prEN ISO 19901-2

Oil and gas industries including lower carbon energy - Specific requirements for offshore structures - Part 2: Seismic design procedures and criteria (ISO/DIS 19901-2:2024)

This document contains requirements for defining the seismic design procedures and criteria for offshore structures; guidance on the requirements is included in Annex A. The requirements focus on fixed steel offshore structures and fixed concrete offshore structures. The effects of seismic events on floating structures and partially buoyant structures are briefly discussed. The site-specific assessment of jack-ups in elevated condition is only covered in this document to the extent that the requirements are applicable.
Only earthquake-induced ground motions are addressed in detail. Other geologically induced hazards such as liquefaction, slope instability, faults, tsunamis, mud volcanoes and shock waves are mentioned and briefly discussed.
The requirements are intended to reduce risks to persons, the environment, and assets to the lowest levels that are reasonably practicable. This intent is achieved by using:
a) seismic design procedures which are dependent on the exposure level of the offshore structure and the expected intensity of seismic events;
b) a two-level seismic design check in which the structure is designed to the ultimate limit state (ULS) for strength and stiffness and then checked to abnormal environmental events or the abnormal limit state (ALS) to ensure that it meets reserve strength and energy dissipation requirements.
Procedures and requirements for a site-specific probabilistic seismic hazard analysis (PSHA) are addressed for offshore structures in high seismic areas and/or with high exposure levels. However, a thorough explanation of PSHA procedures is not included.
Where a simplified design approach is allowed, worldwide offshore maps, which are included in Annex B, show the intensity of ground shaking corresponding to a return period of 1 000 years. In such cases, these maps can be used with corresponding scale factors to determine appropriate seismic actions for the design of a structure, unless more detailed information is available from local code or site-specific study.
NOTE      For design of fixed steel offshore structures, further specific requirements and recommended values of design parameters (e.g. partial action and resistance factors) are included in ISO 19902, while those for fixed concrete offshore structures are contained in ISO 19903. Seismic requirements for floating structures are contained in ISO 19904, for site-specific assessment of jack-ups and other MOUs in the ISO 19905 series, for arctic structures in ISO 19906 and for topsides structures in ISO 19901‑3.

Erdöl- und Erdgasindustrie - Spezielle Anforderungen für Offshore-Anlagen - Teil 2: Seismische Auslegungsverfahren und -kriterien (ISO/DIS 19901-2:2024)

Industries du pétrole et du gaz, y compris les énergies à faible teneur en carbone - Exigences spécifiques relatives aux structures en mer - Partie 2: Procédures de conception et critères sismiques (ISO/DIS 19901-2:2024)

Le présent document spécifie les exigences relatives à la définition des procédures et critères de conception parasismique pour les structures en mer; les recommandations concernant les exigences sont indiquées dans l'Annexe A. Les exigences portent sur les structures en mer fixes en acier et en béton. Les effets des événements sismiques sur les structures flottantes et partiellement flottantes sont brièvement décrits. L'évaluation, spécifique au site, des plates-formes auto-élévatrices en situation surélevée est uniquement traitée dans le présent document dans la mesure où les exigences sont applicables.
Seuls les mouvements du sol induits par des séismes sont traités en détail. D'autres risques géologiques tels que la liquéfaction, l'instabilité des pentes, les failles, les tsunamis, les volcans de boue et les ondes de choc sont également mentionnés et brièvement décrits.
Les exigences sont destinées à réduire les risques encourus par les personnes, l'environnement et les installations au niveau le plus bas qui soit raisonnablement réalisable. Ce résultat est obtenu à l'aide:
a) de procédures de conception parasismique qui dépendent du niveau d'exposition de la structure en mer et de l'intensité prévue des événements sismiques;
b) d'un contrôle de conception parasismique à deux niveaux, dans lequel la structure est conçue selon l'état limite ultime (ULS) en matière de résistance et de rigidité avant d'être vérifiée par rapport à des événements environnementaux anormaux ou à l'état limite anormal (ALS), afin de garantir qu'elle satisfait aux exigences de réserve de résistance et de dissipation d'énergie.
Les procédures et exigences s'appliquant à la réalisation d'une analyse probabiliste de l'aléa sismique (PSHA), spécifique au site, sont exposées pour les structures en mer installées dans des zones à forte activité sismique et/ou fortement exposées. Cependant, les procédures de l'étude PSHA ne sont pas expliquées de manière approfondie.
Lorsqu'une approche de conception simplifiée est admise, des cartes des eaux mondiales, incluses dans l'Annexe B, indiquent l'intensité des secousses du sol pour une période de retour de 1 000 ans. Dans de tels cas, ces cartes peuvent être utilisées avec les facteurs d'échelle correspondants pour déterminer les actions sismiques appropriées pour la conception d'une structure, sauf si des informations plus détaillées sont fournies par un code local ou une étude spécifique au site.
NOTE      Pour la conception des structures en mer fixes en acier, d'autres exigences spécifiques et des valeurs recommandées des paramètres de conception (par exemple: coefficients d'action et de résistance partiels) sont indiquées dans l'ISO 19902, tandis que celles relatives aux structures en mer fixes en béton sont énoncées dans l'ISO 19903. L'ISO 19904 intègre des exigences parasismiques relatives aux structures flottantes, la série ISO 19905 des exigences relatives à l'évaluation spécifique au site de plates-formes auto-élévatrices et autres MOU, l'ISO 19906 des exigences relatives aux structures arctiques et l'ISO 19901‑3 des exigences relatives aux superstructures.

Naftna in plinska industrija, vključno z nizkoogljično energijo - Posebne zahteve za naftne ploščadi - 2. del: Postopki potresno varnega projektiranja in potresna merila (ISO/DIS 19901-2:2024)

General Information

• Status: Not Published
• Publication Date: 07-Jun-2026
• ICS: 75.180.10 - Exploratory, drilling and extraction equipment
• Technical Committee: CEN/TC 12 - Materials, equipment and offshore structures for petroleum and natural gas industries
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 14-Nov-2024
• Due Date: 14-Nov-2024
• Completion Date: 14-Nov-2024
• Ref Project: oSIST prEN ISO 19901-2:2025 - Oil and gas industries including lower carbon energy - Specific requirements for offshore structures - Part 2: Seismic design procedures and criteria (ISO/DIS 19901-2:2024)

Relations

• Revises: EN ISO 19901-2:2022 - Petroleum and natural gas industries - Specific requirements for offshore structures - Part 2: Seismic design procedures and criteria (ISO 19901-2:2022)
• Effective Date: 05-Apr-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2025
Naftna in plinska industrija, vključno z nizkoogljično energijo - Posebne zahteve za
naftne ploščadi - 2. del: Postopki potresno varnega projektiranja in potresna
merila (ISO/DIS 19901-2:2024)
Oil and gas industries including lower carbon energy - Specific requirements for offshore
structures - Part 2: Seismic design procedures and criteria (ISO/DIS 19901-2:2024)
Erdöl- und Erdgasindustrie - Spezielle Anforderungen für Offshore-Anlagen - Teil 2:
Seismische Auslegungsverfahren und -kriterien (ISO/DIS 19901-2:2024)
Industries du pétrole et du gaz, y compris les énergies à faible teneur en carbone -
Exigences spécifiques relatives aux structures en mer - Partie 2: Procédures de
conception et critères sismiques (ISO/DIS 19901-2:2024)
Ta slovenski standard je istoveten z: prEN ISO 19901-2
ICS:
75.180.10 Oprema za raziskovanje, Exploratory, drilling and
vrtanje in odkopavanje extraction equipment
91.120.25 Zaščita pred potresi in Seismic and vibration
vibracijami protection
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
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ISO/DIS 19901-2
ISO/TC 67/SC 7
Oil and gas industries including
Secretariat: BSI
lower carbon energy — Specific
Voting begins on:
requirements for offshore
2024-11-11
structures —
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Part 2:
Seismic design procedures and
criteria
ICS: 75.180.10
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Reference number
ISO/DIS 19901-2:2024(en)
DRAFT
ISO/DIS 19901-2:2024(en)
International
Standard
ISO/DIS 19901-2
ISO/TC 67/SC 7
Oil and gas industries including
Secretariat: BSI
lower carbon energy — Specific
Voting begins on:
requirements for offshore
structures —
Voting terminates on:
Part 2:
Seismic design procedures and
criteria
ICS: 75.180.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2024
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland Reference number
ISO/DIS 19901-2:2024(en)
ii
ISO/DIS 19901-2:2024(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions (Pending) . 1
4 Symbols and abbreviated terms (Pending) . 4
4.1 Symbols .4
4.2 Abbreviated terms .5
5 Seismic hazards . 6
6 Performance objectives, limit states and damage states . 6
6.1 General .6
6.2 Limit states and damage states .9
6.3 Performance objectives .10
6.4 Seismic risk category .10
6.5 DL limit state verification (using hazardous events with intensity = S ) .
aE, LE
6.6 NC limit state verification (using hazardous events with intensity = S ) .
aA, LE
6.7 Design procedure . 12
6.8 Methods for limit state verification .14
6.8.1 General .14
6.8.2 Limit state verification methods.14
7 Analysis types for structural response .16
7.1 Response spectrum analysis .16
7.2 Time history analysis .16
7.3 Nonlinear pushover analysis.18
8 Simplified procedure for determining S and S .
aE, LE aA, LE
8.1 General .18
8.2 Spectral accelerations .18
8.3 Site class .18
8.4 Site correction factor coefficients .19
8.5 1 000-year horizontal acceleration spectrum .21
8.6 1 000-year vertical acceleration spectrum . 22
8.7 Damping adjustment . 23
8.8 Determining S and S .
aE, LE aA, LE
9 Detailed procedure for determining S and S .
aE, LE aA, LE
9.1 Probabilistic seismic hazard analysis (PSHA).24
9.2 Deterministic seismic hazard analysis (DSHA) . 26
9.3 Dynamic site response analysis (DSRA).27
9.4 Determining C .
c
9.5 Determining S and S .
aE, LE aA, LE
10 Floating structures .30
10.1 C is either not well-defined or unknown . 30
r
iii
ISO/DIS 19901-2:2024(en)
10.2 effects of shock waves . 30
10.3 ELE (ULS check). 30
Annex A (informative) Additional information and guidance .31
Annex B (informative) Simplified action procedure spectral accelerations .42
Annex C (normative) Regional information .95
Bibliography .100

iv
ISO/DIS 19901-2:2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
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with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (
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