Streetlamp Anchor Failure

[stripez]

I was driving today and saw this streetlamp with damages in pedestal and baseplate:

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What kind of failure mode is it exactly? How many days or weeks do you think before the lamp post falls down? It was just a random street. I have to make about 10 phone calls and many redtapes before it can reach the proper authority and I want to be exact in my description so they can do action.

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[bridgebuster]

stripez - In NY, precast designs are by the contractor. Here's a shop drawing from a current project for 25' poles. In the NYC area, I haven't seen any contractors use CIP foundations for many years. Recently, I worked on two design build projects and I designed the light poles and signal foundations - all precast.

Where you're located, are pole foundations individually designed or does a local authority have standard drawings?

 

[kingnero]

What country is that in?
I haven't seen raised concrete pedestals for light poles, but I can see some advantages of it. I'm just not sure if the advantages outweigh the negatives about this setup.

 

[Ron]

This is in the Phillipines. Not sure how they ever get anything to stay up there! This is just crappy construction. The concrete was wet when placed. The crack coincides with the anchor length...not good. Indicates poor edge distance for the anchor.

 

[dik]

Easier than zero slump... even in the Phillipines...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dik]

I typically use 24 bar diameters for Grade 55S1 stuff... generally a good length to start with... I'd have eliminated the stiffeners and use a BPL twice as thick... for a start.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[stripez]

I pass by that lamp pole daily, and sometimes worry about it. We are now in semi lockdown because of wide spread covid so can't report it yet. And if I'll report it. I have to park in our city hall steel parking. What do you think of their parking column baseplate and pedestral? Perfect?

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This is the city hall steel parking where the columns base are all like that.

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Here the entire 30 inches deep I-beam and about 80 feet length is supported simply by seemingly few joint welding. I sometimes get nervous about it because most of our welders are just laborers and we don't have school for welding.

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We rarely use bolts because they are because expensive. So all connections are welds. And when dik said it may be justified because it's steel special moment frame. Then I'm more relieved.

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Can you share some steel structure with similar span and only supported by a few welds? This is to give me confident because I have to park in that steel parking to report the lamp pole. And I have to go there about 10 times more to get building permit for something.

 

[Rabbit12]

This is morphing into a very weird thread. We were initially asked about a light pole anchor. Seemed reasonable as there is a fairly pronounced crack at the anchor rod.

Now we are getting pictures from across the city questioning other engineered structures. Are you scared the sky is going to fall too?

 

[dik]

Welds appear to be well executed... I've seen a lot worse. Waskally Wabbit has it correct... start a new thread; this is a bit out of place.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[stripez]

Yes I feel the sky falling at least in one of my projects.

We haven't mentioned the lamp pole weld. But these same welders did the steel carpark and my project and here is the result:

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Even butt weld not done properly. There is no gap for the two flanges to be welded properly. So I feared the moment capacity of the w8x21 is not optimum. And we just let them put plate over the web, At least the web is very strong, but the whole I-beam can no longer carry any loads, but just used for bracing against the wall at the side, isn't it? bTW, the welding with cover plate inside the W8 looks just like in the parking, neat and thick. But what if there is problem lurking underneath like mine.

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Question. If I let these welders put plate over my flange at top and bottom. It can maintain the moment capacity of the w8x21? What is the rule about putting plates at the flange when connecting them together?

 

[dik]

Now those are some ugly welds...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[stripez]

Now those are some ugly welds...

The reason I brought up welding was because I wanted to know if you were supposed to weld the pole at baseplate in the field or at factory. In my place, we always weld them on site.

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This is example of welding done on site. They connected 2 w8x21 I-beam at L/3. They used acetylene torch to cut it. How else can you cut it in the middle. The welder who is a veteran who built 50 storey steel building did it that way. It's ugly but it has appreciable moment strength, doesn't it? Actually we still didn't put anything above the I-beam because I couldn't verify how good is the welding and not sure it couldn't even carry 39 inches of parapet wall. It's too costly to ultrasound or xray it.

Anyway. The anchor in the street lamp pole above is 3 feet right? How can it even suffer cone pullout failure? I don't know how to present it to city hall to have it replaced. If anyone is free, during lockdown. Can you help write a report about possible failure modes so I can forward it to city hall? Thank you.

 

[kingnero]

I wouldn't bother getting the above weld UT or RT tested, unless you're working according to the farm code (which has fairly loose acceptance criteria).
The "moment" strength is basically achieved by the welds in both flanges. The horizontal portion of the cut doesn't do much. And to be honest, if that's the weld quality, I'd prefer as little weld as poosible. None at all preferably.

 

[r6155]

I will try to avoid passing near these structures with my Rolls Royce.

Regards

 

[stripez]

I wouldn't bother getting the above weld UT or RT tested, unless you're working according to the farm code (which has fairly loose acceptance criteria).
The "moment" strength is basically achieved by the welds in both flanges. The horizontal portion of the cut doesn't do much. And to be honest, if that's the weld quality, I'd prefer as little weld as poosible. None at all preferably.

If you will give it a thought. It is cut through acetylene torch. Meaning the cut is uneven, hence the weld is uneven. Gets? If you will weld it yourself and and surfaces are uneven, you can do better than it?

I know the moment strength is in the flange but for the welders here, the web is the strength.

Anyway. If you know of 39 inches depth beam with 80 feet span I-beams only welded at the end like in the city engineering steel parking, let me know. Because the few welds at the end can support hundreds or thousands of tons but the w8x21 i-beam welds above can't even carry 39 inches of concrete parapet masonry wall?

And this is all connected to topic of street lamp pole because they mostly weld at site, but the eccentric load of lamp pole is only little. I'm more concerned of the traffic light poles with huge eccentricity.

 

[r6155]

All beams should be in one piece, if possible. Otherwise, all welds shall be full penetration with a qualified welder and must be flush with the base material to facilitate ultrasonic testing (to verify full penetration weld) and to facilitate painting.
Avoid welding in situ.

Regards