●Cover：Tokunoshima Kametoku Port（Kagoshima Prefecture）2009.05

Dolos R

+81-3 -5644-85847-2,NIHONBASHI-KOAMICHO,CHUO-KU,TOKYO,103-0016,JAPAN

ht tp: / /www.fudotet ra.co .jp

Head office

+81-29-831-7411Technical Research Institute 2-7,HIGASHI NAKANUKI,TSUCHIURA IBARAKI, 300-0006,JAPAN

Dolosse will continue to play an important role to protect port and harbor areas from

very severe wave conditions, the kind that other wave-dissipating concrete blocks cannot withstand.

●Naha Port（Okinawa prefecture）

Dolosse in Japan is fully reinforced to prevent breakage caused by high interlocking forces, as experienced in Sines Port in Portugal in 1978 and other Dolos applications around the world .The weight amount of reinforcing bar used in Dolosse in Japan is about 100 kg/㎥, while thatin Sines and Humbold Bay were 40 kg/㎥ and 45 kg/㎥(Magoon et al. 1971).

Dolosse of 40 and 50 ton have been utilized in Japan since 1980s.In Naha Port in Okinawa, more than 10,000 units of 40 and 50ton Dolosse, reinforced with steel bars in the amount above, have already been used.

Dolosse of 40 and 50ton have been found use in many ports other than Naha under high wave conditions. The success in actual site applications in Japan especially in Naha Port with us more than 30 year experience is considered strong evidence that the reinforcement for Dolos in Japan is satisfactory.

Shape and Dimensions●Shape and Dimensions of Dolos

●Dimensions of Dolos

※1 Actual Mass and Actual Weight include Reinforcing Steel Weight※2 Actual Weight＝9.80665×Actual Mass

Actual Mass※1 ※2

Type (t) Actual Weight Volume Form area（t） （KN） （ｍ3） （ｍ2） ｈ ａ ｅｄｃｂ

units in mm

41.1240 403.25 17.391 50.041 4823 1543 7814011441830986

51.4250 504.26 21.739 58.067 5196 1663 84151015528941062

82.3280 807.28 34.787 79.443 6077 1945 991765

ｆ Ｉ

270

291

340181610451242

Advantages of Dolos

Dolos wave-dissipating works maintain large surface roughness and suitable porosity. They allow the reduction of wave pressure on the breakwater, wave runup, and wave reflection.

H i g h W a v e - D i s s i p a t i n g P e r f o r m a n c e

Thanks to the reduction in block size, we can freely select machinery, ships and the area of fabrication yard. No particular skill for block placement is needed because we can naturally obtain the entanglement of blocks caused by the shape of the block.

E a s e o f F a b r i c a t i o n a n d P l a c e m e n t

High stability of Dolos enable required mass against waves to be reduced up to a half of other conventional blocks. Therefore, the machinery for transport and installation can be reduced in size. Moreover, the high porosity of Dolos wave-dissipating works makes the total number of blocks fewer. Due to the characteristic above, Dolos wave-dissipating works indicate superior economy.

S u p e r i o r E c o n o m y

Combining two anchors forms shape of a single Dolos. Dolos wave-dissipating work realizes high stability due to the interlocking of blocks caused by such an anchor-like shape.

H i g h S t a b i l i t y

Reinforcing Bar Arrangement●40ton　

■Main Reinforcement

■Shear Reinforcement

■Reinforcement for Haunch

■Supplement Reinforcement

■Table of Reinforcing Bar

●50ton　

■Main Reinforcement ■Reinforcement for Haunch

■Shear Reinforcement

■Supplement Reinforcement

■Table of Reinforcing Bar

D32

D29

D32

D32

D22

D19

D19

D19

D19

D19

D19

D19

4500

4600

3740

3600

4760

4460

4380

4130

3880

3630

3380

3130

16

32

8

8

6.23

5.04

6.23

6.23

3.04

2.25

2.25

2.25

2.25

2.25

2.25

2.25

28.035

23.184

23.300

22.428

14.470

10.035

9.855

9.293

8.730

8.168

7.605

7.043

448.560

741.888

186.400

179.424

159.170

80.280

39.420

37.172

34.920

32.672

30.420

28.172

1556.272 ｋｇ

22.014 ｋｇ

（ＳＤ295）

814.384 ｋｇ

741.888 ｋｇ

159.170 ｋｇ

283.056 ｋｇ

22.014 ｋｇ

2020.512 ｋｇ

442.226 ｋｇ

11

8

4

4

4

4

4

4

D29

D32

D22

D19

D16

1

2

3

4

5

D16 1000 1.56 1.560 6.240413

D16 1050 1.56 1.638 4.914314

D16 1160 1.56 1.810 10.860615

6

7

8

9

10

11

12

φ length(mm)no. Shapethe

numberUnit weight(kg/m)

a piece of weight

(kg)Weight( kg )

D29

D25

D29

D29

D22

D19

D19

D19

D19

D19

D19

D19

4140

4360

3420

3310

4420

4130

4090

3840

3580

3330

3070

2820

16

32

8

8

5.04

3.98

5.04

5.04

3.04

2.25

2.25

2.25

2.25

2.25

2.25

2.25

20.866

17.353

17.237

16.682

13.437

9.293

9.203

8.640

8.055

7.493

6.908

6.345

333.856

555.296

137.896

133.456

147.807

74.344

36.812

34.560

32.220

29.972

27.632

25.380

1160.504 ｋｇ

20.656 ｋｇ

605.208 ｋｇ

555.296 ｋｇ

147.807 ｋｇ

260.920 ｋｇ

20.656 ｋｇ

1589.887 ｋｇ

408.727 ｋｇ

11

8

4

4

4

4

4

4

D25

D29

D22

D19

D16

1

2

3

4

5

D16 910 1.56 1.420 5.680413

D16 1000 1.56 1.560 4.680314

D16 1100 1.56 1.716 10.296615

6

7

8

9

10

11

12

SubTotal

（ＳＤ295）

Total

no. φ length(mm)

thenumber

Unit weight(kg/m)

a piece of weight

(kg)Weight( kg ) Shape

SubTotal

Total

■Reinforcement for Haunch

φ thenumber

Basic Design

Calculation of Required Mass

In general, the required mass is calculated by using the following Hudson formula:

●KD Value of Dolos

Random placement Damage ratio 0 to 1 % 20

BreakwaterTrunk

ＫＤCondition Position

Hudson Formula

Recently, the “Hudson Formula with the Stability Number (Ns)” has become popular in ports and harbors design.

(“Technical Standards and Commentaries for Port and Harbour Facilities in Japan”, http://www.ocdi.or.jp/en/technical-st-en.html）

Hudson Formula with the Stability Number (Ns)

Inclination of Slope

1：1.3 1.43

3.881：4/3 1.46

1：1.5 1.58

● Coefficients that are determined

by the inclination of the Dolosse

Equation(1) is an expression obtained by replacing Ns by KD･cotα in Equation(2).

The following equation for wave-dissipating concrete blocks that are randomly placed in all the front face of an upright wall

have been proposed. In this formulation, various wave and structural conditions can be taken into account.

The value of H1/20/H1/3 in Eq.4 can be obtained by the diagram prepared in the Technical Standards.

(Technical Standards for Port and Harbor Facilities and their Explanations).

Where M : Mass of Dolos (t)

ρr : Density of Dolos (2.36 t/㎥) Sr : Specific gravity of Dolos to the seawater (ρr / ρw) ρw : Density of sea water (ρw = 1.03 t/㎥) H : Design wave height (m)

KD : Stability constant determined by the shape of the armor units

and the damage ratio (KD = 20)

α : Angle of the slope from the horizontal line

Eg.(1)

Where M : Mass of Dolos (t)

ρr : Density of Dolos (2.36 t/㎥) Sr : Specific gravity of Dolos to the seawater (ρr / ρw) ρw : Density of sea water (ρw = 1.03 t/㎥) H : Design wave height (m)

Ns : Stability number determined by the shape of

　　　　　　　the armor unit, slope angle and degree of damage

Where CH : Coefficient of wave breaking

(CH = 1.0 in the case of non-breaking wave)

NO : Degree of damage that is presented by the number of

damaged blocks on width of representative diameter of the

block (in the direction of the breakwater alignment)

N : Number of wave attack

a, b : Coefficients that depend on the shape of the concrete

block and the slope angle. (please refer to the following table)

●80ton

■Main Reinforcement

■Shear Reinforcement

■Table for Reinforcing Bars

Eg.(2)

Eg.(3)

Eg.(4)

3no.

D41

D35

D41

D25

D22

D22

D22

D22

D22

D22

D22

5300

5430

3310

5690

5280

5020

4760

4500

4240

3980

3720

16

32

8

10.5

7.51

10.5

3.98

3.04

3.04

3.04

3.04

3.04

3.04

3.04

55.650

40.779

34.755

22.646

16.051

15.261

14.470

13.680

12.890

12.099

11.309

890.400

1304.928

278.040

294.398

64.204

61.044

57.880

54.720

51.560

48.396

45.236

1168.440 ｋｇ

1304.928 ｋｇ

294.398 ｋｇ

512.664 ｋｇ

3280.430 ｋｇ

2473.368 ｋｇ

（ＳＤ345）

807.062 ｋｇ

13

D22 5330 3.04 16.203 129.6248

4

4

4

4

4

4

4

D35

D41

D25

D22

123

54

6789101112

SubTotal

Total

φ Length(mm)

Unit weight(kg/m) ShapeTotal weight

( kg )Weight(kg)

Number

Confidence and Achievements

Tokunoshima Kametoku Port

●Owner

●Year Built

●Tonnage

●Design Wave

： Kagoshima Prefecture.

： 1977・1978

： 50 ton

： Hｏ=11.80m,Tｏ=16.80s

Plan view Cross section

Typical Sectional Dimensions

The required number is calculated by using the following equation:

Typical inclination is 1 : (1.3～1.5)

Calculation of Required Number

Upright Wall

Sloping Type Breakwater

●Dimensions (Typical slope angles)

●The dimensions above are default values. Please contact us for other desighs.

Ｂ’

3 rows width

1：1.3Ｂ

Type (t)

units in m

8.640

9.350

10.9

13.0

14.0

16.4

7.1

7.7

9.0

1：4/3

7.3

7.8

9.1

1：1.5

7.8

8.4

9.8

Ｂ’

4 rows width

1：1.3Ｂ

17.3

18.7

21.8

11.4

12.4

14.4

1：4/3

11.6

12.5

14.5

1：1.5

12.1

13.1

15.280

●Dimensions (Typical slope angles)

Thickness

of two layerＢ’

2 rows width

1：1.3Ｂ

Type (t)

units in m

8.640

9.350

10.9

8.6

9.3

10.9

5.7

6.1

7.2

1：4/3

5.7

6.2

7.3

1：1.5

6.0

6.5

7.6

Ｂ’

2 rows width

1：1.3Ｂ

13.0

14.0

16.4

10.1

10.8

12.7

1：4/3

10.1

10.9

12.8

1：1.5

10.4

11.2

13.180

Ｂ

Ｂ’1：（1.3～1.5） 1：（1.3～1.5）

Ｂ

1：（1.3～1.5） 1：（1.3～1.5）

●Two layer placementＢ

Ｂ’1：（1.3～1.5）

●Entire cross-section placementＢ

1：（1.3～1.5）

Thickness

of two layer

●Entire cross-section placement●Two layer placement

Thickness

of two layer

Where N : Required Number of Dolosse V : Volume to be filled with Dolosse (㎥) v : Volume of a Dolos (㎥) P : Porosity (57.5%)

Thickness

of two layer

MAP

： Okinawa General Bureau

： 1981～

： 50 ton

： Ho=11.50m,To=15.10s

： H1/3=10.70m,T1/3=15.10s

Naha Port　New port breakwater(No.1)

： Okinawa General Bureau

： 1980

： 40 ton、50 ton

： Ho=11.50m,To=15.10s

： H1/3=9.70m,T1/3=15.10s

Naha Port　New port breakwater(No.1)

Naha Port　Urazoe breakwater(No.1)

●Owner

●Year Built

●ton type

●design wave

●Owner

●Year Built

●ton type

●design wave

Plan view Plan viewCross section Cross section

Locality

map

Locality

map

Fabrication Process

Assembly needs support frames.

Reinforcing bar assembly

Concrete pouring

Mold assembly

Mold removal

Completion