Volunteers from the Wellington Regional Emergent Management Office standing on a pile of bricks from an earthquake damaged building in Christchurch.
Natural catastrophes are increasing worldwide. They are becoming more frequent but also more severe and impactful on our built environment leading to extensive damage and losses. Earthquake events account for the smallest part of natural events; nevertheless seismic damage led to the most fatalities and significant losses over the period 1981-2016 (Munich Re). Damage prediction is helpful for emergency management and the development of earthquake risk mitigation projects. Recent design efforts focused on the application of performance-based design engineering where damage estimation methodologies use fragility and vulnerability functions. However, the approach does not explicitly specify the essential criteria leading to economic losses. There is thus a need for an improved methodology that finds the critical building elements related to significant losses. The here presented methodology uses data science techniques to identify key building features that contribute to the bulk of losses. It uses empirical data collected on site during earthquake reconnaissance mission to train a machine learning model that can further be used for the estimation of building damage post-earthquake. The first model is developed for Christchurch. Empirical building damage data from the 2010-2011 earthquake events is analysed to find the building features that contributed the most to damage. Once processed, the data is used to train a machine-learning model that can be applied to estimate losses in future earthquake events.
A photograph of the earthquake damage to a house in Christchurch. The bricks on the side wall have crumbled and damaged the fence below. Plywood has been used to board up the front window.
Earthquake damaged building on a Walk around the city, May 1, 2014 Christchurch New Zealand. Demolition work on Christchurch's "distinctive" former civic building is under way. The category-2 heritage building was designed by G A J Hart and opened in 1939 as the Miller's department store. It featured the South Island's first escalator, which...
A photograph of Mike Hewson's installation 'Homage to the Lost Spaces' on the earthquake-damaged Cranmer Courts building.
A photograph of Mike Hewson's installation 'Homage to the Lost Spaces' on the earthquake-damaged Cranmer Courts building.
A photograph of the earthquake-damaged tower of the ChristChurch Cathedral. A crane and a large pile of rubble are sitting in front of the tower.
A photograph of emergency management personnel exiting the car park of the earthquake-damaged Press House on Gloucester Street.
A photograph of the earthquake damage to a house in Christchurch. The side wall has crumbled, exposing the inside of the house.
A photograph of the earthquake damage to a house in Christchurch. The side wall has crumbled, exposing the inside of the house.
A photograph of an earthquake-damaged house in Christchurch. The bricks on the side of the house have crumbled, exposing the inside.
A photograph of the earthquake damage to a residential street in Christchurch. Portaloos can be seen on both sides of the road.
A paper prepared for the Ozwater 2013 conference detailing the story of the damage to, and subsequent repair of, Huntsbury Reservoir.
For the first time in November 2011, Christchurch residents finally had the opportunity to see the earthquake-damaged city centre on the Red Zone bus tours organised by CERA. Damage to the Odeon Theatre can be seen out the window.
For the first time in November 2011, Christchurch residents finally had the opportunity to see the earthquake-damaged city centre on the Red Zone bus tours organised by CERA. Damage to the Odeon Theatre can be seen out the window.
For the first time in November 2011, Christchurch residents finally had the opportunity to see the earthquake-damaged city centre on the Red Zone bus tours organised by CERA. Damage to buildings on Cashel Street can be seen out the window.
A view down Cashel Street from the Bridge of Remembrance, showing earthquake damage to several buildings along Cashel Mall. In the background the Hotel Grand Chancellor can be seen, a Christchurch hotel that was badly damaged in the February 2011 earthquake. The collapse of a key supporting shear wall caused the building to visibly lean to one side.
Helicopter Flight over Christchurch New Zealand
A photograph of an earthquake-damaged suitcase in the South Quad of the Christchurch Arts Centre. The suitcase is resting on a pile of scaffolding which had been constructed around the Observatory tower. The scaffolding collapsed along with the tower during the 22 February 2011 earthquake.
A photograph of a car parked off Montreal Street which has been crushed by bricks falling from an earthquake-damaged building.
A photograph of a car parked off Montreal Street which has been crushed by bricks falling from an earthquake-damaged building.
A photograph of part of Mike Hewson's installation 'Homage to the Lost Spaces' on the earthquake-damaged Cranmer Courts building.
A photograph of the earthquake damage to Grenadier House on Madras Street. The glass windows have shattered and the section of wall between has buckled.
A photograph of an earthquake-damaged house in Christchurch. The bricks on the side of the house have crumbled and damaged the fence. A red sticker on the front window indicates that the building is unsafe to enter.
A photograph of members of the Dog Section of the New Zealand Police at the site of an earthquake-damaged building in central Christchurch.
A photograph of the earthquake damage to a house in Christchurch. The house has fallen off its foundations and is on a severe lean.
A photograph of an earthquake-damaged house in Christchurch. The walls on the side of the house have crumbled and the bricks have damaged the fence. A red sticker on the front window indicates that the building is unsafe to enter.
This has made a huge mess for the residents to clean up. I heard on the news that homes have been damaged by subsidence in areas of earthquake-caused liquefaction like this.
The 2010-2011 Christchurch earthquakes generated damage in several Reinforced Concrete (RC) buildings, which had RC walls as the principal resistant element against earthquake demand. Despite the agreement between structural engineers and researchers in an overall successfully performance there was a lack of knowledge about the behaviour of the damaged structures, and even deeper about a repaired structure, which triggers arguments between different parties that remains up to these days. Then, it is necessary to understand the capacity of the buildings after the earthquake and see how simple repairs techniques improve the building performance. This study will assess the residual capacity of ductile slender RC walls according to current standards in New Zealand, NZS 3101.1 2006 A3. First, a Repaired RC walls Database is created trying to gather previous studies and to evaluate them with existing international guidelines. Then, an archetype building is designed, and the wall is extracted and scaled. Four half-scale walls were designed and will be constructed and tested at the Structures Testing Laboratory at The University of Auckland. The overall dimensions are 3 [m] height, 2 [m] length and 0.175 [m] thick. All four walls will be identical, with differences in the loading protocol and the presence or absence of a repair technique. Results are going to be useful to assess the residual capacity of a damaged wall compare to the original behaviour and also the repaired capacity of walls with simpler repair techniques. The expected behaviour is focussed on big changes in stiffness, more evident than in previously tested RC beams found in the literature.
A pdf copy of a PowerPoint presentation prepared for the Ozwater 2013 conference detailing the story of the damage to, and subsequent repair of, Huntsbury Reservoir.