Hello,
I have a question regarding shear and torsion design in RC Pier.
In RC Pier, under Analysis---AD Parameters---Shear and Torsion Calculation, there is option which says "Shear force is equally distributed among stirrups".
I read the Help Document, and find it hard to understand. It says "Option of Shear force is equally distributed among stirrups, and the default is unchecked. However, when this option is checked, it assumes the equal distribution of shear force among all legs at failure, where the demand of transverse reinforcement is based on the controlling case of exterior legs." Can someone help me explain what it means?
I did an example to see what this option does, see the screen shots. Basically one is check shear force is equally distributed among stirrups and the other is not.
I compared the shear design result at a specific location between the two method, see below.
According to the comparison I noticed that when you check the shear force is equally distributed among stirrups , Av/s is calculated as the sum of Avs/s and quantity of Ats/s times the number of legs. When unchecked, Av/s is calculated as the sum of Avs/s and quantity of Ats/s times two.
But I also noticed phi*Vn is different, because Vs is different. I can't understand why. Can someone explain this for me?
Thanks.