FprEN 1991-1-8
(Main)Eurocode 1 - Actions on structures - Part 1-8: Actions from waves and currents on coastal structures
Eurocode 1 - Actions on structures - Part 1-8: Actions from waves and currents on coastal structures
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 to, or in close vicinity to the shore.
NOTE 1 Provisions in EN 1991 1 8 are limited to hydrodynamic actions that can be directly quantified in terms of wave and/or current induced pressures and associated forces and moments on structures or structural parts.
NOTE 2 As opposed to offshore conditions, waves or currents in the coastal zone are generally affected by the presence of the seabed or shore.
NOTE 3 The coastal zone is typically defined as the area between the shoreline and the deep-water limit.
(2) EN 1991 1 8 describes the principles for defining the hydrodynamic conditions to be used for design, including sea water levels.
(3) EN 1991 1 8 addresses specifically actions from currents and waves on the following structure types:
— cylindrical structures;
— subsea pipelines;
— suspended decks;
— vertical face structures;
— permanently moored floating structures.
NOTE 1 Additional guidance can be needed for:
— moored structures in the coastal zone for renewable energy production or related to oil and gas production or processing;
— moored structures spanning areas with variable wave and current states (e.g. floating aquaculture farms or floating bridges).
NOTE 2 For hydraulic pressures caused by quasi-static water levels, and ground water, see EN 1997 (all parts).
(4) Actions addressed in EN 1991 1 8 do not cover:
— hydraulic resonance in sheltered areas or basins (phenomena also known as harbour resonance);
— translation waves, e.g. tsunamis;
— waves and currents induced by maritime operations, i.e. vessel wake, berthing and mooring;
— hydrodynamic actions induced by earthquakes;
— ice-induced pressures and forces;
— 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) In addition, it is assumed that actions from waves and currents on coastal structures are determined by personnel appropriately qualified and experienced in 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 interaction with 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.
Eurocode 1 - Einwirkungen auf Tragwerke - Teil 1-8: Einwirkungen infolge von Wellen und Strömungen auf Küstenbauwerke
1.1 Anwendungsbereich von EN 1991 1 8
(1) EN 1991 1 8 enthält Grundsätze und Regeln zum Bestimmen der Werte von Wellen und Strömungseinwirkungen auf Bauwerke und Ingenieurbauwerke im Küstengebiet, d. h. Bauten in Verbindung mit der oder in unmittelbarer Nähe zur Küste.
ANMERKUNG 1 Die in EN 1991 1 8 angegebenen Bestimmungen sind auf hydrodynamische Einwirkungen begrenzt, die direkt in Bezug auf wellen und/oder strömungsinduzierte Drücke sowie zugehörige auf Tragwerke oder Bauwerksteile einwirkende Kräfte und Momente quantifiziert werden können.
ANMERKUNG 2 Im Gegensatz zu Bedingungen auf offener See werden Wellen oder Strömungen im Küstengebiet im Allgemeinen durch das Vorhandensein von Meeresboden oder Küste beeinflusst.
ANMERKUNG 3 Das Küstengebiet wird üblicherweise als der Bereich zwischen der Küstenlinie und der Tiefwassergrenze definiert.
(2) EN 1991 1 8 beschreibt die Grundsätze zum Definieren der für die Bemessung zu verwendenden hydrodynamischen Bedingungen, einschließlich Meeresspiegel.
(3) EN 1991 1 8 behandelt insbesondere Einwirkungen infolge Strömungen und Wellen auf die folgenden Tragwerkstypen:
zylindrische Bauwerke;
Unterwasser-Rohrleitungen;
Hängedecks;
Bauwerke mit vertikaler Fläche;
dauerhaft festgemachte schwimmende Bauwerke.
ANMERKUNG 1 Zusätzliche Hinweise können erforderlich sein für:
festgemachte Bauwerke im Küstengebiet für die Erzeugung von erneuerbarer Energie oder in Bezug auf die Förderung oder Verarbeitung von Öl und Gas;
festgemachte Bauwerke, die Flächen mit veränderlichen Wellen und Strömungszuständen (z. B. schwimmende Aquakulturanlagen oder schwimmende Brücken) überspannen.
ANMERKUNG 2 Zu Wasserdrücken infolge quasi-statischer Wasserstände und Grundwasser siehe EN 1997 (alle Teile).
(4) Die in EN 1991 1 8 behandelten Einwirkungen decken Folgendes nicht ab:
hydraulische Resonanz in geschützten Bereichen oder Becken (auch als Hafenresonanz bekannte Erscheinungen);
Translationswellen, z. B. Tsunamis;
Wellen und Strömungen infolge Seeverkehr, d. h. Nachstrom, Anlegen und Festmachen von Wasserfahrzeugen;
hydrodynamische Einwirkungen infolge Erdbeben;
Drücke und Kräfte infolge Eisbildung;
Küstenbauwerke, bei denen der Umgang mit Überflutungsrisiken und/oder das Erosions oder Sedimentmanagement die überwiegende Funktion darstellt.
1.2 Voraussetzungen
(1) Für dieses Dokument gelten die Voraussetzungen nach EN 1990.
(2) Darüber hinaus wird vorausgesetzt, dass Einwirkungen auf Küstenbauwerke infolge Wellen und Strömung durch Personal bestimmt werden, das angemessen erfahren und qualifiziert ist auf den folgenden Gebieten:
a) physikalische Küstenumgebung einschließlich Physik von Wellen und Strömungen, statistische Eigenschaften und deren Ausbreitung;
b) Hydrodynamik des Meeres, Wellen und Strömungsinteraktionen mit Bauwerken im Allgemeinen sowie Wellen und Strömungseinwirkungen auf Bauwerke in Küstengebieten einschließlich i) fester Bauwerke und ii) schwimmender Bauwerke;
c) erweiterte Verfahren, einschließlich wahrscheinlichkeitsbasierter Methodik und physikalischer Modellprüfungen.
Eurocode 1 - Actions sur les structures - Partie 1-8 : Actions des vagues et des courants sur les structures côtières
Evrokod 1 - Vplivi na konstrukcije - 1-8. del: Vplivi valov in tokov na obalne konstrukcije
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 1991-1-8:2024
01-junij-2024
Evrokod 1 - Vplivi na konstrukcije - 1-8. del: Vplivi valov in tokov na obalne
konstrukcije
Eurocode 1 - Actions on structures - Part 1-8: Actions from waves and currents on
coastal structures
Eurocode 1 - Einwirkungen auf Tragwerke - Teil 1-8: Einwirkungen durch Wellen und
Strömungen auf Küstenbauwerke
Eurocode 1 - Actions sur les structures - Partie 1-8 : Actions des vagues et des courants
sur les structures côtières
Ta slovenski standard je istoveten z: prEN 1991-1-8
ICS:
91.010.30 Tehnični vidiki Technical aspects
oSIST prEN 1991-1-8:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN 1991-1-8:2024
oSIST prEN 1991-1-8:2024
DRAFT
EUROPEAN STANDARD
prEN 1991-1-8
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2024
ICS 91.010.30
English Version
Eurocode 1 - Actions on structures - Part 1-8: Actions from
waves and currents on coastal structures
Eurocode 1 - Actions sur les structures - Partie 1-8 : Eurocode 1 - Einwirkungen auf Tragwerke - Teil 1-8:
Actions des vagues et des courants sur les structures Allgemeine Einwirkungen - Einwirkungen durch
côtières Wellen und Strömungen auf Küstenbauwerke
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 250.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1991-1-8:2024 E
worldwide for CEN national Members.
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prEN 1991-1-8:2024 (E)
Contents
European foreword . 10
Introduction . 11
1 Scope . 14
1.1 Scope of EN 1991-1-8 . 14
1.2 Assumptions . 15
2 Normative references . 15
3 Terms, definitions and symbols . 16
3.1 Terms and definitions . 16
3.1.1 Terms relating to physical environment and environmental processes. 16
3.1.2 Terms relating to analysis of metocean parameters . 19
3.1.3 Terms relating to statistical metocean parameters . 22
3.1.4 Terms relating to metocean effects in interaction with structures . 27
3.1.5 Terms relating to coastal structures . 30
3.2 Symbols and abbreviations . 33
3.2.1 Latin upper-case letters . 33
3.2.2 Latin lower-case letters . 36
3.2.3 Greek upper-case letters . 37
3.2.4 Greek lower-case letters . 37
4 Basis of wave and current action assessment . 39
4.1 General. 39
4.2 Design approaches . 39
4.2.1 General. 39
4.2.2 Semi-probabilistic design approach . 39
4.2.3 Reliability-based design approach . 39
4.2.4 Risk-informed decision-making design approach . 40
4.2.5 Design assisted by physical testing . 40
4.3 Action modelling . 40
4.3.1 Classification of actions from waves and currents . 40
4.3.2 Metocean parameters. 40
4.3.3 General methods for the assessment of the hydrodynamic loads . 41
4.4 Design situations . 41
4.5 Geometrical parameters . 42
4.6 Hydrodynamic estimate approaches . 43
4.7 Representative values of hydrodynamic loads . 45
4.7.1 General. 45
4.7.2 Characteristic value . 47
4.7.3 Combination value . 47
4.7.4 Frequent value . 47
4.7.5 Quasi-permanent value . 48
4.8 Design value and importance factor . 48
4.9 Specific combinations rules for metocean parameters . 49
4.9.1 General provisions . 49
4.9.2 Combination rules using marginal distributions of the metocean parameters
(marginal deep-sea extremes method) . 50
4.9.3 Combination rules using joint distributions of the metocean parameters (joint deep-
sea extremes method) . 50
4.9.4 Specific combination rules between waves, currents and wind . 51
4.10 Accidental metocean events . 52
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5 Hydrodynamic conditions . 53
5.1 General . 53
5.1.1 Metocean design description . 53
5.1.2 Metocean data . 53
5.1.3 Wave and current interactions with structures . 53
5.2 Design event probability and extreme values analysis . 54
5.2.1 General . 54
5.2.2 Extreme value analysis . 55
5.3 Water levels . 56
5.3.1 Design water level . 56
5.3.2 Water level measurements . 56
5.3.3 Tides . 56
5.3.4 Surges . 57
5.4 Waves . 57
5.4.1 General . 57
5.4.2 Wave set-up . 58
5.4.3 Frequency and directional distribution of waves . 58
5.4.4 Spectral wave description . 58
5.4.5 Storm-representative wave parameters . 59
5.4.6 Wave data sources . 59
5.4.7 Wave transformation . 60
5.4.8 Wave data for extreme value analysis . 61
5.4.9 Nearshore wave processes . 61
5.4.10 Regular wave theories . 62
5.4.11 Wave shape and kinematics . 62
5.4.12 Long waves . 64
5.5 Currents . 65
5.5.1 General . 65
5.5.2 Current data sources . 65
5.5.3 Current velocity and profile . 66
5.6 Climate change . 66
6 Wave and current actions on fixed cylindrical structures and suspended decks . 67
6.1 General . 67
6.1.1 Applications . 67
6.1.2 Principles for assessing actions from waves and currents . 68
6.1.3 Conditions for disregarding actions from waves and currents . 69
6.1.4 Current actions . 69
6.1.5 Wave and current actions on cylinders from non- breaking waves . 70
6.1.6 Wave and current actions from breaking waves . 72
6.1.7 Slamming actions from waves . 72
6.1.8 Wave actions on small diameter pipelines . 72
6.1.9 Current and wave induced vibrations . 72
6.1.10 Seabed scour at cylinders due to waves and currents . 72
6.2 Current actions on slender structures . 72
6.3 Wave Actions on slender bodies . 73
6.3.1 Wave actions on single slender cylinder . 73
6.3.2 Wave actions on clusters of circular cylinders . 75
6.4 Wave Actions on large volume bodies . 75
6.5 Wave Impact and slamming actions . 76
6.5.1 Wave slamming on slender structures . 76
6.5.2 Wave in deck forces and air gap . 76
6.5.3 Dynamic amplification and vibrations . 76
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6.6 Wave actions on pipelines and subsea structures . 76
6.7 Vortex induced vibration (VIV) of pipelines . 77
7 Wave and current actions on mound breakwaters . 77
7.1 Introduction and structure types . 77
7.2 Design approach for wave and current actions on mound breakwaters . 78
7.2.1 General. 78
7.2.2 Return periods for the verification of serviceability limit states . 79
7.2.3 Return periods for the verification of ultimate limit states . 81
7.3 Wave and current actions . 83
7.3.1 General. 83
7.3.2 Wave action on the seaward slope . 83
7.3.3 Wave actions on the seaward toe . 83
7.3.4 Wave overtopping. 84
7.3.5 Wave action on the rear armour slope. 84
7.3.6 Wave action on geotechnical member . 84
7.3.7 Wave actions on roundheads . 85
7.3.8 Wave action on breakwater crest and crown walls. 85
7.3.9 Wave and current action on filter layers and underlayers . 86
7.3.10 Wave action related to stresses in armour units. 86
7.3.11 Wave and current actions related to local seabed scour . 86
8 Wave and current actions on vertical face breakwaters . 86
8.1 Introduction and structure types . 86
8.2 Design approach for wave and current actions on vertical face breakwaters . 87
8.3 Hydrodynamic loads due to waves and currents . 88
8.3.1 Types of wave actions . 88
8.3.2 Wave pressure, uplift, and buoyancy . 88
8.3.3 Wave overtopping. 89
8.3.4 Effect of wave action on geotechnical failure . 89
8.3.5 Wave and current actions related to local seabed scour . 89
9 Wave and current actions on composite breakwaters . 89
9.1 Introduction and structure types . 89
9.2 Design approach for wave and current actions on composite breakwaters . 90
9.3 Wave and current actions on vertical-composite breakwaters . 90
9.3.1 Main types of wave action . 90
9.3.2 Wave overtopping. 91
9.3.3 Wave action on mound filter layers . 91
9.3.4 Wave action on prefabricated armour units . 91
9.3.5 Effect of wave action on geotechnical failure . 91
9.3.6 Wave and current actions at the vertical face toe . 91
9.3.7 Wave and current actions on the seaward toe of the mound . 91
9.4 Wave and current actions on horizontal-composite breakwaters . 92
9.4.1 Main types of wave action . 92
9.4.2 Wave overtopping. 92
9.4.3 Effect of wave action on geotechnical failure . 92
9.4.4 Wave action on roundheads . 92
9.4.5 Wave action on breakwater crest . 92
9.4.6 Wave action on filter layers . 92
9.4.7 Wave action related to stresses in armour units. 93
9.4.8 Wave and current actions related to local seabed scour . 93
10 Wave and current actions on coastal embankments . 94
10.1 Introduction and structure types . 94
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10.2 Design approach of wave and current actions on coastal embankments . 94
10.3 Revetments . 95
10.3.1 Type of wave and current actions . 95
10.3.2 Wave action on seaward slope . 95
10.3.3 Wave action on seaward toe . 96
10.3.4 Wave overtopping . 96
10.3.5 Effect of wave action on geotechnical failure . 96
10.3.6 Wave and current actions related to local seabed scour . 96
10.4 Seawalls . 96
10.4.1 Types of wave and current actions . 96
10.4.2 Wave reflection . 97
10.4.3 Wave actions on seaward toe . 97
10.4.4 Wave overtopping . 97
10.4.5 Wave-induced forces . 97
10.4.6 Seabed scour due to waves and currents . 98
11 Wave and current actions on floating structures . 98
11.1 Definitions and types of floating structures . 98
11.2 Wave actions on floating structures . 101
11.2.1 General . 101
11.2.2 Analytical approach . 101
11.2.3 Numerical modelling approach . 102
11.2.4 Physical modelling approach . 103
11.3 Current actions on floating structures . 103
11.4 Physical modelling approach . 104
12 Wave and current action assessment assisted by physical model testing . 104
12.1 General . 104
12.2 Purposes of testing . 104
12.3 Organization of a physical model study . 105
12.4 Physical model concept and layout . 105
12.4.1 Input data . 105
12.4.2 Contents of the modelling methodology (test plan) . 107
12.4.3 Scaling laws and model scale . 108
12.4.4 Choice of a facility . 109
12.4.5 Model layout . 110
12.4.6 Construction of the model: bathymetry and tested structure . 111
12.4.7 Measurement equipment . 112
12.4.8 Installation and calibration of the instrumentation . 113
12.4.9 Validation of input conditions . 113
12.5 Model testing . 114
12.5.1 General . 114
12.5.2 Wave and current generation procedure . 114
12.5.3 Data acquisition and processing . 115
12.5.4 Analysis of hydraulic measurements . 115
12.5.5 Analysis of wave overtopping . 116
12.5.6 Assessment of stability of rubble mound structures . 116
12.5.7 Analysis of pressure and load measurements . 116
12.5.8 Assessment of floating structures motions and of forces on mooring equipment . 117
12.6 Reporting of test results . 117
12.7 Miscellaneous . 117
12.7.1 Inherent model uncertainty and model setup effects . 117
12.7.2 Minimizing model scale effects . 118
12.7.3 Instrument accuracy . 118
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13 Wave and current actions in reliability analysis . 118
13.1 Introduction . 118
13.2 Probability models for wave and current actions on coastal structures . 119
13.3 Extrapolation of exceedance probability . 120
13.4 Target reliability . 120
13.5 Resilience . 121
Annex A (informative) Additional guidance on environmental sea conditions . 122
A.1 Use of this annex . 122
A.2 Scope and field of application . 122
A.3 Water levels . 122
A.3.1 Tide levels . 122
A.3.2 Design water levels . 122
A.4 Waves . 123
A.4.1 Short-term wave condition . 123
A.4.2 Wave climate (long-term) statistics . 128
A.4.3 Extreme wave statistics . 129
A.4.4 Wave kinematics . 131
A.4.5 Wave transformations . 133
A.5 Currents . 133
A.5.1 General. 133
A.5.2 Stretching of current to wave surface . 134
A.5.3 Numerical simulation of current flows – current hindcast . 136
A.5.4 Current properties . 136
Annex B (informative) Additional guidance for fixed cylindrical structures and suspended
decks . 138
B.1 Use of this annex . 138
B.2 Scope and field of application . 138
B.3 Classification. 138
B.4 Principles of design . 139
B.4.1 General. 139
B.4.2 Storm-representative wave approach . 140
B.5 Wave and current actions on structures . 141
B.5.1 General. 141
B.5.2 Waves and current actions on slender structures . 141
B.5.3 Waves actions on large volume bodies . 148
B.6 Seabed scour at cylinders due to waves and currents . 150
B.7 Clusters of cylinders . 150
B.8 Long-crested and short-crested wave action . 151
B.9 Wave impact and slamming actions . 151
B.9.1 General. 151
B.9.2 Slamming actions on vertical and inclined cylinders on uniformly sloping or
horizontal bottoms . 152
B.9.3 Wave actions, including slamming actions, on vertical cylinders on reefs and shoals
................................................................................................................................................................ 154
B.9.4 Wave-in-deck forces . 154
B.9.5 Air gap calculations and recommendations . 156
B.9.6 Dynamic amplification and vibrations . 157
B.10 Subsea pipelines . 158
B.11 Vortex induced vibration of pipelines . 160
B.12 Tools to support design . 161
B.12.1 Numerical models . 161
B.12.2 Model tests . 162
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Annex C (informative) Additional guidance for mound breakwaters . 163
C.1 Use of this annex . 163
C.2 Scope and field of application . 163
C.3 Conventional mound breakwaters . 164
C.3.1 Failure modes . 164
C.3.2 Fault tree . 165
C.3.3 Design approaches and formulae . 167
C.3.4 Wave action on the seaward rock-armoured slope . 169
C.3.5 Wave action on the seaward slope of artificial units . 169
C.3.6 Wave actions on the seaward toe. 169
C.3.7 Wave run-up and wave overtopping . 170
C.3.8 Wave action on the rear armour slope . 170
C.3.9 Wave actions on roundheads . 171
C.3.10 Wave action on crown walls . 171
C.3.11 Local seabed and underlayers erosion . 171
C.4 Berm breakwaters . 172
C.4.1 Introduction . 172
C.4.2 Failure modes . 172
C.4.3 Fault tree . 173
C.4.4 Design approach and formulae . 173
C.4.5 Wave action on the seaward face . 173
C.4.6 Rear side stability . 173
C.4.7 Stability and reshaping of the berm breakwater head . 174
C.4.8 Wave overtopping . 174
C.4.9 Abrasion and crushing of stones . 174
C.4.10 Local scour and scour protection . 175
C.5 Low-crested and submerged mound breakwaters . 175
C.5.1 Failure modes . 175
C.5.2 Fault tree . 175
C.5.3 Design approach and formulae . 175
C.5.4 Wave action on the seaward rock-armoured slope . 175
C.5.5 Wave action on the crest and rear armour slope . 176
C.5.6 Wave overtopping in low-crested mound breakwaters . 176
C.5.7 Wave transmission . 176
C.6 Qualitative cumulative damage assessment of mound breakwaters loaded by waves
and currents . 176
Annex D (informative) Additional guidance for vertical face and composite breakwaters
................................................................................................................................................................ 178
D.1 Use of this annex . 178
D.2 Scope and field of application .
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