Design of Base Plates for Circular Columns 1

[abjr]

Does anyone know of any literature on the design of base plates for circular columns? We are particularly interested in the calculation of the thickness required for these plates when the width and length is known.

 

[DaveAtkins]

I do not know of any reference. I design base plates for circular columns using the AISC ASD Manual, pages 3-106 to 3-110. To calculate "c", I use the formula for "m", since the formula for "n" does not apply. Also, it seems to me that the formula for "n'" will not apply unless the column is very large in diameter (allowing the portion of the base plate inside the column to bend). DaveAtkins

 

[VoyageofDiscovery]

Hi abjr,

If your column is required to transfer moment to the base plate, whether square, rectangular or circular, one must determine the yield line based on the geometry of the anchor bolts in relation to the column. If the plate thickness gets excessive, utilize stiffners welded to both the base plate and column to shift the yield line. Shifting this line reduces the eccentricity thus minimizing the thickness of the base plate.

If your column is required to transfer axial loads only, the design will be similar to circular flanges in tension.

Regards

VOD

 

[Taro]

AISC's Design Guide 1 "Column Base Plates" suggests using a critical section based on 0.95 times the outside column dimension for rectangular sections and 0.80 time the outside dimension for round sections.

 

[meca]

There are several references that cover the design of baseplates for cylindrical pressure vesselts, process columns, and stacks.

Pressure Vessel Design Manual - Moss
Pressure Vessel Handbook - Bednar
Process Equipment Design - Brownell and Young (I think it may be out of print).

I offer a spreadsheet on my website (

http://www.mecaconsulting.com)

which designs circular baseplates per the last reference.

Regards,

Chris
chris@mecaconsulting.com