Reliability-Based Dam Erodibility Assessment

When dam overtopping occurs, the hydraulic power of the impinging water jet might cause rock foundation erosion/scouring, which potentially could lead to significant consequences. As future flood events are expected to be more severe due to climate change, dam erodibility is becoming a significant risk concern. This paper: (1) provides an overview of erodibility analysis, including project examples to illustrate the use of Annandale's Erodibility Index method, Bolleart's Comprehensive Scour Model, and Goodman and Shi's rock block theory; (2) describes a reliability-based approach to address the issues of uncertainties, such as first-order reliability method and importance sampling; and (3) discusses the measurement of rock properties for developing probabilistic models, including a field example of using land-based LiDAR to obtain rock joint statistics.