The second-generation Eurocodes

What is happening

Renewing the Eurocodes is a long process: new editions of the individual parts appear gradually, and the national annexes follow them. Meanwhile the earlier and the new editions are both in use.

The part for thin-walled steel, EN 1993-1-3, has been renewed too — design software generally supports both editions as a setting.

Why it matters on a project

The result can differ

The new editions bring methodological changes too. The same structure does not necessarily give the same result under the two editions.

The authority and the design checker will ask

At a review the first question is which edition of which standard the design was made to.

The national annex follows on its own schedule

Publication of the national annex belonging to a new edition can lag behind the standard. Until it exists, work continues under the earlier system.

What to do

Record it

At the start of the structural calculations: which parts of which standard, which edition, which national annex.

Do not mix within a project

A structure has to be carried through under one system. Partial transfer gives inconsistent results.

Check the software setting

If the program defaults to the new edition but the project started under the old one, that difference has to be noticed.

Allow for the change on a long project

On an investment running for several years the regulation may change midway. That does not mean the existing design has to be reworked — but the question has to be settled.

What does not change

The principles: the system of limit states, the logic of partial factors, the central role of stability in thin-walled structures. Understand those and a change of edition is a matter of settings, not of relearning.

The point

The standard is a moving target. On a project it is not enough to work “to the Eurocodes” — write down which edition.