Thank you Decker and sticksandtriangles for both your responses.
Decker, I very much like your suggestion to design the coupling beams to remain elastic. In one of my particular "beams" Vu = Ω0 = 270 kips while Mpr/L =1600 kips. It's a significant difference. I'm not sure that the AHJ will...
Thank you for that NIST report reference. It was interesting. I think calling this a perforated wall would be what I would want to do, but I didn't see any recommendations for perforated walls in that report. I don't think the word "perforated" shows up in the report at all. Appendix D of...
I'm hoping to not call them coupling beams at all. Surely there must be some point at which a section of wall above an opening isn't considered a beam. Per the chart above, which I'm familiar with, I would need to do the strut and tie method for my 3'-4" wide, 53' tall "beam" above a man door...
I have a special concrete shear wall building with coupling beams (ACI 318-14). It's a 3 story low rise building made entirely out of shear walls. The gravity system is thick slabs (14") with stout beams and columns. My question is about when is a coupling beam a coupling beam. I have many...
dik, the problem is, at least with a flexible diaphragm, is that your shear walls at the alcove take a large percentage of your building shear (SDS=1.0) and that just can't be handled with such short wall lengths. I'll have to check out what the forces are with a semi-rigid diaphragm.
https://res.cloudinary.com/engineering-com/image/upload/v1509578065/tips/Alcove_z0pdtd.pdf
I attached a sketch. Does that help?
There is a ledger angle all around. The deck supports the walls out of plane on the end walls. There is a ledger angle at the alcove.
Once20036, I agree, I...
I have a single story CMU building with a steel roof deck supported by steel joists. The building is in a high seismic zone (SDS=1.0). It's an industrial facility but it looks pretty similar to a strip mall building.
The architect has shown an alcove in the middle of the long walls (~100ft...
The Guide to Stability Design Criteria for Metal Structures was the best resource. It has a great summary. It didn't have the particular interaction that I was looking for, but it had several similar interactions. It was helpful. Thanks for the suggestion.
I'll take a look at those. I'm about 30 percent utilized in compression via the ASME BPVC. From the limited amount we can see, only 1 part of the wall caved in, so it would be more of a local type buckling. Thanks for the input.
It's a type of well casing. Round thin walled pipe. They're also applying torque to it. Yes, it's some sort of local buckling. We can't really see the buckled shape.
Exterior pressure can certainly cause local buckling. It's pretty well documented. I have quite a bit of pressure, but not...
The compression is not axial. It's from an exterior pressure. I don't think that AISC covers this.
The torsional buckling is from a torsionally induced shear. AISC covers this, but I think it's fairly simplistic. The subject is fairly extensively researched.
I don't think that AISC cover...
I'm investigating the buckling of a thin walled long tube that apparently buckled under torsion. The tube also had an external pressure on it, but that pressure was not large enough to buckle to tube. I can figure out the torsional buckling of the tube and the compression buckling of the tube...
I'd vote for researching the strength of anchor bolts in masonry with respect to the masonry crushing failure mode in shear. This always controls by a long shot. A higher value would definitely ease some design woes.
