Correct Answer - Option 2 : Bending Moment, Shear force and punching shear
Explanation:
The design depth of footing is based on the following three criteria:
1. Depth based on maximum BM at the face of column
For illustration consider square footing of width B resting on uniform soil pressure ‘p’. The maximum BM is
\(M = \frac{{pB{{\left( {B - b} \right)}^2}}}{8}\)
Where b is column size.
The depth is given as
\(d = \sqrt {M/Rb} \)
Where R is designed constant.
2. Maximum shear at a distance of d from the face of the column, where d is the effective depth of footing.
\(Nominal\;shear\;stress = \frac{V}{{Bd}}\) < permissible one way shear in footing
Using the above equation we can calculate d.
3. Based on punching shear stress at a distance of d/2 from face of column, where d is the effective depth
\({\rm{Punchings\;shear\;stress}} = \frac{{{\rm{Net\;punching\;force}}}}{{{\rm{perimeter}}\; \times \;{\rm{d}}}} < {\rm{permissible\;puhing\;shear\;stress}}\)
Using the above equation, we can calculate d.
