Experimental study on self-healing of crack in clay seepage barrier

• We simplify the embankment dam as a five-layer structure.
• We suggest a cylindrical sample with a five-layer structure.
• We conduct 12-experiment to investigate the self-healing of crack in seepage barrier.
• The self-healing of crack is induced in testing under water pressure 300 kPa.
• We analyze the mechanism of self-healing of crack in clay seepage barrier.

Present study focuses on the factors affecting the self-healing of the crack in clay seepage barrier. The factors include the depth of crack, the grain size of base soils, and the gain size of filter soils. In order to investigate the influence of the factors, the embankment dam is simplified as a five-layer structure, and a cylindrical sample with a five-layer structure is suggested. Twelve experiments are conducted. Experimental results indicate that the self-healing of the crack is induced during the testing under the water pressure 300 kPa. The maximum of the flow rate through the sample before the occurrence of the self-healing of the crack (called as critical flow rate in the present study) is different in different experiments. The critical flow rate is increasing with the increase of the crack depth or/and the value of D15/d85. The clogging of the inflow part of the outflow filter due to the accumulation of the transported particles may be the main reason why a reduced percolation rate is observed in the present experiments.