calculation note for tank foundation (recovered).docx

8/14/2019 Calculation note for tank foundation (Recovered).docx

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Sheet: Page 1 of 8Document Number :

Document Title:

I.P.D.C.

15000 m 3 GASOIL TANK

RING WALL FOUNDATION


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Document Title:

I.P.D.C.

UNITS: ton & m (unless noted otherwise)

Input Data

Concrete

f'c (kg/cm2) 250

c (ton/m3) 2.4

Soil Parameter

(degree) 30C (kg/cm 2) 0.04

Ks (kg/cm 3) 1.35

s (ton/m3) 1.8

qnet (kg/cm2) 1.5

S settlement (m) 0.025

Equipment Data

B.C.D 38.2 Anchor bolts NoneShell thickness 0.012

Bottom Plate Thickness 0.008D, Tank outside diameter 38.212 H 13.2

Foundation Assumption

B 1.1H1 0.5H2 1.5D1, Ring Diameter 39.312

Loading (ton & m)

W operate 13189Earthquake Shear 2068Earthquake Coefficient 0.16


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Stability Check

Bearing Capacity Check

Description(Elastic Condition) P1 P2 max AllowFactor BearingCapa.

Conclusion

EmptyDL+EMPTY+WL 5.26 1.05 4.75 1.33 15.00 OKDL+EMPTY+EL 5.26 0.22 4.13 1.33 15.00 OK

TestDL+ET+0.2WL 12.07 0.21 9.24 1.33 15.00 OKDL+ET+0.2*EL 12.07 2.63 11.06 1.33 15.00 OK

OperateDL+EO+WL 11.25 1.05 9.25 1.33 15.00 OKDL+EO+EL 11.25 11.57 17.16 1.33 15.00 OK

DL+EO 11.25 0.00 8.46 1.00 15.00 OK

A1 132.05 m 2 Area of footing

A2 65.08 m 2 Area of tank bott. that settled on the footing

F1(Test) 13.09 ton/m 2 Stress on tank bott. due to Test load

F2(Op.) 11.50 ton/m 2 Stress on tank bott. due to Operate load

Atank bott.

1146.80 m 2

W steel bott. 72.02 ton Steel bott. Weight

Av 0.140 Vertical earthquake acceleration coefficent %g according to API-650

P1 = {(Empty wt. - W steel bott. ) + (Ring Wall wt.) + (F1 or F2)*A2} / A1

P2 = (1.273*M) / (D 2 * B) M : Wind or Seismic Moment

Ultimate ConditionFor Reinforcement Design

Description(Ultimate Condition) P1 P2 max

Empty0.9(DL+EMPTY)+1.3WL 4.74 1.37 6.110.9(DL+EMPTY)+EL 4.74 0.22 4.96

Test1.2(DL+ET)+1.3*(0.2*WL) 14.49 0.31 14.801.2(DL+ET)+1.6*(0.2*EL) 14.49 4.21 18.70

Operate

1.2(DL+EO)+1.3WL 13.50 1.37 14.871.2(DL+EO)+EL 13.50 11.57 25.07

1.4(DL+EO) 15.75 0.00 15.75


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Document Title:

I.P.D.C.

Settlement

s = (qB / Es) * f 1.42 cm OK

Es 1800 ton / m 2 f 1.35

max 17.16 from table 4

Design

Hoop TensionWall Height (H2) 1.50Wall Width (B) 1.10Tank Shell dia. (D) 38.21K0 = 1 - Sin ( ) 0.50

Horizontal Compact Load :

Phc =( 2 * P * s / )0.5 3.04 ton/m 2

Phc : max horizontal pressure on the ring wall from the soil and compaction combinedlP : line load from the compaction equal to sum of static and dynamic pressureP = 451 lbs/inch=8.06 t/m (Assume, vibratory roller)

s 1.8 ton/m3

Radial Force,Fr1 = Phc * H2 4.56 ton/m


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Document Title:

I.P.D.C.

Horizontal Load :

Pw : Max ( F1 & F2 ) 13.09 ton/m 2 Radial Force,Fr2 = (K 0 * Pw * H2) + (0.5 * K 0 * s * H2

2)

Radial Force,Fr2 10.83ton

T ( Axial Tansion in Ring ) = 0.5 * MAX (Fr1&Fr2) * DMAX (Fr1&Fr2) 10.83 ton

T ( Axial Tansion in Ring ) 206.85 ton

Tu (Ultimate Axial Tension in Ring) = (Soil Pressure Load Factor Acc.to ACI 2005) * T

Tu (Ultimate Axial Tension in Ring) 330.96ton

Reinforcing

Vertical Bar

As the shell will be placed at the center of the ring wall, the torsional moment due to shell eccentricity can be negligible.

So, MIN re-bar is provided.

bw 100 cm B 110 cm

min 0.002 (for temperature and shrinkage for wall in ACI 318-7.12)

Asmin = 0.0020 * bw * B 22.00 cm 2

Horizontal Bar

B 110 cmH2 150 cm

min 0.0035 (for structural walls of uniform thickness as stated in ACI 318, chapter 14)

fy 4000 kg/cm 2

Asreq = Tu / (0.9 * fy) 91.93cm 2

Asmin = min * B * H2 57.75cm 2

Asreq = Max ( Asreq & Asmin ) 91.93cm 2


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I.P.D.C.

Checking of Min. wallthk.

As the differential settlement is disadvantageous for the tank, minimum thickness of concrete wallrequired to equalize soil pressures between under tank and ring wall.

test 1 ton/m3

operate 1.4 ton/m3

f = Max ( test & operate ) 1.4 ton/m 3

Soil presure

P1 = f * H + s * H2 21.18 ton/m 3

P2 = W / t' + 0.5 * f * H + c * H2

W = ( Empty wght. - W steel bott. ) / ( * D ) 1.52ton

t' 18.28 cm OK

Concrete Stress

C (shrinkage coeff.) 0.003

Es 2.10E+06 kg / cm 2 n = Es / Ec 9

fct = 0.7 * ( fc ) 0.5 23.69kg / cm 2

t" 93.15 cm OK

calculation note for tank foundation (recovered).docx

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