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DATA PERHITUNGAN CALIFORNIA BEARING RATIO (CBR)

Data Perhitungan CBR

I. Data Perhitungan Banyaknya Air yang Digunakan Pada Percobaaan CBR

1 = 13.1 gr

2 = 43.28 gr

3 = 33 gr

4 = 10.28 gr

5 = 19.9 gr

Kadar Air =Berat Air

x 100%Berat Tanah Kering

=10.28

x 100%19.9

= 51.66%

No. Container I II

13.1 13.37

43.28 34.63

33 31.18

10.28 3.45

19.9 17.81

Kadar Air (w) 51.66% 19.37%

Kadar Air Rata - rata 35.51%

Jadi banyaknya air yang digunakan pada percobaan CBR

=-

x Berat sample100 +

=31.95 - 35.51

x 8716100 + 35.51

= -229 cc

Berat Container (w1)

Berat Container + tanah basah (w2)

Berat Container + tanah kering (w3)

Berat Air (w2 - w3 ) = (w4)

Berat Tanah Kering (w3 - w1 ) = w5

Berat Container (w1)

Berat Container +Tanah Basah (w2)

Berat Container + Tanah Kering (w3)

Berat Air (w2 - w3 ) = (w4)

Berat Tanah Kering (w3 - w1 ) = w5

wCBR

wopt wawal

wawal

II. Perhitungan Kadar Air CB (Untuk 10 x Tumbukan)

a. Untuk lapisan atas :

Diketahui :

1. Berat container = 7.7 gr

2. Berat container + tanah basah = 40.03 gr

3. Berat container + tanah kering = 32.64 gr

4. Berat air = 40.03 - 32.64 = 7.39 gr

5. Berat tanah kering = 32.64 - 7.7 = 24.9 gr

Kadar air (w) =7.39

x 100% = 29.63%24.94

b. Untuk lapisan tengah :

Diketahui :




4. Berat air = 43.9 - 36.43 = 7.47 gr


Kadar air (w) =7.47

x 100% = 34.34%21.75

c. Untuk lapisan bawah :

Diketahui :




4. Berat air = 40.11 - 32.51 = 7.6 gr


Kadar air (w) =7.6

x 100% = 30.4%25.01

Jadi kadar air rata-rata =29.63% + 34.34% + 30.39%

= 31.45%3

Untuk perhitungan selanjutnya ditabelkan sebagai berikut :

Jumlah Berat Berat Berat

BeratBerat

KadarKadar

Container + Container + Tanah Air

Tumbukan Container Tanah Basah Tanah Kering Air Kering Air Rata rata

(x) (gr) (gr) (gr) (gr) (gr) (%) (%)

10

A 7.7 40.03 32.64 7.39 24.94 29.63

31.45T 14.68 43.9 36.43 7.47 21.75 34.34

B 7.5 40.11 32.51 7.6 25.01 30.39

25

A 15.82 48.87 36.39 12.48 20.57 60.67

41.26T 14.08 46.92 39.17 7.75 25.09 30.89

B 15.38 40.46 34.35 6.11 18.97 32.21

56

A 7.30 40.11 32.51 7.60 25.21 30.15

42.40T 7.35 40.12 34.00 6.12 26.65 22.96

B 7.38 47.84 30.62 17.22 23.24 74.10

III. Data Perhitungan Berat Volume Tanah CBR

Untuk Tumbukan 10 x

1. Berat Mould = 3105 gr

2. Berat Mould + Tanah Basah = 8490 gr

3. Berat Tanah Basah = 5385 gr

4. Volume Mould = 3344.85

5. Kadar Air Rata-rata = 31.45 %

Berat Volume Tanah Basah :

=Berat tanah

cm3

γs

=volume mould

=5385

3344.85

= 1.610

Berat volume tanah kering (dry density) :

=γs

1 + w

=1.610

1 + 0.31455

= 1.225

Untuk perhitungan selanjutnya ditabelkan sebagai berikut :

Mould I II III

Jumlah Tumbukan 10 x 25 x 56 x

Kadar Air Rata-rata (w) (%) 31.45 41.26 42.40

(gr) 3105 3105 3105

(gr) 8490 9270 9865

(gr) 5385 6165 6760

Volume Mould (V) 3344.85 3344.85 3344.85

1.610 1.843 2.021

Berat Vol. Tanah Kering (γdry) 1.225 1.305 1.419

Perhitungan Calibration Load dan Pressure Dial Reading CBR

Diameter Piston = 1.9016 inch

Faktor Calibrasi = Lbs

Calibration Load (CL) = Proving dial x faktor calibrasi

Pressure Dial Reading =CL

γs

gr/cm3

γdry

gr/cm3

Berat Mould (W1)

Berat Mould + tanah Basah (W2)

Berat Tanah Basah (W2 - W1 = W)

cm3

Berat Vol. Tanah Basah (γw) gr/cm3

gr/cm3

5.447 . 10-4

Pressure Dial Reading =Luas Piston (A)

Luas Piston (A) = ¼ π

= ¼ 3.14 1.9016 2

= 2.839

Beban Standar CBR

Penetrasi (Inch) 0.1 0.2 0.3 0.4 0.5

Satuan Beban Standar(Psi) 1000 1500 1900 2300 2500

Perhitungan CBR Untuk Contoh Tanah 10 x Tumbukan

Waktu Pembacaan = 0.5 menit

Penetrasi = 0.32 mm = 0.0126 inch

Faktor Calibration (fk) = lbs

Proving Dial Reading (DL) = 2

Calibration Load (CL) = DL x fk

= 2 x 5.447

= 10.894 lbs


A

=10.894

2.839

= 3.838 lbs/inch

d2

inch2

5.447 . 10-4

Untuk Perhitungan selanjutnya dapat dilihat pada tabel

Waktu PenetrasiProving Dial

Calibration Load Pressure Dial ReadingReading

menit mm inch 10x 25x 56x 10x 25x 56x 10x 25x 56x

0 0 0 0 0 0 0 0 0 0 0 0

0.5 0.32 0.013 2 3 5 10.894 16.341 27.235 3.8378 5.7567 9.5944

0.75 0.64 0.025 4 6 10 21.788 32.682 54.47 7.6755 11.513 19.189

1 1.27 0.050 7 10 16 38.129 54.47 87.152 13.432 19.189 30.702

1.5 1.90 0.075 9 13 21 49.023 70.811 114.39 17.27 24.946 40.297

2 2.34 0.092 11 15 25 59.917 81.71 136.18 21.108 28.783 47.972

3 3.10 0.122 13 18 30 70.811 98.046 163.41 24.946 34.54 57.567

4 5.10 0.201 15 23 37 81.705 125.28 201.54 28.783 44.134 70.999

6 7.62 0.300 17 26 43 92.599 141.62 234.22 32.621 49.891 82.512

8 10.20 0.402 18 28 45 98.046 152.52 245.12 34.54 53.729 86.35

10 12.70 0.500 19 30 47 103.49 163.41 256.01 36.459 57.567 90.188

Perhitungan Nilai CBR Setelah Koreksi

Untuk 56 x Tumbukan

1. Penetrasi 0.1 mm


A

=160

= 56.365 lbs/inch2.839

CBR =Pressure Dial Reading

x 100%Psi

=56.3653

x 100%1000

= 5.64%

2. Penetrasi 0.2 mm


A

=208

= 73.275 lbs/inch2.839

CBR =Pressure Dial Reading

x 100%Psi

=73.2749

x 100%1500

= 4.88%

NoPenetrasi CBR

(mm) 10 x 25 x 56 x

1 0.1 2.82% 3.95% 5.64%

2 0.2 2.14% 3.15% 4.88%

NoPenetrasi CBR

(mm) 10 x 25 x 56 x

1 0.1 2.11% 2.88% 5.64%

2 0.2 1.92% 2.94% 4.88%

3 0.3 1.72% 2.63% 4.34%

4 0.4 1.50% 2.34% 3.75%

5 0.5 1.46% 2.30% 3.61%

GRAFIK

HUBUNGAN ANTARA COMPACTION DENGAN C.B.R. DESAIGN

0 2 4 6 8 10 12 14 16 18 20 221.00

1.10

1.20

1.30

1.40

1.50

1.60

33

C.B.R. Design

Hubungan Antara Berat Volume Kering (γdry) Dengan Kadar Air (w)

Hubungan Antara Berat Volume Kering (γdry) Dengan CBR Design

γ dry max = 1.37gr/cm3 γ dry max = 1.36gr/cm3

CB

R 0

.1 =

8,2

5 %

CB

R 0

.2 =

13,

25%

Ber

at V

olu

me

Ker

ing

(γ d

ry)

Bera

t Volu

me K

eri

ng

(γ d

ry)

20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 501.00

1.10

1.20

1.30

1.40

1.50

1.60

6

6

W OPTIMUM (KADAR AIR (%)

DR

Y D

EN

SIT

Y (

gr/

cm3

)

0 0.1 0.2 0.3 0.4 0.5 0.60

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

GRAFIK Hubungan Antara Calibration Load Dengan

Penetrasi

Penetrasi (inch)

Calibra

tion L

oad M

M

10 x tumbukan

25 x tumbukan

56 x tumbukan

0.20.10

0.20.10

0.20.10

130.5

224.5

262

470

174

329

DATA PERHITUNGAN COMPACTION (MODIFIED A.A.S.T.H.O)

Data perhitungan Compaction :

1. Berat mould = 3195 gr

2. Tinggi mould = 17.5 gr

3. Diameter mould = 15.6 gr

4. Berat mould + tanah basah = 7000 gr

5. Berat tanah basah = 3805 gr

6. Volume mould = ¼ π t = 3344.854

I. Data Perhitungan Specific Grafity Compaction

a. Untuk Picno A

Diketahui :

1. = 143.50 gr

2. = 243.50 gr

3. = 702.00 gr

4. = 641.10 gr

5. Suhu (T) = 0.9965

Gs =-

x- - -

=243.5 - 143.5

x 0.9965641.1 - 143.5 - 702 - 243.5

= 2.549

b. Untuk Picno B

Diketahui :

1. = 133.10 gr

2. = 233.10 gr

3. = 691.80 gr

4. = 630.70 gr

5. Suhu (T) = 0.9965

Gs =-

x- - -

=233.1 - 133.1

x 0.9965630.7 - 133.1 - 691.8 - 233.1

= 2.562

d2 cm3

Berat picnometer (w1)

Berat picnometer + tanah (w2)

Berat picnometer + tanah + air (w3)

Berat picnometer + air (w4)

27ºC

w2 w1

w4 w1 w3 w2

Berat picnometer (w1)

Berat picnometer + tanah (w2)

Berat picnometer + tanah + air (w3)

Berat picnometer + air (w4)

27ºC

w2 w1γw

w4 w1 w3 w2

Jadi Gs rata - rata =2.549 + 2.562

= 2.5552

II. Data Perhitungan Kadar Air Compaction (Untuk Campuran Air = 700 cc)

a. Untuk lapisan atas :

Diketahui :

* Lapisan 5A




4. Berat air = 51.30 - 43.20 = 8.100 gr

5. Berat tanah kering = 43.20 - 25 = 18.2 gr

6. Kadar air (w) =8.10

x 100% = 44.505%18.2

* Lapisan 5 B




4. Berat air = 49.00 - 43.10 = 5.900 gr



x 100% = 28.641%20.6

Jadi kadar air rata - rata =

44.505 + 28.641= 36.573 %

( Lapisan Atas ) 2

b. Untuk lapisan tengah :

* Lapisan 3 A

Diketahui :




4. Berat air = 50 - 41.50 = 8.5 gr



x 100% = 50.000%17.00

* Lapisan 3 B

Diketahui :




4. Berat air = 46.4 - 42.30 = 4.1 gr



x 100% = 21.244%19.30


50.000 + 21.244= 35.622 %

( Lapisan Tengah ) 2

c. Untuk lapisan bawah :

* Lapisan 1 A

Diketahui :




4. Berat air = 41.7 - 35.80 = 5.9 gr



x 100% = 44.361%13.30

* Lapisan 1 B

Diketahui :




4. Berat air = 44 - 37.50 = 6.5 gr



x 100% = 41.935%15.50


44.361 + 41.935= 43.148 %

( Lapisan Bawah ) 2

Jadi kadar air rata - rata =36.573 + 35.622 + 43.148

= 38.4477 %3

III. Data Perhitungan Berat Volume Compaction

Rumus yang digunakan :

a. Berat volume tanah basah dalam mould :

=Berat tanah

volume mould

b. Berat volume tanah kering (dry density) :

=γs

1 + w

c. Angka pori (e)

e =Gs 1 + w

- 1

d. Porositas (n)

n =e

1 + e

e. Dry density pada Sr tertentu :

=

1 +Gs w

Sr

1. Berat volume tanah basah dalam mould :

=Berat tanah

=3805

= 1.138volume mould 3344.85

2. Berat volume tanah kering (dry density) :

=γs

1 + w

=1.138

1 + 0.384477

= 0.822

3. Angka pori (e)

e =Gs 1 + w

- 1

=1 x 2.555 1 + 0.38448

- 10.822

= 3.30536

γs

γdry

γw

γdry

γdry

Gs . γw

γs gr/cm3

γdry

gr/cm3

γw

γdry

4. Porositas (n)

n =e

1 + e

=3.305

1 + 3.305

= 0.76773

5. Dry density pada Sr tertentu :

a. Untuk Sr = 80 %

=

1 +Gs w

Sr

=2.555 x 1

1 +2.555 x 0.3845

0.8

= 1.147

b. Untuk Sr = 100 %

=

1 +Gs w

Sr

=2.555 x 1

1 +2.555 x 0.3845

1

= 1.289

6. Perhitungan % kepadatan

a. 100% - 80% = 20%

Jarak Sr 100 % ke titik puncak = 2 mm (a)

Jarak Sr 80 % ke titik puncak = 24 mm (b)

= 26 mm (c)

b. d =20% x a

c

d =20% x 2

26

d = 1.54%

γdry

Gs . γw

gr/cm3

γdry

Gs . γw

gr/cm3

c. e =20% x b

c

e =20% x 24

26

e = 18.46%

d. 100% - d = 100% - 1.54%

= 98.46%

e. 80% + e = 80% + 18.46%

= 98.46%

Jadi nilai kepadatan = 98.46%

TABEL PERHITUNGAN KADAR AIR COMPACTION

Jumlah Air Berat.Cont Berat Cont. + T.Bsh Berat Cont.+ T.Krng Berat Air Berat TK Kadar Air Average

(cc) (gr) (gr) (gr) (gr) (gr) (%) ( %)

700

A (5a ) 25.00 51.30 43.20 8.10 18.20 44.51

38.45

(5b ) 22.50 49.00 43.10 5.90 20.60 28.64T (3a ) 24.50 50.00 41.50 8.50 17.00 50.00 (3b ) 23.00 46.40 42.30 4.10 19.30 21.24B (1a ) 22.50 41.70 35.80 5.90 13.30 44.36 (1b) 22.00 44.00 37.50 6.50 15.50 41.94

800

A (5a ) 13.30 67.00 53.10 13.90 39.80 34.92

42.13

(5b ) 7.30 51.00 37.40 13.60 30.10 45.18T (3a ) 13.00 51.00 46.21 4.79 33.21 14.42 (3b ) 13.00 59.50 39.90 19.60 26.90 72.86B (1a ) 13.70 44.50 35.70 8.80 22.00 40.00 (1b) 13.80 45.50 35.60 9.90 21.80 45.41

900

A (5a ) 12.00 57.50 42.80 14.70 30.80 47.73

46.89

(5b ) 13.00 52.50 39.40 13.10 26.40 49.62T (3a ) 12.50 55.00 42.00 13.00 29.50 44.07 (3b ) 13.40 53.20 40.30 12.90 26.90 47.96B (1a ) 12.00 56.50 42.70 13.80 30.70 44.95 (1b) 7.20 56.00 40.40 15.60 33.20 46.99

1000

A (5a ) 13.00 50.11 37.70 12.41 24.70 50.24

52.59

(5b ) 13.30 55.48 40.40 15.08 27.10 55.65T (3a ) 12.70 60.78 44.60 16.18 31.90 50.72 (3b ) 12.40 59.73 43.40 16.33 31.00 52.68B (1a ) 12.70 49.81 36.80 13.01 24.10 53.98 (1b) 13.10 53.60 39.70 13.90 26.60 52.26

1100

A (5a ) 13.00 23.00 19.00 4.00 6.00 66.67

57.74

(5b ) 17.00 27.50 23.50 4.00 6.50 61.54T (3a ) 23.50 32.00 29.10 2.90 5.60 51.79 (3b ) 16.50 28.20 24.20 4.00 7.70 51.95B (1a ) 23.50 33.30 29.60 3.70 6.10 60.66 (1b) 16.00 28.00 23.80 4.20 7.80 53.85

TABEL PERHITUNGAN KEPADATAN KERING COMPACTION (DRY DENSITY)

Jumlah air (cc) 700 800 900 1000 1100

Kadar air rata-rata (%) 38.45 42.13 46.89 52.59 57.74

berat mould + tanah (gr) 7000 8000 8500 8480 8300

Berat tanah (gr) 3805 4805 5305 5285 5105

1.138 1.437 1.586 1.580 1.526

0.822 1.011 1.080 1.035 0.968

Angka pori 3.305 2.593 2.476 2.765 3.166

Porositas 0.768 0.722 0.712 0.734 0.760

Dry density 80 % 1.147 1.089 1.023 0.954 0.898

Dry density 100 % 1.289 1.230 1.162 1.090 1.032

Volume mould 3344.854

Berat mould 3195

GRAFIK COMPACTION

Wet density (gr/cm3)

Dry density (gr/cm3)

Hubungan Antara γdry Vs Kadar Air

36 38 40 42 44 46 48 50 52 54 56 58 600.75

0.80

0.85

0.90

0.95

1.00

1.05

1.10

1.15

1.20

1.25

1.30

1.35

W OPTIMUM (KADAR AIR (%)

DR

Y D

EN

SIT

Y (

gr/

cm3

)

SR 100 %

SR 80 %

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