Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

Hydraulic power can lead to the erosion of rock and cause dams to be at risk of failure. Methods exist to predict the degree of erosion for rock masses in spillways; however, these deterministic approaches are unable to consider the uncertainties of rock mass parameters. We develop a methodology that determines the vulnerability of a rock mass to hydrological erosion, and this approach takes into consideration the uncertainties related to the parameters of the rock mass at the study site. Monte Carlo simulation is used to create a dataset for each class of rock for then developing fragility and vulnerability curves. The effects of each geomechanical parameter on erosion level can be determined by applying this methodology to individual spillway sites. As a result, sensitivity analysis shows that the discontinuity orientation factor is a critical parameter for explaining the erosion of a rock mass; increasing this parameter decreases the vulnerability of the rock mass to erosion. Our approach has an advantage over deterministic methods as the uncertainties of rock mass parameters have been considered. The error associated with the predicted erosion level via our probability-based approach is significantly less than the error obtained via deterministic methods.