Question

Which of the following is true about depth requirement of beam considering deflection control criteria for same span and loading?
1. Depth required for simply supported beam < cantilever beam < continuous beam
2. Depth required for cantilever beam > simply supported beam > continuous beam
3. Depth required for simply supported beam > cantilever beam > continuous beam
4. Depth required for simply supported beam < continuous beam > cantilever beam

Answer 1

Correct Answer - Option 2 : Depth required for cantilever beam > simply supported beam > continuous beam

Explanation:

According to code IS: 456-clause (23.2.1)

The vertical deflection of limits:

1. Basic values of span to effective depth ratios for spans up to 10 m;

Beams	x (span to the effective depth ratio)
Cantilever	7
Simply Supported	20
Continuous	26

According to span/depth ratio, depth required of beam for same span and loading is

Cantilever > Simply supported > Continuous

2. For span above 10 m, the value in (1) will be multiplied by 10/span in meters.