Abstract
Due to the inherent uncertainties in ground and groundwater conditions, tunnel projects often have to face potential risks of cost overrun or schedule delay. Risk analysis has become a required tool to identify and quantify risk, as well as visualize causes and effects, and the course (chain) of events. Various efforts have been made to risk assessment and analysis by using conventional methodologies with precise probabilities. However, because of limited information or experience in similar tunnel projects, available evidence in risk assessment and analysis usually relies on judgments from experienced engineers and experts. As a result, imprecision is involved in probability evaluations, which leading the results of risk assessment based on precise probability to the imprecise results. In this paper, a failure tree analysis method based on imprecise probability is established for the risk assessment of tunnel project, which making the results of risk assessment are more accurate and more reasonable.
