JP2001323773A - Tunnel excavation method utilizing advancing drift - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an excavating cycle time by performing timbering construction operation such as spraying operation and lock bolt operation along with mucking work immediately after blasting. SOLUTION: After an advancing drift P is formed before the face excavation of the pit 1 in the design section of the pit 1, a spraying machine 7 is installed in the advancing drift P, blasting excavation of the pit 1 is made, and spraying operation is made to a newly exposed tunnel wall surface by the spraying machine 7 that is located in the advancing drift P along with the mucking work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention aims to improve the efficiency of main shaft excavation and to reduce the congestion of construction machinery by using an advanced shaft excavated prior to a face in a section of the main shaft. Tunnel excavation method.

[0002]

2. Description of the Related Art Conventionally, mountain tunnel excavation methods include a full cross section excavation method for excavating a design section at a stretch, a full cross section method with an auxiliary bench, and excavation by dividing the design section into an upper half section and a lower half section. Bench cut method such as long bench cut, short bench cut, mini bench cut, etc. A suitable excavation method is appropriately selected according to the properties of the ground, the cross-sectional shape of the tunnel, and the like.

[0003] On the other hand, in tunnels with a large amount of spring water, it is difficult to apply shotcrete and rock bolts as support members, or it is not possible to secure high-grade construction. It may be excavated prior to excavation. The pilot tunnel is a small-section tunnel formed prior to main tunnel excavation inside and outside the design section of the tunnel main tunnel for drainage and geological survey, and the side wall tunnel also serves as a pilot tunnel. May be adopted.

[0004]

In the above-mentioned conventional construction method, basically, the excavation procedure includes face drilling, charging, blasting, shearing, and spraying (in some cases, installing a steel arch support). )), Excavation is performed sequentially according to the procedure of drilling and placing rock bolts. In each of these steps, it is difficult to perform parallel work due to the fact that construction machines to be used differ for each type of construction, and it is difficult to parallel construction machines in many tunnel sections except large sections, This was a factor that shortened the cycle process time and, consequently, made tunnel excavation less efficient.

[0005] In a tunnel with a large cross section, a rock jumbo is drilled while a drill jumbo is arranged in front of a face.
Placement and face drilling and charging are performed concurrently, but if the installation intervals of the construction machines are narrow, contact accidents such as booms due to congestion between machines and accidents involving workers Was a concern.

Further, in the case of a bad ground such as a collapsed ground, a support by spraying and rock bolting (in some cases, a steel arch support is also performed) is constructed early after blasting and excavation. Desirably, since the work space is occupied by the slip loading machine and the dump truck, there is a problem that the face cannot be entered until the slip is completed.

Therefore, a main problem of the present invention is that, in a tunnel excavation method in which an advanced shaft is formed in a design section of a main pit prior to excavation of the main pit, a spraying operation or a lock bolt operation is performed in parallel with a shearing operation. To shorten the excavation cycle time, and to be able to start the support construction work immediately after blasting, so that it can respond quickly to bad ground. An object of the present invention is to eliminate congestion between machines and eliminate accidents of contact between machines and accidents caused by workers, so that excavation can be performed safely.

[0008]

According to a first aspect of the present invention, an advanced shaft is formed in a design section of the main shaft prior to excavation of a face of the main shaft, and then the advanced shaft is formed in the advanced shaft. And a spraying operation is performed by the spraying machine located in the advanced pit in parallel with the slippage operation of the main shaft.

According to a second aspect of the present invention, a drill jumbo provided with a drilling boom is installed in the advanced shaft after forming an advanced shaft in a design section of the main shaft prior to face drilling of the main shaft. It is characterized in that, in parallel with the slippage operation of the main shaft, the rock jumbo drilling and setting operation is performed by the drill jumbo positioned in the advanced shaft. The operation of the spraying machine or the drill jumbo installed in the advanced shaft is desirably remote-controlled because it is difficult for a worker to enter.

In these cases, it is desirable that the advanced shaft is formed at a position substantially above the center in the design section of the main shaft, and it is desirable that the advanced shaft be constructed by a tunnel boring machine in terms of construction efficiency. Excavation of the main pit may be blasting excavation or mechanical excavation. However, the mechanical excavation excludes a full-section excavator such as a tunnel boring machine, and includes a free-section excavator called a boom header, a cutter head, or the like. In this mechanical excavation, the shears are sequentially discharged from the shearing conveyor at the back of the machine at the same time as the excavation, but especially in a large section tunnel, the face is divided into an excavation area and a spray or lock bolt work area to prevent interference between machines After that, the spraying work or rock bolt drilling /
The efficiency of excavation work can be improved by performing the driving in parallel.

In the present invention, the operation of spraying onto the tunnel wall surface of the main shaft and the operation of driving a rock bolt are performed by using an advanced shaft which has not been used at all. In other words, a construction machine for supporting such as a spraying machine or a drill jumbo is installed in an advanced shaft excavated prior to the excavation of the main pit for the purpose of drainage pit and geological survey, etc. At the time of shearing, the support construction machine performs spraying or rock-bolt support construction in parallel with the shearing operation. As a result, the spraying or rock bolt drilling / placement work, which could only be performed after waiting for the displacement, can now be performed in parallel with the displacement, so that the cycle time of excavation can be reduced and the excavation efficiency can be reduced. Is improved.

Conventionally, if the shearing work is not completed after the blasting excavation, the support construction work such as spraying and lock bolts could not be performed. Even if it is a mountain or a collapsible ground, the construction can be efficiently performed while quickly suppressing the loosening of the ground.

Further, conventionally, in the mini bench cut method in a large-section tunnel, for example, two drill jumbo are arranged in parallel in a main pit to improve efficiency, and a rock bolt drilling / driving and a face drilling / charging are performed. Or when two spraying machines are arranged in parallel to perform spraying work, but when the installation intervals of these construction machines are narrow, interference between machines and the involvement of workers And so on.
However, according to the present invention, since the spray jumbo and the drill jumbo for drilling and placing the lock bolt are located in the advanced shaft, congestion between the construction machines is eliminated and the work can be performed safely and efficiently. . Of course, even if the tunnel space is large and, for example, construction can be performed while ensuring contact accidents and safety even if two construction machines are installed,
A spraying machine or a drill jumbo installed in an advanced shaft can assist spraying or drilling work so that work can be performed efficiently.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention in which a spraying operation is performed in parallel with a shearing operation, and a lock bolt drilling and placing operation is performed in parallel with a shearing operation. This will be described in detail separately from the second embodiment. [First Embodiment] FIG. 1 is a construction flow chart of a tunnel excavation method according to the present invention, and FIG. 2 is a cross sectional view of a tunnel.

As shown in FIG. 2, in the tunnel targeted by the present tunnel excavation method, an advanced shaft P such as a pilot shaft is formed in a design section of the main shaft 1 prior to the main shaft excavation. It is a tunnel. The advanced pit P is a small-section tunnel excavated prior to the main pit 1 for the purpose of drainage, geological survey, and the like. It is preferably formed at the approximate center of the upper half X and at the upper center when viewed from the cross section of the tunnel so that it is within the boom working range. It can be formed by a tunnel boring machine or the like. The bottom plate portion of the advanced shaft P is leveled with earth and sand 11 so that the spraying machine 7 can run.

On the other hand, the main shaft 1 has a blasting material 2 such as mortar or concrete sprayed on the wall surface during the excavation.
And the lock bolts 3, 3... Inserted and driven in the radial direction of the tunnel constitute a support. In some cases, a steel arch member is used together.

In this example, a large-section tunnel, specifically 1
00m ² or more, specifically to show the 140 m ² or more construction cases, drilling method includes the upper half X design cross section, and the lower half the large back Y, the lower half Dotaira Z, divided into a Z, wherein The upper half X and the lower half large back Y are constructed by two drill jumbo, and the lower half soil Z, Z are constructed by another drill jumbo (not shown). The advantage of this excavation method is that when the upper half X and the lower half large back Y are blasted and slipped, the lower half horizon Z and Z are left on both sides, so that it collapses even on unstable ground. The point is that tunnel excavation can be performed safely without causing such an event. Needless to say, excavation may be performed without forming the lower half ground Z, Z when the ground is good even in a large cross section. In addition, this excavation method can be applied to a full-section excavation method, a long bench cut method, a short bench cut method, and the like, in addition to the above-mentioned mini bench cut method.

Hereinafter, the tunnel excavation method will be described in detail while following the excavation procedure. In the following description, the excavation procedure of the lower half soil Z, Z follows a normal excavation procedure, and therefore, the explanation is omitted.

This tunnel excavation method is a conventional excavation cycle process in which charging hole drilling shown in FIG. 13 → charging → blasting → shearing → spraying → rock bolt drilling / placement in this order. As shown in the construction flow chart of FIG. 1, a spraying machine 7 installed in the advanced shaft P enables parallel work of a slip-out operation after blasting and a spraying operation.

First, as shown in FIG. 3, two drill jumbo units 4 are located in front of a mini bench (lower half large back Y) having a length of about 3 to 4 m in the tunnel direction below the face. State. As the drill jumbo 4, at least two or more drilling booms 5 are used in terms of work efficiency.
It is desirable to use a drill jumbo provided with at least two charging gauges 6L and 6R while having L and 5R.

An operator who got on the charging gauges 6L and 6R marks the blast hole in the upper half X and marks the lock bolt hole on the wall surface of the upper half tunnel. The drilling of the charging hole is performed from the face of the head in the forward direction, and the drilling of the lock bolt hole is performed.

Next, as shown in FIG. 4, the drill jumbo 4 is retracted by several meters, and rock bolts 3, 3... Are struck against the upper half tunnel wall while using the charging gauges 6L, 6R. At the same time, the charging hole is drilled in the lower half large back Y at the same time. Then the first half X
The dynamite is charged into the blast holes of the above, and the dynamite is charged into the lower half large back Y.

When the preparation for blasting is completed, the dynamite loaded in the upper half X and the lower half large back Y is exploded to break the face and form a new upper half face and a lower half large back face. After the blasting, as shown in FIG. 5, the sand load is removed by a wheel loader 8 and a dump truck 9 located in the main shaft, and the spraying machine 7 installed in the advanced shaft P is moved to the advanced shaft. The blasting member 2 such as mortar or concrete is sprayed on a newly exposed tunnel wall by turning the nozzle toward the upper half and turning the nozzle toward the upper half. In addition, if necessary, the steel arch members are installed.
The nozzle operation of the spraying machine 7 is desirably remote-controlled because it is difficult for an operator to enter, and since it is difficult to supply the spraying material from within the advanced shaft P, the lower half of the nozzle is operated. The spraying material is supplied from a spraying machine 20 with a pump for spraying the soil Z, Z portion, or supplied by a spraying material pump (not shown) separately installed in the main well. With the above steps, one cycle of the excavation step is completed. Thereafter, this excavation cycle is repeated to extend the tunnel sequentially.

[Second Embodiment] Next, FIGS. 7 to 12 show a second embodiment in which the shearing after blasting and the work of drilling and placing a lock bolt on the upper half tunnel wall surface are performed in parallel.
It will be described in detail with reference to FIG.

As shown in the construction flow chart of FIG. 7, the drill jumbo 4 only drills a charging hole for the upper half X face and the lower half large back Y face, and is located in the main pit after blasting. After the spraying is performed by the spraying machine 12, the shearing and the work of drilling and placing the lock bolt on the upper half tunnel wall surface are performed in parallel.

First, as shown in FIG. 8, in front of a mini bench (lower half large back Y) having a length in the tunnel direction of about 3 to 4 m below the face, the drill jumbo 4 is preferably placed in front of the mini bench. ~ 2 units are located. After marking the blast hole in the upper half X, the operator who got on the charging gauges 6L and 6R drills the charging hole from the face of the upper half X toward the front.

Next, as shown in FIG. 9, the drill jumbo 4 is retracted by several meters, and the charging hole is drilled in the lower half large back Y. Thereafter, dynamite is charged into the blast holes of the upper half X, and dynamite is charged into the lower half large back Y.

When the preparation for blasting is completed, the dynamite loaded in the upper half X and the lower half large back Y is exploded to break the face to form a new upper half face and a lower half large back face. After the blasting, as shown in FIG. 10, a spraying material such as mortar or concrete is sprayed on the newly exposed upper half tunnel wall by the spraying machine 12 located in the main pit without immediately performing the shearing. wear. In addition, if necessary, the steel arch members will be erected. Thereafter, when the spraying operation is completed, as shown in FIG. 11, the sand load is removed by the wheel loader 8 and the dump truck 9 located in the main shaft, and the lock installed in the advanced shaft P Bolt drill jumbo 10 with advanced shaft P
The rock bolt hole is drilled while turning the boom while being positioned at the wellhead, and then the worker who got on the charging cage performs the work of setting the lock bolt.
As shown in the figure, the lock jumbo drill 10 preferably has two drilling booms 13L, 13L.
It is preferable that the drilling is performed while the upper right half and the upper left half are shared with each other.
4 is desirable. Note that the boom operation of the rock bolt drill jumbo 10 is difficult for an operator to enter as in the case of the spraying machine 7.
It is desirable to use remote control.

When the work of installing the lock bolts is completed, one cycle of the excavation process is completed, and thereafter, the excavation cycle is repeated, and the tunnel is sequentially extended.

[0030]

As described in detail above, according to the present invention, in a tunnel excavation method in which an advanced pit is formed in a design section of a main pit prior to excavation of the main pit, a spraying operation or a lock bolt operation is performed. Since the operation can be performed in parallel with the work, the excavation cycle time can be shortened. In addition, since it becomes possible to start the support construction work immediately after the blast, it is possible to quickly respond to a bad ground. Further, the congestion between the construction machines is eliminated, and the excavation can be performed safely by eliminating the contact accident between the machines and the personal injury of the worker.

[Brief description of the drawings]

FIG. 1 is a construction flowchart of a tunnel excavation method according to a first embodiment.

FIG. 2 is a cross-sectional view of a tunnel.

FIG. 3 is a longitudinal sectional view showing a tunnel excavation procedure (1).

FIG. 4 is a longitudinal sectional view showing a tunnel excavation procedure (No. 2).

5A and 5B show a tunnel excavation procedure (No. 3), wherein FIG. 5A is a longitudinal sectional view and FIG. 5B is a plan view.

FIG. 6 is a view taken along line VI-VI in FIG. 5;

FIG. 7 is a construction flowchart of a tunnel excavation method according to the second embodiment.

FIG. 8 is a longitudinal sectional view showing a tunnel excavation procedure (1).

FIG. 9 is a longitudinal sectional view showing a tunnel excavation procedure (No. 2).

FIG. 10 is a longitudinal sectional view showing a tunnel excavation procedure (No. 3).

11 (A) is a longitudinal sectional view and FIG. 11 (B) is a plan view showing a tunnel excavation procedure (No. 4).

FIG. 12 is a view taken along line XII-XII of FIG. 11;

FIG. 13 is a construction flow chart of a conventional tunnel excavation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main shaft, 2 ... Shot material, 3 ... Rock bolt, 4 ... Drill jumbo, 7 ... Spraying machine, 8 ... Wheel loader, 9 ... Dump truck, 10 ... Drill jumbo for rock bolt,
P… Advanced shaft

Claims (4)

[Claims] (1) After an advanced shaft is formed in a design section of the main shaft prior to excavation of a face of the main shaft, a spraying machine is installed in the advanced shaft to perform a slipping operation of the main shaft. A tunnel excavation method using an advanced shaft, wherein a spraying operation is performed by the spraying machine located in the advanced shaft. 2. An advanced pit is formed in the design section of the main pit prior to the excavation of the face of the main pit. Then, a drill jumbo provided with a drilling boom is installed in the advanced pit, and A tunnel drilling method using an advanced shaft, wherein a rock bolt hole drilling and setting operation is performed by the drill jumbo positioned in the advanced shaft in parallel with the shearing operation. 3. The operation of a spraying machine or a drill jumbo installed in the advanced shaft is performed by remote control.
A tunnel excavation method using the advanced shaft described in any of the above. 4. The tunnel excavation method using an advanced shaft according to any one of claims 1 to 3, wherein the advanced shaft is formed at a substantially upper central position in a design section of the main shaft.