JP2695319B2 - Tunnel construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel construction method applied to urban tunnel construction on unconsolidated ground.

[0002]

2. Description of the Related Art As a construction method of this type, the inventors of the present invention, in Japanese Patent Application No. 2-61243, successively form a radial solid wall along the outer circumference of a drill hole in the drilling direction prior to the drilling work. A method of constructing a tunnel was proposed.

[0003]

However, it is extremely difficult to construct a tunnel while reliably securing the stability of the cutting face by the conventional method in the case of a relatively loose ground or a ground where there is pressurized water, which easily collapses. There was a problem in terms of safety. The present invention has been proposed in view of the above problems of the prior art, and the purpose thereof is to ensure the safety of the face even in the case of a relatively loose ground that easily collapses or a ground where pressurized water exists. However, the point is to provide a construction method that can efficiently construct a tunnel.

[0004]

In order to achieve the above-mentioned object, according to the tunnel construction method of the present invention, a radial outer peripheral solid body having a constant depth length in the excavating direction along the outer periphery of the excavating hole. After forming the connecting wall, a tip closed solidifying wall that closes the tip of the outer peripheral solidifying wall is formed, and the inner unsolidified ground surrounded by the solidifying walls is excavated.

[0005]

According to the present invention, as described above, the radial outer peripheral consolidating wall having a constant depth length in the excavating direction is formed along the outer periphery of the excavating hole, and then the tip portion of the outer peripheral consolidating wall is formed. By constructing the confined solid wall at the tip, the tunnel excavation work is performed in a state where it is completely sealed by both solid walls, so the collapse of the tunnel face is reliably prevented, and it is safe and highly efficient. Tunnel construction work is performed.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. A is a tunnel drilling hole, B is a face, C is a tunnel inner wall, D is an unconsolidated ground, and from a predetermined position outside the drilling hole A using a drilling machine 1 such as a water jet from inside the tunnel drilling hole A. Drilling is performed in the direction of excavation by the drilling rod 2, and pressure water is jetted from the tip nozzle 3 to radially drill. (See FIG. 4) Then, while slowly pulling out the hole-forming rod 2, a solidified material is injected at high pressure from the tip nozzle 3 to form a plate-shaped solidified soil 4. (See FIG. 5) Note that the solidifying material injection angle α of the nozzle 3, the length L of the plate-like solidified soil 4,
The thickness t is selected according to the tunnel diameter.

Further, the same steps as above are repeated at regular intervals along the outer periphery of the excavation hole A so that the plate-like solidified soils 4 are connected to each other, and the plate-like solidified soils 4 are formed in the excavating direction. A radial outer peripheral solidified wall a is formed. Then, boring is performed by the boring machine 1 from the face B of the face in the tunnel excavation hole A to the tip position of the radial outer peripheral solidified wall a.
(Refer to FIG. 7) While slowly rotating the boring rod 2, a high-concentration solidifying material is jetted from the tip nozzle 3 to form a circular solidified soil 5 having a diameter d and a thickness t. Solidified soil 5
The above steps are repeated at regular intervals so that they are connected to each other, and the tip closing consolidating wall b is attached to the tip of the outer peripheral consolidating wall a.
Create (See FIGS. 8 and 11) Thus, as shown in FIG. 2, after forming the outer peripheral solidified wall a and the tip closed solidified wall b, the internal unsolidified ground D surrounded by the solidified walls a and b is formed. The tunnel is excavated by a known technique. C'in the figure is a tunnel inner wall line. (See FIG. 3) Hereinafter, a tunnel is constructed by alternately repeating the step of forming the solidified walls a and b and the step of boring.

[0008]

As described above, according to the present invention, the outer peripheral solidified wall and the tip closed solidified wall are formed prior to excavation,
After surrounding the outer peripheral part of the excavation hole and the front by each solidified wall, the unsolidified ground surrounded by the solidified walls was excavated, and thereafter the tunnel was constructed while reversing the above process. The tunnel excavation work is carried out in a state where the solidification walls are sealed, and the collapse of the tunnel face can be reliably prevented. Therefore, let alone ordinary unconsolidated ground,
Enables highly safe and efficient construction while securing the stability of the face even in relatively loose ground that easily collapses, in the presence of pressured water, and in large depths where large water pressure acts. .

Further, since the outer peripheral portion and the front of the excavation hole are sealed by the above-mentioned solidified wall, the water is completely stopped, and excavation work is facilitated.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing a peripheral solidified wall forming step in an embodiment of a tunneling method according to the present invention.

FIG. 2 is a vertical cross-sectional view showing a step of forming a solid wall with a closed tip according to the present invention.

FIG. 3 is a vertical sectional view showing an excavation step in the present invention.

FIG. 4 is a vertical cross-sectional view showing a hole making step in forming an outer peripheral solidified wall.

FIG. 5 is a vertical cross-sectional view showing a step of injecting a solidifying material in forming the outer peripheral solidifying wall.

FIG. 6 is a front view showing a state of forming plate-like solidified soil by injecting the solidifying material.

FIG. 7 is a vertical cross-sectional view showing a hole-drilling step in forming the tip solidified wall.

FIG. 8 is a vertical cross-sectional view showing a step of injecting a solidifying material in forming the tip solidifying wall.

FIG. 9 is a front view showing a state of forming circular solidified soil by injecting the solidifying material.

FIG. 10 is a side view showing a state of creation of the circular solidified soil.

FIG. 11 is a front view showing a construction state of a solidified wall with a closed tip.

FIG. 12 is a vertical cross-sectional view showing a solidifying wall for one element.

[Explanation of symbols]

 A tunnel excavation hole B cutting face C tunnel inner wall D unconsolidated ground a peripheral solidified wall b tip closed solidified wall 1 drilling machine 2 drilling rod 3 tip nozzle 4 plate-shaped solidified soil 5 circular solidified soil

Claims (3)

(57) [Claims] 1. A tip closing consolidating wall for forming a radial outer peripheral consolidating wall having a constant depth length in the excavating direction along the outer periphery of the excavation hole and then closing the tip of the outer peripheral consolidating wall. And excavating an internal unconsolidated ground surrounded by the respective consolidation walls. 2. An excavating machine from inside the tunnel excavation hole,
Excavation is carried out for a prescribed length in the direction of excavation from a prescribed position outside the same hole, and then while the rod for drilling of the excavating machine is being pulled out, a high-concentration material is injected from a nozzle at the tip of the rod to inject a solid plate into the ground. Create soil, and then repeat the above-mentioned steps at regular intervals along the outer periphery of the drilling hole to successively apply the plate-like solidified soil, and the adjacent plate-shaped solidified soil comrades The method for constructing a tunnel according to claim 1, wherein the radial outer peripheral solidified walls are formed by connecting together. 3. A hole is drilled from a face of a tunnel excavation hole to a tip position of the radial outer peripheral consolidating wall, and a consolidating material is injected at high pressure from a nozzle at the tip of the rod while rotating the rod for boring. Create a circular solidified soil, and then repeat the above-mentioned steps at regular intervals from the face face to sequentially form the circular solidified soil, and the adjacent circular solidified soils. 2. The tunnel construction method according to claim 1, wherein said solidified walls are formed by connecting them to each other.