Fluid-Structure Interaction: Impact of Reservoir Simulation Approach Considering Far-Field Boundary Condition in Dam Seismic Response

Abstract

Given the vitality of dams to life and the catastrophe caused by their failure, an adequate safetymargin must be considered while designing for permanent and transient loads. Neglecting the transient loads indesign make the dam structure vulnerable to damage; consequently, the earthquake load is crucial as a transientdynamic load. The horizontal component of an earthquake causes acoustic waves to exert hydrodynamicpressure on the dam's upstream face in addition to hydrostatic pressure. This study aims to assess the dynamicresponse of a dam using Lagrangian-Lagrangian and Lagrangian-Eulerian modeling approaches for a solidliquid interaction. To this end, as a case study, time-domain analysis is carried out using ANSYS to determinethe PINE FLAT dam response subjected to the horizontal component of the TAFT ground motion. The resultsindicate that considering the following points, the dam's dynamic responses in both approaches are almostidentical. In order to absorb the scattered acoustic waves in the Eulerian reservoir, a condition involving aparticular boundary element at the far field with a specific geometry must be provided. Also, the length-toheight ratio of the reservoir must not be less than a specific value in the Lagrangian fluid to minimize the effectof propagated acoustic wave reverberation.