Normalized Axial force by EC8

[giga]

Hi
My question have to concern with normalized axial force by EC into columns

Under thew desired ductility conditions EC require this conditions


ni=Ned/(Ac*fcd) <= 0.55 for DCH ... 1
ni=Ned/(Ac*fcd) <= 0.65 for DCM ... 2
ni=Ned/(Ac*fcd) <= 0.75 for DCL .... 3

Where Ned is axial force ( kN for ex.) given from seismical situations.

My question is
Which value of Axial force must be included in equations 1,2, and 3
N = Ng+0.3NP+Ns or N = 1.35Ng+1.5Np
Or equations 1,2,3 must be checked with both values of axial forces
Any reference or any example would be helpfull,

Regards
z.g.

[rigid_joint]

N = Ng+0.3NP+Ns

this value

[giga]

dear Rigid_Joint

Thanks for reply

any reference or any example if you have would bee very helpfull.

I agree to you that the axial force should be taken from seismic design situations
(Ng+0.3Np+Ns), but i have seen in some books that is taken 1.35Ng+1.5Np, and this have confused mee very much.

One reference book in which the author use N = 1.35Ng+1.5Np and Ng+0.3Np+Ns, is book of author Jure Radiq - Betonske Konstrukcije - ( is in croatian Language).

Regards
z.g.

[rigid_joint]

the one and only right combination is the Ng+0.3q+Nseismic.

[giga]

because is related with seismic design situation
which value of Gamac should be used for calculating of fcd.

[DamirDz]

Dear giga, i would advise you not to take to much reference from the Jure Radic book, one example being this you mentioned here. I had the same doubt a while ago just because of that book.

One other reference i can come up with now is the El Ghazouli (don't know the exact spelling) book on EC8 which you can find here on the forum.

Best regards!

DamirDz

[rigid_joint]

which value of Gamac should be used for calculating of fcd.

γc=1.5