Normalized axial load ratio for Columns in EC8

[patkson]

Hi all,

I think I would commend RSA team for improving on the column design by including the computation of the normalized axial laod which is 

to me a very important factor under seismic loading.

However I have a little bit of misunderstanding that I would like to seek some clarification. In computing this, robot uses material factor of 1.2 for concrete thus fcd =fck/1.2

However  EC8 5.4.2 (2p) " seem to indicate otherwise. Infact this justifiation seem to suggest a factor of 1.5 for transient and persistent be adopted for ULS verifaction which makes the fcd=fck/1.5.

I will like to seek some insight on that.

Thank you all.

Regards

POk.

[Artur.Kosakowski · Accepted solution]

Robot follows the general rules of the code which defines yc as 1.2 for accidental ULS (Robot classifies seismic action as accidental) but you can change this factor manually in the way shown on the attached picture.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[TienDat.NGUYEN.Engineer]

As I understand,we limit the normalized axial force in column (0.65 in DCM and 0.55 in DCH) or wall (0.4 in DCM and 0.3 in DCH) to avoid the "brittle failure" and the choosen section is reasonable in thsi range.

Is there any other different meaning for normalized axial force ? Why do we need to limit it ?