Standards Development

Scope

1.1 Scope of EN 1991-1-8

(1) EN 1991-1-8 gives principles and rules to determine the values of wave and current actions on structures and civil engineering works in the coastal zone, i.e. works connected or in close vicinity to the shore.

NOTE 1 As opposed to offshore conditions, waves or currents in the coastal zone are substantially affected by the presence of seabed or shore.

NOTE 2 In typical seabed morphology the affected area lies between the shoreline and the deep-water limit.

(2) EN 1991-1-8 describes the principles for defining the design sea conditions, including design water level variability for structures in the coastal area.

NOTE Wave and current conditions vary for different construction sites. It is very important to assess the wave and current conditions at a given site. Assessment procedures for these conditions and for their uncertainties are included in this document.

(3) In EN 1991-1-8 the following structure types are specifically addressed:

—     cylindrical structures;

—     suspended decks;

—     sub sea pipelines;

— breakwaters:

— mound breakwaters;

— vertical face breakwaters;

— composite breakwaters;

— coastal embankments:

— revetments;

— seawalls;

— permanently moored floating structures.

NOTE  Additional guidance can be needed for:

— floating platforms in the coastal zone related to oil and gas production or processing;

— floating platforms in the coastal zone for renewable energy production.

(4) EN 1991-1-8 does not fully cover principles for determining actions from waves and currents on:

     port structures like piers, jetties, quay walls, marine terminals in sheltered marine areas;

     installations for mooring and berthing of ships.

(5) For hydraulic pressures on structural envelopes caused by quasi-static water levels, and for under pressures in the ground, see EN 1997 (all parts).

(6) EN 1991-1-8 does not cover:

     tsunamis;

     hydraulic consequences of an accidental breakdown of water actions from retaining structures;

     waves from passing ships;

     currents induced by jets or ship’s propellers;

     coastal structures where flood risk and/or erosion or sediment management is the dominant function.

1.2 Assumptions

(1) The assumptions given in EN 1990 apply to this document.

(2) Qualification and experience related to this document refer also to the following fields:

a)      physical coastal environment including physics of waves and currents, statistical properties and propagation of such;

b)     marine hydrodynamics, wave and current disturbance by structures in general and wave and current actions on structures in the coastal zone including i) fixed structures, and ii) floating structures;

c)      advanced methods including probabilistic methodology and physical model testing.