Artificial Surf Reef on Maasvlakte 2

The growing need for space to offer the opportunities for growth and renewal of port related activities for the port of Rotterdam has lead to the project mainport development Rotterdam. Within the framework of this project, a land reclamation has been foreseen, Maasvlakte 2. For this land reclamation two different types of sea defences will be applied, on the northern boundary a hard flood defence and on the western boundary a soft flood defence. Between these two types of flood defences a transitional construction must be placed. In the design of Maasvlakte 2, the transition between the hard and the soft flood defence has not yet been sufficiently defined. Furthermore, the transition construction of Maasvlakte 2 may offer a unique opportunity to apply an artificial surf reef. In this thesis research a number of alternatives for the construction of a combination between the transition construction and an artificial surf reef will be presented, where the surfing conditions have been analysed for each of the alternatives. For the design of the construction hydraulic boundary conditions are required at different locations. With the aid of the model SWAN the hydraulic boundary conditions, as they are determined at several locations in the North Sea are translated to near shore conditions. The hydraulic conditions on the North Sea have been transferred from marginal probability to condition with combined statistics with the aid of physical relations that exist between the different hydraulic parameters. To determine the optimum working point for the design the functions of the construction have been divided into three basic functions: constraining of the sand profile, blocking of the longshore transport, and creation of surfable waves. The optimum dimensions of the construction for the first two functions are defined with an economical analysis. The result of this was a relatively long dam which costs slightly less than 40,000,000. The toe depth in this case is NAP - 7.2 m and the crest height is NAP - 1.0 m. The surfing optimum was found with a reef that starts at a water depth of 2 meter. The optimum dimensions for the surf reef were found to be to rather different for the toe depth and the crest height of the dam with respect to the morphological functions. For a better fulfilment of the functions it is advisable to split the functions into two different constructions. The design that provides the best fulfilment of the functions is the alternative with a separate reef (see figure). The stability calculations show that constructing the Westdam similar to the Noorderdam is a reasonable option. The calculations of the sand containers that will be used for the construction of the surf reef show that the elements need a nominal diameter, Dn50 of 3.4 m. Due to the dynamic behaviour of the beach in the zone where the reef is placed, it is recommended to do additional research on the morphology around the reef on the beach.Civil Engineering and Geoscience