ISO 19901-2-2022 PDF

Full title and description

Petroleum and natural gas industries — Specific requirements for offshore structures — Part 2: Seismic design procedures and criteria. This International Standard specifies seismic design procedures and criteria for offshore structures, with guidance in Annex A and seismic-intensity maps in Annex B; it focuses on fixed steel and fixed concrete offshore structures and addresses earthquake-induced ground motions and related geologically induced hazards.

Abstract

This document contains requirements for defining seismic design procedures and criteria for offshore structures, including a two-level seismic design approach (ultimate limit state and abnormal limit state), guidance for site-specific probabilistic seismic hazard analysis (PSHA) in high-seismic areas, simplified seismic-action procedures using worldwide offshore maps, and brief discussion of effects on floating and partially buoyant units. Guidance material is provided in annexes.

General information

• Status: Published.
• Publication date: 22 June 2022.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 75.180.10 (Exploratory, drilling and extraction equipment).
• Edition / version: Edition 3 (ISO 19901-2:2022).
• Number of pages: 55 pages.

Scope

Specifies seismic-design requirements and procedures for offshore structures used in the petroleum and natural gas industries. The standard addresses earthquake-induced ground motions in detail, mentions related hazards (liquefaction, slope instability, faults, tsunamis, mud volcanoes, shock waves), covers site-specific assessment considerations (including limited jack-up elevated-condition guidance), and provides both detailed and simplified (map-based) procedures for determining seismic actions appropriate to exposure level and regional seismicity.

Key topics and requirements

• Two-level seismic design approach: design to Ultimate Limit State (ULS) for strength/stiffness and check to Abnormal Limit State (ALS) for reserve strength and energy dissipation.
• Procedures and requirements for site-specific Probabilistic Seismic Hazard Analysis (PSHA) where needed.
• Simplified seismic-action procedure using worldwide offshore ground-shaking maps (return period ~1 000 years) and scale factors (Annex B).
• Guidance on seismic risk categories, spectral acceleration data, and soil/site investigation needs for offshore contexts.
• Focus on fixed steel and fixed concrete offshore structures; brief treatment of floating and partially buoyant structures and limited jack-up assessment guidance.
• Normative and informative annexes providing explanatory guidance and mapping data.

Typical use and users

Used by offshore structural and geotechnical engineers, seismic/hazard specialists, design offices for fixed-platform projects, operators and owners of offshore assets, classification societies, regulatory authorities, and consultants preparing site-specific seismic assessments and design reports for oil, gas and related offshore facilities.

Related standards

Part of the ISO 19900/19901 series and closely linked to other parts and standards for offshore structures, including ISO 19900 (general requirements), ISO 19901 series parts (e.g., Part 1 metocean, Part 3 topsides, Part 4 geotechnical/foundations, Part 6 marine operations, etc.), and the companion structural support standards ISO 19902 (fixed steel), ISO 19903 (fixed concrete), ISO 19904 (floating structures) and ISO 19905/19906 for jack-ups and arctic structures. For a complete listing of related parts see the ISO 19901 series documentation.

Keywords

seismic design, offshore structures, PSHA, abnormal limit state, ultimate limit state, seismic maps, fixed steel platform, fixed concrete platform, offshore hazard, ISO 19901-2:2022

FAQ

Q: What is this standard?

A: ISO 19901-2:2022 is the Part 2 International Standard in the ISO 19901 series that defines seismic design procedures and criteria for offshore structures in the petroleum and natural gas industries.

Q: What does it cover?

A: It covers seismic-design principles and methodology for offshore structures (primarily fixed steel and concrete), including seismic actions, spectral acceleration data, seismic risk categories, site investigation, PSHA guidance for high-seismic areas, a two-level ULS/ALS design check, and simplified map-based procedures (Annex B).

Q: Who typically uses it?

A: Offshore structural and geotechnical engineers, seismic specialists, asset owners/operators, classification societies, regulatory bodies and consultants working on the design, assessment and verification of offshore platforms and related structures.

Q: Is it current or superseded?

A: ISO 19901-2:2022 is the current published edition (published 22 June 2022), replacing earlier editions (2017, 2004). It is subject to periodic review under ISO procedures.

Q: Is it part of a series?

A: Yes. It is part of the ISO 19900 family (general requirements for offshore structures) and the ISO 19901 series of specific requirements for offshore structures; it is intended to be used together with other ISO 1990x parts and with ISO 19902/19903/19904 as applicable to particular support-structure types.

Q: What are the key keywords?

A: Seismic design, offshore structures, PSHA, ULS, ALS, spectral acceleration, seismic maps, fixed platform, ISO 19901-2.