Abstract
A new tsunami overflow-seepage-coupled centrifuge experiment system was applied to investigate the concurrent processes of the instability involving the scour of the mound/sandy seabed, bearing capacity failure, flow of the ground and the failure of breakwaters, with high-resolution image analysis. The experimental results demonstrate that the scour development due to progressive slip failure of rubble mounds induced the bearing capacity failure of the mounds, resulting in the failure of the breakwaters. The effects of placing an embankment as countermeasures were also examined. It is shown that the stability of the breakwaters was improved with decreasing hydraulic gradient manifested beneath the caissons due to the embankment effect. These findings will facilitate better assessment and improvement of the stability of rubble mounds of breakwaters.
