---

Seawalls are commonly constructed to prevent landward erosion of the shoreline and to maintain the configuration of the area behind them against wave action. In order to consider the effect of seawalls on surf zone hydrodynamics, experiments have been performed at laboratory model scale on partially reflective seawalls located in the surf zone. The main objectives of these experiments were to undertake a quantitative comparison of near-bed velocities in two cases (i.e. with and without the reflective structure). The presence of a reflective structure and the influence of reflected waves result in significant changes in the mean flow and the near-bed horizontal velocities in the surf zone. The latter is illustrated by comparing the probabilistic properties of velocities measured with and without a reflective structure. In this paper, a semi-empirical approach based on the measured probability density functions of near-bed horizontal velocities, is presented to predict the short-term response of a partially reflective seawall to random wave attack. The results obtained from the model and comparison with the experimental results, which have been reported previously are promising and encouraging for further developments of the preliminary model.