East Coast Connection Design
East Coast Connection Design
(OP)
Without getting into the debate a few posts below, I am interested in how your companies delegate connection design. Currently, we design shear type connections and provide loads for moment connections. For a variety of reasons, I would like to see us delegate more of this to the fabricator.
Internally, there is some resistance and I can only speculate the reasons; however, a well thought out work flow might help things along. I am interested in what works well and what does not. At what stage of the design in a typical Design-Bid-Build do you involve the fabricator? How does it affect your bottom line and does it contribute to everyone on the project being profitable? How does it effect your risk profile? How do you guard against liability issues with your loads being published on a drawing or spec? How do you handle a building that gets re-purposed later (potentially impacting loads)? I'm interested in the good and bad, but not interested in a debate on whether it should be an accepted practice. Thanks!
Internally, there is some resistance and I can only speculate the reasons; however, a well thought out work flow might help things along. I am interested in what works well and what does not. At what stage of the design in a typical Design-Bid-Build do you involve the fabricator? How does it affect your bottom line and does it contribute to everyone on the project being profitable? How does it effect your risk profile? How do you guard against liability issues with your loads being published on a drawing or spec? How do you handle a building that gets re-purposed later (potentially impacting loads)? I'm interested in the good and bad, but not interested in a debate on whether it should be an accepted practice. Thanks!






RE: East Coast Connection Design
RE: East Coast Connection Design
RE: East Coast Connection Design
http://www.nceng.com.au/
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
RE: East Coast Connection Design
With that said I believe a system that has worked well is for the EOR to hire the connection designer up front to design the connections for them. That way the EOR gets the expertise of seasoned connection engineers, the connection engineer working closely with the EOR will fully understand the loads and load paths, the project benefits at bid time by all fabricators understanding fully their intended scope for connections thus all will be on equal footing, and the approval process goes more smoothly.
A major problem though with this approach is getting the owner to pay these connection design fees up front. The owner needs to be educated that they are paying the fees regardless of whether they are on the front end with the EOR or the back end with the fabricator, but either way they are paying. The savings comes in at bid time with the fabricators knowing full well what is expected. This process also helps to mitigate "extras" and law suits.
RE: East Coast Connection Design
Unfortunately, most companies continue to specify the archaic note about designing the connection for 50% (or 55%) of the distributed load shown in the AISC Table. That, I think, is bad practice. I don't necessarily see anything wrong with delegating when connections are simple, but I think the actual loads should be specified on the plan to assist the connection engineer.
RE: East Coast Connection Design
I detail all my own connections. I don't ever want a gray area of who is responsible for what. If my seal is on the plans- the connections will be designed.
RE: East Coast Connection Design
The issue that I see where I work is not with connections for a 3 story office building, mall, etc., it is with the complex buildings with potentially thousands of connections and configurations. In such cases it is not as simple to have a table or typical detail saying all W8s to W12s have X connection. Fees are getting pushed lower and lower on these projects and it is increasingly difficult to be competitive with other firms that are delegating connection design.
STrPE:
Assuming a very progressive owner that accepted such terms, where would the line be drawn (no pun intended) as to shop drawings? Or did we just add an extra set of eyes and $? Also, on these complex projects where the arch or owner iterates the design 10 or more times, what is the benefit of having the connection engineer being involved through the iterations versus being on the back end? It seems that if the connections are done by the same group of professionals performing the shop drawings and the structural design is set (i.e.-no longer iterating), the process would be more efficient. I'm not criticizing the process, just trying to understand the benefits. Finally, in your scenario I assume the SEOR would not want to include the member loads on the drawings, correct?
RE: East Coast Connection Design
That would be a good example of not an ordinary connection.
The advantage of delegating connection design is primarily an economic one for the owner. An experienced connection engineer will almost certainly be able to provide greater efficiency to the owner.
If I had to design each and every connection, you can be sure I'd take the worst case for each beam size and design all the connections for that capacity. It's not efficient, but our fees do not cover the expense of having me go through all of the beams.
A connection engineer has the capacity and experience to do it in a much more efficient manner than I can.
RE: East Coast Connection Design
The iterative design process mentioned is killer to a connection designer. At some point, which may differ from job to job, the designs should try to be "frozen" so that changes can be minimized yet connection design can progress forward to meet schedule demands. Otherwise, you are correct again, money is wasted.
Most connection engineers are not detailers therefore do not produce shop drawings; connx design is tedious enough. Leave the shop drawings to detailers and leave the connection design to engineers.
RE: East Coast Connection Design
RE: East Coast Connection Design
I dont compete on fees, most of my client retain my services for other reasons.
http://www.nceng.com.au/
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
RE: East Coast Connection Design
You have made my case. Complex buildings are exactly where the EOR should design the connections, as he is the only one who knows how the whole structure works.
However, I will admit that having never tried this system, I can't argue many of the issues intelligently.
Low fees are a separate issue...I think abdicating responsibility for critical elements of a structure is not the way out of that problem.
RE: East Coast Connection Design
I like doing connection detailing if the client is willing to pay for it, mainly because I like to know that I handled the complete the design from top to bottom. But if they don't want to pay for it, I don't want to do it.
www.idecharlotte.com
RE: East Coast Connection Design
As I have mentioned before, there are a long list of practical and responsible reasons for delegating the connection design. I would suggest discussing this with a firm experienced in the practice. There are several ways to address this delegation, but they are not all equally beneficial to the project.
http://www.FerrellEngineering.com
RE: East Coast Connection Design
RE: East Coast Connection Design
This is always a concern when we work directly with design firms. Complex structures and architects always have changes and the design is worked through. In these cases a project can benefit from a large connection design team. A fast and efficient connection design process is important. Consideration for the connections can also result in minor design revisions that benefit the project. We have found that working directly with the designer has significant benefit on the project. Fabrication and erection budgets have less assumptions and can reflect major discounts. As mentioned connection design is a cost the owner will pay a some stage of the process. An educated owner benefits every time.
http://www.FerrellEngineering.com
RE: East Coast Connection Design
I may make it a personal mission to change your position.
Post Hyatt collapse the intent is to have a second professional share the responsibility for review of the connections. A second set of eyes with a specific concentration on the connections. However, as with most things the practice falls short of the ideal. Many fabricators provide the very minimum and the advantages of participating in the design process are lost. Or the EOR provide insufficient guide for the connection design requirements and quality of calculations required. Calculation errors and approval comments, or lack of information create bad experiences for the EOR. There is a professional and high quality way to delegate connection design. Done correctly the project benefits because the design product is better.
http://www.FerrellEngineering.com
RE: East Coast Connection Design
Probably not worth your effort, as both rowingengineer and I practice in Australia, and your approach is unheard of here, as far as I know. We do delegate certain structural tasks, but generally have a different way of doing things than in the US. Structural steel in buildings is for the most part only used for the roof structures and wall systems of low rise buildings, and we have architects who present some weird challenges in those areas. Most of our multi-storey buildings are reinforced concrete, with a lot of post-tensioning, and the PT is sometimes subbed out, although I am one who resists that method.
We don't use bar joists, metal deck diaphragms, PEMB, and a lot of other things common in the US. I had a big learning curve when I first came to Australia from the US, as the predominant vertical load was uplift rather than the snow load I was used to.
Another thing different in the way we present designs here...the structural drawings show very little in the way of dimensions, instead depending on the architectural drawings. I don't know how they do it sometimes, but the steel detailers seem to be able to work out the structural dimensions. Fabricators do constantly complain about the quality of drawings they have to work with, so I am sure they don't want the added task of designing connections.
RE: East Coast Connection Design
We have worked with a couple detailers in Australia and New Zealand. But come to think of it, never on a local project. I have reviewed some excellent connection design research from Australia, that later was incorporated in some AISC examples. Australia is at the top of my list for a future vacation. As a diver and golfer, I would probably do very little connection design if I lived there.
Thoughtofthis
Sorry, I am not hijacking your post. I do know a good resource if you want to discuss the pros/cons of delegating the connection design.
http://www.FerrellEngineering.com
RE: East Coast Connection Design
For those who have made this transition, how did you suggest the process to architects, owners, and/or contractors (for design build) to get the team on board?
RE: East Coast Connection Design
RE: East Coast Connection Design
as far as revit goes, with limited experience, the steel fabricators have not used my revit model. they start from scratch using their own BIM software.
RE: East Coast Connection Design
Most detailing software does NOT offer connection design. As with any engineering process there is packaged software for simple conditions. And there are very expensive software packages ($20k +) (for example SDS) that offer very good connection design information integrated into the model and shop drawings. For the best software the limitation is the experience of the user, which is rarely an engineer.
I believe the front runner in the BIM software is TEKLA. We are involved in an increasing number of BIM projects. And honestly I have mixed feelings on the value. But, I believe this will be a big part of the engineer's responsibility in the future. Ideally a BIM would incorporate the models of all the trades and provide an immediate representation of interferences and practical concerns. However, many of the modeling softwares do not communicate well, so an additional party must combine the information. Also structural models lack the geometric precision required for final shop drawings. And today a fabricator may have invested in SDS and the BIM may be in TEKLA. I can see a future where the fabricator is awarded a project with a BIM package. Having the appropriate software, the fabricator can push a button and generate the shop drawings. This will create some new contract clauses over erection and fabrication fit-up and tolerances.
It is coming, but I don't think it is mainstream yet.
http://www.FerrellEngineering.com
RE: East Coast Connection Design
1) How do you handle shop drawing review regarding connections, RFIs, and SI? I am thinking specifically about the workflow and who does what (in the case of the fabricator providing the engineer). In some cases we are also the SI.
2) How do you show connections on your structural drawings? For certain projects we show sections at the same locations as the arch and additional sections and enlarged plans at complicated areas. If you show a representational connections do you just not provide notes? or do you show it as hidden or not at all?
3) In my state, state projects are required to undergo review by the state construction office. Is this an issue on these projects because technically none of the connections will have been designed at this point?
RE: East Coast Connection Design
Otherwise you might artistically draw something in so that a zoomed in detail doesn't look stupid, but you wouldn't provide any sizes, dimensions or other information about the connection other than the required loads.
A problem I've often seen is that the detailers in the design engineer's office get overexcited and put dimensions and details all over connections that are supposed to be designed by others. The engineer stamps them without doing much of a check because he figures it's the fabricator's responsibility to check. The fabricator then looks and sees a stamped detail with all this information on it and just builds it because it's already designed. In this case this is an oversight of the design engineer, but it's a dangerous situation no matter who is at fault.
Personally, I never provide any extra information at the connections unless it's conceptually necessary to make my member arrangement work. I also have a note on every drawing saying that, unless specifically noted, all connections shown on the design drawings are conceptual in nature only and detailed design is the responsibility of the fabricator's engineer.
Specs from large clients drive me crazy, because they tend to be full of really poorly worded connection design specifications where it tells the fabricator to design to the greater of, or least of, or some other series of really complicated tests that you'll never be sure are being used properly and have no relationship to the actual forces in the structure.
RE: East Coast Connection Design
Other times it'll come in two stages and you'll get a copy of some connection calcs first.
Sometimes you never really see much in the way of calcs and you just get a pile of shops stamped by the connection design engineer.
RE: East Coast Connection Design
Most jobs don't have enough steel to make that work in full, but all of my jobs were based on maximum information and communication; by the end, these engineers and I could finish each other's sentences, but we were, of course, too respectful to do that.
When the lawyers and bean counters moved in, we were to "not interfere in means and methods" because they were the Constructor's job. It is surprising what they can say does, or may, interfere with means and methods.
As I approached retirement, I tried sending complete copies of the program results, but "that belongs to us" and we won't give it away.
I should perhaps have mentioned that I detailed steel for a while.
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: East Coast Connection Design
I think we are a generation apart on big coal plants.
I started off working on plants in the range from 600 to 1250 MW.
Connect-
I last used TEKLA in 2007.
At that point the shop drawing you could "scrub" out of a model were absolutely horrible. I would be embarrassed to give them to a shop for fab. They were cartoonish and had no where near the info you'd find on the good ole hand drawn or CAD shop drawings (I was always partial to American Bridge drawings).
QC on the drawings was almost impossible....The drawings had to be checked against a model....oops, hope no one changed my connections from the last night!
Often times I would open the "official" model to go back and check the connection and OH SH&^%!!!! there is no connection at all. The documentation process was non-existent and once we finally had some in place it TOOK LONGER THAN JUST DETAILING THE CONNECTIONS IN CAD!!!! AHH I hated it at times.
The BIM thing is also hard for me to believe in. We'd have entire power plants modeled in TEKLA/BIM and when you ran an interference check you would literally get millions of "interferences". Sometimes an interference between a piece of steel and a flue would show up as 500 separate interferences. Again, tracking, finding, and documenting these things was next to impossible.
I really think a lot of this stuff comes from owners wanting to do things quicker than the technology will allow.
RE: East Coast Connection Design
Many of our customers now use TEKLA or SDS for their shop drawings. We do not review connections within the model, so shop drawings must show sufficient information for review. I have received useless drawings, but simply mark the revise/resubmit. But, the traditional shop drawing information is becoming less important and less common on the drawings. But the internal detailing within the model shop be done be an real draftsman. These skilled people are disappearing. The fabricator wants the CNC data files for their equipment. A beam line with do all the drilling/punching and cutting from the magic uploaded file. Similar for the cutting tables. The shop drawings are primarily for the miscellaneous fitted material. Shear tabs, stiffener plates, gusset plates, etc.
I recently bled red marker over a set of shop drawings. The obvious fit up and detailing errors were to obvious to not mark. I charge to much per hour to be a detailing checker. But, when I asked if the drawings had been checked before submitted, the response was "we have never used a checker". They expect the software to catch the geometry issues. The fabricators are increasingly relying on this mentality and accepting a language barrier with the lowest bid detailers. But, in fairness they are not all this bad.
http://www.FerrellEngineering.com