allowable defelection

[Lutfi]

Any comments as to what the allowable deflection should be for a steel frame, fixed at base that will support high tension electric lines?

Kind Regards,
Lutfi

 

[dlew]

Lufti,

I would check two items:

1) That the distance from the deflected power lines (at maximum sag) to any not insulated object complies with the clearances specified on the Electrical Code.

2) That the frame is stiff enough not to produce a dynamic problem if the presence of wind or seismic loads.

The deflection of the frame is going to be small when compared with the change in sag and lateral sway of the lines.

Regards

AEF

 

[UcfSE]

I have never checked this reference, but I believe the ASCE publishes a guide to design of steel transmission towers, have you checked here?