JP2002038871A - Tunnel boring machine and tunnel boring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tunnel boring machine and a tunnel boring method, enabling a reliable boring operation by preventing the sliding section of a double-cylindrical structure from being clogged with sediment. SOLUTION: In the tunnel boring machine, the intermediate barrel shield 2 of a shield body 4 has the double-cylindrical structure composed of an inner shield 2A and an outer shield 2B, which are mutually slidable, and the shields 2A and 2B are slid for the purpose of excavating a natural ground with a cutter head 5 while expanding/contracting the shield body 4. The sediment is drawn in with water through a suction port 44 from a space P in the vicinity of the sliding section of the shields 2A and 2B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel excavation machine and a tunnel excavation method for performing so-called excavation.

[0002]

2. Description of the Related Art Conventionally, there is a shield machine as a tunnel machine for a soft soil layer. The shield excavator includes a shield body, a cutter rotatably supported on the front side of the shield body in the excavation direction, and a cutter for excavating the ground, a cutter driving device for rotating and driving the cutter, and a rotation of the cutter driving device. A rotation transmission mechanism for transmitting the rotation to the cutter. During excavation, the cutter is rotationally driven by the driving force of the cutter driving device, and the ground is excavated by a cutter bit provided on the cutter. At this time, the segments are sequentially assembled by the erector provided at the rear part of the shield main body, and the existing segment is used as a reaction force receiver of the shield jack arranged annularly at the rear part of the shield main body to extend the shield jack. As a result, a propulsive force is applied to the cutter during excavation. And when the soft soil layer is targeted for excavation, the rotational reaction force of the cutter is small,
It can be countered only by the segment reaction force by the shield jack.

However, when such a shield machine is to be used for hard rock in a so-called mountain tunnel or the like,
Since the excavation target is hard rock, the rotary reaction force of the cutter becomes large, and cannot be countered only by the segment reaction force by the shield jack, and therefore cannot be applied to hard rock excavation as it is.

On the other hand, as a tunnel excavator for hard rock,
Conventionally, there is a tunnel boring machine (TBM). This tunnel boring machine is a cutter that is rotatably supported in the forward direction of the excavation direction and excavates the ground, a cutter driving device that rotationally drives the cutter, a rotation transmission mechanism that transmits the rotation of the cutter driving device to the cutter, And a conveyor for sending excavated earth and sand backward. At the time of excavation, similarly to the shield excavator, the cutter is rotationally driven by the driving force of the cutter driving device, and the ground is excavated by the cutter bit provided on the cutter. And grippers and support legs are provided so as to protrude radially from the cutter and the rotation transmitting mechanism, and the rock is gripped by these to oppose the cutter rotation reaction force. In addition, by operating the gripper and the support leg, the direction of excavation can be changed to make a turn.

However, when such a tunnel boring machine is used for a soft soil layer, if spring water is generated, the whole machine may be submerged or the gripper and the support leg may be buried in the pit wall. Therefore, it cannot be applied to soft soil layers as it is.

As described above, the conventional tunnel machine is
It is necessary to use different types of excavator for soft soil layer and for hard rock excavation, and if the soil layer changes during construction, the work efficiency in construction will be reduced and excavation must be stopped It was not possible.

[0007] To solve this, for example,
As described in JP-B-62-32319, the shield body has a three-part structure including a front body, a middle body, and a rear body, and a double body including an inner cylinder and an outer cylinder that can slide the middle body with each other. There has been proposed a tunnel excavator in which a shield body (more specifically, a middle body) can be extended and contracted by making the inner cylinder and the outer cylinder reciprocate while sliding the inner cylinder and the outer cylinder.

In this tunnel excavator, when excavating a soft soil layer, it is used in the same manner as a conventional shield excavator, and an existing segment is used as a reaction force receiver of a shield jack provided on a rear body to provide a propulsive force to a cutter. I do. Thereby, even when springing in the tunnel, the submersion of the entire machine can be prevented by the watertight structure of the segments and the shield body.

When excavating a hard rock layer, it is used similarly to a conventional tunnel boring machine. That is, the gripper (main gripper or rear gripper) provided on the rear trunk is extended in the radial direction to grip the rock and take the cutter rotation reaction force, and the thrust jack connecting the inner cylinder of the rear trunk and the middle trunk is extended in the axial direction. While propelling the front and middle barrels forward,
Excavate with a cutter. In addition, by operating the main gripper and the front gripper separately provided on the front body and appropriately taking a reaction force, it is possible to easily change the excavation direction and turn.

As described above, in the above-described conventional tunnel machine, excavation can be performed on any soil layer regardless of the excavation target.

[0011]

However, the above-mentioned prior art has the following problems.

That is, as described above, when excavating a hard rock layer, excavation is carried out with a cutter while holding the bedrock with the main gripper of the rear body and pushing the front body and the inner body cylinder forward with the thrust jack. After excavating for one stroke of the thrust jack, the cutter is stopped. Then, the front gripper of the front trunk is extended in the radial direction to grip the rock, and the extended main gripper is contracted. Then, in this state, the rear trunk is pulled forward by contracting the thrust jack. In this way, the procedure of pulling the rear trunk after the front trunk and the middle trunk advance first is repeated to excavate (so-called excavation).

[0013] In the above-described excavating operation, the inner cylinder and the outer cylinder of the middle body having the double cylinder structure repeat the relative reciprocating motion by sliding with each other. Due to the difference in outer diameter, a substantially annular space having a certain axial length is generated in the sliding portion (the inlet portion where the inner cylinder enters or exits the outer cylinder). Therefore, there is a regret that the earth and sand from the ground falls into this space, and the leftovers of the cutter excavated earth and sand on the front side are apt to accumulate.

If the earth and sand in these spaces increases and becomes clogged with the progress of the excavation work, it becomes impossible to gradually shrink the rear trunk side during the above-mentioned measuring operation, and in a remarkable case, it becomes difficult to continue the excavation. . In particular, since the excavation target is a hard rock layer, the residue of the cutter excavation soil is debris,
The sliding portion has almost no fluidity and tends to be clogged in the first place, and tends to be pressed and solidified by the above-mentioned measuring operation.

An object of the present invention is to provide a tunnel excavator capable of performing a reliable excavation work by preventing earth and sand clogging in a sliding portion of a double cylindrical structure.

[0016]

(1) In order to achieve the above-mentioned object, the present invention provides at least a part of a shield main body having a double cylinder structure comprising an inner cylinder and an outer cylinder which are slidable with each other. In a tunnel excavator which excavates while sliding an inner cylinder and an outer cylinder to expand and contract the shield main body, suction means is provided near a sliding portion of the inner cylinder and the outer cylinder for sucking earth and sand.

When a so-called excavation is performed in which the shield body is extensible by sliding the inner cylinder and the outer cylinder having a double cylinder structure to excavate the ground with a cutter, the outer diameter of the inner cylinder and the outer cylinder is determined. The difference tends to cause earth and sand from the ground to fall into the substantially annular space formed in the sliding portion, and the leftover of the cutter excavated earth and sand on the front side to easily accumulate. Therefore, in the present invention, by providing the suction means and sucking the earth and sand together with water from near the sliding portion and sequentially removing the earth and sand, it is possible to prevent the earth and sand from increasing and clogging as the excavation work proceeds. Therefore, reliable excavation work can be performed.

(2) In the above (1), preferably,
Water injection means for injecting water is provided near the sliding portion.

Thus, the flow of water flowing from the water injection means to the suction means can be generated, so that the earth and sand can be removed more smoothly and efficiently from the vicinity of the sliding portion together with the water.

(3) In the above (1) or (2), preferably, the shield main body is divided into a plurality of body portions, and one of the plurality of body portions has the double cylinder structure. Has become.

(4) In any one of the above (1) to (3), preferably, the suction means includes a suction port provided at a lower portion of the shield main body.

(5) In any one of the above (1) to (3), preferably, a cover is provided to cover at least a part of a sliding portion of the inner cylinder and the outer cylinder in a circumferential direction.

As a result, it is possible to reduce the drop of earth and sand from the ground to the sliding portion, which is one of the factors that hinder the progress of the excavation as the excavation work progresses, so that a more reliable excavation can be ensured.

(6) At least a part of the shield main body has a double cylinder structure including an inner cylinder and an outer cylinder which can slide with each other,
In a tunnel digging method in which the inner cylinder and the outer cylinder are slid to extend the shield body while expanding and contracting, the tunnel is excavated from the vicinity of the sliding part while the water is injected near the sliding part of the inner cylinder and the outer cylinder. With water.

(7) At least a part of the shield main body has a double cylinder structure including an inner cylinder and an outer cylinder slidable with each other,
In the tunnel digging method of digging while sliding the inner cylinder and the outer cylinder to expand and contract the shield main body, water is injected near the sliding portion of the inner cylinder and the outer cylinder to stop the water injection, and then the sliding is performed. The excavated soil is sucked together with water from near the moving part.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing the entire structure of a tunnel machine according to the present embodiment, and FIG.
FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1, FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1, and FIG. FIG. 6 is a cross-sectional view taken along the line VV in FIG. 1, and FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG.

In FIGS. 1 to 6, the tunnel excavator is a body of the tunnel excavator, and has a front body shield 1 and a middle body shield 1 for enabling the below-described excavation and middle folding operations. 2, a shield body 4 having a three-node structure in which the rear trunk shield 3 is connected so as to be able to bend (bend), and a ground (not shown) rotatably supported in the front trunk shield 1. A cutter head 5, a sediment hopper 7 provided in an excavation chamber (cutter chamber) 6 immediately behind the cutter head 5 in the front trunk shield 1, and receiving excavated earth and sand by the cutter head 5; The excavated sediment received in the excavation site is transported to the opposite side (the right side in FIG. 1) of the excavation direction together with water (details will be described later), and the drainage pipe 8 discharges the excavated sediment. 7, a partition wall (bulk head) 9 for isolating the rear side portion of the front body shield 1 from the excavated earth and sand in the cutter chamber 6, and a cutter driving device (for example, hydraulic pressure) for rotating the cutter head 5 A motor or an electric motor) 10 and a cutter head supporting mechanism (including a gear box) that is attached to the partition wall 9 and supports the cutter head 5 and transmits the driving force from the cutter driving device 10 to the cutter head 5. 11 are provided. The front body shield 1 is provided with a front gripper 12 for suppressing vibration of the cutter head 5 during excavation and for taking a reaction force to draw the rear body shield 3 during excavation to be described later. As shown in detail in FIG. 3, the front gripper 12 is provided at a total of four locations, two locations above and below the front fuselage shield 1. The front gripper jack 12a is extended to grip the substantially cylindrical gripper shoe 12b. By protruding the shield 1 in the radial direction, the ground is grasped, and the above-mentioned rear trunk shield 3 can be attracted, the vibration of the cutter head 5 can be suppressed, and the excavation direction can be controlled. The middle shield 2
Is an inner shield (inner cylinder) 2A slidable in the axial direction with respect to each other.
The outer shield (outer cylinder) 2B has a double cylinder structure, and the inner shield 2A and the outer shield 2B are slid to expand and contract the middle body shield 2 (in other words, the entire shield body 4) in the axial direction. It is possible. Thus, the middle trunk shield 2 also functions as a guide for the forward movement of the front trunk shield 1 at the time of excavation to be described later. Further, between the front body shield 1 and the partition wall 13 provided at the front of the middle body inner shield 2A, there is provided a middle folding mechanism 14 for connecting them rotatably to each other. That is, a sliding portion 15 having an outer peripheral surface substantially in a spherical shape is provided at the end of the inner-body shield partition 13 on the side of the front body shield 1, and the sliding portion 15 and the rear end of the front body shield 1 are provided. Between them, there is provided a seal portion 16 provided with a substantially ring-shaped seal member 16a which slides on the sliding portion 15 and seals between them (prevents intrusion of earth and sand, groundwater).

Upper and lower brackets 17 are fixed to two upper and lower portions on the rear side of the front torso shield 1, and these upper and lower brackets 17 and the upper and lower brackets 18 fixed to the inner-body inner shield partition 13 are vertically connected. The pins 19 are rotatably connected to each other. At this time, the partition 9 of the front trunk 1 and the partition 13 of the inner shield 2A are formed.
And a plurality of (e.g., left-right 1: 2) half-fold jacks 20 are provided between the left and right middle-fold jacks 20.
The front body shield 1 and the middle body shield 2 are bent via the middle bending mechanism 14 (by making a stroke difference between left and right), and the excavation direction can be changed by changing the angle between them. It has become. In addition,
Keys 21 on the left and right inside shield 2A
(See FIG. 4), the guide groove 22 (the same) of the key 21 is provided in the middle body outer shield 2B, and the movement of the middle body inner shield 2A in the left-right direction and the up-down direction is regulated. Middle outer shield 2B guided by key 21
Slides freely in the front-rear direction. Thereby, at the time of the below-mentioned excavation excavation operation, the outer middle trunk shield 2B smoothly follows the preceding inner trunk shield 2A.

The shield partition 13 in the middle trunk,
A plurality of (for example, two to four on the left and right) thrust jacks 24 are provided between the rear trunk shield 3 and a partition wall 23 provided at a front portion thereof. By extending these thrust jacks 24, the reaction force is transmitted through the inner trunk shield partition 13, the middle folding jack 20, and the front trunk partition 9,
The cutter head 5 is provided as a propulsive force. The middle folding mechanism 25 similar to the above-described middle folding mechanism 14 is also provided between the middle outer trunk shield 2B and the rear trunk shield 3.
Is provided. That is, the sliding portion 26 is provided at the end of the middle outer shield 2B on the side of the rear body shield 3, and a substantially ring-shaped seal member 27a is provided between the sliding portion 26 and the front end of the rear body shield 3. A seal portion 27 is provided. The upper and lower brackets 28 fixed to the rear trunk shield 3 and the upper and lower brackets 30 fixed to the partition wall 29 provided on the middle outer shield 2B are rotatably connected to each other by upper and lower pins 31. Similarly to the above-mentioned center bending jack 20, by making a stroke difference between left and right in the left and right thrust jacks 24, the middle torso shield 2 and the rear torso shield 3 are bent, and the excavation direction is changed by changing the angle between them. It is supposed to be. It should be noted that almost the entire circumference of the outer shield 2B (excluding the range of the central angle of 90 degrees around the lowest point) is covered so as to cover the sliding portion between the inner shield 2A and the outer shield 2B. A thin cylindrical earth and sand cover 2Ba (see FIG. 4) is provided;
By doing so, it is taken into consideration that earth and sand fall between the inner-body shield 2A and the outer-body shield 2B during excavation and do not enter the sliding portions thereof. Further, the rear trunk shield 3 is provided with a main gripper 32 for taking a rotational reaction force of the cutter head 5 during excavation. As shown in detail in FIG. 6, the main grippers 32 are provided at two positions on the left and right sides of the rear trunk shield 3.
2a, the gripper shoe 32b of a substantially rectangular shape (bowed side) protrudes in the radial direction of the rear trunk shield 3 to hold the ground (rock) while suppressing the ground pressure so as not to damage the ground. It takes a rotational reaction force.
In the rear trunk shield 3, there is provided a shield jack 34 which is used when a segment 33 is assembled and a propulsion reaction force is obtained (described later) in the same manner as a normal shield machine when rock properties are poor. Correspondingly, a space for assembling the segments 33 is provided in the rear trunk shield 3 in advance. Further, a rolling jack 35 for performing a rolling correction by expansion and contraction is provided in the rear trunk shield 3.

The front body shield 1, the middle body shield 2,
In addition, fixed sleds 36a, 36b, and 36b are provided below the rear trunk shield 3 for the purpose of adjusting the horizontal height (level).
36c is provided.

As shown in FIG. 2, the cutter head 5 is of a so-called face plate type having no gap except for a sediment intake port to be described later when viewed from the front.
(11 in this example), a roller bit device 37, a face scraper 38 and a side scraper 39 for taking in crushed pieces, and a regulating plate 40 for limiting the size of the taken-in pieces when taking in crushed pieces. . The cutter head 5 is of a so-called peripheral support type (drum type) which is supported by the cutter head support mechanism 11 at an intermediate portion between a radial center portion and an outer peripheral portion. And
The rock is crushed by the bit 37a of each roller bit device 37 by rotating the cutter head 5 while the front body shield 1 is propelled by the thrust jack 24, and the crushed rock is scraped by the scrapers 38 and 39. The collected soil is taken into the cutter chamber 6 behind the cutter head 5 through a soil / sand intake port (slit) 41 and is put into the earth / sand hopper 7.

The above-mentioned flow-in facility includes the above-mentioned drainage pipe 8, water supply pipe 41, and return pipe 42, which extend below the front body shield 1, the middle body inner shield 2A and the rear body shield 3. ing. That is, the water sent from the water supply equipment on the ground side is supplied into the earth and sand hopper 7 through the water supply pipe 41. The inside of the earth and sand hopper 7 contains water and a return pipe 42 through the water pipe 41.
The work (see below) returned from the water is almost always full during the work, and the excavated earth and sand taken in as described above is sequentially put into the water. The injected excavated earth and sand is sent backward in the mud drain pipe 8 together with water, and is crushed to a predetermined size by a crusher (not shown) provided in the middle of the mud pipe 8. Thereafter, a part of a water component of the mixture of excavated earth and sand and water sent up to that point is separated by a flow divider (not shown) provided further behind the sludge pipe 8, and the return pipe 42 Is returned to the earth and sand hopper 7 again. The mixture of excavated earth and sand and water in which a part of the water component is diverted by the recirculation pipe 42 is guided further back (to the ground side) through the small-diameter drainage pipe 8 with the diverter as a boundary, and is discharged. You.

Reference numeral 43 denotes a walkway arranged above the drainage pipe 8 and the return pipe 42 for cutter bit replacement and equipment maintenance.

In the above description, the main part of the present embodiment is that the middle outer shield 2 is located near the center folding mechanism 14 for connecting the front body shield 1 and the inner middle shield 2A.
B and the structure in the vicinity of the sliding portion between the middle trunk inner shield 2A. VII-VII in FIG. 1 showing a detailed structure near the sliding portion.
FIG. 7 is a cross-sectional view of the section, and FIG.
Shown in

In FIGS. 7 and 8, a suction port 44 and a water injection port (not shown) are provided at substantially the same height below the partition wall 13 at the front of the inner shield 2A.

A thread is formed in a front portion 44a of the suction port 44, and one side of a threaded joint 45 is screwed and fixed to the thread. And this screw joint 4
5 is connected to one side of a suction line 46 made of, for example, a hose, and the other side of the suction line 46 is connected to a suction pump 48 driven by a motor 47.
Is connected, sucks earth and sand together with water from the suction port 44,
The liquid is discharged to a tank 49.

Although not shown in detail, the water inlet side has substantially the same structure as described above, and one side of the threaded joint 50 is screwed into a thread at the front part of the water inlet and fixed. A water supply pump driven by a motor is connected to a water supply pipe connected to the other side of the threaded joint 50, and water is supplied from a water supply port.

In the above configuration, the cutter head 5
Constitutes a cutter, a suction port 44, a screw joint 45, a suction conduit 46, a suction pump 48, a motor 47, and a tank 49.
Constitutes suction means for sucking earth and sand together with water from near the sliding portion of the inner cylinder and the outer cylinder.
0, a water injection pipe, a water injection pump, and a motor constitute water injection means for injecting water near the sliding portion. The earth and sand cover 2Ba constitutes a cover that covers at least a part of the sliding portion of the inner cylinder and the outer cylinder in the circumferential direction.

Next, the operation and operation of the tunnel excavator will be described below.

In the tunnel excavator having the above configuration, when excavating relatively hard geology (hard rock layer), so-called excavation excavation is performed.

That is, as shown in FIG. 9 (a), the main gripper 32 provided on the rear trunk shield 3 is extended in the radial direction to grip the rock to take a cutter rotation reaction force, and to interlock with the rear trunk shield 3. The cutter head 5 is rotated by the cutter driving device 10 while the thrust jack 24 connecting the body shield inner cylinder 2A is extended in the axial direction and the front body shield 1 and the middle body shield inner cylinder 2A are propelled forward, and the cutter head 5 is rotated. Is excavated by the roller bit device 37 of FIG. At this time, the front gripper 12 is slightly extended so as to be in contact with the rock, so that the vibration of the cutter head 5 is suppressed.

The excavated earth and sand is scraped by the scrapers 38 and 39 of the cutter head 5 and then taken into the cutter chamber 6 from the earth and sand intake port 41, further injected into the earth and sand hopper 7 and discharged by the mud pipe 8. Is done.

After digging a predetermined distance (for example, one stroke of the thrust jack 24) in this way, the cutter head 5 is stopped, and the front gripper 12 is further extended as shown in FIG. 9B. In this state, the rock is held, and the main gripper 32 is fully contracted. Thus, the tunnel machine is fixed to the bedrock through the front gripper 32. And
By shrinking the thrust jack 24, the rear body shield 3 and the middle body shield outer cylinder 2B are drawn to the front body shield 1 and the middle body shield inner cylinder 2A that are ahead (FIG. 9).
(C)). Thereafter, the above operation is repeated to dig. At this time, by operating the main gripper 32 and the front gripper 12 and appropriately taking a reaction force, the angle formed between the front body shield 1 and the middle body shield 2 or the middle body shield 2 and the rear body shield 3 is changed. The direction of excavation can be easily changed to turn. When performing the excavation with a tunnel excavator as described above, as described above,
In the middle-body shield 2 of the double-cylinder structure, the inner cylinder 2A
In order to extend and contract the middle body shield 2 by sliding the outer cylinder 2B and the outer cylinder 2B in the axial direction, the inner cylinder 2A and the outer cylinder 2B
The earth and sand from the ground collapses and falls into the lower part of the substantially annular space P (see FIGS. 1 and 8) formed near the sliding portion due to the difference in outer diameter from the front side. Excavation earth and sand (debris) easily accumulates. If the earth and sand in the lower part of the space P increases and becomes clogged with the progress of the excavation work, the middle body shield outer cylinder 2B and the rear body shield 3 cannot be gradually drawn during the above-mentioned measuring operation. Continuation of excavation becomes difficult. In particular,
Since the excavation target is a hard rock layer, the residue of the cutter excavation soil is debris, so there is almost no fluidity and it is easy to clog the sliding part originally, and it is pressed by the above measuring operation and it is further consolidated Tends to be prone.

Therefore, in the present embodiment, water is injected from the water injection port and suction is performed from the suction port 44 so that water flows from the water injection port to the suction port 44 in the lower part of the space P. The sediment and debris can be smoothly and efficiently introduced from the vicinity of the sliding portion together with the flowing water, and can be sequentially discharged to the rear of the excavator. Therefore, it is possible to prevent the earth and sand from increasing and clogging with the progress of the excavation work, or even if the clogging occurs, it can be immediately removed, so that the excavation work can be performed reliably. At this time, the water sent from the water inlet also plays a role of loosening the sediment deposited in the space P.

Further, at this time, the earth and sand protection cover 2Ba that covers most of the space P other than the lower portion is further provided, so that the ground excavation is one of the factors that hinder the excavation work as the excavation work proceeds. It is possible to reduce the amount of earth and sand falling from the sliding part to the sliding part, thereby performing more reliable excavation work.

In addition, as long as the effect of removing earth and sand and debris from the vicinity of the sliding portion and ensuring the secure excavation as compared with the conventional structure can be obtained, a water injection means including the above-described water injection port and a sediment protection cover can be used. 2Ba is not necessarily required, and only the suction means including the suction port 44 may be used. However, conversely,
It goes without saying that the above-mentioned clogging of soil cannot be eliminated by the water injection means alone since there is no place for the accumulated earth and sand or debris to go.

Although the above description has been made taking the case of excavating relatively hard geology as an example, when excavating a soft soil layer, it is used in the same manner as a normal shield machine. That is, although a detailed description is omitted, the existing segments 33 sequentially assembled by the rear trunk shield 3 are used as reaction force receivers of the shield jack 34 to apply a propulsive force to the cutter head 5 and to apply the propulsive force to the cutter head 5. Rotate to excavate.
Thus, even when springing in the tunnel, the watertight structure of the segments 33 and the shield body 4 can prevent the entire machine from being submerged. In the embodiment of the present invention, as described above with reference to FIG.
In the lower part of the partition 13 at the front of A, the suction port 4 is almost at the same height.
Although one and four water inlets (not shown) are provided respectively, the invention is not limited to this, and a plurality of water inlets may be provided. FIG. 10 shows such a modification.

FIG. 10 shows the main structure of this modification.
FIG. 8 is a cross-sectional view illustrating a detailed structure near a sliding portion between a middle-body outer shield 2B and a middle-body inner shield 2A, and is a diagram corresponding to FIG. 7 of the embodiment of the present invention. 7 and 8 are denoted by the same reference numerals.

In FIG. 10, the inner shield 2
A two suction ports 44 and a screw joint 45 connected to the suction ports 44 are provided at substantially the same height in the lower part of the partition wall 13 in the front part of A, and two water injection ports are separately provided at a position higher than the two suction ports 44 (FIG. (Not shown) and a threaded joint 50 connected thereto. These water injection threaded joints 50 are further provided with water injection pipes 5.
1 connected. That is, in this modified example, water is injected from the two water inlets provided above and the space P
The soil and debris to be deposited at the lower part of the water is washed down by water, and is sucked up together with water from two suction ports 44 provided below. According to this modified example, the same effect as in the above-described embodiment of the present invention can be obtained.

Further, in the above-described embodiment of the present invention, while the water is injected from the water inlet, the suction port 44 is simultaneously opened.
However, the present invention is not limited to this, and it is also conceivable that a predetermined amount of water is collectively injected first and then a predetermined amount of suction is collectively performed. Such a modification will be described with reference to FIG.

This modification is different from the suction port 44 shown in FIG.
(Corresponding to the position of the screw joint 45) and the water inlet (screw joint 5)
(Corresponding to the position of 0) is first used as a water injection port to perform water injection, and then the connection relationship of the pipes is switched, and suction is performed using any of them as a suction port.

That is, as shown partially in FIG. 11, in this modified example, a lower part of the partition 13 at the front of the inner-body shield 2A has a structure similar to the suction port 44 and the water injection port. Two suction / water inlets 52A and 52B are provided, respectively. A water injection pump 55 driven by a motor 54 is connected to the suction / water injection port 52A via a water injection pipe 53 provided with a valve 53a. A suction pump 58 driven by a motor 57 is connected to the suction / water inlet 52B via a suction pipe 56 having a valve 56a. At this time, the water supply pipe 53 and the suction pipe 56 are connected to the connection pipe 5 having the valve 59a.
9.

When water is injected into the lower part of the space P, the valves 53a and 59a are opened and the valve 56a is closed, and the water injection pump 55 is driven. As shown in the drawing, the water in the tank 60 is suctioned and injected through a water injection pipe 53.
Water is injected from A, and water is also injected from the suction / water injection port 52B via the connection pipe line 59. Then, by closing the valve 53a and opening the valve 56a, and driving the suction pump 58, the soil and water at the lower part of the space P are passed through the suction pipe 56 as shown by the broken line a in FIG. In addition to the suction from the suction / water injection port 52B to the tank 61, the suction is also performed from the suction / water injection port 52A via the connection pipe 59.

As can be understood from the above description, in the above configuration, the suction / water injection ports 52A and 52B, the water injection pipe 53, the water injection pump 55, the suction pipe 56, and the suction pump 5
8. The motors 54, 57 and the tanks 60, 61 constitute suction means for sucking earth and sand together with water from near the sliding portion of the inner cylinder and the outer cylinder, and provide water injection means for injecting water near the sliding portion. Will also be configured. In addition, valve 5
It is needless to say that the function is the same as that of the embodiment of the present invention as long as 9a is kept in the normally closed state.

Further, in the above-mentioned embodiment of the present invention, the present invention provides a shield body 4 having a three-bar structure including a front body shield 1, a middle body shield 2, and a rear body shield 3, and Has been described as an example in which the invention is applied to a tunnel machine having a double cylinder structure of an inner cylinder 2A and an outer cylinder 2B, but the invention is not limited to this. That is, even if the shield body has a two-node structure of a front trunk and a rear trunk that can be folded in each other, or a shield body of a single-node structure that does not have a middle-fold structure, a part of the trunk or the trunk of them can be used. The present invention can be applied as long as a part is slid in a double cylinder structure that can slide with respect to each other, and it is needless to say that a similar effect can be obtained in those cases.

In the above description, both the water injection port and the suction port are open to the partition wall 13, that is, the face side of the sliding portion between the outer shield 2B and the inner shield 2A (FIG. 1).
(Middle left side), in other words, it is installed on the face side of the space P. However, the present invention is not limited to this, and it may be mounted on the wellhead side, for example, on the part of the middle outer shield 2B facing the space P. Further, a water inlet on the face side and a suction port on the wellhead side may be provided so as to face each other, or the arrangement may be reversed.

[0058]

According to the present invention, the suction means is provided to suck and remove the earth and sand near the sliding portion of the inner cylinder and the outer cylinder of the shield body together with the water, so that the earth and sand are removed as the excavation work progresses. It is possible to prevent the clogging due to the increase. Therefore, reliable excavation work can be performed.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing the entire structure of a tunnel machine according to an embodiment of the present invention.

FIG. 2 is a view as viewed from an arrow A in FIG.

FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is a cross-sectional view taken along the line VV in FIG. 1;

FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG.

FIG. 7 is a transverse sectional view taken along the line VII-VII in FIG. 1;

FIG. 8 is an enlarged view of a portion B in FIG. 1;

FIG. 9 is a view for explaining a shaving excavation operation of the tunnel excavator shown in FIG. 1;

FIG. 10 is a view showing a modification in which a plurality of suction ports and a plurality of water injection ports are provided.

FIG. 11 is a view showing a modification in which a predetermined amount of water is collectively injected and then a predetermined amount of suction is collectively performed.

[Explanation of symbols]

Reference Signs List 1 front torso shield (torso) 2 middle torso shield (at least part of the torso, shield body) 2A inner shield (inner cylinder) 2B outer shield (outer cylinder) 2Ba mudguard cover (cover) 3 rear torso (body) 4) Shield body 5 Cutter head 44 Suction port (suction means) 45 Screw joint (suction means) 46 Suction line (suction means) 47 Motor (suction means) 48 Suction pump (suction means) 49 Tank (suction means) 50 Screw joint (water injection means) 52A, B Suction / water injection port (suction means, water injection means) 53 Water injection pipeline (suction means, water injection means) 54 Motor (suction means, water injection means) 55 Water injection pump (suction means, water injection means) 56 Suction line (suction means, water injection means) 57 Motor (suction means, water injection means) 58 Suction pump (suction means, water injection means) 60 Tank (suction means, water injection means) 6 1 Tank (suction means, water injection means) P Substantially annular space

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunori Ueda 650 Kandamachi, Tsuchiura-shi, Ibaraki F-term in the Tsuchiura Plant of Hitachi Construction Machinery Co., Ltd. (Reference) 2D054 AD02 AD17 FA00

Claims (7)

[Claims] At least a part of a shield main body has a double cylinder structure including an inner cylinder and an outer cylinder that can slide with each other, and excavates while sliding the inner cylinder and the outer cylinder to expand and contract the shield main body. In a tunnel excavator, suction means for sucking earth and sand is provided near a sliding portion of the inner cylinder and the outer cylinder. 2. The tunnel machine according to claim 1,
A tunnel machine comprising a water injection means for injecting water near the sliding portion. 3. The tunnel machine according to claim 1, wherein the shield body is divided into a plurality of trunks, and one of the plurality of trunks has the double cylinder structure. A tunnel machine comprising: 4. The tunnel machine according to claim 1, wherein said suction means includes a suction port provided at a lower portion of said shield body. 5. The tunnel machine according to claim 1, further comprising a cover that covers at least a part of a sliding portion of the inner cylinder and the outer cylinder in a circumferential direction. Tunnel excavator. 6. At least a part of the shield body has a double cylinder structure comprising an inner cylinder and an outer cylinder which can slide with each other, and excavates while sliding the inner cylinder and the outer cylinder to expand and contract the shield body. In the tunnel excavation method, while performing water injection near the sliding portion of the inner cylinder and the outer cylinder,
A tunnel excavating method, wherein the excavated earth and sand is sucked together with water from near the sliding portion. 7. At least a part of the shield main body has a double cylinder structure including an inner cylinder and an outer cylinder which can slide with each other, and excavates while sliding the inner cylinder and the outer cylinder to expand and contract the shield main body. In the tunnel excavation method, a method of injecting water near a sliding portion of the inner cylinder and the outer cylinder to stop the water injection, and then sucking excavated earth and sand together with water from the vicinity of the sliding portion.