Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: commercial sign structure

[Subject Prev][Subject Next][Thread Prev][Thread Next]
On 04 Apr 1998 20:50:11 +0800 Alex Nacionales  wrote:
> The forces on this frame is more than twice in magnitude than the forces
> for the wind load alone without the torsion.  The resulting members are
> quite big so I  advised my client
> to place the tower at the center of the billboard to avoid the torsion.
> Actually a similar structure is already being constructed here with the
> tower at the center. The second structure is for another city where the
> site has an  existing small shed that will be affected by the foundation
> if the tower is in the center. It will be cheaper to demolish the shed
> and rebuild it at about 500 US dollars.

You should exercise some caution.  Even if the billboard is centered 
on the tower, (in reality) torsional response still results when the 
wind blows at an angle to the face.  If your structure is very 
sensitive to such torsion (for instance due to its flexibility), you 
should still consider some torsional response.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Michael Valley                                   E-mail: mtv(--nospam--at)skilling.com
Skilling Ward Magnusson Barkshire Inc.                  Tel:(206)292-1200
1301 Fifth Ave, #3200,  Seattle  WA 98101-2699          Fax:        -1201