Rehabilitation method for existing sewer pipes

Abstract

The present invention provides an existing pipe rehabilitation method for repairing and rehabilitating existing pipes consisting of manholes having irregular shapes, including circular and / or rectangular, horseshoe, and triangular shapes, and which also exhibits excellent chemical resistance and abrasion resistance. [Solution] A method for repairing and rehabilitating existing pipes, which have a circular and / or irregular shape, wherein the method is: A step of fixing a sheet-like and / or panel-like structure made of synthetic resin to the surface of the manhole with fasteners, A step of allowing an injection material to flow into the space formed between the reinforcing material and the structure and curing and solidifying it, After the injection material has cured and solidified, the process involves welding the synthetic resin to the joints formed in the structure. A method for rehabilitating existing pipes, characterized by comprising the above.

Description

Technical Field

[0001] The present invention relates to an existing pipe rehabilitation method for repairing and rehabilitating existing pipe conduits including manholes, and particularly relates to an existing pipe rehabilitation method excellent in chemical resistance.

Background Art

[0002] Manholes are provided at locations where the starting point, direction, gradient, pipe diameter and the like of a pipe conduit change, locations where steps occur, locations where pipe conduits meet, and locations necessary for maintenance and management. Manholes are fundamental facilities for maintaining and managing the entire pipeline facility including pipe conduits, rainwater discharge chambers, outlets, catch basins, connecting pipes and the like, and performing inspection, diagnosis and investigation, repair and reconstruction. Therefore, except for small manholes that cannot be accessed by people, it is important to keep manholes accessible for people at all times, and in particular, it is necessary to ensure safety for ascending and descending.

[0003] Sewerage facilities including manholes need to be maintained with as long a service life as possible through proper maintenance. However, in recent years, the deterioration and corrosion of sewer concrete structures caused by sulfuric acid resulting from the generation of hydrogen sulfide gas has attracted growing attention. Similar to other civil engineering facilities, concrete structures of manholes may also deteriorate due to neutralization, alkali-aggregate reaction and the like. In particular, sulfuric acid corrosion (hereinafter referred to as concrete corrosion), which is classified as biochemical erosion specific to sewer structures, has the widest scope of impact and a high deterioration rate, so urgent and appropriate countermeasures are required. Furthermore, concrete corrosion caused by sulfuric acid is prone to occur at manholes at pressure feed pipe outlets, downstream pipe conduits thereof, and manhole sections with large steps or drops.

[0004] Various construction methods have been conventionally proposed as methods for repairing existing pipe conduits. Among these methods, the pipe forming method is one of the representative methods. In this pipe forming method, after a spacer is installed on the upper inner surface of the existing pipe, a long strip-shaped pipe constituent member is spirally wound in the existing pipe, and adjacent wound side edges are joined to assemble a tubular body. It is known that performing this assembly process using pipe-making equipment can reduce the amount of manual labor required and increase the daily progress made in the process.

[0005] The above process involves passing a nozzle and hose for injecting backfill material between the existing pipe and a spacer installed on the upper inner surface of the pipe, and injecting backfill material through the nozzle to fill the space between the existing pipe and the tubular body. At this time, the spacer ensures space for inserting the nozzle and hose, space to facilitate the distribution of backfill material, and prevents the tubular body from floating up due to the buoyancy of the backfill material. Subsequently, as the backfill material hardens, the existing pipe and the tubular body become integrated, and the existing pipe is rehabilitated.

[0006] However, installing the above-mentioned spacers causes the internal cavity of the rehabilitated existing pipe to become significantly uneven, reducing the effective cross-section of the internal cavity. Therefore, in pipe rehabilitation methods, it is necessary to increase the effective cross-section of the rehabilitated existing pipe.

[0007] Furthermore, in manhole rehabilitation methods, it is sometimes necessary to increase the strength of the manhole after rehabilitation. Traditionally, this has been achieved by placing and reinforcing steel between the existing pipe and the pipe components. However, because reinforcing steel is prone to rusting, Patent Documents 1 and 2 disclose methods for reinforcing existing pipes and concrete structure walls using reinforced fiber lattice reinforcement, which is made by laminating carbon fibers or glass fibers in a lattice pattern, as an alternative to reinforcing steel.

[0008] Furthermore, Patent Document 3 discloses a corrosion-resistant sheet made of synthetic resin, a corrosion-resistant concrete structure, and a construction method applicable to corrosion protection of concrete structures such as manholes and pipelines in sewers. It discloses that the corrosion-resistant sheet is applied to the concrete surface by impregnating a fabric with a room-temperature curing adhesive and then adhering it to it.

[0009] However, each document highlighted various challenges, such as the increased number of work steps due to the large-scale installation of equipment into pipes and manholes, seismic resistance during natural disasters, and increased wear and tear due to aging, necessitating countermeasures. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 5774467 [Patent Document 2] Japanese Patent Publication No. 2010-189834 [Patent Document 3] Japanese Patent Publication No. 2001-32309 [Overview of the project] [Problems that the invention aims to solve]

[0011] This invention was made to solve the problems of the prior art described above, and provides a rehabilitation method for existing pipes consisting of manholes. [Means for solving the problem]

[0012] The invention according to claim 1 is, A method for repairing and rehabilitating existing pipes, which have a circular and / or irregular shape, wherein the method is: A step of fixing a sheet-like and / or panel-like structure made of synthetic resin to the surface of the manhole with fasteners, A step of allowing an injection material to flow into the space formed between the reinforcing material and the structure and curing and solidifying it, After the injection material has cured and solidified, the process involves welding the synthetic resin to the joints formed in the structure. This is a method for rehabilitating existing pipes, characterized by consisting of the following.

[0013] The invention according to claim 2 is, Before the process of fixing the aforementioned structure, The existing pipe and culvert rehabilitation method according to claim 1, comprising a step of fixing a grid-shaped reinforcement made of inorganic fibers to an inner surface of the existing pipe and culvert.

[0014] The invention according to claim 3 relates to the existing pipe and culvert rehabilitation method according to claim 2, wherein the inorganic fibers are carbon fibers.

[0015] The existing pipe and culvert rehabilitation method according to claim 1, wherein the invention according to claim 4 is characterized in that the synthetic resin is a polyethylene-based resin.

[0016] The invention according to claim 5 relates to the existing pipe and culvert rehabilitation method according to claim 4, wherein staggered protrusions are provided at regular intervals on a back surface of the structure.

[0017] The invention according to claim 6 relates to the existing pipe and culvert rehabilitation method according to claim 4, wherein the synthetic resin is thermally fused to the joint portion.

[0018] The invention according to claim 7 relates to the existing pipe and culvert rehabilitation method according to claim 1, wherein the injection material is made of mortar that does not generate an excess amount of water after mixing.

Effects of the Invention

[0019] According to the existing pipe and culvert rehabilitation method for repairing and rehabilitating an existing pipe and culvert formed of a manhole having a circular shape and / or an irregular shape in the invention according to claim 1, the method is excellent in chemical resistance and wear resistance even under a dangerous situation where sulfide gas is generated in sulfuric acid-based acidic drainage such as sewage, so that deterioration is less after rehabilitation construction. Furthermore, since the number of work steps on site can be greatly reduced, the construction period can be shortened, and the effect that rehabilitation construction can be performed easily and effectively is achieved.

[0020] In the invention according to claim 2, before the step of fixing the structure, a lattice-shaped reinforcing material made of inorganic fibers is fixed to the inner surface of the existing conduit. Manholes are installed in the vertical direction, and the gravitational force acting 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 may have a large cross-sectional area and may require reinforcement. In the present invention, a step is provided in which reinforcing material is installed inside the manhole prior to the above step. This makes it possible to obtain a manhole with a reinforced wall surface.

[0021] The existing pipe rehabilitation method according to claim 1, characterized in that the inorganic fiber of the invention according to claim 3 is made of carbon fiber, provides excellent chemical resistance and high mechanical strength such as tensile strength, as it does not rust like steel frame due to acidic wastewater such as sewage.

[0022] The existing pipe rehabilitation method according to claim 1 or 2, characterized in that the synthetic resin of the invention according to claim 4 is made of polyethylene resin, provides the effects of high airtightness and corrosion resistance, excellent abrasion resistance because it is less prone to breakage, and easy processability. Polyethylene 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 pipe, such as in an earthquake.

[0023] According to the existing pipe rehabilitation method described in claim 4, characterized in that staggered projections are provided at regular intervals on the back surface of the structure according to claim 5, after the injection material has cured and solidified, the staggered shape of the projections on the back surface of the structure provides excellent anchoring effect, preventing air from entering the space formed between the reinforcing material and the structure, and further preventing shifting or peeling after construction due to the structure becoming heavier due to its own weight as it deteriorates over time, thus providing the effect of stable maintenance.

[0024] The invention according to claim 6 is characterized by heat-fusing the joint portion with the synthetic resin. According to the existing pipe rehabilitation method described in claim 4, the joint portions, which are gaps, are firmly adhered to each other by the synthetic resin, so that the rehabilitation surface becomes seamless without gaps and can be formed into an integrated synthetic resin lining (tubular body).

[0025] The invention of claim 7 is characterized in that the injection material is made of mortar that does not produce excess water after mixing. According to the existing pipe rehabilitation method described in claim 1, the water used when mixing the mortar can suppress the separation of sand, cement, aggregate, etc., after placement, thereby ensuring high strength and reducing the likelihood of cracking. [Brief explanation of the drawing]

[0026] [Figure 1A] This is a schematic diagram showing the first step of the existing pipe rehabilitation method according to the present invention. [Figure 1B] This is a schematic diagram showing the second step of the existing pipe rehabilitation method according to the present invention. [Figure 1C] This is a schematic diagram showing the third step of the existing pipe rehabilitation method according to the present invention. [Figure 1D] This is a schematic diagram showing the fourth step of the existing pipe rehabilitation method according to the present invention. [Figure 2A] This is a schematic diagram of the construction of the existing pipe rehabilitation method according to the present invention, and is a cross-sectional view of a circular pipe. [Figure 2B] This is a schematic diagram of the construction of the existing pipe rehabilitation method according to the present invention, and is a cross-sectional view of a rectangular pipe. [Figure 3] (a) A schematic diagram showing a reinforcing structure for the existing pipe rehabilitation method according to the present invention, a schematic diagram showing a front view. (b) A schematic diagram showing a reinforcing structure for the existing pipe rehabilitation method according to the present invention, a schematic diagram showing the intersection of the reinforcing bars of the reinforcing structure. [Figure 4] This is a schematic diagram showing the structure of the existing pipe rehabilitation method according to the present invention, where (1) is a front view and (2) is a cross-sectional view. [Figure 5]This is a schematic diagram showing the welding process to the joints of the existing pipe rehabilitation method according to the present invention. [Modes for carrying out the invention]

[0027] The following describes in detail, with reference to the drawings, a preferred embodiment of the existing pipe rehabilitation method according to the present invention.

[0028] As described above in the background art, the method for rehabilitating existing pipelines according to the present invention is suitably used, for example, in cases where cracks such as damage or cracks occur on the wall surface of manholes in acidic corrosive environments such as sewers and drainage channels. A manhole is a facility provided for inspection, cleaning, and ventilation of the inside of a pipeline. In sewer facilities, it serves both as a pipeline and as a facility for the maintenance and management of the pipeline. Manholes are generally small (inner diameter 220 mm) to large (inner diameter 600 mm). A manhole consists of a manhole frame, adjustment ring, slanted wall, straight wall, pipe mounting wall, and floor slab. The slanted wall may also have 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, rectangles, horseshoes, and triangular portal shapes. These shapes may be combinations of multiple shapes. Furthermore, steps or landings for people to ascend and descend may be provided on the vertical walls inside the manhole.

[0029] In particular, the walls of manholes located above culverts such as sewers are exposed to a hydrogen sulfide atmosphere generated from sewage, and when hydrogen sulfide adheres to the walls of these existing culverts, it reacts with water to form sulfuric acid, which corrodes the walls of the manholes.

[0030] The rehabilitation method of the present invention is applicable to manholes exposed to such acidic corrosive environments, particularly when corrosion, cracks, and damage to the manhole itself occur due to sulfuric acid, making it difficult to maintain its structural and functional integrity. In particular, it is a method for rehabilitating the entire manhole, including sloping walls, vertical walls, and pipe attachment walls. In this embodiment, the term "acidic corrosion environment" refers to an acidic atmosphere with a pH of 1 to 3.

[0031] In the rehabilitation method described above, if necessary, a primer or other coating with high adhesive properties may be applied to the wall surface of the existing pipe before fixing the grid-like reinforcing material described later (see Figure 1A). This step is not always necessary. The application method involves evenly coating the wall surface using a brush or sprayer, but it is advisable to first ascertain the condition of the wall surface inside the pipe using a television camera or visual inspection before starting the application work.

[0032] In the situations described above, if damage to the wall surface or water infiltration occurs, it is desirable to take appropriate action. Furthermore, to enhance the adhesive effect after coating, it is preferable to perform surface preparation such as scraping or cleaning, or to perform high-pressure water washing on the wall surface.

[0033] Next, the reinforcing material 2 shown in Figures 3(a) and 3(b) may be attached and fixed to the wall surface after the coating process (not shown). This step is not mandatory. In the case of large manholes installed in large cities, etc., the strength of the manhole wall surface is required. In such cases, this step is performed to increase the strength of the manhole wall surface. Reinforcement 2 is composed of a grid of high-tensile carbon fibers integrally laminated together, as shown in Figures 3(a) and 3(b).

[0034] Reinforcement 2 has a very low specific gravity, and because the intersections of the grid are flush, it is thinner than reinforcing bars. Furthermore, because reinforcement 2 has high-strength and high-elasticity continuous reinforcing fibers arranged in both vertical and horizontal directions, it has the same reinforcing effect as reinforcing bars. Furthermore, since structure 2 does not rust and has excellent corrosion resistance, deterioration due to corrosion can be avoided.

[0035] Here, we will explain reinforcement 2 in detail with reference to Figure 3(b). The reinforcing element 2 typically comprises multiple reinforcing bars arranged in a grid pattern at right angles to each other, namely, longitudinal reinforcing bars 21 and transverse reinforcing bars 22. In this embodiment, each reinforcing bar 21, 22 is formed by laminating multiple carbon fiber layers 20a, in which carbon fibers are arranged in one direction, and then curing them.

[0036] Reinforcement 2 has a reinforcement width (w) of 1 to 50 mm, usually 2 to 20 mm, a thickness (t) of 1 to 100 mm, usually 2 to 20 mm, and a grid spacing (W) of 1 to 50 cm. Specifically, it is preferable that the reinforcement width (w) × thickness (t) is 6.6 square mm to 17.5 square mm, and the grid spacing (W) is 5 to 10 cm. Furthermore, although each reinforcing bar 21 and 22 is arranged perpendicular to each other, it is also possible to configure them to intersect at predetermined angles other than 90°, as desired, to form a grid.

[0037] Examples of reinforcing fibers used include inorganic fibers such as carbon fibers, glass fibers, and ceramic fibers; organic fibers such as fully aromatic polyamide fibers, fully aromatic polyester fibers, and aramid fibers; and metallic fibers such as titanium and steel. However, inorganic fibers are preferred due to their superior chemical resistance and mechanical strength, such as tensile strength, and carbon fibers are the most preferred.

[0038] 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 fasteners that are spaced a predetermined distance from the repaired or rehabilitated surface of the manhole. It is preferable that reinforcement 2 be embedded and fixed in the injection material, as this improves the reinforcement effect. Two or more reinforcement 2 may be stacked and fixed. It is important that when installing reinforcement 2, there are no areas where reinforcement 2 is absent. It is important to avoid leaving any areas where reinforcement 2 is absent, for example, by installing and fixing two reinforcement 2 so that the lattice structure overlaps at the edges of reinforcement 2.

[0039] Thus, when carbon fiber is used as the reinforcing fiber, the reinforcing material 2 has a strength of 1400 N / mm². 2 The above tensile strength, and 100,000 N / mm²2 It has the above tensile modulus of elasticity. For example, the reinforcing material 2 can be shrunk into a roll shape and easily transported into an existing pipe. Furthermore, it is preferable that the surface of the carbon fiber, which is the reinforcing material 2, be surface-treated, as this can prevent scratches.

[0040] Furthermore, fasteners (concrete anchors) are used to secure the reinforcing material 2 (not shown). Plastic fasteners are preferred. Using plastic fasteners reduces the risk of corrosion due to acid.

[0041] Furthermore, the method of fixing the reinforcing bar 2 with the fasteners is not limited, but the fasteners are driven into the inner surface of the pipe at the corners of the grid of the reinforcing bar 2, that is, at the intersections of the grid bars 21 and 22 (see Figure 3(b)), and if necessary, a fastener retaining plate (not shown) or the like is used to press and fix the reinforcing bar 2 toward the inner surface of the pipe. The fasteners are driven into the ground every two or three squares of the reinforcing material 2, but the placement is not limited to this.

[0042] 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 the upper surface of the fixed reinforcing member 2, or on the surface of the manhole to be repaired, and fixed using fasteners (see Figure 1B). On the back surface of the above-mentioned structure 3, protrusions are arranged at predetermined intervals to enhance integration with the solidified and cured injection material, which will be described later.

[0043] Structure 3 has a sheet-like and / or panel-like form. The sheet-like structure is effective when repairing and rehabilitating existing pipes that have curved surfaces because it conforms to the curved surface. The panel-like structure is effective when repairing and rehabilitating existing pipes that have flat surfaces, such as rectangular or triangular portal-type structures, because it can be assembled facing the flat surface. Structure 3 is fixed at a position where the desired thickness can be obtained, spaced apart from the repaired and rehabilitated surfaces of the existing pipe, as well as from the reinforcing material 2.

[0044] Structure 3 is provided with projections having a roughly V-shaped cross-section (see Figure 4(2)). As a result, these projections improve the entanglement with the grout material through an anchoring effect, allowing for greater integration between structure 3 and the grout material. Furthermore, the roughly V-shaped projections are arranged in a roughly staggered pattern on the sheet-like or panel-like structure (see Figure 4(1)). Therefore, when the grout material is injected, no air is trapped near structure 3, ensuring that the structure and the grout material are firmly fixed together, enabling robust pipe rehabilitation.

[0045] Furthermore, it is desirable to install the above-mentioned protrusions at intervals of 40 to 100 mm, and especially at 44 mm intervals.

[0046] Here, synthetic resins such as polyester, polyamide (nylon), polyethylene, and polypropylene can be used as the above-mentioned structure. From the viewpoint of chemical resistance and abrasion resistance, polyethylene resin is preferable. Polyethylene resin has approximately 30 times the abrasion resistance of polyvinyl chloride. In addition, polyethylene resin has excellent extensibility of approximately 600%. As a result, even if strain occurs in the existing conduit due to earthquakes or other events, it can expand and follow the bending displacement.

[0047] Furthermore, since the manhole becomes narrower, restricting the movement of people and materials, it is preferable to use a material that is strong even if it is thin for the structure. The thickness of this structure is preferably in the range of 2 to 10 mm, and especially 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 difficult in areas with small diameters, and the structure will be heavy, which may cause displacement or spalling after construction.

[0048] Furthermore, when fixing the above-mentioned structure, the structure is first installed on the formwork and then secured with fasteners.

[0049] After fixing the structure 3 inside the manhole to the inside of the reinforcement 2, the injection material is poured into the gap S between the reinforcement 2 and the structure 3 via the hose 8, filling the gap and allowing it to solidify and cure (see Figure 1C). Mortar is preferred as the injection material, and inorganic cement mortar, polymer cement mortar, asphalt mortar, resin mortar, etc. can also be used, but it is particularly preferable to use one that does not shrink and does not have bleeding properties, meaning that no excess water is generated after mixing with the mortar.

[0050] Finally, the joints 10, which are gaps at the ends of the structure, are heat-sealed with a sealant made of the same material as the structure, such as a fast-curing polyethylene resin (see Figures 1D and 5). Additionally, scaffolding hardware and other necessary items will be restored inside the manhole as needed.

[0051] As explained above, according to the construction method of the present invention, rehabilitation work on concrete manholes in sewers can be completed in a short construction period. In particular, because it uses polyethylene structures with a thickness of 3-5 mm, it is self-supporting and can be constructed in a short time. Furthermore, it allows for appropriate rehabilitation and repair depending on the degree of deterioration of the concrete on the manhole wall. [Examples]

[0052] The effects of the present invention will be made clearer by showing the following examples of the existing pipe rehabilitation method according to the present invention. However, the present invention is not limited in any way to these examples.

[0053] The following describes one embodiment of the rehabilitation method for existing pipes according to the present invention. This embodiment involves the rehabilitation of the vertical wall section of an existing manhole, No. 1. This vertical wall section is equipped with steps that allow workers and materials to ascend and descend. On the vertical wall surface, the sulfuric acid had caused cracks in the concrete of the vertical wall, and water was seeping in through the cracks.

[0054] Herein, the reinforcing materials, structures, and injection materials used in this embodiment will be described below. Reinforcement 1 is a grid reinforcement made of carbon fiber. Considering the ease of construction during on-site work, reinforcement 1 was made with a reinforcement width (w) x thickness (t) of 6.6 square mm and a grid spacing (W) of 5 cm. Furthermore, regarding the carbon fibers used in the reinforcement according to the present invention, strength tests were conducted on their tensile strength and tensile modulus using a test method in accordance with the Japan Society of Civil Engineers standard JSCE-E531-1999 "Tensile Test Method for Continuous Fiber Reinforcements". The tensile strength was found to be 1400 (N / mm²). 2 ) or more, tensile modulus is 100,000 (N / mm²). 2 The above results were obtained for each case, confirming that they possess high strength.

[0055] Furthermore, the structure in this embodiment is made of polyethylene panels, and multiple panels were fixed to the wall surface according to the construction conditions to carry out the rehabilitation. Furthermore, the structure in this embodiment was tested for strength (tensile strength, tear strength, elongation at fracture), specific gravity, and brittleness temperature, etc., using test methods compliant with Japanese Industrial Standards JIS K6760 and 6301, respectively, and it was confirmed that the measured values ​​converged within the range of the standards.

[0056] Furthermore, the chemical resistance and abrasion resistance of this structure were tested using test methods compliant with the Japan Sewage Works Agency's "Guidelines and Manual for Corrosion Inhibition and Corrosion Prevention Technologies for Concrete Sewage Structures" and Japanese Industrial Standard JIS K7204. It was confirmed that the structure possessed extremely high chemical resistance to water, sodium chloride, sulfuric acid, nitric acid, and sodium hydroxide. Abrasion resistance was tested according to the abrasion test method using plastic abrasion wheels specified in JIS K 7204.

[0057] Furthermore, the injection material M used in this embodiment is a mortar having the aforementioned characteristics of being free from shrinkage and bleeding, and experiments were conducted on its compressive strength after curing for a predetermined number of days. The results are shown in Table 1.

[0058] [Table 1]

[0059] First, we examined the structure of the manhole wall to be rehabilitated and estimated its bending, shearing, and thrust-shearing strength. While detailed calculations are omitted as the purpose was to determine the strength of the wall to be rehabilitated and confirm its strength in its existing state, the results indicated that it possessed sufficient bending, shearing, and thrust-shearing strength.

[0060] Next, we examined the current condition of the existing wall surface and considered its potential for rehabilitation. In this example, although the load-bearing capacity was confirmed to be sufficient in all cases during the load-bearing capacity verification, the current condition of the wall surface shows cracks and damage in the concrete. Therefore, after examining the factors causing the discrepancy between the structural calculation results obtained above and the current condition, it was determined that the current wall deterioration is due to these factors, and a construction plan was created based on the calculation results and the condition of the wall surface.

[0061] Next, I will explain the construction process. First, as a preliminary step, wire protection and drainage treatment were carried out. Since the power transmission line conduit opening is located in wall 4, which is to be reinforced, and the power transmission line is drawn into it, it is necessary to protect the power transmission line. In addition, water has seeped into wall 4 through cracks and accumulated in the conduit, so the accumulated water was removed beforehand.

[0062] Waterproofing treatment was carried out on the waterlogged sections of the wall that needed repair. Since it was not possible to install reinforcements while the wall was flooded, waterproofing materials such as urethane-based waterproofing agents were injected into the leaking areas. In areas where the injection of this waterproofing material was insufficient to stop water ingress, measures such as installing water conduits were taken to prevent water from seeping in from the wall surface being constructed.

[0063] Furthermore, the wall surface that needed rehabilitation was chipped away and its cross-section repaired. When the wall surface is severely deteriorated, it may be difficult to integrate it with the reinforcement and install it in its original state. In such cases, the wall surface is chipped away and its cross-section repaired. In this example, due to the severe deterioration, the wall surface was chipped away to a depth of 5 cm, and polymer cement mortar was used to fill in cracks and areas with cross-sectional defects to repair it.

[0064] After repairing the aforementioned wall surface, the reinforcement 2 was set in the designated location according to the construction plan and secured using fasteners. At this point, it became necessary to connect and extend the reinforcing structures, and since the reinforcing structures were arranged in a grid pattern, they were installed and fixed in place, overlapping every two sections.

[0065] Furthermore, after setting and fixing the reinforcing members 2 in the designated locations, the formwork was installed in the direction of fluid flow in the pipe, and the panel-shaped structures 3 were 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 structure 3, and then cured and solidified. Reinforcement 2 was embedded in the mortar.

[0066] After the injected material had cured and solidified, the formwork attached to the structure was removed, and, if necessary, the joints of reinforcement 2 were sealed by heat fusion using polyethylene resin wire.

[0067] By implementing this construction method, the pipe wall P, the reinforcing material 2, and the structure 3 are integrated, allowing for reinforcement of cracks in the wall surface and suppression of wall displacement due to water pressure. Furthermore, compared to conventional rehabilitation methods, this method eliminates the need for rebar placement and concrete pouring, thus improving construction efficiency.

[0068] In this embodiment, the rehabilitation method was applied to rehabilitate a straight wall, but the rehabilitation method according to the present invention can be applied to various locations. Furthermore, when applying the reinforcing materials, structures, and injection materials used in the method according to the present invention, the shape of the wall surface to be rehabilitated is not limited to a flat surface, but can also be curved.

[0069] In addition to the embodiments described above, the present invention can be modified in various ways without altering the essence of the invention. In the above embodiment, a reinforcement made of carbon fiber was exemplified, but the present invention is not limited thereto, and a reinforcement made of reinforcing fibers mixed with fibers that have excellent chemical resistance and mechanical strength can also be applied.

[0070] Furthermore, although the above embodiment shows an example in which the reinforcing material 2 is fixed to the wall surface of the existing manhole P using a fastener 5, the present invention is not limited to this, and the reinforcing material 2 may also be fixed to the wall surface of the existing pipe P using simple fastening members such as small pegs or nails, and any method is applicable as long as it reduces the stress generated in the existing pipe P when attached to the wall surface of the existing pipe P.

[0071] Furthermore, while the above embodiment illustrates an example in which an injection material M is flowed and filled into the gap S between the pipe wall of the conduit and the structure 3, 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 appropriately set considering the size of the tubular body and the gap S.

[0072] Furthermore, in the supply of the injection material, a step of mixing short fibers into the injection material M may be incorporated. The short fibers mixed into the injection material M will entangle with the staggered protrusions of the structure, and after the injection material M has cured and solidified, the bonding force between the injection material M, the reinforcement 2, and the structure 3 will increase, making it possible to further increase the strength of the rehabilitated existing pipe P.

[0073] In the embodiments described above, examples were given of applying the method of the present invention to the rehabilitation of existing circular and rectangular conduits P. However, the method of the present invention can also be applied to the rehabilitation of existing conduits with irregular shapes, such as horseshoe-shaped or triangular conduits. [Industrial applicability]

[0074] The present invention is particularly suitable for use in narrow sections of manholes and waterways, as well as in environments where corrosive gases such as hydrogen sulfide are generated, in addition to conduits. The rehabilitation method, reinforcing materials, structures, and injection materials used in this invention are suitable for these environments. [Explanation of Symbols]

[0075] 1: Rehabilitated pipes 2: Reinforcements 3: Structure 5: Fixtures 8: Hose 10: Joint area 20a: Carbon fiber layer 21, 22: Grid lines P: Existing conduit S: Gap M: Injection material

Claims

1. A method for repairing and rehabilitating a portion of a manhole having a circular and / or irregular shape, wherein the method is: A step of fixing a sheet-like and / or panel-like structure made of synthetic resin to the surface of the manhole with fasteners, A step of allowing an injection material to flow into the space formed between the reinforcing material and the structure and curing and solidifying it, After the injection material has cured and solidified, the process involves welding the synthetic resin to the joints formed in the structure. A method for rehabilitating existing pipes, characterized by comprising the following.

2. Before the process of fixing the aforementioned structure, The method for rehabilitating an existing pipe according to claim 1, further comprising the step of fixing a lattice-shaped reinforcing material made of inorganic fibers to the inner surface of the existing pipe.

3. The method for rehabilitating an existing pipe according to claim 2, characterized in that the inorganic fiber is made of carbon fiber.

4. The method for rehabilitating an existing pipe according to claim 1, characterized in that the synthetic resin is made of a polyethylene resin.

5. The method for rehabilitating an existing pipe according to claim 4, characterized in that staggered projections are provided at regular intervals on the back surface of the aforementioned structure.

6. The method for rehabilitating an existing pipe according to claim 4, characterized in that the synthetic resin is heat-fused to the joint portion.

7. The method for rehabilitating an existing pipe according to claim 1, characterized in that the injection material consists of mortar that does not generate excess water after mixing.

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