Recent content by tomzeb

The increase in strength reduction factor to 0.8 is helpful. The column is on an end wall so ACI refers to it as an edge column. The code does not seem to give any procedures for taking advantage of post tensioning for the shear punching calculations. I guess they assume the positioning of the...

I'll checkout out, but it seems that its missing limit by too much for a small factor adjustment.

Yes, the column will have to be "cut in" to the existing CMU wall. Sounds like you think it is feasible, just tricky at high elevations. Feasibility is what I'm after. The existing b0 is 66 inches for an 8x36 inch column and the demand/capacity ratio is above 2. It would take adding 5.5 ft to...

In order to improve shear punching without interior drop panels, would construction of a column on an outside end wall (shown below) of a multi-story building be doable? Walls are 8" CMU sitting on the slab. Removing the CMU at each level gives access to the edge of the floor slab. Adding the...

The state of Florida requires recertification of buildings at the 40 year mark as a result of the Surfside collapse. So, the do nothing option is not available. I think Brian's point wss related to calling something defective; if a building passed requirements from a code many years ago, but...

Interesting comments Gentlemen - Thank you. I am trying to understand how the building design fails the shear punching limits based on recent analyses. I think the link on "corner slab/column reexamination" that Brian provided presents a good history of the shear punching requirements and...

Hey Brian, Some good ideas at those links, thank-you. I will take a look at them. The worse case is an 8x36 inch edge column with unbalanced moments of 78 ft-kips about both the weak and strong axes and axial load of 81.7 kips. It will be interesting to see if the steel plate would be...

Brian Thanks for the very insightful comments. The Cay Harbor report is a good relative to the code and construction capabilities for analysis at that time. I'm familiar with ICES-Strudl code. Even though the ACI 318-77 code they used just generally points to looking at shear near a...

New to the site, sorry for the confusion.

I'm looking at a condo building in Florida with drawings dated December 1979. It has post-tensioned 8" thick slabs (9 stories) held up by columns and some interior shear walls (no under-slab beams). A detail of a typical interior column shows some rebar and banded post tensioning tendons going...