My response was directly related to his proposed scenario. Where he indicated that he was trying to get the reactions to match. I assumed this meant he was trying to use standard beam theory to get the reactions on his diaphragm shear diagram. Which is incorrect.
However, your response is good...
I'm assuming the previous engineer was fired for a reason. Therefore tell the client your opinion on the matter. I agree with you that there should be some form of membrane. That opinion is based on having seen situations where a leak in the boiler room equipment causing damage to rooms below...
There are so many suppliers, you won't really be able to get a definitive answer without more information.
I do know that the Steel Joist Institute has a form that you can submit the information you have and they'll try providing a manufacturer etc. But I don't know if you have given enough...
Yes, that does sound correct. Your shear diagram is no longer applicable in a rigid diaphragm scenario as it's viewed as strictly rigid body motion. Shear diagrams only work in flexible diaphragms where conventional statics allows you to determine the reactions.
That's a bit unfortunate.
Is it possible to design a wind girt at roughly mid-height of the wall that is stiff enough/strong enough to provide lateral support for the shear walls? Then you could consider it two walls that are each roughly 12 feet tall. Then you should be within your 3.5:1 ratio.
We transfer lateral loads around all the time, can you confirm where you've seen this requirement that they're full height? The AHJ has never flagged that as a concern. That being said, it may be a part 9 requirement only and our projects are all submitted as engineered solutions as opposed to...
Stacking frames sounds like a terrible idea. what will brace them?
That being said, a sketch of the situation usually will help immensely with getting constructive advice.
Are there not other walls that aren't 23 feet tall and only 4 1/2 feet wide that you can use as shear walls?
Can confirm @KootK does not dominate a conversation with engineering problems that are way above most of our heads. Him and I had a great visit and I look forward to doing it again the next time I'm through Calgary. Maybe this time it will include some research on dimpled ball flight physics...
We do this fairly regularly, but our typical underpinning consists of cast-in-place friction piles 25-30 feet long. The way we detail them with one of our repeat clients allows for jacking of the house to an extent. We've pushed some houses an impressive amount back to somewhat level. But none...
I can't say I've ever known anyone to take this into account directly. But yet this unequal spans, or different framing schemes on each side of flush beams, is extremely common. Often due to the physical dimensions of the beams, they're inherently more stable for torsion. The one time I actually...
My former mother-in-law asked for my help designing her pergola. I gracefully declined. When she asked why, I said because after a season or two, you're going to want to cover it in a roof and/or walls.
She said she wouldn't. I still didn't help.
I did however help erect it after they did...
If you dig into fire rating of heavy timber, the char layer develops and then provides protection for the remainder of the wood. So there's some credence to improving fire resistance by providing an intentional char layer on the materials.
Not counting on the roof, assuming it has plywood, is being overly conservative in my mind.
What if? You can't plan for future removal of structure in every project, or else you must be panicking all the time. What if someone busted out the slab adjacent the wall to put in a new sump pit? I've...
He may need the depth for frost. Where I practice the frost is routinely over 6 feet. 8 foot basements are the norm.
This wall has the loads on it that are there. The roof diaphragm would provide support for the top of the wall.
We always sawcut slabs-on-grade except in extremely rare cases. And in those cases, we're providing something like 0.5% Ag as the steel to mitigate the size and randomness of the cracking.
We also specify that the contractor needs to layout the sawcuts before the pours, and cut half of the bars...
Have a plan in place, even if just in your back pocket, for what you're going to do if you discover voids in the wall when you remove the insulation to do any reinforcing for the opening. I've had it on multiple instances where there are notable, unacceptable voids in ICF walls.
Vibration is going to be the largest concern for a running track. I'd do some digging into that side of things and then come back with questions. I anticipate needing likely stiffer than even what you're proposing to keep the vibration checks in place.
When I do these, I notch the column and beam to allow a bearing connection for the brace. And I also only design them for compression. When in tension I ignore the contribution.
