JPH09151691A - Tunnel protection construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve construction efficiency and improve the strength of a protection wall by digging a continuous groove which is inclined on a construction scheduled line in cross from a ground surface by an excavator and forming the protection wall which crosses obliquely under the ground on the construction scheduled line by pouring a solidification material into the continuous groove before a tunnel is digged. SOLUTION: A first continuous groove G1 which is inclined is digged by moving a travelling cart 1 while rotating a cutter 2 in a condition in which the cutter 2 is put in the ground. Solidification liquid is poured into the first continuous groove G1 to form a first protection wall W1. After or before the first protection wall W1 is solidified, a position of an excavator is moved to the opposite side for the center of a construction scheduled line, and a second continuous groove G2 which is inclined is digged in cross with the first continuous groove G1. After the second continuous groove G2 is digged, solidification liquid is poured into the second continuous groove G2 to form a second protection wall.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel protection method for performing a protection work on a planned tunnel construction line before excavating the tunnel.

[0002]

2. Description of the Related Art Particularly in the case of an underground tunnel, it is necessary to provide protective work to reinforce the ground above the tunnel as an auxiliary method so that the structure on the ground surface will not be damaged or collapsed due to ground subsidence due to excavation. is there.

Further, when adopting a method for stabilizing the face by pressurizing the inside of the tunnel, such as a pressure shield construction method and a muddy water shield construction method, it is necessary to prevent leakage of air to the ground surface and spouting of muddy water.

In particular, in the case of the large-diameter shield construction method, the earth pressure difference between the upper and lower ends of the tunnel is large, and the pressure on the lower end side is balanced to stabilize the face, so the pressure in the upper part of the tunnel becomes higher than the earth pressure. , Air leaks and spouts are likely to occur, and there is a high need for protective work.

Conventionally, as a tunnel protection method for reinforcing air and preventing leakage and spouting in the shield method, a pipe roof method, that is, pipes (steel pipes) are inserted in parallel along the outer periphery of the excavated section, There is known a construction method in which a grout material such as concrete is filled to form a roof having a tunnel shape.

[0006]

However, according to the conventional tunnel protection construction method including this pipe roof construction method, since the protection work such as pipe insertion is performed from inside the tunnel (face), the construction distance of one time is reduced. There was a problem in that it was short and construction efficiency was poor, and because the protective work was discontinuous, it was also disadvantageous in terms of strength, and that it required advanced construction technology.

Therefore, the present invention provides a tunnel protection construction method capable of continuously and efficiently constructing protection work for reinforcement of the ground and prevention of air leaks and jets in the shield construction method from the ground surface side. Is.

[0008]

According to a first aspect of the present invention, prior to excavation of a tunnel, an excavator excavates a continuous groove inclined on the planned construction line of the tunnel from the ground side, and the continuous groove is excavated. By injecting the solidifying material, a protective wall diagonally crossed in the ground is formed on the planned tunnel construction line.

According to a second aspect of the present invention, in the structure of the first aspect, a chain type cutter, in which an endless chain with an excavating blade is bridged between upper and lower end portions of a cutter post, is attached to a traveling carriage while being inclined. In the state where the cutter of the excavator is installed diagonally in the ground on the planned line of construction of the tunnel, the inclined continuous groove is excavated by moving the cutter while rotating the cutter. is there.

According to a third aspect of the present invention, in the configuration of the second aspect, the cutter is attached to the traveling carriage so as to be up and down freely about a horizontal axis, and is supported by a retractable back stay so that the inclination angle can be adjusted. Is.

According to a fourth aspect of the present invention, in the third aspect, the back stay is configured to be extendable / contractible by a hydraulic cylinder.

[0012] According to the above-mentioned constitution, the protection wall which is diagonally crossed in a state of covering the tunnel to be constructed like a roof is continuously formed, and the ground on the tunnel is reinforced by the protection wall to prevent ground subsidence, Moreover, leakage of air and spout of mud during tunnel excavation by the shield method are prevented.

According to this construction method, since the protective wall can be easily and continuously formed from the ground surface side, the construction efficiency is good and the strength is advantageous.

In this case, according to the second aspect of the present invention, since the continuous groove is excavated by moving the traveling carriage while rotating the cutter, compared with the case where the continuous groove is formed by repeating the drilling work with a drill, for example. Thus, continuous grooves can be excavated with a uniform width and much more efficiently.

According to the third aspect of the invention, the inclination angle of the continuous groove, that is, the protective wall can be arbitrarily adjusted according to the outer diameter of the tunnel and the like.

In this case, according to the invention of claim 4, the angle adjustment can be easily and quickly performed by the expansion and contraction action of the hydraulic cylinder.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the entire construction of an excavator used in the tunnel protection method according to this embodiment.

This excavator is basically a self-propelled traveling carriage (for example, a crawler crane base machine) 1
A chain type cutter 2 is attached to the, and while the cutter 2 is built in a hole excavated by an appropriate means such as a hydraulic excavator, the cutter 2 is rotated and moved horizontally along with the traveling carriage 1. Thus, the continuous groove G having a predetermined length is excavated.

As shown in FIG. 2, the cutter 2 has a drive wheel (sprocket) 4 provided at the upper end of a cutter post 3 which is a vertically long box-shaped frame, and an idle wheel (pulley) provided at the lower end. 5, an endless chain 6 is laid between the endless chains 6 and 5, and the groove G is excavated by a large number of excavating blades 7 provided on the outer peripheral side of the chain 6.

The cutter 2 is attached to the traveling carriage 1 as follows.

As shown in FIG. 1, a main frame 8 is attached to the traveling carriage 1.

The main frame 8 is supported at its lower end by a horizontal shaft 9 and at its upper end by a retractable backstay 10 consisting of a hydraulic cylinder, respectively, on the traveling carriage 1, and the horizontal shaft 9 is supported by the retractable action of the backstay 10. Can be raised and lowered about the center, that is, the inclination angle θ with respect to the horizontal plane can be adjusted.

The reader 1 is provided on the front surface of the main frame 8.
1, a slide frame 12 is attached to the upper ends of the cutter 2 (cutter post 3), and the slide frame 12 is attached to the reader 11 so as to be movable up and down.

Reference numeral 13 is a reader 11 and a slide frame 12.
With a lifting hydraulic cylinder provided between and, the slide frame 12 (cutter 2) is lifted and lowered by the expansion and contraction of the cylinder 13 to adjust the excavation depth.

In this manner, the excavator is constructed by mounting the cutter 2 on the traveling carriage 1 in a tilted state and adjusting the tilt angle θ so that it can be adjusted.

According to this construction method, prior to excavation of the tunnel, roof-like protection walls W1 and W diagonally crossing the ground on the planned construction line of the tunnel T as shown in FIG.
Build 2 along the planned line.

The procedure for constructing the protective walls W1 and W2 is as follows.

As shown in FIG. 1, the traveling carriage 1 of the excavator is arranged so as to be movable in parallel with the planned construction line, and the cutter 2 is underground (diagonal vertical hole excavated by an appropriate means in advance) as described above. In the state of being built in, the traveling carriage 1 is moved while rotating the cutter 2 to excavate the inclined first continuous groove G1.

The inclination angle of the continuous groove G1 (the inclination angle θ of the cutter 2) is adjusted according to the outer diameter dimension of the tunnel T and the like.

After the excavation of the trench, a solidification liquid (cement slurry) is injected into the trench G1, the solidification liquid is stirred and mixed with the in-situ soil, and then solidified to thereby solidify the soil cement wall as shown in FIG. The first protection wall W1 is formed.

After solidification of the first protective wall W1 or before solidification, the position of the excavator is moved to the opposite side to the center of the tunnel construction planned line as shown in FIG.
The continuous groove G2 of is crossed with the first protective wall W1 and excavated.

Even after the first protective wall W1 is solidified, the cutter 2 can sufficiently excavate the second continuous groove G2 through the protective wall W1.

Similar to when the first protective wall W1 is created,
After excavating the continuous groove G2, the solidification liquid is injected into the groove, stirred and mixed with the in-situ soil, and solidified, whereby the second protection wall W2 is changed to the first protection wall as shown in FIG. Created by crossing diagonally with respect to W1.

The protection walls W1 and W2 thus constructed reinforce the ground on the tunnel to prevent ground subsidence after the tunnel construction, and also prevent leakage of air and muddy water during tunnel excavation by the shield construction method. To be done.

According to this construction method, since the protection walls W1 and W2 can be continuously formed from the ground side, protection such as inserting a pipe from inside the tunnel to the periphery of the tunnel cross section as in the conventional pipe roof construction method. Compared with the construction method, the construction efficiency is good and the strength is advantageous.

By the way, in the above embodiment, the continuous groove G
As the most preferable method for excavating the G1 and G2, a method using an excavator in which the chain cutter 2 is attached to the traveling carriage 1 is used, but other than that, for example, a continuous groove G1 is formed by repeating a drilling operation with a plurality of drills. , G2 may be excavated.

In the above embodiment, the solid cement (cement slurry) is injected after the continuous trench is excavated, and the soil cement protective walls W1 and W2 are formed by stirring and mixing with the in-situ soil. After digging trenches, inject concrete
It may be solidified to form a concrete protective wall.

Further, in the above embodiment, after the first protective wall W1 is formed, the second continuous groove G2 is excavated, and the solidifying liquid is injected and solidified to form the second protective wall W2. However, the first and second continuous grooves G1 and G2 may be excavated one after another, and a solidifying material (for example, concrete) may be simultaneously injected into these to solidify them to form the protective walls G1 and G2.

On the other hand, in the above embodiment, the back stay 10 is used.
Was constructed by a hydraulic cylinder, and the tilt angle was adjusted by expanding and contracting it. However, this back stay 10 is constructed by a simple inner cylinder and an outer cylinder so that it can be expanded and contracted to assist other lifting machines such as cranes. Alternatively, the inclination angle may be adjusted.

Alternatively, the back stay 10 may be a non-expandable type, and the inclination angle of the cutter 2 may be constant.

[0042]

As described above, according to the present invention, the excavator excavates a continuous groove that is inclined on the planned construction line of the tunnel, and the solidification material is injected into the continuous groove so that the solidified material is injected into the tunnel. Since the ground is reinforced to prevent ground subsidence and to create a diagonally crossed protection wall that prevents leakage and mud spray during tunnel excavation using the shield construction method, the protection work can be easily performed from the ground side. Moreover, it can be applied continuously.

Therefore, compared with the conventional pipe roof construction method and the like, the construction efficiency of the protective work can be remarkably improved, and the continuity of the protective wall can be secured to construct a high-strength protective wall. You can

In this case, according to the second aspect of the present invention, since the continuous groove is excavated by moving the traveling carriage while rotating the cutter, for example, as compared with the case where the continuous groove is formed by repeating the drilling work with a drill. Thus, continuous grooves can be excavated with a uniform width and much more efficiently.

According to the third aspect of the invention, the inclination angle of the continuous groove, that is, the protective wall can be arbitrarily adjusted according to the outer diameter dimension of the tunnel and the like.

In this case, according to the invention of claim 4, this angle adjustment can be easily and quickly performed by the expansion and contraction action of the hydraulic cylinder.

[Brief description of the drawings]

FIG. 1 is an overall side view of an excavator used in a construction method according to an embodiment of the present invention.

FIG. 2 is a front view of a chain type cutter of the excavator.

FIG. 3 is a schematic cross-sectional view showing a stage in which a first protective wall is created in the construction method according to the embodiment.

FIG. 4 is a schematic cross-sectional view showing a step of excavating a second continuous groove for forming a second protective wall in the same construction method.

FIG. 5 is a schematic cross-sectional view of a completed construction state.

[Explanation of symbols]

 1 traveling carriage 2 chain type cutter 3 cutter post 6 endless chain 4 chain drive wheel 5 chain idler wheel 7 excavating blade 9 horizontal axis that serves as the undulating fulcrum of the cutter 10 backstay consisting of hydraulic cylinder G continuous groove G1 first continuous Groove G2 Second continuous groove W1 First protective wall W2 Second protective wall T Tunnel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Kondo 2-3-1, Niihama, Arai-cho, Takasago, Hyogo Prefecture Kobe Steel Works Takasago Works

Claims (4)

[Claims] 1. Prior to excavation of a tunnel, an excavator excavates a continuous groove inclined on the planned construction line of the tunnel from the ground surface side, and a solidifying material is injected into the continuous groove to construct the tunnel. A tunnel protection method characterized by constructing a diagonally crossed protection wall on the planned line. 2. The tunnel protection construction method according to claim 1, wherein an endless chain with an excavating blade is attached to a traveling carriage by slantingly attaching a chain type cutter formed by being spanned between upper and lower end portions of a cutter post. It is characterized in that the cutter of the excavator is built diagonally in the ground on the planned line of construction of the tunnel, and the inclined carriage is excavated by moving the cutter while rotating the cutter with the traveling carriage. And tunnel protection method. 3. The protection of the tunnel according to claim 2, wherein the cutter is attached to the traveling carriage so as to be capable of undulating about a horizontal axis and is supported by a retractable back stay so that the inclination angle can be adjusted. Construction method. 4. The method for protecting a tunnel according to claim 3, wherein the back stay is configured to extend and contract by a hydraulic cylinder.