JP2023110366A - Method for regenerating existing pipe and pipe opening seal structure - Google Patents

Abstract

To seal both end opening parts in a gap between an existing pipe and a regeneration pipe in a good workability manner prior to filling a back-filling material into the gap.SOLUTION: A pipe opening seal structure 5U, 5D that, prior to filling a back-filling material into a gap 4 between an existing pipe 1 and a regeneration pipe 3, seals openings positioned at both ends in a pipe axial direction of the gap 4 includes a plurality of pieces having shapes corresponding to the openings of the gap 4, namely, a pair of lower pieces 20, a pair of intermediate pieces 30, and an apex piece 40.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for rehabilitating an existing pipe, particularly a step of sealing both end openings of the gap between the existing pipe and the rehabilitated pipe in order to fill the gap with a back-filling material (pipe mouth sealing step); The present invention relates to a tube mouth seal structure constructed in an opening.

BACKGROUND ART It is well known to install a resin-made rehabilitation pipe in an existing pipe such as an aged sewage pipe, and to rehabilitate the existing pipe by lining it. After installing the rehabilitation pipe over the entire length of the existing pipe, the gap between the existing pipe and the rehabilitation pipe is filled with a backfilling material. This opening must be sealed to prevent leakage. This seal is called a tube mouth seal.

As disclosed in Patent Literature 1, a pipe mouth seal is constructed by filling the opening of a gap between an existing pipe and a rehabilitated pipe with clay cement over the entire circumference.

JP 2018-9649 A

However, the workability of pipe mouth seal construction using clay cement is low. In other words, it is necessary to knead the clay cement on site, and usually requires a kneader and a person to fill the gap between the existing pipe and the rehabilitated pipe with the kneaded clay cement. . In particular, when the diameter of the existing pipe increases, the amount of clay cement also increases, making the work even more difficult. Furthermore, when the pipe mouth seal is constructed while water is flowing in the existing pipe, the filled clay cement is washed away, so it is necessary to fill the clay cement while replenishing that amount.
In addition, the backfilling work cannot be started until the clay cement of the pipe mouth seal hardens, and there is a possibility that the hardened clay cement cracks and the backfilling material leaks.

In order to solve the above problems, the present invention provides openings positioned at both ends of the gap in the axial direction of the pipe prior to filling the gap between the existing pipe and the rehabilitated pipe installed in the existing pipe with a back-filling material. A tube mouth seal structure for sealing a portion is characterized by comprising a plurality of pieces having a shape corresponding to the opening of the gap, and closing the opening with these pieces.
According to this configuration, by installing a plurality of pieces in the opening of the gap between the existing pipe and the rehabilitated pipe, workability can be significantly improved compared to the work of filling with clay cement. In addition, the work of filling the back-filling material can be started immediately after the piece is installed in the opening. Moreover, since cracks unlike clay cement do not occur, leakage of the backfilling material can be suppressed.

Preferably, the plurality of pieces includes at least a pair of side pieces that close left and right portions of the opening of the gap and a top piece that closes the top of the opening, and the at least a pair of side pieces are connected to each other. The external shape seen from the axial direction is bilaterally symmetrical.
According to this configuration, the end of the rehabilitating pipe can be positioned at the center in the left-right direction of the end of the existing pipe.

Preferably, the at least one pair of side pieces includes a pair of left and right lower pieces that close a lower portion of the opening, and at least a pair of left and right pieces that are located between the lower piece and the top piece and close an intermediate portion of the opening. and an intermediate piece of
According to this configuration, since the side piece is divided into the lower piece and the intermediate piece, the installation work to the opening can be performed smoothly.

Preferably, the top piece consists of a single piece, and the top piece that closes the top of the opening on one end side in the pipe axial direction is formed with a hole for injecting a back-filling material. The top piece closing the top of the opening on the end side is formed with a hole for overflowing the backfill material.
With this arrangement, the holes in the top piece can be used to inject and spill out the backfill material.

Preferably, a first engaging portion is formed on the outer circumference of the rehabilitating pipe, and a second engaging portion is formed on the inner circumference of the side piece, and the first engaging portion and the second engaging portion are formed. The engagement of the side piece restricts the axial movement of the side piece with respect to the rehabilitating pipe.
With this configuration, the side piece can be firmly held at a predetermined position even under the filling pressure of the backfilling material.

Preferably, the rehabilitating pipe is obtained by spirally winding a strip-shaped member and joining the side edges of adjacent wound portions, and the strip-shaped member includes a strip-shaped main portion, It has at least two ridges protruding from the outer surface of the main portion, an engagement groove as the first engagement portion is formed between the ridges, and the inner peripheral surface of the side piece has the An engaging protrusion that engages with the engaging groove is formed as a second engaging portion.
According to this configuration, the side piece can be held using the ridges of the belt-shaped member.

Preferably, the plurality of pieces are arranged on a plane orthogonal to the pipe axis, and the engaging protrusions of the side pieces extend in a spiral at an angle equal to the spiral of the belt-shaped member of the rehabilitating pipe. ing.
According to this configuration, it is possible to hold the side piece more firmly. Further, by positioning the engaging projections of the side pieces and the engaging grooves of the rehabilitating pipe and dropping them from above, the fitting projections and the engaging grooves guide the pipes so that they can be accurately installed at the predetermined positions.

Preferably, it further comprises connecting means for connecting the ends of circumferentially adjacent pieces.
According to this configuration, by connecting the pieces together, the strength of the tube mouth seal structure can be increased.

Preferably, the connecting means is formed in the fitting recess formed in the end of one of the adjacent lower piece and the intermediate piece, and in the fitting recess formed in the end of the other piece. and a mating protrusion that fits.
According to this configuration, the intermediate piece can be easily connected by moving downward in the circumferential direction toward the lower piece.

Preferably, the connecting means includes a pressure bolt screwed into the end of one of the adjacent top piece and the intermediate piece, and the tip of the pressure bolt is pressed against the end surface of the other piece. connects the top piece and the intermediate piece so as not to move relative to each other.
According to this configuration, the top piece and the intermediate piece can be connected by the pressing bolt, and the connecting strength of the entire plurality of pieces can be increased.

Preferably, the upper end of the side piece is formed with a bolt hole for screwing a hook bolt.
According to this configuration, when removing the side piece after the backfilling material is filled and hardened, even if the side piece is fixed, it can be pulled upward along the circumferential direction via the hook bolt. can be removed.

Another aspect of the present invention includes a rehabilitating pipe installation step of installing a rehabilitating pipe in an existing pipe; and a backfilling material filling step of filling the gap with a backfilling material, wherein in the pipe mouth sealing step, a plurality of pipes having a shape corresponding to the opening of the gap A piece is used to close the opening.

Preferably, the plurality of pieces are positioned between a pair of left and right lower pieces that close the lower portion of the opening, one top piece that closes the top of the opening, and the lower piece and the top piece. and at least a pair of left and right intermediate pieces for closing the intermediate portion of the opening. a step of closing the lower portion of the opening by moving it downward; and a step of plugging the top of the opening by inserting the top piece between the intermediate pieces in the pipe axial direction.
According to this method, the lower piece and the intermediate piece are moved downward along the circumferential direction by utilizing the fact that the lower piece and the intermediate piece are tapered downward, so that the installation work of these pieces can be performed smoothly.

Preferably, the method further includes a piece removal step of removing the plurality of pieces from the opening after the backfilling material filling step is completed and the backfilling material is hardened.
This method allows multiple pieces to be reused for other site port seals.

Preferably, in the piece removing step, the intermediate piece and the lower piece are removed from the opening by pulling their upper ends upward.
According to this method, the downward tapering of the lower piece and the intermediate piece is utilized to move them upward along the circumferential direction, thereby making it possible to smoothly remove these pieces.

ADVANTAGE OF THE INVENTION According to this invention, it is possible to construct a pipe mouth seal with good workability, and to start filling the back-filling material without any delay, and to suppress leakage of the back-filling material.

FIG. 4 is a schematic vertical cross-sectional view showing a state in which pipe mouth seals according to one embodiment of the present invention are applied to openings at both ends of a gap between the existing pipe and the rehabilitated pipe after installing the rehabilitated pipe in the existing pipe. It is the front view which looked at the pipe-mouth seal structure of the upstream from the manhole side. It is a top view of the pipe mouth seal structure. It is an exploded front view of the pipe mouth seal structure. (A) and (B) are cross-sectional views showing engagement states of the intermediate piece and the rehabilitating pipe of the pipe mouth seal structure at different positions. It is a figure which shows the end surface above the main part of the same intermediate piece. It is a figure which shows the end surface above the lower piece of the pipe mouth seal structure. It is the front view which looked at the pipe mouth seal structure of the downstream from the manhole side.

An embodiment of the present invention will be described below with reference to the drawings. An existing pipe 1 shown in FIG. 1 is, for example, a sewage pipe, and is laid between an upstream manhole 2A and a downstream manhole 2B. A deteriorated existing pipe 1 is rehabilitated by lining its inner circumference with a rehabilitative pipe 3. - 特許庁The outline of this rehabilitation method will be described below.

<Installation process of rehabilitation pipe>
In this embodiment, the rehabilitating pipe 3 is constructed by spirally winding a belt-shaped member 10 (profile) made of a synthetic resin such as polyvinyl chloride, and joining the side edges of adjacent wound portions. As exemplified in FIG. 5, the belt-shaped member 10 has the same cross-sectional shape in the longitudinal direction, and includes a belt plate-shaped main belt portion 11 and a female fitting formed on one side edge of the main belt portion 11. It has a portion 12, a male fitting portion 13 formed on the other side edge, and two stiffening ribs 14, for example. One surface of the main belt portion 11 is a smooth surface, and a female fitting portion 12, a male fitting portion 13, and reinforcing ribs 14 are formed so as to protrude from the other surface. The female fitting portion 12 and the reinforcing rib 14 are protrusions having the same height.

By spirally winding the belt-shaped member 10 and overlapping the side edges of adjacent wound portions and compressing them in the radial direction, the female fitting portion 12 and the male fitting portion 13 are fitted to form a retreaded pipe. 3 is obtained. Between the female fitting portion 12 and one reinforcing rib 14, an engaging groove 15 (first engaging portion) is formed which functions as described later.

As shown in FIG. 1, the rehabilitation pipe 3 is installed over the entire length of the existing pipe 1 and protrudes from both ends of the existing pipe 1 by a predetermined amount. Since the outer diameter of the rehabilitating pipe 3 is smaller than the inner diameter of the existing pipe 1 , a gap 4 is formed between the existing pipe 1 and the rehabilitating pipe 3 . Since the rehabilitating pipe 3 rests on the bottom of the existing pipe 1 by its own weight, the gap 4 is largest at the top and gradually becomes smaller toward the bottom.

<Tube mouth sealing process>
After the step of installing the rehabilitating pipe 3, the step of sealing the pipe mouth is performed prior to the step of filling the gap 4 with a back-filling material (not shown). That is, as shown in FIG. 1, the opening of the upstream end of the gap 4 is closed with the tube mouth seal structure 5U, and the opening of the downstream end of the gap 4 is closed with the tube mouth seal structure 5D. As will be described later, these pipe mouth seal structures 5U, 5D are composed of a plurality of pieces 20, 30, 40 (see FIG. 4).

<Filling process of backfilling material>
After the pipe mouth sealing step, a backfilling material filling step is performed. First, the injection device 6 is connected to the top of the upstream port seal structure 5U, and the overflow device 7 is connected to the top of the downstream port seal structure 5D. The injection device 6 and overflow device 7 respectively have pipes 6a, 7a and valves 6b, 7b provided in the pipes 6a, 7a.

When a backfilling material (not shown) is injected from the injection tool 6 , the gap 4 between the existing pipe 1 and the rehabilitation pipe 3 is filled with the backfilling material. The overflow device 7 evacuates air from the gap 4 while the gap 4 is filled with the backfilling material. When the filling of the back-filling material into the gap 4 is completed, the completion of filling can be confirmed by overflowing the back-filling material from the overflow device 7. - 特許庁After confirming that the overflowed back-filling material has the same properties as the injected back-filling material, the valves 6a and 7b of the injection device 6 and the overflowing device 7 are closed to complete the filling of the back-filling material.

<Piece removal process>
After the filling process of the back-filling material is completed and the back-filling material is hardened, the pieces 20, 30, 40 of the pipe mouth seal structures 5U, 5D are removed. The removed pieces 20, 30, 40 can be reused for other site port seals. Finishing mortar is applied to the space after removal.

<Details of pipe mouth seal structure>
The pipe mouth sealing structure that characterizes the present invention will be described in detail. Since the upstream side pipe mouth seal structure 5U and the downstream side pipe mouth seal structure 5D have substantially the same configuration, the same numbers are given to the components. The following description will focus on the pipe mouth seal structure 5U on the upstream side.

As shown in FIG. 4, the pipe mouth seal structure 5U of the present embodiment includes a plurality of, for example, five arc-shaped pieces, that is, a pair of left and right lower pieces 20 (side pieces) and a pair of left and right middle pieces 30 (side pieces). ) and one top piece 40 . These pieces 20, 30, and 40 are preferably made of metal, such as steel, from the viewpoint of workability and strength, but they may be made by carving out wood.

The pair of lower pieces 20, the pair of intermediate pieces 30, and the top piece 40 are based on the inner diameter of the existing pipe 1 and the outer diameter of the rehabilitating pipe 3. It is designed to correspond to the cross-sectional shape of the gap 4 and has an outer shape capable of substantially closing the gap 4 . Therefore, the pair of lower pieces 20 have laterally symmetrical external shapes when viewed from the tube axis direction, and the pair of intermediate pieces 30 also have laterally symmetrical external shapes. One top portion 40 has a symmetrical outer shape. Details will be described below.

Each of the pair of lower pieces 20 has an angular range of approximately 90°, has a shape and dimensions corresponding to approximately the lower half of the opening of the gap 4, and closes the lower half. The pair of intermediate pieces 30 have an angular range of approximately 60°, and have shapes and dimensions corresponding to the left and right portions of the approximately upper half of the opening of the gap 4, excluding the top portion. It has become. The top piece 40 has a shape and dimensions corresponding to the top of the opening of the gap 4 and closes the top. These pieces 20, 30, 40 are arc-shaped, and the lower piece 20 and the intermediate piece 30 are tapered so that the thickness gradually decreases from the upper end to the lower end. The pieces 20, 30, and 40 are preferably of a size that can be carried by a single person and can be carried in through a manhole with a diameter of 600 mm.

As shown in FIG. 4, the intermediate piece 30 includes a main portion 30A curved in an arc shape and two engaging protrusions 30B (second engaging portion) provided on the inner peripheral side of the curved shape of the main portion 30A. ). As shown in FIG. 5, the main portion 30A has an inner peripheral wall 31 and an outer peripheral wall 32 that face each other in the radial direction, and a back wall 33 located on the back side in the pipe axial direction (opposite side of the manhole 2A). , has a U-shaped cross section.

Further, the main portion 30A has end walls 34 and 35 at both ends in the circumferential direction (longitudinal direction), that is, the upper end and the lower end. Further, the main portion 30A has front walls 36 (see FIG. 4) facing the manhole side at two locations spaced apart in the circumferential direction. Therefore, the main portion 30A has a rectangular cross section (box shape) at the portion having the front wall 36 . The front wall 36 is used as a grip when the intermediate piece 30 is installed in or removed from the opening, as will be described later.

The dimension (width) of the main portion 30</b>A in the tube axis direction is constant, and is twice as wide as the belt-like member 10 . The radial dimension (thickness) of the main portion 30A gradually decreases from the upper end to the lower end. As shown in FIG. 4, the lower end wall 35 is formed with a fitting protrusion 37 (connecting means). For example, two fitting projections 37 are formed apart from each other in the tube axis direction. As shown in FIG. 6, a bolt hole 38 is formed in the center of the upper end wall 34 in the pipe axial direction.

As shown in FIGS. 5A and 5B, the two engaging projections 30B are separated in the tube axial direction by the pitch of the spiral of the band-shaped member 10. As shown in FIGS. The engaging projection 30B extends over the entire length of the main portion 30A so as to draw a spiral at an angle equal to the spiral of the belt-shaped member 10 of the rehabilitation pipe 3 described above, and is Inclined. The engagement projection 30B has a certain height, which is approximately equal to the female fitting portion 12 and the reinforcing rib 14 of the strip member 10. As shown in FIG. The two engaging projections 30B engage with the engaging grooves 15 of the two wound portions of the rehabilitating pipe 3, respectively.

As shown in FIG. 4, the lower piece 20 also includes a main portion 20A curved in an arc shape and two engaging protrusions 20B (second engaging portions) provided inside the curved shape of the main portion 20A. have. In this embodiment, the main portion 20A is hollow with a rectangular cross section, but it may be solid. The main portion 20</b>A has a constant dimension (width) in the tube axis direction and is equal to the main portion 30</b>A of the intermediate piece 30 . The radial dimension (thickness) of the main portion 20A gradually decreases from the upper end to the lower end.

The main portion 20A has an end wall 21 at its upper end. As shown in FIG. 7, the end wall 21 is formed with a bolt hole 22 in the center in the pipe axial direction, and fitting recesses 23 (connecting means) are formed on both sides in the pipe axial direction.

The two engaging projections 20B of the lower piece 20 are separated in the tube axial direction by the spiral pitch of the band-shaped member 10, like the engaging projections 30B of the intermediate piece 30. As shown in FIG. Similar to the engaging projection 30B of the intermediate piece 30, this engaging projection 20B also extends in a spiral with an angle equal to that of the spiral of the band-shaped member 10, and is inclined with respect to the extending direction (longitudinal direction) of the main portion 20A. are doing. The height of the engaging projection 20B is equal to that of the engaging projection 30B of the intermediate piece 30. As shown in FIG. As will be described later, when the intermediate piece 30 is joined to the lower piece 20, the position of the main portion 30A of the intermediate piece 30 in the pipe axis direction coincides with the main portion 20 of the lower piece 20, and the two threads of the intermediate piece 30 are engaged. The protrusion 30B is substantially connected to the two engaging protrusions 20B of the lower piece 20 in a spiral manner.

As shown in FIG. 4, the top piece 40 does not have engaging projections like the middle piece 30 and the bottom piece 20. FIG. Similar to the main portion 30A of the intermediate piece 30, the top piece 40 has an inner peripheral wall 41, an outer peripheral wall 42, and a rear wall 43 to form a U-shaped cross section. It has front walls 46 at two spaced apart locations. The top piece 40 has the same axial dimension (width) as that of the main portion 30A of the intermediate piece 30, and its radial dimension (thickness) gradually decreases from the center toward both ends. This radial dimension change may be slight and constant. Left and right end walls 44 of the top piece 40 are formed with two bolt holes (not shown) spaced apart in the pipe axial direction, and pressure bolts 50 (connecting means) are screwed into the bolt holes. It has become so.

As exaggeratedly shown in FIG. 3, the circumferential length of the top piece 40 gradually decreases from the manhole side toward the back, and both circumferential end faces (end walls 44) of the top piece 40 extend toward the back. are inclined with respect to the tube axis direction so that they approach each other. That is, the top piece 40 has a wedge shape when viewed from above. Correspondingly, the end face of the intermediate piece 30 on the side of the top piece 40 is also inclined. As shown in FIG. 4, a hole 48 (a hole for injecting a back-filling material) is formed in the center of the inner wall 43 of the top piece 40 in the circumferential direction.

As shown in FIG. 8, the downstream side pipe mouth seal structure 5D has all the configurations of the above-described upstream side pipe mouth seal structure 5U. A hole 48 formed in the top piece 40 of this mouth seal structure 5D is used to allow the backfill material to overflow. Furthermore, in the pipe mouth seal structure 5D on the downstream side, the back wall 33 of the intermediate piece 30 is formed with a plurality of holes 39 for overflow of the backfilling material.

<Details of pipe mouth sealing process>
As described above, the upstream and downstream openings of the gap 4 between the existing pipe 1 and the rehabilitated pipe 3 are sealed by constructing the pipe mouth seal structures 5U and 5D. Specifically, first, the left and right lower pieces 20 are fitted into the lower half of the opening of the gap 4 to close the lower half. Specifically, above the final installation position of the lower piece 20, the lower piece 20 is inserted into the opening of the gap 4 from the pipe axial direction, and the two engaging projections 20B are engaged with the two winding portions of the rehabilitating pipe 3. It is dropped while aligned with the groove 15.例文帳に追加As a result, the lower piece 20 moves downward along the circumferential direction and is fitted into the lower half of the opening while the engaging projection 20B is engaged with the engaging groove 15. As shown in FIG. Since the lower piece 20 is tapered downward and the engaging protrusion 20B is guided by the engaging groove 15, the lower piece 20 can be smoothly fitted into the predetermined position of the lower half of the opening. .

Next, the left and right intermediate pieces 30 are fitted into the left and right portions of the upper half of the opening of the gap 4 excluding the top portion to close the left and right portions. Specifically, the intermediate piece 30 is inserted above the final fitting position, that is, at the top of the opening of the gap 4 or in the vicinity thereof from the pipe axial direction, and the engaging projection 30B is aligned with the engaging groove 15 of the rehabilitating pipe 3. Drop it in the state of As a result, the end wall 35 of the intermediate piece 30 contacts the end surface of the lower piece 20 , and the fitting projection 37 fits into the fitting recess 23 . The two engaging projections 30B engage with the engaging grooves 15 of the two winding portions of the rehabilitating pipe 3, respectively, and are connected to the two engaging projections 20B of the lower piece 20 in a spiral manner. Since the intermediate piece 30 is also tapered downward and the engaging protrusion 30B is guided by the engaging groove 15, it can be smoothly fitted into a predetermined position in the intermediate portion of the opening.

Next, the top piece 40 is pushed into the top of the opening of the gap 4, that is, the space between the left and right intermediate pieces 30 from the pipe axial direction. Since the top piece is wedge-shaped as described above, it can be smoothly pushed in, and its axial position can be aligned with the main portion 30A of the intermediate piece 30 .
In this manner, the pair of lower pieces 20, the pair of intermediate pieces 30 and the top piece 40 are installed on a plane orthogonal to the pipe axis of the existing pipe 1 (rehabilitation pipe 3).

Next, the pressure bolt 50 screwed into the end wall 44 of the top piece 40 is screwed toward the intermediate piece 30, and the tip 51 (indicated by the two-dot chain line in FIG. 6) is strongly pressed against the end wall 34 of the intermediate piece 30. The pressing joins the top piece 40 and the middle piece 30 together. Also, the intermediate piece 30 is strongly joined to the lower piece 20 by the pressing force of the pressing bolt 50 .

The outer circumferences of the pieces 20 , 30 , 40 have the same radius as the inner circumference of the existing pipe 1 and are in surface contact with the inner circumference of the existing pipe 1 . The inner circumferences of the pieces 20, 30, and 40 have the same radius as the outer circumference of the rehabilitation pipe 3 (the radially outer ends of the female fitting portion 12 and the reinforcing ribs 14). touch. In this way the opening of the gap 4 is sealed.

When the existing pipe 1 deteriorates, unevenness is formed on its inner peripheral surface and gaps are formed between the outer circumferences of the pieces 20, 30, and 40, and mortar is rubbed into the gaps. Even if a gap is formed between the pieces 20, 30, 40, the gap is filled with mortar. In this way, construction of the tube mouth seal structures 5U and 5D is completed.

Since the opening of the gap 4 is sealed with the pieces 20, 30, 40 without using a large amount of clay cement as described above, workability can be greatly improved.
In addition, even when the pipe mouth seal is constructed while water is flowing through the existing pipe 1 and the rehabilitation pipe 3, once the lower piece 20 is fitted into the lower half of the opening of the gap 4, the work can be carried out without being washed away. The lower piece 20 can be stably fitted into the opening of the gap 4 due to the engagement between the engaging protrusion 20B and the engaging groove 15 of the rehabilitating pipe 3 .

When water is flowing in the existing pipe, the water level should be 30% or less of the inner diameter of the existing pipe in principle. is preferred. More preferably, the lower half of the opening is closed as in this embodiment.

<Action of pipe mouth sealing structure in backfilling process>
When filling the back-filling material, the above-described injection device 6 is inserted into the hole 48 formed in the top piece 40 of the upstream pipe mouth seal structure 5U, and the hole formed in the top piece 40 of the downstream pipe mouth seal structure 5D is inserted. The above-described overflow device 7 is inserted into the hole 48, and the injection device 6 is filled with the back-filling material.

Since the engaging projections 20B, 30B of the lower pieces 20, 30 are engaged with the engaging grooves 15 of the rehabilitating pipe 3, the lower piece 20 and the intermediate piece 30 are prohibited from moving relative to the rehabilitating pipe 3 in the pipe axial direction. It is Further, since the fitting concave portion 23 of the lower piece 20 and the fitting convex portion 37 of the intermediate piece 30 are fitted together, and the bolt 50 of the top piece 40 is strongly pressed against the end wall 34 of the intermediate piece 30, the pieces 20, 30, 40 are strongly connected. Therefore, even if the filling pressure of the back-filling material is applied to the tube mouth seal structures 5U and 5D, the tube mouth seal structures 5U and 5D can reliably maintain the installation position and exhibit a good sealing function. can be done.

Since the intermediate piece 30 of the pipe mouth seal structure 5D on the downstream side is formed with a hole 39 for overflow of the backfilling material, the backfilling material overflows from the hole 39 in the process of filling the backfilling material. , the filling status of the backfilling material can be confirmed. After confirming the overflow of the back-filling material, the hole 39 is closed with a cap or the like.

<Details of the piece removal process>
After the filling process of the back-filling material is completed and the back-filling material is cured, the pieces 20, 30, 40 of the pipe mouth seal structures 5U, 5D are removed. Details are given below.
First, the top piece 40 is removed by loosening the bolts 50 of the top piece 40, grasping the front wall 46 of the top piece 40 and pulling it axially toward the manhole. If the top piece 40 is stuck and cannot be pulled out easily by hand, it is pulled out by hooking a wire to the front wall 46 and pulling it with a lever lock (pulling device).

Next, the intermediate piece 30 is grasped by the front wall 36 and pulled upward along the circumferential direction. If the intermediate piece 30 is fixed and cannot be easily pulled out manually, hit the front wall 36 from below with a hammer to release the fixation and then pull it out. If the fixation is stronger, a hook bolt (not shown) is screwed into a bolt hole 38 (see FIG. 6) formed in the upper end wall 34 of the intermediate piece 30, and a wire is passed through the hook bolt to secure the lever lock. Pull out by pulling.

Next, the lower piece 20 is pulled upward along the circumferential direction. Specifically, a hook bolt (not shown) is screwed into a bolt hole 22 (see FIG. 7) formed in the end face of the lower piece 20, and a wire is attached to the hook bolt to pull it out with a lever lock.

Since the intermediate piece 30 and the lower piece 20 are tapered downward, they can be removed smoothly by pulling them upward.

<Other embodiments>
The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the scope of the invention.
As shown in FIGS. 3 and 4, by fixing a plate-like stopper 100 projecting toward the top piece 40 to the rear surface of the main portion 30A of the intermediate piece 30, the top piece 40 is prevented from moving backward. may be regulated. In this case, the top piece 40 may not be wedge-shaped (that is, both end faces of the top piece 40 and the end faces of the intermediate piece 30 may extend in the pipe axial direction).
The number of pieces of the tube mouth seal structure may be three. That is, it may be composed of a pair of left and right side pieces and one top piece. Also, the tube mouth seal structure may include a plurality of pairs of intermediate pieces.

Water stoppage may be improved by providing rubber on the surface of the piece that contacts the existing pipe or by using rubber on the engaging projections. In this case, it is preferable to use hard slippery rubber.

A pressing bolt may be screwed into a bolt hole formed in the upper end of the intermediate piece, and the pressing bolt may be pressed against the end face of the top piece. In this case, the bolt holes in the intermediate piece are used both for the screwing of the pressure bolt and the screwing of the hook bolt, and no bolt hole is formed in the top piece.
Alternatively, the lower piece may be provided with a fitting protrusion and the intermediate piece may be provided with a fitting recess.

Instead of extending along the spiral, a plurality of engagement projections of the lower piece and the intermediate piece may be formed at intervals along the spiral. Also, the engaging projection may be locally formed only in one place and engaged with the engaging groove of the rehabilitating pipe.

The lower ring, intermediate ring and top ring may be arranged in a spiral along the strip of rehabilitated pipe instead of being placed on a plane perpendicular to the pipe axis. In this case, the engaging protrusions are formed parallel to the extending directions of the main portions of the lower ring and the intermediate ring.
The rehabilitating pipe is not limited to a form in which a belt-like member is spirally wound, and various forms such as those formed by plate-like segments can be adopted. A structure in which the belt-shaped member 10 is joined to the adjacent belt-shaped member 10 via a separate connecting member may be employed.
Existing pipes may be water supply pipes, agricultural water pipes, hydroelectric power transmission pipes, gas pipes, tunnels, and the like.

INDUSTRIAL APPLICABILITY The present invention can be applied to rehabilitation technology for existing pipes such as aged sewage pipes.

1 Existing pipe 3 Rehabilitation pipe 4 Gap 5U, 5D Pipe mouth seal structure 10 Belt-shaped member 11 Main belt portion 12 Female fitting portion (projection)
14 Reinforcement rib (ridge)
15 engagement groove (first engagement portion)
20 lower piece (side piece)
20A Main portion 20B Engagement projection (second engagement portion)
22 bolt hole 23 fitting recess (connecting means)
30 middle piece (side piece)
30A Main portion 30B Engagement projection (second engagement portion)
37 fitting protrusion (connecting means)
38 bolt hole 40 top piece 48 hole (hole for injection of backfill material; hole for overflow of backfill material)
50 pressure bolt (connecting means)

Claims (14)

In a pipe mouth seal structure for sealing openings located at both ends of the gap in the axial direction of the pipe before filling the gap between the existing pipe and the rehabilitated pipe installed in the existing pipe with a backfilling material,
A tube mouth seal structure comprising a plurality of pieces having a shape corresponding to the opening of the gap, and closing the opening with the pieces. The plurality of pieces has at least a pair of side pieces that close left and right portions of the opening of the gap, and a top piece that closes the top of the opening. 2. The tube mouth seal structure according to claim 1, wherein the external shape when viewed is bilaterally symmetrical. The at least one pair of side pieces includes a pair of left and right lower pieces that close a lower portion of the opening, and at least a pair of left and right intermediate pieces that are located between the lower piece and the top piece and close an intermediate portion of the opening. 3. The tube mouth seal structure according to claim 2, further comprising: The top piece consists of a single piece, and a hole for injecting a back-filling material is formed in the top piece that closes the top of the opening at one end in the pipe axial direction, and is formed at the other end in the pipe axial direction. 4. The tube mouth seal structure according to claim 2, wherein the top piece that closes the top of the opening is formed with a hole for overflowing the back-filling material. A first engaging portion is formed on the outer circumference of the rehabilitating pipe, a second engaging portion is formed on the inner circumference of the side piece, and the first engaging portion and the second engaging portion are engaged. 5. The pipe mouth seal structure according to any one of claims 2 to 4, wherein the axial movement of the side piece with respect to the rehabilitating pipe is restricted. The rehabilitating pipe is obtained by spirally winding a belt-shaped member and joining the side edge portions of adjacent wound portions. has at least two ridges protruding from the outer surface of the ridge, and an engagement groove as the first engagement portion is formed between the ridges,
6. The tube mouth seal structure according to claim 5, wherein an engaging projection that engages with the engaging groove is formed as the second engaging portion on the inner peripheral surface of the side piece. The plurality of pieces are arranged on a plane perpendicular to the pipe axis, and the engaging protrusions of the side pieces extend in a spiral with an angle equal to the spiral of the belt-shaped member of the rehabilitating pipe. The tube mouth seal structure according to claim 6. 4. The pipe mouth seal structure according to claim 3, further comprising connecting means for connecting the ends of the pieces adjacent in the circumferential direction. The connecting means includes a fitting recess formed at an end of one of the adjacent lower piece and the intermediate piece, and a fitting fitted into the fitting recess formed at an end of the other piece. 9. The tube mouth seal structure according to claim 8, comprising: a projection. The connecting means includes a pressure bolt screwed into the end of one of the adjacent top piece and the intermediate piece, and by pressing the tip of the pressure bolt against the end surface of the other piece, the The tube mouth seal structure according to claim 8, wherein the top piece and the intermediate piece are connected so as not to move relative to each other. The tube mouth seal structure according to any one of claims 2 to 10, wherein a bolt hole for screwing a hook bolt is formed in the upper end of the side piece. A rehabilitation pipe installation process for installing a rehabilitation pipe in an existing pipe;
a pipe mouth sealing step of sealing the openings located at both ends in the pipe axial direction of the gap between the existing pipe and the rehabilitated pipe;
a back-filling material filling step of filling the gap with a back-filling material;
In the existing pipe rehabilitation method comprising
A method for rehabilitating an existing pipe, wherein in the pipe mouth sealing step, the opening is closed using a plurality of pieces having a shape corresponding to the opening of the gap. The plurality of pieces include a pair of left and right lower pieces that close the lower portion of the opening, one top piece that closes the top of the opening, and a portion of the opening that is positioned between the lower piece and the top piece. At least a pair of left and right intermediate pieces closing the intermediate portion,
In the pipe mouth sealing step,
a step of closing the lower part of the opening by inserting the lower piece into the opening from the pipe axial direction and moving it downward along the circumferential direction of the opening;
a step of closing an intermediate portion of the opening by inserting the intermediate piece into the opening from the direction of the tube axis and then moving the intermediate piece downward along the circumferential direction of the opening;
13. The method for rehabilitating an existing pipe according to claim 12, wherein the step of plugging the top of the opening by inserting the top piece between the intermediate pieces in the axial direction of the pipe is sequentially performed. 14. The existing pipe according to claim 13, further comprising a piece removing step of removing the plurality of pieces from the opening after the backfilling material filling step is completed and the backfilling material is cured. Rehabilitation method.

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