Repair method for flexible joint

Abstract

To provide a method for repairing a flexible joint, which can be easily carried out at an installation place, and which hardly causes interference between a repaired flexible water cut-off member and a member located around the flexible water cut-off member.SOLUTION: A method for repairing a flexible joint 2 provided with a flexible water cut-off member 1 which is placed in a gap 5 between structures 3, 4, is fixed at one end to the structure 3 and at the other end to the structure 4, and seals the gap 5 in a watertight manner includes a patch material sticking step of sticking a patch material 11 to a surface of an object portion of the flexible water cut-off member 1 to be repaired to cover the object portion, and a film material fixing step of overlapping a film material 13 on the patch material 11 stuck to the object portion to cover the flexible water cut-off member 1 with the film material 13 and fixing an end portion of the film material 13 to the structures 3, 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for repairing a flexible joint. [Background technology]

[0002] In underground structures such as box culverts and marine structures such as seawalls, it is necessary to seal the inside and outside of the joints between the structures, while also allowing for uneven settlement of the structures on both sides of the joints, displacement during earthquakes, and expansion and contraction of the wall parts due to temperature changes, etc. Flexible joints equipped with flexible water-stopping members such as waterstop plates made of rubber or synthetic resin are installed between the structures spanning the joints or inside the joints (for example, Patent Document 1).

[0003] After installation of a flexible joint, damage to the flexible water-stopping member may occur. If damage occurs to the flexible water-stopping member, it must be repaired at the installation site while the flexible water-stopping member remains installed. This is because the flexible water-stopping member is quite large, making it difficult to remove the entire flexible water-stopping member from the installation site and transport it back to the repair work base. Furthermore, if a partially damaged flexible water-stopping member is removed in its entirety from the installation site, there will be no way to prevent water leakage or the like at the installation site.

[0004] There are roughly two methods for repairing flexible water-stopping members in place. One is to apply a paste of naturally vulcanizing rubber to the surface of the cracked part of the flexible water-stopping member and allow the rubber to harden by natural vulcanization. The other is to cut out the cracked part of the flexible water-stopping member, place a mold over the cracked part, sandwich the rubber between the molds, and apply heat to vulcanize and harden the rubber. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-133346 Summary of the Invention [Problem to be solved by the invention]

[0006] The former method is relatively easy to implement, but requires a thick layer of rubber to ensure the necessary strength in the repaired area. This results in a thick rubber layer after repair, which can cause problems such as the flexible waterproofing member interfering with the metal fittings that secure the flexible waterproofing member. This can result in problems with securing the flexible waterproofing member.

[0007] The latter method requires that the mold and other materials be brought to the installation site. Furthermore, the mold may interfere with surrounding structures, making it impossible to install the mold at all. Furthermore, depending on the environment of the installation site, vulcanization, which involves heating, may not be possible. In other words, the latter method may be difficult or impossible to implement.

[0008] The present invention aims to provide a method for repairing a flexible joint that can be easily performed at the installation site and is less likely to cause interference between the repaired flexible water-stopping member and components surrounding the flexible water-stopping member. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the method for repairing a flexible joint according to the present invention is a method for repairing a flexible joint having a flexible water-stopping member that is placed in a gap between two structural members, with one end fixed to one structural member and the other end fixed to the other structural member, thereby watertightly sealing the gap, and is characterized by comprising a patch material application step in which a patch material is applied to the surface of the target portion of the flexible water-stopping member to be repaired, thereby covering the target portion, and a membrane material fixing step in which a membrane material is overlaid on the patch material applied to the target portion, thereby covering the flexible water-stopping member with the membrane material, and fixing the ends of the membrane material to each of the two structural members.

[0010] It is preferable that the patch material be a face material made of the same type of material as the flexible water-stopping member. It is even more preferable that the patch material be a face material made of the same material as the flexible water-stopping member.

[0011] It is preferable that the membrane material is made of a fabric as a base material, and it is even more preferable that the fabric is made of polyester fiber.

[0012] It is preferable that the flexible water-stopping member has its end sandwiched between a pressure plate fixed to the structural member and the structural member, and the end pressed by the pressure plate to fix it to the structural member, and that in the membrane material fixing process, the end of the membrane material is sandwiched between the flexible water-stopping member and the pressure plate to fix the membrane material to the structural member.

[0013] In the patch material application step, the patch material may be heated after being applied to the surface of the target portion of the flexible water-stopping member. [Effects of the Invention]

[0014] According to the present invention, when damage occurs to a flexible water-stopping member that constitutes a flexible joint, a repair method can be provided that can easily repair the flexible joint at the location where the flexible joint is installed, and that is less likely to cause interference between the repaired flexible water-stopping member and surrounding members. [Brief explanation of the drawings]

[0015] [Figure 1] 1A and 1B are cross-sectional views showing a state in which a flexible joint according to an embodiment of the present invention is fixed to a structural member, where FIG. 1A shows the state before repair and FIG. 1B shows the state after repair. [Figure 2] 1A to 1C are explanatory diagrams illustrating a patch material application process according to an embodiment of the present invention, showing the process in chronological order. [Figure 3] FIG. 10 is an explanatory diagram illustrating a step of heating the patch material using a heat gun in the patch material application step. [Figure 4] 1A to 1C are explanatory diagrams illustrating a membrane material fixing step according to an embodiment of the present invention, showing the steps in chronological order. [Figure 5]FIG. 10 is a cross-sectional view showing another example of a flexible water-stopping member to which the present invention is applied, showing the state after repair has been performed. [Figure 6] FIG. 10 is a cross-sectional view showing yet another example of a flexible water-stopping member to which the present invention is applied, showing the state after repair has been performed. DETAILED DESCRIPTION OF THE INVENTION

[0016] Specific embodiments of the present invention will be described in detail below with reference to the drawings.

[0017] FIG. 1(A) is a cross-sectional view showing the state of the flexible water-stopping member 1 before repair using a repair method according to an embodiment of the present invention, and FIG. 1(B) is a cross-sectional view showing the state of the flexible water-stopping member 1 after repair. The flexible water-stopping member 1 is one of the components of a flexible joint 2 (described later) and, as shown in FIGS. 1(A) and 1(B), is a water-stopping member placed in a gap 5 between concrete structures 3 and 4 to watertightly seal the gap 5. In the state shown in FIGS. 1(A) and 1(B), the bottom surface of the flexible water-stopping member 1 is in contact with water. Therefore, the flexible water-stopping member 1 is subjected to water pressure from below. In other words, the flexible water-stopping member 1 is subjected to water pressure in the direction indicated by the arrow in FIG. 1(A). Therefore, the flexible water-stopping member 1 is required to have flexibility that can follow the relative displacement of the structure 3 with respect to the structure 4 and strength that can withstand water pressure and maintain watertightness. For this reason, the flexible water-stopping member 1 is made of rubber, a flexible rigid resin, or the like. The cross-sectional shape of the flexible water-stopping member 1 is selected appropriately depending on the direction and magnitude of the expected relative displacement. The structures 3 and 4 are examples of two structural members across which the flexible water-stopping member constituting the flexible joint to which the repair method according to the present invention is applied is spanned.

[0018] As shown in FIGS. 1(A) and 1(B), anchor bolts 6 are embedded in the structures 3 and 4. Metallic retaining plates 7 are placed on the left and right ends of the flexible water-stopping member 1. The anchor bolts 6 are inserted into bolt holes (not shown) that penetrate the flexible water-stopping member 1 and the retaining plates 7. Nuts 8 are screwed onto the tip of the anchor bolts 6 that protrude above the retaining plates 7. By tightening the nuts 8, the ends of the flexible water-stopping member 1 are fixed to the structures 3 and 4. In this way, one end of the flexible water-stopping member 1 is fixed to the structure 3, and the other end of the flexible water-stopping member 1 is fixed to the structure 4. The retaining plates 7 are long plates that extend in the longitudinal direction of the flexible water-stopping member 1, i.e., in the direction penetrating the plane of the drawing. A plurality of anchor bolts 6 are arranged in the longitudinal direction of the flexible water-stopping member 1.

[0019] In addition, block-shaped protective members 9 are disposed on both the left and right sides of the flexible water-stopping member 1 and fixed to the presser plates 7. The protective members 9 abut against the sides of the flexible water-stopping member 1 to prevent the flexible water-stopping member 1 from falling over, i.e., to prevent the flexible water-stopping member 1 from displacing in the left-right direction. By preventing the flexible water-stopping member 1 from falling over, excessive stress is less likely to be generated in the flexible water-stopping member 1, making the flexible water-stopping member 1 less likely to be damaged. In this embodiment, the flexible joint 2 is composed of all of the components shown in FIG. 1(A) except for the structures 3 and 4, the gap 5, and the crack 10 described below. In other words, the entire configuration shown in FIG. 1(A), excluding the structures 3 and 4, the gap 5, and the crack 10, corresponds to the flexible joint 2 in this embodiment. Meanwhile, the flexible water-stopping member 1 is the most important component of the flexible joint 2, and it goes without saying that it is the repair target to which the repair method described below is directly applied. In addition, components not labeled with symbols in FIG. 1(A) are also included in the flexible joint 2.

[0020] However, if the flexible joint 2 is cut by an unexpected sharp blade or if external stress is applied, the flexible water-stopping member 1 may be damaged. For example, as shown in FIG. 1(A), a crack 10 may occur in the flexible water-stopping member 1. If a relatively small crack 10 occurs in the flexible water-stopping member 1, it is not economical to replace the entire flexible water-stopping member 1. Therefore, by applying the repair method described below, the flexible water-stopping member 1 can be partially repaired to prevent water leakage from the crack 10.

[0021] As shown in FIG. 1(B), according to the repair method of this embodiment, a patch material 11 is applied to the target area, i.e., the outer surface of the area where a crack 10 has occurred in the flexible water-stopping member 1. The patch material 11 is a surface material that is applied to the target area, and by applying the patch material 11 to the target area, water leakage from the crack 10 is prevented. A membrane material 13 is placed on top of the patch material 11, covering the flexible water-stopping member 1. Both ends of the membrane material 13 are sandwiched between the presser plate 7 and the flexible water-stopping member 1 and fixed to the structures 3 and 4. The membrane material 13 is fixed to the structures 3 and 4 so that an appropriate tension is generated when the flexible water-stopping member 1 is significantly deformed by water pressure. The provision of the membrane material 13 limits deformation of the flexible water-stopping member 1. Specifically, the flexible water-stopping member 1 can deform in response to the relative displacement of the structures 3 and 4, but is limited so that it does not deform significantly when subjected to water pressure. By limiting the deformation of the flexible water-stopping member 1 in this way, the stress applied to the flexible water-stopping member 1 is alleviated, thereby suppressing the expansion of the crack 10.

[0022] 2(A) to 2(C) are diagrams showing the details of the repair method according to this embodiment in chronological order, illustrating the patching process. When a crack 10 shown in FIG. 1(A) is discovered in the flexible water-stopping member 1 at the installation location of the flexible water-stopping member 1, the protective member 9, nut 8, and presser plate 7 are first removed to create the state shown in FIG. 2(A). This is to facilitate access by tools and the like to the area of ​​the flexible water-stopping member 1 where the crack 10 has occurred. In this state, a brush or the like is used to remove sand particles and the like adhering to the outer surface of the area of ​​the flexible water-stopping member 1 where the crack 10 has occurred. Next, a solvent is applied to the outer surface to cover it. This is to remove any fine particles that may interfere with the effectiveness of the adhesive, as described below. The outer surface is then buffed. This is to appropriately roughen the outer surface to improve adhesive adhesion.

[0023] After the outer surface has been buffed, adhesive is brushed onto the outer surface as shown in FIG. 2(B). The adhesive is also brushed onto the surface of the patching material 11. After leaving it for a while, the adhesive is dried to the point where it no longer sticks to the fingers when touched. Then, the patching material 11 is placed on the adhesive-coated surface of the flexible water-stopping member 1 and adhered to it. This results in the state shown in FIG. 2(C). Once the state shown in FIG. 2(C) is achieved, the patching material 11 is heated using a heat gun 12 to harden the adhesive, as shown in FIG. 3. The heat gun 12 is a well-known tool that sprays hot air generated by electrical heating toward an object. In this example, the patching material 11 was heated to 130°C and maintained at that temperature for 10 minutes. This completes the patching material application process.

[0024] In this embodiment, as shown in FIG. 3, a windshield 12a is attached to the tip of the heat gun 12. The windshield 12a is literally a "windshield" that prevents the diffusion of hot air. FIG. 3 shows an example in which the windshield 12a is made of a flexible sheet-like material. If the windshield 12a is made of a flexible sheet-like material, it can be deformed to fit the shape of the flexible water-stopping member 1, thereby reducing the gap between the windshield 12a and the flexible water-stopping member 1 and enabling efficient heating. Furthermore, if the windshield 12a is made of a transparent material, the worker can directly view the target to be heated, i.e., the patch material 11, improving workability. However, the material of the windshield 12a is not limited to a flexible or transparent material. The windshield 12a may be made of an opaque, rigid material, such as an aluminum plate.

[0025] The type of adhesive used in the patch material application process is not particularly limited. Any adhesive that is compatible with the flexible water-stopping member 1 and the patch material 11 can be selected and used from a variety of known adhesives. The heating with a heat gun described above is merely an example and is not a required step. The necessity of heating, the heating temperature, and the heating time can be determined according to the properties of the adhesive. Alternatively, the technical instructions of the adhesive manufacturer can be followed.

[0026] The size of the patching material 11 is not particularly limited, but it is required to be large enough to at least cover the entire area of ​​the outer surface of the flexible water-stopping member 1 where the cracks 10 are visible. It is even better if the patching material 11 is large enough to cover the entire area of ​​the outer surface of the flexible water-stopping member 1 where the cracks 10 are visible, with some room to spare. The material of the patching material 11 is not particularly limited, but it is required to have flexibility that allows it to deform in accordance with the deformation of the flexible water-stopping member 1, as well as waterproofness and strength that allow it to prevent water leakage. In addition, it is required that the patching material 11 have the same compatibility with the flexible water-stopping member 1 for adhesives, so it is desirable that the patching material 11 be made of the same type of material as the flexible water-stopping member 1, or the same material as the flexible water-stopping member 1.

[0027] 4(A) to 4(C) are diagrams illustrating the details of the repair method according to this embodiment in chronological order, illustrating the membrane material fixing process. In the patch material application process, once the patch material 11 has been bonded, as shown in FIG. 4(A), a membrane material 13 is placed on top of the patch material 11 to cover the flexible water-stopping member 1 with the membrane material 13. After the flexible water-stopping member 1 is covered with the membrane material 13, as shown in FIG. 4(B), a presser plate 7 is placed on the membrane material 13, that is, the end of the membrane material 13 is sandwiched between the presser plate 7 and the flexible water-stopping member 1, and nuts 8 are tightened to fix the flexible water-stopping member 1 and the membrane material 13 to the structures 3 and 4. At this time, the membrane material 13 is fixed to the structures 3 and 4 so that, in the state shown in FIG. 4(B), a moderate amount of slack is generated in the membrane material 13. Furthermore, if the flexible water-stopping member 1 is significantly deformed by water pressure, the membrane material 13 is fixed to the structures 3 and 4 so that the flexible water-stopping member 1 receives surface pressure from the membrane material 13. Because it is configured in this way, small deformations of the flexible water-stopping member 1 caused by relative displacement of the structures 3 and 4 are permitted, but when the flexible water-stopping member 1 is subjected to water pressure from below the flexible water-stopping member 1 in the figure, upward expansion of the flexible water-stopping member 1 is restricted. In other words, large deformations of the flexible water-stopping member 1 are suppressed, so the internal stress of the flexible water-stopping member 1 is reduced and the expansion of the crack 10 is suppressed. This completes the membrane material fixing process.

[0028] After the membrane material fixing process is completed, a protective member 9 is attached to the pressing plate 7 as shown in Fig. 4(C). As a result, the state shown in Fig. 1(B) is obtained. In other words, the repair work is completed.

[0029] The size of the membrane material 13 is not particularly limited, but it is required to be at least large enough to cover the entire patch material 11. It is even better if the membrane material 13 is large enough to cover the entire patch material 11 with some room to spare. The material of the membrane material 13 is not particularly limited, but it is required to have flexibility that allows it to bend to fit the cross-sectional shape of the flexible water-stopping member 1, and strength that allows it to apply surface pressure to the flexible water-stopping member 1 and suppress large deformation of the flexible water-stopping member 1. The material of the membrane material 13 can be selected arbitrarily from materials that satisfy the above conditions.

[0030] Although the above describes an example in which the patching material 11 does not interfere with the presser plate 7, the position where the patching material 11 is applied and the size of the patching material 11 are not restricted by the presser plate 7. Depending on the position and size of the crack 10, in the state shown in FIG. 1(B), the end of the patching material 11 may extend below the presser plate 7 and be sandwiched between the presser plate 7 and the flexible water-stopping member 1 via the membrane material 13. Because the patching material 11 is a relatively thin and flexible member, sandwiching the patching material 11 between the presser plate 7 and the flexible water-stopping member 1 does not cause any major inconvenience.

[0031] In this embodiment, the membrane material 13 is a woven polyester fiber fabric, but the membrane material 13 may be made of a fabric made of other fibers, a synthetic resin film, or a composite material.

[0032] Furthermore, the flexible water-stopping member 1 to which the present invention is applied is not limited to those having the shapes and configurations shown in Figures 1 to 4. For example, the flexible water-stopping member 1 may have the shape shown in Figure 5, that is, a cross-sectional shape with a continuous corrugated cross section. The flexible water-stopping member 1 to which the present invention is applied is not limited to those in which anchor bolts 6 are inserted into the ends of the flexible water-stopping member 1. The flexible water-stopping member 1 may be of a type called a "bolt hole-less" as shown in Figure 6, in which anchor bolts 6 are not inserted into the ends of the flexible water-stopping member 1. In other words, the flexible water-stopping member 1 may be fixed to the structures 3, 4 by having its ends sandwiched between the structures 3, 4 and clamp members 14, which are fixed to the structures 3, 4 by anchor bolts 6.

[0033] As explained above, the repair method according to this embodiment does not require any special equipment or tools. All work can be completed using only handheld tools. The size and mass of the materials used for repair are limited to what the worker can carry by hand. Furthermore, the repair method according to this embodiment does not require a large amount of power. The power required is, at most, the electricity required for the heat gun 12. Therefore, the repair method according to this embodiment can be easily performed at the location where the flexible water-stopping member 1 is installed.

[0034] Furthermore, according to the repair method of this embodiment, the change in the shape of the flexible water-stopping member 1 before and after repair is small, so the repaired flexible water-stopping member 1 is less likely to interfere with surrounding members. Therefore, the repair method of this embodiment is less subject to restrictions due to the location of the crack 10.

[0035] However, the technical scope of the present invention is not limited to the above examples, and the present invention can be freely applied, modified, or improved within the scope of the technical idea defined in the claims.

[0036] In particular, the specific forms and shapes of the flexible water-stopping member 1, the patch material 11 and the membrane material 13 are merely examples, and the technical scope of the present invention is not limited to these.

[0037] Furthermore, the mechanical configuration of the flexible joint 2 shown above is merely an example, and the technical scope of the present invention is not limited by the above mechanical configuration. In particular, the specific means for fixing the flexible water-stopping member 1 or the membrane material 13 to the structures 3, 4 are merely examples, and the technical scope of the present invention is not limited by the above specific fixing means.

[0038] There are no limitations on the material, structure, or use of the structures 3 and 4. There are no limitations on the location where the structures 3 and 4 are installed. Therefore, there are no limitations on the location where the flexible joint 2 is installed. [Explanation of symbols]

[0039] 1 flexible water-stopping member, 2 flexible joint, 3, 4 structure, 5 gap, 6 anchor bolt, 7 retaining plate, 8 nut, 9 protective member, 10 crack, 11 patch material, 12 heat gun, 12a windshield, 13 membrane material, 14 clamp member

Claims

1. A method for repairing a flexible joint having a flexible watertight member that is placed in a gap between two structural members, one end of which is fixed to one of the structural members and the other end of which is fixed to the other structural member, and that watertightly seals the gap, comprising: a patching step of applying a patch material to a surface of a target portion of the flexible water-stopping member to be repaired, thereby covering the target portion; and a membrane material fixing step of overlaying a membrane material on the patch material attached to the target area to cover the flexible water-stopping member with the membrane material and fixing ends of the membrane material to each of the two structural members. How to repair a flexible joint.

2. The patch material is a surface material made of the same material as the flexible water-stopping member.

2. The method of repairing a flexible joint according to claim 1.

3. The patch material is a surface material made of the same material as the flexible water-stopping member.

3. The method for repairing a flexible joint according to claim 2.

4. The membrane material is characterized in that it is made of a fabric as a base material.

2. The method of repairing a flexible joint according to claim 1.

5. The fabric is made of polyester fiber.

5. The method for repairing a flexible joint according to claim 4.

6. The flexible water-stopping member has an end sandwiched between a pressing plate fixed to the structural member and the structural member, and the end is pressed by the pressing plate to be fixed to the structural member, and In the membrane material fixing step, the end of the membrane material is sandwiched between the flexible water-stopping member and the pressing plate to fix the membrane material to the structural member. A method for repairing a flexible joint according to any one of claims 1 to 5.

7. In the patch material application step, the patch material is applied to the surface of the target portion of the flexible water-stopping member, and then the patch material is heated. A method for repairing a flexible joint according to any one of claims 1 to 5.

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