JP2000257386A - Cutter head, shield machine and method for excavation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutter head which can excavate the ground wherein rocks, conglomerate layers, cohesive soil layers and others appear, without producing an adverse effect on bits other than ones being used, and moreover can reduce the amount of secondary treatment by collecting the soil of the cohesive soil layers and the like as clods in solid states with the skeletal strength of the natural ground maintained. SOLUTION: These cutter head and shield machine have preceding bits 34 in a pair at least which form streak-like preceding excavated grooves in a facing at prescribed intervals, following bits 34 which dig up, in a solid state, the natural ground left to be dug between the preceding excavated grooves formed by the preceding bits 34, and cut them, and roller bits 44 for excavating the natural ground of rocks, conglomerates, etc. The preceding bits 34 and the roller bits 44, at least, are driven to move forward and backward longitudinally according to the conditions of the natural ground to be excavated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutter head, a shield machine and an excavation method, and more particularly to a cutter head suitable for excavation of rocks, gravel layers, clay soil layers, and the like, and capable of collecting excavated soil as solids. The present invention relates to a shield machine and an excavation method.

[0002]

2. Description of the Related Art Generally, in tunnel excavation using a shield machine, a cutter head is rotated to excavate a face, and a bit corresponding to the soil characteristics of the face is provided on the cutter head. Is to be attached.

For example, a soft bit such as a cohesive soil is excavated by attaching a cutter bit having a cutting blade, and a soil bit such as rock or gravel is excavated by attaching a roller bit for crushing. Like that.

In the case where different types of soils such as a viscous soil layer, rocks and gravel layers appear in one excavation section, both a cutter bit for cutting and a roller bit for crushing are previously provided. It is installed on one cutter head for excavation.

However, if a cutter bit and a roller bit are attached to one cutter head in advance in this way, the roller bit is digged in when the clay bit is excavated by the cutter bit, so that the cutting resistance increases and the excavation proceeds. The roller bit may not be able to rotate due to the adhesion of the clay, and the cutter bit may be damaged or damaged by the impact of the rock or gravel when excavating the rock or gravel layer with the roller bit. There is a problem that they are generated or worn by rocks, gravel or the like.

In recent years, laws and regulations regarding the handling of industrial waste have become strict, and in particular, "sludge"
A great deal of labor and cost is required for the treatment of the excavated residual soil generated as a result, and the place where the waste is disposed is limited.

[0007] Accordingly, as for the excavated soil generated due to shield excavation, the amount of solid-liquid separation by the primary treatment using a vibrating sieve or the like is increased as much as possible, and the "sludge" generated in the secondary treatment is reduced. Is an important issue.

[0008] In particular, technological development is being carried out in various fields with respect to a method of excavating and treating a viscous soil layer containing fine particles (particle diameter of 74 μm or less).

[0009] On the other hand, when coarse-grained soil such as a sand layer or a gravel layer is to be excavated, solid-liquid separation can be easily performed using a vibrating sieve. The same handling as gravel is possible.

Therefore, in the present invention, when excavating a cohesive soil layer, particularly a cohesive soil layer having a certain skeletal strength, the solid state in which the skeletal strength in the ground state is maintained is maintained. It is cut (hereinafter, referred to as “cutting excavation”) as a block of earth,
It is intended to greatly reduce the amount of subsequent processing.

Further, the present invention provides a method for properly setting a cutter bit according to the ground characteristics even in a ground condition in which a rock or a gravel layer and a cohesive soil layer appear alternately or in a ground condition in which these layers are alternated. An object of the present invention is to provide a cutter head, a shield excavator, and an excavation method that enable selection and solve the above-described problems.

[0012]

In order to achieve the above object, a cutter head according to the present invention comprises at least a pair of leading bits for forming streak-like leading digging grooves on a face at predetermined intervals;
A trailing bit that digs up and cuts the remaining ground between the preceding digging trenches formed by the preceding bit in a solid state, and a roller bit for digging the ground such as rocks and gravel, and at least the The leading bit and the roller bit are driven forward and backward in the direction of excavation according to the condition of the ground to be excavated.

According to the present invention, at the time of excavating the ground such as rocks and gravel, at least the leading bit is retracted from the front surface of the cutter head, and the roller bit is projected from the front surface of the cutter head. The rock bit, gravels, etc. can be reliably crushed by the roller bit while protecting the relatively fragile preceding bits from rocks, gravel, etc., and the preceding bits are prevented from being damaged, chipped, or worn. Can be.

When excavating ground such as clayey soil,
The roller bit is retracted from the front surface of the cutter head, and the leading bit is made to protrude from the front surface of the cutter head, so that the excavation by the leading bit and the trailing bit can be reliably performed while the roller bit is protected, and In addition, it is possible to prevent the roller bit from sinking into the ground to increase the cutting resistance, thereby hindering digging, and preventing rotation due to adhesion of clay.

Further, a streak-shaped leading excavation groove at a predetermined interval is formed on the face of the cohesive soil or the like by a preceding bit, and the remaining ground excavated between the preceding excavation grooves is skeletal strength in the ground state by a following bit. It can be cut out and excavated as a solid mass of soil that retains its height, and carried out of the tunnel pit.
The amount of subsequent processing can be greatly reduced.

In the present invention, a plurality of preceding bits for forming the plurality of preceding excavation grooves are arranged, and a plurality of succeeding bits for cutting out and excavating the remaining ground between the plurality of preceding excavation grooves are provided. Preferably, they are arranged.

By providing a plurality of leading bits and trailing bits in this way, the entire face can be efficiently excavated, and even when excavating a large-diameter shield tunnel, the ground can be cut out and excavated in a solid state. .

In this case, the plurality of trailing bits include a trailing bit for forward excavation and a trailing bit for reverse drilling, and the trailing bit for forward drilling and the trailing bit for reverse drilling are provided. It is preferable that the row bits can be driven forward and backward respectively.

In this way, during forward rotation or reverse rotation, excavation can be performed with only one trailing bit protruding from the front surface of the cutter head and the other retracted from the front surface of the cutter head. And at the same time,
The durability of the following bit can be improved.

In particular, when controlling the position and attitude of the shield machine, the cutter head may be rotated forward and backward, and such a case can be dealt with.

Further, when the roller bit is used, both trailing bits can be retracted, so that the trailing bit can be prevented from being damaged, lost, worn, etc., and the durability can be improved.

In the present invention, the roller bit is
It is preferable that a plurality of roller bits are provided and each roller bit can be individually driven forward and backward.

By doing so, for example, when the cutting faces are in alternating layers, by independently controlling the roller bits to advance and retreat, rocks, gravel, etc. can be reliably crushed and the function of the roller bits is impaired. Or hindrance to excavation can be reliably prevented.

By providing a plurality of roller bits, it is possible to arrange the bits so that the entire section to be excavated can be excavated with only the roller bits.

Further, in the present invention, it is preferable that the plurality of preceding bits are constituted by a plurality of preceding bit groups, and that each of the preceding bit groups can be integrally driven.

In this case, it is preferable that a plurality of preceding bits having different trajectories generated by the rotation of the cutter head are integrally formed as a preceding bit group.

As described above, by driving the plurality of leading bit groups forward and backward, for example, when the cutting faces are in the alternate layer state, the leading excavation groove is reliably formed at the ground position where the cohesive soil layer appears. In addition, it is possible to reliably prevent breakage, loss, abrasion, and the like of the preceding bit group at the ground position such as rocks and gravel.

Further, since the advance / retreat driving is performed for each preceding bit group, the space for the driving means can be reduced, and more various bits can be mounted within the limited space.

The shield machine according to the present invention includes any one of the cutter heads described above, a forward exploring means for exploring the soil in front of the face, and an advance / retreat of the preceding bit and the roller bit based on the exploration result by the forward exploring means. Control means for performing drive control.

According to the present invention, the soil in front of the face is searched by the front searching means, and the control means controls the advance / retreat driving of the preceding bit and the roller bit based on the result, thereby excavating according to the situation of the face. Can be performed reliably.

In particular, even in a face in an alternate layer, excavation according to the face condition can be easily performed by using a roller bit in a rock or gravel layer portion and using a preceding bit in a cohesive soil layer.

[0032] The excavation method of the present invention is a method of excavating a rock, a gravel layer, a cohesive soil layer, or the like, in which a soil layer configuration is changed by rotation of a cutter head having at least a pair of a leading bit, a trailing bit, and a roller bit. An excavation method for digging while cutting a mountain and constructing a tunnel, wherein the rock and the gravel layer are excavated, the preceding bit is retracted from the front of the cutter head, and the roller bit is moved to the front of the cutter head. A step of crushing rocks, gravel, etc. by the roller bit, and during the excavation of the cohesive soil layer, the roller bit is retracted from the front of the cutter head, and the preceding bit is projected from the front of the cutter head. A preceding excavation groove forming step of forming streak-like excavation grooves at substantially equal intervals in the ground by at least a pair of the preceding bits; Accordingly, dig digging remaining natural ground between the preceding excavation, characterized in that it comprises a cut-out excavation process, the drilling cut as drilling soil holding the solid state.

According to the present invention, when excavating rocks, gravel, etc., the rocks, gravel, etc., are crushed by the roller bit while the relatively easily damaged preceding bits are protected from the rocks, gravel, etc. And the leading bit is damaged,
Loss or wear can be prevented.

When excavating ground such as clayey soil,
Excavation by the leading bit and the following bit can be performed reliably while the roller bit is protected, and the roller bit sinks into the ground, increasing the cutting resistance, hindering the excavation, and causing adhesion of clay. It is possible to prevent the rotation from becoming impossible.

Further, the face of soil such as cohesive soil can be cut out as a solid mass of soil having a skeletal strength in the ground state, excavated and carried out of the tunnel pit, and the secondary throughput of excavated earth and sand can be reduced. The weight can be significantly reduced.

In the present invention, the step of exploring the soil in front of the face by the front exploring means provided on the cutter head, and the step of exchanging the preceding bit and the roller bit with the rock, gravel layer and And a step of driving forward and backward according to the viscous soil layer.

By doing so, excavation according to the condition of the face can be reliably performed.

Further, in the present invention, the step of driving the preceding bit and the roller bit forward and backward in accordance with the rock, the gravel layer and the cohesive soil layer is performed during one rotation of the cutter head in the alternate layer section. Is preferred.

In this way, while the cutter head makes one rotation in the alternate layer section, a roller bit is used in a rock or gravel layer portion, and a preceding bit is used in a cohesive soil layer. Excavation can be performed accordingly.

[0040]

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

FIGS. 1 to 9 show a muddy shield excavator according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a muddy type shield machine. The shield machine 10 is a bent type for curved construction, and includes a front body 12 and a rear body. The part 14 and the center bendable jack 16 can be bent.

A chamber 22 is defined on the front end side of the front body 12 by the partition wall 18 and the cutter head 20, and muddy water is supplied from the mud pipe 21 into the chamber 22 to stabilize the cutting face 24. By rotating the cutter head 20, the ground is excavated and the mud used for stabilizing the face 24 is stirred and mixed with the excavated earth and sand in the chamber 22 and discharged to the ground via the mud drain pipe 23. It has become.

The cutter head 20 is provided with a drive motor 2
6 is driven to rotate.

Further, a shield jack 28 and an erector 30 are disposed on the rear body portion 14, and the shield jack 28 advances by a predetermined distance, for example, a distance of one ring of the segment 32 as the cutter head 20 is excavated. The segment 32 is assembled by the erector 30, and the assembled segment 32 is subjected to a reaction force to construct a tunnel while being advanced by the shield jack 28.

FIG. 1 is a front view showing the cutter head 20 of the shield machine 10.

This cutter head 20 has a leading bit 3
4. Cutter bits for cutting various face attached to spokes (not shown) such as trailing bit 36, outermost bit 38, center bit 40, copy cutter 42 shown in FIG. 2, and rollers for crushing face And a bit 44 is provided,
Excavation of the ground where rocks, gravel layers, clayey layers, etc. appear.

A plurality of, for example, nine leading bits 34 are arranged on a line passing through the center of the cutter head 20, and FIG.
As shown in FIG. 5, the leading excavation groove 46 having a streak shape is formed on the face 24 at predetermined intervals.

The plurality of leading bits 34 are a leading bit group 35a including five leading bits 34 located above center bit 40 in FIG. 1 and a leading bit group including four leading bits 34 located below. Group 35b
It is composed of

The preceding bit groups 35a and 35b are arranged at least every other row so that the preceding bits 34 do not form adjacent preceding excavation grooves 46 at the same time, and have a predetermined shape without impairing the skeletal strength of the ground 52. Is formed.

In the conventional method, the leading bits protrude from the cutter head with substantially the same amount to form leading digging grooves adjacent to each other. In this method, however, the leading bits give the ground given when cutting the ground. Due to the disturbance to the mountains, the skeletal strength in the mountainous state cannot be maintained, and it is difficult to cut and excavate as solid excavated soil.

In this embodiment, in order to suppress such an adverse effect when the preceding bit is interactively formed in the preceding digging groove, the phase angle corresponding to the position of the preceding bit 34 in accordance with the rotation of the cutter head 20 in the present embodiment. By utilizing the occurrence of the deviation, the arrangement of the preceding bit 34 is adopted so that adjacent preceding excavation grooves 46 are not cut at the same time.

That is, at least one leading bit 34 arranged on the same line segment (cross section from the center of rotation of the cutter head 20 to one point on the circumference) having a phase angle generated by the rotation of the cutter head 20 is provided. Adjacent excavation ditch 4
6 is arranged so as to form the preceding excavation groove 34 at the position.

That is, the preceding bits 34 forming the adjacent preceding excavation grooves 46 are arranged on the cutter head 20 so that the preceding bits 34 have different phase angles as the cutter head 20 rotates.

By arranging the preceding bit 34 in the cutter head 20 in this manner, it is possible to cut and excavate as solid excavated soil in a solid state without impairing the skeletal strength of the ground when the preceding excavation groove 46 is formed.

More specifically, each leading bit 34 can form a plurality of streak-like leading digging grooves 46 on the face 24 along a equally-spaced circular trajectory shown by a wavy line in FIG.

The preceding bit groups 35a, 35b
As shown in FIG. 3, each preceding bit 34 is attached to a mounting pedestal 48, and by driving this mounting pedestal 48 with a leading bit jack 50, each preceding bit group 35a, 35b is individually moved in the front-rear direction. It is possible to go back and forth.

Note that the leading bit 34 is
0 forward direction (arrow C direction in FIG. 1) and reverse direction (FIG.
(In the direction of arrow D in FIG. 3), the cutting blade 24 can be cut in both forward and reverse directions.

As shown in FIGS. 6 (B) and 6 (C), the trailing bit 36 is formed of a plurality of undigged grounds 52 between the preceding digging grooves 46 formed at predetermined intervals and formed by the plurality of preceding bits 34. Is cut and excavated as a solid block of solid state having a cuboid shape, preferably a shape close to a cubic shape, which retains the skeletal strength of the ground pile 52, and a plurality of such blocks are arranged corresponding to the trajectories of the preceding bits 34. .

The succeeding bit 36 indicates that the cutter head 20
Has a blade for cutting only in one of the rotation directions of the above, and has a blade for normal rotation excavation in which the blade is oriented in one of the forward bit groups 35a and 35b in the normal rotation direction (the direction of arrow C in FIG. 1). Subsequent bit group 54a, 54b having subsequent bit 36a
And a following bit group 56a, 5b having a reverse bit 36b for reverse excavation arranged with the blade facing in the reverse direction (direction of arrow D in FIG. 1) on the other side of the preceding bit groups 35a, 35b.
6b.

Each of the following bit groups 54a, 54b, 56a,
56b are arranged alternately so that the trailing bits 37a, 37b do not simultaneously excavate the ground 52 between the adjacent preceding excavation grooves 46, and are alternately arranged.
Excavation of the ground 52 between 6 and the leading excavation groove 4 at the outermost peripheral position
The ground 52 between all the preceding excavation trenches 46 can be excavated, leaving the ground 52 between six.

The following bit groups 54a, 54
The following bits 37a, 37b of b, 56a, 56b are
As shown in FIG. 4, each of the following bit groups 54a, 54b, 56 is attached to the mounting base 58, and the mounting base 58 is driven by the following bit jack 60.
a and 56b can be individually moved forward and backward.

The main bit in a normal shield machine can be used as the one that functions as the following bit 36.

The outermost peripheral bit 38 is used as a part of the following bit 36, and is attached to the mounting base 58 at four outermost peripheral positions of the cutter head 20, respectively.
Each of the following bit groups 54a, 54b, 56a, 56b can be driven forward and backward.

The outermost bits 38 are the following bits 37
Similar to a and 37b, it has a cutting blade on one side only, and is arranged in the same blade direction as the following bits 37a and 37b on each mounting base 58.

Then, the outermost bit 38 is larger than the excavation width of the trailing bit 36 by the outermost bit 38 so that the ground 52 between the preceding excavation groove 46 at the outermost position and the ground outside thereof are excavated. Excavation width is made large.

The ground 52 between the preceding excavation grooves 46 at the outermost position, which has been cut by the outermost bit 38, is recovered as a solid state solid mass maintaining the skeletal strength of the ground 52. ing.

The center bit 40 is
The leading bit 34 and the following bit 37a, 3
A plurality of facers 24 which are not excavated by 7b are arranged in a row so as to be able to excavate the front surface of the central part.

The outermost center bit 40 of the center bits 40 also plays the role of the innermost preceding bit of the innermost preceding bit 34, and is located at the innermost side. Trailing bit 37
a and 37b are a leading excavation groove 46 formed by the innermost preceding bit 34 and a center bit 40 located at the outermost position.
The excavated portion 52 formed between the excavated portion and the excavated portion is excavated as a solid state solid mass that maintains the skeletal strength of the excavated portion.

The copy cutter 42, as shown in FIG.
Attached to the back side of the preceding bit groups 35a, 35b,
The copy cutter jack 62 enables the cutter head 20 to protrude outward from the cutter head 20, so that extra cutting can be performed during curve construction.

As described above, by attaching the copy cutter 42 to the rear side of the preceding bit groups 35a and 35b, it is possible to attach a large number of bits to the front of the cutter head 20.

The roller bit 44 is, as shown in FIG.
A plurality of, for example, six pieces are attached around various cutter bits so as to be able to cope with the face 24 such as rocks and gravel.

The roller bit 44 is used for the face 2
4, not only the ones that are mounted facing the front, but also those that are mounted diagonally outward,
Excavation is also possible in the gravel layer.

Further, as shown in FIG. 5, each roller bit 44 is mounted on a mounting seat 66 of a cylindrical pedestal 64, and this pedestal 64 is formed in a cylindrical outer case 68 integrated with the cutter head 20. Inner case 70 provided integrally with
It is slidably mounted within.

A seal 72 is provided between the inner case 70 and the pedestal 64 at the front and rear positions in the axial direction, and a two-system oil passage 74 is provided between the seals 72.
hydraulic chambers 76a and 76b connected to the hydraulic chambers a and 74b are provided. By supplying pressure oil to the hydraulic chambers 76a and 76b, the roller bits 44 together with the pedestal 64 are driven forward and backward so as to be able to protrude and retract from the outer case 68. Has been enabled.

In this way, the roller bit 44 is
The roller bit 4
Compared to the case where the 4 is retracted by itself, strength and rigidity can be easily secured, and a durable retracting structure capable of withstanding a high load can be obtained. In addition, by using a hydraulic drive, small size and high output can be achieved. It is possible.

Further, in addition to the various bits described above, the cutter head 20 has a transmission radar 78a and a reception radar 78 which constitute a forward search means 78 for searching for soil in front of the face 24 as shown in FIG. 78b is arranged on the outer periphery,
The advance / retreat driving of the preceding bit 34, the roller bit 44, and the like is controlled based on the search result by the front search means 78.

As the forward search means 78, for example,
Known underground radar devices can be used.

Next, a method of excavating using the shield machine 10 will be described with reference to FIG.

First, for example, a high-frequency pulsed radio wave is transmitted from the transmission antenna 78a of the forward search means 78 toward the front of the face 24 while rotating the cutter head 20.
The surface propagation wave and the reflected wave are received by the receiving antenna 78b.

Based on the propagation time and attenuation of the surface propagating wave received by the receiving antenna 78b, the soil, for example, the type and the water content in front of the face 24 are determined, and the soil data is stored in the storage unit 80.

Further, an obstacle ahead of the face is detected by the reflected wave.

In parallel with the search ahead of the face 24 by the front search means 78, the rotation angle detection unit 82 detects the rotation angle of the cutter head 20 corresponding to the search position, and stores the rotation angle data in the storage unit 80. Remember.

When the cutter head 20 makes one rotation in this way, the soil quality at the outer peripheral position of the face 24 is detected, and accordingly, whether the soil quality of the entire face 24 is a rock, a gravel layer, a cohesive soil layer, or the like. Are determined to be in an alternate layer state in which are mixed.

When the cutter head 20 starts the next rotation, the control unit 84 reads the soil data and the rotation angle data from the storage unit 80, and controls the leading bit driving unit 83, the roller bit driving unit 85, etc. based on the search result. Then, the leading bit 34 and the roller bit 44 are driven forward and backward according to the soil.

That is, when the result of the search is a face 24 consisting only of a rock and a gravel layer, the leading bit group 35a, 3
5b is retracted so as not to protrude from the front surface of the cutter head 20, and the oil pressure in the hydraulic chambers 76a and 76b formed in the inner case 70 of each roller bit 44 is adjusted to move the roller bit 44 together with the pedestal 64 from the outer case 68. It is in a state of being projected forward.

In this case, the trailing bit jacks 60 can also retract the trailing bit groups 54a, 54b, 56a, 56b from the front surface of the cutter head 20 so that the trailing bit 36 is not used. .

In this state, the roller bit 44 is
By rotating the cutter head 20 against
You can excavate while crushing rocks and gravel layers.

In this case, the crushed rock, gravels and the like can be easily separated into solid and liquid by a vibrating sieve, and the secondary treatment can be omitted.

When the roller bit 44 excavates, the leading bit 34 and the trailing bit 36 are retracted from the roller bit 44. Without
The durability will be improved.

Next, when the result of the search is a face 24 of a relatively hard clay layer, the roller bit 44 is retracted together with the pedestal 64 into the outer case 68 by hydraulic pressure, and the outer case 68 is retracted.
And the leading bit jack 5
0 causes the leading bit groups 35a and 35b to be
0 protrudes forward from the front surface.

The trailing bit 36 indicates that the cutter head 2
The following bit 3 for forward excavation corresponding to the rotation direction of 0
7a or a subsequent bit group 56a having a backward bit 37b for reverse drilling,
One of 56b is advanced by the trailing bit jack 60 and is projected from the front surface of the cutter head 20.

In this state, while the cutter head 20 is being rotated, the cutting face 24 made of a viscous soil layer is excavated by using the preceding bit groups 35a and 35b and the following bit groups 54a and 54b or 56a and 56b.

In this case, a plurality of streak-like leading excavation grooves 46 are cut at substantially equal intervals on the surface of the face 24 by the leading bit groups 35a and 35b.
b, the remaining ground 52 between the preceding excavation grooves 46 that has not been cut by the b bits 54a, 54b or 5
6a and 56b cut and excavate as a solid state mass of soil that retains the skeletal strength of the ground 52.

By performing such excavation, the excavated material cut out and excavated in the solid state is carried out of the mine as it is without being dissolved in the muddy water during transportation of the fluid (muddy water), and excavated sediment. Can be easily solid-liquid separated in the first treatment as a solid state mass, and the amount of the second treatment can be greatly reduced.

By recovering the excavated earth and sand in a solid state in this way, for example, the N value in the standard penetration test is 10
At a rate of about 10 to 80% from the above soil face 24,
It can be recovered as a solid mass of solid which retains the skeletal strength of the ground 52 that does not require secondary treatment.

Thus, it is possible to reduce the area of the shaft site including the secondary processing equipment, and to reduce the influence on the environment and the processing cost.

In this excavation, the following bit 3
6 is the following bit group 54a, 54b or 56a, 56
Since only one of the following bits b is used, when the following bit 36 used is worn or when the position of the shield
In the case of controlling the attitude, the excavation can be continued without changing the trailing bit 36 by rotating the cutter head 20 in the reverse direction.

Further, the roller bit 44 is attached to the outer case 6
Since the roller bit 44 is stored in the roller 8, it is possible to prevent the roller bit 44 from digging into the ground and increasing the cutting resistance to hinder the excavation or prevent the roller bit 44 from rotating due to the adhesion of clay. Can be.

When the face 24 is made of a soft clay soil layer, only the trailing bit 36 is projected from the front surface of the cutter head 20, and the leading bit 34 is excavated in a state of being retracted from the front surface of the cutter head 20. be able to.

Next, as shown in FIG. 8, when the exploration result shows an alternate layer consisting of the upper clay layer 86 and the lower rock and gravel layer 88, the cutter head 20 is rotated once. In the meantime, in the rotation range A corresponding to the clay layer 86, the leading bit 34 and the trailing bit 36 are advanced and the roller bit 44 is retracted to perform excavation, and the cutter head 20 corresponding to the rock and gravel layer 88 is excavated. In the rotation range B, the leading bit 34 and the trailing bit 36 are retracted, and the roller bit 44 is moved forward to perform excavation.
The system is designed to cope with alternating layers and to collect solids from excavated earth and sand.

Further, as shown in FIG.
Upper layer soft clay layer 86a and middle layer rock and gravel layer 88
When the cutter head 20 makes one rotation, the rotation of the cutter head 20 corresponding to the upper soft clay layer 86a is performed when the cutter head 20 makes one rotation. In the range A1, the leading bit 34 and the roller bit 44 are retracted, and only the trailing bit 36 is advanced to perform excavation. In the rotation range B of the cutter head 20 corresponding to the intermediate rock and the gravel layer 88, the leading bit 34 and the roller bit 44 are moved forward. The bit 34 and the following bit 36 are retracted, and the roller bit 44
The excavation is carried out by moving
In the rotation range A2 corresponding to 6b, the leading bit 34
The excavation is controlled by moving the trailing bit 36 forward and retreating the roller bit 44 to cope with the three-layer alternating state and to collect the excavated soil.

When the layer is thin like the upper soft clay layer 86a, the following bit groups 54a, 54b, 56
Preferably, a and 56b are divided in the radial direction to control the forward and backward driving individually.

The present invention is not limited to the above embodiment, but can be modified into various forms within the scope of the present invention.

For example, in the above embodiment, nine leading bits are provided, but at least one pair is sufficient.

The application of the present invention is not limited to the muddy shield method, but may be applied to, for example, an excavation method using muddy water in an underground continuous wall method, a reverse method, or the like.

Further, as the cutter head, it is effective to apply the present invention not only to the disk-shaped cutter head described above but also to a drum cutter used for a shield excavator having a rectangular cross section.

[Brief description of the drawings]

FIG. 1 is an enlarged front view showing a cutter head of the muddy shield excavator shown in FIG. 2;

FIG. 2 is a schematic sectional view of a shield machine according to one embodiment of the present invention.

FIG. 3 is an enlarged sectional view showing a mounting state of a preceding bit.

FIG. 4 is an enlarged sectional view showing a mounting state of a succeeding bit.

FIG. 5 is an enlarged sectional view showing a mounted state of a roller bit.

FIG. 6 is a schematic plan view showing a ground excavation state due to advance and retreat of a leading bit and a following bit, and FIGS. 6A to 6C show the ground excavation state of a leading bit and a following bit. FIG.

FIG. 7 is a functional block diagram showing a control state of forward search means and a preceding bit and a roller bit.

FIG. 8 is an explanatory diagram showing excavation control of a face in a two-layer alternating state.

FIG. 9 is an explanatory diagram showing excavation control of a face in a three-layer alternating state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Shield machine 20 Cutter head 24 Face 34 Leading bit 35a, 35b Leading bit group 36 Trailing bit 37a Trailing bit for forward drilling 37b Trailing bit for reverse drilling 44 Roller bit 46 Prior drilling groove 52 Excavation remains Tajiki 54a, 54b, 56a, 56b Trailing bit group 64 Pedestal 78 Forward exploration means 84 Control unit 86 Cohesive soil layer 88 Rock, gravel layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kounosuke Nakamura 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Ken Construction Co., Ltd. (72) Yoshio Iwai 1-1-7-1 Kyobashi, Chuo-ku, Tokyo Toda (72) Inventor Yasuhiko Asai 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda-ken Incorporated Corporation (72) Inventor Yoshiharu Shimizu 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Ken (72) Inventor: Ei Yoshida, 1-7-1, Kyobashi, Chuo-ku, Tokyo Toda Kensetsu Construction Co., Ltd. (72) Inventor: Norio Mitani 2-3-6, Akasaka, Minato-ku, Tokyo Komatsu Ltd (72) Inventor Mitsuyuki Iwakiri 2-3-6 Akasaka, Minato-ku, Tokyo F-term in Komatsu Ltd. (reference) 2D054 BA04 BA06 BA07 BB04

Claims (9)

[Claims] At least one pair of leading bits forming streak-shaped leading excavation grooves at predetermined intervals on a face, and the remaining ground between the leading excavation grooves formed by the preceding bits is excavated in a solid state and cut. It has a trailing bit and a roller bit for excavating the ground such as rocks and gravel, and at least the preceding bit and the roller bit are driven forward and backward in the excavation direction according to the situation of the ground to be excavated. A cutter head characterized in that: 2. The plurality of trailing bits according to claim 1, wherein a plurality of leading bits for forming the plurality of leading digging grooves are arranged, and the remaining ground between the plurality of leading digging grooves is cut out and drilled. A cutter head in which bits are arranged. 3. The method according to claim 2, wherein the plurality of trailing bits include a trailing bit for forward excavation;
And a trailing bit for reverse excavation, wherein the trailing bit for forward excavation and the trailing bit for reverse drilling are each capable of being driven forward and backward. 4. The cutter head according to claim 1, wherein a plurality of the roller bits are provided, and each of the roller bits is individually drivable. 5. The plurality of preceding bits according to claim 2, wherein the plurality of preceding bits are constituted by a plurality of preceding bit groups, and each of the preceding bit groups is integrally driven forward and backward. A cutter head characterized by the following. 6. A cutter head according to any one of claims 1 to 5, a forward exploring means for exploring soil in front of a face, and a forward / backward drive control of the preceding bit and the roller bit based on a result of the exploration by the forward exploring means. And a control unit for performing the operation. 7. The excavation ground whose rock layer structure such as rock, gravel layer and cohesive soil layer is changed by rotation of a cutter head having at least one pair of leading bit, trailing bit and roller bit. Digging, a digging method for constructing a tunnel, wherein the rock, at the time of excavating a gravel layer, the preceding bit is retracted from the front of the cutter head, and the roller bit is projected from the front of the cutter head, A step of crushing rocks, gravel, etc. by a roller bit, during the excavation of the viscous soil layer, the roller bit is retracted from the front of the cutter head, and the preceding bit is projected from the front of the cutter head, and at least one pair of the A preceding excavation groove forming step of forming streak-like excavation grooves at substantially equal intervals in the ground by the preceding bit, and the preceding bit by the following bit An excavation method, comprising: excavating the remaining ground between excavation trenches, excavating and excavating as excavated earth and sand in a solid state. 8. The method according to claim 7, further comprising the steps of: exploring soil in front of the face by a front exploring means provided on the cutter head; and estimating the leading bit and the roller bit based on a result of the exploration by the front exploring means. A step of driving forward and backward according to the layer and the clay soil layer. 9. The method according to claim 8, wherein the step of driving the leading bit and the roller bit forward and backward according to the rock, the gravel layer and the clay layer is performed during one rotation of the cutter head in the alternate layer section. A drilling method characterized by the following.