1. An Najah National University Faculty of Engineering
4/9/2019
بسم الله الرحمن الرحيم
An Najah National University
Faculty of Engineering
Civil Engineering Department
Prepared by :
1. Bashar abu hajji
2. Ahmad abu asbih
3. Adham suliman
Supervisor :
Dr. Hafez Q. Shaheen
4/9/2019

2. Study and conceptual design of Al-Malaqi
bridge dam
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3. Jeser Al Malaqi is located 3.5 km from the main intersection of
Study area :
Jeser Al Malaqi is located 3.5 km from the main intersection of
Al-Badan village with Al-Faria and linking with the Jordan Valley
(Al Ghor) and Jericho City.
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4. 4/9/2019

5. The selected location of the dam is approximately 500m downstream from Jesser Al-Malaqi at the confluence Wadi Al-Faria and wadi Al-Badan.
Wadi Al Faria
Wadi Al Badan
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6. The wastewater comes from Nablus city and the amount of
Wastewater and springs flow :
The wastewater comes from Nablus city and the amount of
wastewater flow about (6000m³/day – 8000m³/day), only
Small portion of it reaches the dam. the spring flow is natural
Storage in al faria catchment, the number of spring is 13
springs distributed as groups (Al-faria, Al-badan, Nablus).
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7. The area of the watersheds is : A1 = 14.35 km2 A2 = 20.04km2
B1 = km2
the four sub- catchments for the upper part of Wadi Al-Faria and Wadi Al-Badan.
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8. TP = qP= SCS is used to construct the unit hydrograph (example)
Tc= ( L / V ) / 60
TP =
qP=
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9. approximate average velocities in ft/s runoff flow for calculating time of concentration
Description of water course
Slope in percent
0 – 3
4 – 7
8 – 12
Larger than 12
Unconcentrated
Woodland
Larger than 3.25
Pastures
3.5 – 4.25
Larger than 4.25
Cultivated
3 – 4.5
4.5 – 5.5
Larger than 5.5
Pavement
0 -8.5
8.5 – 13.5
13.5 – 17
Larger than 17
Concentrated
Outlet channel-determine velocity by manning formula
Natural channel not well defined
0 -2
2 – 4
Larger than 7
(chow, 1989)
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10. t / Tp q / qp t(hr) q=(m3/s.cm) 0.000 0.500 0.400 1.18 5.01 1.000 2.36
this table shows the coordinates to construct the 1 cm-unit hydrograph of area (A3).
t / Tp
q / qp
t(hr)
q=(m3/s.cm)
0.000
0.500
0.400
1.18
5.01
1.000
2.36
12.54
1.500
0.660
3.54
8.27
2.000
0.320
4.72
4.01
2.500
0.100
5.9
1.25
3.000
0.050
7.08
0.62
3.500
0.015
8.26
0.19
4.000
0.025
9.44
0.31
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11. Unit hydrograph for area 1
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12. Flow Routing
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13. attenuation and translation. The modal value is about 0.2.
S= K {XI + (1 - X) O}
K: is a constant, approximates travel time of the flood wave through the reach.
X: is a factor that weighs the relative influence of inflow and outflow upon the
storage for most river channels, X lies between 0.1 and 0.3, indicating both
attenuation and translation. The modal value is about 0.2.
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14. The routed unit hydrograph is shown below.
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15. I: intensity of rainfall (mm). A: area of the catchment (m2).
CIA method (peack value) :
Runoff volume = C * I * A
Where:
C: runoff coefficient.
I: intensity of rainfall (mm).
A: area of the catchment (m2).
Runoff coefficient = 0.2
(example) For I = 2.5 mm/day
Q = C * I * A
= 0.2 * (m / day) * 138 * 106 m2 = MCM/day
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16. 4/9/2019

17. Dam design Dam height(m) Dam face Soil conditions >50% gravel
>15% clay
>50% sand
>55%clay 3
Upstream
2.5:1
3:1
Downstream
2:1
3.1-6
6.1-15
3.5:1
Nelson (1985)
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18. 4/9/2019

19. 4/9/2019

20. Cumulative volume (m³)
Storage volume
The calculation of storage volume done by using the following equation (prismoidal
formula):
V = L/3 (A1 + An + 2 ( A3+A5+ …… + An-2) +4(A2+A4+……+An-1)
For n = 3:
V = L/3 * (A1 + 4A2 + A3)
Height of dam (m)
Depth of water(m)
Area of surface (m²)
Cumulative volume (m³) 5
5108
8514
24403
73778 10
54303
180362 15
99087
517355
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21. 4/9/2019
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22. pan Evaporation rate(mm/month) January 49.6 February 67.2 March 99.2
Evaporation volume :
Month
pan Evaporation rate(mm/month)
January
49.6
February
67.2
March
99.2
April
149.1
May
202.7
June
225.9
July
237.9
August
218.2
September
177.6
October
131.1
November
74.4
December
48.6
Summation
1681
Average for winter seasons
67.8
Evaporation Volume=Evaporation rate*area
Evaporation Volume= (67.8/ (1000*30))* = m3/day (average daily )
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23. Infiltration volume
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24. From the above figure we get the infiltration rate:
Infiltration rate = 10 mm/hr
Infiltration volume = infiltration rate * area
= (10/1000)*45, *24 = 10,974 m3/day
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25. Hydraulic conductivity (K)
Seepage volume
(L.Casagrande’s method 1932)
q = k Lsinϴ² in (m²/s)
L = (√ (d²+H²) –√ (d²- H²cotϴ²)) in (m)
For k : the value depend on the type of the soil .
The type of soil is silty clay K =
Hydraulic conductivity (K)
Soil type
Cm/sec
Ft/min
Clean gravel
Coarse sand
Fine sand
Silty clay
Clay
<
<
From Principles of geotechnical engineering
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26. q = (0.0005) *(13.61) (sin21)2 = 8.73*10^-4 (m²/s)
H=15 m , D=69.55m , ϴ=21⁰ , K=0.0005
L= √ √ = 13.61m
q = (0.0005) *(13.61) (sin21)2 = 8.73*10^-4 (m²/s)
Take length of the dam = 85m
Q= 8.73*10^-4 (m²/s)* 85 (m) = m3/s
Q= *60*60*24=64.2 m3/d
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27. Design of spillway The time of concentration = 2.5hr = 150 min
I = 8 mm/hr
Q = C *I *A
= 0.2 * (m/hr) * 138 * 10 6 m2 / 3600s
= m3/s
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28. We will use 3 pipes with diameter 2.5 m each.
For three pipes :
Q = m3/s
Assume velocity = 5 m/s
A = Q / V = / 5 = m2
D = m
We will use 3 pipes with diameter 2.5 m each.
(this is for emergency outflow to avoid damage of dam).
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29. Requirements
1. Change the road connect Nablus to Jordan valley such as the new road become over the reservoir level.
2. Badan sub-catchment wastewater flowing from Nablus East should be treated and stored with the runoff water and to recharge into the aquifer and used for agricultural activities.
3. Studies are needed to investigate the infiltrated water quality at the site of the dam.
4. Evaluate the required infiltration rate (hydraulic conductivity) and treat the soil of the dam accordingly.
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30. Happy to answer your question
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