Abstract
At Shirashima Petroleum Storage Base rubble is used in the foundation mound for a caisson type breakwater. The resistance of the caisson breakwater against waves is expected to be the frictional force between the bottom slab of caisson and the rubble mound foundation. In the design a value of μ=0.6 was used for the coefficient of friction. Laboratory experiments were conducted so that an identical value could be guaranteed with the same grading method as used on site. The results of the experiments give, μ=0.66 as the average maximum coefficient of friction.
