I love this stuff, I did a lot of detailing early on in my career. With that background, back in the days of manual calculations, I used to send my wind and seismic diagrams to the detailer. He could check or suggest modifications to the ones that we had detailed on the design drawings, and was comfortable knowing the actual combinations rather than just max and min. I still did this with computer printouts later.
I don't know if the printouts can now show the forces for the individual load cases, diagrammatically, but I bet the detailers would like it if you sent then .
Michael.
Timing has a lot to do with the outcome of a rain dance.
May seem exageration but CTE for example is asking the micropile wall providers 8 times stronger than they sell. Outlawing citizens has always amusing business for barons.
Paddington
I started on the drawing board as well. For most structural steel detailers the force combinations might cause more harm than good. Regretfully many detailers are facing the same computer transformation. They don't use calculators to determine angles and detail geometry. They must lay them out to scale in CAD or model them. They are rarely even taught engineering vocabulary. An even less about statics or basic engineering design. Force tables are not very helpful without a basic understanding of shear, moment , and torsion.
This said, detailing has come a long way since I had to practice with letterguides and rolling pencil.
It's really just vertical bracing and horizontal bracing all meeting at a column. To me, the only thing that makes the connection appear unwieldy is the number of bolts, which off the top of my head looks out of proportion to the member sizes. Maybe a smaller number of larger bolts would have been preferable.
Hokie-
I have a suspicion that the out-of-proportion number of bolts may be because of seismic detailing requirements (again, I defer to Connect here, hi-jack as required, I never really asked a question this post anyway). Same might be true for all the doubler plates.
My only complaint(from past dealings with these things) is some of the problems can be mitigated in these connections by simply choosing a different beam size. On a much simpler level, there has been times when I was doing powerhouse work (not working like a powerhouse) where I would be tasked to design connections for another engineers framing. There would be times when a simple pair of clip angles would suffice for a lightly loaded strut (pure axial) and the design engineer would have something like a heavy W10 or W12. My standard clips (3/8", 1/2", 5/8", 3/4" thick) wouldn't work on a beam of that depth but might have worked on W14. Again, just a simple example.
When I design my own steel and connections I try to use a little foresight; is this beam going to be easy to connect. Member design is mush simpler and less time consuming than connection design.
Regarding the bolt size. We typically select two bolt sizes for a project with a 1/4" gaps in size to avoid confusion in the field. For example 7/8" A325 and 1 1/8" A490. And a line in the sand is drawn for the cross over in bolt size. It does appear that reasonably large bolts were used in the beam connection to the gusset plate. If the beam connection is designed for moment, axial, and shear. The flanges will be designed for the proportionate axial load and the flange axial load resulting from the moment couple. This combination and the hole diameter, apparently result in an inadequate net capacity, thus the reinforcement. If only the axial force exceeded the net capacity, then the web would also have a doubler. "Clawed-angles" may have been another option, putting the flange bolts in double shear. But the horizontal bracing, may have required a shear plate instead of the angles shown to fit. But the flange reinforcement would still be required.
Often these connections are more like a puzzle. Tracing the forces and where the components are taken, the eccentricities, and how will it be erected. This is art.
This reminds me of the connections on the New York Times building. I only worked on a few floors, but other engineers in our office had many connections like this to deal with. One issue driving the complexity was the need for redundancy. The client (or perhaps the City of New York) wanted the building to remain stable if a main column is taken out.
DHK
You are referring to progressive collapse and "tie forces". This will be a requirement for many structures with the next IBC. New York adopted this requirement almost immediately after 9/11. We provided the connections for Building 7, the one that was allowed to burn until it collapsed. And one of the first rebuilt. The design requirements have been refined, but for Building 7 every beam to column was designed for a minimum axial load of 150kips.
