JP3573801B2 - Rust prevention method at the anchoring part of the construction cable - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a method for rust-proofing a fixing portion of an installation cable that is stretched with a predetermined tension in a cable-stayed bridge, a suspension bridge, or the like.
[0002]
[Prior art]
The rust-proofing or corrosion-proofing treatment of the fixing portion of this type of erection cable includes the following: JP-B-2-37463 and b. The one disclosed in Japanese Patent Publication No. 3-30644 is known as a conventional example.
[0003]
Conventional example a. , A pipe having a bottom plate provided with a predetermined through hole is connected to the fixing plate inside the cable fixing section, and after the cable is inserted through the through hole, a filler is injected into the pipe. At the same time, an elastic material is inserted between the bottom plate and the steel plate or the plastic plate, and the two are tightened to deform the elastic material so that the elastic material is brought into close contact with the covering portion of the cable.
[0004]
Further, in the conventional example b. In, a durable elastic material having a predetermined through hole is arranged between the inside of the cable fixing device and the steel plate or the hard plastic plate, and the fixing device and the steel plate or the hard plastic plate are tightened with bolts from the outside of the fixing device. Deforming the elastic material and bringing it into close contact with the sheath sheath of unbonded PC steel strand, or making the elastic material into an inflatable material and expanding it in a humid environment to form a sheath sheath of unbonded PC strand wire. The close contact enables water to stop even after the cable is tensioned and fixed.
[0005]
[Problems to be solved by the invention]
Conventional example a. Is a configuration in which a tube having a bottom plate is attached to a fixing plate, and the tube is buried in a through-hole provided in a fixing portion such as a cable-stayed bridge, and after the cable is installed substantially However, it is difficult to tighten the bolt from outside the bottom of the tube, and there is a problem that workability is poor.
[0006]
Further, in the conventional example b. In the anti-corrosion treatment, the elastic material is disposed directly inside the cable fixing device and the bolt is deformed by tightening the bolt from the outside of the fixing device. The workability is good, but the fixing device and the elastic material are adjacent to each other. In the state, in order to fix the long unbonded PC steel stranded wire to the fixing device, the dimensional accuracy of the length to remove the covering sheath and make it a bare wire is strictly required, taking into account the degree of tension and looseness, etc. Not only does the work efficiency for fixing decrease, but a cap for waterproofing must be provided on the outside of the fixing device, which also has the problem that the work efficiency decreases.
[0007]
Furthermore, in the above-mentioned two conventional examples, the elastic material is deformed by tightening to adhere to the sheath sheath of the unbonded PC stranded wire. In order to improve the adhesion, the elastic material and the steel plate or the hard plastic plate are used. The insertion hole of the unbonded PC steel wire provided in the above cannot be made so large, and the work of inserting the unbonded PC steel wire into these elastic materials and the steel plate or the hard plastic plate is troublesome and the workability is poor. There is also a problem that.
[0008]
[Means for Solving the Problems]
As a specific means for solving the problems of the conventional example, the present invention is directed to a fixing section in which an end portion of an erecting cable composed of a large number of cables supporting a cable-stayed bridge or the like is fixed to a fixing member. A protective tube for protecting the fixing end side of the cable is provided, and a spacer having a large number of through holes corresponding to the number of cables and maintaining the arrangement of the cables is provided on the free end side of the protective tube, An elastic material is previously provided in each through hole of the spacer, and the elastic material and the cable are pressed into contact with each other by inserting a cable into each through hole. Wherein the plurality of spacers are arranged adjacent to each other , and an elastic material is arranged between the spacers; the elastic material is plate-shaped; Position corresponding to the through hole of spacer Than the outer diameter of the cable provided with the small-diameter through holes; elastic member is an O-ring-shaped, than the outer diameter of the cable and the small diameter of the inner diameter; a waterproofing agent is applied and the portion of the cable The technical idea of the present invention also includes that at least a part of the through hole of the spacer is filled with a waterproofing agent by being squeezed with an elastic material .
[0009]
[Action]
On the fixing part side of the cable, a spacer that maintains the arrangement of the cable and a protective tube with an elastic material are provided, and the end of the fixed part side of the cable is simply inserted through the corresponding through hole of the spacer. In addition, the cable is pressure-welded and supported in a waterproof state by the elastic material, which not only improves the workability of cable erection, but also shields the inside of the protective tube from the outside and prevents the moisture that travels through the cable from entering at all. Substantially complete rust prevention in the fixing section can be achieved.
[0010]
【Example】
Next, the present invention will be described in more detail with reference to the illustrated embodiment. In the first embodiment shown in FIGS. 1 to 4, reference numeral 1 denotes a main girder such as a cable-stayed bridge, and the main girder and a column (not shown). The bridge girder is supported by stretching or erection of a large number of cables between them, and the large number of cables are made of, for example, PC steel stranded or unbonded PC stranded with polyethylene resin. A predetermined number, for example, 19, of these cables are combined into a single cable, and a large number of these cables are erected.
[0011]
In the embodiment of the present invention, a fixing portion of one cable among a plurality of cables installed will be described. An outer tube 3 is disposed in a cable fixing through hole 2 provided in the main girder 1, and a fixing member 4 is attached to one end of the outer tube 3.
[0012]
The fixing member 4 includes, for example, a fixing plate 5, a support member 6, and a fixing block 7. The outer tube 3 is attached with one end thereof substantially fixed to the fixing plate 5. .
[0013]
A protection tube 8 is disposed inside the outer tube 3, and the protection tube 8 is attached with one end fixed to the support member 6 or the fixing block 7, and is substantially combined with the outer tube 3. It has a double tube structure.
[0014]
A plurality of (three in the illustrated embodiment) spacers 9 and an elastic member 10 arranged in a sandwich between the spacers are provided on the free end side of the protective tube 8 via an adapter 8a. A single cable 11 is fixed to the fixing member 4 through the spacer 9 and the elastic member 10, and is laid in a tensioned state.
[0015]
As a method of fixing each end of the cable 11 to the fixing member 4, a conventionally used fixing means using a wedge member can be employed as it is. That is, the bare ends of the cable 11 from which the sheath has been peeled are inserted into a plurality of tapered through holes provided in the fixing block 7, and the wedge members 12 are fixed by being bitten.
[0016]
In the cable 11 fixed in this manner, an important component for so-called rust-prevention or water-stopping treatment of the fixing portion includes a spacer 9 attached to the protective tube 8 via an adapter 8a and an elastic material. 10, and these components will be described in detail.
[0017]
A plurality of spacer 9 is attached to the adapter 8a is, for example, metal or synthetic resin disc, also, the elastic member 10 is, for example, rubber or sponge, and spacer 9 and the elastic member 10 Are sandwiched and fastened at appropriate locations with appropriate bolts 13 to prevent water leakage between the two. Note that the adapter 8a is attached to the free end of the protective tube substantially integrally by welding or bonding means.
[0018]
The spacer 9 and the elastic member 10 are provided with through holes 14 and 15 in a predetermined arrangement at substantially equal intervals, respectively, in a number corresponding to the number of one cable 11. These through-holes 14 and 15 substantially correspond to the through-holes for fixing provided in the fixing block 7 in arrangement and spacing. In particular, the spacer 9 maintains the arrangement of the cables 11. Things.
[0019]
Further, the inner diameter of the through hole 14 provided in each spacer 9 is formed to be about 10% larger than the outer diameter of the single cable 11 to be inserted, and conversely, the through hole 15 provided in the elastic material 10 is formed. Is formed about 10% smaller than the outer diameter of the cable 11.
[0020]
For example, if the outer diameter of the single cable 11 used is 18 mm, the inner diameter of the through-hole 14 formed in the spacer 9 is formed to be approximately 20 mm, and the inner diameter of the through-hole 15 provided in the elastic member 10. Is formed to approximately 15 to 16 mm.
[0021]
The cable 11 to be used is, for example, a PC steel stranded wire or an unbonded PC steel stranded wire, and as shown in FIG. The bare wire portion 11b having a predetermined length is exposed.
[0022]
Then, at the end of the cable 11 on the side to be inserted into the outer tube 3 and the protection tube 8, a water stopping agent 16 such as grease is applied to the surface of the sheath portion 11a over a predetermined length. Is inserted into the determined through-hole 14.
[0023]
At this time, the waterproofing agent 16 is applied so as not to reach the bare wire portion 11b, and is inserted into the through hole 14 from the bare wire portion 11b. In general, a guide wire of a predetermined length is previously inserted from the through hole of the fixing block 7 through the through holes 14 and 15 of the spacer 9 and the elastic member 10, and one end of the guide wire is inserted into one end of the guide wire. The cable 11 passes through the through holes 14, 15 of the spacer 9 and the elastic member 10 in sequence by engaging or connecting the bare wire portion 11 b at the tip and pulling the other end of the guide wire from outside the fixing block 7. As a result, the fixing block 7 is inserted up to the through hole.
[0024]
At this time, since the through hole 14 of the spacer 9 is formed larger than the outer diameter of the cable 11, the through hole 14 is inserted without receiving any resistance in this portion. However, since the through-hole 15 of the elastic member 10 is formed smaller than the outer diameter of the cable 11, the through-hole 15 is first pushed through the bare wire portion 11b so as to expand, and then passes through the sheath portion 11a. The covered portion further pushes through the through hole 15 and passes therethrough.
[0025]
As described above, the cable 11 is pushed through the small through hole 15 of the elastic member 10 and inserted therethrough, so that the waterproofing agent 16 applied to the peripheral surface and brought in is firstly laddered by the first-stage elastic member 10. Then, it accumulates in the through hole 14 of the spacer 9 located on the insertion side. Still, some of the water stopping agents 16 pass through the first-stage elastic member 10, but are further squeezed by the second-stage elastic member 10, so that the space between the first-stage elastic member and the second-stage elastic member, particularly, the second-stage elastic member 10 It also accumulates in the vicinity of the through hole of the eye elastic material 10.
[0026]
The elastic material 10 itself tightens the cable 11 by the through hole 15 and at the same time, is deformed so as to be pulled and inclined in the cable insertion direction due to the strong tightening. The portion is fixed to the fixing block 7, and when the wedge member 12 is used at the time of fixing, the portion acts to return in a direction opposite to the insertion direction, though slightly, and the elastic member 10 abuts on the cable 11 by the return operation. The operation is further increased, and the cable is tightly pressed, and the cable is laid while maintaining the pressure and a predetermined degree of tension.
[0027]
When the cable 11 is inserted from the side opposite to the above, the cable is extended once and then pulled back in the opposite direction, so that the form of the elastic member 10 with respect to the cable 11 is the same as that described above. Can be located.
[0028]
Therefore, when the cable 11 is laid, the fixing end side of the cable 11 can be almost completely stopped or waterproofed by the elastic member 10 and the waterproofing agent 16.
[0029]
5 to 7 show a second embodiment. The second embodiment is characterized in that a tubular O-ring is used as the elastic member 10. That is, a ring-shaped recess 17 is provided along the circumferential direction in the through hole 14 provided in the spacer 9, and the O-ring 10 a is housed in the recess 17. It is designed to be pressed against.
[0030]
In this case, the inner diameter of the through hole 14 provided in the spacer 9 is formed to be larger than the outer diameter of the cable 11 as in the above embodiment, and the adjacent spacers 9 are formed in the through hole 14. A recess 17 is formed between them. One recess 17 is formed for one through-hole 14, and one O-ring 10 a is provided in one through-hole.
[0031]
In other words, in the spacers 9 provided in a plurality (three), the through holes 14 provided in the respective spacers are provided relatively close to each other. When the recesses 17 are provided for the respective through holes, all of the recesses are connected to each other, and a substantially established recess is not formed.
[0032]
Accordingly, in each spacer, for example, every other or every other two recesses are formed so that no recesses are formed in the through holes adjacent to each other, and communication is performed by a combination of three spacers. One recess 17 may be provided in one through hole 14 to be provided, and one O-ring 10a may be provided.
[0033]
The O-ring 10 a provided in the recess 17 has a central hole facing the through hole 14 having a diameter of approximately 15 to 16 mm, and is formed to have a smaller diameter than the outer diameter (18 mm) of the cable 11.
[0034]
By inserting the cable 11 into each through-hole 14 by the same means as in the above-described embodiment, the O-ring 10a is pushed and expanded in each of the through-holes 14, and the pushed-and-spread O-ring 10a is inserted into the recess 17 side by the amount of the push-and-expand. The O-ring 10a is strongly pressed, and as a result, the inserted cable 11 is pressed against the outer peripheral surface by the presence of the O-ring 10a, and is held tightly and in a waterproof state.
[0035]
Further, by applying a waterproofing agent 16 such as grease to a part of the insertion end side of the cable 11 to be inserted, not only is it easy to pass through the inside of the O-ring 10a, but also a stop which is squeezed by the O-ring. The liquid agent 16 accumulates in the through-hole 14, and the water stopping effect is further improved.
[0036]
In any of the embodiments, the fixing of the cable 11 in the fixing unit 4 prevents the bare wire portion 11b of the cable 11 from rusting. Only allows the cable 11 and the protective tube 8 to be joined in a waterproof state, and furthermore, the length of the bare wire portion 11b can substantially correspond to the length of the protective tube 8, and The stripping length and its operation do not require precision. After the cable 11 has been installed, the protective tube 8 may be filled with an appropriate filler.
[0037]
【The invention's effect】
As described above, the rust-prevention treatment method in the fixing portion of the erection cable according to the present invention is performed in a fixing portion in which an end portion of an erection cable composed of a large number of cables supporting a cable-stayed bridge or the like is fixed to a fixing member . The fixing member is provided with a protective tube for protecting the fixing end side of a large number of cables, and a free end of the protective tube is provided with a number of through holes corresponding to the number of cables and maintaining the arrangement of the cables . A spacer is provided, and an elastic material is provided in advance in each through hole of the spacer, and the elastic material and the cable are pressed into contact with each other by inserting the cable into each through hole. is made from the free end side of the protective tube, just as plug according to the arrangement order simply by mounting, so attained is waterproofing or waterproof substantially intact is between inserted through the cable and the protective tube To exhibit the anti-corrosion function, moreover an excellent effect say the workability is remarkably improved.
[0038]
In addition, a plurality of spacers are disposed adjacent to each other, and an elastic material is disposed between the spacers. The elastic material is plate-shaped, and the cable is positioned at a position corresponding to the through hole of the spacer. By providing a through hole with a diameter smaller than the outer diameter and making the elastic material O-ring-shaped and having an inner diameter smaller than the outer diameter of the spacer, the cable to be erected is free end portion of the protective tube. By simply attaching the cable from the side in the order of arrangement , the adhesion to the cable is further strengthened, and an excellent effect that substantially complete water stoppage and waterproofing can be achieved is achieved.
[0039]
Further, a water-stopping agent is applied to a part of the cable and at least a part of the through hole of the spacer is filled with the water-stopping agent by being squeezed with an elastic material. Has an excellent effect of being further improved.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view schematically illustrating an example of a fixing portion of an erection cable to which a rust prevention method according to a first embodiment of the present invention is applied.
FIG. 2 is an enlarged sectional view showing only a main part of the rust prevention mechanism in the embodiment.
FIG. 3 is a side view schematically showing a fixing end side of the construction cable in the embodiment.
FIG. 4 is a schematic enlarged cross-sectional view for explaining a situation in which the erection cable in the embodiment is inserted through a rust prevention mechanism.
FIG. 5 is a schematic enlarged sectional view of a main part to which a second embodiment according to the present invention is applied.
FIG. 6 is an enlarged sectional view showing only a main part of the rust prevention mechanism in the embodiment.
FIG. 7 is a schematic enlarged cross-sectional view for explaining a situation in which the erection cable in the embodiment is inserted through a rust prevention mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main girder 2 Cable fixing through hole 3 Outer tube 4 Fixing member 5 Fixing plate 6 Support member 7 Fixing block 8 Protective tube 8a Adapter 9 Spacer 10 Elastic material 10a O-ring 11 Cable 11a Sheath portion 11b Bare wire portion 12 Wedge material 13 Bolt 14, 15 Through hole 16 Waterproofing agent 17 Recess

Claims (5)

In a fixing section in which the ends of an erection cable composed of a large number of cables supporting a cable-stayed bridge or the like are fixed to a fixing member, a protective tube for protecting the fixing end side of the large number of cables is provided in the fixing member , A spacer having a large number of through holes corresponding to the number of cables and maintaining the arrangement of the cables is provided on the free end side of the protective tube, and an elastic material is provided in advance in each through hole of the spacer. A method for rust-proofing a fixing portion of an installation cable, wherein the cable is pressed into contact with the elastic material by inserting the cable into each through hole . The method for preventing rust in a fixing portion of an installation cable according to claim 1, wherein a plurality of spacers are disposed adjacent to each other , and an elastic material is disposed between the spacers. The rustproofing method for an installation cable according to claim 1 or 2, wherein the elastic material has a plate shape, and a through hole having a diameter smaller than an outer diameter of the cable is provided at a position corresponding to the through hole of the spacer. The rust-proofing method according to claim 1 or 2, wherein the elastic material has an O-ring shape, and an inner diameter of the O-ring is smaller than an outer diameter of the cable . The rustproofing of the construction cable according to claim 1 , wherein a waterproofing agent is applied to a part of the cable , and at least a part of the through hole of the spacer is filled with the waterproofing agent by being squeezed with an elastic material. Processing method.

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