Eurocode Head Code

[MIStructE_IRE]

Hi,

I have a very good FE package that designs to Eurocode head code or using several different National Annexes…except now for the country I’ve landed a project in!

In reality I know there’s not enough difference between the annex values to make or break anything. But to be compliant, as I’m expecting a checker to pick me up on this, is it ever appropriate to design to the head code, and not apply the country’s national annex?

Really I’m looking to avoid shelling out another €10k on new software and having to learn how to use it!

 

[kingnero]

You'll see in the beginning of each main standard that is not to be used without the appropriate national annex (NA)...
For a very good reason, you'll find most of the loads/factors/... in the national annexes.

That said, you'll design in Mauritsius (Africa) using the french NA, as it's (or used to be) a french colony.
Obviously, Mainland Europe has very different conditions than an island almost in the middle of the indian ocean.
I'd choose the NA of the neighbouring country (preferably with the worst conditions regarding snow/wind/seismic) and call it a day.
After of course, checking with the FE software if they don't offer the NA values of the country you're looking for, for a (small) fee?

 

[ThomasH]

But to be compliant, as I’m expecting a checker to pick me up on this, is it ever appropriate to design to the head code, and not apply the country’s national annex?

Since you ask in a general context I will answer in the same way. The answer in my opinion is "No". There are information in the National Annexes that are necessary in order for us to meet the specific requirements in different countries. The obvious is of course snow load, wind load etcetera. Less obvious is perhaps that sometimes an Appendix should be used or may not be used in a country for some reason.

As I understand your question, the problem is a software and not the Eurocodes national annex. Is there anything in the National Annex for a country that stops the use of the software in that country. Can't you simply override that parameter or whatever it is?

 

[Janni]

I understand you'd like to see a positive response without the need for an NDA, but unfortunately, that would be an incorrect answer. For instance, BS EN 1990 (in UK) specifies in the Forward that 'to enable EN1990 to be used in the UK, the NDPs will be published in a National Annex'. Hence, it is not possible to use it without the UK NA. A similar requirement would likely be applicable in the country where your design landed. kingnero rightly suggested exploring nearby countries, and ThomasH suggested to check into software parameters and making necessary changes. All software allow for such adjustments, and it is considered good practice to get familiar with the software inputs.

 

[GeorgeTheCivilEngineer]

I would take a less onerous position - in the UK standards are not legal requirements and there isn't anything inherently unsafe about the recommended values in the eurocodes.

You may have an issue with your contract if you're obligated to use a certain standard. Also it may be that German law gives standards a higher legal standing.

 

[ThomasH]

@MIStructE_IRE

Without more info I don't see how anyone can give you more that a general response.

I would not be very worried about the utilization in specific members of a structure, you can limit that. But before you decide that NA for X with a certain limit in utilization is safe compared to NA for Y, you need to know what the difference is. If your usual approach is to select the appropriate NA and leave the details to the software, I would not recommend that now.

My comment now is for the design methods. Loads, like snow loads, have to be correct and load combinations have to be valid.

Just out of curiosity, if you feel like sharing, what country is it and what software are you using? Perhaps somebody has local knowledge.