JPH0557399B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shield excavation method.

[Prior art] Conventionally, Japanese Patent Application Laid-Open No. 55-26332 and Japanese Utility Model Publication No. 61-45277
A shield excavation method as shown in the above publication is known, but in the former shield excavation method, the leading cutting edge located at the front of the shield is pressed into the face prior to the rotation of the cutter head to remove the ground to be excavated. The cutting head is then rotated and excavated by moving it in the axial direction while injecting mud-forming material onto the ground carved by the inner surface of the leading cutting edge, and the cutting head is placed at a predetermined position in the excavation direction within the cutting edge. After the excavation is carried out until the depth is excavated, the shield is propelled while discharging the excavated soil contained in the chamber.In the latter method, the cutter is used to move the earth and sand taken into the chamber in the shield skin plate into the shield skin. By moving in the axial direction within the plate, the material is cut into small pieces and stirred, and in any construction method, such excavation work is performed for only one ring, and during segment assembly after the shield has been propelled, the excavation work is carried out. It does not perform any work.

However, assembling the segments usually requires a long time of 30 minutes or more, which is extremely time-consuming and causes a decrease in excavation efficiency.

Figure 3 is a diagram showing the relationship between segment assembly time and shield excavation, and the conventional construction method shown here requires 30 minutes for segment assembly and 30 minutes for normal excavation.

[Purpose of the invention]

An object of the present invention is to provide a shield excavation method that allows excavation work to be continued even during segment assembly, thereby reducing time loss and improving excavation efficiency.

[Structure of the invention]

The shield excavation method of the present invention includes the step of moving the cutter forward in the excavation direction while rotating the cutter beyond the tip of the excavation device body when assembling the segment when the excavation device body is stopped, and excavating the face by a predetermined length. , causing the cutter to rotate and retreat in a direction opposite to the excavation direction at a predetermined speed relative to the excavation device main body, and to excavate the excavation device main body at a speed n (n>1) times the retreating speed of the cutter. It is characterized by comprising the steps of excavating the face while moving forward in the direction, and assembling the next segment.

[Embodiments of the invention]

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

In the figure, 1 is a large number of cutter bits, 2 is a spoke-shaped cutter with the cutter bit 1 provided on its front surface, 3 is a cutter drive shaft, 4 is a bearing that supports the cutter drive shaft 3 slidably in the axial direction, and 5 is a A cutter extension and retraction device using a hydraulic jack, 6 a cutter rotation drive hydraulic motor, 7 a shield jack, 8 a screw conveyor, 9 an erector,
Reference numeral 10 denotes a shield skin plate, and in the apparatus for carrying out the shield excavation method of the present invention, the cutter 2 and the cutter drive shaft 3 are moved beyond the shield skin plate 10 by the cutter extension device 5 in the axial direction, that is, in the excavation direction. The shield skin plate 1 is movable forward and the shield skin plate 1 is movable forward.
0 is provided with a gripper 11 which can be protruded radially outward from its outer peripheral surface by hydraulic operation.

In the shield excavation method of the present invention using such an excavation device, when assembling the segment, the gripper 11 is operated to keep the excavation device main body including the shield skin plate 10 stationary relative to the surrounding earth and sand. 2, and the cutter telescopic device 5 advances the cutter 2 from the tip of the shield skin plate 10 forward in the digging direction as shown in FIG. 1 at a speed of V per minute for one stroke (approximately half of one ring). For example, a 45cm face is excavated. Then, the operation of the gripper 11 is released, and the cutter 2 is removed.
While rotating, the excavation device main body including the shield skin plate is moved forward in the excavation direction by the shield jack 7 at the same time as the excavation device main body including the shield skin plate is moved backward relative to the excavation device main body at a speed of V per minute as shown in Fig. 2. It is moved forward at a speed of 2V, and when the cutter 2 further excavates the face by one stroke (approximately half of one ring) due to the relative speed between the two, the excavation work for the first ring is completed, and the next segment is assembled. Do it like this.

Note that if the friction between the outer circumferential surface of the shield skin plate 10 and the surrounding earth and sand is sufficiently large, the gripper 11 is not necessary.

Figure 3 shows that the method of the present invention is used for segment assembly.
This shows the case where it takes 15 minutes for cutter 2 to move forward by 45 cm, and the total time required to assemble the segments and excavate the face by one stroke is 45 minutes, reducing the work time by 15 minutes compared to the conventional method. can do.

In addition, in the shield excavation method of the present invention, the excavation device main body may be set to nV (here, n is a number larger than 1), for example, 1.5V, depending on the state of the face, instead of 2V.

〔Effect of the invention〕

Since the shield excavation method of the present invention is as described above, there is a great advantage that the time during segment assembly can be effectively used for excavation and work efficiency can be improved.

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams of an apparatus for implementing the shield excavation method of the present invention, respectively, and FIG. 3 is an explanatory diagram. 1... cutter bit, 2... cutter, 3...
... cutter drive shaft, 4 ... bearing, 5 ... cutter expansion and contraction device, 6 ... cutter rotation drive hydraulic motor,
7...Shield Jack, 8...Screw Conveyor, 9...Erekta, 10...Shield Skin Plate, 11...Gritzper.

Claims (1)

[Scope of Claims] 1. A step of moving the cutter forward in the excavation direction while rotating beyond the tip of the excavation device main body when assembling the segment when the excavation device main body is stopped, and excavating the face by a predetermined length. , causing the cutter to rotate and retreat in a direction opposite to the excavation direction at a predetermined speed relative to the excavation device main body, and to excavate the excavation device main body at a speed n (n>1) times the retreating speed of the cutter. A shield excavation method characterized by comprising a step of excavating the face while moving forward in a direction, and a step of assembling the next segment. 2. The shield excavation method according to claim 1, wherein when the cutter is advanced forward in the excavation direction, the excavation device main body is fixed to surrounding earth and sand by a gripper.