UNDERSTANDING TSUNAMI RISK TO STRUCTURES: A CANADIAN PERSPECTIVE

The potential catastrophic effects of tsunami-induced loading on built infrastructure in the vicinity of shorelines have been brought to the fore by recent global events. However, state- of-the-art building codes remain silent or provide conflicting guidance on designing near- shoreline structures in tsunami-prone areas. This paper focuses on tsunami-induced loading and its effect on structures within the Canadian context. The mechanics of tsunami-induced loading is described based on knowledge gained during reconnaissance visits after the 2004 south-east Asia Tsunami, as well as post-construction visits to countries significantly affected by the destructive forces of the tsunami. To gain an appreciation of the magnitude of tsunami-induced bores for a given seismic event along the western coastal region of Canada, structural analysis of a simple near-shoreline structure was performed considering a proposed loading protocol for tsunami-induced hydraulic bores. These loads were further compared to seismic loading in order to provide an estimation of the tsunami risk and its impact. The work was complemented by experimental results from a large-scale testing program conducted with the purpose of estimating the forces experienced on structural components. Square-, rectangular-, and diamond-shaped columns were used to study the influence of shape. Furthermore, results from debris impact testing are also discussed.