JP2003155895A - Exchange method of cutter bit of excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of inexpensively and safely exchanging a cutter bit of an excavator by coping with needs where a shield tunnel is made a longer distance and deeper. SOLUTION: At first, a ditch 3 is excavated toward an excavation plan route of a shield machine 1 from a ground surface 2a, and backfilled up to the ground surface 2a after an NOMST wall 5 which can be excavated by the shield machine 1 is constructed on the excavation plan route of the shield machine 1 of the ditch 3. Next, at a time point when the shield machine 1 arrives in the neighborhood of the NOMST wall 5, only a front shell part 1a of the shield machine 1 is advanced to excavate a part of the NOMST wall 5. Next, the front shell part 1a is retreated to form a cavity part 6 between the front shell part 1a and the excavated NOMST wall 5. Next, a worker 7 moves from the shield machine to the cavity part 6, exchanges the cutter bit 1b as a working space, and maintains the cutter bit 1b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of exchanging a cutter bit of an excavator for exchanging a cutter bit provided in a cutter head of an excavator such as a shield machine.

[0002]

2. Description of the Related Art In a long-distance shield tunnel construction or the like, it is necessary to replace the cutter bit due to wear of the cutter bit or necessity of excavating various soils. In particular, in recent years, shield tunnel construction has been increasing in which the depth is large in addition to the long distance, and the ground at the large depth is hard, so that the cutter bit is easily worn. Therefore, in shield tunnel construction that requires a long distance and a large depth, it is necessary to exchange many cutter bits in the excavation process. In the conventional construction method, for example, a starting shaft and a reaching shaft formed of concrete wall bodies as shown in JP 2000-64771 A and JP 11-210369 A are constructed as intermediate shafts in the middle of the excavation hole. However, in this intermediate shaft, the cutter bit was replaced and the cutter head was maintained. At this time, in order to prevent the collapse of the ground around the intermediate shaft, it was necessary to improve the ground by a chemical injection method, a freezing method, or the like.

[0003]

However, especially in an urban area, it may be difficult to construct an intermediate shaft due to difficulty in acquiring land and dense surface structures. In addition, the deepening of the excavation holes may make it difficult to improve the ground around the intermediate shaft from the surface. That is, the conventional method is difficult to apply to excavation work in which the depth is deeper in an area where urbanization has advanced. Furthermore, depending on the ground, the effect of ground improvement may not be obtained as expected, and there remains a problem in worker safety.

An object of the present invention is to replace a cutter bit of an excavator, which enables inexpensive and safe replacement of a cutter bit of an excavator in response to needs for a longer distance and a larger depth of a shield tunnel. Is to provide a method.

[0005]

In order to solve the above problems, the invention according to claim 1 provides an excavator (shielding machine 1).
In the method of exchanging the cutter bit, first, the recess (groove 3) is excavated from the ground surface 2a toward the excavation planned route of the excavator (shield machine 1), and then the recess (groove 3) is excavated. A wall part (NOMST wall 5) that can be excavated by the excavator (shield machine 1) on the excavation planned route of the excavator (shield machine 1).
And then backfilling the recess (groove 3), and then when the excavator (shield machine 1) progresses in the vicinity of the wall portion (NOMST wall 5), the excavator ( The wall part (NOMST wall 5) is partially excavated by advancing only the front body part 1a of the shield machine 1), and then the front body part 1a is retracted to partially leave the wall part. (NOMST
A cavity 6 is formed between the wall 5) and the front body 1a, and then the cutter bit is exchanged using the cavity 6.

According to the first aspect of the present invention, the wall portion provided on the excavation planned route of the excavator in the recess and capable of excavating by the excavator advances only the front body portion of the excavator. Part of it will be excavated. After that, the cutter bit is exchanged or maintenance such as the cutter head is performed by utilizing the partially left wall formed by retracting the front body and the cavity between the front body. Be done. At this time, the hollow part is stabilized by earth retaining by the partially left wall part. In addition, since the recess is backfilled after the wall is provided, the ground can be prevented from collapsing and the construction can be performed stably, and the environmental influence on the ground is small.

Therefore, for example, in an urban area or the like, when it is difficult to construct an intermediate shaft due to dense surface structures, or when it is difficult to improve the ground from the surface due to the large depth of the excavation hole, excavation is performed. It becomes possible to easily and safely perform the maintenance of the cutter bit and the exchange of the cutter bit of the machine.

The recesses are, for example, grooves or holes formed in the ground.

The wall portion that can be excavated by the excavator means, for example, a so-called NOMST (Novel Material Shi).
eld-cuttable Tunnel-wall System), but is not particularly limited, it can be excavated by the excavator without entwining with the cutter bit, and by retracting the front body of the excavator, It suffices if the hollow portion is stably formed between the left wall portion and the front body portion.

According to a second aspect of the present invention, in the method of exchanging the cutter bit of the excavator (shielding machine 1) according to the first aspect, the wall portion (NOMST wall 5) is made of limestone coarse aggregate and has high strength. It is characterized in that concrete is reinforced by carbon fiber reinforced plastic (CFRP strand).

According to the second aspect of the present invention, the wall portion is made of high-strength concrete made of coarse limestone aggregate and reinforced with carbon fiber reinforced plastic. The carbon fiber reinforced plastic has a Young's modulus close to that of a reinforcing bar, is excellent in corrosion resistance, has better workability than a reinforcing bar, and is entangled with a cutter bit when excavated by the shield machine 1. do not do. Therefore, it is possible to easily and inexpensively construct the wall portion that is not inferior in performance to the conventional one and that can be excavated by the excavator.

The wall portion is a so-called NOMST (Novel
Material Shield-cuttable Tunnel-wall System) Also called a wall, it is a wall that has been constructed in recent years at the starting point and reaching point of an excavator.

As the carbon fiber reinforced plastic,
CFRP (Carbon Fiber Reinforced Plastic)
There is a strand. This is formed by twisting carbon fibers having a Young's modulus close to that of a reinforcing bar, is excellent in corrosion resistance, and has a property of not being entangled with a cutter bit when excavated by a shield machine.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a method for exchanging a cutter bit of an excavator according to the present invention will be described in detail with reference to FIGS. 1 and 2, reference numeral 1 denotes a shield machine (excavator) according to the present invention. The shield machine 1 is provided with a cutter head 1b by expanding and contracting a cutter head retracting jack (not shown). Only the body portion 1a can be moved forward and backward.

FIG. 1 shows a NOMST (Novel Material Shield-cuttable) constructed on the excavation planned route of the shield machine.
(Tunnel-wall System) A diagram showing a situation in which a wall 5 (wall portion) is being excavated by the shield machine 1. Here, the NOMEST wall 5 is a CFRP (Carbon Fiber Reinforce) in which high-strength concrete using coarse limestone aggregate is twisted with carbon fiber impregnated with resin and cured.
d Plastic) Strands are reinforced. The CFRP strand is a carbon fiber reinforced plastic, has a Young's modulus close to that of rebar, has excellent corrosion resistance, and does not become entangled with the cutter bit when excavated by the shield machine 1.

The NOMEST wall 5 is constructed in a groove 3 excavated from the ground surface 2a toward the excavation planned route of the shield machine 1, and the groove 3 is backfilled with the excavated earth and sand 4.

A method of exchanging the cutter bit of the shield machine 1 will be described below. First, excavation is performed from the ground surface 2a toward the excavation planned route of the shield machine 1 so that the groove 3 that is substantially orthogonal to the excavation planned route is formed. Here, the length and width of the groove 3 depends on the NOMST wall 5 to be constructed.
The length and width that can be buried. In addition, N buried
The vertical and horizontal dimensions of the OMST wall 5 are set to be larger than the diameter of the shield machine 1 by a predetermined dimension so that the shield machine 1 can excavate. The thickness of the NOMST wall 5 is
It is set to have a soil retaining function even in a state where it is partially excavated by the shield machine 1.

Next, a NOM that can be excavated by the shield machine 1 on the planned excavation route of the shield machine 1 in the groove 3.
The ST wall 5 is provided. At this time, the NOMST wall 5 may be formed by suspending CFRP strands assembled in a cage shape in the groove 3 and then pouring high-strength concrete using coarse limestone aggregate on site, or at a factory or the like. In the above, the one formed in advance as described above may be suspended in the groove 3.

Next, the groove 3 is backfilled to the ground surface 2a.
Next, as shown in FIG. 2 (a), when the shield machine 1 reaches the vicinity of the NOMST wall 5, the cutter head retracting jack (not shown) of the shield machine 1 is extended so that only the front body portion 1a is extended. To advance the NOMST
Part of the wall 5 is excavated. At this time, the excavated NOMST wall 5 is discharged to the rear of the shield machine 1 by an unillustrated earth discharging conveyor in the same manner as ordinary earth and sand.

Next, the front body 1a is retracted by contracting the cutter head retracting jack to form a cavity 6 between the front body 1a and the partially left NOMST wall 5. To do. Next, as shown in FIG. 2 (b), the worker 7 moves from the shield machine 1 to the hollow portion 6 and uses the hollow portion 6 as a working space for exchanging the cutter bit or maintaining the cutter head 1b or the like. To go.

After exchanging the cutter bit and finishing the maintenance of the cutter head 1b and the like, the shield machine 1 as a whole is advanced to excavate the partially remaining NOMST wall 5 to continue the shield excavation.

As described above, by forming the groove 3 and burying the NOMST wall 5 at every predetermined distance, it is possible to regularly replace the cutter bit and maintain the cutter head 1b and the like.

According to this embodiment, the following effects can be obtained. The NOMST wall 5 constructed on the excavation planned route of the shield machine 1 in the groove 3 and excavable by the shield machine 1 is partially excavated by advancing only the front trunk portion 1a of the shield machine 1. It Then, the front body 1a
The cutter bit is exchanged or the maintenance of the cutter head 1b and the like is performed by utilizing the partially left NOMST wall 5 formed by retreating the blade and the cavity portion 6 between the front body portion 1a. Or At this time, the hollow portion 6 is stabilized by soil retaining by the partially left NOMST wall 5. Further, the groove 3 is formed in the NOMST wall 5
Since it is backfilled after the construction, the ground 2 can be prevented from collapsing and the construction can be stably performed, and the environmental influence on the ground 2 is small.

Therefore, for example, when it is difficult to construct an intermediate shaft due to the crowding of surface structures in an urban area, or when it is difficult to improve the ground from the surface 2a due to the deepening of the excavation holes, It becomes possible to easily and safely perform replacement of the cutter bit of the shield machine 1 and maintenance of the cutter head 1b and the like.

The NOMST wall 5 is made of carbon fiber made of high strength concrete using coarse limestone aggregate.
This CF is reinforced with RP strands.
The RP strand has a Young's modulus close to that of the reinforcing bar, is excellent in corrosion resistance, has better workability than the reinforcing bar, and when excavated by the shield machine 1,
Does not get tangled with the cutter bit. Therefore, it is possible to easily and inexpensively construct a wall portion that is not inferior in performance to the conventional one and that can be excavated by the shield machine 1.

In the present embodiment, the so-called NOMS is used as the wall that can be excavated by the shield machine 1.
T (Novel Material Shield-cuttable Tunnel-wall Sys
tem) wall is used, but it is not particularly limited and can be excavated by the shield machine 1 without being entangled with the cutter bit, and by retracting the front body part 1a of the shield machine 1, It suffices if the cavity 6 is stably formed between the partially left wall and the front body 1a.

[0027]

According to the invention as set forth in claim 1, for example, in an urban area or the like, when it is difficult to construct an intermediate shaft due to the crowding of surface structures, or when the depth of the drilling hole increases, Even when it is difficult to improve the ground, it becomes possible to easily and safely replace the cutter bit of the excavator and maintain the cutter head.

According to the second aspect of the invention, not only the effect of the first aspect can be obtained, but also the wall portion which is not inferior in performance to the conventional one and which can be excavated by the excavator is provided. Can be built easily and cheaply.

[Brief description of drawings]

[Fig. 1] NO constructed on the excavation planned route of the shield machine
It is a figure which shows the condition which is excavating the MST wall by this shield machine.

FIG. 2 (a) is a diagram showing a situation in which only the front trunk of the shield machine is advanced to excavate the NOMST wall,
(B) is a figure which shows the situation which is exchanging a cutter bit using the hollow part formed between the NOMST wall and a cutter head.

[Explanation of symbols]

1 Shield machine (excavator) 1a front torso 2 ground 2a Ground surface 3 grooves 5 NOMST wall (wall part) 6 cavity

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toru Watanabe             Nishimatsuken 1-20-10 Toranomon, Minato-ku, Tokyo             Inside the corporation (72) Inventor Shigeaki Saito             Nishimatsuken 1-20-10 Toranomon, Minato-ku, Tokyo             Inside the corporation (72) Inventor Masatsugu Sugimura             Nishimatsuken 1-20-10 Toranomon, Minato-ku, Tokyo             Inside the corporation (72) Inventor Takeshi Taguchi             Nishimatsuken 1-20-10 Toranomon, Minato-ku, Tokyo             Inside the corporation F term (reference) 2D054 AA10 AC02 AD02 BB07

Claims (2)

[Claims] 1. A method of exchanging a cutter bit of an excavator, which comprises first excavating a recess from the surface of the earth toward a planned excavation route of the excavator, and then excavating a planned excavation route of the excavator in the recess. A wall part that can be excavated by the excavator is provided on the top, then the recess is backfilled, and then, when the excavator advances to the vicinity of the wall part, the front body part of the excavator Part of the wall is excavated by advancing only one, and then the front body is retracted to form a cavity between the partially left wall and the front body, Next, a method of exchanging a cutter bit of an excavator, characterized in that the cutter bit is exchanged using the cavity. 2. The excavator cutter bit replacement method according to claim 1, wherein the wall portion is made of high-strength concrete made of coarse limestone aggregate reinforced with carbon fiber reinforced plastic. Characteristic excavator cutter bit replacement method.