JP2006057830A - Sheath pipe jacking construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly perform blocking work of a start shaft side end of a sheath pipe. <P>SOLUTION: A construction method for pipe-jacking by letting a new pipe 2 float by buoyancy is adopted, and only a cap 30 is first fitted into the sheath pipe 1 to block the start shaft side end of the sheath pipe at this time. When an arrival shaft side end of the sheath pipe 1 is blocked, a scope of selection of work for pouring a buoyancy material into the sheath pipe 1 is enlarged to improve work efficiency. When fitting a tip of the new pipe into the cap, the most leading new pipe is fitted while preventing insertion of the cap into the sheath pipe and then the new pipe is inserted into the sheath pipe together with the cap. Even if the cap is first fitted into the sheath pipe, fitting is not performed well if the cap is inserted into the sheath pipe. A divided-into-two ring 35 is adopted as an insertion prevention means of the cap into the sheath pipe 1, a screw is screwed into a screw hole around it, and its tip is abutted on an outer peripheral face of the cap to attach the ring 35 to the cap 30. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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, and the sheath The present invention relates to a cap used for a pipe propulsion method and a ring for preventing the cap sheath from being inserted into the sheath.

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. 21, in the sheath pipe propulsion method, only the start pit S and the arrival mine T are excavated on the ground W. From the start pit S, first, a fume pipe or a steel pipe is put into the soil W as a sheath pipe 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 a new pipeline.

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 construction 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. 21, and receiving a reaction force H at the rear part of the hydraulic jack J and a 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 stand 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. 22, the seismic pipe joint, for example, the PII type joint, is inserted after the rubber ring 3 for sealing is inserted inside the receiving port 2b of the pipe 2 and the lock ring 4 is loaded 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

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, a buoyancy material such as water is injected into the conventional sheath 1 to give buoyancy to the new tube 2, and the buoyancy material into the sheath 1 in the construction method in which the new tube 2 is propelled and inserted into the sheath 1 Is covered with a cap on the tip of the newest tube 2, and the tip of the new tube 2 is inserted into the end of the sheath tube 1 at the start pit S side, and the tube 2 or the seal plate is used to connect the tube 2 and the sheath tube. After the gap of 1 is closed, injection is performed.
However, there is a case where it is desired to inject buoyancy material into the sheath tube 1 before inserting the tip of the new tube 2 into the end of the sheath pit S of the sheath tube 1 due to the work procedure. It is not easy to insert the first start pit S side end and close the end reliably due to the weight of the new pipe.

  This invention makes it a subject to make it possible to perform smoothly the whole operation | work including the obstruction | occlusion work of a sheath end in the propulsion method by the said buoyancy material.

In order to achieve the above object, according to the present invention, only the cap is first fitted into the sheath tube, one end thereof is closed, and the buoyancy material is injected into the sheath tube.
Thus, if only the cap is fitted to the sheath pipe first and its one end is closed, if the other end of the sheath pipe is closed, the new pipe tip is inserted into the start shaft side end of the sheath pipe before it is inserted. While the range of selection of operations such as the ability to inject buoyancy material into the tube is widened, it is also easy to close the end of the tube and improve workability.

  As described above, according to the present invention, only the cap is first fitted into the sheath tube and one end thereof is closed, so that workability is improved.

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 tube propulsion method in which material is injected to give buoyancy to the new tube, and the friction between the new tube and sheath is reduced, Insert the tip of the earliest new tube into the cap while preventing the cap sheath from being inserted into the tube, and then insert the new tube with the cap into the sheath tube while keeping the end of the sheath tube closed. Adopt the configuration.
Even if the cap is fitted to the sheath tube first, if the cap is inserted into the sheath tube when the new tube is fitted into the cap, the fitting is not successful. For this reason, it is meaningful to prevent the cap sheath from being inserted into the tube.

As a means for preventing the cap sheath from being inserted into the sheath, for example, a protrusion can be provided on the outer surface of the cap, and the protrusion can be engaged with one end of the sheath. When the insertion of the tip of the new tube into the cap is completed, the protrusion is removed from the cap so that there is no hindrance to the insertion of the new tube with the cap into the sheath.
At this time, as a means for detachably attaching the protrusion, it is common to screw the protrusion, and at that time, the necessary number of protrusions are provided at a required interval around the outer peripheral surface of the cap, preferably at equal intervals, For example, the protrusion may be configured by a ring that fits on the outer peripheral surface of the cap.

  For example, the ring is divided into two parts, and is composed of two members that are screwed together with the divided surfaces, and there is a circumferential required distance around the two annular members that are screwed together. A structure in which a ring is attached to the cap by passing a screw through the screw hole and abutting the tip of the screw with the outer peripheral surface of the cap is adopted. When the screw holes are equally spaced in the circumferential direction of the cap, the ring is easily centered with respect to the cap.

FIG. 1 to FIG. 8 show an embodiment. This embodiment 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. A conical cap 30 is fitted and closed at the leading end of the new pipe 2 inserted into the sheath pipe 1 so that the buoyancy material a does not flow into the new pipe 2.

As shown in FIG. 4, 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 opening 2 a by welding or the like (see Patent Document 2). 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 material 8 and the inner end of the insertion opening 2 a and the inner surface of the receiving opening 2 b. While maintaining the gap with the back end surface 2b ′ (maintaining the state of FIG. 4), 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. 21, 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 FIG. 4, the water stopping mechanism 10 for the sheath pipe 1 on the start pit S side requires expansion / contraction tubes 12a and 12b in the axial direction on the inner surface of a cylindrical tube 11 with a flange 11a made of ductile or steel. They are provided at intervals, and a solid rubber ring (tube) 13 is provided between them. The cylindrical tube 11 has its flange 11a attached to the sheath tube 1 at its end surface by bolting (screwing), welding or the like. The tubes 12a, 12b, and 13 are fixed by bonding or screwing.

  A hose 14 connected to an air compressor, an air pump, or the like is connected to both the expansion / contraction tubes 12a and 12b with holes formed in the sheath tube 1, and a three-way valve (not shown) of each hose 14 is connected. As a result of this, air (fluid) b is selectively injected into the both expansion / contraction tubes 12a, 12b, and each expansion / contraction tube 12a, 12b expands to a required pressure, or both expansion / contraction tubes 12a, 12b are selective. And the expansion / contraction tubes 12a and 12b contract. At this time, it is preferable that the inflow amount (inflow pressure) of the fluid b into the expansion / contraction tubes 12a and 12b is automatically controlled so as to have an appropriate value corresponding to the external pressure received by sliding with the new tube 2.

  When the expansion / contraction tubes 12a, 12b expand to the required pressure, the expansion / contraction tubes 12a, 12b come into pressure contact with the outer peripheral surface of the straight tube portion (insertion port 2a portion) of the new tube 2 to cause leakage of a buoyancy material a described later. This allows the straight pipe to slide. At this time, the material of the expansion / contraction tubes 12a and 12b and the fluid b pressure are appropriately set so as to allow the sliding and prevent leakage while preventing the sliding and damaging itself.

  The inner diameter of the rubber ring 13 is set to be larger than the outer diameter of the straight pipe portion of the new pipe 2 and slightly smaller than the outer diameter of the receiving port 2 b, and the outer peripheral surface of the receiving port 2 b is formed on the inner surface of the rubber ring 13. The contact 2b is allowed to slide while preventing leakage of the buoyancy material a. At this time, the material and the diameter of the rubber ring 13 are appropriately set so as to allow the sliding and prevent leakage while preventing the rubber ring 13 from rubbing and being damaged.

  The diameter and number of the rubber rings 13 are determined so that the parallel length is equal to or greater than the length of the tapered portion from the straight tube portion to the receiving portion. For example, since the diameter of the rubber ring 13 is determined by the difference between the inner diameter of the sheath tube 1 and the outer diameter of the receiving portion 2b of the new tube 2, the cross-sectional diameter is larger than the difference and as shown in FIG. In addition, when the required number of rubber rings 13 are arranged so as to contact each other in the axial direction of the sheath tube 1, the rubber ring 13 provided closest to the start shaft S side from the center of the cross section in the expanded state of the front expansion / contraction tube 12a. The diameter and the number of arrangement of the rubber ring 13 are determined so that the sheath L at the center of the cross section is equal to or longer than the length t of the tapered portion extending from the straight portion to the receiving portion. Thus, as will be described later, before the fluid b sealed in the front expansion / contraction tube 12a is removed, the rubber ring 13 is pressed against the outer peripheral surface (maximum diameter outer peripheral surface) of the receiving port 2b to ensure water stoppage. To be made.

In addition, the cross-sectional shape of each expansion / contraction tube 12a, 12b and the rubber ring 13 is not limited to a circle, and may be any shape such as an ellipse or a polygon as long as it can be slid by pressure. If a lubricant is applied to the surfaces of the expansion / contraction tubes 12a and 12b and the rubber ring 13, the frictional resistance when the new tube 2 is inserted can be reduced.
Further, the supply / discharge fluid b to the expansion / contraction tubes 12a, 12b may be water or the like in addition to air. In the case of water, if the water tank is installed on the ground and the pressure in the expansion / contraction tubes 12a, 12b is kept constant due to the difference in water head, the expansion / contraction tubes 12a, 12b will pass even if the receiving port 2b passes. The surface pressure with the receiving port 2b becomes constant, and the pressure load and air venting (supply / discharge) steps are not required as in the case of air. In the case of air, an accumulator mechanism that provides a constant pressure may be applied.

  The other end closing and centering jig 20 of the sheath tube 1 has a shape (reducer shape) that changes from a cylindrical portion 22 fitted to the outer peripheral surface of the tip portion of the sheath tube 1 to a truncated cone portion 23 and further to a cylindrical portion 24. The flanged water-stopping lid 21 is screwed to the cylindrical portion 24 at the tip thereof and is closed. A rubber ring (packing) 25 is provided on the inner surface of the cylindrical end portion 24 of the jig 20. When the insertion opening 2 a (cap 30) of the earliest new tube 2 enters the cylindrical portion 24, The rubber ring 25 is sealed (liquid-tight) to prevent leakage of the buoyancy material a (see FIG. 8B). For this reason, even if the water stop lid 21 is removed, the buoyancy material a does not flow out from the sheath tube 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.

  For example, as shown in FIG. 2, the cap 30 is fixed to the insertion opening 2 a of the new tube 2 by providing a circumferential groove 32 on the rear outer peripheral surface of the cap cylindrical portion 31. After being inserted into the tubular portion 31, the rear portion of the tubular portion 31 is supported so as to protrude from the end surface of the sheath tube 1 to the start shaft S side, and after inserting the new tube insertion port 2 a into the tubular portion 31 from the support state, A band 33 made of steel or the like is fitted into the groove 32 and tightened. 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 pit S, as shown in FIG. 5 (a), the expansion / contraction tubes 12a and 12b and the cylindrical tube 11 with the rubber ring 13 are fitted to the start pit S side (one end) of the sheath tube 1 to fix the screws. And the cap 30 is fitted into the cylindrical tube 11. At this time, the air b may be supplied into the expansion / contraction tubes 12 a and 12 b or may be supplied after the cap 30 is fitted. On the other hand, a jig 20 with a water stop lid 21 is attached to the end of the sheath pipe 1 on the T side (the other end) via a sealing material 26 to close both ends of the sheath pipe 1 (the inside of the sheath pipe 1 is liquid-filled). Dense).

  Next, the buoyancy material a is filled into the sheath tube 1 from the filling port 40 at an appropriate location (see FIG. 1). The buoyancy material a is a filler using a post-curing friction reducing material (for example, product name: AHL manufactured by Yakuhin Development Center Co., Ltd.) that cures after inserting all of the new tube 2 into the sheath tube 1. The filling amount (injection amount) may be the entire cross-section in the sheath 1 as shown in the figure, but it is sufficient that buoyancy is given to the new tube 2 and friction with the inner surface of the sheath 1 does not occur. You are free as long as you meet it.

  After the filling of the buoyant material a is completed or before the filling, the cap 30 in which the insertion port 2a of the earliest new pipe 2 is fitted to the sheath pipe 1 as shown in FIGS. Fit into the cylindrical portion 31. If the buoyancy material a is filled, the new tube 2 is further pushed in as shown in FIG. 5C, and if not filled, the buoyancy material a is pushed in similarly after filling. Since the pushing and insertion of the new pipe 2 by this pushing is performed in the buoyancy material a, the buoyancy is received by buoyancy from the buoyancy material a and the outer peripheral surface of the straight pipe portion is slidably pressed against both the expansion / contraction tubes 12a and 12b. While preventing leakage of the material a, it advances through the sheath 1 with low friction.

At this time, the liquid level of the buoyancy material a in the sheath 1 rises due to the loading (progress) of the new pipe 2, but the buoyancy material a is discharged from the air vent hole 41 or the discharge hole 45, and the liquid level is at a certain level. Maintained.
The liquid level is such that the new pipe 2 can be propelled even if the new pipe 2 slides on the inner surface of the sheath 1 such that the axis of the new pipe 2 is slightly below the axis of the sheath 1. To do.

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 (receiving port 2a portion) approaches the rear expansion / contraction tube 12b, the air b therein is discharged by the three-way valve of the hose 14 of the expansion / contraction tube 12b as shown in (b) to (c). On the other hand, the receiving port 2b is inserted and slid into the expansion / contraction tube 12b, and then inserted and slid into the rubber ring 13. When the rubber ring 13 reaches the outer peripheral surface of the receiving port 2b, the rubber ring 13 is pressed against the receiving port 2b to prevent leakage of the buoyancy material a ((c) in the figure).
As long as the rubber ring 13 is pressed against the receiving port 2b, leakage of the buoyancy material a is prevented, and before the receiving port 2b reaches the front expansion / contraction tube 12a, the three-way valve of the hose 14 of the front expansion / contraction tube 12a The outlet 2b is inserted and slid into the rubber ring 13 while discharging the air b inside (FIG. 4D).

  When the rear expansion / contraction tube 12b reaches the propulsive force transmission member 8 of the receiving port 2b (FIG. 5e)), the air b is supplied and expanded in the open state of the on-off valve of the hose 14 of the expansion / contraction tube 12b. Then, the new tube 2 is further pushed in, and the rear expansion / contraction tube 12b is pressed against the outer peripheral surface of the insertion port 2a of the subsequent new tube 2 (figure (f)), and leakage of the buoyancy material a can be prevented by this pressure contact. Then, the new pipe 2 is further pushed in, and eventually, the air b is supplied to the front expansion / contraction tube 12a to be inflated to be brought into pressure contact with the outer peripheral surface of the insertion opening 2a of the subsequent new pipe 2 ((g) in the figure).

  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 without causing leakage of the buoyancy material a.

  The propulsion insertion of the new pipe 2 proceeds, and as shown in FIG. 8 (a), the insertion opening 2a of the earliest new pipe 2 approaches the arrival tunnel T, and as shown in FIG. 8 (b), the insertion opening When 2a fits into the distal end cylindrical portion 24 of the jig 20, the jig 20 is centered with water-stop (watertightness) (with the other end of the sheath 1 closed). At this time, even if the core is displaced before the insertion opening 2 a enters the jig 20, the center is brought into contact with the inner surface of the truncated cone portion (tapered portion) 23.

  If the insertion slot 2a fits in the jig 20, the water stop lid 21 is removed, and the insertion slot 2a of the new pipe 2 is further projected into the access shaft T by the required length, as shown in FIG. . At this time, leakage of the buoyancy material a is prevented by the rubber ring 25. If the insertion port 2a is protruded to the required length in the arrival shaft T, the cap 30 is removed ((d) in the figure). Thereafter, after the required time, the buoyancy material a hardens to become a filler. At this time, if the buoyancy material a is not filled in the entire cross-section of the sheath 1, it is replenished and filled in the entire area.

In this embodiment, the cylindrical tube 11 of the water stop mechanism 10 on the start pit S side is not attached to the inner surface of the sheath tube 1, as shown in FIGS. It can be attached via 43b. The outer packing 43b can be replaced by welding.
In this way, an installation space for the expansion / contraction tube 12a and the like can be secured regardless of the gap between the outer diameter of the sheath tube 1 and the new tube 2, so that the gap between the inner diameter of the sheath tube 1 and the outer diameter of the new tube 2 is narrow. It is effective when sufficient water stop performance cannot be expected.

Further, water can be used for the buoyancy material a in place of the post-curing friction reducing material, and at that time, after propulsion insertion of the new pipe 2 into the entire length of the sheath 1, the water is replaced with the filler. In this case, for example, as shown in FIG. 11, an injection tube 44 is inserted between the sheath tube 1 and the expansion / contraction tubes 12a and 12b and the rubber ring 13, and a filler such as mortar is injected from the injection tube 44. To be able to. At this time, since the specific gravity of the filler such as mortar is larger than that of water, the filler is gradually filled from the bottom of the sheath tube 1, and as the filling, the water is removed from the air vent 41 or the discharge hole 45 at the other end of the sheath 1. (See Fig. 1).
When this injection tube 44 is used, as shown in the figure, the cylindrical tube 11 of the water stop mechanism 10 is provided on the outer surface of the sheath tube 1 so that a wide gap between the sheath tube 1 and the new tube 2 can be secured. Is preferred.

  As the post-curing type friction reducing material, a material obtained by adding a retarder to mortar may be employed. Incidentally, the post-curing friction reducing material of the example is cured after about one month after filling.

  The expansion / contraction tubes 12a and 12b and the rubber ring 13 are not necessarily provided. For example, as shown in FIG. 12, one expansion / contraction tube 12 is provided, and the expansion of the tube 12 depends on the amount of fluid supplied to the tube 12. By adjusting the degree, the tube 12 is pressed and slid at a constant pressure corresponding to the change in the diameter of the outer peripheral surface of the new tube 2 as shown in FIGS. It may be possible to prevent leakage. At this time, the number of the expansion / contraction tubes 12 is arbitrary.

Further, as shown in FIG. 13 or FIG. 14, a front or rear expansion / contraction tube 12 a or 12 b (expansion / contraction tube 12) and a rubber ring 13 are provided, and the expansion or contraction is performed depending on the amount of fluid supplied to the expansion / contraction tube 12. By adjusting the expansion degree of the contraction tube, the expansion / contraction tube 12 is pressed and slid at a constant pressure corresponding to the change in the diameter of the outer peripheral surface of the new tube 2 as shown in FIGS. Thus, leakage of the buoyancy material a can be prevented.
At this time, in the former, when the expansion / contraction tube 12 is separated from the receiving port 2b, the supply amount is adjusted so that the expansion / contraction tube 12 is in pressure contact with the outer peripheral surface of the straight tube portion, and the expansion port 12b is expanded. When the contraction tube 12 climbs, the fluid b may be released, and the latter adjusts the supply amount when the expansion / contraction tube 12 climbs to the receiving port 2b, so that the expansion / contraction tube 12 becomes the outer peripheral surface of the receiving unit. The fluid b is supplied to the expansion / contraction tube 12 until the rubber ring 13 is separated from the receiving port 2b, and the straight tube is pressed to eliminate leakage.

The expansion / contraction tubes 12a, 12b, 12 and the rubber ring 13 do not need to be attached to the sheath tube 1 via the cylindrical tube 11, but can be directly attached to the sheath tube 1.
In addition, the shape of the jig 20 is not limited to the illustration, and may be, for example, a cannula. Furthermore, the other end side (the jig 20 side) of the sheath tube 1 can be closed by the same structure as the water stop mechanism 10 with the cap 30 shown in FIG. In this case, the cap of the water stop mechanism has a diameter larger than that of the cap 30, and centering is performed by fitting the new tube insertion opening 2a (cap 30) into the cap.

  The caps 30 are not limited to the shape shown in the figure, but the function of the water stop lid on the start pit S side (preventing leakage of the buoyancy material a when the top pipe 2 is inserted), the end face water stop and the sheath pipe, etc. of the top pipe 2 Any material and shape may be used as long as it can exhibit the function of end stop water (preventing the inflow of the buoyant material a into the new pipe 2 and closing the other end of the sheath).

For example, the cap 30 shown in FIG. 16 can be used. As shown in the figure, the cap 30 is composed of a cylindrical portion 31 and a truncated cone portion 34 provided at the tip thereof, and the rear end portion of the cylindrical portion 31 is reduced in diameter so that its entire circumference is obtained. A groove 32 is formed in the groove. A packing 134 is fitted into the groove 32.
An insertion preventing ring 35 shown in FIG. 20 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 (bolts) 38 are attached to the surrounding screw holes 37. The screw 30 is attached to the cap 30 by screwing its tip to the outer peripheral surface of the cap 30. By adjusting the screwing degree of each screw, the ring 35 and the cap 30 can be aligned.

As shown in FIG. 15, 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. At this time, by adjusting the screwing degree of each screw of the prevention ring 35, the center of the ring 35 is adjusted to be the axis of the new pipe 2 to be inserted.
The cap 30 is attached in such a manner that the rear side of the cylindrical portion 31 of the cap 30 protrudes from the end surface of the cylindrical tube 11 toward the start shaft S, and the new tube insertion port 2a is formed on the outer surface of the cylindrical portion 31 from the supported state. Is inserted into the sheath 1 of the cap 30 by the prevention ring 35 so that the new tube 2 is connected to the cap 30, and the water-tightness of the two 2 a and 30 is sealed by the packing 134 in the groove 32. Sex is maintained.

As shown by a chain line in FIG. 16, when a horizontal support bar 32 a is provided at an appropriate location around the rear end of the cylindrical portion 31, and the new tube 2 is fitted on the outer surface of the rear end of the cap 30, If 32a is applied to the inner surface of the new tube 2 to support the new tube 2, the inclination of the new tube 2 due to its own weight can be suppressed. The number of the support rods 32a is arbitrary as one, two, and so on, and the installation position is arbitrary as long as the circumference is equal, only the upper part, and the like.
Further, the cap 30 can have its rear surface closed with a lid 34a as shown by a chain line in FIG.
In the cap 30 shown in FIG. 2 and the like, since the new pipe 2 is fitted inside, the support bar 32a is in a position where it abuts on the outer surface of the new pipe 2 such as the lower side as shown in FIG.

As shown in FIG. 15, 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, the 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 It is a new tube 2 and 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.

As shown in FIG. 18, the water stop member 112 according to this embodiment is an integrally molded product of rubber, and a cylindrical portion 112 a screwed to the inner surface of the sheath tube 1 and the sheath tube 1 on the entire inner periphery thereof. The flap 112b faces the shaft center (cylinder shaft center), and a rubber ring 112c having a solid cross-sectional circle with a larger diameter than the tip edge is formed on the entire circumference of the tip edge of the flap 112b.
The thickness and length of the flap 112b (length toward the axial center) and the diameter of the ring 112c may be appropriately set in consideration of the degree of deflection and the pressure contact degree (water density), but the thickness of the flap 112b is flexible. It is preferable that the thickness of the ring 112c is thin as long as the ring 112c can be held.
As shown in FIG. 15, the water stop member 12 has its cylindrical portion 112a applied to the inner surface of the cylindrical tube 11, and a ring-shaped stopper 114 having a single split opening shown in FIG. The screw 115 is attached to the cylindrical tube 11.

When the cap 30 or the new pipe 2 is inserted into the water stop member 112, the ring 112c and the flap 112b are expanded in diameter, and the flap 112b is the other end side of the sheath pipe 1 as shown in FIG. The ring 30c is allowed to slide on the cap 30 or the new tube 2 while being tightly pressed against the outer peripheral surface of the cap 30 or the new tube 2.
At this time, since the ring 112c has a larger diameter than the leading edge of the flap 112b, the ring 112c is hardly affected by the deflection of the flap 112b, and the size (diameter) of the outer surface of the cap 30 or the new tube 2 on which the flap 112b 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. In FIG. 15, 11 c is a packing, and 11 d is a fastening screw for the cylindrical tube 11 to the sheath tube 1. A lubricant may be applied to the inner surface of the water stop member 112 (the sliding surface with the new tube 2 and the cap 30).

Further, as shown in FIG. 15, a buoyancy material supply / discharge tube 15 with a supply / discharge valve 15 a is provided in the cylindrical tube 11, and the buoyancy material a is injected into the sheath tube 1 from the supply / discharge tube 15, or the buoyancy material a is injected. It can also be made to discharge. Level of the axis C ₂ of the new tube 2 may be adjusted by appropriately feeding that fluid such as water to the sheath tube 1. At this time, it can be used together with level adjustment of the buoyancy material a.
Since the level adjustment of the axis C ₂ by feeding the fluid into the sheath tube 1 can absorb the liquid level fluctuation of the buoyancy material a, the buoyancy material a serves as a filler between the sheath tube 1 and the new tube 2. It is advantageous when it also serves. For example, the buoyancy material a seems to be filled in the sheath tube 1 when the buoyancy material a is injected into the sheath tube 1 after the new tube 2 is completely loaded (the state shown in FIG. 8D). Can be set to At this time, the filling amount of the filled buoyancy material a may be from the beginning (FIG. 5A) or in the middle.

  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 The transmission material 8 has an advantage that a material having a relatively low mechanical strength such as the above resin foam can be used. In addition, it goes without saying that the sheath pipe 1 is not limited to the existing pipe. However, 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 propulsive force is extremely small. 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.
Furthermore, the insertion promotion of the new pipe 2 can also be performed from the arrival shaft T side.
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.

Schematic sectional view of one embodiment 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 water stoppage on the sheath pipe reaching mine (other end) side of the same embodiment FIG. Insertion of the earliest new pipe into the sheath pipe of the same embodiment example Propeller insertion action diagram of sheath pipe start pit (one end) part of new pipe receiving part of same embodiment Enlarged view of the action 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 of another embodiment Main part enlarged view of the same embodiment Schematic sectional view of another embodiment Propeller insertion action figure of sheath pipe start pit part of new pipe receiving part of other embodiments Propeller insertion action figure of sheath pipe start pit part of new pipe receiving part of other embodiments Propeller insertion action figure of sheath pipe start pit part of new pipe receiving part of other embodiments Cross-sectional view of the main part at the time of insertion into the sheath of the earliest new pipe of another embodiment 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). 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. 15, (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 cap insertion prevention ring of the same Example is shown, (a) is a front view, (b) is a left side view. Schematic of sheath tube propulsion method Cross section of PII joint

Explanation of symbols

1 sheath pipe (existing pipe)
2 New pipe 3 Water stop rubber ring 4, 4a, 4b Lock ring 8 Propulsive force transmission material 10 Saddle pipe start pit side water stop mechanism 11 Cylindrical pipes 12, 112 of the water stop mechanism (expansion / contraction tube, rubber with flap) ring)
13 Rubber ring (elastic tube)
14 Hose 15a for supplying / discharging fluid to expansion / contraction tube 20 Supply / discharge valve 20 Sheath pipe pit side water stop / centering jig 21 Water stop cover 30 Newest pipe insertion cap 35 Cap insertion prevention ring 35a , 35b Two-part member 37 for cap insertion prevention ring Screw hole 38 for cap insertion prevention ring Ring screw a for cap insertion prevention ring a Buoyancy material b Fluid for expansion / contraction of expansion / contraction tube (air)

Claims (4)

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.
After the cap 30 is fitted on the inner surface of the sheath tube 1 and the end is closed, the cap 30 is prevented from being inserted into the sheath tube 1 while the tip of the earliest new tube 2 is attached. A sheath tube propulsion method characterized by inserting the new tube 2 together with the cap 30 into the sheath tube 1 while fitting in a watertight manner and then maintaining the closure of one end of the sheath tube 1.   Providing a detachable protrusion on the outer surface of the cap 30 and locking the protrusion to one end of the sheath tube 1 prevents the cap 30 from being inserted into the sheath tube 1. The sheath pipe propulsion method according to claim 1, characterized in that it is characterized in that   The sheath pipe propulsion method according to claim 2, wherein the protrusion is configured by fitting a ring 35 on the outer peripheral surface of the cap 30 and screwing.   The ring 35 used in the sheath tube propulsion method according to claim 3, comprising two members 35 a and 35 b that are divided into two parts and screwed together with the divided surfaces attached to each other. Around the two annular members 35a and 35b that are integrated, a radial screw hole 37 is formed at equal intervals in the circumferential direction, and a screw 38 is threaded through the screw hole 37 and the tip thereof. A ring for preventing the cap 35 from being inserted into the sheath in the sheath propulsion method in which the ring 35 is attached to the cap 30 by contacting the outer periphery of the cap 30.

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