Understanding and limiting the risks inherent to natural and cut slopes are now recognized to be a priority in achieving an acceptable quality of life. Various methods of risk management that have been proposed in the last three decades have evolved into a general framework for landslide risk management. In particular, quantitative risk assessments can assist in communicating risks. They also provide a clear and systematic framework to analyze slope failure processes, from origin, to movement, to consequence;​ and the effect of different remedial works and strategies.

Some of the challenges and perceived limitations of quantitative risk assessments are related to the necessary input of expert opinion when estimating the risk levels in a quantitative manner. One objective of this work is the systematic assessment of the uncertainties in the estimated values of risk. Quantitative risk analyses are carried out for two case histories, where population of the analyses input parameters is done as probability distributions rather than fixed values. The probability distributions of the input parameters cover the range of values believed realistic for each input parameter. The risk is then estimated through a Monte Carlo simulation technique, and the outcome of the analysis is a probability distribution of the estimated risk. This methodology shows the potential for evaluating the uncertainties related to risk estimations.

The full potential of the risk management framework is best met with the establishment of risk evaluation criteria. The other objective of this work focuses on the development of risk evaluation criteria. It is not the intention of this work to develop case specific criteria, as this responsibility should lie with owners and regulators, but to propose a framework for developing the criteria, where the risk analyst takes an active role.

A summary of the state of practice for quantitative risk assessments is included as part of the thesis. The work on the evaluation of uncertainty related to the estimated risks and a proposed framework for developing risk evaluation criteria are then presented. The last two chapters of the thesis present a summary of the research results, conclusions and proposed future research.