Countdown to Eurocode Implementation
Latest news on National Annexes
Significant progress has been made on the development of the National Annexes for Eurocodes 3 and 4. The National Annexes for the general part (Part 1.1), the fire part (Part 1.2) and the part on joint design (Part 1.8) are now complete and it is anticipated that they will be available in spring 2008. Similarly the general and fire parts of Eurocode 4 are also complete.
For UK designers, the Eurocode approach to brittle fracture was rather complicated, especially for building designers who are used to the simplicity of Tables 3 and 4 in BS 5950. This difficulty will be resolved with a Published Document (PD) from BSI, which will present simple look up tables that will be no more difficult than the current Standard. The draft of the PD has been prepared, and the limiting thicknesses are very similar to those in BS 5950.
The situation on the wind loading National Annex is rather different. A recent calibration exercise
has highlighted significant differences between
our national standard, BS 6399-2 and EC1 Part 1.4 for wind pressures on roof and wall cladding. A corrigenda top EC1 Part 1.4 will be issued later this year, which will allow the coefficients to be decided in the National Annex. A consequence of this is that the National Annex for EC1 Part 1.4 is likely to be still some time off.
Update on the design guides
SCI, Corus and the BCSA are developing a series of guides to help designers. In addition to the books of section properties and member resistances, there will be design guides on:
- Multi-storey braced frames
- Worked examples in open and hollow sections
- Fire design
- Concise Eurocodes for buildings
- Composite highway bridges
- Examples for students(without any National Annex values)
These guides should be available from spring 2008. Work has also started on simple connections to
the Eurocodes, and it is expected that work will
also start on a guide to composite construction, combined bending and torsion and an update of the Slimdek design guides.
Anything not covered in the Eurocodes, and yet useful for design, is classed as NCCI. This may range from technical articles in New Steel Construc- tion, publications, PDs, information on websites etc. NCCI is referenced in the National Annex. In the steel world, the National Annexes will reference a single website, http://www.steel-ncci.co.uk where links to all NCCI can be found easily. This site should be fully operational by the end of February.
For designers keen to prepare their own spread- sheets or other software, nothing beats some definitive examples. Model examples, flow charts and guidance for application of the Eurocode rules (NCCI) are already freely available on the access- steel website.