Influence of Orientation and Arrangement of Structures on Tsunami Impact Forces: Numerical Investigation with Smoothed Particle Hydrodynamics

This paper explores the influence of onshore structures' orientations and arrangements during a tsunami impact using the numerical method of smoothed particle hydrodynamics (SPH). Observations from previous tsunami events often reveal variation in the damage and survivability of impacted similar structures. Such variation can be due to shielding effects and other interactions that occur when the tsunami wave incident occurs in an urbanized location. The SPH model used in this work was first validated against previous experimental results and was then used to explore the resulting hydrodynamic behavior to a level of detail hitherto unobtainable from physical experiments. Groups of three and five structures were modeled with varying spatial separation and orientation to the incoming tsunami bore, characterized by the wake clearance angle (A) and the rotation angle (R), respectively. The results reveal significant reductions in total force on a structure can be made via strategic spatial positioning and orientation. Such reductions may mean the difference between superficial damage and wholesale structural collapse and allow the development of more resilient structures in tsunami-prone regions.