JP2810853B2 - How to install diagonal cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laying a diagonal cable used for a structure such as a cable-stayed bridge or a suspension bridge.

[0002]

2. Description of the Related Art Conventionally, for example, it is necessary to tension and bridge a cable 1 of a cable-stayed bridge as shown in FIG. 2 between a fixing portion of a main tower 2 and a main girder 3 with a required tension. As shown in FIG. 3, for example, the anchor head 2 in the anchoring section on the main tower side
The strand 1a is sent out from the through hole a and supplied from the drum by an apparatus or the like and sent out to the main girder side.

In the fixing section on the main girder side, the strand exposed by peeling off the PE coating of the strand 1a is connected to a through hole of the anchor head 3a by a guide rod or the like and inserted while being guided, and is divided into two parts. Wedge 4a,
4b is inserted into the through hole and fixed.

On the other hand, on the main tower side, the strand 1a is cut at an appropriate place, the PE coating is peeled off from the cut surface by a required length to expose the strand, and the wedge 4a is removed.
a, 4b are inserted into the through holes of the anchor head 2a, and the strand is gripped to fix the strand 1a.

[0005] Thereafter, a center hole type jack 5 is set in the fixing section, and each strand 1a is tensioned. The amount of tension is determined by the amount of extension of the jack 5, and the amount of tension of each strand 1a is made uniform. Thereafter, the anchor head 2a is pulled by a large jack, and the fixing nut is tightened by an amount corresponding to the movement, so that all the strands 1a are collectively pulled by a predetermined amount, and final tension and fixing are performed.

[0006] Then, all the strands 1a are bundled together by a clamp or the like, and this is covered with a rust-preventive mantle protection tube made of synthetic resin or the like over the entire length, and an oblique portion is provided between the main tower and the fixing portion of the main girder. The material cable 1 is erected.

[0007]

However, the tension amount of each of the strands 1a is different from each other because the tension state when the strands are erected between the fixing portions of the main tower and the main girder is actually different. Even if each of the 19 strands 1a is jacked and then the entire strand is pulled, each strand 1a
The amount of tension was not the same, and it could not be said that it was an ideal erection state. Also, even if a mark or the like is attached to the end of the strand and fixing is performed based on this mark, it is difficult and time-consuming to actually align the marks of many strands and fix the fixing device. there were.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a method for laying a diagonal cable in which a plurality of strands have the same amount of tension and which can be easily tensioned. I do.

[0009]

The gist of the present invention to solve the above-mentioned problems and to achieve the above-mentioned object is to form both ends of a plurality of strands made of PC steel wire or PC steel wire into a main girder side and a main tower. In the method of laying a diagonal cable, which is installed between the two fixing sections on the side, and is fixed by tensioning each strand with a required tension by a pulling means, the respective strands are trimmed to a predetermined length and the two fixing sections are fixed. In this case, each strand is tensioned and fixed by tension means so that the sum of the amounts of protrusion from both fixing portions at both ends of each strand is equal.

[0010]

According to the method for laying a diagonal cable according to the present invention, the sum of the lengths of the strands protruding from both anchoring portions of the main tower and the main girder is equal, so that a plurality of ( For example, the tension applied to (19) strands becomes equal.

Therefore, when each of the strands of the single-cable cable is tensioned by the jack, for example, even if the projecting amount of the strand from the fixing portion on the main girder side is different for each strand, the fixing portion on the main tower side. By adjusting each so that the output of the strands becomes equal in total, a uniform tension can be applied. In this way, it is possible to easily perform the tensioning work without taking the trouble of making the marks or the like on the strands to equalize the tension.

[0012]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. Parts corresponding to those of the conventional example will be described with the same reference numerals.

In the method for laying a diagonal cable according to the present invention, first, as shown in FIG. 1, 19 strands 1a, 1b,... The required length between the fixing sections 2a, 3a on the main tower side and the main girder side is trimmed to a required length.

Then, each of the trimmed strands 1a, 1
Each of a total of 19 b,... is wound around a drum.

The drum is carried on a main girder at the site, and the strand is sent out from the drum and a delivery device to a fixing section on the main tower side via a scaffold of the main tower.

Next, the anchor head 2 in the fixing section on the main tower side
a, the strand 1a is passed through the through hole and sent out to the fixing section on the main girder side. On the main girder side, if there is a PE coating portion on the fed strand 1a, the work of peeling this coating portion within a required range is performed.

Then, the tip of the strand 1a is fixed to the anchor head 3a by the wedges 4a and 4b by being inserted into the through hole of the anchor head 3a in the fixing portion on the main girder side using a guide block or the like. In this case, the projecting amount L1 of the tip of the strand from the fixing unit does not need to be set to a fixed length. What is necessary is just to be approximately the length visually, and it can be set roughly.

On the other hand, also in the fixing section on the side of the main tower, if there is a coating section made of PE, this coating section is peeled off in a required range,
Strand 1 on anchor head 2a with wedges 4a and 4b
a is fixed.

The remaining strands 1b, 1c,
Are installed between the fixing sections on the main tower side and the main girder side in the same manner as above.

Next, in the fixing section on the main tower side, the strands are sequentially tightened by jacks. The amount of protrusion L1 of the tip of the strand in the fixing section on the main girder side differs for each strand. The total value k = L1 of the protrusion amount L2 and the protrusion amount L1 in the fixing section on the main tower side.
Each of the strands is jacked with the amount of protrusion L2 so that + L2 becomes constant.

Each of the 19 strands 1a, 1b, 1
With respect to c,..., the total length k of the protrusions is kept constant as described above, so that the entire length of the strand is the same at L, so that both the main tower side and the main girder side are fixed. The length L3 of each strand between the parts is L3 = Lk, and consequently all the strands have the same length.

Therefore, the tension between the two fixing portions of the nineteen strands becomes equal. Thereafter, the anchor head 2a is pulled by a predetermined amount by a large jack, and all the strands are tensioned and fixed by the fixing nut.

Then, the 19 strands are bundled to cover the outer jacket protection tube over the entire length, and a rust preventive or the like is grouted in the outer jacket protection tube. In this way, the installation of the one-cable cable is completed.

[0024]

As described above, according to the method for laying a diagonal cable according to the present invention, both ends of a plurality of strands composed of PC steel wires or PC steel strands are fixed to both the main girder side and the main tower side. In the method of laying a diagonal cable, which is laid between the fixing portions, and each strand is tensioned with a required tension by a tensioning means and fixed, the respective strands are trimmed to a predetermined length and laid between the fixing portions. Then, the respective strands are tensioned and fixed by the pulling means so that the sum of the protruding amounts from both fixing portions at both ends of the respective strands is equal, so that the protruding amount of each strand at one fixing portion is Can be set roughly without having to set a constant value, which facilitates the work, shortens the construction period, and has an excellent effect of ensuring the certainty in setting the tension of each strand uniformly.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a erection method according to the present invention.

FIG. 2 is an explanatory diagram of a method of erection of a diagonal cable of a cable stayed bridge according to a conventional example.

FIG. 3 is an explanatory diagram of a method of erection of a diagonal cable according to the conventional example.

[Explanation of symbols]

 1 diagonal cable, 1a, 1b, 1c strand, 2 main tower, 2a anchor head on main tower side, 3 main girder, 3a anchor head on main girder side, 4a, 4b wedge, L1, L2 Strand from anchoring section Projection length, L Total length of strand.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Wataru Ohashi 12th, Nibancho, Chiyoda-ku, Tokyo SAI Co., Ltd. (72) Inventor Hiroshi Kibe 12th, Nibancho, Chiyoda-ku, Tokyo Sui Co., Ltd. (72 ) Inventor Masamitsu Takei 1-Shinhama-cho, Chuo-ku, Chiba-city, Chiba Pref. In the Kawatetsu Technowire Co., Ltd. Kimio Kimio, 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Corporation, Tokyo Head Office (72) Inventor Toshikuni Sakayoshi 2-3-2, Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Corporation, Tokyo Main Office (72) Inventor Shigeki Nakamura 2-3-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo Kawasaki Steel Corporation Tokyo Head Office (58) Fields surveyed (Int. Cl. ⁶ , (DB name) E01D 11/04 E01D 21/00

Claims (1)

(57) [Claims] 1. Both ends of a plurality of strands made of a PC steel wire or a PC steel strand are bridged between both fixing portions on a main girder side and a main tower side, and each strand is tensioned by a tension means at a required tension. In the method of laying a diagonal cable that is fixed by being tensioned, the respective strands are trimmed to a predetermined length and laid between the two fixing portions, and the projecting amount of both ends of each strand from the both fixing portions is determined. A method for laying a diagonal cable, wherein each of the strands is tensioned and fixed by a tension means so that the sum becomes equal.