Assessing tsunami vulnerability of structures designed for seismic loading

Wave movement with large velocity triggered by strong earthquake occurring at the sea bed is generally the primary cause of the tsunami. Occurrence of tsunami (like the one during the Sumatra earthquake in 2004 or the one during the Tohoku earthquake in Japan in 2011) causes devastating damages to the coastal structures and tremendous casualties. Seismic resistant design procedure is more popularly followed in various countries as per the relevant seismic codes. It is the need of the hour to see whether the lateral load-resisting capability attributed through seismic design is sufficient to resist tsunami loading. The present study using available design guidelines in various seismic codes and well accepted design literature for tsunami loading attempts to achieve this end in a limited form. The study may be helpful in providing a broad overview of tsunami vulnerability of coastal structures which are designed following the mandatory requirements of seismic codes. Such tsunami vulnerability is attempted to be recognized in terms of critical height that corresponds to maximum inundation depth of tsunami wave which the structure may withstand because of being aseismically designed. Thus, the results presented in this study may prove useful in assessing and reducing tsunami vulnerability of coastal structures.