JP3751619B2 - Backfilling material injection device in shield method - Google Patents

Description

  The present invention relates to a backfilling material injection apparatus in a shield method for filling a backfilling material into a gap portion remaining between a segment constructed immediately after excavation by a shield machine and a ground excavation surface.

  As a tunnel construction method, a shield method in which a tunnel is constructed by excavating a natural ground using a shield machine is widely used.

  As shown in the schematic cross-sectional view of FIG. 6, the shield method is a tunnel in which segments b are sequentially assembled in an arch shape by an assembling device in the shield machine on the ground excavated by a disk-shaped shield machine a. Although it has a structure, a backfilling material f such as mortar is injected and solidified in a void portion e (tail void) remaining between the outer surface of the segment b and the excavation surface d of the natural mountain c to prevent the natural mountain from collapsing. To be made.

  As the backfill material f, mortar is usually used. However, it is necessary to gel the mortar immediately after the injection in order to prevent dilution by the groundwater after the injection into the void portion e. Used by mixing the binder.

  On the other hand, the backfilling material injection apparatus as described above includes, for example, a piston that pushes out the backfilling material supplied from the backfilling material pumping device mounted on the shield machine, as shown in the known document 1. Thus, the injection into the gap portion e is performed through the injection pipe from the tip thereof to the rear of the shield machine in synchronization with the excavation by the shield machine.

  By the way, after the backfilling material is pumped through the injection tube as described above, if the backfilling material remains in the injection tube, it solidifies and adheres to the inner wall surface of the injection tube, which may hinder subsequent injection operations. It is necessary to clean the inside of the injection tube.

For this reason, the washing water supply pipe is connected to the injection pipe, the piston is moved to the most advanced position, the tip of the injection pipe is closed, and then the washing water is supplied, and the inside of the injection pipe is washed and discharged. It is common.
JP-A-9-132996

  However, in the above conventional backfilling material injection device, the backfilling material injection state and the cleaning state of the injection tube are switched by the back and forth movement of the backfilling material injection piston. The backfilling material tends to adhere and remain in the tube, among which the backfilling material gelled by the quick setting material remains adhered to the tip of the injection tube, and this solidifies to cause malfunction or inoperability of the piston, This will cause trouble that cannot be injected.

  Especially at the time of cleaning, the tip of the injection tube is closed by the piston, so that the cleaning water does not reach the inner peripheral surface of this portion of the injection tube, and a gelled backfilling material tends to remain, causing problems early. Cause it to occur.

  When such troubles occur, the excavation process by the shield machine has to be interrupted, resulting in a major obstacle in the construction of the tunnel construction, and there is a problem that it is very troublesome to solve the trouble.

  In some cases, the injection tube is made of a flexible material such as rubber, and the outer back surface of the injection tube is compressed by air pressure and crushed to discharge the residual backfill material in the injection tube. In this way, the means for compressing and crushing the injection tube with air pressure in this way, even if the problem due to the blockage of the piston is avoided, the injection tube and the backfill material supply system of the injection device The stress concentrates on the connection part (connection part by the nipple) and deforms locally, and the injection tube at that part is damaged early, shortening the service life of the injection pipe, and if bent at that part, the injection The backfilling material remains in the tube and solidifies, which becomes an obstacle and the entire area of the injection tube is not evenly crushed, making it difficult to remove the remaining backfilling material and causing troubles in the injection tube. It is inevitable to wake up There is a problem that.

  As a means for solving the above problems, the present invention comprises a backfill material injection tube made of a tube made of a flexible material such as rubber, and the necessary range of this tube is mechanically pressed to make it empty. To discharge all of the backfilling material in the tube, so that no clogging occurs due to no residual backfilling material in the tube, and the injection position of the quick setting material mixed in the backfilling material is In the tube, the quick setting material is prevented from adhering and remaining in the tube near the tip of the tube. The backfilling material supply system, the cleaning water supply system, and a base portion formed by these merging pipes, and the merging A tube for backfilling material injection made of an elastic flexible material such as rubber connected to the tube, and the diameter of the tube in contact with the outer surface of one side of the tube in the longitudinal direction except for the junction tube connecting portion. Move in the direction A pressing rod that squeezes the tube into a non-empty state, and an operating mechanism that translates the pressing rod across the non-squeezed state and the compressed state of the tube, and the backfilling material supply system is the main raw material of the backfilling material. B which consists of elastic liquid materials, such as rubber of the B liquid supply system which consists of two lines, A liquid, such as a certain mortar, and B liquid, such as quick setting material mixed with this. A liquid supply pipe is inserted into the tube and its tip extends to the vicinity of the tip of the tube, and is moved in cooperation with the pressing rod at a position between the tip of the tube and the tip of the B liquid injection pipe. A locking means for squeezing a part of the tube is provided so as to be able to move forward and backward in the diameter direction of the tube in conjunction with the operation of the operating mechanism, and restrains the piece in the tube pressing state when the operating mechanism is released. At the end of the release movement of the operating mechanism Releasing the locking means to retract the piece, the tip of the tube is characterized in that so as to be fully opened.

  In this way, the operating mechanism is operated prior to cleaning to move the pressing rod together with the piece, and the necessary range of the tube is squeezed completely into the empty state by the movement of the pressing rod and the tube of the B liquid injection tube The entire area located inside is squeezed completely into the airless state, and the back liquid A liquid (mortar) in the tube and the B liquid (quickly bonding material) in the B liquid injection pipe are all discharged to the tip side and the base side. The

  Next, the cleaning water is pumped through the cleaning water supply system, so that the A liquid of the backfill material existing in the base is discharged from the discharge system together with the cleaning water through the A liquid supply system.

  Next, when the operating mechanism is moved backward in the opposite direction to the vicinity of the operating end, only the pressing rod is moved away and the tube is uncompressed, while the piece maintains the compressed state of the tube so that only the tip of the tube is Placed in an obstructed state.

  If the above-described cleaning is continued in this way, the cleaning water also enters the tube, and both the inner peripheral surface of the tube and the outer peripheral surface of the B liquid injection pipe are cleaned, and the liquid A and B adhering to these are cleaned. The liquid is washed off and discharged in the same manner as described above.

  When the back end of the operating mechanism is reached, the piece is unlocked and the piece is also moved away, the tube is released and the tube is fully opened, and the backfilling material can be injected.

  Therefore, troubles due to clogging of the backfill material of the injection device can be eliminated. In particular, the backfilling material injection tube is made of a flexible material rich in elastic restoring force, and the entire area of the necessary range is compressed evenly mechanically so that no backfilling material remains. Since it is poured out near the tip, the B liquid does not remain inside the tube other than the tip, and there is no adhesion and solidification of the backfilling material, so that the backfilling material can be discharged more efficiently by pressing the tube. be able to.

  In particular, even if the liquid B is concentrated at the tip of the tube, the cleaning step can be completely performed without any trouble because the portion is locally blocked by the piece.

  According to a second aspect of the present invention, the piece is engaged with and supported by the tip of the pressing rod of the operating mechanism, and it can be lifted when the pressing rod is raised, and is free when the pressing rod is lowered.

  And in order to make the latching means which maintains the said piece in a tube pressing state at the time of the retreat of the said press tackle at the time of the operation | movement terminal end of this press tackle, the state which the piece is pressing the tube like Claim 4 In order to simplify the structure, it is preferable to have a structure that includes a locking body that protrudes with a spring so as to maintain the above and restrains the piece and releases the restraint of the piece at the end of operation of the operating rod.

  On the other hand, as the operating mechanism, an operating rod that is opposed to the surface of the pressing rod opposite to the tube contact surface and is provided so as to be movable back and forth in the longitudinal direction of the tube by a hydraulic cylinder is used. It is suitable to form a plurality of cams in the longitudinal direction of the sliding surface, and to form the cam with an inclined surface that displaces the pressing rod in the tube pressing direction when the operating rod slides (Claim 3). Since the above-mentioned locking means can be released by utilizing the sliding movement, a preferable mode can be obtained.

  In addition, since the multiple cams operate evenly and the pressing rod can be completely translated, the required range of the tube can be uniformly squeezed, and all the backfill material in the tube can be reliably discharged. Can do.

  If the confluence pipe of the base and the tube are connected in a detachable manner (Claim 5), even if the backfilling material is clogged or remaining, it is possible to separate the tube and eliminate the backfilling material. And can easily deal with troubles.

  According to the sixth aspect of the present invention, if the tube, the pressing rod and the operating rod of the operating mechanism, the piece, and the locking means are built in by aligning the pair of outer shells and fastening them with bolts, the device configuration is as follows. This is preferable because it can be simplified.

  As described above, according to the present invention, the backfill material injection tube in the shield method is constituted by a tube made of an elastic flexible material such as rubber, and the required length range of the tube is compressed by mechanical means. Since the back-filling material does not remain because it is closed in an empty state, and B liquid is poured out near the tip of the tube, there is no remaining B liquid other than the tip of the tube. There is no adhesion solidification, and the back-filling material can be discharged more favorably by squeezing the tube.

  In particular, even when the liquid B gels at the tip end portion of the tube, the portion is locally closed with a piece, so that good cleaning can be performed.

  According to the second aspect, the tube can be squeezed and released by the piece using the movement of the pressing rod and the operating mechanism, so that it is not necessary to incorporate a special complicated mechanism, and the object can be achieved by a simple configuration. Can do.

  If the pressing rods are pushed by a plurality of cams arranged in the longitudinal direction as in claim 3, the entire required range of the tube can be squeezed uniformly with uniform pressure, and the residue can be more reliably retained. Backfill material can be discharged.

  If the pressing state of the piece is released by pushing the locking body at the end of operation of the operating mechanism as in claim 4, the tube end is reliably closed without providing a special device. It is possible to clean and discharge the backfill material remaining in the tube.

  If the base part and the tube can be separated as in claim 5, it is possible to quickly solve the trouble when the backfilling material should remain, which greatly impedes the tunnel excavation process. Can be avoided.

  As in claim 6, if the tube, the pressing rod, its operating mechanism, the piece, and its locking means are held by the outer shell in the middle, a simple and reliable operation can be performed. Can do.

  The present invention will be described below with reference to embodiments shown in the drawings.

  FIG. 1 is a side view showing an example of the internal structure of an embodiment of a backfilling material injection apparatus according to the present invention. (A) is when the backfilling material is injected, (B) is when the injection is stopped, and (C) is the same tube. Each state at the time of cleaning is shown, and FIGS. 2A and 2B are enlarged sectional views taken along lines AA and BB in FIGS. 1A and 1B, respectively.

  The backfilling material injection apparatus 1 includes an A liquid supply pipe 2 for supplying mortar as a main raw material of the backfilling material of the backfilling material supply system mounted in the shield machine body, and B for supplying the quick setting material. A base 6 composed of a junction pipe 5 to which a liquid supply system 3 and a cleaning water supply pipe 4 of a cleaning water supply system are connected, respectively, and a backfilling material injection tube made of an elastic flexible material connected to the tip of the junction pipe 5 7, a pressing rod 8 that is in contact with one outer surface of the tube 7 in the entire longitudinal direction, an operating mechanism 9 that translates the pressing rod 8 in the diameter direction of the tube 7, and the B liquid supply system 3 and a B liquid injection tube 10 made of an elastic flexible material that is inserted into the axial center of the tube 7 and a piece 11 that is positioned at the tip of the pressing rod 8 and that squeezes the tip of the tube 7. When the pressing rod 8 is withdrawn, the piece 11 is held in the tube compressed state. It is composed of a locking means 12 for, which are incorporated suitable outer body 13.

  The tube 7 and the B liquid injection tube 10 are made of a material rich in elastic restoring force, and preferably made of natural rubber containing reinforcing fibers, but may be made of synthetic resin. The tube 7 has an inner diameter of 40 to 50 mm and a wall thickness of 10 to 15 mm, and the length is selected according to the situation at the construction site. The B liquid injection tube 10 has a thickness that does not hinder the discharge of the A liquid.

  The length of the B liquid injection tube 10 extends to a position slightly deeper than the tip of the tube 7 (fixing nipple 7a at the backfilling material discharge end), and B liquid is discharged at this position.

  As shown in FIGS. 1, 3, and 4, the connection between the merging pipe 5 and the tube 7 of the base portion 6 includes a flange 5 a at the end of the merging pipe 5, and a flange 14 a of the nipple 14 for press-fitting the tube 7. The bolts are integrated by fastening the bolts, and are configured such that the bolts can be removed and separated when necessary (maintenance).

  The pressing rod 8 has a flat plate shape and extends over a range (referred to as a necessary range) from a position separated from the inner end of the nipple 14 of the tube 7 by a required distance to a position beyond the tip of the B liquid injection tube 10. It has the tube contact surface 8a of the length which contact | abuts.

  In the illustrated embodiment, the operating mechanism 9 that translates the pressing rod 8 in the diameter direction of the tube 7 includes an operating rod 15 that is opposed to the surface of the pressing rod 8 opposite to the tube contact surface 8a. And a hydraulic cylinder 16 that drives the operating rod 15 forward and backward, and a plurality of (5 in the figure) for moving the pressing rod 8 in parallel with the forward and backward movement of the operating rod 15 on the opposing surfaces of the pressing rod 8 and the operating rod 15. ... Are formed.

  The cam 17 is composed of inclined surfaces 8b and 15b (shown in FIG. 1B) for displacing the pressing rod 8 in the tube pressing direction when the operating rod 15 is slid. When 15 is pulled (when leftward in FIG. 1), the pressing rod 8 is moved in the tube pressing direction, and when the operating rod 15 is pressed (when rightward in FIG. 1), the restraint of the pressing rod 8 is released. Accordingly, the pressing rod 8 is inclined by the elastic restoring force of the tube 7 so as to follow the operating rod 15 and retreat.

  It should be noted that the inclined direction of the inclined surfaces 8b and 15a may be reversed so that the pressing rod 8 is pushed up when the operating rod 15 is pushed, and the pressing rod 8 is lowered when the operating rod 15 is pulled. One of the inclined surfaces may be a roller.

  The piece 11 that squeezes a part of the tube 7 in cooperation with the pressure rod 8 is provided at the tip of the pressure rod 8, and the piece 11 squeezes the tube 7 below the piece 11. Locking means 12 is provided for maintaining the state in which the piece 11 is released and releasing the restraint of the piece 11 at the end of operation of the operating rod 15 in the pressing rod release direction.

  An example of the piece 11 and the locking means 12 is shown enlarged in FIGS. 5A to 5D including the operating state.

  The piece 11 has a hooking portion 11a consisting of a downward stepped portion on one side thereof, and this hooking portion 11a is hooked and held on the upward stepped portion 8c of the tip of the pressing rod 8, and the piece 11 The upper surface is arranged on the same surface as the tube contact surface 8a of the pressing rod 8.

  The locking means 12 is provided with a locking body 19 slidable in the moving direction of the operating rod 15 on a block 18 that also serves as a guide for the vertical movement of the piece 11, and this locking body 19 is provided in the block 18. The springs 20, 20 are urged so as to be in constant contact with the distal end surface of the operating rod 15, and the lower end corner portion of the piece 11 is engaged with the engaging step portion 19 a formed at the upper corner of the locking body 19. It has come to be stopped.

  Accordingly, when the pressing rod 8 advances in the tube pressing direction, the pressing rod 8 squeezes the tube 7 that has advanced with the piece 11, and the piece 11 engages with the engaging step portion 19 a of the locking body 19 to squeeze the tube. At the end of operation of the operating rod 15, the tip end surface abuts against the locking body 19 and pushes against the springs 20, 20, and the piece 11 is disengaged from the engaging step portion 19 a. The tube 7 is pushed back by the restoring force of the tube 7 so that the tube 7 is restored to the fully open state (the backfilling material can be injected).

  The tube 7, the pressing rod 8, the operating rod 15, the piece 11, and the outer body 13 that holds the locking means 12 are integrated with bolts 21 and 22 in the middle as shown in an enlarged sectional view in FIG. 2. It comprises a pair of outer members 13A, 13A.

  13 A of said outer members are the tube holding part 23 which consists of a semicircular recessed part which the outer periphery of the half part of the tube 7 at the time of no load closely_contact | adheres, and the said press rod 8, the operating rod 15, the piece 11, and a latching means The tube holding portion 23 and the plate 24 are reinforced by ribs 25. The plates 24 are opposed to each other with an interval that does not prevent sliding of the 12 locking bodies 19.

  The backfilling material supply system and the cleaning water supply system are constituted by a piping system as shown in FIG. 3 and FIG.

That is, the backfilling material supply system has an A liquid supply pipe 2 having one end obliquely connected to one side of the merging pipe 5 of the base 6 and the other end connected to the A liquid supply pump, and one end inside the merging pipe 5. A B liquid supply pipe 3 connected to the B liquid injection pipe 10 and having the other end connected to a B liquid supply pump. The A liquid supply pipe 2 has a discharge pipe 26 branched in the middle. In addition, valves V ₁ and V ₂ are interposed above and downstream of the branch point, and a valve V ₃ is interposed in the discharge pipe 26 so that discharge is turned on and off.

A branch pipe 27 is branched in the middle of the B liquid supply pipe 2, and this branch pipe 27 is connected to the washing water supply pipe 4, and the valve V is positioned downstream from the branch pipe connecting portion of the washing water supply pipe 4. ₄ the valve V ₅ to the branch pipe 27 with being interposed, the valve V ₆ is interposed respectively on the upstream side of the branch portion.

  One end of the washing water supply pipe 4 is connected to the rear end of the junction pipe 5 of the base 6, and the other end is connected to a washing water supply pump.

  These valves are solenoid valves. In each of the operation diagrams of FIGS. 3A, 3B, 4A, and 4B, the white valves are in a “closed” state and are black. The valve shown shows the “open” state.

  Next, the operation of the above embodiment will be described.

  When the backfill material is injected, the hydraulic cylinder 16 of the operating mechanism 9 is extended to push out the operating rod 15. Thereby, the pressing rod 8 and the piece 11 are pushed back by the elastic restoring force of the tube 7, and the inclined surfaces 8b of the cams 17, 17... Of the pressing rod 8 slide along the inclined surface 15b of the operating rod 15 as shown in FIG. ) And the entire length of the tube 7 in the longitudinal direction is fully opened (shown in FIGS. 1A and 3A).

In this state, as shown in FIG. 3A, the valves V ₁ and V ₂ of the A liquid supply pipe ₂ and the valve V ₆ of the B liquid supply pipe 3 are opened, and the discharge pipe 26 and the washing water supply pipe 4. Each valve V ₃ , V ₄ , V ₅ of the branch pipe 27 is “closed”, and the A liquid (mortar, etc.) pumped from the A liquid supply pump enters the tube 7 via the junction pipe 5. Supplied and flows toward its tip. Further, the B liquid (quickly linking material) pumped from the B liquid supply pump is sent to the B liquid injection pipe 10 in the tube 7 and is discharged from the tip into the A liquid flowing in the tube 7. The B liquid is mixed to become a backfill material, and is injected from the fixed nipple 7a at the tip of the tube 7 into the gap portion e between the excavation surface d of the natural ground and the segment b.

  When the injection of the predetermined amount of backfill material is completed, the cleaning process is started.

  In this cleaning process, first, the hydraulic cylinder 16 is shortened and the operating rod 15 is pulled, and the inclined surface 15b of the operating rod 15 pushes up the inclined surface 8b of the pressing rod 8, whereby the pressing rod 8 is accompanied by the piece 11. The tube 7 advances in the diameter direction of the tube 7, and the necessary range of the tube 7 is uniformly pressed together with the B liquid injection tube 10 by the tube contact surface 8 a of the pressing rod 8 and the tip surface of the piece 11 to eliminate these. Squeezed into an empty state (shown in FIGS. 1 (B) and 3 (B)), the injection of the backfill material is stopped, and at the same time, the A liquid and B liquid in these tubes 7 and B liquid injection pipe 10 are on the base 6 side. Are all discharged.

At the same time, as shown in FIG. 3B, the valves V ₆ and V ₅ of the B liquid supply pipe 3 and the branch pipe 27 are closed, the valve V ₄ of the cleaning water supply pipe 4 and the discharge pipe branch of the A liquid supply pipe 2. more valve _{V 2} on the downstream side, is a valve _{V 3} of the discharge pipe 26 open.

  Next, the hydraulic cylinder 16 is switched to the extending operation, and the operating rod 15 is moved forward to retract the pressing rod 8 by the same action as described above. At this time, since the lower end of the piece 11 is engaged with the engagement step portion 19a of the locking body 19 of the locking means 12 and cannot be moved backward, the tube 7 of the portion 11 remains in the compressed state. (FIG. 1C and FIG. 4A are shown).

Here, the valve V ₅ of the branch pipe 27 of the B liquid supply pipe 3 is also opened (shown in FIG. 4A), and the wash water supplied through the wash water supply pipe 2 flows into the tube 7 from the base 6. Then, the backfilling material remaining on the inner surface and the outer surface of the B liquid injection pipe 10 is washed away, and the cleaning water flows through the A liquid supply pipe 2 and the discharge pipe 26 together with the residual backfilling material and is collected in a drain tank or the like. .

  At the same time, the washing water also flows into the branch pipe 27, flows through the B liquid injection pipe 10, flows out from the tip into the tube 7, and remains in the tip portion of the tube 7 squeezed by the piece 11. The backfill material thus formed is thoroughly washed and flows to the discharge pipe 26 together with the previous washing water, and is discharged and collected.

  Prior to the next injection, the operating rod 15 is further advanced, and when it reaches the operating end position, its tip abuts against the locking body 19 and pushes it against the springs 20, 20. The piece 11 restrained by the locking step portion 19a of the stopping body 19 is removed from the locking body 19 and pushed back by the elastic restoring force of the tube 7, and is returned to the state of FIG.

Note during the injection stand is to a state of being squeezed tube 7 as shown in FIG. 4 (B), and waits all valves V ₁ ~V ₆ as closed.

  When troubles such as the backfill material remaining in the base 6 and the connection part of the tube 7 or in the vicinity thereof occur, the flanges 5a and 14a between the joining pipe 5 and the nipple 14 of the base 6 are fastened. By removing the bolts and separating them, the inside can be cleaned, and trouble can be easily and quickly resolved.

  In addition, it is also included in the technical idea of the present invention that the pressing rod 8 and its operating mechanism 9 in the above-described embodiment are provided as a pair in a vertically symmetrical manner and are pressed from both surfaces of the tube 7. The operating mechanism 9 may be replaced with a toggle mechanism without using a cam.

The internal structure example of one Embodiment of the backfilling material injection apparatus by this invention is shown, (A) at the time of backfilling material injection | pouring, (B) at the time of the injection stop, (C) shows the operation state at the time of tube washing | cleaning Sectional drawing. (A) is an expanded sectional view of AA in FIG. 1 (A), (B) is BB of FIG. 1 (B). An example of the supply system of a backfill material and cleaning water is shown, (A) is an explanatory view at the time of backfill material injection, and (B) is an explanatory view at the time of cleaning. (A) is an explanatory view in waiting for injection while (A) is cleaning the tube and the B liquid injection tube. FIG. 1 shows an enlarged view of the locking means in FIG. 1, (A) at the time of backfilling material injection, (B) at the time of tube pressing, (C) at the time of washing, (D) at the state of (A). Operation | movement explanatory drawing which shows the time of a return. The schematic sectional drawing which shows typically the tunnel construction condition in a shield construction method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Back-filling material injection apparatus 2 A liquid supply pipes, such as mortar 3, B liquid supply pipes, such as quick setting material 4, Wash water supply pipe 5, Joining pipe 6, Base 7 Back-filling material injection tube 8 Press rod 9 Actuation mechanism 10 B liquid Injection pipe 11 Block 12 Locking means 13 Outer body 15 Operating rod 16 Hydraulic cylinder 17 Cam 19 Locking body 20 Spring 26 Discharge pipe 27 Branch pipe

Claims (7)

  Backfill material injection in the shield method, in which segments are assembled into the excavation site of the natural ground excavated by the shield machine, and mortar or other backfill material is injected into the gap between the natural excavation surface and the outer surface of the segment A backfilling material injection tube comprising a backfilling material supply system, a cleaning water supply system, a base portion constituted by these merging pipes, and an elastic flexible material such as rubber connected to the merging pipe And a pressing rod that is brought into contact with one outer surface of the tube except for the merging tube connection portion in the longitudinal direction and moves in the diameter direction of the tube to squeeze the tube into an empty state, and this pressing An actuating mechanism that translates the pestle in a non-squeezed state and a squeezed state of the tube, and the backfilling material supply system is composed of two systems of A liquid such as mortar and B liquid such as quick setting material, In the junction pipe A B liquid injection tube made of an elastic flexible material such as rubber of the B liquid supply system is inserted into the tube and its tip extends to the vicinity of the tube, and the tube tip and the B A piece that squeezes a part of the tube in cooperation with the pressing rod at a position between the tip of the liquid injection tube is provided so as to be movable forward and backward in the diameter direction of the tube in conjunction with the operation of the operating mechanism. A locking means is provided for restraining the piece in a tube compressed state when the mechanism is released, and the locking means is released at the end of the release movement of the operating mechanism to retract the piece, and the tip of the tube is A backfilling material injection device in a shield method characterized by being fully opened.   2. The backfill in the shield method according to claim 1, wherein the piece is supported by being engaged with a tip of the pressing rod, and is lifted together when the pressing rod is compressed, and is free when the pressing rod is retracted. Material injection device.   The actuating mechanism includes an actuating rod that is opposed to a surface of the pressing rod opposite to the tube contact surface and is provided so as to be movable back and forth in the longitudinal direction of the tube by a hydraulic cylinder. 3. A plurality of cams are formed in a longitudinal direction of the sliding surface of the first and second cams, and the cams are formed by inclined surfaces that displace the pressing rod in the tube pressing direction when the operating rod slides. Backfilling material injection device in the shield method of construction.   The locking means of the piece has a locking body that protrudes by a spring bias so as to maintain the state where the piece is pressing the tube and restrains the piece, and releases the restraint of the piece at the end of operation of the operating rod. The backfilling material injection apparatus in the shield construction method according to claim 1.   The backfilling material injection device in the shield method according to any one of claims 1 to 4, wherein the joining pipe of the base portion and the backfilling material injection tube are detachably connected.   The backfilling material injecting tube, a pressing rod and an operating rod of the operating mechanism, the piece, and the locking means are held by a pair of outer bodies that are joined together and integrated by bolt fastening. The backfilling material injection apparatus in the shield method of any one of 3-5.   The backfilling material injection device in the shield method according to any one of claims 1 to 6, wherein the backfilling material injection tube and the B liquid injection tube are formed of natural rubber reinforced with reinforcing fibers.

Images