Mold connection body

Abstract

To provide a mold connection body, which covers an inner wall of a manhole from inside of the inner wall so as to leave a filling space between the inner wall and the mold connection body, and has a first end and a second end that are connected to each other, and has improved tensile strength at overlapping and bonded part of a mold.SOLUTION: A mold connection body covers an inner wall M4F of a manhole M from inside of the inner wall M4F so as to leave a filling space between the inner wall M4F and the mold connection body, and has a first end and a second end that are connected to each other. The first end and the second end overlap each other, and the overlapping parts are bonded with resin. The first end is located closer to the inner wall M4F side than the second end and has a covering part to cover the second end from an opposite side (inside) to an inner wall side (outside).SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a mold connecting body having a first end portion and a second end portion that are connected to each other and cover the inner wall of a manhole from the inside while leaving a filling space between the inner wall and the mold connecting body.

Background Art

[0002] Manholes are generally made of concrete, and over a long period of time, the inner wall surface may be corroded by hydrogen sulfide generated in underground pipes, especially sewer pipes. In addition, in manholes buried in roadways, cracks may occur on the inner wall surface due to vehicle vibrations. Furthermore, the strength of manholes may decrease due to aging deterioration. In these cases, repair of the manhole is required.

[0003] However, due to traffic conditions and to reduce repair costs, it is difficult to repair manholes by excavation.

[0004] Therefore, as a method for repairing manholes using a non-excavation repair material (hereinafter referred to as a mold), an arc-shaped mold is inserted into the manhole from the opening of the manhole entrance in a reduced diameter state, the mold is expanded in diameter, and one circumferential end portion and the other end portion of the mold are joined together to form a cylindrical shape. A filler is filled between the outer peripheral surface of the cylindrical mold and the inner peripheral wall of the manhole, and the filler is cured so that the inner peripheral surface of the mold becomes a new inner peripheral wall of the manhole (see, for example, Patent Document 1, etc.). Patent Document 1 describes that when joining one circumferential end portion and the other end portion of the mold, the one end portion and the other end portion are overlapped, and the overlapped portion is adhered with resin.

[0005] In addition, there are cases where molds divided into a plurality of parts are joined together. In this case as well, it is necessary to overlap the molds and adhere the overlapped portion with resin.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, there arises a problem that the tensile strength of the overlapped and adhered portion of the mold is significantly reduced compared to the tensile strength of the mold itself that is not overlapped. Although this problem seems to be solved by increasing the adhesive strength of the resin, there is a certain limit to increasing the adhesive strength of the resin.

[0008] In view of the above circumstances, an object of the present invention is to provide a mold connector in which the tensile strength of the overlapped and adhered portion of the mold is increased.

Means for Solving the Problems

[0009] The mold connector of the present invention for solving the above object is a mold connector having a first end portion and a second end portion that are connected to each other and cover the inner wall of the manhole from the inside while leaving a filling space therebetween, the first end portion and the second end portion overlap each other, and the overlapped portion is adhered by resin, the first end portion is located closer to the inner wall side than the second end portion, and further, it is characterized in that the second end portion has a covering portion that covers the second end portion from the side opposite to the inner wall side.

[0010] According to the mold connector of the present invention, even if the second end portion is likely to be turned up inward due to a tensile force caused by earth pressure, earthquake, or the like, the second end portion can be held by the covering portion, and the tensile strength of the overlapped and adhered portion is increased.

[0011] Note that the first end portion and the covering portion may be separate bodies.

[0012] Also, a first mold; a second mold; The first mold and the second mold are connected to each other, the first end is an end of the first mold on the second mold side, The second end may be an end of the second mold on the side of the first mold.

[0013] In addition, the two circumferential ends of a single arc-shaped mold may be connected, and the first end may be the end on one circumferential side of the arc-shaped mold, and the second end may be the end on the other circumferential side of the arc-shaped mold.

[0014] Also, The first mold may have a base, the first end, and the cover, and the base, the first end, and the cover may be integrally formed.

[0015] The base portion and the first end portion may be integral, and the cover portion may be separate from the base portion and the first end portion.

[0016] The first mold may also have a first connecting portion that connects the base portion and the first end portion, and a second connecting portion that connects the base portion and the cover portion.

[0017] moreover, The cover portion may have a length extending in a direction opposite to the base portion that is not less than 1 / 5 and not more than 1 / 2 of the length of the first end portion.

[0018] The covering portion needs to be at least 1 / 5 of the original length to hold down the second end portion, which is prone to curling up inward. Furthermore, if the covering portion is less than 1 / 5 of the original length, the longer the longitudinal length of the molded joint body, which is perpendicular to the overlap width, the more difficult it becomes for the covering portion to cover the second end portion over the entire longitudinal length. On the other hand, if the covering portion is more than 1 / 2 of the original length, it becomes difficult to insert the first end portion between the covering portion and the second end portion. [Effects of the Invention]

[0019] An object of the present invention is to provide a mold joint in which the tensile strength of the overlapping and bonded portions of the molds is increased. [Brief explanation of the drawings]

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] FIG. 1 is a diagram showing an example of a manhole to be repaired.

[0023] A manhole is an entrance for people to inspect an underground structure that is normally inaccessible to people, and it is an embedded concrete molded body. Some manholes are made by casting concrete on-site, while others are of a stacked structure made by stacking prefabricated types manufactured in a factory. An example of the latter is shown in Fig. 1. Also, the manhole shown in Fig. 1 is for a sewer.

[0024] Fig. 1(A) is a perspective view schematically showing the manhole, and Fig. 1(B) shows a cross-sectional view seen from the side of the manhole. In Fig. 1(A), the left front side of the figure is the front side, and the right rear side is the back side. Also, in Fig. 1(B), the left side of the figure is the front side, and the right side is the back side.

[0025] As shown in Fig. 1(A), the opening of the entrance Mi of the manhole M of this embodiment is circular, and the inclined wall portion M2 installed via the height adjustment member M1 below the entrance Mi and the straight wall portion M3 connected to the lower part of the inclined wall portion M2 also have a circular horizontal cross-section. On the other hand, the rectangular portion M4 connected to the lower part of the straight wall portion M3 has a rectangular horizontal cross-section.

[0026] The inner diameter IL of the entrance of the manhole M is 600 mm, while the inner dimension XL in the lateral direction of the rectangular portion M4 is 2000 mm, and the inner dimension YL in the longitudinal direction is also 2000 mm. Note that the inner diameter is enlarged by the inclined wall portion M2, and the inner diameter DL of the straight wall portion M3 is 900 mm. Also, in Fig. 1(A), the flat mold 1 that covers the inner wall of the rectangular portion M4 from the inside leaving a filling space between it and the inner wall is represented by a two-dot chain line. On the vertical walls (front wall M4F, right side wall M4R, etc.) of the rectangular portion M4, the flat mold 1 with a width of 650 mm and the mold piece 2 for width adjustment are shown. Also, on the ceiling wall (top plate Mt) of the rectangular portion M4, the flat mold 6 with a width of 350 mm and the mold piece 7 for width adjustment are shown. The installation of each flat mold and the like will be described later.

[0027] Figure 1(B) shows an openable lid MC that closes the opening of the manhole M, a receiving frame MR that receives the lid MC, a height adjustment member M1, an inclined wall portion M2, and a straight wall portion M3. Also shown is a rectangular portion M4 that connects to the lower side of the straight wall portion M3. An elevation bracket SP for lifting is attached to the inner peripheral wall on the back side of the inclined wall portion M2, the straight wall portion M3, and the rectangular portion M4.

[0028] The height adjustment member M1 is a member for adjusting the surface of the lid MC to the height position of the ground, and can be mortar for adjustment, a prefabricated adjustment ring, or a concrete ring cast on-site. The receiving frame MR is installed on the height adjustment member M1.

[0029] The inclined wall portion M2 is made of concrete manufactured in a factory. As shown in Figure 1(B), this inclined wall portion M2 is inclined radially outward downward over the entire circumference.

[0030] The straight wall portion M3 is also made of concrete manufactured in a factory. This straight wall portion M3 is cylindrical, and here, straight wall bodies M30 with different heights are stacked in two layers. Note that there are straight wall bodies M30 with various heights.

[0031] The rectangular portion M4 is composed of a top plate Mt, side wall bodies Ms, and a pipe attachment wall body Ma.

[0032] The top plate Mt is a horizontal plate made of concrete manufactured in a factory. This top plate Mt forms the ceiling portion of the rectangular portion M4.

[0033] The side wall bodies Ms are also made of concrete manufactured in a factory. This side wall body Ms is rectangular and is composed of one layer here. Note that there are side wall bodies Ms with various heights, and they may be stacked in multiple layers.

[0034] The pipe attachment wall Ma is also a rectangular one made of concrete manufactured in a factory. As shown in Fig. 1(B), an inflow pipe IP and an outflow pipe OP are respectively connected to the pipe attachment wall Ma. The arrows in the figure indicate the direction in which the sewage flows. Both the inflow pipe IP and the outflow pipe OP are of large diameter. For example, the diameter exceeds 700 mm to 1000 mm. For such large-diameter inflow pipes IP and outflow pipes OP, it is difficult to use a cylindrical manhole, and a rectangular manhole is used.

[0035] An invert IN is arranged at the bottom of the pipe attachment wall Ma, and the inflow pipe IP and the outflow pipe OP are connected by a groove INg provided in this invert IN.

[0036] Fig. 2 is a diagram showing a flowchart of the manhole lining method shown in Fig. 1.

[0037] First, ground treatment is performed (step S1). In the ground treatment, dirt, deposits, vulnerable parts, and deteriorated parts on the inner peripheral wall of the manhole M are removed by high-pressure cleaning. If there are still deteriorated parts after the high-pressure cleaning, the deteriorated parts are scraped off by scraping work.

[0038] In step S2, pre-construction treatment is performed. In this pre-construction treatment, the foothold fitting SP is cut and removed. Also, when there are large cracks on the inner peripheral surface of the manhole M or when infiltrating water leaks out, a filler is filled and sealing treatment is performed.

[0039] In step S3, a construction surface survey is performed. In the manhole lining method of this embodiment, it is preferable to perform the construction after returning the manhole M to its original inner dimensions. Therefore, a construction surface survey is performed, and the inner peripheral surface of the manhole M may be repaired using a repair material. The repaired inner peripheral surface is preferably processed into an uneven shape in order to improve the adhesiveness with the filler described later.

[0040] Next, a flat mold is placed in the rectangular section M4. The flat mold is placed inside the inner wall of the rectangular section M4 and covers the entire inner wall, forming a filling space between the outer surface of the flat mold and the inner wall of the rectangular section M4 to be filled with a filler.

[0041] In step S4, the flat mold 1 is inserted through the opening of the manhole entrance Mi.

[0042] FIG. 3 is a diagram showing a flat mold.

[0043] The flat mold 1 shown in FIG. 3(A) is a repair material made of a resin whose main component is vinyl ester, which is resistant to hydrogen sulfide. In manholes with high concentrations of hydrogen sulfide, the mold itself and the joints where the molds are joined have been corroded by hydrogen sulfide, and cases have been reported in which the hydrogen sulfide has penetrated into the filler material that has been filled and hardened in the filling space, causing corrosion of the filler material as well. For this reason, in this embodiment, the mold itself is made resistant to hydrogen sulfide. Another example of a resin that is resistant to hydrogen sulfide is polyethylene.

[0044] The width WL of the flat mold 1 is 650 mm. Although the width WL of the flat mold 1 is longer than the inner diameter IL of the entrance Mi of the manhole M shown in FIG. 1(A), in step S4, the flat mold 1 can be bent in the width direction so that it can be inserted into the rectangular portion M4 from the entrance Mi.

[0045] The height of the flat mold 1 shown in Figure 3(A) is 1500 mm, but various heights can be prepared within a range of, for example, 3000 mm or less. In the flat mold 1 shown in Figure 3(A), the front side of the page is the rectangular section M4 side (the side forming the filling space). In the following description, the surface of the flat mold 1 that faces the rectangular section M4 side (the side forming the filling space) may be referred to as the outer surface OS, and the opposite surface may be referred to as the inner surface IS.

[0046] The flat mold 1 has a flat portion 10 with a width of 600 mm and a bifurcated portion 20 with a width WL2 of just over 50 mm.

[0047] The thickness of the flat part 10 is about 2 mm. On the outer surface OS of the flat part 10, four protruding strips 11 protruding toward the rectangular part M4 side (the side where the filling space is formed) are provided in two upper and lower stages. The protruding length of the protruding strip 11 is the designed thickness (for example, 6 mm). These protruding strips 11 come into contact with the inner wall of the rectangular part M4, and a filling space with the above-mentioned designed thickness is formed between the outer surface OS of the flat mold 1 and the inner wall of the rectangular part M4. Each protruding strip 11 has a shorter length in the width direction than in the vertical direction so as not to prevent the filling material from flowing down. That is, the protruding strip 11 is a square bar made of a resin mainly composed of a vinyl ester resistant to hydrogen sulfide, with a vertical length of 300 mm and a lateral width of about 15 mm. When manufacturing the flat mold 1 in the factory, each protruding strip 11 is attached to the outer surface OS of the flat part 10 with an adhesive while ensuring a lateral interval and a vertical interval of about 200 mm each.

[0048] An injection hole 12 for injecting the filling material is drilled on-site at the upper end of the flat part 10, and an anchor hole 13 for driving an anchor at intervals of 250 mm or more and 500 mm or less in the height direction is drilled on-site at the central part in the lateral width direction of the flat part 10. These holes 12 and 13 are indicated by a one-dot chain line in Fig. 3(A).

[0049] The bifurcated part 20 has a covering part 21 extending directly from the flat part 10, which is provided over the entire height at one end side in the lateral direction, a wrap part 22 extending in the lateral width direction while maintaining a parallel relationship with the covering part 21 at a position about 4 mm closer to the manhole M side from the flat part 10, and a connecting part 23 connecting the flat part 10 and the wrap part 22. The lateral width of the wrap part 22 is 50 mm. A screw hole 222 is drilled on-site at a position on the wrap part 22 that does not overlap with the covering part 21. In Fig. 3(A), this screw hole 222 is also indicated by a one-dot chain line. Note that the screw hole 222 may also be drilled in the flat part 10. The screw hole 222 is a through hole smaller than the anchor hole 13.

[0050] Fig. 3(B) is a schematic cross-sectional view of the wrap part 22 in the flat mold 1 shown in Fig. 3(A), with the upper part of the figure being the outer surface OS side.

[0051] The thickness of the lap portion 22 is also approximately 2 mm. The lap portion 22 is constructed by sandwiching a glass roving cloth (woven fabric) sheet GC, woven with flat glass fiber warp threads and the same flat glass fiber weft threads, between chopped strand mat (nonwoven fabric) sheets GM interspersed with short glass fibers, and solidifying these three sheets with a vinyl ester-based resin that is resistant to hydrogen sulfide. The glass roving cloth sheet GC is stronger than the chopped strand mat sheet GM, but is more expensive. By inserting this glass roving cloth sheet GC between the two sheets, the strength and durability of the lap portion 22 are improved. Furthermore, the strength difference between one side and the other side is eliminated, and the glass roving cloth sheet GC functions as a core material. The flat mold 1 is constructed by arranging multiple long, vertically extending, rectangular sheets in the width direction and solidifying them together with a vinyl ester-based resin. Because glass roving cloth sheets GC are expensive, most of the flat plate portion 10 and the covering portion 21 do not use glass roving cloth sheets GC. Instead, they are constructed by stacking three chopped strand mat sheets GM and solidifying them with a vinyl ester-based resin. However, in lining areas requiring high strength or where cost is acceptable, the entire flat plate portion 10 or the covering portion 21 may have a structure in which glass roving cloth sheets GC are sandwiched between chopped strand mat sheets GM. For example, the entire flat plate mold 1 may have a structure in which glass roving cloth sheets GC are sandwiched between chopped strand mat sheets GM. Furthermore, in a three-layer structure, the position of the glass roving cloth sheets GC is not limited to the center position, but may be located on the outer surface OS or the inner surface IS. Furthermore, a three-layer structure may be formed using glass roving cloth sheets GC, or a three-layer structure in which chopped strand mat sheets GM are sandwiched between glass roving cloth sheets GC. Alternatively, the structure is not limited to a three-layer structure, but may be a two-layer structure or a four-layer or more structure including a glass roving cloth sheet GC. In other words, any structure having a glass roving cloth sheet GC may be used.

[0052] Also, when manufacturing the flat mold 1 in the factory, a primer layer PM is provided at locations in contact with the resin, such as the outer surface OS and the inner surface of the wrap portion 22. In Fig. 3(B), the primer layer PM is indicated by a cross mark. As the primer layer PM, for example, a layer coated with a polyester-based primer can be mentioned. The primer layer PM has a function of improving the adhesiveness with the resin and also a function of improving the adhesiveness with the joint material. Therefore, the joint material is less likely to flow down due to the primer layer PM. Furthermore, since the primer layer PM improves the smoothness of the base and also improves the durability of the resin of the joint material, the primer layer PM also has a function as a surfacer layer and can be regarded as a primer surfacer (prasurf) layer.

[0053] Furthermore, when the flat mold 1 is fabricated in a factory, a resin support structure is provided on the inner surface (the surface on the cover portion 21 side) of the lap portion 22. As will be described later, an end of the flat portion 10 of another flat mold 1 is inserted between the bifurcated portions 20 (between the lap portion 22 and the cover portion 21), and an end of another flat mold 1 overlaps the lap portion 22. The overlapped portions where the flat molds 1 overlap are jointed. Joint materials such as silicone putty or acid-resistant epoxy putty are often used for jointing, but in this embodiment, a resin resistant to hydrogen sulfide is used as the joint material. For example, a resin whose main component is vinyl ester, the same resin as that used in the flat mold 1, is used. In this way, using a joint material whose main component is the same resin as that used in the flat mold 1 can increase adhesive strength. Resins whose main component is vinyl ester have low viscosity and tend to drip. Therefore, some means is needed to keep the resin in the lapped area until it hardens. In the resin support structure of this embodiment, a resin support sheet 30 having a communicating space that is open in the thickness direction is attached with double-sided tape 31. The communicating space here refers to a space that connects one surface 30a of the resin support sheet 30 to the other surface 30b, and may be linear or have a complex shape. The one surface 30a is the surface to which the resin support sheet 30 is attached with double-sided tape 31 and is located on the lap portion 22 side. Examples of the resin support sheet 30 include a 1 mm thick felt or foam sheet. It may also be a mesh sheet. It is preferable that the inner surface of the lap portion 22 be covered as much as possible with this resin support sheet 30. That is, it is preferable that the resin support sheet 30 be provided over the entire height of the lap portion 22 and over as wide an area as possible in the width direction. The resin supplied during joint treatment penetrates into the communicating spaces, is held there for a certain period of time, gradually seeps out from both sides 30a, 30b of the sheet, and eventually hardens. Since the double-sided tape 31 may hinder the resin from seeping out, it is preferable that it be as thin and short as possible.

[0054] In addition, as the resin support structure, the inner surface of the wrap portion 22 may be formed into a structure with recesses provided by shot peening (a matte finish structure), or a structure with serrated grooves provided by machining. Alternatively, serrated grooves may be formed when solidifying with the resin during the production of the flat mold 1.

[0055] In step S5 shown in FIG. 2, the lower end portion of the flat mold 1 inserted into the rectangular portion M4 is sized to match the shape of the shoulder in the invert IN shown in FIG. 1, and the flat mold 1 is temporarily lifted up to the ground. On the ground, the lower end portion of the flat mold 1 is machined to match the shape of the shoulder, and at the positions of the inflow pipe IP and the outflow pipe OP, it is cut out to match those pipes.

[0056] When the machining of the lower end portion is completed, the flat mold 1 is inserted again through the opening of the manhole inlet Mi.

[0057] In step S6, the flat mold 1 is installed on the vertical walls (front wall, left and right side walls, rear wall) of the rectangular portion M4. Taking the front wall M4F of the rectangular portion M4 shown in FIG. 1(A) as an example, the first flat mold 1-1 is arranged so that the end portion (the end portion of the flat portion 10) opposite to the bifurcated portion 20 of the first flat mold 1-1 abuts against the left vertical edge M4e1. When the first flat mold 1-1 is arranged, the screw holes 222 shown in FIG. 3(A) are drilled in the wrap portion 22 of the bifurcated portion 20 of the first flat mold 1-1, screws are driven into the front wall M4F, and the first flat mold 1-1 is temporarily fixed with screws. Also, screw holes may be drilled at a plurality of spaced positions of the flat portion 10, and the flat portion 10 may also be temporarily fixed to the front wall M4F with screws. Note that the temporary fixing of the flat portion 10 with screws will be omitted in the description of the second and subsequent flat molds, but it may be performed in the same manner.

[0058] Next, the pressing jig is set.

[0059] FIG. 4 is a view of the state in which the pressing jig is set, taken from above after cross-sectioning in the horizontal direction. In this FIG. 4, the upper side of the figure is the front wall M4F. Also, the flat mold 1 extends to the back side of the paper surface, and the ridge portion 11 is also shown in FIG. 4.

[0060] First, an anchor hole 13 indicated by a dotted line in FIG. 3(A) is drilled in the central portion in the lateral width direction of the flat plate portion 10. Also, at this time, an injection hole 12 indicated by a dotted line in FIG. 3(A) is drilled in alignment with the upper end portion of the flat plate portion 10.

[0061] Next, an anchor AC is driven into the front wall M4F from the anchor hole 13. The anchor AC remains in the front wall M4F even after the lining method is completed.

[0062] The pressing jig 9 has a connecting fitting 91, a pressing plate 92, a pushing member 93, and an angle member 94.

[0063] A screw hole is provided at the tip portion of the anchor AC, and the connecting fitting 91 is inserted into the screw hole while turning the connecting fitting 91 so that the screw portion of the connecting fitting 91 meshes with the screw hole. The pressing plate 92 is provided with a through hole 921 through which the connecting fitting 91 passes. The connecting fitting 91 is passed through the through hole 921, and the pressing plate 92 is brought into contact with the flat mold 1. The connecting fitting 91 protrudes from the pressing plate 92 through the through hole 921. Here, gaps around the connecting fitting 91 are sealed with putty. That is, the gaps between the connecting fitting 91 in the through hole 921, the gaps between the connecting fitting 91 in the anchor hole 13, and the gaps between the connecting fitting 91 and the tip of the anchor AC are sealed with a putty material such as silicon. In FIG. 4, the putty material that seals these gaps is shown in gray. By sealing with the putty material, it is possible to prevent the filling material from leaking out. The connecting fitting 91 is removed from the anchor AC after construction, but if it is difficult to remove due to the hardening of the putty material, the portion of the connecting fitting 91 protruding from the flat mold 1 is cut. Thereafter, it is preferable to coat the cut portion with a resin resistant to hydrogen sulfide. Note that a resin resistant to hydrogen sulfide may be used as the putty material.

[0064] One end of a shaft portion 930 of a pressing member 93 is placed over the protruding portion of the connecting fitting 91. A movable member 931 is passed through the shaft portion 930, and a square piece of material 94 is placed between the movable member 931 and the pressing plate 92 so as to extend into the plane of the drawing. A screw groove 932 is provided on the other end of the shaft portion 930, and a dial 933 is fitted into the screw groove 932. By tightening the dial 933, the movable member 931 moves toward the pressing plate 92, increasing the pressing force with which the pressing plate 92 presses the flat mold 1 against the front wall M4F, and the setting of the pressing jig 9 is completed. Note that by loosening the dial 933, the pressing force weakens, and the pressing jig 9 can be removed by removing the connecting fitting 91 from the screw hole.

[0065] Next, the end of the flat portion 10 of the second flat mold 1-2 is inserted between the bifurcated portion 20 (between the cover portion 21 and the wrap portion 22) of the first flat mold 1-1 shown in FIG. 1(A), and the second flat mold 1-2 is placed. The second flat mold 1-2 has been provided with a cutout in step S5 to fit the inlet pipe IP, and the second flat mold 1-2 is divided into upper and lower halves. Therefore, the upper and lower halves are placed separately. As a result, the wrap portion 22 of the first flat mold 1-1 and the end of the flat portion 10 of the second flat mold 1-2 overlap. Because the width of the wrap portion 22 is 50 mm as described above, the overlap between the first flat mold 1-1 and the second flat mold 1-2 is 50 mm. Furthermore, screw holes may be drilled in the overlapping portion of the two flat molds, and the molds may be fastened to the front wall M4F with screws (the same applies hereinafter). After the arrangement of the second flat mold 1-2, which is divided into an upper part and a lower part, is completed, anchor holes 13 are drilled in each of the upper and lower parts, and each part is held down by a separate holding jig 9.

[0066] Next, the end of the flat portion 10 of the third flat mold 1-3 is inserted between the bifurcated portion 20 of the second flat mold 1-2 shown in Figure 1(A), and the third flat mold 1-3 is placed. The overlap between the second flat mold 1-2 and the third flat mold 1-3 is also 50 mm. Once the placement of the third flat mold 1-3 is complete, the pressing jig 9 is set in the same manner as described above.

[0067] At this point, the flat mold 1 covers the area from the left vertical edge M4e1 to 1850 mm. The remaining 150 mm is covered by a width-adjustment mold piece 2. This width-adjustment mold piece 2 is prepared by processing a flat mold (for example, a flat mold with a width of 300 mm) on-site. That is, the flat mold is cut at a position 150 mm in the width direction from the end of the flat portion 10. As a result, a width-adjustment mold piece 2 with a width of 150 mm is obtained. The width-adjustment mold piece 2 is inserted between the forked portion 20 of the third flat mold 1-3. In this way, the width-adjustment mold piece 2 abuts against the right vertical edge M4e2, and the front wall M4F of the rectangular portion M4 is completely covered from the inside by the mold. Screw holes may also be drilled in the width-adjusting mold piece 2, and the width-adjusting mold piece 2 may also be screwed to the front wall M4F. Alternatively, the presser plate 92 of the presser jig 9 that presses the third flat plate mold 1-3 may be made wide so that the width-adjusting mold piece 2 is also pressed down by the presser plate 92 together with the third flat plate mold 1-3. Alternatively, anchor holes may also be drilled in the width-adjusting mold piece 2, anchors AC may be driven into the anchor holes, and the presser jig 9 may also be set on the width-adjusting mold piece 2.

[0068] In a mold that covers the front wall M4F of the rectangular portion M4 from the inside without any gaps, the pressing jig 9 is set so that the pressing plate 92 covers as much of the mold as possible, except for the areas where the flat molds 1 overlap each other and the areas where the flat mold 1 and the width-adjusting mold piece 2 overlap. However, the pressing plate 92 does not cover the areas where the injection holes, which will be described later, will be drilled.

[0069] Once the flat mold 1 has been installed on the front wall M4F of the rectangular section M4, flat molds 1 are similarly installed on the remaining three vertical walls (right side wall M4R, back wall, and left side wall), completing step S6.

[0070] When the installation of the flat mold 1 on the vertical wall of the rectangular portion M4 is completed, joint treatment is performed on the vertical wall of the rectangular portion M4 (step S7).

[0071] Figure 5 is a horizontal cross-sectional view of the overlapping portions of the flat molds 1, viewed from above. As with Figure 4, the upper side of Figure 5 is the front wall M4F. Hereinafter, the side facing the front wall M4F may be referred to as the outside, and the opposite side as the inside. The flat mold 1 extends toward the back of the page. Figure 5 also shows the filling space S between the flat mold 1 and the front wall M4F.

[0072] 5(A) shows the bifurcated portion 20 of the flat mold 1 shown on the left. Of the cover portion 21 and wrap portion 22 that make up the bifurcated portion 20, the shorter cover portion 21 is located on the inside, and the longer wrap portion 22 is located on the outside. The length of the wrap portion 22 in the width direction is 50 mm, while the length of the cover portion 21 in the width direction is 10 mm. In other words, the length of the cover portion 21 in the width direction is 1 / 5 of the length of the wrap portion 22 in the width direction.

[0073] 5(A) also shows a schematic diagram of the glass robing cloth (woven fabric) sheet GC described with reference to FIG. 3(B). The glass robing cloth sheet GC is provided from the vicinity of the bifurcated portion 20 of the flat plate portion 10 of the flat plate mold 1 shown on the left, through the connecting portion 23, to the leading edge 22e of the lap portion 22. The glass robing cloth sheet GC does not have to be provided up to the leading edge 22e of the lap portion 22, but only partway along the lap portion 22. In other words, the glass robing cloth sheet GC only needs to be provided in the area around the connecting portion, including the connecting portion 23, from the part of the flat plate portion 10 on the connecting portion 23 side to the part of the lap portion 22 on the connecting portion 22 side.

[0074] The end 15 of the flat portion 10 of the flat mold 1 shown on the right is inserted between the bifurcated portion 20 of the flat mold 1 shown on the left (between the cover portion 21 and the wrap portion 22) until the edge 15e of the end 15 abuts the connecting portion 23, and the end 15 overlaps the cover portion 21 by 10 mm and the wrap portion 22 by 50 mm. The flat mold 1 is left in place even after the lining method is completed, and the inner surface of the flat mold 1 becomes the new inner wall of the rectangular portion M4.

[0075] External forces such as earth pressure and earthquakes may be applied to the remaining flat mold 1, generating tension. As shown by the thick arrow in FIG. 5(A), this deformation may occur, causing the end 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right side to curl inward. This deformation is not countered solely by the adhesive strength of the resin; the presence of the cover portion 21 can hold down the end 15, thereby suppressing the deformation. To ensure that the cover portion 21 overlaps with the end 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right side, the width of the cover portion 21 must be at least 1 / 5 of the width of the wrap portion 22. Furthermore, the width of the cover portion 21, which can hold down the end 15, must also be at least 1 / 5 of the width of the wrap portion 22. Tensile forces also act on the outer lap portion 22, but because the glass roving cloth sheet GC is stronger than the chopped strand mat sheet GM, the presence of this glass roving cloth sheet GC in the lap portion 22 is able to withstand the tensile forces and prevent the hardened resin from being destroyed. Also, although the flat plate portion 10 and the area from the flat plate portion 10 to the covering portion 21 are flat, the boundary between the flat plate portion 10 and the connecting portion 23 and the boundary between the connecting portion 23 and the lap portion 22 are curved and susceptible to tensile forces, so glass roving cloth sheets GC are provided at these boundaries to reinforce these boundaries.

[0076] As described above, the resin-supported sheet 30 is attached to the inner surface of the wrap portion 22 (the surface on the covering portion 21 side) with the double-sided tape 31. The thickness of the resin-supported sheet 30 is 1 mm, and the end portion 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right faces the wrap portion 22 through the resin-supported sheet 30. That is, the inner surface (the other surface 30b) of the resin-supported sheet 30 with a thickness of 1 mm is in contact with the end portion 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right. In the resin-supported sheet 30, one surface 30a is located on the wrap portion 22 side, and the other surface 30b is located on the end portion 15 side of the flat plate portion 10 of the flat plate mold 1 shown on the right.

[0077] Also, in this Figure 5 as well, the primer layer PM is indicated by a cross mark. This primer layer PM is provided on the outer surface of the flat plate mold 1 shown on the left. It is also provided on the inner peripheral surface of the bifurcated portion 20. Further, it is also provided on the outer surface of the flat plate mold 1 shown on the right. In addition, the primer layer PM is provided on the edge 15e of the end portion 15 in the flat plate portion 10 of the flat plate mold 1 shown on the right, and is also provided on the surface of the end portion 15 facing the covering portion 21.

[0078] During the installation of the flat mold 1 in step S6, immediately before inserting the end of the flat portion 10 of one flat mold 1 between the bifurcated portion 20 of the other flat mold 1, the resin support sheet 30 is impregnated with a vinyl ester-based resin that is resistant to hydrogen sulfide. The gap GL between the end 15 of the flat portion 10 of the flat mold 1 (shown on the right) facing the cover portion 21 and the cover portion 21 is 1 mm. In the joint treatment in step S7, vinyl ester-based resin is pushed into this gap GL with a spatula, and any resin that overflows from this gap GL is smoothed out. In Figure 5, the resin is represented by small dots. The resin contained in the resin support sheet 30 does not drip downward, but seeps out from both sides 30a, 30b of the resin support sheet 30, filling the gap between the lap portion 22 of the flat plate mold 1 shown on the left and the end 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right with resin, firmly bonding the lap portion 22 of the flat plate mold 1 shown on the left and the end 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right over a length of 50 mm. In addition, the sealing performance is improved, making it possible to prevent hydrogen sulfide from penetrating into the filler and corroding the filler.

[0079] Although FIG. 5(A) shows the flat mold 1 on the right side, the same applies to the width-adjusting mold piece 2.

[0080] When the joint processing on the front wall M4F of the rectangular portion M4 is completed, the joint processing is similarly performed on the remaining three vertical walls (right side wall M4R, rear wall, and left side wall), and step S7 is completed.

[0081] After completing the joint processing of the vertical wall of the rectangular section M4, the filler is filled into the filling space S, which is secured by the protrusions 11 between the vertical wall of the rectangular section M4 and the flat mold 10 (step S8 shown in FIG. 2). As described above, when drilling the anchor holes 13, injection holes 12 (see FIG. 3(A)) are also drilled at the upper end of the flat section 10 of each flat mold 1. Note that injection holes 12 do not need to be drilled in all of the flat molds 1 and the width-adjusting mold pieces 2; instead, only one or two injection holes 12 may be drilled per wall (e.g., the front wall M4F). Furthermore, injection holes 12 may be drilled at a timing separate from the timing of drilling the anchor holes 13 (e.g., immediately before filling with the filler).

[0082] The filler is a room-temperature-setting resin primarily composed of epoxy resin. It is pumped into the fill space S one wall at a time through the injection holes 12. For example, in the fill space of the front wall M4F, the first injection fills the resin to a height of approximately 300 mm, the second injection fills the resin to a height of approximately 700 mm, the third injection fills the resin to a height of approximately 1100 mm, and finally the final injection fills the resin to a height of 1500 mm. Next, the resin is similarly injected into the fill space S of the right side wall M4R in four separate injections, the same four injections into the fill space S of the rear wall, and finally the same four injections into the fill space S of the left side wall. While the resin is injected in multiple injections, the first injection uses the smallest amount to ensure the base of the bottom is formed. The first injection also uses a small amount to ensure that the filler does not leak from the bottom. When filling the vertical wall with filler, the filler may be poured by its own weight without using a pump.

[0083] The holding jig is removed after the filled resin has completely hardened.

[0084] Subsequently, a flat mold that covers the top plate of the rectangular portion M4 from the inside is inserted through the opening of the manhole inlet Mi (step S9). Since the flat mold that covers the top plate of the rectangular portion M4 from the inside has a width of 350 mm, it can be easily inserted through the opening of the manhole inlet Mi. The flat mold that covers the top plate of the rectangular portion M4 from the inside is horizontally installed and thus receives the weight of the filling material. Even if it is pressed by a pressing jig as described later, with a width of 650 mm, the flat mold itself is likely to sag downward, and a flat mold with a narrower width than the vertically arranged flat mold 1 is used. Note that the difference between the flat mold with a width of 350 mm and the flat mold with a width of 650 mm shown in Fig. 3(A) is only that the flat portion of the 350-mm flat mold is 300 mm shorter than the flat portion of the 650-mm flat mold. Hereinafter, components with the same names as the components of the flat mold with a width of 650 mm shown in Fig. 3(A) will be described with the same reference numerals as those previously assigned.

[0085] At the portion of the flat mold inserted into the rectangular portion M4 that comes to the position connecting to the straight wall portion M3 shown in Fig. 1, the dimension of the inner diameter DL of the straight wall portion M3 is measured. The flat mold after the dimension measurement is once pulled up to the ground, and the flat mold is subjected to a cutting process so as to match the inner diameter DL of the straight wall portion M3 (step S10).

[0086] When the process in step S10 is completed, the flat mold is inserted again through the opening of the manhole inlet Mi.

[0087] In step S11, a flat mold is installed on the top plate Mt of the rectangular portion M4. Referring to FIG. 1(A), on one edge Mte1 of the top plate Mt, the first flat mold 6-1 is arranged such that the end portion (the end portion of the flat plate portion 10) opposite to the bifurcated portion 20 of the first flat mold 6-1 abuts, and the first flat mold 6-1 is temporarily fixed to the top plate Mt with screws. Next, anchor holes are drilled in the central portion in the width direction of the flat plate portion 10. Subsequently, anchors are driven into the top plate Mt through the anchor holes drilled in the flat plate portion 10, and the flat mold 6-1 is pressed by a pressing jig. The pressing jig used here has the same configuration as the pressing jig 9 described with reference to FIG. 4, but the width of the pressing plate is narrower than the width of the pressing plate 92 shown in FIG. 4.

[0088] Next, between the bifurcated portions 20 of the first flat mold 6-1, the end portion of the flat plate portion 10 of the second flat mold 6-2 is inserted. This time, the second flat mold 6-2 is screwed, and further, anchor holes are drilled, and the second flat mold 6-2 is pressed by a pressing jig. Thereafter, the same operation is repeated until the end portion of the flat plate portion 10 of the fifth flat mold 6-5 is inserted between the bifurcated portions 20 of the fourth flat mold 6-4. The fifth flat mold 6-5 is provided with a cutout adapted to the straight wall portion M3 in the previous step S10, and the fifth flat mold 6-5 is divided into left and right parts. Therefore, the left and right parts are respectively inserted between the bifurcated portions 20 of the fourth flat mold 6-4. Then, the left and right parts are respectively screwed, and further, anchor holes are drilled in each part, and each part is pressed by a separate pressing jig. The sixth flat mold 6-6 is the same as the fifth flat mold 6-5. Finally, a mold piece 7 for width adjustment for the remaining 150 mm is cut out, and the end portion of the mold piece 7 for width adjustment is inserted between the bifurcated portions 20 of the sixth flat mold 6-6 divided into left and right parts. After this mold piece 7 is also screwed, the mold piece 7 is also pressed by a pressing jig.

[0089] In step S12, joint treatment is performed on the top plate Mt of the rectangular portion M4. For the joint treatment here, a resin mainly composed of vinyl ester is used as the joint material. Although the front wall M4F, which is a vertical wall, was shown in Fig. 5(A), this front wall M4F can be replaced with the top plate Mt, which is a horizontal wall. The following description will continue with reference to Fig. 5(A). In the flat mold installed on the top plate Mt of the rectangular portion M4, the joint material is more likely to drip than in the flat mold installed on the vertical wall, and the effect of the resin support sheet 30 is exerted. That is, if the resin support sheet 30 is filled with resin so as to completely fill the communication space of the resin support sheet 30, although there is no resin oozing upward, the resin flowing downward is blocked by the end 15 of the flat plate portion 10 in the inserted flat mold shown in Fig. 5(A). For this reason, the gap between the lap portion 22 of the flat mold shown on the left side and the end 15 of the flat plate portion 10 of the flat mold shown on the right side is filled with resin, and the lap portion 22 of the flat mold shown on the left side and the end 15 of the flat plate portion 10 of the flat mold shown on the right side are firmly adhered over a length of 50 mm. Also, the sealing performance is improved. Further, in the joint treatment of step S12, resin is pushed into the gap GL shown in Fig. 5(A) with a spatula, and the operation of leveling the resin that is about to drip from this gap GL is performed.

[0090] In step S13 shown in FIG. 2, a filling material is filled into the filling space S secured by the protruding portion 11 between the top plate of the rectangular portion M4 and the flat mold 10. When filling the filling material, an injection hole for injecting the filling material is drilled. The injection hole here is drilled at one end side in the longitudinal direction orthogonal to the width direction of the flat mold or the mold piece for width adjustment. Since the top plate Mt is a horizontal wall, unlike the vertical wall, it is difficult to fill the filling material. Even if an attempt is made to fill the filling material from the central portion in the longitudinal direction, the flow path of the filling material is not determined, and the filling does not proceed well. When filling from one end side in the longitudinal direction, the filling space expands to the other end side, and the filling material is injected toward the other end side by the pressure of the pump. In addition, the protruding portion 11 provided on the outer surface OS of the flat mold and extending from one end side to the other end side may be made to gradually increase the protruding amount from one end side to the other end side so as to ensure an inclination. However, even if it is called an inclination, it is a very slight inclination with an inclination angle of about several degrees. Also, the injection holes do not have to be drilled in all the flat molds and the mold pieces for width adjustment, and may be drilled at only one location, or may be drilled every other one. However, since the wrapping portion 22 is closer to the manhole M side as described above, the filling space S is also thinner accordingly. In order to more surely distribute the filling material to this thinner portion, it is preferable to drill injection holes in all the flat molds. Also, when drilling the anchor holes in step S9, the injection holes may be drilled together.

[0091] Also, as the filling material here, a room temperature curing type resin mainly composed of an epoxy resin is used, and the filling material is injected in multiple portions by the force of the pump from the injection hole. That is, the resin is moved from the one end side provided with the injection hole toward the other end side, and the curing of the resin proceeds from the other end side toward the one end side.

[0092] Note that the pressing jig is removed after the filled resin is completely cured.

[0093] Next, the straight wall mold is installed (step S14). The straight wall mold is a cylindrical member installed inside the straight wall portion M3 shown in FIG. 1, but is an arc-shaped sheet body when inserted through the opening of the manhole entrance Mi. That is, the arc-shaped sheet body is inserted through the opening of the manhole entrance Mi in a reduced diameter state with both circumferential ends of the sheet body overlapped. This sheet body for the straight wall mold is also made of a resin whose main component is vinyl ester, and protrusions protruding outward are evenly distributed at intervals.

[0094] The lower end of the straight wall mold sheet inserted into the manhole is fitted into the opening Mto (see Figure 1) of the top plate Mt, which connects the rectangular portion M4 and the straight wall portion M3. The worker manually expands the diameter of the sheet until the protruding portions of the straight wall mold abut the inner peripheral wall of the straight wall portion. The sheet becomes a cylindrical straight wall mold, with one circumferential end and the other circumferential end overlapping. Then, with the circumferential ends overlapping, anchor bolts are driven toward the inner peripheral wall of the straight wall portion M3 in some of the protruding portions selected from the multiple protruding portions so that they are evenly distributed circumferentially, thereby fixing the straight wall mold to the inner peripheral wall of the straight wall portion M3. Next, a holding jig is installed on the inner peripheral side of the straight wall mold. Although the straight-wall mold is fixed to the inner peripheral wall of the straight-wall portion M3 with anchor bolts, when the filling material is filled into the filling space secured by the protrusions between the inner peripheral wall of the straight-wall portion M3 and the straight-wall mold, the weight of the filling material may cause the straight-wall mold to bulge inward or collapse, making it necessary to hold down the straight-wall mold from the inside with a holding jig. When the installation of the holding jig is complete, step S14 is completed.

[0095] In step S15, the straight wall mold is subjected to joint treatment, which is also performed using a resin whose main component is vinyl ester.

[0096] When the joint process in step S15 is completed, a filler is filled into the filling space secured by the protruding portion between the inner peripheral wall of the straight wall portion M3 and the straight wall mold (step S16). Here too, as the filler, a room temperature curable resin mainly composed of an epoxy resin is used. The filler is poured into the filling space by using gravity from between the upper edge of the straight wall mold and the inner peripheral wall of the straight wall portion M3.

[0097] In step S17, an inclined wall mold is installed. The inclined wall mold is formed by combining a plurality of divided sheet bodies. The inclined wall mold is installed inside the height adjusting member M1 and the inclined wall portion M2 shown in Fig. 1(B). The neck mold installed inside the height adjusting member M1 is a sheet body made of resin mainly composed of arcuate vinyl ester, similar to the sheet body of the straight wall mold. However, the lower end portion is bent radially outward and extends obliquely downward. In addition, on this sheet body, protrusions are evenly provided at intervals in the circumferential direction immediately above the bent lower end portion. The main body mold installed inside the inclined wall portion M2 is a sheet body made of resin mainly composed of vinyl ester, which is divided into a plurality of parts in the circumferential direction.

[0098] In step S17, first, the sheet body of the neck mold is inserted from the opening of the inlet Mi of the manhole in a reduced diameter state with both circumferential ends overlapped. Next, the operator expands the sheet body of the neck mold by hand until the protrusion abuts against the inner peripheral wall of the height adjusting member M1 inside the height adjusting member M1, and the sheet body becomes a cylindrical neck mold with one circumferential end overlapping the other end. In this state, anchor bolts are driven into the inner peripheral wall of the height adjusting member M1 at some or all of the plurality of provided protrusions. As a result, the neck mold is fixed to the inner peripheral wall of the height adjusting member M1 with the filling space secured.

[0099] Next, the sheet body of the main mold is inserted through the opening of the manhole entrance Mi. The sheet body of the main mold is divided into multiple pieces (three in this example) in the circumferential direction. Hereinafter, the three divided sheet bodies will be referred to as the first sheet body, the second sheet body, and the third sheet body. First, the lower end of the first sheet body is fitted inside the upper end of the straight wall mold, and an anchor bolt is driven into the fitted portion. Next, the second sheet body is placed so that one circumferential end of the first sheet body overlaps the other circumferential end of the second sheet body. The lower end of the second sheet body is also fitted inside the upper end of the straight wall mold, and an anchor bolt is driven into the fitted portion. Finally, the third sheet body is placed between the other circumferential end of the first sheet body and one circumferential end of the second sheet body. One circumferential end of the third sheet body and the other circumferential end of the first sheet body overlap each other, and the other circumferential end of the third sheet body and one circumferential end of the second sheet body also overlap each other. The lower end of the third sheet body is also fitted inside the upper end of the straight wall mold, and anchor bolts are driven into the fitted part. The outer surfaces of the upper edges of the first, second, and third sheet bodies come into contact with the inner surface of the lower end of the neck mold that was installed earlier.

[0100] The first, second and third sheets do not have any protrusions, but the upper ends of the straight-wall molds into which their lower ends are fitted have protrusions, and the filling space in the lower parts of each of the three sheets is ensured by these protrusions. On the other hand, the filling space in the upper parts of each of the three sheets is ensured by the protrusions of the neck mold.

[0101] In step S18, the inclined wall mold joints are treated. The joints are treated at the overlapping portions of the neck mold sheet members, where one end and the other end of the sheet members overlap in the circumferential direction, where the first sheet member and the second sheet member overlap in the circumferential direction, where the second sheet member and the third sheet member overlap in the circumferential direction, and where the first sheet member and the third sheet member overlap in the circumferential direction. Again, a resin primarily composed of vinyl ester, which is resistant to hydrogen sulfide, is used as the joint material.

[0102] Note that the inclined wall mold may be an arc-shaped sheet body that is not a three-part division of the main body mold and is integrated with the neck mold, and an arc-shaped sheet body may be used.

[0103] When the joint treatment of the inclined wall mold is completed, a filler is filled into the filling space secured by the protruding portion between the inner peripheral walls of the height adjustment member M1 and the inclined wall portion M2 and the inclined wall mold (step S19). The filling of the filler here is a continuation of the filling of the filler in step S16, and the same filler as the filler used in step S16 is poured using gravity. When the filler is filled up to the upper edge of the neck mold, a sealing treatment is performed with a putty mainly composed of a vinyl ester resistant to hydrogen sulfide, which is the same as the joint material used in the joint treatment, and step S19 ends.

[0104] In step S20, processing is performed from the inner peripheral surface of the mold, and a new hanger fitting is installed. Also, the inner peripheral surface of the mold is cleaned. Thus, the manhole lining construction method is completed.

[0105] By the manhole lining construction method described above, a manhole lining structure covering the inner peripheral wall of the manhole M is completed. In the completed manhole lining structure, the strength is maintained by various molds such as the flat molds 1 and 6 and the cured filler, and the inner surfaces of the various molds become new inner walls of the manhole lined on the back.

[0106] In the vertical walls (front wall M4F, right side wall M4R, back wall, left side wall) of the rectangular portion M4 of this embodiment, the tensile strength of the overlapping portions of the flat molds 1 and the tensile strength of the overlapping portions of the flat molds 6 in the ceiling wall (top plate Mt) of the rectangular portion M4 have been confirmed to be improved to the same level as the tensile strength of the flat portions 10 of the flat molds 1 and 6. Contributing to this effect are the adhesion by the resin retained by the resin support sheet 30, the pressing by the covering portion 21, and the reinforcement by the glass roving cloth sheet GC of the lapping portion. By improving the tensile strength, the resin cured at the overlapping portions of the flat molds is less likely to be broken. As a result, the sealing property is maintained, and hydrogen sulfide can be prevented from entering the filler and corroding the filler as well.

[0107] FIG. 5(B) is a view of a first modification of the structure of the overlapping portion of the flat molds, sectioned horizontally in the same manner as in FIG. 5(A) and viewed from above. Hereinafter, the description will focus on the differences from the example shown in FIG. 5(A). Also, components having the same names as the components described so far will be described with the same reference numerals as those previously assigned.

[0108] While the width of the cover portion 21 shown in FIG. 5(A) is 10 mm, the width of the cover portion 21 in this first modified example is 25 mm, which is half the length of the 50 mm wrap portion 22. In a flat mold with a height of 3000 mm, for example, even if the end 15 of the flat portion 10 of one flat mold is firmly inserted into the bifurcated portion 20 of the other flat mold at the top, there is a risk that it may come loose at the bottom if the other flat mold is even slightly tilted. To ensure secure insertion across the entire height, the width of the cover portion 21 in this first modified example is set to 25 mm. Note that the longer the width of the cover portion 21, the more difficult it becomes to insert the other flat mold into the bifurcated portion 20. Furthermore, not only is it more difficult to manufacture the bifurcated portion 20 itself, but it also makes it more difficult to attach the resin-carrying sheet 30 and to impregnate the attached resin-carrying sheet 30 with resin. For these reasons, it is preferable that the length of the cover portion 21 in the width direction be kept to 1 / 2 or less of the length of the wrap portion 22 in the width direction.

[0109] Moreover, the first modification example is an example in which the resin-supported sheet 30 is attached to the inner peripheral surface of the bifurcated portion 20 as much as possible. That is, in addition to the inner peripheral surface of the wrap portion 22 (the surface on the covering portion 21 side), the resin-supported sheet 30 is attached to the inner peripheral surface of the connecting portion 23 and the inner peripheral surface of the covering portion 21 (the surface on the wrap portion 22 side) with a double-sided tape 31. The thickness of each resin-supported sheet 30 is 1 mm. The resin-supported sheet 30 provided on the inner peripheral surface of the wrap portion 22 contacts the outer surface of the end portion 15 of the flat portion 10 of the flat mold 1 shown on the right side. The resin-supported sheet 30 provided on the inner peripheral surface of the connecting portion 23 contacts at least a part of the edge 15e of the end portion 15 in the flat portion 10 of the flat mold 1 shown on the right side. The resin-supported sheet 30 provided on the inner peripheral surface of the covering portion 21 contacts the inner surface of the end portion 15 in the flat portion 10 of the flat mold 1 shown on the right side. The resin contained in each resin-supported sheet 30 is less likely to drip downward, oozes out from both sides of each resin-supported sheet 30, and the gap between the inner peripheral surface of the bifurcated portion 20 of the flat mold 1 shown on the left side and the end portion 15 of the flat portion 10 of the flat mold 1 shown on the right side is filled with resin, and the bifurcated portion 20 of the flat mold 1 shown on the left side and the end portion 15 of the flat portion 10 of the flat mold 1 shown on the right side are firmly adhered as a whole. Also, the sealing property is improved, and it is possible to prevent hydrogen sulfide from entering the filler and corroding even the filler.

[0110] Moreover, in the first modification example, a glass roving cloth (woven fabric) sheet GC is provided around the connecting portion including the connecting portion 23 from the boundary between the flat portion 10 and the connecting portion 23 to the boundary between the connecting portion 23 and the wrap portion 22. The bent portion that is easily affected by the tensile force is reinforced by the glass roving cloth sheet GC, and it is possible to resist the tensile force caused by earth pressure, earthquake, etc. Also, the connecting portion 23 is reinforced by the glass roving cloth sheet GC. In addition, in the wrap portion 22, the glass roving cloth sheet GC may be provided up to the same position as the position of the leading edge 21e of the covering portion 21.

[0111] FIG. 6 is a view showing a second modified example and a third modified example of the structure of the overlapping portion of flat molds, horizontally cross-sectioned in the same manner as FIG. 5(A) and viewed from above. The upper side of the figure is the inner wall M4I side of the rectangular portion. Hereinafter, this inner wall M4I side may be referred to as the outer side, and the opposite side may be referred to as the inner side. Hereinafter, the description will focus on the differences from the example shown in FIG. 5(A). Also, components having the same name as the components described so far will be described with the same reference numerals as those attached so far.

[0112] FIG. 6(A) is a view showing a second modified example.

[0113] Even in the second modified example, it has a covering portion 21 with a width of 10 mm and a wrapping portion 22 with a width of 50 mm. In this second modified example, the covering portion 21 does not extend directly from the flat plate portion 10, but protrudes in the width direction while maintaining a parallel relationship with the wrapping portion 22 at a position about 2 mm inward from the flat plate portion 10. On the other hand, the wrapping portion 22 extends in the width direction while maintaining a parallel relationship with the covering portion 21 at a position about 2 mm outward from the flat plate portion 10. The connecting portion 23 is a portion connecting the flat plate portion 10, the covering portion 21, and the wrapping portion 22 respectively.

[0114] In this second modified example as well, similar to the first modified example, it is an example where the resin-supporting sheet 30 is attached to the inner peripheral surface of the bifurcated portion 20 as much as possible. That is, the resin-supporting sheet 30 is attached to the inner peripheral surface (the surface on the covering portion 21 side) of the wrapping portion 22, the inner peripheral surface of the connecting portion 23, and the inner peripheral surface (the surface on the wrapping portion 22 side) of the covering portion 21 with double-sided tape 31. The edge 15e of the end portion 15 in the flat plate portion 10 of the flat plate mold 1 shown on the right abuts against the resin-supporting sheet 30 attached to the inner peripheral surface of the connecting portion 23. The resin-supporting sheet 30 provided on the inner peripheral surface of the wrapping portion 22 is in contact with the outer surface of the end portion 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right, the resin-supporting sheet 30 provided on the inner peripheral surface of the connecting portion 23 is in contact with the entire edge 15e of the end portion 15 in the flat plate portion 10 of the flat plate mold 1 shown on the right, and the resin-supporting sheet 30 provided on the inner peripheral surface of the covering portion 21 is in contact with the inner surface of the end portion 15 in the flat plate portion 10 of the flat plate mold 1 shown on the right. The resin contained in each resin-supporting sheet 30 does not easily drip downward, oozes out from both sides of each resin-supporting sheet 30, and the gap between the inner peripheral surface of the bifurcated portion 20 of the flat plate mold 1 shown on the left and the end portion 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right is filled with resin, and the bifurcated portion 20 of the flat plate mold 1 shown on the left and the end portion 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right are firmly adhered as a whole. Also, the sealing property is improved.

[0115] Also, in this second modified example, a primer layer PM is provided on the outer surface OS of the flat plate mold 1 that contacts the filler, but it is not provided on the inner peripheral surface of the bifurcated portion 20. In the example shown in Fig. 5(A) as well as in the first modified example, the primer layer PM may be provided on the outer surface OS of the flat plate mold 1 that contacts the filler and not provided at locations where there is no possibility of contacting the filler. Or conversely, in the second modified example, the primer layer PM may also be provided on the inner peripheral surface of the bifurcated portion 20.

[0116] Furthermore, in the second modification example, a glass roving cloth (woven fabric) sheet GC is also provided on the covering portion 21. That is, the glass roving cloth sheet GC shown in Fig. 6(A) is provided from the vicinity of the bifurcated portion 20 of the flat plate portion 10 in the flat plate mold 1 shown on the left side, through the connecting portion 23, to the leading edge 21e of the covering portion 21 and up to the middle of the wrapping portion 22. Also in the second modification example, the strength of the wrapping portion 22 is improved by the glass roving cloth sheet GC, and it can resist tensile forces caused by earth pressure, earthquakes, etc. Furthermore, the strength of the covering portion 21 is also improved by the glass roving cloth sheet GC. For this reason, a deformation (refer to the thick arrow shown in Fig. 5(A)) in which the end portion 15 of the flat plate portion 10 of the flat plate mold 1 shown on the right side is turned up inward due to earth pressure, earthquakes, etc. can be more reliably suppressed by this covering portion 21. Although the glass roving cloth sheet GC is provided for the same length on the covering portion 21 and the wrapping portion 22, the glass roving cloth sheet GC may be provided up to the leading edge 22e of the wrapping portion 22. Also, in the second modification example, the covering portion 21 is closer to the inside from the flat plate portion 10. For this reason, in addition to the portion from the bifurcated portion 20 side of the flat plate portion 10 to the flat plate portion 10 side portion of the wrapping portion 22, the glass roving cloth sheet GC is also provided at the portion from the bifurcated portion 20 side of the flat plate portion 10 to the flat plate portion 10 side portion of the covering portion 21, and these portions are reinforced.

[0117] Fig. 6(B) is a view showing a third modification example.

[0118] Even in the third modification example, it has a covering portion 21 and a wrapping portion 22. In this third modification example, in the flat mold 1 shown on the left side, the flat plate portion 10, the wrapping portion 22, and the connecting portion 23 connecting the flat plate portion 10 and the wrapping portion 22 are integrally formed, but the covering portion 21 is a separate body. That is, the covering portion 21 of the third modification example has a structure in which three sheets of chopped strand mat (non-woven fabric) sheets are stacked and hardened with a resin mainly composed of vinyl ester, and the lateral width is 30 mm. The length of the portion overlapping the wrapping portion 22 is 15 mm. Note that this separate covering portion 21 may be one in which a glass roving cloth (woven fabric) sheet is disposed between the chopped strand mat sheets.

[0119] On the outer surface of the covering portion 21 shown in FIG. 6(B), a resin-supporting sheet 30 having a lateral width of about 30 mm is attached with a double-sided tape 31. In the joint treatment of the flat mold, a resin mainly composed of vinyl ester is included in this resin-supporting sheet 30, and the covering portion 21 is attached from the inside so as to straddle the flat plate portion 10 of the left flat mold 1 and the flat plate portion 10 of the right flat mold 1, and the joint treatment is performed. The resin contained in the resin-supporting sheet 30 attached to the separate covering portion 21 also does not easily drip downward, oozes out from both sides of this resin-supporting sheet 30, and the resin fills from the inner surface of the flat plate portion 10 of the flat mold 1 shown on the left side to the inner surface of the end portion 15 of the flat plate portion 10 of the flat mold 1 shown on the right side. As a result, the three members, i.e., the flat plate portion 10 of the flat mold 1 shown on the left side, the end portion 15 of the flat plate portion 10 of the flat mold 1 shown on the right side, and the separate covering portion 21, are firmly adhered. As a result, even if the covering portion 21 is a separate body, deformation (refer to the thick arrow shown in FIG. 5(A)) in which the end portion 15 of the flat plate portion 10 of the flat mold 1 shown on the right side turns up inward due to earth pressure, earthquake, or the like can be suppressed by this covering portion 21. Also, the sealing property is improved, and it is possible to prevent hydrogen sulfide from entering the filler and corroding even the filler. Further, in this third modification example, the operation of attaching the resin-supporting sheet 30 and the operation of including the resin in the attached resin-supporting sheet 30 are also easy to perform.

[0120] In addition, in the third modification example, the glass roving cross (woven fabric) sheet GC is provided only at two locations, namely, the boundary between the flat plate portion 10 and the connecting portion 23 and the boundary between the connecting portion 23 and the wrap portion 22. This is an example that most conserves the expensive glass roving cross sheet GC. However, the bent portions that are easily affected by the tensile force are reinforced by the glass roving cross sheet GC, and it is possible to resist the tensile force caused by earth pressure, earthquakes, etc.

[0121] Note that the glass roving cross sheet GC may be provided only at the connecting portion 23 among the flat plate portion 10, the connecting portion 23, and the wrap portion 22. Furthermore, the glass roving cross sheet GC may be provided only at at least a part of the connecting portion instead of the entire connecting portion 23.

[0122] Note that a sheet of glass roving cross (woven fabric) may be sandwiched between sheets of chopped strand mat (non-woven fabric) on a straight wall mold or an inclined wall mold (which may be divided or integrated), and a resin mainly composed of vinyl ester may be used to solidify these three sheets.

[0123] In addition, a resin support structure (for example, the resin support sheet 30) may be provided at the overlapping portion of the straight wall mold or the inclined wall mold (which may be divided or integrated). Furthermore, a bifurcated portion 20 may be provided at one end in the circumferential direction of an arc-shaped straight wall mold or a neck mold, and the other end in the circumferential direction may be inserted between the bifurcated portions 20 to form a mold connection body. In this case, the base portion is the portion between one end in the circumferential direction and the other end in the circumferential direction. Alternatively, a bifurcated portion 20 may be provided at one end in the circumferential direction of each sheet body (the first sheet body, the second sheet body, the third sheet body) constituting the main body mold, and the other end of the sheet body adjacent in the circumferential direction may be inserted between the bifurcated portions 20 to form a mold connection body.

[0124] Furthermore, a grout material may be used instead of the resin as the filling material. As the grout material, a material obtained by mixing powder cement, a mixture liquid, and water on-site, or a premix type in which powder cement and a mixture liquid are previously blended is used.

[0125] What has been described above is described below as an appended note.

[0126] (Appended Note 1) A mold connecting body [for example, the connecting body of the left flat mold 1 and the right flat mold 1 shown in FIGS. 5 and 6] having a first end [for example, the wrap portion 22 shown in FIGS. 5 and 6] and a second end [for example, the end 15 of the right flat mold 1 shown in FIGS. 5 and 6] that are connected to each other and cover the inner wall of the manhole [for example, the front wall M4F, the top plate Mt] from the inside of the inner wall leaving a filling space [for example, the filling space S] therebetween, The first end and the second end overlap each other, and the overlapping portion is adhered by a resin [for example, a resin mainly composed of vinyl ester]. The mold connecting body is characterized in that the first end is provided with a resin supporting structure [for example, the resin supporting sheet 30] for supporting the resin.

[0127] When attempting to adhere the first end and the second end with resin, the resin may flow down, making it impossible to achieve sufficient adhesion, and causing a problem that the tensile strength of the adhered portion is greatly reduced.

[0128] According to the mold connecting body described in Appended Note 1, in the overlapping portion, the resin is likely to stay due to the resin supporting structure provided at the first end, and the first end and the second end are adhered by the remaining resin, and sufficient tensile strength can be obtained even at the adhered portion. In addition, since the resin is not likely to flow down, the sealing property is also improved, and it is possible to prevent hydrogen sulfide from entering.

[0129] Note that the inner wall may be a peripheral wall or a ceiling wall.

[0130] The resin support structure may have a recess (matt structure) or a jagged groove on the surface of the first end facing the second end. Furthermore, the resin support structure may be provided on the entire surface of the first end.

[0131] The first end and the second end may be ends on one side and the other side of a common mold. That is, the mold connection body may be formed by connecting both circumferential ends of a single arc-shaped mold, and the first end may be an end on one side of the arc-shaped mold in the circumferential direction, and the second end may be an end on the other side of the arc-shaped mold in the circumferential direction. Alternatively, the first end and the second end may be ends of different molds.

[0132] (Appendix 2) The molded joint body according to claim 1, wherein the resin is a resin resistant to hydrogen sulfide (for example, a resin primarily composed of vinyl ester).

[0133] It is preferable that both the first end portion and the second end portion are made of a material that is resistant to hydrogen sulfide. The resin and the material may be made of the same material. For example, both may be made of a material that is primarily made of vinyl ester resin.

[0134] (Appendix 3) The resin carrying structure is a structure in which a resin carrying body (e.g., a resin carrying sheet 30) having a first surface (e.g., a surface 30a on one side) located on the first end side and a second surface (e.g., a surface 30b on the other side) located on the second end side is fixed to the first end side (e.g., a structure attached with double-sided tape 31), 3. The molded joint body according to claim 1, wherein the resin support has a communication space that connects the first surface to the second surface.

[0135] The resin carrier may be attached to a surface of the first end portion facing the second end portion.

[0136] The mold connector may be disposed upright, with the resin carrier extending in the vertical direction of the mold connector, or may be disposed lying down, with the resin carrier extending in the horizontal direction of the mold connector.

[0137] Furthermore, the communication space is not limited to being linear, but may have a complex shape.

[0138] (Appendix 4) A first mold (for example, the left flat mold 1 shown in Figures 5 and 6) a second mold (for example, the flat mold 1 on the right side shown in FIGS. 5 and 6 ), The first mold and the second mold are connected to each other, the first end (e.g., lap portion 22) is an end of the first mold on the second mold side, The mold connection body described in Appendix 1 or 2, wherein the second end (e.g., end 15 of the right-hand flat mold 1 shown in Figures 5 and 6) is the end of the second mold on the first mold side.

[0139] That is, it can also be applied to the case where different molds are joined together.

[0140] (Appendix A) A mold combination body (e.g., a combination body of the left flat mold 1 and the right flat mold 1 shown in Fig. 5 or 6) having a first end portion (e.g., a lap portion 22 shown in Fig. 5 or 6) and a second end portion (e.g., the end portion 15 of the right flat mold 1 shown in Fig. 5 or 6) connected to each other, which covers the inner wall (e.g., a front wall M4F, a top plate Mt) of a manhole from the inside of the inner wall, leaving a filling space (e.g., a filling space S) between the inner wall and the mold combination body, The first end portion and the second end portion overlap each other, and the overlapping portion is bonded by a resin [for example, a resin mainly composed of vinyl ester]. The first end portion is located closer to the inner wall side than the second end portion. Furthermore, the mold connecting body is characterized by having a covering portion [for example, covering portion 21] that covers the second end portion from the side opposite to the inner wall side [for example, the outside] [for example, the inside].

[0141] (Appendix B) A first mold [for example, the left flat mold 1 shown in FIGS. 5 and 6], and a second mold [for example, the right flat mold 1 shown in FIGS. 5 and 6], and the first mold and the second mold are connected, the first end portion [for example, the wrap portion 22] is the end portion of the first mold on the side of the second mold, and the second end portion [for example, the end portion 15 of the right flat mold 1 shown in FIGS. 5 and 6] is the end portion of the second mold on the side of the first mold. The mold connecting body according to Appendix A is characterized by this.

[0142] (Appendix C) The first mold has a base portion [for example, the flat portion 10], the first end portion [for example, the wrap portion], and the covering portion [for example, the covering portion 21], and the base portion, the first end portion, and the covering portion are integrally formed [for example, the left flat mold 1 shown in FIG. 5, the left flat mold 1 shown in FIG. 6(A)]. The mold connecting body according to Appendix B is characterized by this.

[0143] (Appendix D) The mold connecting body according to Appendix C is characterized in that the length of the covering portion extending in a direction opposite to the base portion is 1 / 5 or more and 1 / 2 or less of the length at the first end portion.

[0144] (Appendix α) A mold (flat mold 1, flat mold 6) that covers the inner wall of a manhole (e.g., front wall M4F, top plate Mt) from the inside of the inner wall, leaving a filling space (e.g., filling space S) between the inner wall and the mold, A mold characterized in that a portion [for example, from the vicinity of the bifurcated portion 20 of the flat portion 10, through the connecting portion 23 to the tip edge 22e of the lap portion 22] or the entire portion [for example, across the entire flat mold 1] is made by overlapping a woven glass fiber fabric [for example, a glass roving cloth sheet GC] and a nonwoven glass fiber fabric [for example, a chopped strand mat sheet GM] and solidifying them with resin.

[0145] The inside of the mold becomes the new inner wall of the manhole. It has been discovered that the mold, which has become the new inner wall, is subject to corrosion from hydrogen sulfide, the effects of vehicle vibrations, and deterioration over time, as well as external forces such as earth pressure and earthquakes, which generate tensile and compressive forces.

[0146] A woven fabric of glass fiber is stronger than a nonwoven fabric of glass fiber, and therefore, the mold described in Appendix α contains the woven fabric of glass fiber, which further increases the strength.

[0147] The inner wall may be a peripheral wall or a ceiling wall.

[0148] (Appendix β) The mold according to appendix α, wherein the resin is a resin resistant to hydrogen sulfide (for example, a resin mainly composed of vinyl ester).

[0149] Since the mold itself may be corroded by hydrogen sulfide, it is preferable to use a resin that is resistant to hydrogen sulfide, such as a vinyl ester resin.

[0150] (Appendix γ) The mold according to appendix α or β, characterized in that a part or all of the mold is made by sandwiching the glass fiber woven fabric between the glass fiber nonwoven fabrics [for example, FIG. 3(B)].

[0151] There is no difference in strength between one side surface and the other side surface, and the woven fabric of the glass fiber functions like a core material.

[0152] (Appendix ε) A base [for example, the flat plate portion 10 of the left flat plate mold 1 shown in FIGS. 5 and 6, the portion between one circumferential end and the other circumferential end of the arc-shaped sheet body], and A first end portion closer to the inner wall side than the base [for example, the wrap portion 22 of the left flat plate mold 1 shown in FIGS. 5 and 6, one circumferential end of the arc-shaped sheet body], and It has a connecting portion [for example, connecting portion 23] connecting the base and the first end portion, The first end portion overlaps with a second end portion [for example, the end portion 15 of the right flat plate mold 1 shown in FIGS. 5 and 6, the other circumferential end of the arc-shaped sheet body] located on the side opposite to the inner wall side, At least, at the boundary between the base and the connecting portion and at the boundary between the first end portion and the connecting portion respectively, there are portions where the woven fabric of the glass fiber and the non-woven fabric of the glass fiber are overlapped and solidified with resin [for example, FIGS. 5(A), 5(B), 6(A), 6(B)]. The mold according to Appendix α or β, characterized in that

[0153] Note that at least from the portion of the base on the connecting portion side to the portion of the first end portion on the connecting portion side, the woven fabric of the glass fiber and the non-woven fabric of the glass fiber may be overlapped and solidified with resin.

[0154] Also, the first end portion and the second end portion may be one end portion and the other end portion on one side of a common mold. That is, both circumferential ends of a single arc-shaped mold are connected, and the first end portion may be one circumferential end of the arc-shaped mold, and the second end portion may be the other circumferential end of the arc-shaped mold.

[0155] Alternatively, the first end portion and the second end portion may be end portions of different molds. That is, a mold connector having a first mold and a second mold, wherein the first mold and the second mold are connected, the first end portion is an end portion of the first mold on the side of the second mold, and the second end portion may be an end portion of the second mold on the side of the first mold.

[0156] The present invention can be variously modified within the scope described in the claims without being limited to the embodiments, modifications, and appendices described so far. For example, it can be applied not only to manholes for sewers but also to manholes for water supply, transmission lines, communication lines, or gas pipes. Further, as the filling material, in addition to room temperature curable resins, heat curable resins, thermoplastic resins, or light curable resins using a transparent mold may be used. Alternatively, as described above, the filling material may not be limited to resins but may be grout materials or the like.

[0157] Also, even if a constituent element is included only in each of the descriptions of the embodiments, modifications, and appendices described above, the constituent element may be applied to the embodiments, other modifications, and appendices.

Explanation of Reference Numerals

[0158] M Manhole M4 Rectangular portion M4F Front wall Mt Top plate S Filling space 1, 6 Flat molds 2, 7 Mold pieces 10 Flat plate portion 15 End portion 20 Fork portion 21 Covering portion 22 Wrapping portion 23 Connection portion 30 Resin support sheet 30a One side surface 30b The other side surface GC Glass roving cloth sheet Sheet of GM chopped strand mat

Claims

1. A mold connecting body having a first end portion and a second end portion that are connected to each other and cover the inner wall of a manhole from the inside while leaving a filling space between the inner wall and the mold connecting body, wherein the first end portion and the second end portion overlap each other, and the overlapping portion is adhered by resin, the first end portion is located closer to the inner wall side than the second end portion, and further, the second end portion has a covering portion that covers the inner wall side from the opposite side. The mold connecting body is characterized by this.

2. A first mold, and a second mold, wherein the first mold and the second mold are connected, the first end portion is the end portion of the first mold on the second mold side, and the second end portion is the end portion of the second mold on the first mold side. The mold connecting body according to Claim 1 is characterized by this.

3. The first mold has a base portion, the first end portion, and the covering portion, and the base portion, the first end portion, and the covering portion are integrally formed. The mold connecting body according to Claim 2 is characterized by this.

4. The covering portion extends in a direction opposite to the base portion, and the length of the covering portion is 1 / 5 or more and 1 / 2 or less of the length of the first end portion. The mold connecting body according to Claim 3 is characterized by this.

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