This study examines how seawall geometry influences overtopping and bore-induced forces under wet, smooth-bed conditions. Experiments were conducted in a 14.5-m wave flume using a dam-break method to generate tsunami bores at initial reservoir depths H = 13, 15, 17 cm. A 5-cm platform simulated preinundated terrain. On the landward side of the seawall, the overall mean overtopping height (ℎ̄0) and the overall mean peak force (𝐹¯) were computed from three replicates per case for four configurations: slope, curve, step, and box. Results show clear geometry effects. The box-type produced the largest overtopping and forces (ℎ̄0 = 3.48 cm; 𝐹¯ = 0.501 N), consistent with minimal energy dissipation at a vertical face. The slope-type yielded the lowest mean force (𝐹¯ = 0.383 N) but still allowed relatively high overtopping (ℎ̄0 = 3.07 cm). The curve-type showed moderate performance (ℎ̄0 = 2.49 cm; 𝐹¯ = 0.416 N), redirecting part of the flow yet concentrating loads locally. The step-type achieved the best overall balance, combining low overtopping (ℎ̄0 = 2.44 cm) with a comparable force level (𝐹¯ = 0.434 N) by promoting turbulence and energy dissipation; this effect was particularly evident at H = 15 cm. Normalization using the platform height (𝑙𝑝) provided a clearer regression and more consistent statistics than shoreline bore height, reinforcing that energy-dissipating geometries (steps/curves) are advantageous for coastal protection. These findings establish benchmark data for tsunami–structure interaction under wet-bed conditions and support the site-specific design of seawalls to reduce overtopping while maintaining structural stability.
Mateo et al. (Thu,) studied this question.