New from AISC 6

[dik]

FYI...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[phamENG]

33 proposals? If they're much more than "you missed a period here" there's going to be a pretty big uproar over this one, I suspect.

 

[WinelandV]

Or, hopefully, they are in the vein of "when girder depth exceeds XX in." or "when flange thickness exceeds YY in." you need to do/check/verify A, B, and C during your design.

Please note that is a "v" (as in Violin) not a "y".

 

[dhengr]

No problem. They are shooting for the AISC Steel Manual to be 4 volumes, each less than 1000 pages, and 360 new design guides, by the next publication date. The design guides will have worked examples with AISCexample numbers, and right along side each example will be the very same example with blanks where the pretend engineer fills in the blanks with his numbers. He can then look at the example to see if he should multiply or divide by that number to progress. They will have flow charts for every example so that the pretend engineer knows that he must complete step 2300 before going on to step2301. They are going to sell all the AHJ’s problem (example) checking software, just indicate example #6243, guide 327, vol. 6, and the software does the rest, and nobody even has to know it’s a beam problem and not a column problem. This will take some of the subjectivity out of the AHJ plan/calc. approval process. Presumably, a bunch of SE’s did the Transbay Transit Center design in the first place, so they are going to up the SE exam fee to $2400, with more multiple guess questions ($1000 worth) so the test certifies more expert dummies.

 

[Aesur]

Well said dhengr!

 

[WillisV]

https://www.aisc.org/transbay

 

[hokie66]

Classic, dhengr!

 

[dik]

I know Arup was involved with some part of the Trans Bay... I don't know to what extent. I don't know how they are now, but they used to be one of the better consultants, worldwide.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Lomarandil]

It's hard for me to rely on the "brand reputation" of any company near the size of an Arup. Even a dozen great engineers can only keep their eyes on so many subordinates.

 

[BridgeSmith]

I think it would have sufficed for them to have referred designers to the AASHTO bridge design spec when designing a bridge for vehicular traffic, even if it is a component of building.

Of course, IMHO, had they contracted a bridge designer for that part of the structural design, they could have avoided the issues with the beams. It took me about 5 minutes to envision a configuration that was more stable, easier to construct, and wouldn't have suffered from the issues that caused the beam to fail. I'll give you a hint; it involves a pair of beams with a deep diaphragm between them to attach the hanger.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[epoxybot]

The structural design of the Transbay Transit Center was done by Thorton-Tomasetti. Review was done by both SFDBI and the Transbay Joint Powers Authority's 'Structural & Seismic Review Committee'.

You can see the SSRC's review tasks in the attached pdf. They were recommissioned to review the cracked steel beams.

 

[BridgeSmith]

I'm just saying that even before they found the cracks, every bridge engineer I know that has looked at that knew it was a ludicrous idea to put a big hole in the middle of the tension flange of a girder. The second dumbest idea was having a welded joint at the highest tension and fatigue stress location of the flange.

But, but, the structural analysis software said it would work...

Rod Smith, P.E., The artist formerly known as HotRod10

 

[dik]

I don't rely on it either, but due to whatever vetting/training program they had for employees...it seemed to work and, overall, their reputation was stellar.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik