Drainase Rany

7/28/2019 Drainase Rany

1/35

emencenga

(Cs) 2 5 10 15 20 25 50 100 200 500

3 -0.36 0.42 1.18 1.729 1.912 2.278 3.152 4.051 4.97 5.825

2.5 -0.36 0.518 1.25 1.756 1.92466667 2.262 3.048 3.845 4.652 5.3825

2.2 -0.33 0.574 1.284 1.762 1.92133333 2.24 2.97 3.705 4.444 5.1025

2 -0.307 0.609 1.302 1.7605 1.91333333 2.219 2.912 3.605 4.298 4.9025

1.8 -0.282 0.643 1.318 1.7555 1.90133333 2.193 2.848 3.499 4.147 4.71437

1.6 -0.254 0.675 1.329 1.746 1.885 2.163 2.78 3.388 3.99 4.515

1.4 -0.225 0.705 1.337 1.7325 1.86433333 2.128 2.706 3.271 3.828 4.30875

1.2 -0.195 0.732 1.34 1.7135 1.838 2.087 2.626 3.149 3.661 4.09562

1 -0.164 0.758 1.34 1.6915 1.80866667 2.043 2.542 3.022 3.489 3.88312

0.9 -0.148 0.769 1.339 1.6785 1.79166667 2.018 2.498 2.957 3.401 3.77375

0.8 -0.132 0.78 1.336 1.667 1.77733333 1.998 2.453 2.891 3.312 3.66375

0.7 -0.116 0.79 1.333 1.65 1.75566667 1.967 2.407 2.824 3.223 3.55375

0.6 -0.099 0.8 1.328 1.6335 1.73533333 1.939 2.359 2.755 3.132 3.4425

0.5 -0.083 0.808 1.323 1.6165 1.71433333 1.91 2.311 2.686 3.041 3.33125

0.4 -0.066 0.816 1.317 1.5985 1.69233333 1.88 2.261 2.615 2.949 3.21937

0.3 -0.05 0.824 1.309 1.579 1.669 1.849 2.211 2.544 2.856 3.10687

0.2 -0.033 0.842 1.282 1.5165 1.59466667 1.751 2.054 2.326 2.576 2.76875

0.1 -0.017 0.836 1.27 1.5155 1.59733333 1.761 2 2.252 2.482 3.0325

0 0 0.842 1.282 1.5165 1.59466667 1.751 2.054 2.326 2.576 2.76875

-0.1 0.017 0.85 1.258 1.469 1.53933333 1.68 1.945 2.178 2.388 2.97375

-0.2 0.033 0.85 1.258 1.469 1.53933333 1.68 1.945 2.178 2.388 2.54625

-0.29 0.0483 0.8527 1.2463 -1.5079231 1.51323333 1.6467 1.8955 2.1114 2.3034 2.447812

-0.3 0.05 0.853 1.245 1.444 1.51033333 1.643 1.89 2.104 2.294 2.43687

-0.31861 0.0529776 0.853372 1.2423946 1.4392545 1.5048744 1.6361143 1.8795784 2.0900425 2.278368 2.417683

-0.4 0.066 0.855 1.231 1.4185 1.481 1.606 1.834 2.029 2.21 2.33375

-0.5 0.083 0.856 1.26 1.4135 1.46466667 1.567 1.777 1.955 2.108 2.2175

-0.543 0.090 0.856 1.234 1.392215 1.445 1.550 1.752 1.923 2.068 2.173

-0.6 0.099 0.857 1.2 1.364 1.41866667 1.528 1.72 1.88 2.016 2.11312

-0.6845561 0.113 0.857 1.186 1.340 1.391 1.494 1.672 1.817 1.940 2.026

-0.7 0.116 0.857 1.183 1.3355 1.38633333 1.488 1.663 1.806 1.926 2.01-0.8 0.132 0.856 1.166 1.307 1.354 1.448 1.606 1.733 1.873 1.93375

-0.8168904 0.1347025 0.855662 1.1627908 1.3019329 1.34831358 1.441074956 1.5963725 1.72067 1.852056 1.912742

-0.9 0.148 0.854 1.147 1.277 1.32033333 1.407 1.549 1.66 1.749 1.80937

-1 0.164 0.852 1.128 1.247 1.28666667 1.366 1.492 1.588 1.664 1.715

-1.012255 0.16590 0.85151 1.12543 1.2431397 1.28238 1.36085 1.48508 1.57948 1.65401 1.70474

-1.2 0.195 0.844 1.086 1.184 1.21666667 1.282 1.379 1.449 1.501 1.5475

-1.4 0.225 0.832 1.041 1.1195 1.14566667 1.198 1.2701 1.318 1.351 1.39375

-1.6 0.254 0.817 0.994 1.055 1.07533333 1.116 1.166 1.197 1.216 1.24

-1.8 0.282 0.799 0.945 0.99 1.005 1.035 1.069 1.087 1.097 1.10937

-2 0.307 0.777 0.895 0.927 0.93766667 0.959 0.98 0.99 1.995 1.62187

-2.2 0.33 0.752 0.844 0.866 0.87333333 0.888 0.9 0.905 0.907 0.90812

-2.5 0.36 0.711 0.771 0.782 0.78566667 0.793 0.798 0.799 0.8 0.80075

-3 0.396 0.636 0.66 0.663 0.664 0.666 0.666 0.667 0.667 0.66737

Periode Ulang (Tahun)

NILAI K DISTRIBUSI LOG PEARSON TIPE III


2/35

3.1. Data Curah Hujan

Sta A Sta C Sta E1 1982 250

2 1983 215

3 1984 100

4 1985 125 195 180

5 1986 90 185 240

6 1987 110 190 130

7 1988 200 160 175

8 1989 90 80 200

9 1990 165 195 235

10 1991 115 160 180

11 1992 145 185 14012 1993 150 175 220

13 1994 165 150 265

14 1995 120 140 110

15 1996 240 240 175

16 1997 160 90 190

17 1998 150 210 235

18 1999 230

19 2000 90

20 2001 190

21 2002 190

22 2003 24023 2004 215

24 2005 240

BAB IIII

No. TahunCurah Hujan

PERHITUNGAN CURAH HUJAN


3/35

Sta A Sta C Sta E

1 125 195 180

2 90 185 240

3 110 190 130

4 200 160 175

5 90 80 200

6 165 195 235

7 115 160 180

8 145 185 140

9 150 175 220

10 165 150 265

11 120 140 110

12 240 240 175

13 160 90 190

14 150 210 23515

16

2025 2355 2675

n = 14 Koefisien Skewness:

n

x x

n

Cs =

Koefisien cartesius:

Simpangan Baku n2

Ck =

s =

syarat Gumbel : syarat Distribusi Log Normal : syarat Log Pearson III :

Cs = Cs=0 tak ada syarat

Ck =

1.14

5.40

s =

s =49187.769

Cs =

36307409.2670

2.99569457

306480441831.578

= 167.9762

( (n-1)(n-2)(n-3)S4

)1/2

24566587484

12.47549917

61.51158

n-1

)1/2

13(

Ck =

(n-1)(n-2)S3

Cs =

Ck =

413429

397198

643049

206203

15636757

108765908.8

-2.246

50.263

849265

70756.

16359.

35129.

-14964.878

1111.015

-88972.531

27975.811

(x-x

2.94

185.4

368777

11506.

397198

-9676.565

167.976 49187.769 7768993.482

454.096

50.357

-21.310

39336.111 7801662.037

-4338.343

-1446.548

2565.994

266.001

127.905

187.429

1992.985

2535.842 127697.750

16304.255

-88972.531

1.715

13.620

607.270

107.270

1992.985

921.55630.357

-16.310

-11.310

13.690

25.357 642.985

-44.643

x

(x-x ) (x-x )2

(x-x )3

-1.310

3.690

-24.643

10.357

-44.643

Curah Hujan

2351.667

14x =

x =

1991

1993

1996

1997

No.Tahun

1985

1986

1987

1988

193.333

166.667

171.667

143.333

178.333

1994

1989

1990

1992

181.667

123.333

218.333

146.667

2351.667

1995

x

123.333

198.333

151.667

156.667

15473296198.333 198.3331998


4/35

.317

.990

.821

.000

23.631

.687

.302

.773

.682

)4

1

94

.349

.940

.990

37.346


5/35

3.2.3 METODE LOG PEARSON III

Tabel 1.15

No

1

2

3

4

5

6

7

8

9

10

11

12

13

14

16

n= 14

14 .

13 . 12 .

= =

Berdasarkan nilai Cs = maka diperoleh nilai K untuk setiap periode ulang (tabel 3)

Log Xi = Log X + K . Sx

Tabel 1.16

0.07627

Cs =

0.0144

2.1809

2.1950

2.2593

2.2863

5

T (tahun)

0.0756

178.333

0.0756

-0.31861

156.667

2.3391

123.333

0.0045

0.0164

xi=10logx+k.Sx

1988

1989

1991

1990

2.2218

2.2347

2.15632.2512

2.0911

143.333

K

n . S (Log Xi - Log X)3

T (TAHUN)

0.076

31.0680

14

S (Log Xi - Log X)2

2.21911.439

Sx

167.179

2.219141Log X =

0.07626945

=

-0.31860973

31.0680

0.0028146.667

=

(n - 1)(n - 2)(Sx)3

(n - 1)

13

198.333

151.667

1995

123.333

1993 181.667

Jumlah

1994 193.333

198.333

0.0003

0.0000

0.0016

0.0006

-0.0021

0.0001

0.0000

0.0000

Tahun

2.2974

1998

1986

1987

(Log Xi - Log X)2

1985

0.0000

Xi (mm)

0.0010

166.667

171.667

0.0039

(Log Xi - Log X)3Log Xi

0.0000

0.0002

192.410

206.014

213.261

1996 218.333

1992

1997

2.0911

Curah hujan

Sx =

0.0015

0.0164

0.0061

-0.0016

-0.0001

-0.0021

-0.0001

-0.0002

0.0005

Log X

0.853 192.410

-0.0016

Xi (mm)

213.261

=

0.07627

2

5

15

2.2191

0.07627

10

15

206.014

2.2191

1.24210

167.179

2 0.053 2.2191 0.07627

0.0017

2.1663

0.00052.2974 0.0061


6/35

1. Intensitas Curah Hujan Rencana Dengan Metode Mononobe

R 5

5 t

Diketahui :

R2 = mm

R5 = mm

R10 = mm

R15 = mm

1 jam

51

5

1

5

1

5

1

2 jam

5

2

5

2

5

2

5

25

75.896 mm/jam5

I15 =213.261

x ( )2/3 = 78.566 mm/jam

5

I10 =206.014

x ( )2/3

=

61.589 mm/jam5

I5 =192.410

x ( )2/3 = 70.884 mm/jam

Untuk t =

I2 =167.179

x ( )2/3 =

mm/jamI15 =213.261

x ( )2/3 = 124.716

5

mm/jam5

I10 =206.014

x ( )2/3 = 120.478 mm/jam

5

I5 =192.410

x ( )2/3 = 112.522

x ( )2/3 = 97.767

Untuk t =

mm/jam5

I2 = 167.179

167.179

192.410

206.014

213.261

3.3 PERHITUNGAN INTENSITAS CURAH HUJAN

I = X ( )2/3


7/35

3 jam

5

3

5

3

5

3

5

3

4 jam

5

4

5

4

5

4

5

4

5 jam

5

5

5

5

5

5

5

5x ( )

2/3 = 42.652 mm/jam5

x ( )2/3 = 41.203 mm/jam

5

x ( )2/3 = 38.482 mm/jam

5

49.494 mm/jam5

I2 =167.179

x ( )2/3 = 33.436 mm/jam

5

I15 =213.261

x ( )2/3

=

44.654 mm/jam5

I10 =206.014

x ( )2/3 = 47.812 mm/jam

5

I5 =192.410

x ( )2/3 =

mm/jam5

Untuk t =

I2 =167.179

x ( )2/3 = 38.799 mm/jam

I15 =213.261

x ( )2/3 = 59.957

mm/jam5

I10 =206.014

x ( )2/3 = 57.920 mm/jam

5

= 47.001 mm/jam5

I5 =192.410

x ( )2/3 = 54.095

Untuk t =

I2 =167.179

x ( )2/3

5

I5 =192.410

Untuk t =

I10 =206.014

I15 =213.261


8/35

1

2

3

4

97.767

61.589

47.001

38.799

112.522

70.884

54.095

120.478

75.896

57.920

124.716

78.566

59.957

Intensitas (mm/jam)

I 2 I 5 I10 I15t

(jam)

Tabel Intensitas Hujan

44.654 47.812 49.494

5 33.436 38.482 41.203 42.652


9/35


10/35

0

20

40

60

80

100

120

140

0 1 2 3 4 5

In

tensitas(mm/jam)

Waktu Konsentrasi (menit)

Grafik Intensitas Curah Hujan Metode Mononobe


11/35

8

A0 A1 A2 A3 A4 A5 A6

B C D

9

B0 B1 B2 B3 B4 B5

C0 C1 C2 C3

D0

9.5 E0

F0 F1

G0 G1 G2 G3

H0 H1 H2

10

I0 I1 I2

Q3 J0 J1 J2 J3 J4 J5 J6

Q1 Q2

C4

C3A

V

VI

I II III

C4 C1 C4

C1

f F

X

VIII

C3

IX

C3

ea

8.5 7 6

E

g

h

i

5.56.57.5

b c


12/35

Diketahui :

Q1 = m3/detik C1 = C4 =

Q2 = m3/detik C2 =

Q3 = m3

/detik C3 =

a = m f = m k = m

b = m g = m l = m

c = m h = m m = m

d = m i = m

e = m j = m

Lebar Jalan + Trotoar :

Jalan A = m Cjalan =

Jalan B = m

Jalan C = m

Jalan D = m

Jalan E = m

Jalan F = m

0.8

0.7

0.6

300

1460

800900

0.82

0.43

200

0.7

0.5

700

1300

400

1000

0.6

600

600

10

10

10

10

10

1000

10

200


13/35

4

4.1 DATA DASAR

4.1.1 Data Curah Hujan

1

2

3

4

5

6

7

8

9

10

1112

13

14

15

16

17

18

19

20

21

22

23

24

-

- -

90

150

-

PERHITUNGAN DAN PERENCANAAN

2003 240

-

-

1999

2000

2001

265

110

1997

240 2401996 175

190160 90

165 1501994

120 1401995

1851992150 1751993

140

220

1951990

115 1601991

235

180

1901987 130

1601988

90 801989

175

200

-

145

195

185

-

90

200

165

125

1984

1985

1986

110

NoSta A Sta C

Tahun

1982 -

BAB IV

1983

1998

2002

210

2

230

190

190

-

-

- 240

-

2004

2005

215

Sta E

250

215

100

180

240

235

-

-

-

-

-

-

-

Curah Hujan (mm)


14/35

4.1.2 Data Topografi

Rumus perhitungan Elevasi, Panjang Lahan Terjauh, dan kemiringan lahan

n

m

Perhitungan Elevasi Awal dan Akhir

R X P = Jarak areal ke garis berikutnya (m)

P r R = Jarak antar kontur (m)

r = Interval antar kontur yang membatasi titik

Sehingga tinggi elevasi = Kontur -X

Perhitungan panjang lahan terjauh

Lt2 = m

2 + n2

Kemiringan Lahan

Lt

Mencari Luas lahan

A = m x n

Perhitungan Luas Areal

700

78

StE awal - E akhir

x

1300

PETAK

I

=

400

58.4

24

V

(Ha)

Luas

63IX

30XI

II

IVIII

X

VIII

VI

VII

(m)

600

600

Panjang

600

400

42

100%

Lebar

(m)

100024

100

800

700

12

80

36

1000

900

300

400

1000

400

1000

900 400

600

1460

300

110109

108

R


15/35

Dengan mengacu pada denah, dapat dibuat tabel data topografi sebagai berikut :

Panjang lahan ( Lt )

( m )

1 721.11

2 921.95

3 721.11

4 1414.21

5 1431.78

6 1513.80

7 1280.62

8 984.89

9 1140.18

10 500.00

11 1044.03

6.50

24.00

6.50

9.08

9.58

100.00

7.42

8.43

36.00

8.38

5.27

Elevasi ( m )

8.42

7.74

6.50

7.00

5.85

( Ha ) Awal Akhir

8.33

7.87

6.91

8.78

NoLuas Areal

80.00 8.00

8.19

I

Petak

II

III

IV

VIII

IX

VI

VII

63.00

XI

58.40

42.00

V

X

0.09472

0.13200

0.06609

0.14860

0.14700

0.10677

0.12432

0.12419

0.11713

0.11778

8.85

547.40

30.00

12.00

78.00

8.00

6.78

24.00

Jumlah

Kemiringan

Saluran (%)

0.12619


16/35

3.1.3 Data Saluran

Kemiringan

Saluran (%)

1 0.08136

2 0.09775

3 0.11750

4 0.09700

5 0.08333

6 0.06167

7 0.10833

8 0.09900

9 0.10000

10 0.09500

11 0.14000

12 0.11438

13 0.03600

14 0.14875

15 0.09000

16 0.04270

17 0.07778

18 0.08889

19 0.05000

20 0.03700

21 0.10333

22 0.13000

23 0.04750

24 0.03371

25 0.05000

26 0.08000

H3 - E1

G2 - G3

A4 - A5 6.32

7.84

6.87

7.92

6.24

6.50

8.19

8.45

8.50

8.75

6.50B3 - A3

No

6.50

6.50

8.40

8.39

Awal

Elevasi ( m )

5.85

B1 - A1

5.27

5.85

7.42

Akhir

7.00

5.27

E0 - E1

C2 - C3 6.88

C0 - C1

6.26

F1 - C1

6.86

H1 - C3 8.17

B5 - A5

8.80

7.69

9.12

J7 - I3

G0 - G1

J3 - G3

I2 - I3 8.11

D1 - A7

7.74

8.19

8.13

9.53

8.50

8.42

8.00

9.05

8.70

J1 - G1

I0 - I1

J6 - J7

J0 - J1

J4 - J5

J2 - J3

8.78

8.38

8.00

7.65

8.42

7.74

9.34

Saluran

7.90A0 - A1

6.50

A6 - A7

7.37A2 - A3

J5 - I1

7.00

6.50

300

300

400

890

400

1000

1000

800

400

890

900

900

400

1000

1400

400

600

1460

1000

1000

600

600

600

6.50

7.42

Panjang

Saluran ( m )

590

890

400


17/35

Qs =

Ls

v

Lt

St

ket. :

A =

Ls =

Lt =St =

to =

td =

tc =

Cs =

Cr = Koefisien pengaliran rata-rata

I =

v =

(diasumsikan, v = 0.4 m/dtk)

Q3

= 0.7m

3

/dtk

AL = Ha = m2

AJ= Ha = m2

Ls = m

Lt = m

St =

Cj =

CL=

Lt0.77

St

0.77

36.00

0.4

400

984.89

0.001178

0.8

to =

0.82

Waktu pengaliran dalam saluran (menit)

Waktu pengumpulan air (menit)

4.2.2 Contoh Perhitungan Debit

Saluran J0 - J1

Koefisien penampungan

diketahui data-data sbb :

360000

Intensitas curah hujan (mm/jam)

to = 0.0197 x

to = 0.0197 x 984.8858

0.0343

53.3348 menit

=

4000

=

tdCs =

Kecepata rencana (m/dtk)

Cr

to

4.2 PERHITUNGAN DEBIT RENCANA

4.2.1 Rumus Perhitungan Debit

0,00278 . Cs. Cr. I.A

tc

Ajalan + Alahan

to +2 tc

Panjang Saluran (m)

Panjang lahan terjauh (m)

Cjalan . Ajalan + Clahan . Alahan

Waktu untuk mengalir dari permukaan lahan ke saluran terdekat (menit)

=

td =

2 tc + td

0.0197

Luas areal (Ha)

Kemiringan lahan (%)


18/35

Ls

v

0.4 x 60

tc = to + td

tc = +

tc =

2 tc + td +

0.80 . + 0.82 . 36.00

+

= 0.820

Periode ulang 2 tahun untuk Saluran Tersier

Periode ulang 5 tahun untuk Saluran Sekunder

Periode ulang 10 tahun untuk Saluran Primer

dimana : = menit = dtk

= m .....Tabel curah hujan maximum

5

4200.1

Qs = x Cs x Cr x I x A

Qs = x 0.894 x 0.820 x xQs =

Qkomulatif = +

= +

= m3/dtk

AL = Ha = m2

AJ= Ha = m2

Ls = m

Lt = mSt =

Cj =

CL=

Lt 0.77

St

0.8936

Cr =

0.9

16.6667

4200.0873

140.0029

td =

360000

9000

0.82

)2/3

53.3348

36.00

Penentuan Intensitas dengan Metode Mononobe Untuk periode ulang T = 2 tahun

td = v = 0.4 m/det

menit

36.00

900

Q2

Ajalan + Alahan

=

R2 Thn

400= 16.6667

I2 =

16.6667

70.0015

Cjalan . Ajalan + Clahan . Alahan

=

=

menit

0.00278

Saluran J1 - G1


70.0015

Cs =2 tc

tc

0.1672

0.1672(

0.00278

0.40

0.40

140.0029

984.890.0008

0.8

0.7

Q (J0-J1)

to = 0.0197 x

0.9753

0.2753

m/dtk5

= 0.00038

0.2753 m3/dtk

0.00038 360000


19/35

0.77

Ls

v

0.4 x 60

tc = to + td

tc = +

tc =

2 tc + td +

0.80 . + 0.82 . 36.00

+

= 0.820




dimana : = menit = dtk= m .....Tabel curah hujan maximum

5

6004.4


Qs = x 0.842 x 0.820 x x

Qs =

Qkomulatif = +

= +

= m3/dtk

Q (J1-G1)

(

0.0279

100.07400.1924

)2/3 =

0.00034

6004.4404

menit

984.8858

m/det

x

37.5000

62.5740 menit

to = 0.0197

to =

menit

62.5740 37.5000

td = v = 0.4

td =900

=

Cr =Cjalan . Ajalan + Clahan . Alahan

Ajalan + Alahan

2 tc=

200.1480

200.1480

37.5000Cs =

=

=0.90

Q (J0-J1)

0.9753


36.00

R5 Thn

0.2353

m/dtk

0.00278

0.00278

I5 = 0.00034

360000

0.1924

100.0740

0.2353 m3/dtk

0.8422

tc

0.90

1.2106

5


20/35

AL = Ha = m2

AJ= Ha = m2

Ls = m

Lt = m

St =Cj =

CL=

Lt 0.77

St

0.77

Ls

v

0.4 x 60

tc = to + td

tc = +

tc =

2 tc + td +

0.80 . + 0.43 . 24.00

+

= 0.436




dimana : = menit = dtk= m .....Tabel curah hujan maximum

5

3519.5


Qs = x 0.876 x 0.436 x x

Qs =

Saluran A4 - A5

R10 Thn

0.00052 240000

0.1326

)2/3 = 0.00052 m/dtkI2 =

0.2060(

5

0.2060

Cr =Cjalan . Ajalan + Clahan . Alahan

Ajalan + Alahan

=0.40

0.40 24.00

58.6583

117.3166

117.3166 16.6667=

= 0.8756

Cs =2 tc

td = v = 0.4 m/det

to = 41.9916 menit

4000

240000

0.0197

24.00

to =

to = 0.0197 x721.1103

0.0343

0.43

0.8

721.11

0.001175

400

td =400

= 16.6667

x

0.4


tc

58.6583

menit

41.9916 16.6667

menit


m3/dtk

0.00278

0.00278

3519.499


21/35

Tabel 4.2.3.1. Debit Rencana Untuk Periode Ulang 2 Tahun (Saluran Tersier)

1

2

3

4

5

6

7

8

910

11

12

J0 - J1 984.89 0.000475 75.657 0.917 0.820 2

2

0.00031

0.861 0.703 0.00025

400 0.40 16.667

128.78741.667

92.323

1000 0.40I2 - I3 1044.03 0.00037 87.120

0.000410.879 0.442 2I0 - I1 500.00 0.0005 44.012 400 0.40

2

0.000230.874 0.602 2

0.0003616.667

144.706

16.667

75.821 0.901 0.820

60.679

41.667

G0 - G1 984.89 0.0009 59.155 400 0.40

E0 - E1 1280.62 0.00036 103.040 1000 0.40

97.334 0.921 0.820 2

2 0.00024

0.00030C2 - C3 1513.80 0.00095 80.667 400 0.40 16.667

0.821 0.7021400 0.40 58.333 134.102C0 - C1 1431.78 0.001 75.769

2 0.000281000 0.40 41.667 106.409J6 - J7 1044.031 0.0008 64.742 0.836 0.703

60.679 0.879 0.442 2 0.00041 J4 - J5 500.000 0.0005 44.012 400 0.40 16.667

2 0.00024890 0.40 37.083 133.724J2 - J3 1140.175 0.0003371 96.640 0.878 0.820

72.931 0.854 0.439 2 0.00037 A1 - B1 721.110 0.0008 47.931 600 0.40 25.000

2 0.00037590 0.40 24.583 72.959

(m) m/dtk menit menit

0.856 0.439

Cs

A0 - A1 721.110 0.0008 48.376

CrLs V td

Aliran dalam salurantc

T I

Thn m/dtk

Curah Hujan

4.2.3 TABEL PERHITUNGAN DEBIT (Q) CURAH HUJAN UNTUK PERIODE ULANG 2 TAHUN, 5 TAHUN, DAN 10 TAHUN

NoNama

saluran

Aliran Permukaan

Lt St to

menit(m)


22/35

Tabel 4.2.3.2 Debit Rencana Untuk Periode Ulang 5 Tahun (Saluran Sekunder)

1

2

3

4

5

6

7

8

9

10

11

12

Tabel 4.2.3.3 Debit Rencana Untuk Periode Ulang 10 Tahun (Saluran Primer)

1

2

Q total = +

= +

= m3

/dtkQtotal dipakai untuk perencanaan Outfall (Saluran Pembuang)

16.667 58.658 0.876 0.436 10 0.00052A4 - A5 721.11 0.001175 41.992 400 0.4

5 0.00034

5 0.00029890 0.40 0.871 0.82037.083 125.317

J1 - G1 984.89 0.0008 62.574

G2 - G3 1140.18 0.0004 88.233

0.842 0.820900 0.40 37.500 100.074

5 0.00028

5 0.00036800 0.40 0.848 0.60233.333 93.007

H1 - C3 1513.80 0.0011 75.102

H3 - E1 1280.62 0.0015 59.674

0.817 0.8201460 0.40 60.833 135.935

600 0.40 0.880 0.701

D1 - A7 1414.21 0.0010 75.343

F1 - C1 1431.78 0.0014 66.563

1000 0.40 41.667 117.010

25.000 91.563

0.849 0.602

B5 - A5 721.11 0.0011 43.326 600 0.40 0.845 0.43925.000 68.326 5 0.00044

5 0.00031

5 0.00036

0.878 0.701 5 0.00037600 0.40 25.000 90.031B3 - A3 921.95 0.0006 65.031

A2 - A3 921.954

0.602 10 0.00034A6 - A7 1414.214 0.00097 75.937 1000 0.40 41.667 117.604 0.850

Lt St to Ls V td Ttc

Cs Cr

Curah Hujan

I

menit Thn m/dtk

NoNama

saluran

Aliran Permukaan Aliran dalam saluran

(m) menit (m) m/dtk menit

0.00045 66.204 0.914 0.701 5J7 - I3 1044.031 0.0013 53.704 300 0.40 12.500

5 0.00057300 0.40 12.500 45.781J5 - I1 500.000 0.0010 33.281 0.880 0.439

104.032 0.847 0.820 5 0.00033 J3 - G3 1140.175 0.0009 66.532 900 0.40 37.500

0.00036890 0.40 37.083 91.545 0.832 0.702

Ls

menit

V

5

menit (m) m/dtk menit

Cs Cr

0.0010 54.462

m/dtk

td T I

Curah Hujan

Thn

NoNama

saluran

Aliran Permukaan Aliran dalam salurantc

8.2115

6.5932 1.6184

Q (A6-A7) Q (D1-A7)

Lt St to

(m)


23/35

4.3 Perhitungan Dimensi Saluran

Dimensi saluran bentuk trapesium

Dimana:

- Kecepatan rencana (v) = m/dtk

- Koefisien kekasaran Manning (n) =

- Kemiringan talud rencana (m : n) = 1 : 2

T

w

1 h 2 h

m

b

Penampang Ekonomisb = 1.5 h

Luas penampang trapesium (A)

Q

v

Keliling basah (p)

p =

Jari-jari Hidrolik ( R )

Dengan menggunakan rumus Manning, maka v (kecepatan) :

v = 1/n . R2/3 . S1/2

Dimana:

Q A

A p

ket:

Q = debit (m3/dtk)

A = Luas (m2)

p = keliling basah (m)

R = jari-jari hidrolis

S = kemiringan saluran

R =

=(b + m.h).h

v

P

; R =

A =

=

0.4

0.0178

= (b + m.h).h, dimana :

A

A

21.2 mhb ++

21.2 mhb ++


24/35

Q 1 A 2/3 1/2

A n p

=

=

=

Untuk trapesium dimana b = 1.5 h, didapat:

= ( 1.5h + 1 . h ) .h

= 2.5 h2

p =

= 1.5h + 2h.1 + 12

= 1.5 h + 2h . 2

= h

Dari persamaan 1, didapat :

=

=

( 2.5.h2 )5 1/3

h10 Q 3

h2

3

3

3/8

Q

S1/2

h = 0.17958Q

S1/2

Q

.............................. ( 2 )

S1/25.21345 h8 = 0.0000056

h8 = 0.00000108

97.6563

18.7316=

n . Q

S1/2

0.018 .

S1/2

0.0178; n=(4.328.h)2

=

A5/3 n . Q

p2/3 S1/2

S

, misal m = 1

4.328

n . Q . P2/3 A5/3 . S1/2

................................................... ( 1p2/3

A = (b + m.h).h

.= .

n . Q

S1/2A

5/3

21.2 mhb ++


25/35

Tabel Perhitungan Dimensi Saluran Tersier

1

2

3

4

5

6

7

8

9

10

11

12 0.00080 0.381638 0.5226320.0178 1 1.41333 0.18863

0.00050 0.362293 0.3450090.0178 1 1.07841 0.14393

0.00034 0.429192 0.4606920.0178 1 2.23657 0.29850

0.00047 0.483815 0.6918130.0178 1 3.18220 0.42471

0.00081 0.369525 0.4735250.0178 1 1.20362 0.16064

0.24917

0.32655

0.41715

1.10289

0.77515

0.37376

0.48983

0.27665 0.41498

0.62966

0.19335

1.35152

0.66762

0.15521

0.26659

0.40 0.19134

0.40 0.41103

0.09156

0.9349976

0.3075699

0.0535504

0.1393306

A1 - B1 0.0913815

C0 - C1

G0 - G1 0.2632208

A0 - A1

J0 - J1

J2 - J3

0.40

0.40

0.40

0.27810

0.73526

0.51677

A h b R Sw V salura

m m/dtk

Dimensi Saluran

n m P

m2 m m

No. saluranQ maks v

m3/dt m/dt

0.0178 1 1.19735 0.15980 0.00083 0.369163 0.47758

0.3043187 0.40 0.44052 0.41977 0.0178 1 1.81678 0.24248 0.690809

C2 - C3 0.3696334 0.40 0.51958 0.45589 0.68383 0.00095 0.413972

0.001 0.404943

0.0178 1 1.97308 0.26334 0.711402

E0 - E1 0.2710734 0.40 0.59248 0.48682 0.73023 0.0178 1 2.10695 0.28120 0.00036 0.421705 0.457521

0.40548 0.60822

1.07841 0.14393

0.0009 0.4013690.0178 1

0.0005 0.362293I0 - I1 0.0535504 0.40 0.15521

1.75491 0.23422

0.24917 0.37376 0.0178 1 0.345009

0.381884

0.640394

0.00037 0.390921

J4 - J5

J6 - J7

0.40

0.40

1.57402 0.21008I2 - I3 0.1262753 0.40 0.33066 0.36368 0.54553 0.0178 1


26/35

Tabel Perhitungan Dimensi Saluran Sekunder

1

2

3

4

5

6

7

8

9

10

11

12

Tabel Perhitungan Dimensi Saluran Primer

1

2 0.0178 1 1.47346325.79021 0.77279 0.00097 0.634462A6 - A7 6.59317 0.40 4.47461 1.33785 2.00677

A h b R S

m/dtk

Dimensi Saluran

n

m m

m P

1.87790 0.25063

w V saluran

0.00130

No. saluranQ maks v

m3/dt m/dt

0.65084 0.0178 1

0.8466157

m2 m

0.408474

0.0178 1

0.8052109

0.7829804

J5 - I1 0.65355 0.40 0.77196 2.40499 0.32098 0.00103

0.8307153

1.1014762

1.0584529

4.15045 0.553940.0178 1 0.00043 0.539744G2 - G3 1.80015 0.40 2.29909 0.95898 1.43847

0.00130 0.413668

5.25641 0.70154 0.0006167 0.603628

1.96782 0.26263

m/dtk

A2 - A3 0.42933 0.40 0.51682 0.45467 0.68201 0.0178 1

m2 m m m

n mV saluran

A h b P R Sw

Dimensi Saluran

No. saluranQ maks v

m3/dt m/dt

B3 - A3 4.06181 0.40 3.68760

0.0178 1

1.21451 1.82177 0.0178 1

B5 - A5 1.48743 0.40 1.40529 0.74974 1.12462 3.24489 0.43308

0.00099 0.4967563.40624 0.45461

0.0010833 0.487436

0.78702 1.18054 0.0178 1D1 - A7 1.61835 0.40 1.54852 1.0451002

F1 - C1 3.49466 0.40 2.42231 0.98434 1.47651 0.0178 1 4.26022 0.56859 0.0014 0.546085 1.442698

H1 - C3 1.00903 0.40 1.02923 0.64163 0.96245

0.0178 1 2.54445 0.33959

0.0011438 0.4604080.0178 1

0.0014875 0.446976

0.9803661

H3 - E1 0.91132 0.40 0.86408

2.77699 0.37063

0.58790 0.88186

0.0007778 0.482297

1.0546658

0.8803774

A4 - A5 4.62378 0.40 3.19123

0.55568 0.83352

J7 - I3 0.37898 0.40 0.47066

3.15592 0.42120J1 - G1 1.17027 0.40 1.32928 0.72919 1.09378 0.0178 1

0.00118 0.582455 1.4489051.12982 1.69473 0.0178 1 4.88986 0.65262

J3 - G3 1.21132 0.40 1.29747 0.72041 1.08061 0.0178

0.43389

1 0.93359493.11793 0.41613 0.0008889 0.480102

0.438921


27/35

4.5 Perhitungan Dimensi Gorong-gorong dan Kehilangan Energi

Perhitungan Gorong-gorong A1 - A2

Data-data sbb:

Bangunan pelintas gorong-gorong bentuk Segi empat

Qsaluran =m /s

v1 = kecepatan di hulu saluran = m/s

v2 = kecepatan didalam gorong-gorong = m/s

v3 = kecepatan di hilir saluran = m/s

g = perc. Gravitasi = m/s

n = Koefisien kekasaran Manning =

Luas penampang Gorong-gorong

Q

v2

Tinggi permukaan air gorong-gorong (h) dapat dihitung :

A = b x h (Asumsi h = b)

= b x h

h = m

Jadi, lebar gorong-gorong

b = m

Keliling Basah

P = b + 2h

= + 2 .

= m

Jari - jari Hidrolis

A

P

Kemiringan Dasar Saluran

2

1.5 2

0.1830.40

1.5

0.4

0.121958 m2

1.5

0.122

9.81

0.018

0.35

1.04767

0.35

0.34922 0.35

A =

=

0.183

=

S =v2 x n

R2/3

R =

= 1.25 %0.238

0.116408 m1.048

=

=. 0.018

=0.12196

= 0.0125


28/35

Kehilangan Energi :

1. Akibat pemasukan

( 1.5 - 0.40 )

2

2. Akibat gesekan

Nilai koefisien kekasaran Strickler (k) untuk beton 70

1 1/6 1 1/6

k 70

2

2 x

3. Akibat pengeluaran

( 1.5 - 0.40 )2

4. Htotal = hc + hf + ho

= + +

= m

Sketsa Penampang Gorong-Gorong A1 - A2

=

h

b = m

hc = 0.50(v2 - v1)

2

= 0.50 = 0.0308x 9.81

2 . g

hf =Cf . v2

2

Cf2 . g

=

m

0.116 = 0.010 m

=0.00998 x 1.5

=

=

0.0011 m

R

9.81

= 0.11 = 0.0068

ho = 0.11(v2 - v3)

2

2 . g

x 9.81

0.0308 0.0011 0.0068

m

0.0388

0.3

5m

0.35


29/35

Tabel Perhitungan Dimensi Gorong-gorong (Bulat)

SKETSA PENAMPANG GORONG-GORONG

1

2

34

5

6

7

8

9

10

12

3

4

5

6

7

8

9

10

h ( m )

b ( m )

No Nama Gorong-GorongQ1

Kecepatan Aliran

V1 V2 V3 A h

Dimensi Koefisien

b Manning

m3/det m/dt m/dt m/dt m

2 m m ( n )

A1 - A2 0.18 0.40 1.5 0.40 0.1220 0.35

A3 - A4 4.49 0.40 1.5 0.40

0.35 0.0178

2.9941 1.73 1.73 0.0178

A5 - A6 6.11 0.40 1.5 0.40 4.0741 2.02 2.02 0.0178C1 - B3 3.80 0.40 1.5 0.40 2.5327 1.59

C3 - B5 1.38 0.40 1.5 0.40

1.59 0.0178

0.9191 0.96 0.96 0.0178

E1 - D1 1.18 0.40 1.5 0.40 0.7883 0.89 0.89 0.0178

G1 - G2 1.43 0.40 1.5 0.40 0.9557 0.98

G3 - F1 3.01 0.40 1.5 0.40

0.98 0.0178

I1 - H1 0.71 0.40 1.5

1.42 1.42 0.0178

0.40 0.4714 0.69 0.69 0.0178

2.0076

0.0178I3 - H3 0.51 0.40 1.5 0.40 0.3368

No Nama Gorong-Gorong

Kehilangan Energi

hc hf ho S Hm

0.0392

m m

A1 - A2 0.0308 0.0068 0.0388

0.58 0.58

0.0390

A3 - A4 0.0308 0.0015 0.0068

m

A5 - A6 0.0308 0.0015 0.0068

0.0068

0.0011

C3 - B5 0.0308 0.0014 0.0068

0.0068

0.0391

G1 - G2 0.0308 0.0014 0.0068 0.0390

C1 - B3 0.0308 0.0015

0.0068

0.0391

I1 - H1 0.0308 0.0013 0.0068 0.0389

E1 - D1 0.0308 0.0013

0.0391

0.0390

I3 - H3 0.0308 0.0012 0.0068 0.0389

G3 - F1 0.0308 0.0014


30/35

4.4 Perhitungan Inlet pada Trotoar

Definisi Inlet Lubang-lubang di sisi jalan yang berfungsi untuk menampung dan menyalurkan

limpasan air hujan yang berada di sepanjang jalan menuju ke dalam saluran.

Diketahui data-data sebagai berikut:

Jalur Trotoar yang direncanakan A6 - A7

Panjang Saluran = m Lebar jalan = m

lebar trotoar = m

jalan + trotoar = m

Jarak antara Sreet Inlet ( D )

dimana: w = lebar jalan (m)

s = kemiringan jalan (%) = 2%

D = jarak antara sreet inlet (m)

Kapasitas untuk inlet tegak

dimana :

Q = kapasitas inlet (m3/det)

L = lebar bahan inlet (m)

g = kecepatan grafitasi m/det2

d = kedalaman air (m)

*Perencanaan inlet pada jalur trotoar

Dik: w = m

S = = 2%

g = m/det2

S

10008

1

10

50 mw

Q= 0,36 x g x d

3/2

L

D =280

x

A6 - A78

0.02

9.8


31/35

Jarak antara Sreet Inlet ( D )

( Oke !!! )

Selanjutnya jumlah inlet tegak yang dibuat di sepanjang jalan A

Luas 1 inlet

A = 1/2 x w x D

A = 0.5 x 8 x

A = 0.02 Ha

Kapasitas inlet tegak (Curb Inlet)

Data-data :

A = Ha st =

Lt = C =

Ls =

Perhitungan:

1

( st ) 0.5

0.8

( ) 0.5

Ls Untuk kemiringan 0-1% = 0.4

v Untuk kemiringan 1-2% = 0.6

Untuk kemiringan 2-4% = 0.9

tc = to + td

= + =

2 x

( 2 x ) +

Gunakan Curah Hujan Maksimum antara periode ulang 2, 5, 10 dan 15 tahun

R

24

/ 60

D =280

x S 50 mw

280x 2 50

8

49.50 50

N =Ltot

=

1000

1000= 21

D 49.50

49

0.02 2.0 %

td =

4.001 m 0.8

= 0.0439 menit2.000

(

to = 0.0197 (Lt

)

= 0.0197

=1000

= 41.672500.00

4.00079992)

menit0.4

detik

0.043876 41.667 41.71 menit

=

2/3

Cs =

2 . tc

=

I15 = x24

tc / 60

0.672 . tc + td 41.711 41.67

41.711

=

=213.2611

x24

94.21 mm/jam24 41.711

2/3=


32/35

Tinggi Genangan Air

d =

= ( 49 . 94.21 )0.5

( 1 / 2 )0.2

= mm

dimana tinggi genangan maksimum yang diijinkan untuk jalur jalan yang lurus = 6.5 mm

( modul perencanaan drainase permukaan, teknik sipil unhas, hal.2-12 )

Q = 0.36 g. d3/2

. L

dimana : Q = kapasitas inlet tegak ( m3/det )

g = percepatan gravitasi ( m/det2) = 9.8 m/det

2

L = Lebar bukaan curb ( m )

diambil l = 20 cm = 0.2 m

d = kedalaman air dalam curb (m)

diambil d = 10 cm = 0.1 m

Q = 0.36 x 9.8 x 0.0316 x 0.2

= m3/det

= lt/det

Sketsa Inlet :

d =

0.046 ( D . I )0.5

( 1 / S )0.2

0.20 m

0.046

2.734633341

0.0223358

22.3358

0.10 m

L


33/35

8. Perhitungan Outfall ke sungai

Outfall ke sungai yang digunakan adalah bentuk trapesiumDiketahui data sebagai berikut :

Debit Rencana ( Q ) =

Kecepatan air dalam outfall =

Koefisien manning (n) =

8.1. Luas penampang basah ( A )

8.2. Mencari lebar saluran dan kedalaman air

A = ( b + ( m x h )) x h Asumsi b = 1.5 h

A = ( 1,5 h + ( 1,0 x h )) x h

A = ( 1,5 h + 1,0 h ) h

A = 2.5 h2

20.53 = h2

0.5

8.3. Keliling basah ( P )

P = b + 2 h ( m2

+ 1 )0,5

= 4.3 + 2(2,13) (1)2

+ 10.5

P = m

8.4. Jari-jari Hidrolis ( R )

0.4 m/det

BAB VIII

PERHITUNGAN OUTFALL KE SUNGAI

8.2115 m3/det

0.018

A =Q

=8.2115

= 20.5288 m2

V 0.4

4.30 m

12.40

2.5

h =20.53

2.5

h =

A=

20.5288

m b =2.87

mP 12.40

= 1.6551R =


34/35

8.5. Tinggi Jagaan

1.5. Q. h

8.6. Kemiringan Saluran ( S )

2x

2

x2/3

S =

= S rencana

=

OK !!!

8.7. Kontrol Debit

Q = 1

n

Q =

Q =

= Q rencana= OK !!!

8.8. Kehilangan tingkat energi ( z )

Q = f. A. 2. g. z

= 2 z

z = m

f = koefisien debit =

Q saluran

dimana :

fb = ( )0.5

60

= (1.5 8.212 2.87

)0.5

60

= 0.7670 m

S =Q x n 8.2115 0.018

A x R2/3

20.5288 1.66

0.0000265

2/3

x

8.2115

0.000026480.5

S saluran

0.00002648 0.000026

A x R2/3

x S0.5

1

8.2115 8.2115

8.212 0.8 1.6551

1.6620.52880.018 x

9.8

0.3164

0.8


35/35

GAMBAR OUTFALL KE SUNGAI

m

m

h 2.87 m

b = 4.30

fb 0.77

Drainase Rany

Documents