JP6789087B2 - Shield machine - Google Patents

Description

The present invention relates to a shield machine for excavating a non-circular tunnel.

In general, a shield machine is a shield jack that connects the front body part that excavates the face in the front part in the direction of travel, the tail part that is lining by assembling the segment at the rear part, the front body part and the tail part, and is a propulsion facility. It consists of a middle body that is equipped with such equipment inside. When constructing a tunnel having a large cross section by a shield machine without excavation, a method of excavating a tunnel a plurality of times by the shield machine and connecting them to each other is adopted (see, for example, Patent Document 1). The smaller the number of excavations by the shield machine, the shorter the construction period. Therefore, it is considered to reduce the number of excavations by enlarging the shield machine and increasing the cross-sectional area of the tunnel excavated at one time.

Japanese Unexamined Patent Publication No. 2000-73685

However, when the shield machine is enlarged, the load acting from the outside becomes large, so that it is necessary to increase the strength of the skin plate which is the outer shell portion. In this case, in the front body portion and the middle body portion, the strength of the skin plate can be reinforced by a ring garter or the like which is a steel ring-shaped member, but in the tail portion, it is necessary to assemble a segment on the inner wall of the skin plate. Therefore, the strength must be increased by the thickness of the skin plate itself. In particular, a non-circular shield machine such as a rectangle causes a larger amount of stress and deflection than a circular shield machine, and the thickness of the skin plate at the tail portion increases. Therefore, there is a problem that the tail void becomes large and the backfill injection amount becomes large. It should be noted that there is a similar problem because it is necessary to secure the strength of the skin plate even when the construction is carried out with high water pressure.

The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a shield machine capable of reducing the tail void and reducing the amount of backfill injection.

In order to achieve the above object, the present invention is a shield machine for excavating a non-circular tunnel, provided with a tubular front body skin plate having substantially the same cross-sectional shape as the non-circular tunnel, and at the front tip. A front body portion for excavating a face with an arranged cutter drum, and a tail portion provided with a plurality of tail portion skin plates having a plurality of divided regions obtained by dividing the cross section of the front body portion skin plate. The front body portion is provided with an erector for assembling segments on the inner circumference of each of the plurality of tail portion skin plates to construct an inner wall body, and a middle body portion skin plate having the same cross-sectional shape as the front body portion skin plate. It is characterized by including a middle body portion for connecting the tail portion and the tail portion.
Further, in the present invention, the cross section of the front body skin plate is rectangular, and the plurality of tail skin plates form a plurality of divided regions obtained by dividing the longitudinal direction of the cross section of the front body skin plate. It may be the cross-sectional shape of.
Further, in the present invention, a plurality of shield jacks that obtain reaction force from the existing segment at the time of propulsion are attached to the inner circumference of the middle body skin plate, and are hung inside the middle body skin plate. A segment holding jack that holds an existing segment during propulsion may be attached to the passed pillar.

According to the present invention, by dividing the tail portion, the thickness of the skin plate can be reduced as compared with the case where the tail portion is configured to have the same cross-sectional shape as the front body portion. As a result, even if the shield machine is enlarged and the cross-sectional area of the tunnel excavated at one time is increased, the tail void can be reduced and the backfill injection amount can be reduced.

It is a figure which shows the structure of the embodiment of the shield machine which concerns on this invention. It is the figure which looked at the tail part shown in FIG. 1 from the rear side. It is a figure which shows the span in the width direction of the front body part and the tail part shown in FIG. It is a figure which looked at the middle body part shown in FIG. 1 from the rear side.

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

The present embodiment is a shield machine 1 for excavating a rectangular (rectangular) non-circular tunnel having a long cross section in the width direction (horizontal direction) and constructing an inner wall body thereof by segments S. With reference to FIG. 1, the shield machine 1 connects a front body portion 2 for excavating a face at the front portion, a tail portion 3 for lining with a segment S at the rear portion, and a front body portion 2 and a tail portion 3. At the same time, it is composed of a middle body portion 4 equipped with propulsion equipment inward.

The front body portion 2 includes a skin plate 21 made of a rectangular tubular steel shell having a cross-sectional shape substantially the same as that of a non-circular tunnel to be excavated and having a long cross section in the width direction. At the front tip of the front body portion 2, four cutter drums 22 provided for a plurality of disc cutters are arranged side by side in the width direction and rotatably arranged. The cutter drum 22 excavates a tunnel having a square cross section by, for example, rotating three radially protruding arms eccentrically, utilizing the triangular operating principle of the Reuleaux triangle.

A chamber 24 partitioned by a partition wall 23 is formed inside the skin plate 21 located on the rear side of the cutter drum 22. Excavation slips are taken into the chamber 24 as the cutter drum 22 rotates. The excavation scrap is taken out from the chamber 24 by a screw conveyor (not shown) or the like, and is discharged rearward.

With reference to FIGS. 1 and 2, the tail portion 3 is divided into a first split tail portion 3a and a second split tail portion 3b. The first divided tail portion 3a and the second divided tail portion 3b each include a skin plate 31 made of a rectangular tubular steel shell. Each of the skin plates 31 of the first divided tail portion 3a and the second divided tail portion 3b has a plurality of divided regions obtained by dividing the cross section of the skin plate 21 of the front body portion 2 into the respective cross-sectional shapes. In the present embodiment, the skin plate 31 has a cross-sectional shape in which the skin plate 21 of the front body portion 2 is divided into two left and right (the width direction, which is the longitudinal direction, is divided into two). The skin plate 31 of the first split tail portion 3a and the skin plate 31 of the second split tail portion 3b are arranged side by side in the width direction, and the opposing surfaces are joined and integrated by welding or the like.

As shown in FIG. 3A, assuming that the span in the width direction of the skin plate 21 (front body portion 2) is W, the spans of the first split tail portion 3a and the second split tail portion 3b (skin plate 31) are , As shown in FIG. 3 (b), W / 2. Therefore, as shown in FIG. 3C, the first divided tail is compared with the case where the skin plate 31a is configured with the same span W as the skin plate 21 (front body portion 2) without dividing the tail portion 3. The external force acting on the portion 3a and the second split tail portion 3b becomes smaller. As a result, the thickness T1 of the skin plate 31 in the first divided tail portion 3a and the second divided tail portion 3b can be made thinner than the thickness T0 of the skin plate 31 of the span W, and the tail void can be made smaller. Can be done.

In the present embodiment, the cross-sectional shape of the skin plate 31 is a rectangular shape with rounded corners in consideration of the assembly of the segment S. Therefore, a recess 32 extending in the front-rear direction is formed at a position where the rounded corners face each other at the joint between the first divided tail portion 3a and the second divided tail portion 3b. Therefore, a plate-shaped member 33 for preventing the intrusion of earth and sand into the recess 32 is provided. The plate-shaped member 33 is joined to the rounded corners of the skin plate 31 by welding, for example.

Referring to FIGS. 1 and 4, the middle body portion 4 includes a skin plate 41 made of a rectangular tubular steel shell having the same cross-sectional shape as the skin plate 21 of the front body portion 2. A ring garter 42 is provided on the inner circumference of the skin plate 41 over the entire circumference. The ring garter 42 is a steel ring-shaped member, and functions as a reinforcing member for reinforcing the strength of the skin plate 21. The ring garter 42 is provided with a plurality of small chambers, and the shield jack 43, which is a propulsion facility, is housed in the small chambers. The shield jack 43 obtains a reaction force from the existing segment S and extends from the contracted state to propel the shield machine 1. Further, a plurality of shield jacks 43 are attached to the inner circumference of the skin plate 41 at equal intervals so that the reaction force from the segment S acts evenly on the entire circumference of the skin plate 41.

In the inner peripheral space of the ring garter 42, an elector 44a for assembling the segment S on the inner circumference of the first divided tail portion 3a to construct an inner wall body and a segment S assembled on the inner circumference of the second divided tail portion 3b. An erector 44b for constructing an inner wall body is provided. The Elector 44a and the Elector 44b are mechanisms that grip the segment S before installation and transfer it to a predetermined angle position.

Further, a steel reinforcing column 45 for reinforcing the strength of the skin plate 41 (ring garter 42) is laid vertically in the substantially center of the skin plate 41 (ring garter 42) in the width direction. The reinforcing columns 45 are provided with segment holding jacks 46a and 46b that prevent the existing segments S from shifting when the shield machine 1 is propelled.

In the present embodiment, the force required for propulsion of the shield machine 1 is configured to be obtained by a plurality of shield jacks 43. Since the shield jacks 43 are attached to the inner circumference of the skin plate 41 at equal intervals, only the three sides of the segments S assembled on the inner circumferences of the first divided tail portion 3a and the second divided tail portion 3b are used. A reaction force will be obtained, and the force will act unevenly on the existing segment S. Therefore, the segment holding jacks 46a and 46b extend from the contracted state to hold one side on which the force of the shield jack 43 of the existing segment S does not act. As a result, it is possible to prevent the existing segment S from being displaced when the shield machine 1 is propelled.

The pressing force of the segment pressing jacks 46a and 46b is set to be smaller than the pressing force of the shield jack 43. This is because the pressing force of the segment pressing jacks 46a and 46b acts on the reinforcing column 45 as a reaction force from the segment S. That is, since the reinforcing columns 45 are bridged in the vertical direction and have a structure weak against a force applied in the front-rear direction, an excessive reaction force does not act on the reinforcing columns 45.

Further, in the present embodiment, an example in which four cutter drums 22 are provided on the front body portion 2 has been described, but the type and number of cutter drums 22 provided on the front body portion 2 can be appropriately set. Further, in the present embodiment, an example in which the tail portion 3 is divided into two has been described, but the number of divisions of the tail portion 3 can be appropriately set. Further, in the present embodiment, the skin plate 21 of the front body portion 2 and the skin plate 31 of the middle body portion 4 are configured separately, but the skin plate 21 and the skin plate 31 may be integrated.

As described above, the present embodiment is a shield machine 1 for excavating a non-circular tunnel, and a tubular skin plate 21 (front body skin plate) having substantially the same cross-sectional shape as the non-circular tunnel. A plurality of skin plates 31 (tails) having a front body portion 2 for excavating a face with a cutter drum 22 arranged at the tip of the front portion and a plurality of divided regions obtained by dividing the cross section of the skin plate 21 into each cross-sectional shape. A tail portion 3 provided with a part skin plate), electors 44a and 44b for assembling segments S on the inner circumferences of the plurality of skin plates 31 to form an inner wall body, and a skin plate having the same cross-sectional shape as the skin plate 21. It includes 41 (middle body skin plate), and includes a middle body 4 that connects the front body 2 and the tail 3.
With this configuration, by dividing the tail portion 3, the thickness of the skin plate 31 can be reduced as compared with the case where the tail portion 3 has the same cross-sectional shape as the front body portion 2. As a result, even if the shield machine 1 is enlarged and the cross-sectional area of the non-circular tunnel excavated at one time is increased, the tail void can be reduced and the backfill injection amount can be reduced.

Further, in the present embodiment, the cross section of the skin plate 21 is rectangular, and the plurality of skin plates 31 have a plurality of divided regions divided in the longitudinal direction of the cross section of the skin plate 21 as their respective cross-sectional shapes.
With this configuration, the stress and the amount of deflection of the skin plate 31 due to an external force can be reduced.

Further, in the present embodiment, a plurality of shield jacks 43 that obtain reaction force from the existing segment S at the time of propulsion are attached to the inner circumference of the skin plate 41, and reinforcement is laid inside the skin plate 41. The pillar 45 is equipped with segment holding jacks 46a and 46b that hold the existing segment S during propulsion.
With this configuration, it is possible to prevent the existing segment S from being displaced during propulsion.

It is clear that the present invention is not limited to each of the above embodiments, and each embodiment can be appropriately modified within the scope of the technical idea of the present invention.

1 Shielding machine 2 Front body 3 Tail 4 Middle body 21 Skin plate 22 Cutter drum 23 Partition 24 Chamber 3a 1st division tail 3b 2nd division Tail 31 Skin plate 32 Recess 33 Plate-shaped member 41 Skin plate 42 Ring Garter 43 Shield Jack 44a, 44b Elector 45 Reinforcing Column 46a, 46b Segment Holding Jack S Segment

Claims (3)

A shield machine that excavates a non-circular tunnel
A front body having a tubular front body skin plate having substantially the same cross-sectional shape as the non-circular tunnel, and a front body for excavating a face with a cutter drum arranged at the tip of the front.
A tail portion having a plurality of tail portion skin plates having a plurality of divided regions obtained by dividing the cross section of the front body skin plate into each cross-sectional shape, and a tail portion.
Elector that assembles segments on the inner circumference of each of the plurality of tail skin plates to construct an inner wall body,
A shield machine including a middle body skin plate having the same cross-sectional shape as the front body skin plate, and a middle body portion connecting the front body and the tail. The cross section of the front body skin plate is rectangular and has a rectangular shape.
The shield machine according to claim 1, wherein the plurality of tail portion skin plates have a plurality of divided regions obtained by dividing the longitudinal direction of the cross section of the front body portion skin plate into their respective cross-sectional shapes. A plurality of shield jacks that obtain reaction forces from the existing segments during propulsion are attached to the inner circumference of the middle body skin plate, and the pillars spanned inside the middle body skin plate are attached. The shield machine according to claim 1 or 2, wherein a segment holding jack for holding an existing segment at the time of propulsion is attached.

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