Minimum eccentricity as per CSA A.23
Minimum eccentricity as per CSA A.23
(OP)
The Canadian concrete code requires that a minimum eccentricity of P(15+0.03h) shall be required for all columns.
My question is: Does this not mean that all columns shall have biaxial moments? Or is moment from the minimum eccentricity requirement to be considered and taken on the same direction of a uniaxial column with moment due to applied loads.
I hope the above made some sense.
My question is: Does this not mean that all columns shall have biaxial moments? Or is moment from the minimum eccentricity requirement to be considered and taken on the same direction of a uniaxial column with moment due to applied loads.
I hope the above made some sense.
Clansman






RE: Minimum eccentricity as per CSA A.23
RE: Minimum eccentricity as per CSA A.23
Clansman
RE: Minimum eccentricity as per CSA A.23
RE: Minimum eccentricity as per CSA A.23
For reinforced concrete columns that are cast in-situ, it is unlikely that your design should be goverened by minimum moment due to a notional eccentricity, there is always going to be some moment transferred into your column from the slab spanning onto it an I would guess this is larger than your minimum design moment (at least that is what I have found from my experience).
Likewise, there will also be biaxial bending in columns so it is best to rotate the section when designing for strength opposed to the simplifications that are set out in the code.
RE: Minimum eccentricity as per CSA A.23
RE: Minimum eccentricity as per CSA A.23
RE: Minimum eccentricity as per CSA A.23
StructuralEIT: I recall the horizontal cut-off line on the interaction diagram is corresponding to the strength reduction factor (phi). Check me on this.
RE: Minimum eccentricity as per CSA A.23
phi contributes to the vertical location of that horizontal line, but doesn't contribute to the fact that it is horizontal. If phiPn,max were phiPn (and didn't have the additional factor of 0.8 (for tied columns) or 0.85 (for spirally reinforced columns)) then the interaction diagram would not have the horizontal line. The reason it does is because to the left of the horizontal line phiPn is greater than phiPn, max due to that additional factor. Once you get past that point, phiPn is no longer greater than phiPn,max.
RE: Minimum eccentricity as per CSA A.23
RE: Minimum eccentricity as per CSA A.23
RE: Minimum eccentricity as per CSA A.23