JP4969215B2 - Center push piping method - Google Patents

Description

  The present invention relates to a center pushing piping method, and more particularly to a center pushing piping method suitable for laying a new pipe line inside an existing structure such as an existing pipe or a shield.

As a method for laying a new pipe line inside an existing structure such as an existing pipe or shield, there is a pipe-in-pipe method in which a new pipe is laid inside the existing structure by a propulsion method.
FIG. 4 shows a conventional pipe-in-pipe method. Here, 1 is an existing structure such as an existing pipe or shield, and is laid horizontally in the ground. When laying pipes with new pipes 2 and 2 inside the existing structure 1, the start shaft 3 and the reaching shaft 4 are placed at a pair of positions spaced in the length direction of the existing structure 1. Each of them is excavated from the ground surface 5 and an insertion jack 6 is installed inside the start shaft 3. Then, after the pipes 2 and 2 are carried into the start shaft 3, the pipes 2 and 2 are joined to each other, and the rear end portions of the pipes 2 and 2 are pushed by the insertion jack 6 to give a propulsive force. This is sent into the existing structure 1. In the same manner, a plurality of new pipes 2 are sequentially joined and propelled, so that the pipes by the new pipes 2, 2,... Can be laid from the starting vertical shaft 3 to the reaching vertical shaft 4.

  In such a pipe-in-pipe method, when the distance from the starting shaft 3 to the reaching shaft 4 is long, it is necessary to apply a large propulsive force corresponding to the new shaft 2, 2,. Problems may arise in terms of the yield strength of the tube 2 in the axial direction.

  As another construction method for laying a pipeline by the propulsion method, there is a method of directly propelling a new pipe into the ground instead of the existing structure as described above. In this case as well, a problem arises in terms of the proof stress in the axial direction of the pipe as the propulsion distance increases. That is, there is a problem that the axial strength of the new pipe limits the workable length.

In order to solve this problem, for example, an intermediate pressing method described in Patent Document 1 is known. This is because an intermediate sleeve for generating a propulsive force is arranged in the middle of the pipe to be propelled, thereby distributing the propulsive force along the length of the pipe so that a large force does not act on each pipe. It is a thing.
Japanese Patent Laid-Open No. 9-4370

  The intermediate sleeve used in the conventional intermediate pushing method has a telescopic structure that uses a receiving tube and an insertion tube inserted into the receiving tube, and when propelling into the ground, earth and sand are contained in the tube. It is configured not to enter. Further, a jack for generating a propulsive force is disposed between the inner portion of the receiving tube and the distal end portion of the insertion tube inserted into the receiving tube.

  However, the apparatus configuration becomes complicated in order to achieve the telescopic structure. Also, the jack must transmit propulsive force between the back of the receiving tube and the tip of the insertion tube inserted into the receiving tube as described above, and the propulsive force transmission mechanism is complicated. Become.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such problems and to perform an intermediate pushing method in a pipe propulsion method with a simple configuration.

In order to achieve this object, the present invention provides a pipe line in which a plurality of pipes having a receiving port at one end and an insertion port at the other end are joined, and a propulsive force is applied to the rearmost pipe and a rear pipe. Is a method for propelling and laying by sequentially transmitting a propulsive force from the front side pipe to the front side pipe, and one pipe adjacent to the front and rear in front of the rearmost end pipe has an insertion opening at one end. The first tube having a flange portion at the other end is joined with the insertion port of the first tube inserted into the receiving port of the one tube, and the receiving ports at both ends are connected to the other tube. Insert the insertion port of the other tube into one receiving port of the both receiving tubes, the formed both receiving tubes and the second tube having a flange portion at the other end and an insertion port at the other end , Franc of the bonded sequentially while inserting the spigot of the second pipe to the other socket of the two receiving tubes, said first tube Parts and the flange portion of the second tube while arranged at a distance in the axial direction of the tube, placing a jack device between the flange portion and the flange portion of the second tube of the first tube Then, with this jack device, a propulsive force is applied to the pipe on the front side of the jack device for propulsion, and the jack device is removed after propulsion of the pipe line on the front side of the jack device, and then the jack The second pipe body is brought closer to the first pipe body by propelling the pipe line behind the device, and the first pipe body and the second pipe body are joined to each other. In addition, the center pushing piping method of the present invention is particularly suitable when a new pipe line is propelled and laid inside an existing structure.

  In the pipe-in-pipe method, where new pipes are laid inside existing structures such as existing pipes and shields, soil and sand enter the pipes, unlike when they are propelled underground. Therefore, there is no need to use a conventional telescopic structure pushing mechanism, and the distal end portion of the first tubular body and the distal end portion of the second tubular body are separated from each other in the tubular axial direction as described above. And an open space is formed by disposing the jack device in an open space between the distal end portion of the first tubular body and the distal end portion of the second tubular body. Propulsion can be applied to the tube for propulsion. The transmission of the propulsive force between the first tube body and the second tube body is also performed, for example, by sandwiching a jack between the distal end portion of the first tubular body and the distal end portion of the second tubular body. There is no need for a complicated structure. Therefore, according to the present invention, it is possible to realize the intermediate pushing method in the pipe propulsion method with a simple configuration.

In FIG. 1, 1 is an existing structure buried in the ground, 3 is a start shaft, 4 is an arrival shaft, 5 is a ground surface, and 6 is an insertion jack, which have the same configuration as shown in FIG.
12 is a new pipe that constitutes a duct to be laid inside the existing structure 1 and is formed of a ductile cast iron pipe. The pipe has a receiving port 13 at one end and an insertion port 14 at the other end. The tubes 12 and 12 are joined to each other by inserting the insertion port 14 of the other tube 12 into the receiving port 13 of the one tube 12 adjacent in the front-rear direction.

  A plurality of pipes 12, 12,... Are joined and propelled to lay a new pipe line, but the intermediate pushing mechanism 15 is provided between the pipes 12, 12 adjacent to each other on the front side of the rearmost pipe. Is provided. In the illustrated configuration, the insertion port 14 of the rear tube 12 is inserted into the receiving port 13 of the front tube 12 and propulsive force is transmitted between the receiving port insertion ports. Is provided with both receiving pipes 16 joined to the insertion opening 14 of the rear pipe 12. The both receiving pipes 16 are formed with receiving openings 13, 13 at both ends, respectively. Therefore, the receiving end 13 at the rear end of the front pipe 12 and the receiving opening 13 at the front end of both receiving pipes 16 face each other. Will be placed.

  As shown in FIG. 1 and FIG. 2, a first tube body 17 is joined to the receiving port 13 at the rear end of the front tube 12, and the second tube is connected to the receiving port 13 at the front ends of both receiving tubes 16. The body 18 is joined. Both the first tube body 17 and the second tube body 18 are made of a tube material having sufficient axial strength so that a propulsive force for the new tube 12 can be transmitted, such as a steel tube or a cast iron tube. An insertion opening 19 that can be inserted into the receiving opening 13 is formed at one end thereof. Although not shown in FIG. 2 for simplicity, when the pipe 12 is used for transporting fluids such as waterworks, a sealing material is provided between the receiving port 13 and the insertion port 19. Is an essential requirement. Moreover, it is preferable to provide a detachment prevention function or an earthquake resistance function between the receiving port 13 and the insertion port 19.

  The distal end surfaces of the insertion openings 19 of the first tubular body 17 and the second tubular body 18 are both configured to be in contact with the back end face 20 of the receiving opening 13, whereby the receiving opening 13 and the insertion opening 19 are connected to each other. The propulsive force can be transmitted between them.

  An annular bearing flange 21 is provided at the other end of the first tube body 17 and the second tube body 18 opposite to the one end where the insertion opening 19 is formed. The bearing flange 21 may be formed integrally with the pipe bodies 17 and 18 such as the one provided on the first pipe body 17, or may be provided on the second pipe body 18. In this way, the tube bodies 17 and 18 may be formed separately. In the illustrated example, the separate bearing flange 21 is configured to include a flange portion 22 and a cylindrical portion 23 that is concentrically fitted to the second tubular body 18. The second tubular body 18 is fitted and supported, and the flange portion 22 is used in contact with the end face of the second tubular body 18.

  Between the bearing flange 21 of the first tubular body 17 and the flange portion 22 of the bearing flange 21 of the second tubular body, an intermediate press that expands and contracts in the tube axis direction at a plurality of positions along the circumferential direction. Jack 24 is passed.

  When laying a pipe line composed of new pipes 12, 12,... Inside the existing structure 1, the pipe 12 is carried into the start shaft 3 as shown in FIG. A pushing force is applied to the tube 12 by pushing the tube 12 with the insertion jack 6, and the tube 12 is inserted into the existing structure 1. Subsequently, after the next pipe 12 is joined to the pipe 12, the insertion jack 6 is similarly pressed. Thereafter, similarly, the next pipes 12 are sequentially joined and given a propulsive force to be propelled toward the inside of the existing structure 1.

  At this time, as shown in FIG. 1, an intermediate pushing mechanism 15 is provided at an appropriate position in the pipeline to be propelled. If the middle push jack 24 in the middle push mechanism 15 is extended, the pipe 12 in the front side of the middle push jack 24 is moved forward while the portion behind the middle push jack 24 is supported by the insertion jack 6. To be promoted to. At this time, each tube 12 is only subjected to an axial force for propelling forward the tubes 12,... In front of the intermediate push jack 24. Only a small axial force is applied.

  If the pipes 12,... In the front side of the intermediate push jack 24 are pushed forward, the insertion jack 6 is then extended, and the intermediate push jack 24 is contracted in synchronization therewith. Accordingly, it is possible to propel only the pipes 12,... In the portion between the intermediate push jack 24 and the insertion jack 6 on the rear side of the intermediate push jack 24. In this case as well, the axial force that only propels the pipe 12 in the portion between the intermediate push jack 24 and the insertion jack 6 acts on the pipe 12, and therefore the pipe 12 is more than the entire length of the pipe line. Only a small axial force acts.

  By repeating the above operation, a pipe line using the new pipe 12 can be laid inside the existing structure 1 in a state where the axial force acting on each pipe 12 is reduced. If the intermediate pushing mechanism 15 is installed at a plurality of locations along the length direction of the pipe line to be laid, it is possible to perform a longer distance construction.

  By doing in this way, it is not necessary to give the pipe | tube 12 the big axial direction yield strength, Therefore For this reason, pipe material cost can be reduced. Further, the workable extension can be increased, and therefore, it is not necessary to excavate the shaft every short distance, so the number of civil engineering work can be reduced.

  In the case where the existing structure 1 is a sheath pipe and there is a bend in the joint portion between the sheath pipes, if the new pipe is propelled in that portion, the joint portion between the new pipes will be bent accordingly. Become. Then, one-side contact occurs between the adjacent new pipes at the bent portion, and a uniform thrust cannot be transmitted over the entire circumference of the pipe, resulting in stress concentration. For this reason, the allowable strength in the axial direction of the new pipe is reduced, and in some cases, it is necessary to reinforce the pipe material such as a rib. However, by providing the intermediate pushing mechanism 15 and providing the intermediate pushing jacks 24 at a plurality of positions along the circumferential direction of the intermediate pushing mechanism 15, even when the joint portions of the new pipes are bent, By adjusting the extension amounts of the jacks 24 to each other, a uniform driving force can be applied in the circumferential direction. Thereby, generation | occurrence | production per piece can be prevented and the reinforcement for improving the yield strength of a new pipe can be made unnecessary.

  When the cutting edge new pipe 12 arrives at the reaching shaft 4 by propulsion, the intermediate push jack 24 is removed from the state shown in FIG. 2, and the bearing flange 21 is removed as necessary. At this time, if the second tube 18 is configured separately from the bearing flange 21 provided in the second tube 18, the removal work can be easily performed. As a result, a space is formed in the portion where the intermediate push jack 24 was present. Next, the insertion jack 6 is operated to propel the pipe 21 existing behind this space, and this space. Stuff. That is, the aforementioned other ends of the first tubular body 17 and the second tubular body 18 are brought close to each other and joined together.

  In this joining, for example, as shown by a solid line in FIG. 3, the first tubular body 17 and the second tubular body 18 can be welded to each other. Reference numeral 25 denotes the weld joint. Alternatively, as shown by phantom lines in FIG. 3, an appropriate inner joint 26 such as an inner flange can be used. Of course, other bonding methods other than those described above can be applied.

It is a figure which shows the center pushing piping method of embodiment of this invention. It is an expanded sectional view of the principal part in FIG. It is a figure which shows the construction completion state of the part shown in FIG. It is a figure which shows the conventional pipe-in-pipe construction method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Existing structure 6 Insert jack 12 New pipe 15 Middle push mechanism 17 1st pipe body 18 2nd pipe body 24 Middle push jack 25 Welded joint

Claims (2)

Providing propulsive force to the pipe at the end of a pipe line that has a receiving port at one end and an insertion port at the other end, and transmits propulsive force sequentially from the rear tube to the front tube It is a method for promoting and laying by
A first pipe body having an insertion opening at one end and a flange portion at the other end is provided at one pipe adjacent to the front and rear in front of the rearmost pipe, and the first pipe is provided at the reception opening of the one pipe . together joined in a state of inserting the spigot of the tube, the other tube, the second tube having a flange portion at the other end has a spigot on both receiving tube one end socket is formed at both ends The body is inserted into one receiving port of the both receiving tubes, and the insertion tube of the second tube is inserted into the other receiving port of the both receiving tubes in order. Joined,
While arranged at a distance and a flange portion of the flange portion and the second pipe of the first tube in the axial direction of the tube, the flange portion and the flange portion of the second tube of the first tube A jack device is disposed between the jack device, the jack device is used to apply a propulsive force to the pipe on the front side of the jack device, and the jack device is propelled. And then propelling the conduit behind the jack device to bring the second tubular body closer to the first tubular body, and connecting the first tubular body and the second tubular body. An intermediate-pushing pipe method characterized by joining together. 2. An intermediate pushing piping method according to claim 1, wherein a new pipe line is propelled and installed inside the existing structure.

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