NUMERICAL ANALYSIS OF WAVE PRESSURE AND FORCE INDUCED BY TSUNAMIS CONTAINING SEDIMENT

Abstract

 Existing hydraulic experiments on wave pressure and force acting on a vertical wall induced by a bore-like tsunami containing kaolin as a bottom sediment were simulated using a numerical model FS3M, that can consider the apparent density and viscosity of fluid containing the sediment. Through a comparison with experimental data, the predictive capability of the model was demonstrated in terms of water level, quasi-static pressure on the vertical wall, and force on the vertical wall induced by quasistatic pressure, except for surge-front pressure. Furthermore, it was found that the maximum wave force on the vertical wall caused by quasi-static pressure can be larger at low concentrations and is always smaller at high concentrations compared to that for clear water multiplied by the apparent specific weight of the water containing the kaolin. If a suspended sediment concentration of 7% is assumed in tsunamis, the result above supports the ASCE 7 standards and the FEMA P646 guidelines.