JPH0364039B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a method for constructing a tunnel lining, which is used when forming the lining of a tunnel excavated by a shield excavator using cast-in-place concrete. .

(b) Prior Art Recently, a proposal has been made to form the lining of a tunnel excavated by a shield excavator using cast-in-place concrete to avoid the complicated and time-consuming assembly work of segments. .

In this case, there are two methods for making the shield excavator dig: one is to make the excavation proceed after the placed concrete has hardened, and the other is to make the shield excavator dig after the concrete has not yet hardened.

(c) Problems to be solved by the invention In the former case, the excavator cannot dig until the concrete that has been placed has hardened, so there is a drawback that the excavation speed decreases. It will be necessary to fill it.

In the latter case, the excavator can dig before the concrete hardens, increasing the excavation speed, but the stopper does not move as the excavator advances. As such, it is necessary to press the end stop with a jack at all times, and this causes the inconvenience that the jack gets in the way when installing reinforcing materials such as reinforcing bars for a newly constructed lining.

In order to eliminate the above-mentioned drawbacks, the present invention has been developed to solve the above-mentioned drawbacks, even when excavation is carried out before the concrete has hardened.
It is an object of the present invention to provide a method for constructing a tunnel lining that can smoothly install reinforcing materials such as reinforcing bars for a newly constructed lining.

(d) Means for solving the problem That is, in the present invention, after the shield excavator 1 has excavated a predetermined distance L1, the end stop is fixed to the formwork 12, and in this state, the concrete pressurizing means is is released and a new concrete placement space 17 is created.
It is configured so as to form a

Note that the numbers in parentheses are for convenience and indicate corresponding elements in the drawings, and therefore, this description is not limited to the descriptions on the drawings. The same applies to the column "(e) Effect" below.

(e) Effect With the above-described configuration, the present invention fixes the stopper to the formwork 12 and releases the pressurizing operation by the pressurizing means 6 when the shield excavator 1 has excavated a predetermined distance L1, and the pressurizing operation by the pressurizing means 6 is released. Concrete pouring space 1
7.

(f) Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a sectional view showing an example of a shield excavator to which the present invention is applied, and FIGS. 2 and 3 are process diagrams showing an example of the method for constructing a tunnel lining according to the present invention.

As shown in FIG. 1, the shield excavator 1 has an outer shell 2 that is entirely cylindrical.
A cutter 3 is provided on the left side of the outer shell 2 in the figure and is rotatably driven by a drive motor 5. Inside the outer shell 2, a plurality of concrete pressure jacks 6 and propulsion jacks 7 are provided concentrically in double layers along the periphery of the outer shell 2, and each jack 6,
7 is provided with rams 6a and 7a that can protrude and retract in the directions of arrows A and B.

Since the shield excavator 1 has the above configuration, when the shield excavator 1 excavates the tunnel 9, the cutter 3 is rotationally driven by the drive motor 5, and the ram 7 of the propulsion jack 7 is rotated.
A is made to protrude in the direction of arrow B, and the outer shell 2 is pressed in the direction of A using the formwork 12 as a foothold. When the outer shell 2 is pressed in the direction A, the cutter 3 is pushed in the direction of the face 13 with a predetermined excavation pressure, and the earth and sand in the face part is excavated. When the earth and sand in the 13th part of the face is excavated,
The outer shell 2 is propelled in the direction A by the pushing force of the propulsion jack 7 by the amount that the face 13 is excavated, and the tunnel 9 is formed. The propulsion jack 7 drives the ram 7a to protrude in the B direction in accordance with the moving speed of the outer shell 2 while the outer shell 2 moves a predetermined distance L1 in the A direction, so that a predetermined digging pressure is always applied to the cutter 3. I'll do what I do.

In this way, the tunnel 10 is A for a predetermined distance L1.
When the excavation is completed in the direction A, the ram 6a is moved back in the A direction as shown in FIG. 2, and in this state,
As shown in Figure 3, reinforcing members 1 such as reinforcing bars and iron plates
0 and the end stop ring _15B are installed at the position where the lining 11 is to be cast and constructed. The end stop ring 15 has an annular shape as a whole, and the reinforcing member 1
0 is installed between the end stop ring 15 _A on the right side in the figure, where concrete has already been placed, and the end stop ring 15 _B on the left side in the figure, which has been newly installed.
The end stop ring 15 is provided with known guide means (guide holes, guide grooves, etc.) for installing the reinforcing member 10, so that the reinforcing member 10 can be installed smoothly.

The end stop ring 15 _A on the right side of FIG. 3 is fitted into the outer shell 2 and the formwork 12, and can be moved in the directions of arrows A and B with respect to the formwork 12 by pins 16. Since the reinforcing member 10 is installed in a restrained manner, even if the ram 6a of the concrete pressure jack 6 is moved back in the A direction, the end stop ring _15A will not move in the A direction. Therefore, even if the concrete on the right side of the end retaining ring _15A in the figure is not yet hardened, the concrete is securely held in the concrete placement space 17 by the end retaining ring _15A . , good concrete solidification takes place.

In this way, the end stop ring 15 and the reinforcing member 10
is installed as shown in Figure 3.
The ram 7a of the propulsion jack 7 is moved backward in the direction A, and the formwork 12 is installed in a cylindrical shape between the formwork 12 on the right side of the figure and the tip of the ram 7a, as shown in Fig. 1. , formwork 12, end stop ring 15 _A , 15 _B
and a cylindrical concrete placement space 17 between the two outer shells.
form. In this state, concrete is poured into the newly formed concrete placement space 17 to fill the concrete placement space 17 with concrete. When the concrete casting space 17 is filled with concrete, the propulsion jack 7 is then driven to project the ram 7a in the direction B, and the outer shell 2 and therefore the shield excavator 1 are moved using the formwork 12 as a foothold. Press in direction A and start digging with the cutter 3.

As the shield excavator 1 excavates in the direction A, the ram 6a of the concrete pressurizing jack 6 also
It is made to protrude in synchronization with the movement of the ram 7a in the B direction, and when the outer shell 2 moves in the A direction, the end retaining ring 15 is held so that it does not hang and move in the A direction. concrete at a specified pressure. Shield excavator 1 is A
When moving in the direction, a tail void occurs after the outer shell 2 passes, but the concrete in the concrete placement space 17 pressurized by the concrete pressurizing jack 6 immediately flows in and blocks the tail void, so the lining 11 is constructed in good condition in close contact with the ground 19. Note that since the concrete in the concrete placement space 17 at this point has not yet hardened, the tail void is filled with concrete smoothly. Furthermore, the stopper ring 15 is not fixed to the formwork 12 during pouring of concrete, and therefore moves in the directions of arrows A and B between the formwork 12 and the outer shell 2. Since it is possible to do so,
Pressurizing the concrete in the concrete placement space 17 by the concrete pressurizing jack 6 is performed smoothly.

When the shield excavator 1 excavates in the A direction by a predetermined distance L1, the rear end 2a of the outer shell 2 moves from the right side surface _15a of the end stop ring 15A in FIG. Right side part 15 of _B
Although the moving portion corresponds to the concrete placement space 17, the operation of filling the above-mentioned tail void with concrete from the concrete placement space 17 is performed smoothly.

When the shield excavator 1 excavates by a distance L1, the end stop ring 15 is attached to the pin 1 against the formwork 12.
6, and in that state, move the ram 6a of the concrete pressure jack 6 back in the direction A (second
As shown in Figure 3, following the steps already described, a new stopper ring 15 and reinforcing member 10 are installed, and concrete is poured in a manner that continues with the lining 11 that was just poured. A space 17 is formed, and the lining 11 is constructed in the same manner.

In addition, although the above-mentioned Example described the case where the reinforcing member 10 was provided in the concrete placement space 17, it goes without saying that the present invention can be applied regardless of whether or not the reinforcing member 10 is installed. be.

(g) Effect of the Invention As explained above, according to the present invention, after the shield excavator 1 has excavated a predetermined distance L1, the end stop is fixed to the formwork 12, and concrete is added in this state. Since the pressure means is released and a new concrete placement space 17 is formed, even if the excavator 1 excavates with the concrete not hardened, the predetermined distance L1 of the end shield excavator 1 can be maintained. When the excavation is completed, it is fixed to the formwork 12, and therefore, movement relative to the formwork 12 is mechanically prevented, so the end stop is constantly pressed by the concrete pressurizing means. This eliminates the need for this, and work such as installing the reinforcing member 10 in the concrete placement space 17 can be performed smoothly and easily.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a shield excavator to which the present invention is applied, and FIGS. 2 and 3 are process diagrams showing an example of a method for constructing a tunnel lining according to the present invention. 1... Shield excavator, 6... Pressurizing means (concrete pressurizing jack), 12... Scaffolding (formwork),
15... End stop (end stop ring), 17... Concrete placement space, L1... Distance.

Claims (1)

[Scope of Claims] 1. An end stop is provided so as to be movable in the excavation direction of a shield excavator with respect to the formwork, and concrete poured into the concrete placement space via the end stop is processed by concrete. A method in which a shield excavator is pressurized using a pressure means, excavates through the scaffolding in that state, and a lining is constructed while filling the resulting tail void with the injected uncured concrete. When the shield excavator has dug a predetermined distance, the end stop is fixed to the formwork, and in this state, the concrete pressurizing means is released to form a new concrete pouring space. A method of constructing a tunnel lining made up of