JPS6156357B2 - - Google Patents

Description

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

The above cable is usually protected by covering its outer circumferential surface with a cylindrical anti-corrosion covering, but if the above covering is attached to the cable in advance, it can be wound around a reel. However, it is extremely inconvenient to store. For this reason, in the past, scaffolds were assembled in advance at predetermined intervals along the cable to be constructed, a cylindrical covering was installed on the scaffolding, and then the cable was coated with anti-corrosion protection, or
Alternatively, a scaffold is provided along the entire length of the pre-erected cable, and a worker climbs onto the scaffold to attach the sheath to the cable. These methods require the installation of scaffolding to attach the sheathing, and the drawbacks are that, especially for long cables, large-scale scaffolding is required, resulting in high construction costs and long construction times.

Therefore, in order to eliminate this drawback, a cylindrical sheath of a certain unit length is formed around the outer periphery of the cable at one end of the installed cable, and this sheath is extended by approximately that length toward the other end of the cable. A method of covering approximately the entire length of the cable with each sheath by forming a new sheath in the same way on the outer circumference of the cable in continuation with the above-mentioned sheath, and then repeating this process one after another. is possible. However, in this method, a unit-length covering is formed by joining a pair of half-tubular pieces, and then this covering and the next covering are connected at each other's ends. When joining and connecting, joining metal fittings, etc. for connecting each covering are required, and the machining and joining work is troublesome. In addition, problems such as a lump-like connecting portion occurring for each unit length remain undesirable from an aesthetic point of view.

In view of these circumstances, the present invention is capable of attaching a covering to almost the entire length of a cable erected at the site without requiring scaffolding, thereby shortening the construction period and reducing the construction cost. In particular, it is an object of the present invention to provide a method for anti-corrosion coating of a cable, which can simplify the work of forming the coating and improve the appearance.

The present invention provides a method of shifting the lengthwise positions of radially adjacent split pieces by a predetermined amount from each other by a predetermined amount at one end of an installed cable, by using a large number of split cylindrical pieces that are fitted onto the cable from both sides. Tsutsu,
A covering is sequentially formed around the cable by sequentially joining the divided pieces to the adjacent preceding divided piece along the length direction at corresponding locations on the side parts, and By repeating the joining work and the work of moving the covering body to the other end of the cable by the joined length, the covering body covers substantially the entire length of the cable.

Embodiments of the present invention will be described below with reference to the drawings.

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 sheathing part 3, which is a part of the sheathing body, is formed on the outer periphery of the lower end of the cable 2 on the bridge girder 11, and then a rope 13 is formed around a pulley 12 provided at the upper end of the tower 10. The covering part 3 is moved upward along the cable 2 by a certain length, and the covering part 3 is added below. By repeating this operation, a sheath covering the entire length of the cable 2 is formed.
In this case, the covering body 3 is formed and extended using a large number of half-tube-shaped divided pieces 30, 30'..., 31 made of plastic such as polyethylene, copper, aluminum, stainless steel, etc., and The divided pieces are sequentially joined with the longitudinal positions of the divided pieces that are adjacent to each other in the radial direction shifted by a predetermined amount.

To explain this method in detail with reference to FIG. 2, at the lower end of the cable 2, first, in order to form the starting end portion of the sheathing part, a divided piece 30 of a predetermined length and a divided piece 31 of approximately half the length are formed. cover cable 2 from both sides. And both divided pieces 30, 31
are aligned at the upper end side and offset in the length direction at the lower end, and the corresponding parts of the side parts along the length direction of both are connected with rivets 32... or bolts,
Joined with screws, fitting, slits, welding, etc.
stick. At this time, if necessary, cover the cable 2 with a guide wrapper tube 33 formed in a split shape in advance, and cover the splitter piece 3 with this wrapper tube 33.
Connect the upper ends of 0 and 31. Next, after moving both of the joined divided pieces 30, 31 upward by a certain length as shown by the arrow using the rope 13, one (longer) divided piece 30 is connected to another divided piece. 30′ to the other (shorter) divided piece 31
It is joined with the following. In other words, divided piece 3
0 and 30' face each other in a state shifted in the length direction, and in this state, their corresponding side portions are joined and fixed by rivets 32, etc.

Thereafter, the operation of joining a new divided piece 30' or 30 to the previously joined divided piece 30 or 30' is repeated in the same manner. Then, each time a divided piece is joined, it is moved upward by the length of the divided piece, or after two divided pieces 30, 30' are joined in succession, it is moved upward by the length of the divided piece. Then, while moving the joined divided pieces by a certain amount, additional divided pieces are sequentially added to the lower end side of the cable 2.

By doing this, the divided pieces 30, 30' which are deviated by a certain length and face each other in the radial direction are joined to each other, and the divided pieces 30, 30' which are adjacent in the length direction are joined to each other.
30 (or 30', 30') are also connected via divided pieces 30' (or 30) that straddle and oppose each other. Therefore, there is no need for coupling fittings for connecting in the length direction, and the connecting work is also simplified. However, when longitudinally adjacent divided pieces are butted together, a back-up material such as silicone rubber or double-sided tape should be used on the back side to prevent water from entering from the butting part.
It is preferable to wrap the hoop ring 35 on which the hoop ring 6 is attached tightly around the circumferential surface of the above-mentioned abutting portion, and secure it with a caulking fitting 37 or the like (see Fig. 2).
(See Figure 3). Note that the hoop ring 35 can be omitted by providing corresponding fitting portions (not shown) on adjacent divided pieces so that they can be fitted into each other.

As a means of pulling up the divided pieces with the rope 13,
For example, as shown in FIG. 4, a half-split rope-like cable grip 15 is placed over the split pieces 30 and 31 on the starting end side and fixed at appropriate points, and the tip of this grip 15 is connected to the rope 13. By winding up the rope 13 with the winch 14 shown in FIG. 1, the grip 15 tightens as it is pulled, gripping the divided pieces 30 and 31 and pulling them up.

In this way, the number of split pieces is increased until the split pieces 30 and 31 on the starting end side reach the upper end of the cable 2,
By repeating the movement, as shown in Figure 5,
A continuous cylindrical covering A is formed over the entire length of the cable 2. The terminal end side of the covering body A is aligned with the ends using short divided pieces 31 in the same way as the starting end side. Further, both ends are connected to the casing 2 provided in the cable sockets 21, 21 via the above-mentioned wrapper tube 33, etc.
2 and 22. In this embodiment, a large number of half-tube-shaped division pieces are used, but the shape of the division pieces is not limited to the half-tube shape, but may be any multi-tube shape.

In this method, in order to reduce the movement resistance when moving the divided pieces upward, each divided piece 30
..., 30'..., 31 and the outer circumferential surface of the cable 2, it is desirable to provide an appropriate gap. In this case, in order to prevent the sheath A and the cable 2 from vibrating individually after installation, causing collision noise and damage to the sheath A, for example, as shown in FIG. One or more inflatable tubes 38 or 3 are arranged linearly (FIG. 6a) or spirally (FIG. 6b) along the
8', and after forming the covering, filler is injected into the tubes 38, 38' and allowed to swell, thereby filling the gap. Alternatively, a cushion material such as a sponge or a spring, silicone, or the like may be attached to the outer peripheral surface of the cable 2 in advance as a spacer.

In the above embodiment, the divided pieces are sequentially attached to the rope 13.
However, instead of this, it is also possible to push it up a predetermined length at a time.Also, the divided pieces are joined and added at the top of the tower 10, and the divided pieces are sequentially moved downward from there. You can also do this.

As described above, according to the method of the present invention, a sheath covering approximately the entire length of the cable is formed by sequentially moving the joined halves and joining and adding on the halves at one end of the cable. This has the great advantage of not requiring scaffolding for mounting the body, making it possible to keep construction costs low and shorten the construction period. Furthermore, by shifting the lengthwise positions of the radially opposing split pieces and joining them, the split pieces are sequentially connected in the length direction as well. There is no need for joining work, and the manufacturability and workability are further improved, and the aesthetics can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a front view schematically showing an embodiment of the present invention, FIG. 2 is an enlarged perspective view showing the process of connecting the divided pieces,
FIG. 3 is an enlarged sectional view of the portion lined with - in FIG. 2, FIG. 4 is a perspective view showing an example of the divided piece lifting means, FIG. FIG. 3 is a cross-sectional view showing an example of means for preventing individual vibrations of the sheath and the cable. 2...Cable, 3...Sheathing part, 30,3
0', 31...Divided piece, A...Coating.

Claims (1)

[Claims] 1 At one end of the installed cable, by using a large number of divided cylindrical pieces that are fitted onto the cable from both sides, the lengthwise positions of the radially adjacent pieces are shifted by a predetermined amount from each other, and Each split piece is joined to the adjacent preceding split piece at corresponding locations on the side portions along the length direction, so that a sheath is sequentially formed around the cable, and the split piece is A cable characterized in that substantially the entire length of the cable is covered with the sheathing by repeating the work of moving the sheath to the other end of the cable by the length of the joined work alternately with the joining work. anti-corrosion coating method.