ANALYSIS ON DAMAGE OF RUBBER PROTECTORS FOR STEEL PLATFORM DUE TO COLLISION OF RUBBLE STONES ACTIVATED BY WAVE ACTION

Abstract

 A steel platform with concrete bottom plates has been constructed as a mooring facility for small boats in a fishing port. Rubber protectors covering the steel piles were damaged due to the collision of rubble stones activated by the wave action during under construction stage. This study clarified the moving patterns of rubble stones in front of the steel platform by random wave experiments at a scale of 1/30 for the wave and tidal conditions when the damage happened. In addition, the characteristics of moving speed of the sphere type model for the maximum wave condition were examined by dam-break wave experiments at a scale of 1/10. The relationship between the collision force and the flow speed was shown based on the momentum conservation law. As a result, it was shown that the collision force was peak for the typical diameter conditions.