THE DEVELOPMENT REALIZATION OF A CURRENT DEFLECTING WALL IN ESTUARINE CONDITIONS (SALINITY GRADIENTS) TO REDUCE SILTATION IN THE TIDAL DEURGANCKDOK, PORT OF ANTWERP

摘要

In August 2011 the Current Deflecting Wall (CDW) was realized at the entrance of the tidal dock 'Deurganckdok' in the port of Antwerp, Belgium. Equipped with container terminals, Deurganckdok can receive vessels with a draught of 13,10m independent of the tide. Due to its position in a stretch of the Schelde estuary with salinity gradients near the estuarine turbidity maximum, Deurganckdok is subject to siltation. Accumulation of fine-grained cohesive sediments in the dock runs up to 1 million m~3 annually and requires regular maintenance dredging. During the early stages of preliminary investigations for Deurganckdok (1997-1999), the Current Deflecting Wall (CDW) was selected as a measure to reduce sedimentation. The design was adapted to function in an environment with salinity gradients during the feasibility research (2001-2004), which included physical and numerical modelling, supported by field measurements. Initial calculations predicted a reduction of 10-20% in sediment accumulation. In the final phase of investigations (2005-2007), state-of-the-art numerical models were calibrated with field measurements to enhance sediment accumulation predictions under a range of boundary conditions. In this paper the results are summarized of the preliminary investigations that have led to the design of the Current Deflecting Wall (CDW).