DA1 and DA2 - ULS and SLS

[ac4u2nv]

Hi
in Geo 5 you have DA1 and DA2 - is this the same as Ultimate limit state and Servicibility Limit State respectively?

or are these two completely different things.
I.e. im looking at sheet pile design - how do i know or decide when the SLS has been reached or the ULS has been reached - the deflection might show 25mm and the settlement behind the sheet pile might be 40mm? - how do i know/decide is this beyond repair (ULS exceeded) or within repair (SLS not exceeded).
I do find that my sheet pile design passes in DA1 and fails in DA2 - or is that coincidental?

Thanks

 

[Settingsun]

DA = design approach. You use the one that your country's version of Eurocode adopted. I think it's DA1 for Britain. DA1 has two cases and both must be satisfied. They are both ULS cases.

SLS will be as defined in the Eurocode (which I'm not greatly familiar with). It's usually just an analysis with best estimate or slightly conservative parameters. No load or resistance factors applied.

If DA1 passes but DA2 fails, your design is adequate in a DA1 country but inadequate in a DA2 country. Presumably quite a lean design.

 

[EireChch]

EC7 is used all across Europe. It’s the same standard, National Annexes are what is used to refine EC7 for each country. NAs typically include different material factors, partial factors etc.

In the UK it’s Design Approach 1 - Combination 1 (DA1-C1) or DA1-C2.

SLS just assumes partial factors equal to 1