Pipe rehabilitation method and support device

Abstract

In pipe rehabilitation work to rehabilitate existing water supply pipes, the aim is to reduce the burden on workers and improve work efficiency in preventing the rehabilitated pipes from floating or deforming, by implementing float prevention or deformation prevention and support structures. [Solution] The rehabilitated pipe 3 is lined to the inner circumference of the existing water-carrying pipe 1. A hollow member 19, whose apparent specific gravity (the ratio of apparent volume to weight, including the hollow portion 19a) is 1 or less, is prepared as a component of the support device 10. The hollow member 19 is transported to the installation location by floating it on the water W inside the rehabilitated pipe 3. After the support device 10, including the hollow member 19, is installed inside the rehabilitated pipe 3, backfill material 4 is injected between the existing pipe 1 and the rehabilitated pipe 3. When removing the support device 10 thereafter, the hollow member 19 is transported away from the installation location by floating it on the water W inside the rehabilitated pipe 3.

Description

Technical Field

[0001] The present invention relates to a pipe rehabilitation method in which a rehabilitation pipe is lined on the inner circumference of an existing pipe and backfilled between the existing pipe and the rehabilitation pipe, and particularly to a pipe rehabilitation method suitable for existing water-carrying pipes such as sewer pipes, and a support device for preventing the floating or deformation of the rehabilitation pipe during backfilling in the method.

Background Art

[0002] As a method for rehabilitating existing water-carrying pipes such as aging sewer pipes in the ground, for example, a pipe manufacturing method in which a spiral-shaped rehabilitation pipe is manufactured on the inner circumference of an existing pipe is known (see Patent Document 1, etc.). A backfilling material is backfilled into the pipe gap between the existing pipe and the rehabilitation pipe.

[0003] In order to prevent the floating or deformation of the rehabilitation pipe during backfilling, prior to the backfilling process, a floating prevention work or a deformation prevention and support work by a support device is performed inside the rehabilitation pipe. The support device includes, for example, a belly-lifting material installed along the inner surface of the rehabilitation pipe, and a columnar or beam-shaped support material for bracing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Many of the constituent members of the support device such as the belly-lifting material and the support material are usually made of metal materials such as steel round pipes and steel angle pipes, and the weight per piece is, for example, about several kg to several tens of kg, which is heavy. The floating prevention work or the deformation prevention and support work requires manually transporting and installing dozens to hundreds of such heavy metal materials in the narrow space inside the pipe, which is the most strenuous and labor-intensive work in the pipe rehabilitation operation. In view of these circumstances, the present invention aims to improve work efficiency by reducing the burden on workers in pipe rehabilitation work, which involves rehabilitating existing pipes for water transport such as sewer pipes, in order to prevent the rehabilitated pipes from floating or deforming during the implementation of anti-floating work or deformation prevention and support work. [Means for solving the problem]

[0006] To solve the aforementioned problems, the present invention provides a pipe rehabilitation method comprising installing a support device inside the rehabilitation pipe to prevent the rehabilitation pipe, which is lined on the inner circumference of the existing pipe for water transport, from floating or deforming, and then injecting backfill material between the existing pipe and the rehabilitation pipe, A hollow member having an apparent specific gravity of 1 or less, which is the ratio of the apparent volume including the hollow portion to the weight, is prepared as a component of the support device. The hollow member is transported by floating it in the water inside the rehabilitation pipe, thereby being brought into or removed from the installation location.

[0007] Since the hollow member has an apparent specific gravity of 1 or less, it can float in the water inside the rehabilitation pipe. By floating the hollow member, workers are not required to bear its entire weight. Therefore, the workload is reduced and work efficiency is improved, at least for the transportation of the hollow member, which is one of the components of the support device.

[0008] Preferably, before transport, the opening of the hollow portion of the hollow member is closed with a closing member. This prevents water from flowing into the hollow section of the rehabilitation pipe through the opening. Therefore, the hollow component can be reliably transported while floating on the water inside the pipe.

[0009] If the hollow member is a member installed in the water inside the rehabilitation pipe, preferably, when installing it, the blocking member is removed and water is poured into the hollow portion through the opening. This makes it possible to increase the specific gravity of the hollow member, including the added water, to more than 1. Therefore, the hollow member can be stably installed by submerging it in the water of the rehabilitation pipe. Examples of such hollow members include bracing members.

[0010] Preferably, before removal, the water in the hollow section is drained from the opening, and then the opening is closed with the closing member. Discharge can reduce the apparent specific gravity of the hollow portion to 1 or less. Therefore, the hollow member can be reliably floated on the water inside the rehabilitated pipe and transported out.

[0011] Preferably, the hollow member is transported in or out on the downstream side in the direction of water flow within the pipe. This allows the hollow components to be carried down by the flow of water inside the rehabilitated pipe, making transportation even easier.

[0012] The support device according to the present invention is installed inside a rehabilitated pipe lined with the inner circumference of an existing pipe for water passage, and is a support device for preventing the rehabilitated pipe from floating or deforming when backfilling between the existing pipe and the rehabilitated pipe, The invention is characterized by having a hollow member as a component, the apparent specific gravity of which is the ratio of the apparent volume including the hollow portion to the weight is 1 or less. The hollow member can be floated on the water inside the rehabilitation pipe and transported to and from its installation location within the pipe. This reduces the workload on workers and improves work efficiency.

[0013] Preferably, the hollow member contains resin or fiber-reinforced resin as its main material. This allows for a reduction in the weight of the hollow components, ensuring that the apparent specific gravity is reliably less than 1. This weight reduction reduces the burden on workers during the assembly and disassembly of the support system, further improving work efficiency. By constructing the hollow component from fiber-reinforced plastic (FRP), the required strength of the hollow component can be sufficiently ensured.

[0014] Preferably, the hollow member is a tubular body having a circular or polygonal cross-section with both ends open. The inside of the tubular body forms a hollow portion.

[0015] Preferably, the hollow member includes a web member, a beam member, or a column member.

Advantages of the Invention

[0016] According to the present invention, in the pipe rehabilitation work for rehabilitating an existing water pipe, the burden on workers in the buoyancy prevention work or the deformation prevention and support work for preventing the floating and deformation of the rehabilitated pipe can be reduced, and the workability can be improved.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a cross-sectional view orthogonal to the pipe axis of an existing water pipe being rehabilitated with a support device according to an embodiment of the present invention installed. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. [Figure 3] FIG. 3 is an enlarged cross-sectional view showing a circular portion III of FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view along the pipe axis of the existing water pipe being rehabilitated, showing the process of transporting the hollow member of the support device to the installation position inside the rehabilitated pipe. [[ID=3�]] [Figure 5] FIG. 5(a) is a cross-sectional view showing the state of closing the opening at the end of the hollow member with a closing member. FIG. 5(b) is a cross-sectional view of the end of the hollow member closed with the closing member. [Figure 6] FIG. 6(a) is a cross-sectional view of a circular cross-section hollow member bundled for the transportation. FIG. 6(b) is a cross-sectional view of a square cross-section hollow member bundled for the transportation. [Figure 7] FIG. 7 is a cross-sectional view showing the state of carrying out the hollow member from inside the rehabilitated pipe.

Embodiments for Carrying out the Invention

[0018] One embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows the process of rehabilitating an existing water pipe 1, which consists of an aging sewer pipe. Note that the existing water pipe to be rehabilitated is not limited to sewer pipes; it may also be a water supply pipe, agricultural water pipe, or hydroelectric power generation water conduit. As shown in Figure 2, the existing pipe 1 has a flow gradient for water passage. Note that the flow gradient in the diagram is exaggerated compared to reality.

[0019] As shown in Figures 1 and 2, the rehabilitation pipe 3 is lined along the inner circumference of the existing pipe 1. Although detailed illustrations are omitted, the rehabilitation pipe 3 has a spiral pipe structure formed by spirally winding a long strip-shaped member (profile) made of synthetic resin such as polyvinyl chloride. The rehabilitation work is carried out while the sewer system is in use. Therefore, sewage enters the rehabilitation pipe 3 as pipe water W. The pipe water W flows along the bottom of the rehabilitation pipe 3 from the upstream side (left side in Figure 2) to the downstream side (right side in Figure 2) of the flow gradient.

[0020] As shown in Figure 1, the annular gap 2 between the inner circumference of the existing pipe 1 and the outer circumference of the rehabilitated pipe 3 is filled with a backfill material 4 such as mortar. Prior to the backfilling process, a support device 10 is installed inside the rehabilitated pipe 3 to prevent the pipe from floating or deforming during backfilling, thereby providing a float prevention or deformation prevention and support system.

[0021] As shown in Figures 1 and 2, the support device 10 includes components such as a bracing member 11, support members 12 (columns), jacks 13, and fastening members 14. Of these components of the support device 10, at least the bracing member 11 and the support members 12 are hollow members 19 including a hollow section 19a.

[0022] More specifically, the bracing members 11 are tubular bodies with a hollow rectangular cross-section (polygonal cross-section) that extend straight in the direction of the pipe axis (the direction perpendicular to the plane of the paper in Figure 1). Both ends of the bracing member 11 in the longitudinal direction are open to form openings 11e (19e). The length of a single bracing member 11 is, for example, more than 1m to several m, preferably about 2m. The vertical and horizontal dimensions of the cross-section of the bracing member 11 are, for example, about 50mm × 100mm to 100mm × 100mm. As shown in Figure 2, multiple bracing members 11 are arranged in a straight line on the inner surface of the bottom of the rehabilitation pipe 3. As shown in Figure 3, the opposing ends of adjacent bracing members 11 may be butting against each other, or they may be fitted together. These bracing members 11 are submerged in the water W inside the pipe. A portion of the water W inside the pipe, Wa, has entered the hollow portion 11a (19a) within the bracing material 11.

[0023] As shown in Figure 1, the support material 12 is a columnar tubular body including a support body 15 and a stopper 16. More specifically, the support body 15 is a hollow tubular body with a circular or square (polygonal) cross-section. The outer diameter of the support body 15 with a circular cross-section is, for example, about 50 mm, but the present invention is not limited to this. The length and width dimensions of the cross-section of the support body 15 with a square cross-section are, for example, about 50 mm × 50 mm to 100 mm × 50 mm, but the present invention is not limited to this. The stopper 16 is attached to the tip (upper end in Figure 1) of the support body 15. The stopper 16 is a short tubular body with a hollow circular cross-section. The outer diameter of the tip is, for example, about 50 mm, but the present invention is not limited to this. The total length of the support material 12 depends on the diameter of the rehabilitated pipe 3 and thus the diameter of the existing pipe 1, but is, for example, about 0.7 m to 2 m.

[0024] Both ends of the support member 12 in the longitudinal direction are open, forming openings 12e (19e). The support member 12 is erected on the bracing member 11 with its longitudinal direction perpendicular to the pipe axis direction and oriented vertically. The abutment member 16 is inserted through the through hole 3b at the top of the rehabilitation pipe 3. As shown in Figure 2, multiple support members 12 are arranged at intervals from each other in the pipe axis direction (left-right direction in Figure 2).

[0025] The hollow members 19, namely the bracing members 11 and the support members 12, each contain resin or fiber-reinforced plastic (FRP) as their main material. The main material refers to the hollow member component that accounts for 50% or more, preferably 60% or more, and more preferably 80% or more, of the total volume of the hollow member 19. Preferably, the bracing members 11 and the support members 12 are each made of FRP. This ensures the required strength of the bracing members 11 and the support members 12. The specific gravity of FRP is generally around 1.4 to 2.0, which is sufficiently smaller than the specific gravity of metal (generally around 7 to 8).

[0026] The apparent specific gravity of the bracing member 11, which is the ratio of its apparent volume to its weight including the hollow portion 11a, is 1 or less. Similarly, the apparent specific gravity of the support member 12, which is the ratio of its apparent volume to its weight including the hollow portion 12a(19), is 1 or less. In short, these hollow members 19 have a material, hollow portion volume, and pipe thickness such that their apparent specific gravity is 1 or less.

[0027] As shown in Figures 1 and 2, a jack 13 is interposed between the lower end of each support member 12 and the bracing member 11. By operating the jack 13, the abutment member 16 is strongly pressed against the top of the existing pipe 1, and a vertical bracing force is applied to the support members 12.

[0028] As shown in Figure 1, a retaining member 14 is provided at the bottom of the jack 13. The retaining member 14 is formed in a U-shaped cross-section and is placed over the bracing member 11. As shown in Figure 3, at least a portion of the retaining member 14 is positioned on the joint between two adjacent bracing members 11, and by straddling these bracing members 11, it connects them.

[0029] Existing pipe 1 is rehabilitated as follows: First, the rehabilitation pipe 3 is lined to the inner circumference of the existing pipe 1. Next, a float prevention or deformation prevention and support structure is installed for the rehabilitation pipe 3. Specifically, each component 11 to 14 of the support device 10 is prepared and transported to the designated installation location inside the rehabilitation pipe 3.

[0030] As shown in Figure 4, during transport, hollow members such as the bracing members 11 and support members 12 are transported floating in the water W inside the rehabilitation pipe 3. Since the hollow member 19 has an apparent specific gravity of 1 or less, it can float in the water W inside the pipe. Therefore, of the components 11 to 14 of the support device 10, the worker does not have to bear the entire weight of the hollow member 19. This reduces the burden on the worker during transport and improves work efficiency.

[0031] Preferably, the hollow member 19 is flowed from the manhole 5 on the upstream side in the direction of the flow of water W inside the pipe to the downstream side (in the direction of arrow a in Figure 4). This allows the hollow member 19 to be transported to the installation location using the flow of water W inside the pipe, further reducing the burden on workers for carrying it in and further improving work efficiency.

[0032] Furthermore, since the hollow member 19 is made of FRP or resin, which is lighter than metal, the workload can be further reduced. In particular, the weight reduction effect is significant by using resin for the long, large-area bracing members 11.

[0033] Preferably, as shown in Figure 4, the openings 19e at both ends of the hollow member 19 are sealed with cap-shaped sealing members 21 before transport to seal the hollow portion 19a. This prevents water from flowing into the hollow portion 19a, and allows the hollow member 19 to be reliably transported floating on the water W inside the pipe.

[0034] As shown in Figures 5(a) and 5(b), the sealing member 21 is of the spigot type, for example, inserted into the opening 19e. This allows the outer surface of the sealing member 21 to be in close contact with the inner surface of the opening 19e of the hollow member 19, thus providing a seal. The material of the sealing member 21 is preferably rubber. This ensures a good seal. The specific gravity of rubber is generally around 0.9 to 0.98. Therefore, the hollow member 19 does not sink in water when the sealing member 21 is installed. As shown in Figure 4, more preferably, the two sealing members 21 at both ends of each hollow member 19 are connected by a connecting strip 23 such as a string.

[0035] Furthermore, the outer sealing portion of the sealing member 21 that is in close contact with the inner circumferential surface of the hollow member 19 may be made of rubber, and the core portion that holds the outer sealing portion may be made of metal. As a result, the specific gravity of the sealing member 21 alone may be 1 or more. Since the sealing member 21 is sufficiently smaller than the hollow member 19, attaching a sealing member 21 with a specific gravity of 1 or more to the hollow member 19 has almost no effect on the apparent specific gravity of the hollow member 19, and the hollow member 19 will hardly sink in water.

[0036] As shown in Figures 6(a) and 6(b), multiple hollow members 19 may be bundled together with a binding material 30 and then flowed together into the water W inside the pipe. This allows for efficient transportation of the hollow members 19. Preferably, the hollow members 19 of the same type and shape are bundled together. This simplifies the bundling process and parts management. In addition, different types of hollow members 19 may be bundled together as one.

[0037] In this way, after transporting each component 11 to 14 of the support device 10 to the installation position, the support device 10 is constructed by assembling these components 11 to 14 (Figure 1). Since some of the components 11 and 12 of the support device 10 are made of lightweight FRP or resin, assembly can be made easier.

[0038] As shown in Figure 7, the closure members 21 are removed from the hollow members 19 during assembly. By connecting the pair of closure members 21 at both ends of each hollow member 19 with a connecting strip 23, it is possible to prevent the individual closure members 21 from being washed away and lost by the water W inside the pipe. Furthermore, if the closure member 21 includes a metal part and has a specific gravity of 1 or more, the closure member 21 that detaches from the hollow member 19 will sink to the bottom of the water, thus preventing the loss of the closure member 21 even without the connecting strip 23. The upper end of the support material 12 may be left closed with the closing member 21.

[0039] As shown in Figure 7, for the bracing material 11 installed in the water W inside the pipe, after removing the occlusion member 21, a portion of the water W Wa inside the pipe is injected into the hollow section 11a through the opening 11e. This causes the specific gravity of the bracing material 11, including the injected water, to become greater than 1. Therefore, the bracing material 11 can be submerged in the water W inside the pipe and stably installed at the bottom of the rehabilitation pipe 3.

[0040] As shown in Figures 1 and 2, after the construction of the support device 10, backfill material 4 such as mortar is filled into the gap 2 between the pipes. At this time, the support device 10 can prevent the rehabilitation pipe 3 from floating or deforming. By constructing the bracing material 11 and the support material 12 from FRP, the required strength can be ensured, and the floating or deformation of the rehabilitation pipe 3 can be reliably prevented.

[0041] After the backfill material 4 has been cured and hardened, the support device 10 is dismantled and removed from the rehabilitation pipe 3. Of the components 11 to 14 of the support device 10, the hollow members such as the bracing material 11 and the support material 12 are transported floating on the water W inside the rehabilitation pipe 3, just as they were transported (Figure 4). Preferably, the hollow member 19 is floated downstream from the installation position in the direction of the flow of the water W inside the pipe. This allows the hollow member 19 to be transported and recovered to the manhole 6 downstream from the installation position using the flow of the water W inside the pipe.

[0042] During removal (transportation), the openings 19e of each hollow member 19 are closed in advance with the closing members 21 to prevent water from flowing into the hollow section 19a. For the bracing members 11, the water Wa inside the hollow section 11a is discharged from the opening 11e before removal, and then the opening 11e is closed with the closing members 21. This ensures that the apparent specific gravity of the bracing members 11 is 1 or less, allowing the bracing members 11 to float on the water W inside the pipe. Preferably, multiple hollow members 19 are bundled together with a binding material 30 and transported out as a group (Figure 6).

[0043] In this way, the workload on workers can be reduced and work efficiency can be improved even during dismantling, removal, and disposal. Furthermore, since the hollow member 19 is made of lightweight FRP or resin, the dismantling, removal, and disposal work can be made even easier.

[0044] The present invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit. For example, the support device 10 may include horizontal beams or diagonal members (such as braces), and the beams or diagonal members may be made of hollow members with an apparent specific gravity of 1 or less, which is the ratio of the apparent volume including the hollow part to the weight. The shape of the bottom of the support material may be formed into an arc shape along the circumferential direction of the rehabilitation pipe 3. Walers may be placed on both sides in the circumferential direction of the rehabilitation pipe 3, flanking the bottom. The cross-sectional shape of the hollow member is not limited to a circular or square hollow cross-section; it may also be a triangular or polygonal cross-section with pentagons or more, or any other irregular hollow cross-section. When the hollow member 19 is allowed to flow down into the water W inside the pipe, a simple ship-like body having a bottom and a bow may be attached to the hollow member 19. [Industrial applicability]

[0045] This invention can be applied, for example, to rehabilitation techniques for aging sewer pipes. [Explanation of Symbols]

[0046] W Sewer (water in pipes) Wa (part) 1 Existing pipe 2. Gap between pipes 3 Rehabilitation pipe 3b Through hole 4. Backing material 5 Upstream manhole 6 Downstream manhole 10 Shoring device 11. Bracing material (hollow member) 11a Hollow part 11e opening 12. Support materials (columns, hollow members) 12a Hollow part 12e opening 13 Jack 14 Retaining member 15 Support Body 16. Butt piece 19 Hollow member 19a Hollow part 19e opening 21 Closure member 23 Connecting striatum 30 Binding material

Claims

1. A pipe rehabilitation method comprising installing a support device inside the rehabilitation pipe to prevent the rehabilitation pipe, which is lined on the inner circumference of the existing pipe used for water transport, from floating or deforming, and then injecting backfill material between the existing pipe and the rehabilitation pipe, A hollow member having an apparent specific gravity of 1 or less, which is the ratio of the apparent volume including the hollow portion to the weight, is prepared as a component of the support device. A pipe rehabilitation method characterized by transporting the hollow member while floating it in the water inside the rehabilitation pipe, thereby transporting it to or from the installation location.

2. The pipe rehabilitation method according to claim 1, wherein, before the aforementioned transport, the opening of the hollow portion of the hollow member is closed with a closing member.

3. The hollow member is a member that is installed in the water inside the rehabilitation pipe, The pipe rehabilitation method according to claim 2, wherein, during the installation, the blocking member is removed and water is poured into the hollow portion through the opening.

4. The pipe rehabilitation method according to claim 3, wherein, before the aforementioned removal, the water in the hollow section is discharged from the opening, and then the opening is closed with the closing member.

5. The pipe rehabilitation method according to any one of claims 1 to 4, wherein the hollow member is transported in or out on the downstream side in the direction of water flow in the pipe.

6. A support device installed inside a rehabilitation pipe lined with the inner circumference of an existing water-carrying pipe, for preventing the rehabilitation pipe from floating or deforming when backfilling between the existing pipe and the rehabilitation pipe, A support device characterized by having a hollow member as a component, the apparent specific gravity of which is the ratio of the apparent volume including the hollow portion to the weight is 1 or less.

7. The support device according to claim 6, wherein the hollow member mainly comprises resin or fiber-reinforced resin.

8. The support device according to claim 6, wherein the hollow member is a tubular body with a circular or polygonal cross-section and open at both ends.

9. The support device according to any one of claims 6 to 8, wherein the hollow member includes a bracing member, a beam member, or a column member.

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