JP2651862B2 - Installation method of stay cable of cable stayed bridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for laying stay cables of a cable-stayed bridge.

<Conventional technology> The installation of stay cables for cable-stayed bridges is an operation at a high place, so there are various restrictions in terms of safety, economy, and reliability of construction.

Further, the stay cable may be manufactured not only in a factory but also in the field, but when using such a field manufactured stay cable, the conventional method may not be able to cope with the situation.

<Object of the present invention> It is an object of the present invention to provide a method for securely and efficiently erection of a stay cable of a cable-stayed bridge.

It is a further object of the present invention to provide a method that allows a stay cable to be erected even when assembled on site.

<Configuration of the Present Invention> Next, an embodiment of the present invention will be described.

<A> Overall Configuration In FIG. 1, reference numeral 1 denotes a column built in the center of a cable-stayed bridge, and has a structure in which a bridge body 3 is supported by a stay cable 2 extending diagonally from the column 1.

The stay cable 2 extends while extending the support column 1 and the bridge body 3 while supporting the extended ends thereof.

For this purpose, a stay cable upper end through hole 21 is formed in the support column 1 at a position where the upper end of the stay cable 2 is fixed.

On the other hand, a stay cable lower end through hole 22 is opened near the tip of the bridge body 3 at a position where the lower end of the stay cable 2 is fixed.

Then, the upper end of the stay cable 2 is attached to the column 1, and the lower end is attached to the tip of the bridge 3, and a pulling force is applied from either side to form a structure.

<B> Temporary placement of stay cable (FIG. 1) A stay cable 2 having a predetermined length is manufactured at a factory, carried into the site, and temporarily placed on the bridge 3.

The following description will focus on the case where the stay cable 2 is manufactured at a factory and carried in.

However, when assembling this on site, the "stay cable" is replaced by the "polyethylene pipe" that forms the outer cylinder.
Since the same construction is possible if it is read as, a description will be added only when the process is different.

<C> Guidance of guide cable A guide cable 4 is attached to both ends of the stay cable 2.

When assembling the stay cable 2 on site,
The guide cable 4 penetrates the inside of a polyethylene pipe as an outer cylinder of the stay cable, and both ends thereof are extended long.

One end of the guide cable 4 is configured to be able to be pulled by a winch from the opposite side of the support 1 through the stay cable upper end through hole 21 of the support 1.

On the other hand, the other end of the guide cable 4 is configured so as to be able to be pulled by a winch from the lower side of the bridge 3 through a stay cable lower end through hole 22 of the bridge 3.

<D> Searching for hypothetical rope The hypothetical rope 5 is used to lift the stay cable 2.

This hypothetical rope 5 has one end fixed near the distal end of the bridge 3 and closer to the distal end than the stay cable lower end through hole 22.

The other end of the hypothetical rope 5 is configured to apply a pulling force toward the upper end of the column 1.

For this purpose, for example, a hypothetical roller provided at the upper end of the column 1
It is configured so that it can be folded back at 51 and pulled to the tip side of the bridge 3.

<E> Clamp (FIG. 3) The clamp 6 is used to grip the stay cable 2 with the hypothetical rope 5.

That is, a large number of clamps 6 are attached to the hypothetical rope 5, and a stay cable is gripped and lifted by the group of clamps 6.

The structure of the clamp 6 consists of two arms 61 in the form of scissors and a pin for opening and closing.
They are connected by 62 and are configured to be freely opened and closed around the pins 62.

A holding container 63 is attached to the lower end of the arm 61 by a container rotation pin 64 positioned in a direction orthogonal to the opening / closing pin 62.

The shape of the gripping container 63 is formed by cutting the cross section of the object to be gripped in half. However, since the cross section of the stay cable 2 is circular, the gripping container 63 is formed in a semi-cylindrical shape in which a cylinder is cut in half. I do.

Since this clamp 6 is hung with a wire, a hanging frame 65 for inserting a wire is attached to the upper end of the arm. Further, a guide plate 66 is also attached to one arm 61 with a pin. Opens slot 67.

The elongated hole 67 is formed by rolling the end of the straight portion downward in the orthogonal direction, or is formed larger than the cross section of the elongated hole 67 to form the end groove 68.

The other arm 61 has a guide pin 69 projecting therefrom, and the guide pin 69 is inserted into the elongated hole 67.

Then, the guide pin 69 moves in the elongated hole 67 according to the opening and closing of the arm 61.

When the arms 61 are opened at an angle exceeding a certain value, the guide pins 69
Falls into the end groove 68 and cannot be closed unless the guide pin 69 is manually lifted.

Further, if an extension spring is interposed between the arms 61, the arms 61
The arm 61 can always be opened when no load is applied to the arm.

<F> Lifting work (FIG. 5) The upper ends of the hypothetical rope 5 and the guide rope 4 are rolled up by a winch.

As the hypothetical rope 5 rises, the tip of the clamp 6 attached to the hypothetical rope 5 closes, and the gripping container 63 approaches from both sides of the stay cable 2 and securely grasps it.

<G> Fixing stay cable When the upper end of the stay cable 2 reaches the support 1, fix both stay cables.

Next, the lower end of the stay cable 2 is also fixed to the bridge 3, and the installation of the stay cable 2 is completed.

Thereafter, tension is applied to the steel wire of the stay cable 2 from either side to complete the installation of one stay cable 2.

<H> In case of on-site assembly When assembling the stay cable 2 on site,
As shown in FIG. 6, the steel wire bundle W is attached to the guide cable 4, and the guide cable 4 is pulled down, so that the steel wire bundle W can be introduced into the polyethylene pipe to complete the stay cable 2.

Thereafter, tension is applied to the steel bundle of the stay cable 2 from either side to complete the installation of one stay cable 2 in the same manner.

<Re> Opening of hypothetical rope 5 When the stay cable 2 is tensioned, the existence of the hypothetical rope 5 becomes unnecessary.

When the load acting on the hypothetical rope 5 disappears, the clamp 6 of the present invention opens the arm 61 and is automatically released from the gripped state.

Therefore, since the stay cable 2 and the hypothetical rope 5 are separated, the hypothetical rope 5 can be loosened and the clamp 6 can be moved downward.

In particular, since it is difficult to return when the arm 61 of the clamp 6 is opened to a certain angle, the gripping container 63 once opened does not close again.

<Effects of the present invention> Since the present invention is the above-described erection method, a reliable stay cable can be erected only by operating the rope.

In particular, the clamp is used only when a lifting load is applied, and a clamp is used to hold the stay cable. Can be canceled.

Further, the present invention can be used not only when a stay cable is manufactured in a factory, but also when a steel wire bundle is inserted into a polyethylene pipe and assembled on site.

[Brief description of the drawings]

 Fig. 1: Illustration of the state before the stay cable is erected Fig. 2: Layout of the tip of the bridge body Fig. 3,4: Illustration of the clamp Fig. 5, 6, Fig.

Claims (2)

(57) [Claims] In the construction of a cable-stayed bridge supporting a bridge body with a stay cable protruding from a central pillar, one end of a temporary cable is attached to an upper part of the pillar so as to be able to be lifted,
Attach the other end to the tip of the bridge body, attach a number of clamps to the temporary cable to hold the stay cable only when a load is applied, temporarily place the stay cable on the bridge body, and pull up the temporary cable The clamp is used to hold the stay cable, lift the stay cable, fix the end of the stay cable to the support and the bridge, and then remove the load acting on the clamp by tensioning the stay cable. Method of laying stay cable of cable-stayed bridge by opening connection 2. Construction of a cable-stayed bridge supporting a bridge body with a stay cable protruding from a central pillar, wherein one end of a temporary cable is attached to the upper part of the pillar so as to be liftable,
The other end is attached to the tip of the bridge body, and a number of clamps that hold the stay cable are attached to this temporary cable only when a load is applied. By pulling up the temporary cable, grasping the sheath with a clamp and lifting it up, fixing the end of the sheath to the column and bridge, then pulling a bundle of steel wires into the sheath, assembling the stay cable, and tensioning the stay cable Method of erection of stay cable of cable-stayed bridge by eliminating load acting on clamp and opening connection between temporary cable and stay cable