Residents of Christchurch's coastal suburbs around New Brighton are being promised they won't have to wait another decade for an urgently needed new bridge. The existing one is a critical emergency escape route but is almost 100 years old and suffered significant damage in the 2011 earthquake. And as Timothy Brown reports, plans for an upgrade are grinding slowly ahead.
View down Re:Start mall, the Bridge of Remembrance can be seen down the end.
Cracks on the steps and along the footpath leading up to the Bridge of Remembrance.
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Photograph captioned by Fairfax, "Necessary job: Port-a-loo contractors Grant Bridge (left) and Garry Quayle".
People examine large cracks running alongside Bridge Street where the land has slumped towards the river.
A photograph of a make-shift bridge over the dug-out basement of the Cranmer Centre.
Workers preparing materials for a new bridge over the Avon from University Drive to the Recreation Centre.
Workers preparing materials for a new bridge over the Avon from University Drive to the Recreation Centre.
Workers preparing materials for a new bridge over the Avon from University Drive to the Recreation Centre.
The badly twisted Medway Street footbridge. The photographer comments, "The September 4th 2010 earthquake in Christchurch was so violent that the banks of the Avon River moved towards each other. This footbridge being metal had to twist sideways to release the pressure of being pushed from both river banks. It looked like it had been wrung out like a wet towel".
This paper describes pounding damage sustained by buildings and bridges in the February 2011 Christchurch earthquake. Approximately 6% of buildings in Christchurch CBD were observed to have suffered some form of serious pounding damage. Almost all of this pounding damage occurred in masonry buildings, further highlighting their vulnerability to this phenomenon. Modern buildings were found to be vulnerable to pounding damage where overly stiff and strong ‘flashing’ components were installed in existing building separations. Soil variability is identified as a key aspect that amplifies the relative movement of buildings, and hence increases the likelihood of pounding damage. Pounding damage in bridges was found to be relatively minor and infrequent in the Christchurch earthquake.
Construction of the new bridge from University Drive to the Recreation Centre, giving access to the new Oval Village.
There is a critical strand of literature suggesting that there are no ‘natural’ disasters (Abramovitz, 2001; Anderson and Woodrow, 1998; Clarke, 2008; Hinchliffe, 2004). There are only those that leave us – the people - more or less shaken and disturbed. There may be some substance to this; for example, how many readers recall the 7.8 magnitude earthquake centred in Fiordland in July 2009? Because it was so far away from a major centre and very few people suffered any consequences, the number is likely to be far fewer than those who remember (all too vividly) the relatively smaller 7.1 magnitude Canterbury quake of September 4th 2010 and the more recent 6.3 magnitude February 22nd 2011 event. One implication of this construction of disasters is that seismic events, like those in Canterbury, are as much socio-political as they are geological. Yet, as this paper shows, the temptation in recovery is to tick boxes and rebuild rather than recover, and to focus on hard infrastructure rather than civic expertise and community involvement. In this paper I draw upon different models of community engagement and use Putnam’s (1995) notion of ‘social capital’ to frame the argument that ‘building bridges’ after a disaster is a complex blend of engineering, communication and collaboration. I then present the results of a qualitative research project undertaken after the September 4th earthquake. This research helps to illustrate the important connections between technical rebuilding, social capital, recovery processes and overall urban resilience.
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A worker inside a digger, building a new bridge over the Avon river from University Drive to the Recreation Centre.
A worker inside a digger, building a new bridge over the Avon river from University Drive to the Recreation Centre.
Taken 10th Jan well through the controversial demolition of Manchester Courts
A view of Cashel Mall looking looking towards the Bridge of Remembrance. Buildings on the right of the mall are behind cordon fencing.
A view of Cashel Mall looking looking towards the Bridge of Remembrance. Buildings on the left of the mall are behind cordon fencing.
Photograph captioned by Fairfax, "Quake symbol: Jenny Marsh holds up the design by graphic artist Susan Bocock of Kaiapoi's twisted swing bridge".
Cashel Mall/Cashel Street
Still awaiting a repair, but with so many bridges closed or partially closed we are lucky this one had what maybe minor damage.
Prior to the earthquakes the stone wall at right was near road level. Now it is about 1.5m (4-5ft) lower.
Eighty years and then the damage was done. Result of the earthquake on 22/02/11.
Text reads 'Uses for Christchurch rubble?...' The cartoon shows a bridge made partially of earthquake rubble leading from Lyttelton Harbour to Diamond Harbour on Banks Peninsula. Someone in a van says 'At long last... A bridge to Diamond Harbour!' And someone else says 'And somewhere to fish!' Context - Rubble from the earthquake may be used for the construction of watersides and bridges. This cartoon is a fanciful use for Christchurch earthquake rubble. Currently a ferry connects Diamond Harbour to Lyttelton, on the harbour's northern shore. In combination with buses from Lyttelton to downtown Christchurch, this allows residents of Diamond Bay to commute to the city. Quantity: 1 digital cartoon(s).
The 22 February 2011, Mw6.2 Christchurch earthquake is the most costly earthquake to affect New Zealand, causing an estimated 181 fatalities and severely damaging thousands of residential and commercial buildings. This paper presents a summary of some of the observations made by the NSF-sponsored GEER Team regarding the geotechnical/geologic aspects of this earthquake. The Team focused on documenting the occurrence and severity of liquefaction and lateral spreading, performance of building and bridge foundations, buried pipelines and levees, and significant rockfalls and landslides. Liquefaction was pervasive and caused extensive damage to residential properties, water and wastewater networks, high-rise buildings, and bridges. Entire neighborhoods subsided, resulting in flooding that caused further damage. Additionally, liquefaction and lateral spreading resulted in damage to bridges and to stretches of levees along the Waimakariri and Kaiapoi Rivers. Rockfalls and landslides in the Port Hills damaged several homes and caused several fatalities.
A view of the bridge over the Avon River at Hereford Street. Buildings in the background have been cordoned off and an army truck can be seen in the background.
A view of Cashel Mall looking looking towards the Bridge of Remembrance, which can be seen in the background. A section of the street has been cordoned off from the public.
After a high-intensity seismic event, inspections of structural damages need to be carried out as soon as possible in order to optimize the emergency management, as well as improving the recovery time. In the current practice, damage inspections are performed by an experienced engineer, who physically inspect the structures. This way of doing not only requires a significant amount of time and high skilled human resources, but also raises the concern about the inspector’s safety. A promising alternative is represented using new technologies, such as drones and artificial intelligence, which can perform part of the damage classification task. In fact, drones can safely access high hazard components of the structures: for instance, bridge piers or abutments, and perform the reconnaissance by using highresolution cameras. Furthermore, images can be automatically processed by machine learning algorithms, and damages detected. In this paper, the possibility of applying such technologies for inspecting New Zealand bridges is explored. Firstly, a machine-learning model for damage detection by performing image analysis is presented. Specifically, the algorithm was trained to recognize cracks in concrete members. A sensitivity analysis was carried out to evaluate the algorithm accuracy by using database images. Depending on the confidence level desired,i.e. by allowing a manual classification where the alghortim confidence is below a specific tolerance, the accuracy was found reaching up to 84.7%. In the second part, the model is applied to detect the damage observed on the Anzac Bridge (GPS coordinates -43.500865, 172.701138) in Christchurch by performing a drone reconnaissance. Reults show that the accuracy of the damage detection was equal to 88% and 63% for cracking and spalling, respectively.