Rapid, accurate structural health monitoring (SHM) assesses damage to optimise decision-making. Many SHM methods are designed to track nonlinear stiffness changes as damage. However, highly nonlinear pinched hysteretic systems are problematic in SHM. Model-based SHM often fails as any mismatch between model and measured response dynamics leads to significant error. Thus, modelfree methods of hysteresis loop tracking methods have emerged. This study compares the robustness and accuracy in the presence of significant measurement noise of the proven hysteresis loop analysis (HLA) SHM method with 3 emerging model-free methods and 2 further novel adaptations of these methods using a highly nonlinear, 6-story numerical structure to provide a known ground-truth. Mean absolute errors in identifying a known nonlinear stiffness trajectory assessed at four points over two successive ground motion inputs from September 2010 and February 2011 in Christchurch range from 1.71-10.52%. However, the variability is far wider with maximum errors ranging from 3.90-49.72%, where the second largest maximum absolute error was still 19.74%. The lowest mean and maximum absolute errors were for the HLA method. The next best method had mean absolute error of 2.92% and a maximum of 10.51%. These results show the clear superiority of the HLA method over all current emerging model-free methods designed to manage the highly nonlinear pinching responses common in reinforced concrete structures. These results, combined with high robustness and accuracy in scaled and fullscale experimental studies, provide further validation for using HLA for practical implementation.
A video about the Red Zone in the Christchurch Central City after the 22 February 2011 earthquake. The video includes footage of damaged buildings and cars, the New Zealand Police and Army patrolling the streets, and an interview with Michael Harvey, a squad leader in the New Zealand Urban Search and Rescue.
A photograph of the earthquake damage to the a gable of the Cranmer Courts on the corner of Kilmore and Montreal Street. Wooden bracing has been used to hold the rest of the stones together, and neon tape has been wrapped around the other gables to help keep them secure during aftershocks.
A photograph of the earthquake damage to the Piko Wholefoods Building on the corner of Kilmore and Barbadoes Street. Sections of the top storey of the building have collapsed and the bricks and other rubble have spilled onto the footpath below. Steel fences have been placed around the building as a cordon.
A photograph of the earthquake damage to the a gable of the Cranmer Courts on the corner of Kilmore and Montreal Street. Wooden bracing has been used to hold the rest of the stones together, and neon tape has been wrapped around the other gables to help keep them secure during aftershocks.
Photograph captioned by Fairfax, "John Key on his visit to Kaiapoi and Hororata to meet badly-affected people and see the damage from the earthquake. John Key talks to Murray Rowlands, the Federated Farmers North Canterbury Grain and Feeds Chairperson, with Agriculture Minister David Carter. They are on the Deans' property in Homebush".
During 2010 and 2011, major earthquakes caused widespread damage and the deaths of 185 people in the city of Christchurch. Damaged school buildings resulted in state intervention which required amendment of the Education Act of 1989, and the development of ‘site sharing agreements’ in undamaged schools to cater for the needs of students whose schools had closed. An effective plan was also developed for student assessment through establishing an earthquake impaired derived grade process. Previous research into traditional explanations of educational inequalities in the United Kingdom, the United States of America, and New Zealand were reviewed through various processes within three educational inputs: the student, the school and the state. Research into the impacts of urban natural disasters on education and education inequalities found literature on post disaster education systems but nothing could be found that included performance data. The impacts of the Canterbury earthquakes on educational inequalities and achievement were analysed over 2009-2012. The baseline year was 2009, the year before the first earthquake, while 2012 is seen as the recovery year as no schools closed due to seismic events and there was no state intervention into the education of the region. National Certificate of Educational Achievement (NCEA) results levels 1-3 from thirty-four secondary schools in the greater Christchurch region were graphed and analysed. Regression analysis indicates; in 2009, educational inequalities existed with a strong positive relationship between a school’s decile rating and NCEA achievement. When schools were grouped into decile rankings (1-10) and their 2010 NCEA levels 1-3 results were compared with the previous year, the percentage of change indicates an overall lower NCEA achievement in 2010 across all deciles, but particularly in lower decile schools. By contrast, when 2011 NCEA results were compared with those of 2009, as a percentage of change, lower decile schools fared better. Non site sharing schools also achieved higher results than site sharing schools. State interventions, had however contributed towards student’s achieving national examinations and entry to university in 2011. When NCEA results for 2012 were compared to 2009 educational inequalities still exist, however in 2012 the positive relationship between decile rating and achievement is marginally weaker than in 2009. Human ethics approval was required to survey one Christchurch secondary school community of students (aged between 12 and 18), teachers and staff, parents and caregivers during October 2011. Participation was voluntary and without incentives, 154 completed questionnaires were received. The Canterbury earthquakes and aftershocks changed the lives of the research participants. This school community was displaced to another school due to the Christchurch earthquake on 22 February 2011. Research results are grouped under four geographical perspectives; spatial impacts, socio-economic impacts, displacement, and health and wellbeing. Further research possibilities include researching the lag effects from the Canterbury earthquakes on school age children.
Text top left reads 'A tale of two quakes' In the first frame a man runs from 'radiation leaks' yelling 'The end of the world!' and in the second frame a man runs from the notion 'No World Cup?' yelling 'The end of the world!' Context - the terrible earthquake and tsunami in Japan 11 March 2011 that have led to the overheating of several nuclear power plants that are leaking radiation and threaten a nuclear catastrophe and the Christchurch earthquakes of 4 September 2010 and 22 February 2011 that have led to the decision that because of the amount of damage to the venue plus infrastructures and accommodation for visitors the Rugby World Cup will not be played in Christchurch. Quantity: 1 digital cartoon(s).
Scene set at Santa Claus' 'Online Christmas Orders Dept' at the North Pole. One elf remarks 'ANOTHER Marmite order from New Zealand'. The sole Marmite factory in New Zealand was damaged in the Christchurch Earthquake of 2011. Further aftershocks led to the shutting down of the factory until late 2012. The remaining stocks ran out, leading to panic buying at inflated prices by Marmite aficionados. Quantity: 1 digital cartoon(s).
20160703_144759_GT-S7275T-04 New sea wall at Redcliffs (185/366) I went for a drive in my second car mainly to charge the battery up and forgot to take my camera gear so only had my phone. This is the new rock wall to replace the severely damaged previous one (in the February 2011 earthquake). Work is still underway on the car parking and p...
A man reading a newspaper wails and sobs when he discovers that Christchurch will not be hosting any Rugby World Cup games. The newspaper is covered with real disaster news like the Japanese earthquake and potential nuclear disaster, economy problems , and 'aftershock anxiety'. Context - The Christchurch earthquakes of 4 September 2010 and 22 February 2011 that have led to the decision that because of the amount of damage to the venue plus infrastructures and accommodation for visitors the Rugby World Cup will not be played in Christchurch. Quantity: 1 digital cartoon(s).
During the Christchurch earthquake of February 2011, several midrise reinforced concrete masonry (RCM) buildings showed performance levels that fall in the range of life safety to near collapse. A case study of one of these buildings, a six-story RCM building deemed to have reached the near collapse performance level, is presented in this paper. The RCM walls on the second floor failed due to toe crushing, reducing the building's lateral resistance in the east–west direction. A three-dimensional (3-D) nonlinear dynamic analysis was conducted to simulate the development of the governing failure mechanism. Analysis results showed that the walls that were damaged were subjected to large compression loads during the earthquake, which caused an increase in their in-plane lateral strength but reduced their ductility capacity. After toe crushing failure, axial instability of the model was prevented by a redistribution of gravity loads. VoR - Version of Record
Many large-scale earthquakes all over the world have highlighted the impact of soil liquefaction to the built environment, but the scale of liquefaction-induced damage experienced in Christchurch and surrounding areas following the 2010-2011 Canterbury earthquake sequence (CES) was unparalleled, especially in terms of impact to an urban area. The short time interval between the large earthquakes presented a very rare occasion to examine liquefaction mechanism in natural deposits. The re-liquefaction experienced by the city highlighted the high liquefaction susceptibility of soil deposits in Christchurch, and presented a very challenging problem not only to the local residents but to the geotechnical engineering profession. This paper summarises the lessons learned from CES, and the impacts of the observations made to the current practice of liquefaction assessment and mitigation.
An adviser tells the minister that the PM is going to make sure that no cowboy builders make a quick buck out of the massive rebuilding project. The minister curses because he is in the process of getting his box of tools ready. Refers to rebuilding damaged buildings in the wake of the Canterbury earthquake of 4th September 2010. Quantity: 1 digital cartoon(s).
A man reads a newspaper report about dung beetles being imported to process organic waste. In the second frame someone in one of a row of three portaloos wonders whether dung beetles would be better at it than the Council. Refers to the need for portaloos in the Canterbury region after the 4th September earthquake that damaged much plumbing infrastructure. Quantity: 2 digital cartoon(s).
The current seismic design practice for reinforced concrete (RC) walls has been drawn into question following the unsatisfactory performance of several RC wall buildings during the Canterbury earthquakes. An overview of current research being undertaken at the University of Auckland into the seismic behaviour of RC walls is presented. The main objectives of this research project are to understand the observed performance of RC walls in Christchurch, quantify the seismic loads on RC walls, and developed improved design procedures for RC walls that will assist in revisions to the New Zealand Concrete Structures Standard. A database summarising the performance of RC wall buildings in the Christchurch CBD was collated to identify damage modes and case-study buildings. A detailed investigation is underway to verify the seismic performance of lightly reinforced concrete walls and initial numerical modeling and small-scale tests are presented in addition to details of planned experimental tests of RC walls. Numerical modelling is being used to understand the potential influence that interactions between walls and other structural elements have on the seismic response of buildings and the loads generated on RC walls. The results from finite element analysis of a severely damaged RC wall in Christchurch highlighted the effect that the floor diaphragms have on the distribution of shear stains in the wall.
The cartoon shows a monstrous machine with an enormous crushing ball attached to a giant crane. It moves past a signpost that points towards Christchurch. A man watches and tells his friend 'Gerry Brownlee borrowed it from Auckland! Context - Brownlee has caused a stir by suggesting that if he had his way some of Christchurch's older buildings would be "down tomorrow". He also said the price of saving some historic buildings badly damaged in the February 22 earthquake was too high. People had died in the quake because of attempts to save historic buildings badly damaged in the September 4 quake. Brownlee said he had no regrets despite the stir his comments caused - but he was annoyed by suggestions the Cathedral and Riccarton House were among buildings he thought should be bowled. He believed those buildings should be saved, and they would be. "I'm not a philistine; I was chairman of the trust that actually saved Riccarton House from the bulldozers in 1990. "I understand conservation architecture very well and I do have an appreciation of heritage buildings." Colour and black and white versions available Quantity: 2 digital cartoon(s).
The 4 September, 22 February, and 13 June earthquakes experienced in Canterbury, New Zealand would have been significant events individually. Together they present a complex and unprecedented challenge for Canterbury and New Zealand. The repetitive and protracted nature of these events has caused widespread building and infrastructure damage, strained organisations’ financial and human resources and challenged insurer and investor confidence. The impact of the earthquakes was even more damaging coming in the wake of the worst worldwide recession since the great depression of the 1930s. However, where there is disruption there is also opportunity. Businesses and other organisations will drive the physical, economic and social recovery of Canterbury, which will be a dynamic and long-term undertaking. Ongoing monitoring of the impacts, challenges and developments during the recovery is critical to maintaining momentum and making effective mid-course adjustments. This report provides a synthesis of research carried out by the Resilient Organisations (ResOrgs) Research Programme1 at the University of Canterbury and Recover Canterbury in collaboration with Opus Central Laboratories (part of Opus International Consultants). The report includes discussions on the general state of the economy as well as data from three surveys (two conducted by ResOrgs and one by Recover Canterbury) on business impacts of the earthquakes, population movements and related economic recovery issues. This research and report offers two primary benefits:
We examine the role of business interruption insurance in business recovery following the Christchurch earthquake in 2011 in the short- and medium-term. In the short-term analysis, we ask whether insurance increases the likelihood of business survival in the aftermath of a disaster. We find only weak evidence that those firms that had incurred damage, but were covered by business interruption insurance, had higher likelihood of survival post-quake compared with those firms that did not have insurance. This absence of evidence may reflect the high degree of uncertainty in the months following the 2011 earthquake and the multiplicity of severe aftershocks. For the medium-term, our results show a more explicit role for insurance in the aftermath of a disaster. Firms with business interruption insurance have a higher probability of increasing productivity and improved performance following a catastrophe. Furthermore, our results show that those organisations that receive prompt and full payments of their claims have a better recovery, in terms of profitability and a subjective ‘”better off” measure’ than those that had protracted or inadequate claim payments (less than 80% of the claim paid within 2.5 years). Interestingly, the latter group does worse than those organisations that had damage but no insurance coverage. This analysis strongly indicates the importance not only of good insurance coverage, but of an insurance system that also delivers prompt claim payments. As a first paper attempting to empirically identify a causal effect of insurance on business recovery, we also emphasize some caveats to our analysis.
A bollard covered in tattered posters. The photographer comments, "After the Christchurch February 2011 earthquake no more adverts were pasted onto this advertising pillar. Over a year later the posters are starting to peel off and reveal older ones. It seems that the constant addition of new posters was keeping everything in equilibrium, but with no new posters everything is literally falling apart".
We measure the longer-term effect of a major earthquake on the local economy, using night-time light intensity measured from space, and investigate whether insurance claim payments for damaged residential property affected the local recovery process. We focus on the destructive Canterbury Earthquake Sequence (CES) 2010 -2011 as our case study. Uniquely for this event, more than 95% of residential housing units were covered by insurance, but insurance payments were staggered over 5 years, enabling us to identify their local impact. We find that night-time luminosity can capture the process of recovery and describe the recovery’s determinants. We also find that insurance payments contributed significantly to the process of economic recovery after the earthquake, but delayed payments were less affective and cash settlement of claims were more effective than insurance-managed repairs in contributing to local recovery.
A photograph of the earthquake damage to a group of shops on the corner of Barbadoes Street and Edgeware Road. The second storey of the shops has collapsed, and the bricks have fallen to the footpath, taking the awnings with them. Police tape and road cones have been placed around the buildings as a cordon.
A photograph of the earthquake damage to a group of shops on the corner of Barbadoes Street and Edgeware Road. The second storey of the shops has collapsed, and the bricks have fallen to the footpath, taking the awnings with them. Police tape and road cones have been placed around the buildings as a cordon.
A photograph of staff from the Department of Physics and Astronomy from the University of Canterbury recovering parts of the Townsend Telescope from the rubble of the Observatory tower. The telescope was housed in the tower at the Christchurch Arts Centre. It was severely damaged when the tower collapsed during the 22 February 2011 earthquake.
A photograph of staff from the Department of Physics and Astronomy from the University of Canterbury recovering parts of the Townsend Telescope from the rubble of the Observatory tower. The telescope was housed in the tower at the Christchurch Arts Centre. It was severely damaged when the tower collapsed during the 22 February 2011 earthquake.
A photograph of the earthquake damage to Stonehurst Accommodation on Gloucester Street. The bottom storey of the closest building has collapsed and the top two storeys are sitting on a pile of rubble. More rubble has also spilled into the driveway to the right. Wire fencing has been placed around the buildings as a cordon.
A digitally manipulated image of a sign reading "A bit of dirt never hurt". The photographer comments, "This was a sign put up on a section of land in the Port of Lyttelton where an earthquake damaged building had been removed. The cliff at the back had collapsed down probably during the demolition process".
A photograph of the site of a demolished house on the corner of Springfield Road and Bealey Avenue. "No go" has been spray-painted on the earthquake-damaged fence. Wire fencing and police tape has been placed across the entrance as a cordon. In the background, rubble from the demolished building can be seen.
A photograph of Anderson and Hill Sports Power on the corner of St Asaph and Colombo Streets. Wire fences have been placed across the street as a cordon. In the background, rubble from earthquake-damaged buildings and crushed cars line the left side of the road. There is also foliage from a fallen tree.
A photograph of a house on Glenarm Terrace in Dallington. The chimney fell off the roof during the September earthquake and the bricks are still lying on the ground. A tarpaulin has been placed over the top of the hole to prevent water damage inside the house. Ironically, it has been weighed down with bricks.