Design of a Wide Berm and Low Height Breakwater for High Wave Loading

This paper presents the investigations, including laboratory testing, carried out to design a wide berm and low-crested breakwater that aims to absorb the wave energy and prevent overtopping of an exposed section of the E10, National Tourist Road, near Reine, Norway, using graded rock from a nearby tunneling project. The study concludes that low-crested structures are a realistic alternative to high-crested berm structures at sites where scenic qualities are important, and may also be viable from an economic point of view if the bathymetry in front of the breakwater is favorable.

E10 is the designation of a main road that runs East-West from Luleå from the Gulf of Bothnia in Sweden to the extreme western end of the Lofoten Archipelago in Norway. Though the road through the Lofoten Islands has been upgraded with 5 major bridges, 6 major tunnels and 2 under-sea tunnels, the road is still largely a windy 2-lane road which at places narrows to a single lane road. One particularly difficult location is at Hamnøy, near Reine, where the road first runs through a rock slide prone area, and then runs over a series of small islets on a very low and narrow strip of rock fill, see Figure 1 and Figure 2. The site is exposed to open ocean waves, which cause frequent overtopping and inundation of the road. This happens so frequently that automatic traffic lights have been installed to close the road during periods of high waves and strong winds.