Question

what are the tump rule to design a multi storeyd building in detail

Answer 1

Thumb rule is used to design multistoreyd buildings having components slabs, beams, columns and foundation.

S0, there are some basic thumb rules which helps in column design as:

1) The minimum size of RCC column should not be less than 9" * 9" with 4 number of bars of 12 mm diameter and grade of steel used is FE500

2) Thumb rule gives the min. grade of concrete in RCC column is M20

3) with the help of thumb rule, column length of 5 m is quite safe

4) Due to the thumb rule the longitudinal bars should not be less than 12mm diameter.

5) Thumb rule involves the use of 8mm diameter stirupps at a distance of 150mm c/c in columns.

Basic thumb rules for design of slab in multistoreyd building are as:

1) if a slab have a span upto 4.5 m then depth of slab is calculated as L/30

2) Reinforcement is provided in slab with 10mm diameter at a distance of 150mm c/c bothways in one way slab by thumb rule

3) In two way slab reinforcement for torsion is provided at edges

Basic thumb rules for Beams :

1) If a beam have span upto 4.5 m then minimum depth of foundation is calculated as L/12

2) In a beam, 2 numbers of 12mm diameter is provided in top reinforcement and 3 numbers of 16mm diameter is provided in bottom reinforcement

3) In a beam, striupps are provided of 10mm diameter with spacing 100mm c/c and in case of ductile detailing spacind should be less than 150 mm

Basic thumb rules for foundation :

1) By the thumb rule, the foundation should be 1.5m below ground and depth shall be 600mm.

2) In bottom, 20mm @ 200 mm c/c reinforcement is provided and in top, 16mm @ 200mm c/c is provided by thumb rule when seismic loads are also taken in consideration( upto zone 3) .