Seismic Crack Investigation in an Earth Dam by Centrifugal Loading Test

Abstract

There are many Earth-fill dams in Japan, which are mostly used for irrigation use. Most of these dams in Japan were constructed by experience over 100 years ago. There are so many irrigation dams, which suffered earthquake damage in the past. Due to the damages, the cracks at the crest in the dam-axis direction have been reported in many cases. For the rock-fill dam recently constructed, the crack on the crest in the dam-axis direction has also been found in the case of a large earthquake. The mechanism of such a crack has not been discussed well. In this study, to clarify the mechanism of a crack in the dam-axis direction, a centrifugal loading test was applied to the dam with a 50 G gravity field. As a result, the critical level of strain was observed at the crest of the model, and it was found that the horizontal displacement at the upper part of the dam was excessive. It can be concluded from the study that the seismic cracks in the dam-axis direction occurred due to the excessive tensile stress, which was not considered in the design process.