Download - Zapata Staad.foundation Memoria
-
8/12/2019 Zapata Staad.foundation Memoria
1/20
Isolated Footing Design(ACI 318-05)
Design For Isolated Footing 1
Footing No. Group ID Foundation Geometry
- - Length Width Thickness
1 1 2.900 m 2.900 m 0.400 m
Page 1 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
2/20
Footing No. Footing Reinforcement Pedestal Reinforcement
-
BottomReinforcement
(Mz)
BottomReinforcement
(Mx)
TopReinforcement
(Mz)
TopReinforcement
(Mx)Main Steel Trans Steel
1#5 @ 22 cm
c/c#5 @ 20 cm
c/c#4 @ 22 cm
c/c#4 @ 22 cm
c/cN/A N/A
Page 2 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
3/20
Isolated Footing 1
Input Values
Footing Geomtery
Footing Thickness (Ft) : 0.40 m
Footing Length - X (Fl) : 1.00 m
Footing Width - Z (Fw) : 1.00 m
Eccentricity along X (Oxd) : 0.00 m
Eccentricity along Z (Ozd) : 0.00 m
Page 3 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
4/20
Column Dimensions
Pedestal
Design Parameters
Concrete and Rebar Properties
Soil Properties
Sliding and Overturning
Column Shape : Rectangular
Column Length - X (Pl) : 0.50 m
Column Width - Z (Pw) : 0.50 m
Include Pedestal? No
Pedestal Shape : N/A
Pedestal Height (Ph) : N/A
Pedestal Length - X (Pl) : N/A
Pedestal Width - Z (Pw) : N/A
Unit Weight of Concrete : 2400.000 kg/m3
Strength of Concrete : 4.000 ksi
Yield Strength of Steel : 60.000 ksi
Minimum Bar Size : # 4
Maximum Bar Size : # 10
Minimum Bar Spacing : 10.00 cm
Maximum Bar Spacing : 30.00 cm
Pedestal Clear Cover (P, CL) : 8.00 cm
Footing Clear Cover (F, CL) : 8.00 cm
Soil Type : Drained
Unit Weight : 1600.00 kg/m3
Soil Bearing Capacity : 205.95 kN/m2
Soil Surcharge : 0.00 kip/in2
Depth of Soil above Footing : 0.70 m
Cohesion : 0.00 kip/ft2
Coefficient of Friction : 0.50
Factor of Safety Against Sliding : 1.50
Factor of Safety Against Overturning : 1.50
Page 4 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
5/20
------------------------------------------------------
Page 5 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
6/20
Design Calculations
Footing Size
Initial Length (Lo) = 1.00 m
Initial Width (Wo) = 1.00 m
Applied Loads - Allowable Stress Level
LCAxial
(Mtonf)
Shear X
(Mtonf)
Shear Z
(Mtonf)
Moment X
(kNm)
Moment Z
(kNm)101 79.860 2.790 11.840 132.880 166.713
Page 6 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
7/20
Applied Loads - Strength Level
LCAxial
(Mtonf)Shear X(Mtonf)
Shear Z(Mtonf)
Moment X(kNm)
Moment Z(kNm)
102 79.860 2.790 11.840 132.880 166.713
Page 7 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
8/20
Final Footing Size
Reduction of force due to buoyancy = -0.00 MtonfEffect due to adhesion = 0.00 Mtonf
Min. area required from bearing pressure, Amin
= P / qmax
= 3.888 m2
Area from initial length and width, Ao= Lo* Wo= 1.00 m2
Length (L2) = 2.90 m Governing Load Case : # 101
Width (W2) = 2.90 m Governing Load Case : # 101
Depth (D2) = 0.40 m Governing Load Case : # 101
Area (A2) = 8.41 m2
Page 8 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
9/20
-
8/12/2019 Zapata Staad.foundation Memoria
10/20
Check for stability against overturning and sliding
Critical Load Case And The Governing Factor Of Safety For Overturning And Sliding - X Direction
Critical Load Case And The Governing Factor Of Safety For Overturning And Sliding - Z Direction
- Factor of safety againstsliding
Factor of safety againstoverturning
Load CaseNo.
Along X-Direction
Along Z-Direction
About X-Direction
About Z-Direction
101 17.397 4.099 7.697 8.861
Critical Load Case for Sliding along X-Direction : 101
Governing Disturbing Force : 2.790 Mtonf
Governing Restoring Force : 48.536 Mtonf
Minimum Sliding Ratio for the Critical Load Case : 17.397
Critical Load Case for Overturning about X-Direction : 101
Governing Overturning Moment : 179.324 kNm
Governing Resisting Moment : 1380.316 kNm
Minimum Overturning Ratio for the Critical Load Case : 7.697
Critical Load Case for Sliding along Z-Direction : 101
Governing Disturbing Force : 11.840 Mtonf
Governing Restoring Force : 48.536 Mtonf
Minimum Sliding Ratio for the Critical Load Case : 4.099
Critical Load Case for Overturning about Z-Direction : 101
Governing Overturning Moment : 155.769 kNm
Governing Resisting Moment : 1380.316 kNm
Page 10 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
11/20
Minimum Overturning Ratio for the Critical Load Case : 8.861
Page 11 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
12/20
Shear Calculation
Punching Shear Check
Effective depth, deff
, increased until 0.75*Vc Punching Shear Force
Punching Shear Force, Vu = 73.86 Mtonf, Load Case # 102
Total Footing Depth, D = 0.40m
Calculated Effective Depth, deff
= D - Ccover
- 1.0 = 0.29 m
For rectangular column, = Bcol/ Dcol= 1.00
From ACI Cl.11.12.2.1, bofor column= 3.18 m
Equation 11-33, Vc1
= 249.82 Mtonf
Equation 11-34, Vc2
= 237.64 Mtonf
Equation 11-35, Vc3
= 166.54 Mtonf
Punching shear strength, Vc= 0.75 * minimum of (V
c1, V
c2, V
c3) = 124.91 Mtonf
0.75 * Vc> V
uhence, OK
Page 12 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
13/20
One-Way Shear Check
Along X Direction
Check that 0.75 * Vc> V
uxwhere V
uxis the shear force for the critical load cases at a distance d
efffrom the
face of the column caused by bending about the X axis.
Along Z Direction
From ACI Cl.11.3.1.1, Vc= 75.98 Mtonf
Distance along Z to design for shear, Dz= 1.99 m
From above calculations, 0.75 * Vc= 56.98 Mtonf
Critical load case for Vux
is # 102 33.06 Mtonf
0.75 * Vc> Vuxhence, OK
Page 13 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
14/20
Check that 0.75 * Vc> V
uzwhere V
uzis the shear force for the critical load cases at a distance d
efffrom the
face of the column caused by bending about the Z axis.
From ACI Cl.11.3.1.1, Vc= 75.98 Mtonf
Distance along X to design for shear, Dx= 0.91 m
From above calculations, 0.75 * Vc= 56.98 Mtonf
Critical load case for Vuz
is # 102 31.99 Mtonf
0.75 * Vc> V
uzhence, OK
Page 14 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
15/20
Design for Flexure about Z axis
Calculate the flexural reinforcement along the X direction of the footing. Find the area of steel required, A, as per
Section 3.8 of Reinforced Concrete Design (5th ed.) by Salmon and Wang (Ref. 1)
Critical Load Case # 102
The strength values of steel and concrete used in the formulae are in ksi
Calculate reinforcement ratio for critical load case
Factor from ACI Cl.10.2.7.3 for Fc' 4 ksi, 0.85
From ACI Cl. 10.3.2, = 0.02851
From ACI Cl. 10.3.3, = 0.02138
From ACI Cl. 7.12.2, = 0.00180
From Ref. 1, Eq. 3.8.4a, constant m = 17.65
Design for flexure about Z axis isperformed at the face of the column
at a distance, Dx=
1.20 m
Ultimate moment, 252.36 kNm
Nominal moment capacity, Mn= 280.40 kNm
Required = 0.00276
Since OK
Area of Steel Required, As= 3.66 in2
Page 15 of 20Isolated Footing Design
23/07/2013file://D:\Staad Foundation Advanced\CalcXsl\footing.xml
-
8/12/2019 Zapata Staad.foundation Memoria
16/20
Find suitable bar arrangement between minimum and maximum rebar sizes
Because the number of bars is rounded up, make sure new reinforcement ratio