JPH07189213A - Suspension method of diagonal cable - Google Patents

Abstract

PURPOSE:To improve the workability of suspension work of strands and at the same time the loading balance of the tension against the main tower, regarding the suspension method of diagonal cables in a diagonal tension bridge. CONSTITUTION:In a suspension method of diagonal cables to symmetrically suspend the diagonal cables between both anchorage bodies 3, 4 at least at two positions of both sides of the main tower and tense and fix them there, guide wires 26 provided with a required number of hanging rings 25 are arranged so as to make a pair at the same suspension level at least in one side of the main tower. A winding-up wire 28 inserted in the hanging rings 25 of a pair of guide wires 26, 26 and endlessly wound by a drive means so as to be freely rotatable is provided to hold the ends of respective strands with the winding-up wires 28. The winding-up wires are rotated by the drive means to suspend a required number of strands 6 in turn between both anchorage bodies 3, 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a diagonal cable which is tensioned between a main tower and a main girder of a cable-stayed bridge.

[0002]

2. Description of the Related Art Conventionally, as a method of constructing a cable of a cable-stayed bridge, the first method of first constructing a protective tube of the cable of the diagonal cable and then inserting each strand, and vice versa. In addition, a second method is known in which each strand that has been previously subjected to anticorrosion treatment is installed in advance and tensioned, and then a protective tube is covered.

The first method will be described with reference to FIG.
As shown in (A) to (D), the fixing members 3 and 4 are assembled on the main tower 1 side and the main girder 2 side, respectively. Then, on the bridge surface, a cylindrical protective tube 5 made of synthetic resin is connected to a predetermined length necessary for erection between the main tower 1 and the main girder 2.

Next, one strand 6 is paid out from the drum 7, and its tip is passed through a fixing device (not shown) of the fixing member 3 of the main tower 1 and further inserted into the protective tube 5 to make the main girder. It is fixed to the fixing body 4 on the second side. Then, one end of a wire 10 wound around a winch 8 and a pulley 9 provided on the upper part of the main tower 1 side is connected to the tip of the protection tube.

Then, the wire 10 is wound up by the winch 8 to bridge the protective tube 5 and the strand 6 between the fixing bodies 3 and 4. At the same time, the drum 7 is wound so as to remove the slack of the strand 6. Then, after fixing the strand 6 on the main tower 1 side with a tapered wedge in the anchor head of the fixing body 3, marking is performed in order to manage the length after tension to secure a required protruding length. And disconnect.

Next, as shown in FIG. 4B, the monostrand jack 11 is attached to the fixing body 3 side, and the first strand 6 is tensioned with a predetermined tension. Further, the tip of the protective tube 5 is temporarily fixed to the main tower 1 side with a wire 12.

Then, as shown in FIG. 4C, in the same manner as described above, the second and subsequent strands are inserted into a protective tube and are erected between the fixing members 3 and 4, and each strand is also marked. Then, the length is controlled by the mono-strand jack 11 so as to match the marking position of the first strand, and the tension is set to the same tension.

Next, as shown in FIG. 4D, the protective tube 5
After inserting and erection the required number of strands 6 into the main tower 1,
The center hole type jack 13 is attached to the fixing member 3 on the side, and the one diagonal member is collectively tensioned to adjust to a predetermined tension.

After that, connection processing is performed at both ends of the protection tube 5 on the main tower side and the main girder side, and cement grout or the like is injected into the protection tube 5. In this way, the diagonal cable is installed.

Next, the second method will be described with reference to FIG.
As shown in (1), first, the strands 14 which are poly-coated on the girder by a treatment method such as galvanizing and anticorrosion-treated are cut into a predetermined length necessary for installation.

Next, as shown in FIG. 5B, a guide wire 15 is erected between the fixing members on the main tower 1 side and the main girder 2 side, and is suspended by the guide wire 15 at a predetermined interval. The pulleys 16, 17, 1 are inserted into the respective rings 15a.
The winding wire 20 is wound around the drive pulley of the double-acting winch 19 and wound into a substantially triangular draw wire 20.

Then, as shown in FIG. 5C, the tip of the strand 14 is connected to the pull-in wire 20, and the pull-in wire 20 is connected to the double-action winch 19.
To drive the strand 14 to rotate the ring 15
The strand 14 is erected while being pulled up to the fixing body on the side of the main tower 1 while being inserted into a.

Such erection work is repeated and erected for each required number of strands 14 by rotationally driving the double-action winch 19 and circulating movement of the pull-in wire 20. Then, each strand 14 is tensioned with a mono-strand jack.

Next, as shown in FIG. 5 (d), bundled clamps 21 are provided at both ends of the diagonal cable after tensioning the required number of strands 14 to eliminate the radial gaps between the strands and integrate them. Turn into.

Then, as shown in FIG. 5 (e), the main girder 2
Attach the protective tube mounting device 22 on the fixing body 4 side of
The diagonal cable is covered with a protective tube 23 divided into upper and lower parts of a predetermined length, and the diagonal cables are pushed up from the bottom to be connected continuously. As shown in FIG. Two
3 is attached and the installation of the monoclinic cable is completed. The same operation is performed for each diagonal cable.

[0016]

However, in the above-mentioned first and second erection methods, there is a problem in workability of erection of each strand. That is, there are a total of four diagonal cables installed on both the main tower side and the main girder side, two at each of the left and right sides of the main tower in the drawing, and a strand is installed at each installed location. Because it is done, the workability is poor,
In addition, it has been troublesome to replace the erection equipment with the next erection location. Further, when the strands installed at one place are tensioned with a jack, there is a problem that the load balance of the tension force on the main tower is poor because the strands are not installed symmetrically across the main tower.

The present invention has been made in view of the above problems, and provides a method for constructing a diagonal cable, which improves the workability of the work for constructing a strand and at the same time improves the load balance of the tension force on the main tower. The purpose is to

[0018]

The gist of the method for constructing a diagonal cable according to the present invention to solve the above-mentioned problems and achieve the above-mentioned object is between the main tower and both fixing members provided on the main girder. A diagonal cable consisting of the required number of strands is installed symmetrically at least at two points on each side of the main tower, and tension
In the method of erection of a diagonal cable to be fixed, a pair of guide wires provided with a required number of suspension rings are installed side by side at the same level of the erected portion on at least one side of the main tower, and the pair of guide wire suspension rings are provided. A pull-in wire that is endlessly wound around and rotatably driven by drive means is disposed, the ends of each strand are held by the pull-in wire, and the pull-in wire is rotated by the drive means to rotate the pull-in wire. That is, the required number of the strands are sequentially installed between both fixing bodies.

Further, in order to improve workability, the pull-in wire is normally or reversely rotated, and the strands are alternately inserted through the suspension ring of the guide wire provided in pairs, and the suspension wire is installed. In order to balance the tensile force with respect to the main tower during the tensioning work of the strands, each of the strands installed between the two fixing bodies is to be symmetrically tensioned with the main tower interposed therebetween. In order to improve the work efficiency of the erection work of the strand, each of the pair of guide wires is equipped with a strand drum around which the supplied strand is wound, and further, the construction period at the erection work site can be shortened. Therefore, the strand drum is to be wound with a strand having a length substantially corresponding to the length to be installed.

[0020]

According to the method for constructing the diagonal cable of the present invention, the strand is pulled into the pulling wire by rotating the pulling wire which is inserted into the hanging ring of the guide wire which is paired and is wound endlessly. The wire is pulled up and laid between the main tower and the fixing member of the main girder, and the strands can be laid continuously on the pair of guide wires by rotating the lead wire in the forward and reverse directions. By tensioning each strand laid between both fixings symmetrically with respect to the main tower, tension work can be performed in a balanced manner without imposing a biased load on the main tower. Further, by disposing the strand drum on each of the pair of guide wires, the workability of the work of holding the end portion of the strand by the pull-in wire is improved. Further, since the strand having the length required for the erection is wound around the strand drum, the work of cutting the strand at each erection work site is eliminated, and the construction period is shortened.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment according to the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall perspective view of an embodiment of a method for constructing a diagonal cable according to the present invention. 2 to 3 are enlarged detail views of the fixing portion. For ease of understanding, the portions corresponding to those in the conventional example will be described with the same reference numerals.

The method of constructing a diagonal cable according to the present invention is one main cable comprising a required number of strands between both fixing members 3 and 4 provided on the main tower 1 and the main girder 2 of the cable-stayed bridge. In the method of constructing the diagonal cable, which is installed symmetrically at least at two locations on each side of the tower, tensioning and fixing the diagonal cable,
Guide wire 26 provided with the required number of suspension rings 25
At least on one side of the main tower 1 as a pair at the same level of the erection site, and the pair of guide wires 26,
A pulling wire 28, which is inserted into the suspension ring 25 of 26 and wound endlessly and is rotatable by a driving means such as an electric winch 27, is arranged to hold the end of each strand 6 on the pulling wire 28. The pulling wire 28 is rotated by the driving means so that the required number of the strands 6 are sequentially installed between the both fixing bodies 3 and 4.

The guide wires 26 are installed in advance in the vicinity of a diagonal cable which is installed in pairs at two positions on the both sides of the main tower 1 at the same level. Further, a suspension ring 25 made of metal or synthetic resin is suspended from the guide wire 26 at appropriate intervals.

The pull-in wire 28 which is inserted into the suspension ring 25 and wound endlessly is composed of the main girder 2 side and the main tower 1.
Side at least four pulleys 29 rotatably arranged
An electric winch 27 which is made rotatable by a, 29b, 29c, 29d and has a part of wire wound around it.
It is designed to be driven to rotate by.

Strand drums 30a, 30b, around which the strands 6 supplied for erection are wound, are arranged on the pair of guide wires 26, 26.
The guide pipes 31a and 31b are inserted into and guided by the strand pulleys 32a and 32b.

Then, the strand drums 30a, 3
One end portion of the strand 6 fed from 0b is held by the guide wires 26, 26 by a wire clip 33.

Thus, both the fixing members 3 of the main tower 1 and the main girders 3,
In order to construct a pair of diagonal cables at the same level between the four, on both sides with the main tower 1 in between, when viewing the main tower 1 from the front, the back side is A, C, the front side is B, As D, the guide wires 26 are erected at the erected positions of A, B, C, and D, and the pull-in wires 28 are inserted into the suspension ring 25 and wound endlessly. Note that FIG. 1 shows a state in which the main tower 1 is provided only on one side for convenience.

Next, in A and C on the back side, the strand 6 is pulled out from the strand drum 30a through the guide pipe 31a and the strand pulley 32a, and one end of the strand 6 is drawn in by the wire clip 33 and the wire 28 is drawn.
To hold.

After this, the electric winch 27 is driven to circulate the guide wire 28 in the direction of arrow a. Then, the drive of the electric winch 27 is stopped when one end of the strand 6 reaches the vicinity of the fixing body 3.

Next, as shown in FIG. 2, the end portion of the pilot wire 36 inserted into the sheath tube 34 of the fixing member 3 from the anchor head 35 side is connected to one end portion of the strand 6 by a clip 33a, The other end of the pilot wire 36 is pulled by a jack or the like, the strand 6 is inserted into the sheath tube 34 of the fixing body 3, and is assumedly attached by the wedge 37 of the anchor head 35.

Then, the engagement between the pilot wire 36 and the strand 6 is released, and the wire clip 33 is removed to release the engagement between the strand 6 and the pull-in wire 28.

Thus, after the post-fixing work on the fixing body 3 of the main tower 1 or simultaneously, on the fixing body 4 side of the main girder 2, as shown in FIG. 3, the strand 6 drawn out from the strand drum 30a and pulled up. The other end is cut with a proper length secured for tensioning work, and is connected to one end of the pilot wire 36 inserted into the sheath tube 34 from the anchor head 35 side of the fixing body 4 with a clip 33a.

Then, the other end of the pilot wire 36 is pulled by a jack or the like, the strand 6 is inserted into the sheath tube 34 of the fixing member 4, and the anchor 37 is assumedly attached by the wedge 37. Then, the pilot wire 36 is disengaged from the other end of the strand.

In this way, one strand 6 is erected between the fixing members 3 and 4 at the erection points of A and C, and then, as shown in FIG.
As shown in FIG. 3, the strand 6 is pulled out from the strand drum 30b through the guide pipe 31b and the strand pulley 32b, and one end of the strand 6 is pulled in by the wire clip 33 as shown in FIG.
Hold at 8.

Then, the electric winch 27 is rotated in the opposite direction to that at the time of erection described above, and the pulling wire 28 is circulated in the direction of the arrow b. Strands 6 are installed between both fixing bodies 3 and 4 in the same manner as described above. At the same time, the wire clip 33 located near the fixing body 3 at the installation location of A and C descends toward the fixing body 4 side of the main girder 2.

In this way, the electric winch 27 is rotated in the forward / reverse direction and the pull-in wire 28 is alternately circulated in the directions a and b to repeat the erection work, and on both sides of the main tower 1, a pair of wires of the same level are installed. The strands 6 can be continuously installed alternately at the erected portions of A, C and B, D so that the strands 6 can be continuously pulled up.

Next, after a required number of strands 6 are installed between the fixing members 3 and 4 at the installation positions of A, B, C and D, both ends of each strand 6 are monostrand jacks (not shown). Then, apply a predetermined tension to temporarily tension. Then, the variation in the tension force of each strand 6 is adjusted.
In order to apply this tension, tension work is performed symmetrically with the main tower 1 in between, and the tension work is balanced.

Then, a bundling clamp is attached near the outlet side (the side facing each other) of the sheath tubes 34 of the fixing bodies 3 and 4, whereby a required number of strands 6 are brought into contact in the radial direction to form one bundle. The above-mentioned bundled clamp is fitted into the sheath tube by hammering it into the outlet end of the sheath tube with a vibration-proof rubber or the like interposed therebetween.

Then, a bisected protective cover is coated on the diagonal cable from the main girder side, and construction is performed such that the diagonal cable is pushed up in order to cover the entire diagonal cable with the protective cover.

Thus, when the erection work at the erection points of A, B, C, D of the same level on both sides of the main tower 1 is completed, the erection work of the next level is started, and from the lower side to the upper side. And the erection work is performed by the same erection method as above.

In the erection method according to the present invention, the strand 6 wound around the strand drums 30a and 30b is cut at a length substantially corresponding to the erection length, and one or a plurality of pieces are pre-wound. Eliminating the work of cutting the strand on site, or marking at the required length and winding it and cutting it when the mark comes out at the time of erection, erection work Can be done more efficiently.

[0042]

As described above, the method for constructing the diagonal cable according to the present invention is the method of constructing the diagonal cable comprising the required number of strands between the main tower and both fixing members provided on the main girder. In a method of constructing a diagonal cable in which at least two portions are symmetrically erected on both sides of the sandwiching cable and tensioned and fixed, a guide wire having a required number of suspension rings is provided at least on one side of the main tower at the same erection location A pull-in wire which is installed side by side on a level and which is inserted through the pair of suspension rings of the guide wires and wound endlessly so as to be rotatable by a driving means is arranged, and the end of each strand is connected to the pull-in wire. Since the pulling wire is rotated by the driving means to sequentially lay the required number of the strands between the both fixing bodies, the strands are alternately installed at a pair of laying locations at the same level. It is possible to erected the toland and the erection work is continuous to improve the work efficiency, and only one drive device is required to circulate the pull-in wire endlessly. It has an excellent effect that it does not take.

Further, the strands can be continuously erected by rotating the pull-in wire in the normal direction and in the reverse direction so that the strands are alternately inserted into the suspension rings of the guide wires that are provided as a pair and laid alternately. As a result, the work efficiency is improved, and moreover, there is an excellent effect that a balanced tension work is achieved by tensioning each strand laid between both fixing bodies symmetrically with the main tower in between.

Then, for each of the pair of guide wires,
Equipped with a strand drum around which the supplied strands are wound, the work of pulling the strands and holding them on the wire can be performed independently, which improves work efficiency. By wrapping a strand with a length that roughly corresponds to the expected length, it is not necessary to do the strand cutting work on site, shortening the construction period and improving work safety. Produce the effect.

[Brief description of drawings]

FIG. 1 is an overall perspective view of an embodiment of a method for constructing a diagonal cable according to the present invention.

FIG. 2 is an enlarged vertical sectional view of a fixing member portion on the main tower side.

FIG. 3 is an enlarged vertical sectional view of a fixing member portion on a main girder side.

FIG. 4 is an explanatory diagram of a first erection method of strands according to a conventional example.

FIG. 5 is an explanatory diagram of a second erection method of strands according to the conventional example.

[Explanation of symbols]

 1 main tower, 2 main girder, 3, 4 fixing body, 25 suspension ring, 26 guide wire, 27 electric winch, 28 pull-in wire, 29a, 29b, 29c, 29d pulley, 30a, 30b strand drum, 31a, 31b guide Pipes, 32a, 32b Strand pulleys, 33 Wire clips, 34 Sheath tubes, 35 Anchor heads, 36 Pilot wires, 37 Wedges.

Claims (5)

[Claims] 1. A tension cable is constructed by symmetrically arranging a diagonal cable composed of a required number of strands between at least two fixing members provided on a main tower and a main girder on both sides of the main tower.
In the method of erection of a diagonal cable to be fixed, a pair of guide wires provided with a required number of suspension rings are installed side by side at the same level of the erected portion on at least one side of the main tower, and the pair of guide wire suspension rings are provided. A pull-in wire that is endlessly wound around and rotatably driven by drive means is disposed, the ends of each strand are held by the pull-in wire, and the pull-in wire is rotated by the drive means to rotate the pull-in wire. A method of constructing a diagonal cable, characterized in that a required number of the strands are sequentially constructed between both fixing bodies. 2. A normal / reverse rotation of the pull-in wire,
The method of constructing a diagonal cable according to claim 1, wherein the strands are alternately inserted into the suspension rings of the guide wires that are provided as a pair and are installed alternately. 3. The method for laying a diagonal cable according to claim 1, wherein each of the strands laid between the two fixing members is tensioned symmetrically with respect to the main tower. 4. The method for constructing a diagonal cable according to claim 1, wherein each of the pair of guide wires is equipped with a strand drum around which a supplied strand is wound. 5. The method for laying a diagonal cable according to claim 4, wherein the strand drum is wound with a strand having a length substantially corresponding to a length to be laid.