Description of loading conditions due to violent wave impacts on a vertical structure with an overhanging horizontal cantilever slab

Abstract A vertical structure with an overhanging horizontal cantilevering slab is tested in a small-scale test set-up (with a scale factor of 1:20) under loading conditions of violent wave impacts. Tests are conducted using regular waves for different values of water depth and wave period. All the events are recorded by a high speed camera and pressures are measured with 10 Quartz pressure sensors using a 20 kHz sampling frequency. A single approaching wave creates two individual impacts which occur sequentially on the vertical and horizontal parts. Both impact pressures and forces are non-repeatable under nominally identical conditions. Beneath the horizontal part, the shock pressures occur even for non-breaking waves which are the result of accelerated water jets along the vertical part. Waves are classified into four breaker types based on Oumeraci et al. (1993). The largest peak pressures are recorded at the still-water level on the vertical part (109 kPa) and at the fixed corner of the cantilever slab (123 kPa). In addition to these locations, the local pressures measured at the upper corner of the vertical part are also high. Consequently, the presence of a horizontal structural part increases the vulnerability of the vertical structures against violent wave impacts.