WT shelf bracket supporting crane girder

[WiSEiwish]

Hello,

I am trying to design a column bracket that is going to support a runway beam for a bridge crane. The beam is a WF beam with a cap channel. The bracket will be either a WT or a built up T section. My question doesn't really involve designing the bracket per se, but rather the interaction between the bracket and the runway girder.

The runway girder will be running perpendicular to the bracket stiffener which means that the bearing length of the reaction on the girder is going to be equal to the thickness of the stiffener rather than the length of a stiffener as a normal seated connection would be. This could require the girder to need stiffeners.

My question is that if it is the case the the runway girder requires stiffeners at the bracket, could I have plates welded perpendicular to the bracket stiffener to provide a longer bearing length and thus eliminate the need for stiffeners? If that is an option, would it have any real affect on the design of the bracket?

Thanks.

 

[JAE]

Can you post a sketch?

 

[WiSEiwish]

I think I somewhat answered my own question in the sketch. Without the added plate the shelf plate would be in minor axis bending and it would be unstiffened. The plate is required, not to spread out the load but to stiffen the plate in the direction of the beam. If the girder were to run continuous over the shelf bracket then my original concern would be valid.

Describing something to someone else with a sketch makes it much easier to understand the actual intent of the design.

 

[dik]

Can you use a W section instead of a T? I have often used a W for the bracket and the web of the W often provides the stiffness at the crane beam.

A sketch would help...

Dik

 

[WiSEiwish]

I have attached a sketch in my previous post. Please let me know if you would like to see any more annotation.

With regards to a W section, if there were a joint in the crane beam wouldn't the same problem persist when the MWL is applied adjacent to the joint? How would you prevent the flange from bending? Just curious.