National foreword

This British Standard is the UK implementation of EN 1993‑1‑8:2024. It supersedes BS EN 1993‑1‑8:2005, which will be withdrawn on 30 March 2028.

The UK participation in its preparation was entrusted to Technical Committee CB/203, Design & execution of steel structures.

A list of organizations represented on this committee can be obtained on request to its committee manager.

National choice is allowed in this standard where explicitly stated within notes. The National Annex to this standard contains the national choices to be used for buildings and civil engineering works constructed in the UK.

The first generation of EN Eurocodes was published between 2002 and 2007, with conflicting British Standards withdrawn in 2010. This document forms part of the second generation of EN Eurocodes.

The second generation of EN Eurocodes is expected to be published between 2023 and 2026. These documents are being published as soon as they are available. This is being done to enable users to prepare for the transition from the first generation to second generation of EN Eurocodes.

UK adoptions of the first generation of EN Eurocodes will be withdrawn by BSI on 30 March 2028. Until that date, the first generation documents should be considered as the applicable standards for buildings and civil engineering works constructed in the UK unless otherwise specified by the relevant authority or in the specification for a particular project.

This standard is intended to be used with its National Annex and other referenced documents, including other second generation Eurocodes, as an interdependent suite of documents.

While the use of provisions in this standard in conjunction with first generation Eurocodes is not precluded, it should be undertaken with care and should only be done when users are satisfied that it will not result in a lower level of reliability than the minimum level set in the first generation Eurocodes and associated UK National Annexes.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This European Standard was approved by CEN on 1 January 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and United Kingdom.

European foreword

This document (EN 1993‑1‑8:2024) has been prepared by Technical Committee CEN/TC 250 “Structural Eurocodes”, the secretariat of which is held by BSI. CEN/TC 250 is responsible for all Structural Eurocodes and has been assigned responsibility for structural and geotechnical design matters by CEN.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2027 and conflicting national standards shall be withdrawn at the latest by March 2028.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN 1993‑1‑8:2005 and its amendments and corrigenda.

The first generation of EN Eurocodes was published between 2002 and 2007. This document forms part of the second generation of the Eurocodes, which have been prepared under Mandate M/515 issued to CEN by the European Commission and the European Free Trade Association.

The Eurocodes have been drafted to be used in conjunction with relevant execution, material, product and test standards, and to identify requirements for execution, materials, products and testing that are relied upon by the Eurocodes.

The Eurocodes recognize the responsibility of each Member State and have safeguarded their right to determine values related to regulatory safety matters at national level through the use of National Annexes.

The main changes compared to the previous edition are listed below:

the Scope was extended to steel grades up to S700;
the Scope was extended to the design of nominally pinned connections;
new provisions for the design and fabrication of connections with bolts in threaded holes;
new provisions for the design of butt welds in steel grades higher than S460;
new provisions for the design of column bases with fasteners between steel and concrete;
revision of the Table of contents, with four Normative Annexes (A-D) summarizing (A) the structural properties of basic components; (B) provisions for the design of moment-resisting beam-to-column joints and splices; (C) provisions for the design of nominally pinned connections (new); and (D) provisions for the design of column bases;
a non-linear model to calculate the deformation of the bolt hole due to bearing of fasteners against the plate was introduced, including a revised formulation for the design value of bearing resistance;
revision of the requirements for the design of a group of fasteners in bearing-type connections;
an alternative method for the verification of the design resistance of welds explicitly accounting for the filler material properties was introduced;
revision of the requirements for the design of pins;
revision of the requirements for the evaluation of the design resistance and stiffness coefficients of the component “column web panel in shear”;
revision and clarification of the design tables for hollow section joints.

Any feedback and questions on this document should be directed to the users’ national standards body. A complete listing of these bodies can be found on the CEN website.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United Kingdom.

0 Introduction

0.1 Introduction to the Eurocodes

The Structural Eurocodes comprise the following standards generally consisting of a number of Parts:

EN 1990, Eurocode: Basis of structural and geotechnical design
EN 1991, Eurocode 1: Actions on structures
EN 1992, Eurocode 2: Design of concrete structures
EN 1993, Eurocode 3: Design of steel structures
EN 1994, Eurocode 4: Design of composite steel and concrete structures
EN 1995, Eurocode 5: Design of timber structures
EN 1996, Eurocode 6: Design of masonry structures
EN 1997, Eurocode 7: Geotechnical design
EN 1998, Eurocode 8: Design of structures for earthquake resistance
EN 1999, Eurocode 9: Design of aluminium structures
New parts are under development, e.g. Eurocode for design of structural glass.

0.2 Introduction to EN 1993

EN 1993 (all parts) applies to the design of buildings and civil engineering works in steel. It complies with the principles and requirements for the safety and serviceability of structures, the basis of their design and verification that are given in EN 1990 — Basis of structural and geotechnical design.

EN 1993 (all parts) is concerned only with requirements for resistance, serviceability, durability and fire resistance of steel structures. Other requirements, e.g. concerning thermal or sound insulation, are not covered.

EN 1993 is subdivided in various parts:

EN 1993‑1, Design of Steel Structures — Part 1: General rules and rules for buildings;

EN 1993‑2, Design of Steel Structures — Part 2: Bridges;

EN 1993‑3, Design of Steel Structures — Part 3: Towers, masts and chimneys;

EN 1993‑4, Design of Steel Structures — Part 4: Silos and tanks;

EN 1993‑5, Design of Steel Structures — Part 5: Piling;

EN 1993‑6, Design of Steel Structures — Part 6: Crane supporting structures;

EN 1993‑7, Design of Steel Structures — Part 7: Sandwich panels.

EN 1993‑1 in itself does not exist as a physical document, but comprises the following 14 separate parts, the basic part being EN 1993‑1‑1:

EN 1993‑1‑1, Design of Steel Structures — Part 1-1: General rules and rules for buildings;

EN 1993‑1‑2, Design of Steel Structures — Part 1-2: Structural fire design;

EN 1993‑1‑3, Design of Steel Structures — Part 1-3: Cold-formed members and sheeting;

NOTE Cold-formed welded hollow sections supplied according to EN 10219 (all parts) are covered in EN 1993‑1‑1.

EN 1993‑1‑4, Design of Steel Structures — Part 1-4: Stainless steel structures;

EN 1993‑1‑5, Design of Steel Structures — Part 1-5: Plated structural elements;

EN 1993‑1‑6, Design of Steel Structures — Part 1-6: Strength and stability of shell structures;

EN 1993‑1‑7, Design of Steel Structures — Part 1-7: Plate assemblies with elements under transverse loads;

EN 1993‑1‑8, Design of Steel Structures — Part 1-8: Joints;

EN 1993‑1‑9, Design of Steel Structures — Part 1-9: Fatigue;

EN 1993‑1‑10, Design of Steel Structures — Part 1-10: Material toughness and through-thickness properties;

EN 1993‑1‑11, Design of Steel Structures — Part 1-11: Tension components;

EN 1993‑1‑12, Design of Steel Structures — Part 1-12: Additional rules for steel grades up to S960;

EN 1993‑1‑13, Design of Steel Structures — Part 1-13: Beams with large web openings;

EN 1993‑1‑14, Design of Steel Structures — Part 1-14: Design assisted by finite element analysis.

All parts numbered EN 1993‑1‑2 to EN 1993‑1‑14 treat general topics that are independent from the structural type like structural fire design, cold-formed members and sheeting, stainless steel structures, plated structural elements, etc.

All parts numbered EN 1993‑2 to EN 1993‑7 treat topics relevant for a specific structural type like steel bridges, towers, masts and chimneys, silos and tanks, piling, crane supporting structures, etc. EN 1993‑2 to EN 1993‑7 refer to the generic rules in EN 1993‑1 and supplement, modify or supersede them.

0.3 Introduction to EN 1993‑1‑8

EN 1993‑1‑8 gives rules for the design of joints in steel structures. It includes rules for resistance, stiffness, and deformation capacity of components and recommendations for the properties to be used in analyses. It assumes that the execution of its provisions follows the requirements given in EN 1090‑2.

0.4 Verbal forms used in the Eurocodes

The verb “shall” expresses a requirement strictly to be followed and from which no deviation is permitted in order to comply with the Eurocodes.

The verb “should” expresses a highly recommended choice or course of action. Subject to national regulation and/or any relevant contractual provisions, alternative approaches could be used/adopted where technically justified.

The verb “may” expresses a course of action permissible within the limits of the Eurocodes.

The verb “can” expresses possibility and capability; it is used for statements of fact and clarification of concepts.

0.5 National Annex for EN 1993‑1‑8

National choice is allowed in this document where explicitly stated within notes. National choice includes the selection of values for Nationally Determined Parameters (NDPs).

The national standard implementing EN 1993‑1‑8 can have a National Annex containing all national choices to be used for the design of buildings and civil engineering works to be constructed in the relevant country.

When no national choice is given, the default choice given in this document is to be used.

When no national choice is made and no default is given in this document, the choice can be specified by a relevant authority or, where not specified, agreed for a specific project by appropriate parties.

National choice is allowed in EN 1993‑1‑8 through notes to the following clauses:

The National Annex can contain, directly or by reference, non-contradictory complementary information for ease of implementation, provided it does not alter any provisions of the Eurocodes.

1 Scope

1.1 Scope of EN 1993‑1‑8

EN 1993‑1‑8 provides rules for structural design of joints subject to predominantly static loading using all steel grades from S235 up to and including S700, unless otherwise stated in individual clauses.
NOTE As an alternative to the design rules provided in Clause 9, the design rules given in CEN/TS 1993‑1‑8011 “Eurocode 3: Design of steel structures — Part 1-801: Hollow section joints design according to the component method” can be used.
The provisions in this document apply to steels complying with the requirements given in EN 1993‑1‑1 and to material thickness greater than or equal to 3 mm, unless otherwise stated in individual clauses.

1.2 Assumptions

Unless specifically stated, EN 1990, EN 1991 (all parts) and the other relevant parts of EN 1993‑1 (all parts) apply.
The design methods given in EN 1993‑1‑8 are applicable if:
- the execution quality is as specified in EN 1090‑2,
  and
- the construction materials and products used are as specified in the relevant parts of EN 1993 (all parts), or in the relevant material and product specifications.

2 Normative references

3 Terms, definitions and symbols

3.1 Terms and definitions

3.2 Symbols and abbreviations

4 Basis of design

4.1 General rules

4.2 Design assumptions

4.3 Structural properties of joints

4.4 Hybrid connections

4.5 Joints loaded in shear subject to impact, vibration and/or load reversal

4.6 Eccentricity at intersections

5 Connections using bolts, rivets or pins

5.1 Bolts, nuts and washers

5.2 Rivets

5.3 Anchor bolts and fasteners between steel and concrete

5.4 Bolted connections

5.5 Pin connections

5.6 Riveted connections

5.7 Design criteria

5.8 Positioning of holes for bolts and rivets

5.9 Design resistance of individual fasteners subject to shear, bearing and/or tension

5.10 Design slip resistance of individual preloaded bolts

5.11 Design resistance of a group of fasteners loaded in bearing type connections subject to axial force

5.12 Design resistance of a group of fasteners in slip-resistant connections subject to axial force

5.13 Design resistance of Category A, B, and C connections subject to bending and axial force

5.14 Design block tearing resistance

5.15 Design resistance of angles connected by one leg and other asymmetrically connected members in tension

6 Welded connections

6.1 General

6.2 Welding consumables

6.3 Geometry and dimensions

6.4 Welds with packings

6.5 Design resistance of fillet welds

6.6 Design resistance of fillet welds all round

6.7 Design resistance of butt welds

6.8 Design resistance of plug welds

6.9 Distribution of forces

6.10 Connections to unstiffened flanges

6.11 Design resistance of long joints

6.12 Eccentrically loaded single-sided fillet or single-sided partial penetration butt welds

6.13 Angles connected by one leg

6.14 Welding in cold-formed zones

7 Structural analysis

7.1 Global analysis

7.2 Modelling of beam-to-column joints

7.3 Classification of joints

8 Structural joints connecting H or I sections

8.1 General

8.2 Structural properties

8.3 Equivalent T-stub in tension

8.4 Equivalent T-stub in compression

9 Hollow section joints

9.1 General

9.2 Parameters for hollow section joints

9.3 Specific requirements

9.4 Design

9.5 Design resistance of welds

9.6 Welded joints between brace members and CHS chords

9.7 Welded joints between plates, CHS or RHS brace members, and RHS chord members

9.8 Welded joints between CHS or RHS brace members, and I or H section chords

9.9 Welded overlap joints between CHS or RHS brace members, and CHS, RHS, I, H or channel section chord members

Bibliography

BS EN 1993-1-8:2024

Eurocode 3. Design of steel structures - Joints

Current

Published:

31 Mar 2024