In the design of isolated column footing of thickness d, the critical section from the consideration of single shear is
- Aat column face
- Bat a distance d/4 from the column face
- Cat a distance d/2 from the face of the column
- Dat a distance d from the face of the columnCorrect
Solution
Concept
One-way shear in isolated footings (IS 456 cl. 34.2.4)
Step-by-step solution
1. Single (one-way) shear is checked at a section a distance d from the face of the column. 2. Punching shear is checked at d/2.
Explanation
The critical section for beam-type shear is at the effective depth from the face of the column.
Why the other options are wrong
The column face and d/2 are for punching shear or bending.
Shortcut
One-way: d; two-way: d/2.
Common mistake
Choosing d/2.
Correct answer: D) at a distance d from the face of the column