Stability of sloping structures in relation to ξ = tanα/√H/Lo risk criteria in design

This paper discusses the importance of wave period to the stability of sloping-faced waveprotection structures (permeable and impermeable). A summary of wave breaking, run-up and run-down is given using a one parameter system ξ = tanα/√H/Lo. The nature of hydrodynamic forces during the time history of flow is analysed and the most destructive wave vs slope combinations are described as a function of ξ. Model test data are presented in connection with the theory. A risk criterion in the design for stability and wave run-up is given using the joint distribution of wave heights and periods. Three case histories are demonstrated which verify the importance of wave period as well as wave height in the design.