Need a book? Engineering books recommendations...

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

Re: pole structure connections

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Reminds me of a problem with some utility poles.  They were welded up and then hot-pipped galvanized which, I think caused hydrogen embrittlement.  They vibrated in the wind and some actually fractured and fell to the ground.

I guess I'm saying to oversize the welds if you galvanize.


--- On Mon, 6/28/10, Tom.Hunt(--nospam--at) <Tom.Hunt(--nospam--at)> wrote:

From: Tom.Hunt(--nospam--at) <Tom.Hunt(--nospam--at)>
Subject: Re: pole structure connections
To: seaint(--nospam--at)
Date: Monday, June 28, 2010, 1:40 PM


Unless you are in a terrifically windy area or  your structure is subject to significant vortex shedding issues you normally do not have to design for fatigue.  However, this is a case where some prudent engineering judgement might be necessary.  Who knows if you might get a couple of bored teenagers pushing and shoving on your structure.  You may want to show a full depth PJP weld which is close to a full pen weld without the backing or perhaps some very generous fillet welds.  Quality control is probably your biggest concern.  If I remember right, this same issue came up a few years ago with a lot of damaged light poles which I believe had some bad welds.

Thomas Hunt, S.E.

06/28/2010 01:06 PM
Please respond to seaint

pole structure connections

I am working on  a project that includes a canopy shade structure supported by a single pole.  The pole is welded to a base plate that is anchored to a concrete footing.  (not possible to embed pole in concrete).  The pole has architectural limits on size, but at that dimension, I have double capacity when subjected to a 1g lateral load and am also within code displacement limits (0.02)h (sx).  
However, the pole oscillates when pushed on.  Do I need to be concerned with fatigue at the joint of the pole to the plate?  Should I spec a special electrode for that joint?  The model is similar to the pole structures that support light in parking lots or street intersections - is anything special done in those instances for welding and material space?
Thank you,
Paul Franceschi, S.E.
The information transmitted is intended only for the person
or entity to which it is addressed and may contain
proprietary, business-confidential and/or privileged material.
If you are not the intended recipient of this message you are
hereby notified that any use, review, retransmission, dissemination,
distribution, reproduction or any action taken in reliance upon
this message is prohibited. If you received this in error, please
contact the sender and delete the material from any computer.

Any views expressed in this message are those of the individual
sender and may not necessarily reflect the views of the company.