Integral Design of Work Channels and Basins for the Execution of Dredging Projects

Abstract

During the execution of reclamation projects by Boskalis, often a temporary work channel and basin are required. This work channel is used by the dredging equipment to reach the project site as close as possible. The project site is often located in very shallow water which makes a channel necessary. The basin is used to transport the dredged material ashore and to make a turn. Often, these work channels are only used during the execution of the project and are only used by trailing suction hopper dredgers (TSHD’s). Nowadays, the design of such a work channel is based on the guidelines regarding approach channels for ports. This often leads to an over- or underestimation of the channel dimensions, which could result in unnecessary high costs. Research on the optimization of the design of a work channel could lead to a saving in costs. During this thesis, first an inventory is made of the currently used guidelines for the design of approach channels. An analysis of projects executed by Boskalis and interviews with TSHD captains gave insight in the behavior of a TSHD in a shallow, restricted work channel. Combining this knowledge has led to a new design-tool for the dimensions of a work channel and basin for an arbitrary TSHD and project location. The reliability of the design tool is examined in a case study by means of a fast-time simulation. Eventually a rough analysis of the costs is made to gain insight in the differences between applying a one-way or a two-way channel.