JP3565582B2 - Cable laying method - Google Patents

Description

[0001]
[Industrial applications]
The present invention is intended to prevent crossing of cables when tensioning and fixing a large number of diagonal members, that is, cables made of PC stranded wires, between a column and a bridge girder in a cable-stayed bridge or the like. Regarding the method of erection.
[0002]
[Prior art]
As a cable laying means for a cable stayed bridge of this kind, a technique for inserting a cable into a fixing portion includes, for example, (1) the erection method disclosed in Japanese Patent Publication No. 4-11683, and (2) JP-A-6-26011. A cable mounting guide device disclosed in the official gazette is known as a conventional example.
[0003]
In the conventional example of the above (1), a fixing sheath is provided at a fixing portion on a bridge girder side of a cable stretched over a column and a bridge girder, and an index hole is provided in an anchor head provided at an end of the fixing sheath. A lead rope is inserted through the index hole in advance, the end of the cable is fitted to a lead cap provided at the tip of the lead rope, and the cable is guided to the index hole by guiding the lead rope. It was done.
[0004]
Also, in the conventional example (2), the same mantle tube heavy tube and pilot wire as those in the conventional example (1) are used, and the pilot wire is inserted into the through hole of the fixing block in advance and the mantle tube heavy tube is used. A magnet is provided in a sleeve provided at the tip of the pilot wire, and the tip of the cable is attracted to the magnet so that the cable is inserted into the heavy tube of the mantle tube and the through hole of the fixing block. It is intended to be.
[0005]
In each of the conventional examples, a cable narrowing portion is provided in the fixed sheath or the outer tube. The inner diameter of these narrowed portions is approximately 150 mm when, for example, when using 7 strands of PC steel having an outer diameter of 15.2 mm, when 37 strands of PC steel stranded wire are installed, It is approximately 200 mm with 73 lines. The circumscribed circle diameter of the PC steel strand in the anchor head portion is approximately 220 mm for 37 wires and approximately 300 mm for 73 wires.
[0006]
[Problems to be solved by the invention]
In the conventional example of (1), a socket is provided between the fixed sheath and the anchor head, and the stretched cable is configured to be narrowed in the fixed sheath. The insertion direction of the cable is bent so that the cable insertion space is further narrowed.
[0007]
Also, in the conventional example of (2), the cable to be stretched is bent and narrowed in front of the fixing block by the trumpet tube provided inside the outer tube heavy tube.
[0008]
In any of the conventional examples, a large number of cables to be stretched are sequentially guided by a lead rope or a pilot wire provided in advance and inserted into an index hole or a through hole of a fixing block. If the cable bends due to the presence, and if the number of inserted cables approaches the final number, the space of the constricted portion is narrowed by the previously inserted cable, and further, the fixed sheath or outer tube of the heavy tube from the constricted portion. Due to the considerable spacing to the openings, cables often crossed each other.
[0009]
When such cables cross each other, a rubbing phenomenon occurs between the cables after the cable is erected, and there is a serious problem that the cables are fatigue-ruptured at the rubbed portions.
[0010]
Therefore, the conventional example has a problem to be solved in that the cables on the fixing unit side are properly inserted without crossing.
[0011]
[Means for Solving the Problems]
As a specific means for solving the problems of the conventional example, the present invention comprises a fixing portion of a pillar or a bridge girder to which a cable is fixed, which is constituted by an outer tube and a protection tube having no throttle portion, and one end of the protection tube. A fixing block having a predetermined number of through-holes is provided in the portion, and a water stop mechanism having an insertion hole corresponding to the through-hole is provided at the other end, and the corresponding through-hole and the insertion hole are respectively provided. After inserting a lead wire having a predetermined length and a cable connecting portion at one end, the protective tube is inserted and attached from one end of the outer tube to prevent crossing at the other end of the outer tube. Using a jig, the ends of the inserted lead wires are supported in accordance with the positional relationship of the through holes of the fixing block, so that the lead wires are maintained in a parallel state and supported, and a cable is provided for each lead wire. Let me join Providing a method of laying a cable, wherein the water stopping mechanism comprises a spacer for maintaining a straight state of the cable and an elastic body for performing water stopping; and The prevention jig includes forming a circular hole having an arc-shaped notch at a position adjacent to a plurality of plate members.
[0012]
[Action]
After the protective tube has no constriction and the lead wire is placed in advance in the protective tube in an appropriate state, it is inserted into the outer tube, and at the other end of the outer tube, an anti-crossing jig is used. By using each of the lead wires in a parallel state to support them, and by pulling out the corresponding cables one by one individually with each lead wire, each cable is separated from the protective tube to the outer tube and to the intersection. Since all of the prevention jigs are inserted properly and in a parallel state, even if a large number of cables are inserted in the fixing portion, they do not intersect.
[0013]
【Example】
Next, the present invention will be described in more detail based on the illustrated embodiment. FIG. 1 schematically shows a cable-stayed bridge. A cable-stayed bridge is formed in a state in which a column 2 projects upward from a bridge girder 1 by a predetermined length, and between the bridge girder 1 and the column 2. A plurality of diagonal members 3 are arranged in tension on both sides, and the bridge girder 1 is supported by the columns 2 via the diagonal members 3.
[0014]
The present invention relates to a method of erection such that cables do not cross at the time of tension fixation of the diagonal members 3 in such a cable-stayed bridge, and the single diagonal member 3 to be erected is composed of a large number of cables. Have been. This cable is made of, for example, a PC stranded wire, and both ends of the cable are fixed to the bridge girder 1 and the support 2 with appropriate fixing members by the same fixing means.
[0015]
FIG. 2 shows an anti-crossing jig 4 used in the method of the present invention. This jig 4 for preventing crossing is used when one slanted member 3 is composed of, for example, 19 PC steel strands, that is, cables.
[0016]
The intersection prevention jig 4 includes a U-shaped frame member 5 and a plurality of plate members 6 detachably mounted on the frame member. The frame member 5 is formed of, for example, a channel material and has a groove 7 along the inside thereof, and has a so-called U-shaped cross section.
[0017]
The plate member 6 has a predetermined width and thickness, and both ends thereof are guided by the groove 7 of the frame member 5 so that a plurality of the plate members 6 are arranged adjacent to each other. Then, arc-shaped notches 8a and 8b are formed at predetermined positions and adjacent positions on one side or both sides along the longitudinal direction of the plate material 6, that is, provided on the adjacent plate materials 6. A round hole 8 is formed when these notches coincide. The round hole 8 has a size that allows the individual cables constituting the one slant member 3 to be inserted.
[0018]
In the illustrated embodiment, since 19 cables can be inserted, 19 round holes 8 are formed by using, for example, seven plate members 6 and these round holes 8 The arrangement or the coordinates substantially correspond to the through holes provided in the fixing block or the like to which the ends are fixed.
[0019]
The round hole 8 through which the cable is inserted can correspond to the number of cables constituting one slant member 3 by combining a plurality of plate members 6. It is preferable that the number of the round holes 8 formed in the plate member 6 correspond to the number of cables, but it is possible to use even more than two or three cables. In use in this case, it is better to leave the round holes located at the upper and lower ends as much as possible.
[0020]
Reference numeral 9 in the figure denotes a stopper plate, which is detachably locked to the frame member 5 by an appropriate locking means 9a, and supports the plate member 6 so as not to come off. Reference numeral 10 denotes a hanging string, which can be hung and held at an appropriate position. If necessary, a so-called index number or the like indicating the fixing order of the fixing block or the like can be attached to each round hole.
[0021]
The anti-crossing jig 4 of the present invention thus configured is used, for example, as shown in FIG. In this case, in order to stretch and fix the diagonal member 3 to the column 2 of the cable-stayed bridge, the column 2 is provided with a through-hole in advance, and an outer tube 11 is provided. A fixing plate 12, a support member 13, and a fixing block 14 are attached to the fixing end side.
[0022]
Further, the fixing block 14 is provided with through holes 14a corresponding to the number of cables constituting one slant member 3. A protection tube 15 supported by the support member 13 is provided inside the outer tube 11, and the protection tube 15 has a length equal to or less than の of the outer tube 11. A water stop mechanism 16 is provided on the end side.
[0023]
The water stopping mechanism 16 is composed of, for example, a spacer 17 and an elastic material 18 such as rubber, and has an insertion hole 16a corresponding to the through hole 14a provided in the fixing block 14, respectively.
[0024]
The intersection prevention jig 4 is used by disposing it on the opening end side of the outer tube 11 opposite to the fixing block 14. That is, it is necessary to arrange a lead rope or a lead wire 19 before the diagonal member 3 is stretched, and it is used to support the lead wire 19 in an appropriate state.
[0025]
In other words, the lead wire 19 is necessary for a large number of cables constituting the single diagonal member 3 to be inserted in a proper state and to be fixed based on a proper positional relationship (arrangement and coordinates). It is necessary to pass through the through hole 14a provided in the fixing block 14 through the through hole 16a of the water stopping mechanism 16 and to the free end of the outer tube 11 so as to be pulled out.
[0026]
The lead wire 19 used here has a connecting part 20 at one end to which the end of the cable is connected or connected, and a gripping part 21 at multiple ends, and corresponds to the length of the outer tube 11. Only by changing the length of the wire in the middle part, it is possible to correspond to the outer tube 11 of various lengths.
[0027]
The pre-arranged lead wire 19 has a connecting portion 20 at one end protruding from the fixing block 14 by a predetermined length. In order to maintain the protruding state, for example, a pin or a clip 22 is used. Temporarily. The grip 21 at the other end is inserted into and supported by one of the round holes 8 provided in the jig 4.
[0028]
In arranging the lead wires 19, before attaching the protection tube 15 to the outer tube 11, the lead wires 19 are inserted in advance through the respective insertion holes 16 a of the water stopping mechanism 16 in the protection tube 15, The connecting portions 20 of the lead wires 19 are inserted into the through holes 14 a of the fixing block 14, respectively, and temporarily fixed with pins or clips 22 in a state where the fixing wires 14 protrude by a predetermined length. It is fixed with bolts 23 or the like.
[0029]
In this case, before the protection tube 15 is attached, the lead wire 19 is visually checked in the work on the ground, and the lead wire 19 is in an appropriate state in the insertion hole 16a of the water blocking mechanism 16 and the through hole 14a of the fixing block 14, that is, in a large number. It is possible to check whether or not the inserted lead wire 19 is inserted substantially in parallel without intersecting between the water stopping mechanism 16 and the fixing block 14, and after the checking, the protective tube 15 is connected to the outer cylinder. The support member 13 is mounted in the tube 11 and is fixed to the fixing plate 12 by bolts 24 or the like.
[0030]
In this case, after confirming that the lead wires 19 have been set correctly with respect to the protection tube 15 and the fixing block 14, the grip portions 21 of the respective lead wires 19 follow the arrangement or coordinates of the through holes 14 a of the fixed block 14. It is better to insert and attach them in the outer tube 11 after attaching the numbers and the like.
[0031]
Then, the grip portion 21 side of the lead wire 19 is taken out from the other end of the outer tube 11 and is supported by the round hole 8 of the intersection prevention jig 4 at the other end. In this case, it is necessary to support the round hole 8 while checking whether the lead wires 19 cross each other after the protection tube 15.
[0032]
Therefore, the many lead wires 19 taken out at the other end of the outer tubular tube 11 do not intersect one by one in accordance with the arrangement or the coordinate number assigned to the grip portion 21. It is inserted into and supported by the round hole 8 while visually confirming this.
[0033]
This insertion support work is preferably performed sequentially from the lower side of the intersection prevention jig 4. For example, first, only the lower two plate members 6 are fitted into the frame 5 to form only the lower three round holes 8, and the other end of the outer tube 11 is opened from the space between the frames 5 on both sides. By holding the predetermined grip portion 21 of the lead wire 19 to see if it intersects with another lead wire, and see through the through hole 16a of the water stopping mechanism 16 and the through hole 14a of the fixing block 14. The lower three lead wires 19 are inserted and supported in the corresponding round holes 8 while confirming whether or not they are in an appropriate state.
[0034]
Next, the third plate member 6 is fitted into the frame 5 to form a second row of round holes 8, and the inside of the outer tube 11 is looked into from the other end side in the same manner as described above. While checking whether the lead wire 19 inserted and supported in the hole 8 does not cross another lead wire, the grip portion 21 is inserted and supported in the corresponding round hole 8.
[0035]
While repeating such operations, the upper plate members 6 are sequentially fitted into the frame 5, and the corresponding gripping portions 21 of the lead wires 19 are supported in the round holes 8 in each row in an appropriate state. All lead wires 19 from 14a through the insertion hole 16a of the water stopping mechanism 16 to the intersection prevention jig 4 are inserted while maintaining a parallel state.
[0036]
In particular, since the lead wire 19 from the fixing block 14 to the water stopping mechanism 16 is visually inserted outside in advance, the lead wire 19 is inserted in an appropriate state in the protective tube 15, What is necessary is just to maintain it so that it may not cross until it reaches the other end of the pipe 11, and the work of inserting and supporting the jig 4 through the cross prevention jig 4 can be easily performed.
[0037]
As described above, the lead wire 19 is provided by using the cross-prevention jig 4, and at the stage of laying the cable, for example, among a large number of cables constituting a single diagonal member 3 from the fixing block 14 side, One end of each cable 3a is connected to the corresponding connecting portion 20 of the lead wire 19, and the pin or clip 22 of the connected lead wire 19 is removed. The cable 3a is pulled out from the through hole 14a of the fixing block 14, through the insertion hole 16a of the water stop mechanism 16, and out of the round hole 8 of the intersection prevention jig 4.
[0038]
By performing this operation for each lead wire 19, the cables 3a are inserted into all the through holes 14a, the insertion holes 16a, and the round holes 8, and the inserted cables 3a are connected to the fixing block 14 and the intersection prevention jig. 4 and are arranged in parallel without intersecting at all.
[0039]
The rear end side of the cable 3a is fixedly fixed to the through hole 14a of the fixing block 14 using a commonly used wedge material, and the front end side of each cable 3a taken out from the intersection prevention jig 4 is At the other fixing section, that is, the fixing section on the bridge girder side, the same operation as described above is performed to fix and fix.
[0040]
In this case, since the fixing portion of the bridge girder 1 faces in the opposite direction to the fixing portion of the column 2 described above, the direction of the lead wire 19 is opposite to the above, and the lead wire 19 is connected to the intersection prevention jig 4 side. The wire 19 is inserted in advance so that the connecting portion 20 of the wire 19 is located, and the gripping portion 21 is located on the fixing block 14 side, and is temporarily fixed with a pin or clip 22 on the intersection prevention jig 4 side.
[0041]
Therefore, the end of the cable 3a pulled out from the column 2 is inserted from the intersection prevention jig 4 side on the bridge girder 1 side. The end of the cable 3a is connected to the corresponding connecting portion 20 of the lead wire 19 inserted into the round hole 8 of the fixing block 14, and the holding portion 21 of the lead wire 19 is pulled out on the fixing block 14 side. Each cable 3a is erected by being inserted through the cable 14a.
[0042]
Then, it can be visually confirmed whether or not the cable 3a is stretched between the column 2 and the bridge girder 1. Whether or not the cable 3a is crossed is visually confirmed. After all the cables 3a are stretched, the intersection prevention jig 4 is removed. In this case, contrary to the above, by removing the locking means 9a and extracting the frame 5 from the stopper 9 and the plate member 6, the plate members 6 at each stage can be easily removed.
[0043]
Finally, after the cables 3a constituting the one slant member 3 are finished and tightened in a well-balanced manner, the vicinity of the opening side end of the outer tube 11, that is, the position where the cross-prevention jig 4 is disposed. In the vicinity, the cable 3a is narrowed down to a predetermined diameter, the narrowed portion is shifted in the outer tube 11, and the opening of the outer tube 11 is closed with an appropriate material. The installation of the cable is completed by attaching a protective cover or the like.
[0044]
【The invention's effect】
As described above, the method for laying a cable according to the present invention includes a fixing part of a support or a bridge girder where a cable is fixed, which is constituted by an outer tube and a protection tube having no constriction, and one end of the protection tube. A fixing block having a predetermined number of through holes, and a water stop mechanism having an insertion hole corresponding to the through hole at the other end. After inserting a lead wire having a length and a cable connecting portion at one end, the protective tube is inserted and attached from one end of the outer tube, and a cross-prevention treatment is performed at the other end of the outer tube. By supporting the ends of the inserted lead wires according to the positional relationship of the through holes of the fixing block, the lead wires are maintained in a parallel state and supported, and a cable is connected for each lead wire. Let me By passing through, a large number of cables to be bridged are positioned in parallel at the fixing end side without intersecting from the through hole of the fixing block, and due to the rubbing phenomenon which has conventionally occurred due to intersection. It has an excellent effect that fatigue rupture is eliminated.
[0045]
In addition, since the water stopping mechanism provided on the protection tube includes a spacer for maintaining a straight state of the cable and an elastic body for performing water stopping, the fixing portion side of the installed cable is in a waterproof state. And has an excellent effect that the bare wire portion for fixing does not rust over a long period of time.
[0046]
Further, the cross-prevention jig is formed with a circular hole formed of an arc-shaped notch at a position adjacent to a plurality of plate members, so that the lead wire can be easily inserted and pulled out by the lead wire. It has an excellent effect that the cables can be reliably maintained without crossing.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing a part of a cable-stayed bridge to which a cable erection method according to the present invention can be applied.
FIG. 2 is a front view of an intersection prevention jig used in the cable erection method according to the present invention.
FIG. 3 is a cross-sectional view schematically showing only a main part of a fixing portion of the cable for explaining a method of erection of a cable according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bridge girder 2 Support 3 Diagonal material 3a Cable 4 Crossing prevention jig 5 Frame 6 Plate material 7 Groove 8 Round hole 8a, 8b Notch 9 Stopper 9a Locking means 10 Suspension cord 11 Outer tube 12 Fixing plate 13 Supporting member 14 Fixing Block 14a Through hole 15 Protective tube 16 Water stopping mechanism 16a Insertion hole 17 Spacer 18 Elastic material 19 Lead wire 20 Connecting part 21 Holding part 22 Pin or clip 23, 24 Bolt

Claims (5)

A fixing portion of a support or a bridge girder where a cable is fixed is constituted by an outer tube and a protection tube having no throttle portion, and a fixing block having a predetermined number of through holes is provided at one end of the protection tube. The other end is provided with a water stopping mechanism having an insertion hole corresponding to the through hole, and the corresponding through hole and the insertion hole each have a predetermined length and a lead wire having a cable connecting portion at one end. After the insertion, the protective tube is inserted and attached from one end of the outer tube, and an end of each of the inserted lead wires is attached to the other end of the outer tube by using a juncture preventing jig. A method of laying cables, comprising supporting each lead wire in a parallel state by supporting the fixing block in accordance with the positional relationship of the through holes, and connecting and inserting a cable for each lead wire. 2. The method according to claim 1, wherein the water stopping mechanism comprises a spacer for maintaining a straight state of the cable and an elastic body for performing water stopping. The cable laying method according to claim 1, wherein the intersection prevention jig has a circular hole formed of an arc-shaped notch at a position adjacent to the plurality of plate members. The cable laying method according to claim 1, wherein one end of the lead wire passed through the protective tube is temporarily fixed. The method of laying a cable according to claim 1, 2, 3, or 4, wherein the cable is a PC steel strand.

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