JPH02194928A - Engineering method for lining existing pipe - Google Patents

Abstract

PURPOSE:To make unnecessary the filling of back filling agent after the insertion of a spiral pipe in an existing pipe and consequently contrive to shorten the term of lining works by a method wherein the back filling agent, which is made of one-pack type expandable urethane resin and expands and hardens by moisture, is provided along the outer peripheral surface of the spiral pipe inserting in the existing pipe. CONSTITUTION:A pipe-making machine 20 spirally winds band-like body. At this time, the engaging rib 13 of the band-like body 10 fits in the socket 14 of the band-like body 10, which is spirally wound so as to engage side edge parts, which are adjacent to each other, of the band-like body with each other. At this time, an inclined rib 15, which continuously connects to the socket 14, is fastened to the flange part 16b of a reinforcing rib 16 and, at the same time, an abutting part 17 is put on a portion between the engaging rib 13 and the reinforcing rib 16 of a base plate 12. Back filling agent is applied onto the outer peripheral surface of the base plate 12 of the band-like body 10, which is formed to a spiral pipe 10'. As the back filling agent, one-pack type expandable urethane resin, which expands and hardens by moisture, is exampled. Its expansion starting time and expansion ratio can be controlled by properly changing the mixing ratio of auxiliary agent. After that, the expandable back filling agent expands so as to fill the gap between the spiral pipe 10' and the existing pipe 81.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lining method for existing pipes that is carried out when rehabilitating aging existing pipes. To be more detailed, 2
This invention relates to a method for lining an existing pipe, in which a helical pipe is manufactured by spirally winding a synthetic resin band, and the pipe is directly inserted into the existing pipe to line the existing pipe with the inserted helical pipe.

(Conventional technology) For buried pipes used for water supply and sewerage.

Metal pipes and Huyum pipes have been used since ancient times.

Such buried pipes become obsolete after long-term use, and there is a risk that water may leak due to cracks or corrosion. For this reason, recently, synthetic resin pipes are inserted into existing pipes such as aged buried pipes to line them.

One of the methods for lining existing pipes is a method of lining existing pipes with a spiral pipe manufactured by spirally winding a band-shaped body made of synthetic resin. This method is disclosed in, for example, Japanese Patent Laid-Open No. 61-48690. The method disclosed in this publication is carried out by installing a pipe making machine capable of manufacturing a spiral pipe so as to face the end opening of the existing pipe. The pipe-making machine is sequentially supplied with synthetic resin strips whose side edges can engage with each other, and the pipe-making machine winds the strips in a helical manner, and by the winding. A helical tube is sequentially manufactured by engaging the side edges of adjacent strips. The manufactured spiral tubes are sequentially guided out of the tube making machine while rotating. Then, the spiral pipe led out from the pipe making machine is directly introduced into the existing pipe and is propelled while rotating within the existing pipe. When the spiral pipe is inserted over substantially the entire area of the existing pipe, a backfilling agent such as cement mortar is filled between the spiral pipe and the existing pipe to fix the spiral pipe within the existing pipe. As a result, the existing pipe is lined with the spiral pipe.

The belt-shaped body considered to be a spiral tube is made of polyvinyl chloride. Flexible synthetic resins such as polyethylene and polypropylene are used. The band is usually 9.

A protruding strip is continuously provided in the longitudinal direction on one side edge, and a groove that can be engaged with the protruding strip is continuously provided on the other side edge in the longitudinal direction. When the strip is wound spirally, the protrusions and grooves on the side edges of adjacent strips fit together to form a spiral tube.

(Problems to be Solved by the Invention) In such a lining method, a spiral pipe inserted into an existing pipe is propelled through the existing pipe while rotating once. and,
When the spiral pipe is inserted into the existing pipe, a backfilling agent such as cement mortar is filled between the existing pipe and the spiral pipe, and the spiral pipe is fixed to the existing pipe.

The filling operation with such backfilling material is performed with the spiral pipe completely inserted into the existing pipe, so the work efficiency is poor and it takes a long time. Moreover, in the case of a long existing pipe, it is not easy to fill the backfilling agent up to the longitudinal center of the pipe. A construction method aimed at solving this problem is disclosed in Japanese Patent Laid-Open No. 194029/1983. The foamable synthetic resin used in the construction method disclosed in the above-mentioned publication is a two-component thermally heated foamable synthetic resin consisting of a polyol component and an isocyanate component.

However, 22-liquid heating foam polyurethane.

If the ambient temperature in the existing pipe is low, around 15°C, the time it takes to start one foaming process is relatively long, 60 to 100 minutes, so this does not pose much of a problem when manufacturing spiral pipes. If the ambient temperature in the existing pipeline is 30°C or higher, the chemical reaction that occurs when the two liquids are mixed will be significantly accelerated by the high temperature, so even if a foaming retardant is mixed, the two liquids will not be mixed. Since the time from when the helical tube is moved until the foaming starts is short, about 20 minutes, the foamable synthetic resin foams while the helical tube is being propelled, making it impossible to insert the helical tube throughout the entire area of the existing tube. There was a point. In other words, in the case of sewage pipes, the distance between manholes is about 50 meters, and it usually takes about 30 to 40 minutes to manufacture and insert a spiral pipe into one span of such length, so it is not safe. There is a problem in that unless a foamable synthetic resin has a foaming time of 100 minutes or more in consideration of the foaming rate, it cannot actually be used under high temperature conditions in the summer.

The present invention has been made in view of the above-mentioned conventional problems by focusing on utilizing the extremely high temperature working conditions of existing pipes buried underground.

The purpose is to provide a method for lining an existing pipe, which can fill the entire space between the existing pipe and the spiral pipe with a backfilling agent, and which can significantly shorten the construction period.

(Means for Solving the Problems) The lining method for existing pipes of the present invention includes the steps of spirally winding a synthetic resin strip whose side edges can engage with each other, and A process of manufacturing a helical tube by engaging the side edges of adjacent strips, and an I-liquid type foamable urethane resin that foams and hardens with moisture along the outer circumferential surface of the manufactured helical tube. and a process of sequentially disposing backfilling agents.

The method includes a step of sequentially inserting the manufactured helical tubes into an existing pipe and propelling the inserted helical tubes into the existing pipe, thereby achieving the above object.

(Example) The present invention will be described below with reference to Examples.

For example, the method for lining existing pipes according to the present invention is as follows.

As shown in FIG. 1, this is carried out when rehabilitating an existing concrete sewer pipe 81. The method of the present invention begins with a synthetic resin strip 10 that is unwound from a drum 1.
is made into a spiral tube of 10° using the pipe making machine 20. The pipe making machine 2
0 is a manhole 82 to which one end of the sewer pipe 81 is connected.
The spiral pipes 10' that have been installed inside and made into pipes are sequentially inserted into the sewer pipe 81.

The spiral pipe 10' has an outer diameter such that it does not come into contact with the inner circumferential surface of the sewer pipe 81 except at the bottom.

The strip 10 used in the method of the present invention has a cross-sectional shape, for example, as shown in FIG. The strip 10 is molded from polyvinyl chloride, polyethylene, polypropylene, polycarbonate, polyester, or a resin obtained by reinforcing these resins with glass fiber. The strip-shaped body 10 has a strip-shaped substrate 12 . An engagement rib 13 is provided continuously in the longitudinal direction on one side edge of the substrate 12 . On the same side of the other side edge of the substrate 12.

The socket 14 is in an upright state with respect to the board 12.
are provided continuously in the longitudinal direction.

The engagement rib 13 has an upright portion 13a that stands upright from the substrate 12.

The engagement portion 13b has a circular cross section and is provided at the tip of the upright portion 13a.

The socket 14 has a shape that allows the engagement rib 13 to fit therein, and the portion of the board 12 where the socket 14 is disposed has a side edge on the side where the engagement rib 13 is disposed. In order to achieve this, there is a step down to the side where the socket 14 is disposed by the thickness of the board 12. The internal shape of the socket 14 is formed to approximately match the external shape of the engaging rib 13. Socket 140 base end.

A contact portion 17 stepped down by the thickness of the substrate 12 is continuously provided outward from the base end portion.

An inclined rib 15 extending diagonally upward on the outside is provided continuously in the longitudinal direction.

between the engagement rib 13 of the board 12 and the socket 14.

A plurality of longitudinally continuous reinforcing ribs 16.1.6.・
... are provided at predetermined intervals. Each reinforcing rib 16 has an upright portion 1 that stands upright with respect to the substrate 12.
6a and a flange portion 16b provided at the tip of the upright R16a, which has a T-shaped cross section.

When the substrate 12 is wound spirally and the engagement rib 13 is fitted into the socket 14, the tip of the inclined rib 15 touches the flange portion 16b of the reinforcing rib 16 located next to the engagement rib 13. At the same time, the contact portion 17 is brought into contact with the substrate 12.

Such a band-shaped body 10 is made into a spiral pipe of 10° by a pipe making machine 20 installed in the manhole 82. Pipe making machine 20
refers to the band-shaped body 10 introduced into the pipe making machine 20.

The band 10 is forcibly bent by a pipe forming roller 21 disposed on the cylindrical circumferential surface with a predetermined helical angle to wind the band 10 in a spiral shape. 1. As shown in FIG.
The engaging ribs 13 of the strip-like bodies 10 introduced into the f&20 are fitted, and the side edges of the mutually adjacent strip-like bodies 10 are engaged with each other. At this time 7, the inclined rib 15 connected to the socket 14 is locked to the flange part 16b of the reinforcing rib 16, and the contact part 17 is connected to the part between the engagement rib 13 and the reinforcing rib 16 of the board 12. superimposed on

In the lining method of the present invention, the pipe making machine 20
After the engagement rib 13 of the strip 10 newly fed into the pipe making machine 20 is fitted into the socket 14 of the strip 10 wound spirally, the helical tube 10' and A backfilling agent is applied to the outer peripheral surface of the substrate 12 in the strip-like body 10. A one-component foamable urethane resin that is foam-cured by moisture and used as a backfilling agent is a mixture of 2, for example, triene diisocyanate (TD[) and diphenylmethane diisocyanate (MDI), and 1 dioctyl as a foaming retardant. It is a mixture of phthalate (DOP), silicon as a foaming agent, silicic anhydride (si02) as a thickener, and Ca/5il12 as a filler at an appropriate ratio, and the mixing ratio of each can be changed appropriately. By doing so, the foaming start time and foaming ratio can be adjusted.

As shown in FIG. 1, such backfilling agent is supplied from a tank 31 placed on the ground through an injection hose 33 to the outer circumferential surface of a helical pipe 10'' manufactured by a pipe making machine 20. The 1M coating vat 36 applies the backfilling agent to the outer peripheral surface of the helical tube 10'.

The backfilling agent is applied to the substrate of the strip 10 constituting the helical tube 10' between the reinforcing ribs 16 on the outer peripheral surface and between the reinforcing ribs 16 and the socket 14. The applied amount is such that it does not flow out between each reinforcing rib 16 or between the reinforcing rib 16 and the socket 14, and that it does not leak out from between each reinforcing rib 16 and between the reinforcing rib 16 and the socket 14.
1, so as to be able to contact the inner peripheral surface of the pipe 81 and fill the gap between the existing pipe 81 and the spiral pipe 10'.

The foaming start time of the backfilling agent is longer than the time required for the spiral pipe 10' to be formed by the pipe making machine 20 over the entire length of the existing pipe 81. In addition, the backfilling agent improves thixotropy by adjusting the amount of thickener mixed so that no wave riding occurs when applied to the 10° outer circumferential surface of the helical tube. Considered to have high viscosity.

In this way, the spiral tube 10' is manufactured.

The spiral pipe 10' is inserted directly into the sewer pipe 81 from the pipe making machine 20. The spiral pipe 10° is connected to the sewer pipe 81.
It is propelled in the axial direction while rotating once inside. The spiral tube 10°
When the leading end in the direction of propulsion reaches the end of the sewer pipe 81, the manufacture of the spiral pipe 10' by the pipe making machine 20 is stopped. Thereafter, after a predetermined period of time has elapsed, the foaming backfilling agent applied to the outer peripheral surface of the spiral tube 10' foams.

The foam fills the gap between the spiral pipe 10° and the existing pipe 81. The foam is then fixed to the spiral pipe 10' and the existing pipe 81.

The backfilling agent is not limited to the configuration in which it is applied to the outer circumferential surface of the helical tube 10°. It may also be wound between the reinforcing rib 16 and the socket 14. In the case of such a configuration, as shown by the two-dot chain line in FIG. A pair of protrusions 1 capable of locking the wire 41 between the two and on the back side of the contact portion 17
8 may be provided.

The wire rod 41 impregnated with the backfilling agent is, as shown in FIG.
The pipes are sequentially fed out from a drum 42 placed on the ground near the manhole 82 where the pipe making machine 20 is installed.

For example, the liquid tank 43 of the one-component foamable urethane resin mentioned above.
The wire rod 41 is impregnated with the foaming backfilling agent mixture in the dipping tank 44 to which the mixture is supplied. This wire 41 is
It is wound around the 10° outer peripheral surface of the helical tube manufactured by the pipe making machine 20. Then, after a predetermined period of time has elapsed after the spiral pipe 10'' was inserted into the sewer pipe 81.

The backfilling agent impregnated into the wire 41 foams, and the foam fills the gap between the spiral pipe 10' and the sewer pipe 81.

The most preferred backfilling agent composition and foaming onset time are discussed below.

[Composition] Mixture of triene diisocyanate (TDI) and diphenylmethane diisocyanate (λ101) [manufactured by Tensei Bayer Urethane ■, trade name 5Btl-1 socyanate-0631] ----
-100 parts by weight silicone (foaming agent') -----
-1.5 parts by weight dioctyl phthalate (foaming retardant)
------60 parts by weight Ultrafine particle silicic anhydride (thickener') ---8 parts by weight [Foaming start time: 30°C and 60% humidity -----160 minutes 30
℃, humidity 80% condition ----120 minutes 30℃,
Under conditions of 100% humidity ---- 110 minutes (effects of the invention) The lining method for existing pipes of the present invention is as described above, in which the lining of a spiral pipe is foamed and hardened by moisture along the outer circumferential surface of the spiral pipe inserted into the existing pipe. Since a backfilling agent made of a one-component foamable urethane resin is installed, when a spiral pipe is inserted into an existing pipe, the backfilling agent foams and the gap between the existing pipe and the spiral pipe is filled. Filled with the foam. Therefore, there is no need to fill the helical pipe with backfilling agent after inserting it into the existing pipe.

The construction period can be significantly shortened. Moreover, the spiral tube is long and can be used under high temperature working conditions in the summer.

A backfilling agent may be filled throughout the space between the helical tube and the existing tube.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the implementation steps of the method of the present invention. FIG. 2 is a sectional view of a strip used in carrying out the method of the present invention, FIG. 3 is a sectional view of a main part of a spiral tube formed from the strip, and FIG. 4 is a sectional view of another embodiment of the method of the present invention. It is a sectional view showing a process in an example.

Claims (1)

[Claims] 1. A step of spirally winding a synthetic resin band whose side edges can engage with each other; and a step of spirally winding the side edges of the band that are adjacent to each other as a result of the winding. a step of manufacturing a helical tube by engaging them with each other, and a step of sequentially disposing a backfilling agent made of a one-component foamable urethane resin that foams and hardens with moisture along the outer peripheral surface of the manufactured helical tube. , a step of sequentially inserting the manufactured spiral tubes into an existing pipe and propelling the inserted spiral tubes into the existing pipe,
Lining method for existing pipes.