I am seeing more and more SE’s not design the Steel connections and instead leave this item to be done by the fabricator. I don’t mind because we are often hired by fabricators to complete their work. But if you are hired to do a job, do it, don’t just spec “connections by others”. What do you do, design the Connections or Specify them?
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Structural Connections 4
- Thread starter BRGENG
- Start date
I am a big advocate for the consultant to design the connections for two reasons.
Firstly that is how they do it in Australia where I started
Secondly, you often spend just as much time checking the fabricators engineers drawings as you would just designing them.
Firstly that is how they do it in Australia where I started
Secondly, you often spend just as much time checking the fabricators engineers drawings as you would just designing them.
Just to give you the perspective from the other side of the coin................. We can spend quite a bit of time designing and documenting shear tabs, only to have the fabricator come back and ask to do double clip angles because that's what their shop is set up for and is easiest and cheapest for them to do.
When that happens, and it almost always does, we've spend time designing and documenting connections only to have to review what they want to change to anyway. Some say just design and document and don't allow changes, but that often gets a lot of pushback from owners, because the contractor and fabricator are in their ear telling them they can save money if they can change the connections.
It's even to the point where this happens with braced frame connections. The fabricator sees the details and wants to do something different, again, because it's easier for them.
When that happens, and it almost always does, we've spend time designing and documenting connections only to have to review what they want to change to anyway. Some say just design and document and don't allow changes, but that often gets a lot of pushback from owners, because the contractor and fabricator are in their ear telling them they can save money if they can change the connections.
It's even to the point where this happens with braced frame connections. The fabricator sees the details and wants to do something different, again, because it's easier for them.
UnthoughtKnown
Structural
Design delegate the connections. Put the reactions on the drawings. Connections are detailed with computer software by the detailer anyways. They have the ability to design and detail them most economically.
Plus we wouldn't get the job if we included connection design. Our competitor's would underbid us because they are design delegating connections among other items.
Plus we wouldn't get the job if we included connection design. Our competitor's would underbid us because they are design delegating connections among other items.
On the West coast- we show the connections. If the fabricator wants to change them, they can submit an alternate design for approval.
Connections are where most of the structural issues come about- I don't want to delegate this to someone I don't know.
Connections are where most of the structural issues come about- I don't want to delegate this to someone I don't know.
I've read and heard this is a geographic thing in the US, with west coast being almost always done by the EOR with the east coast often being delegated. As both sides have been represented here, there is a good case for both methods, which I have also read good cases for both in Modern Steel Construction... I have been the EOR on many steel projects in Florida and never delegated (but could see why you would, obviously it can save you time), but have been the specialty engineer for fabricators several times on FL projects so it happens here too. I have even designed moment connections a few times. I always request the actual service moment and reaction for economic design rather than this cop-out "max service capacity".
AISC pretty clearly indicates that if you delegate connection design, you must show the reactions and whether ASD/LRFD. As the specialty engineer I obviously like it when people delegate the connection design, as these are pretty nice, clean jobs. We submit details and calcs as needed. EOR's have usually been very responsive to any questions or comments also.
I have often wondered whether an architect or owner has ever been savvy enough to ask the EOR up front during fee and contract negotiation, does this include the connection design? Because essentially the EOR is subtly shedding scope and pushing cost over onto the construction side. The fabricator hopefully catches this during their bid and adds the specialty engineer's bid into their fee, although its usually a drop in the bucket of a mutli-story steel frame fab package....
I think everyone in Florida should delegate their connection design
AISC pretty clearly indicates that if you delegate connection design, you must show the reactions and whether ASD/LRFD. As the specialty engineer I obviously like it when people delegate the connection design, as these are pretty nice, clean jobs. We submit details and calcs as needed. EOR's have usually been very responsive to any questions or comments also.
I have often wondered whether an architect or owner has ever been savvy enough to ask the EOR up front during fee and contract negotiation, does this include the connection design? Because essentially the EOR is subtly shedding scope and pushing cost over onto the construction side. The fabricator hopefully catches this during their bid and adds the specialty engineer's bid into their fee, although its usually a drop in the bucket of a mutli-story steel frame fab package....
I think everyone in Florida should delegate their connection design
In Spain theoretically the designer has to define everything, yet it is asked then the revision of the fabricator shop plans. This means regulators themselves are aware of that the shop, fo fit their means and intent, uses to get with their changes ahead. And in fact this happens.
Plus, when acting as a consultant for others, I have found they shy from the double or triple fee they are made aware will have to be charged if with a complete design and check of the connections; in the end they want to believe the connections will be changed at the shop and everything will go fine. This usually goes fine in behaviour mainly because the fabricators themselves use not to be fools, otherwise would be recipe for disaster. We have scarce disasters on this as of now, so it is more than anything an attempt to scrape off some bucks at design time.
Roughly as Lion06 says.
Plus, when acting as a consultant for others, I have found they shy from the double or triple fee they are made aware will have to be charged if with a complete design and check of the connections; in the end they want to believe the connections will be changed at the shop and everything will go fine. This usually goes fine in behaviour mainly because the fabricators themselves use not to be fools, otherwise would be recipe for disaster. We have scarce disasters on this as of now, so it is more than anything an attempt to scrape off some bucks at design time.
Roughly as Lion06 says.
A large reason why they design their connections on the west coast is because of the seismic design and the importance of the type of connection on the ductility requirements.
In Australia, the main designer almost always designs the connections.
In the UK the main designer most often does not design the connections for larger buildings but probably will do for smaller ones.
I have worked both ways.
In Australia, the main designer almost always designs the connections.
In the UK the main designer most often does not design the connections for larger buildings but probably will do for smaller ones.
I have worked both ways.
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1
- Thread starter
- #10
I often hear, as stated above, that we can’t include the design because then are fee would be higher and we would lose the job to another engineer. That is exactly why we point this out to Architects and Owners, especially if you can talk to the owner. They don’t sign contracts with Architects expecting to get a partial design. Some Architect want it specified out to lower the SE fee and pocket the difference and making the owner pay twice. I firmly believe that all connections should be designed by the EOR, but I am also happy to make easy cash of the EOR that can’t design everything and only provide 95% of the work.
Owners do not use to be overly rational at every point; and know very well how not to see what they should. I have seen owners happy for years with just someone they have the custom to work by whatever the reason, "chemistry" may be, or whatever. They can ignore completely some aspects of the process that others astutely or compliantly are blackboxing for them. And usually the "chemistry" involves a lot of "what a great idea, boss" and alike ... they love to play the puppet master.
connectegr
Structural
We provide connection design for both EOR's and fabricators. Many structural engineers recognize that without a background in fabrication and erection they are ill equipped to provide the most economical options. But, they have educated their clients that this design is a pay now or pay later item, so they are able to negotiate the additional fee. Although we have traditionally worked for fabricators who were delegated the connection responsibility, working for large and small design firms directly is a fast growing trend. Our clients are finding considerably better results when the construction drawings are released for bids. Closer estimates in tonnages and in some cases savings of millions of dollars in fabrication and erection estimates. Since many projects are pushing the design schedule, we are working concurrently with the EOR to provide the connection details. We also provide suggestions to minimize fabrication labor or simplify erection. Weld sizes, connection material, and minimizing reinforcement, take the "just in case" factors out of the estimates. The EOR can certainly provide the technical knowledge to design the connections, but without fabrication or erection experience they can actually increase fabrication and erection estimates. In these cases it is better to delegate the connection design and save the owner in the long run.
On a recent project, the final bids from 100% construction drawings where $1.1 million less than the 75% CD estimates (without connection design). The total tonnage estimates by all bidders were within 15 tons. The total connection design cost was $160k, which would have been more if the fabricator had designed for the connections, and determined the reinforcement which was eliminated by our coordination with the EOR. Obviously the fabrication and erection would have also increased due to the reinforcement. Our results will certainly vary based on the complexity of the structure and magnitude of the forces. For simple shear connections nearly anyone can provide adequate design. And in the near future standardized tables for most simple conditions will be available. But for complex geometry and design systems with significant load paths, a connection engineer should be involved. These projects also benefit from direct coordination between the EOR and the connection designer. Over the last 15-20 years connection design has become a specialty within structural engineering. Very little connection design is taught in school. And even in graduate programs, the connection courses are more theoretical than practical.
On a recent project, the final bids from 100% construction drawings where $1.1 million less than the 75% CD estimates (without connection design). The total tonnage estimates by all bidders were within 15 tons. The total connection design cost was $160k, which would have been more if the fabricator had designed for the connections, and determined the reinforcement which was eliminated by our coordination with the EOR. Obviously the fabrication and erection would have also increased due to the reinforcement. Our results will certainly vary based on the complexity of the structure and magnitude of the forces. For simple shear connections nearly anyone can provide adequate design. And in the near future standardized tables for most simple conditions will be available. But for complex geometry and design systems with significant load paths, a connection engineer should be involved. These projects also benefit from direct coordination between the EOR and the connection designer. Over the last 15-20 years connection design has become a specialty within structural engineering. Very little connection design is taught in school. And even in graduate programs, the connection courses are more theoretical than practical.
Connectengr,
Some very good points there.
I agree that most consultants are not very good at the connection side of things, though how much of that is symptom and how much is cause I am not too sure.
In buildings where there is considerable complexity to the connections then there is a great deal of merit for it to be looked at concurrently with the member design. Often heavier members or differently configured members can make the connections much simpler and lead to overall savings.
I find that sizing the members is often the easy part and it is the connections that hold all the major complexity.
Some very good points there.
I agree that most consultants are not very good at the connection side of things, though how much of that is symptom and how much is cause I am not too sure.
In buildings where there is considerable complexity to the connections then there is a great deal of merit for it to be looked at concurrently with the member design. Often heavier members or differently configured members can make the connections much simpler and lead to overall savings.
I find that sizing the members is often the easy part and it is the connections that hold all the major complexity.
Csd-
I think I have told Connect on a few occasions that I admire his vocation.
I worked for a firm at one point that did a lot of power plant design. IMO, the connection design was the lion's share of the design work and was much, much more difficult.
Half of the battle in connection design is simply know what to check!
Throw in seismic requirements and there is simply no doubt that connection design is considerably more difficult.
These are just my opinions and maybe I'm just not that bright.
I think I have told Connect on a few occasions that I admire his vocation.
I worked for a firm at one point that did a lot of power plant design. IMO, the connection design was the lion's share of the design work and was much, much more difficult.
Half of the battle in connection design is simply know what to check!
Throw in seismic requirements and there is simply no doubt that connection design is considerably more difficult.
These are just my opinions and maybe I'm just not that bright.
msquared48
Structural
Generally, I design them. I am also on the West coast.
However, in the case of one wood girder truss framing into another wood girder truss though, I leave the specification of the connection to the girder truss designer, as the structural engineer for the trusses has the truss member size and loads required to properly sizr the hanger.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
However, in the case of one wood girder truss framing into another wood girder truss though, I leave the specification of the connection to the girder truss designer, as the structural engineer for the trusses has the truss member size and loads required to properly sizr the hanger.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
I have always worked in offices which designed all of the connections in steel structures. They were not always designed in the best or most efficient way, and we could certainly have benefitted from a specialist like connectegr. Unfortunately, there are not enough like him around, and the ones who hold themselves out as specialist connection designers are not always as advertised.
connectegr
Structural
Some of our EOR clients apply our connection standards and special connections to their contract drawings, and make no reference to our company's participation. While others find it an advantage to note that the connection details provided are ours. For some clients our scope is specifically the details of significant concern and the remaining details not shown are delegated to the fabricator. On some projects we work for the EOR on important details relevant to the bidding, then continue the design for the fabricator after award. I have had 2 projects on which the EOR listed us on the General Notes or specifications for design of specific trusses or complex connections (I always welcome this approach). No matter what the project requirements, we always provide the same thorough professional submittals, sealed calculations and clear details for the detailer/fabricator.
I just returned from the NASCC and as usual there were presentations concerning what the fabricator/detailer need for estimating projects and/or providing connection calculations. The comments were full or "I never get this" and "we don't understand this". The 2010 AISC Specification provides a role for connection engineer, for the first time. I think communication between the EOR and a specialty engineer is always a benefit to a project. This year is my 18th consecutive NASCC. This topic of contract drawing information and bidding information has been present ever year in some form. Perhaps a solution is for an intermediary, a connection engineer. Not necessarily the fabricators in-house engineer. But a professional with shared liability and an understanding of both design and construction. In my opinion, the EOR should be involved in the selection of connection engineer. This relationship can minimize errors, RFI's, and provide the best example of the EOR's intent. However, when the EOR simply delegates responsibility to the fabricator, and enormous barrier is created. In the best cases, RFI's and approval comments eat any remaining EOR fees. In worst cases, a lowest bidder detailer in some third world country makes engineering decisions which can significantly impact the structural system. The hope is that these decisions or clarifications are clearly show by their engineer or by the software program used. The challenge we are finding is in educating the owner/client on where this connection design cost will apply and what potential advantages available.
As a company we don't design structures or provide shop drawings. Thankfully I don't have to entertain architects or contractors (although another excuse for golf would be nice). Or study the latest structural analysis trends or detailing software. We concentrate all our attention on the specialty design of connections. I am sure that other consultants make the same sacrifices in providing the most current and economical solution within their specialty. We are constantly updating our software for the changes in the specifications and fabrication trends. In some cases, such as seismic, this is a constantly moving target. A specialty connection engineer, allows the EOR to concentrate on what they do best.
Sorry, I am preaching...
I just returned from the NASCC and as usual there were presentations concerning what the fabricator/detailer need for estimating projects and/or providing connection calculations. The comments were full or "I never get this" and "we don't understand this". The 2010 AISC Specification provides a role for connection engineer, for the first time. I think communication between the EOR and a specialty engineer is always a benefit to a project. This year is my 18th consecutive NASCC. This topic of contract drawing information and bidding information has been present ever year in some form. Perhaps a solution is for an intermediary, a connection engineer. Not necessarily the fabricators in-house engineer. But a professional with shared liability and an understanding of both design and construction. In my opinion, the EOR should be involved in the selection of connection engineer. This relationship can minimize errors, RFI's, and provide the best example of the EOR's intent. However, when the EOR simply delegates responsibility to the fabricator, and enormous barrier is created. In the best cases, RFI's and approval comments eat any remaining EOR fees. In worst cases, a lowest bidder detailer in some third world country makes engineering decisions which can significantly impact the structural system. The hope is that these decisions or clarifications are clearly show by their engineer or by the software program used. The challenge we are finding is in educating the owner/client on where this connection design cost will apply and what potential advantages available.
As a company we don't design structures or provide shop drawings. Thankfully I don't have to entertain architects or contractors (although another excuse for golf would be nice). Or study the latest structural analysis trends or detailing software. We concentrate all our attention on the specialty design of connections. I am sure that other consultants make the same sacrifices in providing the most current and economical solution within their specialty. We are constantly updating our software for the changes in the specifications and fabrication trends. In some cases, such as seismic, this is a constantly moving target. A specialty connection engineer, allows the EOR to concentrate on what they do best.
Sorry, I am preaching...
- Thread starter
- #19
It sounds like we have a lot of engineers out there that are 90% structural engineers. I just don’t understand why you consider yourself an SE if you can’t design the entire project including connections. What other Professionals design pieces but leave it up to the owner or contractor to figure out how to connect them? Like one of the post stated, you have to see the entire picture to design it properly.
BRGENG-
I agree with what you are saying, however the answer probably lies more with $$$ than knowledge.
I see no problem with a Structural teaming up with another firm like Connectegr runs.
On big projects (especially those with A-Typical connections), connection design can really bog down schedules.
Having said that, I have always designed my own.
I agree with what you are saying, however the answer probably lies more with $$$ than knowledge.
I see no problem with a Structural teaming up with another firm like Connectegr runs.
On big projects (especially those with A-Typical connections), connection design can really bog down schedules.
Having said that, I have always designed my own.
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