I've never designed one of these wooden bulkhead walls, but I have seen them up to 15' in height. What is the tieback connection to the wood timbers? Surely there is a big spike connected at each intersection sized for the tieback load. This can definitely be analyzed with a few simple calcs...
@Joe O
You run into this issue also with commercial storefronts in which the front wall provides little to no resistance so often neglected. Personally I'd avoid the moment frame unless you can get a 3-sided diaphragm to work. Here is a design example for some...
@phamENG
Glulam is definitely more expensive as compared to LVL. I'm in the Virginia Beach / Chesapeake area -- Kempsville Building Materials is a major player in these parts as you mentioned for all wood materials. I've worked with AJ and his team over there a few times with the development...
@phamENG
You can get PWT Treated LVL from 1-1/2" x 3-1/2" up to 1/2" x 11-1/2". For a recent project, the contractor was able to find them at a local 84 Lumber location. They can also be special ordered as well -- if you try hard enough, you can find it. LVL sill plates are a must-have in...
I've used that detail from Kootk several times with the bottom beam tab which slides into the gang stud pack or engineered wood post bolted into place. One builder I work with cuts off the bottom tab of the beam and simply rests the beam on the column claiming that the joists that run above the...
@DoubleStud
I agree -- beam directly below the veneer is absolutely the way to go to support the load.
"Engineers only know about 80% of the truth, the next 10% is very difficult to achieve, and the last 10% impossible. If we are bound to be wrong, we may as well be wrong simply and...
Nice solution. I would have installed a flush LVL beam within the floor cavity with end joist hangers given the ease of construction, but there is nothing wrong with this approach. Amazing you were able to find drawings of the existing home...I see too many walls opened up with beams/posts...
@driftLimiter
This is true..oh those poor nuts that are about to pull through the chair. My gut tells me there probably isn't much uplift to transfer into but you're right about the compression.
The stiffener below the concrete is continuously braced so it cannot buckle..I'd just check the...
@driftLimiter
Where are you seeing this compression load in the stiffeners? It looks to me that this chair assembly is welded to the side of the column and does not participate in the compression load distribution. If indeed a lazy column, the only force those stiffeners will see is tension...
@yhginkim
Given this is an interior column, I doubt there is much if any shear at the base or even moment -- is this acting as part of the LFRS from the framing configuration that you see? The baseplate which is buried below the concrete is taking the column compression load, not the anchor...
I like your boss' suggestion to leave the existing stiffeners and weld new. The column baseplate looks like it is buried within the concrete so the stiffeners facilitate chairs to give the anchor bolts stretch length for ductility. When you do this, however, you loose a good amount of shear...
@YoungGunner
This is a classic case which I see on many residential structures. I prefer to drag the shear load further down the wall line away from the garage and use a portal frame at the garage to serve as a collector element. If the house is skinny and this is all you have, you will not...
I've done this before to check the thickness of an existing warehouse slab. Drill a hole with a hammer drill until you encounter dirt, stick a long paper clip or rod down the hole with the end bent at a 90 degree angle. Stick it all the way to the bottom of the hole and pull upward until the...
Design the exterior firewall freestanding and switch from CMU to concrete construction. CMU is not the right building material for this application in my view. I've designed many firewalls to provide line of sight separation (NFPA 850) between heavy duty transformers in coal fired power...
@jerseyshore
I've done 2" OC nailing for a few jobs, one of which was double-sheathed with FTAO straps around openings. So far in residential, I haven't had the need to use a strong wall yet given the capacity you can get out of an FTAO strapped shear wall. One of my clients always prefers a...
@phamENG
This link shows a conventional shear wall almost as a contrast to the continuous tension rod system:
https://www.strongtie.com/products/lateral-systems/strong-rod-systems/ats
The phenomenon I am referring to is not something that is commonly considered, but as the wall rotates, the...
@phamENG
No, I am discussing the effective behavior of these continuous rod systems if one tried to idealize them to take in-plane shear through pulling on the tension end rod as the wall rotates. I am in agreement that these should only be used for uplift in conjunction with conventional...
@driftLimiter and @phamENG
Thank you both for your input -- much appreciated. To your point, if one did indeed try and use these systems to resist in-plane shear through the tension side effectively "pulling" at the end as the wall rotates, you wouldn't have much stiffness at all and the drift...
@driftLimiter
The system resists moment by forming a coupled force between the tension rod on one side and a gang stud on the other which resolves the compression load. This provides stability via overturning and shear coupled with the fact that the cables are thin... so you wouldn't need much...
Have any of you used continuous tiedown rod systems as an alternative to steel moment frames in residential design? Seems cleaner, cheaper and easier to construct in general as opposed to steel moment frames. I've considered this on a couple jobs, but decided against it due to the specialty...
