European Coasts - An Introductory Survey
Chapter 3: Man-induced interference in coastal processes

3.1 Scour near structures

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Fig 60: laboratory model of scour under a pipeline, Delft Hydraulics, the Netherlands Fig 61: Laboratory model of scour around an oil platform, Delft Hydraulics, the Netherlands Fig 62: Damage to a seawall due to erosion, Valencia, Spain

Each structure in the coastal zone affects the local flow around it.

Concentrations in the flow around a structure increase the flow velocity. This leads to local erosion: scour holes. It is important to estimate the depth of the scour hole at the planning stage of a project. The depth of the foundation for a structure has to exceed the scour depth in order to prevent instabilities. The depth of scour holes can be measured in physical models (see Fig. 60 and Fig. 61).

Waves that break or reflect on a structure induce a concentration of wave energy at its toe. Toe erosion and eventual instability and damage to the structure (see Fig. 62) will occur if no additional protective measures are taken.

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This page is from the book "European Coasts", produced in the framework of the Erasmus project under EC contract ICP 92-G-2013 and placed on the Internet in the framework of the PIANC-MarCom initiative on Education.