Overview
ISO 21650:2007 - Actions from waves and currents on coastal structures sets out principles for determining wave and current loads on a range of structures in the coastal zone and estuaries. The standard focuses on detailed design guidance for breakwaters (rubble mound, vertical, composite), wave screens, floating breakwaters, coastal dykes and seawalls, and cylindrical structures (jetties, dolphins, pipelines, lighthouses). It is intended for application at the detailed design stage and emphasizes site-specific assessment of water levels, waves and currents and their uncertainties.
Key topics and technical requirements
- Scope and exclusions
- Covers wave and current actions on coastal structures; excludes harbour layout, sediment-transport layout, scour/beach stability design and most flexible dynamic responses (vortex-induced vibrations are included).
- Basic variables
- Assessment of water levels, wave climate (spectra, significant and peak wave periods) and currents for coastal and estuarine sites.
- Structural action models
- Guidance for estimating forces and pressures on different structure types, including treatment of wave breaking, impulsive and pulsating pressures, reflections and run-up.
- Treatment of cylindrical members using drag, inertia and lift concepts (coefficients such as drag and inertia are defined).
- Design levels
- Recognizes concept, feasibility and detailed design phases; ISO 21650:2007 is aimed at detailed design.
- Uncertainty and reliability
- Procedures for probabilistic analysis, extreme value estimation (annual maxima, peaks-over-threshold), and reliability assessment of structures exposed to waves and currents.
- Informative annexes
- Annexes A–J provide supportive material on water levels, wave parameters, currents, and specific guidance for each structure type and probabilistic methods (informative only).
Applications and users
Who uses ISO 21650:2007:
- Coastal, hydraulic and marine structural engineers
- Port and harbour designers (for coastal-facing structures)
- Consultants performing coastal risk and reliability assessments
- Authorities and asset owners specifying design loads for seawalls, dykes, breakwaters and jetties
Practical uses:
- Determining design water level and extreme wave conditions for structural sizing
- Estimating wave pressures, overtopping and mooring loads on floating breakwaters
- Selecting armour unit requirements for rubble mound breakwaters (based on hydraulic model-derived relations)
- Performing probabilistic reliability checks and extreme event analyses
Related standards
Keywords: ISO 21650:2007, coastal structures, wave action, current action, breakwaters, seawalls, coastal dykes, floating breakwaters, probabilistic analysis, design water level.
