An experimental investigation of a vertical wall response to breaking wave impact

Laboratory experiments are conducted to measure the impact pressures and resulting deflections from breaking oscillatory waves on a vertical wall with 1/10 foreshore slope. The maximum impact pressure data on the wall are statistically analysed and the relationships between the magnitudes of impact pressures and forces, and their durations, are investigated. The maximum impact pressures, among the 90 wave impacts, are found to vary between 1.37 × 104 and 28.3 × 104 Pa. The maximum impact pressures are shown to reasonably satisfy the log-normal probability distribution and they occur most frequently slightly below the still-water level. The greatest wall deflection at the point of measurement is caused by an impact which has a maximum pressure of 3.6 × 104 Pa, corresponding to 50% probability in the log-normal distribution. It is found that the longer-lasting low impact forces are more effective in producing the larger wall deflections. In this respect, the maximum impact pressures in the range between 2.5 × 104 and 5 × 104 Pa obtained in this study are found to be the most effective. The upper limit of this range (when non-dimensionalised by the specific weight of water and deep-water wave steepness) is suggested as a design value for vertical walls. © 1990.Alexander von Humboldt-StiftungAcknowledgements--The experiments are carried out at the Leichtweiss-lnstitut for Wasserbau at the Technical University of Braunschweig, F.R.G., under a fellowship program sponsored by the Alexander von Humboldt Foundation. The writer would like to express his gratitude to the AvH Foundation for its support