Rigid formwork material used for cable corner bending buffer structure and functional variable method of cable corner bending buffer structure

Abstract

To provide a rigid formwork material and a function variable construction method that are effective to suppress corner bend in a cable corner bend buffer structure, and can change the function to a structure that does not interfere with the function of a cable vibration control device when installing and using a cable vibration control device in combination with the cable.SOLUTION: A rigid formwork material 3 used in a cable corner bend buffer structure 1 is configured to have a tubular shape along an outer circumferential surface of a cable 10 with a plurality of members (31, 32) arranged in a circumferential direction of the cable 10, and to be detachably disposed between the cable 10 and a corner bend buffer material 2. This rigid formwork material 3 is configured such that, when left between the cable 10 and the corner bend buffer material 2, displacement and vibration of the cable 10 are transmitted to the corner bend buffer material 2, and, when removed from between the cable 10 and the corner bend buffer material 2, a corner bend buffer material 2 with a gap is formed, in which an annular gap 5 is provided between the cable 10 and the corner bend buffer material 2.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a cable kink buffer structure provided at a fixing portion of a cable stretched on a bridge, and more particularly to a rigid formwork material and a construction method that enable changing the function of the cable kink buffer structure.

Background Art

[0002] Cables stretched on bridges such as cable-stayed bridges and Nielsen bridges move due to weight fluctuations of vehicles traveling on the bridge, etc., and bending stress is generated on the fixing points where the cables are fixed. This phenomenon is called kinking. As a countermeasure to suppress this kinking, at the fixing portion of the cable, a cable kink buffer structure is provided in which a kink buffer material (cushion material) is installed between the cable and a fixing pipe surrounding the outer periphery of the cable. The displacement of the cable is received and suppressed by the elastic force of the kink buffer material to suppress kinking.

[0003] On the other hand, cable vibration occurs in which the cable vibrates spontaneously and periodically due to the influence of wind, etc. A cable vibration damping device is installed for the purpose of suppressing this cable vibration. The cable vibration damping device has, for example, a configuration in which a damping member composed of a rubber member having viscoelasticity, oil, etc. is interposed between a fixing portion fixed to a fixing pipe, a bridge girder, etc. and a cable-side fixing portion fixed to the cable. The force of the cable vibration is transmitted to the damping member, and the vibration is attenuated by the resistance of the damping member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The cable kink buffer structure can suppress the kinking of the cable, and further suppress the cable vibration due to the vibration damping effect of the kink buffer material itself. However, depending on the environment, traffic conditions, etc. at the actual bridge installation site, the vibration damping effect of the kink buffer material may not be able to sufficiently suppress the cable vibration in some cases. In such cases, it is effective to install a cable vibration damping device on the cable. Since the cable vibration damping device is usually installed on the cable within a range from the tip of the fixing pipe to several meters ahead, if the kink buffer material remains in the fixing pipe, the movement of the cable at the position of the cable vibration damping device will be restricted to some extent, and the vibration damping effect of the cable vibration damping device will not be fully exerted. Therefore, when installing a cable vibration damping device on the cable, all the kink buffer materials in the fixing pipe are removed, and a kink buffer material with a gap, which provides a certain gap around the cable again, is constructed. However, such work is time-consuming and costly.

[0006] The present invention has been made in view of the above circumstances, and in the cable kink buffer structure, when suppressing kinking and installing and using a cable vibration damping device on the cable, it is an object to provide a cable kink buffer structure that can change its function to a structure that does not interfere with the function of the cable vibration damping device. That is, for achieving the above object, the present invention provides a rigid formwork material used for a cable kink buffer structure and a method for varying the function of the cable kink buffer structure.

Means for Solving the Problems

[0007] The rigid formwork material used for the cable kink buffer structure according to the present invention is a rigid formwork material used for a cable kink buffer structure in which a kink buffer material is installed between a cable and a fixing pipe surrounding the outer periphery of the cable at the fixing portion of the cable stretched on a bridge, formed in a cylindrical shape along the outer peripheral surface of the cable by a plurality of members arranged in the circumferential direction of the cable, and configured to be detachably disposed between the cable and the kink buffer material. In a state where it is left between the cable and the angled buffer material, the displacement and vibration of the cable are configured to be transmitted to the angled buffer material, and by removing it from between the cable and the angled buffer material, an angled buffer material with a gap is formed in which an annular gap is provided between the cable and the angled buffer material.

[0008] The method for varying the function of the cable angled buffer structure according to the present invention is a method that enables changing the function of a cable angled buffer structure in which an angled buffer material is installed between a cable and a fixing pipe that surrounds the outer periphery of the cable at the fixing portion of the cable stretched on a bridge, arrange the rigid formwork material according to claim 1 so as to cover the entire circumference of the outer peripheral surface of the cable with respect to the cable portion surrounded by the fixing pipe, install an angled buffer material in the annular space between the rigid formwork material and the fixing pipe, and leave the rigid formwork material between the cable and the angled buffer material so that the displacement and vibration of the cable are transmitted to the angled buffer material through the rigid formwork material, and construct a first cable angled buffer structure, When a cable vibration damping device is installed and used in combination with the cable, remove the rigid formwork material in the first cable angled buffer structure to form an angled buffer material with a gap in which an annular gap is provided between the cable and the angled buffer material, and construct a second cable angled buffer structure so as not to interfere with the function of the cable vibration damping device.

Advantages of the Invention

[0009] According to the configuration of the present invention described above, in the cable angled buffer structure in which the rigid formwork material is left between the cable and the angled buffer material, the displacement of the cable acting on the fixing point of the cable is transmitted to the angled buffer material through the rigid formwork material, and the angling of the cable can be suppressed. In addition, the vibration in which the cable swings spontaneously and periodically (hereinafter referred to as cable vibration) is transmitted to the angled buffer material through the rigid formwork material and can be suppressed by the vibration damping effect of the angled buffer material itself.

[0010] In addition, in the cable corner folding buffer structure in which the rigid formwork material is removed and changed to a corner folding buffer material with a gap, by setting a cable vibration damping device for the cable, it is possible to suppress cable vibrations that could not be suppressed by the corner folding buffer material alone. That is, the corner folding buffer material with a gap can be made not to interfere with the function of the cable vibration damping device by not exerting a restraining force on the cable vibration due to the gap. Therefore, the cable vibration damping device can suppress cable vibrations without being affected by the corner folding buffer material. When the cable swings greatly and displacement occurs, the displacement of the cable is transmitted to the corner folding buffer material with a gap, and the corner folding of the cable can be suppressed.

[0011] Therefore, according to the present invention, in the cable corner folding buffer structure, while having the effect of suppressing corner folding, when a cable vibration damping device is installed and used in combination with the cable, the structure can be functionally variable to a structure that does not interfere with the function of the cable vibration damping device. In addition, the corner folding buffer material with a gap suppresses the overload on the damping device due to excessive cable displacement, contributes to the long life of the cable vibration damping device, and can also function as a fail-safe after the deterioration of the cable vibration damping device.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The cable corner bending buffer structure in the embodiment is a structure provided at the cable fixing part of a bridge girder or a tower where the end of the cable stretched on the bridge is fixed, and suppresses the corner bending of the cable. Here, in this specification, "corner bending" refers to a phenomenon in which a bending stress is generated with respect to a fixing point where the cable is fixed due to the movement of the cable caused by the weight fluctuation of a vehicle traveling on the bridge. Further, "cable vibration" described later refers to a phenomenon in which the cable vibrates spontaneously and periodically due to the influence of wind or the like. As shown in FIG. 1, the cable corner bending buffer structure 1 includes a cable 10 stretched on a bridge, a cylindrical fixing pipe 13 fixed to a bridge girder (fixing part) 11 and surrounding the outer periphery of the end of the cable 10, and a corner bending buffer material 2 installed in an annular space between the cable 10 and the fixing pipe 13 in the fixing pipe 13. A rigid formwork material 3 is detachably disposed between the cable 10 and the corner bending buffer material 2. In this embodiment, an application example of filling the corner bending buffer material in a cable-stayed bridge is shown, but it is applicable not only to cable-stayed bridges but also to bridges where the cable 10 is stretched, such as a Neilson bridge or a suspension bridge. Further, the corner bending buffer material 2 is applicable not only to the construction of filling with a liquid material but also to the construction of forming a corner bending buffer structure in the fixing pipe 13, such as inserting and installing a solid molded product.

[0014] A disc-shaped cable hat 14 is attached to the cable 10 near the opening of the fixing pipe 13. This cable hat 14 can block the water running along the cable 10 and prevent water from entering the cable fixing part. Also, by attaching the cable hat 14 close to the rigid formwork material 3, it is possible to prevent the rigid formwork material 3 from lifting. Note that instead of the cable hat 14, a conical cable cover (not shown) that is externally fitted between the outer peripheral surface of the opening of the fixing pipe 13 and the outer peripheral surface of the cable 10 may be installed.

[0015] The cable 10 has a configuration in which a large number of steel wires are bundled and covered with a coating pipe made of a resin such as polyethylene. Note that the cable 10 may be various cables for bridges, such as those in which plated steel wires are bundled in parallel, or those in which steel wires are bundled and solidified with resin to form a rod shape. Each end of the cable 10 is provided with an anchor and fixed to the bridge girder 11 and the tower 12, and the bridge girder 11 is supported by the cable 10 stretched between the bridge girder 11 and the tower 12. The fixing pipe 13 is composed of a steel cylinder and is fixed to the bridge girder 11 that serves as a fixing part. The end of the cable 10 fixed to the bridge girder 11 is inserted into the fixing pipe 13. Note that the fixing pipe 13 may be a fixing pipe fixed to the tower 12 side that serves as a fixing part. The angled bend buffer material 2 is composed of a cushioning material having rubber elasticity such as polybutadiene.

[0016] When the cable 10 moves and displaces due to weight fluctuations of vehicles traveling on the bridge or the like, the cable angled bend buffer structure 1 can receive and suppress the displacement of the cable 10 with the elastic force of the angled bend buffer material 2, and suppress the angled bend at the fixing point of the cable 10. Also, when cable vibration occurs in which the cable 10 shakes spontaneously and periodically due to the influence of wind, rain, etc., the cable angled bend buffer structure 1 can suppress the cable vibration by attenuating the vibration with the material characteristics of the angled bend buffer material 2 itself. However, through observation, when it is found that the cable vibration cannot be sufficiently suppressed by the vibration attenuation effect of the angled bend buffer material 2 depending on the environment, traffic conditions, etc. at the actual bridge installation site, it becomes necessary to install a cable vibration damping device 6 on the cable 10.

[0017] This embodiment has a configuration with variable functionality so that it can also handle the case where a cable damping device is installed and used in combination with the cable 10 in the cable kink buffer structure 1. Here, in this specification, "variable functionality" (the same as the description "changing the function" in the specification) means that in the cable kink buffer structure 1, the kink buffer material 2 suppresses the kinking of the cable 10, and due to the material characteristics of the kink buffer material 2, it is also possible to suppress cable vibration. From this function, while the kink buffer material 2 (kink buffer material with a gap) can suppress the kinking of the cable 10, it does not exert a restraining force on cable vibration, and the vibration damping performance of the subsequently installed cable damping device 6 is maximally exerted. Changing to this function is what is meant. Also, the "variable functionality method" described later refers to the construction method for making the above-mentioned variable functionality in the cable kink buffer structure 1. As a configuration for enabling this variable functionality, a rigid formwork material 3 is detachably disposed between the cable 10 and the kink buffer material 2. That is, as shown in FIG. 2, the first cable kink buffer structure 1A in a state where the rigid formwork material 3 is left between the cable 10 and the kink buffer material 2 (see FIG. 2(A)), and the second cable kink buffer structure 1B in which the rigid formwork material 3 is removed to form an annular gap 5 between the cable 10 and the kink buffer material 2 (see FIG. 2(B)) can be constructed. Note that the size of the "gap 5" can be arbitrarily set within a range that does not cause the effect of suppressing the kinking of the cable 10 to be lost. As an example, the setting of the size of the "gap 5" may be calculated from the allowable bending angle at the fixing point of the cable 10.

[0018] The rigid formwork material 3 has a cylindrical shape along the outer peripheral surface of the cable 10, which is formed by combining a plurality of members arranged in the circumferential direction of the cable 10. The length of the rigid formwork material 3 in the cable axis direction is set to be equal to or greater than the length of the kink buffer material 2 in the cable axis direction. Specifically, as shown in FIG. 2(A), the rigid formwork material 3 is composed of a plurality of rod-shaped formwork materials 31 arranged along the outer peripheral surface of the cable 10 and a plurality of covering formwork materials 32 arranged so as to cover the outer peripheral surfaces of the plurality of rod-shaped formwork materials 31.

[0019] As shown in FIG. 3, the rod-shaped formwork member 31 is an elongated flat member having a quadrangular cross-section. The rod-shaped formwork member 31 is formed of a hard material such as carbon steel or alloy steel (for example, SUS304). Note that the material of the rod-shaped formwork member 31 may be any material having a hardness equal to or greater than that of the cable 10, and may be other metals, hard plastics, or the like. Further, the rod-shaped formwork member 31 is formed with a locking portion 31a bent in a hook shape on one end side in order to be easily withdrawn from between the cable 10 and the corner break buffer member 2. Note that the locking portion 31a is not limited to being formed by bending the end portion of the rod-shaped formwork member 31 in a hook shape, and may be a hole, a groove, or the like formed on one end side of a linear rod-shaped formwork member 31.

[0020] Each rod-shaped formwork member 31 is arranged with the locking portion 31a on the opening side of the fixing pipe 13 so that the length direction is aligned with the axial direction of the cable 10 and is arranged side by side along the outer peripheral surface of the cable 10 over the entire circumference in the circumferential direction, and is arranged in a cylindrical shape without any gaps (see FIG. 2(A)). The number of rod-shaped formwork members 31 used is such that the entire outer peripheral surface of the cable 10 can be covered without any gaps, and is arbitrarily determined by the width of the rod-shaped formwork member 31 and the outer diameter of the cable 10. For example, when the diameter of the cable 10 is 140 mm or more, if the rod-shaped formwork member 31 has a width of 15 mm, about 30 to 35 are used. The rod-shaped formwork member 31 of the embodiment has a flat quadrangular cross-sectional shape, but in addition to this, it may have a quadrangular cross-sectional shape curved in an arc shape, or a cross-sectional shape such as a polygon or a circle. Note that the rod-shaped formwork member 31 having a flat or arc-shaped curved quadrangular cross-sectional shape can be formed with a small thickness and a wide width, so that the entire outer peripheral surface of the cable 10 can be covered without any gaps with a smaller number compared to a rod-shaped formwork member having a circular cross-sectional shape such as a round bar with respect to a certain gap 5 between the cable 10 and the corner break buffer member 2.

[0021] As shown in Fig. 4, the coated formwork member 32 is a plate-shaped member with a semi-circular cross-section, and two of them are combined to form a cylindrical shape. The coated formwork member 32 is made of a hard material such as carbon steel or alloy steel (for example, SUS304). Note that the material of the coated formwork member 32 may be any material as long as it has a hardness equal to or greater than that of the cable 10, and other metals, hard plastics, etc. may also be used. Each coated formwork member 32 is assembled and arranged in a cylindrical shape so as to cover the entire plurality of rod-shaped formwork members 31 arranged on the outer peripheral surface of the cable 10 from the outside (see Fig. 2(A)). The length of the coated formwork member 32 in the cable axis direction is formed shorter than the length of the rod-shaped formwork member 31 in the cable axis direction. The thickness of the coated formwork member 32 is formed thinner than the thickness of the rod-shaped formwork member 31. Since the coated formwork member 32 can make the outer peripheral surface, which is convex and concave due to the plurality of rod-shaped formwork members 31, into a smooth surface, the vibration of the cable 10 and the displacement of the cable 10 can be well transmitted to the angled bend buffer member 2. In addition, since the coated formwork member 32 is arranged on the side of the angled bend buffer member 2, the angled bend buffer member 2 will not be damaged when the rod-shaped formwork member 31 is taken out from between the cable 10 and the angled bend buffer member 2. Note that the coated formwork member 32 is not limited to two semi-circular plate-shaped members, and may be about 3 to 5 arc-shaped plate-shaped members that are combined to form a cylindrical shape.

[0022] Next, the construction (function variable method) of the cable angled bend buffer structure 1 will be described. The cable angled bend buffer structure 1 of the embodiment can construct the first cable angled bend buffer structure 1A and the second cable angled bend buffer structure 1B by installing or removing the hard formwork member 3.

[0023] 1. Construction of the first cable angled bend buffer structure 1A As shown in Fig. 5(a1), first, a backup material 4 made of foamed plastic is inserted from the opening of the fixing pipe 13 to a predetermined depth inside the fixing pipe 13.

[0024] Then, an annular temporary assembly pedestal 7 is attached to the outer peripheral surface of the cable 10 that protrudes slightly from the opening of the fixing pipe 13, and the rigid formwork material 3 is assembled on this temporary assembly pedestal 7 (rigid formwork material temporary assembly process). The assembly of the rigid formwork material 3 on the temporary assembly pedestal 7 is first carried out by arranging a plurality of rod-shaped formwork materials 31 over the entire circumference on the outer peripheral surface of the cable 10. At this time, for each rod-shaped formwork material 31, the other end that does not form the locking portion 31a is brought into contact with the upper surface of the temporary assembly pedestal 7, the length direction is aligned with the axial direction of the cable 10, and it is arranged along the outer peripheral surface of the cable 10, and they are arranged in a cylindrical shape without gaps over the entire circumferential direction of the cable 10. When arranging the rod-shaped formwork materials 31, a metal band may be wound around the outer periphery to hold each rod-shaped formwork material 31 so that it does not shift in position. When the arrangement of the plurality of rod-shaped formwork materials 31 is completed, two covering formwork materials 32 are assembled in a cylindrical shape so as to cover the outer peripheral surfaces of the plurality of rod-shaped formwork materials 31, and the temporary assembly of the rigid formwork material 3 on the temporary assembly pedestal 7 is completed.

[0025] After the temporary assembly of the rigid formwork material 3, the temporary assembly pedestal 7 is removed from the cable 10, and as shown in Fig. 5(a2), the temporarily assembled rigid formwork material 3 is slid down onto the backup material 4 in the fixing pipe 13 along the cable 10 and installed in the fixing pipe 13 (rigid formwork material installation process).

[0026] After installing the rigid formwork material 3 inside the fixing pipe 13, a closing lid (not shown) with a filling port is installed at the opening of the fixing pipe 13, and the material of the liquid corner break buffer material 2 is filled into the fixing pipe 13 from the filling port (corner break buffer material installation step). When the material of this corner break buffer material 2 hardens, as shown in Fig. 5(a3), the closing lid is removed, and a corner break buffer material 2 is formed between the rigid formwork material 3 disposed on the outer peripheral surface of the cable 10 and the fixing pipe 13. After the material of the corner break buffer material 2 has hardened, a metal band 8 (see Fig. 2(A)) is tightened and fixed to the outer peripheral surfaces of the rod-shaped formwork material 31 and the covering formwork material 32 exposed from the opening of the fixing pipe 13. Thereby, the construction of the first cable corner break buffer structure 1A with the rigid formwork material 3 remaining between the cable 10 and the corner break buffer material 2 is completed. In this embodiment, after the construction of the cable corner break buffer structure 1A, a disk-shaped cable hat 14 is attached to the cable 10 near the opening of the fixing pipe 13 (see Fig. 1).

[0027] 2. Construction of the second cable corner break buffer structure 1B For the second cable corner break buffer structure 1B, the rigid formwork material 3 of the first cable corner break buffer structure 1A is removed. As shown in Figs. 6(b1)(b2)(b3), to remove the rigid formwork material 3, the cable hat 14 is removed, and the rod-shaped formwork material 31 and the covering formwork material 32 are removed in this order. When removing the rod-shaped formwork material 31, the locking portion 31a of the rod-shaped formwork material 31 is held and removed by pulling it out from between the cable 10 and the corner break buffer material 2 (see Fig. 6(b2)). By removing all the rod-shaped formwork materials 31, a space is formed on the outer periphery of the cable 10. Using this space, the covering formwork material 32 is released from the corner break buffer material 2 and removed by pulling it out from between the cable 10 and the corner break buffer material 2 (see Fig. 6(b3)). By removing the rigid formwork material 3 in this way, the construction of the second cable corner break buffer structure 1B with a gap-provided corner break buffer material 2 having an annular gap 5 provided between the cable 10 and the corner break buffer material 2 is completed (see Fig. 6(b4)).

[0028] Then, as shown in FIG. 7, in the second cable corner bending buffer structure 1B, it is possible to install and operate the cable vibration damping device 6 for the cable 10. After installing the cable vibration damping device 6, a cable hat 14 may be installed on the cable 10 near the cable vibration damping device 6. The cable vibration damping device 6 has a configuration in which a damping member 63 composed of a rubber member or oil having viscoelasticity is interposed between a fixing pipe side fixing portion 61 fixed to the outer peripheral surface of the opening of the fixing pipe 13 and a cable side fixing portion 62 fixed to the outer peripheral surface of the cable 10. According to the cable vibration damping device 6, when cable vibration occurs in which the cable 10 vibrates spontaneously and periodically due to wind, rain, etc., the cable vibration is transmitted to the damping member 63 through the cable side fixing portion 62, and the cable vibration can be attenuated by the resistance of the damping member 63. That is, since the gap-provided corner bending buffer material 2 does not exert a restraining force on the cable vibration due to the gap 5, the cable vibration can be suppressed by the cable vibration damping device 6 without the corner bending buffer material 2 interfering.

[0029] In addition, after constructing the second cable corner bending buffer structure 1B, the rigid formwork material 3 can be reinstalled to form the first cable corner bending buffer structure 1A. When reinstalling the rigid formwork material 3, in the reverse order of the removal order, that is, the covering formwork material 32 is first inserted into the gap 5 between the cable 10 and the corner bending buffer material 2, and then the rod-shaped formwork material 31 is installed between the cable 10 and the covering formwork material 32.

[0030] As described above, according to the present embodiment, by configuring the rigid formwork material 3 to be detachably disposed between the cable 10 and the corner bending buffer material 2, the first cable corner bending buffer structure 1A with the rigid formwork material 3 left and the second cable corner bending buffer structure 1B with the rigid formwork material 3 removed can be constructed as needed.

[0031] For example, at the initial stage of the operation start of the cable kink buffer structure 1, the first cable kink buffer structure 1A in a state where the rigid formwork material 3 is left between the cable 10 and the kink buffer material 2 is constructed. According to this first cable kink buffer structure 1A, the displacement of the cable 10 acting on the fixing point of the cable 10 is transmitted to the kink buffer material 2 via the rigid formwork material 3, and the kinking of the cable 10 can be suppressed. Moreover, the cable vibration caused by the swaying of the cable 10 is transmitted to the kink buffer material 2 via the rigid formwork material 3 and can be suppressed by the vibration damping effect due to the material characteristics of the kink buffer material 2 itself.

[0032] After the start of operation in the first cable kink buffer structure 1A, through observation, if the vibration damping effect due to the material characteristics of the kink buffer material 2 itself cannot sufficiently suppress the cable vibration depending on the environment, traffic conditions, etc. at the actual bridge installation site, the rigid formwork material 3 is removed and the function is changed to the second cable kink buffer structure 1B in which the kink buffer material 2 with a gap is used. In this case, by installing the cable vibration damping device 6 for the cable 10, the cable vibration that could not be suppressed by the kink buffer material 2 can be suppressed. That is, the kink buffer material 2 with a gap can be made not to exert a restraining force on the cable vibration due to the gap 5 and not to interfere with the function of the cable vibration damping device 6. On the other hand, when the cable 10 sways greatly and displacement occurs, the displacement of the cable 10 is transmitted to the kink buffer material 2 with a gap, and the kinking of the cable 10 can be suppressed.

[0033] Therefore, according to the present embodiment, in the cable kink buffer structure 1 (1A, 1B), it has the effect of suppressing the kinking of the cable 10. On the other hand, when the cable vibration damping device 6 is installed and used together for the cable 10, the function can be changed to the second cable kink buffer structure 1B that does not interfere with the function of the cable vibration damping device 6 by removing the rigid formwork material 3 in the first cable kink buffer structure 1A.

[0034] In addition, the angled cable buffer material 2 with a gap in the second cable angled buffer structure 1B suppresses an overload on the cable vibration damping device 6 due to excessive displacement of the cable 10, contributes to extending the service life of the cable vibration damping device 6, and can also function as a fail-safe after the deterioration of the cable vibration damping device 6.

[0035] When operating with the first cable angled buffer structure 1A, when forcibly vibrating the cable 10 to inspect the state of the cable 10, the rigid formwork material 3 can be removed to form the second cable angled buffer structure 1B. Thereby, the cable 10 can be inspected without being affected by the restraining force of the angled cable buffer material 2 on the movement of the cable 10, and the current performance state of the cable 10 itself can be correctly inspected. After the inspection, the rigid formwork material 3 can be reinstalled to return to the first cable angled buffer structure 1A.

[0036] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. The rigid formwork material 3 is not limited to being composed of a plurality of rod-shaped formwork materials 31 and a plurality of coated formwork materials 32 as in the embodiment, and may be composed of a plurality of members arranged in the circumferential direction of the cable 10 and having a cylindrical shape along the outer peripheral surface of the cable 10. For example, it may be composed of a plurality (about 2 to 5) of plate-like members whose cross-sectional shapes are curved in an arc shape so as to form a cylindrical shape in combination. In addition, for the purpose of surface protection of the cable 10 and the angled cable buffer material 2 and improving the mold release property from the rigid formwork material 3, a protective material such as a thin film may be provided on the contact surface between the members.

Explanation of Reference Numerals

[0037] 1 Cable angled buffer structure 1A First cable angled buffer structure 1B Second cable angled buffer structure 2 Angled cable buffer material 3 Rigid formwork material 4 Backup material 5 Gap 6 Cable Vibration Damping Device 7 Temporary Erection Base 8 Metal Band 10 Cable 11 Bridge Girder 12 Tower 13 Fixing Pipe 14 Cable Hat 31 Rod-shaped Formwork Material 31a Locking Part 32 Coated Formwork Material 61 Fixing Pipe Side Fixing Part 62 Cable Side Fixing Part 63 Vibration Damping Member

Claims

1. A rigid formwork material used for a cable kink buffer structure in which a kink buffer material is installed between a cable and a fixing pipe surrounding the outer periphery of the cable at a fixing portion of the cable stretched on a bridge, It is composed of a plurality of members arranged in the circumferential direction of the cable, forming a cylindrical shape along the outer peripheral surface of the cable, and is configured to be detachably disposed between the cable and the kink buffer material, In a state of remaining between the cable and the kink buffer material, it is configured such that displacement and vibration of the cable are transmitted to the kink buffer material, and by removing it from between the cable and the kink buffer material, an annular gap is provided between the cable and the kink buffer material. A rigid formwork material used for a cable kink buffer structure configured to form a kink buffer material with a gap.

2. Composed of elongated rod-shaped members, a plurality of rod-shaped formwork materials arranged side by side along the entire circumference in the circumferential direction along the outer peripheral surface of the cable with the length direction aligned with the axial direction of the cable, Composed of plate-shaped members with an arc-shaped cross-section, and a plurality of covering formwork materials covering the plurality of rod-shaped formwork materials arranged on the outer peripheral surface of the cable from the outside. A rigid formwork material used for the cable kink buffer structure according to Claim 1.

3. Each of the plurality of rod-shaped formwork materials is provided with a locking portion for enabling the rod-shaped formwork material to be pulled out and removed from between the cable and the kink buffer material at one end side. A rigid formwork material used for the cable kink buffer structure according to Claim 2.

4. A construction method that enables changing the function of a cable kink buffer structure in which a kink buffer material is installed between a cable and a fixing pipe surrounding the outer periphery of the cable at a fixing portion of the cable stretched on a bridge, Arrange the rigid formwork material according to Claim 1 so as to cover the entire circumference of the outer peripheral surface of the cable portion surrounded by the fixing pipe, install a kink buffer material in the annular space between the rigid formwork material and the fixing pipe, and leave the rigid formwork material between the cable and the kink buffer material. Construct a first cable kink buffer structure in which displacement and vibration of the cable are transmitted to the kink buffer material through the rigid formwork material, When a cable damping device is installed and used in combination with a cable, the rigid formwork material in the first cable corner bending buffer structure is removed to form a corner bending buffer material with an annular gap provided between the cable and the corner bending buffer material, and a second cable corner bending buffer structure is constructed so as not to interfere with the function of the cable damping device. This is a method for varying the function of a cable corner bending buffer structure.

5. The rigid formwork material includes the rod-shaped formwork material and the coated formwork material according to claim 2 or 3. When constructing the first cable corner bending buffer structure, the rod-shaped formwork material is constructed with one end side located on the opening side of the fixing pipe exposed from the coated formwork material. When constructing the second cable corner bending buffer structure, when removing the rigid formwork material from between the cable and the corner bending buffer material, the rod-shaped formwork material is removed by holding and pulling out one end side of the rod-shaped formwork material, and then the coated formwork material is removed. This is the method for varying the function of the cable corner bending buffer structure according to claim 4.

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