JPH09189191A - Excavator and excavating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce thrust by loosening the peripheral bedrock of an excavated tunnel when an excavator is arranged into a pipe and both the excavator and the pipe are propelled when a duct is laid without constructing an arrival shaft. SOLUTION: An excavator A is disposed into a pipe C, and both the excavator A and the pipe C are connected by a thrust transmission member D and a shear pin 4 while a pull-out force transmission member E is joined with the excavator A. A cutter head B installed at the front end of the excavator A is composed of a face plate and a cylindrical section, and a tapered surface or a curved surface is formed extending over a center from the outer circumference of the face plate while a plane is formed on the central side. A roller bit, a roller cutter and a scraper are mounted on the face plate, and a bit for crushing gravel and a notch, into which crushed gravel is taken, are shaped to the outer circumferential surface of the cylindrical section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for burying a pipe in the ground. When the pipe is buried inside the pipe, it is propelled together with the pipe while excavating the ground and reaching a predetermined propulsion length. With regard to the excavator that is pulled back to the starting shaft through the inside, in particular, it is possible to loosen the ground around the inner periphery of the excavated tunnel to reduce the thrust when propelling the pipe and excavator. And an excavation method using the excavator.

[0002]

2. Description of the Related Art When laying a sewer pipe or a gas pipe in the ground, a propulsion method is often adopted. In this propulsion method, a starting shaft and an arrival shaft are constructed on the planned laying line of the pipeline, and the excavator equipped with a cutter head at the tip and the pipe following the excavator are propelled by the pusher installed in the starting shaft. Then, the excavator arrives at the arrival shaft and is removed from the shaft, thereby laying a pipeline between the starting shaft and the arrival shaft.

As described above, in the propulsion method, it is essential to construct the starting shaft and the arrival shaft. The starting shaft must have a space where equipment such as a pusher and equipment for removing excavated earth and sand can be installed, and a space where the work can be performed by supplying an excavator and a pipe following the excavator to the pusher. In addition, the incoming shaft requires space to eliminate the excavator that has arrived and to carry out this work. Therefore, a large area is required for both the start shaft and the arrival shaft.

However, a propulsion method has also been developed in which the excavator and the pipe are propelled without constructing the arrival shaft, and when the propelled pipe reaches a predetermined length, only the excavator is pulled back to the starting shaft. For example, the construction method of the drainage pipeline developed by the applicant and applied for a patent (Japanese Patent Application No. 4-108392)
Is a perforator with a perforated pipe arranged around the perimeter, followed by a sheath pipe with a perforated pipe and a perforated pipe with a perforated pipe of the same length as the sheath pipe. After propelling the pipe at the same time and propelling the perforated pipe for a predetermined length, the sheath pipe and the excavator are returned to the starting shaft.

[0005]

In the above technique, since the excavator is pulled back to the starting shaft through the inside of the perforated pipe, the cutter head is formed with an outer diameter smaller than the inner diameter of the perforated pipe. Therefore, the tunnel excavated in the ground by the cutter head passes through the excavator at best, and the tip of the perforated pipe is pierced into the ground around the tunnel according to the thrust acting, and the ground is collapsed. It is promoted while letting it. Therefore, there is a problem that a large thrust force is required and the capability of the original pushing device must be increased.

In recent years, it has been required to construct a vertical shaft of about a manhole or to lay a pipeline without constructing an incoming vertical shaft in consideration of traffic conditions and influences on surrounding private houses.

An object of the present invention is to provide an excavator which can be propelled at the same time as a pipe by unraveling the ground around the tunnel without significantly increasing the capacity of the original pusher.

[0008]

In order to solve the above-mentioned problems, an excavator according to the present invention has a cutter head for excavating the natural ground, and the cutter head is larger than the inner diameter of a pipe buried in the ground. Has a small outer diameter, is connected to the pipe through a thrust transmission member and a shear pin, and is propelled together with the pipe by the thrust acting on the pipe, and when the pipe reaches a predetermined propulsion length, the pulling force transmission member is used. In the excavator that cuts the shear pin by the extracted pulling force transmitted through the pipe and is pulled back to the starting shaft through the inside of the pipe, the cutter head has a face plate and a tapered portion or a curved face portion on the outer periphery of the face plate. A cutter head main body composed of a tubular portion provided with a roller cutter or a roller bit on the outer peripheral portion of the cutter head such that the peripheral surface thereof is along the tapered surface or the curved surface portion. And wherein the Rukoto.

In the above excavator, when thrust is applied to the pipe while the cutter head is not driven, this thrust acts on the excavator via the thrust transmission member, and the cutter head presses against the face. For this reason, the portion facing the tapered surface or the curved surface formed from the outermost periphery to the center of the cutter head, that is, the portion where the inner peripheral surface and the end surface of the excavated tunnel intersect with each other, is divided by the vertical direction with respect to the tapered surface and the curved surface. Power acts.

When the cutter head is driven from the above state, the vertical component force acting on the tapered surface and the curved surface is combined with the driving force of the cutter head. This resultant force acts in the downstream direction of rotation of the cutter head and outward from the inner circumferential surface of the tunnel, and this force can loosen the inner circumferential surface of the tunnel and the ground in the radial direction (depth direction). .

Therefore, the tip of the tube having the inner diameter larger than the outer diameter of the cutter head is inserted into the ground loosened by the cutter head, and the thrust to be applied can be reduced.

After the pipe has been propelled for a predetermined length, when the pulling force is transmitted to the excavator via the pulling force transmitting member, the shearing pin is cut by the pulling force and is pulled back to the starting shaft through the inside of the pipe. At this time, since the outer diameter of the cutter head is formed to be smaller than the inner diameter of the tube, the head does not interfere with the tube and can be easily pulled back.

In the above machine, it is preferable to provide a gravel crushing bit on the outer peripheral surface of the cutter head.
It is preferable to provide a notch for capturing gravel on the outer peripheral surface of the cutter head.

In the excavator constructed as described above, it is difficult to loosen the inner peripheral surface of the tunnel and the ground in the depth direction from the inner peripheral surface of the tunnel due to the combined force of the thrust acting on the excavator and the driving force of the cutter head. It can be applied to rocks containing gravel or rocks having rock layers, and gravel in the vicinity of the inner surface of the tunnel can be crushed by a gravel crushing bit and taken from the notch.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the excavator will be described below with reference to the drawings. FIG. 1 is a diagram for explaining the overall configuration of the excavator, showing a state in which it is arranged inside a pipe, FIG. 2 is a front view of a cutter head, FIG. 3 is a sectional view of the cutter head, and FIG. 4 is a cutter head. And FIG. 5 is a perspective view including a tip portion of the pipe, FIG. 5 is a diagram illustrating a state of propelling the excavator and the pipe, and FIG. 6 is a diagram illustrating an initial state when the excavator is pulled back after propelling a pipe of a predetermined length. FIG. 7 is a diagram illustrating a state when the excavator is pulled back.

First, a schematic structure of the excavator A and a connection structure with the pipe C will be described with reference to FIG. This machine A is
A shield body 1 having a cutter head B rotatably attached to its tip and a tail shield 2 are connected by a plurality of direction control jacks 3 and a rod (not shown). The shield body 1 and the tail shield 2 are arranged inside a pipe C to be buried in the ground, the tail shield 2 and the pipe C are connected via a thrust transmission member D, and the shield body 1 and the pipe C are connected to each other by a shear pin 4. Connected through. The tail shield 2 of the excavator A is connected to a pulling force transmission member E that transmits a pulling force to the excavator A.

A partition wall 5 is provided at a predetermined position of the shield body 1, a soil cutting chamber 6 is formed on the front side (left side in FIG. 1) of this partition wall 5, and a rear side (in FIG. 1) of the partition wall 5 is formed. (Right side)
Therefore, the in-machine room 7 is formed inside the tail shield 2. The cutter head B and the cone rotor 8 are arranged on the side of the earth cutting chamber 6, and the cutter head B is installed in the machine chamber 7.
A motor 9 for driving the machine, an optical system 10 for monitoring a deviation of the excavator A from a planned laying line, and other necessary instruments are arranged.

A bracket 11 is provided at the rear end of the tail shield 2.
The thrust transmission member D and the extraction force transmission member E are attached to the bracket 11.

After the excavator A is pulled back, the pipe C is left in the ground to form a part of the pipe line, and may be any pipe as long as it can meet the intended pipe line specifications. It is not a limitation. That is, the pipe C may be substantially equal to or longer than the excavator A. However, it is preferable that the deviation from the planned laying line that may occur with the propulsion of the excavator A and the pipe C can be controlled.

Therefore, in the present embodiment, the pipe C is connected to the front casing 21 corresponding to the shield body 1 of the excavator A.
And a tail casing 22 corresponding to the tail shield 2, so that when the direction control of the excavator A is performed, the respective casings 21 and 22 can bend together with the corresponding shield body 1 and tail shield 2. doing.

Rails 21a and 22a having flat surfaces are fixed to the inner circumferences of the casings 21 and 22 along the longitudinal direction, and the outer circumferences of the shield body 1 and the tail shield 2 are
Sliding member 1 that slides in contact with the rails 21a, 22a
a and 2a are fixed.

A taper surface whose diameter increases toward the outside is formed at the tip of the front casing 21, and a sharp tip 21b is formed by this taper surface. Therefore,
When the thrust is applied, the tip 21b is the cutter head B.
It is possible to stab at a position radially separated from the inner peripheral surface of the excavated tunnel, scrape off the inner peripheral surface, and introduce the earth and sand into the earth cutting chamber 6.

The thrust transmission member D is for transmitting the thrust applied to the pipe C by the original pushing device to the excavator A,
The structure is not particularly limited as long as it has this function. In this embodiment, the bracket 23 is fixed to the inner peripheral surface of the tail casing 22, and the rod 24 is attached to the bracket 23 and has a tip connected to the bracket 11 provided at the rear end of the tail shield 2. . However, a configuration other than the above may be used, for example, a plurality of hydraulic jacks are arranged on the outer periphery of the tail shield 2, and the hydraulic jacks are driven to apply a pressing force to the tail casing 22 to connect the two. It is also possible to configure.

The pull-out force transmitting member E is composed of a plurality of steel bars (PC steel bars) 25 arranged in parallel, one end of the PC steel bars 25 is connected to the bracket 11 provided on the tail shield 2, and the other. The end is connected to the push wheel of the pusher. This PC steel bar 25 has a length substantially equal to that of the pipe 26 following the tail casing 22, and has already been propelled.
It is extended every time a new pipe 26 is connected to 26.

Next, the cutter head B will be described with reference to FIGS.
Will be described in detail. The cutter head B is
A disk-shaped face plate 31 and a cylindrical portion 32 provided on the outer periphery of the face plate 31.
And a boss 33 that fits a shaft (not shown) that transmits the driving force of the motor 9, and a rib that connects the boss 33 to the face plate 31 and the tubular portion 32.
34, and has sufficiently high rigidity.

The face plate 31 is formed with a taper portion 31a having a predetermined angle from the outer peripheral side to the center side, and a flat surface portion 31b is formed continuously with the taper portion 31a. The angle of the tapered portion 31a is not particularly limited. However, it is preferably about 30 to 45 degrees. Further, although the tapered portion 31a is formed on the outer peripheral portion of the face plate 31 in the present embodiment, the tapered portion 31a does not necessarily have to be tapered and may be a curved surface.

A roller bit 35 and a roller cutter 36, which are arranged parallel to the inclination angle of the tapered portion 31a, are rotatably attached to the tapered portion 31a. A plurality of roller bits 35 are rotatably attached to the flat surface portion 31b. Furthermore, from the tapered portion 31a to the flat portion 31
The scraper 37 is attached to b.

Further, the face plate 31 is formed with a hole 38 for taking in earth and sand or gravel excavated from the ground to the side of the corn rotor 8.

Bits 39 for crushing gravel are attached to the outer peripheral surface of the cylindrical portion 32 at a predetermined interval. As shown by the chain double-dashed line in FIG. 2, the diameter of the circle connecting the tops of the bits 39 is the diameter of the circle connecting the outermost parts of the roller bit 35 and the roller cutter 36 attached to the tapered portion 31a of the face plate 31. And the diameter of the circle is smaller than the inner diameter of the pipe C.

A plurality of notches 40 are formed at predetermined positions of the tubular portion 32 so that the gravel crushed by the bit 39 and the earth and sand scraped by the tip portion 21b of the pipe C are taken into the cone rotor 8 side through the notches 40. It is configured.

In the cutter head B constructed as described above, when the thrust S acts on the excavator A, as shown in FIG. 4, the taper portion 31a of the face plate 31, the roller bit 35 attached to the taper portion 31a, the roller A component force P corresponding to the inclination angle of the tapered portion 31a is generated in the cutter 36. When the cutter head B is driven by the driving force F, this driving force F
The resultant force R of the component force P and the component force P acts in the depth direction of the inner peripheral surface of the excavated tunnel, and it is possible to loosen a predetermined depth portion in the natural ground.

Particularly, when the ground is a layer containing gravel, the gravel existing on the outer peripheral portion of the head B is crushed by the gravel crushing bit 39 attached to the tubular portion 32 of the cutter head B. Is possible. Therefore, the vicinity of the inner peripheral surface of the excavated tunnel does not contain gravel, and the obstacle when the tip end portion 21b of the front casing 21 forming the pipe C is pierced on the inner peripheral surface of the tunnel is removed. Is possible.

The gravel crushed by the bit 39 and the earth and sand scraped off by the tip portion 21b are the cutter head B.
It is introduced into the crushing chamber 6 through the notch 40 formed in the cylindrical portion 32, is compacted inside the chamber 6 by the cone rotor 8, and is discharged to the outside. Further, the gravel and the earth and sand excavated from the cutting face pass through the hole 38 formed in the face plate 31 and the crushing chamber 6
Is discharged to the outside while being compacted by the cone rotor 8.

Therefore, when the excavator A and the pipe C are propelled, the tip 21b of the front casing 21 forming the pipe C is formed.
Will be stabbed in the inner peripheral surface of the tunnel that has been loosened by the cutter head B in advance, and it will be possible to easily propel it with a small thrust.

Next, a procedure for propelling the excavator A and the pipe C configured as described above and for retracting the excavator A through the inside of the pipe C will be described with reference to FIGS.

The pipe C and the excavator A arranged inside the pipe C and connected to the front casing 21 via the shear pin 4 and the tail casing 22 via the thrust transmission member D are the starting shaft (not shown). The tail casing 22 or the casing 22 is
A thrust S is applied to the pipe 26 following the pipe. Simultaneously with the application of the thrust S, the cutter head B is driven to excavate the face with the roller bit 35, the roller cutter 36, and the scraper 37 attached to the head B, and a predetermined depth from the inner peripheral surface of the excavated tunnel. The part is loosened by the roller bit 35 and the roller cutter 36 attached to the taper part 31a (see FIG. 5).

When the excavator A is arranged inside the pipe C, the cutter head B is arranged in front of the tip portion 21b of the front casing 21. Therefore, the tip portion 21b is excavated by the cutter head B and stabbed in a tunnel whose inner peripheral surface is loosened, and is easily propelled by a small thrust S.

When the propulsion length of the pipe 26 matches the preset length, the excavator A is pulled back through the pipe C and the pipe 26 to the starting shaft. This operation is performed by releasing the connection between the tail casing 22 of the pipe C and the tail shield 2 of the excavator A by the thrust transmission member D, connecting the PC steel bar 25 to the original pushing device, and pulling it back.

When the pulling force is transmitted to the excavator A through the PC steel bar 25, the pulling force is transmitted from the tail shield 2 to the shield body 1 and further to the front casing 21 via the shear pin 4. Then, the shear pin 4 is cut and the connection between the shield body 1 and the front casing 21 is released (see FIG. 6).

After cutting the shear pin 4, the excavator A is pulled back to the starting shaft through the insides of the pipe C and the pipe 26 by the pulling force continuously applied, and the pipe C and the pipe left in the ground.
A pipeline is laid by 26 (see FIG. 7).

[0041]

As described in detail above, in the excavator according to the present invention, a taper surface or a curved surface is formed from the outer periphery to the center of the cutter head so that the thrust acting on the excavator and the tapered surface or the curved surface can be adjusted. It is possible to loosen the ground at a predetermined depth from the inner peripheral surface of the tunnel by generating an outward component force and a resultant force of the component force and the driving force of the cutter head. For this reason, the tip end portion of the propelled pipe is stabbed into the ground that has been loosened in advance, and it can be easily propelled with a small thrust.

Further, by providing a gravel crushing bit on the outer peripheral surface of the cutter head, the gravel in the vicinity of the inner peripheral surface of the tunnel can be crushed to easily insert the tip of the pipe into the ground. Can be done.

Further, by providing a notch on the outer peripheral surface of the cutter head for taking in the crushed gravel, the gravel crushed by the bit and the earth and sand scraped by the tip of the pipe stuck in the tunnel are taken into the crushing chamber. It has features such as being able to.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the overall configuration of a machine, showing a state in which it is arranged inside a pipe.

FIG. 2 is a front view of a cutter head.

FIG. 3 is a sectional view of a cutter head.

FIG. 4 is a perspective view including a cutter head and a tip portion of a tube.

FIG. 5 is a diagram illustrating a state in which a machine and a pipe are propelled.

FIG. 6 is a diagram illustrating an initial state when the excavator is pulled back after propelling a pipe of a predetermined length.

FIG. 7 is a diagram illustrating a state when the excavator is pulled back.

[Explanation of symbols]

 A Excavator B Cutter head C Pipe D Thrust transmission member E Extraction force transmission member 1 Shield body 2 Tail shield 3 Directional control jack 4 Shear pin 5 Partition wall 6 Soil chamber 7 Machine room 8 Cone rotor 9 Motor 10 Optical system 11 Bracket 21 Front Casing 21b Tip part 22 Tail casing 23 Bracket 24 Rod 25 PC steel bar 26 Tube 31 Face plate 31a Tapered part 31b Flat part 32 Cylindrical part 33 Boss 34 Rib 35 Roller bit 36 Roller cutter 37 Scraper 38 Hole 39 Bit 40 Notch

Claims (4)

[Claims] 1. A cutter head for excavating a natural ground,
The cutter head has an outer diameter smaller than the inner diameter of a pipe buried in the ground, is connected to the pipe through a thrust transmission member and a shear pin, and is propelled together with the pipe by the thrust acting on the pipe. Is an excavator that cuts the shear pin by the pulling force transmitted through the pulling force transmitting member when it reaches a predetermined propulsion length and is pulled back to the starting shaft through the inside of the pipe, wherein the cutter head is A cutter head main body composed of a face plate and a cylindrical portion provided on the outer periphery of the face plate via a tapered portion or a curved surface portion is provided, and a roller cutter or a roller bit is provided on the outer peripheral portion of the cutter head. An excavator characterized by being provided along a surface or a curved surface portion. 2. The excavator according to claim 1, wherein a gravel crushing bit is provided on an outer peripheral surface of the cutter head. 3. The excavator according to claim 1, wherein a notch for taking in gravel is provided on an outer peripheral surface of the cutter head. 4. The excavator according to any one of claims 1 to 3 is used, and a component force corresponding to an inclination angle with respect to the excavation direction is generated in a roller cutter or a roller bit according to a thrust acting on the excavator. At the same time, a resultant force of the component force and the driving force of the cutter head is generated, and the resultant force excavates while unraveling a natural ground portion corresponding to the outer peripheral portion of the cutter head.