![]() ![]() The following pictures show the process of reshaping of a low crested breakwater consisting of relatively small rubble at SOGREAH’s Laboratory in 2006 (offshore is on the left side and waves propagate from left to right). Many other examples are to be found in “ Remains of ancient breakwaters ”. This ancient harbour has been intensively studied by Vasif Sahoglu and his colleagues from the Ankara University Research Centre for Maritime Archaeology. ![]() It must be noted that the location of this structure is rather sheltered from offshore waves and this may explain why this structure has survived so well in time. Due to tectonics, the ancient seabed was around 0.50 m higher, and the water level was about 0.50 m lower (according to N. The crest of the structure is now at 1 to 1.5 m below present seawater level. The remains are 140 m long and 45 m wide in a water depth of around 4 m at its seaward roundhead. In such cases, a “ design wave” for the structure is required.Ī typical example of a submerged breakwater is at Klazomenae, at Liman Tepe (near Izmir, Turkey). Similarly, breakwaters located in water depths larger than say 10 m are not likely to be subjected to breaking waves in the Mediterranean area and are therefore not considered here. Hence, the local wave climate must include waves large enough to break on the water depth in front of the submerged structure and breakwaters in very sheltered areas are not considered in this analysis. This means that we consider only cases with waves breaking between the toe and the crest of the submerged structure. The present analysis of long-term stability concentrates on the worst possible wave conditions, considering that they will eventually occur in the long term. The process of destruction by waves was not all that clear and further analysis was undertaken by the author. However, most of the ancient breakwaters were destroyed by wave action and remains are found under water as “submerged breakwaters” ( more on breakwater remains …). This particular structure has been preserved as it survived 2000 years of wave attack … as it was raised by tectonic movement. A typical example is shown above (Kissamos in Crete, from Hariclia Hampsa’s PhD thesis in 2006). Many rubble mound breakwaters have been built in antiquity to improve sheltering for ships. Kissamos (Crete) rubble mound breakwater (picture H. ![]()
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