JP2879283B2 - Preparation method for pretreatment work such as ground improvement in tunnel excavation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction method for preparing a pre-treatment work such as ground improvement, preparatory work or ground exploration in front of a face to be excavated from a face.

[0002]

2. Description of the Related Art Generally, in a shield method, a tunnel boring machine which excavates a gripper as an excavation reaction force when the ground is solid such as rock, or a tunnel lining portion such as a segment or a cast-in-place in soft ground is used as an excavation reaction force. An excavating shield machine or, more recently, a machine having both of these machines is used. All of these excavators excavate tunnels with the excavator on the cutter surface while rotating the cutter head. Etc. may be performed.

[0003] In order to perform this pre-processing operation, the excavator is largely retreated from the face, and after excavating to the front of the face, boring or excavation is performed on the horizontal shaft or the upper shaft by hand digging or blasting. As shown in FIG. 3, the boring 40 is performed diagonally forward from behind the cutter head 10 and then the ground 7 is removed.
In some cases, ground improvement such as press-fitting of a chemical solution 8 is performed.

[0004]

However, the above-mentioned conventional work on the front face of the face has a defect in safety, affects work efficiency, and has problems in terms of construction period and economy.
In addition, drilling diagonally forward and then improving the ground may require injecting a chemical solution into a useless area for excavation, or lacking the reliability of ground exploration due to insufficient position of the transmitter in the borehole. There were challenges.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and an object of the present invention is to improve the efficiency of excavation work and to accurately perform a pre-treatment work for excavation such as ground improvement. An object of the present invention is to provide a preparation method for pretreatment work in excavation.

Another object of the present invention is to prepare for a pretreatment operation in a tunnel excavation in which the pretreatment operation can be quickly performed by simple means without largely changing the basic configuration of a conventional excavator. No construction method will be provided.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned object, and its gist is that an apparatus main body and a cutter rotatably supported by the apparatus main body and having a cutter surface on a front surface in a digging direction. Using an excavator equipped with a head and a tilting means for tilting the cutter head at an arbitrary angle with respect to the excavation direction, by tilting the angle of the cutter head in the front-rear direction, and cutting between the upper end or lower end of the cutter head and the pit wall. By providing a gap in the ground and drilling a borehole in the ground in the tunnel line to be excavated from the gap, the boring hole can be used for pretreatment work such as ground improvement, pre-reception work, or ground exploration. It is in the preparatory method for pre-treatment work such as ground improvement in tunnel excavation used.

[0008]

According to the present invention, a clearance is provided between the upper end or lower end of the cutter head and the pit wall only by inclining the angle perpendicular to the tunnel excavation axis by the tilting means in the forward or backward front-rear direction. Pre-excavation processing such as ground improvement is performed from the borehole.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for preparing a pretreatment operation in tunnel excavation according to the present invention will be described below with reference to a tunnel boring machine as an excavator used in the present invention.

A tunnel boring machine as one of the excavators used in the present invention will be described as an example with reference to the accompanying drawings.

In FIG. 1, a tunnel boring machine includes a cutter head 10 located in front of a digging direction.
The main part is constituted by a main frame 20 as an apparatus main body that supports the cutter head 10 and a gripper part 30 for taking excavation reaction force.

The cylindrical cutter head 10 has a circular cutter surface 11 on the front surface in the direction of excavation.
Are provided with a large number of excavating cutters 12, and the cutter head 10 is driven to rotate by an electric motor 14 to excavate the ground. Further, the cutter head 10 is supported by the main frame 20 behind it via a connecting rod 21 ′ of the movable connecting portion 21 so as to be tiltable.

A main frame 20 having a box shape
Is a tilting cylinder 2 for tilting the cutter head 10
6, and a gripper portion 30 that is slidably fitted to the main frame 20 is disposed at a rear portion. The tip of the tilt cylinder 26 is the cutter head 1
The cutter drum 1 is fixed to the lower end of the
Numeral 0 rotates up and down around the connecting rod 21 'of the movable connecting portion 21 so that the inclination angle of the cutter surface 11 with respect to the excavation direction can be set arbitrarily. At the rear end of the main frame 20, a rear support 23 for supporting the main frame 20 from below when the fixing by the gripper unit 30 is released is provided. It is a mechanism that can expand and contract depending on the structure. A belt conveyor 22 is fixed to the side of the main frame 20, and the cutter head 10
The cutting scrap scraped up by the scraping plate 13 provided on the belt conveyor falls on the belt conveyor 22 and is transported rearward.

The gripper section 30 includes a main frame 20.
The gripper cylinder 31 is provided with a gripper cylinder 31 protruding from both sides in the horizontal direction so as to extend and contract, and a gripper shoe 32 that is curved in an arc shape along the pit wall 7 is disposed at a tip end thereof. When the excavation reaction force is taken, the gripper cylinder 31 is used.
Is extended, and the pit wall is pressed by the gripper shoe 32, thereby fixing the gripper portion 30 at this position. Also, the base end of the thrust cylinder 24 is connected to the gripper part 3.
0, and the tip is fixed to the main frame 20 side as a machine main body. At the time of excavation, by extending the thrust cylinder 24, a reaction force is applied to the gripper unit 30 fixed as described above, Frame 2
The cutter drum 10 is advanced integrally with the cutter drum 10.

[0015] The tunnel boring machine includes:
There is a cutter head support 15, which advances with the excavation of the cutter head using the gripper portion 30 as a reaction force, and supports the tunnel boring machine with the rear support 23 after excavation. Steps of excavating a tunnel by the tunnel boring machine A configured as described above will be described in order.

First, the tilting cylinder 26 is expanded and contracted so that the cross section of the excavation has a predetermined elliptical shape, and the cutter head 10 is inclined forward and upward at a predetermined angle with respect to the excavation direction.

Simultaneously with or before or after this step, the gripper cylinder 31 is extended to both sides in the horizontal direction, the downhole wall is pressed by the gripper end 32, and the gripper section 30 is fixed. The initial position of the gripper portion 30 at the time of starting excavation is located at a position indicated by a broken line with reference numeral 30 'in FIG. At this time, the rear support 23 at the rear end is in a contracted state.

Next, the cutter head 10 is driven to rotate by the electric motor 14, the thrust cylinder 24 is extended, and the cutter head 10 is advanced by applying a reaction force to the fixed gripper portion 30 described above. Thereby, the gripper unit 30 maintains the fixed position, and the cutter head 10 moves forward together with the main frame 20.

Excavation is continued as described above, and excavation is temporarily stopped when a predetermined span is excavated. At this time, the rear support 23 at the rear end is extended so that the main frame 20 can be supported. Next, the gripper cylinder 31 is contracted, and the fixing of the gripper unit 30 is released.
At this time, the main frame 20 is supported by the rear support 23. Next, the thrust cylinder 24 is contracted, and the gripper portion 30 is moved to the above-described initial position (reference numeral 30 ') to prepare for the next excavation. These steps are repeated to excavate tunnels sequentially.

As described above, when a tunnel is excavated by the cutter surface 11 which is inclined in the vertical direction, the excavation cut is made.
The surface is a horizontally long ellipse suitable for road construction (FIG. 2). This oval is a horseshoe-shaped tunnel to be built
It has a very close shape to the cross section, wasteful Yohori portion C
Can be reduced. If the tilting cylinder 26 is expanded and contracted, the cutter head 10 can be excavated in an elliptical shape by changing the setting of the tilt angle of the cutter head 10.
Since the inclination of the connecting portion between the cutter head 5 and the cutter head 10 also changes, the cylinder of the cutter head support 15 is expanded and contracted.
Let it.

Therefore, in the present invention, a pretreatment operation using the above-described tunnel boring machine, for example, improvement of the ground to be excavated will be described.

First, the upper part of the cutter head 10 perpendicular to the excavation axis is inclined forward to leave a gap h between the upper end of the cutter head 10 and the wellhead wall 7.

Next, a boring machine 43 mounted on a pedestal 41 fixed on the main frame 20 of the tunnel boring machine via cylinders 42 and 44 is driven to form a boring hole 40 at a required position on the upper surface of the face. The cylinders 42 and 44 adjust the vertical movement and the tilt movement of the boring machine 43.

In this way, the same boring machine 43
Inject chemicals such as cement milk and quick-setting admixture from around the nozzle at the tip of the. Although this chemical solution is used also as a boring machine as shown in FIG. 1, a separate injection device may be used.

In this way, the excavation of the tunnel boring machine is resumed after the ground improvement, thereby preventing the discharge of groundwater and the collapse of the ground into the tunnel.

In the present invention, in addition to the ground improvement as a pretreatment operation, an ultrasonic transmitter and a receiver for ground exploration are mounted in the boring hole 40 by the ground improvement preparation method to excavate the ground in the excavation direction. It is possible to investigate beforehand.

In the above embodiment, the lower portion of the cutter head is lowered backward so as to provide a gap between the upper end of the cutter head 10 and the pit wall as shown in FIG. It is also possible to perform the pretreatment work after retreating or tilting the upper portion of the cutter head backward to leave a gap between the pit walls.

[0028]

According to the present invention, the cutter head of the excavator can be inclined at an arbitrary angle, and the cutter head is inclined in the front-rear direction to provide a gap between the upper end or lower end thereof and the pit wall. Since the boring hole as a preparation process of the pretreatment work such as ground improvement is drilled in front of the excavation, the ground improvement and the ground exploration can be performed safely and efficiently in the work.

In addition, this work method enables the ground improvement and the like to be rapidly performed by a simple operation such as simply adjusting the cutter head of the excavator to an arbitrary angle.

[Brief description of the drawings]

FIG. 1 is a sectional view of an excavator for explaining a method of the present invention.

FIG. 2 is an explanatory view of a tunnel section showing a state of a gap between a cutter head and a pit wall when the cutter head of the excavator in FIG. 1 is inclined.

FIG. 3 is a schematic diagram showing a pre-excavation processing state of an excavator by a conventional method.

[Explanation of symbols]

 8 Chemical solution 10 Cutter head 20 Main frame 30 Gripper part 40 Boring hole 43 Boring machine h Clearance between cutter head and pit wall

──────────────────────────────────────────────────続 き Continuing on the front page (74) One of the above-mentioned agents Patent Attorney Kazui Sakai (72) Inventor Takahiro Fujii 2-10-2 Otowa, Bunkyo-ku, Tokyo Otowa NS Building 7F Inside the Advanced Construction Technology Center ( 72) Inventor Shin Terauchi 2-5-8 Kita-Aoyama, Minato-ku, Tokyo Hazama Co., Ltd. (72) Inventor Yoshiaki Ishida 4-12-20 Nihonbashi Honcho, Chuo-ku, Tokyo Inside Sato Kogyo Co., Ltd. (72) Inventor Minami Good friend 3-1-1 Ueno, Hirakata-shi, Osaka Inspector in Osaka Plant of Komatsu Manufacturing Co., Ltd. Toshiaki Nakamaki (56) References JP-A-62-220694 (JP, A) JP-A-4-353192 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) E21D 9/06 301 E21D 9/04 E21D 9/10

Claims (1)

(57) [Claims] An apparatus main body, a cutter head rotatably supported by the apparatus main body and having a cutter surface on a front surface in a digging direction, and a tilting means for tilting the cutter head at an arbitrary angle with respect to the digging direction. Using an excavator equipped with, a gap is provided between the upper end or lower end of the cutter head and the pit wall by inclining the angle of the cutter head in the front-rear direction, and a boring hole is dug into the ground in a tunnel line to be dug from the gap. A preparation method for a pretreatment operation such as a ground improvement in a tunnel excavation in which the borehole is used for a pretreatment operation such as a ground improvement, a preparatory work, or a ground exploration by drilling in a forward direction.