Abstract

The purpose of this study was to estimate the decreasing effects of diffracted wave fields in-and around selected harbours (Kashima and Soma Harbours) including the region of outer breakwater, when a navigation channel is dredged at the vicinity of the harbour entrance. The wave field in the problem is considered to be in a two dimensional plane, and the configuration of the submarine pit breakwater in the sea bed is designated by a single rectangular type. The numerical simulation is performed by using the solution of the boundary integral equation based on the Green function. The incident wave conditions are specified using a discrete form of the Mitsuyasu directional spectrum. Incident wave height is to be decreased in-and behind a pit region by depth discontinuity. It is observed that the wave energy is decreased when a submarine pit has been placed.

Key words: Green function, harbour, navigation channel, Mitsuyasu directional spectrum, pit.