JP2000160987A - Shield machine and tunnel excavating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a tunnel excavator from running away when a hard rock bed appears at a part of tunnel cross section in shield tunnel excavation. SOLUTION: A cutter head 11 for cutting a working face by rotation is fitted to the front face of an excavator body 10. The excavator body 10 is provided with a support member 30 with a hydraulic jack 32 built therein to support the cutter head 11 rotatably and extensibly. The working face is cut by the rotation of the cutter head 11 while elongating the hydraulic jack 32 toward the working face in the stopped state of the excavator body 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator and a tunnel excavation method using the same, and more particularly to an excavator even when hard rock or the like partially appears in the course of excavating a shield tunnel. TECHNICAL FIELD The present invention relates to a shield excavator and a tunnel excavation method capable of excavating without a runaway.

[0002]

2. Description of the Related Art There is a case where a hard rock is partially present in the ground and a shield tunnel is excavated such that a part of the hard rock is in a tunnel cross section.

[0003] FIG. 7 shows a rock bed 6 in which a shield excavator 50 excavating in a relatively soft ground 60 is located forward in the traveling direction.
It is a state explanatory view showing typically the excavation state approaching to 1. As shown in the figure, in this example, a hard rock 61 slightly inclined to the side of the shield excavator 50 exists. In a normal shield excavator 50, the cutting face 62 is cut by a cutter bit mounted on a rotating cutter head, and a plurality of shield jacks (not shown) arranged on the inner periphery of the shell constitute a shield excavator 50 body. Is to be promoted.

[0004]

However, the hard rock 61 and the relatively soft ground 6 are rotated while rotating the cutter head.
If the face 62 composed of 0 (hereinafter referred to as the soft layer 60) is excavated at the same time, the soft soft layer 60 side is cut much. When the shield jack is operated and the shield excavator 50 is propelled in this state, the shield excavator 50 receives resistance on the side of the bedrock 61, so that the shield excavator 50 escapes toward the soft layer 60 having a low resistance and a low resistance. .

FIG. 8 is a state explanatory view schematically showing the escape state of such a shield excavator 50. As shown in the figure, when the shield excavator 50 is propelled, the resistance of the rock side 61 causes the stroke between the rock jack 61 and the shield jack on the soft layer 60 side to vary, so that the shield excavator 50 The traveling direction deviates from the base line of the tunnel alignment set in a straight line. Once deviating from the tunnel baseline, the only option is to adjust the traveling direction by changing the stroke of the shield jack of the shield excavator 50 one by one, and the tunnel alignment will meander until the displacement is completely eliminated. There is.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems of the prior art, and to provide a shield capable of excavating such that a tunnel excavator does not escape even when hard rock appears in a tunnel cross section. An object of the present invention is to provide an excavator and an efficient tunnel excavation method using the excavator.

[0007]

In order to achieve the above object, the present invention provides a cutter head mounted on a front surface of an excavator body and cutting a face by rotation, and enabling the cutter head to rotate to a bulk head. An extensible support member for supporting, the cutting face being cut by rotation of the cutter head while extending the support member toward the face while the excavator body is stopped. It is characterized by.

[0008] As a method of excavating a tunnel, an extensible support member for rotatably supporting a cutter head on a bulkhead is provided with the excavator body stopped while extending toward the face face while the excavator body is stopped. The face face is cut by rotation, and the excavator body is propelled to the ground portion loosened by the cutting.

Preferably, the supporting member is a hydraulic jack housed in a jack cover.

[0010] In the tunnel excavation method, it is preferable that the rotary cutting of the cutter head accompanying the extension of the support member is performed in a state in which the hard rock appears on a part of the face.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the shield excavator according to the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a schematic sectional view of a shield excavator according to the present invention. The cutter head 11 of the shield excavator 10 of the present invention is equipped with an open-type cut-spoke 20. In the present embodiment, the cutter spoke 20 employs an intermediate support system. That is, the bulkhead 12 has a ring-shaped bulkhead peripheral portion 12A whose peripheral edge is fixed to the shell, and a circle located on the inner peripheral side of the bulkhead peripheral portion 12A and rotated by the rotational driving force from the turning motor 14. It comprises a plate-shaped bulkhead swivel part 12B. The cutter spoke 20 is supported by the bulkhead turning portion 12B via a support beam 30. The support beam 30 is mounted on the bulkhead swivel unit 12.
B is fixed via an earth and sand seal (not shown). An external gear 13 is provided on the peripheral surface of the bulkhead turning portion 12B.
Are formed, and rotation of the rotation motor 14 is controlled by the external gear 1.
3 is transmitted. This allows the cut spokes 20 to rotate with the rotation of the turning motor 14.

As shown in FIG. 2, three circular tubular cuts spokes 20 are
They are arranged at equal angular intervals of 0 °. On the front surface of the cutter spokes 20, cutter bits 26 are attached in two rows at predetermined intervals along the longitudinal direction of the spokes. A support beam 30 is fixed to an intermediate position in the longitudinal direction of each cut spoke 20. If necessary, an overcutter or a copy cutter (not shown) that can be extended by hydraulic operation can be attached to the outer peripheral end of each of the cut spokes 20. At the lower end of the bulkhead 12, a screw conveyor 15 according to a known technique is attached. The screw conveyor 15 plays a role of carrying the earth and sand taken into the cutter chamber 16 with the excavation from the cutter chamber 16 to a discharge path.

For excavation, a plurality of shield jacks 17 according to the prior art are arranged at predetermined intervals along the inner periphery of the shell 18 on the inner surface of the shell 18 of the shield body.
The shield jack 17 is a propulsion device for advancing the shield excavator 10 main body while applying a reaction force to the already assembled segment 1 by hydraulic operation.

FIG. 3A shows the configuration of each support beam 30 for imparting rotation to the three cut spokes 20.
This will be described with reference to FIG. FIG. 3A is a partially enlarged cross-sectional view illustrating the configuration of the support beam 30. The support beam 30 is 2
It comprises a jack cover 31 having a heavy cylinder structure, and a hydraulic jack 32 as a drive unit. The jack cover 31 is composed of an inner cylinder 31A and an outer cylinder 31B which can be extended and contracted by sliding on a contact surface, and O-rings as sealing materials are attached to two places near the inner peripheral surface of the outer cylinder 31B. An earth and sand seal 33 is formed. Further, a hydraulic jack 32 is accommodated in a space surrounded by the cover 31. In the hydraulic jack 32, the base of the jack body is fixed to the surface of the bulkhead 12 </ b> B, and the other end of the cylinder rod 32 a is fixed to the back side of the cut spoke 20. Then, the rod 35 expands and contracts due to the operation of the pressure oil supplied from the pressure source P (known hydraulic pump). The hydraulic jacks 32 in each support beam 30 can be operated and controlled simultaneously and independently. The extension of the rod 35 of each hydraulic jack 32 allows the cut-spoke 20 to protrude toward the face by the maximum protrusion amount Δ. (See FIG. 3B). At the base of each jack, a load cell 36 for checking the load state of the jack is interposed. By measuring the value of the load cell 36 with the measuring device 37, the resistance when cutting the hard rock by rotating the cut spoke 20 can be detected, and thereby the tendency of the cut surface to tilt can be grasped.

The hydraulic jack 32 is moved from the retracted state of the rod to the initial position, and the rod 35 is extended to extend the cut spoke 2.
0 is advanced to the face side. Drive unit 33
For example, a driving means such as a hydraulic motor or an electric motor can be appropriately selected. Further, gear means such as a rack and pinion can be used instead of the rod. Further, the jack cover 31 may have a bellows-like synthetic rubber bellows which can be extended and contracted, instead of the double cylinder structure.

FIG. 4 is a sectional view of a tunnel showing a normal tunnel excavation state by the shield excavator 10 of the present invention. As shown in the figure, in the ordinary tunnel excavation, the rotary excavation of the cut-spoke 20 and the shield jack 17 are performed.
The extension of the rod 17a causes the shield excavator 10 to perform straight excavation. The excavation amount of the shield excavator 10 can be adjusted by controlling the extension amount of the rod 17a of the shield jack 17. At this time, as shown in the same figure, assuming that a hard rock layer 61 appears at the lower end side of the shield excavator 10 traveling in the soft layer 60, a tunnel excavation method using the shield excavator 10 is described. explain.

FIGS. 5 and 6 are state diagrams showing a state where the excavation of the shield excavator 10 in the hard rock layer 61 has progressed to some extent. When the shield excavator 10 encounters the hard rock layer 61, first, the propulsion by the shield jack 17 is stopped. Then, while extending the rod 35 of the hydraulic jack 32 in the support beam 30, the cut-spoke 20 is rotationally driven to cut the bedrock layer 61 and the soft layer 60. Also in this case, since the bedrock layer 61 is hard, there is a possibility that the face face cut by rotating the cut spokes 20 may be inclined.
The inclination of the face can be estimated by a load cell 36 attached to the support beam 30 attached to the support beam 30. When it is confirmed that the face face is tilted and the direction of the shield excavator 10 is eccentric, the rod 35 of the hydraulic jack 32 of the support beam 30 is once retracted and the Katus spoke 20 is moved to the shell of the shield excavator 10. Then, the support beam 30 is extended again to cut the face. Thereby, the inclined face is shaped so as to be perpendicular to the traveling direction. FIG. 5 shows a state in which the hard rock layer 61 and the soft layer 60 are excavated evenly by repeating the face cutting operation by the cut spokes 20. When performing only rotary excavation with the cutter spokes 20, it is preferable to set the amount by which the cut spokes 20 project from the tip of the shell 18 in consideration of the stability of the excavated ground.

Then, as shown in FIG. 6, the cut spokes 20 are stopped in contact with the face, and the rod 17a of the shield jack 17 is extended so that a reaction force is applied to the end face of the segment 1. This shield jack 17
In synchronization with the extension of the rod 17a
Retracts the rod 35 of the hydraulic jack 32 of the support beam 30 in the extended state. Thereby, the shield excavator 1
0 can be propelled to the excavation completion position shown in FIG. At this time, the shield excavator 10 is
0, which can be propelled through the loose ground by loosening due to the rotation cutting of 0
Can be prevented, and predetermined straight-line propulsion can be performed.

In the above description, the operation has been described using an open type cut-spoke as an example. However, the same effect can be obtained by sliding a closed type face plate by expansion and contraction of a support beam. In addition, the structure for supporting the cutter head is not limited to the intermediate support system, and the same effect can be realized by appropriately installing a telescopic shaft in the center shaft support system and the peripheral support system.

[0020]

As described above, when a hard rock layer appears on a part of the excavated section of a shield excavator,
Hard rock was cut in advance independently of the propulsion operation of the shield excavator by rotary cutting of only the cutter spokes, so even if propulsion by the shield jack, the shield excavator did not escape to the soft layer side, A highly accurate tunnel excavation can be realized along the alignment of the tunnel.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a shield excavator according to the present invention from the front.

FIG. 2 is a front view showing a configuration of a cutter head of the shield excavator in FIG. 1;

FIG. 3 is a partial cross-sectional view showing a stretched state of a support beam of the shield excavator according to the present invention.

FIG. 4 is a state explanatory view showing a tunnel excavation state by the shield excavator shown in FIG. 1;

FIG. 5 is a vertical cross-sectional view showing a state in which only the cut spokes are extruded and rotationally cut from the state shown in FIG. 4;

FIG. 6 is a longitudinal sectional view showing a state in which the shield jack is propelled from the state shown in FIG. 5 and the shield excavator is propelled.

FIG. 7 is a construction state explanatory diagram showing a state of excavation by a conventional shield excavator.

8 is a state explanatory view showing a state in which the shield excavator has run away when excavating the hard rock layer from the state shown in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Shield excavator 11 Cutter head 12 Bulk head 16 Cutter chamber 17 Shield jack 18 Hull 20 Cutter spoke 30 Support beam 31 Jack cover 32 Hydraulic jack 35 Rod

Continuation of front page (72) Inventor Yoshihiro Taniguchi 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation F-term (reference) 2D054 AA01 BA07 BB02

Claims (4)

[Claims] 1. An excavator body, comprising: a cutter head attached to a front surface of an excavator body and configured to cut a face by rotation; and a telescopic support member rotatably supporting the cutter head to a bulkhead. A shield excavator wherein the cutting face is cut by rotation of the cutter head while extending the support member toward the face while the cutting is stopped. 2. An extensible support member for rotatably supporting a cutter head on a bulk head is extended toward the face while the excavator body is stopped, and the face is cut by rotation of the cutter head. A method for excavating a tunnel, characterized in that the excavator body is propelled to the ground portion loosened by the cutting. 3. The shield excavator according to claim 1, wherein said support member comprises a hydraulic jack housed in a jack cover. 4. The tunnel according to claim 2, wherein the rotary cutting of the cutter head accompanying the elongation of the support member is performed in a state in which hard rock is exposed on a part of the face. Drilling method.