Methods for repairing existing pipes

Abstract

This invention provides a method for repairing existing pipes that spans multiple manhole sections, thereby reducing the effort required for repairs and shortening the construction period. [Solution] Before inserting the tubular hardening lining material 4 into the two existing pipes 1 that open into the manhole 2 in an unhardened state, a restricting sleeve 5, made of a deformable cylindrical body having an inner diameter equal to the inner diameter of the existing pipe 1, is fixed and attached to the portion of the lining material 4 that passes through the manhole, so as to cover the lining material 4 from the radial outside. Subsequently, when the lining material 4 is expanded and pressed against the inner surface of the existing pipe 1, the radial elongation, i.e., bulging, of the portion of the lining material 4 that passes through the manhole is restricted. In this state, the lining material 4 is hardened to form the rehabilitated pipe 3, and then the hardened lining material 4 and restricting sleeve 5 are removed from inside the manhole 2.

Description

Technical Field

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

Background Art

[0002] Existing pipes buried underground, such as sewer pipes, deteriorate due to long-term use, and their service life is generally about 50 years. In recent years, the number of sewer pipes exceeding their service life has been increasing. In deteriorated sewer pipes, groundwater and sediment around the pipe may flow into the pipe due to cracks or the like in the pipeline, resulting in the formation of cavities underground and causing ground subsidence. In addition, sewer pipes are easily affected by ground movements such as earthquakes, and for various reasons, some kind of repair is required at a predetermined time.

[0003] As a method for repairing existing pipes such as sewer pipes, for example, there is known a repair method of forming an inner layer pipe (rehabilitation 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). Among these, in the repair method using the thermosetting lining material described in Patent Document 1 below, an uncured thermosetting light lining material is inserted into the existing pipe in a folded state, for example, and both ends are sealed with a sealing member. Then, in that state, compressed air is supplied into the lining material to expand the diameter of the lining material and make it adhere to the inner peripheral surface of the existing pipe. In that state, the lining material is heated to start the polymerization crosslinking reaction of the thermosetting resin and cure it, forming a rehabilitation pipe made of the cured lining material on the inner peripheral surface of the existing pipe.

[0004] Furthermore, in the repair method using a photocurable lining material described in Patent Document 2 below, the uncured photocurable lining material is inserted into the existing pipe, for example, in a folded state, and then both ends are sealed with sealing members. In this state, compressed air is supplied to the inside of the lining material to expand its diameter and make it adhere closely to the inner surface of the existing pipe. In this state, the photoirradiation device is moved inside the photocurable lining material and irradiated with light to initiate the polymerization crosslinking reaction of the photocurable resin and cure it, forming a rehabilitated pipe made of the cured 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 Publication No. 2009-214407 [Overview of the project] [Problems that the invention aims to solve]

[0006] As described above, the existing pipe repair method, which involves expanding and hardening the lining material to form a rehabilitated pipe on the inner surface of the existing pipe, is generally carried out on each section of the existing pipe between adjacent manholes that are spaced at predetermined intervals along the extending existing pipe. In other words, the existing pipe is repaired one section at a time between adjacent manholes. The distance between adjacent manholes is generally around 30 to 70 meters. However, since manholes are usually located along roads, and existing pipes are laid in a straight line, the distance between manholes often decreases when the road is curved, for example. That is, since the concrete pipes that make up the existing pipes are straight, the direction of extension of the existing pipes is linear, whereas manholes are located at the intersection of these linearly extending existing pipes and curved roads, so the distance between manholes tends to decrease when the road is curved. A similar tendency can be seen in existing pipes laid along steep slopes. When the spacing between manholes becomes smaller, the length of existing pipe that can be repaired in a single operation decreases. This increases the number of sections that make up one unit of repair work, which in turn increases the amount of work involved and lengthens the construction period. Furthermore, when repairing one section of existing pipe, the rehabilitation pipes inside the manholes on both sides are also expanded and hardened. However, since these hardened rehabilitation pipes inside the manholes are simply removed after the work is completed, there is a lot of waste of repair materials. When inserting lining material into two adjacent existing pipes with a manhole in between to expand and harden the lining material, one possible method is to attach a cylindrical member to the portion of the lining material that passes through the manhole to pre-regulate the expansion. However, since the lining material is quite heavy and rubs against the inner surface of the existing pipe when pulled inside, when attaching the cylindrical member to the lining material, it is necessary to ensure that the cylindrical member is in the correct position when the lining material is inserted.

[0007] The present invention has been made in view of the above problems, and its purpose is to provide an existing pipe repair method that can reduce the effort required for repairs and shorten the construction period when repairing existing pipes that span multiple sections. [Means for solving the problem]

[0008] The method for repairing existing pipes to achieve the above objective is: In a method for repairing existing pipes, in which a cylindrical, hardenable lining material is inserted into an existing pipe installed between manholes arranged at predetermined intervals, and the lining material is expanded in diameter and hardened inside the existing pipe to form a rehabilitated pipe, the existing pipe is repaired. The insertion of the lining material into the existing pipe is performed for at least one of the existing pipes that pass through the manhole and open into the manhole. Before inserting the lining material into the existing pipe, a sleeve attachment step is performed, in which a regulating sleeve is fixed to the outer circumference of the portion of the lining material that passes through the manhole, the regulating sleeve having an inner diameter equivalent to the inner diameter of the existing pipe, being deformable and less prone to radial expansion than the lining material, and which restricts the expansion of the lining material when it expands in diameter. A rehabilitation pipe formation process involves introducing a lining material with the aforementioned restrictive sleeve fixedly attached into the existing pipe to perform the diameter expansion and hardening, The method is characterized by including a manhole removal step of removing the hardened lining material and regulating sleeve inside the manhole.

[0009] A further configuration of the above-described method for repairing existing pipes is characterized in that the attachment of the restricting sleeve to the lining material is by bonding with an adhesive and / or by locking with a locking member.

[0010] In this configuration, a cylindrical, hardening lining material is inserted into two existing pipes opening into a manhole while it is still unhardened, passing through the manhole. The portion of the lining material that passes through the manhole is covered from the radially outer side by a restricting sleeve having an inner diameter equal to the inner diameter of the existing pipe. Therefore, when the lining material is subsequently expanded and pressed against the inner surface of the existing pipe, the radial elongation, i.e., bulging, of the portion of the lining material that passes through the manhole is restricted by the restricting sleeve. In this state, the lining material is hardened to form a rehabilitated pipe, and after the formation of the rehabilitated pipe, the hardened lining material and restricting sleeve inside the manhole are removed. Therefore, this rehabilitation pipe installation method allows for the simultaneous formation of rehabilitation pipes on the inner surfaces of two existing pipes spanning at least one manhole. By extending this method, for example, if the existing pipe between adjacent manholes is considered one section, then by simultaneously forming rehabilitation pipes within multiple sections of the existing pipe, it becomes possible to repair multiple sections of the existing pipe at once, as if they were a single existing pipe. As a result, this rehabilitation pipe installation method reduces the effort required for repairing multiple sections of existing pipe, and simultaneously shortens the repair period.

[0011] Furthermore, by pre-attaching a deformable restricting sleeve to the outer circumference of the portion of the lining material that passes through the manhole before it is inserted into the existing pipe, for example, by folding the restricting sleeve together with the lining material and inserting the lining material into the two existing pipes opening into the manhole, it becomes possible to position the restricting sleeve covering the portion of the lining material that passes through the manhole. In addition, because the restricting sleeve is fixed to the lining material, if the lining material is pulled inside the existing pipe and the lining material and restricting sleeve rub against the inner surface of the existing pipe, the restricting sleeve can remain attached to the outer surface of the lining material to withstand the friction.

[0012] A further configuration of the above-described method for repairing existing pipes is characterized by having a cylindrical body arrangement step, prior to the rehabilitation pipe formation step, in which a cylindrical member is arranged on the radially outer side of the lining material to be expanded, protruding into the manhole from the opening of the existing pipe in the manhole by a predetermined dimension, having an inner or outer diameter equivalent to the inner diameter of the existing pipe, and having rigidity that does not deform in the radial direction when the lining material is expanded, and in the manhole removal step, the cylindrical member inside the manhole is removed.

[0013] This configuration prevents the formation of wrinkles in the rehabilitated pipe, particularly at the manhole opening of the existing pipe, during the formation of the rehabilitated pipe by the expansion and hardening of the lining material. Specifically, 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 the manhole, when the lining material inserted into the two existing pipes after passing through the manhole is expanded, the radial elongation of the lining material is restricted by the restricting sleeve. However, at the manhole openings of the existing pipes, the elongation of the lining material differs, with the upper part of the higher existing pipe opening elongating more than the lower part, and conversely, the upper part of the lower existing pipe opening elongating less than the lower part. This difference in elongation can cause wrinkles to form at the manhole opening of the rehabilitated pipe (after the manhole passage portion has been removed) made of hardened lining material, and these wrinkles may form a gap between the rehabilitated pipe and the existing pipe. These wrinkles, and the 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 there is misalignment, such as when the two existing pipes opening into a manhole have different extension directions, or when there is a difference in the inner diameter of the existing pipes. When a gap forms between the manhole opening of the existing pipe and the manhole opening of the rehabilitated pipe in this way, groundwater and accompanying sediment that have flowed in from cracks or other damaged areas of the existing pipe may flow into the pipeline through the gap between the existing pipe and the rehabilitated pipe. If groundwater and sediment flow into the pipeline, there is a risk that cavities may form underground, which could cause ground subsidence or other problems. By having a cylindrical member that protrudes into the manhole by a predetermined length on the outside of the lining material and regulating sleeve before the diameter is expanded at the opening of the existing pipe that opens into the manhole, the elongation of the lining material at the manhole opening of the existing pipe is made uniform around the entire circumference, thereby preventing a gap from forming between the rehabilitated pipe, which is made of 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 opening into the manhole, if the regulating sleeve deforms radially, the radial elongation of the lining material at the manhole opening of the rehabilitated pipe after completion can be suppressed, thereby suppressing fluctuations in the thickness of the manhole opening of the rehabilitated pipe.

[0014] A further configuration of the above-described method for repairing existing pipes is that the cylindrical member is provided with a notch that is recessed in the extension direction at least a portion of its end, and in the cylindrical member placement step, the cylindrical member is positioned such that the notch is located at the bottom of the existing pipe.

[0015] In this configuration, within a manhole, the openings of two existing pipes that open into the manhole are connected by a groove with a roughly semicircular cross-section, made by piling up concrete or mortar, and the bottoms of these grooves are formed in a continuous manner. In such cases, by positioning the notch of the cylindrical member at the bottom of the existing pipe, it is possible to prevent the cylindrical member from entering the bottom of the inside of the existing pipe. By doing so, if the hardened lining material and cylindrical member inside the manhole are removed after the lining material has expanded and hardened, there will be no bulge at the bottom of the existing pipe, i.e., the bottom of the rehabilitated pipe. Since it is difficult to remove the cylindrical member inserted inside the existing pipe after the lining material has expanded and hardened, the bottom of the rehabilitated pipe resting on this cylindrical member will bulge. As described above, if there is a bulge in the rehabilitated pipe where the bottom of the roughly semicircular cross-section groove and the bottom of the existing pipe are formed in a continuous manner, garbage and filth tend to accumulate in that area, but by not creating this bulge, such problems can be avoided. [Effects of the Invention]

[0016] As explained above, the above-described method for repairing existing pipes allows for the simultaneous formation of rehabilitated pipes on the inner surfaces of two existing pipes spanning at least one manhole. By expanding this, it becomes possible to repair multiple sections of existing pipes spanning three or more manholes at once. Therefore, the effort required for repairing multiple sections of existing pipes can be reduced, and the repair period can also be shortened. [Brief explanation of the drawing]

[0017] [Figure 1] This is an explanatory diagram of the lining material insertion step in the first embodiment of the existing pipe repair method of the present invention. [Figure 2]It is an explanatory diagram of the state before the regenerated pipe forming process in the existing pipe repair method of FIG. 1. [Figure 3] It is an explanatory diagram of the lining material and the restraint sleeve used in the lining material insertion process of FIG. 1. [Figure 4] It is an explanatory diagram of the regenerated pipe forming process in the existing pipe repair method of FIG. 1. [Figure 5] It is a detailed diagram of the manhole passing portion of the lining material in FIG. 4. [Figure 6] It is an explanatory diagram of the manhole inner removal process in the existing pipe repair method of FIG. 1. [Figure 7] It is an explanatory diagram of the state after the cylinder arrangement process in the existing pipe repair method of FIG. 1. [Figure 8] It is an explanatory diagram of the state before the regenerated pipe forming process in the embodiment of the existing pipe repair method. [Figure 9] It is an explanatory diagram of the regenerated pipe forming process in the existing pipe repair method of FIG. 8. [Figure 10] It is a front view of the cylindrical member used in the second embodiment of the existing pipe repair method of the present invention. [Figure 11] It is a detailed diagram of the regenerated pipe forming process in the existing pipe repair method of FIG. 10. [Figure 12] It is an explanatory diagram of the existing pipe and inside the manhole where the existing pipe repair method of FIG. 10 is implemented. [Figure 13] It is a detailed diagram of the regenerated pipe forming process when the cylindrical member of FIG. 2 is used for the existing pipe and manhole shown in FIG. 12.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the existing pipe repair method of the present invention will be described in detail with reference to the drawings. Figures 1 to 6 are explanatory diagrams of the existing pipe repair method according to the first embodiment of the present invention, where Figure 1 is an explanatory diagram of the lining material insertion process, Figure 2 is an explanatory diagram of the state before the rehabilitation pipe formation process, Figure 3 is an explanatory diagram of the lining material 4 and regulating sleeve 5 used in the lining material insertion process of Figure 1, Figure 4 is an explanatory diagram of the rehabilitation pipe formation process, Figure 5 is a detailed view of the manhole passage portion of the lining material 4 of Figure 4, and Figure 6 is an explanatory diagram of the removal process inside the manhole. The lining material 4 used in the existing pipe repair method of this embodiment can be either a lining material made of a photocurable resin tubular member as described above, or a lining material made of a thermosetting resin tubular member, both of which are cylindrical and are used by inserting them into the existing pipe 1 in an uncured state. As is well known, photocurable resin lining materials have the advantage of a shorter curing time by light irradiation compared to thermosetting resin lining materials, but there is a risk that the temperature of the lining material 4 may rise too high due to the exothermic reaction during photocuring. Here, as an example, a thermosetting resin lining material was used.

[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 Figure 1, the lining material 4 is inserted into a total of four existing pipes 1 (four sections if the space between adjacent manholes 2 is considered one section) by passing through three manholes 2. The lining material insertion process is the same as the conventional lining material insertion process, for example, by feeding the uncured lining material 4 in a folded state from the lining material feeding device 7 from one of the manholes 2 at both ends that sandwich the four sections (four pipes) of existing pipes 1. Then, for example, the end of the lining material 4 in the feeding direction is pulled from the other (outlet side) manhole 2 by winding up the cable 8 attached to the feeding end of the lining material 4 with the cable winding device 9. In this manner, when the lining material 4 is inserted into the existing pipe 1, straddling the manhole 2, and pressurized gas, specifically compressed air, is supplied to the inside of the lining material 4 to expand its diameter, there is a risk that the lining material 4 inside the manhole 2 will expand significantly in the radial direction, exceeding 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 step). 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 becomes approximately equal to the inner diameter of the existing pipe 1. That is, the restricting sleeve 5 consists of 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, as a material characteristic, it is required that when the lining material 4 is expanded, it is at least less likely to expand radially than the lining material 4.

[0020] This restricting sleeve 5 can be made of various materials. Examples include fabric and synthetic resin. As it is a sleeve, it is a cylindrical body, but it is also possible to make a cylindrical body by winding a sheet material into a cylindrical shape and joining or connecting the butt or overlapping parts to each other. In this embodiment, a restricting sleeve 5 made of fabric was used. Although it may be difficult to completely prevent the radial elongation of the lining material 4 when the diameter is expanded, fabric has the characteristics of being highly deformable and having a small thickness, i.e., being thin. In this embodiment, the deformability of this fabric restricting sleeve 5 is utilized, and for example as shown in Figure 3, the restricting sleeve 5 is attached in advance to the outer surface of the portion of the lining material 4 that passes through the manhole before insertion of the existing pipe 1 (sleeve attachment process). Since the length of each existing pipe 1 is known and the size of the inside of the manhole 2 is also known, the portion of the lining material 4 that passes through the manhole is also known. Therefore, if the restricting sleeve 5 is pre-attached to the outer surface of the manhole passage portion, the restricting sleeve 5 can be positioned to cover the manhole passage portion of the lining material 4 simply by inserting the lining material 4 into the interior of the existing pipe 1. The restricting sleeve 5 can be attached to the lining material 4 by means of adhesive bonding or by locking with individual locking members. As is well known, the lining material 4 is quite heavy. When this heavy lining material 4 is pulled inside the existing pipe 1, it rubs against the inner surface of the existing pipe 1. Therefore, the fabric restricting sleeve 5 also rubs against the inner surface of the existing pipe 1, similar to the lining material 4, so it is necessary to fix the two together so that the restricting sleeve 5 remains on the outer surface of the lining material 4 against this rubbing. Note that the restricting sleeve 5 is not shown in Figure 1.

[0021] The above-described process of arranging the restrictive sleeves can also be carried out by methods other than those described above. For example, as will be described later, in the case of a cylindrical restrictive sleeve 5 made of synthetic resin with poor deformability, for example, two restrictive sleeves 5 shorter than the radius of the manhole 2 can be used. Before inserting the lining material 4 into the existing pipe 1 through the manhole 2, the synthetic resin restrictive sleeves 5 can be placed at the manhole openings of each of the two existing pipes 1 (hereinafter referred to as the manhole openings of the existing pipes 1) by inserting them into the respective openings of the two existing pipes 1 within the manhole 2 or by placing them against the manhole openings. After that, the lining material 4 can be inserted into the existing pipe 1 through the manhole 2, thereby positioning the synthetic resin restrictive sleeves 5 on the outside of the manhole openings of the existing pipes 1 in the portion of the lining material 4 that passes through the manhole. Furthermore, when constructing the restricting sleeve 5 from a plastically deformable sheet material, such as a metal plate, it is also possible to position the restricting sleeve 5 outside the portion of the lining material 4 that passes through the manhole, for example, by first inserting the lining material 4 into the existing pipe 1 through the manhole 2, and then, within the manhole 2, winding a metal plate in a cylindrical shape corresponding to the inner diameter of the existing pipe 1 around the outer circumference of the lining material 4, and joining or connecting the abutting or overlapping portions of the metal plate to each other as needed. This restricting sleeve 5 does not have to be a continuous series within the manhole 2. As will be described later, since the portion of both the restricting sleeve 5 and the hardened lining material 4 inside the manhole 2 is removed, radial restriction of the lining material 4 during diameter expansion is sufficient at least at the manhole opening of the existing pipe 1. When applying the restricting sleeve 5 to the manhole opening of the existing pipe 1, ensure that there is no gap between the inner wall of the manhole 2 and the restricting sleeve 5 at the manhole opening.

[0022] In this embodiment, a regulating sleeve 5 made of fabric is used, so a cylindrical member 6 is pre-installed at the manhole opening of the existing pipe 1. The regulating sleeve 5 made of fabric in this embodiment does not stretch radially as much as the lining material 4 when it is expanded, but it stretches (expands) slightly radially as the lining material 4 expands. Even if the radial expansion of the lining material 4 when it is expanded is uniform in the circumferential direction, if the lining material 4 stretches radially inside the manhole 2 rather than at the manhole opening of the existing pipe 1, the lining material 4 becomes thinner in that inner portion, and as a result the thickness of the rehabilitated pipe 3 made of the hardened lining material 4 becomes thinner at the manhole opening of the existing pipe 1 than in other parts. Therefore, a cylindrical member 6 is pre-installed at the manhole opening of the existing pipe 1 to prevent radial expansion in which the outer diameter of the regulating sleeve 5 and the lining material 4 becomes larger than the inner diameter of the existing pipe 1 (cylindrical member installation process). Therefore, this cylindrical member 6 is required to protrude from the manhole opening of the existing pipe 1 into the manhole 2 by a predetermined dimension, and to have rigidity that prevents radial deformation when the lining material 4 expands in diameter. For such a cylindrical member 6, for example, a metal that allows for a thin wall thickness of the cylinder, such as stainless steel, is used. The cylindrical member 6 having these characteristics is inserted into the existing pipe 1 from the manhole opening of the existing pipe 1 before the lining material 1 is inserted into the existing pipe, and is attached to the manhole opening of each existing pipe 1 so that its end protrudes into the manhole 2. In this case, the outer diameter of the cylindrical member 6 is approximately equal to the inner diameter of the existing pipe 1. As will be described later, and similar to the regulating sleeve 5, the cylindrical member 6 may also be arranged so that it fits against the manhole opening of the existing pipe 1. When the cylindrical member 6 is fitted against the manhole opening of the existing pipe 1, care should be taken to ensure that there is no gap between the inner wall of the manhole 2 and the cylindrical member 6 at the manhole opening. In this case, the inner diameter of the cylindrical member 6 is made approximately the same as the inner diameter of the existing pipe 1.

[0023] Figure 2 shows the state before the rehabilitation pipe formation process, where the regulating sleeve placement process is completed simultaneously by the lining material insertion process, in which the lining material 4 with the regulating sleeve 5 shown in Figure 3 is inserted into the four existing pipes 1 through three manholes 2. The lining material 4, inserted into a total of four existing pipes 1, protrudes into the manhole 2 at the right end of Figure 2 and also protrudes into the manhole 2 at the left end. In this embodiment, after this, the open ends at both ends of the lining material 4 are closed with end packers 10 in order to supply compressed air to the lining material 4 and expand its diameter. As is well known, the end packer 10 is provided with ventilation holes for supplying and exhausting compressed air, and holes for inserting a cable for pulling the light train 11 (described later) and for supplying power to the light train 11. Therefore, for example, compressed air is supplied from the ventilation hole of the end packer 10 at the left end of the lining material 4 by a compressed air supply device (not shown), and excess air is exhausted from the ventilation hole of the end packer 10 at the right end of the figure. As a result, as shown in Figure 4, the lining material 4 is expanded in diameter and pressed against the inner surface of the existing pipe 1. In this state, the lining material 4 is hardened to form the rehabilitated pipe 3 (rehabilitated pipe formation process). In this embodiment, since a thermosetting resin lining material is used for the lining material 4, when the light is turned on while the light train (light irradiation / heating device) 11 is passed inside the expanded lining material 4, the lining material 4 is heated and hardened by the temperature of the light. Similarly, in the case of a photocurable resin lining material 4, the light is turned on while the light train 11 is passed inside the expanded lining material 4, and the lining material 4 is irradiated with light and hardened.

[0024] Figure 5 is a detailed view of the portion of the hardened lining material 4 that passes through the manhole, formed in the rehabilitation pipe formation process shown in Figure 4. The figure shows that, except for the portion covered by the cylindrical member 6, the inner diameter of the regulating sleeve 5 and the outer diameter of the hardened lining material 4 are slightly larger radially than the inner diameter of the existing pipe 1. The regulating sleeve 5 in this embodiment is made of fabric. Note that the figure is a schematic representation, and the 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 extension direction. Also, the size of the weave of the warp and weft threads, that is, the size of the gap (spacing) between adjacent fibers, varies. Thus, if the fibers that make up the fabric are easily stretched, or if the spacing between adjacent fibers is large, the fabric has the characteristic of being easily stretched in the direction of surface expansion. Therefore, when the lining material 4 expands in diameter, the woven fabric restricting sleeve 5 can restrict the radial elongation of the lining material 4, but it may not be able to prevent radial elongation. However, since the portion of the lining material 4 that passes through the manhole after hardening is removed as described later, it is sufficient if the radial elongation of the lining material 4 can be restricted to some extent during expansion and hardening. Furthermore, by using fibers that do not stretch easily for weaving the fabric, or by reducing the spacing between adjacent fibers in the fabric to tighten the weave, the elongation in the direction of surface expansion of the fabric can be reduced, and by using such a fabric, the radial elongation of the lining material 4 during expansion or hardening can be further restricted. Alternatively, a restricting sleeve 5 made of other fibers can be used instead of fabric.

[0025] As described above, once the lining material 4 inserted into the existing pipe 1 has been expanded and hardened to form the rehabilitated pipe 3, as shown in Figure 6, the portion of the hardened lining material 4 that passes through the manhole, the regulating sleeve 5, and the cylindrical member 6 are removed, leaving only the rehabilitated pipe 3 inside the existing pipe 1 (manhole removal process). As a result, in this embodiment of the existing pipe repair method, rehabilitated pipes 3 can be installed simultaneously in four existing pipes 1 that span three manholes 2, thereby reducing the effort required for installing the rehabilitated pipes 3, i.e., for repairing the existing pipes, and shortening the construction period. As is well known, the process of expanding and hardening the lining material 4 does not require much effort. On the other hand, as mentioned above, the lining material 4 is quite heavy, and inserting this heavy lining material 4 into the inside of the existing pipe 1 is time-consuming. In the conventional repair method, the lining material 4 is inserted into each section of the existing pipe 1 between adjacent manholes 2, and then the lining material 4 is expanded and hardened. This method is very time-consuming because the lining material 4 must be inserted into each section of the existing pipe 1 across multiple sections. In contrast, the existing pipe repair method of this embodiment allows the rehabilitation pipe 3 to be installed almost simultaneously in multiple sections of the existing pipe 1 spanning multiple manholes 2. This significantly reduces the effort required for existing pipe repair, thereby shortening the repair period. As shown in the figure, the existing pipes 1 through which the lining material 4 is inserted are not only arranged in a straight line, but can also be used for pipes whose extension directions intersect, pipes that are misaligned (so-called off-center) such as those with a difference in height across a manhole 2, or pipes with different inner diameters.

[0026] Figure 7 is an explanatory diagram of a modified example of the existing pipe repair method in Figure 1, showing an example where, of two existing pipes 1 opening into a manhole 2, the existing pipe 1 on the left in the figure is taller and the existing pipe 1 on the right is shorter. In this example, it is assumed that the regulating sleeve 5 made of cloth does not stretch radially even when the diameter of the lining material 4 is expanded. In such a case, even if the regulating 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 the lining material 4 is 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 part of the lining material 4 stretches greatly, while the lower part stretches less. Conversely, at the manhole opening of the existing pipe 1 on the right in the figure, the upper part of the lining material 4 stretches less, while the lower part stretches greatly. These differences in elongation cause wrinkles during the expansion and hardening of the lining material 4, i.e., during the formation of the rehabilitated pipe 3. In this example, we show 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 cylindrical member 6, which abuts against the entire inner circumference of the existing pipe 1 and protrudes into the manhole 2 by a predetermined length, is inserted into the manhole opening of the existing pipe 1, and the regulating sleeve 5 and lining material 4 are arranged inside the cylindrical member 6, and the rehabilitation pipe formation process is carried out in this manner. In this way, by having a cylindrical member 6 that has rigidity that does not deform in the radial direction protrude from the entire inner circumference of the existing pipe 1 into the manhole 2 by a predetermined length, the elongation of the lining material 4 at the manhole opening of the existing pipe 1 during diameter expansion and hardening can be made substantially uniform in the circumferential direction, thereby preventing the formation of wrinkles in the rehabilitation pipe 3 at the manhole opening of the existing pipe 1. After the rehabilitation pipe is formed, the portion of the cylindrical member 6 that protrudes into the manhole 2 is removed at the same time as the portion of the hardened lining material 4 and regulating sleeve 5 that passes through the manhole. As mentioned above, if wrinkles form in the rehabilitated pipe 3 at the manhole opening of the existing pipe 1, a gap may form between the existing pipe 1 and the rehabilitated pipe 3. When such a gap forms between the existing pipe 1 and the rehabilitated pipe 3, groundwater and accompanying sediment flowing in from cracks or other damaged areas of the existing pipe 1 may flow into the pipeline through the gap between the existing pipe 1 and the rehabilitated pipe 3. If groundwater and sediment flow into the pipeline, a cavity may form underground, which could cause ground subsidence. In this example, by preventing the formation of wrinkles in the rehabilitated pipe 3 at the manhole opening of the existing pipe 1, the formation of a gap between the existing pipe 1 and the rehabilitated pipe 3 can also be prevented.

[0028] Next, Figures 8 and 9 are explanatory diagrams of other existing pipe repair methods; Figure 8 is an explanatory diagram of the state before the rehabilitation pipe formation process, and Figure 9 is an explanatory diagram of the rehabilitation pipe formation process. For example, the state after the manhole removal process in this existing pipe repair method is equivalent to Figure 6 of the first embodiment described above. The following describes only embodiments that differ from the first embodiment. In this existing pipe repair method, as an example, the above-mentioned photocurable resin lining material 4 was used.

[0029] In this existing pipe repair method, a synthetic resin regulating sleeve 5 is used. Compared to the fabric regulating sleeve 5 of the first embodiment, the synthetic resin regulating sleeve 5 does not have superior deformability. Therefore, for example, prior to inserting the lining material 4 into the multiple existing pipes 1, it is necessary to insert the regulating sleeve 5 into the two existing pipes 1 that open inside the manhole 2. In this existing pipe repair method, for example, two synthetic resin regulating sleeves 5 shorter than the radius of the manhole 2 are used for each manhole 2. These are inserted one by one into the manhole openings of the two existing pipes 1 that open inside the manhole 2 beforehand. Then, the lining material 4 is inserted into the existing pipe 1 by passing through the manhole 2, that is, by passing through the two regulating sleeves 5 for each manhole 2. As mentioned above, if the material constituting the restrictive sleeve 5 is sheet-shaped, the lining material 4 may be inserted into the existing pipe 1 through the manhole 2, and then the sheet-shaped restrictive sleeve material may be wrapped around the outer circumference of the lining material 4 inside the manhole 2, and the butt joint or overlapping joint may be joined or connected to form the restrictive sleeve 5. As mentioned above, the restrictive sleeve 5 made of synthetic resin may also be used by applying it to the manhole opening of the existing pipe 1.

[0030] Figure 9 is an explanatory diagram of the rehabilitation pipe formation process, and more specifically, it shows the state in which the light train 11 is passed through the inside of the enlarged lining material 4 to allow it to be light-cured. As mentioned above, the lining material 4 made of photocurable resin has the advantage of a short curing time by light irradiation. In this rehabilitation pipe formation process, since the restricting sleeve 5 is a restricting sleeve made of synthetic resin that is difficult to deform, radial elongation of the lining material 4 is prevented in the portion of the manhole passage of the lining material 4 that is covered by the restricting sleeve 5. Then, after the photocurable resin lining material 4 is light-cured to form the rehabilitation pipe 3, as mentioned above, the cured lining material 4 and restricting sleeve 5 inside the manhole 2 are removed, leaving the rehabilitation pipe 3 only inside the existing pipe 1. In the portion of the manhole passage of the lining material 4 that is not covered by the restricting sleeve 5, the lining material 4 has expanded radially and bulged, but this portion is removed together with the rest of the manhole interior, so it does not cause any problems for the rehabilitation pipe 3. Furthermore, even with a similar light train 11, the light train 11 in this rehabilitated tube formation process does not require heating the lining material 4, unlike the light train 11 in the first embodiment. Therefore, it is possible to use lights that do not heat up significantly, such as light-emitting diodes.

[0031] Next, a second 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. Figure 10 is a front view of the cylindrical member used in the existing pipe repair method of this embodiment, and Figure 11 is a detailed diagram of the rehabilitated pipe formation process in the existing pipe repair method of this embodiment. Figure 12 is an explanatory diagram of the existing pipe and manhole in which the existing pipe repair method of this embodiment is implemented, and Figure 13 is a detailed diagram of the rehabilitated pipe formation process when the cylindrical member of Figure 2 is used in the existing pipe and manhole shown in Figure 12. The existing pipe repair method of this embodiment is broadly a modified version of the first embodiment described above.

[0032] First, the structure of the manhole targeted by the existing pipe repair method of this embodiment will be explained using Figure 12. In this manhole 2, the bottom of the manhole 2 is raised with concrete or mortar to form a groove 8 with a roughly semicircular cross-section between the upstream existing pipe 1 and the downstream existing pipe 1 that open into the manhole 2. Such a manhole structure is also called an invert. In such a manhole structure, generally, the bottoms of the two existing pipes 1 that open into the manhole 2 and the bottom of the groove 8 are formed in a continuous manner.

[0033] As shown in Figure 10, the cylindrical member 6 used in the existing pipe repair method of this embodiment has a notch 7 formed by recessing a part of its end in the direction of cylindrical extension. When using this cylindrical member 6, the cylindrical member 6 is positioned so that the notch 7 is at the bottom of the groove 8, so that the main body (cylindrical part) of the cylindrical member 6 does not enter the inside of the existing pipe 1. In this way, the cylindrical member 6 is positioned so that the notch 7 is at the bottom of the existing pipe 1, and furthermore, the main body (cylindrical part) of the cylindrical member 6 does not enter the inside of the existing pipe 1 at the notch 7. In this embodiment, the cylindrical member 6 is positioned by placing the end of the cylindrical member 6 against the manhole opening of the existing pipe 1. When placing the end of the cylindrical member 6 against the manhole opening of the existing pipe 1, ensure that there is no gap between the inner wall of the manhole 2 and the cylindrical member 6 at the manhole opening. Figure 11 is a detailed view of the manhole opening in which the regulating sleeve 5 and lining material 4 are inserted inside the cylindrical member 6, and the lining material 4 is expanded and hardened. The figure particularly emphasizes the thickness of the cylindrical member 6 and the lining material 4. As shown in this figure, a raised portion 9 consisting of the cylindrical member 6, the regulating sleeve 5, and the hardened lining material 4 is formed near the bottom of the manhole opening of the existing pipe 1. However, since this raised portion 9 is formed outside the existing pipe 1, i.e., at the bottom of the groove 8 (= inside the manhole 2), when the hardened lining material 4 inside the manhole 2 is removed, the raised portion 9 can also be removed together.

[0034] Figure 13 is a detailed view of the manhole opening in which the cylindrical member 6 of the first embodiment described above, i.e., a cylindrical pipe member without a notch, is used in an invert structure manhole 2 and the lining material 4 has been expanded and hardened. The cylindrical member 6, which is made of a cylindrical pipe member without a notch, is inserted into the existing pipe 1 so that its end abuts against the entire inner circumference, and the lower end of the end abuts against the bottom of the existing pipe 1. In this state, when the regulating sleeve 5 and the lining material 4 are inserted inside and the lining material 4 is expanded and hardened, the rehabilitated pipe 4 made of the hardened material bulges out at the bottom of the existing pipe 1. The bulge 9 of the rehabilitated pipe 4 at the bottom of the existing pipe 1 becomes larger as the thickness of the cylindrical member 6 increases. For example, if the cylindrical member 6 is made of resin, the thickness of the cylindrical member 6 increases in order to restrict the expansion of the lining material 4 while avoiding deformation or damage to the cylindrical member 6. In such cases, the raised portion 9 of the rehabilitated pipe 4 at the bottom of the existing pipe 1 becomes particularly large. Inside the existing pipe 1, it is difficult to remove both the rehabilitated pipe 4, which is formed when the lining material 4 expands and hardens, and the cylindrical member 6 sandwiched between the constituent pipe 4 and the existing pipe 1. Therefore, even after removing the rehabilitated pipe 4, the regulating sleeve 5, and the cylindrical member 6 from inside the manhole 2, the raised portion 9 of the rehabilitated pipe 4 remains at the bottom of the existing pipe 1. When there is a raised portion 9 at the bottom of the existing pipe 1 in this way, garbage and sewage can accumulate there, potentially 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 the manhole 2 into two existing pipes 1 that open into a single manhole 2, and at least the manhole opening of the existing pipe 1 in the portion of the lining material 4 that passes through the manhole is covered from the radially outside with a regulating sleeve 5 made of a cylindrical body having an inner diameter approximately the same as the inner diameter of the existing pipe 1. Therefore, when the lining material 4 is then expanded and pressed against the inner surface of the existing pipe 1, the radial elongation, i.e., bulging, of the portion of the lining material 4 that passes through the manhole is restricted by the regulating sleeve 5. In this state, the lining material 4 is hardened to form a rehabilitated pipe 3, and after the formation of the rehabilitated pipe 3, the hardened lining material 4 and regulating sleeve 5 inside the manhole 2 are removed. Therefore, this existing pipe repair method allows for the simultaneous formation of rehabilitated pipes 3 on the inner surfaces of two existing pipes 1 spanning at least one manhole 2. By extending this, for example, by forming rehabilitated pipes 3 on multiple sections of existing pipes 1 passing through multiple manholes 2, multiple sections of existing pipes 1 spanning multiple manholes 2 can be repaired at once as if they were a single existing pipe. As a result, this existing pipe repair method reduces the effort required for repairing multiple sections of existing pipes 1 spanning multiple manholes 2, and simultaneously shortens the repair period.

[0036] Furthermore, by pre-attaching a deformable restricting sleeve 5 to the outer circumference 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 inserting the lining material 4 into the two existing pipes 1 that open into the manhole 2, thereby simplifying the process from the lining material insertion process to the sleeve placement process.

[0037] Furthermore, prior to the rehabilitation pipe formation process, a cylindrical member 6 is placed at the manhole opening of the existing pipe 1 on the radially outer side of the lining material 4 that is to be expanded. This cylindrical member 6 protrudes into the manhole 2 from the opening of the existing pipe 1 at a predetermined length, has an inner or outer diameter approximately equal to the inner diameter of the existing pipe, and has rigidity that is approximately non-deformable in the radial direction when the lining material 4 is expanded. This prevents wrinkles and variations in thickness of the rehabilitation pipe 3, particularly at the opening of the existing pipe 1 inside the manhole, when the rehabilitation pipe 3 is formed by the expansion and hardening of the lining material 4.

[0038] Furthermore, by positioning the cylindrical member 6 such that the notch 7 at the end of the cylindrical member 6 is located at the bottom of the existing pipe 1, it is possible to prevent the cylindrical member 6 from entering the bottom of the inside of the existing pipe 1. Therefore, after the lining material 4 has expanded and hardened, removing the hardened lining material 4 and cylindrical member 6 from inside the manhole 2 will prevent any bulges from forming at the bottom of the existing pipe 1, i.e., at the bottom of the rehabilitated pipe 4.

[0039] Although 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 modified version of the first embodiment described above, the cylindrical 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 there is misalignment or a difference in inner diameter between those existing pipes 1. However, even if there is no difference in height, misalignment, or inner diameter between the manhole openings of the two existing pipes 1, the cylindrical member 6 can be similarly inserted into the manhole opening of the existing pipe 1 to form a rehabilitated pipe 3 without any problem.

[0040] Furthermore, in the above embodiment, the restricting sleeve 5 is used by inserting it into the existing pipe 1. However, since the restricting sleeve 5 restricts the radial elongation of the lining material 4 at least at the manhole opening of the existing pipe 1, it is sufficient for it to be located inside the manhole 2 rather than the manhole opening of the existing pipe 1, and therefore it is not necessary to insert it into the existing pipe 1. It is also possible to pre-integrate the restricting sleeve 5 and the cylindrical member 6 with an adhesive or the like. In this case, the sleeve placement process and the cylindrical body placement process are performed almost simultaneously. [Explanation of Symbols]

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

Claims

1. In a method for repairing existing pipes, in which a cylindrical, hardenable lining material is inserted into an existing pipe installed between manholes arranged at predetermined intervals, and the lining material is expanded in diameter and hardened inside the existing pipe to form a rehabilitated pipe, the existing pipe is repaired. The insertion of the lining material into the existing pipe is performed for at least one of the existing pipes that pass through the manhole and open into the manhole. Before inserting the lining material into the existing pipe, a sleeve attachment step is performed, in which a regulating sleeve is fixed to the outer circumference of the portion of the lining material that passes through the manhole, the regulating sleeve having an inner diameter equivalent to the inner diameter of the existing pipe, being deformable and less prone to radial expansion than the lining material, and which restricts the expansion of the lining material when it expands in diameter. A rehabilitation pipe formation process involves introducing a lining material with the aforementioned restrictive sleeve fixedly attached into the existing pipe to perform the diameter expansion and hardening, A method for repairing an existing pipe, characterized by comprising a manhole removal step of removing the hardened lining material and regulating sleeve inside the manhole.

2. The method for repairing an existing pipe according to claim 1, characterized in that the regulating sleeve is attached to the lining material by bonding with an adhesive and / or by locking with a locking member.

3. Prior to the rehabilitation pipe formation process, there is a cylindrical body arrangement process in which a cylindrical member is arranged radially outside the lining material to be expanded, protruding into the manhole from the opening of the existing pipe in the manhole by a predetermined dimension, having an inner or outer diameter equivalent to the inner diameter of the existing pipe, and possessing rigidity that does not deform radially when the lining material is expanded. The cylindrical member has a notch that is recessed in the extension direction at least a portion of its end, In the cylindrical body placement step, the cylindrical member is positioned such that the notch is located at the lower part of the existing pipe. The existing repair method according to claim 1 or 2, characterized in that the removal step inside the manhole involves removing the cylindrical member inside the manhole.

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