Greenfield deep-sea port design

Abstract

This MSc thesis report discusses a greenfield deep-sea port development in a developing country along a shallow oceanic coast. A port layout is developed based on a fictional cargo forecast. In the interest of port adaptivity, this layout is kept flexible as possible. The design is subsequently checked with regard to wave penetration and morphology. The wave modelling shows that it is possible to achieve a sufficiently calm wave climate inside the port, by making use of the interaction between waves and the port’s approach channel. Morphological analysis indicates that a large amount of maintenance dredging will be required to keep the channel at guaranteed depth; this negatively influences the feasibility of the port development. The port layout is based on guidelines and design rules. It features a container terminal, a multi-purpose terminal, three dry bulk terminals and a liquid bulk terminal. The bulk terminals are located downwind of the other terminals. Due to long cargo dwell times, large terminal areas are required. The layout can be expanded step-wise and most terminals can be converted or re-purposed. The breakwater layout is optimised; it extends into the sea beyond the closure depth, preventing immediate bypassing of sediment. The approach channel is designed as a one-way system with a guaranteed depth of -17 m MSL. This depth necessitates a very long dredged channel; the channel length is more than sixteen kilometres. The channel is designed completely according to PIANC guidelines. The main part of the channel is orientated in the dominant wave direction. Near the port entrance it bends and then enters the port at an angle of 55° with the dominant wave direction. The channel shows unexpected interactions with the long swell waves: the waves attune on the channel edge and are subsequently focused on the port entrance, enhancing wave penetration. This interaction is related to wave refraction. The refraction modes depend strongly on the critical wave angle; which is related to changes in water depth. The wave-channel interaction is thoroughly investigated. This investigation leads to measures which can reduce wave penetration.