Feed-back on the development of a small scale Contact Erosion Test in the laboratory (characteristic size ~ 30 cm)

To determine the hydraulic load requested to initiate contact erosion process, tests are performed with an apparatus called the “Contact Erosion Test”. This device originally results from research carried out by Grenoble University, Electricite de France and Compagnie Nationale du Rhone, at the scale of ~60 cm. It has been adapted to a smaller scale in geophyConsult laboratory to conduct tests on samples extracted from core drilling. The instrumentation was improved to enable a better control of the hydraulic loading and avoid biases. The test protocol was modified, especially to better constrain the soil density at the interface. From the first series of test, we drew conclusions on the test repeatability and on the influence of parameters of the soil state. Discrepancies with previous results obtained at the scale of ~60 cm were identified. Therefore, a new erosion test campaign was planned to confirm and determine the reasons for these differences.