Impact Pressure and Forces on a Vertical Wall with Different Types of Parapet

Abstract

This paper will discuss the variations in wave loads on a vertical seawall structure due to the addition of parapets. A 1:8 model scale experiments on a wall with parapets will be carried out. The models will be tested for monochromatic waves that have different breaking characteristics that are identified based on the amount of air entrapped during breaking. These include slightly-breaking waves (SBW), breaking waves with small air trap (BWSAT), and breaking waves with large air trap (BWLAT). The relative reduction in impact pressure will be used to quantify parapet performance. This paper revealed that with the addition of a parapet, wave force increases compared to a vertical wall (VW) until incident wave height [(Hi < 0.125 m)]. However, with further increases in wave height (H), the wave force reduces for large (LP) and medium parapets (MP) compared with a small parapet (SP). The exit angle of the parapet plays a vital role to decrease the wave loads for higher H; the extent of the decrease is dictated by the movement of deflected water. Based on the tested parapets and wave characteristics, an LP (45°) attracted less load on the overall structure compared with other parapet types for higher Hi (Hi > 0.125 m).