JPS5945074B2 - Tunnel face excavation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tunnel face excavation method.

Generally, when excavating a tunnel in a soft soil layer consisting of an unconsolidated layer such as sandy soil or sandy soil, there is a considerable risk of the face collapsing.

Therefore, in such soil layers, the tunnel peripheral wall is ring-cut using the conventional sidewall tunnel advanced ring-cut method, and construction is carried out while protecting the ring-cut face with sheet piles. The current situation is that the excavation speed is extremely slow because it is necessary to erect and dismantle the sheet piles each time.

Furthermore, in the case of poor geological conditions, several stages of small shafts may be excavated around the outer periphery of the tunnel, and construction may be carried out after the outer periphery of the tunnel has been solidified. The current situation is that construction costs are increasing.

In order to solve the above-mentioned conventional problems, the present invention aims to provide a method for excavating a tunnel face that enables easy and efficient excavation while preventing the face from collapsing.

The present invention will be explained below using the drawings. The illustrated embodiment shows a case where a face made of an unconsolidated layer such as sandy soil or sandy soil is excavated. At the same time, a plurality of pile bodies 2 are driven in, and a retaining plate 3 is attached to the rear of each pile body 2, and the face 1 is covered with each retaining plate 3.

For example, as shown in FIG. 2, the pile body 2 is made of a steel pipe or steel rod with a sharp tip, and some gaps 4 are provided in the front and rear sides of the pile body so that the anti-slip member 5 and wings 5' of the retaining plate 3 can be secured. It is installed protrudingly.

The wing 5' is provided for driving into the unconsolidated layer face, but if it is difficult to drive the pile body 2 into the face,
It is also possible to remove this.

On the other hand, the earth retaining plate 3 to be attached to this is formed from a steel plate or the like into a required shape such as a rectangular shape as shown in FIG. A notch hole 7 is provided through which the material can be inserted.

This notch hole 7 corresponds to the anti-slip member 5 of the pile body 2, and by rotating, the retaining plate 3 is brought into close contact with the face to prevent collapse. Conceivable.

Then, the retaining board 3 is secured to the non-slip member 5 by inserting the pile body 2 into the through-hole 6, inserting the non-slip member 5 into the notch hole 7, and slightly rotating it at the position of the gap 4. It can be attached so as not to fall off, and can be easily removed from the pile body 2 by performing the reverse operation.

Incidentally, if a plurality of anti-slip members 5 are provided before and after the pile body 2 as required, the mounting position of the retaining board 3 can be adjusted as shown in FIG.

By driving the pile bodies 2 into the face 1 in this way, the face 1 is consolidated to some extent and is supported by each pile body 2, and the face surface is covered by the retaining plate 3, so that it does not collapse. It is in an extremely stable state.

When excavating, start from the upper part of the face as shown in Fig. 5 a, b, c, and rotate the retaining plate 3 of the upper pile body 2 to align the notch hole 7 with the position of the anti-slip member 5. After removing the pile body 2, excavate the earth and sand around the pile body 2, dig out the pile body 2, insert the retaining plate 3 into the pile body 2 again, apply it to the excavated surface, and push the pile body 2 with a hammer or machine. Including, anti-slip member 5
Attach the retaining board 3 to the

Then, the surrounding areas of the laterally adjacent pile bodies 2 are excavated in the same way, and further pile bodies 2 are driven into the new face 1 of each excavated part, and the collapse is prevented by covering each with the retaining plate 3 attached to each part. To prevent.

After completing the horizontal row of excavation work in this way,
Further, the pile bodies 2 in each row below are excavated in the same manner, and the excavation is continued while repeating the steps shown in FIG. 5 a + b + c.

The illustrated example shows a case where the application is applied to a face made of unconsolidated layers such as sandy soil or sandy soil, but this method is not limited to this method.When excavating a part of a collapsible slope, earth retaining piles can be used. It goes without saying that this invention can be carried out even when you cannot hit the ball.

As described above, according to the present invention, by driving a plurality of antibodies into the face, the earth and sand at the face can be somewhat compacted, and the earth and sand at the face are supported by each antibody, and the face surface is covered by the retaining plate. Therefore, collapse of the face can be prevented even in soft soil layers.

In this way, while preventing collapse, the area around each antibody is partially excavated one after another, so the excavation can be carried out in a consistent manner without collapse during excavation, and all that is required is driving the antibody and attaching/detaching the retaining plate. This is a simple process, and the antibodies and retaining plates are used repeatedly, making it possible to reduce construction costs and construction time, making it possible to perform construction efficiently and cost-effectively.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the antibody implanted state, FIG. 2 is a perspective view of the antibody according to the present invention, FIG. 3 is a perspective view of the soil covering plate, and FIG.
The figure is a longitudinal cross-sectional view showing the state of antibody implantation, Figures 5a, b,
c is a longitudinal cross-sectional view showing the construction state according to the invention construction method. 1... Face, 2... Pile body, 3...
・・Earth retaining plate, 4・・・・Gap, 5・・・・Slip member, 5′, 5″・・・Wing or anti-slip member, 6・・・・Transparent Hole, 7... Notch hole.

Claims (1)

[Scope of Claims] 1. A tunnel characterized in that a plurality of antibodies are driven into a face, a retaining plate is detachably attached to the rear of each antibody, and the area around each antibody is sequentially excavated while removing the retaining plate. Excavation method for face. 2. Drive multiple piles at specified intervals on the top, bottom, left and right sides of the face. First, excavate the area around the antibody at the top of the face, drive the excavated antibody into the new face, and attach the retaining board to this. 2. The tunnel face excavation method according to claim 1, wherein the tunnel face excavation method according to claim 1, characterized in that the tunnel face excavation method is characterized in that the excavation is carried out while successively performing construction from the upper part to the lower part by performing construction in the same manner one after another around the antibody at the lower part.