The Minimum thickness required at the edge of a footing according to IS:456-2000 is
- A230 mm
- B150 mmCorrect
- C100 mm
- D450 mm
Solution
Concept
Minimum edge thickness of concrete footing
Formula
NONE
Step-by-step solution
1. As per IS 456-2000 clause 34.1.2, footings on soil must maintain a minimum structural edge thickness. 2. The minimum specified thickness at the edge of a footing on soils is 150 mm. 3. This minimum depth prevents punching shear failure and guarantees sufficient anchorage. Answer: B
Explanation
Per IS 456-2000, the thickness at the edge of a reinforced concrete footing on soil must not be less than 150 mm. For footings supported on piles, the minimum edge thickness requirement is increased to 300 mm. This baseline depth prevents edge punching and maintains adequate structural rigidity and concrete cover over reinforcement.
Why the other options are wrong
A) 230 mm exceeds the minimum code-specified edge thickness for footings. C) 100 mm is the minimum thickness for footings on piles, whereas 150 mm is required for footings on soil. D) 450 mm is much larger than the required minimum edge thickness.
Shortcut
Minimum thickness at the edge of footing on soil = 150 mm.
Common mistake
Confusing the minimum edge thickness for soil footings (150 mm) with pile footings (300 mm).
Correct answer: B) 150 mm