Structural Framing Plan and Details

[UBGrad]

Hello all,
I am in the process of reviewing an existing structural framing plan with the hope of answering a constructibility question for an upcoming turnaround. My question to this forum is:

Why would a detailer call out the tension of select horizontal members on an elevation drawing of the framing plan? I have attached a PDF for your reference.​

I appreciate your help in this matter.

-UBGrad

 

[jayrod12]

My first thought is connection design.

 

[UBGrad]

Jayrod12, that is a good thought but wouldn't the detailer include moments as well?

 

[Brad805]

Those appear to be drag struts for a tension only bracing scheme. I doubt they used anything but simple shear connections so there would be no significant moment.

 

[manstrom]

It's the chord of a diaphragm. There should be tension through the connections.

When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.

-R. Buckminster Fuller

 

[JLNJ]

The force needs a load path, and there should be loads, or at least decent design criteria, for the entire length of the path from top to bottom. This includes horizontal members and forces which need to be transmitted through connections (as manstrom indicates above).

Look out for the tension in the connection of that horizontal leg of the large kneebrace in the upper left. You don't want to pry that connection off the column.

Why the WTs for bracing?

 

[TLHS]

The overall odd arrangement looks industrial (although the bracing seems more like something governed by architecture, so who knows). You see WTs for bracing in industrial steel frames. I like double angles better, but sometimes WTs are useful in a strength and slenderness zone that falls somewhere in between double angles and HSS. They're certainly easier to connect than HSS or full on W sections if you detail them right.

 

[BUGGAR]

Since the loads are clouded in red, they look like "reviewer please verify" notes. There seems no other reason for showing these arbitrary loads and clouding them.

Although you are reviewing for constructability, you might mention to the designer that his design intent is apparently not clear to the shop drawing guy.