JPS6059350B2 - Corrosion-proof coating method for cables - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for anti-corrosion coating of cables used in suspension bridges, suspended roofs, cable-stayed bridges, etc.

The above-mentioned cable is usually protected by covering its outer peripheral surface with a cylindrical anti-corrosion coating.

If the above covering is attached to the cable in advance,
This cannot be wound onto a reel, making storage etc. extremely inconvenient. For this reason, conventionally, scaffolds were assembled in advance at predetermined intervals along the cable to be erected, a cylindrical covering was installed on the scaffolding, and the cable was then inserted into the covering. Provide anti-corrosion coating or scaffolding along the entire length of the pre-erected cable;
A worker climbs onto this scaffold to attach the sheath to the cable. In this way, in the past, it was necessary to install scaffolding to attach the sheathing, and especially when installing long cables, large-scale scaffolding was required, increasing the construction cost and lengthening the construction period. There were flaws.

This invention was made to eliminate the above-mentioned drawbacks, and there is no need to provide a scaffold to attach the sheathing to the cable, making it possible to keep the construction cost low and shorten the construction period. The present invention provides a method for coating cables with anti-corrosion coating. That is, the present invention forms a cylindrical covering around the outer periphery of the cable over a predetermined length at one end of the installed cable, and extends the covering by approximately that length to the other end of the cable. After the cable is moved, a new sheath is formed on the outer circumference of the cable so as to be continuous with the above-mentioned sheath, and the cable is moved, and by repeating this process one after another, each sheath is made to cover approximately the entire length of the cable. This is what I did.

Hereinafter, the present invention will be explained with reference to drawings of embodiments.

FIG. 1 shows a part of a cable-stayed bridge 1, in which cables 2 made of a large number of steel wires are installed between the upper end of a tower 10 and a bridge girder 11.

A cylindrical covering 3 of a predetermined length is attached to the outer periphery of the lower end of the cable 2 on the bridge girder 11. This sheath 3 is formed by a pair of divided pieces 30, 30 made of plastic such as polyethylene, copper, aluminum, stainless steel, etc. (see Fig. 2), and these divided pieces 30, 30 are attached to the cable 2. After fitting, the joint portions of the two divided pieces are fixed to the cable 2 by means of bolts, rivets, press-fitting, welding, or the like. Then tower 10
Robe 1 stretched over a pulley 12 provided at the upper end
3, the sheathing 3 is moved upward along the cable 2 by that length, and a new sheathing 3 is attached below. Thereafter, the tip of the lower sheath 3 is inserted into the rear end of the upper sheath 3, and the joint between the two sheaths 3 is fixed with bolts or the like. Note that the connecting portions of both the coverings 3, 3 may be fixed by butt welding. Then, both the coverings 3, 3 are moved upward by the lobes 13, and a new covering 3 is attached below. Thereafter, by sequentially repeating this operation, the entire length of the cable 2 is covered with each sheath 3. Note that the covering 3 is attached to the lobe 1.
3, the cable 2 may be pushed up by a predetermined length at a time. Alternatively, a covering 3 may be attached to the outer periphery of the upper end of the cable 2 at the top of the tower 10, and this covering 3 may be sequentially moved downward. After that, a new covering 3 may be connected above it.

Further, the covering body 3 does not necessarily have to be formed by a pair of divided pieces 30, 30, but can be divided into three or more pieces, and can be formed by a cylindrical body having a slit in the length direction. However, it can also be configured to be elastically deformed and fitted onto the cable 2. Furthermore, as shown in FIG. 3, a long strip member 31 is wound spirally around the outer periphery of one end of the cable 2, and the overlapping portion of the strip member 31 is wrapped with a pen. The covering 3 of a predetermined length is fixed by fixing with
It is also possible to form a. Like this cable 2
After forming a covering 3 of a predetermined length at one end of the holder and moving this covering 3 to the other end, a new covering 3 is formed. Therefore, there is no need to provide scaffolding along the cable 2 as in the past, and there are advantages in that the construction cost can be kept low and the construction period can be shortened.

In order to suppress the movement resistance when moving the sheathing 3 toward the other end of the cable 2, a predetermined gap (usually 2-6
It is desirable to establish a ``degree''.

However, if the above-mentioned gap exists after installation, the sheathing 3 and the cable 2 will vibrate individually due to the influence of wind, etc., which may cause noise or damage to the sheathing 3. be. In order to prevent this, the covering 3 and the cable 2 may be integrated by the following means. That is, as shown in FIG. 4, if a cushioning material 20 such as sponge, sponge rubber, stainless steel sponge, or spring is provided on the inner peripheral surface of the covering 3 or the outer peripheral surface of the cable 2 in advance, the covering 3 When moving, the cushioning material 20 is elastically deformed, so the movement resistance is small, and the covering 3 and the cable 2 are integrally connected by the cushioning material 20 after installation. Further, the same effect can be obtained by providing a time-hardening high-viscosity material such as silicone or foamable urethane in place of the cushioning material 20. Furthermore, as shown in Figure 5A,
One or more inflatable tubes 21 are installed below the cable 2 in advance, and after the covering 3 is formed, a filler 22 is injected into the tube 21 as shown in FIG. 5B. By inflating the tube 21, the gap between the sheath 3 and the cable 2 may be filled and the two may be integrated.Also, as shown in FIG. 6A, both ends of the cable 2 may be clamped. 23 to form the sheath 3 in a state where the diameter of the cable 2 is reduced, and then by removing the clamp 23, the cable 2 is restored and the diameter is increased as shown in FIG. 6B. It is also possible to integrate the sheath 3 and the cable 2.Also, as shown in FIG. 7, both upper and lower ends of the cable 2 are fixed by sockets 14, By configuring both ends of the sheath 3 to be fitted onto the vibrator 15 made of polyethylene, steel, etc. held by the cables 14, 14, both ends of the cable 2 can be prevented from being exposed to the outside, and the cable 2 can be prevented from being exposed to the outside. The corrosion resistance of the end portions 2 and 2 can be improved and an excellent appearance can be obtained.

Further, in order to further improve the corrosion resistance of both ends of the cable 2, it is desirable to form a filler 16 made of plastic, rubber, or the like inside the vibrator 15. Further, by forming a drain hole 17 at a position corresponding to the lower end of the inclined surface of the filler 16 on the lower end side, water that has entered the interior through the rivet joint of the covering body 3 can be discharged. In addition, as shown in FIG.
It is also possible to have a structure in which both sides of the covering 3 are fitted into casings 18, 18 provided in the casings 18, 18. In addition, if the linear expansion coefficients of the cable 2 and the sheathing 3 are different, the above seventh and eighth
As shown in the figure, a gap S is provided between the upper end of the sheath 3 and the socket 14 to absorb differences in temperature expansion and contraction, or an expansion joint is provided in the middle of the sheath 3.
In addition, in the case of a long cable 2, the cable 2 may slide inside the sheathing 3 due to the above temperature expansion/contraction difference, and there is a risk that the anti-corrosion coating layer of the cable 2 may be damaged. The cushioning material 20 will work effectively. Therefore, it is desirable to provide the cushioning material 20 between the outer surface of the cable 2 and the inner surface of the cover 3 also in the embodiments shown in FIGS. 5A and 5B and 6A and 6B. In addition, in the coverings 3 and 3a shown in FIGS. 2 and 3, both divided pieces 3
If through-holes and screw holes for rivets or bolts for fixing the joints of 0 and 30 and both sheaths 3, 3, etc. are formed at the installation site, the cable 2 may be damaged by a drill, etc. In order to prevent
, 3a, or provide a protrusion on the inner surface of the covering 3, 3a.
It is desirable to provide a predetermined gap between the sheath 3 and the cable 2 by interposing a spacer between the sheath 3 and the cable 2. As explained above, this invention does not require the provision of scaffolding for attaching the anti-corrosion coating to the cable, and the coating can be easily formed, making it possible to keep construction costs low and shorten the construction period. It has the advantage of being able to

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of the present invention, Fig. 2 is a perspective view showing the structure of the covering, Fig. 3 is a perspective view showing another embodiment of the covering, and Figs. 4 and 5. A, B, Figure 6 A, B
7 and 8 are cross-sectional views each showing a means for integrating the sheath and the cable, and FIGS. 7 and 8 are cross-sectional views showing the structure of the cable end, respectively. 2...Cable, 3,3a...Coating.

Claims (1)

[Claims] 1. At one end of the installed cable, a cylindrical sheath is formed around the outer periphery of the cable over a predetermined length, and after this sheath is moved to the other end of the cable by approximately that length, , a new sheathing body is similarly formed on the outer circumference of the cable in continuation with the above-mentioned sheathing body, and the new sheathing body is moved in the same way, and by sequentially repeating this operation, each sheathing body is made to cover approximately the entire length of the cable. Corrosion-proof coating method for cables.