STORAGE TANK

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7.0.0

7.0.0 DETADETAILED ILED STRUCSTRUCTURATURAL L CALCALCULACULATIONSTIONS 7 7..11..00 DDaattaa Conversion factors Conversion factors 1 1NN//ssqqmmmm== ppssii 114455 1 1ppoouunndd== NN 44..4455 L Leennggtthh mm 33..0000 W Wiiddtthh mm 22..0000 h heeiigghhtt mm 33..5500 E

Eaarrtth h ccoovveer r oovveer r ttoop p ssllaabb mm 00..2200 S

Sooiil l ddeennssiittyy kkNN//ccuumm 1199 Angle of internal friction for soil

Angle of internal friction for soil degreesdegrees 3030 As per soil reportAs per soil report Coeff of earth pressure at rest = 1- sin

Coeff of earth pressure at rest = 1- sin ff 0.500.50 D

Deennssiitty y oof f wwaatteer r kkNN//ccuumm 1100 D

Deennssiitty y oof f ccoonnccrreettee kkNN//ccuumm 2255 L

Liivve e llooaad d oon n rrooooff kkNN//ssqqmm 55 f

f cc', specified compressive strength', specified compressive strength NN//ssqqmmmm 2255

o

of f ccoonnccrreette e GG330 0 ccuubbe e ssttrreennggtthh ppssii 33662255 (equivalent to G25 cylinder strength)

(equivalent to G25 cylinder strength) Y

Yiieelld d ssttrreennggtth h oof f rreebbaar r ppssii 6600000000 N

N//ssqqmmmm 441144 Allowable bearing pressure ( net )

Allowable bearing pressure ( net ) kN/sqmkN/sqm 100100 Allowable bearing pressure ( gross) at

Allowable bearing pressure ( gross) at founding level = net bearing pr + founding level = net bearing pr + ggdd

k

kNN//ssqqmm 116688 Strength reduction factor for flexure &

Strength reduction factor for flexure & tension

tension ff 0.900.90 As per As per cl. 9.3cl. 9.3.2.1.2.1

Strength reduction factor for shear

Strength reduction factor for shear ff 0.850.85 As per As per cl. 9.3cl. 9.3.2.3.2.3 Durability coefficient for flexure as per

Durability coefficient for flexure as per ACI 350

ACI 350 for water retaining structuresfor water retaining structures for limiting crackwidths

for limiting crackwidths

1.30

1.30 Reinforcement required to be Reinforcement required to be multiplied by this multiplied by this factor as per factor as per cl.9.2.8.1cl.9.2.8.1

Durability coefficient for direct tension Durability coefficient for direct tension as per ACI 350 for water retaining as per ACI 350 for water retaining structures for limiting crackwidths structures for limiting crackwidths

1.65

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7.2.0 Assumed thickness

Top slab thickness m 0.15

Long wall thickness m 0.25

Short wall thickness m 0.25

Baseslab m 0.25

Base slab projection m 0.25

7.3.0 Weight calculations

Nos Length Breadth thickness Density Weight

m m m kN/cum kN

Topslab 1 3.50 2.50 0.15 25 32.81

Longwall 2 3.25 3.50 0.25 25 142.19

Shortwall 2 2.25 3.50 0.25 25 98.44

Baseslab 1 4.00 3.00 0.25 25 75.00

Soil cover above roof slab 1 3.50 2.50 0.20 19 33.25

Soil over base projection 1 13.00 3.85 0.25 19 237.74

(perimeter) (height)

Totalweight(DL) 619.43

waterweight 3.00 2.00 3.50 10 210.00

Live load on roof 3.50 2.50 5 43.75

(kN/sqmm)

Total live load (water+roof live load ) 253.75

7.4.0 Check for bearing capacity

Totalload 873.18 kN

Basearea 12.00 sqm

BearingpressduetoDL 51.62 kN/sqm

BearingpressduetoLL 21.15 kN/sqm

TotalBearingpressure 72.76 kN/sqm

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7.5.0 Analysis & Design 7.5.1 Top slab

Dead load (DL)

Self weight of slab kN/sqm 3.75

Soil weight kN/sqm 3.80

TotalDL kN/sqm 7.55

Live Load(LL) kN/sqm 5.00

Loadfactor-DL 1.40

Loadfactor-LL 1.70

Factored total Load kN/sqm 19.07

Simply supported condition- coefficients from table 50 of Reynold's handbook

Span ratio Remarks

span support span support (ly/lx)

Effective span (clear+ wall thickness) m 1.44

Shear coeff 0.50 0.50 Max at the centre of span (approx)

Moment coeff ax3, ay3 0.548 0.126

Shear = Coeff x wlx kN/m 21.45 21.45

Moment Mu =Coeff *wl^2/8 kNm/m 6.62 3.18 generally

Partia fixity factors at span 1.00 0.25

Design Mu considering partial fixity kNm/m 6.62 6.62 3.18 3.18 Partia fixity factors at support 1 0.75

tension Tu kN/m 24.26 24.26 23.36 23.36 Overalldepth mm 150 150 150 150 clear cover mm 50 50 effective depth d mm 92 94 78 80 Allowable Shear = f x Vc Vc =2*fc'^0.5*b*d as per cl.11.3.1.1

kN/m 64.95 55.07 Safe as actual stress less than

allowable Ast from solving fMu = f [Ast x fy x d

(1-0.59 x r x (fy/fc'))], sqmm/m 270 264 151 147 Solving qua equation.

Ast for tension on each face = 1.65*Tu/( f f y)/ 2

sqmm/m 54 54 52 52

TotalAst sqmm/m 323 317 203 199

Min Ast per face(0.15% of gross area) sqmm/m 225 225 225 225 as per table 7.12.2.1 of ACI 350

Short span - lx Long span- ly

2.25 3.25

Shear from wall due water pressure ( from 7.5.2, b) & 7.5.3, b) )

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7.5.2 Long wall

a) w ear ou s e+surc arge an

no water inside

earth pressure at top kN/sqm 3.32

earth pressure at bottom kN/sqm 38.94

Earth pressure due to surcharge load

of 20 kN/sqm (UDL) kN/sqm 2.50

The earth pressure due to soil weight is split up into two components-udl and triangular

udl kN/sqm 3.32

triangular kN/sqm 35.61 inside

Load Factor for Earth pressure 1.70 As per ACI 350

Load factor for surchage load 1.70 9.90 60.54

Factored loads

udl (soil+surcharge) kN/sqm 9.90

triangular kN/sqm 60.54

Slab fixed at sides& bottom, top hinged

Walls analysed using Moody's charts- fig 10 for udl and fig 13 for triangular

Span ratio Remarks

span support span support (a/b)

Effective span (clear+ wall thickness) 0.4392 Coefficients corresponding to a/b=1.0 are

udl taken

Shearcoeff-top 0.4020

Shear coeff - bottom 0.5980

shear coeff -sides 0.5491

Moment coeff 0.0617 0.1093 0.0227 0.0664

Shear - top kN/m 14.72

Shear - bottom kN/m 21.90

Shear-sides kN/m 20.11

Moment Mu kNm/m 8.36 14.81 3.08 9.00

tension kN/m Notensionunderthiscondition

triangular load

Shear coeff - top 0.1102

shearcoeff-sides 0.2583

Moment coeff 0.0259 0.0593 0.0098 0.0289

Shear-top kN/m 24.68

Shear-bottom kN/m 89.33

Moment Mu kNm/m 21.47 49.15 8.12 23.95

Total

vertical span - b horizontal span- 2a

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Moment Mu kNm/m 29.83 63.96 11.20 32.95

Redistributed moment Mu kNm/m 49.39 44.39 32.96 Refer Moment distribution in Annex A

Design Moment Mu (higher of the two) kNm/m 49.39 63.96 11.20 32.96

tensionTu kN/m Notensionunderthiscondition

Overalldepth mm 250 250 250 250

clearcover mm 50 50

effectivedepth mm 94 90 74 74

Allowable Shear = f x Vc Vc

=2*fc'^0.5*b*d as per cl.11.3.1.1

kN/m 66.36 52.24 Safe as actual stress less than allowable

Ast from solving fMu = f [Ast x fy x d

(1-0.59 x r x (fy/fc'))], sqmm/m 2635 4608 598 2352 Solving qua.equation

sqmm/m 0 0 0 0

Total Ast sqmm/m 2635 4608 598 2352

b) with no earth outside and wate r inside

water pressure at bottom 35.00 kN/sqm

LoadFactor 1.70 AsperACI350 inside

Factored loads 59.50 kN/sqm

Walls analysed using Moody's charts- fig 13 for triangular load 59.50

Span ratio Remarks

Effective span (clear+ wall thickness) 0.44 Coefficients corresponding to a/b=1.0 are

Shear coeff - top 0.1102 taken

Moment coeff 0.0259 0.0593 0.0098 0.0289

Moment Mu kNm/m 21.10 48.30 7.98 23.54

Resistributed Moment Mu kNm/m 53.21 16.19 24.60 Refer Moment distribution in Annex A

3.70 3.25

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Tension kN/m 57.59 57.59 Overalldepth mm 250 250 250 250 clearcover mm 50 50 effectivedepth mm 94 90 74 74 Allowable Shear = f x Vc Vc =2*fc'^0.5*b*d as per cl.11.3.1.1 kN/m 66.36 52.24

(1-0.59 x r x (fy/fc'))], 2990 710 416 1512 Solving qua.equation

sqmm/m 0 0 128 128

Total Ast sqmm/m 2990 710 543 1640

7.5.3 Short wall

a) with earth outside and no water inside

earth pressure at top(mid depth of top

slab) kN/sqm 2.61 inside

earth pressure at bottom(mid-depth of

bottom slab) kN/sqm 37.75

Earth pressure due to surcharge load

of 20 kN/sqm (UDL) kN/sqm 2.50 8.69 59.73

The earth pressure due to soil weight is split up into two components-udl and triangular

udl kN/sqm 2.61

Load Factor for earth pressure 1.70

Load factor for surchage load 1.70

Factored loads

udl (soil+surcharge) kN/sqm 8.69

Walls analysed using Moody's charts- fig 10 for udl and fig 13 for triangular

Shear from short wall due water pressure (from 7.5.3, b) )

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Span ratio Remarks

Effective span (clear+ wall thickness) 0.30 Coefficients corresponding to a/b=0.75

udl are taken

Moment coeff 0.0473 0.0898 0.0274 0.0695

Shear - top (kN/m) kN/m 12.45

Shear - bottom (kN/m) kN/m 18.76

Shear-sides(kN/m) kN/m 17.57

Moment Mu (kNm/m) kNm/m 5.63 10.68 3.26 8.27

triangular load

Moment coeff 0.0198 0.0505 0.0119 0.0302

Total Load

Redistributed Moment Mu kNm/m 43.69 30.11 Refer Moment distribution in Annex A

clearcover mm 50 50

effectivedepth mm 94 92 78 78

=2*fc'^0.5*b*d as per cl.11.3.1.1 kN/m

66.36 55.07 Safe as actual stress less than allowable

sqmm/m 0 0 0 0

Total Ast sqmm/m 2191 3035 661 2081

3.70 2.25

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b) with no earth outside and wate r inside

water pressure at bottom 35.00 kN/sqm

LoadFactor 1.70

Factored loads 59.50 kN/sqm inside

Walls analysed using Moody's charts- fig 13 for triangular load

59.50 Span ratio Remarks

Shearcoeff-top 0.1061 aretaken

shearcoeff-sides 0.2616

Moment coeff 0.0198 0.0505 0.0119 0.0302

Resistributed Moment Mu kNm/m 49.58 7.69 Refer Moment distribution in Annex A

Design moment kNm/m 49.58 7.69 9.69 24.60 tension kN/m 56.86 56.86 Overalldepth mm 250 250 250 250 clearcover mm 50 50 effectivedepth mm 94 92 78 78 Allowable Shear = f x Vc Vc =2*fc'^0.5*b*d as per cl.11.3.1.1 kN/m 66.36 55.07

sqmm/m 0 0 126 126

Total Ast sqmm/m 2650 315 607 1516

vertical span - b horizontal span- 2a

Shear from long wall due water pressure (from 7.5.2, b) )

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7.5.4 Bottom slab

a) with earth outside and no water inside

Dead load (DL)

Self weight of slab 6.25 kN/sqm

Loadfactor 1.40

Factored DL due to self weight 8.75 kN/sqm

Soil pressure due to Dead loads 51.62 kN/sqm

Soil pressure due to live load on roof 3.65 kN/sqm

Factored Bearing pressure 78.46 kN/sqm

Net upward factored bearing pressure ( Soil pressure - slab self weight)

69.71 kN/sqm

Base slab support condition - All four sides fixed based onfig 34 of Moody's chart

Span ratio Remarks

Shear coeff 0.5143 0.4648 are taken

Moment coeff 0.0376 0.0765 0.0159 0.0547

Shear kN/m 80.67 72.91

Moment Mu kNm/m 13.27 27.00 5.61 19.31

Redistributed moment Mu kNm/m -4.12 44.39 -5.19 30.11

tension Tu kN/m 0.00 0.00 No tension under this condition

clear cover mm 50 75

effective depth d mm 192 167 178 151

=2*fc'^0.5*b*d as per cl.11.3.1.1 kN/m 135.55 125.67 Safe as actual stress less than allowable

(1-0.59 x r x (fy/fc'))], sqmm/m -78 1030 -106 764 Solving qua equation

sqmm/m 0 0 0 0

TotalAst sqmm/m -78 1030 -106 764

2.25 3.25

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b) with no earth outside and water inside

Dead load (DL)

Self weight of slab kN/sqm 6.25

Loadfactor 1.40

Factored DL due to self weight kN/sqm 8.75

Soil pressure due to Dead loads

(without soil load ) kN/sqm 29.04

Soil pressure due to live loads kN/sqm 0.00

Factored Bearing pressure kN/sqm 40.65

Net upward factored bearing pressure ( Soil pressure - slab self weight)

kN/sqm 31.90

Base slab support condition - All four sides fixed based on fig 34 of Moody's chart

Span ratio Remarks

Shear coeff 0.5143 0.4648 are taken

Moment coeff 0.0376 0.0765 0.0159 0.0547

Shear kN/m 36.92 33.36

Moment Mu kNm/m 6.07 12.35 2.57 8.83

Redistributed moment kNm/m 34.62 -16.19 19.09 -7.69 Minus sign indicates tension on inner face

tension Tu kN/m 87.80 87.80 84.27 84.27

clear cover mm 50 75

effective depth d mm 192 167 178 151

=2*fc'^0.5*b*d as per cl.11.3.1.1 kN/m 135.55 125.67 Safe as actual stress less than allowable

This portion should be hidden fMn = f [ As x fy x d (1-0.59 x p x (fy/ f' c))]

Short span-top Long Span

Top Bottom Top Bottom

M M(kN-m) = 34.62 16.19 19.09 -7.69 b b(in) = 39.37 39.37 39.37 39.37 d d(in) = 7.56 6.57 7.01 5.94 a a = 9.765517 9.765517 9.76552 9.76552 b b = -1 -1 -1 -1 c c = 0.0034 0.0021 0.002 -0.001 r r = 0.0035 0.0022 0.0022 -0.0012

As(req.) As(req.) in sq in. = r x b x d r x b x d r x b x d r x b x d

= 1.054 0.559 0.619 -0.284

2.25 3.25

Short span - a

Shear from wall due water pressure (from 7.5.2, b) & 7.5.3, b))

Water load not considered as it cancels each other while calculating the net upward pressure

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As(req.) As(req.) mm2 = 680 361 399 -183

(1-0.59 x r x (fy/fc'))], sqmm/m 680 361 399 -183 Solving qua equation

sqmm/m 194 194 187 187

TotalAst sqmm/m 874 555 586 187