gte,
The current design envisions threaded high-strength rod cast into the slab. The anchors themsleves would be cast-in-place through rods.
Regarding the likely resolution of this peer review, I agree. I expect that she will go back and use ACI 318 Appendix D to get the right bolt size and...
SAIL,
Yes, I agree. These are the questions and I believe they could only be answered adequately by a testing program designed to separate out the variables.
This is what started this whole thread. I was hoping to find this testing, but it probably doesn't exist. For my current problem I...
gte,
In answer to your question, the designer's calculations were incorrect regarding both load distribution and capacity of the connection. This got me wondering what capacity could be justified for this connection and why.
Assuming no oversize (standard) holes, which would be easy to do...
Thank you all for your contributions.
Ishvaaag, I like your native American name, "I always correct," but when practicing engineering as a business, you're better off with the native American name, "You always correct!"
Thank you for the FEM outputs and your observations and comments on them...
a2mfk,
Good question and good point, but my preference is not to demand that the designer redesign if what they are proposing works. I don't know that it doesn't and I suspect that it does, given the right bolt size and plate thickness.
The difficulty with this problema and the reason I...
I think what we are seeing is that this is not a problem that can be addressed with a finite element model because it is not elastic. Even a plastic model of some kind may not be able to adequately predict the ultimate strength and deformation of this connection because we could probably not...
Ishvaaag,
I ran the problem through Hilti's Profis program. Based on steel strength alone, it indicated that 1 3/4" bolts at 105 ksi yield would work. We ignored concrete effects, just to see how strong the bolts would have to be.
Thanks for presenting these numbers. What program are you...
a2mfk,
In my case, I am a peer reviewer for a design that is already done. One of my tasks as such is to determine a bolt size and capacity of this connection, as designed. If I were convinced that the connection is inadequate, then of course I would have to recommend revision. At this...
dik, I will check AISC to see what they say; however, it's seems strange to me that a steel organization would opine on what seems to be a concrete performance issue under the steel plate. Do you have the doc and section of the AISC reference?
a2mfk, one plate is far away from edges. The...
Thank you all for your contributions and attempts to help with this.
My condition, as is shown in the attached pdf, is a plate with large shear loads. Because of the confining effect of the plate below the slab, the limit state for shear in the bolts is unclear to me.
I met with the local...
I have some very highly loaded anchor bolts ("through bolts") in shear. The service load shear force is 32kips to the worst case bolt of an 8-bolt group. The bolts are "through bolts" through an 8" slab with a thick steel plate at both the top and bottom of the slab. The concrete crushing of...
jberg,
Thanks for the contribution. Just for clarification, when I used the 5,000# load there was no safety factor associated with it. It truly was a breaking strength. In other words, the first element in the support system load path will physically break at 5,000#. I would even consider...
My experience has been to design for 1000# at a working stress level and then use the 5,000# as a "breaking strength" of the system. I have designed window washing tie-offs for this criteria.
