Foreword

Introduction

1Scope

2Normative references

3Terms and definitions

4Symbols

5Effects of icing

5.1General

5.2Static ice loads

5.3Wind action on iced structures

5.4Dynamic effects

5.5Damage caused by falling ice

6Fundamentals of atmospheric icing

6.1General

6.2Icing types

6.2.1General

6.2.2Glaze

6.2.3Wet snow

6.2.4Rime

6.2.5Other types of ice

6.3Topographic influences

6.4Variation with height above terrain

7Icing on structures

7.1General

7.2Ice classes

7.3Definition of ice class, IC

7.4Glaze

7.4.1General

7.4.2Glaze on lattice structures

7.5Rime

7.5.1General

7.5.2Rime on single members

7.5.2.1General

7.5.2.2Slender structural members with object width u 300 mm

7.5.2.3Single members with object width (W) > 300 mm

7.6Rime on lattice structures

7.6.1General

7.6.2Direction of ice vanes on the structure

7.6.3Icing on members inclined to the wind direction

8Wind actions on iced structures

8.1General

8.2Single members

8.2.1General

8.2.2Drag coefficients for glaze

8.2.3Drag coefficients for rime

8.3Angle of incidence

8.4Lattice structures

9Combination of ice loads and wind actions

9.1General

9.2Combined loads

10Unbalanced ice load on guys

11Falling ice considerations

Annex AFormulae used in this document (informative)

A.1Formulae connected to figures

A.2Formulae connected to tables

Annex BStandard measurements for ice actions (informative)

B.1General

B.2General considerations

B.3Recommended measurements

B.3.1Standard reference measurements

B.3.2Other observations

B.3.3Output of measurements

B.3.4Additional meteorological measurements

B.4Measurements on other objects

B.5Responsibility

Annex CTheoretical modelling of icing (informative)

C.1Fundamentals

C.2Rate of icing

C.2.1General

C.2.2Collision efficiency

C.2.3Sticking efficiency

C.2.4Accretion efficiency

C.3Numerical modelling

C.4Discussion

Annex DClimatic estimation of ice classes based on weather data (informative)

D.1General

D.2Data

D.3Methods

D.3.1Freezing precipitation

D.3.2In-cloud icing

D.3.3Wet snow

D.4Application

Annex EHints on using this document (informative)

E.1General

E.2Find ice class(es) for the building site

E.3Find ice accretion on types of profiles in question

E.3.1Structures built of single members (e.g. lattice structures)

E.3.2Non-lattice structures or large profile dimensions

E.4Find drag coefficients for iced members in question

E.5Adjustment of drag coefficients for angle of incidence

E.6Calculation of wind action on the iced structure

E.7Calculation of ice load of the iced structure

E.8Combination of wind action and ice load

Bibliography