In several populous regions, the risk associated with the tsunami hazard is high. Despite the recognition of the problem, the paucity of design criteria considering earthquake-tsunami (ET) effects in structures lead to an underestimation of action-effects in structural design, typically considering individual seismic or tsunami actions. The facilities-at-risk from tsunami with near-field tectonic origin may be affected by the ground-motion, reducing their structural resistance for the income tsunami. The safety of social and economic assets may depend on the inclusion of the cascading ET actions in the structural design.
The objective of this study is threefold: 1) improve the ET-hazard assessment to optimize the structural design; 2) propose a numerical methodology to deal with the cumulative loss of resistance associated to the successive ET actions; 3) contribute to developing standard guidelines explicitly considering the cascading ET actions in structures.
To this end, we link the geophysical knowledge of the phenomena and the mathematical expertise to model an engineering case-study: the structural response of Sines pile-supported quay subjected to ET actions. Sines port is located in a tsunami-prone region of the NE-Atlantic and is one of the most important deep-water port of the Iberian-Peninsula. In addition, open-type constructions are recent solutions for the water-front quay, preferred in less-hazardous American and European zones, in opposition to the traditional close-type solutions, preferred in the more-hazardous Asia.
The dynamic analysis of the pile-supported quay requires a multi-hazard assessment to define the ET time-histories. Considering the potential tsunamigenic sources of the region, five tectonic scenarios were simulated using a home-developed tool, based on the finite-volume method. The tsunami wave(s) height (18m) and flow-velocity (13cm/s2) that impact the structure(s) at the inundated area (4km2) were estimated. From the source parameters of the tsunami worst-scenario, the seismic accelerograms were derived. A structural non-linear dynamic analysis is performed.