Column base plates w/ biaxial moments
Column base plates w/ biaxial moments
(OP)
Can anyone direct me towards a hand-calculation method for designing column base plates for biaxial bending? So far, the only thing I've found is an equivalent uniaxial method used by STAAD etc. The plate thickness appears reasonable with this method, but the anchor bolt requirements do not. I'm developing a spreadsheet to do column base plate, anchor bolt, pedestal and footing design for up to 25 load cases, otherwise I'd simply purchase existing design programs.
The only other method I can think of would be the Bresler reciprocal method. 1/Pi = 1/Pnx + 1/Pny - 1/Po
Another question, how accurate/valid is the AISC method for designing base plates with uniaxial moment? Aside from a finite element approach, is there a more accurate/valid method?
Any help would be greatly appreciated!
The only other method I can think of would be the Bresler reciprocal method. 1/Pi = 1/Pnx + 1/Pny - 1/Po
Another question, how accurate/valid is the AISC method for designing base plates with uniaxial moment? Aside from a finite element approach, is there a more accurate/valid method?
Any help would be greatly appreciated!






RE: Column base plates w/ biaxial moments
RE: Column base plates w/ biaxial moments
Thanks for the reply.
RE: Column base plates w/ biaxial moments
RE: Column base plates w/ biaxial moments
RE: Column base plates w/ biaxial moments
RE: Column base plates w/ biaxial moments
Still, both references only consider uniaxial bending. Anyone have suggestions for biaxial bending? Does the Bresler reciprocal method seem valid here?
RE: Column base plates w/ biaxial moments
Thanks!
RE: Column base plates w/ biaxial moments
Note:Blodgett is commonly used. However, it is inaccurate for a couple of cases. The design guide has a very good discussion about the theory. In synopsis, different theory applies for the axial load; small eccentricity and large eccentricity cases.
Oops... Just saw "BI-Axial Moments". The design guide does NOT cover bi-axial conditions. Although, you can make some reasonable projection based on their discussion.
Imagineer
RE: Column base plates w/ biaxial moments
As long the reasonable thickness is accepted won't be ruined nor by the bolts in tension if any or by the bending of the base-plate in compression, one can always find a value for tension in the bolts for Pxy cases as a Reinforced Concrete section in compatibility of deformations. That is, as a rectangular section under Pxy (forfeit the in compression bolts compressive strength). From this an anchor bolt can be derived, then enlarged if in doubt.
RE: Column base plates w/ biaxial moments
1) AISC Steel Design Guide Series - Column Base Plates by J. T. DeWolf and D. T. Ricker.
2) Analysis and Design of Structural Connection by L.H. Martin
As for software, STAAD.etc is the only one that I know of that does it without having to buy a full FEM package. Enercalc has a base plate module but I am not sure if it handles biaxial bending.
RE: Column base plates w/ biaxial moments
There is a program called RISABase which will design baseplates for biaxial conditions using a FEM solution. It can be found at www.risatech.com.
RE: Column base plates w/ biaxial moments
Since I am not in USA, the "AISC Steel Design Guide Series - Column Base Plates by J. T. DeWolf and D. T. Ricker" is not available to me. Where can I found online this great guide which, I am sure, worthy a reading?
Again thank you for reply.
RE: Column base plates w/ biaxial moments
RE: Column base plates w/ biaxial moments
I have another question here abou the design methods of tension base plates, which, for example, are used in cable structures as the connections between the cable and the anchors underground. Where can I find the information about that?
RE: Column base plates w/ biaxial moments