JP2002061486A - Earth-retaining wall excavating method and tunnel excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability and safety by surely excavating a starting opening of a predetermined shape when starting a tunnel excavator in a shaft in an earth-retaining wall excavating method and the tunnel excavator. SOLUTION: A shield excavator is transferred into a starting shaft 51. A reaction force is received by a reaction force receiving facility 53 and a temporarily assembled segment S. An oil hydraulic jack 39 is extended in an earth- retaining wall supporting device 38 to bring a presser plate 40 into contact with the earth-retaining wall 54. With the earth-retaining wall 54 pressed, a location in the earth-retaining wall 54 corresponding to a protrusion 35 is cut by a workman with a drill 55 to form a through hole 56.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavation method for excavating an earth retaining wall provided in a starting shaft or the like, and a tunnel excavator such as a tunnel boring machine or a shield machine.

[0002]

2. Description of the Related Art In general, a shield excavator is provided with a disk-shaped cutter head rotatably rotatable at the front of a cylindrical excavator body, and a number of cutter bits are attached to the cutter head. On the other hand, a large number of shield jacks for advancing the excavator body are mounted at the rear, and an erector device for mounting a segment on the inner wall surface of the existing tunnel is mounted. Therefore, when the shield jack is extended while rotating the cutter head, the excavator body moves forward by obtaining the excavation reaction force from the existing segment, and each cutter bit excavates the ground in front, thereby forming a tunnel. .

When a tunnel is to be constructed at a predetermined position using such a shield excavator, a starting shaft and a reaching shaft are excavated in advance, and a shield excavator is carried into the starting shaft, and the starting shaft is set in the starting shaft. With the excavation reaction force secured, excavation is performed along a predetermined route by penetrating from the starting port to the ground.
Then, when the shield excavator digs into the reaching shaft, the shield body is pulled out from the reaching hole formed in advance into the reaching shaft. In this way, a tunnel is constructed at a predetermined position.

[0004] In the tunnel excavation work using such a shield excavator, when the shield excavator is started from the starting shaft, it is necessary to open the starting port in advance. In this case, in order to prevent the collapse of the ground, the collapse of the road surface, and the like, the ground near the start port is generally improved by injecting a chemical solution. However, it is expensive and uneconomical to use a chemical solution used for improving the ground, and the work time is long and workability is not good. Therefore, recently, a temporary wall having a predetermined thickness is formed at a formation position of a starting port in a shaft, and this temporary wall is directly excavated by a cutter head of a shield excavator, thereby making it unnecessary to improve the surrounding ground. Things have been suggested.

[0005]

By the way, the shield excavator moves forward while excavating the ground in front by the rotation of the cutter head, while the erector device assembles segments into a ring shape on the inner wall surface of the existing tunnel to form the tunnel. Since the segments are assembled inside the excavator body, a gap is generated between the inner wall surface of the existing tunnel and the outer peripheral surface of the ring-shaped existing segment. for that reason,
A backfill injection device is provided on the outer periphery of the excavator body, and this backfill injection device injects mortar or concrete into the gap between the existing tunnel and the existing segment to stabilize the existing segment at an early stage. ing.

Since the backfill injection device is provided on the outer periphery of the main body of the shield excavator so as to protrude outward, when the shield excavator is started from the above-described start shaft, the temporary shaft is temporarily stopped. It is necessary to form a starting port having the same shape as the excavator body on the wall and to form an auxiliary port corresponding to the backfill injection device. In this case, the cutter head can form the starting port, but cannot form the auxiliary port, and must form the auxiliary port with another tool in advance. However, the temporary wall of the shaft is subjected to a large earth pressure from the ground, and the strength is reduced by forming the auxiliary port in advance, and there is a possibility that the temporary wall may fall into the starting shaft.

SUMMARY OF THE INVENTION The present invention solves such a problem, and an excavation method for a retaining wall in which a start port having a predetermined shape is surely excavated when a tunnel excavator is started to improve workability and safety. And a tunnel excavator.

[0008]

According to a first aspect of the present invention, there is provided a method for excavating a retaining wall, wherein a cutter head is rotatably mounted on a front portion, and a backfill injection portion is provided on an outer peripheral portion. In the tunnel excavator provided with, the tunnel excavator is disposed facing the earth retaining wall in the tunnel, a support member is protruded from the tunnel excavating machine to press the earth retaining wall, and in this state, the tunnel excavator in the earth retaining wall is A portion corresponding to the backfill injection portion is removed by a predetermined tool.

In the method of excavating a retaining wall according to a second aspect of the present invention, after removing a portion of the retaining wall corresponding to the backfill injection portion, the tunnel excavation is performed while the support member holds down the retaining wall. Moving the machine forward to support the cutter head in contact with the retaining wall, storing the support member in the tunnel excavator, and excavating the retaining wall by moving the cutter head forward while rotating the cutter head. It is characterized by.

A tunnel excavator according to a third aspect of the present invention has a tubular excavator body, a propulsion jack for advancing the excavator body, and a drive rotatably mounted on a front portion of the excavator body. A cutter head, an erector device for assembling a lining member in a ring shape along the wall surface of the existing tunnel, a backfill injection portion provided on an outer peripheral portion of the excavator body, and a retaining wall provided in the tunnel. Soil retaining wall support means.

The tunnel excavator according to the invention is characterized in that the retaining wall support means is provided detachably with respect to the excavator body.

In the tunnel excavator according to the fifth aspect of the present invention, the retaining wall supporting means may include a hydraulic jack mounted on the excavator body, and a support for projecting forward from an opening of the cutter head by the hydraulic jack. And a member.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic sectional view of a shield excavator according to an embodiment of the present invention, FIG. 2 is a front view of the shield excavator, and FIGS. Is shown.

In the shielded excavator of the present embodiment, as shown in FIGS. 1 and 2, the excavator body 11 has a cylindrical front body 11a and a rear body 11b, which are flexibly connected by a spherical bearing 12. It can be bent by a plurality of middle folding jacks 13. Front body 1 of this excavator body 11
A cutter head 15 is rotatably mounted on a front portion of the blade 1a by a bearing 14. The cutter head 15 includes a plurality of radially provided cutter spokes 16 and a face plate 17.
A number of cutter bits 18 for excavating the ground, a cutter bit 19 for excavating the earth retaining wall described later, and an opening 20 for taking in excavated earth and sand are formed.

On the other hand, a ring gear 21 is fixed to the rear portion of the cutter head 15, while a turning motor 22 is mounted on the front body 11 a, and a driving gear 23 of the turning motor 22 meshes with the ring gear 21. I have. Therefore,
When the rotation motor 22 is driven to rotate the drive gear 23, the cutter head 15 can be rotated via the ring gear 21.

A bulkhead 24 is mounted on the front trunk 11a behind the cutter head 15.
A chamber 25 is formed between the cutter head 15 and the bulk head 24. And this chamber 25
Pipe 2 with one end extended outside the shield excavator
6 and the other end of the drain pipe 27 are open, and an agitator 28 for stirring and mixing excavated earth and sand and muddy water is mounted near the opening of the drain pipe 27.

Furthermore, a plurality of shield jacks 29 are arranged along the circumferential direction around the front inside of the rear trunk 11b of the excavator body 11, and the shield jacks 29 extend rearward in the excavation direction to excavate the tunnel. By pressing against the existing segment S constructed on the inner peripheral surface, the excavator body 11 can be advanced by the reaction force. Further, a swing ring 31 is freely swingable by a support member 30 on the rear trunk 11b, and is swingable by a drive motor 32.
An erector device 33 for assembling the segment S is mounted on the turning ring 31.

A backfill injection device 34 for injecting a backfill material into a gap between the inner wall surface of the existing tunnel and the outer wall surface of the existing segment S is provided on the outer peripheral portion of the rear trunk 11b of the excavator body 11. . The backfill injection device 34 is provided with
Two projecting portions 35 are formed in the upper part of the outer periphery of b along the excavation direction, an injection pipe 36 is provided in the projecting portion 35, and the base end extends into the front trunk 11 a via the connecting pipe 37. While being connected to a backfill material supply device (not shown), the distal end portion is configured to open to a gap between the inner wall surface of the existing tunnel and the outer wall surface of the existing segment S. In this case, for example, mortar, concrete, or the like is used as the backfill material.

When a tunnel is constructed using such a shield excavator, the starting shaft and the reaching shaft are excavated in advance, and the shield excavator is carried into the starting shaft and formed in the starting shaft. The tunnel penetrates the ground from the start port and excavates a tunnel along a predetermined route to the arrival shaft. In this case, in the present embodiment, a retaining wall having a predetermined thickness is formed at a position where the starting port is formed in the starting shaft, and the cutter head 15 of the shield excavator directly excavates the retaining wall, so that the starting port is formed. As described above, a large number of cutter bits 18 for excavating the ground and cutter bits 19 for excavating the retaining wall are mounted on the cutter head 15 as described above.

Further, the cutter head 15 can excavate a circular cross section slightly larger than the outer diameter of the excavator body 11, but cannot excavate a portion through which the protrusion 35 of the backfill injection device 34 penetrates. Therefore, a portion corresponding to the protruding portion 35 in the retaining wall is excavated with a predetermined tool in advance to form a through hole. However, since the earth retaining wall of the starting shaft receives a large earth pressure from the ground, the strength is reduced by forming a through hole in advance, and there is a possibility that the earth falls into the starting shaft.

Therefore, in the present embodiment, the excavator body 11
A retaining wall support device 38 for pressing the retaining wall is provided at a front portion of the front trunk 11a. Two retaining devices 38 are provided corresponding to the projecting portions 35 of the backfilling and injecting device 34, and a hydraulic jack 39 detachably mounted on the bulkhead 24, and excavated sediment by the hydraulic jack 39. The take-in opening 20 is constituted by a holding plate 40 which can move forward and backward.

Here, a tunnel excavation operation by the shield excavator of the present embodiment configured as described above will be described.

In order to excavate and form a tunnel, as shown in FIG. 3 (a), first, a starting shaft 51 is excavated to a predetermined depth at an excavation start position, and a pedestal 52 and a reaction force are placed in the starting shaft 51. The receiving equipment 53 is installed, and the retaining wall 54 is formed corresponding to the formation position of the starting port. The retaining wall 54 is made of a new material concrete using carbon fiber reinforced composite material strands or rods as reinforcing bars.
Can be excavated by the cutter bit 19 for excavation of the earth retaining wall attached to the wall. Then, the shield excavator is carried into the starting shaft 51, placed on the receiving stand 52 and positioned in a predetermined direction, and the segment S is temporarily assembled between the excavator body 11 and the reaction force receiving equipment 53. I do. At this time, the retaining wall support device 38 is mounted in advance on the shield excavator.

When the shield excavator is set in the starting shaft 51 in this way, as shown in FIG. 3B, the hydraulic jack 39 in each retaining wall support device 38 is extended, and the holding plate 40 is moved to the cutter head. The protruding portion 15 protrudes from the excavated sediment intake opening 20 and contacts the retaining wall 54. In this case, each retaining wall support device 38 is provided at a position corresponding to the protruding portion 35 of the backfill injection device 34, and the cutter head 15 is moved so that the holding plate 40 and the excavated sediment intake opening 20 coincide with each other. It is positioned at a predetermined rotation position. When the holding plate 40 of the retaining wall support device 38 contacts and retains the retaining wall 54 in this manner, the operator can use a predetermined tool, for example, a drill 5.
5 is used to cut a position corresponding to the protrusion 35 on the retaining wall 54 to form a through hole 56.

When the through holes 56 are formed in the retaining wall 54 corresponding to the respective projecting portions 35, as shown in FIG. 4A, the plurality of shield jacks 22 are rotated without rotating the cutter head 15.
The excavator body 11 is advanced by the reaction force against the existing segment S, and the hydraulic jack 39 is contracted while the holding plate 40 holds the retaining wall 54. Then, as shown in FIG.
The hydraulic jack 39 is further contracted as it contacts the retaining wall 54, and the presser plate 40 is stored in the cutter head 15. At this time, the segments S are assembled by the erector device 33.

Then, as shown in FIG. 5 (a), when the cutter head 15 presses the retaining wall 54 instead of the retaining plate 40, the operator moves the retaining wall support device 38 from within the excavator body 11.
Remove. Here, as shown in FIG. 5B, since the cutter head 15 is not rotated by the turning motor 22, the plurality of shield jacks 29 are extended to extend the existing segment S.
The excavator main body 11 is moved forward by the reaction force against the excavation, whereby the retaining wall 54 is excavated mainly by the cutter bit 19 for excavating the retaining wall, and the starting port 57 is formed. Subsequently, while the cutter head 15 is not rotated, the plurality of shield jacks 29 are extended to move the excavator body 11 forward, so that the ground in front is mainly excavated by the cutter bit 18 for excavating the ground. Then, the excavated earth and sand is taken into the chamber 25 and discharged to the outside from the drain pipe 27 together with the water supply from the pipe 26. On the other hand, the elector device 33 continuously assembles the segments S.

By repeating this operation, a tunnel of a predetermined length is excavated and formed, and the tunnel is communicated with an arrival shaft (not shown).

As described above, in the tunnel excavator of the present embodiment, the shield excavator is loaded into the starting shaft 51,
In response to the reaction force received by the reaction force receiving device 53 and the temporary assembly segment S, the hydraulic jack 39 of the retaining wall support device 38 is extended and the pressing plate 40 is brought into contact with the retaining wall 54 to press the drill 55, and Accordingly, a position corresponding to the protruding portion 35 in the retaining wall 54 is cut to form a through hole 56. Therefore, even if the strength of the retaining wall 54 is reduced due to the formation of the through hole 56, the retaining wall 54 does not fall into the starting shaft 51 because of the support by the holding plate 40, and safety is secured. .

When a through hole 56 is formed in the retaining wall 54 corresponding to the projecting portion 35, the holding plate 40 holds the cutter head 15 together with the excavator main body 11 while keeping the retaining wall 54 pressed.
Is moved forward without rotating to hold the retaining wall 54, and then the retaining wall support device 38 is removed, and then the cutter head 15 is rotated to excavate the retaining wall 54 so that the starting port 57 is formed. Therefore, the cutter head 15 excavates while holding down the earth retaining wall 54, thereby improving work efficiency and securing sufficient safety.

In the above-described embodiment, the hydraulic jack 39 attached to the bulkhead 24 is extended by the retaining wall support device 38 so that the holding plate 40 projects from the excavated sediment intake opening 20 of the cutter head 15. However, the hydraulic jack 39 may be provided on the front surface of the cutter head 15. Further, the operator cuts the position corresponding to the protruding portion 35 on the retaining wall 54 with the drill 55 to form the through hole 56, but another tool may be used, or the drilling machine body 11 may be used.
Or the cutter head 15.

In this embodiment, the present invention is applied to the case where the retaining wall 54 of the starting shaft 51 is excavated. However, when excavating a new tunnel from the existing tunnel, the retaining wall provided in the existing tunnel is excavated. Also applicable to cases.

Further, in the above-described embodiment, the tunnel excavator of the present invention is mounted on the cutter head 15 with the cutter bit 18,
Although the shield excavator equipped with 19 has been described, the present invention can also be applied to a tunnel boring machine provided with a disk cutter. Furthermore, although the tunnel excavator of the present invention has been described as a muddy shield excavator, a mud pressure shielded excavator may be used. In this case, a screw conveyor may be used instead of the water pipe, the drain pipe, and the agitator.

[0034]

As described in detail in the above embodiment, according to the method for excavating a retaining wall according to the first aspect of the present invention, a tunnel excavator is disposed facing a retaining wall in a tunnel,
Protruding the support member from the tunnel excavator and holding down the retaining wall,
In this state, the portion corresponding to the backfill injection portion in the retaining wall is removed by a predetermined tool, so that the retaining member is excavated while the retaining member holds down the retaining wall, and the retaining wall is removed from the tunnel. It is possible to improve the workability and safety by reliably excavating the start port having a predetermined shape when the tunnel excavator starts moving without falling down.

According to the method of excavating a retaining wall according to the second aspect of the invention, after removing a portion of the retaining wall corresponding to the backfilling portion, the tunnel excavator is moved forward while the support member holds down the retaining wall. Support the cutter head by contacting the retaining wall,
After storing the support member in the tunnel excavator, the cutter head was rotated and moved forward to excavate the retaining wall, so the retaining member continued to press the retaining wall and excavated the retaining wall. As a result, work efficiency and safety can be improved.

According to the third aspect of the present invention, the tubular excavator body can be advanced by the propulsion jack, and a drive rotatable cutter head is mounted on the front of the excavator body. An erector device for assembling the lining member in a ring shape along the wall surface of the existing tunnel, a backfill injection portion provided on an outer peripheral portion of the excavator body, and a retaining wall supporting means for pressing a retaining wall provided in the tunnel. Since the retaining wall support means presses the retaining wall, the retaining wall excavates the retaining wall, and the retaining wall does not collapse into the tunnel, and the predetermined shape is reliably formed when the tunnel excavator starts. Excavation of the entrance can improve workability and safety.

According to the tunnel excavator of the fourth aspect of the present invention, since the retaining wall support means is provided detachably with respect to the excavator body, the retaining wall support means is mounted at the start of excavation of the retaining wall, and the excavation ends. By removing it sometimes, the retaining wall support means does not hinder the excavator from excavating earth and sand.

According to the tunnel excavator of the fifth aspect, the retaining wall support means is constituted by the hydraulic jack mounted on the excavator body and the support member projecting forward from the opening of the cutter head by the hydraulic jack. Therefore, the earth retaining wall can be reliably pressed with a simple configuration, and the earth retaining wall can be prevented from collapsing during excavation.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a shield excavator according to one embodiment of the present invention.

FIG. 2 is a front view of the shield excavator.

FIG. 3 is a schematic diagram illustrating an operation of a shield excavator when starting a shaft.

FIG. 4 is a schematic diagram illustrating an operation of the shield excavator when starting a shaft.

FIG. 5 is a schematic view showing an operation of the shield excavator when starting a shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Excavator main body 15 Cutter head 18 Many cutter bits for ground excavation 19 Cutter bits for earth retaining wall excavation 20 Excavation earth and sand intake opening 22 Swing motor 29 Shield jack (propulsion jack) 33 Electa device 34 Backfilling injection device 35 Projecting portion 38 Retaining wall support device 39 Hydraulic jack 40 Holding plate 51 Starting shaft (tunnel) 54 Retaining wall 55 Drill 56 Through hole 57 Starting port

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Mitsunori Tsuda 1-1-1, Wadazakicho, Hyogo-ku, Kobe City, Hyogo Prefecture Inside the Kobe Shipyard of Mitsubishi Heavy Industries, Ltd. (72) Inventor Junji Kawashima 1 Tsukudocho, Shinjuku-ku, Tokyo No. 8 Inside Kumagaya Gumi Tokyo Branch (72) Inventor Shigeki Abe 1-8 Tsukudo-cho, Shinjuku-ku, Tokyo Tokyo (72) Inventor Masao Kajiyama 1-8 Tsukudo-cho, Shinjuku-ku, Tokyo No. F-term in Kumagaya Gumi Tokyo Branch (reference) 2D054 AA05 AC04 AC05 AD19 AD22 BA03 BB02 CA01 EA01 EA07 FA09

Claims (5)

[Claims] 1. A tunnel excavator in which a cutter head is rotatably mounted on a front portion and a backfill injection portion is provided on an outer peripheral portion, wherein the tunnel excavator is arranged to face a retaining wall in the tunnel. And extruding a support member from the tunnel excavator to hold down the retaining wall, and in this state, removing a portion of the retaining wall corresponding to the backfill injection portion with a predetermined tool. . 2. The excavation method for a retaining wall according to claim 1, wherein after removing a portion of the retaining wall corresponding to the backfill injection portion, the tunnel excavator is maintained with the support member pressing the retaining wall. Moving the cutter head in contact with the retaining wall to support the cutter head, storing the supporting member in the tunnel excavator, and then excavating the retaining wall by rotating the cutter head and moving forward. Excavation method of earth retaining wall. 3. A tubular excavator body, a propulsion jack for advancing the excavator body, a cutter head mounted rotatably at the front of the excavator body, and along a wall surface of an existing tunnel. An erector device for assembling the lining member in a ring shape, a backfill injection unit provided on an outer peripheral portion of the excavator body, and a retaining wall supporting means for pressing a retaining wall provided in the tunnel. And tunnel excavator. 4. The tunnel excavator according to claim 3, wherein said retaining wall support means is provided detachably with respect to said excavator body. 5. A tunnel excavator according to claim 4, wherein said retaining wall support means is provided with a hydraulic jack mounted on said excavator body and a support member projecting forward from an opening of said cutter head by said hydraulic jack. A tunnel excavator comprising: