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- To: seaint(--nospam--at)seaint.org
- Subject: Re: Disclaimer Notes
- From: Scott Maxwell <smaxwell(--nospam--at)engin.umich.edu>
- Date: Fri, 21 May 2004 14:30:40 -0400 (EDT)
Andrew: Since Paul was nice enough to agree with me, I will return the favor and agree with him. <grin> As SEOR, you are responsible for the design intent. But this also includes an implied "workable" design intent in my opinion. This includes making sure that you have enough shear area when coping beams or a connection is feasible when a member frames in at a tight angle. What you don't need to do is figure out what the exact length the beam/column needs to be cut to, what the exact edge distances need to be (as long as they are more than minimum and enough for the applied loads), etc. In otherwords, the SEOR need not determine all the specific, "nitty-gritty" details for fabrication...just that any such items meet or exceed what is needed from an engineering point of view. Now, one can certainly debate as to how this should be accomplished. This can be the "East Coast" way, which is to show design intent but not necessarily design all the connections as it allows the fabricator some leeway to determine what best works for how their fab shop is setup. If this method is chosen, then it is still the SEOR's responsibility to review the designed connections on the shop drawings to make sure they are fine to carry required loads. From my past experience, this means running connection capacity calculations during the shop drawing review. Or it can be the "West Coast" way, which means that the SEOR will in effect "fully" design all the connections and show them on the his/her drawings. Thus, the capacity calculations by the SEOR are done during CD production (as opposed to during shop drawing review). The end result is that to my knowledge the SEOR is still responsible of the capacity/engineering of the connections no matter how it is done. In theory, sealed shop drawings only can really help the SEOR get a "warm fuzzy feeling", but the SEOR is still ultimately responsible whether they are sealed or not. At least that is how I understand it... Regards, Scott Adrian, MI On Fri, 21 May 2004, Paul Feather wrote: > MessageAndrew, > > 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. > > > Paul Feather PE, SE > pfeather(--nospam--at)SE-Solutions.net > www.SE-Solutions.net > ----- Original Message ----- > From: Andrew Kester > To: seaint(--nospam--at)seaint.org > 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 > > > > ******* ****** ******* ******** ******* ******* ******* *** * 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. 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