Rubble-mound breakwaters are subject not only to wave action but, also, to other types of environmental loading, such as earthquakes. The design of coastal structures should take into account the most relevant factors in each case, including seismic loading. The objective of this study is to present the dynamic response of breakwaters during earthquakes. An experimental work has been carried out for homogeneous breakwater structures for different seismic frequencies and amplitudes. However this paper has presented preliminary results of the study about seismic response of the rubble-mound breakwaters yet.
Earthquakes may provide a destructive loading in many areas around the world, and, therefore, should be considered for inclusion in the design of coastal structures, especially in areas of high seismicity. The coastal structures should resist to the seismic loads even on the poor soil. The foundation soil of coastal structures can be quite soft at sea, and also they interact with sea water. Failures of rubble mound breakwaters due to seismic loading have been report in the past, especially for cases where the structure was founded on poor soil (Memos et al., 2000, Yuksel et al., 2004). Many countries around the world, such as Turkey, lie in an active seismic zone.
The 17 August 1999 Kocaeli-Turkey earthquake was an event of magnitude MW = 7.4, and caused extensive landslides, subsidence's and liquefaction-induced ground deformations along the coast of İzmit Bay. Some seismically-induced deformations occurred on sea structures such as Ereğli Fishery Port Breakwater along the southern coast of İzmit Bay (Figure 1). Ground deformations and displacements at the rubble breakwaters observed after the earthquake. Large settlements of the order of 1.5 m were observed at the sea side of the breakwater (Yuksel et al., 2004).
