Author(s): Constantine Memos; Areti Kiara; Constantine Vardanikas
Linked Author(s): Constantine Memos
Keywords: Breakwaters; Earthquakes; Hydrodynamic pressure; Rubble-mound; Seismic loading
Abstract: Rubble-mound breakwaters are subject not only to wave action but, also, to other kinds of environmental loading such as earthquakes. During seismic excitation hydrodynamic pressures are being developed upon the inclined faces of the mound. A major investigation including experimental work was undertaken aiming at gaining insight in the behaviour of the above structures under seismic action. The present paper reports on the part of this investigation associated with the prediction of the values of the above-mentioned pressures and their characteristics. A boundary element code was developed, tailored to the needs of the rubble-mound type of breakwater. The model results were compared against the measured data, the comparison being favourable. A useful advance over current practice employing Westergaard's formula is that the model can take into account the effect of the predominant frequency of the excitation which in turn can reveal dangerous resonance conditions. Otherwise, rubble-mound breakwaters were found to behave as rigid rather than as elastic bodies. However, as the strength of the excitation increases the maximum pressures among those acting on the faces of the mound tend to be located higher than the toe of the structure. This trend increases with increasing ground acceleration. Finally the code can detect areas where dangerous sub-pressures could be developed.
Year: 2001