JP4847789B2 - Cable laying method - Google Patents

Description

  The present invention relates to a cable laying method for bundling tension members laid between fixing portions between a main girder and a main tower in an efficient work, for example, in a cable-stayed bridge cable.

  Conventionally, a cable 21 in a cable-stayed bridge, a suspension bridge, or the like is a strand led by a guide wire or the like between fixing portions 3 and 4 between a main beam 1 and a main tower 2 as shown in FIGS. 6 is inserted into the conical through-hole 20 of the anchor head 18 and fixed with a wedge 19 to be installed, and then the strand 6 is tensioned with a jack set on the fixing portion and tightened with the wedge 19, and this is a plurality of strands. It is known that all the plurality of strands 6 are collectively tightened and fixed by a jack after each is applied to 6 and brought to a uniform tension.

  The cable 21 is formed by bundling a plurality of strands 6 made of a PC steel wire or the like, covering them with a sheath protection tube (protective sheath) 10a, and preventing a gap between the bundled strands 6 and the sheath protection tube 10a. It is formed by filling grout such as rust material.

  In the cable 21, since the conical through-holes of the anchor head 18 are arranged concentrically with a required gap, if the strands laid in parallel with a gap are directly covered with a mantle protective tube, The diameter of the mantle protective tube 10a is increased. Therefore, as shown in FIG. 12 (B), the plurality of strands 6 are bundled with a clamp member 22 to reduce the diameter of the outer sheath protective tube 10b to improve workability and to fill the gap. It is necessary to reduce the amount of water used and reduce the vibration caused by wind and rain.

As a countermeasure, conventionally, in order to bundle a plurality of strands constructed and tensioned in parallel with an appropriate interval between the fixing portions of the main tower and the main girder, A cable erection method is known in which a plurality of strands are shaped into, for example, a hexagonal shape by a temporary clamp and bundled, and then bundled by a permanent clamp to form a single cable (see Patent Document 1 and Patent Document 2). ).
Japanese Patent Laid-Open No. 08-27725 JP 2000-282409 A

  However, in the conventional cable laying method, the hexagonal four sides and the two sides of the hexagonal shape are symmetrically attached to the strands that are tensioned in parallel between the fixing portions. This is a method of tightening a pair of temporary clamps consisting of clamps having ½ sides symmetrically on both sides of the cable in the radial direction of the cable with bolts, or a method of bundling by restricting the position with a stepped clamp. Temporary clamps are required in addition to the existing clamps, increasing the number of parts and increasing the cost of parts management. After the strands are shaped and the permanent clamps are attached, it is necessary to remove the temporary clamps. In contrast to the conventional erection method which requires such overlapping strand tightening work, further reduction in work man-hours and cost of parts are desired. The cable laying method according to the present invention has been proposed in order to solve such a problem.

  The gist for solving the above-mentioned problems of the cable laying method according to the present invention and achieving the object is to provide a plurality of cables on the free end opening side of the sheath tube provided for laying and fixing the strands. The cylindrical clamp material that bundles the strands is divided in half into an upper clamp and a lower clamp, and the upper clamp is fixed by a position fixing means at a position lower than the position where the strand is installed, and the upper clamp is installed. The lower clamp is disposed at an opposing position through the position fixing means, and then a strand to be accommodated in the upper clamp is passed through the inner side of the upper clamp to be laid between the fixing portions and tensioned. The remaining strand is inserted between the upper clamp and the lower clamp, and is stretched between the fixing portions to be tensioned, and then the lower clamp is connected to the upper clamp. The lower clamp and the upper strand clamped together with the remaining strand, and the lower clamp and the upper clamp are fastened together by fastening means, and then the position fixing means is removed. It is to be.

The upper clamp is provided with a guide member for pressing the strand inside the clamp;
And the upper clamp is fixed directly to the free end opening of the sheath tube via a detachable position fixing means;
Is included.

According to the cable laying method of the present invention, the cylindrical clamp material for bundling a plurality of strands is divided in half into an upper clamp and a lower clamp, and the upper clamp is fixed from the beginning to the main position. Then, by installing and tensioning the upper clamp through the strand, about half of the plurality of strands are installed at a position lower than the strand installation position, for example, at the main installation position, Since the remaining strands are bundled by the lower clamp, the operation of bundling the strands into one cable is substantially half and the construction period is shortened.
Further, since the clamp is not a temporary jig but a permanent clamp material, it is not removed after completion of the strand construction, and there is no need for component management.
Since the upper clamp has the guide member, the strand can be smoothly inserted inside the clamp when it is installed, and the insertion operation is facilitated without the strand being diffused and scattered.
Further, if the upper clamp is directly fixed to the sheath tube, the structure of the position fixing means becomes simple, the manufacturing cost is reduced, the installation work is also simplified, and the construction period is shortened.

  As shown in FIG. 1, the cable-cable erection method according to the present invention is constructed, for example, by installing an oblique cable 5 between the fixing portions 3 and 4 in the main girder 1 and the main tower 2 of the cable-stayed bridge. In the case of covering with a mantle protective tube 10, on the side of the free end opening 7a of the sheath tube 7 arranged for laying and fixing the strand 6 formed by coating a PC steel wire or the like with PE (polyethylene), A cylindrical clamp member 8 for bundling a plurality of strands 6 into a single cable is divided in half into an upper clamp 8a and a lower clamp 8b, and the upper clamp 8a is positioned at the main position by the position fixing means 9. Install securely.

  As shown in FIG. 1, together with the upper clamp 8a, the lower clamp 8b is disposed below the upper clamp 8a via the position fixing means 9 so as to be separated from the upper clamp 8a. The arrangement of the upper clamp 8a and the lower clamp 8b may be set first depending on the situation at the site.

  The clamp member 8 is made of, for example, steel and has a hexagonal cylindrical shape. As shown in FIG. 2, the clamp member 8 is divided into an upper clamp 8a and a lower clamp 8b, both of which are bolts and nuts. Are provided with flanges 8c and 8d having through holes 8e for bolts for fastening in a hexagonal cylindrical shape. The through-holes 8e are provided at three locations on the one flange 8c, two of which are used for inserting the turnbuckle 11 of the position fixing means 9, and after the turnbuckle 11 is removed, A fastening bolt is inserted.

  As shown in FIGS. 2 to 3, the position fixing means 9 is formed by welding a pair of brackets 13 to a rectangular steel fixed substrate 12 fixed to a scaffold on the main girder 1 or main tower 2 side. Standing at four places, the end 11a of the turnbuckle 11 is interposed between the pair of brackets 13 and 13, the bolts 14 are passed through the through holes 11b and the through holes of the bracket 13, and fastened with nuts 15. Configured.

  Next, in the cable laying method according to the present invention, after the upper clamp 8a and the lower clamp 8b are arranged by the position fixing means 9, the strand 6 to be accommodated in the upper clamp 8a, for example, the strand as a whole In the case where the number 6 is 37, the upper 22 strands 6 are passed through the inner side of the upper clamp 8a to be laid between the fixing portions 3 and 4 and tensioned.

  As shown in FIG. 1, the strand 6 is pulled out from a strand winding drum 16 on the main girder 1 and pushed up by a pusher 17 or the like, and from the main tower 2 side, a guide wire for messenger. Etc. (not shown).

  As a result, as shown in FIGS. 4 to 5, the upper strand 6 is stopped at the anchor head 18 in the fixing portions 3 and 4 by a wedge 19 to which a required tension is applied by a jack. When the mantle protection tube 10 is disposed between the main beam 1 and the main tower 2 in advance, the mantle protection tube 10 naturally moves downward, so Twenty-two strands 6 gather on the upper side, and the lower half of the outer tube 10 becomes a large gap 10c, which is convenient for inserting the remaining 15 strands 6.

  Therefore, as shown in FIG. 4, the remaining strand 6 is inserted between the upper clamp 8a and the lower clamp 8b, and is inserted between the left and right turnbuckles 11 and 11, and the both fixings are performed. Build between the parts 3 and 4 and tighten with a jack.

  Thereafter, as shown in FIG. 4, the four nuts 15 are rotated so as to travel substantially uniformly in a required direction, and the lower clamp 8 b is moved toward the upper clamp. The lower strand 6, for example, the remaining 15 strands 6 are gradually gathered up, down, left and right, and are shaped and packed together in the same manner as the upper strand 6.

  The remaining strand 6 is bundled with the lower clamp 8b and united with the upper clamp, and the bolts of the fastening means are inserted into the bolt through holes 8e of the flanges 8c and 8d and fastened with nuts. As a result, the lower clamp 8b and the upper clamp 8a are united to form the cylindrical clamp member 8 of the main installation. Thereafter, the position fixing means 9 is removed.

  In this way, a plurality of strands 6 are bundled with the clamp member 8 to form the diagonal cable 5, and a spacer or the like may be provided at an appropriate position in the longitudinal direction in the gap between the diagonal cable 5 and the outer tube protection tube 10. is there. Further, a damper for vibration isolation is attached to the bundled diagonal cable 5. When the outer sheath protecting tube 10 is covered after the diagonal cable 5 is installed, the outer sheath protecting tube 10 is divided in half, for example, the oblique member cable 5 is divided in half from the main girder side. The outer cover tube 10 is covered over the entire length of the diagonal cable 5 by closing it into a tubular shape by sandwiching it with the outer tube, and pushing it up while connecting it continuously from the bottom to the top. It is intended to make it. In this case, since it is not necessary to have an extra space for facilitating the cable insertion in the mantle protective tube 10, it is possible to make the tube smaller in diameter than the mantle protective tube 10 shown in FIG.

  As shown in FIG. 6, the second embodiment of the diagonal cable laying method according to the present invention is such that the upper clamp 8 a of the clamp member 8 is sheathed by a position fixing means 23 detachably attached to the sheath tube 7. In this example, the tube 7 is directly fixed to the free end opening.

  As shown in FIGS. 6 to 7, the upper clamp 8a has a mounting plate 24a at the rear end in the longitudinal direction, a reinforcing plate 24b for reinforcement at the center along the longitudinal direction, and a guide mounting at the front end in the longitudinal direction. The plates 24c are welded and integrally provided, and are formed as a steel fixed sheath upper clamp 8a.

  The mounting plate 24 a is provided with bolt through holes 24 d at four locations, and the sheath fixing type upper clamp 8 a is connected to the position fixing means 23 with bolts 29 using the screw holes 23 c provided in the position fixing means 23. Fixed. The guide mounting plate 24c is provided with a laterally long hole 24e. The position is adjusted in the horizontal direction so that it can be attached.

  As shown in FIG. 7, the position fixing means 23 is made of a semi-circular plate 23a made of steel and having a desired thickness, and a plurality of mounting holes 23d are provided in the peripheral portion at equal intervals in the circumferential direction. Bolts 25 are inserted into the mounting holes 23d, inserted into the bolt holes of the flange 7b of the sheath tube 7 and fastened with nuts 26, whereby the position fixing means 23 is detachably fixed to the upper side of the flange 7b of the sheath tube 7. To do.

  A T-shaped presser reinforcing plate 23b is erected on the plate 23a by welding so as to be orthogonal to the flat plate surface. The reinforcing plate 23b is pressed so that the sheath fixing type upper clamp 24 is pushed upward by the tension of the strand 6 so that the sheath fixing type upper clamp 8a is not deformed upward.

  The construction method of the diagonal cable 5 according to the second embodiment will be described. As shown in FIG. 7, the sheath fixing type upper clamp 8 a is attached to the position fixing means 23 by bolts 29 and fixed. As shown in FIG. 8, the position fixing means 23 to which the sheath fixing type upper clamp 8a is fixed is attached and fixed to the flange 7b on the free end opening 7a side of the sheath tube 7 with bolts 25 and nuts 26.

  As shown in FIG. 6, the lower clamp 8b is disposed under the sheath fixed type upper clamp 8a. For this purpose, four long bolts 27 are inserted into the bolt through-holes 8e of the sheath fixed upper clamp 24 integrated with the position fixing means 23, and the lower clamp 8b is inserted below the bolt 27. The bolts 27 are inserted into the bolt through holes of the flanges 8c and 8d, and the nuts 28 are attached to the bolts 27 so that the lower clamp 8b does not fall.

  Next, a plurality of upper strands 6 are inserted between the sheath-fixed upper clamp 24 and the lower clamp 8b and between the left and right bolts 27 when the sheath tube opening is viewed from the front, and fixed. Tension between sections 3 and 4 and tighten. Thereafter, as in the first embodiment, the remaining lower clamp 6 is installed and tensioned between the fixing portions.

  Thereafter, the lower clamp 8b is pushed up by rotating the nut 28, and united with the upper clamp 8a in the sheath fixed upper clamp 8a. Thereafter, the bolt is inserted into the bolt through hole 8e at the center of the flanges 8c and 8d and fastened with a nut, and the upper clamp 8a and the lower clamp 8b in the sheath fixed type upper clamp 24 are integrated. Further, all the four bolts 27 are removed, the bolts are inserted into the vacant bolt through holes 8e, and fastened with nuts. In this way, the clamp member 8 composed of the upper clamp 8a and the lower clamp 8b is firmly integrated.

  Next, the bolt 29 of the through hole 24d of the mounting plate 24a is removed from the screw hole 23c of the position fixing means 23. Thereby, the fastening state of the sheath fixing type upper clamp 8a and the position fixing means 23 is released. Further, the bolt 25 and the nut 26 that fix the position fixing means 23 to the flange 7b are removed. In this way, the position fixing means 23 is removed from the sheath tube 7.

  Thus, if the sheath fixing type upper clamp 8a is directly attached to the sheath tube 7 of the fixing portion in the main girder or main tower via the position fixing means 23 and the strand 6 is installed, the position fixing is performed. Since the means 23 is attached using the flange of the sheath tube 7, the trouble of having to attach the position fixing means by preparing an attachment hole or the like on the main girder side or the main tower side is eliminated.

  Further, in the third embodiment, as shown in FIGS. 9 to 10, the sheath fixing type upper clamp 8a is provided with a guide member 30 for pressing the strand 6 inside the clamp. The guide member 30 is made of steel and has an L-shaped cross section. As shown in FIG. 10, a bolt is inserted through the bolt through hole 30a into the guide mounting plate 24c of the sheath fixed upper clamp 8a, and is inserted into the long hole 24e of the guide mounting plate 24c, and fastened with a nut.

  The guide member 30 is mounted on the left and right sides so as to face up and down, and one side 30b of both angles is directed inward so as to face each other. Thus, when the strand 6 is installed between the fixing portions, it can be prevented from spreading outward in the left and right directions. When the lower strand 6 is bundled up by the lower clamp 8b, the work can be easily performed.

  Thus, the clamp 8 material in which the strands 6 are bundled is then covered with, for example, a conical cover projecting from the free end opening 7a of the sheath tube 7, or as shown in FIG. 7 or the like.

It is explanatory drawing which shows the outline of the construction method of the cable-stayed cable which concerns on this invention. It is a whole perspective view of the position fixing means 9 used in the construction method of the cable-stayed cable of the same invention. It is a partially enlarged view (A), (B) in the same position fixing means 9. It is explanatory drawing which shows a mode that the lower strand 6 is bundled with the lower clamp 8b, after the upper strand 6 is bundled and constructed by the upper clamp 8a. It is sectional drawing which shows the penetration state of the dense strand 6 and the scattered lower strand 6 of the strand 6 inside the mantle protective tube 10. It is explanatory drawing which shows the construction method of the diagonal cable which concerns on 2nd Example. It is explanatory drawing which shows a mode that the sheath fixed type | mold upper clamp 24 is attached to the position fixing means 23 in the 2nd Example. They are a perspective view (A) and a front view (B) of a state in which the position fixing means 23 and the sheath fixing type upper clamp 24 integrated with the sheath tube 7 are assembled. It is a disassembled perspective view which shows a mode that the guide member 30 is provided in the sheath fixed type | mold upper clamp 24 based on 3rd Example. It is a perspective view explaining a mode that guide member 30 guides strand 6 inside a clamp. It is explanatory drawing which shows the construction method of the diagonal cable which concerns on a prior art example. It is sectional drawing (A) which shows a mode that the strand 6 is fixed to the anchor head 8, and a perspective view (B) which shows a mode that the strand 6 was bundled with the clamp material 22.

Explanation of symbols

1 main digit,
2 main tower,
3, 4 fixing part,
5 Diagonal cable,
6 strands,
7 sheath tube, 7a free end opening,
8 Clamp material, 8a Upper clamp,
8b Lower clamp,
8c, 8d flange, 8e bolt through hole,
9 Position fixing means,
10 Mantle protection tube,
10a, 10b Mantle protection tube, 10c Air gap,
11 turnbuckle, 11a end,
11b through-hole,
12 Fixed substrate,
13 Bracket,
14 bolts, 15 nuts,
16 drums,
17 Pusher,
18 anchor head,
19 Wedge,
20 conical through hole,
21 cable,
23 position fixing means, 23a plate,
23b Reinforcing plate for holding, 23c Screw hole,
23d mounting hole,
24a mounting plate, 24b reinforcing plate,
24c guide mounting plate, 24d bolt through hole,
24e long hole,
25 bolts, 26 nuts,
27 bolts, 28 nuts,
29 volts,
30 Guide member, 30a Bolt through hole.

Claims (3)

At the free end opening side of the sheath tube that is installed to lay and fix the strands, the cylindrical clamp material that bundles multiple strands is divided in half into an upper clamp and a lower clamp, and the upper clamp Is fixed by a position fixing means at a position lower than the erection position of the strand,
The lower clamp is disposed via the position fixing means at a position opposed to the upper clamp,
After that, the strand to be accommodated in the upper clamp is passed through the inner side of the upper clamp, and is laid between the fixing portions to be tensioned.
The remaining strand is inserted between the upper clamp and the lower clamp and is stretched between the fixing portions and is tensioned.
Then, move the lower clamp toward the upper clamp,
Bundling the remaining strands with the lower clamp, uniting with the upper clamp and fastening the lower clamp and the upper clamp together with fastening means,
Then removing the position fixing means;
A cable-laying method characterized by the above. The upper clamp is provided with a guide member that holds the strand inside the clamp,
2. A cable laying method according to claim 1, wherein the cable is laid. The upper clamp is directly fixed to the free end opening of the sheath tube via a detachable position fixing means;
A cable laying method according to claim 1 or 2, characterized in that.

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