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  1. DTS419

    NYC Building Code Presumptive Load Bearing Values

    No thoughts on this??
  2. DTS419

    When does a uniform load become a series of point loads?

    Hmmm. KootK had me convinced to go with Vu @ d, now that blog post has me second guessing...
  3. DTS419

    When does a uniform load become a series of point loads?

    KootK, I agree about the strutting. In the NDS, you can ignore shear on a wood joist if it is within d from the support because of this effect. However, what do you make of ACI's exclusion of a point load between FOS and d?
  4. DTS419

    When does a uniform load become a series of point loads?

    Most of us are familiar with the concept of designing a concrete beam for Vu @ d, that is for the shear at a distance 'd' from the face of the support. At this critical distance, the shear in a simple span beam is typically less than at the end or face of support (FOS) which results in a...
  5. DTS419

    NYC Building Code Presumptive Load Bearing Values

    Just realized I copied the link for the NY State building code by mistake above. Here is the link to the NYC code, page 257... https://www.nyc.gov/html/dob/downloads/bldgs_code/bc27s11.pdf
  6. DTS419

    NYC Building Code Presumptive Load Bearing Values

    The NYC Building code gives presumptive load bearing values for soil types that are considerably higher than the presumptive bearing values of the IRC/IBC codes. The Data Book for Civil Engineers by Elwyn E. Seele cited these values from the NYC code back in the 1940s-1950s in a manner that...
  7. DTS419

    NDS "Fastener Head Perimeter" for fastener head pull-through in wood

    NDS Equation C12.2.5-2 for fastener head pull-through uses "Fastener Head Perimeter", P-sub-H. What is "fastener head perimeter" and how is this obtained for common hex head bolt sizes? And, how does using a washer come into play when used with fasteners with other than round heads such as hex...
  8. DTS419

    Post-installed or cast-in anchor?

    So for the purpose of determining a breakout strength, would you treat the anchor as cast-in or post-installed?
  9. DTS419

    Post-installed or cast-in anchor?

    I don't disagree, but what's the difference between this mechanism, and an embedded headed anchor that is imparting its load on the concrete through the head of the bolt?
  10. DTS419

    Post-installed or cast-in anchor?

    Thanks Koot, you get it! By applying the one-way shear to the punching shear frustum, do you mean using Vc = 2 f'c^(1/2) * bo * d ? Interestingly, if I look at this as plain concrete (very little reinforcing actually), then I get a result that is very near to what I get by considering it a...
  11. DTS419

    Post-installed or cast-in anchor?

    So the interesting thing about punching shear, which I know a lot of engineers use for through-bolts, is that is returns a less conservative result. Since 17.1.5 gives us a pass on Ch. 17, I think using punching shear could be justified. My only hang-up with that is that it is counterintuitive...
  12. DTS419

    Post-installed or cast-in anchor?

    I will add that I know this is not precisely in the scope of ACI 318 Ch. 17 since 17.1.5 excludes though-bolts, which is what this is. So we need to use some engineering judgment to model some capacity from this situation, and best I can tell this will behave like an embedded headed bolt.
  13. DTS419

    Post-installed or cast-in anchor?

    Yes, this is exactly the scenario. The sketch shown here is almost identical to the ACI figure showing a headed anchor bolt (Fig. R17.6.2.1). The only difference is that a cast-in headed bolt is embedded in the concrete whereas this one passes through it. The load is transferred from the bolt...
  14. DTS419

    Post-installed or cast-in anchor?

    Yes, this!
  15. DTS419

    Post-installed or cast-in anchor?

    Guys, this is getting rather over-complicated. It is simply a headed stud that is in a pre-formed hole rather than cast in to the concrete. There is no adhesive or need to roughen anything. This is done by a pre-caster and has been done tens of thousands of times. Just looking to establish...
  16. DTS419

    Post-installed or cast-in anchor?

    It's simply a bolt inserted through hole in the concrete so that it in effect looks like an external headed stud.
  17. DTS419

    Post-installed or cast-in anchor?

    Just a solid concrete slab, say 3-4" thick. Hole is formed by a plastic tube that is removed.
  18. DTS419

    Post-installed or cast-in anchor?

    Then how would you determine capacity if not ACI 318?
  19. DTS419

    Post-installed or cast-in anchor?

    Let's say a 3/4" hole is formed in precast concrete slab so that a 1/2" or 5/8" bolt can later be inserted through the hole to be an anchor. Would this anchor be considered cast-in or post-installed for the purpose of determining factors per ACI 318-19 Ch. 17? An argument for considering the...
  20. DTS419

    Does ACI 318 Ch. 17 apply to masonry?

    I will add that if you look at the section of ACI 530 that governs anchorage, Equation 9-1 gives a result for breakout that is unconservative as compared to ACI 318 17.6.2.

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