Technical Info.

 

    Our plant produces kinds of road products with high quality. Especially, expressway safety cable barriers. It has an annual output of 5,000 tons of expressway cable barriers. Cable barriers is the main representative form of flexible barrier. It is a structure which a few of tension cable fixed on the columns. And it mainly rely on the tensile stress in the cable to resist the collision of vehicles, to absorb impact energy. Cable barriers for highway is a flexible structure, which can be repeated use and easy fix when the vehicle collision within the elastic range. The distance between the column is flexible, for the influence of uneven settlement is smaller. It is more beautiful used in scenic. In snow area, it will be more comfortable for cleaning the snow. However, the construction of cable barriers is complex and it is difficult to repair the end support posts. That is why not suitable for using in the small radius curve section. Cable barriers can be classfied according to the location,  anti-collision grade  and the way of embedment. According to the set location can be divided into two categories, roadside and median road. The level of anti-collision of roadside is divided into two classes--class A and class S. S-class is enhanced, that it is applicable to the dangerous sections. The anti-collision grade of median road is A. Embedment conditions can be divided into two categories--buried in the soil and concrete.

 

 Here are the technical of the cable barriers:

1.      Dimensions & Allowable Deviation

1.1.   End Uprights

1.1.1. End uprights are divided into types I and II, according to the number of connecting rods.

1.1.2. An end upright is made up of a column, a diagonal brace, a base (floor), and connecting rods. For their appearance and labelling, please refer to Figure 1. Their structural dimensions and allowable deviations shall comply with the requirements shown on Table 1.



Type I                                                           Type II

1 – End Upright Column 3 – End Upright Base (Floor)

2 – End Upright Diagonal Brace 4 – End Upright Connecting Rod


Figure 1: Cross-Sectional View of an End Upright

1.1.3. The welds between the various components of an end upright should be smooth and firm.

1.1.4. There shall not be any obvious twist at the column, diagonal brace and base (floor); the column shall not be extended by way of welding.

1.1.5. The column, diagonal brace and connecting rods shall be on the same surface.

1.1.6. The incision of the end surface of the column shall be vertical. The tolerance of verticality shall not exceed 1°.



Table 1: Structural Dimensions and Allowable Deviations of an End Upright (in mm)

Symbols

H

h1

h2

F1

F2

a

b

Nominal Dimensions & Allowable Deviations

Type I

1500±10

50±1

130±1

168±1.68

32±0.5

45±1

10±1

Type II

1630±10

194±1.94

Symbols

L

l1

l2

m

t1

t2

-

Nominal Dimensions & Allowable Deviations

Type I

1700±10

1420±10

120±1

200±2

5.0±0.5

6±0.5

-

Type II

1800±10

1600±10

250±2



1.2.   Middle End Uprights

1.2.1. Middle end uprights are divided into types I and II, according to the number of connecting rods.

1.2.2. A middle end upright is made up of a column, diagonal braces, a base (floor), and connecting rods. For their appearance and labelling, please refer to Figure 2. Their structural dimensions and allowable deviations shall comply with the requirements shown on Table 2.

1.2.3. The welds between the various components of a middle end upright should be smooth and firm.

1.2.4. There shall not be any obvious twist at the column, the diagonal braces and the base (floor); the column shall not be extended by way of welding.

1.2.5. The column, diagonal braces and connecting rods shall be on the same surface.

1.2.6. The incision of the end surface of the column shall be vertical. The tolerance of verticality shall not exceed 1°.


1 – Middle End Upright Column 3 – Middle End Upright Base (Floor)

2 – Middle End Upright Diagonal Brace 4 – Middle End Upright Connecting Rod


Figure 2: Cross-Sectional View of a Middle End Upright


Table 2: Structural Dimensions and Allowable Deviations of a Middle End Upright (in mm)

Symbols

n

H

h1

h2

F1

F2

F3

Nominal Dimensions & Allowable Deviations

4

1500±10

50±1

130±1

168±1.68

32±0.5

140±1.4

5

1630±10

Symbols

L

l1

l2

m

t1

t2

t3

Nominal Dimensions & Allowable Deviations

2000±10

1930±10

35±1

200±2

5.0±0.5

4.5±0.45

6.0±0.5



1.3.   Middle Uprights

1.3.1. Middle uprights are divided into types I and II, according to the screw position.

1.3.2. Steel pipes shall be used as the middle uprights. For their appearance and labelling, please refer to Figure 3. Their structural dimensions and allowable deviations shall comply with the requirements shown on Table 3.

Type I                                  Type II


Figure 3: Cross-Sectional View of a Middle Upright

1.3.3. The definite lengthHof a middle upright shall comply with the provisions of JTG/T D81 or determined by a design blueprint. The allowable deviation ofHshall be±10mm. The middle upright shall not be extended by way of welding.

1.3.4. The curvature of the middle upright shall not exceed 1.5mm per meter. The total curvature shall not exceed 0.15% of the definite length of the middle upright.

1.3.5. The incision of the end surface of the middle upright shall be vertical. The tolerance of verticality shall not exceed 1°.


Table 3: Structural Dimensions and Allowable Deviations of a Middle Upright (in mm)

Symbols

F

h1

h2

h3

t

Nominal Dimensions & Allowable Deviations

140±1.4

50±1

130±1

260±2

4.5+0.45



1.4. Brackets

1.4.1 Bracketsare divided into T-shaped and R-shaped, depending on the cross-sectionalshape.

1.4.2 For the appearance and labelling of a T-shaped bracket, please refer to Figure 4.Its structural dimensions and allowable deviations shall comply with the requirements under Table 4.


(in mm)

Type T-I                                                       Type T-II


Figure 4: Cross-Sectional View of a T-Shaped Bracket

Table 4: Structural Dimensions and Allowable Deviations of a T-Shaped Bracket (in mm)

Symbols

H

L

D

e

d

l

m

n

t

Nominal Dimensions & Allowable Deviations

210±2

200±2

147±5

70±2

50±1

130±1

40±1

29±1

3±0.16



1.4.3  For the appearance and labelling of an R-shaped bracket, please refer to Figure 5. Its structural dimensions and allowable deviations shall comply with the requirements under Table 5.

Type R-I Type R-II

Figure 5: Cross-Sectional View of an R-Shaped Bracket

Table 5: Structural Dimensions and Allowable Deviations of an R-Shaped Bracket (in mm)

Symbols

H

L

D

l

m

n

t

Nominal Dimensions & Allowable Deviations

210±2

192±2

148±5

130±1

40±1

29±1

3.2±0.17


1.4.4 There shall not be any obvious twist at the brackets.

1.4.5 The incision of the end surface of a bracket shall be flat and burr-less.

1.5. Connecting Rods

1.5.1  For the appearance and labelling of a connecting rod, please refer to Figure 6. Its structural dimensions and allowable deviations shall comply with the requirements under Table 6.


Figure 6: Cross-Sectional View of a Connecting Rod


1.5.2 The definite lengthBof a connecting rod shall be determined by a design blueprint. After installation, the length of the external exposed parts of a connecting rod shall meet the relevant maintenance and construction requirements.

1.5.3  After coating, the parts with screws shall continue to work properly despite the coating.


Table 6: Structural Dimensions and Allowable Deviations of a Connecting Rod (in mm)

Symbols

B

F1

F2

l

Nominal Dimensions & Allowable Deviations

920±5

32±1

24±0.5

15±0.5

850±5




720±5

600±5

500±5


1.6 Cable End Chucks

1.6.1 For the appearance and labelling of a cable end chuck, please refer to Figure 7. Its structural dimensions and allowable deviations shall comply with the requirements under Table 7.



Figure 7: Cross-Sectional View of a Cable End Chuck

1.6.2 After coating, the parts with screws shall continue to work properly despite the coating.


Table 7: Structural Dimensions and Allowable Deviations of a Cable End Chuck (in mm)

Symbols

F1

F2

d1

d2

a

Nominal Dimensions & Allowable Deviations

48±1

40±1

19.5±0.5

22.5±0.5

11±0.5

Symbols

L

l1

l2

l3

e

Nominal Dimensions & Allowable Deviations

110±2

30±1

6±0.5

25±0.5

2±0.2


1.7. Chuck Nuts

1.7.1 For the appearance and labelling of a chuck nut, please refer to Figure 8. Its structural dimensions and allowable deviations shall comply with the requirements under Table 8.


Figure 8: Cross-Sectional View of a Chuck Nut

1.7.2 After coating, the parts with screws shall continue to work properly despite the coating.


Table 8: Structural Dimensions and Allowable Deviations of a Chuck Nut (in mm)

Symbols

F1

d1

d2

L

l1

l2

Nominal Dimensions & Allowable Deviations

48±1

25±1

38±0.5

60±1

18±0.5

44±1


1.8 Wedges

1.8.1 For the appearance and labelling of a wedge, please refer to Figure 9. Its structural dimensions and allowable deviations shall comply with the requirements under Table 9.


Figure 9: Cross-Sectional View of a Wedge


1.8.2 The conical angle of the end of the wedge shall be 9°±1°.

Table 9: Structural Dimensions and Allowable Deviations of a Wedge (in mm)

Symbols

F1

F2

F3

F4

F5

Nominal Dimensions & Allowable Deviations

15±0.5

11±0.5

3±0.1

15.8±0.2

12±0.5

Symbols

L

l1

l2

a

e

Nominal Dimensions & Allowable Deviations

65±1

18±0.5

24±0.5

3±0.1

3±0.1

1.9 Clips

1.9.1 For the appearance and labelling of a clip, please refer to Figure 10. Its structural dimensions and allowable deviations shall comply with the requirements under Table 10.

(in mm)



Figure 10: Cross-Sectional View of a Clip

1.9.2  There shall not be any obvious twist at the outside of the clips.

1.9.3   After coating, the parts with screws shall continue to work properly despite the coating.

Table 10: Structural Dimensions and Allowable Deviations of a Clip (in mm)

Symbols

B

l1

l2

F

Nominal Dimensions & Allowable Deviations

30±1

20±0.5

30±0.5

10±0.2

1.10 Steel wire rope

1.10.1  3x7 steel wire ropes are used for cable fence systems. A  3x7 steel wire rope has three strands. Each strand is made up 7 identical wire ropes wound around a center(i.e. 6 of them are outer wires, and the other one is in the center). Three strands are helically around a hollow core. The lay lengths of these wire are equal, as shown in Figure 11.

1.10.2  There are 4 ways of laying the ropes, namely"Right Lay(Regular Lay)","Left Lay(Regular Lay)", Right Lay(Lang Lay)" and "Left Lay(Lang Lay)".

1.10.3  For the appearance and labelling of a steel wire rope, please refer to Figure 11. Its structural dimensions and allowable deviations shall comply with the requirements under Table 11.



Figure 11: Cross-Sectional View of a Steel Wire Rope

1.10.4  For the appearance and labelling of a steel wire rope, please refer to Figure11. Its structural dimensions and allowable deviations shall comply with the requirements under Table 10.

Table 11: Structural Dimensions and Allowable Deviations of a Steel Wire Rope (in mm)

Symbols

D

d

Nominal Dimensions & Allowable Deviations

18+0.9-0

2.86±0.08

1.10.5  The other structural dimensions of a steel wire rope shall comply with the requirements of the standard"GB/T2583"

2.  Technical Requirements

2.1 Material Requirements

2.1.1  The base metal material used for the end uprights, middle end uprights, middle uprights, brackets, wedges and clips shall be ordinary carbon structural steel. The standard of their mechanical properties and chemcial compositions shall not be inferior to the requirements for Q235 steel set forth by the standard:GB/T700"

2.1.2  The base metal material used for the connecting rods, cable end chucks, chuck nuts and the fasteners connecting with them shall be premium-quality carbon structural steel. The standard of their mechanical properties and chemical compositions shall not be inferior to the requirements for steel type no.45 set forth by the standard "GB/T699"

2.1.3  The base metal material used for the bolts, nuts, washers and sheet gaskets connectiing with brackets and uprights shall be ordinary carbon structural steel. The standard of their mechanical properties shall not be inferior to the requirements for Q235 steel set forth by the standard "GB/T700".

2.1.4  The steel wire ropes shall be made up of wire rods that are in compliance with "GB/T 25833" or other requirements.

2.1.5   The breaking load of the φ18 3x7 steel wire ropes shall not be less than 170KN, and the tensile strength of the steel wire shall not be less than 1570MPa.

2.1.6   The ductility of steel of the steel wire rope shall comply with the requirements of "GB/T 25833".

 

2.2  Processing Requirements

2.2.1  The welds of the column, diagonal brace,floor and connecting rods of an end uprights shall not overlap. A column cap shall be installed at the top of the column.

2.2.2  The welds of the column, diagonal braces and connecting rods of a middle end upright shall not overlap. A column caps shall be installed at the top of the column.

2.2.3  Steel pipes may be welded vertically to form the middle uprights. The welds shall not overlap with the connecting holes of the uprights. A column cap shall be installed at the top of each upright.

2.2.4   The brackets shall be formed by way of cold-bending and press-forming. Welding and splicing are prohibited.

2.2.5   The laying of the steel wire ropes shall be in conformity with the requirements of "GB/T 25833".

2.2.6   The anchorage of the steel wire ropes may use other types of cable-end anchoring devices. When a steel wire rope is fastened by anchors, the overall breaking load shall not be lower than the least breaking load of the connecting steel wire ropes.

 

2.3  Appearance Quality&Corrosion Treatment

2.3.1   All parts and components of a fence shall receive proper corrosion treatment. All parts and components with screws shall be hot-dip galvanized with zinc.

2.3.2    The quality of the zinc-coating of the steel wires in the steel wire ropes shall comply with GB/T 25833. For other parts and components, when hot-dip galvanizing zinc, the thickness and weight of the zinc-coating shall comply with the requirements shown on Table 12. Its adhesion properties and corrosion resistance properties (based on a “salt spray test”) shall meet the requirements set forth by the standard “GB/T 18226”.

Table 12: Zinc-Coating Thickness Requirements

Names of Components

Average Zinc-Coating Thickness (μm)

Average Zinc-Coating Weight (g/m3)

End Uprights, Middle End Uprights, Middle Uprights

85

600

Brackets, Cable-End Anchors and Other  Connectors

50

350

Steel Wire inside
the Steel Wire Rope

---

230

 

2.3.3   If paint-coating is used as a corrosion treatment, all the parts and components of the fence shall first be coated with a metallic layer as a corrosion treatment. When hot-dip galvanizing aluminum or paint-coating, etc., the corrosion protection layer shall meet the requirements set forth by the standard “GB/T 18226”.


Tag: road products|cable barreiers for highway|expressway safety cable barriers