ET 1 of 2

1 SUMP( R.C.C)Size of sump : 6x 3.4 x 1M depth + 0.3M Free BoardData:Length 5.975 mBredth 3.8 mDepth 1 mFree Board 0.3 mAssumed thickness of Base Slab 0.25 mAssumed thickness of cover Slab 0.125 mAssumed Side Wall thickness 0.15 mConcrete grade 30 N/mm2

Grade of Steel 500 N/mm2

Unit weight of water 9.81 Kn/m3

Unit weight of soil 18 Kn/m3

Unit weight of Concrete 25 Kn/m3Projection of base slab Y 0.25 mPipes & other fixtures Load 100 KnSBC 85 KN/m2Edge coefficient 0.1Clear cover for Wall 0.025 mArea of Bottom Slab 27.8425 SqmDia of Bars for Base Slab 10 mmDia of Bars for Side walls 10 mm

a) Design of Bottom slab( Using uncracked theory)Load transformed to Foundation

Load from water (L x B x H x Unit Weight of water ) 222.73605Self weight of Side Wall ( L x H x Thick x Unit wt of Concrete) 114.3675Weight of cover slab (L+Y)X(B+Y) X Depth x (Unit Weight of Concrete) 70.953125Weight of base slab (L+Y)X(B+Y) X Depth x (Unit Weight of Concrete) 170.2875Pipes & other fixtures 100Total 678.344175 KN 69.185Pressure on soil 24.36362 KN/m2 SAFE

i) When tank is EmptyUp ward pressure on base slab W 10.248 KN/M2

As a two way slab ly/lx 1.51 Two way

Bending Moment Coefficient from table 22 of IS 456 14.11596Positive

(P) Negative ( N)***** Enter the value from table 26 of IS 456 0.1 0.056

Mx ( + Ve)= P x W x (Lx)2 0.1 14.12 3.95 = 22.02 KN-MMx ( - Ve)= N x W x (Lx)2 0.056 14.12 3.95 = 12.33 KN-MK=Effective depth( d') /Total depth(d) 0.90

***** As per uncracked theory M/bD2 = 0.3*****

22.02 x 1000 x 1000overall thickness 0.3 x 1000 = 270.95 mm

***** Provided thickness = 0.25 m or 250 mmEffective depth Provided = 250 mm 250Area of Steel Required = 6.75 cm2

= 675.08 mm2 900Spacing required = 116.28Provided Spacing = 125 c/c UnsafeCheck for minimum reinforcement for base slabPercentage of steel coefficients 0.12

= 3.00 cm2 0.28832Required minimum area of steel = 300.00 mm2 Safe

DESIGN OF SUMP (50 bedded Gov. Hospital Upgradation, Allur, Nellore)

ET 2 of 2

b) Design of side wall Ratio Breadth(b)/Depth ( a) = 3.8 3.80

1Asper Is 3370 part IV

0.1 0.1Mx ( + Ve)= P x W x (Lx)2 0.014 9.81 1 = 0.14 KN-MMx ( - Ve)= N x W x (Lx)2 0.126 9.81 1 = 1.24 KN-M

0.1 0.1My ( + Ve)= P x W x (Lx)2 0.025 9.81 1 = 0.25 KN-MMy ( - Ve)= N x W x (Lx)2 0.092 9.81 1 = 0.90 KN-MK=Effective depth( d') /Total depth(d) = 0.98As per uncracked theory M/bD2 = 0.3

1.24 x 1000 x 1000overall thickness 0.3 x 1000 = 64.19 mmeffective depth provided < = 120.00 mmProvide overal Thickness = 150 mmArea of Steel Required 63.14

= 63.14 mm2

Spacing required = 1243.17 mm 0.0109Provided Spacing = 200 c/c SafeCheck for minimum reinforcement Percentage of steel coefficients 0.12Required minimum steel = 180.00 mm2

Provide 10mm @175c/cCheck for tension on wallFrom Table 8 of 3370-Part IVWall coefficient = 0.59 w x a2

Tension on wall = 5.7879 Kn

Permissible tensile stress = 150 N/mm2Ast = 38.586 mm2

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