SR110 Calibration studies for landslide quantitative risk assessment (2007)

Quantitative risk assessment (QRA) procedures are well established but their application to the evaluation of slope stability has not been widely adopted in New Zealand. This publication reviews QRA procedures and applies QRA to four case studies that are considered typical slope failure events in the New Zealand context and are amenable to analysis. Each case study site and the QRA procedures adopted are described and illustrated.

In three cases, QRA shows the risk of death to an occupant of a house is unacceptably high by international guidelines and that, while there are no accepted guidelines, the risk of damage to a dwelling would probably be considered by a house owner to be unacceptable.

The other case study demonstrated that, while commercially the risk may have been tolerated, its economic effects could have been minimised had the developer been appraised of the risk in advance.