JPH02210189A - Shield machine - Google Patents

Abstract

PURPOSE:To reduce term of works and construction cost by a method wherein in a construction work in which a tunnel the size of which is partially increased is continuously excavated, a slave shield machine capable of being mounted and demounted to and from the interior of a parent shield machine and movable forward and backward along an axis is used in common. CONSTITUTION:During a construction work for a tunnel for a subway in which a large station part P and a small railroad track part R are continuously excavated, two parent and slave shield machines 12 and 13 are moved forward in an integrally formed state from a starting vertical shaft 21 as a ground is excavated by means of cutters 16 and 17. The large station part P is then formed, and consecutively the parent and slave shield machines 12 and 13 are released from coupling and only the slave shield machine 13 is moved forward to continuously form the small railroad track part R. This method eliminates the need to excavate a starting vertical shaft again at a change spot of an excavation size being a boundary between the station part P and the railroad track part R, and enables reduction of a term of works and a construction cost resulting from shortening of a process.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a shield machine used in a shield construction method for forming tunnels, and in particular, it is used to continuously construct tunnels whose diameter partially increases, such as subway tunnels. The present invention relates to a shield machine suitable for use in forming shields.

[Prior Art] A subway tunnel usually consists of a plurality of stations and a track section on which trains run between these stations.
Tunnels in station areas have larger diameter walls than tunnels in railway areas because platforms are built and multiple tracks are drawn into them.

In order to continuously form such tunnels with different diameters, conventionally, as shown in Fig. 23, the underground area corresponding to the station area P is excavated below the ground surface, and this is used as the starting shaft L, and the track area R is
After excavating the track section R with a shielding machine 2A having a diameter commensurate with the diameter of the line, and lining the surrounding wall with segments, etc., the structure of the station section P is constructed within the starting shaft L, and then the starting shaft 1 is excavated. A method that applies the cut-and-cover method, such as backfilling, is being used.

In addition, as shown in Fig. 24, points where the excavation diameter changes,
In other words, a starting shaft 3 is excavated at the boundary between the station part P and the track part R, and the large-diameter side shield @ 2 is excavated from here to the station part P.
There is also a method in which the track section R and the station section P are excavated by moving the shield machine 2A on the small diameter side, which excavates the track section R, forward in different directions.

Generally, the shield machines 2A and 2B move forward while excavating a face using a cutter attached to the front part of a cylindrical skin plate, and the excavated soil is taken into a chamber provided at the rear of the cutter. , which is configured to be discharged backwards.

[Problem to be solved by the invention]

However, in the case of the former of the above methods, it has become difficult to secure land for excavating a long starting shaft due to the dramatic increase in road traffic and the overcrowding of buildings in recent years. It cannot be applied to form a deep subway that passes through the ground.

In the latter case, at least two shield machines must be prepared, and a starting shaft must be excavated at each point where the excavation diameter changes, which increases construction costs and requires many steps. The problem is that the period is extended.

The present invention has been made in view of the above circumstances, and provides a shielding machine that can shorten the construction period and reduce construction costs when forming tunnels such as subways where the diameter partially expands. The purpose is to

[Means for Solving the Problems] The present invention has been made to achieve the above object, and includes a cutter provided at the front of a cylindrical skin grate, and an excavation performed by the cutter at the rear of the cutter. A cutter is provided at the front of a cylindrical skin plate having a smaller diameter than the skin plate of the parent shield. It consists of a child shield that is provided with a chamber to take in the excavated soil,
The child shield is removably attached to the inside of the parent shield in a state where the axes of the skin plates of the child shield and the parent shield are substantially parallel, and when the child shield is uncoupled, the skin plates extend along the axis. It is characterized by a device that allows it to move forward and backward.

Further, in addition to the above, the child shield is arranged eccentrically with respect to the parent shield, and furthermore, a plurality of child shields are installed with respect to the parent shield, and each of the parent shield and child shield is arranged eccentrically with respect to the parent shield. The cutters are connected by a connecting member, and the cutter on the parent shield side is driven in conjunction with the cutter on the child shield side, and furthermore, the cutter of the child shield can be slid back and forth with respect to the skin plate of the child shield. In addition, when the shield is slid forward, the chambers of both the parent and child shields are integrally formed.

r effect] According to the shield machine of the present invention, after the parent and child shields are integrated and a large diameter tunnel is excavated by the entire shield machine,
By keeping the parent shield in place and advancing the child shield independently from the parent shield, a small diameter tunnel is formed continuously from the large diameter tunnel.

Therefore, when forming a tunnel for a subway, there is no need to excavate a long starting shaft for constructing a station area, as in the past, and it is not necessary to excavate a long starting shaft for setting the shield machine of the present invention into the ground. All you have to do is secure the land necessary for excavation, so you can build a station even in areas with heavy road traffic or crowded buildings. By digging deep, it is possible to form deep tunnels. Additionally, since there is no need to excavate a starting shaft at each point where the excavation diameter changes, which is the boundary between the station area and the track area, the tunnel formation process is reduced and the construction period is shortened.

In addition, if the parent and child shields are placed eccentrically from each other so that the parent shield is placed on the side of the area where the tunnel diameter is planned to be expanded, there is almost no need to excavate a cross section where the parent shield is not needed, that is, wasted space. Most of the excavated cross section can be used effectively, and as a result, secondary construction can be omitted, leading to a reduction in construction costs.

Furthermore, if a plurality of child shields are provided for the parent shield, a plurality of small diameter tunnels can be successively formed from the large diameter tunnel formed by the parent shield.

Furthermore, if the cutters of the parent shield and the child shield are connected by a connecting member and the cutter on the parent shield side is driven in conjunction with the cutter on the child shield side, a drive mechanism for rotating the cutter on the parent shield can be created uniquely. There is no need to provide it.

Further, if the cutter of the child shield is provided so as to be slidable back and forth with respect to the skin plate of the child shield, and when the cutter is slid forward, each chamber of the parent-child shield is formed integrally. The excavated soil discharge means provided on either shield allows the excavated soil generated by excavation of the parent-child shield to be discharged to the rear of the tunnel, which simplifies the structure, makes it easy to maintain, and is inexpensive. becomes.

[Embodiments] First to fourth embodiments of the present invention will be described below with reference to the drawings.

1st Embodiment (FIGS. 1 to 8) Reference numeral 11 in the figures is a shield machine according to the present invention, which is composed of a parent shield 12 and a child shield 13 disposed inside this parent shield 12. .

The parent-child shields 12.13 are each provided with a cutter 16.17 for excavating a face G1 of the ground G at the front of the cylindrical skin plates 14, 15, but the skin plate of the child shield 13 is The diameter of the shield 15 is set smaller than that of the parent shield 12. and,
As shown in FIG. 2, the child shield 13 is disposed inside the skin plate 14 of the parent shield 12, with its axis L1 being eccentric to the -side with respect to the axis of the parent shield 12.

The cutter 17 provided at the front part of the child shield 13 is a face plate type or spoke type, and excavates the face G1 by rotating around an axis. 18 is attached telescopically, and by protruding this over cutter 18,
It is designed to be able to excavate a tunnel T with a larger diameter than the cutter 17.

Behind the cutter 17, there is a chamber into which the excavated soil, which is dirt and rock debris produced by the excavation of the cutter 17, is taken in, and a conveyance means such as a screw conveyor for discharging the excavated soil from the chamber. (not shown)
is provided.

Further, inside the skin plate 15 and at the rear end, a child shield 13 is provided along a local part of the skin plate 15.
A plurality of shield jacks 19 are provided for propelling the jack forward in the excavation direction, and an erector device (not shown) is further provided for assembling the segment S to the peripheral wall of the tunnel T after excavation.

As described above, the child shield 13 having the above configuration is disposed inside the skin plate 14 of the parent shield 12, and the skin plate 14 is connected to the skin plate 14 by a connecting means (not shown).
By being removably connected to the main shield 12, and by releasing the connection, it is possible to move forward and backward along the axial direction independently from the parent shield 12.

On the other hand, as shown in FIGS. 1 and 2, the cutters 16 of the parent shield 12 are divided into a plurality of divided cutter groups 16a to 16h having different diameters to fill the spaces between the skin plates 14.15 of both the shields 12.13. It is made up of.

That is, face plate-type or spoke-type cutters 16a to 16g having diameters that approximately match the spacing between both skin plates 14 and 15 and having different diameters fill the gap.
are arranged in an arc shape, and furthermore, these cutters 16a to 16
A small-diameter spoke-shaped cutter 16h is arranged to fill the gap between the main shield 12 and the skin plate 14 of the parent shield 12. These divided cutter groups 16a to 6h excavate the face G by rotating around the axis.

In the parent shield 12, behind each of the cutters 16a to 16h and between each skin plate 14 and 15 of the rain shield 12.13, there is a chamber into which excavated soil generated by excavation by the cutters 16a to 16h is taken in; A conveyance means (none of which is shown) such as a screw conveyor is installed for discharging the excavated soil inside. Further, a shield jack 2 is provided at the rear end inside the skin plate 14 for propelling the parent shield 12 forward in the digging direction along a local part of the skin plate 14.
0 in multiple stages, and is further equipped with an erector device (not shown) for assembling the segments S to the peripheral wall of the tunnel T after excavation.

A case in which a subway tunnel T is formed using the shield machine 1 having the above configuration will be described with reference to FIGS. 3 and 4.

First, as shown in FIG. 3, a starting shaft 21 is excavated to a predetermined depth in the ground G that forms the station part P.

Next, the child shield 13 is inserted into the inside of the parent shield 12, and the shield machine 11 in which both shields 12 and 13 are interconnected and integrated is moved in the direction of excavating the tunnel T by each cutter l6 (16a). ~16h), 17 and set it at the bottom of the starting shaft 21.

Next, the cutters 16 and 17 of both shields 12 and 13 are rotated to excavate the face Gl. At this time, the overcutter 18 attached to the outer periphery of the cutter 17 in the child shield 13 is made to protrude, and this overcutter 1
8, the outer periphery of the cutter 17 indicated by diagonal lines in FIG.
Excavate face G in the gap between 6g and 6g. Further, the skin plate 14 of the parent shield 12 excavates the face G between the skin plate 14 and each of the cutters 16a to 16h.

At this time, each cutter 16.1 of the parent and child inner shields 12, 13
The excavated soil produced by the excavation in step 7 is taken into each chamber and discharged backward by the transport means, and then transported to the starting shaft 21 by a trolley or the like, and then transported by a transport means such as an elevating elevator or a skip. carry it to the ground.

When the excavation has progressed a predetermined distance, the parent shield 12 is attached to the peripheral wall of the tunnel T excavated by the parent and child inner shields 12.
Assemble the segment S using the erector device on the side and temporarily lining it. Next, the shield jack 20 of the parent shield 12 is extended by taking a reaction force from the front end of the assembled segment S, thereby propelling the entire shield machine 11 forward.

As mentioned above, each cutter 1 of the parent and child inner shield 12.13
The tunnel T of the station part P is formed by repeating the steps of excavation in 6.17, assembly of the segments S, and advancement of the shield machine 11.

After excavating a predetermined length of the station part P using both shields 12.13, the connection between the parent and child shields 12.13 is released. Then, the main shield 12 is kept in place, and the sub-shield 13 is used to dig into the track portion R. That is, as shown in FIG. 4, the cutter 17 of the child shield 13
is rotated to excavate the face G, and the segment S is installed on the peripheral wall of the rear tunnel T formed by this using an erector device to provide the primary lining, and then the shield jack 20 is used to excavate the segment S. The front end takes a reaction force and expands to move the child shield 13 forward.

In this way, the line portion R is formed by repeating the steps of digging with the cutter 17°, assembling the segments S, and advancing with the shield jack 20.

As a result, the large-diameter station portion P and the small-diameter track portion R are continuously formed, and the cross-sectional outline thereof has a substantially horseshoe-shaped cross-section, as shown in FIG. The child shield 13 is connected to the next station shaft.

After the segments S are assembled to the station part P and the track part R and the primary lining is applied, if necessary, the surface is subjected to a secondary lining by pouring concrete or the like to form the final lining structure.

In addition, in the tunnel T of the station part P, as shown in No. 51!1, a slab 22 is laid at the bottom of the tunnel T.
2, a track 24 for a train 23 is laid in the space formed by the child shield 13, and a platform 25 is constructed in the space formed by the parent shield 12. In addition, 51 in FIG. 5 is a secondary lining.

6 to 8 show various forms of the tunnel T formed by the shield machine 11.

In FIG. 6, two shield machines 11 are advanced from the starting shaft 21 at the same level in different directions, and tunnels T are excavated in the order of station P1 track [R] as described above. A state in which a tunnel T is similarly excavated from a starting shaft (not shown) excavated in the extension direction toward a starting shaft 21 shown in the drawing is shown.

FIG. 7 shows two shield machines 11 moving forward at the same level in one direction from the starting shaft 21 with the child shields 13 placed on the outside, and moving through the tunnel T in the order of the station part P1 and the track part R. The figure shows a state in which a tunnel T is similarly excavated from a starting shaft (not shown) in the other direction toward a starting shaft 21 (not shown).

FIG. 8 shows two shield machines 11 arranged one above the other being moved forward in one direction from the starting shaft 21, and from the starting shaft (not shown) in the other direction toward the starting shaft 21 shown in the figure. The shield machine 11, which was advanced at the level, is branched up and down,
A state in which each tunnel T is connected is shown.

As described above, according to the shield machine 11 of this embodiment, by moving the parent and child inner shields 12.13 together from the starting shaft 21 while excavating the ground with the cutter 16.17, the diameter can be reduced. A large station area P is formed,
Subsequently, by releasing the connection between the parent and child inner shields 12 and 13 and moving only the child shield 13 forward, a small diameter line portion R is continuously formed.

In other words, there is no need to excavate a long starting shaft for constructing the station part P as in the past, and the land necessary for excavating the starting shaft 21 for setting the shield machine 11 into the ground G is secured. As a result, the station P can be constructed even in areas with heavy road traffic or areas with crowded buildings, and the starting shaft 21 can be connected to the existing tunnel T.
By excavating deeper than the above, it is possible to form a tunnel T with a large depth.

In addition, since there is no need to excavate a starting shaft at each point where the excavation diameter changes, which is the boundary between the station part P and the track part R,
The process of forming the tunnel T is reduced, and the construction period can be shortened.

In addition, since the child shield 13 that excavates the track section R is eccentrically provided with respect to the parent shield 12, the parent shield 12 does not need to excavate an unnecessary cross section, that is, a wasted space, and most of the excavated cross section is not excavated. can be used effectively.

Second Embodiment (FIGS. 9 to 11) Reference numeral 30 in FIGS. 9 to 11 indicates a shielding machine of a second embodiment based on the present invention, and this shielding machine 30 is shown in FIG. 9. As shown, two child shields 32 are arranged inside the parent shield 31.

The parent shield 31 includes a cylindrical skin plate 33 having a substantially elliptical cross section, and a face plate-type or spoke-type cutter attached to a rotating shaft 34 whose axis substantially coincides with the skin plate 33 and protrudes from the front thereof. 35.

Inside the skin plate 33 of the parent shield 31, on both sides in the radial direction, the skin plate 36 of the child shield 32, which has a smaller diameter than the cutter 35 of the parent shield 31, is eccentric to that of the parent shield 31. and are removably connected together.

A cutter 38 is attached to the front part of the skin plate 36 of the child shield 32 via a rotating shaft 37 that projects further forward than the cutter 35 of the parent shield 31. That is,
The cutter 38 of the child shield 32 is disposed further forward than the cutter 35 of the parent shield 31, and when viewed from the front, the vines 35 and 38 partially overlap each other.

In addition, each cutter 35.38 of both the parent and child shields 31.32
An overcutter similar to that provided on the child shield 13 of the first embodiment is provided on the outer periphery of the shield, and
Both the parent and child shields 31 and 32 are provided with a chamber for taking in the excavated soil, a conveyance means for discharging the excavated soil, and a shield jack (all not shown) for advancing itself.

According to the shield machine 30 having the above configuration, as shown in FIG. 10, with both the parent and child shields 31 and 32 connected, the respective cutters 35 and 38 are rotated to excavate the face G1. At this time, the overcutter 18 of each cutter 35.3B of both the parent and child shields 31 and 32 is made to protrude, and the overcutter 18 is used as shown in FIG.
Excavate the outer periphery of each cutter 35 and 38 shown in part a).

Also, due to the skin plate 33 of the parent shield 31, the remaining portion between this skin plate 33 and each overcutter (
(the shaded area in Figure 9).

After excavation has progressed for a predetermined distance, both shields 31 and 32 are attached to the peripheral wall of the tunnel T excavated by the parent and child shields 31 and 32.
．． Segment S by the erector device installed at 32
Assemble and temporarily cover.

Next, by the shield jack on the parent shield 31 side,
The entire shield machine 30 is propelled forward.

As mentioned above, each cutter 3 of both the parent and child shields 31 and 32
The tunnel T of the station part P is formed by repeating the steps of excavation, assembly of the segment S, and advancement of the shield machine 30 in step 5.38.

After excavating a predetermined length of the station part P using both shields 31, 32, each cutter 35, 38 is temporarily stopped, and the cutter 35 of the parent shield 31 shown in part (B) of FIG.
The overlapping portion of the cutter 38 of the Heiko shield 32 is cut to allow the Heiko shield 32 to move forward. Note that the wrap portion of the cutter 35 may be made separable in advance.

Next, as shown in FIG. 11, a stand 39 that receives the reaction force of the shield jack of the child shield 32 is installed at the front end of the assembled segment S, and then the parent and child shields 31 and 32 are connected. Release.

The main shield 31 is kept in place, and the track portion R is dug using the second shield 32. That is, the 11th
As shown in the figure, each cutter 38 of the Heiko shield 32 is rotated to excavate the face Gr, and the segment S is assembled by an erector device to the M wall of the rear tunnel T formed thereby, and the primary cover is Then, the shield jack of the child shield 32 is extended by taking the reaction force from the table 39, and the child shield 32 is moved forward.

In this way, the line portion R is formed by repeating the steps of excavating the Heiko shield 32 with each cutter 38, assembling the segments S, and advancing the Heiko shield 32 using the shield jack.

Incidentally, after the primary lining is applied by the segments S, the surface of the segments S may be subjected to a secondary lining by pouring concrete or the like.

According to the shield machine 30 of this embodiment, the large-diameter station part P;
Two small-diameter track sections R are formed in succession, especially at the station section P.
As shown in FIG. 9, the cross-sectional shape of the tunnel T forms an elliptical tunnel T in which the resistance force against the tonosho acts effectively.

Third embodiment (Figures 12 to 15) Next, a third embodiment of the present invention will be described.

The shielding machine of this embodiment, indicated by reference numeral 40 in the figure, is a muddy water type shielding machine, and is composed of a paddy shield 41 and a child shield 42 disposed inside the main shield 41.

The parent shield 41 includes a cylindrical skin plate 43, a ring-shaped cutter 44 provided at the front of the skin plate 43, a shield jack 45 for propulsion provided at the rear end of the skin plate 43, and a skin plate 43. An erector device 46 is provided at the rear end inside the plate 43 and assembles the segment S to the tunnel Te wall.

Connecting bins 47 connecting the skin plate 43 and the cutter 44 are provided at multiple locations in the front of the skin plate 43.
It is built into the skin plate 43 so that it can move back and forth along the axial direction, and by extending the connecting pin 47, the connecting pin 47 is inserted into the connecting hole 48 formed on the cutter 44 side, thereby connecting the cutter 44 and the skin plate. 43 are in a connected state. Further, a chamber 49 is formed between the front surface of the skin plate 43 and the cutter 44 to receive the excavated soil by the cutter 44.

On the other hand, the child shield 42 includes a cylindrical skin plate 50 having a smaller diameter than the skin plate 43 of the parent shield 41, a disc-shaped cutter 51 provided at the front of the skin plate 50, and a disc-shaped cutter 51 disposed inside the skin plate 50. Cutter 51
a cutter drive mechanism 52 that rotates and drives the skin plate 50; a plurality of shield jacks 53 provided at the rear end of the skin plate 50 along a local part of the skin plate 50; Tunnel Tj! ! The erector device 54 is attached to the wall.

The cutter drive mechanism 52 is provided within the skin plate 50.
The skin plate 50 is installed movably along the axial direction. A rotating member (not visible in 1!l) that is rotated by the cutter driving mechanism 527 is provided at the front of the cutter driving mechanism 52, and this rotating member is provided with a plurality of arms 55 extending forward. It is being

The cutter 51 is supported at the tip of the arm 55, and by operating the cutter drive mechanism 52, the cutter 51 is rotated about an axis via the rotating member, the arm 55.

Further, on the outer circumferential portion of this cutter 51, a plurality of locations (in this case, four locations) that equally divide the circumferential direction are provided with connection bins (connection bins) that connect this cutter 51 and the cutter 44 on the parent shield 41 side. A member) 56 is built in so that it can move forward and backward along the radial direction of the cutter 51. In other words, the cutter drive mechanism 52 is moved forward to move the cutter 51 to the cutter 4.
4, and when the connecting pin 56 is extended, the connecting pin 56 is inserted into the connecting hole 57 formed in the inner circumference of the cutter 44, and each cutter 44,
The cutters 51 are connected to each other. Therefore, when the cutter 51 on the side of the child shield 42 is rotated in this state, the cutter 44 on the side of the parent shield 41 is also interlocked with this, so that the dual force vines 44 and 51 rotate together.

Also, the cutter drive mechanism 52 is moved backward to remove the cutter 51.
When the skin plate 50 is brought close to the skin plate 50, a chamber 58 is formed between the skin plate 50, the cutter drive mechanism 52, and the cutter 51 to take in the excavated earth excavated by the cutter 51.

Further, when the cutter driving mechanism 52 is advanced and the cutters 44, 51 of the parent-child shields 41, 42 are connected as described above, the parent-child shields 41, 42 are connected as shown in FIG. The chambers 49 and 58 are integrated to form a chamber 59 as the shield machine 40.

Further, the child shield 42 includes a mud feeding pipe 60 that supplies muddy water to the front surface of each cutter 44, 51, and a chamber 59 (4
Mud removal pipes 61 for discharging excavated soil containing muddy water to the rear of the tunnel T are provided in each of the tunnels 9 and 58).

According to the shield machine 40 having the above configuration, first, the twelfth
As shown in the figure, each cutter 44.51 of the parent-child shield 41.42 is connected by a connecting bottle 56, and the chamber 5
form 9.

In this state, while supplying mud water from the mud feeding pipe 60 to the front surface of each cutter 44.51, the cutter drive mechanism 52 is operated to rotate both cutters 44.51 as one, and excavate the face G. To go.

The excavated soil containing mud is taken into the chamber 59, and is then forced to be sent to a mud water treatment tank on the ground by a mud drain pipe 61, where the mud and the excavated soil are separated.

When the excavation has progressed a predetermined distance, the parent shield 41 is attached to the peripheral wall of the tunnel T excavated by the parent and child cylinder shields 41 and 42.
The segment S is assembled using the erector device 46 installed at the same time, and a temporary lining is applied.

Next, the entire shield machine 40 is propelled forward by the shield jack 45 of the parent shield 41.

As mentioned above, each cutter 4 of the parent and child cylinder shields 41 and 42
The tunnel T of the station part P is formed by repeating the steps of excavation in step 4.51, assembly of the segments S, and advancement of the shield machine 40.

After excavating a predetermined length of the station P using both shields 41 and 42, the cutter drive mechanism 52 is temporarily stopped to stop the rotation of each cutter 44 and 51.

Next, as shown in FIG. 14, the skin plate 43 and cutter 44 in the parent shield 41 are connected by a connecting pin 47, and the connecting pin 56 provided on the outer periphery of the cutter 51 in the child shield 42 is connected to the cutter 51.
By disengaging the cutters 44 and 51 from each other, the child shield 42 is uncoupled from the parent shield 41.

Also, the cutter drive mechanism 52 is moved backward, and the child shield 4
The second cutter 51 is brought close to the front surface of the skin plate 50 to form the chamber 49 as the child shield 42. In this state, the parent shield 41 is kept in place,
The track portion R is dug by the child shield 42. That is, as shown in FIG. 15, the cutter 5 of the child shield 42
1 to excavate the face G□, and the erector device 54 is attached to the peripheral wall of the rear tunnel T formed thereby.
The segments S are assembled and the primary lining is applied, and then the shield jack 53 of the child shield 42 is extended by taking a reaction force to the front end of the segment S, and the child shield 42 is
advance.

In this way, the child shield 42 is excavated by the cutter 51,
The line portion R is formed by repeating the steps of assembling the segments S and advancing the child shield 42 using the shield jack 53. The track section R is formed coaxially with the station section P.

In addition, after the primary lining is applied by segment S..., the secondary lining is applied by concrete pouring, etc.

In this way, in the shielding machine 40 of this embodiment as well, the large diameter station portion P and the small diameter line portion R are continuously formed, as in each of the above embodiments.

The cutter 44 of the parent shield 41 is connected to the cutter 51 of the child shield 42 by a connecting pin 56, and is rotated by a cutter drive mechanism 52 that rotates the cutter 51 of the child shield 42. That is, there is no need to independently provide a drive mechanism for rotating the cutter 44 of the parent shield 42.

Furthermore, when excavating the station part P using the parent and child cylinder shields 41 and 42, the chambers 49 and 58 formed in these parent and child cylinder shields 41 and 42 are integrated to form one chamber 59, The excavated soil taken into this chamber 59 is discharged to the rear of the tunnel T by a mud discharge pipe 61 provided in the child shield 41. In other words, parent shield 41
There is no need to provide a separate mud feeding pipe for discharging the excavated soil taken into the chamber 49 of the present invention, and the excavated soil from excavation of not only the child shield 42 but also the parent shield 41 can be discharged by one mud feeding pipe 61. Can be done.

With these features, the structure of the shield machine 40 can be simplified, maintainability is excellent, and the cost is low.

4th Embodiment (FIGS. 16 to 21) FIGS. 16 to 19 show a fourth embodiment of the present invention, and a shield machine 70 of this embodiment includes a main shield 71 and an inside of this main shield 71. A plurality (in this case, two) of child shields 72 are arranged in the shield.

The parent shield 72 includes an elliptical skin rate 73,
The skin plate 73 and the rear end of the skin plate 73 include a plurality of shield jacks 74 arranged along the circumference of the skin plate 73, and an erector device (not shown) for assembling the segment S to the tunnel TM wall. It is equipped with

The skin plate 73 has inner cylinders 75B and 76, respectively.
It is comprised of a front skin plate 75 and a rear skin plate 76, each having an outer cylinder 75b and an outer cylinder 75b176b. There are 18th
As shown in the figure, a cylindrical engaging portion 77 is formed in an arc shape with an outwardly convex curved surface, and this retaining portion 77 is
A face seat 77a formed at the front end of the backup skin plate 76
By being engaged with both skin plates 75, 76
are connected with their mutually opposing end surfaces slightly spaced apart. As a result, the front skin plate 75 can rotate with respect to the rear skin plate 76 with the engaging portion 77 as an axis.
Moreover, it is possible to swing left and right within a permissible gap between both skin plates 75 and 76.

In addition, as shown in FIG. 19, the inner cylinder 76a and the outer cylinder 76b of the rear skin plate 76 have an orthogonal cross section, and a ring-shaped connecting member 78 is provided with a port 79 on both cylinders 76a, 76b. They are interconnected by being fixed by.

Each of the child shields 72 is arranged inside the skin plate 73 of the parent shield 71, parallel to the skin plate 73, and in a parallel state.

These child shields 72 include a skin plate 80 of the same diameter, a cutter 81 that is provided in front of the skin plate 80 and excavates a face G of the ground G, and a skin plate 80 that excavates a face G of the ground G.
A plurality of shield jacks 82 are provided at the rear end along the circumference of the skin plate 80, and shield jacks 82 (not shown) are provided at the rear end inside the skin plate 80 to assemble the segment S to the tunnel TJii wall. and an erector device.

The skin plate 80 is fixed to the inner cylinder 75a of the front skin plate 75 of the parent shield 71 by ports 83 screwed in from the inside at a plurality of locations along its circumferential direction. are detachably connected together. Specifically, as shown in FIG. 20, a spacer 84 is interposed between the inner cylinder 75a and the skin rate 80 at the portion where the bolt 83 is screwed, so that a predetermined distance is provided between the inner cylinder 75a and the skin rate 80. is screwed into a nut member 85 fixed to the outer periphery of the inner cylinder 75a.

The front part between the inner cylinder 75a and the skin plate 80 is sealed by interposing a shield packing 86 and injecting grease 87 to the rear thereof, so that the skin of both the parent and child shields 71 and 72 is sealed. Water is stopped between plates 73 and 80.

A cutter drive unit 88 that rotates around the axis of the skin plate 80 is disposed at the front of the skin plate 80, and a plurality of arms 89 that are extendable and retractable toward the front are attached to the cutter drive unit 88. The cutter 81 is fixed to the tips of these arms 89. The cutter 81 is stored in the front part of the skin plate 80 by retracting the arm 89, and at this time, the cutter 81
and the cutter 81 by the partition wall 90 provided behind it.
A chamber 91 is formed to take in the excavated soil.

An overcutter 92 that protrudes radially from the circumferential surface of the cutter 81 is extendably attached to the outer circumference of the cutter 81 . This overcutter 92 can be extended with the arm 89 extended, and in this state, its tip approaches the inner circumferential wall of the front end of the skin plate 73 in the parent shield 71. In this state, a chamber 93 on the parent shield 71 side that is integrated with the chamber 91 of the child shield 72 is formed behind the overcutter 92.

According to the shield machine 70 having the above configuration, as shown in FIG. 16, both the parent and child shields 71 and 72 are connected, the arm 89 to which the cutter 81 is attached is extended, and the over cutter 92 is extended. , cutter drive unit 88
Activate the cutter 81 and over cutter 92 to rotate the face G.

We will continue to excavate.

After excavation has progressed for a predetermined distance, both shields 71 and 72 are attached to the peripheral wall of the tunnel T excavated by the parent and child shields 71 and 72.
, 72 by the erector device installed on the segment S
Assemble and temporarily cover.

Next, by the shield jack on the parent shield 31 side,
Shield ll! The entire 30 is propelled forward.

At this time, the skin plate 73 of the parent shield 71 allows
The remaining portion between the skin plate 73 and the over cutter 92 is scraped off.

As described above, by repeating the steps of excavating with the cutter 81 and over cutter 92, assembling the segments S, and advancing the shield machine 70, the tunnel T of the station part P is formed as shown in FIGS. 21 and 22. I will do it.

After excavating a predetermined length of the station P using the parent-child inner shield 71172, the operation of the cutter drive unit 88 is temporarily stopped, and the rotation of the cutter 811 and the over cutter 92 is stopped. As shown in FIG. 16, after installing a stand 94 that receives the reaction force of the shield jack 82 of the child shield 72 on the inner peripheral wall of the front end of the assembled segment S... Inner cylinder 7 of plate 75
5a and the skin plate 80 of the child shield 72 is removed, and the parent and child inner shields 71.5a are removed.
72 is unlinked. Further, the over cutter 92 is retracted and housed within the cutter 81.

From this state, the main shield 71 is kept in place and the track portion R is dug using each child shield 72. That is, by operating the cutter drive unit 88 of each child shield 72, the cutter 81 is rotated to excavate the face Gi, and the segment S is assembled by the erector device to the peripheral wall of the rear tunnel T formed thereby. Then, the shield jack 82 of the child shield 72 is extended by taking a reaction force from the table 93, and the child shield 72 is advanced. The child shield 72 is allowed to dig to the next station shaft.

In this way, the steps of excavating each child shield 72 with the cutter 81, assembling the segments S, and advancing each child shield 72 with the shield jack 82 are repeated to form two line portions R.

Incidentally, after the primary lining is applied by the segments S, the surface of the segments S may be subjected to a secondary lining by pouring concrete or the like.

FIG. 22 shows an example of a T-shaped tunnel excavated by the shield machine 70.

[Effects of the Invention] As explained above, according to the shielding machine of the present invention, a cutter is provided at the front of the cylindrical skin plate, and the excavated soil excavated by the cutter is taken in behind the cutter. A cutter is provided at the front of the cylindrical skin plate with a smaller diameter than the parent shield provided with a chamber and the skin plate of this face shield. a child shield provided with a chamber for taking in the child shield, and the child shield is removably attached to the inside of the parent shield in a state where the axes of the skin plates of the child shield and the parent shield are substantially parallel, and , when the connection is solved,
Since the device is characterized in that it can advance and retreat along the axis, after a large diameter tunnel is excavated by the parent and child inner shields, the parent shield is kept in place and the child shield is independent of the parent shield. By moving the tunnel forward, a small diameter tunnel is formed continuously from the large diameter tunnel. Therefore, when forming a tunnel for a subway, there is no need to excavate a long starting shaft for constructing a station area, as in the past, and it is not necessary to excavate a long starting shaft for setting the shield machine of the present invention into the ground. All you have to do is secure the land necessary for excavation, so you can build a station even in areas with heavy road traffic or crowded buildings. By drilling deeply,
Can form deep tunnels.

Additionally, since there is no need to excavate a starting shaft at each point where the excavation diameter changes, which is the boundary between the station area and the track area, the tunnel formation process is reduced and the construction period is shortened.

In addition, by placing the parent and child inner shields eccentrically from each other so that the parent shield is placed on the side of the area where the tunnel diameter is planned to be expanded, there is almost no need to excavate a cross section where the parent shield is not needed, that is, wasted space. Most of the excavated cross section can be used effectively, and as a result, secondary construction can be omitted, leading to a reduction in construction costs.

Furthermore, if a plurality of child shields are provided for the parent shield, a plurality of small diameter tunnels can be successively formed from the large diameter tunnel formed by the parent shield.

Furthermore, if the cutters of the parent shield and the child shield are connected by a connecting member and the cutter on the parent shield side is driven in conjunction with the cutter on the child shield side, a drive mechanism for rotating the cutter on the parent shield can be created uniquely. There is no need to provide it.

Further, if the cutter of the child shield is provided so as to be slidable back and forth with respect to the skin plate of the child shield, and when the cutter is slid forward, the chambers of both the parent and child shields are formed integrally. The excavated soil discharge means provided on either shield allows the excavated soil generated by excavation of both the parent and child shields to be discharged to the rear of the tunnel, which simplifies the structure, makes maintenance easier, and is inexpensive. becomes.

[Brief explanation of the drawing]

1 to 8 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a side view, FIG. 2 is a schematic view taken along the line ■-■ in FIG. 1, and FIG. Figure 4 is a side view of the entire shield machine digging through a subway station. Figure 4 is a side view of the sub-shield digging through a railway track. Figure 5 is a side view of the subway tunnel being dug by the shield machine. 6 and 7 are plan views showing examples of the forms of various tunnels formed by shield machines, FIG. 8 is a side view of the same, and FIGS. 9 to 11 are views showing the present invention. FIG. 9 is a schematic front view, FIG. 1O is a side view of the entire shield machine digging into a subway station, and FIG.
1 is a side view of a state in which a railway line is being dug by a child shield, and FIGS. 12 to 15 are views showing a third embodiment of the present invention, in which FIG. 12 is a side sectional view, and FIG. The figure is a front view, Figure 14 is a side view of the entire shield machine digging through a subway station, Figure 15 is a side view of the sub-shield digging through a railway track, and Figures 16 to 14 are $
FIG. 21 is a diagram showing the fourth embodiment of the present invention, and is a diagram showing the 16th embodiment.
The figure is a side sectional view, Figure 17 is an enlarged view of section A in Figure 16, 91
Figure 8 is an enlarged view of part B in Figure 16, and Figure 19 is an enlarged view of part C in Figure 16.
FIG. 20 is an enlarged view of the D section in FIG. 16, FIG. 21 is a schematic side view showing a tunnel being dug by a shield machine, and FIG. 22 is a form of a tunnel formed by a shield machine. An exemplary schematic plan view, FIGS. 23 and 24, respectively, are side views illustrating a method of forming a conventional subway tunnel. 11.30,40170...Shield machine, 12
．． 31.41171 River...Parent Shield, 13.32.
42.72... Child shield, 14.33.43
．． 73...Skin plate (parent shield side),
15.36.50.80...Skin plate (
Child shield side), 16.35.44... Cutter (Main shield side), 17.38.51.81...
・Cutter (child shield side), 18.92... Over cutter, 49.58.59.91.93...
...Chamber, G...Ground, G8...
Face, T...Tunnel. Figure 1 ■ - Figure 2 1 ■

Claims (5)

[Claims] (1) A parent shield with a cutter provided at the front of a cylindrical skin plate, and a chamber provided behind the cutter to take in the excavated soil by the cutter, and a skin plate of this parent shield. A cutter is provided at the front of a small-diameter cylindrical skin plate, and a child shield is provided at the rear of the cutter to take in the excavated soil excavated by the cutter. With the axes of each skin plate of the child shield and the parent shield being approximately parallel, the device can be attached to and removed from the inside of the parent shield, and when the connection is released, the device can move forward and backward along the axis. A shield machine characterized by the following. (2) The shield machine according to claim 1, wherein the child shield is arranged eccentrically with respect to the parent shield. (3) The shield machine according to claim 1 or 2, characterized in that a plurality of said child shields are provided for said parent shield. (4) The cutters of the parent shield and the child shield are connected by a connecting member, and the cutter on the parent shield side is driven in conjunction with the cutter on the child shield side. shield machine. (5) The cutter of the child shield is provided so as to be slidable back and forth with respect to the skin plate of the child shield, and when the cutter is slid forward, the chambers of both the parent and child shields are formed integrally. Claim 1,
The shield machine described in 2, 3 and 4.