JP2010001653A - Working method by worker during tunnel excavation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shield machine provided with a shield cylinder 1 and an excavation unit 2 and a ring body 16 fixed at the inner periphery of a front part of the shield cylinder, providing the excavation unit with a bulkhead 21 fitted into the ring body internally, and having a cutter head 22 extending and contracting freely in the radial direction and supported on the bulkhead 21 and a driving unit 23 for driving the cutter head on a rear surface of the bulkhead to allow a worker to enter a space 25 between the cutter head and the bulkhead and work safely during excavation by use of this shield machine. <P>SOLUTION: In this working method, the shield cylinder 1 is made to advance up to a working face while fixation of the bulkhead 21 on the ring body 16 is released to store the cutter head 22 in the ring body 16, next the driving unit 23 is removed from the bulkhead 21 to insert an injection pipe 5 into the working face through the bulkhead 21 in this condition in order to pour chemical into the ground in front of the working face and cut off water on the working face, and then the worker enters the space 25 between the cutter head 22 and the bulkhead 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a work method performed by an operator when an obstacle difficult to excavate with a cutter head appears on a face during tunnel excavation using a shield excavator.

  Conventionally, as a shield excavator, a shield cylinder and an excavation unit having a cutter head for excavating a face at a position ahead of the front end of the shield cylinder are provided, and the inner diameter of the shield cylinder is the inner diameter of the other part of the shield cylinder. A ring body having a smaller diameter is fixed, and the excavation unit has a partition wall fitted into the ring body, and the partition wall is retractable with respect to the ring body by releasing the fixing to the ring body. In addition, there is known one that pivotally supports a cutter head that is freely expandable and contractable, and that is provided with a drive unit that rotationally drives the cutter head on the back surface of the partition wall (see, for example, Patent Document 1). The drive unit is mounted on a gear case fixed to a partition wall that supports the shaft portion of the cutter head, and is attached to the gear case with a circumferential interval therebetween, and the shaft portion of the cutter head is rotationally driven via a gear in the gear case. The plurality of drive motors are configured such that the cutter head can be driven to rotate with high torque by the plurality of drive motors.

  According to this shield excavator, after the tunnel excavation is completed, the fixing of the bulkhead to the ring body is released, and the bulkhead is pulled rearward with the cutter head reduced in diameter, so that the entire excavation unit is moved to the rear of the ring body. Can be pulled out. The excavation unit can then be recovered through the tunnel.

  By the way, during excavation of a tunnel, obstacles such as rocks that are difficult to excavate with a cutter head may appear on the face, and further excavation may not be possible. In this case, conventionally, a shaft is generally dug from the ground to the place where the obstacle is buried, and the obstacle is removed. However, this requires large-scale construction, which increases the construction cost and the construction period.

  Here, when the shield excavator of the conventional example is used, when an obstacle appears on the face, the fixing of the partition wall to the ring body is released, and the shield cylinder is advanced to the face with the diameter of the cutter head reduced. The cutter head is housed in the inner periphery of the ring body, and then a chemical such as a ground improvement agent is injected into the face using an injection pipe from the back side of the bulkhead to stop muddy water from seeping out from the face. After watering, it is conceivable that an operator enters the space between the cutter head and the partition wall and crushes and removes the obstacle using a rock drill or the like.

However, in the shield excavator of the above-described conventional example, since the drive unit for the cutter head provided on the partition wall is a large one having a plurality of drive motors, the drive unit gets in the way and is injected into the central portion of the face. The pipe cannot be inserted. For this reason, water stoppage of the face is likely to be insufficient, and it becomes difficult to ensure the safety of work in the space between the cutter head and the partition wall.
Japanese Patent No. 3836467

  In view of the above points, the present invention provides a working method by an operator during tunnel excavation that can ensure the safety of the work performed by the worker in the space between the cutter head and the partition wall. That is the issue.

  In order to solve the above-described problems, the present invention includes a shield tube and a drilling unit having a cutter head for drilling a face at a position ahead of the front end of the shield tube. A ring body having a smaller diameter than the inner diameter of the other part is fixed, the excavation unit has a partition wall fitted into the ring body, and the partition wall can be retracted relative to the ring body by releasing the fixing to the ring body, During the tunnel excavation using a shield excavator in which a cutter head that is radially expandable and contractable is supported by the bulkhead and a drive unit that rotationally drives the cutter head is provided on the back of the bulkhead, the cutter head and the bulkhead A method in which a predetermined work by an operator is performed in a space between the two and a shield excavator in which a drive unit is removable from a partition wall, and the predetermined work is required. At that time, the fixing of the bulkhead to the ring body is released and the cutter head is reduced in diameter, the shield cylinder is advanced to the face, and the bulkhead and the cutter head are moved backward relative to the shield cylinder. The step of storing the head in the inner periphery of the ring body, the step of removing the drive unit from the partition wall, the injection pipe is inserted into the face through the partition wall and the cutter head from the back side of the partition wall, and the ground is forward through the injection pipe. The method includes a step of water-stopping the face by injecting a chemical, and a step of entering the space between the cutter head and the partition wall to perform the predetermined operation.

  According to the present invention, by removing the drive unit from the partition wall, the injection pipe can be inserted into the face without being obstructed by the drive unit. In particular, by forming a through hole in the part where the drive unit of the partition wall is installed, the injection pipe can be easily inserted into the central part of the face through the through hole with the drive unit removed. Therefore, the face can be reliably stopped over the central portion. Therefore, it is possible to ensure the safety of work such as removal of an obstacle when an operator enters the space between the cutter head and the partition wall.

  Further, in the present invention, if the shield excavator is provided with an advancing / retreating drive source that advances and retracts the partition wall in the front-rear direction with respect to the ring body, the step of attaching the drive unit to the partition wall after the completion of the predetermined operation and the cutter head drive A step of fixing the partition wall to the ring body in a state where the partition wall is advanced with respect to the ring body by the advancing / retreating drive source and the cutter head is returned to the front position from the front end of the shield tube while being rotated by the unit and expanded in diameter. By doing so, the return operation to the normal excavation state can be easily performed.

  FIG. 1 shows a shield excavator for excavating a tunnel in the ground. The shield excavator includes a shield cylinder 1 and an excavation unit 2 assembled to the shield cylinder 1. The shield cylinder 1 is composed of a front cylinder 11 and a rear cylinder 12. At the front end of the rear cylinder 12, a spherical joint portion 13 that is fitted into the rear end portion of the front cylinder 11 is provided, and the front cylinder 11 can be bent in any direction with respect to the rear cylinder 12. Then, a plurality of middle folding jacks 14 for connecting the front cylinder 11 and the rear cylinder 12 are provided at intervals in the circumferential direction, and the direction of the front cylinder 11, that is, the direction of advancement of the shield excavator is determined by these middle folding jacks 14. It can be adjusted.

  The rear cylinder 12 is provided with an erector 3 for assembling the segment S in a ring shape on the inner wall surface of the excavated tunnel, and a propulsion jack 15 for advancing the shield cylinder 1 using the installed segment S as a reaction force. A plurality are attached at intervals in the circumferential direction. A tail seal 12 a that seals the gap between the segment S is attached to the rear end of the rear cylinder 12. Further, a ring body 16 having an inner diameter smaller than the inner diameter of the other part of the shield tube 1 is integrally fixed to the inner periphery of the front portion of the front tube 11.

  The excavation unit 2 includes a partition wall 21 fitted in the ring body 16 and a cutter head 22 supported by the partition wall 21 for excavating a face in front of the front end of the shield tube 1. On the outer periphery of the partition wall 21, a cylindrical flange portion 21 a that fits in the ring body 16 is provided. The partition wall 21 is bolted to a fixed position of the ring body 16 at the flange portion 21a.

  The cutter head 22 is pivotally supported by a support cylinder 21b provided on the front surface of the partition wall 21 at a shaft portion 22a extending rearward. A drive unit 23 for the cutter head 22 is provided on the back surface of the partition wall 21. The drive unit 23 has a gear case 23a that is detachably attached to the partition wall 21 by a bolt (not shown), a drive shaft 23b that is pivotally supported in the gear case 23a, and a circumferential interval between the gear case 23a as shown in FIG. And a plurality of drive motors 23c attached thereto. A gear 23d that is externally fitted and fixed to the drive shaft 23b is provided in the gear case 23a, and a gear 23e on the output shaft of each drive motor 23c is engaged with the gear 23d. Thereby, the cutter head 22 can be rotationally driven with high torque by the plurality of drive motors 23c.

  Further, the rear end portion 22b of the shaft portion 22a of the cutter head 22 is inserted into the gear case 23a, and the drive shaft 23b is spline-fitted to the rear end portion 22b so as to be separable in the axial direction. Thus, when the gear case 23a is removed from the partition wall 21, the drive shaft 23b is detached from the shaft portion 22a of the cutter head 22, and the entire drive unit 23 can be detached from the partition wall 21 without being restrained by the shaft portion 22a.

  A front end of a jack 24 that is an advancing / retreating drive source is connected to each of the left and right sides of the partition wall 21 via a bracket 24a (see FIGS. 5B and 5C). The rear end of the jack 24 is connected to the front portion of the rear cylinder 12 via a bracket 24b. The partition wall 21 can be moved forward and backward with respect to the ring body 16 by the jack 24 in a state where the bolting of the partition wall 21 to the ring body 16 is released.

  As shown in FIG. 3, the cutter head 22 includes a plurality of radial spokes 22d to which a cutter bit 22c is attached and an extension jack (not shown) built into each of the cutter spokes 22d from the outer end of each of the cutter spokes 22d. And an overcutter 22e that protrudes outward in the radial direction. The cutter head 22 can be switched between an expanded state of substantially the same diameter as the outer diameter of the shield tube 1 and a reduced diameter state equal to or smaller than the inner diameter of the ring body 16 by the appearance of the overcutter 22e. In addition, the cutter head 22 includes a face plate 22f positioned between the respective cutter spokes 22d. The face plate 22 f is formed with an opening 22 g for taking excavated soil into the earth and sand chamber 25 between the cutter head 22 and the partition wall 21.

  At the lower part of the partition wall 21, a soil discharge port 21 c communicating with the earth and sand chamber 25 is provided. A screw conveyor 4 as a soil discharging means for discharging the excavated soil in the earth and sand chamber 25 is connected to the soil discharge port 21c. The screw conveyor 4 is disposed in a rearwardly inclined posture. Then, the excavated soil is dropped from a discharge port 4a at the rear end of the screw conveyor 4 onto a belt conveyor (not shown) installed in the excavated tunnel, and the excavated soil is carried out of the mine via the belt conveyor. ing.

  Here, when the screw conveyor 4 is provided separately from the drive unit 23, the screw conveyor 4 becomes an obstacle when the drive unit 23 is removed from the partition wall 21. Therefore, it is necessary to remove the screw conveyor 4 from the partition wall 21 prior to removal of the drive unit 23. Therefore, in the present embodiment, the screw conveyor 4 is assembled to the gear case 23a. According to this, the drive unit 23 can be removed from the partition wall 21 together with the screw conveyor 4, and the removal work becomes easy.

  Further, the inner diameter of the front end portion of the ring body 16 is larger than the inner diameter of the portion of the ring body 16 into which the partition wall 21 is fitted. Then, when the cutter head 22 is reduced in diameter on the inner periphery of the ring body 16 to the same extent as the inner diameter of the front end portion of the ring body 16 and stored in the front end portion of the ring body 16, the cutter head 22 is radially outside. A stepped portion 16a in the radial direction is formed on which the rear surface of the end portion, that is, the rear surface of the overcutter 22e can abut.

  Further, the partition wall 21 is formed with a plurality of through holes 21d over a portion where the drive unit 23 is installed. As shown in FIG. 4, the through hole 21d is normally closed by an elastic plate 21e attached to the front surface of the partition wall 21, and the elastic plate 21e is pushed open when an injection pipe 5 described later is inserted into the through hole 21d. It is trying to be. In addition, a seal member 21f that seals a gap between the injection pipe 5 and the injection hole 5 is provided in the through hole 21d. Further, a hatch 21 g for allowing an operator to enter the earth and sand chamber 25 is provided on the upper part of the partition wall 21.

  By the way, during tunnel excavation, it may be necessary for an operator to enter the earth and sand chamber 25 to perform work. For example, as shown in FIG. 1, an obstacle A such as a rock that is difficult to excavate by the cutter head 22 appears on the face, and an operator P enters the earth and sand chamber 25 to remove the obstacle A. There is a case. Hereinafter, the procedure for removing the obstacle A will be described with reference to FIG.

  When the obstacle A appears on the face, first, the fixing of the partition wall 21 to the ring body 16 is released. Thereafter, the cutter head 22 is reduced in diameter to the same extent as the inner diameter of the front end portion of the ring body 16, and the shield cylinder 1 is advanced to the face by the propulsion jack 15 while the jack 24 is free. At this time, since the partition wall 21 can be retracted relative to the ring body 16, when the shield cylinder 1 is advanced, the partition wall 21 retracts relative to the ring body 16 together with the cutter head 22 that is prevented from moving forward by the face. . As a result, the cutter head 22 is accommodated in the inner periphery of the front end portion of the ring body 16 as shown in FIG. Further, the rear surface of the overcutter 22e comes into contact with the stepped portion 16a of the ring body 16.

  Next, the fixing of the gear case 23 a to the partition wall 21 is released, and the drive unit 23 is removed from the partition wall 21 together with the screw conveyor 4. At this time, the cover plate 21h is attached to the soil discharge port 21c to prevent mud from entering from the soil discharge port 21c. Thereafter, as shown in FIG. 5 (b), the injection pipe 5 is inserted into the periphery of the face through the through hole formed in the front cylinder 11, and the injection pipe 5 is inserted into the face through the through hole 21d formed in the partition wall 21. Plug in. The cutter head 22 is stopped at a phase where the opening 22g is positioned in front of the through hole 21d, and the injection pipe 5 inserted into the through hole 21d is inserted into the face through the opening 22g.

  And a chemical | medical agent, such as a ground improvement agent, is inject | poured into the front ground of a face through these injection | pouring pipes 5, and the face is stopped. Here, in this embodiment, since the chemical solution injection operation can be performed with the drive unit 23 removed from the partition wall 21, the drive unit 23 does not interfere with the operation, and the chemical solution injection operation can be performed with good workability. it can. Furthermore, the injection pipe 5 can be inserted into a through hole 21d formed in the part where the drive unit 23 of the partition wall 21 is installed, so that the chemical solution can be injected into the central part of the face, and the entire face is reliably stopped.

  Next, after mud remaining in the earth and sand chamber 25 is scraped from the earth discharge port 21c and the like, the hatch 21g is opened, and an operator P enters the earth and sand chamber 25 as shown in FIG. Using this, the obstacle A is removed. Here, it is prevented by the shield cylinder 1 that muddy water enters the earth and sand chamber 25 from the natural ground before the face, and intrusion of muddy water from the face into the earth and sand chamber 25 is prevented by injection of chemical liquid into the face. Therefore, work safety is ensured.

  In FIG. 5 (c), the obstacle A is illustrated as having been completely removed together with the surrounding face part. However, if the obstacle A is crushed and does not interfere with excavation, a fragmented piece is obtained. May remain buried in the face. That is, in the obstacle A removing operation, it is sufficient to treat the obstacle A so as not to obstruct excavation.

  When the removal work is completed and the worker P retreats to the back side of the partition wall 21, the drive unit 23 and the screw conveyor 4 are attached to the partition wall 21. Next, while rotating the cutter head 22 by the drive unit 23 and expanding the diameter, the partition wall 21 is advanced to a fixed position with respect to the ring body 16 by the operation of the jack 24, and the partition wall 21 is fixed to the ring body 16. As a result, as shown in FIG. 5 (d), the cutter head 22 returns to the front position from the front end of the shield tube 1 while excavating the face, and returns to the normal excavation state.

  Further, when a work other than the obstacle removal (for example, the work of replacing the cutter bit 22c) is required in the earth and sand chamber 25 during tunnel excavation, the work can be performed in the same procedure as described above. When exchanging the cutter bit 22c, after performing the chemical solution injection operation shown in FIG. 5 (b), the cutter head 22 is contracted to the same diameter as the inner diameter of the rear portion of the ring body 16, and in this state The partition wall 21 is slightly retracted by the jack 24. As a result, the cutter head 22 is pulled away from the face, and the cutter bit 22c can be replaced.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, in the above-described embodiment, the jack 24 that is an advance / retreat drive source is always installed, but the jack 24 may be installed only when necessary. In the above embodiment, the cutter head 22 is provided with the face plate 22f, but the cutter head 22 may be provided without the face plate 22f.

The longitudinal cross-sectional view of the shield excavator used for implementation of this invention. The cross-sectional view cut | disconnected by the II-II line | wire of FIG. The front view of the shield excavator of FIG. Sectional drawing of the formation part of the through-hole of the partition with which the shield excavator of FIG. 1 is equipped. Explanatory drawing which shows the procedure of the obstruction removal operation | work of embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Shield pipe | tube, 16 ... Ring body, 2 ... Excavation unit, 21 ... Partition, 21d ... Through-hole, 22 ... Cutter head, 23 ... Drive unit, 24 ... Jack (advance drive source), 5 ... Injection pipe.

Claims (3)

A shield cylinder and a drilling unit having a cutter head that excavates the face at a position forward from the front end of the shield cylinder. A ring body having an inner diameter smaller than the inner diameter of the other part of the shield cylinder is fixed to the front inner periphery of the shield cylinder. The excavation unit has a partition wall that fits in the ring body, and the partition wall can be retracted from the ring body by releasing the fixing to the ring body, and a cutter head that is radially expandable and contractable is provided on the partition wall. During tunnel excavation using a shield excavator that is pivotally supported and is provided with a drive unit that rotationally drives the cutter head on the back of the bulkhead, predetermined work by the operator in the space between the cutter head and the bulkhead A method of performing
Use a shield excavator that allows the drive unit to be freely removed from the bulkhead,
When the predetermined work becomes necessary, the shield cylinder is released from the ring body and the shield head is reduced in diameter, the shield cylinder is advanced to the face, and the partition wall and the cutter head are relative to the shield cylinder. And retracting the cutter head into the inner periphery of the ring body,
Removing the drive unit from the partition;
Inserting the injection pipe into the face through the bulkhead and the cutter head from the back side of the bulkhead, and injecting the chemical into the front ground of the face through the injection pipe,
A method of working by an operator during tunnel excavation, comprising the step of entering the space between the cutter head and the partition wall and performing the predetermined work.   The work method by an operator at the time of tunnel excavation according to claim 1, wherein the injection pipe is inserted into a face through a through hole formed in a portion of the partition where the drive unit is installed.   The shield excavator includes an advancing / retreating drive source for advancing and retracting the partition wall in the front-rear direction with respect to the ring body, and after the predetermined work is completed, attaching the drive unit to the partition wall, and cutting the cutter head by the drive unit A process of fixing the partition wall to the ring body in a state where the partition wall is advanced with respect to the ring body by the advance / retreat drive source while rotating and expanding the diameter, and the cutter head is returned to the front position from the front end of the shield tube. The work method by the worker at the time of tunnel excavation according to claim 1 or 2.