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Research papers, The University of Auckland Library

The rapid classification of building damage states or placards after an earthquake is vital for enabling an efficient emergency response and informed decision-making for rehabilitation and recovery purposes. Traditional methods rely heavily on inspector-led on-site surveys, which are often time-consuming, resource-intensive, and susceptible to human error. This study introduces a machine learning-supported surrogate model designed to streamline the assessment of building damage, focusing on the automated assignment of damage placards within the context of New Zealand's post-earthquake evaluation frameworks. The study evaluates two key safety evaluation protocols—Rapid Building Assessment (RBA) and Detailed Damage Evaluation (DDE)—and integrates corresponding databases derived from the 2010–2011 Canterbury Earthquake Sequence (CES) in Christchurch. Six ML classifiers—Multilayer Perceptron (MLP), Random Forest (RF), Support Vector Machine (SVM), K-Nearest Neighbours (KNN), Gradient Boosting Classifier (GBC), and Gradient Bagging (GBag)—were rigorously tested across both databases. The results indicate that the RF-based surrogate model outperforms the other classifiers across both RBA and DDE protocols. Two distinct sets of critical predictors have been further identified for each protocol, allowing for the rapid retrieval of essential data for future on-site surveys, while retaining the RF model's predictive accuracy. The developed surrogate model provides a pragmatic tool for practising engineers to rapidly assign placards to damaged structures and for policymakers and building owners to make informed recovery decisions for earthquake-affected buildings.

Research papers, The University of Auckland Library

New Zealand's devastating Canterbury earthquakes provided an opportunity to examine the efficacy of existing regulations and policies relevant to seismic strengthening of vulnerable buildings. The mixed-methods approach adopted, comprising both qualitative and quantitative approaches, revealed that some of the provisions in these regulations pose as constraints to appropriate strengthening of earthquake-prone buildings. Those provisions include the current seismic design philosophy, lack of mandatory disclosure of seismic risks and ineffective timeframes for strengthening vulnerable buildings. Recommendations arising from these research findings and implications for pre-disaster mitigation for future earthquake and Canterbury's post-disaster reconstruction suggest: (1) a reappraisal of the requirements for earthquake engineering design and construction, (2) a review and realignment of all regulatory frameworks relevant to earthquake risk mitigation, and (3) the need to develop a national programme necessary to achieve consistent mitigation efforts across the country. These recommendations are important in order to present a robust framework where New Zealand communities such as Christchurch can gradually recover after a major earthquake disaster, while planning for pre-disaster mitigation against future earthquakes. AM - Accepted Manuscript

Images, UC QuakeStudies

The remains of Simply Catering Cafe on the corner of Salisbury and Madras Streets, which have been cordoned off by a safety fence. The business' owners have spray painted on the back wall of the building, "We'll be back". Behind the building an orange tarpaulin can be seen draped over a roof.

Images, UC QuakeStudies

The remains of Simply Catering Cafe on the corner of Salisbury and Madras Streets, which have been cordoned off by a safety fence. The business' owners have spray painted on the back wall of the building, "We'll be back". Behind the building an orange tarpaulin can be seen draped over a roof.

Images, UC QuakeStudies

Damage to the church hall of St John the Baptist Church in Latimer Square. The roof has been weather proofed with plywood and there are cracks in the buildings masonry. The remains of fallen bricks can be seen on the footpath. A safety fence has been erected around the building.

Images, UC QuakeStudies

Damage to the church hall of St John the Baptist Church in Latimer Square. The roof has been weather proofed with plywood and there are cracks in the buildings masonry. The remains of fallen bricks can be seen on the footpath. A safety fence has been erected around the building.

Images, UC QuakeStudies

A digitally manipulated image of demolition machinery, with the Hotel So in the background. The photographer comments, "Strange things happen when you use technicolor film".