JPH045083B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a method for forming cables for suspended structures, and more specifically, for constructing composite cables for cable-stayed bridges, which are made by attaching sheathing materials to stranded PC steel wires. Regarding the method of forming in the field.

BACKGROUND TECHNOLOGY Conventionally, cables used for bridges have parallel wire strands covered with a synthetic resin cover, PC steel strands covered with steel pipes or synthetic resin pipes, and the internal voids covered with anti-corrosive material such as cement. There are two types: one injected with solidified filler and the other in which a plated locked coil is painted. In such prior art, the cable is manufactured in advance in a factory, and after being strung at the installation site, it is painted, coated with a cover, or injected with a coagulating filler for rust prevention. It's summery. When performing such painting work, it is necessary to provide scaffolding along the entire length of the stretched cable. Therefore, workability is poor and construction costs are high.

Furthermore, the prior art has the following problems. That is, since the cover or tube is made of synthetic resin, it deteriorates within a short period of time and has a short service life. Furthermore, it is time-consuming to insert the stranded wires and spacers for positioning the stranded wires into the steel pipe or synthetic resin pipe, and the filling material cannot be injected smoothly. Furthermore, the plating and painting process increases the cost and reduces the service life.

Problems to be Solved by the Invention The purpose of the present invention is to solve the above-mentioned technical problems,
At the construction site, it is possible to form and construct cables that are made of prestressed steel strands and sheathing material and have a dramatically improved service life.Moreover, the scaffolding area during cable formation is reduced as much as possible, making it economical and quick. It is an object of the present invention to provide a method for forming a cable for a suspended structure, which enables easy construction.

Means for Solving the Problems The present invention stretches a guide wire rope obliquely near the position where the cable is to be stretched, and partially stretches the guide wire rope near the lower end of the guide wire rope. Scaffolding is set up on the platform, one end of the flexible stranded PC steel wire is raised along the guide wire rope, and an operator stands on the scaffold and the PC is aligned in a straight line along the guide wire rope. A rigid sheathing material having a straight axis is attached to the stranded steel wire, and the above-mentioned raising step and sheathing material installation step are repeated to cover the entire length of the PC steel stranded wire with the sheathing material. This is a method for forming a cable for a suspended structure.

Effect According to the present invention, a guide wire rope is stretched diagonally, and a scaffold is partially provided along the guide wire rope near the bottom of the guide wire rope.
Since workers can attach the sheathing material to the prestressed steel strands while riding on this scaffolding, there is no need to form a scaffolding over the entire length of the cable as in the case of conventional methods, thereby reducing construction costs and construction time. This makes it possible to reduce the Additionally, since the PC steel strands are coated with an exterior material, it is possible to install cables with excellent corrosion resistance.

Embodiment FIG. 1 is a diagram for explaining the outline of the cable forming method according to the present invention, and FIG. 2 is a schematic diagram of a cable-stayed bridge constructed by the cable forming method shown in FIG. 1. . A tower 2 is erected on the girder 1 and extends vertically. A guide wire rope 5 is stretched between a fixing section 3 fixed to the top 2a of the tower 2 and a fixing section 4 fixed to the girder 1 side. Above this guide wire rope 5, a guide wire rope 5
Cable lifting wire rope 6 extending along
is placed. One end of this wire rope 6 for lifting the cable is wound around a roller 7 attached to the fixing section 4, and the other end of the wire rope 6 is wound around a winch 10 via pulleys 8 and 9. A plurality of cable lifting jigs 11 are attached to the wire rope 6 at regular intervals.

A scaffold 12 is provided near the anchoring portion 4 of the guide wire rope 5. A worker stands on this scaffold 12, and a cable 1 consisting of a plurality of PC steel stranded wires 20 (see FIG. 3) is supplied via the fixing section 4.
3, the work of attaching the protective exterior material 14 is performed. When one sheathing member 14 is attached to the cable 13, the winch 10 is operated to raise the cable 13 along the guide wire rope 5 using the jig 11. Then, the sheathing material 14 is attached to the next part of the cable 13 in the same manner as described above, and the winch 10 is operated to raise the cable 13. At this time, a joint 70 is interposed between the exterior materials 14 to connect each exterior material 14. This joint 70 is, for example, a practical application already devised by the present inventor in 1983.
110709 (Jitsuhei 2-45286) and the like are used.

Such a rising step of the cable 13,
By repeating the step of attaching the sheathing material 14 to the cable 13, the composite cable 15, in which the cable 13 is covered with the sheathing material 14, is stretched between the fixing sections 3 and 4. By stretching a predetermined number of such composite cables 15 in relation to the tower 2, a cable-stayed bridge 16 is constructed as shown in FIG.

3 is a cross-sectional view taken from the cutting plane line - in FIG. It is a diagram. The unit protective sheathing material 14 of the cable 13, which is made up of a required number (19 in this embodiment) of PC steel stranded wires 20 arranged in parallel, is made of a lightweight, corrosion-resistant, and rigid material such as aluminum. This exterior material 14 is composed of a pair of half-split covers 21, and a male fitting part 22 and a female fitting part 23 provided on both side edges of the cover 21 so as to be connected to each other by fitting.
The female fitting part 23 and the male fitting part 22 have grooves 23a.
and a protrusion 22a that is pushed into the groove 23a, and the groove 23a and the serrated grooves provided on both sides of the protrusion 22a are engaged with each other to maintain a bonded state without detachment.

Also, provided inside the cover 21 is an elastic spacer 24 that is fitted into and engaged with the cover 21 and maintains the assembled shape of the cables 13. This elastic spacer 24 includes an elastic plate 24a made of rubber or soft synthetic resin, and an elastic plate 24a made of rubber or soft synthetic resin.
The parallel grooves 24b are provided on the surface of the cover 21 so that a part of the outer periphery of the PC steel strands 20 fits therein, and are arranged in a dotted manner inside the cover 21.

The elastic spacer 24 is engaged with the cover 21 by integrally providing parallel protrusions 25 having bulges on the side edges in the axial direction of the inner surface of the cover 21, and by fitting the protrusions 25 into the elastic spacer 24. First, the elastic spacer 24 is bent to widen the groove 26, and then the groove 26 is fitted to the protrusion 25, and the elastic spacer 24 is unbent and attached. In this way, the elastic spacer 24 that maintains the collective shape of the cables 13 is arranged inside the cover 21, so the elastic spacer 24 prevents the PC steel strands 20 from spreading outward from the center. absorbs, so that the cover 21 is not affected by the cable 13 and therefore the cover 2
No extra force is applied to the side edge joint portion 1, and a reliable joint state can be maintained.

Note that the cover 21 is formed by cutting an extruded aluminum material into predetermined lengths.

Further, in this embodiment, the PC steel strands 20 are of an unbonded type coated with polyethylene resin.

Sockets 27 are attached to both ends of the cable 13. A steel pipe 6 is attached to one end of this socket 27.
2 is installed. A plurality of PC steel strands 20 are connected to a steel pipe 6
2 with a cable band 28 and a crimp clip 29 near the end of the socket 27.
established by

FIG. 5 is an enlarged view of the cable lifting jig 11. The cable lifting jig 11 includes a socket lifting jig 30 and a lifting jig 31 for lifting the portion to which the sheathing material 14 is attached. The socket lifting jig 30 is a lifting wire rope 6.
It includes a pair of brackets 32 fixedly spaced apart from each other and a base 33. A roller 34 is rotatably supported on the bracket 32, and this roller 34 is in contact with the guide wire rope 5. Therefore, when the wire rope 6 rises in the direction of arrow A, the roller 34 rotates while being guided along the guide wire rope 5.

A hook 35 is provided at the lower end of the bracket 32. This hook 35 is connected to a locking ring 36 provided on the base 33 via a locking member 37. As a result, the base 33 is supported by the bracket 32. A locking piece 38 is provided on the base 33, and the socket 27 is locked on the base 3 by this locking piece 38.

The lifting jig 31 includes a bracket 32 and a roller 34 rotatably supported by the bracket.
and a hook 3 fixed to the end of the bracket 32.
5, and a support member 39 that supports the cable 13 to which the sheathing material 14 is attached.

Figures 6 and 7 show cable 13 with sheathing material 1.
Exterior material fitting jig 4 used when installing 4
FIG. 8 is a side view of the exterior material fitting jig 40 seen from the arrow B side in FIG. 7. The exterior material fitting jig 40 includes a main body 41, a hydraulic jack 42, and half-split gripping members 43, 44. The main body 41 consists of a pair of support pieces 45 that are roughly U-shaped and a connection piece 46 that connects the support pieces 45 together. The support piece 45 includes a base 47 and a pair of legs 48a and 48 extending downward from both ends of the base 47.
b.

The hydraulic jack 42 is supported by the connecting piece 46. The drive shaft 49 of the hydraulic jack 42 is attached to a mounting tube 50 at its lower end with a bolt 51 and a nut 5.
Connected by 2. The mounting tube 50 is fixed to the outer peripheral surface of the gripping member 43 by welding or the like. The lower end of the leg portion 48a and one end of the connecting member 53 are pivotally supported by the bottle 54, so that the connecting member 53 can swing freely around the axis of the bottle 54.
The connecting member 53 has a cross section perpendicular to the axis having a roughly semicircular arc shape. The gripping member 44 is fixed to the inner peripheral surface of the connecting member 53. The other end of the connecting member 53 can be connected to the lower end of the leg 48b with a bolt 55 and a nut 56.

In the normal state, the exterior material fitting jig 40 is disconnected from the other end of the connecting member 53 and the leg portion 48b, as shown in FIG. In the state shown in FIG. 6, the cable 13 is placed below the gripping member 43 and on the legs 48a and 48b. Then, the pair of covers 21 are placed facing the cable 13, and then the connecting member 53 is placed on the bin 54.
The end portion of the connecting member 53 is fixed to the leg portion 48b with a bolt 55 and a nut 56 by angularly displacing the connecting member 53 around the axis of the connecting member 53. In this way, the cable 13 is housed within the cover 21 via the gripping members 43 and 44. In this state, the hydraulic jack 42 is driven. As a result, the drive shaft 49 is displaced downward, and the protrusions 22a and grooves 23a of the covers 21 are engaged with each other, so that the pair of covers 21 are engaged with each other. In this way, the sheathing material 14 is attached to the cable 13. Note that such work is performed by a worker on the scaffolding 12.

FIG. 9 is a diagram showing the manufacturing process of the composite cable 15, and FIG. 10 is a flowchart thereof.
Moving from step n1 to step n2, the PC steel stranded wire 20 is cut into a predetermined length. Then, the process moves to step n3, and as shown in FIG. 9, the polyethylene resin at the ends of the PC steel strands 20 is removed. Then, the process moves to step n4, and winding onto the drum 50 is performed as shown in FIG. 92. At this time, for example, in this embodiment
All 19 pieces are wound at once. The operations in steps n2 to n4 are performed in advance at the factory. In this way, the drum 50 has multiple
After the PC steel stranded wire 20 is wound, it is transported to the construction site, and the following processes at the construction site are performed.

In step n5, the cable 13 is unfolded. That is, FIG. 9 3 and FIG. 9 4
As shown in FIG. 2, the cable 13 is shaped using the shaping plate 60 for the PC steel strands 20 wound around the drum 50. This shaping plate 60 has a plurality of honeycomb-shaped through holes formed at predetermined positions. By this shaping plate 60, the cable 13
After the expansion is completed, proceed to step n6 and insert the PC steel stranded wire 20 into the socket 27 on the fixed side as shown in Fig. 9.
As shown in FIG. 2, the locking member 61 is inserted from the direction of arrow C, and the locking member 61 is also inserted. Then, in step n7, the locking member 6 of the PC steel stranded wire 20 is
Attach the crimp clip 29 to the end through which 1 was inserted. Then, proceeding to steps n8 and n9, the cable band 28 and the steel pipe 62 are attached as shown in FIG. 9. Thus step n5
~In step n9, the fixed side socket 27
The installation work is completed.

Next, in step n10, the exterior material 14
is attached to the cable 13, and the cable is pulled up. That is, as shown in FIG. 9, a worker on the scaffold 12 uses the exterior material fitting jig 40 to attach the exterior material 14 to the cable 13.
Attach to. When one sheathing material 14 is attached, the cable lifting jig 11 is attached to the cable 13 and the winch 10 is operated to raise the cable 13 to which the sheathing material 14 is attached. Then, apply the next new exterior material 14 to the cable 13.
Attach to. Note that at this time, a joint 70 is interposed between the exterior materials 14 to connect each exterior material 14. Such a rising step of the cable 13 and the sheathing material 1
By sequentially repeating step 4 of attaching the cable 13 to the cable 13, the cable 13 can be covered with the sheathing material 14 over the entire length between the fixing parts 3 and 4.

Next, the process moves to steps n11 and n12, and as shown in FIG. 9, cable temporary drawing and cable marking operations are performed. step n1
In step 3, the extra length of the cable 13 is cut, and then the process moves to step n14, where the adjustment side socket 27 is added. Then, the process moves to step n15, and as shown in FIG. 9, the cable is pulled in. In step n16, the socket 27 is filled with resin or the like. Then, in step n17, all the work in the cable manufacturing process is completed.

In this way, the pre-fabricated PC steel stranded wire 2
0 are bundled together at the construction site to create cable 13.
This cable 13 is covered with an exterior material 14, and the composite cable 15 can be stretched at a place where it is to be stretched. By suspending a required number of such composite cables 15 in connection with the tower 2, it becomes possible to construct the cable-stayed bridge 16.

Although the above-mentioned embodiment describes a cable-stayed bridge cable, the present invention is not limited thereto, and the present invention can be suitably implemented when forming cables for other suspended structures.

Effects As described above, according to the present invention, it is possible to form a composite cable consisting of a cable and a sheathing material covering the cable at the construction site. In addition, only partial scaffolding is required, and there is no need for full scaffolding or catwalks as in the past, making it possible to carry out economical and rapid construction.

Further, since the cable formed according to the present invention is covered with an exterior material, corrosion of the cable due to rainwater etc. can be prevented, and a composite cable with a long service life can be realized.

[Brief explanation of drawings]

Fig. 1 is a diagram for explaining the outline of the cable forming method according to the present invention, Fig. 2 is a schematic diagram of a cable-stayed bridge realized by the present invention, and Fig. 3 is a cross section of Fig. 1. 3A is a perspective view showing how the exterior material 14 and the elastic spacer 24 are attached, FIG. 4 is a diagram showing the entire cable 13, and FIG. 5 is a cable lifting jig 11. An enlarged view of the surrounding area, FIG. 6 is a front view of the exterior material fitting jig 40 with the continuous member 53 open, and FIG. 7 is a front view of the exterior material fitting jig 40 with the connecting member 53 closed. 8 is a side view of the exterior material fitting jig 40 seen from the arrow B side in FIG. 7, FIG. 9 is a diagram showing each step of the cable forming method, and FIG.
The figure is a flowchart showing each step in the cable forming method. 5... Guide wire rope, 6... Wire rope for lifting cables, 10... Winch, 11...
...Cable lifting jig, 12...Scaffolding, 13...
... Cable, 14 ... Exterior material, 15 ... Composite cable, 16 ... Cable-stayed bridge, 20 ... PC steel stranded wire, 2
1... Cover, 24... Elastic spacer, 27...
Socket, 40...Jig for fitting exterior material.

Claims (1)

[Scope of Claims] 1. A guide wire rope is strung obliquely near the position where the cable is to be strung, and a scaffold is partially provided along the guide wire rope near the lower end of the guide wire rope, One end of the flexible stranded PC steel wire is raised along the guide wire rope, and the part of the stranded PC steel wire is aligned in a straight line along the guide wire rope with an operator on the scaffold. A rigid sheathing material having a linear axis is attached to the PC steel strand, and the above-mentioned raising step and sheathing material attaching step are repeated to cover the entire length of the PC steel strands with the sheathing material. Method of forming cables for suspended structures.