Wood Shear Wall Distribution

[NLOKyle]

I'm having trouble determining the best way to distribute shear throughout the walls on this floor plan. If anyone has any suggestions or has designed a plan with mostly angled walls I would love to see an example. The diaphragm design force at the roof level is 30k seismic.

 

[driftLimiter]

I would shear as much of the perimeter as possible. Ftao perf and segmented.

I would try to get shear or frame action on the 4 lines that are exterior but not protruding.

From there I'd make sure I can resolve statics and strength of lateral elements and iterate.

The tough part as mentioned is where to put collectors. Because one eventually some (most) of your collectors will be diagonal to your framing. What a mess. If you can make a regular box in the middle and shear the 3 sides of the protrusions you might be in luck.

I won't jump on OP for calling me out. It's true I didn't fully absorb the info from the post. In any case this is complex. Next time OP would be better served by describing his proposed solution the. Asking for comments /advice. Rather than asking for the approache from zero.

 

[NLOKyle]

What? I never attacked anyone and i said I appreciate the input given. The point of this post wasn't to ask someone to do it for me. The point was to see how other engineers would approach working through this lateral system because theres more than 1 way to look at it. I've spoken with two senior engineers at my company and both of them are still scratching their head considering different design approaches for this project. Given that the framing material is wood, seismic loads govern, and this funky wall layout, I was more so asking if people would approach it as one whole structure, try to separate the "wings" off on their own, flexible vs semi rigid diaphragm, etc.

 

[NLOKyle]

DL, that was exactly the input i was looking for & similar to my thought process. I think its going to end up needing a steel frame(s) for the "rectangular box" in the middle in addition to shearing all 3 sides of each protrusion.

 

[driftLimiter]

Then you just have one area left which is the 'inside' line of the protrusions.

Ideally you have a drag strut there or a shearwall / frame line.

The drag approach would get one component of the protrusion diaphragm reaction into your frame line on the 'box'.
But then the other component would need to go into the diaphragm as a transfer force.

I would try to avoid this scenario, my goal would be to provide 4 sides of lateral elements on each diaphragm region.

 

[lexpatrie]

I don't know the scale of the building, but the exterior wall lines are so torn up compared to the "door" openings. It doesn't feel so big it needs separate wings and firewalls but I'm not the architect. If those are in the plan we can't see them and it's a big monkey wrench. If you're trying to design this one time and be done with it, I think your impulse to design steel braced or moment frames is on target. Drift limiter's suggestion seems on target for wood shear walls as an alternate.

As to flexible diaphragm, if you have wood floor sheathing, that's probably likely permissible, if not realistic, it should still function at ultimate, unless they put too much poured GypCrete on the floor (>1 1/2"? 2?" yeah, 1 1/2" 12.3.1.1 ASCE 7-16), then ASCE wants you to design the diaphragm as semi-rigid or model it or whatever their term is lately.