Oil Sump Pit

Design as a uncracked section as per IS 3370

Oil capacity = Litres.Taking 30% more = Litres

Volume of tank required = CuM

Cap. of tank = x x

Volume = CuM OK

Density of oil = T/m3

Data: For M25 and Fe 500

Perm Stress in concrete (c) = N/mm2 ( IS 456 Table 21) For M25 concrete

Perm Stress in steel (t) = N/mm2 ( IS 3370 Part II - Table 2)

m = 280/3c =

mc/t = nc / (d-nc) therefore nc = d

4.40

9

3.70

35000

40.32.7

0.8040250

0.79 0.79

150

43.2

0.9

4 4 2.7

11

0.62

ALIF ENGINEERS ANDPLANNERS Design calculation For Burnt Oil pit

DOC.NO:M2011EP008A-88

REV R0

c

c

c

c

c

c

c

c

1Sterling Wilson Ltd.

a = d - nc/3 = d therefore j =

MR = b nc c/2 a = bd2 therefore Q =

Density of soil = T/m3

Angle of repose = deg Ka =

Case I - When tank is full. (Neglecting earth pressure)

Using design charts of IS 3370 Part IV - considering top and bottom hinged.

As per Table 1 IS 3370 (Part IV) - 1967

a = height of wall = m Density of liquid w =

b = Width of wall = m Depth of wall below ground = m

c = Width of wall = m

c/a = b/a =

Moment coefficients (Taking Maxm values) for b/a =

Mx = My = Table 6 - IS 3370 Part IV

1.25

0.79 0.79

2.08

1.70

10 0.7

2.08

3.7 0.9

4.4

4.4

1.2 1.2

0.030 0.019-0.010 -0.045

3.4

c

c

c

c

c

c

c

c




REV R0

c

c

c

c

c

c

c

c

Maximum Horizontal moment = Mx w a ^3= x x ^3= TM (Inside face)

Maximum Horizontal moment = Mx w a ^3 Oil Press.= x x ^3 Horzt. Moment= TM (Outside face)

Maximum Vertical moment = My w a ^3= x x ^3= TM (Outside face)

Maximum Vertical moment = My w a ^3 Oil press.= x x ^3= TM (Inside face)

Vert. Moment

Case II - When tank is empty (Full earth pressure)

Soil pressure Ka = x = T/m2

Using design charts of IS 3370 Part IV - considering top and bottom hinged.


2.7

2.7

2.7

1.2

0.030 0.90.53

0.010 0.9

0.045 0.9 2.7

0.34

0.8

0.019 0.9

0.70 1.70

0.18



Moment coefficients (Taking Maxm values) for b/a =

Mx = My = Table 1 - IS 3370 Part IV Soil Press.

Maximum Horizontal moment = Mx w a ^3= x x ^3= TM (Outside face) Horzt. Moment

Maximum Horizontal moment = Mx w a ^3= x x ^3= TM (Inside face)

Maximum Vertical moment = My w a ^3= x x ^3= TM (Inside face) Soil Press.

Maximum Vertical moment = My w a ^3= x x ^3 Vert. Moment= TM (Outside face)

1.25

3.2

3.21.2

0.030 1.2

0.030 0.019-0.010 -0.045

1.18

0.39

0.045

0.010 1.2 3.2

0.019 1.2 3.2

1.77

0.75

c

c

c

c

c

c

c

c




REV R0

c

c

c

c

c

c

c

c

Depth of wall required = Sqrt ( M/Q b)

d = x 107

x

Required d = Provide overall depth = mm

Provided d = - - = mm

Shear due to oil pressure will cause tension in walls and slab.

Shear coefficients (Taking Maxm values) for b/a =

Sx = Table 7 - IS 3370 Part IV

Tension in wall = Coefficient x x a^2 = x ^2 (depth of oil considered) =

Area of horzt. steel required = M-Tx / t j d + T/t (For Maxm Values of BM)

Horizontal steel outside face = Ast1 + Ast2

1.25

w0.90

3.3592

0.512

0.512 x

200

200 25 12 163

92

0.100x

1000

2.7

1.772.08

c

c

c

c

c

c

c

c


Ast1 = M-Tx / t j d

Ast1 = x 10 ^7 - 10^4 xx 10 ^7 x

= mm2

Ast2 = T/t ` = x 10 ^4

= mm2

Total Ast = Ast1 + Ast2 = + = mm2

Horizontal steel inside face = Ast1 + Ast2Ast1 x 10 ^7

x 10 ^7 x

= mm2

Ast2 = x 10 ^4 `

= mm2Total Ast = Ast1 + Ast2

= + = mm2

Provide Y @ c/c Ast provided = mm2 > mm2 OK

151

3.36

=

295

754

467.22

150

150 0.79

0.53

467

220

12 150 686.9

x

0.79 151

150

219.7

295

224

223.9

1503

519.3

1.18

687

3.36 100




REV R0

c

c

c

c

c

c

c

c

Area of Vertical steel required = M / t j d (For Maxm values of BM)

Vertical steel x 10 ^7 = mm2(Outside face) x 10 ^7 x

Vertical steel x 10 ^7 = mm2(Inside face) x 10 ^7 x

Provide Y @ c/c Ast provided = mm2 (Inside face)

Provide Y @ c/c Ast provided = mm2 (Outside face)

Mimimum steel required 0.3 for 100mm to 0.2% for 450mm (Cl. 7.1 IS 3370 part IV)

For thickness of mm mimimum steel shall be = % (10% reduction for HYSD steel)

Minm Area of steel required = x x = mm2

< OK

Design of top slab.Thick =Loads -Span = m d = mm

Self weight = x = T/m2

100

410

0.244

9000.79 163

200

150

100

163

12 100

12

0.25

1501.77

65

0.80.79

200

=

=

1131

1131

11314.40

0.244 4891000

100

4.20

0.100 2.50.1

c

c

c

c

c

c

c

c


Self weight = x = T/m2Live Load = T/m2

Total Load = T/m2

Designing as a two way slab for Ly/Lx = x = Table 26 IS 456

Maximum BM = x x2

= TM

Area of steel required = M-Tx / t j d + T/t (For Maxm Values of BM)

Ast1 required = x 10 ^7 - 10^4 xx 10 ^7 x

= mm2

Ast2 = x 10 ^4 `

= mm2

Total Ast = Ast1 + Ast2 = + = mm2


Provide minm reinforcement in bottom of slab For mm p = %

Ast = 0.2 x x = mm2

Provide Y @ c/c Ast provided = mm2 > mm2 OK100

10 200 393

236.6

0.7912.678

10 200 393

3.36 x

3.36

0.200

150224

0.056 0.35

100

0.056

0.35

1000 100

0.25

4.20 0.35

1.0

0.100 2.50.1

150 65

200

0.35

200

100

236.612.7 223.9

c

c

c

c

c

c

c

c




REV R0

c

c

c

c

c

c

c

c

Design of base slab. Thick d =

Critical - when tank is full

Weight of Roof slab = x x x 2.5 = TWeight of wall = x x x 2.5 x 2.5 = TWeight of oil = x x x 0.9 = TWeight of base slab = x x x 2.5 = T

Total Load = T

Upward pressure = /2

= T/m2 (250mm projection on each side)

Net pressure = - x - x = T/m2

Designing as a two way slab for Ly/Lx = x = Table 26 IS 456

Maximum BM causing tension on liquid side = x x2

= TM

Area of steel required = M-Tx / t j d + T/t (For Maxm Values of BM)

Ast1 required = x 10 ^7 - 10^4 xx 10 ^7 x

= mm2175.09

170

4.40

200

0.10 4.844.4029.92

4.00 4.00 38.94.40

3.57

4.90 4.90

0.20 3.4

0.69

0.056

4.400.056

0.9 2.7 0.2 2.5

150 170100

0.64

0.64

1.0

0.793.36 x0.69

85.65

85.65

3.6

2.70.2

4

4.90

12.01

c

c

c

c

c

c

c

c


= mm2

Ast2 = x 10 ^4 `

= mm2

Total Ast = Ast1 + Ast2

= + = mm2


Provide minm reinforcement in bottom of slab For mm p = %

Ast = 0.25x x = mm2


10 150

175

175.09

399.0

399.0

3.36

0.244

1000 200 488

524 48810 150

200

150224

223.9

524

100

c

c

c

c

c

c

c

c


Documents

Oil Sump Pit