ABSTRACT
In recent years, a number of immersed tunnel projects have been in preparation for execution in which complex tidal flow loads were involved as well as passing vessel loads. In some of these projects, Computational Fluid Dynamics have been applied to assess the current loads and passing vessel loads on the tunnel element during installation. From these calculations, a drag coefficient can be derived and then used to design the anchoring and hoisting system used during installation. It was found that in some cases a textbook drag coefficient can be applied, but that in most cases this will lead to a significant over- or underestimation of these loads. In the present paper the applied models for both current loads and passing vessel loads are presented. In addition, an analysis is made of the conditions in which a standard drag coefficient is insufficient to assess current loads on floating tunnel elements.
