diversion dam (design...)sample
TRANSCRIPT
0 1 2 3 4 5 671.00
71.50
72.00
72.50
73.00
73.50
74.00
74.50
0
0.197156242964486
0.426909896576956
1.23184767998935
3.04864613788368
6.06964022069263
TAIL WATER RATING CURVE
Rating Curve
DISCHARGE, (cms)
EL
EV
AT
ION
, (m
.)
PROJECT: PROPOSED DIVERSION DAMLOCATION : BRGY. Burabod, McArthur, Leyte
A.) DETERMINE THE DESIGN FLOOD DISCHARGE:
METHOD 1. EMPERICAL FORMULA:
Drainage Area: 780 sq. km.
Discharge, Qrare = 150*A/sqrt(A+13) = 4,154.79
Discharge, Qocc = 85*A/sqrt(A+9) = 2,360.34
TENTATIVE DESIGN, Q = 3,257.57
METHOD 2. CORRELATION METHOD:
Correlate this stream flow with the record published by National WaterResources Board, utilizing the annual peak flows for a gage watershed more or lesssimilar watershed characteristics as with the damsite:
Drainage Area of Gaging Station, Ag : 900.000 sq.km.Standard Deviation, Ds : 680.000 Mean Flow, Q : 1,540.000 cu.m./sec.
FOR RETURN PERIOD, Tr : No. of years 25 50 100 Tr -1 = 24 49 99lnTr/Tr-1 = 0.0408 0.0202 0.0101
Reduced Variate, Y = 3.196 3.902 4.600
Other Reduced Variate Equation:
Qr = (Y-C)Ds/a' - Q ; N : 25
Where: N a' C10 0.970 0.500 a' = 1.09215 1.021 0.513 C = 0.53120 1.063 0.52425 1.092 0.531
FROM CREAGER'S FORMULA: Where, A: 10
No. of years Qr C Discharge,Q25 3,199.56 106.65 2,978.63 50 3,639.12 121.30 3,387.84
100 4,073.90 135.80 3,792.60
DESIGN FLOOD DISCHARGE, Q = 3,525.08 CMS
B.) PLOT THE TAIL WATER RATING CURVE:
Roughness Coeficient, n : 0.2Slope Gradient, S : 0.03
ELEV.WETTED HYDRAULIC VELOCITY DISCHARGE
AREA PERIMETER RADIUS R^2/3 S^1/2 (mps) (cms)(sq.m.) (m) R=A/P
72.00 0 0 0 0 0 0 072.50 3.98 9.20 0.433 0.572 0.017 0.050 0.19773.00 7.86 15.80 0.497 0.628 0.017 0.054 0.42773.50 17.68 24.50 0.722 0.805 0.017 0.070 1.23274.00 35.48 35.90 0.988 0.992 0.017 0.086 3.04974.50 54.98 38.20 1.439 1.275 0.017 0.110 6.07075.00 74.48 38.2 1.950 1.561 0.017 0.135 10.06776.00 113.48 38.2 2.971 2.067 0.017 0.179 20.309
C.) DETERMINE THE REQUIRED LENGTH OF DIVERSION DAM:
Based on the cross-section taken from the dam axis the approximate stable river width: 264.00 meters. The Maximum Flood Concentration, q: 15.00
Actual: q = Q/L 13.40 cms/m SAFE
L = Q/q 235.01 m
Check : LACEY'S Minimum stable river width
Pw = 2.67 sqrt Q where:Q = 124,435.39 cfs
Pw = 941.85 ft. 287.15 m.
USE: L = (L+Pw)/2 261.08 mSAY: 261.00 m
cms/m
D.) DETERMINE THE AFFLUX ELEVATION:
FOR HIGH STAGES: FOR LOW STAGES:q :cms/s 13.40 cms/m Flr. Line : 40.00 q :
TW EL.: 47.500 m. Dam Crest: 43.00 TW El.P : 3.000 m. P 3.00 P :
PARTICULARS FORMULATRIALS
1 2 3 4 1Afflux Elev. Assummed 48.100 47.800 47.650 47.600 46.6
Ht. Of Afflux Elev., da da = Afflux El. - Flr. Line 8.100 7.800 7.650 7.600 6.60Velocity of Approach, Va Va = q/da 1.654 1.718 1.752 1.763 1.403
Head of Approach, ha ha = Va^2/2g 0.139 0.150 0.156 0.158 0.100Energy Elevation, He He = Afflux Elev. + da 48.239 47.950 47.806 47.758 46.70
Ho Ho = Energy El-Dam Crest 5.239 4.950 4.806 4.758 3.70P/Ho 0.573 0.606 0.624 0.630 0.811
Free Flow Coef., Co From Fig. A-4 3.820 3.830 3.835 3.835 3.69hd hd = Energy El.-TW El. 0.739 0.450 0.306 0.258 -0.80
hd + da 8.839 8.250 7.956 7.858 5.80hd/Ho 0.141 0.091 0.064 0.054 -0.216
hd + da/Ho 1.687 1.667 1.655 1.651 1.568Coef. Of Decrease, Co From Fig. A-5 0.160 0.250 0.390 0.395 0.17
Coefficient, Cs Cs = (100-Co')*Co/100 3.209 2.873 2.339 2.320 3.063Discharge, q q = Cs/1.811*(Ho)^3/2 21.250 17.471 13.611 13.298 12.038ANALYSIS Try Again Try Again Try Again O.K. Try Again
E. HYDRAULIC JUMP ANALYSIS AND LENGTH OF DOWNSTREAM APRON: FOR HIGH STAGES: FOR LOW STAGES:
q :cms/m 13.40 TW El. : 47.50 q: 9.26Ho = Afflux El.-Dam Crest 4.650 Flr. Line: 40.00 HE : 6.400
P : 3.00 d2 :Sup. 7.50 P : 0.30HE = Afflux El.-D/S Apron El. 7.650 V2 1.79 m/s Ho : 2.249
PARTICULARS FORMULATRIALS
1 2 3 4 1d1 Assumed 1.500 1.300 1.250 1.200 0.900V1 q/d1 8.933 10.308 10.720 11.167 10.288hv1 V1^2/2g 4.068 5.415 5.857 6.355 5.395HE hv1 + d1 5.56750 6.71532 7.10721 7.55548 6.295
ANALYSIS: Difference: -2.08250 -0.93468 -0.54279 -0.09452 -1.35529OK OK OK OK OK
Jump Height d2=-d1/2+sqrt(d1^2/4+2v1^2d1/9.81) 4.247 4.696 4.823 4.956 3.980
d2 Theor./d2 Supplied OK OK OK OK TRYFroud Number V1/sqrt(g*d1) 2.33 2.89 3.06 3.25 3.46
From A - 9APRON LENGTH F<4.5, TYPE I , La: 13.734 16.981 17.863 18.779 15.399
2.5>F<4.5, TYPE II, La: Next 16.437 16.879 17.345 13.929F>4.5, TYPE III, La: OK Lang OK Lang OK Lang OK Lang OK Lang
From Fig. A-8, F<4.5,C: 5.6L = Cd2 23.78 26.30 27.01 27.75 22.29
RIPRAP LENGTH LRa = 1.5(L-La) 15.072 13.977 13.715 13.460 10.332LRb = (0.65Ho/d2)^3/2*V2^2 4.044 3.478 3.342 3.208 4.458
LR = (LRa + LRb)/2 9.558 8.727 8.529 8.334 7.395LR minimum 10.00 9.00 9.00 8.00 7.00
Ht. Of Chute Blocks: 30 cm. 40 to 60 cm. 40 to 60 cm. 40 to 60 cm. 40 to 60 cm.Ht. Of Baffle Blocks: 60 cm 80 to 120 cm. 80 to 120 cm. 80 to 120 cm. 80 to 120 cm.
Ht. Of End Sill: 30 cm. 30 to 40 cm. 30 to 40 cm. 30 to 40 cm. 30 to 40 cm.
FREE BOARD 1.64 1.64
PARTICULARS FORMULA HIGH LOW
Discharge q : cub. ft/sec/ft 144.163 99.61
V2: fps 5.860 4.05 RIPRAP SIZE From Fig. A-12(dia. In inch) 6.30 2.5
WT. OF RIPRAP 4/3*3.14*R^3*165: Lbs. 12.501 0.781RIPRAP THICKNESS 1.5*Stone dia.(2.54), mm 240.03 95.25GRAVEL BLANKET
RIPRAP THICKNESS/2, mm 120.015 47.625THICKNESS
Note: 40% of riprap layer shouldconsist smaller sizes to fill
voidsFrom Fig. A - 13
DEPTH OF SCOUR Depth of Scour, ft.: 25 19Depth of Scour, m.: 7.62 5.79 S = Riverbed Slope 0.20 0.20
Q = cfs 123,414.68 85,278.25 q^2 20,782.84 9,923.11
f f = (1788S)^3/5*Q^1/10 109.94 105.96R R = 0.9(q^2/f)^1/3 1.57 1.25
Tail Water Depth,m. 7.50 6.10Depth of Cut-off Wall R - Tail Water Depth,m. 0.12 -0.31
USE:
FOR LOW STAGES:9.26
47.503.00
TRIALS2 3 4
46.40 46.250 46.26.40 6.25 6.20
1.447 1.481 1.4930.107 0.112 0.11446.51 46.36 46.31
3.51 3.36 3.310.856 0.892 0.905
3.67 3.67 3.67-0.99 -1.14 -1.195.41 5.11 5.01
-0.283 -0.339 -0.3581.542 1.521 1.513
0.27 0.27 0.01 2.679 2.679 3.6339.714 9.119 12.102
Try Again OK Try Again
TW El. : 47.50Flr. Line : 40.00d2 :Sup. 7.5
V2 1.23 m/s
TRIALS2 3 4
0.890 0.880 0.87010.404 10.522 10.643
5.517 5.643 5.7736.407 6.523 6.643
-1.24337 -1.12728 -1.00682OK OK OK
4.009 4.038 4.068
TRY TRY TRY3.52 3.58 3.64
15.594 15.792 15.99214.031 14.134 14.239
OK Lang OK Lang OK Lang
22.45 22.61 22.7810.283 10.235 10.186
4.410 4.362 4.3137.346 7.298 7.250
7.00 7.00 7.00
40 to 60 cm. 40 to 60 cm. 40 to 60 cm. Width & Space of Endsill (Dentated)80 to 120 cm. 80 to 120 cm. 80 to 120 cm. Top Width of Sill30 to 40 cm. 30 to 40 cm. 30 to 40 cm.
-1.200
-1.000
-0.800
-0.600
-0.400
-0.200
0.000
CREST SHAPE
CREST SHAPE
X COORDINATE
Y C
OO
RD
INA
TE
DETERMINE THICKNESS OF DOWNSTREAM APRON:
POINT LENGTH OF HEAD LOSSNET HEADEFFECTIVE HEAD EQUATION
CREEP Lc, m HL = Lc/C Hw H-HL,m h, ft.
9 8.187 2.416 -0.976 -3.20 T9(150) = 4/3(62.5)(2.08+T9)
D 8.853 2.612 -1.172 -3.85 TD(150) = 4/3(62.5)(1.87+TD)
E 9.520 2.809 -1.369 -4.49 TE(150) = 4/3(62.5)(1.65+TE)
Y9 = 0.75Ho = YD = YE 1.44 From Fig. A - 15, Type 10 Flow
SOLVING THE EQUATION:
T9(150) = 4/3(62.5)(2.08 + T9)
T9(150 - 83.33) = -266.70
T9 = -4.000 ft.
-1.220 m.
TD(150) = 4/3(62.5)(1.87 + TD)
TD(150 - 83.33) = -320.47
TD = -4.807 ft.
-1.466 m.
TE(150) = 4/3(62.6)(1.65 + TE)
TE(150 - 83.33) = -374.24
TE = -5.613 ft.
-1.711 m.
T9(150) = 4/3(62.5)(2.08+T9)
TD(150) = 4/3(62.5)(1.87+TD)
TE(150) = 4/3(62.5)(1.65+TE)
DETERMINATION FOR TENSILE REINFORCEMENT AT POINT 7 AT THE
DAM SECTION DUE TO UPLIFT DURING NORMAL OPERATION
POINT
P7-8H 415.80 0.3 124.74
P8-9V 654.00 0.4 261.60
W5 (218.03) 0.4 (87.21)
W6 (775.20) 0.2 (155.04)
SUMMATION OF MOMENT: 144.09 lbs. - m.
472.61 lbs. - ft.
641,343.56 n - mm.
IF THE OGEE SECTION BUILT UP OF RUBBLE MASONRY WITH
CLASS B CONCRETE BINDER
USING WORKING STRESS DESIGN: USING ULTIMATE STRESS DESIGN:
fs = 15,000.00 psi. fy = 206.80 Mpa
n = 12.00 fc' = 17.24 Mpa
j = 0.84 Pmin. = 0.00677
k = 0.47 w = 0.0812064965
fc' = 2,500.00 d^2 = 484.62
fc = 1,125.00 psi. d = 22.01 mm.
d = 0.495 m. AREA, As = 149.03 sq. mm.
19.482 inches SPACING, S = 527.00 mm.
AREA = Moment/fsjd 52.70 cm.
0.02 sq. inches USE: 30.00 cm. o.c.
Try: 10 mm dia 78.54 sq. mm.
SPACING = 63.39 inches
161.01 cm.
USE: 30 cm. o.c.
FOUNDATION REACTION:
fa = (f toe + f Heel) = 3,478.12
A = Moment/fsjd = 2.04
SPACING = 0.72 inches
1.82 cm.
USE: 1.82 cm.
FORCES/WEIGHTS (lbs.)
LEVER ARM (m)
MOMENT ABOUT PT. 7 (lbs -m)
STABILITY ANALYSIS
POINT OVERTURNING
P0-1 V 1.64 359.16 589.02 2.550 1,502.01
P1-2 H 3.28 483.60 1,586.19 0.500 793.10
P2-2' V 1.64 563.75 924.55 4.800 4,437.84
P3-4 H 1.312 464.66 609.63 0.400 243.85
P4-5 V 3.608 -420.55 (1,517.34) 2.850 4,324.42
P5-6 H 1.968 -268.50 (528.42) 0.300 158.52
P6-7 V 4.92 -178.39 (877.69) 1.550 1,360.42
P7-8H 1.968 211.28 415.80 0.300 124.74
P8-9V 2.624 -249.24 (654.00) 0.400 261.60
P10-11 V 0.984 438.29 431.28 0.150 64.69
P11-12 V 1.92 364.29 699.43 0.550 384.68
P11-12 H 1.476 -364.29 (537.68) 0.850 457.03
P12-13 V 4.1 298.48 1,223.77 1.254 1,534.61
P12-13 H 1.4104 -298.48 (420.98) 0.725 305.21
P13-0 V 0.82 305.86 250.81 0.125 31.35
P13-0 H 0.0656 -305.86 (20.06) 1.580 31.70
Sum (FV) 4,118.85 Sum of
Sum (FV)^ (3,049.03) MOMENT 8,907.65 7,108.12
Sum (FH) 1,104.48
LENGTH (ft.)
PRES. (PSF)
EXTERNAL FORCES (lbs.)
LEVER ARM (m.)
MOMENT ABOUT TOE RIGHTING
(m-lbs.)
UNIT WEIGHT OF CONCRETE 1615 lbs/sq.m/ft
SECTION WEIGHT LEVER ARM MOMENT ABOUTAREA PER STRIP THE TOE
(sq.m.) (lbs.) (m) (lbs.-m)
W1 0.660 1,065.90 2.850 3,037.82
W2 0.560 904.40 2.550 2,306.22
W3 0.276 446.14 2.175 970.36
W4 0.888 1,433.31 1.425 2,042.47
W5 0.135 218.03 0.600 130.82
W6 0.480 775.20 0.400 310.08
SUM W 4,842.98 SUM Mr 8,797.76
SUMMARY: CASE I:
Summation of MOMENT: 10,597.29
Summation of FORCES VERTICAL: 5,912.80
Summation of FORCES HORIZONTAL: 1,104.48
MEAN, X = Summation of Moment/Summation of Vertical Forces 1.792
e =B/2- Mean X -0.092
FOUNDATON REACTIONS:
f toe = Sum.Forces Vert./B(1+6e/b), (psf) 1455.918 SAFE
f heel = Sum. Forces Hor./B(1-6e/B), (psf) 2022.202 UNSAFE
FACTOR OF SAFETY OVERTURNING: 2.49 SAFE
FACTOR OF SAFETY SLIDING: 0.19 SAFE FOR GRAVEL & COARSE SAND
CASE II: DURING NORMAL OPERATION WITH SIESMIC FORCES:
1.) LATERAL FORCE DUE TO EARTHQUAKE 0.15W
F = 0.15 W 726.45 Lbs.
M toe = F(Lever Arm) 762.77 Lbs.-m.
2.) LATERAL FORCE DUE TO HYDRODYNAMIC FORCE:
From Fig. !-17: Fw = 0.583wH^2a/g
Using: a = 0.15g
Fw = 58.801 Lbs.
M toe = 61.741 Lbs. - m.
3.) COMBINING THE COMPUTED FORCES:
MOMENT Righting = 9,772.77 Lbs. - m.
VERTICAL FORCES = 5,912.80 Lbs.
HORIZONTAL FORCES = 1,889.73 Lbs.
THEREFORE: Mean X = Summation of Moment/Summation of Vert. Forces
Mean X = 1.6528 m. OK, within middle third
e = B/2- Mean X 0.047
FOUNDATION REACTION:
f toe = Sum.Forces Vertical/B(1+6e/b), (psf) 1883.865 Lbs. - m. SAFE
f heel = Sum. Forces Vertical/b(1-6e/b), (psf) 1594.255 Lbs. - m. SAFE
FACTOR OF SAFETY, OVERTURNING = 2.23 SAFE
FACTOR OF SAFETY, SLIDING = 0.320 SAFE OF ROCK, JOINTING & LAMINATION
F.) DETERMINATION OF CREST SHAPE:
Maximum Afflux Elev. 98.25Energy Elev. 98.42Dam Crest Elev. 96.50
Ho = Energy El.-Dam Crest El. 1.92ha = Energy El. - Afflux El. 0.17
ha/Ho 0.089From Fig. A-3: Xc/Ho 0.455
Yc/Ho 0.169To Simplify: Xc=Ho/4 0.48
Yc=Ho/8 0.24
Using: y/Ho = -K(x/Ho)^n Where: K 0.51n 1.838
From Fig. A-24: R1/Ho 0.48R1 0.922
R2/Ho 0.20R2 0.384
ASSIGN COORDINATES:X X/Ho (X/Ho)^n Y
0.25 0.130 0.024 -0.0230.50 0.260 0.084 -0.0830.75 0.391 0.178 -0.1741.00 0.521 0.302 -0.2951.25 0.651 0.454 -0.4451.50 0.781 0.635 -0.6221.75 0.911 0.843 -0.8262.00 1.042 1.078 -1.055
G.) STABILITY ANALYSIS:
Length of Creep from A to C 1.00 + 0.80 + 4/3 + 0.40 + 1.20 = 4.733Distance BC = sqrt((4)^2+(.8)^2) = 4.079 OK
Determine what type of foundation material the dam would be judged safe:Total Creep Length up to point F = 1.00 + 0.80 + 1.60 + 1.20 + 0.80
+(4.0 + 0.50 + 2.30 + 7.50)/3 = 10.167
Weighted Creep Ratio, C = 3.389 Safe for Boulders, Gravel & Sand
Case I @ Maximum Flood Condition:
Calculate the Pressure Head above OGEE CREST: Hd+da/Ho 1.655 Dam Crest Height = 3.00 hd/Ho 0.064 @ Point 10 = Dist. Fr. Crest 1.562
From Fig. A-15 Type 10 Flow: Y = C*Ho C,factor Crest Dist. Y
@ Point 10 0.80 0.65 2.186 @ Point 11 0.75 0.65 2.090 @ Point 12 0.45 0.60 1.464 @ Point 13 0.65 0.20 1.448 @ Point 0 0.80 0.00 1.536 @ Point 1 0.90 0.24 1.968
Calculate Hydrostatic Pressure on the Dam:
Percolation Factor, C = Total Creep Length/Diff. In Water Level 3.773
POINTLENGTH OF CREEP,Lc(m)AvailableHead Loss Net HeadPressure Head
Head (m) Lc/c h(m)=H-HLP=205h (psf)
0 1.536 1.536 314.881 1.968 1.968 403.442 2.75 2.750 563.752' 2.75 2.750 563.753 3.133 2.95 0.830 2.120 434.534 3.533 3.35 0.936 2.414 494.804' 5.933 3.35 1.572 1.778 364.415 6.267 3.35 1.661 1.689 346.306 6.867 2.75 1.820 0.930 190.717 7.320 2.75 1.940 0.810 166.088 7.920 3.35 2.099 1.251 256.489 8.187 3.35 2.170 1.180 241.99
10 2.186 2.186 448.1311 2.090 2.090 428.4512 1.464 1.464 300.1213 1.448 1.448 296.84