Studies of rock erosion mechanisms downstream of spillways through large-scale experimental simulations.

Hydroelectric dams are generally equipped with spillways excavated in rock. A serious concern is that erosion caused by flowing water can reach the immediate dam foundation. This project aims to develop a new and improved approach for predicting erosion in a given rock mass condition. First, it is necessary to identify the geomechanical parameters having the greatest influence on the degree of erosion and determine the relative importance of each parameter in the erosion process. To determine the parameters, we constructed an instrumented spillway at a pilot–plant scale. This equipment allows for studying several rock mass geomechanical parameters via an experimental approach and establishing the relative importance of each. Experimental test results and the observed erosion database are then combined to calibrate numerical models that can determine the effects of the geomechanical parameters on erosion at an actual scale. Through this research, we aim to develop novel models for predicting rock mass erodibility in rock spillways.