I've encountered the issue where the Punching Shear Audit envelope does not include the reactions from a load combination that has a 'strength design' ruleset.
In this case, it's unconservative.
1.2G + 1.5Q Reactions Plan:
Punching Shear Audit:
Please share your model using the Secure File Upload link below and then post the file name here. We will review and see if we can determine why that load combination is missed.
Hi Karl, I've uploaded the file. Offending column is #39.
Cheers
The result is associated with the option "Include Tendon Component in Punch Check Reaction" in the Calc Options dialog. See below:
When this option is used, the program deducts the concentrated forces from the Balance Loading that are within the column shape from the punch check reactions. Moment reactions are affected by x and y direction forces that are eccentric to the centroid of the slab element. Chapter 68 "Punching Shear Design Notes" in the RAM Concept Manual has more discussion on this option. As noted in the Manual, we recommend using this option with extreme caution since the method is approximate and dependent on the way the tendons are modeled. It is important that the modeled tendon layout closely matches the actual tendon layout in the field.
Answer Verified By: Trent Byrne