Abstract
The method to pile up stones behind a caisson is gathering attention after Great East Japan Earthquake for reinforcing breakwaters against a tsunami. Past experiments and analyses showed that piled stones could increase the sliding resistance and bearing capacity of foundation mound. The assessment method was also proposed. However, there is no research that investigated subgrade reaction acting on the bottom of a caisson backfilled with stones. Large edge pressure might damage the corner of a caisson and crush stones constituting mound. In this study, subgrade reaction of a caisson was examined by conducting centrifuge model tests. The test results showed that piling up stones could largely reduce the edge pressure. Additionally, simplified model calculating the subgrade reaction could simulate the model tests.
