JPH0367199B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a shield excavator that can reliably backfill tail voids.

(b) Prior Art Recently, a proposal has been made to construct the lining of a tunnel excavated by a shield excavator using cast-in-place concrete, regardless of the segments.

(c) Problems to be solved by the invention However, in this type of shield excavator,
It is important to be able to reliably backfill the tail voids that occur after shield excavation in order to increase the reliability of construction.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a shield excavator that can construct a lining with cast-in-place concrete and also reliably backfill tail voids.

(d) Means for solving the problem That is, the present invention focuses on the fact that if the injection material can be injected into the tail void with uniform pressure, good backfilling can be achieved, and shell 3
An outer formwork 29 formed in a ring shape is placed inside the
The outer formwork 29 is provided so as to be freely movable and driveable in the direction of excavation of the shield excavator 2 so as to form a gap 37.
A tail void injection device 31 is provided for injecting an injection material into the cavity 37.

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 in the drawings. The same applies to the column "(e) Effect" below.

(e) Effect With the above-described configuration, the present invention moves the outer form 29 to form the void 37 after concrete is placed in the concrete placement space 21 formed from the outer form 29 and the like. Filling the gap 37 with the injection material via the tail void injection device 31, and then driving the outer mold 29 in the opposite direction to push the injection material in the gap 37 into the tail void 25, The ring-shaped outer formwork 29 plays a piston-like role with respect to the tail void 25, and acts so that the injection material can be injected with uniform pressure.

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

Fig. 1 is an operational diagram showing how the outer formwork is driven; Fig. 2 is a diagram showing an example of a tunnel excavation site to which an embodiment of the shield excavator according to the present invention is applied; 4 is a sectional view taken along the - line in FIG. 2; FIG. 5 is a sectional view taken along the - line in FIG. 2.

At the excavation site of the tunnel 1, as shown in FIG. has been done. Inside the outer shell 3, there are a plurality of digging jacks 7, a fifth
As shown in the figure, the excavating jack 7 is provided with a ram 7a which can be freely driven and protruded in the directions of arrows A and B. As shown in FIG. 3, at the inner rear end portion of the outer shell 3, that is, the right end portion in FIG. The outer formwork 29 is provided with a drive cylinder 3 disposed inside the outer shell 3, as shown in FIGS. 1 and 2.
0 is connected via piston rod 30a.

In addition, as shown in FIG. 3, the outer formwork 29 has
A tail void injection pipe 31 is buried at a predetermined pitch, and an injection material supply pipe 31a is connected to the tail void injection pipe 31.

On the other hand, a pedestal 13 is constructed in the excavated tunnel 1 along the excavation direction of the tunnel 1, and a formwork attachment/detachment device 15 is provided on the pedestal 13 so as to be movable along the tunnel 1. The formwork attachment/detachment device 15 is provided with an erector 15a.

The lining 17 of the tunnel 1 excavated by the shield excavator 2 is made of cast-in-place concrete as shown in FIG. A formed connecting formwork 23 is installed. Connecting formwork 23
is a cylindrical frame 22 with a width of L3 and an outer diameter of D1.
are formed by connecting a plurality of them in the directions of arrows A and B, which are the construction directions of the lining 17, and the forming frame 22
is constructed by arranging and connecting a plurality of formworks 20 along the circumferential cross section of the tunnel 1. Each formwork 20 is
The width is L3, and as shown in FIG. It is assembled into a formwork 20.

Further, a reaction force receiving and fixing device 32 is provided on the right side of the connecting formwork 23 in FIG.
It is possible to freely move in the direction perpendicular to the plane of FIG. 4, which is the excavation direction of the tunnel 1, via the tires 32a rotatably supported by the wheels 2b. Four reaction force receivers 32c are supported on the frame 32b by guide rods 32d so as to be movable in the directions of arrows C and D. Each reaction force receiver 32c and the frame 32b
A jack 32e is provided between them so that the reaction force receiver 32c can be moved and driven in the directions of arrows C and D. Note that the number 33 is a running rail of the formwork attachment/detachment device 15.

Since the shield excavator 2 and the like have the above configuration, when excavating the tunnel 1 with the shield excavator 2, first the ram 7a of the excavation jack 7 on the outside in FIG. 5 is driven to protrude in the direction of arrow B. do,
The tip of the ram 7a is brought into contact with the end stop 35 provided to close the concrete placement space 21 of the lining 17 in the construction state, where the concrete placement has been completed. At the same time, the ram 7a of the excavation jack 7 on the inside in FIG. and are brought into abutting engagement via the end stop 35. In this state,
When the ram 7a is further driven to protrude in the B direction, the shield excavator 2 receives a reaction force in the A direction from the lining 17 and the connecting formwork 23. A reaction force receiving fixing device 32 is installed at the rear end of the connecting formwork 23, that is, on the right side of FIG.
The end face 32f of c on the face 19 side is provided in abutting engagement with the rear end of the connecting formwork 23. The reaction force receiver fixing device 32 is held in a state in which the four reaction force receivers 32c are driven to protrude in the direction D in FIG. 4, that is, in the direction of the lining 17 by driving the jack 32e. The receiving and fixing device 32 is securely held fixed to the constructed lining 17, and can also sufficiently withstand the pressing force in the direction B of the shield excavator 2 transmitted via the connecting formwork 23. . Therefore, the reaction force in the A direction that the shield excavator 2 receives from the excavation jack 7 is sufficient to cause the shield excavator 2 to dig.

In this state, when the hydraulic motor 6 is next driven to rotate the cutter 5, the reaction force in the A direction causes
The portion of the face 19 facing the cutter 5 is excavated, and the shield excavator 2 as a whole moves in the A direction at the same time. When the shield excavator 2 excavates in the A direction, the ram 7a is synchronously protruded in the B direction, and the reaction force from the connecting formwork 23 and the lining 17 is always maintained at an appropriate value, so that the Adjustments are made so that a proper digging operation is performed.

In this way, the shield excavator 2 moves a certain distance in the direction of A.
When the ram 7a has been excavated, the ram 7a is moved back in the direction A, and reinforcing bars are placed along the outer formwork 29 of the shield excavator 2 in the cylindrical space created as a result of the excavation where the lining 17 is to be constructed. Arrange reinforcement.

In this state, the erector 15 of the formwork attachment/detachment device 15
The formwork 20 divided into segments at a is arranged and connected around the arranged reinforcing bars to form a concrete placement space 21 between the formwork 20 and the outer formwork 29. After the concrete placement space 21 has been formed, the left side in FIG. concrete injection hole 20
Early strength concrete is poured into the concrete placement space 21 from a. The poured concrete is
Solidification immediately starts, and a new lining 17 having a length of L1 is constructed.

In this way, when concrete has been placed in the concrete placement space 21 and a new lining 17 has been constructed, the ram 7a of the excavation jack 7 is
is driven to protrude in the direction of arrow B, so that the tip of the ram 7a abuts and engages with the end stop 35. Then, as described above, the shield excavator 2 receives a reaction force in the A direction, so it rotates the cutter 5 and starts digging in the A direction again.

Note that when the shield excavator 2 starts digging in the direction A, the outer shell 3 and the outer form 29 also move in the direction A, and the moving outer shell 3 and the outer form 29 cover the cover that has already reached the solidified state. Move Work 17 leaving it underground. At this time, a tail void 25 corresponding to the thickness T is created between the poured concrete and the outer shell 3.
occurs as shown in FIG. It is moved in the direction A as shown in FIG. Therefore, the injection material is press-fitted into the gap 37 from the tail void injection pipe 31, and the gap 37 is filled with the injection material. In this state, when the shield excavator 2 starts excavating and the outer shell 3 moves in the direction A, in synchronization with this, the outer formwork 2 moves as shown in FIG.
9 is moved in the B direction via the drive cylinder 30. Then, the injection material filling the void 37 is press-fitted into the tail void 25 that is generated as a result of the movement of the outer shell 3 in the direction A, and the tail void 25 is filled with the injection material without causing any defects. Note that the outer formwork 29 is formed in a ring shape over the entire circumference of the outer shell 3 in a shape that matches the ring-shaped cross-sectional shape of the tail void 25, so that the outer formwork 29 acts as a kind of piston with respect to the tail void 25. Therefore, the injection pressure of the injection material becomes uniform around the entire circumference of the tail void 25, and injection is performed in a uniform state.

The injection timing of the injection material into the tail void 25 due to the movement of the outer formwork 29 in the A and B directions is as follows:
Of course, various applications other than those described above are possible.

During this time, the concrete in the right part of the connecting formwork 23 in Figure 2 solidifies sufficiently and reaches practical strength, so the shield excavator 2 excavates a predetermined distance in the direction A and pours concrete again. When doing this, remove the rightmost set formwork 22 in the figure from the connection formwork 23,
Further, the formwork attachment/detachment device 15 is moved, the erector 15a is positioned under the separated formwork 22, and the formwork 22 is disassembled into each formwork 20. The formwork 20 disassembled in this way is transported in the direction A by the formwork attachment/detachment device 15, and is connected to the assembled formwork 22 at the left end of FIG. It is reassembled to form the concrete pouring space 21 and reused.

(g) Effect of the invention As explained above, according to the present invention, the outer formwork 29 formed in a ring shape inside the outer shell 3
is provided so as to be freely movable and driveable in the excavation direction of the shield excavator 2 so as to form a void 37, and a tail void injection device 31 for injecting the injection material into the void 37 is provided in the outer form 29. Therefore, the outer form frame 29 is moved and driven to form the gap 37, the gap 37 is filled with the injection material, and the outer form frame 29 is driven in the opposite direction again to fill the injection material in the gap 37. can now be press-fitted into the tail void 25 using the outer formwork 29, and the tail void 2
It becomes possible to inject the injection material with uniform pressure over the entire circumference of the structure 5, and the reliability of the construction can be improved.

[Brief explanation of drawings]

Fig. 1 is an operation diagram showing the driving mode of the outer formwork;
Figure 3 shows an example of a tunnel excavation site to which an embodiment of the shield excavator according to the present invention is applied.
The figures are a sectional view taken along the - line in FIG. 2, FIG. 4 is a sectional view taken along the - line in FIG. 2, and FIG. 5 is a sectional view taken along the - line in FIG. 2...Shield excavator, 3...Outer shell, 17...
Lining, 29...Outer formwork, 31...Tail void injection device, 37...Void.

Claims (1)

[Scope of Claims] 1. In a shield excavator that constructs a lining by using a part of the shield excavator as a formwork for cast-in-place concrete, a ring-shaped member is formed inside the outer shell of the shield excavator. An outer formwork is provided so as to be movable and driveable in the direction of propulsion of the shield excavator so as to form a void, and a tail void injection device is provided on the outer formwork to inject injection material into the void. A shield excavator configured with