Building damage in Thailand in the 2004 Indian Ocean tsunami and clues for tsunami-resistant design

The unprecedented devastating Indian Ocean tsunami, which struck the western coast of southern Thailand on 26 December 2004, caused more than 5300 deaths, and heavy damage to buildings in the affected areas. This paper presents field observations of damage to buildings and infrastructure hit by the tsunami in southern Thailand. The clues obtained from the performance of these structures, which have not been designed for seismic or tsunami loadings, are valuable for improvements in safe and economical design of buildings against future tsunamis. Two important features beneficial for disaster reduction on coasts are low seawalls and openings in walls in buildings. The former helps partially dissipate the energy of the incoming waves while the latter serves to reduce the unbalanced pressure on the walls of buildings. The survival of a large number of buildings suggests that it is possible to design tsunami-resistant structures with reparability performance level, with a consequence of fast recovery and minimum economic loss. This is of practical significance for the design of evacuation shelters to save human lives. Consideration of a suitable tsunami design velocity is also addressed.