Using Bar Grating as a Diaphragm

[pat2]

I am designing a large industrial mezzanine in state of LA. I would like to weld my bar grating to the structural steel, so it may be used as a diaphragm to transfer my forces to my bracing system. I do not know how to quantify the diaphragm capacity of the grating. I called the McNichols Company for information, but they could not help at all. Has anyone used bar grating as a diaphragm? What are your thoughts on it?

Horizontal rod or angle bracing would not be easy to install.

Thanks

Paul

 

[jike]

Grating is not typically used to create diaphragm action. I have always used angle iron bracing below the grating to transfer lateral forces. I believe is easy to do and quite common.

 

[pat2]

Thank you for your answer:

I realize it is not typical to use bar grating as a diaphragm. The reason I would like to use it as a diaphragm is because using rods or angle iron is not easily done in this case due to the equipment being supported.

The equipment are cooling towers, which protrude below the grating levels, thereby creating obstructions to using typical bracing methods.


Paul

 

[Lutfi]

I never use it for diaphragm. Use bracing instead.

Good luck

 

[jike]

Usually there is grating around the equipment for access and this is usually sufficient for providing a bracing scheme.

If there is enough floor area for you to want to use a diaphragm, there should be enough floor area to provide bracing.

You might have to add struts as well as diagonals to come up with a workable bracing pattern.

Good Luck!

 

[SlideRuleEra]

In industrial applications I have used welded metal bar grating with welded anchorages (such as type W-19) to create diaphram action. This was accomplished by having the grating fabricated with checkered steel plate welded to the (top) of the grating.

 

[Lutfi]

SlideRuleEra,

Then you are using the plate element to carry the horizontal shear. I have not seen any published data by any grating manufacturers with diaphragm values.

If any one knows of any, please let me know.

Regards,

 

[pat2]

Thank you all for your comments. From the responses, I will have to find a way to brace the mezzanine with angle iron.

paul

 

[dbuzz]

I work in the minerals processing indusrty and we never take account of grating or floorplate contributing to lateral restaint of beams, simply because the flooring may well be removed or replaced with a less-stiff flooring system.

Angle bracing set, say 75mm, below the beam top of steel is fairly conventional.