Contract Issues - Structural Steel Connection Design in the Midwest
Contract Issues - Structural Steel Connection Design in the Midwest
(OP)
I am located in the midwest (New Madrid Fault Zone).....An area that is relatively new to serious seismic design. On several projects we have fallen into the scope of the AISC seismic provisions. Because our industry here is set up in a way that is not conducive for the EOR to design lateral force resisting system connections, the connection design responsibility is forwarded on to the fabricator. Bottom line, the EOR is not given enough time and/or fee to do connection design. It it becoming more and more common that fabricators are coming back during the project demanding more money (hundreds of thousands of dollars) because the connections geomectrically dont work, they didnt budget large connections, or they just make up excuses to cover their losses.
We have tried several ways to make it clear to the fabricators that the connections will be larger than normal, and that the seismic provisions are to be followed. But it still ends up that the fabricator claims that he/she cannot properly bid the connections because it takes the technical experience of an engineer to do so.
Has anyone else run into this problem and how have you remedied it? Anything to put on the contract documents? Any good published information out there? I assume this problem extends over to the east coast.
We have tried several ways to make it clear to the fabricators that the connections will be larger than normal, and that the seismic provisions are to be followed. But it still ends up that the fabricator claims that he/she cannot properly bid the connections because it takes the technical experience of an engineer to do so.
Has anyone else run into this problem and how have you remedied it? Anything to put on the contract documents? Any good published information out there? I assume this problem extends over to the east coast.






RE: Contract Issues - Structural Steel Connection Design in the Midwest
A good set of drawings will indicate the seismic requirements. They'll also show details with large gusset plates, bend lines, brace reinforcement, etc. An experienced fabricator and connection engineer should be able to bid these projects accurately.
As far as communicating this to the fabricator, the only thing I can think of is to make specific mention of the seismic requirements and show some details that truly represent the larger connections that will be required.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
RE: Contract Issues - Structural Steel Connection Design in the Midwest
It feels like the more typical connection details we put on the drawing, the more problems we get...the fabricators tend to look at them as set in stone. When the fabricator's engineer turns around and tells them the connection cant work exactly as the detail shows it, they proceed with a change order.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
The beefed-up seismic connections would be quite a shock to the contractor/fabricator/detailer if they weren't shown on the drawings, so to keep from surprising anyone (and incurring extra costs), I think you have to show some sort of typical detail.
Doing connection design, we see drawings from engineers all over the country. This is pretty standard practice, and an experienced fabricator shouldn't be surprised by this.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
I would suggest that you take a stand with your firm and get what's necessary to do a proper design. You've already laid out the case (change orders/claims). If they are unwilling to listen, then yes, it's time for you to move on. You're in a situation that could easily attempt to compromise your integrity and that of the engineering profession.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
That's beside the point. I was just looking for ideas of what to put on the contract documents to avoid these change orders. It appears we're doing all that we can do at the moment in the current situation.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
As far as being our own worst enemies, I think the thought comes from the idea that I can design something for a cheaper price than Ron can and I'm prepared to do this (not serious, Ron). This, in my opinion, has caused the decline in the quality of trades available, too; contractors cannot afford to hire quality people. In our environs, a real estate agent can make more money selling a building than the engineer that designed the building.
Dik
RE: Contract Issues - Structural Steel Connection Design in the Midwest
When a job gets to a fabricator the above items are already established. This may result in a geometry which may makes it difficult or almost impossible to design the connections. When a fabricator encounters this problem he doesn't have the option of adding another frame, increasing the column or beam size, ect.
Unless the EOR has atleast done some preliminary designs on the critical connections to verify that they workable and reasonable, he may be creating a problem that can't be solved by the fabricator. A problem which could be avoided if anticipated by the engineer, who can adjust elements before the job is bid.
A simple example is an engineer who decides to pin the base of all columns. I have dealt with wood jobs where the engineer designed all column bases as pins and assumed that the wood beams and columns where acting as rigid frames to resist the lateral load. On one job I indicated to the engineer that I could develop fixity at the top of the columns but that the architect and owner would not be happy with the amount of steel required to solve the problem.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
RE: Contract Issues - Structural Steel Connection Design in the Midwest
Indeed, I recall Edward Phrang once spoke at a seminar on the Hyatt Regency disaster in Kansas City in the 70's and his concluding remarks were something like: "We engineeers need to get past this notion that we are designers of frame members that just happen to be connected. We should rather think of our structures as a multitude of connections linked together by members."
Passing on connection design (the most critical part of any structure) is indeed passing the lateral design of the building off to someone else. Its really what "caused" the KC disaster.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
I believe the more appropriate "cause" of the Hyatt collapse (in 1981, by the way) was a combination of poor design in the office and poor communication during construction as the contractor tried to provide a "better" (at least more erectable) connection.
And the Hyatt collapse was in 1981.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
RE: Contract Issues - Structural Steel Connection Design in the Midwest
I understand and believe that connection design should be completed in the bid documents. I'm not even arguing this point...AND THAT IS NOT THE PURPOSE OF THIS THREAD. In the midwest for typical five story or less structures, the industry has pressured the engineer into passing connection design off to post bid work. I cannot change the industry....Only large groups of engineers can. Therefore I'm F*'d into doing it this way. If you and all the respected senior structural engineers cant gather enough clout to change codes and remedy this solution then please help me deal with what I've got.
What Edward Phrang said makes no difference because in the 25 years since his quote, nothing in my area has changed because of it. Edward Phrang should have worked with ASCE or some other organization to change the situation instead of placing the responsibility to fight the battle on the individual engineer. Also, I believe the KS failure was due to a fabricator changing a detail for constructability, not the engineer failing to design the connection.
You can call connection design part of the lateral design. But in no way can you say the lateral design of the building has been completely passed off to the fabricators engineer.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
This is my opinion for what it's worth: If you think the connection design is your responsibility, then design the connections. If you are sealing and signing drawings, the entire structural design is your responsibility even if the contractor/detailer provides connection design. you are not off of the hook for liability and protecting public safety just because the owner has a tight schedule and doesn't pay you enough to design connections.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
When the Owner’s Designated Representative for Design shows the complete design of the Connections in the structural Design Drawings, the following information is included:
(a) All weld sizes and lengths;
(b) All bolt sizes, locations, quantities and grades;
(c) All plate and angle sizes, thicknesses and dimensions; and,
(d) All work point locations and related information.
The intent of this approach is that complete information necessary for Connection detailing, fabrication and erection is shown in the structural Design Drawings. The Steel Detailer will then be able to transfer this information to the Shop and Erection Drawings, applying it to the individual pieces being detailed.
When the Owner’s Designated Representative for Design allows the Fabricator to select or complete the Connections, this is commonly done by referring to tables in the Contract Documents or in the AISC Manual of Steel Construction, or by schematically showing the types of Connections required in the structural Design Drawings. The Steel Detailer will then configure the Connections based upon the design loads and other information given in the structural Design Drawings. If the desired Connection is not covered in those tables, a detail of the “special” Connection should be contained in the structural Design Drawings. This detail should provide such information as weld sizes, plate thicknesses and quantities of bolts. However, there may be some geometry and dimensional information that the Steel Detailer must develop. The intent of this method is that the Steel Detailer will select the Connection materials and configuration from the referenced tables or complete the specific Connection configuration (i.e. dimensions, edge distances and bolt spacing) based upon the Connection details that are shown in the structural Design Drawings. This method will require the skill of an experienced Steel Detailer, who is familiar with the AISC requirements for Connection configurations, capable and experienced in the use of the Connection tables in the AISC Manual of Steel Construction and capable of calculating dimensions and adapting a typical Connection detail to similar situations. Notations of loadings in the structural Design Drawings are only to facilitate selection of the Connections from the referenced tables. It is not the intent of this method that the Steel Detailer practice engineering.
Yes, there are two parts to this topic - what is the "standard practice" which I've posted above AND what is the "prevalent practice" and how can we effect the politics of it all to allow better control over our designs. I would recommend and refer you to archeng59's post above - we aren't that helpless.
I also work in the Midwest US and I guess I haven't found that much resistance to setting a fee appropriate to do the connection designs. I have to admit we don't do a lot of work in southern Illinois, but we have done work in San Francisco and LA and detailed the connections.
nutte - the Hyatt Regency collapse, according to Jack Gilliam, the EOR, and the multitude of reports that came out of it, was that Gilliam didn't design the connections, he only showed a concept with a design load and expected the fabricator to design it.
The fabricator started the shops, and a bit of the design, but half-way through the process, farmed the work to another fabricator who ASSUMED that the design had been completed by the first fabricator and simply passed the un-checked un-designed connection through their process.
Gilliam's firm quickly reviewed the shop drawings and assumed the connection was also designed and didn't check it closely.
This original design (the continuous rod) wasn't ever built but was later determined to have been very poor and lacked sufficient capacity had it been built. The Contractor's alternative (splitting the rod) only made a bad detail worse.
The whole point here was that farming off a connection design to a fabricator carries additional risks for the EOR and I agree with Loui1 that there's frustration out there in our engineering industry in that we are being squeezed to design less due to tigher fees. But is it a problem or a challenge for us?
RE: Contract Issues - Structural Steel Connection Design in the Midwest
Yes, engineers in my state are pretty much on their own. If I go ahead and start charging adequete fees and time to design all the lateral system connections I will be out of a job because there are plenty of engineers in my state who will gladly outbid me and farm out the connections and risk the lawsuit later. I have no options but to go with the industry or move out of this state.
The jobs done in california, yes, of course you designed the connections....because THEY'RE REQUIRED BY THE STATE CODE and the industry is already set up correctly there!!! I dont think CA even allows the EOR to farm out the connections. I'm talking about the midwest, not the west.
I totally understand your reasoning, quotes from the Code of Practice, and ethical ideas, but you still have not given me any input to my initial question other than trying to unknowingly convince me to place my balls in the guillotine :) I will try to change my local NCSEA when the time comes and that's about all I can do. This is a industry problem, not a personal challenge. Maybe you have to come visit and see for yourself how messed up things are here.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
The Hyatt connection originally called for one continuous rod, threaded along the entire length, supporting multiple levels. The contractor realized the difficulty in threading nuts the entire length of this threaded rod (bad original design) and proposed a new connection with two separate rods (really bad design). The revised design fell through the cracks in communication, got approved by the EOR, and was built, resulting in the disaster. More here: http:
The original design was structurally adequate but not erectable. The connection design was not farmed out to the fabricator. In an effort to make the connection erectable, the contractor proposed another detail, which was wholly inadequate, that the EOR carelessly approved. The problem here is the poor communication, not the delegation of connection design.
Back on topic, I think there are benefits to the way we do things, that is letting the fabricator perform connection design. For simple framing especially, this allows the fabricator to choose the best conneciton for them (bolted clip angles, welded clip angles, shear tabs, end plates, etc). Similarly with bracing connections, the fabricator can choose one of several methods to connect the pieces to expedite the entire construction process.
I also feel (as I mentioned above) that a lot, maybe most, of the structural engineers out there who don't regularly performc connection design know very little about the process. If a small-time engineer doing convenience stores checks a shear plate connection, does he check bolt shear and plate shear and stop? Does he even know about the other limit states (plate bending, both gross and net section, bolt bearing, eccentric bolt shear, eccentric welds, bending/buckling on the beam cope, and so on)? Maybe he has a good grasp of these processes. What about the Uniform Force Method? Designing truss connections? I think we're better off leaving connection design to engineers that specialize in it.
The challenge is to provide good information on the structural drawings so the fabricator can design the connections economically and efficiently. Get rid of the 50% allowable load capacity crap. Give reactions on beams, or at least a table that's not so conservative it's useless. We go round and round with EOR's that insist we develop 25 kips shear in the W8x10 filler beam that spans 3', just because their standard notes, which haven't been updated since 1980, say to do it that way. Show the types of connections you're looking for, with the note that they're representative of the type of connection you want. Make the fabricator provide connection design calculations that you can review. You'll learn real quick if the connection engineer knows what he's doing or not.
And to get back to the first post, show a sketch of one of these super-strong seismic connections so everybody's bidding the same thing and you don't get hit with extras at the end. That way we, as engineers, can exert some influence and weed out inferior fabricators in the beginning. Otherwise, the good fabricators are priced out of the job, and you get an inferior product that winds up costing the same or more than the good fabricator with considerable more headache.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
In the 25 years + I've been a structural engineer, the common consensus is that fabricators on large projects generally do standard beam connections but for anything unique, the EOR should design it. The extended quote from the Code of Standard Practice that I posted above implies that this is the desired case.
nutte:
Your quote
about the Hyatt is not correct. The original design (single long rod) was checked and tested by the NBS and found wanting. The split rod concept was simply a worse condition from that.
You also say
This is not so. Jack Gilliam stated that his original detail was not designed (this was his primary defence) but that it was a schematic detail with a given tension load that he fully expected the fabricator to design.
Finally, you say
The entire ramification of this disaster was all about the issue of delegation. The concluding comments that Gilliam makes when speaking around the country on this was "you can delegate engineering tasks to others, but as EOR you cannot delegate responsibility".
RE: Contract Issues - Structural Steel Connection Design in the Midwest
Here, Here!!! Sounds like you run into the same stuff we deal with. I could not have said it better myself. I too am a connection design engineer, thats all we do. I believe the best thing an EOR can do to help with connection design, is do as Nutte said and avoid the 50% UDL stuff, furnish the real reactions, transfer forces, etc. on the drawings, like AISC recommends. And, pay close attention to the R of the building your designing. This too can have an adverse effect on the size of the connections. And lastly, if you are going to specify that seismic provisions apply, at least be familiar with what that means to the connection design. I just had a conference call with a detailer, fabricator, EOR and Myself where the EOR had done a great job of furnishing beam reactions and actually gave moment values for the moment connections, but he specified that seismic conditions apply. We spent 45 minutes walking him through the seismic provisions of AISC and afterwards he still insisted we design the moment connections for the small moment loads given yet provide full column stiffeners as if designing for the full moment capacity of the beam.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
"In addition, you should clearly note that the fabricator is responsible for the design and procurement of a registered engineer to undertake the connection design and that no additional fees will be entertained in the design of same."
"It is not the intent of this method that the Steel Detailer practice engineering."
I find the contrast between the first two statements and the last illuminating- the Code of Standard Practice assuming that the any connection design by the fabricator will be so cook-booked that it doesn't even constitute engineering to do it, while the design engineers are assuming it will require a registered structural engineer to complete.
My idea: If you're farming out the connection design, include a line item in the bid for "PE-design of all connections"- it might be illuminating to all concerned. Of course, it sounds like they have to do a lot of this work prior to the bid, but it still might make it a lot easier to justify your cost.
RE: Contract Issues - Structural Steel Connection Design in the Midwest
RE: Contract Issues - Structural Steel Connection Design in the Midwest
We used to have a client who was a large grocery store chain. They had their own construction management group and many times did their own architectural design for their smaller projects. I recall once that an architect on their staff had struggled with a detail for a grease trap or something. It was a small feature in their design, but fairly intricate.
They would detail it, only to find that the construction group within their company couldn't, or wouldn't build it as he wished. So he detailed it further, showing more data. Still no luck. They'd screw it up.
After a series of three or four further refined details, with no luck in getting the thing constructed properly, he finally did a whole series of details on one big sheet, including an isometric. In the middle of the sheet he added a large note in a box:
"If you can't build this properly based upon these details, you're an absolute idiot."
He claims it finally got built right -
RE: Contract Issues - Structural Steel Connection Design in the Midwest
RE: Contract Issues - Structural Steel Connection Design in the Midwest