ishvaaag
Structural
- Aug 17, 2001
- 3,665
In ACI 318-08 you are given data for punching check shear acting at some critical section accounting for the fraction of moment passed in shear to the column. This starts with the fraction of moment to be met in a band 1.5 h to the sides of the column, and then you estimate critical section shear.
R11.11.7.2 gives separate checks for every direction; i.e., no interaction checks for simultaneous action of moments in both directions.
I have seen this separate checks so performed in PCA's Design of Concrete Buildings for Earthquake and Wind Forces, Ghosh and Domel. It is also clear that as a "punching" shear check is well suited to the Direct Design and Equivalent Frame determination of forces. "Lateral load" analysis is permitted to be combined with the previously named for gravity.
It is also clear that a correct analysis of any kind is permitted as per 13.5.1.
Now I am interested in some manual check (or design) for punching shear -that may be acceptable to third parties in one ACI318 fame- for an analysis made in some finite element program (not in an equivalent frame setup) that may or not provide for design in shear of the two-way slabs. Assume the structure is regular enough to be force-fitted within the ACI-318 schemes.
The main questions are:
Would you stand with NO interaction checks with both bending directions at the same time?
You will get column joint forces. How from them you would adjudicate or apportion values to the ACI checks?
In the end, do you think there is definition enough within ACI-318 08 for manual punching shear checks when analysis is made in FEM as allowed for 13.5.1?
R11.11.7.2 gives separate checks for every direction; i.e., no interaction checks for simultaneous action of moments in both directions.
I have seen this separate checks so performed in PCA's Design of Concrete Buildings for Earthquake and Wind Forces, Ghosh and Domel. It is also clear that as a "punching" shear check is well suited to the Direct Design and Equivalent Frame determination of forces. "Lateral load" analysis is permitted to be combined with the previously named for gravity.
It is also clear that a correct analysis of any kind is permitted as per 13.5.1.
Now I am interested in some manual check (or design) for punching shear -that may be acceptable to third parties in one ACI318 fame- for an analysis made in some finite element program (not in an equivalent frame setup) that may or not provide for design in shear of the two-way slabs. Assume the structure is regular enough to be force-fitted within the ACI-318 schemes.
The main questions are:
Would you stand with NO interaction checks with both bending directions at the same time?
You will get column joint forces. How from them you would adjudicate or apportion values to the ACI checks?
In the end, do you think there is definition enough within ACI-318 08 for manual punching shear checks when analysis is made in FEM as allowed for 13.5.1?