A study of factors influencing post-earthquake decisions on buildings in Christchurch, New Zealand
Jenna Jihyun Kim, Kenneth J. Elwood, Stephanie E. Chang, Frederic Marquis
The 11th Canadian Conference on Earthquake Engineering, Canadian Association for Earthquake Engineering
Abstract
The consequences of the 2010-2011 Canterbury Earthquakes alerted many urban communities to seismic risk. Considering the performance of reinforced concrete (RC) buildings was acceptable and as expected (Kam et al., 2011), the high demolition rate (~60%) of RC buildings is surprising. In an effort to understand such an outcome, various factors influencing the post-earthquake decisions on buildings (demolition or repair) are explored, focusing on multi-storey RC buildings in Christchurch Central Business District (CBD). Information on building characteristics, assessed post-earthquake damage, and post-earthquake decision (demolish or repair) for 223 buildings was collected and studied. Logistic regression analyses were conducted based on the empirical data to develop probability-of-demolition function accounting for the relative effects of various factors; assessed damage, occupancy type, heritage status, number of floors, and construction year were identified to influence the likelihood of building demolition. From in-person interviews conducted in New Zealand, contextual factors such as insurance policy and changes in legislation were also found to play a significant role in the post-earthquake decisions on buildings.