JPH04231509A - Laying method for cable - Google Patents

Abstract

PURPOSE:To lay easily and safely a main cable constituting a suspension structure such as suspension bridge between the steel skeletons of main tower in a short time. CONSTITUTION:A main beam steel skeleton 2 is laid between the main tower steel skeletons 1, and a main cable 7 is extended to the upside of the main beam steel skeleton 1. A hanger cable 13 is attached to the main cable 7 and repairing operations for rustproofed portions are made on the main beam steel skeletons 1. The main cable 7 is lifted up by a lifter such as wrecker truck directed to near the steel skeleton 1 and laid on the top of the steel skeleton 1, and the intermediate part of the main cable 7 is fixed to the saddle of the tower top. Both ends of the main cable 7 are fixed to the main beam steel skeleton 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable installation method for constructing suspension bridges and similar suspension structures.

0002

BACKGROUND OF THE INVENTION In recent years, there have been a variety of methods for constructing column-free spaces with long spans in civil engineering structures. Among them, the long span of structures using suspended structures is especially important.
In the civil engineering field, as seen in suspension bridges, they have a long history.
Its usefulness in the future is clear.

[0003] Generally, suspension bridges are constructed using the following procedure: main cables are installed between the tops of main tower steel frames, and then main girder steel frames are installed between the main tower steel frames.

That is, as shown in FIG. 7(a), after constructing the main tower steel frames 1, 1, as shown in FIG. 7(b), the pilot wire (main cable pulling wire) 10 is connected to the main tower. By installing the pilot wire between the tower tops of the tower steel frames 1 and 1 and pulling one end of the pilot wire 10 with the winch 9,
The main cable 7 connected to the other end of the pilot wire 10 is expanded and installed between the tops of the main tower steel frames 1, 1, and then, as shown in FIG. 7(c), a hanging hardware is attached to the main cable 7. Attach the hanger cable 13 through the
The main girder steel frame 2 was erected between the main tower steel frames 1, 1 while being suspended and supported by the hanger cables 13.

However, in the above cable installation method, when the main cable 7 is deployed, the main cable 7 bends significantly downward before and after the tower top, as shown in FIG. 7(b). Not only is it easy to damage, but a large force is required to deploy the main cable 7 (pull by the pilot wire 10), a large-scale winch 9 must be installed, and a complicated guide roller is installed at the top of the tower. It needed to be installed.

[0006] Furthermore, since the work of attaching the hanging hardware for attaching the hanger cable to the main cable 7 and the work of attaching the hanger cable 13 to the hanging hardware are performed at a high place, a complicated temporary structure is required and the construction period becomes long.
There were also difficulties in terms of safety management.

[0007]

[Problem to be Solved by the Invention] When construction is to be carried out in a place with poor conditions such as the sea or a deep valley, it may be necessary to rely on the above conventional method. However, for example, when constructing a suspension bridge that spans a road or a similar suspended structure, it is possible to drive a lifting machine such as a crane truck into the vicinity of the main tower steel frame, so it is not always possible to do so. There is no need to adopt the conventional method described above, and the main girder steel frame can also be temporarily supported with temporary struts erected on the ground, so it can be constructed prior to the erection of the main cable. It should be.

The present invention has been made from the above-mentioned viewpoint, and its object is to provide a cable installation method which is advantageous in terms of quality and safety management, and which allows main cables to be installed in a short construction period and at low cost. It is about providing.

[0009]

[Means for Solving the Problems] The technical means taken by the present invention to solve the above problems are as follows. That is, in the cable installation method according to the present invention, after a main girder steel frame is erected between main tower steel frames, a main cable is deployed on the main girder steel frame, a hanger cable is attached to the main cable, and then a lifting machine is used to install a main girder steel frame. The main cable is lifted to the top of the main tower steel frame.

0010

[Operation] According to the above configuration, since the main cable is deployed on the main girder steel frame, there is less bending of the main cable when the main cable is deployed, and a large force is required to deploy the main cable (pulling by the pilot wire). No need for complicated guide rollers.

[0011] In addition, various operations on the main cable, such as attaching hanging hardware for attaching a hanger cable,
Attachment of the hanger cable to the hanging hardware, modification of the anti-corrosion treatment of the main cable and hanger cable, etc. can all be done while working on the main girder steel frame.
Work at heights will be significantly reduced.

0012

[Example] As shown in Fig. 1(a), main tower steel frames 1, 1
After constructing the main tower steel frame 1, as shown in Figure 1(b),
, 1, the main girder steel frame 2 will be erected. 3... is main tower steel frame 1,1
Temporary supports supporting the main girder steel frame 2 between, 4... are the main tower steel frames 1
, 1 is a permanent support supporting the main girder steel frame 2 located outside.

To construct the main girder steel frame 2, for example, as shown in FIG. 3, a main girder steel frame unit 2a equipped with temporary supports 3 is lifted by a lifting machine 5 such as a crane truck, and connected to the main tower steel frame 1. However, the main girder steel unit 2 with similar temporary supports 3 will be explained below.
This can be done by adding a.

Although not shown, the required number of temporary supports 3 are erected on the ground at predetermined intervals in advance, and then the main girder steel frame unit 2a is connected to and added to the main tower steel frame 1. Main girder steel frame 2 between main tower steel frame 1 and 1
may be constructed. In either case, the temporary supports 3 are removed when the support of the main girder steel frame 2 is no longer required.

When the span is relatively short or the scale of the main girder steel frame unit 2a is small, a temporary suspension wire 6 is suspended from the main tower steel frame 1, as shown in FIG. The main girder steel frame 2 may be constructed while supporting the unit 2a.

After that, FIG. 1(c) and FIG. 2(a)
And as shown in FIG. 2, the main cable 7 is deployed on the main girder steel frame 2. That is, a drum 8 around which the main cable 7 is wound is installed at one end of the main girder steel frame 2, and a winch 9 is installed at the other end.
By pulling one end of pilot wire 1
The main cable 7 connected to the other end of the main girder steel frame 2 is deployed on the main girder steel frame 2. 7a in FIG. 5 is a fixing metal fitting at the tip of the main cable 7.

The fixing hardware 7a at the tip of the main cable may be placed on a trolley and moved over the main girder steel frame 2, but in this embodiment, as shown in FIG.
1b in an appropriate shape, and a resin pipe 11c is rotatably fitted over the horizontal single pipe 11a and the vertical single pipes 11a connected on both sides thereof to form a running path 11 for the main cable 7. The fixing hardware 7a is mounted on a sled body 12 and moved on a running path 11.

After the main cable 7 is deployed, work on the main girder steel frame 2 is performed to attach hanging hardware for attaching the hanger cable to the main cable 7, and to attach the hanger cable 13 to the hanging hardware, as shown in FIG. Installation, modification of the anti-corrosive parts of the main cable 7, hanger cable 13, etc.

After that, as shown in FIG. 2(b) and FIG.
The main cable 7 is lifted to the top of the main tower steel frames 1, 1, and a predetermined position of the main cable 7 is fixed to the saddle 14 at the top of the tower, and both ends of the main cable 7 are fixed to the main girder steel frame 2. . 15... connects the loose wires 16... connected to both ends of the main cable 7 to the main cable 7.
This is a chill hole that is used to gradually extend the lift as the load is lifted.

In this state, as shown in FIG. 2(c),
After the lower ends of the hanger cables 13 are fixed to the main girder steel frame 2, the temporary supports 3 are removed.

[0021]

[Effects of the Invention] As described above, the present invention deploys the main cable on the main girder steel frame, so there is less bending of the main cable when the main cable is deployed, and it is easy to deploy the main cable (pulling by the pilot wire). Doesn't require a lot of force. Therefore, the main cable can be expanded using a relatively small winch, and damage to the main cable can be minimized. Also,
Various work on the main cable, such as installing hanging hardware for attaching the hanger cable, attaching the hanger cable to the hanging hardware, reworking the anti-corrosion treatment section of the main cable and hanger cable, etc., is all done on the main girder steel frame. This significantly reduces the need for work at heights. The main cable can be constructed in a short construction period and at low cost, and is also advantageous in terms of quality and safety management.

[Brief explanation of the drawing]

FIG. 1 is a process explanatory diagram of a cable installation method according to the present invention.

FIG. 2 is a process explanatory diagram following the process of FIG. 1;

FIG. 3 is an explanatory diagram of a method for constructing a main girder steel frame.

FIG. 4 is an explanatory diagram of another method for constructing the main girder steel frame.

FIG. 5 is a perspective view of a main part illustrating a main cable deployment process.

FIG. 6 is a perspective view of a main part illustrating a main cable lifting process.

FIG. 7 is an explanatory diagram of a conventional example.

[Explanation of symbols]

1...Main tower steel frame 2…Main girder steel frame 5... Lifting machine 7...Main cable 13...Hanger cable

Claims (1)

[Claims] [Claim 1] After erecting the main girder steel frame between the main tower steel frames,
A method for constructing a cable, which comprises deploying a main cable on a main girder steel frame, attaching a hanger cable to the main cable, and then hoisting the main cable to the top of the main tower steel frame using a lifting machine.