7.1), 22 February 2011 (Mw=6.2), 13 June 2011 (Mw=5.3 and Mw=6.0) and 23 December 2011 (M=5.8 and (M=5.9) earthquakes. As shown in Figure 1, the causative faults of the earthquakes were very close to or within the city boundaries thus generating very strong ground motions and causing tremendous damage throughout the city. Christchurch is shown as a lighter colour area, and its Central Business District (CBD) is marked with a white square area in the figure. Note that the sequence of earthquakes started to the west of the city and then propagated to the south, south-east and east of the city through a set of separate but apparently interacting faults. Because of their strength and proximity to the city, the earthquakes caused tremendous physical damage and impacts on the people, natural and built environments of Christchurch. The 22 February 2011 earthquake was particularly devastating. The ground motions generated by this earthquake were intense and in many parts of Christchurch substantially above the ground motions used to design the buildings in Christchurch. The earthquake caused 182 fatalities, collapse of two multi-storey reinforced concrete buildings, collapse or partial collapse of many unreinforced masonry structures including the historic Christchurch Cathedral. The Central Business District (CBD) of Christchurch, which is the central heart of the city just east of Hagley Park, was practically lost with majority of its 3,000 buildings being damaged beyond repair. Widespread liquefaction in the suburbs of Christchurch, as well as rock falls and slope/cliff instabilities in the Port Hills affected tens of thousands of residential buildings and properties, and shattered the lifelines and infrastructure over approximately one third of the city area. The total economic loss caused by the 2010-2011 Christchurch earthquakes is currently estimated to be in the range between 25 and 30 billion NZ dollars (or 15% to 18% of New Zealand’s GDP). After each major earthquake, comprehensive field investigations and inspections were conducted to document the liquefaction-induced land damage, lateral spreading displacements and their impacts on buildings and infrastructure. In addition, the ground motions produced by the earthquakes were recorded by approximately 15 strong motion stations within (close to) the city boundaries providing and impressive wealth of data, records and observations of the performance of ground and various types of structures during this unusual sequence of strong local earthquakes affecting a city. This paper discusses the liquefaction in residential areas and focuses on its impacts on dwellings (residential houses) and potable water system in the Christchurch suburbs. The ground conditions of Christchurch including the depositional history of soils, their composition, age and groundwater regime are first discussed. Detailed liquefaction maps illustrating the extent and severity of liquefaction across Christchurch triggered by the sequence of earthquakes including multiple episodes of severe re-liquefaction are next presented. Characteristic liquefaction-induced damage to residential houses is then described focussing on the performance of typical house foundations in areas affected by liquefaction. Liquefaction impacts on the potable water system of Christchurch is also briefly summarized including correlation between the damage to the system, liquefaction severity, and the performance of different pipe materials. Finally, the characteristics of Christchurch liquefaction and its impacts on built environment are discussed in relation to the liquefaction-induced damage in Japan during the 11 March 2011 Great East Japan Earthquake.
Following the magnitude 6.3 aftershock in Christchurch, New Zealand, on 22 February 2011, a number of researchers were sent to Christchurch as part of the New Zealand Natural Hazard Research Platform funded “Project Masonry” Recovery Project. Their goal was to document and interpret the damage to the masonry buildings and churches in the region. Approximately 650 unreinforced and retrofitted clay brick masonry buildings in the Christchurch area were surveyed for commonly occurring failure patterns and collapse mechanisms. The entire building stock of Christchurch, and in particular the unreinforced masonry building stock, is similar to that in the rest of New Zealand, Australia, and abroad, so the observations made here are relevant for the entire world.
A digitally manipulated image of the damaged statue of Scott which was removed from its original site beside Worcester Boulevard for safekeeping. The photographer comments, "During the February 2011 earthquake in Christchurch, New Zealand the statue of Robert Falcon Scott broke across the ankles and most of the statue came crashing to the ground. To commemorate a 100 years of association with Antarctica Christchurch council has laid out for viewing the statue in a prostrate position. I was lucky to encounter the statue before it was put into its glass display enclosure".
Plastic and wood model of three liquefaction volcanoes. The working model pumps water over the grey surface which is decorated with a basket of laundry, a bucket of pegs and a football. The model is surrounded by artificial green grass and rests atop a black wooden base.
In this edition: The report into the collapse of the CTV building in the Christchurch earthquake a year ago is released, the Maori Council lodges claims with the Waitangi tribunal that could throw a spanner in the works of the Government's asset sales programme, the Earthquake Recovery Minister nearing the end of his tether with the Christchurch City Council, more from the Pike River Royal Commission, Radio Live could face a potential one hundred thousand dollar fine under the electoral act over John Key's hour long radio show in the run up to the 2011 election, banks lift their collective profits for the second half of 2011 by 25 percent and the winners are announced at the 2012 Halberg Awards.
A photograph captioned by BeckerFraserPhotos, "Christ's College, Rolleston Avenue. Portacoms and bike stands installed after the earthquakes of 2011 on cleared sections in Gloucester Street near the college".
A video of Press journalist Martin Van Beynen talking about the Canterbury Television Building which collapsed during the 22 February 2011 earthquake. Beynen investigates the construction manager of the building, Gerald Shirtcliff, who allegedly faked an engineering degree and stole the identity of an engineer he knew in South Africa. The video also includes footage of Shirtcliff giving evidence about the CTV Building at the Canterbury Earthquake Royal Commission.
Graffiti on a wooden wall depicts a child pointing at a site across the street and reads "I remember when the Kazbah was over there." The photographer comments, "A local street artist has commemorated Christchurch's deadliest earthquake. The anniversary is tomorrow. Where the photograph was taken was the site of the Ozone Hotel, which has now gone as well. For some of us who live and work in the East of Christchurch the earthquake was not what happened in the City as we were almost unaware of it. We had no water, toilets and most of all no electricity for weeks. For myself petrol was low and with tales of all the petrol stations on our side of town being damaged we could not take the chance of venturing out on severely damaged roads to find no petrol and the possibility of not getting home. We walked around and saw the damage that was local to us. TJ's Kazbah was one that stood out. A building that had a beauty with its round tower standing proud and always looked well kept - it was now collapsed. Its tower, which was once pointing towards the sky was laying on its side. It had kept its shape, but had a lightning shaped crack through it. The one thing that kept us feeling almost normal through the coming weeks was The Press our daily paper still being delivered even though the Press building and staff had suffered so badly themselves.
A photograph of equipment from the New Zealand Fire Service Urban Search and Rescue team on display in the Canterbury Quakes exhibition at the Canterbury Museum. The equipment was used during the emergency response to the 22 February 2011 earthquake.
An aerial photograph captioned by BeckerFraserPhotos, "CTV site, IRD building and Latimer Square". Seats set up in Latimer Square in preparation for the commemoration of the anniversary of the 22 February 2011 earthquake can be seen on the left.
A digitally manipulated image of a fallen headstone. The photographer comments, "Since the September 2010 earthquake in Christchurch, New Zealand a lot of the headstones have fallen, but sadly a lot have not been resurrected to their former places".
A badly damaged house in Burwood. Parts of the house have moved in different directions, leaving walls and doors misaligned. The photographer comments, "Although this looks like an extreme wide angle shot it is actually a house tilted in every direction at the same time. The earthquake caused the ground to vibrate and compress so much that the sandy soil liquefied and caused the ground to collapse under this modern home".
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.
This paper provides an overview of the salient aspects of the dense array of ground motions observed in the 4 September 2010 Darfield and 22 February 2011 Christchurch earthquakes. Particular attention is given to inferred physical reasons for the observed ground motions, which include: (i) source features such as forward directivity effects; (ii) The effects of the Canterbury Plains sedimentary basin on basin-generated surface waves, and waveguide effects through the region; and (iii) the importance of local site response as evidenced by observations of large long period amplification and liquefaction. The significance of vertical ground motion intensity is also examined.
A video of an interview with Helen and Edna Yates about their Worcester Street house which is to be demolished due to earthquake damage. The 96-year-old identical twins lived in the house for 95 years before it was damaged in the 22 February 2011 earthquake. The video includes footage of Helen and Edna visiting the house before it is demolished.
An earthquake-damaged bridge, the approach to which has slumped. The photographer comments, "Due to lateral spread and the land slumping the road leading to this bridge has moved down greatly. Just imagine making the street lamps upright and how much that section of road would rise up at the end. When you go over bridges in the east side of Christchurch it is quite a climb up and a big drop down on the other side. The bridges in most cases coped very well, but not so the land leading to them".
The Cranmer Court demolition started today in Christchurch. The 1876 building was originally a Normal School and was in a derelict state in the early 1980s when it was rescued and converted into apartments. The heritage-listed building was red-stickered after the February 2011 earthquake.
Photograph captioned by BeckerFraserPhotos, "185 Chairs, an art installation by Peter Majendie, as a memorial to those who died as a result of the 22 February 2011 earthquake. The chairs were chosen to reflect the variety of people who died".
A photograph of a letter on display in the Canterbury Quakes exhibition at the Canterbury Museum. The letter was found in a time capsule in the plinth of the statue of John Robert Godley in Cathedral Square after the 22 February 2011 earthquake.
A photograph of a letter on display in the Canterbury Quakes exhibition at the Canterbury Museum. The letter was found in a time capsule in the plinth of the statue of John Robert Godley in Cathedral Square after the 22 February 2011 earthquake.
The old New Brighton Power Boat Club building was badly damaged in the February 2011 earthquake, and is only now (July 2012) being demolished. The building is just down the road from where I grew up and is a New Brighton iconic building.
The old New Brighton Power Boat Club building was badly damaged in the February 2011 earthquake, and is only now (July 2012) being demolished. The building is just down the road from where I grew up and is a New Brighton iconic building.
Following the Christchurch earthquake of 22 February 2011 a number of researchers were sent to Christchurch, New Zealand to document the damage to masonry buildings as part of “Project Masonry”. Coordinated by the Universities of Auckland and Adelaide, researchers came from Australia, New Zealand, Canada, Italy, Portugal and the US. The types of masonry investigated were unreinforced clay brick masonry, unreinforced stone masonry, reinforced concrete masonry, residential masonry veneer and churches; masonry infill was not part of this study. This paper focuses on the progress of the unreinforced masonry (URM) component of Project Masonry. To date the research team has completed raw data collection on over 600 URM buildings in the Christchurch area. The results from this study will be extremely relevant to Australian cities since URM buildings in New Zealand are similar to those in Australia.
A digitally manipulated image of two stained glass windows. The photographer comments, "This is an abstract of the stained glass window of St Peter's Church in Christchurch, New Zealand. The church was seriously damaged in the Christchurch earthquake".
Spray-painted writing on the side of a car parking building reads "0 cars". The photographer comments, "Strangely and appropriately this graffiti was on a car park. In fact the graffiti was 100% correct as the car park is in the Christchurch earthquake red zone and there should be zero cars now inside it. It may have been put on by an anti car protester or just an indication that the car park is empty. One of the suggestions for the City plan for the rebuilt Christchurch was for a pedestrian and cycle only area, which also fits in with 0 CARS".
Ingham and Biggs were in Christchurch during the M6.3, 22 February 2011 earthquake and Moon arrived the next day. They were enlisted by officials to provide rapid assessment of buildings within the Central Business District (CBD). In addition, they were asked to: 1) provide a rapid assessment of the numbers and types of buildings that had been damaged, and 2) identify indicator buildings that represent classes of structures that can be used to monitor changing conditions for each class following continuing aftershocks and subsequent damage. This paper explains how transect methodology was incorporated into the rapid damage assessment that was performed 48 hours after the earthquake. Approximately 300 buildings were assessed using exterior Level 1 reporting techniques. That data was used to draw conclusions on the condition of the entire CBD of approximately 4400 buildings. In the context of a disaster investigation, a transect involves traveling a selected path assessing the condition of the buildings and documenting the class of each building, and using the results in conjunction with prior knowledge relating to the overall population of buildings affected in the area of the study. Read More: http://ascelibrary.org/doi/abs/10.1061/9780784412640.033
The September 2010 Canterbury and February 2011 Christchurch earthquakes and associated aftershocks have shown that the isolator displacement in Christchurch Women's Hospital (Christchurch City's only base-isolated structure) was significantly less than expected. Occupant accounts of the events have also indicated that the accelerations within the hospital superstructure were larger than would usually be expected within a base-isolated structure and that residual low-level shaking lasts for a longer period of time following the strong-motion of an event than for non-isolated structures.
A photograph of The Press newspapers on display in the Canterbury Quakes exhibition at the Canterbury Museum. The newspapers where discovered inside a time capsule found in the plinth of the statue of John Robert Godley in Cathedral Square after the 22 February 2011 earthquake.
A photograph of The Press newspapers on display in the Canterbury Quakes exhibition at the Canterbury Museum. The newspapers where discovered inside a time capsule found in the plinth of the statue of John Robert Godley in Cathedral Square after the 22 February 2011 earthquake.
A video of an interview with Mayumi Asakawa, a Japanese student from Kanagawa prefecture who was in Christchurch during the 22 February 2011 earthquake. Asakawa returned to Christchurch to ring the Peace Bell in the Botanic Gardens during the Festival of Flowers commemorative ceremony.