Abstract
Many types of floating pier have been developed for Marina. When we evaluate the safety of activity on a floating pier, it is important to know the characteristics of motions in ship waves. Because when ship waves come to a floating pier, the motions become large unexpectedly. The characteristics of motions of a floating body in group waves like ship waves are investigated by experiments and approximate calculations. The obtained results are summarized as follows. (1) When the waves come from fore and aft, the nondimensional maximum motions of heave and pitch devided by maximum wave height in group waves are equal to the nondimensional motions in monochromatic waves with same wave length. (2) The nondimensional motions of heave and roll in group waves are less than the nondimensional monochromatic motions in beam seas.
