For a continuous slab of 3 m x 3 5 m...

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For a continuous slab of 3 m x 3.5 m size, the minimum overall depth of slab to satisfy vertical deflection limits is

A. 50 mm

B. 75 mm

C. 100 mm

D. 120 mm

Answer: Option B

Solution (By Examveda Team)

The given slab dimensions are 3m x 3.5m. Since (3.5/3) < 2, it is classified as a two-dimensional slab.

Deflection criteria as per IS 456:2000:
- For a simply supported slab, the span/depth ratio = 35
- For a continuous slab, the span/depth ratio = 40

Since we always design the slab for the shorter span (3m):

Effective depth (d) = 3000 mm / 40 = 75 mm

Thus, the minimum overall depth of the slab should be 75 mm to satisfy vertical deflection limits.

This Question Belongs to Civil Engineering >> Concrete Technology And Design Of Concrete Structures

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Comments (5)

Rajesh Bishnoi:

10 months ago

Thanks Lokesh Kapse
Sanjay Kuthyal:

5 years ago

Thanks
Lokesh Kapse:

5 years ago

3m x 3.5m here long/small (3.5/3) is less than 2
Means slab is Two dimensional slab
We know for two dimensional slab
Vertical deflection -
For Simply supported slab = 35
For Continuous Slab = 40

(we design slab for shorter span always)
So for given question
3/depth = 40
So depth = 3000 (in mm)/ 40
Eff. Depth = 75mm
Muhammad Saqib:

6 years ago

Thanks Mandal
Avijit Mandal:

6 years ago

For continuous slab L/d ratio is 40, where L is the smaller dimension of slab.
3000/40=75mm

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