STUDY ON EARTH PRESSURE INFLUENCE OF INNER CORE RUBBLE IN FRONT OF CAISSON OF BREAKWATER UNDER TSUNAMIS

There are two kinds of breakwaters covering with wave- dissipating blocks in Japan. If breakwater is covered with pure wave-dissipating blocks, it is known that the wave-dissipating blocks in front of caisson are self-supporting so that their horizontal loads are not expected to act on the caisson under basic conditions such as calm water1). If rubble, as an inner core, is substituted for some, particularly inside the block group, the rubble may exert a horizontal force on the caisson as the earth pressure. In addition, installing of wave-dissipating blocks on the rubble part may result in stronger horizontal force. These situations have not been sufficiently investigated. In this study, hydraulic model experiments are conducted to investigate the earth pressure of inner core rubble. Further, the impact of the breakwater under tsunami is also investigated.