Existing pipe rehabilitation method

Abstract

Provided is an existing pipe rehabilitation method for partially repairing and rehabilitating an existing pipe consisting of a circular and / or irregularly shaped manhole, which has excellent chemical resistance. [Solution] This is an existing pipe rehabilitation method for repairing and rehabilitating a part of an existing pipe consisting of a manhole and a sewer pipe having a circular shape and / or an irregular shape, and the method includes: a step of fixing a lattice-shaped reinforcement material made of inorganic fibers to the inner surface of the existing sewer; a step of fixing a sheet-like and / or panel-like structure made of synthetic resin to the back surface of the reinforcement using a fixing tool; a step of flowing an injection material into a space formed between the reinforcement and the structure and curing and solidifying the injection material; a step of welding the synthetic resin to a joint portion generated in the structure after the injection material has cured and hardened; This is an existing pipe rehabilitation method characterized by comprising the steps of:

Description

[Technical Field]

[0001] The present invention relates to a method for rehabilitating an existing pipe by repairing and rehabilitating a portion of an existing pipe consisting of a manhole, and in particular to a method for rehabilitating an existing pipe that has excellent chemical resistance. [Background technology]

[0002] Manholes are installed at the starting point of a sewer, at points where the direction, gradient, or diameter of the pipe changes, where there are steps, where sewer junctions, and at other locations where they are necessary for maintenance. Manholes are essential facilities for maintaining and managing the entire sewerage facility, including the sewer, storm water overflow chamber, outfall, manhole, lateral pipe, etc., and for inspecting, diagnosing, repairing, and rebuilding. For this reason, with the exception of small manholes that do not allow people to enter or exit, it is important to keep manholes accessible at all times, and it is particularly important to ensure safety for people climbing in and out.

[0003] Sewerage facilities, including manholes, need to maintain their service life as long as possible through proper maintenance. However, in recent years, attention has been focused on the deterioration and corrosion of sewerage concrete structures caused by sulfuric acid, which is the result of the generation of hydrogen sulfide gas. Like other civil engineering facilities, manholes are also susceptible to deterioration of concrete structures due to neutralization, alkali-aggregate reaction, etc. Corrosion by sulfuric acid (hereinafter referred to as concrete corrosion), which is classified as a type of biochemical corrosion specific to sewerage structures, has the widest range of effects and the fastest rate of deterioration, so immediate and appropriate measures are required. In addition, corrosion of concrete by sulfuric acid is likely to occur in manholes at the discharge outlet of pressure pipes, in downstream culverts, and in manholes with large steps or drops.

[0004] Various methods have been proposed for repairing existing pipes. Among these methods, the pipe weaving method is one of the most representative. In this method, a spacer is installed on the upper inner surface of the existing pipe, and then a long, strip-shaped pipe component is spirally wound inside the existing pipe. Adjacent wound side edges are joined to assemble the tubular body. It is known that by performing this assembly process using a pipe manufacturing machine, it is possible to reduce the amount of manpower required and increase the daily progress of the process.

[0005] In the above process, a nozzle and hose for injecting backfill material are passed between the existing pipe and a spacer installed on the inner surface of the pipe, and the backfill material is injected from the nozzle to fill the gap between the existing pipe and the tubular body. At this time, the spacer ensures space for the nozzle and hose to pass through and space to make it easier to spread the backfill material, and also prevents the tubular body from floating up due to the buoyancy of the backfill material. The backfill material then hardens, integrating the existing pipe with the tubular body and rehabilitating the existing pipe.

[0006] However, when the spacer is installed, the hollow interior of the existing pipe after rehabilitation becomes significantly biased, and the effective cross-section of the hollow interior becomes smaller. Therefore, in sewer rehabilitation methods, it is necessary to increase the effective cross-section of the existing pipe after rehabilitation.

[0007] Furthermore, in the case of manhole rehabilitation methods, it is sometimes necessary to increase the strength of the manhole after rehabilitation. Conventionally, this has been achieved by placing reinforcing bars between the existing pipe and the pipe components. However, because reinforcing bars are prone to rust, Patent Documents 1 and 2 each disclose a method of reinforcing the walls of existing pipes and concrete structures using reinforced fiber lattice bars made by laminating carbon fiber, glass fiber, or the like in a grid pattern as an alternative to reinforcing bars.

[0008] Furthermore, Patent Document 3 discloses a corrosion-resistant sheet made of synthetic resin, as well as a corrosion-resistant concrete structure and construction method, which are applied to the corrosion prevention of concrete structures such as sewer manholes and pipes, and discloses that the corrosion-resistant sheet is made by impregnating a fabric with a room-temperature curing adhesive and then adhering it to the concrete surface to provide corrosion protection.

[0009] However, each of the documents pointed out various issues, such as an increase in the number of work processes due to the need to transport large-scale equipment into culverts and manholes, earthquake resistance in the event of a natural disaster, and increased wear due to aging, and it was necessary to take measures.

[0010] Furthermore, manholes are made by burying and connecting components such as straight walls and inclined walls underground. There are cases where the entire manhole must be repaired and rehabilitated due to the natural disasters and deterioration over time mentioned above. On the other hand, depending on the installation location, there are cases where a portion of the manhole is severely damaged. In such cases, the entire manhole can be repaired and rehabilitated. However, depending on the cost of repair and rehabilitation and the extent of the damage, there are cases where only a portion of the manhole is desired. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Patent No. 5774467 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-189834 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-32309 Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention has been made to solve the above-mentioned problems of the prior art, and provides a method for rehabilitating an existing pipe culvert consisting of a manhole. [Means for solving the problem]

[0013] The invention according to claim 1 is An existing pipe rehabilitation method for repairing and rehabilitating a part of an existing pipe consisting of a manhole and a sewer pipe having a circular shape and / or an irregular shape, the method comprising: a step of fixing a lattice-shaped reinforcement material made of inorganic fibers to the inner surface of the existing sewer; a step of fixing a sheet-like and / or panel-like structure made of synthetic resin to the back surface of the reinforcement using a fixing tool; a step of flowing an injection material into a space formed between the reinforcement and the structure and curing and solidifying the injection material; a step of welding the synthetic resin to a joint portion generated in the structure after the injection material has cured and hardened; This is an existing pipe rehabilitation method characterized by comprising the steps of:

[0014] The invention according to claim 2 is the method for rehabilitating an existing pipe or conduit according to claim 1, characterized in that the inorganic fiber is made of carbon fiber.

[0015] The invention according to claim 3 is the method for rehabilitating an existing pipe or conduit according to claim 1 or 2, characterized in that the synthetic resin is made of a polyethylene-based resin.

[0016] The invention according to claim 4 is the existing pipe and conduit rehabilitation method according to claim 3, characterized in that staggered protrusions are provided at regular intervals on the back surface of the structure.

[0017] The invention according to claim 5 is the existing pipe and conduit rehabilitation method according to claim 3, characterized in that the synthetic resin is heat-sealed to the joint portion.

[0018] The invention according to claim 6 is the existing pipe rehabilitation method according to claim 1, characterized in that the injection material is made of mortar that does not produce excess water after mixing. [Effects of the Invention]

[0019] According to the existing pipe rehabilitation method of the invention of claim 1, which repairs and rehabilitates a portion of an existing pipe consisting of a manhole having a circular and / or irregular shape, the method has excellent chemical resistance and abrasion resistance, even in dangerous situations where sulfuric acid-based acidic wastewater such as sewage discharge generates sulfide gas, and therefore there is little deterioration even after the rehabilitation work. Furthermore, the number of on-site work steps can be significantly reduced, shortening the construction period and enabling rehabilitation work to be carried out easily and effectively. In particular, the above-mentioned effects can be obtained even when only a portion of a manhole is repaired or rehabilitated.

[0020] In the invention of claim 1, a step of fixing a lattice-shaped reinforcement material made of inorganic fibers to the inner surface of the existing sewer is carried out before the step of fixing the structure. Manholes are installed vertically, and gravity in the vertical direction is small, so the cross-sectional area of ​​manholes is generally small. For this reason, reinforcement work is not usually required. However, manholes installed in large cities have large cross-sectional areas and may require reinforcement. In this invention, a step of installing reinforcement material inside the manhole is carried out prior to the above step. This makes it possible to obtain a manhole with reinforced walls.

[0021] According to the method for rehabilitating existing pipes and culverts described in claim 1, characterized in that the inorganic fiber of the invention according to claim 2 is made of carbon fiber, the method does not rust due to acidic wastewater such as sewage, unlike steel frames, and has excellent chemical resistance, as well as high mechanical strength such as tensile strength.

[0022] According to the method for rehabilitating existing pipes as set forth in claim 1 or 2, characterized in that the synthetic resin of the invention set forth in claim 3 is made of polyethylene-based resin, the method has the effects of high airtightness and corrosion resistance, excellent wear resistance because it is difficult to break, and easy processability. Polyethylene-based resin has high extensibility, and has the effect of being able to follow the force and not break even when a large force is applied to the existing pipes, such as in an earthquake.

[0023] According to the existing pipe rehabilitation method described in claim 3, which is characterized in that staggered protrusions are provided at regular intervals on the back surface of the structure of the invention according to claim 4, after the injection material has cured and hardened, the protrusions arranged on the back surface of the structure are staggered, which provides an excellent anchoring effect, prevents air from entering the space formed between the reinforcement and the structure, and further prevents the structure from shifting or peeling after construction due to its own weight becoming heavier due to deterioration over time, thereby achieving the effect of maintaining stability.

[0024] In the invention of claim 5, the method for rehabilitating existing pipes described in claim 3, which is characterized in that the joints are heat-sealed with the synthetic resin, makes the gaps in the joints tightly adhered together by the synthetic resin, thereby making the rehabilitated surface seamless and eliminating gaps, and achieving the effect of forming an integrated synthetic resin lining (tubular body).

[0025] According to the existing pipe rehabilitation method described in claim 1, in which the injection material of the invention of claim 6 is made of mortar that does not produce excess water after mixing, the water used when mixing the mortar can suppress separation due to the settlement of sand, cement, aggregate, etc. after pouring, thereby ensuring high strength and making cracks less likely to occur. [Brief explanation of the drawings]

[0026] [Figure 1A] 1 is a schematic diagram showing a first step of an existing pipe rehabilitation method according to the present invention. [Figure 1B] FIG. 4 is a schematic diagram showing a second step of the existing pipe rehabilitation method according to the present invention. [Figure 1C] FIG. 4 is a schematic diagram showing a third step of the existing pipe rehabilitation method according to the present invention. [Figure 1D] FIG. 4 is a schematic diagram showing the fourth step of the existing pipe rehabilitation method according to the present invention. [Figure 2A] 1 is a schematic diagram of an existing pipe rehabilitation method according to the present invention during construction, showing a cross section of a circular pipe. FIG. [Figure 2B]1 is a schematic diagram of an existing pipe rehabilitation method according to the present invention during construction, showing a cross section of a rectangular pipe. FIG. [Figure 3] 1A is a schematic diagram showing a reinforcement of an existing pipe rehabilitation method according to the present invention, which is a schematic diagram showing a front view, and FIG. 1B is a schematic diagram showing a reinforcement of an existing pipe rehabilitation method according to the present invention, which is a schematic diagram showing the intersection of reinforcing bars of the reinforcement. [Figure 4] 1A and 1B are schematic diagrams showing a structure of an existing pipe rehabilitation method according to the present invention, in which (1) is a front view and (2) is a cross-sectional view. [Figure 5] 1 is a schematic diagram showing a welding process to a joint portion of an existing pipe rehabilitation method according to the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, preferred embodiments of the existing pipe rehabilitation method according to the present invention will be described in detail with reference to the accompanying drawings.

[0028] As described above in the Background Art, the method for rehabilitating an existing sewer according to the present invention is suitably employed when, for example, damage to the manhole wall or cracks, etc., occur in a portion of the manhole wall due to an acidic corrosive environment in a sewer system, drainage channel, or the like. A manhole is a facility established for the inspection, cleaning, ventilation, etc. of the inside of a sewer. In a sewerage facility, it serves both as a sewer and for the maintenance and management of the sewer. A manhole is generally small (inner diameter 220 mm) to large (inner diameter 600 mm). A manhole is composed of a manhole receiving frame, an adjustment ring, a sloped wall, a straight wall, a pipe mounting wall, and a deck slab. It may also be a sloped wall with an internal slope. These components are constructed by assembling multiple components. The cross-sectional shape of the manhole may be circular and / or irregular. Irregular shapes include, for example, a rectangle, a horseshoe, and a triangular portal. A combination of multiple shapes may also be used. In addition, inside the manhole, steps or a landing for people to climb up and down may be provided on the straight walls.

[0029] As described above in the Background Art, the method for rehabilitating an existing pipe according to the present invention is suitably employed, for example, when a crack occurs in a part of the wall surface due to damage or cracks in the manhole itself, or in an acidic corrosive environment such as in a sewer or drainage channel. The example in Figure 1 shows an example in which a part of a straight wall 11 and a pipe mounting wall 12 are rehabilitated.

[0030] In particular, the walls of manholes located above pipes such as sewers are exposed to the hydrogen sulfide atmosphere generated from sewage, etc., and when hydrogen sulfide adheres to the walls of the existing pipes, it reacts with water to form sulfuric acid, which corrodes part of the manhole wall.

[0031] The rehabilitation method of the present invention is applied to manholes that are placed in such an acidic, corrosive environment, particularly when corrosion and cracks such as those caused by sulfuric acid, as well as damage to the manhole itself, make it difficult to maintain its structure and functionality. In this embodiment, the acidic corrosive environment means an acidic atmosphere with a pH of 1 to 3.

[0032] In the above rehabilitation method, if necessary, a paint such as a primer with high adhesive properties can be applied to the wall surface (see Figure 1A). This step is not necessarily required. The application method is to apply it evenly to the wall surface using a brush or spray, but before starting the application work, it is advisable to check the condition of the wall surface inside the sewer in advance by using a television camera or visual inspection.

[0033] In the above situation, if part of the wall to be repaired or rehabilitated is damaged or has water seepage, it is advisable to take appropriate measures. In order to improve the adhesive effect after the coating operation, it is more desirable to roughen the wall surface by scraping or the like, or to perform a cleaning process such as high-pressure water washing.

[0034] Next, the reinforcement 2 shown in Figures 3(a) and 3(b) may be fixed to the wall surface using a fixture after the application process (not shown). This process is not essential. In the case of huge manholes such as those found in large cities, the strength of the manhole wall is required. In such cases, this process is carried out to increase the strength of the manhole wall. As shown in Fig. 3(a) and Fig. 3(b), the reinforcement 2 is made up of lattice bars formed by integrally laminating high-tensile carbon fibers.

[0035] The reinforcement 2 has a very low specific gravity and is thinner than steel bars because the intersections of the lattice are flush. In addition, the reinforcement 2 has high-strength, highly elastic continuous reinforcing fibers arranged in both the vertical and horizontal directions, so it has the same reinforcing effect as steel bars. Furthermore, the structure 2 does not rust and has excellent corrosion resistance, so deterioration due to corrosion can be avoided.

[0036] Here, the reinforcement 2 will be described in detail with reference to FIG. 3(b). The reinforcement 2 usually comprises a plurality of reinforcing bars, namely vertical reinforcing bars 21 and horizontal reinforcing bars 22, arranged in a grid pattern and intersecting at right angles. In this embodiment, each of the reinforcing bars 21, 22 is formed by laminating and curing a plurality of carbon fiber layers 20a in which carbon fibers are aligned in one direction.

[0037] The reinforcement 2 has a reinforcing bar width (w) of 1 to 50 mm, typically 2 to 20 mm, a thickness (t) of 1 to 100 mm, typically 2 to 20 mm, and an inter-lattice distance (W) of 1 to 50 cm. Specifically, it is preferable that the reinforcing bar width (w) x thickness (t) is 6.6 to 17.5 square mm, and the inter-lattice distance (W) is 5 to 10 cm. Furthermore, although the reinforcing bars 21, 22 are arranged perpendicular to each other, they can also be configured to intersect at a predetermined angle other than 90° to form a lattice pattern, if desired.

[0038] Examples of reinforcing fibers that can be used include inorganic fibers such as carbon fibers, glass fibers, and ceramic fibers; organic fibers such as wholly aromatic polyamide fibers, wholly aromatic polyester fibers, and aramid fibers; and metal fibers such as titanium and steel. However, inorganic fibers are preferred because of their excellent chemical resistance and mechanical strength such as tensile strength, and carbon fibers are most preferred.

[0039] The reinforcement 2 is fixed to the inner surface of the manhole using a physical fixing method. In particular, it is preferable to fix it using a fixing device that is spaced a specified distance from the repaired or rehabilitated surface of the manhole. It is preferable for the reinforcement 2 to be embedded and fixed in the injection material, as this improves the reinforcing effect. Two or more reinforcement 2 may be fixed in layers. In particular, in areas with severe damage, it is preferable to fix multiple layers in layers. When installing the reinforcement 2, it is important to ensure that there are no areas where the reinforcement 2 is not present. It is important to install and fix two reinforcement 2 so that the lattice structures overlap at the edges of the reinforcement 2, for example.

[0040] In this way, the reinforcement 2 when carbon fiber is used as the reinforcing fiber has a strength of 1400N / mm 2 Tensile strength of 100,000N / mm 2 For example, the reinforcement 2 can be shrunk into a roll and easily carried into an existing sewer. It is preferable that the surface of the carbon fiber serving as the reinforcing material 2 is surface-treated, since this can prevent scratches.

[0041] Furthermore, a fixing tool (concrete anchor) (not shown) is used to fix the reinforcement 2. The fixing tool is preferably made of plastic. By using a plastic fixing tool, the risk of corrosion by acid is reduced.

[0042] Furthermore, the method of fixing the reinforcement 2 with the fixing device is not limited, but the fixing device is driven into the corner of the square of the reinforcement 2, i.e., into the inner surface of the culvert at the intersection of the lattice bars 21 and 22 (see Figure 3(b)), and if necessary, a fixing device holding plate (not shown) or the like is used to press and fix the reinforcement 2 toward the inner surface of the culvert. The fixing devices are driven into the reinforcement 2 every two or three squares, but the driving positions are not limited to this.

[0043] Next, a structure 3 (see Figure 4), which is a lining made of synthetic resin in the form of a sheet or panel, is inserted or placed on top of the fixed reinforcement 2 or on the surface of the manhole to be repaired, and fixed using a fixing device (see Figure 1B). On the back surface of the structure 3, protrusions are provided at predetermined intervals to enhance integration with the grouting material that has been hardened and cured, as will be described later.

[0044] The structure 3 has a sheet and / or panel shape. A sheet-shaped structure is effective when repairing and rehabilitating an existing curved pipe because it conforms to the curved surface. A panel-shaped structure is effective when repairing and rehabilitating an existing flat pipe, such as a rectangular or triangular gate-shaped structure, because it can be assembled facing the flat surface. The structure 3 is fixed in a position away from the repair and rehabilitated surface of the existing pipe and the reinforcement 2, so that the desired thickness can be obtained.

[0045] The structure 3 is provided with protrusions having a substantially V-shaped cross section (see Figure 4(2)). As a result, these protrusions have an anchoring effect that improves the entanglement with the grout, enabling the structure 3 and the grout to be more integrated. The substantially V-shaped protrusions are also arranged in a substantially staggered pattern on the sheet-like or panel-like structure (see Figure 4(1)). This prevents air from being trapped near the structure 3 when the grout is injected, ensuring a firm bond between the structure and the grout, and enabling robust sewer rehabilitation.

[0046] The projections are preferably provided at intervals of 40 to 100 mm, and particularly preferably at intervals of 44 mm.

[0047] Here, synthetic resins such as polyester, polyamide (nylon), polyethylene, and polypropylene can be used for the structure. From the viewpoint of chemical resistance and abrasion resistance, it is preferable to use polyethylene-based resin. Polyethylene-based resin has abrasion resistance approximately 30 times that of polyvinyl chloride. Polyethylene-based resin also has excellent extensibility of approximately 600%. As a result, even if strain occurs inside the existing pipe due to an earthquake or other cause, it can expand and follow the bending displacement.

[0048] Furthermore, since manholes become narrower and restrict the movement of people and materials, it is preferable to use thin but strong materials for the structure. The thickness of this structure is preferably in the range of 2 to 10 mm, and particularly 3 to 5 mm. If the thickness is less than 2 mm, the structure will be weak and will have difficulty standing on its own. Conversely, if the thickness exceeds 10 mm, the structure will be too strong, making construction in places with small diameters difficult and increasing the structure's own weight, which may cause it to shift or peel off after construction.

[0049] Furthermore, when fixing the structure, the structure is placed in the formwork in advance and then fixed with fixing devices.

[0050] After fixing the structure 3 to the inside of the reinforcement 2 inside the manhole, injection material is poured into the gap S between the reinforcement 2 and the structure 3 via a hose 8, filling it and allowing it to harden and cure (see Figure 1(C)). As the injection material, mortar is preferred, and inorganic cement mortar, polymer cement mortar, asphalt mortar, resin mortar, etc. can also be used, but it is particularly preferable to use mortar that does not shrink and has no bleeding properties, which means that no excess moisture is generated after mixing with the mortar.

[0051] Finally, the gaps at the ends of the structure, that is, the joints 10, are heat-sealed using a sealing material made of the same material as the structure, such as a fast-curing polyethylene resin (see Figures 1D and 5). In addition, if necessary, scaffolding hardware etc. will be restored inside the manhole.

[0052] As described above, according to the construction method of the present invention, the rehabilitation work of a concrete manhole in a sewer system can be completed in a short construction period. In particular, the use of a 3-5mm thick polyethylene structure allows for self-supporting and short construction times even when repairing or rehabilitating pipe walls. Furthermore, appropriate rehabilitation and repair can be carried out according to the degree of deterioration of the concrete on the pipe walls. [Example]

[0053] The effects of the present invention will be more clearly demonstrated by showing examples of the existing pipe rehabilitation method according to the present invention below, but the present invention is not limited to these examples.

[0054] An embodiment of the method for rehabilitating an existing pipe according to the present invention will be described below. This example involves the rehabilitation of a portion of the existing No. 1 manhole. The straight wall and pipe attachment section of this manhole were partially damaged. Steps were installed on the straight wall to allow workers and materials to ascend and descend. In parts of the wall surface of the straight wall 11 and the pipe attachment section 12, cracks had appeared in the concrete of the straight wall due to sulfuric acid, and water was seeping in through the cracks.

[0055] The reinforcement, structure and injection material used in this embodiment will now be described. Reinforcement 1 is a lattice reinforcement made of carbon fiber. Taking into consideration the ease of work on site, reinforcement 1 was used with a reinforcement width (w) x thickness (t) of 6.6 square mm and a lattice spacing (W) of 5 cm. Regarding the carbon fiber used in the reinforcement according to the present invention, a strength test was carried out to determine the tensile strength and tensile modulus of elasticity using a test method conforming to the Japan Society of Civil Engineers standard JSCE-E531-1999 "Tensile test method for continuous fiber reinforcement materials." The tensile strength was 1400 (N / mm 2 ) or more, tensile modulus is 100,000 (N / mm 2 ) The above results were obtained, confirming that the material has high strength.

[0056] The structure in this example was a polyethylene panel, and multiple panels were fixed to the wall surface according to the construction conditions to carry out rehabilitation. The structure according to this example was tested for strength (tensile strength, tear strength, elongation at break), specific gravity, brittle temperature, etc. using test methods conforming to Japanese Industrial Standards JISK6760 and 6301, respectively, and it was confirmed that the measured values ​​fell within the standard ranges.

[0057] Furthermore, the chemical resistance and abrasion resistance of this structure were tested using test methods in accordance with the Japan Sewage Works Agency's "Guidelines and Manual for Corrosion Suppression and Prevention Techniques for Sewerage Concrete Structures" and the Japanese Industrial Standard JISK7204, and it was confirmed that the structure possessed the above-mentioned properties.

[0058] Furthermore, the injection material M used in this example is a mortar with the above-mentioned characteristics of being free from shrinkage and bleeding, and an experiment was conducted to measure the compressive strength after curing for a specified number of days. The results are shown in Table 1.

[0059] [Table 1]

[0060] First, the structure of the pipe wall to be rehabilitated was examined, and the bending, shear, and punching shear strength of the existing wall were calculated. The purpose of calculating the strength of the wall to be rehabilitated was to confirm its strength in its existing state, and detailed calculations will be omitted, but the results showed that it had bending, shear, and punching shear strength.

[0061] Next, the current state of the existing wall and rehabilitation were examined. In this example, the strength check showed that all of the walls had the required strength, but the current condition of the walls was such that cracks had appeared in the concrete and water was seeping in through the cracks. As a result of examining the factors behind the difference between the structural calculation results obtained above and the current situation, it was determined that the current deterioration of the walls was due to these factors, and a construction plan was created based on the calculation results and the condition of the walls.

[0062] Next, the construction process will be described. First, as a preliminary step, power line protection and drainage treatment were carried out. The wall 4 to be reinforced has a power line pipe entrance and the power line is pulled in, so the power line needs to be protected. In addition, water had seeped in through cracks in the wall 4 and was pooling in the box culvert, so the pooled water was removed in advance.

[0063] The leaking parts of the wall to be rehabilitated were sealed and water-conducting treatment was carried out. Since reinforcement could not be installed in a state where water had seeped into the wall, water-stopping materials such as urethane-based water-stopping materials were injected into the leaking parts. In areas where the injection of this water-stopping material was not sufficient to stop the water from leaking, measures such as installing water pipes were taken to stop the water from leaking from the wall surface being constructed.

[0064] Furthermore, we chipped off parts of the wall that needed to be rehabilitated and repaired the cross sections. When the wall is severely deteriorated, it may be difficult to integrate the reinforcement in its current state, making installation difficult. In such cases, we chipped off the wall and repaired the cross sections. In this example, the deterioration was so severe that the wall surface was chipped off by 5 cm, and the cracks and cross-sectional defects were filled with polymer cement mortar for repair.

[0065] After the wall surface was repaired, the reinforcement 2 was set in a predetermined position based on the construction plan and fixed using a fixing device. In this case, it became necessary to connect the reinforcements together and extend them, and because the reinforcements were in a grid pattern, they were installed and fixed in layers of two squares each. In areas where the wall surface was severely deteriorated, two pieces of reinforcement were fixed in layers, and in the surrounding areas, one piece of reinforcement was fixed.

[0066] Furthermore, after the reinforcement 2 was set and fixed in place, a formwork was installed in the direction of fluid flow in the pipe, and a panel-like structure 3 was attached to the dedicated formwork. Next, an injection material (PL mortar, manufactured by Chichibu Concrete Industry Co., Ltd.) was poured between the repaired and rehabilitated surfaces of the pipe and the structure 3, and cured and hardened. The reinforcement 2 was embedded in the mortar.

[0067] After the injection material had cured and hardened, the formwork attached to the structure was removed, and if necessary, the joints of the reinforcement 2 were sealed by heat fusion using polyethylene resin wire.

[0068] By carrying out this type of construction, the pipe wall P, the reinforcement 2 and the structure 3 are integrated, which also makes it possible to reinforce cracks in the wall and suppress wall displacement due to water pressure. Furthermore, compared to conventional rehabilitation methods, this method eliminates the need for reinforcement work, concrete pouring, etc., thereby improving construction efficiency.

[0069] In this example, this rehabilitation method was applied to rehabilitate part of a manhole, but the rehabilitation method of the present invention can be applied to various locations, and further, when applying the reinforcements, structures, and injection materials used in the method of the present invention, the shape of the wall surface to be rehabilitated is not limited to flat surfaces, and can also be curved surfaces.

[0070] The present invention can be modified in various ways other than the above-described embodiments without departing from the spirit of the present invention. In the above embodiment, a reinforcement made of carbon fiber is exemplified, but the present invention is not limited to this, and reinforcement made of reinforcing fibers mixed with fibers that have excellent chemical resistance and mechanical strength can also be applied.

[0071] Furthermore, in the above embodiment, an example is shown in which the reinforcement 2 is fixed to the wall surface of the existing pipe P using the fixing device 5, but the present invention is not limited to this, and the reinforcement 2 may be fixed to the wall surface of the existing pipe P using a simple fixing member such as a small peg or nail, and any fixing member that reduces the stress generated in the existing pipe P when attached to the wall surface of the existing pipe P is applicable.

[0072] Furthermore, in the above embodiment, an example was given in which the injection material M was flowed and filled into the gap S between the pipe wall of the sewer and the structure 3, but the present invention is not limited to this. For example, holes may be drilled from the inside of the tubular body formed by the structure using a drill or the like, and the injection material M may be filled through the holes using a nozzle or hose for injecting backfill material. The location and number of holes to be drilled can be set appropriately taking into account the size of the tubular body and the gap S, etc.

[0073] In addition, when supplying the injection material, a process of mixing short fibers into the injection material M may be incorporated. The short fibers mixed into the injection material M will become entangled with the staggered protrusions of the structure, and after the injection material M has cured and hardened, the bonding strength between the injection material M and the reinforcement 2 and the structure 3 will increase, making it possible to further increase the strength of the existing pipe P after rehabilitation.

[0074] In the above-described embodiment, examples have been given in which the method of the present invention is applied to partially rehabilitating existing circular and rectangular pipes P, but the method of the present invention can also be applied to rehabilitating existing pipes with irregular shapes such as horseshoe shapes and triangles. [Industrial Applicability]

[0075] The present invention is suitable for use with the rehabilitation method, reinforcements, structures and injection materials used in the present invention not only in culverts, but also in narrow areas of manholes themselves, waterways, and in environments where corrosive gases such as hydrogen sulfide are generated. [Explanation of symbols]

[0076] 1: Rehabilitated sewer 2: Reinforcement 3: Structure 5: Fixtures 8: Hose 10: Joint section 11: Straight wall 12: Pipe mounting wall 20a: Carbon fiber layer 21, 22: lattice bars P: Existing pipes S: Gap M: Injection material

Claims

1. An existing pipe rehabilitation method for repairing and rehabilitating a part of an existing pipe consisting of a manhole and a sewer pipe having a circular shape and / or an irregular shape, the method comprising: a step of fixing a lattice-shaped reinforcement material made of carbon fiber to an inner surface of the existing pipe; a step of fixing a sheet-like and / or panel-like structure made of synthetic resin to the back surface of the reinforcement with a fixing device without using heat treatment; The structure has a surface facing the culvert to be repaired that is provided with a plurality of protrusions having a substantially V-shaped cross section, and a back surface of the structure that is provided with staggered protrusions at regular intervals, a step of flowing an injection material into a space formed between the reinforcement and the structure and curing and solidifying the injection material; The injection material is made of mortar that does not generate excess water after mixing, a step of welding the synthetic resin to a joint portion generated in the structure after the injection material has cured and hardened; An existing pipe rehabilitation method comprising the steps of:

2. 2. The existing pipe rehabilitation method according to claim 1, wherein the synthetic resin is a polyethylene resin.

3. 2. The existing pipe rehabilitation method according to claim 1, wherein the synthetic resin is heat-sealed to the joint portion.

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