JP4638287B2 - Saya tube propulsion method - Google Patents

Description

  In this invention, when a new pipe is inserted into a sheath pipe to construct a conduit, a sheath propelling method for inserting a new pipe by injecting a buoyant material into the sheath pipe to give buoyancy to the new pipe, and its buoyancy The present invention relates to a material level adjusting device.

Steel pipes and ductile iron pipes are used for fluid transportation in various fields such as water and sewage, agricultural water, industrial water, etc., and 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. 16, the sheath tube propulsion method cuts only the start pit S and the arrival mine T on the ground W, and from the start pit S, first, a fume tube or a steel tube as the sheath tube 1 is put into the soil W. 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 pit S as shown in FIG. 16, and receiving a reaction force H at the rear of the hydraulic jack J and a pushing angle at the front. 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. 17, 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 6, if the insertion force increases, the lock ring 4 is twisted and broken. 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 maintaining force of the propulsive force transmission member, and the middle maintenance of the 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 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 around the inner circumference of the sheath 1 in the axial direction (Patent Document 4), and the tube or seal plate is slidably pressed against the outer surface of the new tube 2 Is going by.
Japanese Patent Laid-Open No. 10-238655 JP 2000-291827 A

In the construction method in which buoyancy is given to the new pipe 2 and the new pipe 2 is propelled and inserted into the sheath pipe 1, in order to smoothly promote the new pipe 2, the new pipe 2 and the existing pipe 1 are It is necessary to reduce the frictional resistance with the inner surface as much as possible. The frictional resistance is influenced by the buoyancy exerted by the new pipe 2 and depends on the level of the buoyant material in the sheath 1.
For this reason, it is necessary to keep the buoyant material level in the sheath 1 constant so that the new tube 2 can be propelled even if it touches the inner surface of the sheath 1.

  Conventionally, a drainage pipe is provided at a required level of the other end surface of the sheath pipe, and a buoyancy material is overflowed in the drainage pipe to maintain a constant buoyancy material level in the sheath pipe 1 (paragraph 0033 of Patent Document 3). Lines 1-5).

  However, the amount of drainage of buoyancy material by the promotion of the new pipe 2 is quite large, and in order to perform all of the drainage with the drain pipe, it is necessary to adopt a large diameter drain pipe, which increases the cost and increases the cost. In some cases, a diameter drain pipe cannot be installed.

  An object of the present invention is to smoothly discharge a buoyant material with an inexpensive and simple structure.

In order to achieve the above-mentioned problems, the present invention maintains the level of the buoyant material by overflow and performs the overflow by a long hole as in the case of Patent Document 3.
The drainage structure by overflow is simple and inexpensive, and if the overflowing hole is a long hole, the edge of the overflow becomes longer and smooth discharge (overflow) is performed.
At this time, if the long hole is large, the propulsion status of the new pipe can also be confirmed from the long hole depending on the propulsion length.

  In the present invention, as described above, the buoyancy material is overflowed with a long hole and discharged to maintain the level of the buoyancy material in the sheath, so that the configuration is simple and inexpensive. In addition, since the buoyancy material does not overflow smoothly, the buoyancy material does not overflow smoothly, so that the new tube does not collide with the inner surface of the tube, and the smooth new tube can be promoted.

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 material is placed in the sheath pipe. Inject a buoyancy to the new pipe to reduce friction between the new pipe and the sheath, and provide a jig for closing the other end at the other end of the sheath, In the sheath tube propulsion method in which the buoyant material in the sheath tube is poured out from this hole and the level of the buoyant material is made constant, the jig is composed of a covered cylindrical body coaxial with the sheath tube, It is possible to adopt a configuration in which a hole is formed in the side surface of the covered cylindrical body, and the hole is a long hole that is long in the tube axial direction of the sheath.
As a level adjusting device for the buoyancy material, a coaxial covered cylindrical body is fitted to the other end of the sheath tube, the other end is closed, a hole is formed in the side surface of the covered tubular body, and the hole is formed into the sheath tube. A long hole in the cylinder axis direction is 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. The water stop mechanism 10 is attached to the end (one end) of the starting pit S of the existing pipe (sheath pipe) 1 between them and closed, and the water stop / centering jig is provided at the end of the arrival pit 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.

The joint portion is inserted into the sheath tube 1 while the new tube 2 is sequentially propelled and inserted from one end to the other end of the sheath tube 1 by the propulsive force transmitting material 8 and the tip of the insertion port 2 and the inner surface of the receiving port 2b. 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. 16, 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. When the caps 30 are fitted into the cylindrical tube 11 as shown in the figure because the axial centers C ₁ and C ₂ of the cylindrical portions 11 a and 11 b before and after the cylindrical tube 11 are different, the axial center is the sheath tube 1. It is a little lower than the axis. Therefore, new pipe 2 becomes to be inserted to the axis C ₁ in a sheath tube 1 a little downward.
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, 10, and 11, the water-stop member 12 is made of an integrally molded product of rubber, and has a cylindrical portion 12 a that is screwed to the inner surface of the sheath tube 1, and the entire inner periphery thereof. The flap 12b faces the shaft center (cylinder shaft center) of the sheath 1 and a rubber ring 12c having a solid cross-section circular shape larger in diameter than the tip edge on the entire circumference of the tip 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 12 c and the flap 12 b are expanded in diameter as shown in FIG. 10, and the flap 12 b is the other end side of the sheath pipe 1. The ring 30 c is allowed to slide on the cap 30 or the new tube 2 while being in watertight pressure contact with the outer periphery of the cap 30 or the new tube 2.
At this time, since the ring 12c has a larger diameter than the leading edge of the flap 12b, the ring 12c is not easily affected by the deflection of the flap 12b, and the size (diameter) of the outer surface of the cap 30 or the new pipe 2 on which the flap 12b slides is changed or shaken. Even if it bends correspondingly flexibly, the water tightness is ensured by maintaining a certain pressure contact with the cap 30 or the outer peripheral surface of the new pipe 2.

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 on the outer peripheral surface or inner peripheral surface at equal intervals around the periphery (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 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 opened on the side surface of the cylindrical body is formed in the upper part of the cylindrical body. The buoyancy material a in the sheath 1 overflows from the through hole 26, and the level of the buoyancy material a in the sheath 1 is maintained constant. The overflow height (lower edge height of the through hole 26) is preferably such that the new pipe 2 and the inner surface of the existing pipe 1 are not in contact with each other, but considering the complexity of buoyancy material supply and discharge operations, etc. However, it is not necessarily required to be non-contact, and is optional as long as the new tube 2 can be driven by reducing the frictional resistance between the new tube 2 and the sheath 1 inner surface. For example, if propulsion is possible even if sliding, the degree of reduction is sufficient. If buoyancy acts on the new pipe, the frictional resistance will be reduced.
The size of the hole 26, such as the length L and width T (see FIG. 7), is appropriately set by experiments, actual operations, etc. so that the buoyancy material a can be smoothly poured out. As shown in FIG. 1, the level adjusting member 23 is supported by an appropriate leg 27 so as to have the same axis as the sheath 1.

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, both of which are fastened by bolts 36. Screws 38 are threaded through the surrounding screw holes 37, and the tips of the rings 35 are the outer periphery of the cap 30. It is attached to the cap 30 by being pressed against the surface. The ring 35 and the cap 30 are aligned by adjusting the screwing degree of each screw.

  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.
In the start shaft S, as shown in FIG. 10, the cylindrical tube 11 with the water stop member 12 is fitted to the start shaft S side (one end) of the sheath tube 1 via a rubber ring (packing) 11c, and the screw 11d is stopped. The cap 30 with the insertion preventing ring 35 is fitted into the cylindrical tube 11 (FIG. 1A).
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.
If the insertion port 2a is fitted in the cap 30, after the insertion preventing ring 35 is removed from the cap 30, if the buoyancy material a is filled, the new tube 2 is further pushed in. If not, the buoyancy material a After filling, push in the same way.

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, and 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, as the new pipe 2 advances, 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. . By the maintenance of the liquid surface level of the buoyant member a, the axis C ₂ of the new tube 2 is also maintained at a substantially constant level, the new pipe 2 and the frictional resistance between the sheath tube 1 inner surface is reduced new tube 2 smoothly Can be promoted. At this time, although depending on the propulsion length, the propulsion status of the new pipe 2 can be confirmed from the through hole 26.

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.
When the insertion slot 2a fits into the jig 20 and reaches the level adjustment member 23, the level adjustment member 23 is removed as shown in FIG. 2a is protruded in the required 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. Drain the water into the required bucket. At this time, the new pipe 2 is maintained at a required height and position in the sheath pipe 1 by an appropriate means.

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). Thereafter, the mortar is fed from one water supply / drainage pipe 13 into the sheath pipe 1 and filled, and the new pipe 2 is fixed in the sheath pipe 1 The mortar is charged from one water supply / drainage pipe 13 and the other water supply / drainage pipe The buoyancy material a may be discharged from 13 as appropriate.

  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.

Further, as shown in FIG. 15, the water stopping mechanism 10 of the sheath pipe 1 on the start pit S side is provided with expansion / contraction tubes 112a and 112b on the inner surface of a cylindrical tube 11 made of ductile or steel, with a required interval in the axial direction. Provided with a solid rubber ring (tube) 113 therebetween.
The cylindrical tube 11 is attached to one end of the sheath tube 1 via a packing 43. Each tube 112a, 112b, 113 is fixed by bonding or screwing.

  A hose 114 connected to an air compressor, an air pump, or the like is connected to both the expansion / contraction tubes 112a and 112b with holes formed in the sheath tube 1, and a three-way valve (not shown) of each hose 114 is connected. As a result, air (fluid) b is selectively injected into both the expansion / contraction tubes 112a and 112b, and each expansion / contraction tube 112a and 112b expands to a required pressure, or both expansion / contraction tubes 112a and 112b are selective. And the expansion / contraction tubes 112a and 112b contract. At this time, the inflow amount (inflow pressure) of the fluid b into the expansion / contraction tubes 112a and 112b is automatically controlled so as to have an appropriate value corresponding to the external pressure received by sliding with the new pipe 2.

  If the expansion / contraction tubes 112a, 112b expand to the required pressure, the expansion / contraction tubes 112a, 112b are pressed against the outer peripheral surface of the straight tube portion (insertion portion 2a) of the new tube 2 to prevent leakage of the buoyancy material a. However, the straight pipe part is allowed to slide. At this time, the material of the expansion / contraction tubes 112a and 112b and the fluid b pressure are appropriately set so as to allow the sliding and prevent leakage while preventing the sliding and damaging itself.

  In this embodiment, the new pipe 2 advances in the sheath pipe 1 with low friction while preventing the leakage of the buoyancy material a by sliding the outer peripheral surface of the new pipe 2 against both the expansion / contraction tubes 112a and 112b. At this time, according to the change of the diameter of the new pipe 2, the supply / exhaust of air to both the expansion / contraction tubes 112a and 112b is adjusted to ensure a reliable seal and smooth sliding.

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 pushed 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 cut side view. 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 same Example is shown, (a) is a front view, (b) is a left side view, Cross-sectional view of the main part at the time of insertion into the sheath pipe of the earliest new 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 The principal part schematic sectional drawing of another Example 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 pipe (2) is inserted into the sheath pipe (1) embedded in the ground (W) from the one end (S) to the other end (T) in succession, the sheath pipe (1) The buoyancy material (a) is injected into the sheath tube (1) to give buoyancy to the new tube (2), and the friction between the new tube (2) and the sheath tube (1) is blocked. A jig (20) for closing the other end is provided at the other end of the sheath tube (1), and a hole (26) is provided in the jig (20). In the sheath tube propulsion method in which the buoyancy material (a) in the sheath tube (1) is poured out and the level of the buoyancy material (a) is made constant,
The jig (20) is composed of a covered cylindrical body (23) coaxial with the sheath tube (1), and the hole (26) is opened on the side surface of the covered cylindrical body (23). , the hole (26) and a long long hole in the cylinder axis direction of the sheath tube (1), a certain level of buoyancy material (a) by overflowing the buoyant material of (a) from the long hole (26) In addition, the sheath tube propulsion method characterized by confirming the propulsion status of the new pipe (2) from the opening of the long hole (26) . It is a level adjustment apparatus of the buoyancy material (a) in the sheath pipe | tube used for the sheath pipe propulsion method of Claim 1, Comprising: A coaxial covered cylindrical body (23) is provided at the other end of the sheath pipe (1). fitted to close the other end, the lidded cylindrical body bore (26) to the side of (23) is formed by opening to the bore (26) and the cylinder axis direction length longer hole sheath tube (1) The buoyancy material (a) is overflowed from the long hole (26) to make the level of the buoyancy material (a) constant, and the propulsion status of the new pipe (2) is confirmed from the long hole (26). A buoyancy material level adjusting device in a sheath that is characterized by being made to do so .

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