JPH06173180A - Stay cable and improvement of its constitution - Google Patents

Abstract

PURPOSE:To reduce the influence of winds on stay cables by allowing them to have a profile of round cross-section and a smaller diameter. CONSTITUTION:This invention relates to a stay cable (hauban) 1 whose intermediate part (portion courante) is constituted with bundles of strands 4 (torons) whose side faces are coated. The intermediate part is placed in parallel with the strand bundles so that any gap may not be formed and the surface of the cable is covered with the round profile case formed with two flexible conduits (gouttieres) 5 to be combined to each other in the lengthwise direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable or stay cable which is subjected to a large traction force and is composed of a plurality of strands which are individually constituted by a steel wire or an assembly of steel wires which are juxtaposed or laid together, Particularly, the present invention relates to a stay cable used for connecting a bridge tower and a bridge floor among stay cables.

[0002]

2. Description of the Prior Art Stay cables of the known type generally collect the many strands that make up the stay cable in a common protective cover and fill each other with grease, or the space in the cover, by another binder. It is connected.

A large number of strands are rustproofed and protected by this binder.

However, this method has some drawbacks such as an increase in weight and hardness, a risk of cracking in the hardened bonding material, and the cable stay as an integral casting. For example, for stay cables,
When any of these strands (torons) is damaged as a result of the impact or load of a vehicle passing over the bridge deck, there is a problem that the damaged strands (torons) cannot be individually replaced.

To remedy these drawbacks, each strand of the stay cable is individually coated and protected, or the strand itself is coated in the middle part. There are also proposals for arranging (torons) side by side or tightening the strand bundles with an appropriate band.

However, the intermediate portion of the stay cable thus provided has an irregular surface and is recessed by a narrow groove in the longitudinal direction, or generally has an angular shape like a prism.

[0007] Such a shape has a disadvantage that it is relatively greatly affected by wind, and the effect becomes more serious if the contour of the cross section of the stay cable is far from circular.

The above problems are particularly serious for stay cables of extremely large bridges where the distance between steel towers exceeds 500 m. This is because the effect of wind on the stay cables in such a case is one of the important factors to be considered in designing these stay cables.

To alleviate this drawback, individual or bundled strands (to
rons) was considered.

Such a system has a thickness (typically 5 m) arranged at a predetermined place by using complicated scaffolding means.
m) A method of using a metal tube case has been considered in the past, but it is not only expensive, but also a strand (torons) is attached to the cylinder.
Since there is a gap in the cylinder due to the passage of the gas, there is a drawback that the increase in the diameter caused by this causes an increase in the pressure of the wind that is desired to be reduced.

[0011]

SUMMARY OF THE INVENTION The present invention aims at eliminating the above-mentioned drawbacks, in particular by the effect of wind, by means of stay cables having a circular cross-section profile and a small diameter.

[0012]

In order to achieve the above object, the stay cable of the present invention is provided with an intermediate portion (portio).
n courante) is made up of a bundle of strands (torons) with protective coatings on the sides and juxtaposed, and is lined up on the bundle of pre-tensioned strands (torons) substantially without gaps. And a large number of torons covered by a circular contoured case made up of at least two flexible gout tieres which are interdigitated at their longitudinal edges.

In the present invention, in addition to or in addition to the above, any one of the means described later may be selectively adopted.

For example, a gutter-shaped member (gout
tieres) shall have two approximately semi-cylindrical shapes.

Along the two vertical edges of each goutier, one edge bulges in the axial direction, is provided with a hooking claw on the inner side surface, and is open to the outside in the radial direction. 7 and a gutter-shaped member (gouttier) having a side surface provided with a hook and a claw on the other edge and connected to each other.
Providing a projection 6 having the characteristic of cooperating with the above-mentioned groove of es).

A filler is inserted into the gap between the inner surface of the case and the outer surface of the bundle of strands (torons) covered with the case.

The gutter-shaped member is made of an extruded plastic material having a thickness of about 3 to 6 mm.

The gutter-shaped member is made of steel strip having a thickness of about 1 to 2 mm.

The cases are joined at the ends in the vertical direction and are juxtaposed at the ends, and are combined with each other to form a case that is continuous in the vertical direction.

Providing ventilation holes in the case.

[0021] The case should be a bright color, especially white that can suppress the temperature rise under sunlight.

In addition to the main structure as described above, the present invention can also include, at the same time, another structure particularly preferably adopted as will be apparent below.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings, although the present invention is not limited thereto.

FIG. 1 schematically shows a part of a bridge having a cable stay, and the cable stay is laid as shown in an enlarged partial view A.

FIG. 2 is an enlarged cross-sectional view taken along the line II-II of FIG.

Reference numeral 1 in the figure denotes a cable stay for suspending the bridge deck 2 by at least one tower 3.

These stay cables 1 spread along diagonal line segments and are divided into the left and right sides of the tower 3 of the bridge, and this spread is one vertical plane (n) at the center of the width of the bridge floor.
contained in two vertical planes (parallel) when the stay cable is connected to the width edge of the bridge deck 2, and also in at least one curved vertical plane. included.

Each of the stay cables 1 described above is composed of a plurality of independent strands (torons) 4 which have the same performance and are tensioned independently of each other. ) Can be replaced individually.

[0029] While each strand (Torons) may be comprised of a thick steel wire, core wire 4 ₁ and a plurality of helical windings around those (generally six) configuration wrapped with helically Is preferred. These steel wire 4 _1, 4 _2, the surface is effectively protected by plating. Also often it covers the entire twisted together by a waterproof protective case 4 _3,
Within this coating may generally be present a suitable protecting agent 4 ₄ such as a plastic material such as epoxy type resin.

The intermediate parts, which consist of the torons protected as described above, are also installed at an angle, clamped together by suitable bands and the construction (2,
3) Connected to a cylindrical fuser escaping from this construct such that the ends were independently tethered on top. The terminals are provided for laterally widening each other and connecting and fixing them as described above.

In the case of a large bridge, the number of strands (torons) 4 constituting one stay cable 1 is several tens,
The diameter of the bundle in the middle part made up of such strands (torons) is relatively large, for example about 10 diameters.
It becomes 0 to 300 mm.

In the conventional method, the bundle of cables is not particularly covered, the outer shape of the bundle is irregular, and there are cavities and irregularities for receiving a strong wind. In order to reduce this wind pressure, the present invention eliminates the gap above the bundle and covers the bundle with a case with a fitted, round outer diameter. The case is constituted by at least two flexible semi-circular members assembled together around the bundle along its longitudinal circle.

As a result, the wind pressure on each stay cable can be reduced to the minimum.

The circular cross-sectional shape given to this stay cable is a shape capable of exhibiting the minimum resistance to the wind from various directions.

The diameter of the cross section is relatively small because the thickness of the case is relatively thin and there is no gap between the case and the bundle of strands (torons) coated on the case. .

The two gout tiers 5 have a substantially semi-cylindrical shape.

In the embodiment shown in FIG. 2, these two gout tiers 5 have a thickness 3 above them.
Manufactured from a plastic material such as polyamide or polyolefin (eg PEHD or high density polyethylene) of ~ 6 mm.

One of the vertical edges of the gutter-shaped member (gouttieres) 5 projects toward the inside of the gutter-shaped member (gouttieres) by the projection 6. The other edge is provided with a groove 7 that is open to the outside in the radial direction. The groove also projects into the interior of the gout tieres, each groove adapted to receive an adjacent protrusion for the purpose of joining the two gout tieres together.

Further, the outer surface of the projection 6 and the inner surface of the groove 7 are auxiliaries engaged with each other when the projection is received in the groove so as to ensure an irreversible combination relation called "fir's leg". There is a notch.

FIG. 2 shows, in its upper part, a position before the protrusion 6 is fitted in the groove 7 facing outward, and in the lower part of the same figure, the protrusion is fitted in the groove 7. It shows the combined (unmovable) state.

The case in which the two gout tiers are assembled is a complete rotating cylinder, with each groove 7 entering a gap 8 in the bundle of strands 4.

In order to secure this shape, other fillers or woods are put also in other gaps around the bundle of strands (torons) 4,
Alternatively, it is possible to fill these gaps by inserting a filler into the recess corresponding to at least the exact circle desired.

These can be conveniently constructed by:

For example, ribs or uneven portions 9, 10 and 11 which are raised on the inner surface of a gutter-shaped member (gouttieres), and these uneven portions are formed by extrusion molding.
eres) and is formed as a single block.

Alternatively, a hollow or solid oblong shaped profile 12 independent of the gout tieres is also shown.

The dimensions and external cross section of the gutter-shaped members (gouttieres), the packing material, and the bundle of strands (torons) 4 were prepared so that there was no gap in the case formed during assembly and the external shape was circular. It

The vertical edges of the gutter-shaped members (gouttieres) are
In particular, they are assembled so as to be joined by mechanical engagement, but they may be attached by another method such as bonding or welding with a heating device.

The case of circular cross section made on the middle of the stay cable is only sufficient to provide a guide for the rotation of the sheaves that carries and supports the gondola used to install the case. Has strength.

The case forming the individual cylinders is of commercial length, typically 6-12 m. In this case,
Sequentially installed around the middle of the stay cable to be coated, it is lined up end to end before being assembled, especially by welding, gluing or clamping.

FIG. 1 is a partial view A showing a cylinder of a stay cable covered with a case 5. That is, in this figure, 13 is a vertical line corresponding to the combination of the vertical edges of the two gout tieres that make up the cylinder of the case 5, and 14 is the end and end of these continuous cylinders. The assembly line which put together is shown.

In a second embodiment, not shown, the gout tieres consist of a relatively thin strip of steel. Its thickness is in particular 1 to 1.5 mm.

In this case, two semi-cylindrical gutter-shaped members (gout
tieres) are continuously stretched from a strip of steel to one of the two ends in the middle of the already tensioned stay cable.

It is then installed around this end and mechanically clamped along its edges so as to be joined together to form a tube. The tube is stretched along the tensioned middle section in a rim-to-edge fit.

Therefore, the rollers on the workbench described above are
It can be used by moving over the stay cable to be coated.

In this case, although the radial gap between the replacement cable and the stay cable is extremely small, the slippage between them, which occurs during mounting, is possible because both are strained and linear.

A lubricant coating may be used between the members to facilitate mutual slippage.

The outer diameter of the cable stay thus stretched is obviously smaller than the outer diameter of the pipe of the method of inserting the strand described in the conventional example, and the reduction of its shape is 20.
You can see that it reaches%.

The formed circular case is not limited to the material and can be colored, and a bright color, particularly white is preferable. This is because the temperature rise can be limited under sunlight. This is an excellent feature when constructing bridge stay cables that receive sunlight.

The case of the present invention is not waterproof against rainwater. The reason is that this case covers a bundle of torons which are individually protected against the weather.

Therefore, in this case, ventilation holes can be provided especially in the upper and lower portions. This ventilation removes moisture, and during the hot season, the temperature rise of the stay cable can be suppressed due to the circulation of air in the passage between the case and the torons.

[0061]

The stay cable of the present invention has several advantages as compared with the conventional stay cables as follows.

That is, since the contour of the cross section is strictly circular, the wind pressure against it is extremely weak, and the shape of the circle that determines this cross section is relatively small.

When the color of the case is bright, especially white, the temperature rise due to sunlight can be suppressed.

When the case is provided with ventilation holes, good protection against moisture and temperature rise can be obtained.

It is effective for supplementary protection of the strands (torons) constituting the stay cable against bad weather and UV irradiation.

Needless to say, the present invention is not limited to the embodiments of the invention described above as a better mode, for example, if the gout tiers are not 2 but 3
Or 4 and may include modifications such as the case where each gouttieres makes an arc of 120 ° or 90 ° around the stay cable, respectively.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration outline of a cable-stayed bridge having a stay cable of the present invention, and A in the figure shows an enlarged partial view of the stay cable.

FIG. 2 is a view showing a cross section of a stay cable.

[Explanation of symbols]

1: stay cable, 2: 3, steel tower, 4: strand, 5: trough member, 6: protrusion, 7: groove, 8: gap, 9,
10, 11: rib, 12: oval steel bar.

Claims (12)

[Claims] 1. A bundle of strands (torons) 4 having a protective coating on the periphery and juxtaposed with each other.
te) is formed, the middle portion (portion courante) of which is arranged substantially without gaps on the bundle of the previously tightened and strained torons 4 and in the longitudinal direction. A stay cable, characterized in that it is covered by a circular contoured case made up of at least two flexible gout tieres 5 which are interdigitated at the edges of the. 2. The stay cable according to claim 1, wherein the gout-shaped members (gout tieres) 5 forming the case are two substantially semi-cylindrical. 3. The gout-shaped member (gouttieres) 5 according to claim 1, wherein the gout-shaped member (5) swells in the axial direction along the two vertical edges of the gout-shaped member (5) and has a notch on the inner side surface. The groove 7 open outwards in the direction and the groove mentioned above with the interconnected gout tieres having knurled sides and cooperating for the purpose of joining using this groove. A stay cable, comprising: a protrusion 6 having characteristics. 4. A bundle of strands (torons) 4 surrounded by a case 5 according to any one of claims 1 to 3,
A stay cable in which a filler is inserted in a gap between the inner surface of the case and the case. 5. The filling material according to claim 4, wherein the ridges (9, 10, 11) are formed on the inner surface of the gout-shaped member (gouttieres) 5.
Stay cable characterized by including. 6. The stay cable according to claim 4, wherein the filler includes a thin rod or an elongated rod that is independent of the gout tiers 5. 7. The stay cable according to claim 1, wherein the gout-shaped member (gout tieres) 5 is formed of an extruded plastic material having a thickness of 3 to 6 mm. 8. A stay cable according to claim 1, wherein the gutter-shaped member (gouttieres) 5 is made of a strip steel having a thickness of 1 to 2 mm. 9. The stay cable according to claim 1, wherein the case is formed by a series of vertically arranged cylinders, which are formed by combining the ends with each other. 10. The method according to claim 1, wherein
The stay cable is characterized in that the case has ventilation holes. 11. The stay cable according to claim 1, wherein the case has a bright color, and in particular, has a white color that suppresses an increase in temperature due to sunlight. 12. The strand of torons according to any one of claims 1 to 11, which is fitted together with at least another same trough-shaped member into the bundle of strands (torons) 4 without a gap. A stay cable characterized in that a circular contour case is formed for this purpose, and the gutter-shaped member is also provided on the bundled line and is long in the longitudinal direction.