Can I treat a concrete shearwall like a perforated shearwall?
Can I treat a concrete shearwall like a perforated shearwall?
(OP)
Hey Guys,
So I have a concrete shearwall with a significant amount of openings in it. I'm wondering if I can treat it like a perforated shearwall where I only consider the full height segments for shear but get the full length for OT. Would I need special detailing for this(like diagonals at corners of openings)? My thought is we don't because that's more force transfer around openings but concrete is less flexible than wood and I'm not totally sure I can apply the perforated shearwall theory to it. See Image below for an example of one of the walls I'm looking at.
Thank you!
So I have a concrete shearwall with a significant amount of openings in it. I'm wondering if I can treat it like a perforated shearwall where I only consider the full height segments for shear but get the full length for OT. Would I need special detailing for this(like diagonals at corners of openings)? My thought is we don't because that's more force transfer around openings but concrete is less flexible than wood and I'm not totally sure I can apply the perforated shearwall theory to it. See Image below for an example of one of the walls I'm looking at.
Thank you!
RE: Can I treat a concrete shearwall like a perforated shearwall?
You always want some trim bars around your openings. because there will be a crack there even without lateral loads.
RE: Can I treat a concrete shearwall like a perforated shearwall?
RE: Can I treat a concrete shearwall like a perforated shearwall?
Honestly I think you way off mark on this idea. It doesn't behave anything like a wood shear wall and shouldn't be treated as such. But your question indicates that your mind is in the right place trying to address these openings.
This guide on special shear wall design is very very helpful for understanding the concepts needed.
Definitely review boundary zone detailing, and PIERS from that document above.
Also don't lose sight of the out of plane component of strength this wall needs.
RE: Can I treat a concrete shearwall like a perforated shearwall?
Regarding the OP question, I'd suggest using a strut and tie method. It gives you a clear understanding of what is happening in your wall. Every other method in this case (looks like a squat wall) feels like an approximation to me.
RE: Can I treat a concrete shearwall like a perforated shearwall?
I would consider the out of plane strength in any scenario where the wall needs to resist out of plane loads.
RE: Can I treat a concrete shearwall like a perforated shearwall?
It's not an outer basement wall because of the holes.
The only realistic scenario that even comes to mind is outer wall exposed to wind action. This is usually so small that other things govern.
For example if you have a 20 cm thick wall minimum reinforcement (according to eurocode, but it's probably similar) is 2 cm2/m on each face, usually 2.57 cm2/m is put (a standard mesh of 8mm bars at 15 cm spacing), which leads to 19 kNm capacity. If you assume a simply supported beam of 5 m height (very large storey height) you'd get that capacity is reached at 6 kN/m2. This is extremely high for any wind action that I ever saw.
This is why I asked what would be a practical scenario where minimum reinforcement would not be enough for out of plane.
I am genuinely interested since nothing comes to mind.
RE: Can I treat a concrete shearwall like a perforated shearwall?
RE: Can I treat a concrete shearwall like a perforated shearwall?
Wind loads perpendicular to the wall. seismic load of the wall itself.
Piers that are adjacent to openings steel can easily be governed by out of plane behavior for slender walls with significant out of plane forces.