Welding - splices between two HEBS of different size

[LJ_]

Hello Everyone I have been losing my mind over the following:

How do I join two columns a HEB 300 and a HEB 240 through field weld no bolts.
It is a moderately seismic structure.
So I initially thought of using a plate that joined the two elements and then filling the gaps with vertical plates, also welded. This gives the appropriate moment and shear capacity in the strong axis. But it fails in the weak direction for moment when I apply the weak moment Mn of the HEB column.

I would really appreciate some help thank you

 

[r13]

I assume HEB260 beam connect to the flange of HEB300 column, - provide fillet weld all around, or penetration weld on the flanges, and fillet welds along the web.

 

[LJ_]

Hello @retired13, it is a column to column connection.

 

[r13]

Ok. Then provide a cap plate on top of the lower column. The welding details/methods are still applicable, depends on the strength requirement on the joint.

 

[LJ_]

Thank you for your answer but It doesn’t seem to work.

 

[r13]

Why?

 

[HTURKAK]

The common splice of columns is bolted and I think no need to discuss the use of packs or filler plates to get flush surface for bolting.

I think the alternative ( the use of cap plate or thick division plate ) which retired13 proposed is the known alternative and apparently you do not like.

Another alternative,( if concentric connection ) HEB 300 web will be cut at both sides (near the flanges ) and two triangular web pieces (30w,150h )will be taken and flanges will be bended at the top HEB 300 will transfer to HEB 240 . The flanges of HEB 300 will also be trimmed to match the flange of HEB 240. I assumed the transfer from HEB 300 to HEB 240 will be with a slope 1/5.

 

[r13]

You shall consider replace HEB 240 with HEA 300 for ease of splicing.

 

[robyengIT]

what about this arrangement ?

 

[human909]

That looks like hell to implement to detail and to install and will not be a full strength connection as the joining flange plates are thinner than both flanges.

I don't understand why you aren't considering the two easier to implement solutions that have been proposed.
-a thick cap plate(s) with full strength butt welds
-a HEA column as suggested by HTURKAK