JP6523835B2 - Renewal method of existing pipe - Google Patents

Description

  The present invention relates to a method of renovating an existing pipe connected to a human hole.

  When it is necessary to repair an existing pipe such as a sewer pipe buried in the ground, a construction method is widely used to rehabilitate the pipe by covering the inner surface of the existing pipe with a lining material. After inserting a thermoplastic resin lining material formed to a smaller diameter than the inner diameter into the existing pipe, the lining material is heated and softened, and the diameter is increased by pressure. As a result, the lining material is brought into intimate contact with the inner surface of the existing pipe to form a smooth pipe path (see, for example, Patent Documents 1 and 2).

  In the conventional rehabilitating method, as illustrated in FIG. 8, the heated lining material 9 is pressurized and expanded along the inner surface of the existing pipe 7, and then cooled using air or water. . After the cooling operation, as shown in FIG. 10, the lining material 9 is cut in the vicinity of the pipe port of the existing pipe 7 to finish the end of the pipe port. For example, in the connection portion between the existing pipe 7 and the human hole 8, a finishing material 91 such as mortar or epoxy filler is wound on the connection portion between the pipe port of the lining material 9 and the human hole 8. Integrate with the human hole 8.

Japanese Patent Application Publication No. 11-230412 Japanese Patent Application Publication No. 2003-074114

  In the lining material 9 of this type, after the diameter expansion, a force is generated which tends to contract by the amount of linear expansion. However, as shown in FIG. 9, since the lining material 9 is in close contact with the existing pipe 7, the frictional force generated between it and the existing pipe 7 can not be contracted as it is resisted and the force is used as a residual stress for lining It is stored in the material 9.

  For this reason, even if the human hole 8 and the lining material 9 are connected and integrated by the finishing material 91, the lining material 9 gradually contracts depending on the vibration or the ground fluctuation generated after the service, as shown in FIG. There is a possibility that a crack or a gap may occur between the finishing material 91 and the lining material 9.

  The present invention has been made in view of these problems, and reduces the residual stress generated in the lining material, and prevents the occurrence of a failure in the pipeline and the connection between the human hole and the pipeline after the rehabilitation. The present invention provides a method of reworking existing pipes to be obtained.

  The solution means of the present invention for achieving the above-mentioned purpose is a thermoplastic resin lining material which is formed in an existing pipe which is buried in the ground and connected to a human hole and which has an outer diameter smaller than the inner diameter of the existing pipe. It is premised on a method of reworking an existing pipe which is inserted and diameter-expanded and covers the inner surface of the existing pipe. In the present invention, as a method of renovating the existing pipe, a regulation member having a cylindrical hollow portion having an inner diameter equal to or less than the inner diameter of the existing pipe is brought into close contact with the connection port between the existing pipe and the human hole in advance. The lining material is disposed on the existing pipe, and the regulating member is inserted through the existing pipe to the human hole, and the end of the lining material is extended from the human hole end of the regulating member. After the material is expanded and cooled, the restriction member is removed, and an axial compression load is applied to the lining material, and the end of the lining material is connected to the connection between the existing pipe and the human hole. It is supposed to be fixed.

  By this particular matter, the lining material is pressed in the axial direction and a load is applied in the contraction direction of the lining material, so that the residual stress generated in the lining material can be reduced. Therefore, the influence of the residual stress of the lining material in the pipeline after rebirth can be reduced, and it becomes possible to use the pipeline well over a long period of time.

  In the method of rehabilitating the existing pipe, it is preferable to cool the lining material to a temperature lower than the ambient temperature before the loading step.

  Thus, the residual stress of the lining material can be prevented from increasing after the loading step, and the reduction effect of the residual stress in the loading step can be further enhanced.

  Moreover, it is preferable to equip the outer peripheral surface of the lining material with a sheet material or a sliding material having a smaller frictional resistance than the outer peripheral surface of the lining material.

  Thus, the axial compressive load in the loading step can be applied to the lining material more effectively.

  Further, in the loading step, it is preferable to apply a compressive load to both end portions of the lining material extended from the connection port between the existing pipe and the human hole to the human hole side.

  Also in this case, the axial compressive load in the loading step can be applied to the lining material more effectively, and the reduction effect of the residual stress can be enhanced.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to reduce the residual stress of lining material and to provide the rehabilitated pipeline of a good state over a long period of time.

It is an explanatory view showing one process of a rehabilitating method of the existing pipe concerning an embodiment of the present invention. It is explanatory drawing which shows the following process of FIG. It is explanatory drawing which shows the following process of FIG. It is explanatory drawing which shows the following process of FIG. FIG. 5 is a cross-sectional view showing the inside of a human hole from above, showing the next step of FIG. 4; It is explanatory drawing which shows the following process of FIG. It is explanatory drawing which shows the mode after the existing pipe rebirth by the rebirth method of this invention. It is explanatory drawing which shows the conventional rebirth method. It is explanatory drawing which shows the following process of FIG. It is explanatory drawing which shows the next process of FIG. It is explanatory drawing which shows the mode after the existing pipe | tube rehabilitation by the conventional rehabilitation method.

  Hereinafter, a method of rehabilitating an existing pipe according to an embodiment of the present invention will be described with reference to the drawings.

  According to the present invention, the existing pipe 7 buried in the ground and connected to the human hole 8 is regenerated using the lining material 1. The lining material 1 is a cylindrical member made of thermoplastic resin molded to an outer diameter smaller than the inner diameter of the existing pipe 7, inserted into the existing pipe 7 and enlarged in diameter, and covering the inner surface of the existing pipe 7 It becomes.

  Renewal of the pipeline is performed using human holes 8 located at the upstream end and downstream end of the existing pipe 7 to be rebuilt. As shown in FIG. 1, the bottom portion (invert portion) of the human hole 8 is inserted in advance, and a recess 81 for disposing the regulating member 2 is provided. Next, the restriction member 2 is disposed at the connection between the human hole 8 and the existing pipe 7.

  The regulating member 2 is provided with a cylindrical hollow portion 21 penetrating at the central portion, and the inner diameter of the cylindrical hollow portion 21 is an inner diameter equal to or smaller than the inner diameter of the existing pipe 7. The restricting member 2 is brought into close contact with the connection port between the existing pipe 7 and the human hole 8 and disposed coaxially with the existing pipe 7. The regulating member 2 is preferably made of metal or synthetic resin, and preferably disposed at both the upstream end and the downstream end of the existing pipe 7. The regulating member 2 may be a tubular member such as a hose having a woven fiber layer.

  Next, the lining material 1 is inserted into the existing pipe 7 through the upstream or downstream one of the human holes 8, and the restriction member 2 is inserted from the existing pipe 7 to the other human hole 8 (not shown). For example, after an end member for closing the tip opening is attached to the leading end of the lining material 1 in the pulling direction, a pulling material or the like is connected to the lining material 1 from one manhole 8 to the other manhole 8 Tow.

  The lining material 1 is made of a thermoplastic resin material such as polyvinyl chloride resin or high density polyethylene resin, and is formed in a cylindrical shape. Furthermore, the lining material 1 is deformed into a flat shape or a shape having a recessed groove along the longitudinal direction, and is formed into a reduced cross-sectional shape. Before inserting the lining material 1 into the existing pipe 7, the lining material 1 is preferably heated from the inner surface, and its cross-sectional shape is restored to a substantially elliptical shape having a diameter smaller than the inner diameter of the existing pipe 7. In addition, this heating imparts the lining material 1 with a degree of flexibility that allows easy insertion into the existing pipe 7. When heating, the end member 3 (see FIG. 2) for closing the lining material 1 in a sealed state is attached to heat the inside of the lining material 1.

  At the connection portion between the existing pipe 7 and the human hole 8, as shown in FIG. 1, the end of the lining material 1 extends from the end of the regulating member 2 exposed in the human hole 8 into the human hole 8 Arrange in the state of letting out. The restriction member 2 is not limited to being disposed at the connection portion between the existing pipe 7 and the human hole 8 in advance, but after the lining material 1 is disposed at the existing pipe 7, it extends from the pipe port of the existing pipe 7 The restriction member 2 may be provided outside at the end of the lining material 1 from the side of the human hole 8.

  If the lining material 1 was inserted over the existing pipe 7 and the regulating member 2, as shown in FIG. 2, the end member 3 for closing the lining material 1 in a sealed state was attached to the end or attached in the previous step In the state, the medium introduction pipe is connected to the end member 3. A heating medium such as water vapor is supplied to the inside of the lining material 1 from a not-shown ground steam generating pressurizer through a medium introduction pipe. Thereby, the lining material 1 is heated.

  When the lining material 1 is heated and reaches the shape memory temperature, the shape recovers to the original cylindrical shape. When the lining material 1 recovers in shape, the heating is ended. Then, high pressure air is supplied to the lining material 1 from the steam generating and pressurizing device through the medium introduction pipe. Thereby, the lining material 1 is pressurized and expanded in the radial direction. The diameter-expanded lining material 1 closely contacts the inner surface of the inner surface of the existing pipe 7 as shown in FIG. The end portion of the lining material 1 is expanded in diameter in a state where the outer diameter is regulated by the regulating member 2 disposed in the human hole 8, and closely attached to the inner surface of the regulating member 2 (cylindrical cavity 21: FIG. 1). Further, since the portion of the lining material 1 extending from the end of the regulating member 2 is not accompanied by the regulation of the outer diameter by the regulating member 2, the portion bulges beyond the inner diameter of the regulating member 2.

  The lining material 1 can be cooled by the high pressure air by supplying the high pressure air to the lining material 1 in order to expand the diameter of the lining material 1 and subsequently supplying the same (cooling operation). The lining material 1 is hardened in a state of being in close contact with the inner surface of the existing pipe 7 and its shape is maintained. The inner surface of the existing pipe 7 is covered with the lining material 1. The bulging part of the end of the lining material 1 is cut and removed after completion of the cooling operation, as shown in FIG.

  Thereafter, as shown in FIG. 4, the regulating member 2 which is covered at the end of the lining material 1 is removed from the outer surface of the lining material 1. The restriction member 2 can be removed by pulling out the restriction member 2 from the end of the lining material 1 in the axial direction. Although not shown in detail, a regulating member divided into two may be used to regulate the outer diameter of the lining material 1. In the case of using a two-fold regulating member, the two-divided regulating members are separately attached to the end of the existing pipe 7 and then bound with a tape, a band or the like to be integrally fixed. After the diameter expansion of the lining material 1, the binding of the regulating member can be removed, and the regulating member can be easily removed from the lining material 1.

  During the cooling period of the lining material 1, the lining material 1 shrinks slightly with time, but due to the frictional resistance with the existing pipe 7, it can not be completely shrunk and a residual stress is generated. On the other hand, in the rehabilitation method according to the embodiment, an axial compressive load is loaded on the lining material 1 (loading step). In this loading step, a compressive load in the axial direction is applied to the lining material 1 extended to the side of the human hole 8 from the connection port between the existing pipe 7 and the human hole 8.

  As shown in FIG. 5, at the bottom of the human hole 8, an operating body 4 such as a hydraulic jack that presses the lining material 1 in the axial direction is installed. For example, a support plate 41 for closing the pipe port is provided at the pipe port of the lining material 1 extended from the existing pipe 7, and one end of the working body 4 is fixed to the support board 41. A box-like or plate-like reaction force member 42 is installed on the front side of the connection port of the other existing pipe 7 connected to the same person hole 8 and the other end of the working body 4 is fixed to the reaction force member 42 Do. Then, by extending the working body 4 in the axial direction of the existing pipe 7, an axial compressive load is applied to the lining material 1.

  By this, the residual stress generated in the lining material 1 is reduced. It is preferable to apply a compressive load to the lining material 1 from both ends of the lining material 1.

  In the loading step, while measuring the compressive stress generated in the lining material 1 with a load detector (load cell), the load load is managed so that the compressive stress falls within a predetermined range. In this case, the compressive stress of the lining material 1 is a stress that does not cause buckling in the lining material 1 as an upper limit, and a circumferential surface frictional resistance stress between the lining material 1 and the existing pipe 7 as an extension 5 m is a lower limit. It is desirable to manage the load. The circumferential surface frictional resistance stress of the lining material 1 is confirmed in advance by performing a measurement test, and is used as a standard for applying a compressive load to the lining material 1.

  As an example, a compressive load of 8.5 MPa (20 kN) in the axial direction was applied to the lining material 1 having a bore diameter of 150 mm and a pipe extension of 20 m, which was applied to the rehabilitating pipeline (loading step).

  In this case, since the circumferential friction resistance of the lining material 1 for 5 m in extension is 6.13 MPa, the applied compressive load is within the above-mentioned set range. It was confirmed that the maximum residual stress of the lining material 1 decreased from 18.3 MPa to 5.9 MPa before and after the loading step.

  That is, the residual stress of the lining material 1 is reduced by 12.4 MPa before and after the loading process, and is reduced by about 68% relative to the lining material 1 before loading, and significant improvement of the residual stress is observed. The Even when the attachment pipe was provided in the middle of the existing pipe 7, the improvement of the residual stress was similarly recognized although the reduction width was slightly reduced by the load process. Therefore, it was confirmed that the residual stress produced in the lining material 1 can be significantly reduced by carrying out the loading step after the diameter expansion of the lining material 1.

  Before the lining material 1 is inserted into the existing pipe 7, a sheet material or a sliding material having a smaller frictional resistance than the outer peripheral surface of the lining material 1 may be provided on the outer peripheral surface of the lining material 1 in advance. Thereby, the axial compressive load in the loading step can be applied to the lining material 1 more effectively.

  After the residual stress of the lining material 1 is reduced through the loading step, as shown in FIG. 6, the portion of the lining material 1 extending into the human hole 8 is made of the existing pipe 7 and the human hole 8. Cut and remove in the vicinity of the connection port. In addition, the concave portion 81 formed at the bottom of the human hole 8 is backfilled.

  Next, as shown in FIG. 7, using the finishing material 82, the end of the lining material 1 after cutting is connected to the inner surface of the existing pipe 7 and the inner surface of the manhole 8 to finish the surface of the outer surface . Thereby, lining construction of the existing pipe 7 is completed and the existing pipe 7 is rebuilt.

  As mentioned above, according to the rehabilitating method of the existing pipe concerning the present invention, after reducing the residual stress of lining material 1 constructed on the inner surface of existing pipe 7, lining material 1 can be constructed. As a result, it is possible to prevent the occurrence of cracking, breakage, and the like after the service of the rehabilitation pipeline, and it is possible to maintain a good lining condition in the long run.

  The present invention is suitably applicable to the rehabilitation of buried pipelines connected to human holes.

Reference Signs List 1 lining material 2 regulating member 21 cylindrical hollow portion 3 end member 4 working body 41 support plate 42 reaction force member 7 existing pipe 8 human hole 81 recessed portion 82 finished material

Claims (4)

A method of reworking an existing pipe in which a thermoplastic resin lining material molded to an outer diameter smaller than the inner diameter of the existing pipe is inserted into the underground existing pipe connected to the human hole and the inner surface of the existing pipe is covered with the lining material And
A restriction member having a cylindrical hollow portion having an inner diameter equal to or less than the inner diameter of the existing pipe is disposed coaxially with the existing pipe, closely contacting the connection port between the existing pipe and the human hole,
The lining material is inserted through the existing pipe and disposed to the human hole, and the lining material is expanded in diameter and cooled with the end of the lining material extended from the human hole end of the regulating member. And
After removing the restriction member, an end portion of the lining material is connected to a connection port between the existing pipe and the human hole through a loading step of applying an axial compressive load to the lining material. How to rehabilitate. In the rehabilitation method of the existing pipe according to claim 1,
Before the loading step, the lining material is cooled to a temperature equal to or lower than the ambient temperature. In the rehabilitation method of the existing pipe according to claim 1 or 2,
A sheet material or a sliding material having a smaller frictional resistance than the outer peripheral surface of the lining material is provided in advance on the outer peripheral surface of the lining material. In the rehabilitation method of the existing pipe according to any one of claims 1 to 3,
In the loading step, a compressive load is applied to both end portions of the lining material extended from the connection port between the existing pipe and the human hole to the human hole side.

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