JP2007002970A - Sheath pipe jacking technique - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably prevent buoyancy material from leaking out even if a joint part of the new pipe swells when a new pipe is given buoyancy and is jacked and inserted in a sheath pipe 1. <P>SOLUTION: A water shut off member 12 on one end of the sheath pipe is formed as one unit of rubber, and consists of a cylindrical part 12a fixed on an inner surface of the sheath pipe 1 by a machine screw, a flap 12b facing an axial center of the sheath pipe on an inner circumference whole surface, and a solid cross section round rubber ring 12c of larger diameter than a tip end thereof on a tip end whole circumference of the flap 12b. The flap has normally flexibility and flexibly correspond to change, fluctuation of size (diameter) of the new pipe sliding in the annular shape part of the flap. Then since a solid cross section circular rubber ring is larger in a diameter than a flap tip edge, the flap is not easily influenced by bent of the flap, sure press contact to the new pipe outer circumference surface is maintained even if the flap is deformed to secure water tightness. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In this invention, when a new pipe is inserted into a sheath pipe to construct a pipeline, a sheath propelling method for inserting the new pipe by injecting a buoyant material into the sheath pipe to give buoyancy to the new pipe, the sheath pipe It is related with the obstruction | occlusion structure of the one end.

Steel pipes and ductile iron pipes are used for fluid transportation in various fields such as water and sewage, agricultural water, and industrial water. These pipes are usually buried in the ground and have recently been updated. There is a need to do that.
For example, for the construction (embedding) of pipes using ductile cast iron pipes and the replacement (updating) of old pipes, an open-cut method in which pipes are buried by excavating the ground is generally employed.
However, due to recent traffic conditions and the construction of complex pipelines in the city center and the like, it is difficult to newly construct pipelines by the open-cut method or to replace old pipelines. For this reason, the sheath tube propulsion method and the pipe-in-pipe method are employed as methods that replace the open-cut method.

  As shown in FIG. 15, the sheath tube propulsion method excavates only the start pit S and the reaching pit T on the ground W, and from the start pit S, first, a fume tube or a steel tube is put into the soil W as a sheath tube 1. A new pipe 2 such as a ductile cast iron pipe having a diameter smaller than the sheath pipe diameter from one end (starting pit) S to the other end (arrival pit) T is placed inside the sheath pipe 1 that is propulsion buried. It is a method of inserting sequentially while joining, and is usually adopted for construction of new pipes.

In addition, the pipe-in-pipe construction method uses the existing pipe buried in the soil as the sheath pipe 1, and in the existing pipe 1 as with the sheath pipe propulsion construction method, using the hydraulic jack J or the like from the existing pipe diameter. In this method, new pipes 2 having a small diameter are sequentially inserted while being joined together.
In addition, since the existing pipe in this pipe-in-pipe construction method is one of the sheath pipes 1, in this specification (including the “claims”), the sheath pipe propulsion method, pipe shown in FIG. Unless otherwise specified, a construction method that promotes and inserts a new pipe 2 into a sheath pipe 1 to form a double pipe structure, such as an in-pipe construction method, is generally referred to as a “sheath pipe construction method”.

  In this sheath pipe propulsion method, the new pipe 2 is usually inserted by installing a hydraulic jack J at the start shaft S as shown in FIG. 15, receiving a reaction force H at the rear part of the hydraulic jack J, and pushing angle at the front part. A joint is inserted into the receiving port 2b of the forward new pipe 2 inserted into the sheath pipe 1 after the insertion port 2a of the forward new pipe 2 is suspended from the ground on the starting platform installed in the starting pit S. The joining is performed by pressing the new pipe 2 backward by the hydraulic jack J while inserting the parts (joining part). With this construction method, there is no problem of blocking traffic, and it is possible to construct a pipeline with the new pipe 2 even if a complicated pipeline is constructed.

  In general, after inserting the new pipe 2 into the entire length of the sheath pipe 1 by the sheath pipe propulsion method, the gap between the sheath pipe 1 and the new pipe 2 is filled with a filler such as mortar from the starting pit S or the reaching pit T. It is. This is because it is necessary to prevent ground subsidence or the like by filling the gap with a filler.

In the double pipe structure constructed in this way, in order to ensure the maximum flow area, it is preferable that the new pipe 2 is closer in diameter to the sheath pipe 1, and preferably one bore diameter rather than the sheath pipe diameter. Only those with a small nominal diameter are adopted.
Further, in recent years, the joint has been required to have earthquake resistance, and the earthquake-resistant pipe joint is generally structured such that the insertion port 2a can be expanded and contracted (removable) in the required range with respect to the receiving port 2b. There are PII type, S type, NS type, SII type and so on.

As shown in FIG. 16, the seismic pipe joint, for example, the PII type joint, is inserted after the rubber ring 3 for sealing is installed inside the receiving port 2b of the one pipe 2 and the lock ring 4 is installed outside. The port 2a is inserted into the receiving groove 2 of the receiving port 2b by expanding the diameter of the lock ring 4 and compressed while the rubber ring 3 is compressed, and the lock ring 4 reaches the annular groove 6 on the outer peripheral surface of the insertion port 2a. The structure is such that a set bolt 7 is screwed into the receiving port 2b from several places around the receiving port 2b to reduce the diameter of the lock ring 4 and fit into the groove 6 (see Patent Document 1). In this joint, the thickness of the receiving port 2b is reduced. Usually, when inserting a new pipe 2 having a nominal diameter smaller than that of the sheath pipe 1 by a single diameter, particularly when inserting into the existing pipe 1, It is used as a joint structure for the new pipe 2.
Japanese Utility Model Publication No. 58-130189

On the other hand, in this sheath tube propulsion method, when the new tube 2 is propelled and inserted into the sheath tube 1, the new tube 2 is generally slid on the inner surface of the sheath tube 1, and the insertion length (starting pit) When the distance between S and the reaching pit T) becomes longer, the frictional resistance at the time of sliding increases, and accordingly, the propulsion device such as the hydraulic cylinder J becomes large.
Further, since the insertion force of the new pipe 2 by the PII type joint is transmitted by the contact between the lock ring 4 on the end face side of the receiving port 2b and the end face of the groove 5, the lock ring 4 is twisted and damaged when the insertion force increases. There is a risk that it will not be promoted smoothly. For this reason, when a large driving force is applied, such as when the distance between the start pit S and the arrival mine T is long, a rib is separately fixed to the outer peripheral surface of the insertion port 2a by welding or the like, and the rib is connected to the receiving port 2b. The propulsive force is transmitted by contacting the end face. The mounting of the rib is complicated.

Furthermore, when the crustal deformation such as an earthquake occurs in the S-type and NS-type earthquake-resistant pipe joints, the insertion port 2a does not come out of the receiving port 2b against the pushing or pulling of the insertion port 2a with respect to the receiving port 2b. It is a structure that responds to its crustal deformation by expanding and contracting (pushing and pulling out) within the range.
In the sheath pipe propulsion method for the earthquake-resistant pipe joint having this structure, when the new pipe 2 is inserted into the sheath pipe 1 buried in the underground W sequentially from one end to the other end, A propulsive force transmission material is provided on the outer peripheral surface of the insertion slot 2a, and the propulsive force transmission material is used to propel the propulsive force by maintaining it in the middle of the required length that can move within a range that does not pass through the insertion slot 2a. When a larger pressing force is applied, the pressing force exceeds the maintenance force of the propulsive force transmitting material, and the middle maintenance of a required length that can move within a range that does not pass through the insertion port is released and the insertion port 2a is released. Is further pushed into the receiving port 2b (see FIG. 11, Patent Document 2).

One technique for reducing the frictional resistance at the time of inserting the new pipe 2 in the sheath pipe propulsion method is to provide a warp or a wheel on the outer peripheral surface of the new pipe 2 (see Patent Document 2). However, this technique requires a space for providing a warp or the like between the sheath tube 1 and the new tube 2, and usually inserts the new tube 2 having a nominal diameter smaller than the sheath tube 1 by one caliber. It is difficult.
JP 2002-276284 A

Another technique for reducing the frictional resistance at the time of inserting the new tube 2 is to close both ends of the sheath tube 1 and to inject the buoyant material such as water into the sheath tube 1 to buoyant the new tube 2. The new tube 2 is propelled and inserted into the sheath tube 1 (see Patent Documents 3 and 4).
In this technique, since the new tube 2 must be inserted into the sheath tube 1 while maintaining the blockage in the sheath tube 1, the insertion portion is blocked by the expansion / contraction tube around the inner surface of the sheath tube 1. (Patent Document 3), or a flap-shaped seal plate is provided on the entire inner periphery of the sheath 1 in the axial direction (Patent Document 4), and the tube or seal plate is attached to the outer peripheral surface of the new tube 2. This is done by sliding welding.
Japanese Patent Laid-Open No. 10-238655 JP 2000-291827 A

First, in a pipe-in-pipe construction method in which a new pipe is inserted into an existing pipe 1 to renew the pipe, the existing pipe 1 has rust and foreign matter attached to its inner surface over the course of several decades. In the above-mentioned sled, etc., the propulsion resistance is large and a large propulsive force is required. In addition, the existing pipe 1 is rarely left with construction drawings, and there are many meandering and branch pipes, etc., and there are steps, gaps, etc. in the joint part. Is a big thing.
For this reason, the pipe-in-pipe method is difficult to predict the propulsive force compared to the sheath tube propulsion method, and in particular, the propulsion method in the earthquake-resistant pipe joint using the propulsive force transmitting material is the seismic tube using the propulsive force transmitting material. It is difficult to secure the gap between the joints (pushing allowance).

Next, in the sheath tube propulsion method using the above buoyancy material, the new pipe 2 such as the PII type joint, as can be understood from FIG. 16, is a straight pipe portion having a bulging portion having a receiving port 2b and an insertion port 2a. The joint portion (joint portion) in which the insertion port 2a is inserted into the receiving port 2b is swelled outward as compared with the straight tube portion.
For this reason, in order to propel and insert the new pipe 2 to be a swelled joint part into the sheath pipe 1 by the techniques described in Patent Documents 3 and 4, the outer circumferences having different diameters of the straight pipe part and the joint part are used. A tube or a seal plate is brought into sliding contact with the surface to close the end surface of the sheath 1.

However, sliding pressure welding with the above tube has only two stages of fluid supply / discharge to the tube (since there are only two ways of fluid injection and release of the fluid pressure), the straight pipe part If the fluid pressure is set so that the blockage of the joint can be ensured, the tube is deformed and allowed to pass through the joint during sliding pressure contact with the joint. Normally, the fluid is liquid and its volume increases or decreases. Is difficult, and a large frictional resistance is generated, leading to breakage of the tube.
For this reason, in this technique, the new pipe 2 is limited to a straight pipe having a substantially straight pipe portion (same diameter). In addition, even when the fluid is gas and the tube expands and contracts, in order to obtain a sufficient pressure contact force, the inside of the tube needs to be at a high pressure. When the joint portion passes, a large frictional resistance is generated, which leads to breakage of the tube.

  In the sliding pressure contact with the seal plate, since the pressure contact force is obtained by the elastic force of the seal plate, the pressure contact force cannot be sufficiently obtained, and the buoyancy material is likely to leak. Also, at the time of sliding contact with the joint, the seal plate is deformed and the passage of the joint is allowed. Normally, deformation (deflection) of the seal plate is difficult to make uniform. In the meantime, uniform sliding pressure welding is not performed, and buoyancy material often leaks from insufficient pressure welding points.

  This invention provides a buoyancy material even if the joint (joint part) of the new pipe bulges (when there is a difference in the outer diameter of the pipe) when propagating and inserting the new pipe with buoyancy. It is an object to ensure that no leakage occurs.

In order to achieve the above object, the present invention employs a flap-shaped seal plate of Patent Document 4, and has a solid cross-section circular rubber having a larger diameter than the front end edge on the entire periphery of the front end edge of the seal plate (flap). A configuration with a ring made of steel was adopted.
The flap is usually rich in flexibility, and flexibly responds to the size change (diameter) change and vibration of the new tube that slides in the annular shape of the flap. However, as described above, it is insufficient that the tip edge is pressed against the outer peripheral surface of the new tube to maintain watertightness.
For this reason, if a rubber ring having a solid cross-section circular shape is provided on the entire circumference of the flap tip edge, the ring is pressed against the outer peripheral surface of the new pipe that slides inside the annular ring of the flap. At this time, since the ring has a larger diameter than the front edge of the flap, it has a strong waist and is not easily affected by the flexure of the flap, and flexibly responds to the size (diameter) change / runout of the new pipe on which the flap slides. However, water tightness is ensured by maintaining reliable pressure contact to the outer surface of the new pipe.

  As described above, the flap and the ring at the tip edge of the present invention flexibly cope with the change (in diameter) and vibration of the new tube and maintain watertightness, thus preventing buoyancy material from leaking smoothly. can do. In particular, this is advantageous in a new pipe having a large change in the outer peripheral surface diameter.

  As an embodiment of the present invention, when inserting a new pipe into the sheath pipe buried in the ground while sequentially joining the new pipe from one end to the other end, both ends of the sheath pipe are closed, and the buoyancy is generated in the sheath pipe. In the sheath propulsion method in which material is injected to give buoyancy to the new tube and the friction between the new tube and the sheath tube is reduced, the clogging of one end side of the sheath tube is watertight around the entire inner surface of the sheath tube. The water-stopping member is provided with a flap facing the shaft center of the sheath on the entire inner circumference, and a solid cross-sectional circle having a diameter larger than that of the tip edge on the entire circumference of the tip edge of the flap. The new pipe sheath is inserted into one end of the sheath tube by expanding the diameter of the water stop member ring and flexing its flap toward the other end of the sheath tube. The new ring while water-tightly pressing the ring to the outer peripheral surface of the new pipe It is possible to adopt a configuration that allows sliding.

In this configuration, the water stop member can be provided on the entire inner surface of the cylindrical body that is watertightly fitted to the outer peripheral surface of the sheath tube without providing the waterstop member on the inner surface of the sheath tube.
In this way, if the water stop member is provided in the cylindrical body fitted on the outer surface of the sheath, the inner surface of the tubular body is larger than the inner surface of the sheath (because the diameter is large). In addition, a large allowance for the deflection of the flaps can be obtained, and the response to changes in the size (diameter) and deflection of the new pipe can be made smooth. For this reason, the waterstop is also high.
Furthermore, it is possible to attach the water stop member to the sheath tube simply by fitting the tube body having the water stop member to the sheath tube, and the cylinder body can be used for other sheath tubes. Etc., cost reduction.

The smooth response to changes in the size (diameter) and run-out of the new pipe means that the joint part of the new pipe inserts the insertion port into the reception port, and the receiving port is more straight than the straight pipe part that has the insertion port. This is advantageous for such a large-diameter bulge.
For example, when the joint portion of the new pipe has a seismic pipe joint structure, that is, the joint portion of the new pipe is provided with a propulsive force transmission material on the outer peripheral surface of the new pipe insertion port, and this propulsive force transmission material is used to insert the insertion port. When the propulsion force is maintained in the middle of the required length that can move within the range that does not pass through and a pressing force greater than the propulsive force is applied due to an earthquake, etc., the pressing force exceeds the maintaining force of the propulsive force transmitting material. In the case of a telescopic earthquake-resistant joint structure in which the middle length of the required length that can move within the range of the insertion opening is released and the insertion opening is further pushed into the receiving opening, the size of the new pipe Since the (diameter) change is large, it is very effective.

As an embodiment of the closed structure on the one end side of the sheath pipe in the sheath pipe propulsion method, a water stop member is provided in a watertight manner on the entire inner surface of the sheath pipe, and the water stop member is an axial center of the sheath pipe on the entire inner periphery. Has a rubber ring with a solid cross-section circular shape larger in diameter than the tip edge on the entire circumference of the tip edge of the flap, and when inserted into one end of the sheath of the new pipe, While expanding the diameter of the ring of the water stop member, flexing the flap to the other end of the sheath, allowing the new tube to slide while water tightly contacting the outer periphery of the new tube A configuration in which the sheath is closed at one end can be employed.
Even in this configuration, the water stop member is not provided on the inner surface of the sheath tube, but can be provided water tightly on the entire inner surface of the cylindrical body fitted on the outer peripheral surface of one end of the sheath tube. The effect can be obtained.

  The flap of the water stop member is not limited to an elastic body such as rubber as long as the ring bends toward the other end of the sheath as the diameter of the ring expands, and various flexible materials can be used.

FIG. 1 to FIG. 13 show an embodiment, which relates to the renewal of the existing pipe 1, and as shown in FIG. 1, the start pit S and the arrival pit T are formed at a required interval. A water stop mechanism 10 is attached to the end (one end) of the start pit S of the existing pipe (sheath pipe) 1 between them and closed, and a water stop / centering jig is provided at the end of the arrival mine T (the other end). 20 is attached and closed.
The starting mine S and the reaching mine T may be formed at the same place as when the existing pipe 1 is buried, but are arbitrary as long as the side part of the road can be formed. The tip of the leading tube of the new tube 2 inserted into the sheath tube 1 is closed by fitting a conical cap 30 so that the buoyancy material a does not flow into the new tube 2.

As shown in FIG. 11, the joining portion (joint portion) of the new pipe 2 is formed with axial grooves 6a and 6b on the outer peripheral surface of the insertion port 2a and the inner peripheral surface of the receiving port 2b, respectively. The lock rings 4a and 4b are respectively fitted to 6b, and the state shown in the figure is normal (when new pipe laying is completed). In this state, after inserting the insertion port 2a of the rear new tube 2 into the receiving port 2b of the future new tube 2, (or before inserting), the propulsive force transmitting material is placed on the outer peripheral surface of the insertion port 2a outside the receiving port 2b. 8 and the propulsive force transmission member 8 is fixed by a flange (saddle ring) 9 that is fixed to the outer peripheral surface of the insertion port 2a by welding or the like (see Patent Document 2, Japanese Patent Application No. 2004-50171). The material and configuration of the propulsive force transmission member 8 and the configuration of the flange 9 are not limited to those shown in the figure, and are arbitrary. For example, a resin foam such as polyurethane or polystyrene having a compressive stress of 1 to 30 kgf / cm ² (≈0.1 to 3 MPa) is employed for the propulsive force transmission member 8.

When the new pipe 2 is sequentially pushed and inserted into the sheath pipe 1 from one end to the other end in the sheath pipe 1, the joining portion is pushed by the propulsive force transmitting member 8 and the tip of the insertion opening 2 a and the inner surface of the receiving opening 2 b. While maintaining the gap with the rear end surface 2b ′ (maintaining the state of FIG. 11), the propulsive force is transmitted from the backward new pipe 2 to the forward new pipe 2, and the new pipe 2 is propelled. The pipe of the new pipe 2 is laid along the entire length of the sheath pipe 1.
For the promotion, various means such as the means shown in FIG. 15, the means described in Patent Document 5, and the means described in Japanese Patent Application No. 2004-213203 are adopted.
Japanese Patent Laid-Open No. 2004-238851

  In the new pipeline after laying, the propulsive force transmission member 8 contracts or collapses against a large compressive force such as an earthquake, and the tip of the insertion port 2a abuts or is inserted into the inner end 2b ′ of the inner surface of the receiving port 2b. Until the mouth side lock ring 4a comes into contact with the rear end face side 6a 'of the insertion side groove 6a, the insertion of the insertion port 2a with respect to the receiving port 2b is allowed, and both lock rings 4a, Until the 4b comes into contact with the front end surface of the insertion slot side groove 6a, the insertion slot 2a is allowed to be pulled out from the receiving slot 2b. In other words, the splicing portion has an earthquake resistance function that allows insertion / extraction of the insertion port 2a (see Patent Document 2).

As shown in FIGS. 10 and 11, the water stopping mechanism 10 of the sheath pipe 1 on the start pit S side is provided with a water stopping member 12 in the axial direction on the inner surface of a cylindrical pipe (tubular body) 11 made of ductile or steel. It is provided at a required interval. The number of the water stop members 12 is arbitrary.
As shown in the figure, the cylindrical tube 11 is fitted into one end of the sheath tube 1 via a packing 11c, and is attached to one end of the sheath tube 1 with a screw 11d. Further, the cylindrical tube 11, as shown in FIG. 4, two cylindrical portions 11a which eccentric consists of a 11b, the former of the cylindrical portion 11a is the same center C ₁ fitted to the sheath tube 1, the latter tubular portion 11b is the new pipe 2 with the same center C _2.
The cylindrical pipe 11 is provided with a water supply / drainage pipe 13 with a valve 13 a, and the buoyancy material a is injected into or discharged from the sheath pipe 1 by the water supply / drainage pipe 13.

As shown in FIGS. 2, 5 and 11, the water-stop member 12 is made of an integrally molded product of rubber, and has a cylindrical portion 12a screwed to the inner surface of the sheath tube 1 and a sheath tube on the entire inner periphery thereof. It consists of a flap 12b facing one axial center (cylinder axis) and a rubber ring 12c having a solid cross-sectional circle with a larger diameter than the leading edge on the entire circumference of the leading edge of the flap 12b.
The thickness and length of the flap 12b (length toward the axial center) and the diameter of the ring 12c may be appropriately set in consideration of the degree of deflection and the pressure contact degree (water density), but the thickness of the flap 12b is flexible. It is preferable that the thickness of the ring 12c is thin as long as the ring 12c can be held.
The water stop member 12 has its cylindrical portion 12a applied to the inner surface of the cylindrical tube 11, and a ring-shaped stopper 14 having a single split opening shown in FIG. Install.

When the cap 30 or the new pipe 2 is inserted into the water stop member 12, the ring 12c is expanded in diameter and the flap 12b is bent toward the other end side of the sheath pipe 1 as shown in FIG. Thus, the cap 30 or the new tube 2 is allowed to slide while the ring 12c is pressed against the outer peripheral surface of the cap 30 or the new tube 2 in a watertight manner.
At this time, since the ring 12c has a larger diameter than the front end edge of the flap 12b, it is not easily affected by the deflection of the flap 12b, and the size (diameter) change or fluctuation change of the outer peripheral surface of the cap 30 or the new tube 2 on which the flap 12b slides. -Even if it bends flexibly in response to vibration, it maintains the pressure contact with the cap 30 or the outer peripheral surface of the new pipe 2 to ensure water tightness. When the cap 30 or the new tube 2 is inserted, the flap 12b is also expanded in diameter as necessary.

As shown in FIGS. 1, 3, and 7, the other end closing / centering jig 20 of the sheath tube 1 is a cylinder having a reduced diameter on the end surface of the cylindrical portion 21 fitted to the outer peripheral surface of the distal end portion of the sheath tube 1. The level-adjusting member 23 of the buoyancy material a is connected to the reduced-diameter cylindrical portion 22 via flanges 22a and 23a.
The jig 20 is attached to the outer surface of the other end of the sheath tube 1 with screws, and is provided with a water supply / drainage pipe 13 with a valve 13a as in the water stop mechanism 10. The buoyancy material a is injected or the buoyancy material a is discharged.

  Both cylindrical portions 21 and 22 of the jig 20 are reinforced by ribs 24 provided at equal intervals on the outer peripheral surface or the inner peripheral surface (see FIG. 3). Further, rubber rings (packing) 25 are provided on the inner surfaces thereof, and the water tightness of the jig 20 and the sheath tube 1 is ensured by the rubber ring 25 of the former cylindrical portion 21, and the first newest When the insertion opening 2a (cap 30) of the tube 2 enters the latter cylindrical portion 22, it is sealed (liquid-tight) by the rubber ring 25 of the latter cylindrical portion 22, and leakage of the buoyancy material a is prevented. . For this reason, even if the level adjusting member 23 is removed, the buoyancy material a does not flow out from the sheath 1, and the new tube 2 can be pulled out from the sheath tube 1 by a predetermined length on the arrival tunnel T side.

As shown in FIGS. 3 and 7, the level adjusting member 23 is formed of a cylindrical body in which the opposite end of the flange 23 a is closed, and a through hole 26 is formed in the upper part of the cylindrical body. Therefore, the buoyancy material a in the sheath 1 overflows, and the level of the buoyancy material a in the sheath 1 is maintained constant. The height of the overflow (lower edge height of the through-hole 26), for example, as shown, like a little to below the axis C ₁ of the axis C ₂ Gasaya tube 1 of the new pipe 2, the new tube Even if 2 slides on the inner surface of the sheath 1, it is optional as long as the new tube 2 can be propelled.

As shown in FIG. 8, the cap 30 includes a cylindrical portion 31 and a truncated cone-shaped portion 32 provided at the tip thereof, and the rear end portion of the cylindrical portion 31 is reduced in diameter to the entire circumference. A groove 33 is formed. A packing 34 is fitted in the groove 33.
An insertion preventing ring 35 shown in FIG. 9 is fixed to the outer peripheral surface of the cap 30. As shown in the figure, the ring 35 is composed of two split members 35a and 35b, and both the members 35a and 35b are fastened by bolts 36, and screws 38 are threaded through the surrounding screw holes 37. The tip is attached to the cap 30 by press contact with the outer peripheral surface of the cap 30. The ring 35 and the cap 30 are aligned by adjusting the screwing degree of each screw 38.

  The cap 30 is fitted to one end of the cylindrical tube 11 of the water stop mechanism 10 after the insertion preventing ring 35 is attached. Alternatively, after the cap 30 is fitted to one end of the cylindrical tube 11, the insertion preventing ring 35 is attached. This state is supported so that the rear side of the cylindrical portion 31 of the cap 30 protrudes from the end surface of the cylindrical tube 11 to the start shaft S side, and when the new tube insertion port 2a is inserted into the outer surface of the cylindrical portion 31 from the supported state, The new pipe 2 is connected to the cap 30, and the water tightness of the two 2 a and 31 is maintained by the packing 34 in the groove 33. However, the fixing of the cap 30 and the insertion opening 2a is not limited to that shown in the drawing as long as it can exhibit a water stop function and does not come off the leading new tube 2 during the subsequent insertion of the new tube 2.

This embodiment is configured as described above. Next, its operation will be described. First, as shown in FIG. 1, the start pit S and the arrival pit T are formed at a required interval in the buried path of the existing pipe 1. The start pit S and the arrival pit T are preferably located in the same place as when the existing pipe (sheath pipe) 1 is buried.
In the start pit S, as shown in FIG. 10A, the cylindrical pipe 11 with the water blocking member 12 is fitted to the start pit S side (one end) of the sheath pipe 1 via a rubber ring (packing) 11c. It is attached by screws 11d and the like, and a cap 30 with an insertion preventing ring 35 is fitted into the cylindrical tube 11.
On the other hand, a jig 20 with a level adjusting member 23 is attached to the pit T side (the other end) of the sheath tube 1 to close both ends of the sheath tube 1 (to make the sheath tube 1 liquid-tight).

Next, the sheath pipe 1 is filled with water to be buoyant material a from both the water supply / drain pipes 13 and 13 until it overflows from the through hole 26 of the level adjusting member 23. This injection filling may be performed only from one of the water supply / drainage pipes 13.
After the filling of the buoyant material a is completed or before the filling, as shown in FIG. 10B, the cylindrical portion 31 of the cap 30 in which the insertion opening 2 a of the earliest new pipe 2 is fitted into the sheath pipe 1 is shown. Fit into. At this time, the insertion of the cap 30 into the sheath tube 1 is prevented by the contact of the insertion prevention ring 35 with the end surface of the sheath tube 1.
Next, after the insertion preventing ring 35 is removed from the cap 30, if the buoyancy material a is filled, the new tube 2 is pushed in. If not filled, the new tube 2 is pushed in after the buoyancy material a is filled.

At the time of the propulsion insertion of the new pipe 2 by this pushing, the ring 12c and the flap 12b of the water stop member 12 are expanded in diameter, the flap 12b is bent toward the other end side of the sheath pipe 1, and the ring 12c is the outer periphery of the new pipe 2 The new tube 2 is allowed to slide while being in watertight pressure contact with the surface, and inserted into the sheath tube 1.
Further, since the propulsion insertion of the new pipe 2 is performed in the buoyancy material a, it advances through the sheath pipe 1 with low friction while receiving buoyancy from the buoyancy material a. At this time, due to the progress of the new pipe 2, the pushed buoyancy material a overflows from the through hole 26 of the level adjusting member 23 on the arrival tunnel T side (the other end) of the sheath pipe 1, and the level is maintained constant. axis C ₂ of the new tube 2 is also maintained at a substantially constant level.

The insertion port 2a of the succeeding new tube 2 is inserted and connected to the receiving port 2b of the earliest new tube 2, and the new tube 2 is further inserted. As shown in FIG. When the water stop member 12 (water stop mechanism 10) reaches the water stop member 12 (water stop mechanism 10), the ring 12c and the flap 12b are greatly expanded in accordance with the diameter increase of the receiving port 2b, and the flap 12b is The ring 12c is inserted into the sheath 1 while allowing the sliding of the receiving port 2b while allowing the ring 12c to be in watertight pressure contact with the outer peripheral surface of the receiving port 2b.
At this time, since the ring 12c has a larger diameter than the front end edge of the flap 12b, the ring 12c is not easily affected by the deflection of the flap 12b, and flexibly responds to a large outer diameter change / swing of the receiving port 2b on which the flap 12b slides. However, watertightness is ensured by maintaining reliable pressure contact with the outer peripheral surface of the receiving port 2b.

  Thereafter, the insertion 2a of the new tube 2 is inserted into the receiving port 2b of the future new tube 2 in succession and pushed together, and the same action as described above is performed at the receiving port 2b. The new pipe 2 is propelled toward the pit T of the sheath pipe 1.

The propulsion insertion of the new pipe 2 proceeds, and the insertion opening 2a of the earliest new pipe 2 approaches the access shaft T as shown in FIG. 12 (a), and the insertion opening 2a is the tip cylindrical portion of the jig 20. When fitted into the wire 22, the jig 20 is centered with water stoppage (with the other end of the sheath 1 closed). At this time, even if the core is displaced before the insertion port 2a enters the jig 20, it is abutted against the taper edge of the rib 24 on the inner surface thereof.
If the insertion slot 2a fits in the jig 20 and reaches the level adjustment member 23 (FIG. 5A), the level adjustment member 23 is removed as shown in FIG. Further, the insertion opening 2a of the new pipe 2 is projected into the reaching pit T for a required length. Thereafter, the buoyancy material a is discharged from the sheath pipe 1 by draining from the water supply / drain pipe 13.

  Next, as shown in FIG. 13C, the cap 30 is removed, and the propulsion loading of the new pipe 2 into the sheath pipe 1 is completed (FIG. 13).

  In this embodiment, as shown in FIG. 14, the water stop member 12 can be directly attached to the inner surface of one end of the sheath tube 1.

In this connection, if the new tube 2 is propelled and inserted into the sheath tube 1 with buoyancy, no large force is required for the propulsion. Therefore, when the propellant is inserted via the propulsive force transmission member 8 as in the embodiment, the propulsive force There is an advantage that a material having a relatively low mechanical strength such as the above-mentioned resin foam can be used for the transmission material 8.
In addition, in the pipe-in-pipe method in which the new pipe 2 having the earthquake-resistant pipe joint is propelled and inserted into the existing pipe, the inner surface of the sheath (existing pipe) is a rough inner surface due to adhesion of rust or foreign matter. As compared with the case where the inner pipe is slid and the new pipe 2 is propelled, the propulsion by the buoyancy is moved away from the inner face, so that the propulsive force is very small and more effective. .

The pipe joint structure is not limited to that of the embodiment, and it is possible to adopt well-known non-seismic types such as PII type, S type, NS type, SII type, and non-seismic types such as A type and K type. is there. Further, the structure of thrust transmission is not limited to the illustrated propulsive force transmission member 8 or the like.
Moreover, it cannot be overemphasized that the said Example can be employ | adopted for the said sheath pipe | tube propulsion method which the sheath pipe | tube 1 was newly embed | buried not only in the existing pipe (it is not restricted to a pipe-in-pipe construction method) but a fume pipe | tube and a steel pipe.
Furthermore, the insertion promotion of the new pipe 2 can also be performed from the arrival shaft T side.

Schematic sectional view of one embodiment Cross-sectional view of one end of the sheath tube of the same embodiment Sectional view of the other end of the sheath of the same embodiment It is a longitudinal cross-sectional view of the cylindrical pipe | tube of the sheath one end side water stop mechanism of the Example, (a) is the XX sectional view of FIG. 10 (a), (b) is the YY sectional view. The water stop member of the water stop mechanism of the same Example is shown, (a) is a left side view, (b) is a cut front view. The stop of the water stop member is shown, (a) is a front view, (b) is a plan view, and (c) is a right side view of a main cutting section. The buoyancy material level adjustment member of the sheath pipe other end side water stop mechanism of the Example is shown, (a) is a cut front view, (b) is a left side view, (c) is a cross-sectional view taken along line XX of (a). Figure The cap of the Example is shown, (a) is a cut front view, (b) is a left side view, (c) is a cross-sectional view taken along line XX of (a). The cap insertion prevention ring of the Example is shown, (a) is a front view, (b) is a left side view. Cross-sectional view of main part operation when inserting the earliest new pipe into the sheath pipe of the same embodiment Cross-sectional view of the main part of the new pipe in the same embodiment when the seam is inserted into the sheath pipe Figure of the action of inserting the sheath of the earliest new pipe in the same embodiment into the water stop of the pipe reach (other end) side Schematic sectional view at the end of the new pipe promotion of the same embodiment Cross-sectional view of the main part at the time of insertion into the sheath of the earliest new pipe of another embodiment Schematic of sheath tube propulsion method Cross section of PII joint

Explanation of symbols

1 sheath pipe (existing pipe)
2 New pipe 10 Saddle pipe start pit side water stop mechanism 11 Cylindrical tube 12 of water stop mechanism Water stop member 12a Tubular portion 12b of water stop member 12 Flaps 12c of water stop member 12 Solid ring 13 of water stop member 12 Pipe 20 Sheath pipe pit side water stopping / centering jigs 21, 22 Cylindrical part 23 for water stopping / centering buoyancy material level adjusting member 26 Buoyant material level adjusting through hole 30 Cap for newest new pipe insertion port a Buoyancy material (water)

Claims (2)

When the new tube 2 is sequentially inserted into the sheath tube 1 embedded in the underground W from one end S to the other end T, both ends of the sheath tube 1 are closed, and the sheath tube 1 is inserted into the sheath tube 1. In the sheath propulsion method in which the buoyancy material a is injected to give buoyancy to the new tube 2 and the friction between the new tube 2 and the sheath tube 1 is reduced.
The sheath tube 1 is closed at one end side by a water-stop member 12 that is watertightly provided on the entire inner surface of the sheath tube 1, and the water-stop member 12 faces the axial center of the sheath tube 1 on the entire inner periphery. It has a flap 12b and a rubber ring 12c having a solid cross-section circular shape larger in diameter than the tip edge around the entire tip edge of the flap 12b.
The insertion of the new pipe 2 into one end of the sheath 1 expands the diameter of the ring 12c of the water blocking member 12 and flexes the flap 12b toward the other end of the sheath 1 so that the ring 12c A sheath tube propulsion method characterized by allowing the new tube 2 to slide while being in watertight pressure contact with the outer peripheral surface of the new tube 2. When the new tube 2 is sequentially inserted into the sheath tube 1 embedded in the underground W from one end S to the other end T, both ends of the sheath tube 1 are closed, and the sheath tube 1 is inserted into the sheath tube 1. A buoyancy material a is injected to give buoyancy to the new pipe 2, and the sheath structure of the one end side of the sheath pipe 1 in the sheath propulsion method has reduced friction between the new pipe 2 and the sheath pipe 1,
A water-stop member 12 is provided in a watertight manner on the entire inner surface of the sheath 1, and the water-stop member 12 has a flap 12 b that faces the axis of the sheath 1 on the entire inner periphery, and the entire tip edge of the flap 12 b. It has a rubber ring 12c having a solid cross-section circular shape larger in diameter than its front end edge,
When the new tube 2 is inserted into one end of the sheath tube 1, the ring 12 c of the water stop member 12 is expanded in diameter, and the flap 12 b is bent toward the other end side of the sheath tube 1, so that the ring 12 c is A closing structure on one end side of the sheath tube, wherein the sheath tube 1 is closed at one end while allowing the new tube 2 to slide while being in watertight pressure contact with the outer peripheral surface of the new tube 2.

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