JPH08184286A - Excavation method of large diameter tunnel and excavating device used for the work - Google Patents

Abstract

PURPOSE: To lessen the excavatingload, by enlarging the periphery of an advanced guide tunnel by a first cutter face to form an elliptic shape and further, opening it by a second cutter face to make a similar large diameter tunnel. CONSTITUTION: In the first stage enlarging cutting part B of a reaming machine, the first gripper 28 of the main beam 32 inserted in an advanced guide tunnel 1 is extended and after having pushed the tunnel wall, the front support leg 18 is retracted and the cutter head 22 is rotated and further, the periphery of the advanced tunnel 1 is excavated to form the first stage elliptic tunnel shape while pulling forward the first main beam 32. In parallel with the first stage enlarging cutting part B, the second gripper 42 fitted to the double-pipe structural and the third main beam 30 so as to be able to freely slide is extended by the second stage enlarging cutting part C to press the excavated tunnel wall to get a reactive force and the ground is cut by the second cutter head. In this case, a pushing-up force acts on the first and second roof supports 20, 46 when excavating a laterally long elliptic tunnel and the roof supports prevent the tunnel from bending upward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for excavating a large-diameter tunnel and an excavation device used for the excavation, and more particularly to an excavation method and an apparatus for constructing a large-diameter tunnel having an elliptical cross section in a new or existing advanced tunnel.

[0002]

2. Description of the Related Art Various expansion tunnel construction methods have been proposed for expanding an existing or newly established tunnel. However, in these tunnel construction methods, the leading small-diameter and trailing large-diameter cutter surfaces are both circular, and there is a particular problem if the design cross section is circular, such as a water channel or water supply / sewer system. However, the design cross-sections of railways, roads, etc. with multiple lanes such as two lanes often have a horseshoe-shaped tunnel cross section.Therefore, when excavating with a circular cross section, an overexcavation part will occur and it will excavate to unnecessary areas By doing so, there is a drawback that the construction period is long and the cost is high.

In order to solve this drawback, the applicant has advanced a new advanced pit with a pilot excavator in a normal circular tunnel section, and then a reaming excavator to excavate a large circular cutter surface. We have applied for a method of excavating a large-diameter tunnel that can obtain an elliptical enlarged tunnel by excavating at an arbitrary angle with respect to the direction.

[0004]

However, in the above-mentioned conventional technique, the geology for reaming excavation can be grasped by the advanced shaft of the pilot excavator.
Due to the centering effect of the central part of the tunnel of the advanced mine, the diameter expansion excavation by the reaming excavator becomes easier than the case of excavating the expansion tunnel at once. The advanced pit can be used as a drainage pit and a ventilation pit. When the upper part is excavated, the lower part of the excavation obtains the same effect as so-called nuclear leaving and stabilizes the face. However, this is fine if there is not much difference between the diameters of the advanced pit and the expansion tunnel, but when expanding to a large-diameter tunnel with a larger diameter difference than a small advanced pit, it can be used as a reaming excavator. A heavy load is applied to the caliber machine and a large amount of misalignment must be discharged at one time, and the digging effect due to the above-mentioned core removing effect cannot be sufficiently enhanced. In this case, even if the tunnel diameter of the advanced pit is increased, the excavation of the advanced pit itself becomes a great work, and the excavation efficiency is not good as a whole.

The object of the present invention is to solve the above-mentioned drawbacks, and is a construction method capable of efficiently and safely excavating a large-diameter tunnel having an oval cross section that is very large as compared with an existing or newly constructed advanced pit. And the equipment will be provided.

Another object of the present invention is to install an advanced pit of a pilot excavator or an enlarged tunnel of a reaming excavator with a large cross section at a time so as not to excavate with a large load, or to install a new one. By excavating the continuous cutting surface of the first step and the subsequent second step against the face of the advanced mine tunnel, the excavation method for a large diameter tunnel that reduces the looseness of the ground and enables rapid construction. The digging device is provided. In this case, since the second cutting surface of the reaming excavator almost uniformly hits the ground cut by the preceding first cutting surface, more efficient excavation and excavation of a large-diameter tunnel with less mechanical vibration We can also provide the construction method and equipment that can be used.

[0007]

The present invention has been made based on the above-mentioned object, and the gist thereof is a tunnel having an elliptical cross section having a diameter larger than that of a new or existing advanced tunnel. In order to expand the outer ground of the advanced tunnel using the advanced tunnel as a pilot tunnel, the first circular cutter surface is tilted with respect to the excavation direction to expand the tunnel section into an elliptical shape. In order to further widen the outer circumference of the tunnel, the second circular cutter surface is tilted with respect to the excavation direction in order to further expand the tunnel expansion step and the tunnel expanded in the step. It is a method of excavating a large-diameter tunnel, which consists of a tunnel widening process that expands the cross section of the tunnel.

Another aspect of the present invention is to provide a front support leg and a first gripper installed on a first main beam which is inserted into a new or existing advanced tunnel, and the gripper as a reaction force. The first rotary cutter head, in which the circular cutter surface for expanding the outer peripheral ground of the advanced pit tunnel into an elliptical shape by expanding and contracting the jack No. 1 inclining with respect to the excavation direction, is expanded into an elliptical shape by the rotary cutter head. The rear support leg installed on the second main beam inserted into the opened tunnel, the second gripper, and the second jack expanding and contracting by using the gripper as a reaction force to form the outer peripheral ground of the expanded tunnel into an elliptical shape. The excavation device is used for excavation of a large-diameter tunnel, which is composed of a circular cutter surface that expands in a horizontal direction and a second rotating cutter bed that is inclined with respect to the excavation direction.

The advanced mine may be an existing tunnel or a new tunnel using a pilot excavator such as a tunnel boring machine. For example, in the case of a two-lane road tunnel, the diameter of the cutter surface is 3.5 to 4.5 m. After the pilot excavator, the cutter surface (1
A large-diameter tunnel is opened by a reaming excavator having a diameter of 6.5 m to 7.5 m in the second step and a cutter surface diameter of 10 m to 12 m in the second step. In the case of a 3-lane road tunnel, the diameter of the cutter surface is 5
6m, first stage is 10-12m, and second stage is 20-2
Excavate with a 2m reaming excavator. Here, the pilot excavator is a tunnel boring machine having a circular cutter surface with a small cross section, and the reaming excavator means a circular cutter surface having a larger diameter than the circular cutter surface of the pilot excavator and further than the cutter surface. This is a tunnel boring machine in which a large-diameter horizontal cutter or a vertically-oriented elliptical cross section is obtained by sequentially excavating two stages of large-diameter circular cutter faces with respect to the excavation direction.

In addition to the tunnel boring machine, a shield machine or the like is used as the pilot excavator or the reaming excavator.

Further, a large diameter tunnel having an elliptical cross section excavates a rotating circular cutter surface of an excavator while inclining it with respect to the direction of excavation, but the inclination of the cutter surface is lowered forward (upper part precedes lower part). It is conceivable to excavate with the cutter surface facing up, but it is better to leave the sand at the bottom of the face for stability of face.

[0012]

The present invention uses an existing or newly constructed advanced pit and a reaming excavator capable of excavating with a two-step cutter surface for widening the advanced pit inclined with respect to the direction of excavation to form a large-diameter ellipse. Cross-section excavation is possible, and for tunnel construction that requires a flat cross section such as a horseshoe, economical excavation is possible with less excess excavation than a circular cross section. When constructing a two-lane road tunnel, the amount of excavated soil can be reduced by about 20%, depending on the tunnel design.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The pilot excavator used in the present invention and the reaming advancing device according to the present invention will be described below, and a method for excavating a large diameter tunnel using the mechanical device will be described.

In FIG. 1, the entire excavation device is a pilot excavator A for excavating an advanced pit 1 and is located behind the pilot digging machine A. It consists of a reaming excavator having two diameter-enlarged excavation parts B and C to be formed.

In the pilot excavator A, a cutter head 4 having a circular cutter surface 3 to which an excavation cutter is attached is rotatably attached to a main beam 17 as a main body of an apparatus via a drive shaft 6 of a hydraulic motor 5. I support you. In addition, the main beam 17 is provided with left and right grippers 8 that can expand and contract in the tunnel circumferential direction so that reaction force at the time of excavation is applied to the mine wall 7, and in front of the gripper 8 below the cutter head 4. A front support leg 9 is provided, and a rear support leg 10 is provided below the rear hydraulic motor 5.

In addition, behind the hydraulic motor 5, an auxiliary work carriage 11, a driving carriage 13 on which a driver's cab 12 is mounted, and a hydraulic drive carriage 14 on which a hydraulic pump unit 15 for driving the hydraulic motor 5 is mounted are connected in series. ing. Also, 16
Is a belt conveyor that conveys the scrap excavated by the cutter head 4 rearward.

The features of the reaming excavator are roughly divided into a first-stage diameter-enlarged excavating section B and a second-stage diameter-enlarging excavating section C provided with two circular cutter surfaces.

The first-stage diameter-enlarged excavation section B has a circular cutter surface having a larger diameter than the advanced pit excavated by the pilot excavator, and the cutter surface has a large number of rotatable disk cutters with different orientations. The first electric motor 21 rotates the first cutter head 22 to excavate the outer ground of the advanced mine 1. Further, the cutter head 22 is supported by the first main beam 32, and is inclined forward with respect to the excavation direction. The front portion of the first main beam 32 is equipped with the front support leg 18, the first hydraulic jack 19 for propelling the first cutter head 22, and the first gripper 28.

In order to propel the first cutter head 22 with the first hydraulic jack 19, the main beam 32 is slidably inserted into the main body of the first gripper 28, and the front end 47 of the first jack 47 is slidably inserted. By fixing the rear end 48 to the inside of the main body of the first gripper 28 (FIG. 2) while fixing it to the first main beam 32, the expanded first gripper 28 is applied to the advanced mine 1. When excavating while advancing the advanced mine 1 by the first cutter head 22 that rotates while extending the first hydraulic jack 19 by taking a reaction force, when one digging of the first jack 19 is completed, The front support leg 18 which has been contracted until it is grounded (FIG. 3), and then contracts the first gripper 28 and contracts the first hydraulic cylinder 19 to move the first gripper forward. To do. By stretching the moved gripper, it hits the advanced mine 1 to take reaction force and prepare for the next excavation (Fig. 4).

Reference numeral 20 denotes a roof support which is configured to rotate a support rod 39 having upper and lower ends pin-coupled by a cylinder 37 to move up and down so as to prevent the cutter surface from being raised during excavation.

The second-stage diameter-enlarged excavating section C has a circular cutter surface having a larger diameter than the tunnel 43 excavated and widened by the first-stage diameter-enlarging excavating section B, and the cutter surface has a large number of different directions. The second electric motor 27 rotationally drives the second cutter head 31 to excavate the outer peripheral ground of the tunnel 43 widened at the first stage. The cutter head 31 is supported by the main beam 30 and is slanted forward with respect to the excavation direction. Further, the rear support leg 29 is attached to the third main beam 30,
The rear end 49 of the second hydraulic jack 40 for propelling the second cutter head 31 is fixed to the third main beam 30, and the front end 50 of the second jack 40 is fixed to the inside of the main body of the second gripper 42. By doing so, the second jack 40
By contracting, the cutter head 31 can be rotated to advance forward. In this case, the third main beam 30 is slidably inserted into the main body of the second gripper 42, and is fixed to the first cutter head 22 inside the third main beam 30. Second behind
The main beam 41 and the rear end 51 of the first cutter head 22 and the second cutter 51.
The first and second hydraulic cylinders 19 and 40, which are different from the cutter head 31 of FIG. Of course, although there is some error in the excavation speed between the first and second cutter heads depending on the nature of the ground and the amount of excavation of the widening gap, both cutter heads simultaneously excavate due to the edge cutting. On the upper part of the main frame 44 to which the inclined cutter head 22 is attached, a second roof support 46 that is lifted up and down by a support rod 35 pivotally attached at both ends by a cylinder 38 to be attached to and detached from rock so that it does not float up during excavation. It is installed.

A belt conveyor 26 is installed from the front of the central hole of the first cutter head 22 to the rear of the central hole of the second cutter head 31 to convey the earth and sand excavated by the respective cutter heads. . The support erector 25 supports the outer circumference of the large-diameter tunnel 36, which is finally excavated with H steel, in a circular shape. After that, the rock drill 23 strikes a rock bolt on the rock mass, and the concrete is sprayed by the spraying machine 24. I am trying to spray it. Note that the shovel car 33, the dump truck 34, and the like are used to transport the earth and sand outside the tunnel mine.

Therefore, the first and second cutter heads 2
2 and 31 both incline downward by advancing the upper part, so that the surrounding ground 7 of the advanced mine 1 excavated in a circle by the circular cutter head 4 horizontally expands the tunnel one after another in an oblong oval shape. And widened to a large diameter tunnel 43
To drill. The cutter head 22 may be tilted upward, and by tilting it further to the left or right, a vertically elongated elliptical expanded tunnel can be obtained in the direction perpendicular to the tunnel axis.

When the cutter head 22 having a large diameter is inclined and advanced, for example, as shown in FIG. 1, when the upper portion is inclined forward, a pulling force of the drive cylinder 20 causes an excavation reaction force above the tunnel. In order to prevent the above and enable the tunnel to be accurately opened along the advanced pit, a downward pressing force is applied from above the first and second cutter heads 22 and 31 using the pit wall as a reaction force. For example, the cylinder 3
7,38 for the first and second roof supports 20,46
It is also possible to allow automatic control by a control device (not shown) so as to adjust

The process of the present invention will be described below using the excavation device having the above structure.

First, the gripper 8 is extended and pressure-bonded to the pit wall, and then the rear support leg 10 of the pilot excavator A is raised,
Using the gripper 8 as a reaction force, the gripper 8 is moved by the hydraulic motor 5.
While extending the stroke of the jack which becomes the drive shaft 6 penetrating the center of the drive shaft 6, the cutter head 4 provided at the tip of the drive shaft 6 is rotated to advance the small circular advanced shaft 1 shown in FIG.
After excavating a certain span, the front and rear support legs 9 and 10
Landing on the lower shaft wall and then contracting the gripper 8 and separating the drive shaft 6 from the shaft wall to contract the gripper 8
, And then the gripper 8 is extended again at the advanced position and pressed against the pit wall to support the front and rear support legs 9 and 10.
Is pulled up from the pit wall, and the digging continues again.

On the other hand, the first stage diameter expansion excavation section B of the reaming machine.
Is, after extending the first gripper 28 of the main beam 32 inserted into the advanced mine 1 and pressing against the mine wall of the advanced mine 1,
The front support leg 18 is contracted, and the first electric motor 21
While rotating the cutter head 22 and extending the first hydraulic jack 19 to draw the first main beam 32 inserted into the main body of the first gripper toward the front, the first stage around the advanced mine 1 To the elliptical tunnel 43. The forward movement of the first cutter head 22 at this time is because the second main beam 41 is pivoted in the third main beam 30 by the double tube structure and is edged, so that the second cutter head 22 is cut off. Although it is possible to separate from the advance of 31 and advance,
Either the same forward movement is made according to the forward movement speed of the first and second cutter heads 31 (the contraction of the second hydraulic jack 40 in this case is the same as that of the first hydraulic jack), or the first cutter head. With the second cutter head only (stop the first cutter head) by making the speed faster than that of the second one and simultaneously excavating until the second hydraulic jack extends one stroke. You can also drill.

Thus, when the first cutter head 22 finishes excavating for one span, the front support leg is extended to ground the lower end to the advanced pit, and then the first gripper 28 is contracted to move the pit wall. Away from the first hydraulic jack, the first hydraulic jack is contracted, the gripper 28 is moved forward, and then the first gripper 28 is extended and pressed again at a position close to the front to make them a reaction force, and thereby the first cutter. The head 22 is rotated to make a new dig.

In parallel with the first-stage diameter-enlarged excavating section B, a second
The stepped diameter excavation part C is the third main beam 30 having a double pipe structure.
The second gripper 42, which is slidably fitted with respect to, is extended and pressed against the widened tunnel 43, then the reaction force is applied to contract the second hydraulic jack, and the second electric motor 27
The cutter head is rotated to excavate. 1
After excavating the span, the lower end of the rear support portion 29 is grounded, the second gripper 42 is contracted, and the second hydraulic jack is extended to cover the second gripper with the second main beam 41. To the second hydraulic jack 40 while contracting the second hydraulic jack 40.
The cutter head 31 of is rotated to advance.

The first-stage diameter-expanded excavation portion B and the second-stage diameter-enlarged excavation portion C are merely pivotally connected, and it is not always necessary to interlock them, but the first and second hydraulic jacks are not necessary. 19,40
Simultaneous excavation can be performed by making the expansion and contraction spans of the two substantially the same.

The first roof support 20 and the second roof support 46 prevent the tunnel from being bent upward due to a lifting force when excavating the oblong tunnel. Further, the endless belt conveyor 26 conveys the scrap excavated in the first and second stages of excavation. Further, around the tunnel 36 excavated in the second stage, the support erector 25 supports the tunnel circumference in a ring shape with H steel, sprays concrete with the sprayer 24, and locks with the rock drill 23 if necessary. Construct bolts and tunnels. In the construction method of the present invention, the excavated ground may support the first cutter head 22 and the second cutter head 31 by spraying concrete or the like.

[0032]

As described above, according to the method of the present invention, when excavating a large-diameter tunnel in an existing or newly constructed advanced pit, first, the first cutter surface inclined around the advanced pit in the excavation direction is provided. Since it was expanded to an elliptical shape by using the second cutter surface to expand the expanded elliptical tunnel, a large diameter tunnel with a similar size was expanded. A large excavating load is not applied to the reaming excavator as compared with the case of excavating a tunnel, and a large-diameter tunnel can be excavated smoothly and efficiently at high speed due to the two-stage coring effect.

In a large-diameter tunnel having a final cross section such as a horseshoe, a horizontally elongated elliptical shape can be obtained by tilting a circular cutter head forward in the traveling direction. However, this horizontally elongated elliptical tunnel is weak near the crown. There are still safety issues such as the collapse of soil and sand on the ground, but 2
By excavating at the excavation part of the stage, safety is secured compared to conventional rapid excavation, and if necessary, by improving the ground by injecting chemical liquid, inserting lock bolts, etc. to the ground above the crown, Safer construction is possible.

Furthermore, since this safety is a two-step full-section excavation, the looseness of the ground is less and the safety is higher than the conventional method of excavating a large cross-section at once.

Furthermore, in the excavation of the elliptical tunnel section of the present invention, compared to the conventional horseshoe-shaped excavation, the transmission to the surroundings of the ground is smoother, and the tunnel is also arched and stable.

[Brief description of drawings]

FIG. 1 is an overall schematic vertical sectional view of an apparatus of the present invention.

FIG. 2 is a partially enlarged view showing a digging state of a first-stage diameter-enlarged excavating portion B in the reaming excavator of FIG.

FIG. 3 is a partially enlarged view showing the state immediately before the first gripper is advanced after the excavation of FIG. 2;

FIG. 4 is a partially enlarged view in which the first gripper of FIG. 3 is moved forward and then the first gripper is pressed against the pit wall and the front support leg is extended and grounded.

FIG. 5 is a portion of the reaming machine in a state where the second gripper by the second-stage diameter-enlarged excavating portion C is pressed against the pit wall and then the second hydraulic jack is contracted to advance the second cutter head. FIG.

FIG. 6 is a partially enlarged view of the state in which, after advancing the second cutter head in FIG. 5, the rear support leg is extended and then the second gripper is contracted.

FIG. 7 is a second hydraulic jack extended after the second hydraulic jack shown in FIG.
FIG. 4 is a partially enlarged view immediately before the excavation of the gripper is advanced over the second main beam, the second gripper is extended and pressed against the pit wall, and then the rear support leg is contracted to start the excavation again.

FIG. 8 is a cross-sectional view of the advanced shaft of FIG.

9 is an explanatory cross-sectional view of a large diameter tunnel obtained by the two-stage reaming excavator according to FIG.

[Explanation of symbols]

 A Pilot excavator B 1st stage expanded excavation part of reaming excavator C 2nd stage expanded excavation part of reaming excavator 1 Advanced mine 3 Cutter surface 4 Cutter head 5 Hydraulic motor 6 Drive shaft 8 Gripper 17 Main beam 20 First roof support 46 Second roof support 28 First gripper 42 Second gripper 22 First cutter head 31 Second cutter head 19 First hydraulic jack 40 Second hydraulic jack 30 Third main beam 21 first electric motor 27 second electric motor 32 first main beam 41 second main beam

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000201478 Maeda Construction Co., Ltd. 2-1026 Fujimi 2-chome, Chiyoda-ku, Tokyo (72) Inventor Takashi Sakai 2-10-2 Otowa NS Bunkyo-ku, Tokyo Otowa NS Building 7F Inside Advanced Technology Center (72) Inventor Shouta Takatsu 2-5-8 Kita-Aoyama, Minato-ku, Tokyo Incorporation (72) Inventor Yoshiaki Ishida 4-12-20 Nihonbashihonmachi, Chuo-ku, Tokyo Sato Industrial Co., Ltd. (72) Inventor Taku Arakawa 3-1-1 Ueno, Hirakata-shi, Osaka Komatsu Ltd. Osaka Plant (72) Inventor Yoshio Tashiro 2-10-10 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd.

Claims (2)

[Claims] 1. In a method of excavating a tunnel having an elliptical cross section with a diameter larger than that of a new or existing advanced pit tunnel, in order to expand the outer ground of the advanced pit tunnel as a pilot pit, The tunnel expansion process of expanding the tunnel cross section into an elliptical shape by inclining the circular cutter surface of 1 with respect to the excavation direction, and the tunnel outer ground is further expanded following the tunnel expanded in the process. In order to achieve this, a method of excavating a large diameter tunnel, which comprises a step of widening the tunnel in which the second circular cutter surface is inclined with respect to the excavation direction to expand the expanded tunnel section into an elliptical shape. 2. A front support leg and a first gripper, which are installed so as to be capable of expanding and contracting, respectively on a first main beam that is inserted into a new or existing advanced tunnel, and the first jack is expanded and contracted using the gripper as a reaction force. Then, the outer ground of the advanced mine tunnel is excavated and a circular cutter surface that expands into an elliptical shape is tilted with respect to the excavation direction, and a first rotary cutter head is expanded into an elliptical shape by the rotary cutter head. A rear support leg and a second gripper, which are installed to be extendable and retractable on a second main beam that is inserted into the tunnel, and the second jack that is used as a reaction force to extend and retract the second jack to extend the outer peripheral ground of the tunnel. An excavation device used for excavation of a large-diameter tunnel, which comprises a circular cutter surface that expands into an elliptical shape and a second rotating cutter bed that is inclined with respect to the excavation direction.