Let us make BBS of the retaining wall as shown below.
Given data:
Retaining wall length = 9000mm.= 9m.
Raft width = 2150mm.
Raft depth = 400mm.
Wall height = 2500mm.
Wall width = 300mm
Clear cover = 50mm.
Calculation:
A. Cutting length:
1. Main bar of raft:
Given data:
Reinforcement = T16 @ 150 c/c.
Overlap = 150mm.
Cutting length of raft main bar
= [{2nos.×( a + b + overlap)}  (5nos. × 90° bend)]
Where, a
= [raft width  (2nos. × cover)]
= [ 2150mm.  (2nos. × 50mm.)]
a = 2050mm.
b = [raft depth  (2nos. × cover)]
= [ 400mm.  (2nos. × 50mm.)]
b = 300mm.
Cutting length of raft main bar
= [{2nos.×( 2050mm. + 300mm.+ 150mm.)}  (5nos. × 2d)]
= [ {2nos.× 2500mm}  (5nos. × 2 × 16mm)]
= [ 5000mm  160mm.]
= 4840mm.
= 4.84m.
2. Distribution bar of raft:
Cutting length of distribution bar of the raft
= [ retaining wall length  (2nos. × cover)]
= [ 9000mm.  (2nos. × 50mm.)]
= 8900mm.
= 8.90m.
3. Main bar of RCC wall:
3a. Inner vertical bar:
Given data:
Reinforcement = T16 @ 150 c/c.
Cutting length of the inner vertical bar
= [(300mm.+ a + 150mm.) (2nos. × 90° bend)]
Where
a = [(wall height  cover) + (raft depth  cover)]
= [(2500mm.  50mm.) + (400mm.  50mm.)]
= [2450mm. + 350mm.]
a = 2100mm.
Cutting length of the inner vertical bar
= [(300mm.+ 2100mm. + 150mm.)  (2nos. × 2d)]
= [ 2550mm (2nos. × 2 × 16mm.)]
= [2550mm.  64mm.]
= 2486 mm.
= 2.486m.
3b. Outer vertical bar:
Given data:
Reinforcement = T12 @ 150 c/c.
Cutting length of the outer vertical bar
= [(300mm.+ a + 150mm.) (2nos. × 90° bend)]
Where
a = [(wall height  cover) + (raft depth  cover)]
= [(2500mm.  50mm.) + (400mm.  50mm.)]
= [2450mm. + 350mm.]
a = 2100mm.
Cutting length of the outer vertical bar
= [(300mm.+ 2100mm. + 150mm.)  (2nos. × 2d)]
= [ 2550mm (2nos. × 2 × 12mm.)]
= [2550mm.  48mm.]
= 2502 mm.
= 2.5m.
4. Distribution bar of wall:
Cutting length of distribution bar of the wall
= [ retaining wall length  (2nos. × cover)]
= [ 9000mm.  (2nos. × 50mm.)]
= 8900mm.
= 8.90m.
5. Link bar:
Cutting length of the link bar
= [a + (2nos. × 75mm.)  (2nos. × 90° bend)]
Where
a = [ wall width  (2nos.× cover)]
= [300mm. (2nos.× 50mm.)]
a = 200mm.
Cutting length of the link bar
= [200mm + (2nos. × 75mm.)  (2nos. × 2 × 8mm.)]
= [200mm. + 150mm.  32mm.]
= 318mm.
= 0.318m.
B. No of bars:
1. Main bars of the raft:
No. of main bars in raft
= [{retaining wall length  (2nos. × cover)}÷ c/c distance] + 1
= [{9000mm.  (2nos. × 50mm.)}÷ 150mm.] + 1
= [8900mm. ÷ 150mm.] + 1
= 59.33 +1
= 60.33
By rounding off = 61nos.
2. Distribution bars of the raft:
No. of distribution bars in raft
= [{raft width (2nos. × cover)}÷ c/c distance] + 1
= [{2150mm.  (2nos. × 50mm.)}÷ 150mm.] + 1
= [2050mm. ÷ 150mm.] + 1
= 13.66 +1
= 14.66
By rounding off = 15nos.
The distribution bars are provided at the top & bottom sides of the raft.
So, the total no. of distribution bars in the raft
= [2sides × 15nos.]
= 30 nos.
3a. Inner vertical bar
No. of inner vertical bars in the wall
= [{retaining wall length  (2nos. × cover)}÷ c/c distance] + 1
= [{9000mm.  (2nos. × 50mm.)}÷ 150mm.] + 1
= [8900mm. ÷ 150mm.] + 1
= 59.33 +1
= 60.33
By rounding off = 61nos.
3b. Outer vertical bar
No of outer vertical bars is same as inner vertical bars
= 61 nos.
4. Distribution bars of wall:
No. of distribution bars in the wall
= [{wall depth  cover}÷ c/c distance] + 1
= [{2500mm.  50mm.}÷ 150mm.] + 1
= [2450mm. ÷ 150mm.] + 1
= 16.33 +1
= 17.33
By rounding off = 18nos.
The distribution bars are provided at the inner & outer sides of the wall.
So, the total no. of distribution bars in the wall
= [2sides × 18nos.]
= 36 nos.
5. Link bar:
Link bars are provided along the length side & height of the wall as shown in the above drawing.
No. of link bars along the length side
= [{retaining wall length  (2nos. × cover)}÷ c/c distance] + 1
= [{9000mm.  (2nos. × 50mm.)}÷ 300mm.] + 1
= [8900mm. ÷ 300mm.] + 1
= 29.67 +1
= 30.67
By rounding off = 31nos.
No of link bars along the height side
= [{wall height  cover}÷ c/c distance] + 1
= [{2500mm.  50mm.}÷ 300mm.] + 1
= [2450mm. ÷ 300mm.] + 1
= 8.16 +1
= 9.16
By rounding off = 10nos.
Total no. of link bars required for retaining wall
= [along length side × along height side]
= [ 31nos.× 10nos.]
= 310nos.
To know, how to calculate the concrete volume, Go through the article 👇
👀. How to calculate the concrete volume of a retaining wall?
Now, let us prepare a BBS table for the retaining wall.
Sl. No. 
Type of Bar 
Dia. in mm. 
Nos. 
Length in m. 
Total length in m. 
Weight in Kg/m. 
Total bar wt. in kg. 
1. 
Main bar of raft 
16 
61 
4.84 
295.24 
1.578 
465.89 
2. 
Distribution bar of raft. 
10 
30 
8.90 
267 
0.617 
164.74 
3. 
Main bar of wall 



3a. 
Inner vertical bar. 
16 
61 
2.486 
151.65 
1.578 
239.30 
3b. 
Outer vertical bar. 
12 
61 
2.50 
152.50 
0.888 
135.42 
4. 
Distribution bar of wall. 
10 
36 
8.90 
320.40 
0.617 
197.69 
5. 
Link bar 
8 
310 
0.318 
98.58 
0.395 
38.94 
6. 
Total weight of bars = 
1241.98 

7. 
Add 3% wastage = 
37.26 

8. 
The grand total wt. of rebar's = 
1279.24 
Thank you for going through these calculation steps❤. Have a good day 😄.