In an attempt to keep discussion focused on the 2 questions I posed in original post, I deliberately avoided giving specifics. We have a conservative solution, just looking at possible refinements.
This topic could also influence strategies on enlarging footings so wanted to keep it...
It seems you are viewing the problem from ACI's framework, where the capacity is simply a 4sqrt(f'c) that is presumably uniformly distributed across the cross section. I would agree that this simplified framework would frown upon the 50/50.
However, I am attempting to look at it through lens of...
eh maybe, maybe not.
Either way, the design codes definitely DO have differing philosophies on punching, which is why this thread was created in the first place.
Yesterday I stumbled across a paper that further refines the modeling of punching shear mechanics and offers a fully mechanical model to predict punching capacity.
https://www.sciencedirect.com/science/article/abs/pii/S0141029623006119#f0020
While the approach is impractical to use for...
Not to be combative, but it seems like you (hardbutmild) aren’t familiar with Critical Shear Crack Theory (CSCT)? It is a (semi) mechanical model, so it absolutely does have the ability to extrapolate to some degree. Think of all the weird structures we (designers) can justify using strut and...
Very odd punching shear situation (see attached), with 2 questions below. We do understand what the conservative/ safe routes are, but the question of “can you refine?” is being asked of us.
Looking to assess in a logical manner, I was hopeful to employ mechanical models of punching shear...
I didn't realize the picture would end up so compressed.
blue plot is the moment-curvature diagram when ignoring bottom bars.
orange plot is moment-curvature diagram when considering bottom bars. They diverge after the top bars reach yield. The orange plot increases in nominal moment...
Do you have concerns about being able to develop the stress in that bottom bar, after reviewing the sketch/ discussion in the post? If you do a strain analysis on a cross section just a few inches away from the support (assuming typical span, moment is parabolic distribution), you may find...
I am not overly familiar with MCFT, so this made for some light afternoon reading :) Thanks for sharing this model/ framework.
Although I have my own reservations about utilizing this rebar, I'm not sure I fully understand the theoretical concern from the lens of MCFT - could you help me out...
Thanks for discussion all.
Forgive me, I'm new to using the site, although I stumble across it frequently when researching random topics. I think I am quoting properly....
15' is the column strip width for sample section, although similar situations occur. Demand was taken by using a section...
I'm evaluating an existing condition, with a very lightly reinforced 2-way slab system.
We were trying to eek out capacity by considering compression steel at a support, but noticed that the neutral axis was very small. The "compression" steel was actually in tension at the ultimate limit...
