# Solved numerical examples | Design of Singly reinforced sections

#### Guide to design of Singly reinforced Sections | Building Construction

For the “design of Singly reinforced sections” article series, we have covered the following:

Now we will move on with our next solved numerical example in which we will make use of the formulas that we have derived in our earlier articles.

#### Numerical Problem

Determine the following:

a)      The position of the neutral axis

b)      Lever arm

c)       Moment of resistance

d)      Percentage of steel

(For a rectangular beam section of width b mm and effective depth d mm. Take σcbc = 5 N/mm2, σst = 140 N/mm2, m = 18.66

#### To find Neutral Axis (NA)

σcbc /(σst/m) = xc/(d – xc)

5/(140/18.66) = xc/(d – xc)

Therefore, xc  = 0.399d mm= 0.4dmm

z = d – xc/3

= d – 0.4d/3

= 0.867dmm

= 0.87d mm

#### To find Moment of resistance

Mr = C x z

= bxccbc/2)z

= b (0.4d)(5/2)(0.87d)

= 0.87 bd2 N-mm

#### To find the percentage of steel

Equating, C = T

bxccbc/2 = Ast. σst

Therefore, Ast = bxccbc/2 σst

= [b (0.4d)(5/2)]/140

= bd/140 mm2

Pt = Ast. 100/bd

= (bd/140) x (100/bd)

= 0.71

### 3 thoughts on “Solved numerical examples | Design of Singly reinforced sections”

1. hi
plz can you provide me one 3 storey industrial RCC design with loading details.
thank you

2. 3. 