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  1. calvinandhobbes10

    Sliding resistance from adjacent footing

    Yes. Common technique. Very direct reliable load path. Strip footing behaves as a compression/tension strut transferring the needed sliding. I often use a similar strut between column footings of a standard steel braced frame, for the same reason.
  2. calvinandhobbes10

    Evaluating an Existing Canopy Anchor

    Assuming you’ve got a canopy a few feet below this decorative eyebolt, with diagonal rods or cables connecting the eye to canopy corners or edges—- did you consider doing this the way I’ve seen many modern canopies designed, where the diagonals (and therefore your eyebolt) are ignored for...
  3. calvinandhobbes10

    Shear on insert rebar

    Hand calc- I often treat top two anchors in tension and bottom 4 (or even just 2, extra-conserv) in shear. It’s oversimplification of the statics but good envelope check. Use ACI. Supporting software- Hilti Profis. You can get some results free, subscription is a very cheap must have if you are...
  4. calvinandhobbes10

    Wind vs Seismic Control, whats appropriate?

    I work in east coast US, low seismic SDC B or A. Older engineers have told me that a generation ago it was normal practice to determine one controlling lateral force, and deem it sufficient to completely ignore the other. Even put this determination on the drawing notes. Obviously this does not...
  5. calvinandhobbes10

    Burying Steel Beams in Wood Stud Wall Volumes

    Unfortunately the "normal" thing probably doesn't even ask this question. Which means, "yes". Take your statement, replace 5.5" with 5.0" (which gets me a few favorite wood/steel sizes like W14x22 and HSS_x5's) and that would be my approach. More than 0.5" sweep may be likely, but accommodating...
  6. calvinandhobbes10

    Aircraft utility detail

    Below is a detail I've seen used in air traffic pavement. The idea is to bury a non-traffic-rated precast manhole beneath the concrete pavement, and beef up the concrete to span over this manhole (using a 9" gap). As I look at this detail, I am concerned about the lateral soil pressure applied...
  7. calvinandhobbes10

    RV Garage Shear Wall Design

    If I were hired as an engineer for this design, I would look at flat strap x-bracing on both door jambs. I have seen it used for a similar structure with compromised shearwall, although smaller. I would also consider using this as my “belt and suspenders” for a 3-wall diaphragm check to help...
  8. calvinandhobbes10

    Large Deflections in Concrete Slab Without Cracking

    For deflection, one item in your favor is that ACI requires L/480 for the portion of load applied AFTER attachment of the crack-prone elements....presumably drywall and finishes, in your case. It’s not total deflection. Meaning, one way to look at it is the clock hasn't started yet on your...
  9. calvinandhobbes10

    Reinforcing a PEMB

    Interesting situation. Your proposed method as I read it is to assume the rigid eaves plastically hinge at the original design load, which caps the horizontal thrust that can get transferred to the base (and therefore avoids increased stress on the parapet/kicker). The additional 3psf or so...
  10. calvinandhobbes10

    Cantilever Transfer Slab, Would you design it this way?

    OP you said you are not designing the transfer slab. Does this mean you/your company have subbed out the PT? Have you had this same conversation with the PT designer? Gauged their level of concern? If you are EOR it all flows to you regardless. The typical floors are an easy sub-out. The...
  11. calvinandhobbes10

    Shear load distribution between rc column and shear wall in a building

    If you think your shearwall cant take the lateral moment, you should add lateral stiffness, rather than reduce it. I suspect, however, your wall core may give you more bending strength than you think. Include axial conpression due to floor and self weight. Use the whole core box, all...
  12. calvinandhobbes10

    How do you pick your metal floor deck?

    I often use 2” for composite. If no fire rating, start with 4.5” total. If fire rating, use whatever I need to achieve. 1.5” usually too many beams for my liking, 3” only if the deck span is right to counter the extra concrete. Agree its a gut-feel decision.
  13. calvinandhobbes10

    Design Strip For Irregular Flat Slab?

    Another tactic to suggest. Design strips as was stated above are simply working elements that average out peak stresses. A moment contour map in SAFE shows how high they spike at the columns. You might try littering your whole plan with 4’ wide design strips, both ortho directions. Run each...
  14. calvinandhobbes10

    Warehouse Diaphgragm Expansion Joint - Chord Continuity

    Full joint. Design end walls to take all the transverse base shear for strength. Wind Drift along your joint line will be toughest part. Use fixed bases and grade beams to get more stiffness out of the same steel tonnage. Not saying its easy, but best way to avoid braces and get it to work. You...
  15. calvinandhobbes10

    25% Reduction - Extend to Sliding?

    Curious--- for those of you who take advantage of the 25% reduction in seismic overturning effects prescribed in ASCE 7-10 12.13.4, do you also apply this force reduction to the sliding check? In my experience sliding is often the controlling design check these days. I understand it reads...
  16. calvinandhobbes10

    Walking Column - Strut Capacity

    Interesting questions. 1) I suggest tipping the cage. Wouldnt that better follow the load path? It sounds like some miserable detailing to do global verticals, no? Can you resolve the 2’ walk moment with your lateral shearwalls? Ultimately the axial load will be transferred between the...
  17. calvinandhobbes10

    Concrete Shear/Bearing at Pile-to-Slab Interface

    I would sure consider thickening the mat locally at each pile head. Avoids the stirrups, as you were trying to do, and also provides easy, definite punching shear resistance for that High slab load bearing on the skinny Pile. I agree about the column load being so close to the pile. Check...
  18. calvinandhobbes10

    Concrete Podium Design Live Load Reduction

    Good question. It sounds like you may already have plenty of experience with podiums, but i love talking two-way slabs, so heres a few of my thoughts: I agree uniform load method as a start point. Different LL reduction factors for different failure modes: Slab positive bending, ~0.61L0...
  19. calvinandhobbes10

    RC Core Wall

    Your detail looks similar to how they might build this joint if they slip-form the walls (vertical cold joint at wall face), which i suggest be considered. Often i have seen/shown a full-depth key (as deep as 3/4”) to “receive” the slab pour (form-saver dowel bars/hooks actually carry the...
  20. calvinandhobbes10

    Joint between high and low part of a building

    1. Building looks small in this transverse direction, not wide enough to warrant an expansion joint that way. Check longitudinal length too. 2. Agree with the above about seismic irregularity especially if youre in high seismic. In design I would rather just check/accommodate the irregularity...
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