square

Page 1

Design of square footing F2:

Ult. column load = 85.5 kN Safe bearing capacity = 55Self weight = 43 kN Overburden height = 0.00

Overburden = 0 kN Area of footing reqd. = 1.61Total load = 128 kN Footing size = 2.75

Column breadth = 400 mm Area of footing prvd. = 7.56Column width = 200 mm Footing thickness = 450

Net upward pressure = 11 Max. cantilever proj. = 1.28

Max. B.M. /m width M = 9 kNm Z = 374

= 0.002 As required /m width = 66Diameter of bars = 12 mm Spacing of bars = 200

As provided/m width = 565

Punch shear = 61 kN Dist. to critical section = 638

Punch shear stress = 0.03 Shear force = 7

Allow.shear stress = 0.33 Shear stress = 0.02

kN/m2

K = M/bd2fcu N/mm2

N/mm2

N/mm2

square

Page 2

m

m

mm

m

mm

mm

mm

kN/m

kN/m2

m2

m2

mm2

mm2

N/mm2

rectangular

Page 3

Design of rectangular footing F11:

Ult. column load = 936 kN Safe bearing capacity = 55Self weight = 64 kN Overburden height = 0.00

Overburden = 0 kN Area of footing reqd. = 12.53

Total load = 1000 kN Area of footing provided = 12.60

Net upward pressure = 74 Footing thickness = 400Short span Long span

Width = 3.00 m Length = 4.20Column width = 200 mm Column breadth = 500Max. cantilever proj. = 1.40 m Max. cantilever proj. = 1.85Max. B.M. /m width = 73 kNm Max. B.M. /m width = 127

= 0.022 = 0.036Z = 315 mm Z = 327

As required /m width = 624 As required /m width = 1052Diameter of bars = 12 mm Diameter of bars = 12Spacing of bars = 150 mm Number of bars/side = 100

As provided/m width = 754 As provided/m width = 1131

Punch shear = 799 kN Dist. to critical section = 688

Punch shear stress = 0.43 Shear force = 86

Allow.shear stress = 0.45 Shear stress = 0.26

kN/m2

K = M/bd2fcu N/mm2 K = M/bd2fcu

mm2

mm2

N/mm2

N/mm2

rectangular

Page 4

m

mmLong span

mmmmkNm

mm

mmmm

mm

kN/m

kN/m2

m2

m2

N/mm2

mm2

mm2

N/mm2

axial+moment

Page 5

Design of footing F2:

Ult. column load = 405 kN Safe bearing capacity = 100Ult. Moment = 170 kNm Overburden height = 0.30

Max. upward pressure = 131 Allowable pressure = 133

Min. upward pressure = 7 Footing thickness = 350

Short span Long spanWidth = 2.10 m Length = 2.80Column width = 300 mm Column breadth = 300Max. cantilever proj. = 0.90 m Max. cantilever proj. = 1.25Max. B.M. /m width = 53 kNm Max. B.M. /m width = 84

= 0.022 = 0.033Z = 268 mm Z = 279

As required /m width = 535 As required /m width = 817Diameter of bars = 12 mm Diameter of bars = 12Spacing of bars = 150 mm Number of bars/side = 120

As provided/m width = 754 As provided/m width = 942

Punch shear = 224 kN Dist. to critical section = 588

Punch shear stress = 0.17 Shear force = 88

Allow.shear stress = 0.46 Shear stress = 0.31

kN/m2

kN/m2

K = M/bd2fcu N/mm2 K = M/bd2fcu

mm2

mm2

N/mm2

N/mm2

axial+moment

Page 6

m

mm

Long spanmmmmkNm

mm

mmmm

mm

kN

kN/m2

kN/m2

N/mm2

mm2

mm2

N/mm2

combined

Page 7

Design of combined footing CF4:

Left column load = 60 Safe bearing capacity = 100Right column load = 984 kN Overburden height = 0.00Self weight = 68 kNOverburden = 0 kN Spacing of columns = 1.98Total load = 1112 kN C.G. of load from left = 1.87

Left column breadth = 200 mm Area of footing reqd. = 7.67 width = 200 mm Length of footing = 4.00Right column breadth = 400 mm Width of footing = 3.00 width = 400 mm Footing thickness = 450

Net upward pressure = 87 Area of footing provided = 12.00

Short span Long spanMax. cantilever proj. = 1.40 m Max. cantilever proj. = 1.69Max. B.M. /m width = 85 kNm Max. cant. moment /m = 124

Max span moment/m = 0

= 0.020 = 0.027Z = 359 mm Z = 372

As required /m width = 642 As required /m width = 898Diameter of bars = 12 mm Diameter of bars = 16Spacing of bars = 150 mm Spacing of bars = 180

As provided/m width = 754 As provided/m width = 1117

Punch shear = 774 kN Dist. to critical section = 784

Punch shear stress = 0.37 Shear force = 78

Allow.shear stress = 0.37 Shear stress = 0.20

Design of combined footing CF2:600 800

Footing is designedfor eccentricity of loads 0.50 3.50

Left column load = 600 kN Safe bearing capacity = 100Right column load = 800 kN Overburden height = 0.00Offset on left = 0.50 mSpacing of columns = 3.50 m C.G. of load from left = 2.50Offset on right = 1.00 m C.G. of reaction = 2.50

Eccentricity of load e= 0.00Left column breadth = 200 mm width = 200 mm Pressure at left edge

Right column breadth = 200 mm P/A + P e/Z = 93 width = 200 mm Pressure at right edge

P/A - P e/Z = 93

Length of footing = 5.00 m Max. allow. ult. pressure = 140Width of footing = 3.00 m

kN/m2

K = M/bd2fcu N/mm2 K = M/bd2fcu

mm2

mm2

N/mm2

N/mm2

combined

Page 8

Footing thickness = 400 mm Point of zero shear on footing

Area of footing provid. A= 15.00 from left edge = ###

Short span Long spanMax. cantilever proj. = 1.40 m Max. cantilever proj. = 0.90Max. B.M. /m width = 91 kNm Max. cant. moment /m = 57

Max span moment/m = ###

K = M/bd2fcu = 0.028 K = M/bd2fcu = ###Z = 315 mm Z = ###

As required /m width = 784 As required /m width = ###Diameter of bars = 12 mm Diameter of bars = 12Spacing of bars = 150 Spacing of bars = 100As provided/m width = 754 As provided/m width = 1131

Punch shear = 662 kN Dist. to critical section = 664

Punch shear stress = 0.40 Shear force = 69

Allow.shear stress = 0.39 Shear stress = 0.20

Design of combined footing F8:680 460

Footing is designed for -510 0axial load and moment: 1.50 1.85

Left column load = 680 kNLeft column moment = -510 kNm Safe bearing capacity = 100Right column load = 460 kN Overburden height = 0.30Right column moment = 0 kNm

Length of footing = 4.05Offset on left = 1.50 m Width of footing = 2.90Spacing of columns = 1.85 m Footing thickness = 450Offset on right = 0.70 m Area of footing provid. A= 11.75

Left column breadth = 700 mm Right column breadth = 300 width = 300 mm width = 300

Pressure at left edge

C.G. of load from left = 2.25 m P/A + P e/Z = 65C.G. of footing = 2.03 m Pressure at right edge

Eccentricity of load e= -0.22 m P/A - P e/Z = 129

Max. allow. ult. pressure = 133 Point of zero shear on footingfrom left edge = 2.71

Pressure at left edge

C.G. of load from left = 1.80 m P/A + P e/Z = 130C.G. of footing = 2.03 m Pressure at right edge

Eccentricity of load e= 0.23 m P/A - P e/Z = 65

Max. allow. ult. pressure = 133 Point of zero shear on footingfrom left edge = 2.08

m2

N/mm2

mm2

mm2

N/mm2

N/mm2

Case I Axial loads only:

kN/m2

Case II Axial loads and moments:

kN/m2

combined

Page 9

Short span Long spanMax. cantilever proj. = 1.30 m Max. cantilever proj. = 1.15Max. B.M. /m width = 109 kNm Max. cant. moment /m = 88

Max span moment/m = -55

K = M/bd2fcu = 0.025 K = M/bd2fcu = 0.019Z = 363 mm Z = 374

As required /m width = 816 As required /m width = 634Diameter of bars = 12 mm Diameter of bars = 12Spacing of bars = 125 Spacing of bars = 150As provided/m width = 905 As provided/m width = 754

Punch shear = 328 kN Dist. to critical section = 650

Punch shear stress = 0.13 Shear force = 84

Allow.shear stress = 0.37 Shear stress = 0.22

N/mm2

mm2

mm2

N/mm2

N/mm2

combined

Page 10

m

mm

mmmm

Long spanmkNmkNm

mm

mmmm

mm

kN

1.00

m

mmm

kN/m2

m2

m2

N/mm2

mm2

mm2

N/mm2

kN/m2

kN/m2

kN/m2

kN/m2

combined

Page 11

m

Long spanmkNmkNm

mm

mm

mm

kN

0.70

m

mmmm

mmmm

m

m

N/mm2

mm2

mm2

N/mm2

kN/m2

m2

kN/m2

kN/m2

kN/m2

kN/m2

combined

Page 12

Long spanmkNmkNm

mm

mm

mm

kN

N/mm2

mm2

mm2

N/mm2

combined (2)

Page 13

Design of combined footing F:

Column 1 600 0.00 0.00Column 2 400 0.00 2.00Column 3 700 3.00 0.00Column 4 500 3.00 2.00

Column sizeColumn 1 400 200 0.68Column 2 400 200Column 3 400 200 1.46Column 4 400 200 Length of footing = 6.20

Width of footing = 3.00

Safe bearing capacity = 100 Footing thickness = 500Overburden height = 0.90 m

Area of footing required = 18.57

Self weight = 117 Area of footing provided = 18.60Overburden = 375Total load = 2692 kN C.G.x = 1.64

Net upward pressure = 118.3 C.G.y = 0.82

X Direction Y DirectionBottom

Max. B.M./m under column = 178 kNm Max. B.M./m under column = 27

As required /m width = 1180 As required /m width = 275Diameter of bars = 16 mm Diameter of bars = 12Spacing of bars = 150 mm Spacing of bars = 200

As provided/m width = 1340 As provided/m width = 565Top

Max span moment/m 0 kNm Max span moment/m = 43

As required /m width = 0 As required /m width = 275Diameter of bars = 12 mm Diameter of bars = 12Spacing of bars = 200 mm Spacing of bars = 200

As provided/m width = 565 As provided/m width = 565

= 273 kN = 213

Shear stress = 0.21 Shear stress = 0.08

Allow.shear stress = 0.32 Allow.shear stress = 0.43

Max. Punch shear stress = 0.14 Allow.punch shear stress 0.37

LoadkN

Column location x m y m

bx

mmby

mm

kN/m2

kN/m2

mm2

mm2

mm2

mm2

Shear force at critical section

Shear force at critical section

N/mm2

N/mm2

N/mm2

C1

C2

C3

C4

y

combined (2)

Page 14

m 0.32m 1.46 1.74

mm 0.68

m

m

Y DirectionBottom

kNm

mmmm 114%

206%Top

kNm

mmmm

206%

kN

ShearOK

m2

m2

mm2

mm2

mm2

mm2

N/mm2

N/mm2

N/mm2

x

eccentric

Page 15

Design of eccentric footing:

Load on conc. footing = 137 kN 154 137Load on ecc. footing = 154 kN 6.40Spacing of columns = 6.40 mEdge of ecc. footingto centre of column = 0.15 mConc. footing length = 1.35 m 0.58 width = 1.35 m 169 122Ecc. footing length = 1.45 m

width = 1.45 m Safe bearing capacity = 100Reaction on Reaction on eccentric footing = 169 kN concentric footing = 122

Design of strap beam STB1:

Width = 200 mm Max. B.M. M = 79Depth = 500 mm Max. S.F. V = 15

= 0.068 A's required = 0

Z = 404 mm As required = 526

As provided = 603

Design shear v = 0.17 Diameter of stirrups = 8

Design concrete shear vc = 0.56 Spacing of stirrups reqd. = 200

K = M/bd2fcu N/mm2

N/mm2

N/mm2

eccentric

Page 16

kN

kNmkN

mm

mm

kN/m2

mm2

mm2

mm2

strip-base

Page 17

Design of base for footing F9:

Total column load = 149 kN Area of footing provid. = 15.00

Net upward pressure = 10 Max. cantilever proj. = 1.00Footing thickness = 300

Max. B.M. /m width = 5 kNm

= 0.003 As required /m width = 58Z = 232 mm Spacing of bars = 150

Diameter of bars = 12 mm As provided/m width = 754

Dist. to critical section = 488 mm Shear force = 5

Shear stress = 0.02 Allow.shear stress = 0.48

kN/m2

K = M/bd2fcu N/mm2

N/mm2

strip-base

Page 18

mmm

mm

kN/m

m2

mm2

mm2

N/mm2