JPH06128908A - Tensioning anchorage device and anchorage method - Google Patents

Abstract

PURPOSE:To promote efficiency of tensioning fixed work of a cable by coating the ends of the cable covered with a sheath with a slide cylinder, fitting it to the inside of a fixed cylinder provided to an anchor head, and preventing a clash between the fixed cylinder and sheath in the case the cable is tensed. CONSTITUTION:A connecting section between a cable 2 covered with a sheath 10 and a PC steel material 3 is coated with a slide cylinder 9 and, at the same time, it is fitted to the inside of a fixed cylinder 8 fixed to an anchor head 1. After that, the PC steel material 3 projected from a through-hole 4 of the anchor head 1 is tensioned, and the cable is tensed. At the time, the slide cylinder 9 is so slid in the fixed cylinder 8 that the fixed cylinder 8 is not made to clash with the sheath 10. In addition, after the tension, the PC steel material 3 is fixed with a wedge 6 and a plate 13, and after an overhang section is cut off, it is covered with a cap 11 and is filled with rustproof oil 21. According to the constitution, tension work can be efficiently carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device and a fixing method for tensioning a cable. Furthermore, the present invention relates to a fixing device and a fixing method for fixing a bridge girder of a cable-stayed bridge and a cable supporting a bridge girder of an outer cable.

[0002]

2. Description of the Related Art A cable for supporting a bridge girder of a cable-stayed bridge is fixed to the bridge girder by a fixing device. The fixed cylinder of the fixing device protects the PC steel material from which the sheath has been peeled off, so that the fixed cylinder is in close contact with and fixed to the sheath so that rainwater and the like do not enter the fixed cylinder. The cable has a structure in which the PC steel material and the sheath do not adhere to each other so that the sheath is not pulled in when the PC steel material is pulled by the jack in the fixing operation.

[0003]

Problems to be Solved by the Invention The above-mentioned conventional device has the following problems. A cable in which the PC steel material and the sheath are in close contact cannot be used. If this tight-fitting cable is used, when the PC steel material is jacked, it will be dragged to the sheath and attempt to approach the anchor head. However, since the fixed barrel is fixed to the sheath, it prevents the sheath from approaching the anchor head. As a result, the fixed cylinder is stressed, the fixed cylinder is damaged, and the exposed PC steel material is rusted.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing device and a fixing method which can be used even in a cable having a sheath in close contact with a PC steel material.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a tension fixing device for fixing a cable covered with a sheath, an anchor head having a plurality of through holes through which PC steel material of the cable penetrates, and the anchor head. A fixed cylinder attached to the fixed cylinder and a slide cylinder that is concentric with the fixed cylinder and is slidable. The cable penetrates the fixed cylinder and the slide cylinder, and the sheath and the slide cylinder are hermetically sealed. A tension fixing device characterized in that it is fixed and an inner space constituted by the fixing cylinder and the slide cylinder is closed, and a tension fixing device having an anchor head is covered with a sheath. In a fixing method for tensioning a cable, a step of penetrating a PC steel material of a cable through a plurality of through holes formed in the anchor head, and attaching the cable to the anchor head A step of hermetically fixing a slide cylinder that is slidable in close contact with the fixed cylinder to the sheath, and a step of pulling a PC steel material penetrating the anchor head with a jack to tension the cable, The fixing method is characterized in that the slide cylinder slides with respect to the fixed cylinder as the sheath moves due to the tension, approaches the anchor head, and unnecessary stress is not applied to the sheath.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. The configuration of the tension fixing device is shown in FIG. In order to support bridge girders of cable-stayed bridges and bridge girders of outer cables, many diagonal cables are stretched from the main tower to the left and right. One end of the diagonal cable is fixed to the bridge girder by a tension fixing device. FIG. 1 shows a detailed view of the tension fixing device.

<A> Anchor head The anchor head 1 is screwed by a ring nut 20 fixed to the support plate 7. The anchor head 1 fixes the PC steel material 3 of the cable 2. Therefore, the through holes 4 for penetrating the PC steel materials 3 are provided by the number of the PC steel materials 3. Each PC steel material 3 is penetrated through each through hole 4 and fixed to the anchor head 1 by a wedge 6.
A plate 13 is provided to prevent the wedge 6 from coming off. A protective cap 11 is attached to the anchor head 1 to protect the end of the PC steel material 3. An oil inlet / exhaust port 12 is provided in order to fill the protective cap with rust preventive oil 21.

<B> Fixed Cylinder and Slide Cylinder The fixed cylinder 8 and the slide cylinder 9 protect the PC steel material 3 exposed from the sheath 10 of the cable 2 from rust and the like. The fixed barrel 8 is fixed to the anchor head 1 and is concentric with the slide barrel 9 to form a double barrel. Slide cylinder 9
Is slidable and in close contact with the fixed barrel 8, and is configured so that the rust preventive oil 21 does not leak. In detail, the fixed barrel 8 is provided at one end of the fixed barrel 8, so that the fixed barrel 8 is brought into close contact with the slide barrel 9. Further, a fastening ring 14 is provided at the end of the slide cylinder 9, so that when the PC steel material 3 is attached to the anchor head 1, the PC steel material is prevented from being broken even if the PC steel material 3 is expanded. The spread of 9 is suppressed. Further, at the end of the slide cylinder 9, the exposed PC steel material 3
It is fixed so as to be in close contact with the sheath 10 so that rainwater and the like do not enter. A space covered with the anchor head 1, the fixed cylinder 8, the slide cylinder 9 and the protective cap 11 is filled with rust preventive oil 21. As a result, PC steel 3 is sheath 1
The portion exposed from 0 is protected by rust preventive oil 21.

<C> Casing and boot In order to protect the fixed cylinder 5 and the slide cylinder 9, a casing 24 and a boot 23 are provided so as to cover them. The casing 24 is attached to the anchor head 1 via the support plate 7, and the boot 23 is attached to the end of the casing 24 and the sheath 10.

A method of tensioning and fixing the cable 2 will be described with reference to FIG. <A> Fixation of tip of PC steel material The PC steel material 3 that has passed through the through hole 4 of the anchor head 1 is fixed to the through hole 4 by the wedge 6. Further, the PC steel material 3 penetrating the anchor head is fixed to the pulling head 16 via the center hole jack 15. The fixing method to the pulling head 16 is that the pulling head 16 is provided with holes corresponding to the number of PC steel materials, the PC steel materials are penetrated, and then the wedge 1
Insert 7 into each hole and fix. The center hole jack 15 is fixed to the support plate 7 by a jack chair 26.

<B> Tension of PC steel material by jack Oil is injected into one of the oil injection and discharge ports 25 to apply hydraulic pressure to the jack 15 to extend the piston 18. As a result, the cylinder 19 pushes the anchor head 1, while the piston pushes the pulling head 16. Therefore, PC steel 3
Is tensioned, with which the sheath 10 is pulled towards the anchor head 1. Since the wedge 6 is arranged in the through hole 4 of the anchor head 1 in the direction of loosening, the PC steel material 3
Is easily strained. The slide cylinder 9 fixed to the sheath 10 slides toward the anchor head 1 as the sheath 10 moves. Therefore, the exposed PC steel material 3 is always in a sealed state, and no stress is applied to the sheath 10.

<C> Attaching the protective cap After the tension of the PC steel material 3 is finished, the center hole jack 15 is removed, and the PC steel material is cut leaving a predetermined length. A protection cap 11 is attached to the anchor head 1 so as to cover the PC steel material 3. The rust preventive oil 21 is filled from the oil injection / exhaust port 12 of the protective cap 11 to fill the fixed cylinder 8, the slide cylinder 9 and the protective cap 11 with the oil 21.

[0013]

Since the present invention is as described above, the following special effects can be obtained. Cable P
Since the cylinder that shields the C steel from the outside is doubled and slidable, it can be used even for a cable in which the PC steel and the sheath are in close contact with each other, and a special effect such as rust prevention of the PC steel is produced.

[Brief description of drawings]

FIG. 1 Diagram of tension fixing device

[Figure 2] Diagram of tensioning the cable

Claims (2)

[Claims] 1. A tension fixing device for fixing a cable covered with a sheath, an anchor head having a plurality of through holes through which PC steel material of the cable penetrates, a fixing cylinder attached to the anchor head, and the fixing. A slide cylinder that is concentric with the cylinder and is slidable, and a cable penetrates the inside of the fixed cylinder and the slide cylinder, the sheath and the slide cylinder are hermetically fixed, and the fixed cylinder and the slide cylinder A fixing device for tension, characterized in that an internal space formed by a cylinder is sealed. 2. A fixing method for tensioning a cable covered with a sheath by using a tension fixing device having an anchor head, wherein a PC steel material of the cable is penetrated through a plurality of through holes formed in the anchor head. And a step of hermetically fixing a slide cylinder, which is slidable in close contact with a fixed cylinder attached to the anchor head, to the sheath, and a PC steel material penetrating the anchor head is jacked to tighten the cable. And a step of causing the tension to move, whereby the slide cylinder slides with respect to the fixed cylinder with the movement of the sheath, approaches the anchor head, and unnecessary stress is not applied to the sheath.