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Up Topic American Welding Society Services / Technical Standards & Publications / AISC or D1.1
- - By dschlotz (***) Date 05-02-2007 11:56
With the addition of the D1.8 seismic supplement to D1.1 I'm a bit confused. I just finished participating in a one day seminar on seismic requirements which included some information from D1.1, D1.8 and AISC. I came away with this question unanswered. How do AISC and AWS work together to insure that the job is done properly. My point of misunderstanding is this; If I have a demand critical project, can I service that contract with D1.1 and D1.8 supplement alone. Do I need AISC, FEMA, or any other document to do my job as a fabricator or inspector? The seminar was put on by an AISC person and he also serves on the D1.1 committee. I tried to get an answer to this question at the seminar but the answer was lost in the verbiage.

I'm not trying to be critical of any association regardless of their initials. I just want to do a proper job as an inspector and as the go to guy for my employer. My employer relies on me for good information in a timely way. I need to know what is coming down before it bites us.

I realize that most of the changes that the D1.8 requires are in the engineers arena to define. But I don't want to be in a position of ignorance as D1.8 and who knows what else begins to show up in contract specifications.

Thanks ahead of time for your response.

Dennis
Parent - - By jwright650 (*****) Date 05-02-2007 12:15
Dennis,
Our customer's spec will call out if the fabricator needs to hold an AISC cert with endorcements noted or not. Many times the spec just states that all welded to be in accordance with AWS D1.1 and it might mention the seimic requirements, if that applies. But I think all that is for is to weed out the not certified bidders at bid time.
Parent - By swnorris (****) Date 05-02-2007 13:28
Do I need AISC, FEMA, or any other document to do my job as a fabricator or inspector?

Your contract documents should indicate whether your scope of work is in accordance with D1.1, D1.8, AISC, FEMA.  So, you would definitely need these documents.

How do AISC and AWS work together to insure that the job is done properly.

There are a lot of tables, etc in the AISC manual that are taken straight from D1.1, otherwise, in general, the reader is referred to the related AWS standard.  I see a lot of this, but I can't think of any instance where D1.1 refers the reader to the AISC manual.  As you probably know, AISC handles design, and AWS handles welding.  I guess it's up to us to be smart enough to read between the lines and figure out if there are any contradictions between the two specifications. 
Parent - - By dschlotz (***) Date 05-05-2007 01:19
I was hopping to get the kind of answers that you, jwright650-swnorris-hogan, gave. It is such a benefit to be able to ask an important question  and get responsible reply. I feel honored that you three answered. I have all of the documents mentioned, in the replies to my post, except for "irfd" and "asd". Frankly I have not the foggiest idea what they are. Please inform me. I try to keep up to date so that I can do my job well. 

I am the QC guy and a fabricator and welder. Know body else at my place has the time or the inclination to pursue these topics. I don't have an office so I am not a dedicated asset to total QC. I put on witch ever hat I'm required to ware as the day proceeds, literally. I have had my fanny pulled out of the fire many times by you guys on the forum. It is not only when I post, but in reading the questions and answers of all of you.

Thank you
Dennis
Parent - - By Bob Garner (***) Date 05-17-2007 21:26
Hi Dennis,

LRFD and ASD are basically two different design methods used by engineers.  Regardless of which method the engineers use, the welds will be basically the same so you don't really need to know which method was used in design.  Whatever methodology the engineer uses for design, the engineer will (should) spec the weld size and type and that is what you weld or inspect.  How the engineer comes up with a weld design is his problem and you don't need to know, although I admire you for wanting to know. 

Let me try an oversimplification:  ASD divides the design strength by a safety factor to get the working load.  LRFD amplifies the loads to achieve a safety factor.  Why the different methods?  LRFD is recent and is said to provide a more statistically reliable design by taking into account many more factors for unknowns than ASD does.

Bob Garner.
Parent - By dschlotz (***) Date 05-18-2007 02:31
Bob,

Thanks for the concise and informative reply.

Dennis
Parent - - By thcqci (***) Date 05-24-2007 21:49
I, too, think I am the only guy here that pursues seismic requirements and education.  We just sell jobs without understanding the ramifications.  We have had several projects come to our shop with the words "seismic" verbally attached but with drawings that do not look any different than any others.  Conversely, we had 2 jobs hit the shop with seismic notes all over them and not a word mentioned anywhere previous to them hitting the shop.  Stopped those 2 jobs cold (one until the client finally arranged to have one of those "special inspectors" come in from CA.  I thought "wow, finally going to get to learn something from this guy.  Boy was I disappointed because he surely was "special".  He pretty much got a vacation to sunny FL.)  Anyway, it would seem that there still is little understanding here the difference between siesmic and nonseismic no matter how much I try to educate.  Engineers are not specifying what part of a frame falls under the seismic restraint and just try to call the whole job seismic.  Then detailers don't detail it any different than a "normal" job.  Once again I become a very squeaky wheel.
Parent - By hogan (****) Date 05-24-2007 22:14
almost anyone can get the special inspector cert. if you can read you can pass it. all open book. no experience requirement.
Parent - - By aevald (*****) Date 05-25-2007 00:31
Hello thcqci, I read your post and think you may gain some information regarding your questions by going to the website: www.aisc.org, they have a number of interesting subjects and examples under their Learning Opportunities section. I pulled up some information from their site after reading a response on another thread about moment connections, the information that I was able to retrieve showed in a very informative and simple manner the differences in simple connections and fully-restrained and partially restrained moment connections. It also had a host of other informative topics. I am sure that Hogan can give you other information on the definitions of seismic as he is located in an area where most all of the construction falls under earthquake code requirements very similar to those of california. Good luck and regards, aevald
Parent - - By thcqci (***) Date 05-25-2007 16:34
Yes, I have been there and I have done a bunch of reearch and reading about seismic stuff.  Problem is I need a bunch more people here doing the same instead of just relying on the QC guy to tell them AFTER the job is in the shop.  Lack of planning and all that stuff.
Parent - By aevald (*****) Date 05-25-2007 16:44
Hello again thcqci, is there any way you can convince the shop superintendent to incorporate some presentations on those issues through a powerpoint presentation or a booklet or information pack or something like that? Just a thought. Regards, aevald
Parent - By hogan (****) Date 05-29-2007 14:26
typically most seismic job drawings will look the same as any other drawing (more so if shop drawing). for seismic contract drawings you always start with the general notes. look at the design code ( if seismic than probably ICC). next look at the seismic zone. most additional requirements will come into play in zone 3 or higher. if you have these noted then there will be an additional heading in the general notes titled special inspection. this will tell you what is required to be inspected and if it is continuous or or not. also most of the additional requirements will only apply to the moment frame. keep in mind that there can be say 30 moment connections on a floor, but only 20 are part of the moment frame. different requirements for frame verses a moment connection.
Parent - By js55 (*****) Date 06-04-2007 19:25
"I thought "wow, finally going to get to learn something from this guy.  Boy was I disappointed because he surely was "special". 

LMAO!!!
Parent - - By hogan (****) Date 05-02-2007 14:44
typically what i see as the "chain of command" starts with the local municipality. who will refer you to the building code "as amended", this is typically icc or boca or something similar. this amended code will usually refer you to aisc (lrfd, asd) who in turn will refer you to aws d1.1 and/or awd d1.8 (d1.3, d1.4, ect).  the job specs and drawings will also list additional requirements. i have not yet worked to d1.8 , but i have performed a lot of inspection to the fema seismic requirements. i would think that you would want all building codes that pertain to the project. there are some differences between aws and aisc, and aisc has always overruled aws. because aisc is the referring document
Parent - By swnorris (****) Date 05-18-2007 16:49
Dennis,

LRFD is Load and Resistance Factor Design, and ASD is Allowable Stress Design.  Both are AISC publications, and both have been combined in the more recent Steel Construction Manual (13th edition).
Parent - - By Bob Garner (***) Date 06-04-2007 16:20
I just got my copy of the 2006 AISC Seismic Design Manual.  Under this manual, if the building is subject to seismic, the designer is now required to indicate in the contract documents those welds that are "demand critical welds".  I haven't seen this happen yet but it should be coming soon.

Bob Garner
Parent - - By thcqci (***) Date 06-13-2007 13:03
That has been my biggest complaint about our fabrication drawings and handling of jobs.  Typically, we are told either verbally, or in notes, "this job is seismic".  Then they ask me what do we need to do different and my first response is always, what part of the frame is covered under the seismic provisions?  Looking at these drawings, how are you letting me know that?  They don't seem to understand there can and probably should be parts that are in the SLRS and parts that are not.  This usually ends the conversation because they don't want to take the time to seperate that part of the frame out.  So "you know what, that really doesn't need to be seismic afterall".  Well if it was that unimportant, then why bring it up to begin with.  We have only done 2 jobs, one going to CA and the other to UT, that truely turned out to be seismic.  One was an outside engineer and he provided the required info and required "special inspection", and the other was deemed all seismic.  Only had a handfull CJP shop welds, everything else was fillets.  Used the proper fillers (with certs) and proceeded.  No extra outside inspections were performed.  No other info requested from the shop.  I don't understand why engineers so carelessly throw around the seismic requirements without understanding the full ramifications of doing so.  And as squeaky a wheel as I try to be and as much as I try to reverse educate the process, it seems to mostly fall on deaf ears.
Parent - - By swnorris (****) Date 06-13-2007 16:44
Doug,

Once awarded a project, we have a turnover meeting, where our estimating team turns the project over to the project management and detailing teams.  This is when I get involved with project management and review project specifications.  When we have seismic applications (which are generally greater than R3), we have our detailers note "SLRS Member" on the shop drawings for each applicable member underneath the shipping mark on the shop details. 
Wind and low seismic applications are generally equal to or less than R3, and are generally designed to meet AISC design criteria, but high seismic applications (greater than R3) have to meet both AISC and Seismic design criteria, even if wind effects control.  The R factor is indicated in the contract documents.  If our estimating team sees an R factor greater than 3, they know that the cost of the project will increase because of all the special requirements.

Bob,

I  hope you didn't pay for that manual because it's a free download on the AISC website.     
Parent - - By cwi-cws (*) Date 06-14-2007 03:07
swnorris got it!,we had the first seismic project come through the shop.we had some minor kinks to work out,but we felt good about our finished product.we had a startup meeting with the inspection /eng. firm even before details were sent out for final approval.the biggest problem i see for fabrication shops is under estimation of heavy sections .the special inspector had UT,MT and was a cwi.he was as good as they come,he was very good at keeping his reports up to par.it was his first FEMA project also .everyone did their homework!!! you can get free copies or download all of the FEMA codes free. so the last words of advice C Y A!!!!!!!
Parent - By Phalen (*) Date 07-18-2007 21:30
I just did a big steel job under the 2005 aisc siesmic code.  It was simple to me, the spec called out for the siesmic moment frams to be welded per aisc and the rest was under D.1.  There was 4 differant types of frames one of the most interesting was a EBf frame with a link section kind of like a RBS.  Just read the spec. for what code is for what, look at the plan if it's a SMF frame look up the SMF in the aisc, read the rest of the book for GP and there you go.  If the spec says the frames are under FEMA 353 then look up the demand on the plans, then look under the demand in FEMA and ur of to the races.
Up Topic American Welding Society Services / Technical Standards & Publications / AISC or D1.1

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