ISO 2394-2015 PDF

Full title and description

ISO 2394:2015 — General principles on reliability for structures. This International Standard provides the foundational risk- and reliability-informed principles to support decision making for design, assessment and code development for structures, covering probabilistic, semi‑probabilistic and risk‑based approaches to structural reliability.

Abstract

ISO 2394:2015 constitutes a risk‑ and reliability‑informed foundation for decision making concerning design and assessment of structures both for the purpose of code making and in the context of specific projects. It sets out concepts, definitions, methods (probabilistic, semi‑probabilistic and risk‑informed), levels of verification and guidance for implementation, calibration and lifetime management.

General information

• Status: Published (current; confirmed at systematic review in 2020).
• Publication date: 4 March 2015.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 91.080.01 (Structures of buildings in general).
• Edition / version: Edition 4 (2015).
• Number of pages: 111.

Key bibliographic and lifecycle details above are taken from the ISO record for ISO 2394:2015.

Scope

ISO 2394:2015 provides general principles for achieving and assessing the reliability of structures. It is intended to guide code writers and practitioners in: (a) defining target reliabilities and acceptable failure probabilities for different limit states and consequence levels; (b) selecting and applying probabilistic, semi‑probabilistic (partial‑factor) and risk‑informed verification methods; (c) accounting for model uncertainties, variability of actions and resistances, life‑time effects and inspection/maintenance strategies; and (d) supporting calibration of safety/partial‑factor formats for national or project‑specific codes.

Key topics and requirements

• Fundamental reliability concepts and definitions (failure probability, reliability index, target reliabilities, reference periods).
• Three verification levels: risk‑informed, reliability‑based (probabilistic) and semi‑probabilistic (partial‑factor/design‑value) approaches.
• Methods for calculation and estimation of failure probabilities (FORM/SORM, time‑variant to time‑invariant transformations, out‑crossing approaches).
• Guidance for representative and characteristic values, treatment of model and geometric uncertainties, and sensitivity factors.
• Calibration principles for partial safety factors and safety formats; implementation guidance for probability‑based and semi‑probabilistic design methods.
• Guidance on lifetime and quality management, design based on observation/measurements, and specific notes on geotechnical structures (informative annexes).

Typical use and users

Primary users are structural engineers, code and standards committees, researchers in structural reliability, national standardization bodies and regulators. The standard is used when establishing target reliability levels, calibrating partial factors for design codes, performing probabilistic assessments, and developing or harmonizing national building regulations and design guidance.

Related standards

Commonly associated documents and references include: EN 1990 (Eurocode — Basis of structural design) which shares related terminology and calibration approaches; the JCSS Probabilistic Model Code and supporting literature for probabilistic methods and target reliability guidance; and earlier/superseded editions of ISO 2394 (for example ISO 2394:1998). ISO 2394 is frequently referenced when calibrating code formats such as those in the Eurocodes.

Keywords

structural reliability, target reliability, reliability index, failure probability, probabilistic design, semi‑probabilistic, partial factors, model uncertainty, calibration, limit states, lifetime management, inspection, EN 1990, JCSS.

FAQ

Q: What is this standard?

A: ISO 2394:2015 sets out the general principles and methods for assessing and achieving reliable structural performance; it provides conceptual and methodological guidance for designers, code writers and assessors.

Q: What does it cover?

A: It covers reliability concepts and definitions, probabilistic and semi‑probabilistic verification methods, target reliability specification, calibration of partial factors and safety formats, handling of uncertainties (including model uncertainty), and guidance on lifecycle and quality management for structures.

Q: Who typically uses it?

A: Structural engineers, standards bodies, national code developers, researchers and practitioners involved in design verification, code calibration and structural assessment.

Q: Is it current or superseded?

A: ISO 2394:2015 (Edition 4) is the current version; it was published on 4 March 2015 and was reviewed and confirmed in 2020. It supersedes ISO 2394:1998.

Q: Is it part of a series?

A: ISO 2394 provides general principles that complement other ISO standards and documents in the “Bases for design of structures” family (for example ISO standards addressing assessment of existing structures, material characteristic values and related topics) and is used alongside regional code documents such as EN 1990 and guidance from JCSS.

Q: What are the key keywords?

A: Structural reliability, failure probability, reliability index (β), probabilistic methods, semi‑probabilistic methods, partial factors, model uncertainty, target reliability, limit states.