Volume 9, Issue 2 (June 1986)
A New Technique to Evaluate Erosivity of Cohesive Material
The paper presents a laboratory technique to evaluate the erosivity of cohesive soils, which permits, in addition to determining the critical shear stress, the observation of the rate and the mode of erosion throughout the test. The technique is similar to the pinhole test except that the hydraulic conditions are monitored at the entrance and exit of the specimen and that the eroded soil is recovered for the different stages of the test. The Moody diagram can be used to assess the evolution of the friction factor of the eroded surface during the test. Typical results are presented for tests on intact and sensitive structured clays of Eastern Canada. Erosion of intact clays has not been observed at the clay particle level but rather at the level of coarser grains or clay chunks associated with heterogeneities or fissures.