JP3294187B2 - Rehabilitation of underground pipes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rehabilitating a buried pipe in the ground. It is used when laying a new pipe inside, especially a relatively thin pipe that cannot be inserted by humans.

[0002]

2. Description of the Related Art When damage such as cracks occurs in a relatively thin pipe buried underground for water supply, sewage, agricultural water, industrial water, gas, etc., which is small enough for humans to enter.
As a method of rehabilitating the pipes, a number of tapered pipes of a certain length smaller than the buried pipes are buried in the underground buried pipes, and a packing made of water-expandable rubber is wound on the small diameter portion in advance and nested and connected. Thus, a method of forming a new conduit is known (see Japanese Patent Application Laid-Open No. 9-222182).

[0003] The above-mentioned method using a tapered pipe can reduce the loss of the effective space of an existing pipe as compared with the conventional general method using a plastic pipe with a socket.
In addition, it is possible to cope with the case where the existing pipe is curved, but it is possible to connect many tapered pipes while pushing in the tapered pipes one by one from the upstream manhole and reach the first tapered pipe to the downstream manhole. Therefore, as the laying work progresses, the number of tapered pipes that move in the existing pipe increases, and when the existing pipe is meandering, the resistance increases and the taper pipe deforms or cannot be drawn. There were inconveniences such as becoming possible.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a method for rehabilitating an underground buried pipe in which a tapered pipe is laid in a damaged existing pipe as described above. Another object of the present invention is to prevent the deformation of the tapered tube.

[0005]

A first means for solving the above-mentioned problem is that a number of tapered pipes of a fixed length smaller than the buried pipe are wrapped in a buried pipe underground, and packing is previously wound on a small diameter portion thereof. In a method of rehabilitating a buried pipe that is nested and connected in a nested manner to form a conduit, when the tapered pipe is inserted into one end of the buried pipe connecting two adjacent manholes with its small diameter side inserted first, By attaching a pneumatically operated clamp to the inner surface of the tapered tube, the small diameter portion of the tapered tube and the packing thereon are covered with an umbrella-shaped cover which is connected to the clamp via a stem and elastically opens and closes. After pulling the shaped cover together with the above tapered pipe into the buried pipe by tension, and after the above umbrella shaped cover enters the large diameter portion of the preceding tapered pipe, the connection between the clamp and the tapered pipe is released. Underground characterized by extracting the peripheral portion from between the packing on the tapered pipe and the preceding tapered pipe again by pulling the umbrella-shaped cover and bringing the outer periphery of the packing into close contact with the inner surface of the large diameter portion of the preceding tapered pipe. This is a method of rehabilitating a buried pipe.

The above-mentioned tapered tube can be made of stainless steel, plastic (for example, vinyl chloride), FRP, or the like. However, stainless steel is preferable because it has excellent strength and can be made thin. Its length and outer diameter can be set appropriately according to the degree of curvature and inner diameter of the existing buried pipe, but in any of stainless steel or plastic, the difference between the outer diameter of the large diameter part and the inner diameter of the existing pipe is 10 mm is enough. The taper preferably has a length of about 40 to 60 mm in the connecting portion. For example, when the inner diameter of the existing pipe is 250 mm, the length of the tapered pipe made of stainless steel is 500 to
700 mm, the outer diameter of the large diameter portion is 230 to 240 mm, the thickness is 1.0 to 3.0 mm, and the taper is 1/70 to 1/5.
0 is preferred. In the case of a tapered tube made of plastic, the length is preferably 500 to 700 mm, the outer diameter of the large diameter portion is 230 to 240 mm, the wall thickness is 5 to 9 mm, and the taper is preferably 1/70 to 1/50. .

The above-mentioned tapered pipe is pushed into the existing buried pipe one by one with the small diameter side from one of the two adjacent manholes to the other, and then pulled from the other, so that the large-diameter portion of the preceding tapered pipe is drawn. Connected to. However, it is not necessary to attach an umbrella-shaped cover to all the tapered pipes from one manhole to the other manhole and pull it from the other,
The first one or several tapered pipes can be installed one by one from the other manhole without attaching the above umbrella-shaped cover.
Alternatively, it is possible to insert several cables into an existing buried pipe while connecting them in a nested manner. In addition, the last one or several tapered pipes shall be inserted from one manhole one by one or several nested into the existing buried pipe without attaching the above umbrella-shaped cover. Can be.

When the tapered pipe is inserted into the buried pipe from one of the manholes, a pneumatically operated clamp is attached to the inner surface of the tapered pipe so that the clamp is connected to the clamp via a stem and is elastically opened and closed. The small diameter portion of the tapered tube and the packing thereon are covered with an umbrella-shaped cover. The umbrella-shaped cover may be any one that can elastically open and close to cover the small diameter portion of the tapered tube and the packing thereon, and can pass through the preceding tapered tube when closed. By attaching the umbrella-shaped cover, when the umbrella-shaped cover is pulled toward the other manhole side in the buried pipe, the tapered tube with the umbrella-shaped cover attached can be smoothly moved. After the umbrella-shaped cover enters the large-diameter portion of the preceding tapered pipe, the connection between the clamp and the tapered pipe is released and the umbrella-shaped cover is pulled, so that the periphery of the umbrella-shaped cover and the packing on the tapered pipe advance. The packing is pulled out from between the pipes, the outer periphery of the packing comes into close contact with the inner surface of the large-diameter portion of the preceding tapered pipe, and the connection portions of the front and rear tapered pipes are sealed.

The umbrella-shaped cover includes a top disk having a diameter smaller than the inner diameter of the small diameter portion of the tapered tube, and a cylindrical portion having one end fixed to the outer periphery of the top disk. An example in which the cylindrical portion is formed of a plurality of strip-shaped spring plates densely arranged in the circumferential direction is exemplified. The thickness of the spring plate is preferably about 0.1 to 0.3 mm. If the thickness is less than 0.1 mm, deformation or breakage occurs due to friction with the inner surface of the buried pipe.
If it exceeds 3 mm, it will be too thick, and it will be difficult to withdraw from the space between the packing on the tapered pipe and the preceding tapered pipe.

The umbrella-shaped cover is connected via a stem to a pneumatically operated clamp fixed to the inner surface of the tapered tube. Formed and expanded by air pressure,
It is preferable that it is formed so as to be in close contact with the inner surface of the tapered tube at the time of expansion and smaller than the inner diameter of the small diameter portion of the tapered tube at the time of contraction in terms of structural simplicity. The rubber cylindrical clamp described above can be formed so as to surround a cylindrical drum connected to the stem. In this case, the amount of compressed air to be charged can be reduced to enable quick operation. Then, the weight can be fixed to a part of the inner surface of the trunk to lower the center of gravity. In this case, the posture of the tapered pipe can be kept constant when the tapered pipe is pulled by the cord-like body.

It is not necessary to provide packing at the small diameter portion of the first tapered tube connected to the other manhole, but the second and subsequent tapered tubes need to seal the connection with the preceding tapered tube. A sealing packing is wound on the top and the top, and fixed by bonding. As this packing, a packing made of a water-swellable rubber is preferable. This water-swellable rubber expands by absorbing water,
At this time, the joint between the two tapered tubes is sealed, and is manufactured by mixing a water-absorbing resin with rubber or imparting hydrophilicity to rubber by a chemical reaction. Then, when the laying of the tapered pipe with respect to the entire length of the existing buried pipe is completed, cement mortar is injected between the new pipe made of this tapered pipe and the existing buried pipe according to a conventional method, and the new pipe is fixed. .

A second means for solving the above-mentioned problem is to connect several tapered pipes to one end of a buried pipe connecting two adjacent manholes in a nested manner, and to insert the tapered pipe with its small diameter side first. By attaching pneumatically actuated clamps, which are connected to each other on the inner surfaces of the leading and trailing tapered tubes by a string-like body, the umbrella-shaped cover is connected to the leading clamp via a stem and elastically opens and closes. The small-diameter portion of the tapered tube and the packing thereon are covered, and the umbrella-shaped cover is pulled into the buried tube together with the several tapered tubes by pulling, and the peripheral portion of the umbrella-shaped cover is preceded by the large-diameter portion of the tapered tube. , The connection between the first and second clamps and the tapered pipe is released, and then, by pulling the umbrella-shaped cover again, the peripheral portion is inserted between the packing on the first tapered pipe and the preceding tapered pipe. Drawer, characterized in that is brought into close contact with the large-diameter portion the inner surface of the tapered tube which precedes the outer periphery of the packing to.

In the second means, while the first means attaches an umbrella-shaped cover to one tapered pipe and draws it into the existing buried pipe, several tapered pipes are connected in a nested manner. In this method, one set is drawn into the buried pipe as a unit. In this case, a pneumatically operated clamp is attached to each of the leading and trailing tapered pipes, and an umbrella-shaped cover is fixed to the leading clamp via a stem in the same manner as described above. The part is covered and the tail clamp is tied to the leading clamp with a string to prevent separation of the group of tapered tubes. Therefore, the number of times of attaching the umbrella-shaped cover is reduced to several times as compared with the first means, and the work efficiency is improved accordingly. The structures of the umbrella cover and the clamp may be the same as those of the first means. The number of tapered pipes included in one set is preferably 2 to 10, and is appropriately set according to the radius of curvature of the buried pipe.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 In FIG. 1, a tapered tube 10 is made of stainless steel and has a length of 500 to 700 mm and an outer diameter of a large diameter portion of 230 to 240 m.
m, thickness 1.0-3.0mm, taper 1 / 70-1 / 50
A band-shaped packing 11 made of a water-expandable rubber manufactured by mixing rubber and a water-absorbent resin is wound on the small-diameter portion on the left side, and is fixed by bonding so as not to be displaced. Have been.

An umbrella-shaped cover 20 for covering the small diameter portion of the tapered tube 10 has a top disk 21 having a diameter smaller than the inside diameter of the small diameter portion of the tapered tube 10, and one end fixed to the outer periphery of the top disk 21 with one end fixed. (Right side in the figure). The cylindrical portion 22 is formed in a cylindrical shape with a spring plate having a thickness of 0.1 to 0.3 mm, and has an inward flange formed at one end thereof, and this flange overlaps the top disk 21 and the front surface thereof. Between the holding plate 23 and the bolt 24
It is fixed by tightening. Then, a large number of cuts 22a are densely arranged by forming a large number of cuts in a portion other than the flange in the axial direction.
By forming a into a cone shape spreading backward, the free end of the strip 22a forms a peripheral portion of the umbrella-shaped cover 20 and can surround the packing 11, and at this time, between the adjacent strips 22a. Gaps occur. On the other hand, when the cylindrical portion 22 is compressed in the radial direction against the elasticity, the strip 22 is compressed.
a is closed and the above-mentioned gap disappears to form a cylindrical shape.

At the center of the back surface of the top disk 21, a stem 25 is provided.
A rubber cylindrical clamp 27 is fitted on the surface of the drum 26, and both ends thereof are fixed to the drum 26 by tightening bands 28. An air hole 26a is provided at the lower end of the drum 26, one end of an air hose 29 for supplying compressed air inserted inside the drum 26 is connected to the air hole 26a, and an air compressor (not shown) is connected to the other end. Is connected. A weight is attached to the inner surface of the lower end of the drum 26 as necessary,
The center of gravity of the drum 26 can be lowered. Strings 31a and 31b such as wires, ropes, and chains are detachably connected to the lower front portion of the holding plate 23 and the lower rear portion of the drum 26 via connection fittings 30, respectively. Further, the umbrella-shaped cover 20, the stem 25, the drum 26 and the clamp 27 are attached to the tapered pipe 10 and
A jig for insertion into the inside is constituted.

The above-mentioned umbrella-shaped cover 20 has an air hose 29 removed from the drum 26, and cords 31a and 31b removed from the front and rear connection fittings 30, respectively. (Fig. 2
), The packing 11 on the small-diameter portion of the tapered tube 10 is pushed into the inside of the peripheral portion (free end) of the umbrella-shaped cover 20, and then the air hose 29 is connected to the air hole 26 a of the drum 26. The clamp 27 is expanded by introducing compressed air between the clamp 26 and the clamp 27, and is brought into close contact with the inner surface of the tapered tube 10 (see FIG. 1).

In FIG. 3, reference numeral 1 denotes an upstream manhole;
Is a downstream manhole, and when a crack or the like occurs in the buried pipe 3 connecting the manholes 1 and 2, a tapered pipe 10 is provided at the end of the buried pipe 3 on the downstream manhole 2 side to direct a small diameter portion toward the downstream manhole 2. The string 31b on the downstream side is passed through the entire length of the buried pipe 3 so as to pass through the tapered pipe 10 and the tip thereof is placed at the upstream end of the buried pipe 3. Next, the umbrella-shaped cover 20 is inserted from the upstream manhole 1 together with the drum 26 into the upstream end of the buried pipe 3 in a contracted state of the clamp 27, and the above-mentioned cord-shaped cover is attached to the connection fitting 30 at the lower front part of the umbrella-shaped cover 20. The body 31b is connected.

Subsequently, a second tapered pipe 10 to which the packing 11 is fixed is inserted into the upstream end of the buried pipe 3, and the packing 11 is placed around the cylindrical part 22 in which the umbrella-shaped cover 20 is in a spread state. That is, the strip 22a is pushed to the position where it enters the free end. Further, an air hose 29 and an upstream cord-like body 31a are connected to the drum 26, respectively, and the clamp 27 on the drum 26 is filled with compressed air to fix the drum 27 to the second tapered tube 10, and from the downstream manhole 2 By pulling the downstream cord-like body 31b, the second tapered tube 10 is drawn into the buried tube 3 with the umbrella-shaped cover 20 attached and proceeds downstream, and the umbrella-shaped cover 20 is moved ahead of the first taper. It enters the large diameter portion of the tube 10 together with the packing 11 on the tapered tube 10.

In this case, since the small diameter portion of the tapered tube 10 and the packing 11 are covered with the umbrella-shaped cover 20,
The movement of the tapered pipe 10 in the buried pipe 3 and the fitting of the second tapered pipe 10 to the first tapered pipe 10 are performed smoothly, and the packing 11 is not damaged. Further, since the downstream side string-shaped body 31b is connected to the lower part of the holding plate 23 and the air hose 29 is connected to the lower end of the drum 26, the tapered tube 10 does not roll over during tension. When the weight is fixed to the lower end of the inner surface of the drum 26, the posture of the tapered tube 10 is further stabilized, and
When a horizontal hole for connecting a branch pipe is provided at 0, the position of the horizontal hole does not shift up and down.

When the umbrella-shaped cover 20 attached to the second tapered tube 10 as described above enters the first tapered tube 10, the compressed air in the clamp 27 is released from the air hose 29.
, And the clamp 27 contracts so that the umbrella-shaped cover 20 can be separated from the tapered tube 10. Therefore, when the umbrella-shaped cover 20 is pulled again by the downstream side string-shaped body 31b, the peripheral portion (the free end of the strip 22a) of the tubular body 22 of the umbrella-shaped cover 20 is connected to the first tapered tube 10 and the second tapered tube. Slip through from between the packing 11 on the tapered tube 10,
A pulling jig including the umbrella-shaped cover 20, the stem 25, the drum 26, and the clamp 27 is drawn into the downstream manhole 2. Therefore, the front and rear string members 31a and 31b are removed from the front and rear connection fittings 30, and the pulling jig including the umbrella-shaped cover 20 or the clamp 27 is returned to the upstream manhole 1 via the ground, while the above-described string member is removed. 31a and 31b are connected to each other, pulled to the upstream manhole 1 side, and the connection is returned to the upstream end through the buried pipe 3.

Hereinafter, similarly, the third and subsequent tapered tubes 1
0 is sequentially sent one by one from the upstream end to the downstream side of the buried pipe 3 to form a new pipeline composed of a large number of tapered pipes 10 in the buried pipe 3. During this time, cement mortar is injected to fix the tapered tube 10.

Embodiment 2 As shown in FIG. 4, several tapered tubes 10 (three in the illustrated example) connected in advance in a nested manner are collectively inserted into the buried tube 3. In this case, clamps 27 and 27A are attached to the inner surfaces of the first tapered tube 10 and the last tapered tube 10, respectively. Head clamp 2
7 has an umbrella-shaped cover 20 via a stem 25 as described above.
Are connected to each other, and the umbrella-shaped cover 20 covers the small-diameter portion at the leading end of the leading tapered tube 10. Tail clamp 27A
Has a drum 26A similar to the above, and has a drum 26A similar to the above.
A is a simple cylinder having no connecting end plate of the stem 25 on the front surface, and its front end is connected to the leading drum 26 by a string-like body 31c such as a wire, a rope, or a chain via a connecting fitting 30. The upstream side cord-like body 31a is connected to the lower part of the rear surface via the connection fitting 30.

Air hoses 29 and 29A are connected to the leading drum 26 and the trailing drum 26A, respectively.
Are connected so that compressed air can be individually supplied to the front and rear clamps 27 and 27A. The clamps 27, 27A are inserted into the leading and trailing tapered tubes 10, respectively, and compressed air is supplied to the clamps 27, 27A.
Is attached. A packing 11 is fixed in a headband shape in advance to the small diameter portion of each tapered pipe 10, and the three tapered pipes 10 are embedded at a time by pulling the cord 31 b on the downstream side from the manhole on the downstream side. It is pulled into the tube 3. The second embodiment is suitable when the curvature of the buried pipe 3 is small, and when the length of the buried pipe 3 is constant, the number of times of attaching and detaching the pulling jig including the umbrella-shaped cover 20 and the clamp 27 and the string-like bodies 31a and 31b. And the number of movements is greatly reduced as compared with the first embodiment, and the work efficiency is improved.

[0025]

According to the first aspect of the present invention, a large number of tapered pipes of a fixed length are buried in an underground pipe, a packing is fixed in advance on a small-diameter portion thereof, and nested and connected to form a new pipe line. In forming the pipe, one tapered pipe is pulled and transferred from one end to the other end of the buried pipe. At this time, the packing is fixed on the small diameter part, and the small diameter part and the packing are fixed. Is covered with an umbrella-shaped cover fixed to the tapered pipe, so that the tapered pipe can be sent smoothly even when the existing buried pipe is curved,
There is no possibility that the tapered pipe is deformed or unsendable due to resistance when the tapered pipe is pulled in the buried pipe. Moreover,
It can be implemented even if the damaged existing buried pipe is a thin pipe with an inner diameter of 600 mm or less that can not be inserted, and the utilization rate of the inner space of the existing pipe increases compared to the case of laying a conventional socketed pipe. In addition, even when the existing pipe is curved, rehabilitation can be easily performed.

According to a second aspect of the present invention, several, for example, 2 to 10 tapered tubes are connected as one set,
Since the umbrella-shaped cover is attached to the leading tapered pipe and the set of tapered pipes is fed at one time, when the curvature of the existing buried pipe is small, the work efficiency is significantly larger than that of the invention according to claim 1. To improve. The invention described in claim 3 is:
When the tubular portion of the umbrella-shaped cover is sandwiched between the large-diameter portion of the preceding tapered tube and the packing on the small-diameter portion of the succeeding tapered tube, it is easy to extract this tubular portion, and The clamp connected to the umbrella-shaped cover by a stem can be easily attached to and detached from the inner surface of the tapered tube by remote control.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an attached state of an umbrella-shaped cover according to a first embodiment.

FIG. 2 is a cross-sectional view of the tapered tube before the umbrella cover of FIG. 1 is attached.

FIG. 3 is a cross-sectional view of the underground pipe at the time of construction according to the first embodiment.

FIG. 4 is a cross-sectional view illustrating an attached state of an umbrella-shaped cover according to a second embodiment.

[Explanation of symbols]

1, 2: manhole 3: existing buried pipe 10: tapered pipe 11: packing 20: umbrella-shaped cover 21: top disk 22: cylindrical part 22a: strip 23: holding plate 24: bolt 25: stem 26, 26A: Drum 27, 27A: Cylindrical clamp made of rubber 28: Tightening band 29, 29A: Air hose 30: Connection fittings 31a, 31b,
31c: String-shaped body

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16L 1/00

Claims (3)

(57) [Claims] 1. A buried pipe in which a plurality of tapered pipes of a fixed length smaller than the buried pipe are wrapped in an underground buried pipe, and packing is wound in advance on a small diameter portion thereof and nested and connected to form a conduit. In the rehabilitation method, when the tapered pipe is inserted into one end of a buried pipe connecting two adjacent manholes with its small diameter side first, a pneumatically operated clamp is attached to the inner surface of the tapered pipe. The small diameter portion of the tapered tube and the packing thereon are covered with an umbrella-shaped cover which is connected via a stem to elastically open and close, and the umbrella-shaped cover is pulled into the buried tube together with the tapered tube by tension, After the umbrella-shaped cover enters the large-diameter portion of the preceding tapered tube, the connection between the clamp and the tapered tube is released, and then the peripheral portion is tapered again by pulling the umbrella-shaped cover. A method for rehabilitating an underground buried pipe, wherein the packing is pulled out from between a packing on the pipe and a preceding tapered pipe, and an outer periphery of the packing is brought into close contact with an inner surface of a large diameter portion of the preceding tapered pipe. 2. A buried pipe in which a plurality of tapered pipes each having a fixed length smaller than the buried pipe are wrapped in the underground buried pipe, and packing is previously wound around the small diameter portion and nested and connected to form a conduit. In the rehabilitation method, several tapered pipes are nested at one end of a buried pipe connecting two adjacent manholes, and when inserting with the small diameter side first, the inner surface of each of the leading and trailing tapered pipes By attaching pneumatically actuated clamps which are connected to each other by a string, a small diameter portion of the tapered tube and a packing thereon are connected by an umbrella-shaped cover which is connected to the leading clamp via a stem and which opens and closes elastically. After the umbrella-shaped cover is pulled into the buried pipe together with the several tapered pipes by tension, and after the peripheral portion of the umbrella-shaped cover enters the large-diameter portion of the preceding tapered pipe, the first and the second are covered. K Disconnect the connection between the ramp and the tapered pipe, and then pull the umbrella-shaped cover again to pull out the peripheral part from between the packing on the first tapered pipe and the preceding tapered pipe, and extend the outer periphery of the packing to the preceding tapered pipe. A method for rehabilitating underground buried pipes, which is closely attached to the inner surface of a large diameter portion. 3. The method for rehabilitating a buried pipe according to claim 1, wherein the umbrella-shaped cover is located at the top of the buried pipe, and the top disk having a diameter smaller than the inside diameter of the small diameter section of the tapered pipe. It consists of a cylindrical part whose one end is fixed to the outer circumference. This cylindrical part is formed by a number of strip-shaped spring plates densely arranged in the circumferential direction, and the clamp is formed into a cylindrical shape by rubber and expanded and contracted by air pressure. A method of rehabilitating an underground buried pipe formed so as to be in close contact with the inner surface of the tapered pipe during expansion and smaller than the inner diameter of the small diameter portion of the tapered pipe when contracted.