Specifying seawall crest levels using a probabilistic method Available to Purchase

Probabilistic methods provide a powerful framework for the design of coastal defences. However, present knowledge of the behaviour of these structures is insufficient to permit a full assessment of their safety. It is possible to assess their safety against specific types of failure, such as excessive overtopping by wave action. However, the choice of overtopping model used to describe the failure is crucial to the outcome of the assessment. The paper illustrates the different results obtained from two models used to describe wave overtopping. The models are implemented in a software package known as PARASODE-BALI which employs the Level II First Order Reliability Method (FORM) for the design and safety assessment of coastal structures. For large overtopping discharges relevant to structural safety, the two overtopping models provide similar results. However, the differences are much greater for the small discharges commonly required to ensure the safety of people and property in urban areas.