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Seismic requirements for electrical plans

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SparksRfun

Electrical
Oct 24, 2006
19
US
We are going to start working on some projects in seismic areas. I am not clear what kinds of details are usually included on electrical plans in these situations.

In the past, in some cases we would require the contractor to hire a licensed structural engineer to do calculations for anchorage, bracing, and so forth. Nothing was shown on the plans, it was all submitted later. Now, I understand that those kinds of details are increasingly required on the actual plans. This isn't something I know much about.

What kinds of seismic details are other people providing on plans in seismic zones, or are you doing what we have done, and requiring the Contractor to hire a PE to do seismic detailing based on actual weights of installed items, pipe rack weights, etc?

SparksRfun

"The truth will set you free, but first it will make you madder than a wet bobcat"
 
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Heck, why not just let out a design/build contract and head for the golf course? If you want the contractor to be responsible for engineering, let him do all the engineering. When I was estimating and bidding jobs, we probably wouldn't look at a job that required us to do or be responsible for seismic calculations. If we did bid such a job, the takeoff would be fast and the bid would be high. We would get a price for farming out the seismic engineering and at least double it. If we got the job we would not lose money on it.
I remember one job our mechanical side got. Actually the price was quite low, BUT. Where ever the design engineer didn't bother to provide details and covered it by a disclaimer such as "Fit in the field", my boss would design and draft the special fittings needed. He would then send the design in for the engineer to sign off on. Then he would bill for the work as an extra including charges for designing and drafting. We made money on the contract and even more on the extras.
Actually that boss always did well on a job where the design engineer didn't do complete and professional work.


Bill
--------------------
"Why not the best?"
Jimmy Carter
 
This puts me in a rock-and-hard place position. I am not a structural engineer. Don't know doodly squat about anchorage and bracing. If I put those things on my plans, I'm not only stretching my stamp where it doesn't belong, I'm risking the pipe supports will fall down, since I don't know what I'm doing in the first place.

OK, this problem has been solved before. How do other electrical engineers handle seismic anchorage and bracing in seismic zones?

SparksRfun

"The truth will set you free, but first it will make you madder than a wet bobcat"
 
You hire the seismic engineer. The electrical contractor doesn't know diddly about that stuff either. You won't be saving any of your clients money by forcing the contractor to assume your responsibility. On the other hand, a lot of contractors don't even have stamps so they have not as much to lose. (And some who do have them refuse to use them, I've worked for them too.)

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
What Bill said.

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.
 
Bill got it right, hire a professional to do the work and hopefully everyone ends up happy.

Alan
 
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