Beam to Beam Connection Detail

[chencfp]

I am working on a beam connection design. According to Steel manual and reference book examples, most of connections are both beams' top flange at same level. I did not find any case with one beam placing on top of another beam. Is it adequate to place one beam on top of another beam if room height is allowed? Does this arrangement have any structural issues? i.e., stability?, torsion?...

Please see attached sketch in PDF File. Thank you for your help.

 

[DaveAtkins]

Yes, this is done quite often. You need to check web crippling and web yielding in both beams, and sidesway web buckling in the supporting beam. Add stiffeners if there is any doubt.

DaveAtkins

 

[chencfp]

Thanks DaveAtkins, Can you please talk about how to check sidesway web buckling in the supporting beam? Thank you again.

 

[dik]

YOu might want to remove the note about welding... it's likely more economical to drop in a couple of bolts.

The temporary bracing will provide stability to the system until the deck is installed and the roof beams will likely provide adequate lateral support for the girder.

Dik

 

[DWHA]

Web Sidesway Buckling check is in AISC 13th J10.4

 

[chencfp]

Thanks all. According to my attaching sketch, the concrete wall is parallel with the main support beam. Is it adequate to consider the W27 as W36 compression flange lateral bracing?

 

[civilperson]

Yes, the W27 braces the top flange of the W36, but what will brace the compression flange of the W27? Perhaps some diagonal kickers/stiffeners from the top flange of the W36 to the top flange of the W27.

 

[BAretired]

Hello chencfp,

To carry the comment of civilperson a bit further, the W27 beams must be braced or stiffened at the concrete wall and the supporting W36 beam. Otherwise you will have an unstable structure.

If the W27 beams are supporting a rigid deck on top, then their top flanges are presumably braced by the deck.



Best regards,

BA

 

[chencfp]

Thanks. BArtired, I am also concerning the stability issue around concrete wall and W36 beam. It is easy to understand for adding stiffeners according to AISC 13th J10.4. But it seems still need a diagonal bracing to prevent overall movement such as wall horizontal deflection. We use metal deck with concrete as top floor.