Need a book? Engineering books recommendations...

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

Re: Disclaimer Notes

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Title: Message
Andrew,
 
I will have to take issue with you on this one.  I agree with Scott's summary and the use of shop drawings as verification of design intent.  I do not agree with "leaving it up to the fabricator to make sure your design intent will work with steel".  You are the designer, and it is your responsibility and your responsibility only to be damned sure your design works, and works in the material you specify.  You should be thinking of fit up and detailing when you design the system or you are not performing your duties properly.  If you don't consider a special condition with excessive cope, how did you design the beam for shear?  If the condition does not fit the typical detail condition you as the designer are supposed to be reviewing this and adjusting your design accordingly.  You should be considering these aspects when you layout the framing plan and select the member sizes.  Designing for constructability is every bit as important as designing for serviceability.
 
I guess one of the major differences here is going to be the disparity between East and West coast practice.  I know on the East coast connection design is left up to the fabricator in most instances, but I would think you as the designer are responsible for giving them something realistic to work with.
 
 
----- Original Message -----
Sent: Friday, May 21, 2004 7:14 AM
Subject: Disclaimer Notes

Disclaimer Note

That has been a standard note on all of our drawings and shop drawing stamps at both companies I have worked for. Also the shop dwg stamp always says "REVIEWED for general conformance with design docs but it is still the GC responsibility to ensure the ....."

Scott- well said. The way I have always understood it, when designing in steel our drawings show a design intent. We are not steel fabricators and erectors, this is not our area of expertise. That is why we leave it up to the professional fabricators to make sure our design intent will work with steel. We are not thinking fit up when we size beams all of the time. We are not thinking about how long each beam needs to be, or if a flange needs coping, etc. We get some funky shaped buildings with beams dying into girders at 15.3 degree angles. How do we know how exactly that will connect and the dimensions of everything working out perfectly in the field? We don't have the software, tools, time, or desire (for me at least) to make this happen. (We sure don't get paid for that.) That is why we NEED good steel fabs with good detailers, they are a valuable part of the TEAM.

But on a recent set of shop drawings, afterwards, I thought of a lot of things to improve on our end. Example, framing a small beam like a W8 or W10 into a girder is not a good idea, because after they cope the flange and web, there is not enough room to get a standard bolted shear plate in there. It is much cheaper to bump it up to a W12 or W14 and save the labor of extra fabricating....

Bottom line in our office, is steel detailing and connections are becoming quite a hassle, especially on complicated buildings. We are becoming bigger proponents of putting factored reactions on our plans and leaving the detailing of the connections up to the fab and his specialty engineer, who would of course have to sign and seal the connections if they designed them.

Andrew kester, PE

 Longwood, FL  32750