Numerical study of combined wave and surge overtopping over RCC strengthened levee systems using the smoothed particle hydrodynamics method

Most earthen levee damages occurred on the levee crest and landward-side slope after Hurricane Katrina as a result of either wave overtopping, storm surge overflow, or a combination of both. It is important to understand the overtopping hydraulics in the combined wave and surge overtopping condition for levees strengthened by roller compacted concrete (RCC). In this paper, combined wave overtopping and storm surge overflow of a levee with a trapezoidal cross section, strengthened by RCC, were studied in a purely Lagrangian and meshless approach, two-dimensional smoothed particle hydrodynamics (SPH) model. After verifying the developed SPH model in this study with full-scale overtopping experimental data and previous equations, time series of discharge, and water depths at two locations on the levee crest and flow thickness at five locations on the landward-side slope, 27 combinations of wave/surge overtopping cases were simulated. New equations are presented for average overtopping discharge, mean flow thickness, RMS wave height, mean velocity, and velocity of the wave front down the landward-side slope. The range of the application of these equations is discussed.

► A SPH model was developed.
► An equation for overtopping discharge was developed.
► An equation for mean flow thickness was obtained.