PROJECT: P1803 REMBAU

Average Rainfall Intensity

(equation 2.2)

where:
i = the average rainfall intensity (mm/hr) for selected ARI (T) and storm duration (d)
0.20 ≤ d ≤ 72
T = average recurrence interval, ARI (years) (Table 1.1)
λ, K, θ, η =
d = storm duration (hours);
fitting constants dependent on the raingauge location

(Appendix 2.B, Table 2.B1)

ARI, T Storm Duration , Derived Perimeter
Location & Station ID (years) d (hours) λ K θ
Negeri Sembilan 2 0.5 52.823 0.167 0.159
ID= 2719001 (Setor JPS Sikamat)

From the equation 2.2,

i= 83.17 mm/hr
Perimeter
η

0.811
PROJECT: P1803 REMBAU

Average Rainfall Intensity

(equation 2.2)

where:
i = the average rainfall intensity (mm/hr) for selected ARI (T) and storm duration (d)
0.20 ≤ d ≤ 72
T = average recurrence interval, ARI (years) (Table 1.1)
λ, K, θ, η =
d = storm duration (hours);
fitting constants dependent on the raingauge location

(Appendix 2.B, Table 2.B1)

ARI, T Storm Duration , Derived Perimeter
Location & Station ID (years) d (hours) λ K θ η
Negeri Sembilan
50 0.5 52.823 0.167 0.159 0.811
ID= 2719001 (Setor JPS Sikamat)

From the equation 2.2,

i= 142.38 mm/hr
Drain Label: D1

(i) Determine Design Flows for the Drain

Runoff coefficient, C = 0.5 Refer to Table 2.5

Rainfall intensity, i = 104.50 mm/hr (from design chart in attachment)
Area of Catchment, A = 31200 m2
3.12 ha

Design Flow, Q = 0.45 m3/s

(ii) Calculate Size of Drain Section

Manning's n for concrete = 0.018 Refer to Table 2.3

Assuming: drain longitudinal slope, S = 1: 200
0.5 % OK!
drain width, B = 0.3 m
Side slope, z= 1

y
1
z
Base Width ,B (m)

Q= v × A
where: v = 1/n So R
1/2 2/3

A = (B +ZD)D
P= B + 2D √ (1+Z2)

D (m) A (m2) P (m) R (m) v (m/s) Q (m3/s)

0.5 0.40 1.71 0.23 1.49 0.60 > 0.45 m3/s OK!

Allowing a minimum freeboard = 50 (minimum requirement = 50 mm)

Provide dimension of lined drain (Refer to precast concrete manufactures):

Required Use (m)
Width, B 0.3 m 0.6 >0.5m OK!!
Depth, D 0.55 m 0.35

D (m) A (m2) P (m) R (m) v (m/s) Q (m3/s)

0.55 0.495 2.00 0.25 1.55 0.767

Velocity, v 1.55 m/s

Discharge, Q 0.767 m3/s

Cover/ Handrail Fence Condition Maximum Depth (m)

Without protective covering 0.6
With solid or grated cover 1.2

(iii) Check Flow Velocity

v= 1.55 m/s ≤ 4 m/s OK!!

Velocity Requirement

2 to 4 m/s Provide 1.2m high handrail fence or covered

with metal grates or solid plates for the entire
length of the drain for public safety
Hydraulic Design Calculation
Q= v × A
where: v = 1/n So R
1/2 2/3
y
A = (B +ZD)D 1
ARI 50 years P= B + 2D √ (1+Z2) z
Rainfall intensity, i 142.38 mm/hr Base Width ,B (m)

Manning's n for Concrete 0.018

Runoff Coefficient, C 0.5

Area of Area of Drain Drain Provide

Drain Status Velocity, v Rainfall Required Q Provided Q Status Freeboard
Area (m2) Catchment, Catchment, Width, B (m) Depth, D (m) z A (m2) P (m) R (m) Longitudinal Longitudinal Status for v ARI Width, B Depth, D
Section for S (m/s) Intensity, i (m3/s) (m3/s) for Q (mm)
A (m2) A (ha) Slope,S (1: X) Slope,S (%) (m) (m)
A-B 140,230 140,230 14.0 1.00 1.45 0 1.45 3.90 0.37 300 0.33 OK!! 1.66 OK!! 50 142.38 2.77 2.40 NOT OK!! 50 1.00 1.50
B-C 140,230 140,230 14.0 1.00 1.45 0 1.45 3.90 0.37 100 1.00 OK!! 2.87 OK!! 50 142.38 2.77 4.17 OK!! 50 1.00 1.50
C-D 140,230 140,230 14.0 1.00 1.45 0 1.45 3.90 0.37 100 1.00 OK!! 2.87 OK!! 50 142.38 2.77 4.17 OK!! 50 1.00 1.50

F-H 299,745 299,745 30.0 1.00 1.70 0 1.70 4.40 0.39 100 1.00 OK!! 2.95 OK!! 50 142.38 5.93 5.01 NOT OK!! 50 1.00 1.75

G-H 24,066 24,066 2.4 1.00 0.20 0 0.20 1.40 0.14 50 2.00 NOT OK!! 2.15 OK!! 50 142.38 0.48 0.43 NOT OK!! 50 1.00 0.25

H-I 323,811 323,811 32.4 1.00 1.80 0 1.80 4.60 0.39 100 1.00 OK!! 2.97 OK!! 50 142.38 6.40 5.35 NOT OK!! 50 1.00 1.85
Hydraulic Design Calculation
Q= v × A
where: v = 1/n So R
1/2 2/3
ARI 2 years y
Rainfall intensity, i 83.17 mm/hr A = (B +ZD)D 1
ARI 50 years
Rainfall intensity, i 142.38 mm/hr

Manning's n for Concrete 0.018 P= B + 2D √ (1+Z2) z

Runoff Coefficient, C 0.4 < ARI 10 Base Width ,B (m)
0.5 > ARI 10

Area of Area of Drain Drain Provide

Depth, D Status Velocity, v Status Rainfall Required Q Provided Q Status Freeboard
Drain Section Area (m2) Catchment, Catchment, Width, B (m) z A (m2) P (m) R (m) Longitudinal Longitudinal ARI Width, B Depth, D Category
A (m2) A (ha)
(m)
Slope,S (1: X) Slope,S (%)
for S (m/s) for v Intensity, i (m3/s) (m3/s) for Q (mm) Total B
(m) (m)
A-B 11,067 11,067 1.1 0.30 0.25 1 0.14 1.01 0.14 140 0.71 OK!! 1.24 OK!! 2 83.17 0.10 0.17 OK!! 50 0.30 0.30 A 0.9

C-D 27,793 27,793 2.8 0.40 0.30 1 0.21 1.25 0.17 140 0.71 OK!! 1.43 OK!! 2 83.17 0.26 0.30 OK!! 50 0.40 0.35 B 1.1 TRAPEZOIDAL
A 300 X 300
B-D 38,860 38,860 3.9 0.60 0.80 0 0.48 2.20 0.22 140 0.71 OK!! 1.70 OK!! 50 142.38 0.77 0.82 OK!! 50 0.60 0.85 1 B 400 X 350
C 450 X 400
D 500 X 500
E - E1 30,290 30,290 3.0 0.40 0.30 1 0.21 1.25 0.17 140 0.71 OK!! 1.43 OK!! 2 83.17 0.28 0.30 OK!! 50 0.40 0.35 B 1.1
E1 - F 67,339 67,339 6.7 0.50 0.45 1 0.43 1.77 0.24 140 0.71 OK!! 1.82 OK!! 2 83.17 0.62 0.78 OK!! 50 0.50 0.50 D 1.5
U-DRAIN CAPPING BEAM
D-F 106,199 106,199 10.6 0.90 1.10 0 0.99 3.10 0.32 140 0.71 OK!! 2.19 OK!! 50 142.38 2.10 2.17 OK!! 50 0.90 1.15 2 1 600 X 850 = 600 X 600 + 250
2 900 X 1150 = 900 X 900 + 250
G - G1 43,971 43,971 4.4 0.45 0.35 1 0.28 1.44 0.19 140 0.71 OK!! 1.58 OK!! 2 83.17 0.41 0.44 OK!! 50 0.45 0.40 C 1.25 3 900 X 1350 = 900 X 900 + 450
G1 - H 80,532 80,532 8.1 0.50 0.45 1 0.43 1.77 0.24 140 0.71 OK!! 1.82 OK!! 2 83.17 0.74 0.78 OK!! 50 0.50 0.50 D 1.5 4 1200 X 1300 = 1200 X 900 + 400
5 1200 X 1800 = 1200 X 1200 + 600
F-H 186,731 186,731 18.7 1.20 1.25 0 1.50 3.70 0.41 140 0.71 OK!! 2.57 OK!! 50 142.38 3.69 3.86 OK!! 50 1.20 1.30 4 6 1500 X 2000 = 1500 X 1500 + 500

I - I1 43,971 43,971 4.4 0.45 0.35 1 0.28 1.44 0.19 140 0.71 OK!! 1.58 OK!! 2 83.17 0.41 0.44 OK!! 50 0.45 0.40 C 1.25
I1 - J 80,532 80,532 8.1 0.50 0.45 1 0.43 1.77 0.24 140 0.71 OK!! 1.82 OK!! 2 83.17 0.74 0.78 OK!! 50 0.50 0.50 D 1.5

H-J 267,263 267,263 26.7 1.20 1.65 0 1.98 4.50 0.44 140 0.71 OK!! 2.72 OK!! 50 142.38 5.28 5.38 OK!! 50 1.20 1.70 5

J-K 271,687 271,687 27.2 1.20 1.65 0 1.98 4.50 0.44 90 1.11 OK!! 3.39 OK!! 50 142.38 5.37 6.71 OK!! 50 1.20 1.70 5

L-K 16,256 16,256 1.6 0.30 0.25 1 0.14 1.01 0.14 140 0.71 OK!! 1.24 OK!! 2 83.17 0.15 0.17 OK!! 50 0.30 0.30 A 0.9

K-N 287,943 287,943 28.8 1.20 1.75 0 2.10 4.70 0.45 140 0.71 OK!! 2.74 OK!! 50 142.38 5.69 5.76 OK!! 50 1.20 1.80 5

L-O 7,859 7,859 0.8 0.30 0.25 1 0.14 1.01 0.14 140 0.71 OK!! 1.24 OK!! 2 83.17 0.07 0.17 OK!! 50 0.30 0.30 A 0.9
O-N 19,691 19,691 2.0 0.40 0.25 1 0.16 1.11 0.15 140 0.71 OK!! 1.31 OK!! 2 83.17 0.18 0.21 OK!! 50 0.40 0.30 B 1

M - M1 43,674 43,674 4.4 0.45 0.35 1 0.28 1.44 0.19 70 1.43 OK!! 2.23 OK!! 2 83.17 0.40 0.62 OK!! 50 0.45 0.40 C 1.25
M2 - M1 10,000 10,000 1.0 0.45 0.35 1 0.28 1.44 0.19 280 0.36 OK!! 1.11 OK!! 2 83.17 0.09 0.31 OK!! 50 0.45 0.40 C 1.25
M1 - N 91,309 91,309 9.1 0.50 0.50 1 0.50 1.91 0.26 140 0.71 OK!! 1.92 OK!! 2 83.17 0.84 0.96 OK!! 50 0.50 0.55 D 1.6

P - P1 62,951 62,951 6.3 0.50 0.40 1 0.36 1.63 0.22 140 0.71 OK!! 1.71 OK!! 2 83.17 0.58 0.62 OK!! 50 0.50 0.45 D 1.4
P1 - Q 111,272 111,272 11.1 0.50 0.55 1 0.58 2.06 0.28 140 0.71 OK!! 2.01 OK!! 2 83.17 1.03 1.16 OK!! 50 0.50 0.60 D 1.7

R - R1 28,950 28,950 2.9 0.45 0.35 1 0.28 1.44 0.19 280 0.36 OK!! 1.11 OK!! 2 83.17 0.27 0.31 OK!! 50 0.45 0.40 C 1.25
R1 - R2 40,000 40,000 4.0 0.45 0.35 1 0.28 1.44 0.19 140 0.71 OK!! 1.58 OK!! 2 83.17 0.37 0.44 OK!! 50 0.45 0.40 C 1.25
R2 - S 92,045 92,045 9.2 0.50 0.50 1 0.50 1.91 0.26 140 0.71 OK!! 1.92 OK!! 2 83.17 0.85 0.96 OK!! 50 0.50 0.55 D 1.6

T-U 38,584 38,584 3.9 0.45 0.35 1 0.28 1.44 0.19 140 0.71 OK!! 1.58 OK!! 2 83.17 0.36 0.44 OK!! 50 0.45 0.40 C 1.25

U-V 130,629 130,629 13.1 0.90 1.30 0 1.17 3.50 0.33 140 0.71 OK!! 2.26 OK!! 50 142.38 2.58 2.65 OK!! 50 0.90 1.35 3

1 -2 2.9 0.40 0.35 1 0.26 1.39 0.19 200 0.50 OK!! 1.29 OK!! 2 83.17 0.26 0.34 OK!! 50 0.40 0.40 B 1.2
28,566 28,566
3-2

N1 - POND 454,579.00 454,579 45.5 1.50 1.95 0 2.93 5.40 0.54 140 0.71 OK!! 3.12 OK!! 50 142.38 8.99 9.13 OK!! 50 1.50 2.00 6

V1 - POND 186,265.00 186,265 18.6 1.20 1.25 0 1.50 3.70 0.41 140 0.71 OK!! 2.57 OK!! 50 142.38 3.68 3.86 OK!! 50 1.20 1.30 4