EXAMINATION OF EROSION RESISTANCE OF CLAYS IN EMBANKMENT DAMS

Internal erosion is a possible cause of failure in embankment dams. Erosion may occur when soil in the vicinity of a crack disperses into suspension and is transported by the water into the drainage system. An important factor in assessing the potential of a soil for dispersion is the true cohesion defined as the strength at zero effective stress. A new test, the cylinder dispersion test, has been developed to investigate true cohesion and dispersion in soils. Tests carried out on a number of different soils demonstrated the major influence of the pore water chemistry on the true cohesion and dispersion properties, and hence erosion resistance.