JP2009204014A - Method for reclaiming pipe at existing pipe embedded position, and flexible pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a conventional embedded pipe placing method for reclaiming by inserting a new pipe into an existing pipe is provided basically for inserting a straight pipe thereinto, and therefore, it is adaptable only for inserting the new pipe into a bent portion of the existing pipe which is slightly bent approximately into a straight line in the horizontal direction, but it is not adaptable to a further bend one or a vertically bend. <P>SOLUTION: The new pipe pulled into the existing pipe to pass therethrough is a flexible pipe which has a bellows pipe 11 formed by flexibly machining a stainless pipe, and an elongation preventing blade 12 and an anticorrosive film wound thereon. A head cover 3 to which a pull-in tensile wire 6 is connected is mounted on the flexible pipe in an axially turnable and rockable manner. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe rehabilitation method for an existing pipe burial site when a pipe buried in the ground such as a water pipe or a gas pipe needs to be laid again due to aging, etc., and a flexible pipe used therefor. is there.

  Conventionally, a pipe-in-pipe method disclosed in Patent Document 1 is known as a method for laying a buried pipe in which a new pipe is inserted into an existing pipe for rehabilitation. In this construction method, a new pipe is inserted into the existing pipe while connecting it from the starting pit provided on one end side of the existing pipe to the reaching pit provided on the other end side. Although piping can be performed, the insertion into the bent part can only cope with a slight degree of bending close to a straight line in the horizontal direction, and there is a problem that it can not cope with further bending or bending in the vertical direction. .

  For insertion into the bent portion, for example, as shown in Patent Document 1, when inserting a new tube that is sequentially inserted into an existing tube while joining at the insertion port, the insertion depth of the insertion port is limited. By inserting the distance piece to each joint part, the bending angle at the joint part is increased by the amount that the insertion depth of the insertion opening is shallow, and the pipe bending part is allowed to pass. As shown in Document 2, the new pipe is fixed on the carriage at one end side of the existing pipe, and the new pipes are connected to each other and the carriages are also connected to each other to apply axial thrust to the carriage to create a new one in the existing pipe. There is something that inserts a tube.

  Also, a technology that cleans underground pipes such as steel pipes and iron pipes that have passed the service life or have deteriorated due to corrosion, and uses them to rehabilitate pipes through new polyethylene pipes with smaller diameters in existing pipes. Existed in the past, but all of them were able to cope with a slight bend but could not cope with a bend with a large angle.

Furthermore, for flexible pipes, for example, as shown in Patent Documents 3 and 4, crests and troughs are alternately and in parallel with a bellows shape, and it is not assumed that a tensile force is applied, The new pipe retracting method into the existing pipe, which is based on the assumption that the new pipe is drawn into the existing pipe with a strong tensile force, could not be handled without sacrificing the flexibility.
Japanese Patent Laid-Open No. 11-193882 JP 2003-83470 A JP 2000-81182 A JP 2002-39465 A

  As mentioned above, the old pipe rehabilitation method by drawing new pipes into existing pipes becomes a base port because it cannot cope with pipes with bent parts, especially pipes bent in the vertical direction. There is a problem that construction cannot be performed unless the shaft is dug down to the deepest part of the existing pipe and further a large area is excavated to secure a minimum working space.

  That is, in the conventional new pipe drawing method that cannot cope with the pipe line bent in the vertical direction shown in FIG. 1, for example, to draw the new pipe N into the existing pipe M embedded at a pressure-resistant depth against the pressurization of railway operation. The depth m of the existing pipe M, which is deeply embedded in a U-shape, avoiding the railway operation area that receives pressure directly by the descending pipe d and the rising pipe e that hangs below the normal embedding depth n, is received as the pressure receiving influence range L. A shaft up to a depth of m will be excavated at a site that has been expanded and set back on both sides at an angle of 45 degrees from the interface of the avoidance depth pressurization zone.

  However, since the existing pipe M is laid in a U-shape by the descending pipe d and the rising pipe e at the portion of the depth m from the normal embedding depth n, the downcomer pipe is improved by increasing the bending degree of the new pipe N. It becomes possible to draw the new pipe N into d and the rising pipe e, and excavation from the depth n to the depth m becomes unnecessary. This is a problem which is pointed out even when the existing pipe M is laid 90 degrees in a horizontal plane.

  Further, regarding the pulling force that pulls the new pipe N into the existing pipe M, when the pulling wire is simply connected to the tip axial center of the new pipe N and pulled, the pulling direction is fixed and the pulling direction is There is a problem that a direction difference is generated in the direction in which the tensile force works, the tensile force escapes to the side and the tensile energy is wasted, and a wasteful force is applied to the side portion of the new pipe body to damage the side portion.

  When the material of the flexible pipe structure with a high degree of bending is a metal, the bellows pipe having the bellows structure in which the crests and troughs are alternately and continuously arranged in parallel is effective. In addition to the problem that the basic structure is extended and the stainless steel pipe is used as a new pipe to be drawn into the existing pipe, there is a problem in that a current due to a potential difference is generated between the existing pipe and the new pipe and the material is corroded. is there.

  The present invention is intended to address the above-described problems. As a new pipe drawn into the existing pipe M, a stainless steel pipe is flex-processed, and an extension preventing blade is wrapped around the outer circumference thereof. Is formed by connecting the lead-in wire to one end of the flexible pipe, and pulling the flexible pipe into the existing pipe so as to pass through the pipe.

  That is, by flexing a stainless steel tube and covering the outer periphery with an extension preventing blade, it can be used as a bellows tube to maintain a high degree of bending and to bend at a large angle. It is configured to be able to cope with a pulling tensile force by covering it.

  In addition, by attaching the attachment portion of the lead-in wire connected to one end of the flexible tube so as to be rotatable and swingable with respect to the shaft center of the flexible tube, it is possible to eliminate the difference in direction between the pull-in direction and the direction in which the tensile force acts In addition to preventing the waste of tensile energy where the tensile force escapes to the side, the problem of damaging the flank due to the useless force applied to the flank of the new tube main body was also addressed.

Furthermore, the anti-corrosion film is wrapped around the outer periphery of the new pipe, and the existing pipe and the new pipe are separated by the anti-corrosion film to prevent the generation of current due to the potential difference between the materials, and to reduce the sliding friction during pulling tension. did. In addition, after the flexible pipe is drawn into the existing pipe and penetrated, filler is injected into the gap between the inner circumference of the existing pipe and the outer circumference of the flexible pipe to prevent water from entering the gap and strengthen the existing pipe and the new pipe. I tried to do it.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a flexible tube constituting a new tube N, and a bellows tube 11 having a bellows structure in which crests and troughs are alternately and in parallel is formed by compressing an element tube wound with a stainless steel thin plate from both sides by welding or the like. The wire blade 12 is bonded to an appropriate length, the outer periphery thereof is covered with a wire blade 12 for suppressing the expansion of the bellows, and the anticorrosion film 13 is further wrapped around the outer periphery.

  The wire blade 12 is constructed by knitting with fine stainless steel wires so as not to impair the flexibility of the bellows, and the anticorrosion film 13 wrapped around the outer periphery of the wire blade 12 is composed of two layers of a vinyl chloride synthetic rubber-based outer wrap tape. It is composed by wrapping with. With this configuration, the tension acting on the flexible pipe is received by the wire blade 12 without acting on the bellows pipe 11.

  When the flexible tube 1 is pulled and pulled, the outer periphery of the anticorrosive film 13 is covered with the outer periphery of the flexible tube 1 through a cylindrical sleeve film made of a material having low frictional resistance, such as Teflon (registered trademark) material or polyethylene. Can be retracted.

  A fitting straight pipe portion 2 is joined to the end portion of the flexible pipe 1 configured as described above, and the head cover 3 for connecting the drawing wire for drawing tension is rotated and swinged with respect to the axis of the flexible pipe. It can be attached as possible. That is, a fitting protrusion 21 is set on the distal end side of the fitting joint 2 and is configured to be able to rotate by engaging with a flange 32 protruding from the inner periphery of the base end portion 31 of the head cover 3 in a free state. In addition, the head cover 3 can be swung with respect to the axis of the flexible pipe by the gap 4 formed between the fitting protrusion 21 and the flange 32 when engaged.

  As shown in FIG. 5, the head cover 3 is joined to the flexible pipe 1 by forming insertion pieces 33 which are fitted into the joint parts of the cover pieces 3a and 3b divided into two cones as shown in FIG. Since the projecting piece 33a of the insertion piece 33 is fitted to the fitting portion 33b of the insertion piece 33 facing each other by fitting the cover pieces from both sides, the screw holes 34 are fixed with screws. To do.

  A method of drawing the new pipe N constituted by the flexible pipe 1 as described above into the existing pipe M in the case where the existing pipe M is laid at 90 degrees will be described below with reference to FIG. Since existing pipe M avoids pressurization during railway operation, etc., existing pipe Ma, which is normally buried at embedding depth n, expands to both sides at an angle of 45 degrees from the interface of the pressure receiving avoidance depth pressurization area as pressure receiving influence range L. The bent pipe d and the rising pipe e that hang down from the set-back portion are bent and laid on an existing pipe Mb that is deeply embedded by bending 90 degrees to a depth m in a U-shape.

  First, with respect to the target ground in which the existing pipe M is embedded, the start pipe 5b is formed by adding a working work space to the existing pipe Ma and the downcomer d at a portion where the existing pipe Ma hangs down by the downcomer d. The reach shaft 5b, which is obtained by adding a working space to the existing pipe Ma and the rise pipe e at a portion that is raised by the rise pipe e, is cut.

  The exposed end of the existing pipe Ma, the downcomer pipe d, and the rising pipe e exposed in the excavated part is excised, and the rising of the reaching vertical shaft 5b is passed through the existing pipe Mb deeply embedded from the outlet of the descending pipe d of the start shaft 5a. Set the rehabilitation section through work base to the tube e resection opening.

  Rust bumps etc. have rusted inside the existing pipe M, so they are removed by appropriate means such as pig cleaning, and the inside of the rehabilitated existing pipe M is washed and the retraction wire 6 is rehabilitated. To penetrate. Therefore, the lead-in wire 6 is connected to the shackle 35 at the tip of the head cover 3 fitted to the tip of the flexible pipe 1, the wire 6 is pulled from the reaching shaft 5b side, and the flexible pipe 1 is used as the new pipe N in the reconstructed existing pipe M. It is intended to be pulled through.

  Tensioning is performed by an appropriate means such as a winder. In the bent pipe portion, a tensile force acts on the new pipe N from the side bent side, and the bent portion abuts on the side of the retractable pipe. However, in the present invention, the head cover 3 can swing with respect to the axis of the flexible pipe by the gap 4 formed between the fitting protrusion 21 of the flexible pipe fitting joint 2 and the cover flange 32. In addition, since the fitting protrusion 21 and the flange 32 have a rotating structure, the pulling tube neck can always be directed in the direction in which the pulling force acts, and smooth pulling can be performed.

  When the new pipe N penetrates into the rehabilitated existing pipe M, conduct an energization test to confirm that the iron part of the existing pipe M and the stainless steel part of the new pipe N are completely insulated as necessary. After confirmation, the gap between the inner circumference of the existing pipe M and the anticorrosion film 13 is filled with a filler such as mortar to prevent inundation, and the rehabilitation construction in this rehabilitation section is completed.

  The above is the rehabilitation work in the rehabilitation section with the vertical bent pipe part, and it was able to be constructed by excavating up to the burial depth n of the existing pipe Ma without digging the shaft to the burial depth m of the existing pipe Mb. In the case of a conventional flexible pipe with a slight bend, the vertical shaft must also be excavated for each curved portion of the existing horizontal pipe buried along a cross road or a curved road.

  According to the present invention, since the rehabilitation section including the curved pipe portion can be appropriately set within the bending range of 90 degrees in the horizontal direction, the excavation point of the shaft can be minimized. In this way, the flexible pipes are pulled through the existing pipes in each rehabilitated section and rehabilitated, and the ends of the rehabilitated pipes exposed in the shaft excavation part are rehabilitated, joined, and backfilled. To complete.

Since the present invention is configured as described above, excavation of a vertical shaft for each bent portion of the existing pipe, and for a vertical shaft that had to be drilled down to the deepest buried portion in the case of a buried pipe bent in the vertical direction, It was possible to pull in the flexible pipe by minimizing the location and digging down to the shallowest buried part, and also smoothed the pulling work and greatly improved the work efficiency.

Vertical cross-sectional side view of target ground showing vertical shaft arrangement and excavation range when constructed by conventional construction method when existing pipe is buried by bending 90 degrees vertically The example of the pipe rehabilitation method of the existing pipe burying location by this invention is shown, The vertical cross section of the target ground which shows the arrangement | positioning of a shaft and the excavation range in the case of constructing the construction method by this invention in the target ground of the same conditions as FIG. Side view Similarly, the structure of the flexible pipe according to the present invention is shown, and the upper half is a cutaway section of the main part and the lower half is a side view showing the outer surface. Similarly, an enlarged sectional view of part A in FIG. 7 showing the detailed structure of the flexible pipe end straight pipe part. Similarly, a vertical cross-sectional side view of a head cover that joins the leading end of a flexible pipe and connects a lead-in wire Similarly, a plan view of the head cover showing the fitting structure Similarly, a longitudinal sectional side view of the lead-in wire connecting part at the tip of the flexible pipe

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flexible pipe 11 Bellows pipe | tube 12 which comprises a flexible pipe main body Wire braid | blade 13 of a flexible pipe main body Anticorrosion film 2 of a flexible pipe main body The fitting straight pipe part 21 of a flexible pipe end part The fitting protrusion 3 of a flexible pipe end part Head cover 3a Head cover cover piece 3b Head cover cover piece 31 Head cover base end portion 32 Head cover base end flange 33 Cover piece fitting portion insertion piece 33a Cover piece fitting portion insertion piece protruding piece 33b Cover piece fitting portion Insertion piece fitting portion 34 Cover piece fitting portion insertion piece screw hole 35 Shackle 4 at the head cover tip end Gaps 5a formed at the engagement portion between the fitting protrusion and the flange 5a Starting shaft 5b Reaching shaft 6 Leading wire L Receiving pressure L Affected range M Existing pipe Ma Existing pipe Mb buried at normal burial depth Existing pipe Mb buried at pressure avoidance depth N Retracted new pipe d Existing downcomer e Existing Up tube n usually buried depth m pressure avoidance depth

Claims (6)

Excavate a pair of vertical shafts that divide the predetermined interval of the existing pipe burial site, cut both ends of the divided piping, clean the inside and pass the wire through from one vertical shaft to the other vertical shaft,
The existing pipe is refurbished by connecting the lead-in wire to one end of a flexible pipe whose outer periphery is coated with a corrosion-proof film, and drawing the flexible pipe into the existing pipe to penetrate it. Piping rehabilitation method for buried parts   The pipe rehabilitation method for an existing pipe burial site according to claim 1, wherein the flexible pipe to be drawn into and penetrated into the existing pipe is formed by flexing a stainless steel pipe and covering the outer periphery with a blade for preventing extension.   3. The outer circumference of the flexible pipe 1 is covered with a tubular sleeve film made of a material having a low frictional resistance on the outer circumference of the flexible pipe anticorrosion film when the flexible pipe is drawn and pulled into the existing pipe. Rehabilitation method for existing pipe burial site   The existing pipe-embedded portion according to claim 1, 2 or 3, wherein the flexible pipe is drawn into and penetrated through the existing pipe, and then the filler is injected into the gap between the inner circumference of the existing pipe and the outer circumference of the flexible pipe. Piping rehabilitation method   The connecting portion of the lead-in wire connected to one end of the flexible pipe is attached so as to be rotatable and swingable with respect to the axis of the flexible pipe. Pipe rehabilitation method for existing pipes   A flexible pipe made by flexing a stainless steel pipe, covering the outer periphery with a blade for preventing elongation, and further covering the outer periphery with a corrosion-resistant film.

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