Need a book? Engineering books recommendations...

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

RE: STEEL: Q - What is the proper procedure for submitting/approving an alternate design?

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Bill,

I just went through this with a project of mine.

How things are supposed to happen, if details are not specified, then the
engineer is supposed to give reactions that the connections are supposed to
be designed for.  Normally, standard AISC connections are utilized and
submitted for review.  There are supposed to be calcs to accompany these,
however, in this day and age, there are computer programs out there that
will come up with the detail without any calcs.

Now, keeping that in mind, a similar situation came up my way on this
project that I am knee deep in now (literally).  Connections were left off
of the design drawings until the overall arangement was approved.  The
contractor went ahead and got bids (which he told me were estimates) off of
said preliminary plans.  He was already forming and getting ready to place
concrete, so, in an attempt to speed up the project time, said to forget our
design of the connections and leave that in the fabricator's hands.  Which
we did.

The result of this were inconsistant connections throughout the structure,
structurally inadequate connections, and some level of incompleteness.  Now,
I am not saying this is the fabricator's fault, for the proper information
was not made available to them.  It is also questionable that if said
information was made available, calcs still wouldn't accompany the design,
as they let the program do that for them.  That being said, I only had the
detail to go by and I had to check said detail without any calculations to
go by.  All of the connections were simple shear and tension connectios, so
determining the adequacy of said connections was easier, however,
accompanying calcs would have been nice.  It is also questionable if the
fabricator even looked at these shop drawings before they left their
building, however, there could be other circumstances that could control
this.

It is after this experience that I feel that I will never approve a set of
drawings for bid or fabrication without details on them.  I think details
are way too important and a lot of other issues can surface when said
details are considered.

In your case, the best thing you can do is inform your owner what the
situation is and ask for clarification on your part.  While you have already
designed the connection once, there is still, as you say, other ways to skin
a cat.  Checking connections shouldn't be considered in the design phase of
the project and should be covered under the construction phase and certain
compensations should be met for such services.

As far as calcs accompanying alternate connection designs go, with the
advances in computer programs and what not, this practice is becoming a
thing of the past.  At least, I believe it is.  There are still many
fabricators out there that do this, however, that number is becoming less
and less as people being to trush the all mighty computer and the
information it spits out.

My advice to you, for the future, is to never leave the fabricator in charge
of connection design, unless you have a good working relationship with this
fabricator and are comfortable with their knowledge and attention to said
details.  As for now, I don't think calcs exist for the details you are
looking at.  That being the case, you are going to have to investigate these
details with as much "common sense" as possible and comparing the analyzed
reactions with those from your initial design.  Best of luck.

Dave Maynard, PE
Gillette, Wyoming



> -----Original Message-----
> From: Bill Polhemus [mailto:bill(--nospam--at)polhemus.cc]
> Sent: Tuesday, November 16, 2004 7:39 AM
> To: seaint(--nospam--at)seaint.org
> Subject: STEEL: Q - What is the proper procedure for
> submitting/approving an alternate design?
>
>
> Hello, all.
>
> I have a job where the contractor is submitting though his
> fabricator/detailer an alternate design to that which I submitted for
> permit.
>
> In general, I have no problem with this, as long as it meets the design
> requirements. In fact, I sort of enjoy the opportunity to "learn" from a
> fabricator and erector. More'n one way to skin a cat, as we say in these
> parts.
>
> However, when the submittal arrived, it was in the form of ONLY shop
> drawings, no calculations, not even an engineer's seal or "disclaimer"
> attached. Since I'm the EOR, I guess that much is a "gray area," but my
> response to them was "guys, I don't have anything to approve. Please
> send me calculations, etc., so that I can review it for conformance to
> the design requirements."
>
> Their response has been puzzlement. I think that THEY think "h*ll,
> you're an engineer, you oughta know if it's okay or not!" It's almost as
> if they're pulling something out of their design standards and then
> asking me to verify the design adequacy. Since they're not my client,
> and since my client has already paid me ONCE for the steel design, I
> don't see why I should oblige them.
>
> What I need to know is, what is the proper procedure here? I have
> lookeed through the AISC Code of Standard Practice, but I cannot find
> anything that covers this. I have also looked on AISC's website to no
> avail. I would contact their support hotline, but I'm not a member of
> AISC and I figure I could better get a cross-section of real-world
> opinions here.
>
> Thanks.
>
> ******* ****** ******* ******** ******* ******* ******* ***
> *   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
> *
> *   This email was sent to you via Structural Engineers
> *   Association of Southern California (SEAOSC) server. To
> *   subscribe (no fee) or UnSubscribe, please go to:
> *
> *   http://www.seaint.org/sealist1.asp
> *
> *   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
> *   send to the list is public domain and may be re-posted
> *   without your permission. Make sure you visit our web
> *   site at: http://www.seaint.org
> ******* ****** ****** ****** ******* ****** ****** ********
> ---
> Incoming mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.797 / Virus Database: 541 - Release Date: 11/15/2004
>
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.797 / Virus Database: 541 - Release Date: 11/15/2004


******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********