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Images, eqnz.chch.2010

20130211_2645_1D3-840 South New Brighton bridge damage (under repair) Earthquake damage (that right hand abutment should be vertical with the bridge and the hand rail level). Bridge is closed to eastbound traffic (to left) and has a 3500kg weight limit as well. The eastern approach is the same. Damage caused mainly in the 04/09/10 and 22/02/11...

Images, eqnz.chch.2010

The twisted and buckled bridge over the river. View looking down the bridge. Damaged from the Christchurch Earthquake Twitter | Facebook |

Research papers, University of Canterbury Library

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.

Images, UC QuakeStudies

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".

Images, eqnz.chch.2010

One Month after the Christchurch Earthquake. The mangled remains of the pedestrian bridge over the river Avon Twitter | Facebook | My ...

Images, UC QuakeStudies

A digitally manipulated image of a damaged bridge in Lake Terrace Road in Burwood. The photographer comments, "After the September earthquake this bridge was a little wonky, but you would cross it, possibly without fear, now though it is too far gone".

Images, eqnz.chch.2010

This is the pedestrian bridge in Kaiapoi close to Christchurch. Not the best angle but the whole bridge on the right hand side is twisted and looks like some kind of rollercoaster. Taken one month after the Quake Twitter |

Research papers, University of Canterbury Library

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.

Videos, UC QuakeStudies

A video of the removal of the earthquake-damaged Medway Street bridge from the banks of the Avon River. The video shows members of the Stronger Christchurch Infrastructure Rebuild Team removing the bridge and preparing it for transport to the Ferrymead Heritage Park. It will remain at the park until a permanent home can be found for it as an earthquake memorial.

Images, eqnz.chch.2010

Selective colour full size view from one of my previous shots. Edgeware Road, Christchurch. Damaged from the Christchurch Earthquake Twitter | Facebook |

Research papers, University of Canterbury Library

The Mw 6.2 February 22nd 2011 Christchurch earthquake (and others in the 2010-2011 Canterbury sequence) provided a unique opportunity to study the devastating effects of earthquakes first-hand and learn from them for future engineering applications. All major events in the Canterbury earthquake sequence caused widespread liquefaction throughout Christchurch’s eastern suburbs, particularly extensive and severe during the February 22nd event. Along large stretches of the Avon River banks (and to a lesser extent along the Heathcote) significant lateral spreading occurred, affecting bridges and the infrastructure they support. The first stage of this research involved conducting detailed field reconnaissance to document liquefaction and lateral spreading-induced damage to several case study bridges along the Avon River. The case study bridges cover a range of ages and construction types but all are reinforced concrete structures which have relatively short, stiff decks. These factors combined led to a characteristic deformation mechanism involving deck-pinning and abutment back-rotation with consequent damage to the abutment piles and slumping of the approaches. The second stage of the research involved using pseudo-static analysis, a simplified seismic modelling tool, to analyse two of the bridges. An advantage of pseudo-static analysis over more complicated modelling methods is that it uses conventional geotechnical data in its inputs, such as SPT blowcount and CPT cone resistance and local friction. Pseudo-static analysis can also be applied without excessive computational power or specialised knowledge, yet it has been shown to capture the basic mechanisms of pile behaviour. Single pile and whole bridge models were constructed for each bridge, and both cyclic and lateral spreading phases of loading were investigated. Parametric studies were carried out which varied the values of key parameters to identify their influence on pile response, and computed displacements and damages were compared with observations made in the field. It was shown that pseudo-static analysis was able to capture the characteristic damage mechanisms observed in the field, however the treatment of key parameters affecting pile response is of primary importance. Recommendations were made concerning the treatment of these governing parameters controlling pile response. In this way the future application of pseudo-static analysis as a tool for analysing and designing bridge pile foundations in liquefying and laterally spreading soils is enhanced.

Research papers, University of Canterbury Library

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.

Images, UC QuakeStudies

A digitally manipulated photograph of the badly twisted Medway Street footbridge. The photographer comments, "This bridge over the Avon River in Christchurch, New Zealand has been left in place since the first major earthquake back in September 2010. Graffiti artists or taggers are still leaving their marks on it even though it is nearly twisted at 90 degrees at one point".