transfer beam with column web perpendicular

[sklgleb]

Hello all,

I am designing a connection for a transfer beam whose web is at 90 degree angle to the column which rests on top. I am looking to distribute the load using a base-plate and two(?) stiffeners within the transfer beam. I would like to make sure that the base plate is sufficiently stiff in order to evenly distribute the load, and in turn am wondering if someone can point me to some specifications on the requirements. (side notes; the column web by itself is insufficient to carry the load, the connection is assumed to be a pin, column = W12x72 with 500k load, transfer beam = W33x241 loaded at 5' from edge)

Thanks,
G.S

 

[tstructural]

Are you trying to support a column using a W33x241 beam in weak axis bending? Are you sure about that load - 500 kips?

 

[sklgleb]

No, what I meant to say was - the column from above comes in so that its web (along y axis typical in cross section) lies perpendicular to the z axis of the beam below. The beam is in strong axis bending. Naturally the load has to be spread out to prevent web crippling, however the problem that comes up now is to utilize the full cross sectional area of the column so that yield stress is not violated.

 

[KootK]

This came up recently sklgleb. I believe that you'll find what you need here: Link

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[cliff234]

I would use stiffeners welded to the web of the transfer girder as you describe, and I would also add plates welded to both sides of the web of the column above with the plates aligned above the web of the transfer girder. Those plates may have to be about 36" deep - perhaps deeper. The purpose of those plates is to pull the load out of the column flanges and dump it directly into the web of the transfer girder below - and these plates will do the bulk of the work in transferring the load out of the column and into the transfer girder. If you properly design the stiffener plates (in the column and in the transfer girder), then there really isn't any design to do for the baseplate. You could probably just use a 3/4" baseplate. The specification requirements are in AISC 360-10. There is no specific single place in the AISC specification that addresses the exact connection you are trying to design. The problem with this detail (as you are finding)is that about 80% of the axial load in a W shape column is carried in the flanges. The stiffener plates welded to the column web serve to drain the load out of the column flanges.

 

[PMR06]

How about using WT6x36 for your stiffeners? Then the load path lines up perfect and you have plenty of depth in that W33 to drag the load into the beam web.