I think I found the old Wisconsin code (here...see page 85)...but I don't see any reference to importance factors. It's just a straight pressure based on the height. Does anyone see anything different? I'm also curious if other building codes (BOCA, UBC, and SBC) had adjustments for Risk...
I'm hoping to pick the brain of some more experienced and seasoned engineers. I'm working on a six story college campus building in Wisconsin that has had a 50' tower that was constructed on top of it. The tower itself spans to two sets of exterior concrete columns that seem to be part of the...
I don't have D100 in front of me...but going from my memory, that seems right that there isn't any specific guidance. Maybe there is something in the commentary? I can look tomorrow when I get in the office.
I've analyzed what seems like 100's of tanks for wireless carriers and 95% of the time...
It's not exactly your situation but I work a lot in telecommunications where carriers put equipment of known weight on rooftop platforms. Although this equipment weight is known, it is technically live load. For the purposes of calculations, I call it dead load as it seems overly conservative...
Thanks for your help on this one @KootK . The plan is to go with an idea inspired by your column offset. If you are curious, we are going to going to connect to the bottom of the cold form double channel with a hot rolled C channel (basically coped to a plate to get under the bottom flange of...
I'm trying to wrap my head around this. That's a second HSS going vertical and attached with some sort of plate out between the wall studs and then connecting straight up to a 4' long CFM? With the member being so vertical, can't it only put bending into the roof joist (which I now realize...
RAM will also give you a percentage of where the controlling part is and the resulting internal forces/moments, which can be useful in troubleshooting.
I'd recommend looking at the comprehensive report and seeing what is different with the capacities between the two members (since the loads are the same). RAM is nice that it gives you some breakdown on where the capacities are coming from. My hunch says LTB being the problem (like others said)...
I've got (2) square HSS members that I'm putting between the 6" wall studs @ 16". I'm going to have 2 kickers that are spaced at 4' in the bays (green). These are going to connect directly to the HSS posts that are getting embedded in the wall. These kickers will then connect to 2 members (in...
Got it. I don't work in cold-form or really building design, so I'm trying my best.
That makes sense with the ice load being a diving board. I'm guessing putting in some bracing to help with the LTB will be helpful. I wasn't quite sure what section to really use. I primarily specify square...
I'm not sure I follow. Here is what our drafter preliminarily came up with for this site:
This mount would be attaching in the bays of the 6" light gage studs spaced at 16" O.C. The kicker would come up to member that spans between the two Double C roof joists marked as "60 SJ 16"...
I'm trying to design a knee brace connection to this cold form joist that I can't really find any relevant information on. The section is two cold-formed channels measured to be 8" deep, spanning 13', and they are spaced 4' on center. The plans call out 60 SJ 16 with a design snow load of...
I've had some pretty good success modeling two way slabs in RAM Elements for flexure and shear. The one I'm working on now is from the 60's where everything is f'c=3,000psi concrete and fy=40ksi rebar. I find it interesting that the plans call out allowable steel tension and compression...
I'm hoping to get some mod guidance on this. I'm working on a project where significant rooftop equipment is right above this header. See below:
As you can see in the photos, the joists have already been tripled up (notice the difference in joist width between original and modified) but I...
Yes. DCR is the Demand Capacity Ratio...and it seems original EOR economized the design (in at least the localized location of where I am checking). My structure is from 1983 where I don't have those bent bars. It's actually probably the newest pan and joist structure I've ever worked on...
Thanks for the information all. I've never heard of FRP strips before. Since my client is not the structure owner, it makes performing some of these modifications very difficult. Where can I get more information on these FRP strips?
It turns out that these joists are at a lot higher of DCR...
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Expanding this referenced thread, how have people been handling this for existing structures that weren't designed with this provision in mind? To me it seems really odd to have to say a structure that was completely fine before now is screwed over when the gravity loads (5%)...
True true. I was thinking of just saying the CMU wall didn't need to carry any of the flexure if the WT or channel (which is probably the shape I would lean towards) could carry the flexure alone. I do have a concrete pan and joist penthouse and main roof, so I feel as long as I can get the...
Thanks for the suggestions. The screen tubes don't really provide the capacity that is really needed. Even if it did, I'm struggling to get the global wall to check out (especially since it probably never checked out to current code in the first place). My issue is the penthouse has virtually...
I'm in the process of designing a wall mount to an old unreinforced hollow masonry wall. It was built in the early 60's, so I'm not surprised about the wall construction.
Anyways, my calculations are showing it needs to be grouted solid to support the needed loads. We also don't have have...
