1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

Dubrovnik (Croatia) and Hilo (Hawaii, USA) are two urban centers that frequently face the challenges inherent in cataclysmic tsunamis. This paper will demonstrate better practices for incorporating dynamic aquatic forces in urban planning and project-specific landscape design for metropolitan waterfronts, drawing on the specific tsunami history of Dubrovnik and Hilo; it will also identify innovations in contemporary aquatic interface design. Design professionals can move beyond damage control to inclusion of dynamic aquatic forces in their waterfront rehabilitation projects, and thereby improve urban resiliency in urban centers such as Dubrovnik and Hilo, in the face of foreseeable tsunamis of the same magnitude that have been experienced.

Dubrovnik, Hilo and other urban centers with waterfronts have faced repeated tsunami attacks since they evolved into regional economic centers. Recent technical innovations in structural engineering have expanded the design options for meeting the challenges of foreseeable tsunami attacks in those centers. Design professionals can move beyond traditional preventative systems (such as sea walls) to include channels and robust high-rise framing systems in land forms that accept the dynamic tsunami surge rather than attempting to resist it (often in futility) with brute strength. This approach involves "outwrestling" tsunami forces by improving the ductility of man-made structures and water courses through performance-based design, following recent innovations in design methodology used in earthquake engineering. At its most fundamental level, improved resiliency follows a site-specific understanding of tsunami demand (in part derived from an honest understanding of historical attacks) and science-based predictions of performance based on capacity in excess of demand. This approach will produce better results than in earlier attacks, including reduced death, downtime and destruction.