JPH0626297A - Tunnel drilling method - Google Patents

Abstract

PURPOSE:To enable a tunnel to be drilled and expanded to the required sectional area without any blasting, and enable a pilot tunnel and a main tunnel to be concurrently drilled. CONSTITUTION:A pilot tunnel 3 is drilled within the scheduled drilling section of a main tunnel 1, and the pilot tunnel 3 and the main tunnel 1 are concurrently drilled, while drilling the base end peripheral wall 4 of the pilot tunnel 3 up to the size of the main tunnel 1. As a result, a safe and continuous tunnel drilling method can be realized without any use of blasting, and a construction period can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel excavation method, and more particularly to a method capable of simultaneously excavating a tunnel and a main shaft without using blasting.

[0002]

2. Description of the Related Art When excavating a tunnel, there is a case in which a tunnel is advanced to the main shaft for excavating a geological condition or for a working shaft for a transportation route. This is called an advanced tunnel construction method, one of which is TBM.
(Tunnel boring machine) is used to excavate the entire cross section of the tunnel to advance it, and then the blasting method is used to cut and spread the base end of the tunnel to the required cross section. This construction method is often used in Europe, etc., but is rarely practiced in Japan.

[0003]

However, the above-mentioned construction method has the following problems. At the time of blasting the cut-and-expansion of the main pit, the power line, the blower pipe, and the water pipe to the guide pit cannot be reliably protected.
It is not possible to simultaneously cut and expand the tunnel and the main shaft. Therefore, the whole construction period is long. Since it is necessary to evacuate the equipment to a safe place at the time of blasting, and each work is an intermittent work by replacing individual machines, it is difficult to increase the size of the machine. In addition, a driver is required for each machine, which increases labor costs. There is a great risk of many machines operating in a narrow mine. Automation of blasting work is practically impossible because it is difficult to regulate the handling of explosives by law and ensure safety.
Also, other work is an intermittent work due to blasting, so it is difficult to automate the entire system. After blasting, the environment inside the mine has become a problem due to gas and dust. Handling explosives and ensuring safety is a difficult task.

The present invention has been made in view of the above circumstances, and provides a tunnel excavation method capable of cutting and expanding to a required cross section without blasting and simultaneously excavating a guide shaft and a main shaft. Is intended.

[0005]

In order to achieve the above object, the tunnel excavation method according to claim 1 of the present invention excavates a tunnel in a planned excavation section of the main shaft by a circular full-section excavator method. The pit and the main pit are simultaneously excavated while the base end peripheral wall of the pit is split and the base end peripheral wall of the pit is cut to the size of the main pit.

The tunnel excavation method of claim 2 is the method of claim 1.
At the time of splitting the peripheral wall surface of the base end part of the tunnel, first, near the top end of the peripheral wall surface of the base end, a hole is drilled so that the width becomes gradually narrower toward the upper part, and then the base rock is formed. Characterized by repeating the process of dividing the end peripheral wall surface from the top end of the base peripheral wall to the bottom of the base peripheral wall sequentially along the circumferential direction, and cutting the base peripheral wall to the outside. I am trying.

The tunnel excavation method of claim 3 is the method of claim 2
In the above, when drilling the peripheral wall surface of the base end portion of the tunnel, each hole is formed with a slit-shaped notch extending in the direction of the crack to be generated during the split rock.

The tunnel excavation method of claim 4 is the method of claim 1.
1 to 3, the temporary placement belt conveyor extending from the vicinity of the leading end portion of the leading end to the main shaft side is provided in the guideway, and from the base end portion of the temporary placement belt conveyor to the front end portion of the main shaft. An extended residual soil unloading belt conveyor is provided, and the excavated residual soil generated during tunnel digging is temporarily placed on the temporary placement belt conveyor, and then both belt conveyors are started at a time when there is no hindrance to the main pit excavation work. The excavated soil is discharged to the main shaft.

The tunnel excavation method of claim 5 is the method of claim 4
In the above, the temporary placing belt conveyor and the residual soil discharging belt conveyor are respectively provided so as to be movable in the longitudinal direction of the tunnel.

The tunnel excavation method of claim 6 is the method of claim 1.
1 to 3, a temporary placement belt conveyor that extends in the longitudinal direction of the tunnel and is movable along the longitudinal direction is provided in the tunnel, and the temporary belt conveyor is provided above the temporary belt conveyor. A trolley that conveys the excavated soil left during excavation from the tunnel tip to the temporary conveyor belt is provided so that it can be moved along the longitudinal direction of the tunnel. It is characterized in that the excavated residual soil is discharged to the main pit by moving the temporary placement belt conveyor temporarily placed to the main pit and activating it.

The tunnel excavation method of claim 7 is the method of claim 1.
1 to 3, a protection pipe extending from the base end side of the main shaft to the front end side of the main shaft is installed in the part where the main shaft and the main shaft are connected, and an electric wire, a water pipe, a blast pipe, etc. are installed in this protection pipe. The long linear member and the residual soil discharging belt conveyor are inserted.

The tunnel excavation method of claim 8 is the method of claim 1.
In, the tunnel was excavated so that its top was located above the site that should be the top of the main shaft, and the space between the two intersections of the top of the main shaft and the site that should be the top of the main shaft It is characterized in that a long linear member such as an electric wire, a water pipe, and a blower pipe is inserted.

The tunnel excavation method of claim 9 is the method of claim 1.
In the above, in the planned excavation cross section of the main shaft, a guide shaft is excavated by the circular full-section excavator method, and the base end peripheral wall surface of this guide shaft is split to form the base end peripheral wall surface of the guide shaft. In the case of cutting to the size of the pit, after drilling the lower part from the bottom of the peripheral wall of the base end of the guide pit and breaking the rock, the process of dividing the peripheral wall of the base end is repeated, and the base end of the guide pit. The feature is that the peripheral wall is cut to the size of the main shaft.

According to a tenth aspect of the present invention, in the tunnel excavation method according to the first aspect, a tunnel is excavated at an upper portion of a planned excavation section of the main shaft by a circular full-section excavator method, and a peripheral wall surface of a base end portion of the tunnel. In the case of splitting the base wall of the guide shaft to the size of the main shaft, the base wall of the guide shaft is split and cut above the bottom of the base wall. It is characterized by excavating while drilling the upper half of the main pit and then splitting the lower half of the main pit vertically.

According to the tunnel excavation method of claim 11, a protection pipe extending from the base end side of the tunnel to the main shaft side is installed at a portion where the main shaft where the upper half has been excavated and the tunnel are connected. However, a long line-shaped member such as an electric wire, a water pipe, a blower pipe, etc. and a residual soil discharging belt conveyor are inserted through the protective pipe.

[0016]

According to the tunnel excavation method of claim 1, a tunnel is excavated within the planned excavation cross section of the main shaft, and the peripheral wall surface of the proximal end of the tunnel is split to form a base end of the tunnel. By cutting the peripheral wall to the size of the main shaft and excavating the guide shaft and the main shaft at the same time, safe and continuous tunnel excavation without blasting is realized, and the construction period is shortened.

In the tunnel excavation method of claim 2,
By drilling a hole in the vicinity of the crown of the peripheral wall of the base end part of the tunnel and gradually narrowing it toward the upper part, there is nothing supporting the rock piece after this rock piece, and the rock piece is self-weighted. To fall by. The part where the rock piece is missing becomes a free surface, and thereafter, the rock wall is successively dropped by dividing the base end peripheral wall surface from the free surface to the base end peripheral wall surface bottom along the circumferential direction in sequence. By repeating these steps, cutting with a split rock is performed.

In the tunnel excavation method of claim 3,
When drilling the peripheral wall of the base end part of the tunnel, by forming a slit-shaped notch in each hole that extends in the direction of the crack that should occur during split rock, stress concentration in this notch during split rock It occurs and cracks extend from the notch, which facilitates and ensures the splitting in the desired direction.

In the tunnel excavation method of claim 4,
When the excavation according to any one of claims 1 and 3, the excavated residual soil produced during the tunnel excavation is temporarily placed on a temporary placement belt conveyor,
After that, when there is no hindrance to the main pit excavation work, the temporary placement belt conveyor and the residual soil carry-out belt conveyor are activated to discharge the excavation residual soil to the main pit, thereby completing the main pit excavation work. The efficiency of tunnel excavation will be improved without being affected by the excavation work of.

In the tunnel excavation method of claim 5,
When excavating according to claim 4, by advancing both belt conveyors along with the excavation of the guide shaft and the main shaft, the excavated residual soil is easily and continuously discharged. By moving the residual soil discharge conveyor to the temporary placement belt conveyor side and retracting it, the split rock work can be performed reliably without any hindrance.

In the tunnel excavation method of claim 6,
When the excavation according to any one of claims 1 to 3 is performed, the excavated soil left during the excavation of the tunnel is conveyed by the truck to the temporary conveyor belt conveyor from the tip of the tunnel so that there is no hindrance to the excavation work of the main tunnel. At the time, the temporary excavation belt conveyor in which the excavation residual soil is temporarily placed is moved to the main pit and activated to discharge the excavation residual soil to the main pit, thereby,
The tunnel excavation work will be performed without being affected by the main shaft excavation work, and the efficiency of tunnel excavation will be improved.

In the tunnel excavation method of claim 7,
When excavating according to any one of claims 1 to 3, by inserting a long linear member such as an electric wire, a water pipe, a blower pipe, etc. and a residual soil discharging belt conveyor into the protective pipe, the rock is broken and falls. It protects the linear member from the rock fragments coming from it and enables safe passage, and the excavation residual soil generated during the tunnel excavation is carried out irrespective of the split rock work to improve the efficiency of the excavation work.

In the tunnel excavation method of claim 8,
When the excavation according to claim 1 is performed, the top of the tunnel and the site to be the top of the main shaft are excavated so that the top of the guide shaft is located above the site to be the top of the main shaft. The space between the two intersections with and is a safe area where rock fragments do not fall, and a protective pipe is installed by inserting long linear members such as electric wires, water pipes, and air blow pipes into this space. Without protecting the linear member.

In the tunnel excavation method of claim 9,
When the excavation according to claim 1 is carried out, the lower part of the peripheral wall surface of the base end part of the tunnel is drilled from the bottom to form an opening to form an opening, and then the peripheral wall surface of the base end part is divided to form a split rock. The resulting rock fragments are dropped from the above-mentioned opening and discharged, so that even if there is a tunnel at the upper part of the planned excavation section of the main pit and the excavation section below this tunnel is large, the base end of the tunnel The peripheral wall can be easily cut to the size of the main shaft.

In the tunnel excavation method of claim 10, when the excavation of claim 1 is performed, the peripheral wall surface of the base end portion of the tunnel is split and cut above the bottom of the peripheral wall surface of the base end portion. Excavation while expanding to excavate the upper half of the main shaft, and then split the lower half of the main shaft in the vertical direction, that is, the split rock work is divided into the upper half and the lower half to perform the planned main excavation cross section. Even if there is a tunnel in the upper part and the excavation cross section below this tunnel is large, the peripheral wall surface of the proximal end portion of the tunnel can be easily cut to the size of the main tunnel.

In the tunnel excavation method according to claim 11, when excavating according to claim 10, an electric wire is attached to a protective pipe installed at a connecting portion between the main shaft and the tunnel where the upper half is excavated. By inserting long linear members such as water pipes and blast pipes and the belt conveyor for discharging the residual soil, the linear members are protected from the rock fragments that are broken and fall, and safe passage is also possible. Efficient excavation work will be carried out by carrying out the excavated residual soil generated during the excavation of the mine regardless of the split rock work, and treating this residual excavated soil together with the rock fragments produced by the split rock in the lower half of the main shaft.

[0027]

Embodiments of the tunnel excavation method of the present invention will be described below with reference to the drawings. (Invention Corresponding to Claim 1) First, as shown in FIGS. 1 and 2, a guide shaft 3 is excavated in a planned excavation section of the main shaft 1 by a circular full-section excavator method, that is, a TBM 2.
It is known that, in this state, if the base end peripheral wall surface 4 of the tunnel 3 is drilled and blasted, the tunnel 3 becomes a free surface, the amount of explosive is small, and efficient blasting is possible. In this way, by utilizing the fact that the rock tends to crack toward the free surface, the base end peripheral wall surface 4 of the tunnel 3 is replaced by blast rock instead of blasting and the main shaft 1
Cut to the size of. Then, the tunnel excavation is performed by simultaneously advancing the tunnel 3 and cutting and expanding the base end peripheral wall surface 4 of the tunnel 3, that is, cutting and expanding the main shaft. Therefore, the tunnel can be excavated safely and continuously without using blasting, and the construction period can be shortened.

(Invention equivalent to claim 2) When the base end peripheral wall surface 4 of the guide shaft 3 is split, the base end peripheral wall surface 4 which is a free surface has a circular cross section excavated by the TBM 2. So, even if you put cracks at equal intervals in the rock around this,
Rock pieces stick together (become arched) and cannot be easily removed from the original bedrock. Therefore, since the rock fragments with cracks are dropped by their own weight, the order and method of split rocks are important so that the rock fragments do not touch each other.

Therefore, in the present invention, split rock is performed as follows. That is, as shown in FIG. 3, first, the vicinity of the top end 4a of the peripheral wall surface 4 of the base end part is drilled so that the width becomes gradually narrower toward the upper part and split rocks. Since this rock piece 5a has a trapezoidal shape with a narrow upper part, there is no support for this rock piece 5a after split rock, and the rock piece 5a falls by its own weight, and the notch portion where the rock piece 5a is missing becomes a free surface.

Next, the portion adjacent to the rock piece 5a is
When drilling and splitting rocks in a substantially triangular shape, the rock pieces 6a and 6a 'drop due to their own weight because the rock piece 5a has disappeared. And the adjacent parts one after another,
Drilling and splitting rocks to the bottom of the peripheral wall 4 at the base end in a square shape along the circumferential direction will result in each rock fragment 7
.., 7a ', 8a, 8a', 9a, 9a '... are successively dropped by their own weight, and the tunnel 3 is cut and expanded for one round.

When the split rock advances after the rock pieces 7a, 7a ', it further expands to the outer circle, and the rock pieces 5b and 6 are successively formed.
b, 6b ', 7b, 7b', 8b, 8b ', 9b, 9
When b '... is drilled and split, and the split rock progresses after the rock fragments 7b, 7b', it is further expanded to the outer circle and the split rock is repeated in the same manner. In addition, when entering a new circle breaking work, as with the rock pieces 5a and 5b, firstly, the rock is drilled so that the width becomes gradually narrower toward the upper part and the breaking rock is performed.

Then, when the base end peripheral wall surface 4 of the tunnel 3 is cut and expanded by the split rock, and as shown in FIG. Rock pieces 5e, 5e ', 6e, 6e', 7e, 7e ', 8
The holes e, 8e ′, 9e, 9e ′ are drilled and split, and finally the peripheral wall surface 4 of the base end is cut to the size (diameter) of the main shaft 1. Further, when the base end peripheral wall surface 4 is cut and expanded to become the main shaft 1, the process of splitting and expanding the next base end peripheral wall surface 4 in the same manner as above is repeated,
The main pit 1 is advanced. At the same time as the main shaft 1 is being dug, the guide shaft 3 is also dug by the TBM 2.

(Invention equivalent to claim 3) When performing the above-mentioned drilling, as shown in FIG. 3, a large number of holes 10 ... Are formed mainly at predetermined intervals along the circumferential direction. By forming slit-shaped notches 10a, 10a extending in the respective holes 10 toward the holes 10 adjacent to the holes 10, that is, extending in the direction of the crack to be generated during the split rock, stress concentration occurs in the notches 10a. Since a crack is formed so as to extend from the notch 10a, the split rock can be easily and reliably performed in a desired direction.

Further, in the case where the rock near the top end 4a of the peripheral wall 4 of the base end portion of the guide shaft 3 is first drilled and the rock is split, in the case of the usual notch drilling, a crack is generated from the hole 10c on the free surface (guide shaft). It is easy to enter parallel to the inner wall surface of No. 3, but notches 10a,
10a is formed in the direction of the crack that should be generated when the rock is split,
That is, by forming it obliquely with respect to the free surface, the direction of the crack can be controlled, and the rock piece 5a can be easily and reliably split into a trapezoid.

The notches 10a and 10a can be easily and surely formed by carrying out the "rock drilling and drilling method and apparatus" of the Japanese Patent No. 1253066 owned by the present applicant. When a crack is generated from the notched hole 10 (10c) drilled in this way, the hydraulic breaker 14 is inserted into the hole 10 as shown in FIGS. 31 and 32. This hydraulic type rock breaking machine 14 is provided so as to be able to come in contact with and separate from each other in the radial direction, and has a pair of steel pressure plates 14a, 14a forming a substantially cylindrical shape, and a rubber provided between these pressure plates 14a, 14a. The tube 14b is mainly composed of a tube 14b and a pair of wedges 14c, 14c provided between the rubber tube 14b and the pressure plates 14a, 14a.

In this hydraulic type rock breaking machine 14, as shown in FIG.
As shown in FIG. 2, by expanding the rubber tube 14b by hydraulic pressure, the wedges 14c, 14c are moved in the direction in which they are separated from each other, and the wedges 14c, 14c expand the pressure plates 14a, 14a to cause the internal pressure in the hole 10. The stress is concentrated on the notches 10a, 10a by applying the stress, thereby causing cracks extending from the notches 10a, 10a.

In the above-mentioned embodiment, as shown in FIGS. 1 and 2, an example in which the guide shaft 3 is formed relatively above in the planned excavation cross section of the main shaft 1 has been described.
The position of is not limited to the above, but as shown in FIGS. 5 and 6, the uppermost part in the planned excavation cross section of the main shaft 1, FIG.
As shown in FIG. 8 and FIG. 8, there may be a guide hole 3 at the central portion in the planned excavation cross section, and at the lowest portion in the planned excavation cross section as shown in FIGS. 9 and 10. As described above, the split rock work on the peripheral wall surface 4 of the base end portion of the tunnel 3 is performed.

(Invention equivalent to claims 4 and 5) Now, in order to efficiently excavate the tunnel 3 by the TBM 2 and the excavation of the main pit 1 by the split rock, the construction by the TBM 2 is performed by cutting and expanding by the split rock. It is necessary not to affect the construction and not to be affected. The material used in the excavation by the TBM 2 may be loaded into the tunnel 3 at a time when there is no influence of the cutting and expanding work by the split rock, and may be temporarily placed in the tunnel 3. However, this processing becomes a problem because a large amount of excavated soil is constantly generated during excavation work. Since it is necessary to carry out the excavated surplus soil to the main pit 1 in accordance with the time zone of the work of the main pit 1, a temporary storage place for the residual soil is set up in the tunnel 3. A belt conveyor is used for this, and it is used for temporary storage and removal of residual soil. 11 and 12 show an example of the method.

As shown in these figures, in the tunnel 3,
A temporary placement belt conveyor 15 extending from the TBM 2 at the tip of the tunnel 3 toward the main pit 1 side, and a residual soil unloading belt conveyor extending from below the base end of the temporary placement belt conveyor 15 to the tip of the main pit 1. 16 are provided. The temporary belt conveyor 15 has a pair of wheels 15a, 15a attached to the lower portion in the width direction at predetermined intervals in the longitudinal direction of the tunnel 3, and is movable in the longitudinal direction. Also,
Handrails 15b are provided on the upper side of the temporary placement belt conveyor 15.
An associated passage 15c is installed, and the passage 15c enables safe passage in the tunnel 3.

Further, the above-mentioned remaining soil carrying-out belt conveyor 16
A pair of wheels 16a, 16a are attached to the lower portion of the guide 3 in the width direction at predetermined intervals in the longitudinal direction of the tunnel 3, and are movable in the longitudinal direction. The drive device for moving the residual soil carrying-out belt conveyor 16 may be attached to the belt conveyor 16 or the temporary placement belt conveyor 1
5 or the like (may be other), and may be operated with a wire or the like. Further, the drive device for moving the temporary-placement belt conveyor 15 may be attached to the belt conveyor 15, or may be attached to a wall or the like of the tunnel 3 (or another one) and operated by a wire or the like. Good.

Then, the above two belt conveyors 15 and 16
When the excavation residual soil is carried out using, the excavation residual soil is taken out by the soil discharge conveyor (belt conveyor, screw conveyor, etc.) 17 attached to the TBM 2 and is temporarily placed on the temporary placement belt conveyor 15 through the hopper 18. To go. In this case, the excavated soil is temporarily placed while circling the temporary placement belt conveyor 15.
The excavated soil remaining on the top of the conveyor belt 5 is conveyed on the belt conveyor 1.
When it is located at the base end of 5, the belt conveyor 15 is stopped from rotating and the earth discharging conveyor 17 is also stopped.

After that, when there is no hindrance to the operation of the main pit excavation by the above-mentioned split rock, specifically, when the main pit 1 is unloaded, the residual soil carry-out belt conveyor 16 is moved to the main pit side,
After being positioned at the tip of the main shaft 1, the temporary placement belt conveyor 15 and the residual soil unloading belt conveyor 16 are circulated. Then, the excavated residual soil is transferred from the temporary storage belt conveyor 15 to the residual soil carrying-out belt conveyor 16 and is discharged into the main shaft 1 by the belt conveyor 16. In addition, in the case of carrying out the residual soil by the both belt conveyors 15 and 16 as described above, it is necessary that the excavation speed of the tunnel 3 and the main pit 1 be substantially constant. Make 15 and 16 move forward.

As described above, by discharging the excavated residual soil generated during the excavation of the tunnel 3, the excavation work of the tunnel 3 can be performed without being affected by the excavation work of the main shaft 1. Therefore, the efficiency of tunnel excavation can be improved. Further, by easily advancing both belt conveyors 15 and 16 as the guide shaft 3 and the main shaft 1 advance,
The excavated soil can be easily and continuously discharged.
Furthermore, at the time of the above-mentioned split rock work, the residual soil discharge conveyor 16
It is possible to surely perform the split rock work without trouble by moving the to the temporary conveyor belt conveyor 15 side and retracting it.

(Invention Corresponding to Claim 6) FIGS. 13 to 15 show an example in which the excavation residual soil is discharged by the truck 20 and the temporary placement belt conveyor 15. As shown in these figures, inside the tunnel 3,
The temporary-placement belt conveyor 15 is provided which extends along the longitudinal direction and is movable along the longitudinal direction.
A large number of sleepers 21 that cross the guide shaft 3 are installed above the temporary belt conveyor 15 along the longitudinal direction of the guide shaft 3 at predetermined intervals.
Two pairs of rails 22, 22 extending in the longitudinal direction are installed. Each pair of rails 22, 22 has a truck 2
0 and 20 are movably provided by wheels 20a. In FIG. 13, the right dolly 20 has a dolly 2
A battery locomotive 23 for driving 0, 20 is connected.

When the excavated soil is carried out by using the truck 20 and the temporary placement belt conveyor 15, the TB
The excavated soil excavated by M2 is loaded on the trolleys 20, 20 by, for example, the soil discharge conveyor 17 or the like, conveyed by the trolleys 20, 20 to the temporary placement belt conveyor 15, and temporarily transferred to the belt conveyor 15. Lower it and place it temporarily. In this case, the excavated soil may be unloaded while moving the trucks 20, 20 along the belt conveyor 15, or may be unloaded while the belt conveyor 15 is rotated.

After that, when the main pit excavation by the above-mentioned split rock is completed and the residual soil is to be disposed, that is, when the main pit 1 is slid out, the temporary-placement belt conveyor 15 is moved to the main pit side, and at the tip of the main pit 1. After being positioned, the belt conveyor 1
Circulate 5 and drop the excavated residual soil into the main pit 1 and discharge it, and dispose of it at the same time as the residual soil of the main pit. If you do this, T
The excavation work by the BM 2 can be performed without being affected by the work of the main shaft 1 at the rear.

(Invention equivalent to claim 7) Meanwhile, the tunnel 3
At the base end of the rock, i.e., near the entrance, rock fragments broken during the above-mentioned rock breaking work fall down, and the area below it is extremely dangerous. Workers and materials can enter and leave at a safe time other than split rock work, but since electric wires, water pipes, blowers, etc. are linear, it is necessary to protect them from falling rock fragments.

16 and 17 show the case where the tunnel 3 is formed at the top of the planned excavation cross section of the main shaft 1. A protection pipe 25 extending from the base end side of the main shaft to the front end side of the main shaft is installed at an area where the main shaft 1 and the main shaft 3 are connected to each other.
Passes through the gantry type jumbo mount 26 and the mount 26
Is projected to the rear of. The gantry type jumbo mount 26 is a device equipped with a rock drilling machine, a rock breaking machine, etc. for rock breaking, but the details will be described later. A long linear member such as an electric wire 27, a water pipe 28, and a blower pipe 29 is inserted through the protective pipe 25.

These linear members are T-shaped at the tip of the tunnel 3.
It extends to the BM2 and supplies electric power, water, clean air, etc. to the TBM2, and is protected by the protective pipe 25 from the rock fragments falling during the grooving work. In addition, a residual soil carrying-out belt conveyor 16 is movably inserted in the protective tube 25 at a position below the linear member so as to be movable in the longitudinal direction of the tunnel 3, and the tip end of the belt conveyor 16 is inside the tunnel 3. The base end portion is made to project into the main shaft 1 behind the gantry type jumbo frame 26. Further, a passage (not shown) is formed in the protection pipe 25, which enables safe passage to the tunnel 3.

In the above structure, if the excavated residual soil by the TBM 2 is conveyed to the residual soil conveying belt conveyor 16 by the truck 20 or the like, the excavated residual soil is conveyed out without being affected by the rock breaking work of the main shaft 1. While digging 3
Can be dug. Further, in place of the truck 20, the excavated residual soil may be temporarily placed on the temporary placement belt conveyor 15 and the temporary placement belt conveyor 15 may be moved to the residual soil discharge belt conveyor 16 to discharge the residual soil. Even in this case, since the residual soil can be discharged without being affected by the rock breaking work of the main shaft 1, the temporary-placement belt conveyor 15 can be considerably shortened.

The protection tube 25 has the same structure regardless of the vertical position of the tunnel 3, but the protection tube 25
Since the impact force due to the falling of rock fragments differs depending on the installation height of the rock, it is necessary to increase the strength of the tunnel 3 so as to form it below.

(Invention equivalent to claim 8) FIG. 18 shows an example in which the linear member such as the electric wire 27 can be protected without installing the protective tube 25 as described above. That is, the tunnel 3 is excavated so that the top of the tunnel 3 is located above the site to be the top of the main shaft 1. In this way, the tunnel 3
There is a part that does not require split rocks on the wall surface between the two intersections T1 and T2 of the top of the main shaft and the part to be the top of the main shaft 1.
Therefore, the space S between the intersections T1 and T2 is a safe area where rock fragments do not fall, and the long linear members such as the electric wire 27, the water pipe 28, and the blower pipe 29 are inserted into the space S. For example, the linear member can be protected without installing the protective tube 25.

(Invention Corresponding to Claim 9) Next, an example of a method of splitting rock when the tunnel 3 is located above in the planned excavation section of the main shaft 1 will be described. That is, it is only up to the bottom of the tunnel 3 that the rock can be spread by splitting the base wall of the tunnel at the base end and dropping the rock fragments.
The post-broken rock fragments below the bottom must be removed from the ground by another method. When the tunnel 3 is on the upper side, the excavation cross section below the tunnel 3 is large, and the work of removing the rock fragments becomes a difficult task.

Therefore, in order to solve this, FIG.
As shown in FIGS. 9 to 21, the peripheral wall surface 4 of the base end portion of the tunnel 3
After drilling the lower part from the bottom of the base and splitting the rock, the process of splitting the base end peripheral wall surface 4 is repeated to cut and spread the base end peripheral wall surface 4 of the tunnel 3 to the size of the main shaft 1. To do. When drilling and splitting rocks from the bottom of the base end peripheral wall surface 4 below, a drilling machine 31 for drilling is installed in the tunnel 3 and the bottom part of the base end peripheral wall surface 4 is provided by the drilling machine 31. From below, a hole is drilled and rocks are split. Since this boring machine 31 can also be used as a machine for preliminarily strengthening the ground for excavating the main shaft 1 (installation of rock bolts, ground improvement by chemical injection, etc.), a large increase in cost will occur. Don't

Here, the boring machine 31 will be described with reference to FIGS. 22 and 23. The boring machine 31 is mainly composed of a gantry-shaped bogie 32, an arm 33 connected to the bogie 32 so as to be vertically and horizontally swingable, and a rock drill 34 attached to a tip end of the arm 33. Has been done. The trolley 32 is movable in the longitudinal direction of the tunnel 3 via wheels 37 on a pair of rails 36, 36 laid on a plurality of sleepers 35 that are installed across the tunnel 3. It is provided in. At the center of the upper part of the dolly 32, the rotary shaft 39
Is rotatably provided around a vertical axis by a bearing 39a. A gear 40 is attached to the center of the rotary shaft 39 in the axial direction.
The gear 41 rotated by 1a is meshed. Then, the rotating shaft 39 is rotated by the motor 41a into the gear 4
It is designed to be rotated via 1, 40.

A connecting portion 42 is attached to the lower end of the rotary shaft 39, and an arm 33 extending toward the connecting portion between the guide shaft 3 and the main shaft 1 is vertically moved by a pin 43 to the connecting portion 42. Is swingably connected to. Also,
A telescopic jack 44 is connected to the connecting portion 42, and a tip end portion of a piston rod 44 a of the jack 44 is connected to the arm 33. And this arm 33
Is configured to swing vertically with the pin 43 as an axis by the extension and contraction of the extension jack 44, and to swing left and right with the rotation of the rotary shaft 39.

At the tip of the arm 33, the arm 3
When the support rod 33a is extended from the swivel joint 3
It is rotatably connected about an axis via 3b and is rotated by a driving means (not shown).
The rock drill 34 is attached to the tip of the support rod 33a. This rock drill 34 has a support rod 33
The rock drill body 34a fixed to a and the rock drill body 3
A holding rod 34b which is vertically supported by 4a and is vertically movable.
And a rock drilling rod 34c which is supported by the holding rod 34b so as to project from the lower end portion thereof so as to be vertically movable and rotatable.
The rock cutting rod 34c is rotated and lowered to cut a rock or the like with a cutting edge 34d provided at the tip of the rock cutting rod 34c.
Reference numeral 34e is an operation panel for operating the hole drilling machine 31 having the above-described configuration.

In order to drill and lower rocks from the bottom of the peripheral wall surface 4 of the base end portion of the tunnel 3 by the boring machine 31, first, the bogie 32 is moved to the vicinity of the base end portion of the tunnel 3. Stop it in place. Then, the arm 33 is swung vertically and horizontally to determine the position of the drilled hole, and then the holding rod 34
b is vertically lowered and stopped slightly above the bottom of the peripheral wall 4 of the base end. Next, the rock drilling rod 34c is rotated and gradually lowered to drill a hole from the bottom of the base end peripheral wall 4 to the excavated bottom surface of the main shaft 1. When the drilling of one hole K is completed, the rock drilling rod 34c is lifted and pulled out from the hole K, and the drilling of the next hole K is performed through the same steps as above. Then, as shown in FIG. 21, when the drilling of the four holes K is finished so that the tip side (back side) of the guide shaft 3 becomes smaller, the holes K ... Use it to split rocks. In this way, the broken rock fragments G become columnar bodies having a trapezoidal cross section that spreads toward the main shaft side, so that the rock fragments G easily fall in the direction of the arrow and are taken out to the main shaft 1.

When the rock fragments G are removed, an opening A extending downward from the bottom of the tunnel 3 is formed in the central portion of the main pit 1 so that the rock fragments fall into the opening A. Pit 3
The base end peripheral wall surface 4 of the main shaft 1
Cut to the size of. Specifically, for example, FIG.
As shown in FIG. 3, the wall surface at the position where the upper end of the opening A and the tunnel 3 intersect is split, and the rock fragments G1 and G1 are dropped into the opening A, and then below and below the rock fragment G1. Rock pieces G2, G formed by dividing the wall surfaces adjacent to each other in the circumferential direction of 3
2 is dropped into the opening portion A, and the steps of dropping the rock fragments by breaking down the wall surface adjacent to the lower side and the circumferential direction of the guiding tunnel 3 in sequence are repeated to expand the guiding hole 3 and the opening portion A by a predetermined amount.

Then, by sequentially cutting and spreading the slabs outward, the peripheral wall surface 4 of the base end portion of the tunnel 3 is cut.
Cut to the size of main pit 1. By splitting rocks as described above, even when the tunnel 3 is located above, the split rock fragments can be easily discharged and cut and expanded.

(Invention Corresponding to Claim 10) When the tunnel 3 is located at the upper part, there is a split rock method as described below in addition to the above method. That is, when the guide shaft 3 is cut and expanded by the split rock, as shown in FIG. 25, first, as shown in FIG. 25, the wall surface above the bottom portion of the base end peripheral wall surface 4 is split and cut and expanded to advance the upper half 1a of the main shaft 1. After that, the lower half 1b of the main pit 1 left after the excavation is split rock excavated at a position behind the gantry type jumbo mount 26.

In case of excavating the upper half 1a of the main shaft 1, as shown in FIG.
As shown in FIG. 7, first, in the same manner as in the case of the above-mentioned split rock, first, the vicinity of the top end 4a of the peripheral wall surface 4 of the base end part of the tunnel 3 is drilled so that the width becomes gradually narrower toward the upper part. And then divide the adjacent parts one after another to the bottom of the base end peripheral wall surface 4 along the circumferential direction to form a hole K1 to divide the rock, and to sequentially expand this process to the outside. Done by.

During this grooving work, a hole is mainly drilled in the horizontal direction, and this hole is made by the gantry type jumbo mount 2 described above.
6. Here, the configuration of the gantry type jumbo frame 26 will be described. That is, as shown in FIGS. 29 and 30, wheels 46 are provided on the lower portion of the frame 45.
... are mounted, and the wheels 45 roll on rails 47, 47 laid on the bottom surface of the upper half 1a of the main shaft 1, whereby the frame 45 can be moved back and forth. Further, stopper jacks 48, 48 are provided on both sides of the wheel 46, and the jacks 48, 48 are provided.
The piston rods 48a, 48a of the above are extended and stoppers 49, 49 fixed to the tip end thereof are provided on the upper half 1a of the main shaft 1.
The movement of the frame 45 is locked by pressing it on the bottom surface of the frame.

Further, a plurality of boring machines 50 ... Are attached to the frame 45 toward the guide shaft 3 side. The drilling machines 50 ... are three in the upper stage of the frame 45 and four in the middle stage.
4 machines are provided in the lower stage, and the drilling machines 50 ... Provided in each stage are installed in parallel in the horizontal direction.
Note that the number of the boring machines 50 is not limited to this, and may be appropriately set according to the conditions for tunnel excavation. The boring machine 50
The support block 5 is attached to the frame 45.
1 is provided so as to be movable along the horizontal frame 45a (in the direction orthogonal to the paper surface in FIG. 29), and one end of an expansion jack 52 is rotatably connected to the support block 51. Further, one end of the jack 53 is connected to a midway portion of the telescopic jack 52, and the other end is connected to the support block 50. The expandable / contractible jack 52 swings up and down with the one end of the jack 53 as a fulcrum due to expansion and contraction of the jack 53.

A horizontal rod 54 is attached to the other end of the telescopic jack 52.
A support member 55 is rotatably connected to the tip of the. A slide member 56 is attached to the support member 55 as shown in FIG.
Is provided so as to be slidable in the left-right direction. The slide member 56 is provided with a boring machine body 57 so as to be reciprocally movable in the longitudinal direction of the slide member 56. A boring rod 58 is rotatably attached to the tip of the boring machine body 57 about an axis, and the boring rod 58 is slidably supported by a support portion 59 fixed to a slide member 56. .

In the gantry type jumbo frame 26 having the above-mentioned structure, the frame 45 is moved forward and stopped and locked at a predetermined position, and then the hole drilling machine 50 ... It is designed to drill the wall surface of. In this case, after moving the support block 51 to determine the horizontal drilling position, the telescopic jack 52
To extend the tip of the drilling rod 58 close to the wall surface,
The telescopic jack 52 is rotated by the jack 53 to determine the drilling position in the vertical direction. After that, the boring machine main body 57 is moved forward while rotating the boring rod 58, thereby carrying out boring. Further, in order to facilitate the split rock formation, when the wall surface is drilled vertically, the support member 55 is rotated to move the drilled rod 5 as shown by the chain double-dashed line in FIG.
8 is directed vertically.

After excavating the upper half 1a of the main pit 1 to some extent as described above, as shown in FIGS. 25 and 28, a split rock operation is performed behind the gantry type jumbo mount 26. In this case, the lower half 1b of the main pit 1 is drilled in the vertical direction (vertical direction) to form the vertical hole K2, and split rock is performed. In this drilling, for example, the drilling machine 31 may be used, and if the rock breaking method is the same as when the drilling machine 31 is used, drilling and rock breaking can be easily performed. .
A horizontal hole K1 is horizontally formed on the outer peripheral side of the upper half 1a to divide the rock.

(Invention equivalent to claim 11) When the upper half 1a and the lower half 1b of the main shaft 1 are separately excavated as described above, the upper half is excavated as shown in FIGS. 25 and 26. The protection pipe 25 extending from the base end side of the main shaft to the main shaft side is installed in the part where the main shaft 1 and the main shaft 3 are connected, that is, in the part where the upper half 1a is drilled / broken. A long linear member such as an electric wire, a water pipe, a blower pipe, or the like is inserted into the protective pipe 25, and a remaining soil unloading belt conveyor 60 is inserted. Then, the temporary placement belt conveyor 16 is connected to the tip end of the belt conveyor 60, and the excavated soil by the TBM 2 is temporarily placed on the temporary placement belt conveyor 16 by a truck (not shown) that moves on the rail 22. If the excavation residual soil is transported to the rear of the gantry type jumbo mount 26 from the belt conveyor 16 via the residual soil unloading belt conveyor 60, the excavation of the guide shaft 3 and the excavation of the main shaft 1 can proceed simultaneously.

The excavated residual soil carried out by the residual soil carrying-out belt conveyor 60 may be combined with the rock fragments produced by the excavation of the lower half 1b of the main pit 1. Further, the remaining soil carrying-out belt conveyor 60 and the temporary placement belt conveyor 16 may be integrally formed.

[0070]

As described above, according to the method for excavating a tunnel of claim 1 of the present invention, a tunnel is excavated in the planned excavation section of the main pit by the circular full-section excavator method, and the tunnel is constructed. Since the base end peripheral wall surface of No. 1 was split and the base end peripheral wall surface of the tunnel was expanded to the size of the main shaft, the guide shaft and the main shaft were simultaneously excavated, so it was safe and without blasting. The tunnel can be continuously excavated, and the construction period can be shortened. Further, since blasting is not used, it is not necessary to evacuate or replace the equipment, so that the machine can be upsized and the excavation work can be made more efficient. Furthermore, there is no problem of post gas, dust, etc. due to blasting,
The cost of tunnel excavation can be reduced by automating the entire construction system.

According to the tunnel excavation method of claim 2, when the base end peripheral wall surface of the tunnel is split, first, the vicinity of the base end peripheral wall wall top is gradually narrowed toward the upper part. Since the rock was made by drilling into the rock, there was no support for the rock fragment after this rock break, the rock fragment fell by its own weight, the part where the rock fragment was missing became a free surface, and then the peripheral wall of the base end , From the above free surface, we split the rock along the circumferential direction to the bottom of the peripheral wall surface,
The rock fragments will fall one after another, so that the whole can be easily excavated by the split rock.

According to the tunnel excavation method of claim 3, when the excavation of claim 2 is performed, when the peripheral wall surface of the base end portion of the tunnel is drilled, cracks to be produced in each hole at the time of split rock Since a slit-shaped notch extending in the direction of is formed, stress concentration occurs in this notch during splitting and cracks extend from the notch, so the splitting rock can be easily and reliably placed in the desired direction. It can be carried out.

According to the tunnel excavation method of claim 4, when the excavation according to any one of claims 1 to 3 is carried out,
A temporary placing belt conveyor extending from the vicinity of the leading end of the tunnel to the main pit side is provided, and a residual soil unloading belt conveyor extending from the base end of the temporary placing belt conveyor to the tip of the main pit is provided. The excavated soil after excavation is temporarily placed on the temporary conveyor belt conveyor, and then, when there is no hindrance to the operation of the main shaft excavation, the belt conveyor is circulated to discharge the residual excavated soil to the main shaft. As a result, the tunnel excavation work can be performed without being affected by the main shaft excavation work, and the tunnel excavation efficiency can be improved.

According to the tunnel excavation method of claim 5, when the excavation of claim 4 is performed, the temporary placement belt conveyor and the residual soil discharging belt conveyor are provided so as to be movable in the longitudinal direction of the tunnel. Both belt conveyors can be easily advanced along with the digging of the mine 3 and the main pit 1, and the excavated soil can be discharged easily and continuously. Further, at the time of rock breaking work, the rock breaking work can be surely performed without trouble by moving the residual soil discharging conveyor to the temporary placing belt conveyor side and retracting it.

According to the tunnel excavation method of claim 6, when the excavation according to any one of claims 1 to 3 is carried out,
A temporary placement belt conveyor that extends along the longitudinal direction of the tunnel and is movable along the longitudinal direction is provided, and the excavated residual soil when the tunnel is excavated is located above the temporary placement belt conveyor. A trolley that conveys from the section to the temporary placement belt conveyor is provided so that it can move along the longitudinal direction of the tunnel, and the temporary placement belt conveyor with the remaining excavated soil is temporarily placed at the time when there is no hindrance to the work of the main pit. Since the excavated residual soil is discharged to the main pit by moving to the pit and circulating, it is possible to perform the digging work of the guide shaft without being affected by the digging work of the main pit. The efficiency of tunnel excavation can be improved.

According to the tunnel excavation method of claim 7, when the excavation according to any one of claims 1 to 3 is carried out, the main shaft tip end from the main shaft end side is provided at the mating portion of the main shaft and the main shaft. Since a protective pipe extending to the side of the section was installed, and long linear members such as electric wires, water pipes, and blast pipes and a residual soil discharge belt conveyor were inserted into this protective pipe, it is linear from the rock fragments that are broken and fall. The member can be protected, and the passage inside the protective tube enables safe passage. Moreover, since the excavated soil left from the tunnel excavation can be carried out regardless of the rock breaking work, the efficiency of the excavation work can be improved.

According to the tunnel excavation method of claim 8, when the excavation of claim 1 is performed, the guide pit is excavated so that the top of the guide pit is located above the site to be the top of the main pit. The space between the two intersections of the top of the mine and the site that should be the top of the main mine is a safe area where rock fragments do not fall. Therefore, by inserting a long linear member such as an electric wire, a water pipe, or a blower pipe into this space, the linear member can be protected without installing a protective pipe.

According to the tunnel excavation method of claim 9, when the excavation of claim 1 is carried out, the lower part of the peripheral wall surface of the base end portion of the tunnel is drilled downward to divide the rock, and then the base end periphery is drilled. Since the step of splitting the wall surface is repeated, the split rock fragments can be discharged by dropping from the bottom of the peripheral wall surface of the base end to the opening formed by drilling and splitting rock.
Therefore, even if the tunnel is excavated in the upper part of the planned excavation section of the main shaft, that is, even if the excavation section below the tunnel is large, the peripheral wall of the base end of the tunnel is easily cut to the size of the main shaft. Can be expanded.

According to the tunnel excavation method of claim 10,
When the excavation according to claim 1 is performed, the peripheral wall surface of the base end part of the tunnel is split, and the upper half of the main shaft is excavated by cutting and expanding above the bottom part of the peripheral wall surface of the base end, and thereafter. Since the lower half of the main shaft is split in the vertical direction, that is, the split rock work is divided, the tunnel is excavated in the upper part of the planned excavation section of the main tunnel, and the excavation section below the tunnel is excavated. Even in the case of large diameter, the peripheral wall surface of the base end portion of the tunnel can be easily cut to the size of the main tunnel.

According to the tunnel excavation method of claim 11,
When the excavation according to claim 9 is performed, a protective pipe extending from the base end side of the main shaft to the main shaft is installed at an area where the main shaft where the upper half has been excavated and the main shaft is connected, and an electric wire is provided in this protective pipe. Since long linear members such as water pipes and blast pipes and the residual soil discharge belt conveyor are inserted, the upper members of the main shaft can be split and protected from falling rock fragments. Safe passage is possible by using the passage inside the protective tube. In addition, the excavated residual soil produced by the tunnel excavation can be carried out regardless of the split rock work, and this excavated residual soil can be processed together with the rock fragments produced by the split rock in the lower half of the main shaft. The efficiency of can be improved.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a tunnel and a main shaft for explaining an embodiment of a tunnel excavation method of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a cross-sectional view showing a split rock method in the tunnel excavation method of the present invention.

FIG. 4 is a transverse cross-sectional view showing an essential part of the split rock in FIG. 3 in a final state.

FIG. 5 is a side sectional view showing a tunnel excavation method of the present invention in which a guide shaft is located at an uppermost position.

6 is a sectional view taken along line BB in FIG.

FIG. 7 is a side sectional view showing the tunnel excavation method of the present invention in which the position of the tunnel is at the center.

8 is a sectional view taken along line CC in FIG.

FIG. 9 is a side sectional view showing the tunnel excavation method of the present invention in which the position of the tunnel is at the bottom.

10 is a cross-sectional view taken along the line DD in FIG.

FIG. 11 is a side sectional view showing a method for discharging the excavation residual soil in the tunnel in the tunnel excavation method of the present invention.

12 is a sectional view taken along line EE in FIG.

FIG. 13 is a side cross-sectional view showing another method for discharging the excavation residual soil in the tunnel in the tunnel excavation method of the present invention.

FIG. 14 is a sectional view taken along line FF in FIG.

FIG. 15 is a side cross-sectional view showing a state in which the excavated soil in the tunnel is being discharged in the tunnel excavation method of the present invention.

FIG. 16 is a side sectional view showing a state in which a protective pipe is installed in the tunnel excavation method of the present invention.

17 is a sectional view taken along the line GG in FIG.

FIG. 18 is a transverse cross-sectional view showing a state in which a tunnel has been excavated in the tunnel excavation method of the present invention such that its top is located above the top of the main shaft.

FIG. 19 is a side sectional view showing a method of splitting rock below the bottom of the tunnel in the tunnel excavation method of the present invention.

20 is a sectional view taken along line HH in FIG.

21 is a cross-sectional view taken along the line II of FIG.

FIG. 22 is a side view showing a hole drilling machine in the tunnel excavation method of the present invention.

23 is a sectional view taken along line JJ in FIG.

FIG. 24 is a cross-sectional view showing a split rock method in the tunnel excavation method of the present invention.

FIG. 25 is a side sectional view showing a method of dividing the main shaft into upper and lower parts by dividing the main shaft into two parts in the tunnel excavation method of the present invention.

26 is a sectional view taken along line KK in FIG.

27 is a sectional view taken along line LL in FIG. 25.

28 is a sectional view taken along line MM in FIG. 25.

FIG. 29 is a side view showing a gantry type jumbo mount used in the tunnel excavation method of the present invention.

FIG. 30 is a sectional view taken along line NN in FIG. 29.

FIG. 31 is a transverse cross-sectional view showing a state where a hydraulic rock breaking machine is inserted into the drilled hole.

FIG. 32 is a transverse cross-sectional view showing a state where the drilled hole is expanded and divided by a hydraulic type rock breaking machine.

[Explanation of symbols]

1 Main pit 2 TBM 3 Guide pit 4 Base end peripheral wall of guide pit 4a Near top end of base end peripheral wall 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9
a, 9b Rock piece 15 Temporary belt conveyor 16 Remaining soil conveyor belt conveyor 20 Truck 25 Protective tube 26 Gantry type jumbo stand 27 Electric wire 28 Water pipe 29 Blower pipe T1, T2 Intersection S space 31 Drilling machine 34 Rock excavator 60 Removing residual soil Belt conveyor A Opening G, G1, G2 Rock fragments

Front page continued (72) Inventor Yuzo Koga 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Toshihiko Wada 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Yoshiyuki Obara 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Masaki Imazu 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Invention Hisashi Takenaka 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Kazuhiro Fukuda 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Hiroshi Kazama Tokyo Shimizuura 1-3-2, Minato-ku, Tokyo Shimizu Construction Co., Ltd.

Claims (11)

[Claims] 1. A guide shaft is excavated in a planned excavated cross section of the main shaft by a circular full-section excavator method, and a peripheral wall surface of a base end portion of the guide shaft is split to form a peripheral wall surface of the base end portion of the guide shaft. A tunnel excavation method characterized by simultaneously excavating a guide shaft and a main shaft while cutting and expanding to the size of the main shaft. 2. When splitting the peripheral wall surface of the base end of the tunnel,
First, the vicinity of the base end peripheral wall top surface is drilled so that the width becomes gradually narrower toward the upper part, and the rock is divided, and then the base end peripheral wall surface from the base end peripheral wall top surface near 2. The tunnel excavation method according to claim 1, wherein the base end peripheral wall surface is cut outward by repeating a step of sequentially drilling a hole to the bottom of the base peripheral wall surface along the circumferential direction to split the rock. 3. When drilling the peripheral wall surface of the base end of the tunnel,
3. The tunnel excavation method according to claim 2, wherein each hole is provided with a slit-shaped notch extending in the direction of a crack to be generated during split rock. 4. A temporary placement belt conveyor extending from the vicinity of the tip of the tunnel toward the main tunnel side is provided in the tunnel, and the residual soil extending from the base end of the temporary placement belt conveyor to the tip of the main tunnel. A carry-out belt conveyor is provided, and the excavated soil that comes out during tunnel excavation is temporarily placed on the temporary placement belt conveyor, and then at a time when there is no hindrance to the main pit excavation work.
The tunnel excavation method according to any one of claims 1 to 3, wherein the both belt conveyors are activated to discharge the excavated residual soil to the main shaft. 5. The tunnel excavation method according to claim 4, wherein each of the temporary placement belt conveyor and the residual soil discharging belt conveyor is provided so as to be movable in the longitudinal direction of the tunnel. 6. A temporary placement belt conveyor extending in the longitudinal direction of the tunnel and movable along the longitudinal direction is provided in the tunnel, and a position above the temporary placement belt conveyor is provided.
A trolley that conveys the remaining excavated soil from the tunnel excavation to the temporary belt conveyor is provided movably along the longitudinal direction of the tunnel, at a time when there is no hindrance to the main tunnel excavation work. 2. The excavated soil is discharged to the main pit by moving a temporary placement belt conveyor on which the excavated soil is temporarily placed to the main pit and activating the belt conveyor.
The tunnel excavation method according to any one of 1 to 3. 7. A protective pipe extending from the base end side of the main shaft to the front end side of the main shaft is installed at an area where the main shaft and the main shaft are connected, and the protective pipe has a length of an electric wire, a water pipe, a blower pipe or the like. The tunnel excavation method according to any one of claims 1 to 3, wherein a long linear member and a residual soil discharging belt conveyor are inserted. 8. A tunnel is excavated so that its top is located above a site that should be the top of the main shaft, and the top of the tunnel is excavated.
The tunnel excavation method according to claim 1, characterized in that a long linear member such as an electric wire, a water pipe, a blower pipe, or the like is inserted into a space between two intersections with a site to be the top of the main shaft. . 9. The upper part of the planned excavation section of the main shaft,
In the case of excavating a tunnel by the circular full-section excavator method and breaking the base wall of the tunnel at the base end to cut the base wall of the tunnel to the size of the main shaft, After drilling downward from the bottom of the end wall surface and splitting the rock, the process of splitting the base wall surface is repeated to cut the base wall surface of the tunnel to the size of the main shaft. The method for excavating a tunnel according to claim 1, characterized in that. 10. A guide shaft is excavated at an upper part of a planned excavation section of the main shaft by a circular full-section excavator method, and a peripheral wall surface of a base end part of the guide shaft is split to form a base end periphery of the guide shaft. When cutting the wall to the size of the main shaft, the peripheral wall of the base of the tunnel is split, and the upper half of the main shaft is excavated by cutting and expanding above the bottom of the peripheral wall of the base. ,afterwards,
The tunnel excavation method according to claim 1, wherein the lower half of the main shaft is split in a vertical direction. 11. A protective pipe extending from the base end side of the main shaft to the main shaft side is installed at an area where the main shaft where the upper half has been excavated and the main shaft is connected, and an electric wire, a water pipe, and a blower are installed in the protective pipe. 11. The tunnel excavation method according to claim 10, wherein a long linear member such as a pipe and a residual soil discharging belt conveyor are inserted.