JP5179957B2 - Pipeline rehabilitation method - Google Patents

Description

  The present invention relates to a pipe rehabilitation method for piping a new pipe inside an existing pipe such as an aged water and sewage / agricultural water channel or a tunnel.

  Existing pipes such as water and sewage / agricultural waterways become obsolete with the passage of time, causing irregularities in the pipes and reducing hydraulic characteristics (friction characteristics of flowing water, flow velocity, etc.). . If this hydraulic characteristic deteriorates, problems such as a decrease in the flow rate in the pipeline may occur, so the existing pipes are periodically renewed to prevent the problem.

  As one of the renewal works, there is a method (pipe-in-pipe method) in which new pipes are installed in existing pipes. In this construction method, new pipes are carried one by one from one end of the existing pipe to be renewed, and the new pipes are sequentially connected in the existing pipe.

  A receiving port or an insertion port is formed at the end of the new pipe 2 to be connected, and the other insertion port is inserted into one of the receiving ports for connection. In addition, the connecting portion is usually slightly thicker than the portion other than the connecting portion by the overlapping portion (collar 12) of both mouths, and protrudes in the outer diameter direction (see FIG. 6).

  For this reason, when laying the new pipe 2, it is necessary to adopt the new pipe 2 having a smaller nominal diameter by taking the protrusion of the collar 12 into consideration than the inner diameter of the existing pipe 1. As a result, the cross-sectional area of the water flow is reduced by the amount of protrusion of the collar 12, and a problem may occur in which the flow rate is decreased compared to before the rehabilitation.

In order to solve this problem, a laying method using a pipe processed so that the collar does not protrude in the outer diameter direction of the new pipe is disclosed. This tube has countersinks with reduced thickness at both ends. The end faces of this countersink part are butted against each other, and a collar is provided on the countersinked part so that it does not protrude in the outer diameter direction. It connects (refer FIG. 4 of patent document 1).
JP-A-7-91567

  In the laying method shown in Patent Document 1, it is necessary to previously form a countersink portion in a new pipe used therefor, and there is a problem that the material cost increases due to the processing. Moreover, since the countersink part becomes thin, there also exists a problem that the intensity | strength at the time of a connection falls.

  Therefore, an object of the present invention is to enable the connection operation to be performed at low cost and easily while maintaining the strength of the connection portion.

  In order to solve the above problems, the present invention arranges a new pipe in an existing pipe so that the end faces thereof are opposed to each other, and between the new pipe, the existing pipe and the new pipe are arranged. A spacer for adjusting the gap is provided, and after the gap is set to a predetermined interval by adjusting the spacer, a water stop member is provided to close the gap between the end faces from the inside of the new pipe.

  Since it is not necessary to provide the countersink portion shown in the known invention on the end face of this new pipe, the countersink portion is thin and there is no fear of causing a decrease in strength.

  In addition, the spacer has, for example, contact plates that contact the inner surface of the existing tube and the outer surface of the new tube, and a bolt is provided between the contact plates, depending on the screwing amount of the bolt. It is possible to adopt a configuration in which the distance between both contact plates can be adjusted.

  The position for attaching the spacer is not particularly limited as long as the new pipe can be firmly fixed. However, it is particularly preferable that the spacer is provided at a position facing the tube axis of the new pipe. In this way, if the distance between the contact plates is narrowed by the one spacer at the opposite position and the distance between the contact plates is increased by the other spacer, the new pipe is shifted in the narrowed direction. This is because the position can be easily adjusted.

  In this construction method, since the connecting portion can be visually recognized from the inner surface side of the newly installed pipe, the water stop member can be easily provided from the inner surface side to the connecting portion (the gap between the newly installed tubes). The water stop member may be provided so as to completely cover the spacer from the inner surface side, and the bolt of the spacer protrudes from the water stop member while ensuring water tightness against water leakage or the like. It may be provided. This is because the position of the new pipe can be finely adjusted again by screwing the bolt after the water stop member is provided.

The water-stopping member can be appropriately selected as long as it can prevent water leakage after construction, and water-swelling rubber and butyl-based packing material are particularly suitable.
This water-swollen rubber absorbs surrounding water and swells to several times the dry volume. By this swelling action, the gap of the connecting portion is pressed from the inside to close the gap, so that water leakage can be reliably prevented. Moreover, since the butyl packing material is excellent in weather resistance and chemical resistance, and the material itself is sticky, the gap can be easily and reliably closed over a long period of time.

  In the above-described configuration, it is possible to inject an intermediate material between the existing pipe and the new pipe, and hold the new pipe with the solidified internal material.

  The new pipe is fixed while maintaining a predetermined distance from the existing pipe by spacers provided around the new pipe. By injecting the intermediate material, the new pipe is securely held. . For example, a so-called air mortar made of cement, a foaming agent, dilution water, or the like can be used as the filling material. Since this air mortar hardens with time and firmly supports the new pipe, the stability of the new pipe is significantly improved compared to the support of only the spacer.

  In the injection of the insert material, the spacer is provided on both the lower side and the upper side of the new pipe, and the lower spacer is provided between the floor of the existing pipe and the new pipe. A gap can be maintained, and the upper spacer is in a state of being stretched between the ceiling of the existing pipe and the new pipe, and the new pipe floats during the injection of the insert material. A stop can also be made.

  Since the inside of the new pipe is hollow, a large buoyancy acts on the new pipe when the intermediate material is injected between the existing pipe and the new pipe. As a result, the connected new pipe may be partially distorted and the water flow in the pipe may stagnate. Therefore, by providing a floating spacer as described above, the distortion can be prevented and the hydraulic characteristics in the pipe can be maintained in a good state.

  The new pipes used in each of the above-mentioned structures can employ a wide range of fume pipes, reinforced resin pipes, etc. that are generally used for sewer pipes, etc. It is preferable to employ a laminated tube constituted by: This laminated tube is generally called an FRPM tube. Since this FRPM pipe is very light compared to a steel pipe, it is excellent in workability such as conveyance and connection, and also has high strength, and thus is excellent in reliability after construction.

  According to the present invention, since the new pipes are connected without forming the counterbore part in the connection part, the cost required for processing the new pipe can be reduced. Moreover, since there is no thin part accompanying a countersink part, the intensity | strength of the connection part can fully be ensured. For this reason, the connection reliability of a connection part is high. Also, since the end faces of both new pipes are butted and connected by providing a water stop member from the inner surface side after adjusting the position, the work of inserting the pipes becomes unnecessary and the work is very simple. It is. For this reason, a construction period can be shortened and work cost can be further reduced.

  The pipe line rehabilitated by the pipe line rehabilitation method according to the present invention is shown in FIGS. In this pipe line, a new pipe 2 is carried into an aging existing pipe 1 and a spacer 3 is interposed at a connecting portion between the new pipes 2. The distance between the new pipe 2 and the existing pipe 1 can be adjusted by the expansion and contraction of the spacer 3. A water-stop member 4 (water-swelling rubber) is fitted in the gap between the connecting portions to prevent water leakage from the new pipe 2 and intrusion of outside water, and between the existing pipe 1 and the new pipe 2. The insert material 5 (air mortar) is injected and solidified so that the new pipe 2 is stably supported.

This new pipe 2 is a tube made by laminating resin mortar with glass fiber reinforced plastic (FRPM pipe), and it is significantly lighter than conventional steel pipes while ensuring the necessary strength. We are trying to make it. For this reason, workability is very good.
Moreover, since the countersink part (thin wall part) is not formed in the front-end | tip, sufficient intensity | strength can be ensured when the newly installed pipes 2 are connected.

The procedure of this pipeline rehabilitation method will be described with reference to FIG.
In this method, first, a spacer 3 interposed between the existing pipe 1 and the new pipe 2 is provided at the rear end of the new pipe 2 provided in the existing pipe 1 (further, the side connecting the new pipe 2). The spacer 3 is, for example, as shown in FIG. 4, and is provided with a shaft body 7 having a screw hole formed on the inner surface and an adjusting bolt 8 screwed into the shaft body 7 interposed between two contact plates 6. It has been.

  The adjusting bolt 8 is provided with a nut 9 that rotates integrally with the adjusting bolt 8. By adjusting the adjusting bolt 8, both the contact plates 6 and 6 can be freely connected and separated. It has become. Before the spacer 3 is provided at the rear end of the new pipe 2, the distance between the inner surface of the existing pipe 1 and the outer surface of the new pipe 2 is measured in advance, and the distance and the distance between the contact plates 6 and 6 are roughly the same. It adjusts beforehand so that it may become the same (refer Fig.3 (a)).

  The installation position of the spacer 3 can be appropriately determined as long as the new pipe 2 can be stably supported in the existing pipe 1, but the new pipe 2 is prevented from being lifted in the step of injecting the insert 5 described later. Therefore, it is preferable to provide not only on the lower side of the new pipe 2 but also on the upper side (see FIG. 5B).

  Next, the new pipe 2 is lowered by a crane (not shown) from the shaft formed on one end side of the existing pipe 1, and the new pipe 2 is connected to the next to the new pipe 2 connected by a cart (not shown). It conveys and the front-end | tip of this new pipe 2 is inserted in the spacer 3 of the edge part of the new pipe already provided. At this time, the open end (left end) of the new pipe 2 is supported by a buttery angle 10 (temporary placing square) so that it does not hang down due to its own weight (see FIG. 3C).

  After the fitting, the adjustment bolts 8 provided on the spacers 3 are adjusted so that the new pipe 2 is positioned at a predetermined position, and fine adjustment is performed so that the spacers 3 do not rattle. Furthermore, the spacer 3 is also provided on the open end side, and the distance between the inner surface of the existing tube 1 and the outer surface of the new tube 2 is adjusted in advance (see FIG. 4D).

  When the fine adjustment of the positions of the adjacent new pipes 2 is completed, the water-swelling rubber 4 is fitted as a water-stopping member into the connecting portion between both the new pipes 2 and 2. When the water-swelling rubber 4 absorbs water, it swells to several times the dry volume and closes the gap between the connecting portions.

  After fitting the water-swelling rubber 4, a small amount of water may be poured into the new pipe 2 to test whether water can be smoothly passed in a predetermined direction. If the heads of the adjusting bolts 8 of the spacers 3 are exposed from the water swelling rubber 4, the adjusting pipes 8 are adjusted to incline the new pipe 2 so that the water can flow smoothly. Can be fine-tuned. Thereby, the hydraulic characteristics of the new pipe 2 can be further improved.

  When the inclination of the new pipe 2 is determined, an injection hole formed in the upper part of the new pipe 2 is provided with a partition wall 11 interposed between the existing pipe 1 and the new pipe 2 on the open end side to ensure water tightness. (Not shown), the air mortar 5 is injected into the gap between the pipes 1 and 2 as an intermediate material.

The injection of the air mortar 5 may be performed collectively after all the new pipes 2 are connected. However, each time several new pipes 2 are connected, a partition wall 11 is provided. You may make it carry out by a division | segmentation unit (refer the figure (e)).
If performed together as in the former case, the working time can be shortened, but the air mortar 5 injected first starts to solidify during the work and there is a possibility that it cannot be injected uniformly throughout. On the other hand, if the latter is performed in units of separation, since the amount of the air mortar 5 to be injected at a time is small, the total working time increases, but the air mortar 5 can be injected uniformly.
In consideration of the balance between the working time and the uniformity of the finish, the construction method (such as the installation interval of the partition walls 11) can be appropriately selected.

  The operations shown in FIGS. 3A to 3E are repeated, and the new pipes 2 are sequentially connected by the required number.

  In this work, as shown in FIG. 3B, not only the spacer 3 is provided on the lower side and the upper side of the new pipe 2, but also on the side of the new pipe 2 as shown in FIG. You may make it provide similarly. In this way, it is possible to prevent the newly installed pipe 2 from being displaced in the lateral direction and displaced during the injection of the insert 5.

As the water-stopping member 4 described above, a butyl-based packing material that is excellent in weather resistance and chemical resistance and has adhesiveness to the material itself can be employed in addition to the water-swelling rubber. This is because high water-tightness can be ensured similarly to the water-swollen rubber.
In addition to this, a well-known water stop member 4 used to ensure water tightness can be widely used.

Moreover, since this existing pipe is buried underground, there is a risk that the outer peripheral surface of this existing pipe will be damaged due to high water pressure under circumstances where the groundwater level is high. Therefore, a through hole provided with a filter and a valve body for preventing soil and sand from entering the pipe body of the existing pipe is formed, and a through hole is also formed in the new pipe corresponding to the position of the through hole. Outside ground water is allowed to flow into the new pipe through the through holes formed in both pipes.
Thereby, the water pressure outside the existing pipe is lowered, and the existing pipe is prevented from being damaged by the external water pressure.

Side surface sectional view which shows one Embodiment of the pipe body renovated with the pipe line renovation method which concerns on this invention 1 is a perspective view of a tube body according to FIG. The procedure of the pipeline rehabilitation method according to the present invention is shown, (a) is a side view showing the installation mode of the spacer, (b) is the front view, (c) is the side view showing the loading of the new pipe, (d) Is a side view showing the adjustment of the spacer, (e) is a side view after the injection of the insert material Side view showing an example of spacer Cross-sectional view of tube showing other modes of spacer installation (A) is a perspective view of a tube according to the prior art, and (b) is a sectional view.

Explanation of symbols

1 Existing pipe 2 New pipe 3 Spacer 4 Water blocking member (water swelling rubber)
5 Medium insert (air mortar)
6 Contact plate 7 Shaft body 8 Adjustment bolt 9 Nut 10 Batter angle 11 Partition wall

Claims (4)

  In the existing pipe (1), the new pipe (2) is arranged side by side so that the end faces thereof face each other, and the existing pipe (1) and the new pipe ( 2) is provided with a spacer (3) for adjusting the gap between the end faces, and after adjusting the spacer (3) to make the gap a predetermined interval, the end faces are connected to each other from the inside of the new pipe (2). A pipeline rehabilitation method provided with a water stop member (4) for closing the gap.   The intermediate pipe (5) is injected between the existing pipe (1) and the new pipe (2), and the new pipe (2) is held by the solidified intermediate material (5). The pipeline rehabilitation method described in 1.   The spacer (3) is provided on both the lower side and the upper side of the new pipe (2), and the lower spacer (3) is provided on the floor surface of the existing pipe (1) and the new pipe (2 ) And the upper spacer (3) is stretched between the ceiling of the existing pipe (1) and the new pipe (2). The pipe rehabilitation method according to claim 2, wherein the new pipe (2) is floated when the filling material (5) is injected.   The pipe line rehabilitation method according to any one of claims 1 to 3, wherein the new pipe (2) is made of a composite material in which fiber reinforced plastic and resin mortar are laminated in a pipe radial direction.

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