cable trench design

8/13/2019 Cable Trench Design

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DRN. NAME SIGN DATEPRPD A.K. 20.12.12CHKD S.A 20.12.12 APPD S.A 20.12.12

OWNER M/S GAIL (INDIA) LTD.

CONSULTANTENGINEERS INDIA LTD.

PROJECT:

SWITCHYARDGAIL PETROCHEMICAL COMPLEX-II, PATA

TITLE :-CABLE TRENCH - DESIGN

CALCULATIONSDOC NO:

M2011EP008A-091REV. NO.

0

CONTRACTORS STERLING AND WILSON LIMITED

ALIF ENGINEERS & PLANNERSMUMBAI


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A) Input Data

1 Internal Width of the cable Trench = mm2 Thikness of the wall = mm3 Thikness of the Raft = mm4 Depth of the cable trench below the FFL = mm5 Grade of concrete = N/mm26 Density of concrete = = kn/m37 Grade of steel = N/mm28 Density of the soil(DENS) = kN/m39 Surcharge = Kg/m2

10 Angle of internal friction (f) f

B) Design of wall

200

Coeff of active earth pressure Ka = (1-sin f )/(1+sin f )= 0.33

Height of Wall H = 2125 mmMaximum pressure at the Base Pa = Ka x DENS x H

= 12.74Pressure per meter of run = 12.74 kN/mMaximum pressure due to ps = 0.33 x 20 = 6.66

surcharge/MPressure per meter of run = 6.66 kN/m

Moment Due to Surcharge + due to soil pressure = 0.50 x 12.74 x 2.125 x 2.125 +3

6.66 x 2.1252

= 9.591 + 7.080 = 16.671 Kn-mtr

Total Moment = 16.671 = 16.671 Kn-mtr

2125

23252025

Fe 500

DESIGN OF CABLE TRENCH TYPE -A-A

1500200200

15006.66

182000

30

kN/m2

kN/m2

12.74

kN/m2 kN/m2Pressure Diagram

5 Alif Engineers PlannersSterling Wilson Ltd


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-Main Reinforcement( At Face of wall):Let thickness of Wall = 200 mmEffective Depth = 200 - 20 - 5.00 = 175.00 mm

Mu/bd^2 = 1.5 x 16.67 x 10^6 = 0.81651000 x 175.00 ^2

Corresponding reinforcement % = pt = 0.297983

Area of steel=Ast=ptxBd/100 = 0.297983 x 1000 x 175.001 x 100

= 521.47 mmMin area of steel = 0.12 x 1000 x 200

1 x 100= 240 mm^2

Spacing of steel required = 151 mm C/CProvide Main reinforcement fo dia 10 @ 150 mm C/C At face

Provide Ast = 523 mm

- Distribution Reinforcement;secondary reinforcement = 0.12 x 1000 X 20015% for MS and 12% for tor steel 1 x 100

= 240 mmCorresponding reinforcementspacing = ast*100/Ast = = 0.785 x 8 ^2 x 1000

240= 209 mm

Minimum clear spacing=3xdeff = 3 x 175.00= 525 mm

Provide Sec reinforcement of dia 8 @ 200 mm C/CProvide Ast = 251 mm

C) Design of the BaseSlab:Load calculationWall load = 0.200 x 2.125 x 1 x 25 = 10.625 KnSecond wall = = 10.625 KnSelf wt of slab = 0.200 x 1.9 x 1 x 25 = 9.5 KnLoad due to cable SAND FILLING

1 = 2.125 x 2 x 1 x 19 = 60.563 Kn

Total 91.313 Kn

Pmax = P = = 48.06 KN/m^2 A 1.9 x 1

Moment calculation at base slab48.059 kn/mtr

1.7

91.3125



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Maximum Moment at the Mid = = 48.059 x 1.425^28

= 17.361 Kn-mtr -Main Reinforcement( at center):Let thickness of Wall = 200 mmEffective Depth = 200 - 100 - 5.00 = 95.00 mm

Mu/bd^2 = 1.5 x 17.36 x 10^6 = 2.88551000 x 95.00 ^2




1 x 100= 240 mm^2

Spacing of steel required = 95 mm C/CProvide Main reinforcement fo dia 10 @ 150 mm C/C at Bottom of slabProvide Ast = 523 mm



240= 209 mm


Provide secondary reinforcementat spacing = 170 mmProvide Sec reinforcement of dia 8 @ 200 mm C/CProvide Ast = 251 mm



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A) Input Data

1 Internal Width of the cable Trench = mm2 Thikness of the wall = mm

3 Thikness of the Raft = mm4 Depth of the cable trench below the FFL = mm5 Grade of concrete = N/mm26 Density of concrete = = kn/m37 Grade of steel = N/mm28 Density of the soil(DENS) = kN/m39 Surcharge = Kg/m2

10 Angle of internal friction (f) f11 Live load due to the cable = kg/mtr

B) Design of wall

1075

200

800

150

Fe 50018

2000

30

800150

2001275

DESIGN OF CABLE TRENCH TYPE -B-B

25

Pressure Diagram

6.456.66kN/m2 kN/m2

20



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= 6.45Pressure per meter of run = 6.45 kN/m

Maximum pressure due to ps = 0.33 x 20 = 6.66surcharge/MPressure per meter of run = 6.66 kN/m


6.66 x 1.0752

= 1.242 + 3.582 = 4.823 Kn-mtr


-Main Reinforcement( At face of wall):

Let thickness of Wall = 150 mmEffective Depth = 150 - 20 - 5.00 = 125.00 mm

Mu/bd^2 = 1.5 x 4.82 x 10^6 = 0.4631000 x 125.00 ^2




1 x 100= 180 mm^2

Spacing of steel required = 244 mm C/C

Provide Main reinforcement fo dia 8 @ 200 mm C/C At Each Face




180= 279 mm



C) Design of the BaseSlab:Load calculationWall load = 0.150 x 1.075 x 1 x 25 = 4.0313 KnSecond wall = = 4.0313 KnSelf wt of slab = 0.200 x 1.1 x 1 x 25 = 5.5 Kn

Total 13.563 Kn

kN/m2

kN/m2



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Pmax = P = = 12.33 KN/m^2 A 1.1 x 1


0.95


= 1.391 Kn-mtr -Main Reinforcement( At face):Let thickness of Wall = 200 mmEffective Depth = 200 - 100 - 5.00 = 95.00 mm

Mu/bd^2 = 1.5 x 1.39 x 10^6 = 0.23121000 x 95.00 ^2



= 51.27363mm

Min area of steel = 0.12 x 1000 x 2001 x 100

= 240 mm^2Spacing of steel required = 209 mm C/CProvide Main reinforcement fo dia 8 @ 200 mm C/C at center of wallProvide Ast = 251 mm- Distribution Reinforcement;secondary reinforcement = 0.12 x 1000 X 20015% for MS and 12% for tor steel 1 x 100


240

= 209 mmMinimum clear spacing=3xdeff = 3 x 95.00= 285 mm

Provide secondary reinforcementat spacing = 170 mmProvide Sec reinforcement of dia 8 @ 200 mm C/CProvide Ast = 251 mm

13.5625



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Design of Cable trench Cover Slab For Type B-B

In put data

1 Width of the slab(Ly) = 300 mm2 Length of the slab(Lx) = 940 mm

C/c of support = 840 mm3 Thikness of the slab = 75 mm4 Live load = 1000 kg/mm25 Density of concrete = = 25 kn/m36 Grade of concrete = 20 N/mm27 Grade of steel = Fe 500 N/mm28 Clear cover = 15 mm

Load calculation

Dead Load = 0.075 x 25 = 1.875 Kn/m2Live load = = 10 Kn/m2

Total 11.875 Kn/m2

ultimate Load = 1.5 x 11.875 = 17.8125 Kn/m^2

Ultimate Moment (Mu) = WxL^28

= 17.8125 x 0.84 x 0.848

= Kn-m

Mu = = 0.50b x d^2 1000 x 56 x 56

0.14189= 0.14189 x 1000 x 56.00

1 x 100= 79.5 mm= 0.12 x 1000 x 75

1 x 100= 90 mm

Spacing of steel required = 558 mm C/CProvide Main reinf. dia 8 @ 150 mm C/C ( 3 Y 8)Provide Ast = 334.933 mm

- Distribution Reinforcement;= 0.12 x 1000 x 100

15% for MS and 12% for tor steel 1 x 100= = 120 mm

Spacing of steel required = 419 mm C/C

= 5 x 56.00= 280 mmProvide Dist reinforcement fo 8 @ 200 mm C/CProvide Ast = 251.2 mm

Check for the Deflection :

Fs = 0.58 x Fy X Area of cross section of steel required Area of cross section of steel Provided

= 0.58 x 415 X

= N/mm2pt provided = 0.5981Modification Factor = 2

L = 0.840 = 15 < 40 Safed 0.056

334.957.10

Min area of steel

secondary reinforcement

1.57

1.57

Corresponding reinforcement % = pt Area of steel=Ast

req=ptxBd/100

Minimum clear spacing=3xdeff

79.5


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Sterling Wilson Ltd. 12 Alif Engineers Planners

A) Input Data

1 Internal Width of the cable Trench = mm2 Thikness of the wall = mm3 Thikness of the Raft = mm4 Depth of the cable trench below the FFL = mm5 Grade of concrete = N/mm26 Density of concrete = = kn/m37 Grade of steel = N/mm28 Density of the soil(DENS) = kN/m39 Surcharge = Kg/m2

10 Angle of internal friction (f) f11 Live load due to the cable = kg/mtr

B) Design of wall

825

150






6.66 x 0.8252

= 0.561 + 2.749 = 3.310 Kn-mtr


9752025

Fe 500

DESIGN OF CABLE TRENCH TYPE C-C

800150150

150

800

182000

30

Pressure Diagram

kN/m2

kN/m2

6.66 4.95kN/m2 kN/m2

12 Alif Engineers PlannersSterling Wilson Ltd.


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-Main Reinforcement( at center of wall):Let thickness of Wall = 150 mmEffective Depth = 150 - 75 - 5.00 = 70.00 mm

Mu/bd^2 = 1.5 x 3.31 x 10^6 = 1.01321000 x 70.00 ^2




1 x 100= 180 mm^2

Spacing of steel required = 299 mm C/CProvide Main reinforcement fo dia 8 @ 150 mm C/C at center


- Distribution Reinforcement;

secondary reinforcement = 0.12 x 1000 X 15015% for MS and 12% for tor steel 1 x 100


180= 279 mm



C) Design of the BaseSlab:Load calculationWall load = 0.150 x 0.825 x 1 x 25 = 3.0938Second wall = = 3.0938Self wt of slab = 0.150 x 1.1 x 1 x 25 = 4.125Load due to cable SAND FILLING

1 = 0.825 x 1 x 1 x 17 = 11.22

Total 21.533

Pmax = P = = 19.58 KN/m^2 A 1.1 x 1

21.5325



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KnKnKn

Kn

Kn



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Design of Cable trench Cover Slab For Type C-CIn put data

1 Width of the slab(Ly) = 300 mm2 Length of the slab(Lx) = 950 mm

C/c of support = 850 mm3 Thikness of the slab = 75 mm4 Live load = 1000 kg/mm25 Density of concrete = = 25 kn/m36 Grade of concrete = 20 N/mm27 Grade of steel = Fe 500 N/mm28 Clear cover = 15 mm

Load calculation

Dead Load = 0.075 x 25 = 1.875 Kn/m2Live load = = 10 Kn/m2

Total 11.875 Kn/m2

ultimate Load = 1.5 x 11.875 = 17.8125 Kn/m^2

Ultimate Moment (Mu) = WxL^28

= 17.8125 x 0.85 x 0.858

= Kn-m

Mu = = 0.51b x d^2 1000 x 56 x 56

0.14537= 0.14537 x 1000 x 56.00

1 x 100= 81.4 mm

= 0.12 x 1000 x 751 x 100

= 90 mmSpacing of steel required = 872 mm C/CProvide Main reinforcement 8 @ 200 mm C/C (3 Y 8)Provide Ast = 251.2 mm- Distribution Reinforcement;

= 0.12 x 1000 x 10015% for MS and 12% for tor steel 1 x 100

= = 120 mmSpacing of steel required = 419 mm C/C

= 5 x 56.00= 280 mm

Provide Dist reinforcement fo 8 @ 250 mm C/C

Provide Ast = 200.96 mmCheck for the Deflection :

Fs = 0.58 x Fy X Area of cross section of steel required Area of cross section of steel Provided

= 0.58 x 415 X

= N/mm2pt provided = 0.44857Modification Factor = 1.8

L = 0.850 = 15 < 36 Safed 0.056

1.61

1.61

Corresponding reinforcement % = pt Area of steel=Ast

req=ptxBd/100

251.278.00

Min area of steel

secondary reinforcement

Minimum clear spacing=3xdeff

81.4



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A) Input Data




B) Design of wall

200





Moment Due to Surcharge + due to soil pressure = 0.50 x 12.74 x 2.125 x 2.125 +

36.66 x 2.1252

= 9.591 + 7.080 = 16.671 Kn-mtr




kN/m2

kN/m2

2125

15006.66 12.74

25Fe 500

182000

30


1500200

2002325

20


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= 240 mm^2Spacing of steel required = 95 mm C/CProvide Main reinforcement fo dia 10 @ 150 mm C/C at Bottom of slabProvide Ast = 523 mm- Distribution Reinforcement;secondary reinforcement = 0.12 x 1000 X 20015% for MS and 12% for tor steel 1 x 100

= 240 mm

Corresponding reinforcementspacing = ast*100/Ast = = 0.785 x 8 ^2 x 1000240

= 209 mmMinimum clear spacing=3xdeff = 3 x 95.00

= 285 mmProvide secondary reinforcementat spacing = 170 mmProvide Sec reinforcement of dia 8 @ 200 mm C/CProvide Ast = 251 mm


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A) Input Data




B) Design of wall

200





Moment Due to Surcharge + due to soil pressure = 0.50 x 12.74 x 2.125 x 2.125 +

36.66 x 2.1252

= 9.591 + 7.080 = 16.671 Kn-mtr




1500200

2002325

2025

Fe 50018

2000

30

2125

15006.66 12.74


kN/m2

kN/m2


23/24

Mu/bd^2 = 1.5 x 16.67 x 10^6 = 0.81651000 x 175.00 ^2




1 x 100= 240 mm^2Spacing of steel required = 151 mm C/CProvide Main reinforcement fo dia 10 @ 150 mm C/C At face




240


= 525 mmProvide Sec reinforcement of dia 8 @ 200 mm C/CProvide Ast = 251 mm

C) Design of the BaseSlab:Load calculationWall load = 0.200 x 2.125 x 1 x 25 = 10.625 KnSecond wall = = 10.625 KnSelf wt of slab = 0.200 x 1.9 x 1 x 25 = 9.5 KnLoad due to cable SAND FILLING

1 = 2.125 x 2 x 1 x 19 = 60.563 Kn

Total 91.313 Kn

Pmax = P = = 48.06 KN/m^2 A 1.9 x 1


1.7


= 17.361 Kn-mtr -Main Reinforcement( at center):Let thickness of Wall = 200 mmEffective Depth = 200 - 100 - 5.00 = 95.00 mm

Mu/bd^2 = 1.5 x 17.36 x 10^6 = 2.88551000 x 95.00 ^2




1 x 100

91.3125


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= 240 mm^2Spacing of steel required = 95 mm C/CProvide Main reinforcement fo dia 10 @ 150 mm C/C at Bottom of slabProvide Ast = 523 mm- Distribution Reinforcement;secondary reinforcement = 0.12 x 1000 X 20015% for MS and 12% for tor steel 1 x 100

= 240 mm

Corresponding reinforcementspacing = ast*100/Ast = = 0.785 x 8 ^2 x 1000240


= 285 mmProvide secondary reinforcementat spacing = 170 mmProvide Sec reinforcement of dia 8 @ 200 mm C/CProvide Ast = 251 mm

cable trench design

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