JP2545579Y2 - Shield excavator with cast-in-place concrete lining method - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention uses a shield excavator (also referred to simply as a "shield machine") to excavate a tunnel and then lining with a cast-in-place concrete lining method. The present invention relates to an excavator, and more particularly, to a structure of a tail portion of a shield machine capable of easily performing curve construction and meandering correction of the shield machine.

[Conventional technology]

In a construction method in which a tunnel is excavated while excavating a tunnel with a shield excavator, it is inevitable to correct the direction of the shield machine due to a change in the geology of the ground. In recent years, in the underground development of cities, it has become necessary to construct curved tunnels in relation to the ground.

By the way, in the case of performing a curved construction in the conventional cast-in-place concrete lining method, as shown in FIG. 6, concrete 23 is poured into a space 23a formed by the tail plate 20, the inner formwork 21 and the end frame 22. After installation and filling, the shield machine is displaced in a predetermined direction and excavated.

However, as shown in FIG. 6, the tail plate 20 advances in the tangential direction of the construction curve, and the hatched portion 23b of the currently cast concrete 23 directly in contact with the tail plate 20.
Is pushed out, and the seal 22a of the wife frame 22 is also crushed. Therefore, the maneuverability of the shield machine itself is hindered by the binding force and the resistance force from the existing cast concrete 23 and the like, so that curve construction and meandering correction become difficult. JP
In Japanese Patent Application Laid-Open No. 59-165800, the tail plate 20 is formed in a tapered shape so that the tail portion can be easily separated from the currently cast concrete 23 and advanced, but the stability of the water stop plate provided in the tail portion can be improved. There is difficulty in certainty.

Therefore, in recent years, many proposals have been made for facilitating the curved construction of the shield machine. For example, JP-A-1-256700
No. 1 (conventional example 1) and Japanese Utility Model Laid-Open No. 2-33898 (conventional example 2).

[Problems to be solved by the invention]

Conventional example 1 is a shield machine in which an inner plate is provided inside a skin plate and a tail portion has a double structure, and the inner plate does not affect concrete,
It is intended to be able to be easily removed from the mold and to proceed with turning without any trouble. However, the inner plate may not be bent in close contact with the cast concrete, and it may be difficult to pull out the inner plate, which may adversely affect the concrete and may not necessarily achieve the intended purpose.

In the second conventional example, an airbag is interposed between the tail plate and the auxiliary tail plate to facilitate curve construction. However, the structure is complicated and there is a problem in manufacturing.
There is a drawback in terms of workability due to the necessity of applying air pressure to the airbag and the like.

The present invention solves the above-mentioned problems of the prior art by providing an outer peripheral ring inside the tail plate and a conical frame inside the outer peripheral ring.

[Means for solving the problem]

Therefore, the gist of the present invention is a shield excavator with a method of lining with a cast-in-place concrete lining method.
A cylindrical outer ring that can move in the axial direction is provided inside the tail plate of the shield body, and a wedge frame is provided so as to be slidable on the inner circumference of the outer ring. A cast-in-place concrete lining construction shield excavator characterized in that the end frame is formed in the shape of a conical bowl whose diameter is gradually increased to the rear side so as to secure a play space extending from the sliding contact position toward the front of the excavator. It is in.

[Action]

In the above configuration, for example, when the shield machine is displaced in a predetermined direction for curved construction, the outer peripheral ring inside the tail plate is also displaced, but the divergent shape is provided between the outer peripheral ring and the conical end frame. , The outer peripheral ring moves freely within the range of the play and is displaced along the conical end frame, and does not interfere with the end frame. Therefore, since the shield machine can be smoothly displaced in a desired direction without any trouble, curve construction becomes easy.

〔Example〕

Hereinafter, embodiments of the shield machine according to the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a basic configuration of a shield machine of a cast-in-place lining method. 2 and 3 show a modified embodiment thereof. In these figures, the same components are denoted by the same reference numerals.

As shown in FIG. 1, a cylindrical tail plate 2 is formed on the outer periphery of a tail portion of a shield machine main body M having a cutter disk 1 at a front end, and a cylindrical outer peripheral ring 3 is concentric with the tail plate 2. The end frame 4 is disposed inside the outer peripheral ring 3. Further, on the inside, an inner form 5 is successively constructed with the excavation of the shield machine, and between the ground G and the inner form 5 is poured concrete that has already been poured. The currently cast concrete 7 which is partitioned and pressurized by the end frame 4 is cast and filled via the casting pipe P so as to form a lining body continuous with the already-cast concrete 6. 8 is the casting space before casting concrete
It is a reinforcing bar built in 7a.

The rear end of the outer peripheral ring 3 has a thick portion 3a whose diameter is increased to be the same as the outer diameter of the tail plate 2, and the front end is hinged to the rod end of the movable jack 9. The body of the movable jack 9 is pivotally attached to the shield machine body M side, and the outer peripheral ring 3 is formed by the expansion and contraction of the movable jack 9.
Is movable in the axial direction.

The end frame 4 is formed in the shape of a cone (spot) pot as a whole, and a constant (divergent) play space S is formed between the end frame 4 and the outer peripheral ring 3. This play S works effectively at the time of curve construction of the shield machine described later. This conical wife frame 4
As shown in FIG. 5, a flange portion 4b is formed at the rear end portion in connection with the tapered portion 4a, and the flange portion 4b slides on the inner peripheral surface of the outer peripheral ring 3 via the seal member Q. I have. A rod end of a sliding jack 10 is hinged to a front end portion (a portion corresponding to a bottom portion of a picking pot) 4c, and is in sliding contact with the outer peripheral surface of the inner mold 5 via a seal member R. The body of the sliding jack 10 is pivotally attached to the shield machine main body M side.

Therefore, the expansion and contraction of the sliding jack 10 causes the end frame 4 to slide in the axial direction while contacting the inner peripheral surface of the outer ring 3. The excavation of the shield machine is performed by excavating reaction force on the face end face of the inner formwork 5 by the shield jack 11 which is pivotally or hingedly connected to the shield machine body M via a spherical bearing 11a. .

FIG. 2 shows a modified embodiment. The difference from the embodiment of FIG. 1 is that the thick portion 3a of the outer peripheral ring 3 is extended from the rear end of the end frame 4 to the cast concrete 7 whose diameter has been increased. This is because, when the thick portion 3a of the outer ring 3 is short as shown in FIG. 1, when the casting space 7a is filled with concrete, the concrete turns around the ground G and the space between the outer ring 3 and the ground G This is because if the outer ring 3 enters the space A and hardens, it may be difficult to pull out the outer ring 3. In short, the thick part of the outer peripheral ring 3 in FIG.
3a is made thinner and longer, so that the range of contact between the ground G and the outer peripheral ring 3 is enlarged to ensure the seal. In this example, since the thick portion 3a in FIG. 1 becomes thinner, the thickness of the tail void decreases accordingly, and the amount of concrete filling the tail void portion can be reduced.

FIG. 3 shows a modified embodiment of FIG. 2, in which the shield machine body M is further divided into a front body 2a and a rear body 2b, and a spherical seat 12 and a seal member 13 are provided therebetween. That is connected through. This allows the shield machine to be bent in the middle and facilitates curve construction in cooperation with the existence of the play space S described above. The shield machine shown in FIG. 1 can be provided with a folding mechanism in the same manner.

Now, the execution order of the cast-in-place concrete lining method in the shield machine of FIG. 1 will be described with reference to FIGS. 4 (a) to (d) and FIG.

FIG. 1 shows a state in which concrete is being filled from the casting pipe P into the casting space 7a. As shown in FIG. 4 (a), the moving jack 9 is shortened and the outer peripheral ring 3 is pulled in. By this operation, the tail void after the outer ring 3 is pulled out is filled with concrete. After the rear end of the outer peripheral ring 3 is pulled out to the rear end of the wife frame 4,
As shown in FIG. 4 (b), the shield jack 11 is extended and a reaction force is applied to the inner mold 5 to excavate the shield. This figure shows a straight traveling state.

In the case of curved construction, when the shield machine is displaced in a predetermined direction as shown in FIG. 5, the tail plate 2 advances on a tangent line in the construction curve as shown with time in imaginary lines, and accordingly, the outer periphery The ring 3 is also displaced, but since there is a divergent play space S between the outer ring 3 and the end frame 4, the outer ring 3 can be displaced without interfering with the end frame 4. Since the plate 2 is not in direct contact with the currently cast concrete 7, there is no adverse effect such as being restrained by the currently cast concrete 7 or damaging it. Since the doubling distance between the rear end of the outer ring 3 and the concrete 7 is short, the displacement can be absorbed by the uncured concrete part. This makes it possible to easily perform curved construction or meander absorption of the shield machine. In the case of the present invention, the curve construction can be performed until the outer peripheral ring 3 does not interfere with the end frame 4.

After the completion of the propulsion, when the curing of the cast-in concrete 7 is completed, the sliding jack 10 is shortened as shown in FIG. Since the shape of the wife frame 4 is in the shape of a conical sand pot, the removal can be performed smoothly. The wife frame 4 is drawn in by one lining length to form a new casting space 7b,
As shown in FIG. 4 (d), the reinforcing bar 8 and the inner form 5 are constructed in the casting space 7b. And concrete casting pipe P
After setting, the casting space is again set as shown in FIG.
Fill 7b with concrete. Hereinafter, the above construction is repeated to construct a tunnel.

[Effect of the invention]

As described above, according to the present invention, since the outer peripheral ring and the conical wedge frame are provided, the tail plate itself does not directly contact the concrete, and does not receive the binding force or resistance from the concrete, and the It can be easily advanced on the tangent line, and the play space formed between the outer peripheral ring and the conical frame increases the degree of freedom and facilitates the curved construction. In addition, there is no adverse effect on the concrete lining due to axial movement (eccentricity) at the time of turning.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a shield machine of a cast-in-place concrete lining method according to an embodiment of the present invention, FIG.
FIG. 3 is a longitudinal sectional view of a main part of a shield machine according to a modified embodiment, and FIGS. 4 (a) to 4 (d) are diagrams illustrating a construction sequence of the cast-in-place concrete lining according to the present invention over time.
The figure is an explanatory view in the case of curve construction of the present invention. FIG. 6 is an explanatory view of a conventional curve construction. M: Shield body, 2 ... Tail plate, 3 ...
Outer ring, 4 ... wife frame, S ... play

Claims (1)

(57) [Scope of request for utility model registration] 1. A shield excavator of a type in which lining is performed by a cast-in-place concrete lining method, wherein a cylindrical outer peripheral ring movable in an axial direction is provided inside a tail plate of the shield main body, and an inner periphery of the outer peripheral ring is formed. A wedge frame is provided so as to be slidable, and the wedge frame is gradually expanded rearward so as to secure a play space extending from the sliding contact position toward the front of the excavator between the outer peripheral ring and the wedge frame. A shield excavator using a cast-in-place concrete lining method, which is formed in a conical bowl shape.