Drift Limit for Free Standing Sign

[jmaddox]

I have a sign 100' in the air. The wind force on the sign at the centroid of the sign is =~ 5k. My question is if anyone knows the drift limits for solid freestanding signs. Using a 32" x-Strong Pipe gives me a nodal displacement of =~ 15" (L/80) I know the wind drift limits for buildings are L/400 but I cannot find any limits for signs.
Thanks in advance for any replies.

 

[BadgerPE]

Check out this thread. Also, you might be able to find some information in AASHTO or your local DOT manual for traffic sign structures.

 

[a7x1984]

I agree with Crackerjack - AASHTO or your State DOT is going to be your best bet (hint hint: DOT's tend to give out their standards and spec for free via their websites).

On a side note:

["Typical drift limits in common usage vary from H/100 to H/600 for total building
drift and h/200 to h/600 for interstory drift, depending on building type and the type
of cladding or partition materials used. The most widely used values are H (or h)/400 to H (or h)/500 (ASCE Task Committee on Drift Control of Steel Building Structures, 1988).

Remember that damaging adjacent components, e.g. cladding, is a major part of limiting deflection. Unless secondary effects are limiting the drift or there are adjacent components that could be damaged by excessive deflection, H/100 doesn't sound unreasonable.

In Russia building design you!

 

[JAE]

I think a governing document - or at least one that would be useful, is AASHTO's Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals.

Found here:

https://bookstore.transportation.org/item_details.aspx?ID=2053