Design of Stiffened Rigid Column Base Plate Connections

[dbest69er]

Hi all,

I'm currently designing a fixed column base connection and have found a few guides which explain the design procedure for base plate size, bolt size and other requirements to resist both moment and axial force. However, all of the resources I've found assume no stiffening at the column base which results in quite a large base plate size. I was wondering how do stiffeners reduce the size of the base plate and if you know of any examples which I can follow that have a design guideline for this case. The column is quite small (150UB) and has small moment (4.75 kNm) and axial force (9.85kN) but, this results in a large eccentricity (M/N = 482mm) and if unstiffened, a base plate thickness of 35mm. I want to reduce this size and I think I have no choice but to use stiffeners.

Regards,

Keith

 

[malikasal]

you should check "DESIGN_OF_WELDED_STRUCTURES" by omer W. Blodgett.



ôIf you don't build your dream someone will hire you to help build theirs.ö

Tony A. Gaskins Jr.

 

[hokie66]

It is not that eccentric, because you will have anchor bolts to take tension. The lever arm you need to be concerned with in determining uplift force on the bolts is the distance from the compression flange to the bolt line, so it should be about 190 mm. 4750/190 gives 25 kN for the bolt force, and the moment for designing the base plate would then be 25 x 0.040 = 1 kNm on the tension side. Then check the compression side, and you are done. Such a small column doesn't need stiffeners.