The Panel size outer to outer where
provision made for OHT is = 4.960 x 4.115 m
Considering side wall thickness = 175 mm
Domestic Water Tank = 4.96 x 3.14 m
Drinking Water Tank = 4.960 x 0.98 m
= 0.000 x 0 m
The capacity of Tank provided is = 23000 Lit
Water Depth Rtequired = 1.127 m
Provide Water depth = 1.5 m
Free Board = 0.15 m
Total Height = 1.65 m
The Tank is to be provided with bottom of tank at 2.0m
above terrace level by raising the columns above terrace level.
Design Constants
Grade of Concrete (fck) = 25 N/mm2
Grade of Steel (fy) = 500 N/mm2
scbc = 10 N/mm2
sbt = 2 N/mm2
for sst 130 on water face
m = 9.33333
kc = 0.418
jc = 0.861
Rc = 1.798
for sst 130 on water face
m = 9.33333
kc = 0.418
jc = 0.861
Rc = 1.798
Design of Tank
Storage Capacity is = 6.93x 5.62 x 0.9
= 35.02 Cum
L/B = 1.23 L/H = 7.7 B/H = 6.24
L/H and B/H are greater than 2
Hence the walls span in Vertical direction
since the tank is closed one the walls act as proped cantilevers.
Roof Slab
Slab thickness assumed is = 125 mm
clear cover taken as = 20 mm
assumed dia of bar = 8 mm
where effective depth = 101 mm
The panel size is ly = 4.96
lx = 4.12
ly/lx = 1.21
Density of concrete = 25 KN/m3
Load On slab
self weight = 3.125
Floor finish = 1.5
Live Load = 1.5
Total Load on Slab = 6.125 KN/m2 ~ 6.20 KN/m2
Considering the slab as One long edge continuous
As per code IS 456
Short span -ve moment -αx= 0.071 Mx = αxwlx2 = 7.459 KN-m
2
Short span +ve moment +αx= 0.053 Mx = αxwl x = 5.594 KN-m
2
Long span -ve moment -αy= 0.000 My = αywl x = 0.000 KN-m
2
Long span +ve moment +αy= 0.044 My = αywl x = 4.567 KN-m
Ast required Ast provided
Ast for Short span -ve moment = 175.9 8 286 c/c 200 c/c
Ast for Short span +ve moment = 150.0 8 335 c/c 200 c/c
Ast for Long span -ve moment = 150.0 8 335 c/c 200 c/c
Ast for Long span +ve moment = 150.0 8 335 c/c 200 c/c
Check for deflection
fs = 173.2
Pt = 0.3 Modification factor = 2.0
d required = 79.1
d provided = 101.0 O.K
Tank side walls (Mix M25)
Density of water = 10 KN/m3
Max -Bending moment = 10 x 1.65 ,3
6
= 7.49 KN-m
Overall depth required from cracking stress consideration is = 6xM
σbt x b
D = 149.87 mm
providing overall thickness = 175 mm
clear cover on either side of walls = 30 mm
dia of bar = 8 mm
effective depth = 141 mm
Area of steel required = M
σst x j x d
Ast = = 474.56 mm2
minimum % of steel is = 0.35%"bd
Astmin = 494 mm2
For dia of bar = 10 mm
providing area of steel Ast = 493.50 mm2
spacing required = 159.07 ~ 125 c/c
provide # 10@ 125 c/c vertically on water face and # 8@ 125c/c horizontally
Bottom slab
Panel size ly = 4.96
lx = 4.12
ly/lx = 1.21
assuming slab thickness = 175 load on slab / m2
self weight = 4.375
water weight = 15
finishes = 1.5
Total Load on Slab 20.875 KN/m2 ~ 20.90 KN/m2
Considering the slab as Four edges discontinuous
As per code IS 456
Short span -ve moment -αx= 0.099 Mx = αxwlx2 = 34.974 KN-m
2
Short span +ve moment +αx= 0.074 Mx = αxwl x = 26.230 KN-m
Long span -ve moment -αy= 0.0747 My = αywlx2 = 26.425 KN-m
Long span +ve moment +αy= 0.056 My = αywlx2 = 19.819 KN-m
= Max. -ve B.M = 34.97 KN-m
Overall depth required from cracking stress consideration is = 6xM
σbt x b
D = 323.92 mm
providing overall thickness = 175 mm
clear cover = 30 mm
dia of bar = 10 mm
effective depth = 140 mm
Ast for Short span -ve moment = M
σst x j x d
Ast = = 2232.65 mm2
For providing dia of bar = 20 mm
spacing required = 140.64 ~ 125 c/c
provide # 10@ 125 c/c
Ast for Short span +ve moment = M
σst x j x d
Ast = = 1674.48 mm2
For providing dia of bar = 20 mm
spacing required = 187.52 ~ 150 c/c
provide # 10@ 125 c/c
Ast for Long span -ve moment = M
σst x j x d
Ast = = 1686.91 mm2
For providing dia of bar = 20 mm
spacing required = 186.14 ~ 150 c/c
provide # 8@ 150 c/c
Ast for Long span +ve moment = M
σst x j x d
Ast = = 1265.18 mm2
For providing dia of bar = 16 mm
spacing required = 158.84 ~ 150 c/c
provide # 8@ 150 c/c
Design of Beam supporting tank 2098
B1 span = 4.96 m
wall thickness taken as = 0.175 m
height of wall taken as = 1.50 m
thickness of beam = 0.3 m
depth of beam = 0.75 m
Bending moment from staad = 48.00 KN-m
depth required = M
Rc x b
d = 298.27 mm
Provide Overall depth = 750 mm
clear cover = 30 mm
dia of bar = 20 mm
effective depth = 700 mm
Area of steel required shorter span = M
σst x j x d
Ast = = 612.84 mm2
Provide 2-#16st +2-#16 ext at top and 2-#16 st +2-#16 ext at bottom
Check for Shear
Shear Force (V) From staad = 58.00 KN
Nominal shear stresses ζv = V
bd
= 0.28
% of steel = 0.38
Permissible shear stresses ζc = 0.38
ζv < ζc safe
no shear is required
balance shear Force = -21800 N
Spacing of #8 - 2L stirrups is = -417.43
provide # 8@ 150 c/c
B2 span = 4.12 m
wall thickness taken as = 0.175 m
height of wall taken as = 1.50 m
thickness of beam = 0.3 m
depth of beam = 0.6 m
Bending moment from staad = 31.00 KN-m
depth required = M
Rc x b
d = 239.70 mm
Provide Overall depth = 600 mm
clear cover = 30 mm
dia of bar = 20 mm
effective depth = 550 mm
Area of steel required shorter span = M
σst x j x d
Ast = = 503.74 mm2
Provide 2-#20st +3-#20 ext at top and 2-#20st +3-#20 ext at bottom
Check for Shear
Shear Force (V) From staad = 9.00 KN
Nominal shear stresses ζv = V
bd
= 0.05
% of steel = 0.76
Permissible shear stresses ζc = 0.43
ζv < ζc safe
no shear is required
balance shear Force = -61950 N
Spacing of #8 - 2L stirrups is = -115.42
provide # 8@ 150 c/c
B3 span = 3.50 m
wall thickness taken as = 0.175 m
height of wall taken as = 1.50 m
thickness of beam = 0.23 m
depth of beam = 0.475 m
Bending moment from staad = 56.01 KN-m
depth required = M
Rc x b
d = 367.97 mm
Provide Overall depth = 475 mm
clear cover = 30 mm
dia of bar = 20 mm
effective depth = 425 mm
Area of steel required shorter span = M
σst x j x d 17.45
Ast = = 1177.83 mm 2
Provide 3-#20st at top and 3-#20st +3-#20 ext at bottom
Check for Shear 1
Shear Force (V) From staad = 32.00 KN
Nominal shear stresses ζv = V
bd
= 0.33
% of steel = 1.61
Permissible shear stresses ζc = 0.5
ζv < ζc safe
no shear is required
balance shear Force = -16875 N
Spacing of #8 - 2L stirrups is = -327.41
provide # 8@ 200 c/c
