Abstract:
The structural performance of URM buildings in earthquakes has immediate and long term
social and economic consequences for the affected community. The accurate forecasting of
risks associated with both retrofitted and unretrofitted URM building seismic performance can
provide decision-makers with information to pre-emptively take measures to mitigate the
adverse effects of URM building damage. Thus, the primary objective of the research presented
herein was to advance engineering, social science, and risk knowledge related to URM building
seismic performance through the analysis of empirical earthquake data.
An in-depth analysis of the context and cause of all known fatalities associated with New
Zealand earthquakes was undertaken. URM building damage was identified as the leading
cause of earthquake-related deaths in New Zealand.
Case studies were undertaken to evaluate the overall success of retrofitted URM buildings with
satisfactory in-field seismic performance during the 2010/11 Canterbury earthquakes. Case
study buildings were assessed in terms of the seismic design, architectural appeal, heritage
preservation, economic viability, and observed performance of the seismic retrofit.
A Canterbury masonry building dataset and post-earthquake damage photographs and satellite
images were analysed to determine where masonry debris fell, be it inside or outside of the
damaged building, and to measure the extent of the fallen masonry debris. Approximately 25%
of the evaluated URM buildings experienced volume loss, and 67% of the buildings had debris
that fell outside of the building footprint. Probability functions to predict earthquake-induced
volume loss and debris extent for commercial clay brick URM buildings were developed.
Finally, the volume loss and debris extent probability functions were used to develop indoor
and outdoor casualty models for clay brick URM buildings. Though derived solely from New
Zealand earthquakes, the proposed models are thought to be applicable to other countries with
comparable stocks of commercial clay brick URM buildings.