Steel Transfer Beam Supporting a Cut Column

[MarcellinCollege]

We plan to cut a 300RHS steel column and re-support it on a transfer beam to handle a point load of approximately 100kN.

Our initial design proposed placing a full-length steel beam beneath the column for adequate bearing support.

However, the contractor has presented an alternative approach (refer to the attached proposal), suggesting the transfer beams be connected to the sides of the severed column to handle the point load. What are your thoughts on this detail? Is this solution viable, or can reasons be provided to discourage this approach?

 

[TRAK.Structural]

I think the proposed detail is a bad idea. You are asking the angles/plate at the top/bottom of the cut beam to essentially transfer the beam moment/shear through that joint. The proposed detail also looks like a lot more work and expense than a full length beam positioned below the column would be.

 

[lexeng18]

We would usually run (2) un-interrupted beams, one to each side of the column, with a bunch of misc. steel in between them at the column location to transfer the load. This approach allows all the steel to be fully installed before cutting off the column as well.

 

[HTURKAK]

Our initial design proposed placing a full-length steel beam beneath the column for adequate bearing support.

This is the reasonable approach. The supporting beam should be a full-length beam.

..suggesting the transfer beams be connected to the sides of the severed column to handle the point load. What are your thoughts on this detail?

It is not clear how the moment connection requirements , continuity of transfer beam satisfied. Apparently the compression flange continuity is not justified.

 

[XR250]

We would usually run (2) un-interrupted beams, one to each side of the column, with a bunch of misc. steel in between them at the column location to transfer the load. This approach allows all the steel to be fully installed before cutting off the column as well.

I usually use a full-length channel on each side for ease of attachment.

 

[EngDM]

I usually use a full-length channel on each side for ease of attachment.

Yup, channel each side and 2 bolts thru the column, call it a day. Or weld the column corners to the channel web whatever tickles your fancy.

 

[Tomfh]

That detail will sag a lot.

Sandwiching the column between two channels prior to cutting the bottom is much better detail.

You will get some deflection as the channels bend and the bolts engage. You can preload the channels (eg with jacks or a chain block) if that’s a concern.