ANNEXURE-A
GYASPUR DEPOT
CALCULATIONS FOR STORM WATER DRAINAGE SYSTEM
1.0 CALACULATIONS FOR CARRYING CAPACITY OF MASONRY DRAINS
1.1 450MM WIDE X 660MM HYDRAULIC DEPTH (NODE 1 TO 4) By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:1000n = Manning’s Coefficient = 0.015b = Width of drain = 450mmd = Depth of water flow = 660mm
r = 0.45 x 0.66 = 0.2970.45+ (2x0.66) 1.77
= 0.168
V = 1 x (0.168)2/3 x 1 1/2
0.015 1000
= 1 x (0.168)2/3 x (0.001) 1/2
0.015
= 1 x 0.304x 0.03160.015
= 0.641m3/sec.
Therefore carrying capacity of drain
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ANNEXURE-A
q = b x d xv= 0.45x0.66x0.641 = 0.190m3/sec
1.2 450MM WIDE X 825MM HYDRAULIC DEPTH (NODE 2 TO 3)By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 450mmd = Depth of water flow = 825mm
r = 0.45 x 0.825 = 0.3710.45+ (2x0.825) 2.1
= 0.177
V = 1 x (0.177)2/3 x 1 1/2
0.015 500
= 1 x (0.177)2/3 x (0.002) 1/2
0.015
= 1 x 0.315 x 0.04470.015
= 0.939 m3/sec.
Therefore carrying capacity of drain
q = b x d xv= 0.45x0.825x0.939 = 0.349m3/sec
1.3 450MM WIDE X 1050MM HYDRAULIC DEPTH (NODE 4 TO 5)By using Manning’s formula
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ANNEXURE-A
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:1000n = Manning’s Coefficient = 0.015b = Width of drain = 450mmd = Depth of water flow = 1050mm
r = 0.45 x 1.05 = 0.4730.45+ (2x1.05) 2.55
= 0.185
V = 1 x (0.185)2/3 x 1 1/2
0.015 1000
= 1 x (0.185)2/3 x (0.001) 1/2
0.015
= 1 x 0.325 x 0.03160.015
= 0.685m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.45x1.05x0.685 = 0.324m3/sec.
1.4 600MM WIDE X 1395MM HYDRAULIC DEPTH (NODE 5 TO 8)By using Manning’s formula
V = 1 r2/3 s1/2
n
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ANNEXURE-A
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 600mmd = Depth of water flow = 1395mm
r = 0.60 x 1.395 = 0.8370.60+ (2x1.395) 3.39
= 0.247
V = 1 x (0.247)2/3 x 1 1/2
0.015 500
= 1 x (0.247)2/3 x (0.002) 1/2
0.015
= 1 x 0.394 x 0.04470.015
= 1.173m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.60x1.395x1.173 = 0.982m3/sec.
1.5 450MM WIDE X 1100MM HYDRAULIC DEPTH (NODE 6 TO 7)By using Manning’s formula
V = 1 r2/3 s1/2
n
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ANNEXURE-A
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 450mmd = Depth of water flow = 1100mm
r = 0.45 x 1.100 = 0.4950.45+ (2x1.100) 2.65
= 0.187
V = 1 x (0.187)2/3 x 1 1/2
0.015 500
= 1 x (0.250)2/3 x (0.002) 1/2
0.015
= 1 x 0.327 x 0.04470.015
= 0.974m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.45x1.1x0.974 = 0.482m3/sec.
1.6 600MM WIDE X 1895MM HYDRAULIC DEPTH (NODE 8 TO 11)By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :
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ANNEXURE-A
V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 600mmd = Depth of water flow = 1895mm
r = 0.60 x 1.895 = 1.1370.60+ (2x1.895) 4.39
= 0.259
V = 1 x (0.259)2/3 x 1 1/2
0.015 500
= 1 x (0.259)2/3 x (0.002) 1/2
0.015
= 1 x 0.406 x 0.04470.015
= 1.211m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.60x1.895x1.211 = 1.377m3/sec.
1.7 450MM WIDE X 750MM HYDRAULIC DEPTH (NODE 9 TO 10)By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.
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ANNEXURE-A
r = Hydraulic depth in meters = b x d b + 2d
S = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 450mmd = Depth of water flow = 750mm
r = 0.45 x 0.750 = 0.33750.45+ (2x0.750) 1.95
= 0.173
V = 1 x (0.173)2/3 x 1 1/2
0.015 500
= 1 x (0.173)2/3 x (0.002) 1/2
0.015
= 1 x 0.311 x 0.04470.015
= 0.926m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.45x0.75x0.926 = 0.313m3/sec.
1.8 600MM WIDE X 1805MM HYDRAULIC DEPTH (NODE 10 TO 11)By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500
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ANNEXURE-A
n = Manning’s Coefficient = 0.015b = Width of drain = 600mmd = Depth of water flow = 1805mm
r = 0.60 x 1.805 = 1.0830.60+ (2x1.805) 4.21
= 0.257
V = 1 x (0.257)2/3 x 1 1/2
0.015 500
= 1 x (0.257)2/3 x (0.002) 1/2
0.015
= 1 x 0.404 x 0.04470.015
= 1.206m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.60x1.805x1.206 = 1.306m3/sec.
1.9 600MM WIDE X 2355MM HYDRAULIC DEPTH (NODE 11 TO 13)By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 600mm
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ANNEXURE-A
d = Depth of water flow = 2355mm
r = 0.60 x 2.355 = 1.4130.60+ (2x2.355) 5.31
= 0.266
V = 1 x (0.266)2/3 x 1 1/2
0.015 500
= 1 x (0.266)2/3 x (0.002) 1/2
0.015
= 1 x 0.414 x 0.04470.015
= 1.233m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.60x2.355x1.233 = 1.742m3/sec.
1.10 750MM WIDE X 2420MM HYDRAULIC DEPTH (NODE 13 TO 16)By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:750n = Manning’s Coefficient = 0.015b = Width of drain = 750mmd = Depth of water flow = 2420mm
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ANNEXURE-A
r = 0.75 x 2.420 = 1.8150.75+ (2x2.420) 5.59
= 0.325
V = 1 x (0.325)2/3 x 1 1/2
0.015 750
= 1 x (0.325)2/3 x (0.0013) 1/2
0.015
= 1 x 0.472 x 0.03650.015
= 1.150m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.75x2.420x1.150 = 2.087m3/sec.
1.11 450MM WIDE X 890MM HYDRAULIC DEPTH (NODE 14 TO 15)By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 450mmd = Depth of water flow = 890mm
r = 0.45 x 0.890 = 0.401
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ANNEXURE-A
0.45+ (2x0.890) 2.23
= 0.180
V = 1 x (0.180)2/3 x 1 1/2
0.015 500
= 1 x (0.180)2/3 x (0.002) 1/2
0.015
= 1 x 0.318 x 0.04470.015
= 0.949m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.45x0.89x0.949 = 0.380m3/sec.
1.12 750MM WIDE X 2595MM HYDRAULIC DEPTH (NODE 16 TO 17)By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:750n = Manning’s Coefficient = 0.015b = Width of drain = 750mmd = Depth of water flow = 2595mm
r = 0.75 x 2.595 = 1.9460.75+ (2x2.595) 5.94
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ANNEXURE-A
= 0.328
V = 1 x (0.328)2/3 x 1 1/2
0.015 750
= 1 x (0.328)2/3 x (0.0013) 1/2
0.015
= 1 x 0.475 x 0.03650.015
= 1.157m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.75x2.595x1.157 = 2.252m3/sec.
1.13 750MM WIDE X 2830MM HYDRAULIC DEPTH (NODE 18 TO 20)By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:750n = Manning’s Coefficient = 0.015b = Width of drain = 750mmd = Depth of water flow = 2830mm
r = 0.75 x 2.830 = 2.1230.75+ (2x2.830) 6.41
= 0.331
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ANNEXURE-A
V = 1 x (0.331)2/3 x 1 1/2
0.015 750
= 1 x (0.331)2/3 x (0.0013) 1/2
0.015
= 1 x 0.479 x 0.03650.015
= 1.165m3/sec.
Therefore carrying capacity of drain
q = b x d xv
= 0.75x2.830x1.165 = 2.473m3/sec.
1.14 450MM WIDE X 710MM HYDRAULIC DEPTH (NODE 19 TO 20) By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 450mmd = Depth of water flow = 710mm
r = 0.45 x 0.71 = 0.3200.45+ (2x0.71) 1.87
= 0.171
V = 1 x (0.171)2/3 x 1 1/2
0.015 500
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ANNEXURE-A
= 1 x (0.171)2/3 x (0.002) 1/2
0.015
= 1 x 0.308x 0.04470.015
= 0.918m3/sec.
Therefore carrying capacity of drain
q = b x d xv= 0.45x0.71x0.918 = 0.293m3/sec
1.15 450MM WIDE X 720MM HYDRAULIC DEPTH (NODE 21 TO 22) By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 450mmd = Depth of water flow = 720mm
r = 0.45 x 0.720 = 0.3240.45+ (2x0.720) 1.89
= 0.171
V = 1 x (0.171)2/3 x 1 1/2
0.015 500
= 1 x (0.171)2/3 x (0.002) 1/2
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ANNEXURE-A
0.015
= 1 x 0.309x 0.04470.015
= 0.920m3/sec.
Therefore carrying capacity of drain
q = b x d xv= 0.45x0.720x0.920 = 0.298m3/sec
1.16 600MM WIDE X 1580MM HYDRAULIC DEPTH (NODE 22 TO 23) By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 600mmd = Depth of water flow = 1580mm
r = 0.60 x 1.580 = 0.9480.60+ (2x1.580) 3.76
= 0.252
V = 1 x (0.252)2/3 x 1 1/2
0.015 500
= 1 x (0.252)2/3 x (0.002) 1/2
0.015
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ANNEXURE-A
= 1 x 0.399x 0.04470.015
= 1.190m3/sec.
Therefore carrying capacity of drain
q = b x d xv= 0.60x1.580x1.190 = 1.128m3/sec
1.17 600MM WIDE X 2510MM HYDRAULIC DEPTH (NODE 24 TO 25) By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 600mmd = Depth of water flow = 2510mm
r = 0.60 x 2.510 = 1.5060.60+ (2x2.510) 5.62
= 0.268
V = 1 x (0.268)2/3 x 1 1/2
0.015 500
= 1 x (0.268)2/3 x (0.002) 1/2
0.015
= 1 x 0.416x 0.04470.015
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ANNEXURE-A
= 1.239m3/sec.
Therefore carrying capacity of drain
q = b x d xv= 0.60x2.510x1.239 = 1.866m3/sec
1.18 600MM WIDE X 2970MM HYDRAULIC DEPTH (NODE 26 TO 27) By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 600mmd = Depth of water flow = 2970mm
r = 0.60 x 2.970 = 1.7820.60+ (2x2.970) 6.54
= 0.272
V = 1 x (0.272)2/3 x 1 1/2
0.015 500
= 1 x (0.272)2/3 x (0.002) 1/2
0.015
= 1 x 0.420x 0.04470.015
= 1.253m3/sec.
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ANNEXURE-A
Therefore carrying capacity of drain
q = b x d xv= 0.60x2.970x1.253 = 2.233m3/sec
1.19 1000MM WIDE X 3120MM HYDRAULIC DEPTH (NODE 27 TO 29)
By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:1000n = Manning’s Coefficient = 0.015b = Width of drain = 1000mmd = Depth of water flow = 3120mm
r = 1.00 x 3.120 = 3.1201.00 + (2x3.120) 7.24
= 0.431
V = 1 x (0.431)2/3 x 1 1/2
0.015 1000
= 1 x (0.431)2/3 x (0.001) 1/2
0.015
= 1 x 0.571x 0.03160.015
= 1.203m3/sec.
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ANNEXURE-A
Therefore carrying capacity of drain
q = b x d xv= 1.00x3.120x1.203 = 3.753m3/sec
1.20 450MM WIDE X 585MM HYDRAULIC DEPTH (NODE 28 TO 29) By using Manning’s formula
V = 1 r2/3 s1/2
n
q = b x d x v
Where :V = Velocity in Metres per sec.q = Discharge in litres per sec.r = Hydraulic depth in meters = b x d
b + 2dS = Slope = 1:500n = Manning’s Coefficient = 0.015b = Width of drain = 450mmd = Depth of water flow = 585mm
r = 0.45 x 0.585 = 0.2630.45+ (2x0.585) 1.62
= 0.163
V = 1 x (0.163)2/3 x 1 1/2
0.015 500
= 1 x (0.163)2/3 x (0.002) 1/2
0.015
= 1 x 0.298x 0.04470.015
= 0.888m3/sec.
Therefore carrying capacity of drain
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ANNEXURE-A
q = b x d xv= 0.45x0.585x0.888 = 0.234m3/sec
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