I'm modeling/designing a 2-way transfer slab for a concrete podium building in RAM Concept and the program is adding one-way shear reinforcement around the columns. I was reviewing an audit of the cross section and noticed the following:
Why is the program adding shear reinforcement if the audit indicates they are unnecessary? Is there a setting I can check/update to avoid having the unnecessary shear stirrups added to the slab?
Thanks!
The audit is for a single section there are several envelopes and "design passes" to report, so you might be looking at a pass that is OK, while another requires stirrups, or it might be an adjacent section that controls. This wiki is useful: https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/3094/ram-concept-shear-reinforcement-faq
Seth,
I'm working on this project with Brinn, and we did review the other design passes to verify. The "controlling criteria" pointed us to a strength provision in the code so we dug into the strength design passes and found what Brinn posted above. We also found the article you linked prior to reaching out and went through each of those potential issues (checking the effective depth, running hand calcs on the one-way-shear, etc).
One item we could not reconcile was the effective width of the section taken for shear. It didn't match any ACI calc, column strip width, or design strip width that we could point to to make sense of it. Even with the width presented, the PhiVc was still > Vu so we doubt that's our problem, but it may point us towards another solution.
Thank you again for your time.
The width (bw) for one-way shear is the width of the shear core. See: https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/4514/cross-section-trimming-tn
We have a flat slab at the locations this is ocurring so it shouldn't have any issue calculating the bw unless there is some maximum limit, and our PhiVc is still greater than the Vu even with the smaller bw.
Are there any other settings, Concept specific assumptions, or other conditions for a thicker transfer slab that would do this given we've chased down the suggestions above?
Thank you
Send your file, or log a service request and we can help.
Be sure to indicate what you are checking and your version.
Just uploaded, please note that out workflow is through RAM SS but we have not been updating loads from RAM SS because we have custom load cases and load history calcs that get wiped out with bringing those in.
Ground Floor or Second? Any strip in particular?