Print Calculation Sheet
Isolated Footing Design(ACI 318-14) - Metric
Footing No.
Group ID
-
-
Length
Foundation Geometry
Width
Thickness
1420
9
1.50m
1.50m
0.70m
Footing No.
Footing Reinforcement
-
Bottom Reinforcement(Mz) Bottom Reinforcement(Mx) Top Reinforcement(Mz) Top Reinforcement(Mx)
11 - 16 mm
11 - 16 mm
N/A
N/A
Trans Steel
16 - 19 mm 10 mm @ 300 mm
0.5 m
Isolated
Footing 1420
0.3 m
Elevation
X
1m
0.7 m
0.75 m
Z
0.61 m
1.5 m
0.61 m
0.75 m
1420
Pedestal Reinforcement
Main Steel
1.5 m
Plan
Input Values
Footing Geometry
Design Type :
Calculate Dimension with user
specified minimums as starting
value
Minimum Footing Length - X(Fl) :
1000.00 mm
Minimum Footing Width - Z (Fw) :
1000.00 mm
Footing Thickness (Ft) :
700.00 mm
Eccentricity along X (Oxd) :
0.00 mm
Eccentricity along Z (Ozd) :
0.00 mm
Column Dimensions
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Column Shape : Rectangular
Column Length - X (Dcol) :
0.25 m
Column Width - Z (Bcol) :
0.25 m
Pedestal
Include Pedestal : Yes
Pedestal Shape : Rectangular
Pedestal Height (Ph) :
0.30 m
Pedestal Length - X (Pl) :
0.61 m
Pedestal Width - Z (Pw) :
0.61 m
Design Parameters
Concrete and Rebar Properties
Unit Weight of Concrete :
24.00 kN/m3
Strength of Concrete :
20.00 N/mm2
Yield Strength of Steel :
350.00 N/mm2
Minimum Bar Size :
16 mm
Maximum Bar Size :
16 mm
Top Footing Minimum Bar Size :
16 mm
Top Footing Maximum Bar Size :
16 mm
Pedestal Minimum Bar Size :
19 mm
Pedestal Maximum Bar Size :
32 mm
Minimum Bar Spacing :
100.00 mm
Maximum Bar Spacing :
450.00 mm
Pedestal Clear Cover (P, CL) :
50.00 mm
Bottom Footing Clear Cover (F, CL) :
50.00 mm
Soil Properties
Unit Weight
:
17.60kN/m3
Base Value of Soil Bearing Capacity
:
120.00kPa
Multiplying factor for soil bearing capacity for ultimate
loads
:
1.70
Soil Bearing Capacity Type
:
Gross Bearing Capacity
Soil Surcharge
:
0.00kN/m2
Height of Soil above Footing
:
500.00mm
Type of Depth
:
Fixed Top
Bearing Capacity Input Method
:
Fixed Bearing Capacity
Minimum Percentage of Slab area in Contact for Service
Loads
:
0.00
Minimum Percentage of Slab area in Contact for Ultimate
Loads
:
0.00
Sliding and Overturning
Coefficient of Friction :
0.50
Factor of Safety Against Sliding :
1.50
Factor of Safety Against Overturning :
1.50
Global Settings
Top Reinforcement Option : Calculate only when foundation is subjected to uplift forces
Concrete Design Option : Net Pressure(Gross Pressure - Self Weight Pressure)
Top Reinforcement Factor : 1.00
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------------------------------------------------------
Design Calculations
Footing Size
Initial Length (Lo) =
1.00 m
Initial Width (Wo) =
1.00 m
Load Combinations
Load Combination/s- Service Stress Level
Load
Combination
Number
Load Combination Title
Load Case
Multiplier
(a)
Soil
Bearing
Factor (b)
Self
Weight
Factor (c)
Code
1.00
1.00
1.00
-
Load Case
Multiplier
(a)
Soil
Bearing
Factor (b)
Self
Weight
Factor (c)
Code
1.00
1.00
1.00
-
a - Value specified in the Load Multiplier table
b - Value specified in the Pile/Soil Bearing Capacity Factors table
c - Value specified in the Apply Self Weight and Dead Weight Factor table
10
GENERATED AISC:360-2010 GENERAL 4
Load Combination/s- Strength Level
Load
Combination
Number
Load Combination Title
a - Value specified in the Load Multiplier table
b - Value specified in the Pile/Soil Bearing Capacity Factors table
c - Value specified in the Apply Self Weight and Dead Weight Factor table
10
GENERATED AISC:360-2010 GENERAL 4
Applied Loads on Top of Pedestal
Before consideration of self weight and load multiplier table
Moments are about the center of Column / Pedestal (does not include moments caused by lateral loads)
For the loads shown in this table, the sign convention is the same as that for JOINT LOADS in STAAD.Pro when global Y is the vertical axis.
Applied Loads from Column - Service Stress Level
Load Case
Fx
(kN)
Fy
(kN)
Downwards is
negative Upwards
is positive
Fz
(kN)
Mx
(kNm)
Mz
(kNm)
10
5.21
-9.26
1.49
4.30
-20.28
Applied Loads from Column - Strength Level
Load Case
Fx
(kN)
Fy
(kN)
Downwards is
negative Upwards
is positive
Fz
(kN)
Mx
(kNm)
Mz
(kNm)
10
5.21
-9.26
1.49
4.30
-20.28
Reduction of force due to buoyancy
=
0.00
kN
Effect due to adhesion
=
0.00
kN
Area from initial length and width, Ao
=
Min. area required from bearing pressure, Amin
Lo X W o
=
=
0.55
m
1.00
m
2
2
Note: Amin is an initial estimation considering self-weight, axial load and moment against factored bearing capacity.
Final Footing Size
Length (L2) =
1.50 m
Governing Load Case : # 10
1.50 m
Governing Load Case : # 10
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Width (W2) =
Depth (D2) =
0.70 m
Depth is governed by Ultimate Load Case
(Service check is performed with footing thickness requirements from concrete check)
2.25 m2
Area (A2) =
Final Pedestal Height =
0.30 m
Final Soil Height =
0.50 m
Weight of the footing + pedestal (if any) = 40.52 kN
Soil Weight On Top Of Footing = 16.53 kN
Gross Pressures at 4 Corners
Pressure
Load Case / at top left
Combination
corner
(kN/m2)
Pressure
at top
right
corner
(kN/m2)
Pressure
at bottom
right
corner
(kN/m2)
Pressure
at bottom
left corner
(kN/m2)
Area of
footing in
uplift (Au)
2
(m )
Gross
Bearing
Capacity
(kN/m2)
10
-26.1991
64.5351
85.1414
-5.5928
0.64
120.0000
10
-26.1991
64.5351
85.1414
-5.5928
0.64
120.0000
10
-26.1991
64.5351
85.1414
-5.5928
0.64
120.0000
10
-26.1991
64.5351
85.1414
-5.5928
0.64
120.0000
If Au is zero, there is no uplift and no pressure adjustment is necessary. Otherwise, to account for uplift, areas of negative pressure will be set to zero and the pressure
will be redistributed to remaining corners.
Summary of Adjusted Gross Pressures at four Corners
Load Case /
Combination
Pressure at
top left
corner
(kN/m2)
Pressure at
top right
corner
(kN/m2)
Pressure at
bottom right
corner
(kN/m2)
Pressure at
bottom left
corner
(kN/m2)
Gross Bearing
Capacity
(kN/m2)
10
0.0000
67.1235
95.9200
0.0000
120.0000
10
0.0000
67.1235
95.9200
0.0000
120.0000
10
0.0000
67.1235
95.9200
0.0000
120.0000
10
0.0000
67.1235
95.9200
0.0000
120.0000
Stability Check
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0.3 m
Sliding Force
1m
.
0.7 m
Frictional Force
-
Factor of safety against sliding
Factor of safety against
overturning
Load
Along X- Along ZRequired About X- About Z- Required
Case
Resultant
Direction Direction
FOS
Direction Direction
FOS
No.
10
6.36
22.28
6.12
1.50
8.58
1.95
1.50
Critical Load Case And The Governing Factor Of Safety For Overturning And Sliding - X Direction
Critical Load Case for Sliding along X-Direction :
10
Governing Disturbing Force :
5.21 kN
Governing Restoring Force :
33.16 kN
Minimum Sliding Ratio for the Critical Load Case :
6.36
Critical Load Case for Overturning about X-Direction :
10
Governing Overturning Moment :
5.80 kNm
Governing Resisting Moment :
49.73 kNm
Minimum Overturning Ratio for the Critical Load Case :
8.58
Critical Load Case And The Governing Factor Of Safety For Overturning And Sliding - Z Direction
Critical Load Case for Sliding along Z-Direction :
10
Governing Disturbing Force :
1.49 kN
Governing Restoring Force :
33.16 kN
Minimum Sliding Ratio for the Critical Load Case :
22.28
Critical Load Case for Overturning about Z-Direction :
10
Governing Overturning Moment :
-25.52 kNm
Governing Resisting Moment :
49.73 kNm
Minimum Overturning Ratio for the Critical Load Case :
1.95
Critical Load Case And The Governing Factor Of Safety For Sliding Along Resultant Direction
Critical Load Case for Sliding along Resultant Direction :
10
Governing Disturbing Force :
5.42 kN
Governing Restoring Force :
33.16 kN
Minimum Sliding Ratio for the Critical Load Case :
6.12
Ultimate Gross Pressures
The base pressures reported in this table and the area of footing in contact include the effect of buoyancy (if any).
Load Case /
Load
Combination
ID
Pressure at
top left
corner
(kN/m2)
Pressure at
top right
corner
(kN/m2)
Pressure at
bottom
right
corner
(kN/m2)
10
0.0000
67.1235
95.9200
Pressure at
bottom left
corner
(kN/m2)
Gross
Factored
Bearing
Capacity
For
Ultimate
Load Case
(kN/m2)
Area of
footing in
Contact
with soil
(Au)
2
(m )
0.0000
204.0000
1.61
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Minimum Required Contact Area for Ultimate Loads :
0.00 m2
Actual Area in Contact for all ultimate load cases exceeds the minimum required. Hence Safe
Gross Bearing Capacity for Ultimate Loads :
204.00 kN/m2
Maximum Corner Pressure from all ultimate load cases is less than the allowable. Hence Safe
Shear Calculation
Punching Shear Check
X
0.75 m
0.315 m
0.75 m
Z
Plan
Total Footing Depth, D = 0.70m
Calculated Effective Depth, d =
For rectangular column,
=
D - Ccover - 1 * db
=
0.63 m
Bcol / Dcol
=
1.00
Effective depth, d, increased until 0.75XVc
Punching Shear Force
Punching Shear Force, Vu = 35.52kN, Load Case # 10
From ACI Cl. 22.6.5.2, bo for column=
=
4.97 m
Table 22.6.5.2, (b), Vc1 =
= 7194.80 kN
Table 22.6.5.2, (c), Vc2 =
= 8311.76 kN
Table 22.6.5.2, (a), Vc3 =
= 4655.46 kN
Punching shear strength, Vc =
0.75 X minimum of (Vc1, Vc2, Vc3)
= 3491.59 kN
0.75 X Vc > Vu hence, OK
One-Way Shear in XY Plane
(Shear Plane Parallel to Global X Axis)
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X
0.75 m
0.75 m
Z
Plan
From ACI Cl. 22.5.5.1, Vc =
= 714.06 kN
Distance of critical section from top left corner
along Z, DZ =
=
0.00 m
Check that 0.75 X Vc > Vux where Vux is the shear force for the critical load cases at a distance d from the face of the column caused by bending about the X axis.
From above calculations,
0.75 X Vc
Critical load case for Vux is # 10
= 535.54 kN
=
0.00 kN
0.75 X Vc > Vux hence, OK
One-Way Shear in YZ Plane
(Shear Plane Parallel to Global Z Axis)
X
0.75 m
0.75 m
Z
Plan
From ACI Cl. 22.5.5.1, Vc =
=
Distance of critical section from top left corner along
X, DX =
=
714.06 kN
0.00 m
Check that 0.75 X Vc > Vuz where Vuz is the shear force for the critical load cases at a distance d from the face of the column caused by bending about the Z axis.
From above calculations,
0.75 X Vc
Critical load case for Vuz is # 10
= 535.54 kN
=
0.00 kN
0.75 X Vc > Vuz hence, OK
Flexure About Z-Axis
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Design For Bottom Reinforcement Parallel to X Axis
X
Z
11 - 16 mm
Calculate the flexural reinforcement along the X direction of the footing. Find the area of steel required.
Critical Load Case # 10
The strength values of steel and concrete used in the formulae are in Mpa
Bars parallel to X Direction are placed at bottom
Effective Depth d
=
0.63 m
=
0.85
=
=
0.02607
Maximum Reinforcement Ratio corresponding to εt
= 0.005 =
=
=
0.01548
=
=
0.00200
From Ref.1, Eq. 3.8.4a, constant m =
=
20.59
Factor
from ACI Cl. 22.2.2.4.3 =
From ACI318-2011 Appendix B 8.4.2,
From ACI Cl. 7.6.1.1,
Calculate reinforcement ratio
for critical load case
Design for flexure about Z axis is performed at the face
of the column at a distance from top left corner of
footing, Dx =
=
1.05 m
Ultimate moment =
=
6.85 kNm
Nominal moment capacity required, Mn =
=
7.61 kNm
(Based on effective depth) Required
=
=
(Based on gross depth) x d / Depth
=
Since
ρ < ρmin, select ρ= ρmin
Area of Steel Required, As =
0.00004
0.00003
ρmin Governs
=
2100.00 mm2
Note - "Area of Steel required" reported here is the larger value between the calculated area of steel and minimum steel required as per code stipulations
Selected bar Size = 16 mm
Minimum spacing allowed (Smin) = 100.00mm
Selected spacing (S) = 138.41mm
Smin<= S <= Smax and selected bar size < selected maximum bar size
The reinforcement is accepted.
According to ACI 318 Clause No- 24.3.2
Max spacing for Cracking Consideration = 330.86mm
Safe for Cracking Aspect.
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Based on spacing reinforcement increment; provided reinforcement is
16 mm @ 135mm o.c.
Required development length for bars =
Available development length for bars,DL =
Try bar size
16 mm
=
0.59 m
=
0.40 m
Area of one bar = 199.00 mm2
Number of bars required, Nbar =
=
11
Because the number of bars is rounded up, make sure new reinforcement ratio < ρmax
Total reinforcement area, As_total =
Nbar X (Area of one bar)
=
2189.00 mm2
d=
D - Ccover - 0.5 X (dia. of
one bar)
=
0.63 m
Reinforcement ratio,
=
=
0.00233
From ACI Cl. 25.2.1, minimum req'd clear distance between bars
Cd = max (Diameter of one bar, 1.0" (25.4mm), Min. User Spacing) = 100.00mm
Provided Steel Area / Required Steel Area = 1.04
Flexure About X-Axis
Design For Bottom Reinforcement Parallel to Z Axis
X
Z
11 - 16 mm
Calculate the flexural reinforcement along the Z direction of the footing. Find the area of steel required.
Critical Load Case # 10
The strength values of steel and concrete used in the formulae are in Mpa
Bars parallel to X Direction are placed at bottom
Effective Depth d
=
0.63 m
=
0.85
=
=
0.02607
Maximum Reinforcement Ratio corresponding to εt
= 0.005 =
=
=
0.01548
=
=
0.00200
From Ref.1, Eq. 3.8.4a, constant m =
=
20.59
Factor
from ACI Cl. 22.2.2.4.3 =
From ACI318-2011 Appendix B 8.4.2,
From ACI Cl. 7.6.1.1,
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9/14
Calculate reinforcement ratio
for critical load case
Design for flexure about X axis is performed
at the face of the column at a distance from
top left corner of footing, Dz =
=
1.05 m
Ultimate moment =
=
2.06 kNm
Nominal moment capacity required, Mn =
=
2.29 kNm
(Based on effective depth) Required
= 0.00001
(Based on gross depth)
=
x d / Depth
= 0.00001
ρ < ρmin, select ρ= ρmin
Since
ρmin Governs
Area of Steel Required, As =
=
2100.00 mm2
Note - "Area of Steel required" reported here is the larger value between the calculated area of steel and minimum steel required as per code stipulations
Selected Bar Size = 16 mm
Minimum spacing allowed (Smin) = 100.00mm
Selected spacing (S) = 138.41mm
Smin<= S <= Smax and selected bar size < selected maximum bar size
The reinforcement is accepted.
Max spacing for Cracking Consideration = 330.86mm
Safe for Cracking Aspect.
Based on spacing reinforcement increment; provided reinforcement is
16 mm @ 135mm o.c.
Required development length for bars
=
=
0.59 m
Available development length for bars,
DL =
=
0.40 m
Try bar size
16 mm
Area of one bar = 199.00 mm2
Number of bars required, Nbar=
=
11
Because the number of bars is rounded up, make sure new reinforcement ratio < ρmax
Total reinforcement area, As_total =
Nbar X (Area of one bar)
=
d=
D - Ccover - 1.5 X (dia. of
one bar)
=
Reinforcement ratio,
2189.00 mm2
0.63 m
=
=
0.00233
From ACI Cl. 25.2.1, minimum req'd clear distance between bars
Cd = max (Diameter of one bar, 1.0" (25.4mm), Min. User Spacing) = 100.00mm
Provided Steel Area / Required Steel Area = 1.04
Pedestal Design
Pedestal at Support No.
Axial Capacity Ratio, Critical Load Case, Location
Flexural Capacity Ratio
% of Main Steel
Main Reinforcement
Links
1420
0.00, 10, Bottom
0.07
1.23
16-#19
10 @ 300mm
Pedestal Size
Pedestal Shape = Rectangular
Dimension Along Global X = 609.60
mm
Dimension Along Global Z = 609.60
mm
Longitudinal Reinforcement Details
Area of Longitudinal Bars = 4584.32
sq.mm
Number of Bars and Bar Dia = 16-#19
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Longitudinal Steel Percentage = 1.23
Bar arrangement sequence on each = 5 # 19
side along Global X
Bar arrangement sequence on each = 5 # 19
side along Global Z
Flexure - Governing Load Case Details
Governing Load Case Number = 10
Critical Location = Bottom
Axial load = 18.23
kN
Moment about X axis = 5.80
kNm
Moment about Z axis = -25.52
kNm
Resultant moment = 26.17
kNm
Moment Capacity = 371.95
kNm
Angle of inclination of Neutral Axis
= 12.80 degrees
with respect to local Z
Serial No.
P
(kN)
M
(kNm)
Strength Reduction Factor
(Φ)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
-1444.06
-1443.18
-1412.18
-1186.05
-794.45
-305.12
146.96
594.11
984.29
1149.18
1294.97
1421.39
1532.59
1636.57
1741.64
1842.44
1965.29
2127.80
2290.64
2466.76
2621.47
2772.48
2914.04
3059.11
3199.31
3336.05
3470.72
3734.60
4009.44
4265.65
4497.36
4673.08
4804.90
4882.31
4913.18
4956.46
4992.85
5019.30
5042.01
5062.05
5079.15
5090.38
5097.71
5103.36
5103.98
0.00
0.32
11.00
78.79
184.73
300.74
400.53
481.19
532.46
534.24
530.14
524.49
517.49
509.06
496.87
482.04
470.15
464.50
456.07
446.13
434.99
422.73
409.71
395.11
379.51
362.84
344.96
305.44
257.37
205.72
153.01
108.28
71.69
49.63
42.51
33.92
26.60
20.55
15.29
10.65
6.65
3.81
1.84
0.23
0.00
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.90
0.88
0.83
0.80
0.76
0.73
0.71
0.68
0.66
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
0.65
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Axial Load [kN]
ϕPn,max = 4083.1848511999997
1000
0
-1000
-2000
0
90
180
270
360
450
534.236282
ϕM (12.8 deg) (kNm)
Moment [kNm]
Shear - Governing Load Case Details
Critical Load Case for Shear Along X = 10
Critical Load Case for Shear Along Z = 10
Shear force along X = 5.21
kN
Shear force along Z = 1.49
kN
Transverse Stirrups Details
Rebar Links = 10 @ 300
mm
No. of Legs in X direction = 5
No. of Legs in Z direction = 5
Material Take Off
Footing Reinforcement
Direction
Size
Number
Total Length (m)
Weight (kg)
Along Z on Bottom
Face
16 mm
11
15.40
23.90
Along X on Bottom
Face
16 mm
11
15.40
23.90
Along Z on Top
Face
N/A
N/A
N/A
N/A
Along X on Top
Face
N/A
N/A
N/A
N/A
Pedestal Reinforcement
Type
Size
Number
Total Bar Length
(m)
Weight (kg)
Main Steel
(Vertical)
19 mm
16
17.10
38.22
Transverse Steel
(Ties)
10 mm
3
6.57
3.68
Internal Steel
(Ties)
10 mm
18
11.92
6.67
Total Reinforcement Weight :
96.38 kg
Concrete
3
-
Length (m)
Width (m)
Thickness (m)
Volume (m )
Footing
1.50
1.50
0.70
1.58
Pedestal
0.61
0.61
0.30
0.11
Total Concrete Volume :
1.69 m3
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Formwork
Footing :
4.20 m2
Pedestal :
0.74 m2
Total :
4.94 m2
Soil Excavation
Pit Depth :
Pit Slope (a : b) :
Side Distance, s :
1.20 m
1 : 1 (Assumed)
0 (Assumed)
Excavation Volume :
9.32 m3
Backfill Volume :
7.64 m3
09-Dec-23 13:53:46 PM
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0.61 m
0.75 m
0.75 m
Foundation
1.5 m
Pedestal
0.5 m
0.3 m
D
N/A
AstX(T)
N/A
AstZ(T)
Trans Reinforcement
11 - 16 mm
AstX(B)
11 - 16 mm
AstZ(B)
1m
B
0.7 m
Main Reinforcement
10 mm @ 300 mm
0.7 m
L
1.5 m
h
19 mm - 16
Elevation
1.5 m
b
0.3 m
Reinforcement
l
0.61 m
Dimensions (m)
0.61 m
14/14
09-Dec-23 13:53:46 PM
X
0.61 m
1.5 m
Plan
TOP N/A
BOTTOM 11 - 16 mm
Plan


Z
0.75 m
0.75 m
BOTTOM 11 - 16 mm
TOP N/A