2015 Volume 21 Pages 361-366
Model experiments were carried out to observe the process of the progressive failure of a river levee caused by a permeable foundation ground. Three different stratum of foundation ground were examined in the experiments. First and second is the cases which have a single permeable layer with/without a semi-permeable cover layer. Similar processes of the progressive failures were observed. The failure began from the toe of levee due to heaving and water leakage, then cracks were developed which led major water leakage. Last is the case which has double permeable layers with different permeability with thin semi-permeable cover layer. Sand boil began soon after heaving and water leakage, then the sand boil was accelerated close to the levee toe which resulted in the sand flow-out of foundation ground and the caving of the levee body.
