Thanks to Dr. Michael Olsen for this reference.
Rockfalls and debris avalanches triggered by earthquakes quakes during the 2010–2011 Canterbury earthquake sequence in New Zealand killed five people and caused an estimated US$400 million in damages. In total, about 200 dwellings were directly impacted by some of the ~6000 rockfalls and debris avalanches that occurred across the Port Hills of Christchurch.
This research presents the results of the analysis of a high-quality database of 61 individual rockfall impacts on 29 dwellings in the Port Hills of Christchurch,
New Zealand . Dwellings in the Port Hills are typically simple timber-frame structures with wooden or unreinforced masonry cladding, comparable to most dwellings across New Zealand, North America , Australia, and elsewhere.
Rockfall impacts on dwellings in this study were observed to follow a power law relationship between kinetic energy and (1) the runout distance into and through the dwelling and (2) the impacted area within the dwelling. The results have been quantified and are presented as a damage proportion, which is defined as the proportion of the area
affected by an individual rock block inside the dwelling divided by the total area of the dwelling. These data provide a fundamental input for rockfall risk analysis and will allow the losses from rockfall impacts to be better constrained.
The data were collected through field reconnaissance, terrestrial LiDAR scans, aerial LiDAR terrain analysis, and high-resolution image acquisition made between 2014 and 2015. The results provide a unique, high-quality database on the consequences of rockfall impacts on these dwellings.