JP4277019B2 - Cable routing method in deflection section - Google Patents

Description

  The present invention relates to a cable wiring method in a deflection section.

In recent years, as shown in FIGS. 9 to 11, an outer cable 20 that enables inspection and replacement of cables is wired on the outer surface of a PC girder bridge 21 or the like. In order to convert it into a lifting load, the through hole 23 was filled with a filler 24 after being inserted into the through hole 23 of the deflecting portion 22 and being tensioned with a predetermined tension force. FIG. 10 shows the outer cable 20 using the PC steel wire 25 not covered with the sheath 27, and FIG. 11 shows the outer cable 20 using the PC steel wire 25 covered with the sheath 27. Further, as other external cable wiring methods in the deflection section, there are, for example, the inventions of Japanese Patent Application Laid-Open Nos. 10-148277 and 2005-207218.
JP-A-10-148277 JP-A-2005-207218

  However, since the external cable wiring method as described above has filled the through hole 23 with the filler 24 after the external cable 20 is tensioned, the PC steel wires 25 constituting the external cable 20 come into contact with each other. However, there is a problem that a fretting phenomenon occurs because the wiring is biased to the upper side of the through hole 23 and contacts the hole wall 26. Further, even when a spacer is used as in the invention of JP-A-10-148277, the filler is filled in the through-hole after tensioning the outer cable, so the sheath may be crushed and the function of unbonding may be lost. Moreover, the synthetic resin film of the PC steel stranded wire was also crushed by the abdominal pressure, and there was a possibility that the rust prevention effect would be reduced.

  The present invention has been made in view of the above problems, and its purpose is to prevent the occurrence of fretting phenomenon, to prevent the cable centroid from deviating from the design centroid, and to crush the sheath and the synthetic resin coating. It is an object of the present invention to provide a cable wiring method in a deflecting unit that can prevent the occurrence of the cable.

In order to solve the above problems, the cable wiring method in the deflection unit is an internal intubation in which only one PC steel wire can be inserted into the through hole of the deflection unit for deflecting the cable disposed on the outer surface of the structure. After inserting and wiring the PC steel wire covered with the sheath for each of these intubations, each of the intubation tubes is filled with a filler, and after the filler is cured, It is characterized by tension. Moreover, before PC steel wire is wired or before the inner intubation is installed, it includes fitting the outer intubation into the through hole.

  By tensioning the PC steel wire after the filler is cured, the cable can be routed to the center position of the through hole, and the cable centroid and the design centroid can be matched. Moreover, since the PC steel wires do not come into contact with each other even when abdominal pressure due to tension acts on the cable, the fretting phenomenon can be prevented. Further, since the sheath and the synthetic resin coating can be prevented from being crushed, the fatigue strength of the cable can be increased, and the deterioration of the rust prevention effect can be prevented. Moreover, since the existing external cable can be removed for each internal intubation, the external cable can be easily replaced. Moreover, since the PC steel wire was penetrated and wired in the intubation tube into which only one PC steel wire can be inserted, the PC steel wires can be exchanged one by one. Moreover, since the cross-sectional defect | deletion of a deflection | deviation part can be supplemented with the filler with which the internal intubation was filled, the fall of the intensity | strength of a deflection | deviation part can be prevented. Moreover, the cover body which covered the opening part of the both sides of an intubation plays a role as a spacer which ensures the arrangement | sequence of PC steel wire. Further, the through hole is protected by an external insertion tube fitted into the inner surface of the through hole.

  Embodiments of a cable wiring method (hereinafter referred to as a wiring method) in the deflection unit of the present invention will be described below with reference to the drawings. In this case, the cable is an external cable of a PC girder bridge or a cable stayed cable of a cable-stayed bridge (hereinafter referred to as an outer cable), and is used for a deflection part such as a PC girder bridge or a cable-stayed bridge. In the embodiment, the outer cable wired to the deflection part of the PC girder bridge will be described. In the embodiments, the same components are described with the same reference numerals, and only different components are described with different reference numerals.

  FIG. 1 shows a wiring method according to the first embodiment. This wiring method is shown in (1) of FIG. 1 in order to convert the tension of the outer cable 1 into an eccentric load (lifting load). As shown, the outer cable 1 is inserted into the through hole 5 of the deflecting portion 4 in the cross beam 3 of the PC girder bridge 2.

  The outer cable 1 used in this wiring method is configured by, for example, seven PC steel wires 6 being bundled into one, and each PC steel wire 6 has a core wire 7 as shown in (2) of FIG. PC steel stranded wire 10 is wound in a state where a plurality of side wires 8 are twisted around the outer periphery of the wire, and a synthetic resin coating (hereinafter referred to as a coating) 9 is applied to the outer periphery of the core wire 7 and the side wire 8. . A portion of the PC steel wire 6 in the through hole 5 is covered with a sheath 11, and the sheath 11 is filled with a rust preventive lubricant 11a to be unbonded. The outer cable 1 is not limited to the seven PC steel wires 6, but can be composed of more or less PC steel wires 6.

  Further, the PC steel wire 6 is not limited to the PC steel stranded wire 10 having the coating 9 applied to the outer periphery of the core wire 7 and the side wire 8 as described above, but as shown in (3) and (4) of FIG. The core 9 and the side wires 8 are not coated with the coating 9, but only the sheath 11 is coated (parts in the through holes), and the coating 9 is coated on the outer periphery of the PC steel stranded wire 13, and the sheath 11 Also covered with (coated in the through hole).

  In this wiring method, first, as shown in FIG. 1 (2), the PC steel wire 6 is inserted into the through hole 5 of the deflecting portion 4, and the portion of the through hole 5 covered with the sheath 11 is positioned. Spaces where the portions wired in the through holes 5 do not contact each other are maintained by spacers (not shown). Therefore, seven PC steel wires 6 are wired in the through holes 5 at equal intervals.

  After the PC steel wires 6 are wired to the through holes 5 at equal intervals in this way, a filler 14 such as cement paste, mortar, or resin is press-fitted into the through holes 5 with a grout pump. So that these intervals are maintained, that is, they do not come into contact with each other. And when this filler 14 hardens | cures, while each PC steel wire 6 is fixed to the center position of the through-hole 5, it becomes the wiring where the centroid of the cable and the design centroid correspond.

  Next, the PC steel wire 6 is tensioned with a predetermined force, and this tension force is converted into an eccentric load (lifting load). Since this PC steel wire 6 is unbonded in the through hole 5, it can be tensioned with a predetermined force. When the PC steel wire 6 is tensioned after the filler 14 is cured in this way, the PC steel wires 6 in the through holes 5 do not contact each other or are not biased to one side, so that the occurrence of fretting phenomenon can be prevented. .

  FIG. 3 shows a wiring method according to the second embodiment. In this case, a PC steel wire 6 is wired in an intubation tube 15 installed in the through hole 5 and filled with a filler 14. First, before the PC steel wire 6 is wired to the through hole 5, the inner tube 15 is installed in the through hole 5. Lids 16 are installed at both ends of the inner tube 15, and seven holes 17 into which the PC steel wires 6 are inserted are opened in the lid 16. When the PC steel wire 6 is inserted into the hole 17, the lids 16 on both sides act as spacers, and the intervals between the PC steel wires 6 in the inner intubation 15 are maintained at regular intervals. Thus, the two lids (spacers) 16 function not to bring the PC steel wires 6 into contact with each other, and also function to prevent the filler 14 from leaking.

  Next, when the filling material 14 is filled into the inner tube 15 by the same method as described above, this is filled between the PC steel wires 6. And when this filler 14 hardens | cures, while each PC steel wire 6 is fixed to the center position of the intubation tube 15, it becomes the wiring in which the centroid of the cable and the design centroid correspond. When the PC steel wire 6 is tensioned in the same manner as described above, the fretting phenomenon can be prevented because the PC steel wires 6 in the inner cannula 15 do not contact each other or are not biased to one side. When the outer cable 1 is wired to the inner intubation 15 as described above, the outer cable 1 can be easily replaced because the inner intubation 15 can be removed from the through hole 5 when the outer cable 1 is replaced.

  FIG. 4 shows a wiring method according to the third embodiment. This is one in which an outer tube 18 is installed in the through hole 5 before inserting the inner tube 15, and the other configuration is the same as that of the second embodiment. The outer insertion tube 18 can protect the through-hole 5 and the inner insertion tube 15, and the inner insertion tube 15 can be easily removed when the outer cable 1 is replaced.

  5 and 6 show the wiring method of the fourth embodiment. In this case, seven internal pipes 19 into which only one PC steel wire 6 can be inserted are installed in the through-hole 5, and the filler 14 is filled by penetrating and wiring the PC steel wire 6 for each of these internal pipes 19. To do. The both ends of the inner tube 19 are in contact with the periphery of the hole 17 of the lid body and are installed between the lid bodies 16. The lid body 16 serves as a spacer and holds the inner tube 19 at regular intervals. . In addition, the number of the above-mentioned intubation tubes 19 is not limited to seven, and more or less can be installed.

  When one PC steel wire 6 is inserted into each intubation tube 19, each PC steel wire 6 is fixed at the center position of the through hole 5, and the cable centroid and the design centroid coincide with each other. Become. Next, when each filler tube 14 is filled with the filler 14 in the same manner as described above, and after the filler material 14 is cured, these PC steel wires 6 are tensioned. The occurrence of fretting can be prevented because they do not contact each other or are not biased to one side. In this case, since the PC steel wire 6 can be removed for each internal intubation 19, the PC steel wires 6 can be replaced one by one. In addition, the internal intubation 19 can be installed without being in contact with each other (not shown), and in this case, replacement of the internal intubation 19 can be further simplified.

  7 and 8 show a wiring method according to the fifth embodiment. In the same manner as described above, the outer insertion tube 18 is installed in the through hole 5 before the inner insertion tube 19 is inserted. The through hole 5 and the inner intubation 19 can be protected by the outer intubation 18.

In the present embodiment, the outer cable 1 wired to the deflecting portion 4 of the PC girder bridge 2 has been described. However, this can also be wired by the same method also in the deflecting portion of the cable stayed cable.
Further, the present invention can be applied to various bridges and deflecting portions of buildings based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

  Moreover, although the said Example demonstrated using the PC girder bridge 2 which is a concrete structure as a structure, this is not restricted to a concrete structure, It is used for the wiring of the cable in the deflection | deviation part of a steel structure structure and other structures. Can also be applied.

(1) is a perspective view of a PC girder bridge showing a deflection unit, and (2) is a cross-sectional view of the deflection unit with an external cable inserted. (1) is an AA line sectional view of (2) of Drawing 1, (2)-(4) is a sectional view of PC steel wire. The wiring method of 2nd Embodiment is shown, (1) is sectional drawing of the deflection | deviation part which inserted the external cable, (2) is BB sectional drawing of (1). The wiring method of 3rd Embodiment is shown, (1) is sectional drawing of the deflection | deviation part which inserted the external cable, (2) is CC sectional view taken on the line of (1). The wiring method of 4th Embodiment is shown, (1) is sectional drawing of the deflection | deviation part which inserted the external cable, (2) is an expanded sectional view of a deflection | deviation part. (1) is the DD sectional view taken on the line of (1) of FIG. 5, (2) is an expanded sectional view of a cable. The wiring method of 5th Embodiment is shown, (1) is sectional drawing of the deflection | deviation part which inserted the external cable, (2) is an expanded sectional view of a deflection | deviation part. (1) is the EE sectional view taken on the line of (1) of FIG. 7, (2) is an expanded sectional view of a cable. It is a perspective view of a PC girder bridge showing a conventional wiring method. (1) is sectional drawing of the deflection | deviation part in the conventional wiring method, (2) is FF sectional view taken on the line of (1). (1) is sectional drawing of the deflection | deviation part in the conventional wiring method, (2) is GG sectional view taken on the line of (1).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,20 Outer cable 2,21 PC girder bridge 3 Horizontal girder 4,22 Deflection part 5,23 Through hole 6,25 PC steel wire 7 Core wire 8 Side wire 9 Coating 10, 12, 13 PC steel twisted wire 11, 27 Sheath 11a Antirust Lubricant 14, 24 Filler 15, 19 Inner Intubation 16 Lid 17 Hole 18 External Intubation 26 Hole Wall

Claims (2)

  A plurality of intubation tubes into which only one PC steel wire can be inserted are installed in the through holes of the deflecting portion for deflecting the cables disposed on the outer surface of the structure, and each of these intubation tubes is covered with a sheath. A cable wiring method in a deflecting section, wherein a PC steel wire is penetrated and wired, a filler is filled for each internal intubation, and each PC steel wire is tensioned after the filler is cured. Before before or inner intubation PC steel wires are wired is placed, the cable of a wiring in the deflection unit according to claim 1, wherein the fitting the outer cannula into the through hole.

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