Project XXX
Design of Isolated footing
Designed by Date Page
Client XXX XXX
Checked Revision Job No
Strl. Consultant XXX XXX - XXX
Ref. Calculations
Footing F1 INVALID DESIGN
P= 967 kN fck = 20 N/mm2
Mx = 0 kN-m fy = 415 N/mm2 Density of concrete 25 kN/m3
My = 0 kN-m cover = 50 mm Density of Earth 18 kN/m3
SBC = 150 kN/m 2
Dia. of bar along L 10
along B 10
Depth of excavation (from finished flr.Lvl.) = 1.50 m
Column/Pedestal Details
b= 400 mm
h= 400 mm
Area required = 7.74 m2
Provide
L= 2000 mm
B= 3450 mm
D= 600 mm
Area provided = 6.9 m2
Weight of backfill = 111.78 kN
Self weight of footing = 103.50 kN
Final area of footing reqd.= 7.88 m2
Bearing pressure at four corners Bearing pressure =
Corner 1 = 140.14 kN/m 2
OK P/A ± Mx/Zy ± My/Zx
Corner 2 = 140.14 kN/m2 OK
Corner 3 = 140.14 kN/m2 OK where Zx =BL2/6
Corner 4 = 140.14 kN/m 2
OK and Zy =LB2/6
To find Design Moments
x - direction
Mx = 325.92 kN-m
y - direction
My = 154.72 kN-m
Check for thickness of footing
Mu,lim = 0.138 fckbd2
For, Mx = 325.92 kN-m
d = 297.60116 mm OK
for, My = 154.72 kN-m
d = 156.12 mm OK
Project XXX
Design of Isolated footing
Designed by Date Page
Client XXX XXX
Checked Revision Job No
Strl. Consultant XXX XXX - XXX
Ref. Calculations
Reinforcement
Reqd. Spacing
Axis M Mu/bd2 pt(req) Ast Dia Ast(prov) pt(prov)
Spacing provided
Along L 325.92 0.48 0.14 2557.98 Y10@ 100 c/c 175 c/c 1548.36 0.08
Along B 154.72 0.41 0.12 1284.00 Y10@ 100 c/c 175 c/c 897.60 0.08
Check for punching shear(Two way shear)
The section for punching shear is taken at a distance of d/2 from the face of column/pedestal
Perimeter = 3780.00 mm
Shear force = 841.85 kN
d/2
945
Shear stress = 0.62 N/mm2 OK 945
Permissible stress = 1.118034 N/mm2 d/2
945
Check for One way shear
The section for punching shear is taken at a distance of d from the face of column/pedestal
Along L
Shear force = 123.29 kN
Shear Stress = 0.10 N/mm2 OK
Permissible stress = 0.23 N/mm2
Along B =
Shear force = 274.68 kN
Shear Stress = 0.38 N/mm2 Fails
Permissible stress = 0.24 N/mm2
2000
CHECKS
D = 600 Bearing OK
pressure
One way shear Not OK
Punching
3450
Shear OK
Y10@ 175 c/c
Y10@ 175 c/c
b= 0.4 m l' = 800 mm L= 2
D= 0.4 m l' = 0.8 m B= 3.45
L= 2 m b' = 1525 mm
B= 3.45 m b' = 1.525 m
Pressures 1 2 3 4
140.14 140.14 140.14 140.14
Avg 1 & 2 140.14
Avg 3 & 4 140.1449
Avg 1 & 3 140.1449
Avg 2 & 4 140.14
Along B
Face of column
Left face 140.1449
Right face 140.1449
Mx = 325.9245
Along L
Face of column
Left face 140.1449
Right face 140.1449
My = 154.72
Pressure at d/2 from column face
Along L
d/2 = 272.5
Left face 140.1449
Right face 140.1449
Along B
d/2 = 272.5
Left face 140.1449
Right face 140.1449
Pressure at d from column face
Along L
d= 545
Left face 140.1449
Right face 140.1449
Along B
d= 545
Left face 140.1449
Right face 140.1449
Sl. No. Description L B D Nos Qty
1 RCC qty 2 3.45 0.6 1 4.14
Total 4.14 m3
Sl. No. Description dia wt/m Length Nos Qty
1 Along L 10 0.62 1.9 21 24.60
2 Along B 10 0.62 3.35 13 26.85
Total 51.45 kg
