ISO 12494-2017 PDF

Full title and description

ISO 12494:2017 — Atmospheric icing of structures. International standard giving principles and practical guidance for assessing ice loads on a wide range of structures exposed to atmospheric icing (masts, towers, antennas, cables, ropeways, ski-lift structures, parts of buildings, wind turbine towers and similar).

Abstract

ISO 12494:2017 provides methods to estimate ice mass and the effects of atmospheric icing on structures. It describes types of icing (rime, glaze, wet snow), introduces the concept of ice classes for sites, gives guidance for estimating accreted ice shape and density, and explains how to combine ice loads with wind actions to produce design values. The standard is intended to be used alongside general structural reliability principles (for example ISO 2394) and is aimed at reducing the risk of structural failure due to unforeseen ice accretion.

General information

• Status: Published (Edition 2), confirmed as current at last review.
• Publication date: March 2017 (ISO edition 2, 2017).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 91.080.01 (General — structures of buildings and civil engineering).
• Edition / version: Edition 2 (2017).
• Number of pages: 58 pages (approximate, as published).

Scope

This standard covers general principles for determining ice loads on structures exposed to atmospheric icing. It is applicable to linear and spatial structures such as masts, towers, antennas and their supporting cables, ropeways and ski-lift structures, parts of buildings susceptible to icing, and tower structures for transmission lines and wind turbines. The document is intended to guide designers where dedicated local icing data may be limited; it does not replace sector-specific electrotechnical standards for overhead electrical conductors but may be used for the supporting structures.

Key topics and requirements

• Definitions and classification of icing types: rime, glaze, wet snow and mixed forms.
• Concept of site ice classes and guidance for selecting an appropriate ice class where measured data are limited.
• Methods to estimate ice mass per unit length/area and typical ice densities for different icing types.
• Guidance on ice shape and its influence on projected area and aerodynamic drag.
• Procedures to combine ice loads with wind loads (wind–ice interaction) for structural design.
• Recommendations for special structural elements (cables, stays, antennas, linear objects) and for partial-design of critical components.
• Notes on use with other standards (for example general structural reliability and wind-loading documents) and caveats about local meteorological assessment.

Typical use and users

Used by structural and civil engineers, wind turbine and tower designers, utility and telecommunications asset designers, ski-lift and ropeway engineers, transportation infrastructure planners in cold climates, meteorologists advising on site-class assignment, and standards committees. Typical applications include structural design checks, risk assessments for icing-prone sites, retrofitting/strengthening existing supports, and establishing maintenance/inspection priorities where icing can create operational or safety risks.

Related standards

ISO 2394 (general principles on reliability for structures) is recommended to be used in conjunction with ISO 12494. Sector-specific standards that cover electrical overhead lines and their ice-loading are produced by electrotechnical bodies (IEC) and national bodies; designers should consult relevant IEC and regional/national standards when working with power transmission lines or other electrically sensitive installations. Other related documents include national codes and wind-loading standards that govern combination rules and global structural design principles.

Keywords

atmospheric icing, ice load, ice accretion, rime, glaze, wet snow, ice class, wind–ice interaction, structural design, masts, towers, antennas, cables, ropeways, ski lifts, wind turbines.

FAQ

Q: What is this standard?

A: ISO 12494:2017 is an international standard giving guidance and methods for assessing atmospheric ice loads on structures and for combining those loads with wind actions in structural design.

Q: What does it cover?

A: It covers types of icing, site ice-class concepts, estimation of ice mass and shapes, ice densities for different icing types, and procedures to account for ice when evaluating structural loadings and safety. It is intended for many exposed structure types but does not replace sector-specific electrotechnical standards for conductors.

Q: Who typically uses it?

A: Structural and civil engineers, designers of towers, masts, antennas, cable-supported systems, ropeways and wind-turbine towers, asset owners/operators in cold climates, and meteorological advisers involved in siting and risk assessment.

Q: Is it current or superseded?

A: The 2017 edition (Edition 2) is the current published version of ISO 12494 (it replaced the 2001 edition). Users should verify the most recent status from the publisher before application and note periodic reviews that may confirm or update the standard.

Q: Is it part of a series?

A: ISO 12494 is a standalone international standard but is intended to be used alongside general structural-reliability and loading standards (for example ISO 2394) and with applicable sector-specific standards (for example electrotechnical standards for overhead lines).

Q: What are the key keywords?

A: Atmospheric icing, ice load, ice accretion, ice classes, rime, glaze, wet snow, wind–ice interaction, masts, towers, cable structures.