Existing pipe repair method

Abstract

To provide a method for repairing existing pipes over multiple manhole sections that can reduces time and labor required for repair and shorten the construction period.SOLUTION: A tubular curable lining material 4 is inserted in an uncured state through a manhole 2 into two existing pipes 1 that open into the manhole 2, and a manhole passage part of the lining material 4 is covered from outside in a radial direction with a regulation sleeve 5 consisting of a tubular body having an inner diameter approximately equivalent to an inner diameter of the existing pipe 1. By placing the sleeve 5 on the manhole passage part of the lining material 4, when the lining material 4 is subsequently expanded in diameter and pressed against the inner surface of the existing pipe 1, an expansion, or bulging, of the manhole passage part of the lining material 4 in a radial direction is restricted. In this state, the lining material 4 is cured to form a rehabilitation pipe 3, and then the cured lining material 4 and the regulation sleeve 5 in the manhole 2 are removed.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for repairing an existing pipe, and more particularly to a method for repairing an existing pipe by installing a rehabilitation pipe inside the existing pipe. [Background technology]

[0002] Existing pipes buried underground, such as sewer pipes, deteriorate over many years of use, and their useful life is generally considered to be about 50 years. In recent years, the number of sewer pipes that have exceeded their useful life has been increasing, and aging sewer pipes can allow groundwater and soil around the pipe to flow into the pipe through cracks in the pipe, causing cavities in the ground and causing the ground to collapse. Sewer pipes are also susceptible to the effects of ground movement such as earthquakes, and for various other reasons, some kind of repair is required at certain times.

[0003] One known method for repairing existing pipes, such as sewer pipes, involves forming an inner-layer pipe (rehabilitating pipe) inside the existing pipe using a lining material made of a thermosetting resin or a photocurable resin without removing the existing pipe (Patent Documents 1 and 2). In the repair method using a thermosetting lining material described in Patent Document 1 below, an uncured thermosetting photocurable lining material is inserted into the existing pipe in a folded state, for example, and then both ends are sealed with sealing members. Then, compressed air is supplied to the inside of the lining material to expand the diameter of the lining material and bring it into close contact with the inner surface of the existing pipe. The lining material is then heated to initiate a polymerization and cross-linking reaction of the thermosetting resin, causing it to harden, forming a rehabilitating pipe made of the hardened lining material on the inner surface of the existing pipe.

[0004] In addition, in a repair method using a photocurable lining material described in Patent Document 2 below, an uncured photocurable lining material is inserted into an existing pipe, for example in a folded state, and both ends are sealed with sealing members. Then, in this state, compressed air is supplied to the inside of the lining material to expand the diameter of the lining material and bring it into close contact with the inner surface of the existing pipe. In this state, a light irradiation device is moved inside the photocurable lining material while irradiating it with light, initiating a polymerization and cross-linking reaction of the photocurable resin and causing it to harden, thereby forming a rehabilitated pipe made of the hardened lining material on the inner surface of the existing pipe. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-123279 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-214407 Summary of the Invention [Problem to be solved by the invention]

[0006] The existing pipe repair method, in which the lining material is expanded and hardened to form a rehabilitated pipe on the inner surface of the existing pipe as described above, is generally performed on the existing pipe for each section between adjacent manholes, which are spaced at a predetermined interval along the existing pipe. In other words, the existing pipe is repaired one section at a time between adjacent manholes. The interval between adjacent manholes is approximately 30 to 70 meters. However, since manholes are typically located along roads and existing pipes are laid out straight, the interval between manholes is often small, for example, when the road is curved. That is, since the Hume pipes that make up the existing pipe are straight, the extension direction of the existing pipe is linear, whereas manholes are located at the intersection of this linear existing pipe and a curved road. Therefore, the interval between manholes tends to be small when the road is curved. A similar tendency is also observed in existing pipes laid along steep slopes. As the distance between manholes decreases, the length of existing pipe that can be repaired in one go decreases, which means the number of sections that make up a single unit of repair work increases, increasing the amount of work required and the construction period. Furthermore, when repairing a section of existing pipe, the rehabilitated pipe inside the manholes on both sides is expanded and hardened, but the hardened rehabilitated pipe inside the manholes is simply removed after construction, resulting in a lot of wasted repair material.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a method for repairing existing pipes that can reduce the repair effort and shorten the construction period when repairing existing pipes spanning multiple sections. [Means for solving the problem]

[0008] The existing pipe repair method to achieve the above purpose is as follows: Cylindrical hardening lining Material In a method for repairing an existing pipe, a rehabilitating pipe is formed by expanding and hardening the above-mentioned material in the existing pipe, and the rehabilitating pipe is installed in the existing pipe installed between manholes arranged at predetermined intervals, a lining material insertion step of passing the curable lining material in an uncured state through at least one of the manholes and inserting it into the two existing pipes opening into the manhole; Inner diameter of the existing pipe Same as and the like, and is at least less likely to expand in the radial direction than the curable lining material, and a restricting sleeve that restricts the expansion of the curable lining material when the curable lining material expands is provided at a portion of the curable lining material that passes through a manhole. to a sleeve placement process for placing the sleeve so as to cover it from the radially outer side; a rehabilitating pipe forming step of expanding the diameter of the hardenable lining material and pressing it against the inner peripheral surface of the existing pipe after the lining material inserting step and the sleeve arranging step, and hardening the hardenable lining material in that state to form the rehabilitated pipe; The method is characterized in that it includes, after the rehabilitating pipe forming process, an in-manhole removal process of removing the hardened lining material and the restricting sleeve inside the manhole after they have hardened.

[0009] According to this configuration, a cylindrical hardening lining material is inserted in an unhardened state through the manhole into two existing pipes that open into the manhole, and the portion of the lining material that passes through the manhole is At least the opening of the existing pipe isThe lining material is covered from the radial outside with a restricting sleeve having an inner diameter approximately equal to that of the existing pipe. Therefore, when the lining material is subsequently expanded and pressed against the inner circumferential surface of the existing pipe, the restricting sleeve restricts radial expansion, i.e., expansion, of the portion of the lining material passing through the manhole. In this state, the lining material is hardened to form a rehabilitated pipe. After the rehabilitated pipe is formed, the hardened lining material and the restricting sleeve are removed from the manhole. This rehabilitating pipe installation method allows for simultaneous rehabilitating pipe formation on the inner circumferential surfaces of two existing pipes spanning at least one manhole. Therefore, by expanding the rehabilitating pipe, for example, if the existing pipe between adjacent manholes is considered one section, multiple sections of the existing pipe can be simultaneously rehabilitated. This rehabilitating pipe installation method reduces the labor required for repairing multiple sections of existing pipe and also shortens the repair construction period.

[0010] In another configuration of the above-mentioned existing pipe repair method, the restricting sleeve is deformable, and the sleeve arranging step includes: before the hardenable lining material is inserted into the existing pipe, the restricting sleeve is deformed at the manhole passing portion of the hardenable lining material. Outside The method is characterized in that the restricting sleeve is attached to the circumferential portion in advance, and the hardening lining material is inserted through the manhole into the existing pipe.

[0011] According to this configuration, by attaching a deformable restricting sleeve to the outer periphery of the portion of the lining material that passes through the manhole before it is inserted into the existing pipe, for example, it is possible to fold the restricting sleeve together with the lining material and pass it through the manhole, and then simply insert the lining material into the two existing pipes that open into the manhole, thereby placing the restricting sleeve that covers the lining material at the portion of the lining material that passes through the manhole, which accordingly simplifies the processes from the lining material insertion process to the sleeve placement process.

[0012] A further configuration of the above-mentioned existing pipe repair method includes a cylindrical body arrangement step, prior to the rehabilitating pipe formation step, of arranging a cylindrical member that protrudes a predetermined dimension from the opening of the existing pipe in the manhole into the manhole radially outside the lining material to be expanded, has an inner diameter or outer diameter that is approximately equal to the inner diameter of the existing pipe, and has rigidity that prevents it from deforming radially when the lining material is expanded, and is characterized in that the tubular member within the manhole is removed in the manhole removal step.

[0013] This configuration prevents wrinkles from forming in the rehabilitated pipe, particularly at the manhole opening of the existing pipe, when the lining material expands and hardens to form a rehabilitated pipe. For example, if the restricting sleeve is deformable and there is a difference in height between the openings of two existing pipes that open into a manhole, when the lining material inserted into the two existing pipes passes through the manhole and expands, the restricting sleeve will restrict the radial expansion of the lining material. However, the lining material at the manhole opening of the existing pipe will expand more at the top than the bottom of the higher existing pipe opening, and conversely, the lining material at the top than the bottom of the lower existing pipe opening will expand less than the bottom. This difference in expansion can cause wrinkles to form at the manhole opening of the rehabilitated pipe (after the portion that passes through the manhole has been removed) made of the hardened lining material, and these wrinkles can become gaps between the existing pipe and the lining material. These wrinkles and resulting gaps between the existing pipe and the rehabilitated pipe can occur not only due to differences in elevation between the two existing pipes, but also when the two existing pipes opening into the manhole are misaligned or have different inner diameters. When gaps form between the manhole opening of the existing pipe and the manhole opening of the rehabilitated pipe, groundwater and associated sediment flowing in through cracks or other damage in the existing pipe can flow into the pipeline through the gap between the existing pipe and the rehabilitated pipe. If groundwater or sediment flows into the pipeline, it can form underground cavities, potentially causing subsidence. Because there is a cylindrical member protruding into the manhole by a predetermined dimension outside the lining material and restricting sleeve before expansion at the opening of the existing pipe that opens into the manhole, the expansion of the lining material at the manhole opening of the existing pipe is uniform around the entire circumference, preventing gaps from occurring between the rehabilitated pipe made of the hardened lining material and the existing pipe. Furthermore, even if there is no difference in height, misalignment, or inner diameter between the two existing pipes that open into the manhole, if the restricting sleeve deforms radially, the radial expansion of the lining material at the manhole opening of the rehabilitated pipe after completion can be suppressed, thereby suppressing variations in the thickness of the manhole opening of the rehabilitated pipe.

[0014] A further configuration of the above-mentioned method for repairing an existing pipe is that the tubular member has a notch portion that is recessed in the extension direction in at least a part of the end, and in the tubular body installation process, the tubular member is positioned so that the notch portion is located at the bottom of the existing pipe.

[0015] This configuration allows the openings of two existing pipes to be connected within a manhole by a groove with a roughly semicircular cross section, created by piling up concrete or mortar, and their bottoms to be connected. In this case, by positioning the notch in the tubular member so that it is positioned below the existing pipe, the tubular member can be prevented from penetrating the bottom of the existing pipe. This prevents the bottom of the existing pipe, i.e., the rehabilitated pipe, from being raised by removing the hardened lining material and tubular member from the manhole after the lining material has expanded and hardened. Since the tubular member inserted inside the existing pipe is difficult to remove after the lining material has expanded and hardened, the bottom of the rehabilitated pipe resting on the tubular member will be raised. As described above, if a raised portion of the rehabilitated pipe exists where the bottom of the roughly semicircular cross section groove and the bottom of the existing pipe are connected, debris and filth tend to accumulate there. However, by eliminating this raised portion, this problem can be avoided. [Effects of the Invention]

[0016] As explained above, the existing pipe repair method allows for simultaneous formation of rehabilitating pipes on the inner circumferential surfaces of two existing pipes that straddle at least one manhole, and by expanding this, it is possible to repair multiple sections of existing pipe that span three or more manholes at once. This reduces the amount of work required to repair multiple sections of existing pipe, and at the same time, shortens the repair construction period. [Brief explanation of the drawings]

[0017] [Figure 1] 3 is an explanatory view of a lining material insertion step in the first embodiment of the existing pipe repair method of the present invention. FIG. [Figure 2]2 is an explanatory diagram of a state before a rehabilitating pipe forming step in the existing pipe repair method of FIG. 1. FIG. [Figure 3] 2 is an explanatory view of a lining material and a restricting sleeve used in the lining material insertion step of FIG. 1. FIG. [Figure 4] FIG. 2 is an explanatory diagram of a rehabilitating pipe forming step in the existing pipe repair method of FIG. 1. [Figure 5] FIG. 5 is a detailed view of the portion of the lining material in FIG. 4 that passes through the manhole. [Figure 6] FIG. 2 is an explanatory diagram of the inside-manhole removal step in the existing pipe repair method of FIG. 1. [Figure 7] 2 is an explanatory diagram of a state after a cylindrical body installation step in the existing pipe repair method of FIG. 1. FIG. [Figure 8] FIG. 10 is an explanatory view of a state before a rehabilitating pipe forming step in a second embodiment of the existing pipe repair method of the present invention. [Figure 9] 9 is an explanatory diagram of a rehabilitating pipe forming step in the existing pipe repair method of FIG. 8. FIG. [Figure 10] FIG. 10 is a front view of a cylindrical member used in a third embodiment of the existing pipe repair method of the present invention. [Figure 11] 11 is a detailed view of the rehabilitating pipe forming step in the existing pipe repair method of FIG. 10. FIG. [Figure 12] 11 is an explanatory diagram of the existing pipe and the inside of a manhole where the existing pipe repair method of FIG. 10 is carried out. [Figure 13] 13 is a detailed view of a rehabilitating pipe forming process when the cylindrical member of FIG. 2 is used for the existing pipe and manhole shown in FIG. 12. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of the method for repairing an existing pipe of the present invention will be described in detail below with reference to the drawings. Figures 1 to 6 are explanatory diagrams of a method for repairing an existing pipe according to a first embodiment of the present invention. Figure 1 is an explanatory diagram of the lining material insertion step, Figure 2 is an explanatory diagram of the state before the rehabilitating pipe formation step, Figure 3 is an explanatory diagram of the lining material 4 and the restricting sleeve 5 used in the lining material insertion step of Figure 1, Figure 4 is an explanatory diagram of the rehabilitating pipe formation step, Figure 5 is a detailed diagram of the lining material 4 passing through the manhole of Figure 4, and Figure 6 is an explanatory diagram of the manhole removal step. The lining material 4 used in the existing pipe repair method of this embodiment can be either the lining material made of a tubular member made of a photocurable resin or the lining material made of a tubular member made of a thermosetting resin, both of which are cylindrical and inserted into the existing pipe 1 in an uncured state. As is well known, photocurable resin lining materials have the advantage over thermosetting resin lining materials in that the curing time of photocurable resins by light irradiation is shorter than the curing time of thermosetting resins by thermal fluid, but there is a risk that the temperature of the lining material 4 may rise too much due to the exothermic reaction that occurs when curing by light irradiation. Here, a thermosetting resin lining material is used as an example.

[0019] In this embodiment, it is assumed that the lining material 4 is inserted into two existing pipes 1 that open into at least one manhole 2. For example, as shown in FIG. 1 , the lining material 4 passes through three manholes 2 and is inserted into a total of four existing pipes 1 (four sections, assuming that one section is between adjacent manholes 2). The lining material insertion process is similar to the conventional lining material insertion process, for example, by feeding the uncured lining material 4 in a folded state from one of the manholes 2 at both ends that sandwich the four sections (four sections) of existing pipe 1 from a lining material feeding device 7. Then, for example, a cable 8 attached to the tip of the lining material 4 in the feeding direction is wound up by a cable winding device 9, and the tip of the lining material 4 in the feeding direction is pulled from the other (exit) manhole 2. When the lining material 4 is inserted into the existing pipe 1 across the manhole 2 and expanded by supplying pressurized gas, specifically compressed air, into the lining material 4 as described above, there is a risk that the lining material 4 inside the manhole 2 may significantly expand in the radial direction beyond the inner diameter of the existing pipe 1. Therefore, in this embodiment, a restricting sleeve 5 is placed in the portion of the lining material 4 that passes through the manhole to restrict the radial expansion of the lining material 4 (restricting sleeve placement process). Specifically, by covering the portion of the lining material 4 that passes through the manhole, the radial expansion of the lining material 4 is restricted so that the outer diameter of the lining material 4 is approximately equal to the inner diameter of the existing pipe 1. That is, the restricting sleeve 5 is a cylindrical body having an inner diameter approximately equal to the inner diameter of the existing pipe 1 when the lining material 4 is expanded. Furthermore, the material must have properties that make it at least less likely to expand radially than the lining material 4 when it is expanded.

[0020] The restricting sleeve 5 can be made of various materials. Examples include fabric and synthetic resin. Because it is a sleeve, it is cylindrical. However, it can also be made cylindrical by, for example, rolling a sheet-like material into a cylindrical shape and joining or bonding the butt or overlapping portions. In this embodiment, a restricting sleeve 5 made of fabric is used. While it may be difficult to completely prevent radial stretching of the lining material 4 during diameter expansion, fabric has the characteristics of being highly deformable and thin. In this embodiment, the deformability of the restricting sleeve 5 made of fabric is utilized. For example, as shown in Figure 3, the restricting sleeve 5 is attached to the outer surface of the manhole-passing portion of the lining material 4 before the existing pipe 1 is inserted. Since the length of each existing pipe 1 and the interior size of the manhole 2 are known, the manhole-passing portion of the lining material 4 is also known. Therefore, if the restricting sleeve 5 is attached to the outer peripheral surface of the manhole passage portion in advance, the restricting sleeve 5 can be positioned so as to cover the manhole passage portion of the lining material 4 simply by inserting the lining material 4 into the existing pipe 1. The restricting sleeve 5 can be attached to the lining material 4, for example, by adhesive or by a separate fastening member. As is well known, the lining material 4 is quite heavy. When this heavy lining material 4 is pulled within the existing pipe 1, it rubs against the inner peripheral surface of the existing pipe 1. Therefore, like the lining material 4, the fabric restricting sleeve 5 also rubs against the inner peripheral surface of the existing pipe 1, and the two must be fixed together so that the restricting sleeve 5 remains on the outer peripheral surface of the lining material 4 to prevent this rubbing. The restricting sleeve 5 is not shown in Figure 1.

[0021] The restricting sleeve arrangement step can also be performed by methods other than those described above. As an example, in the case of cylindrical restricting sleeves 5 made of synthetic resin with little deformability, as described later, two restricting sleeves 5 shorter than the radius of the manhole 2 are used, and before the lining material 4 is passed through the manhole 2 and inserted into the existing pipe 1, the synthetic resin restricting sleeves 5 are inserted into the openings of the two existing pipes 1 (hereinafter referred to as manhole openings of the existing pipes 1) within the manhole 2 or placed against the manhole openings to arrange the synthetic resin restricting sleeves 5 at the manhole openings of each existing pipe 1, and then the lining material 4 is passed through the manhole 2 and inserted into the existing pipe 1, thereby allowing the synthetic resin restricting sleeves 5 to be arranged outside the manhole openings of the existing pipe 1 at the portion where the lining material 4 passes through the manhole. Furthermore, when the restricting sleeve 5 is made of a plastically deformable sheet material, such as a metal plate, it is possible to first insert the lining material 4 into the existing pipe 1 through the manhole 2, then wrap a metal plate around the lining material 4 in the manhole 2, for example, in a cylindrical shape corresponding to the inner diameter of the existing pipe 1, and then, as necessary, join or bond the butted or overlapping portions of the metal plates to form the restricting sleeve 5, thereby placing the restricting sleeve 5 outside the portion of the lining material 4 that passes through the manhole. This restricting sleeve 5 does not have to be continuous within the manhole 2. As described below, both the restricting sleeve 5 and the hardened lining material 4 in the manhole 2 are removed from the interior of the manhole 2, so that the radial restriction of the lining material 4 during expansion is sufficient at least at the manhole opening of the existing pipe 1. Note that when the restricting sleeve 5 is applied to the manhole opening of the existing pipe 1, a gap must be prevented between the inner wall of the manhole 2 and the restricting sleeve 5 at the manhole opening.

[0022] In this embodiment, a fabric restricting sleeve 5 is used, and a tubular member 6 is pre-installed at the manhole opening of the existing pipe 1. The fabric restricting sleeve 5 in this embodiment is less likely to stretch radially than the lining material 4 during diameter expansion, but it does expand (swell) slightly radially as the lining material 4 expands. Even if the radial expansion of the lining material 4 during diameter expansion is uniform circumferentially, if the lining material 4 expands radially more inside the manhole 2 than at the manhole opening of the existing pipe 1, the lining material 4 will be thinner at the inner portion. As a result, the thickness of the rehabilitated pipe 3 made of the lining material 4 after hardening will be thinner at the manhole opening of the existing pipe 1 than at other portions. Therefore, a tubular member 6 is pre-installed at the manhole opening of the existing pipe 1 to prevent radial expansion that would cause the outer diameter of the restricting sleeve 5 and the lining material 4 to become larger than the inner diameter of the existing pipe 1 (tubular body installation process). Therefore, the tubular member 6 must protrude a predetermined distance into the manhole 2 from the manhole opening of the existing pipe 1 and must be rigid enough to prevent radial deformation when the lining material 4 expands. For example, a metal capable of thinning the wall thickness, such as stainless steel, is used for the tubular member 6. A tubular member 6 having these characteristics is inserted into the existing pipe 1 through the manhole opening of the existing pipe 1 before the lining material 1 is inserted into the existing pipe 1, and attached to the manhole opening of each existing pipe 1 with its end protruding into the manhole 2. Therefore, in this case, the outer diameter of the tubular member 6 is approximately equal to the inner diameter of the existing pipe 1. As described below, and similar to the restricting sleeve 5, the tubular member 6 may be placed against the manhole opening of the existing pipe 1. When the tubular member 6 is placed against the manhole opening of the existing pipe 1, a gap must be prevented from forming between the inner wall of the manhole 2 and the tubular member 6 at the manhole opening. In this case, the inner diameter of the cylindrical member 6 is set to be approximately equal to the inner diameter of the existing pipe 1 .

[0023] FIG. 2 shows the state before the rehabilitating pipe formation process, in which the lining material 4 with the restricting sleeve 5 shown in FIG. 3 has been inserted through three manholes 2 into four existing pipes 1, completing the restricting sleeve placement process simultaneously. The lining material 4 inserted into a total of four existing pipes 1 protrudes into the manholes 2 at both the right end and the left end in FIG. 2. In this embodiment, the open ends of both ends of the lining material 4 are then closed with end packers 10 to supply compressed air to the lining material 4 to expand its diameter. As is well known, the end packers 10 are provided with ventilation holes for supplying and exhausting compressed air, as well as holes for inserting cables for pulling the light train 11 (described below) and for supplying power to the light train 11. Therefore, for example, compressed air is supplied by a compressed air supply device (not shown) through the ventilation hole of the end packer 10 at the left end of the lining material 4 in the figure, and excess air is exhausted through the ventilation hole of the end packer 10 at the right end of the figure. As a result, as shown in FIG. 4, the lining material 4 is expanded in diameter and pressed against the inner circumferential surface of the existing pipe 1. In this state, the lining material 4 is cured to form a rehabilitated pipe 3 (rehabilitation pipe formation process). In this embodiment, a thermosetting resin lining material is used for the lining material 4. Therefore, when a light train (light irradiation / heating device) 11 is passed through the inside of the expanded lining material 4 and the light is turned on, the lining material 4 is heated by the temperature of the light and cured. In the case of a photocurable resin lining material 4, the light train 11 is passed through the inside of the expanded lining material 4 and the light is turned on to irradiate the lining material 4 with light, causing it to cure.

[0024] FIG. 5 is a detailed view of the manhole passage portion of the cured lining material 4 formed in the rehabilitating pipe forming process of FIG. 4. The figure shows that the inner diameter of the regulating sleeve 5 and the outer diameter of the cured lining material 4 are slightly expanded radially beyond the inner diameter of the existing pipe 1, excluding the portion covered by the tubular member 6. The regulating sleeve 5 in this embodiment is made of fabric. Note that the figure is a schematic illustration; an actual fabric regulating sleeve 5 is much thinner. Fabric is formed by weaving warp threads (fibers) and weft threads (fibers). Some fibers are easily stretched in the elongation direction. Furthermore, the size of the weave between the warp and weft threads, i.e., the size of the gap (spacing) between adjacent fibers, varies. Thus, if the fibers constituting the fabric are easily stretched or the spacing between adjacent fibers is large, the fabric will be more likely to stretch in the surface direction of the fabric. Therefore, while the fabric restricting sleeve 5 can restrict the radial expansion of the lining material 4 when the lining material 4 is expanded, it may not be able to prevent radial expansion. However, since the portion of the lining material 4 that passes through the manhole after curing is removed as described below, it is sufficient if the radial expansion of the lining material 4 can be restricted to some extent when the lining material 4 is expanded and cured. Note that the expansion of the fabric in the surface expansion direction can be reduced by using fibers that are less likely to stretch for weaving the fabric or by narrowing the spaces between adjacent fibers in the fabric to form a tight weave. Therefore, using such fabric can further restrict the radial expansion of the lining material 4 when the lining material 4 is expanded or cured. Also, a restricting sleeve 5 made of other fibers can be used instead of fabric.

[0025] After the lining material 4 inserted into the existing pipe 1 is expanded and hardened to form the rehabilitated pipe 3 as described above, the hardened portion of the lining material 4 that passes through the manhole, the restricting sleeve 5, and the tubular member 6 are removed, leaving only the rehabilitated pipe 3 inside the existing pipe 1 (inside-manhole removal process), as shown in FIG. 6 . As a result, with this existing pipe repair method, rehabilitating pipes 3 can be simultaneously installed inside four existing pipes 1 that straddle three manholes 2, reducing the effort required for installing the rehabilitating pipes 3, i.e., repairing the existing pipe, and shortening the construction period. As is well known, the process of expanding and hardening the lining material 4 does not require much effort. However, as mentioned above, the lining material 4 is quite heavy, and inserting this heavy lining material 4 into the existing pipe 1 is time-consuming. In a conventional repair method in which the lining material 4 is inserted into each section of the existing pipe 1 between adjacent manholes 2 and then expanded and hardened, the lining material 4 must be inserted into each section of the existing pipe 1, which is extremely time-consuming. In contrast, the existing pipe repair method of this embodiment allows the rehabilitation pipe 3 to be installed almost simultaneously within multiple sections of the existing pipe 1 spanning multiple manholes 2, significantly reducing the time required to repair the existing pipe and thereby shortening the repair period. Note that the existing pipes 1 through which the lining material 4 is inserted may be arranged in a straight line as shown in the figure, or may be arranged in a manner in which the extension directions of the existing pipes 1 intersect, or in which the existing pipes 1 are misaligned, such as when there is a difference in elevation between them on either side of a manhole 2, as will be described later, or in which the inside diameters of the existing pipes 1 are different.

[0026] FIG. 7 is an explanatory diagram of a variation of the existing pipe repair method shown in FIG. 1 , showing an example in which, of two existing pipes 1 opening into a manhole 2, the existing pipe 1 on the left side of the figure is higher and the existing pipe 1 on the right side is lower. In this example, it is assumed that the fabric restricting sleeve 5 does not stretch radially, even when the lining material 4 is expanded. In such a case, even if the restricting sleeve 5 does not stretch radially, when the lining material 4 is inserted into the existing pipe 1 through the manhole 2 as shown in the figure and then expanded and hardened to form a rehabilitated pipe 3, wrinkles may occur in the rehabilitated pipe 3 at the manhole opening of the existing pipe 1. That is, as can be inferred from the figure, at the manhole opening of the existing pipe 1 on the left, the upper portion of the lining material 4 stretches more, while the lower portion stretches less. Conversely, at the manhole opening of the existing pipe 1 on the right side of the figure, the upper portion of the lining material 4 stretches less and the lower portion stretches more. This difference in elongation causes wrinkles when the lining material 4 expands and hardens, i.e., when the rehabilitated pipe 3 is formed. This example shows a case where there is a difference in height between the openings of the two existing pipes 1 that open into the manhole 2, but the same applies when the two existing pipes 1 are misaligned or when the inner diameters of the two existing pipes 1 are different.

[0027] Therefore, in this example as well, the tubular member 6, which abuts against the entire inner periphery of the existing pipe 1 and protrudes a predetermined distance into the manhole 2, is inserted into the manhole opening of the existing pipe 1, and the restricting sleeve 5 and lining material 4 are placed inside this tubular member 6, and the rehabilitating pipe formation process is performed. By having the tubular member 6, which has rigidity and is not deformed in the radial direction, protrude a predetermined distance into the manhole 2 from the entire inner periphery of the existing pipe 1, the elongation of the lining material 4 at the manhole opening of the existing pipe 1 during expansion and hardening can be made approximately uniform in the circumferential direction, thereby preventing wrinkles from occurring in the rehabilitating pipe 3 at the manhole opening of the existing pipe 1. After the rehabilitating pipe is formed, the portion of the tubular member 6 protruding into the manhole 2 is removed together with the hardened portions of the lining material 4 and restricting sleeve 5 that pass through the manhole. As mentioned above, if wrinkles form in the rehabilitating pipe 3 at the manhole opening of the existing pipe 1, a gap may form between the existing pipe 1 and the rehabilitating pipe 3. If a gap forms between the existing pipe 1 and the rehabilitating pipe 3, groundwater and associated sediment flowing in through cracks or other damage in the existing pipe 1 may flow into the pipeline through the gap between the existing pipe 1 and the rehabilitating pipe 3. If groundwater or sediment flows into the pipeline, it may form a cavity in the ground, which may cause a ground subsidence or other problems. In this example, by preventing wrinkles from forming in the rehabilitating pipe 3 at the manhole opening of the existing pipe 1, the formation of a gap between the existing pipe 1 and the rehabilitating pipe 3 can also be prevented.

[0028] next ,figure 8, Figure 9 ,other 8 is an explanatory diagram of the existing pipe repair method, and FIG. 9 is an explanatory diagram of the state before the rehabilitating pipe forming process. For example, Already The state after the manhole removal process in the pipe repair method is the same as that shown in FIG. 6 of the first embodiment. Only the aspects that differ from the first embodiment will be described below. Existing pipe repair method As an example, the above-mentioned photocurable resin lining material 4 was used.

[0029] this Existing pipe repair methodIn this embodiment, a synthetic resin restricting sleeve is used as the restricting sleeve 5. The synthetic resin restricting sleeve 5 is not as deformable as the fabric restricting sleeve 5 of the first embodiment. Therefore, for example, before inserting the lining material 4 into the multiple existing pipes 1, it is necessary to insert the restricting sleeve 5 into the two existing pipes 1 that open into the manhole 2. Existing pipe repair method In this example, for example, two synthetic resin restricting sleeves 5 shorter than the radius of the manhole 2 are used for each manhole 2, and one of these sleeves is inserted into each of the two existing pipes 1 through the manhole openings. The lining material 4 is then inserted into the existing pipe 1 through the manhole 2, i.e., through the two restricting sleeves 5 for each manhole 2. As described above, if the member constituting the restricting sleeve 5 is sheet-like, after the lining material 4 is inserted into the existing pipe 1 through the manhole 2, the sheet-like restricting sleeve member may be wrapped around the outer periphery of the lining material 4 inside the manhole 2, and the butt or overlapping portions may be joined or bonded to form the restricting sleeve 5. As described above, the synthetic resin restricting sleeve 5 may also be used by being fitted to the manhole opening of the existing pipe 1.

[0030] FIG. 9 is an explanatory diagram of the rehabilitating pipe forming process, and more specifically shows the state in which a light train 11 is passed through the inside of the expanded lining material 4 to harden it with light. As mentioned above, the lining material 4 made of a light-hardening resin has the advantage that it takes a short time to harden with light irradiation. Rehabilitation pipe formation processIn this example, the restricting sleeve 5 is made of synthetic resin, which is difficult to deform, and therefore the radial expansion of the lining material 4 is prevented in the portion of the lining material 4 that passes through the manhole, which is covered by the restricting sleeve 5. Then, after the lining material 4 made of photocurable resin is photocured to form the rehabilitated pipe 3, the hardened lining material 4 and the restricting sleeve 5 inside the manhole 2 are removed as described above, leaving the rehabilitated pipe 3 only inside the existing pipe 1. In the portion of the lining material 4 that passes through the manhole that is not covered by the restricting sleeve 5, the lining material 4 expands and bulges in the radial direction, but this portion is removed together with the rest of the inside of the manhole, so it does not cause any problems as a rehabilitated pipe 3. It should be noted that even in a similar light train 11, this Rehabilitation pipe formation process Unlike the light train 11 of the first embodiment, the light train 11 does not need to heat the lining material 4, so lights that do not heat up much, such as light emitting diodes, can be used.

[0031] Next, a third embodiment of the existing pipe repair method of the present invention will be described. Figures 10 to 13 are explanatory diagrams of the existing pipe repair method according to this embodiment, with Figure 10 being a front view of a tubular member used in the existing pipe repair method of this embodiment, and Figure 11 being a detailed diagram of the rehabilitating pipe formation step in the existing pipe repair method of this embodiment. Figure 12 is an explanatory diagram of the inside of an existing pipe and a manhole in which the existing pipe repair method of this embodiment is carried out, and Figure 13 is a detailed diagram of the rehabilitating pipe formation step when the tubular member of Figure 2 is used for the existing pipe and manhole shown in Figure 12. The existing pipe repair method of this embodiment is roughly a modification of the first embodiment described above.

[0032] First, the structure of a manhole that is the target of the existing pipe repair method of this embodiment will be described with reference to Figure 12. In this manhole 2, the bottom of the manhole 2 is piled up with concrete or mortar, and a groove 8 with a roughly semicircular cross section is formed between the upstream existing pipe 1 and the downstream existing pipe 1 that open into the manhole 2. This type of manhole structure is also called an invert. In this type of manhole structure, the bottoms of the two existing pipes 1 that open into the manhole 2 and the bottom of the groove 8 are generally formed continuously.

[0033] As shown in FIG. 10 , the tubular member 6 used in the existing pipe repair method of this embodiment has a notch 7 formed by recessing a portion of its end in the extension direction of the tubular body. When using this tubular member 6, the tubular member 6 is positioned so that the notch 7 is the bottom of the groove 8, preventing the main body (cylindrical portion) of the tubular member 6 from entering the interior of the existing pipe 1. In this manner, the tubular member 6 is positioned so that the notch 7 is the bottom of the existing pipe 1, and the notch 7 prevents the main body (cylindrical portion) of the tubular member 6 from entering the interior of the existing pipe 1. In this embodiment, the tubular member 6 is disposed by placing the end of the tubular member 6 against the manhole opening of the existing pipe 1. When the end of the tubular member 6 is placed against the manhole opening of the existing pipe 1, a gap is prevented from forming between the tubular member 6 and the inner wall of the manhole 2 at the manhole opening. Figure 11 is a detailed view of the manhole opening after the restricting sleeve 5 and lining material 4 have been inserted into the tubular member 6 and the lining material 4 has been expanded and hardened. The drawing particularly emphasizes the thickness of the tubular member 6 and the lining material 4. As shown in this figure, a raised portion 9 consisting of the tubular member 6, restricting sleeve 5, and hardened lining material 4 is formed near the bottom of the manhole opening in the existing pipe 1. However, since this raised portion 9 is formed outside the existing pipe 1, i.e., at the bottom of the trench 8 (= inside the manhole 2), the raised portion 9 can be removed when the hardened lining material 4 inside the manhole 2 is removed.

[0034] FIG. 13 is a detailed view of a manhole opening in which the tubular member 6 of the first embodiment, i.e., a cylindrical pipe member without a notch, is used in an inverted manhole 2 and the lining material 4 has been expanded and hardened. The tubular member 6, which is a cylindrical pipe member without a notch, is inserted into the existing pipe 1 so that its end abuts the entire inner periphery, and the lower end abuts the bottom of the existing pipe 1. In this state, a restricting sleeve 5 and a lining material 4 are inserted into the tubular member 6, and the lining material 4 is expanded and hardened, causing the hardened rehabilitated pipe 4 to bulge at the bottom of the existing pipe 1. The thicker the tubular member 6, the larger the bulge 9 of the rehabilitated pipe 4 at the bottom of the existing pipe 1. For example, if the tubular member 6 is made of resin, the thickness of the tubular member 6 will be increased to restrict the expansion of the lining material 4 while avoiding deformation or breakage of the tubular member 6. In such cases, the bulge 9 of the rehabilitated pipe 4 at the bottom of the existing pipe 1 will be particularly large. Inside the existing pipe 1, it is difficult to remove both the rehabilitated pipe 4 formed by the expansion and hardening of the lining material 4 and the tubular member 6 sandwiched between this component pipe 4 and the existing pipe 1. Therefore, even after removing the rehabilitated pipe 4, the restricting sleeve 5, and the tubular member 6 inside the manhole 2, the bulge 9 of the rehabilitated pipe 4 remains at the bottom of the existing pipe 1. If a bulge 9 exists at the bottom of the existing pipe 1, garbage and waste may accumulate there, obstructing the flow inside the pipeline.

[0035] As described above, according to the existing pipe repair method of this embodiment, a cylindrical hardening lining material 4 is inserted in an unhardened state through one manhole 2 into two existing pipes 1 that open into the manhole 2, and at least the manhole opening of the existing pipe 1 where the lining material 4 passes through the manhole is covered from the radial outside with a cylindrical restricting sleeve 5 having an inner diameter approximately equal to that of the existing pipe 1. Therefore, when the lining material 4 is subsequently expanded and pressed against the inner circumferential surface of the existing pipe 1, the radial expansion, i.e., bulging, of the portion of the lining material 4 that passes through the manhole is restricted by the restricting sleeve 5. In this state, the lining material 4 is hardened to form a rehabilitated pipe 3, and after the rehabilitated pipe 3 is formed, the hardened lining material 4 and restricting sleeve 5 in the manhole 2 are removed. Therefore, with this existing pipe repair method, it is possible to simultaneously form a rehabilitating pipe 3 on the inner circumferential surfaces of two existing pipes 1 that straddle at least one manhole 2, and by expanding this, for example, by forming a rehabilitating pipe 3 with multiple sections of existing pipe 1 that pass through multiple manholes 2, it is possible to repair multiple sections of existing pipe 1 that span multiple manholes 2 at once as if they were a single existing pipe. As a result, with this existing pipe repair method, it is possible to reduce the repair effort when repairing multiple sections of existing pipe 1 that span multiple manholes 2, and at the same time, shorten the repair construction period.

[0036] Furthermore, by attaching a deformable restricting sleeve 5 to the outer periphery of the manhole-passing portion of the lining material 4 before it is inserted into the existing pipe 1, it becomes possible to position the restricting sleeve 5 on the outside of the manhole-passing portion of the lining material 4 simply by passing the lining material 4 through the manhole 2 and inserting the lining material 4 into the two existing pipes 1 that open into the manhole 2, thereby simplifying the processes from the lining material insertion process to the sleeve placement process.

[0037] Furthermore, prior to the rehabilitating pipe formation process, a cylindrical member 6 is disposed at the manhole opening of the existing pipe 1. The cylindrical member 6 protrudes a predetermined distance into the manhole 2 from the opening of the existing pipe 1 at the manhole 2 radially outward of the lining material 4 to be expanded, has an inner or outer diameter approximately equal to the inner diameter of the existing pipe, and has rigidity that prevents it from deforming radially when the lining material 4 is expanded. This prevents wrinkles and thickness variations in the rehabilitating pipe 3, particularly at the opening of the existing pipe 1 inside the manhole, when the lining material 4 is expanded and hardened to form the rehabilitating pipe 3.

[0038] Furthermore, by positioning the tubular member 6 so that the notch 7 provided at the end of the tubular member 6 is located at the bottom of the existing pipe 1, the tubular member 6 can be prevented from penetrating into the bottom of the existing pipe 1. Therefore, if the hardened lining material 4 and tubular member 6 inside the manhole 2 are removed after the lining material 4 has been expanded and hardened, no raised portion will be formed at the bottom of the existing pipe 1, i.e., the bottom of the rehabilitated pipe 4.

[0039] Although the embodiments have been described above, the configuration of the present invention is not limited to these embodiments, and various modifications are possible within the scope of the gist of the invention. For example, in the modification of the first embodiment, the tubular member 6 is inserted into the manhole opening of the existing pipe 1 when there is a difference in height between the openings of two existing pipes 1 that open into one manhole 2, or when the existing pipes 1 are misaligned or have a difference in inner diameter. However, even if there is no difference in height, misalignment, or difference in inner diameter between the manhole openings of the two existing pipes 1, there is no problem in inserting the tubular member 6 into the manhole opening of the existing pipe 1 in the same way to form the rehabilitation pipe 3.

[0040] Furthermore, in the above embodiment, the restricting sleeve 5 is used by being inserted inside the existing pipe 1, but since the restricting sleeve 5 restricts radial expansion of the lining material 4 at least at the manhole opening of the existing pipe 1, it is sufficient that the restricting sleeve 5 is located inside the manhole 2 rather than the manhole opening of the existing pipe 1, and therefore there is no need to insert it inside the existing pipe 1. It is also possible to previously integrate the restricting sleeve 5 and the tubular member 6 with an adhesive or the like. In this case, the sleeve placement process and the tubular body installation process are carried out almost simultaneously. [Explanation of symbols]

[0041] 1 Existing pipes 2 Manholes 3 Rehabilitation pipe 4 Lining material 5 Regulatory sleeve 6. Cylindrical member 7 Notch

Claims

1. A method for repairing an existing pipe, comprising: forming a rehabilitating pipe by expanding and hardening a cylindrical hardening lining material within the existing pipe; and installing the rehabilitating pipe within the existing pipe, the existing pipe being installed between manholes arranged at predetermined intervals; a lining material insertion step of passing the curable lining material in an uncured state through at least one of the manholes and inserting it into the two existing pipes opening into the manhole; a sleeve placement process in which a restricting sleeve is placed around a portion of the hardenable lining material that passes through a manhole, the restricting sleeve being a cylindrical body having an inner diameter equivalent to the inner diameter of the existing pipe and being at least less likely to expand radially than the hardenable lining material, and restricting the expansion of the hardenable lining material when the hardenable lining material expands; a cylindrical body disposing step of disposing a cylindrical member that protrudes a predetermined dimension from the opening of the existing pipe into the manhole on the radially outer side of the hardenable lining material to be expanded, has an inner diameter or an outer diameter equal to the inner diameter of the existing pipe, and has rigidity that prevents deformation in the radial direction when the hardenable lining material is expanded; a rehabilitating pipe forming step in which, after the lining material inserting step, sleeve arranging step, and cylindrical body disposing step, the hardenable lining material is expanded in diameter and pressed against the inner peripheral surface of the existing pipe, and the hardenable lining material is hardened in this state to form the rehabilitated pipe; and an in-manhole removal process for removing the hardened lining material and the restricting sleeve from inside the manhole after the rehabilitating pipe forming process, The cylindrical member has a notch recessed in the extension direction in at least a part of an end portion thereof, In the cylindrical body disposing step, the cylindrical member is disposed so that the notch portion is located below the existing pipe, The method for repairing an existing pipe is characterized in that the inside-manhole removal step involves removing a cylindrical member inside the manhole.

2. The restriction sleeve is deformable, 2. The existing pipe repair method according to claim 1, wherein the sleeve placement step is carried out by pre-attaching the restricting sleeve to the outer peripheral portion of the hardenable lining material that passes through the manhole before the hardenable lining material is inserted into the existing pipe, and then inserting the hardenable lining material through the manhole into the existing pipe.

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