7/27/2019 Combined Footing for Clb

1/7

SILPARUPAARCHITECTS AND ENGINEERS

PTC Karimnagar

Classroom Block

CF2

= 1371 KN

= 1593 KN

Working Load on footing W1 = 914.00 KN

= 1062.00 KN

Maximam Load on Column = 2964 KN

Working Load on footing = 1976.00 KN

Self Weight of the Footing = 197.60 KN

2173.60 KN

Safe Bearing Capacity of the Soil = 150 KN/sqm

= 14.49 sqm

Column to column distance = 1.43 m

Available footing length = 4.50

= 4.50 m

= 3.22 m

Adopt Strip Footing Base Size = 3.3 m

= 14.63 sqm

= 148.6 KN/sqm

< 150 KN/sqm

This upward pressure is less than S.B.C of the soil. Hence provided section is safe.

Design Up ward Pressure = 135.111 KN/sqm

= W2*L/(W1+W2)

= 0.769 m

= L/2-X

= 1.481 m

= 1.589p2

p1+X = L/2p1

p1

p2 + l -X

X = C.G of Loads

Footing Base width

Provided Base Area

Up ward Pressure

Required Base Area

Construction of Class room block for P.T.C at karimnagar.

Column Loads

W2

1

7/27/2019 Combined Footing for Clb

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SILPARUPAARCHITECTS AND ENGINEERS

PTC Karimnagar

Classroom Block

Max cantilever Moment = w*l*l/2

= 148.263 KN-m

Max moment at center = w*l*l/8

= 34.536 KN-m

= 222.395 KN-m

1000.0 m

Grade of concrete for foundation M20

= 20.0 N/sqm

Depth from Bending Moment

Depth due to bending Moment = d = Squar root of Mu x 1.15/0.138fckB

= 304.41 mm

to resist the bending moment

Pprovide 400 mm effective depth and 500 mm over all depth .

Overall depth of the footing = 500.00 mm

= 75.00 mm

Assume Max Size of bar = 12.00 mm

Effective depth of the footing = 419.00

= 1.27 N/sqm

Grade of Cocrete M20 , From Table 2 of SP:16

= 0.25%

= 1.048 sqmm

= 10.475 sqcm

Provide 16# @ 100 mm C/C for Main reinforcement. At bottom on both ways

Provide Percentage of Steel = 0.30%

Min distribution reinforcement of 0.12 percent

Provide Percentage of Steel = 0.15%

= 0.629 sqmm

= 6.285 sqcm

Provide 16# @ 100 mm C/C for Distribution reinforcement.

Ast

Ast

Clear cover for footing

Mu/Bd2

Percentage of Steel

Depth d

The effective depth required to resist shear is usually higher than that

Design moment

Per one meter width

Fck

2

7/27/2019 Combined Footing for Clb

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SILPARUPAARCHITECTS AND ENGINEERS

PTC Karimnagar

Classroom Block

3

7/27/2019 Combined Footing for Clb

4/7

SILPARUPAARCHITECTS AND ENGINEERS

PTC Karimnagar

Classroom Block

CF1

= 1975 KN

= 1333 KN

Working Load on footing W1 = 1316.67 KN= 888.67 KN

Maximam Load on Column = 3308 KN

Working Load on footing = 2205.33 KN

Self Weight of the Footing = 220.53 KN

2425.87 KN

Safe Bearing Capacity of the S = 150 KN/sqm

= 16.17 sqm

Column to column distance = 1.96 m

Available footing length = 4.50

= 4.50 m

= 3.59 m

Adopt Strip Footing Base Size = 3.6 m

= 16.20 sqm

= 149.7 KN/sqm

< 150 KN/sqm

This upward presuure is less than S.B.C of the soil. Hence provided section is safe.

Design Up ward Pressure = 136.132 KN/sqm

= W2*L/(W1+W2)

= 0.790 m

= L/2-X

= 1.460 m

= 1.080

p1

p2 + l -X

p2

p1+X = L/2 p1

X = C.G of Loads

Up ward Pressure

Footing Base width

Provided Base Area

Required Base Area

Construction of Class room block for P.T.C at karimnagar.

Column Loads

W2

4

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SILPARUPAARCHITECTS AND ENGINEERS

PTC Karimnagar

Classroom Block

Max cantilever Moment = w*l*l/2

= 145.128 KN-m

Max moment at center = w*l*l/8

= 65.370 KN-m

= 217.691 KN-m

1000.0 m

Grade of concrete for foundation M20

= 20.0 N/sqm

Depth from Bending Moment

Depth due to bending Moment = d = Squar root of Mu x 1.15/0.138fckB

= 301.17 mm

to resist the bending moment

Pprovide 400 mm effective depth and 500 mm over all depth .

Overall deoth of the footing = 500.00 mm

= 75.00 mm

Assume Max Size of bar = 12.00 mm

Effective depth of the footing = 419.00

= 1.24 N/sqm

Grade of Cocrete M20 , From Table 2 of SP:16

= 0.25%

= 1.048 sqmm

= 10.475 sqcm

Provide 16# @ 100 mm C/C for Main reinforcement. At bottom on both ways

Provide Percentage of Steel = 0.30%

Min distribution reinforcement of 0.12 percent

Provide Percentage of Steel = 0.15%

= 0.629 sqmm

= 6.285 sqcm

Provide 16# @ 100 mm C/C for Distribution reinforcement.

Clear cover for footing

Ast

Percentage of Steel

The effective depth required to resist shear is usually higher than

Depth d

Design moment

Per one meter width

Mu/Bd2

Ast

Fck

5

7/27/2019 Combined Footing for Clb

6/7

SILPARUPA

Architects Engineers

PTC Karimnagar

Classroom block

CF3

= 2115 KN

= 1999 KN

Working Load on footing W1 = 1410.00 KN

= 1332.67 KN

Maximam Load on Column = 4114 KN

Working Load on footing = 2742.67 KN

Self Weight of the Footing = 274.27 KN

3016.93 KN

Safe Bearing Capacity of the S = 150 KN/sqm

= 20.11 sqm

Column to column distance = 1.22 m

Available footing length = 6.20

= 6.20 m

= 3.24 m

Adopt Strip Footing Base Size = 3.3 m

= 20.46 sqm

= 147.5 KN/sqm

< 150 KN/sqm

This upward pressure is less than S.B.C of the soil. Hence provided section is safe.

Design Up ward Pressure = 134.050 KN/sqm

= W2*L/(W1+W2)

= 0.593 m

= L/2-X

= 2.507 m

= 2.473

Therefore projection of 1.15 and 1.15 m area provided beyond columns

both columns C.G of Loads coincides with C.G of Footings.

p2

p1+X = L/2

p1

p1

p2 + l -X

X = C.G of Loads

Footing Base width

Provided Base Area

Up ward Pressure

Required Base Area

Construction of Class room block for P.T.C at Karimnagar.

Column Loads

W2

6

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SILPARUPA

Architects Engineers

PTC Karimnagar

Classroom block

Max cantilever Moment = w*l*l/2

= 421.323 KN-m

Max moment at center = w*l*l/8

= 24.940 KN-m

= 631.985 KN-m

1000.0 m

Grade of concrete for foundation M20

= 20.0 N/sqm

Depth from Bending Moment

Depth due to bending Moment = d = Squar root of Mu x 1.15/0.138fckB

= 513.15 mm

to resist the bending moment

Pprovide 500 mm effective depth and 600 mm over all depth .

Overall deoth of the footing = 600.00 mm

= 75.00 mm

Assume Max Size of bar = 12.00 mm

Effective depth of the footing = 519.00

= 2.35 N/sqm

Grade of Cocrete M20 , From Table 2 of SP:16

= 0.25%

= 1.298 sqmm

= 12.975 sqcm

Provide 16# @ 100 mm C/C for Main reinforcement. At bottom on both ways

Provide Percentage of Steel = 0.24%

Min distribution reinforcement of 0.12 percent

Provide Percentage of Steel = 0.15%

= 0.779 sqmm

= 7.785 sqcm

Provide 16# @ 100 mm C/C for Distribution reinforcement.

Ast

Ast

Mu/Bd2

Percentage of Steel

The effective depth required to resist shear is usually higher than

Clear cover for footing

Fck

Depth d

Design moment

Per one meter width

7