Assessment of Water Supply Dam Failure Risk: Development of New Stochastic Failure Modes and Effects Analysis

Abstract

This study presents an innovative stochastic approach based on the failure modes and effects analysis to evaluate the failure risk of Amir Kabir dam in Iran. To compute the risk priority number, several risk factors including, occurrence probability, severity, and detectability are quantified using expert opinions. In this way, the participant experts are divided into four groups including; dam operation staff, water company staff, academic staff and, other experts. Moreover, the weights of the expert groups are also considered to compute the risk priority number. Hence, a new failure modes and effects analysis called modified stochastic failure modes and effects analysis is provided by considering weights of expert groups and risk factors. Furthermore, Monte Carlo simulation is used to consider the weights uncertainty and compute a stochastic-based risk priority number. Results show that the first priority failure modes of the upstream and downstream basins of Amir Kabir dam are the human-based failure modes while a nature-based failure mode is observed with most priority in dam body. In general, the proposed stochastic failure risk method provides reliable results with low uncertainty to evaluate the failure modes through a risk assessment process.