2021 Volume 77 Issue 2 Pages I_955-I_960
In the Great East Japan Earthquake, composite-type breakwaters were collapsed by the tsunami, and the reinforcement of composite breakwaters reinforced by embankment has been studied as a countermeasure. In the previous studies, it was found that the reinforcement increased the resistance of the composite-type breakwater in the failure modes of sliding and bearing capacity. However, it is necessary to analyze the failure process of the composite-type breakwater in order to maintain its function even if it is damaged by a tsunami exceeding its capacity. In this study, the failure process of a composite breakwater with reinforcing embankment by a tsunami overflow was analyzed by centrifuge model tests. In the tests, the caisson turned over due to water level difference, seepage flow, overflow, and scouring of the embankment. It was suggested that the larger the cross-sectional area and width of the embankment, the harder it was for the caisson to fall to the seabed after overtopping the embankment, and the larger the particle size and weight of the rock, the harder it was for the caisson to overturn.
