Rehabilitation structure of existing pipes

Abstract

In the rehabilitation structure of existing pipes, this prevents the propagation of cracks in the backfill material that fills the space between the existing pipe and the rehabilitated pipe. [Solution] The rehabilitation structure for the existing pipe 10 comprises a rehabilitation pipe 20 installed inside the existing pipe 10 and a backfill material 50 filled between the existing pipe 10 and the rehabilitation pipe 20. The rehabilitation pipe 20 has protruding portions that project toward the existing pipe 10 and extend in the circumferential direction, and the highest of these protruding portions are reinforcing ribs 24 and 26, which are spaced apart in the pipe axis direction. Between the reinforcing ribs 24 and 26, crack propagation inhibitors 31 are arranged to extend in the circumferential direction. The crack propagation inhibitors 31 are arranged to obstruct a virtual straight line L connecting the tips of the reinforcing ribs 24 and 26.

Description

Technical Field

[0001] The present invention relates to a structure for rehabilitating aging existing pipes.

Background Art

[0002] As disclosed in Patent Documents 1 and 2, in order to rehabilitate existing pipes such as aging sewer pipes, a rehabilitation pipe is installed inside the existing pipe, and a backfill material is filled between the existing pipe and the rehabilitation pipe, thereby constructing a composite pipe in which the existing pipe, the rehabilitation pipe, and the backfill material are integrated. This method is well-known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a large load acts on the composite pipe due to an earthquake or the like, cracks may occur in the existing pipe or the backfill material. Particularly when cracks also occur in the existing pipe, it is assumed that over time, large cracks may develop starting from the cracks generated in the backfill material due to the pressure of water that has entered from the outside of the existing pipe. These cracks are assumed to progress so as to connect the tips of the portions with the largest diameter (the highest protrusions) in the rehabilitation pipe or the support frame arranged on the outer periphery of this rehabilitation pipe. Such progression of cracks may impair the integration of the composite pipe and may reduce its load-bearing capacity and durability.

Means for Solving the Problems

[0005] To solve the aforementioned problems, the present invention provides a rehabilitation structure for an existing pipe comprising a rehabilitation pipe installed inside an existing pipe, and a backfill material that is filled between the existing pipe and the rehabilitation pipe to integrate the existing pipe and the rehabilitation pipe, The rehabilitation pipe or the support frame supporting the rehabilitation pipe has protruding portions that project toward the existing pipe and extend in the circumferential direction, the highest of the protruding portions being spaced apart in the pipe axis direction, and crack propagation inhibitors extending in the circumferential direction being placed between the highest of the protruding portions, the crack propagation inhibitors being placed so as to obstruct a virtual straight line connecting the tips of the highest of the protruding portions. With this configuration, even if cracks occur in the backfill material due to earthquakes or other events, the crack propagation inhibitor can prevent the cracks from spreading to connect the highest protruding parts, thus ensuring the integrity of the rehabilitated pipe, the existing pipe, and the backfill material.

[0006] Preferably, the crack propagation inhibitor has a height corresponding to the space between the existing pipe and the rehabilitated pipe. This configuration allows for the stable installation of the crack propagation inhibitor between the existing cracked pipe and the rehabilitated pipe.

[0007] In one embodiment, the crack propagation inhibitor is plate-shaped. In this embodiment, preferably, the end of the crack propagation inhibitor on the rehabilitation pipe side and / or the end on the existing pipe side have an overhang that extends laterally from the plate surface of the crack propagation inhibitor. With this configuration, the anchoring effect of the overhang can enhance the integrity between the crack propagation inhibitor and the backfill material.

[0008] Preferably in this embodiment, a plurality of crack propagation inhibitors are connected by a connecting structure positioned between the existing pipe and the rehabilitated pipe to form an inhibitor unit, and the connecting structure has a number of voids connecting the space on the rehabilitated pipe side and the space on the existing pipe side. This configuration allows for the simultaneous installation of multiple crack propagation inhibitors, thus simplifying the installation process. Furthermore, since the backfill material can pass through the gaps in the connecting structure during filling, it ensures reliable filling of the space on both the existing pipe side and the rehabilitation pipe side of the connecting structure, while also ensuring the integrity of the connecting structure and the backfill material.

[0009] The connecting structure may have connecting means for connecting adjacent restraint units in the circumferential and / or pipe axis direction. This configuration allows for stable installation of the deterrent unit, preventing it from being swept away by the water, even when installed in a situation where water is flowing.

[0010] Preferably in this embodiment, the crack propagation inhibitor has a plate portion on the rehabilitation pipe side and a plate portion on the existing pipe side, and these plate portions are fixed to the connecting structure. With this configuration, the plate portion on the existing pipe side ensures a distance between the existing pipe and the connecting structure, thereby ensuring the integration of the backfill material and the existing pipe.

[0011] In this embodiment, the connecting structure is fixed to the existing pipe by an anchor while being spaced apart from the existing pipe. This configuration allows for stable installation of the deterrent unit, preventing it from being swept away by the water, even when installed in a situation where water is flowing.

[0012] In other embodiments, the crack propagation inhibitor has a cage shape. With this configuration, the backfill material fits inside the crack propagation inhibitor, thereby increasing the integrity between the crack propagation inhibitor and the backfill material.

[0013] In one configuration to which the present invention is applied, the rehabilitation pipe is formed as a spiral pipe by spirally winding a strip-shaped member and joining the side edges that are one turn apart, and the highest protruding portion is a reinforcing rib or a reinforcing material attached between reinforcing ribs that protrudes radially outward from the rehabilitation pipe.

[0014] In other configurations to which the present invention is applied, the highest protrusion is a ring of the support frame that supports the rehabilitation pipe.

Advantages of the Invention

[0015] According to the present invention, it is possible to suppress the progress of cracks in the backfill material and ensure the integrity of the rehabilitation pipe, the existing pipe, and the backfill material.

Brief Description of the Drawings

[0016] [Figure 1] It is a longitudinal sectional view of the main part showing an existing pipe rehabilitated by the rehabilitation structure according to the first embodiment of the present invention. [Figure 2] It is a plan view schematically showing a suppression unit used for the crack progress suppression structure of the rehabilitation structure. [Figure 3] It is a side view showing means for connecting the suppression units to each other. [Figure 4] It is a plan view schematically showing another suppression unit used for the crack progress suppression structure. [Figure 5] It is a view corresponding to FIG. 1 showing the second embodiment of the present invention. [Figure 6] It is a view corresponding to FIG. 1 showing the third embodiment of the present invention. [Figure 7] It is a view corresponding to FIG. 1 showing the fourth embodiment of the present invention. [Figure 8] It is a longitudinal sectional view of the upper half of an existing pipe rehabilitated by the rehabilitation structure according to the fifth embodiment of the present invention.

Modes for Carrying Out the Invention

[0017] Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 shows an aged existing pipe 10 to be rehabilitated. The existing pipe 10 is, for example, a sewer pipe buried in the ground, but it may also be a water supply pipe, an agricultural water pipe, a gas pipe, a water conduit for hydroelectric power generation, a tunnel, or the like. Both pipe ends of the existing pipe 10 are connected to manholes.

[0018] <Outline of the rehabilitation structure for existing pipes> The rehabilitation structure for the existing pipe 10 includes a rehabilitation pipe 20 installed inside the existing pipe 10 and a backfill material 50 filled between the existing pipe 10 and the rehabilitation pipe 20. The backfill material 50 creates a composite pipe in which the existing pipe 10 and the rehabilitation pipe 20 are integrated.

[0019] <About rehabilitation officers> The rehabilitation pipe 20 in this embodiment consists of a spiral pipe formed by winding a strip-shaped member 20A (Profile) in a spiral shape. The strip-shaped member 20A is made of a synthetic resin such as polyvinyl chloride (PVC) or polyolefin. The strip-shaped member 20A has a main strip portion 21 that defines the inner circumferential surface of the rehabilitated pipe 20, fitting portions 22 and 23 formed on both side edges of the main strip portion 21, and a plurality of reinforcing ribs 24, 25, and 26 formed on the outer circumference of the main strip portion 21. By fitting the fitting portions 22 and 23 of the side edges of the spiral-shaped strip-shaped members 20A together, that is, the side edges of adjacent strip-shaped members 20A offset by one full turn, the rehabilitated pipe 20, which is made of a spiral pipe, is manufactured.

[0020] The reinforcing ribs 24, 25, and 26 extend in the longitudinal direction of the main strip portion 21 and protrude radially outward (towards the existing pipe 10) of the rehabilitation pipe 20 at a right angle to the main strip portion 21. The height of the two reinforcing ribs 24 and 26 is higher than that of reinforcing rib 25. A metal reinforcing member 28 is attached between the reinforcing ribs 24 and 25, with both ends being secured to the middle portion of the taller reinforcing rib 24 and the shorter reinforcing rib 25 of the strip-shaped member 20A. The height of the reinforcing member 28 is about the same as that of the reinforcing rib 25. In this embodiment, the reinforcing ribs 24 and 26 are provided as the highest protruding portion (maximum diameter portion) of the rehabilitated pipe 20. The reinforcing ribs 24 and 26 are arranged alternately at intervals in the pipe axis direction of the rehabilitated pipe 20.

[0021] <Crack propagation suppression structure> Between the existing pipe 10 and the rehabilitated pipe 20, a crack propagation suppression structure 30 is positioned to suppress the propagation of cracks in the backfill material 50. This crack propagation suppression structure 30 has a plate-shaped steel crack propagation suppression body 31 that extends in the longitudinal direction of the strip-shaped member 20A (extending along the spiral of the rehabilitated pipe 20). The crack propagation inhibitors 31 are positioned between the reinforcing ribs 24 and 26, spaced apart in the axial direction of the rehabilitated pipe 20. The crack propagation inhibitors 31 may have a length equivalent to one full turn of the spiral of the rehabilitated pipe 30, or a length less than one full turn of the spiral, or they may be continuous across multiple turns of the spiral. If the crack propagation inhibitors 31 are continuous across multiple turns, it is considered that multiple crack propagation inhibitors 31 are positioned in the axial direction of the pipe.

[0022] The crack propagation suppression structure 30 further includes a flat steel connecting structure 35 positioned between the rehabilitated pipe 20 and the existing pipe 10. This connecting structure 35 connects a plurality of crack propagation suppression bodies 31 that are spaced apart in the direction of the pipe axis. The crack propagation inhibitor 31 has a rehabilitated pipe side plate portion 32 and an existing pipe side plate portion 33 separated by a connecting structure 35. One end of these plate portions 32 and 33 is welded to the connecting structure 35. The other end of the rehabilitated pipe side plate portion 32 is located on the outer circumference of the rehabilitated pipe 20, and the other end of the existing pipe side plate portion 33 is located on the inner circumference of the existing pipe 10. That is, the crack propagation inhibitor 31 has a height corresponding to the space between the existing pipe 10 and the rehabilitated pipe 20. The other ends of the rehabilitated pipe side plate portion 32 and the other ends of the existing pipe side plate portion 33 have overhangs 32a and 33a that extend laterally from the plate surface, similar to the reinforcing ribs 24 to 26. These overhangs 32a and 33a may have a T-shaped, L-shaped, or arrowhead-shaped cross-section as shown in the figure. The anchoring effect provided by these protruding portions 32a and 33a enhances the integration between the crack propagation inhibitor 31 and the backfill material 50.

[0023] Figure 2 shows an example of the connecting structure 35. When the crack propagation inhibitor 31 is relatively short, connecting it with the connecting structure 35 yields an inhibitor unit 36 ​​that is approximately rectangular, as shown in the figure. The connecting structure 35 is composed of multiple connecting plates 35a that are separated from each other, and therefore has a gap 35b that connects the space on the existing pipe 10 side and the space on the rehabilitation pipe side. The inhibitor unit 36 ​​may have a length equal to or greater than one turn of the spiral of the rehabilitation pipe 20, or it may be shorter than that.

[0024] The crack propagation inhibitor 31 is positioned in the rehabilitated pipe 20 between the highest reinforcing ribs 24, 26 of the same wound section of the strip-shaped member 20A and between the highest reinforcing ribs 24, 26 of the adjacent wound section of the strip-shaped member 20A. The plate portion 32 of the crack propagation inhibitor 31 on the rehabilitated pipe 20 side is positioned to intercept (cross) a virtual straight line L connecting the tips of the highest reinforcing ribs 24, 26.

[0025] <Construction Process for Rehabilitation> In this embodiment, the rehabilitated pipe 20 is manufactured by a self-propelled pipe-making machine. Briefly, a strip-shaped member 20A is drawn out from a drum on the ground near the starting manhole and supplied to the self-propelled pipe-making machine inside the existing pipe 10 through the starting manhole. The supplied strip-shaped member 20A is fed to the tip of the rehabilitated pipe during pipe-making by the drive rollers of the pipe-making machine, and the pipe is manufactured by fitting together the side edges of the fed-in strip-shaped member 20A and the strip-shaped member 20A at the tip of the rehabilitated pipe 30, that is, the fitting portions 22, 23 of the side edges of adjacent strip-shaped members 20A that are offset by one full turn. The pipe-making machine moves along the spiral of the strip-shaped member 20A at the tip of the rehabilitated pipe due to the reaction force during the feeding operation of the strip-shaped member 20A. As a result, the rehabilitated pipe extends toward the receiving manhole, and the pipe-making machine moves toward the receiving manhole together with the tip of the rehabilitated pipe.

[0026] Prior to the pipe manufacturing process of the rehabilitated pipe 20 described above, a number of restraint units 36 are temporarily fixed to the inner circumference of the existing pipe 10 by means such as adhesive to construct a crack propagation restraint structure 30. Then, the rehabilitated pipe 20 is manufactured so that the strip-shaped member 20A is in close contact with the inner circumference of the crack propagation restraint structure 30. The restraint units 36 may be sequentially installed on the existing pipe 10 near the tip of the rehabilitated pipe 20 in accordance with the timing of the pipe manufacturing of the rehabilitated pipe 20. As described above, the crack propagation inhibitor 31 is unitized as an inhibitor unit 36, which facilitates the installation of the crack propagation inhibitor structure 30.

[0027] After the rehabilitation pipe 20 and the crack propagation suppression structure 30 have been installed, backfill material 50 is filled between the existing pipe 10 and the rehabilitation pipe 20. When filling with backfill material, the backfill material 50 can pass through the gap 35b of the connecting structure 35, so that the backfill material 50 can be reliably filled into the space on the existing pipe 10 side and the space on the rehabilitation pipe 20 side of the connecting structure 35, and the unity of the connecting structure 35 and the backfill material 50 can be ensured. Furthermore, the plate portion 33 on the existing pipe 10 side of the crack propagation inhibitor 31 ensures a distance between the existing pipe 10 and the connecting structure 35, thereby ensuring the integrity of the backfill material 50 and the existing pipe.

[0028] Adjacent deterrent units 36 in the circumferential and axial directions can be connected by the connecting means 37 shown in Figures 2 and 3. This connecting means 37 has, for example, hooks 37a provided on two adjacent sides of the deterrent unit 36 ​​and hook receivers 37b provided on the other two sides. By inserting these hooks 37a into the hook receivers 37b, the deterrent units 36 can be connected in the circumferential and axial directions. Alternatively, these hooks 37a and hook receivers 37b may be provided only on two opposing sides of the deterrent unit 36, and the deterrent units 36 may be connected in the circumferential or axial direction. The deterrent units 36 may be separated in the circumferential direction or separated in the axial direction. As described above, by connecting adjacent deterrent units 36, the deterrent units 36 can be installed stably, and even when installed in a situation where water is flowing, for example, it can be prevented from being washed away by the water.

[0029] When a large load is applied to the composite pipe during an earthquake, it is expected that small cracks will occur in the existing pipe 10 and the backfill material 50. In particular, if cracks occur in the existing pipe 10, water pressure will be applied to the backfill material 50, and there is a risk that the cracks in the backfill material 50 will propagate into larger cracks. These cracks are likely to propagate along a virtual straight line L, that is, connecting the tips of the highest reinforcing ribs 24 and 26 of the rehabilitated pipe 20. However, in this embodiment, the plate portion 32 on the rehabilitated pipe 20 side of the crack propagation inhibitor 31 is positioned to block this virtual straight line L, so that the propagation of the crack can be inhibited.

[0030] <Other forms of linked structures> As shown in Figure 4, multiple crack propagation inhibitors 31 may be unitized using perforated metal 38 (connecting structure). The numerous holes 38b in this perforated metal 38 provide a gap that connects the space on the existing pipe 10 side and the space on the rehabilitation pipe 20 side. The aforementioned connecting means 37 may also be provided on this perforated metal 38.

[0031] Other embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, components corresponding to the prior embodiments are given the same or similar numbers, and their detailed descriptions are omitted.

[0032] <Second Embodiment> In the second embodiment shown in Figure 5, the strip-shaped member 20A of the rehabilitation pipe 20 has three reinforcing ribs 27 of the same height. In contrast, a metal reinforcing member 29, which is secured at both ends to two of the reinforcing ribs 27, is higher than the reinforcing ribs 27 and forms the highest protruding part (maximum diameter part) of the rehabilitation pipe 20. This reinforcing member 29 widens towards the tip and forms an anchor shape for the backfill material 50. Similar to the first embodiment, the crack propagation suppression structure 30 is unitized with a crack propagation suppression body 31 and a connecting structure 35. The plate portion 32 on the rehabilitation pipe 20 side of the crack propagation suppression body 31 is positioned to intercept (cross) a virtual straight line L connecting the tips of the reinforcing members 29, thereby suppressing the propagation of cracks along this virtual straight line L.

[0033] Furthermore, in this embodiment, by fixing the connecting structure 35 to the existing pipe 10 with an anchor 40, the crack propagation suppression structure 30 can be installed stably, and even when installed in a situation where water is flowing, for example, the suppression unit can be prevented from being washed away by the water. This anchor 40 can also be used in the first and second embodiments.

[0034] <Third Embodiment> In the third embodiment shown in Figure 6, the connecting structure 35 of the first and second embodiments is not included, and the crack propagation suppression structure consists only of a plate-shaped crack propagation suppressor 34. In this case, the crack propagation suppressor 34 is not divided into a plate portion on the rehabilitation pipe 20 side and a plate portion on the existing pipe 10 side, but is composed of a single plate portion. The crack propagation suppressor 34 has a height corresponding to the space dimension between the existing pipe 10 and the rehabilitation pipe 20, and is positioned to cut across the straight line L connecting the tips of the reinforcing members 29. Overhangs 34a and 34b are formed at both ends of the crack propagation suppressor 34.

[0035] <Fourth Embodiment> In the fourth embodiment shown in Figure 7, a cage-shaped crack propagation inhibitor 39 is provided instead of the plate-shaped crack propagation inhibitor 34 of the third embodiment. Since the backfill material 50 fits inside the crack propagation inhibitor 39, the unity between the crack propagation inhibitor 39 and the backfill material 50 can be improved.

[0036] <Fifth Embodiment> In the fifth embodiment shown in Figure 8, the rehabilitated pipe 60 is supported on the inner circumference of the support frame 70. More specifically, the rehabilitated pipe 60 is constructed by connecting a number of inner plate materials, each having a circular arc cross-section, in the circumferential and axial directions. The support frame 70 has plate-shaped rings 71 arranged at intervals in the axial direction of the existing pipe 10, and rod-shaped spacers (not shown) arranged at intervals in the circumferential direction and connecting the rings 71, and is constructed as a hollow framework. Fitting members (not shown) are provided at intervals in the circumferential direction on the inner circumference of the rings 71, and the inner members of the rehabilitated pipe 60 are connected in the circumferential and axial directions via these fitting members.

[0037] In this embodiment, the ring 71 is the highest protruding part (maximum diameter part). Crack propagation inhibitors 80, similar to those in the third embodiment, are arranged between the rings 71. The crack propagation inhibitors 80 have a height corresponding to the distance between the rehabilitated pipe 60 and the existing pipe 10, and are positioned to obstruct a virtual straight line L connecting the tips of the rings 71.

[0038] The present invention is not limited to the embodiments described above and various other embodiments are possible. In the embodiment described above, the highest protrusions and crack propagation inhibitors are arranged alternately, but multiple highest protrusions may be arranged between crack propagation inhibitors. The connecting structure is not limited to steel plates; it may also be constructed from deformed steel bars or the like. [Industrial applicability]

[0039] This invention can be applied, for example, to a technology for rehabilitating existing pipes such as aging sewer pipes. [Explanation of Symbols]

[0040] 10 Existing pipes 20 Rehabilitation pipe 20A Strip-shaped member 24,26 Reinforcement ribs (highest protrusions) 29. Reinforcement material (highest protruding part) 30 Crack propagation suppression structure 31, 34, 39 Crack propagation inhibitors 32 Plate section on the rehabilitation pipe side 33 Plate section on the existing pipe side 32a,33a,34a,34b Overhang 35 Connection structure 35b void 36 Deterrent Unit 37 Connecting means 38. Perforated metal (connecting structure) 38b Hole (void) 50 backfill material 60 Rehabilitation pipe 70 Support Frame 71 Ring (highest protrusion) L virtual line

Claims

1. In a rehabilitation structure for an existing pipe, comprising a rehabilitation pipe installed inside the existing pipe, and a backfill material filled between the existing pipe and the rehabilitation pipe to integrate the existing pipe and the rehabilitation pipe, The rehabilitation pipe or the support frame supporting the rehabilitation pipe has projections that protrude toward the existing pipe and extend in the circumferential direction, and the highest projections among the projections are spaced apart in the direction of the pipe axis. A rehabilitation structure for an existing pipe, characterized in that crack propagation inhibitors extending in the circumferential direction are arranged between the highest protruding portions, and the crack propagation inhibitors are arranged to obstruct a virtual straight line connecting the tips of the highest protruding portions.

2. The existing pipe rehabilitation structure according to claim 1, characterized in that the crack propagation inhibitor has a height corresponding to the spatial dimension between the existing pipe and the rehabilitation pipe.

3. The rehabilitation structure for an existing pipe according to claim 1, characterized in that the crack propagation inhibitor is in the shape of a plate.

4. The existing pipe rehabilitation structure according to claim 3, characterized in that the end of the crack propagation inhibitor on the rehabilitation pipe side and / or the end on the existing pipe side have an overhang that extends laterally from the plate surface of the crack propagation inhibitor.

5. The existing pipe rehabilitation structure according to claim 3, wherein a plurality of crack propagation inhibitors are connected by a connecting structure positioned between the existing pipe and the rehabilitation pipe to form an inhibitor unit, and the connecting structure has a number of voids connecting the space on the rehabilitation pipe side and the space on the existing pipe side.

6. The existing pipe rehabilitation structure according to claim 5, characterized in that the connecting structure has connecting means for connecting adjacent restraint units in the circumferential direction and / or the pipe axis direction.

7. The existing pipe rehabilitation structure according to claim 5, characterized in that the crack propagation inhibitor has a plate portion on the rehabilitation pipe side and a plate portion on the existing pipe side, and these plate portions are fixed to the connecting structure.

8. The existing pipe rehabilitation structure according to claim 7, characterized in that the connecting structure is fixed to the existing pipe by an anchor while being spaced apart from the existing pipe.

9. The existing pipe rehabilitation structure according to claim 1, characterized in that the crack propagation inhibitor has a cage shape.

10. The rehabilitation structure for an existing pipe according to claim 1, characterized in that the rehabilitation pipe is constructed as a spiral pipe by winding a strip-shaped member spirally and joining the side edges that are one turn apart, and the highest protruding portion is a reinforcing rib that protrudes radially outward from the rehabilitation pipe or a reinforcing material installed between reinforcing ribs.

11. The rehabilitation structure for an existing pipe according to claim 1, characterized in that the highest protruding portion is a ring of the support frame that supports the rehabilitation pipe.

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