SIST EN ISO 19902:2021

SLOVENSKI STANDARD
01-januar-2021
Nadomešča:
SIST EN ISO 19902:2008
SIST EN ISO 19902:2008/A1:2014
Industrija za predelavo nafte in zemeljskega plina - Varjene jeklene konstrukcije
naftnih ploščadi (ISO 19902:2020)
Petroleum and natural gas industries - Fixed steel offshore structures (ISO 19902:2020)
Erdöl- und Erdgasindustrie - Gegründete Stahlplattformen (ISO 19902:2020)
Industries du pétrole et du gaz naturel - Structures en mer fixes en acier (ISO
19902:2020)
Ta slovenski standard je istoveten z: EN ISO 19902:2020
ICS:
75.180.10 Oprema za raziskovanje, Exploratory, drilling and
vrtanje in odkopavanje extraction equipment
91.080.13 Jeklene konstrukcije Steel structures
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 19902
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2020
EUROPÄISCHE NORM
ICS 75.180.10 Supersedes EN ISO 19902:2007
English Version
Petroleum and natural gas industries - Fixed steel offshore
structures (ISO 19902:2020)
Industries du pétrole et du gaz naturel - Structures en Erdöl- und Erdgasindustrie - Gegründete
mer fixes en acier (ISO 19902:2020) Stahlplattformen (ISO 19902:2020)
This European Standard was approved by CEN on 16 June 2020.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 19902:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 19902:2020) has been prepared by Technical Committee ISO/TC 67 "Materials,
equipment and offshore structures for petroleum, petrochemical and natural gas industries" in
collaboration with Technical Committee CEN/TC 12 “Materials, equipment and offshore structures for
petroleum, petrochemical and natural gas industries” the secretariat of which is held by NEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2021, and conflicting national standards shall be
withdrawn at the latest by May 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 19902:2007.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: 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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 19902:2020 has been approved by CEN as EN ISO 19902:2020 without any modification.

INTERNATIONAL ISO
STANDARD 19902
Second edition
2020-11
Petroleum and natural gas
industries — Fixed steel offshore
structures
Industries du pétrole et du gaz naturel — Structures en mer fixes
en acier
Reference number
ISO 19902:2020(E)
©
ISO 2020
ISO 19902:2020(E)
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

ISO 19902:2020(E)
Contents Page
Foreword . xiv
Introduction . xvii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 10
5 Abbreviated terms . 14
6 Overall considerations . 16
6.1 Types of fixed steel offshore structure . 16
6.1.1 General . 16
6.1.2 Jackets . 16
6.1.3 Towers . 17
6.1.4 Jack-ups . 17
6.2 Planning . 18
6.2.1 General . 18
6.2.2 Hazards . 18
6.2.3 Designing for hazards . 19
6.2.4 Design situations and criteria . 19
6.2.5 Design for inspection and maintenance . 19
6.2.6 Foundations and active geological processes . 20
6.2.7 Regulations . 20
6.3 Service and operational considerations . 20
6.3.1 General considerations . 20
6.3.2 Water depth . 20
6.3.3 Structural configuration . 20
6.3.4 Access and auxiliary systems . 21
6.4 Safety considerations. 21
6.5 Environmental considerations . 21
6.5.1 General . 21
6.5.2 Selecting design metocean parameters and action factors . 22
6.6 Exposure levels . 22
6.7 Assessment of existing structures. 23
6.8 Structure reuse . 23
7 General design requirements . 23
7.1 General . 23
7.2 Material properties for steel . 24
7.3 Incorporating limit states . 24
7.4 Determining design situations . 24
7.5 Structural modelling and analysis . 25
7.6 Design for pre-service and removal situations . 25
7.7 Design for the in-place situation. 25
7.8 Determination of component resistances . 25
7.8.1 General . 25
7.8.2 Physical testing to derive resistances . 26
7.8.3 Resistances derived from computer simulations validated by physical
testing . 26
ISO 19902:2020(E)
7.8.4 Resistances derived from computer simulations validated against
design formulae . 26
7.8.5 Resistances derived from unvalidated computer simulations . 26
7.9 Strength and stability checks . 26
7.9.1 Action and resistance factors . 26
7.9.2 Strength and stability equations . 26
7.9.3 Unfactored actions . 27
7.10 Robustness . 27
7.10.1 General . 27
7.10.2 Damage tolerance . 27
7.11 Reserve strength . 28
7.11.1 New structures . 28
7.11.2 Existing structures . 29
7.12 Indirect actions . 29
7.13 Structural reliability analysis. 29
8 Actions for pre-service and removal situations . 30
8.1 General . 30
8.1.1 Coverage . 30
8.1.2 Design situations . 30
8.1.3 Actions . 30
8.2 General requirements . 31
8.2.1 Weight control . 31
8.2.2 Dynamic effects. 31
8.2.3 Action effects . 31
8.3 Onshore lifting . 33
8.3.1 General . 33
8.3.2 Dynamic effects. 33
8.3.3 Effect of tolerances . 34
8.3.4 Multi-crane lift . 34
8.3.5 Local factor . 34
8.3.6 Member and joint strengths . 35
8.3.7 Lifting attachments . 35
8.3.8 Slings, shackles and fittings . 36
8.4 Fabrication . 36
8.5 Loadout . 36
8.5.1 Direct lift . 36
8.5.2 Horizontal movement onto vessel . 36
8.5.3 Self-floating structures . 37
8.6 Transportation . 37
8.6.1 General . 37
8.6.2 Metocean conditions . 37
8.6.3 Determination of actions . 37
8.6.4 Other considerations . 38
8.7 Installation . 38
8.7.1 Lifted structures . 38
8.7.2 Launched structures . 38
8.7.3 Crane assisted uprighting of structures . 38
8.7.4 Submergence pressures . 38
8.7.5 Member flooding . 39
8.7.6 Actions on the foundation during installation . 39
9 Actions for in-place situations . 39
9.1 General . 39
9.2 Permanent actions (G) and variable actions (Q) . 40
iv © ISO 2020 – All rights reserved

ISO 19902:2020(E)
9.2.1 Permanent action 1, G . 40
9.2.2 Permanent action 2, G . 40
9.2.3 Variable action 1, Q . 40
9.2.4 Variable action 2, Q . 41
9.2.5 Unintentional flooding . 41
9.2.6 Position and range of permanent and variable actions . 41
9.2.7 Carry down factors. 41
9.2.8 Representation of actions from topsides . 41
9.2.9 Weight control . 41
9.3 Extreme metocean actions . 42
9.3.1 General . 42
9.3.2 Notation . 42
9.4 Extreme quasi-static action due to wind, waves and current (E ) . 42
e
9.4.1 Procedure for determining E . 42
e
9.4.2 Direction of extreme wind, waves and current . 43
9.4.3 Extreme global actions . 44
9.4.4 Extreme local actions and action effects . 44
9.4.5 Vortex induced vibrations (VIV) . 45
9.5 Extreme quasi-static action caused by waves only (E ) or by waves and
we
currents (E ) . 45
wce
9.5.1 Procedure for determining E and E . 45
we wce
9.5.2 Models for hydrodynamic actions . 46
9.5.3 Hydrodynamic models for appurtenances . 50
9.6 Actions caused by current . 50
9.7 Actions caused by wind . 51
9.7.1 General . 51
9.7.2 Determining actions caused by wind . 51
9.7.3 Wind actions determined from models . 52
9.8 Equivalent quasi-static action representing dynamic response caused by
extreme wave conditions . 52
9.8.1 General . 52
9.8.2 Equivalent quasi-static action (D ) representing the dynamic response . 53
e
9.8.3 Global dynamic analysis in waves . 53
9.9 Factored actions . 55
9.9.1 General . 55
9.9.2 Factored permanent and variable actions . 55
9.9.3 Factored extreme metocean action . 55
9.10 Design situations . 56
9.10.1 General considerations on the ultimate limit state . 56
9.10.2 Demonstrating sufficient RSR under metocean actions . 56
9.10.3 Partial factor design format . 57
9.11 Local hydrodynamic actions . 58
10 Accidental and abnormal situations . 59
10.1 General . 59
10.1.1 Treatment of ALS events . 59
10.1.2 Accidental events . 60
10.1.3 Abnormal environmental events . 60
10.2 Vessel collisions . 60
10.2.1 General . 60
10.2.2 Collision events . 61
10.2.3 Collision process . 61
ISO 19902:2020(E)
10.3 Dropped objects . 61
10.4 Fires and explosions . 62
10.5 Abnormal environmental actions . 62
10.6 Assessment of structures following damage . 63
11 Seismic design considerations . 63
11.1 General . 63
11.2 Seismic design procedure . 63
11.3 Seismic reserve capacity factor . 64
11.4 Recommendations for ductile design . 64
11.5 ELE requirements . 66
11.5.1 Partial action factors . 66
11.5.2 ELE structural and foundation modelling . 66
11.6 ALE requirements . 67
11.6.1 General . 67
11.6.2 ALE structural and foundation modelling. 68
11.6.3 Non-linear static pushover analysis . 68
11.6.4 Time-history analysis . 70
12 Structural modelling and analysis . 70
12.1 Purpose of analysis . 70
12.2 Analysis principles . 71
12.2.1 Extent of analysis . 71
12.2.2 Calculation methods . 71
12.3 Modelling . 71
12.3.1 General . 71
12.3.2 Level of accuracy . 71
12.3.3 Geometrical definition for framed structures . 72
12.3.4 Modelling of material properties . 75
12.3.5 Topsides structure modelling . 75
12.3.6 Appurtenances . 75
12.3.7 Soil-structure interaction . 76
12.3.8 Other support conditions . 77
12.3.9 Local analysis structural models . 77
12.3.10 Actions . 78
12.3.11 Mass simulation . 78
12.3.12 Damping . 79
12.4 Analysis requirements . 79
12.4.1 General . 79
12.4.2 Fabrication . 81
12.4.3 Other pre-service and removal situations . 81
12.4.4 In-place situations . 84
12.5 Types of analysis . 86
12.5.1 Natural frequency analysis . 86
12.5.2 Dynamically responding structures . 86
12.5.3 Static and quasi-static linear analysis . 86
12.5.4 Static ultimate strength analysis . 87
12.5.5 Dynamic linear analysis . 87
12.5.6 Dynamic ultimate strength analysis . 87
12.6 Non-linear analysis . 88
12.6.1 General . 88
12.6.2 Geometry modelling . 88
12.6.3 Component strength . 89
12.6.4 Models for member strength . 89
12.6.5 Models for joint strength . 89
vi © ISO 2020 – All rights reserved

ISO 19902:2020(E)
12.6.6 Ductility limits . 89
12.6.7 Yield strength of structural steel . 90
12.6.8 Models for foundation strength . 90
12.6.9 Investigating non-linear behaviour . 90
13 Strength of tubular members . 91
13.1 General . 91
13.2 Tubular members subjected to tension, compression, bending, shear, torsion
or hydrostatic pressure . 93
13.2.1 General . 93
13.2.2 Axial tension . 93
13.2.3 Axial compression . 94
13.2.4 Bending . 95
13.2.5 Shear . 97
13.2.6 Hydrostatic pressure . 98
13.3 Tubular members subjected to combined forces without hydrostatic pressure . 101
13.3.1 General . 101
13.3.2 Axial tension and bending . 101
13.3.3 Axial compression and bending . 102
13.3.4 Axial tension or compression, bending, shear and torsion . 103
13.3.5 Piles . 105
13.4 Tubular members subjected to combined forces with hydrostatic pressure . 105
13.4.1 General . 105
13.4.2 Axial tension, bending and hydrostatic pressure . 106
13.4.3 Axial compression, bending and hydrostatic pressure . 107
13.4.4 Axial tension or compression, bending, hydrostatic pressure, shear
and torsion . 108
13.5 Effective lengths and moment reduction factors . 108
13.6 Conical transitions . 110
13.6.1 General . 110
13.6.2 Design stresses . 110
13.6.3 Strength requirements without external hydrostatic pressure. 113
13.6.4 Strength requirements with external hydrostatic pressure . 118
13.6.5 Ring design . 118
13.7 Dented tubular members . 121
13.7.1 General . 121
13.7.2 Dented tubular members subjected to tension, compression, bending
or shear . 121
13.7.3 Dented tubular members subjected to combined forces . 126
13.8 Corroded tubular members . 129
13.9 Grouted tubular members . 129
13.9.1 General . 129
13.9.2 Grouted tubular members subjected to tension, compression or
bending . 129
13.9.3 Grouted tubular members subjected to combined forces . 133
14 Strength of tubular joints . 134
14.1 General . 134
14.2 Design considerations . 135
14.2.1 Materials . 135
14.2.2 Design forces and joint flexibility . 136
14.2.3 Minimum joint strength . 136
14.2.4 Weld strength . 136
14.2.5 Joint classification . 136
14.2.6 Detailing practice . 139
ISO 19902:2020(E)
14.3 Simple tubular joints . 142
14.3.1 General . 142
14.3.2 Basic joint strength . 143
14.3.3 Strength factor, Q . 144
u
14.3.4 Chord force factor, Q . 145
f
14.3.5 Effect of chord can length on joint strength . 146
14.3.6 Strength check . 147
14.4 Overlapping joints . 148
14.5 Grouted joints . 148
14.6 Ring stiffened joints . 149
14.7 Other joint types . 149
14.8 Damaged joints . 149
14.9 Non-circular joints . 150
14.10 Cast joints . 150
15 Strength and fatigue resistance of other structural components . 150
15.1 Grouted connections . 150
15.1.1 General . 150
15.1.2 Detailing requirements . 152
15.1.3 Axial force . 152
15.1.4 Reaction force from horizontal shear force and bending moment in
piles . 152
15.1.5 Interface transfer stress . 153
15.1.6 Interface transfer strength .
...