A framework for understanding post-earthquake decisions on multi-storey concrete buildings in Christchurch, New Zealand

• Main Author: Marquis, Frederic
• Language: English
• Published: University of British Columbia 2015
• Online Access: http://hdl.handle.net/2429/54058

The 2010-2011 Canterbury earthquakes, which involved widespread damage during the February 2011 event and subsequent aftershocks, left this community with more than $NZD 40 billion in losses, demolition of approximately 60% of multi-storey concrete buildings, and closure of the core business district for over 2 years. This thesis presents a framework to understand the issues and complexities in relation to post-earthquake decisions (repair or demolish) on multi-storey concrete buildings in Christchurch. The primary research data for this thesis were collected through in-depth investigations on 15 case-study buildings using 27 interviews with various building stakeholders in New Zealand. As expected, the level of damage and repairability (cost to repair) generally dictated the course of action. There is strong evidence, however, that variables such as insurance, business strategies, perception of risks, uncertainty, and building regulations have significantly influenced the decision on a number of buildings. The decision-making process for each building is typically complex and unique, not solely driven by structural damage. The analysis of the case-study buildings and the interviews have shown that the main driving factors in the predominance of building demolitions in Christchurch were the ambiguous wording of insurance policies offered in New Zealand, the changes in building regulations following the earthquakes, and the lack of criteria for the evaluation of the residual capacity of damaged structures. Because of inadequate insurance cover, conservative engineering evaluations due to uncertainties in structural damage and capacity, and the difficulty of satisfying policy clauses, buildings were often considered uneconomical to repair. Furthermore, most property investors interviewed considered it a favourable outcome if their building was declared a total loss by their insurer and subsequently demolished, because of the availability, flexibility, and rapidity of cash settlements. This thesis also argues that the absence of clear criteria for the repairability of earthquake-damaged buildings implicitly counteracts resilience and sustainable development objectives of building codes. This lack of standards contributed to the demolition of potentially salvageable buildings, resulting in a substantial loss of the built environment. === Applied Science, Faculty of === Civil Engineering, Department of === Graduate