JP2005273397A - Tunnel excavating method and shield machine used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To excavate and construct a new tunnel, without performing large-scale open-cut work between a first tunnel and a second tunnel. <P>SOLUTION: This shield machine 1 has a cutter face plate 3 having a substantially circular cross-sectional shape in a boring advancing directional front part, and a shield frame 16 having a substantially circular cross-sectional shape in it rear, and is started form an aboveground part, to construct the new tunnel by excavating the natural ground 25. After making the tunnels 2a and 2b approach each other, the cutter face plate 3 of the shield machine 1 and the side of the shield frame 16 are separated, and are remodeled into the shield machine 1 having the cutter face plate 3 of a deformed cross-sectional shape and the shield frame 16. The mutual tunnels 2a and 2b are excavated by the remodeled shield machine 1, to construct a connecting part 31 of the new tunnel 26 of the deformed cross-sectional shape by joining the first tunnel 2a and the second tunnels 2b to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tunnel excavation method for excavating and constructing a new tunnel between a first tunnel and a second tunnel provided at a predetermined interval, and a shield machine used therefor.

  A new tunnel such as a branch line tunnel is excavated between a first tunnel such as a tunnel for roads and railways that are parallel to each other in the ground and a second tunnel such as a tunnel for downstream lines. In the conventional construction, the branch line tunnel is formed in the open space by excavating the entire length of the excavated portion between the first tunnel and the second tunnel.

  Therefore, large-scale excavation work is required, so after excavating the entire circular cross section of the road etc. to the vicinity between the first tunnel and the second tunnel, the excavation cross section is deformed and the gap between the first tunnel and the second tunnel is There is a need for a shield machine that can excavate.

  As a shield machine that can be excavated with a small excavation section in the middle of excavation, there is a parent-child shield machine that starts a child shield machine that excavates a small excavation section from a parent shield machine that excavates a large excavation section (for example, patent) Reference 1).

Japanese Patent No. 3247852

  However, in the above tunnel formation method, the excavation part between the first tunnel and the second tunnel is very long considering the gradient of the road, etc., so the excavation section is long and the excavation work becomes large-scale, There were many obstacles such as traffic regulation on the roads on the ground and construction costs.

  In addition, the above-mentioned parent-child shield machine excavates the station part of the subway with the whole parent-child shield machine, and excavates the tunnel part for vehicle travel that continues from the station part with the child shield machine started from the parent shield machine. Therefore, it was not applicable when excavating and constructing a new tunnel between the first and second tunnels.

  That is, when excavating between the first tunnel and the second tunnel described above, it is required to excavate a substantially rectangular deformed section, but in the parent-child shield machine of Patent Document 1, the deformed section can be excavated. In addition, there was no shield machine that could excavate the irregular cross section between the first and second tunnels after excavating the circular cross section.

  Accordingly, an object of the present invention is to provide a novel tunnel capable of excavating and constructing a new tunnel without performing a large-scale excavation work between the first tunnel and the second tunnel provided at a predetermined interval. An excavation method and a shield machine used therefor are provided.

  In order to achieve the above object, the present invention provides a tunnel excavation method in which a new tunnel is excavated and constructed between a first tunnel and a second tunnel provided at a predetermined interval. A shield tunneling machine having a cutter face plate having a circular cross-sectional shape and a shield frame having a substantially circular cross-sectional shape behind it is started from the ground, and a new tunnel is constructed by excavating natural ground. And the second tunnel, the cutter face plate of the shield machine and the sides of the shield frame are separated from each other, and modified to a shield machine with a modified cross-section cutter face plate and a shield frame. Excavation between the first tunnel and the second tunnel using a modified shield machine and connecting the first tunnel and the second tunnel to each other. It is a tunnel method excavation so as to build a connection portion shaped for new tunnels.

  The present invention also relates to a tunnel excavation method for excavating and constructing a new tunnel between a first tunnel and a second tunnel provided at a predetermined interval, and a cutter having a substantially circular cross-sectional shape at the front portion in the advancing direction. A shield excavator having a face plate and a shield frame having a substantially circular cross-sectional shape behind it is started from the ground to excavate natural ground to construct a new tunnel, and the first tunnel and the second tunnel After being close to each other, the cutter face plate and the side of the shield frame of the shield machine were separated from each other, and modified to a shield machine with a modified cross-section cutter face plate and a shield frame. A new tunnel having an irregular cross-sectional shape by excavating between the first tunnel and the second tunnel and connecting the first tunnel and the second tunnel to each other. After constructing the connection part, the cutter face plate and the side of the shield frame of the shield machine were attached respectively, and modified to a shield machine with a substantially circular cross-sectional cutter face plate and a shield frame. This is a tunnel excavation method in which a new tunnel is built up to the ground.

  Further, the cutter face plate is driven to rotate when excavating a circular cross section adjacent to the first tunnel and the second tunnel from a natural ground, and swings when excavating the cross section of the first tunnel and the second tunnel. A driven tunnel excavation method is preferred.

  Further, a tunnel excavation method in which the deformed cross-sectional shape exhibited by the cutter face plate and the shield frame of the shield machine is a substantially rectangular shape having arc-shaped portions above and below is preferable.

  In addition, a tunnel excavation method in which the remodeling work of the shield machine is performed in a work space formed in advance in the vicinity of the first tunnel and the second tunnel by a chemical solution injection work or the like is preferable.

  Further, the facing portions of the first tunnel and the second tunnel facing each other are formed in advance by a material that can be excavated by a shield machine, and between the first tunnel and the second tunnel, the cutter face plate having the modified cross-sectional shape and the shield are formed. When excavating with a shield machine equipped with a frame, a tunnel excavation method is preferable in which the opposed portions formed of the excavable material of the first tunnel and the second tunnel are excavated together with natural ground.

  The present invention provides a cutter face plate that can be deformed into a deformed cross-sectional shape by separating both sides thereof from a substantially circular cross-sectional shape, and a cutter face plate that is located behind the cutter face plate and is deformed into a deformed cross-sectional shape. A shield machine comprising a shield frame that is separated from a circular cross-sectional shape at both sides thereof and can be deformed into an irregular cross-sectional shape.

  The shield frame is provided in the center of the shield width direction and mounts various equipment for the shield machine, and the center frame is disposed on both sides of the shield frame and deformed from a substantially circular cross-sectional shape to an irregular cross-sectional shape. A shield machine with a side frame separated from the frame is preferred.

  Further, the cutter face plate includes a center cutter provided at the center in the shield width direction, and a side cutter that is disposed on both sides of the cutter face plate and is separated from the center cutter when deformed from a substantially circular cross-sectional shape to an irregular cross-sectional shape. The shield machine provided is preferred.

  Further, it is preferable to use a shield machine in which the cutter face plate is rotationally driven when excavating a circular cross section and is oscillated when excavating a cross section.

  According to the present invention, a new tunnel can be excavated and constructed with a single shield machine without performing a large-scale excavation work between a first tunnel and a second tunnel provided at a predetermined interval. Exhibits excellent effects such as

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

  As shown in FIG. 7 to FIG. 9, the shield machine 1 according to the present embodiment is a first tunnel such as a tunnel for an upline such as a road or a railway that is arranged in parallel at a predetermined interval in the ground. 2a and a second tunnel 2b such as a down line tunnel or the like, and a new tunnel 26 such as a branch line tunnel is newly constructed.

  In the present embodiment, the shield machine 1 will be described by exemplifying a muddy water shield having a cutter face plate 3 at the tip.

  As shown in FIGS. 1 and 2, the shield machine 1 is provided with a cutter face plate 3 at the tip of a cutter rotating shaft 5 that passes through the center of the bulkhead 4 and extends forward. A plurality of cutter bits 6 are arranged radially on the front surface of the cutter face plate 3. A hydraulic motor 7 that drives the cutter face plate 3 is provided in the shield frame 16 behind the bulkhead 4. A plurality of hydraulic motors 7 are provided along the circumferential direction of the rotating ring 8 so as to mesh with the gear of the rotating ring 8 provided coaxially with the cutter rotating shaft 5. A mud pipe 9 is connected to the upper part of the bulkhead 4, and a mud pipe 12 having an agitator 11 provided at the tip is connected to the lower part. The mud feeding pipe 9 and the mud discharging pipe 12 extend rearward in the digging direction through the inside of a cylindrical erector support member 15 that is provided on the rear side in the machine and supports an erector (see FIGS. 3 and 5) 14.

  By the way, the present invention is characterized in that the cutter face plate 3 and the shield frame 16 are formed so as to be deformable into an irregular cross-sectional shape by separating both side portions from a substantially circular cross-sectional shape.

  As shown in FIG. 1, the cutter face plate 3 includes a center cutter 17 provided on the cutter rotating shaft 5 and side cutters 18 provided on both sides of the center cutter 17 so as to be separable. The cutter face plate 3 has a circular cross-sectional shape in a state where the side cutters 18 are integrally attached to the central cutter 17.

  The central cutter 17 is formed in a shape having chamfered portions 19 on both upper and lower sides so as to excavate a substantially rectangular cross section having an arcuate portion on the top and bottom by swinging a predetermined angle. The chamfered portions 19 are each formed in a straight line, and the chamfered portions 19 located on the diagonal lines are formed in parallel to each other.

  When the central cutter 17 is positioned at the swing-back point, the chamfered portions 19 located on the diagonal lines are directed to each other in the vertical direction to form a side surface portion of the substantially rectangular cross-sectional shape ( (See FIG. 4).

  The side cutter 18 is formed in a shape having an inner side surface along the side surface of the central cutter 17 and an arc-shaped outer side surface. The side cutter 18 is fixed to the central cutter 17 by fixing means (not shown) such as a bolt. The side cutter 18 is separated from the central cutter 17 by removing the fixing means when the shield machine 1 is modified.

  As shown in FIG. 3, the shield frame 16 includes a center frame 21 provided in the center of the shield width direction, and side frames 22 disposed on both sides thereof.

  The center frame 21 has a substantially rectangular cross-sectional shape, and is composed of upper and lower arc-shaped portions and linear portions on both sides. Various equipment such as the hydraulic motor 7, the mud pipe 9, the mud pipe 12 and the erector 14 described above are mounted inside the central frame 21. A plurality of shield jacks 23 are arranged on the upper and lower arc-shaped portions of the center frame 21.

  The side frame 22 is formed in a shape having a linear inner surface along the side surface of the central frame 21 and an arc-shaped outer surface. A plurality of shield jacks 23 are arranged on the side frame 22 along the arcuate outer peripheral surface. The side frame 22 is fixed to the central frame 21 by fixing means (not shown) such as bolts. When the shield machine 1 is modified, the side frame 22 is separated from the central frame 21 by removing the fixing means, and the linear shape along the side surface of the central frame 21 is provided on both sides of the central frame 21 so as to cover the opening. A side vertical frame (see FIG. 5) 24 having an inner surface and a linear outer surface is attached. A plurality of shield jacks 23 are arranged along the longitudinal direction of the side vertical frame 24.

  When the shield machine 1 is remodeled, the excavation cross section becomes small, so that there may be a case where sufficient propulsive force can be obtained only with the shield jacks 23 provided above and below the central frame 21. In this case, the shield jack 23 may not be provided on the side vertical frame 24.

  Next, a tunnel excavation method using the shield machine 1 having the above configuration will be described.

  As shown in FIGS. 7 and 8, first, the shield machine 1 having the cutter face plate 3 having a substantially circular cross-sectional shape at the front portion in the digging direction and the shield frame 16 having a substantially circular cross-sectional shape behind the cutter face plate 3 is grounded. The new tunnel 26 is constructed to the vicinity of the first tunnel 2a and the second tunnel 2b by excavating the natural ground 25 by starting from the section.

  At this time, the shield machine 1 is integrated with the side cutters 18 attached to both sides of the central cutter 17, and the side frames 22 are attached to both sides of the central frame 21 for integration. It has a shape. The cutter face plate 3 is rotationally driven by the hydraulic motor 7 in the shield frame 16 to excavate a circular cross-sectional shape.

  Then, after the shield machine 1 comes close between the first tunnel 2a and the second tunnel 2b, the shield machine 1 is remodeled.

  In the vicinity of the first tunnel 2a and the second tunnel 2b, a work space 27 for modifying the shield machine 1 is formed in advance. In this work space 27, for example, a chemical injection pipe is inserted from the ground in the vicinity of the tunnels 2a and 2b, the chemical is injected at that portion, and the ground is improved to reinforce the natural mountain in a box shape. It is formed by a chemical solution injection method (chemical solution injection method) that forms the working space 27 by hollowing out.

  In this work space 27, the shield machine 1 is fixed, and the cutters 18 on both sides of the cutter face plate 3 are cut off. At the same time, after the side frames 22 of the shield frame 16 are cut off, side vertical frames (see FIG. 5) 24 are attached to both sides of the central frame 21 to form the shield machine 1 having a substantially rectangular cross section. . In FIG. 5, the right side shows a state before the side cutter 18 is detached and the side vertical frame 24 is attached.

  At this time, the remodeling work is performed in the work space 27 formed in advance by a chemical solution injection work or the like, so it is very easy and can be performed smoothly. Further, since the cutter face plate 3 and the shield frame 16 are formed so that the side cutter 18 and the side frame 22 can be separated from each other, the separation work and the attachment work of the side vertical frame 24 can be easily performed in a short time. It can be carried out.

  Then, following the existing segment of the new tunnel 26 assembled in a circular cross section, the segment is assembled in a substantially rectangular cross section, and a shield jack 23 provided at the rear of the central frame 21 and the side vertical frame 24 is positioned in front of the segment. .

  On the other hand, as shown in FIG. 6, the opposing portions 29 of the first tunnel 2a and the second tunnel 2b are excavated together with the natural ground by the shield machine 1, so that materials that can be excavated by the shield machine in advance, For example, it is formed in an unreinforced state where no reinforcing bars are arranged. Further, partition walls 28 for temporarily holding the earth pressure at the time of excavation and reinforcing at the time of joining to the branch line tunnel 26 are respectively formed on the side portions of the facing portions 29 of the tunnels 2a and 2b. Keep it.

  Then, after the earth and sand are backfilled in the work space 27, the shield machine 1 is started again while the cutter face plate 3 from which the side cutters 18 on both sides are separated is driven to swing. At this time, the hydraulic motor 7 is driven by the set amount of hydraulic oil and swings by rotating forward and backward. In order to swing the cutter face plate 3, a hydraulic jack may be used instead of the hydraulic motor 7.

  In this state, the shield machine 1 excavates the natural ground 25 between the first tunnel 2a and the second tunnel 2b together with the bare opposing portion 29 of each tunnel 2a, 2b to a predetermined length (for example, about 200 to 400 m). Then, the connection part 31 of the new tunnel 26 is constructed.

  Thereafter, the upper foundation mountain 32 is improved by injecting a chemical into the upper tunnel mountain 32 of the first tunnel 2a, the connection portion 31 of the new tunnel 26, and the second tunnel 2b. Then, the first tunnel 2a, the connection portion 31 of the new tunnel 26, and the second tunnel 2b are integrally connected and fixed with reinforced concrete or the like, and a road 33 or the like is formed therein.

  On the other hand, as shown in FIG. 9, a work space 27 for remodeling the shield machine 1 is formed in advance at a location where excavation of the connection portion 31 of the new tunnel 26 is completed. In this work space 27, for example, a chemical injection pipe is inserted from the ground in the vicinity of the tunnels 2a and 2b, the chemical is injected at that portion, and the ground is improved to reinforce the natural mountain in a box shape. It is formed by a chemical solution injection or the like that forms the working space 27 by hollowing out. Here, in order to carry the side cutter 18 and the side frame 22 attached to the shield machine 1 into the work space 27, the work space 27 having an upper portion opened to the ground is formed.

  When the side cutter 18 and the side frame 22 removed from the shield machine 1 before excavation of the connection portion 31 are reused, the work space 27 for performing these removal and remodeling operations is also located above the ground. The side cutter 18 and the side frame 22 are collected.

  Then, the shield machine 1 in which the excavation of the connection portion 31 of the new tunnel 26 has been completed is dug into the work space 27, the shield machine 1 is fixed, and the both side cutters 18 of the cutter face plate 3 are attached. At the same time, after the side vertical frame 24 of the shield frame 16 is removed, the side frames 22 are attached to form the shield machine 1 having a substantially circular cross-sectional shape.

  Thereafter, a new tunnel 26 having a circular cross section is excavated and built up to the ground using the modified shield machine 1.

  As described above, the shield machine 1 including the cutter face plate 3 having a substantially circular cross-sectional shape and the shield frame 16 having a substantially circular cross-sectional shape behind the cutter face plate 3 is started from the ground to excavate the natural ground 25. After constructing a new tunnel 26 and approaching between the first tunnel 2a and the second tunnel 2b, the cutter face plate 3 of the shield machine 1 and the side portion of the shield frame 16 are cut off to form a cutter face plate 3 ( The shield excavator 1 having the central cutter 17) and the shield frame 16 (central frame 21) is remodeled and excavated between the first tunnel 2a and the second tunnel 2b to connect the connection portion 31 of the new tunnel 26. After that, the cutter faceplate 3 and the sides of the shield frame 16 are attached, and the shield machine 1 is remodeled into a shield machine 1 having a substantially circular cross section. By constructing the new tunnel 26, the new tunnel 26 can be excavated and constructed with one shield machine 1 without carrying out large-scale excavation work, and the construction efficiency is greatly improved. In addition, a significant reduction in construction costs is achieved.

  On the other hand, from the ground to the vicinity of the first tunnel 2a and the second tunnel 2b, the cutter face plate 3 is rotationally driven to excavate the circular cross section, so the excavation efficiency is high. Then, since the cutter face plate 3 is deformed and driven to swing, it becomes possible to excavate a deformed cross section between the first tunnel 2a and the second tunnel 2b.

  In addition, since the remodeling work of the shield machine 1 is performed in the work space 27 formed by the chemical injection, etc., the remodeling work can be easily performed. Compared to the excavation work that forms the new tunnel in the open space that has been excavated over the entire length of the excavated part as was done in the past, the impact on the ground is greatly increased because it is only about the same size as the conventional area. Can be reduced.

  Further, the cutter face plate 3 of the shield machine 1 is composed of the central cutter 17 and the side cutter 18, and the side cutter 18 is formed so as to be separable from the central cutter 17, and the shield frame 16 is connected to the central frame 21 and the side portion. With the frame 22 and the side frame 22 formed so as to be separable from the central frame 21, the shield excavator 1 can be easily remodeled in a short time.

  In the above embodiment, the work space 27 is formed in a box shape in the ground. However, the work space 27 is not limited to this. The work space 27 may be a work space that is cut to the ground by forming a shaft. . Again, the space required for work on the ground can be very small.

  In the above embodiment, when excavating the new tunnel 26 to the vicinity of the first tunnel 2a and the second tunnel 2b, the cutter face plate 3 having a circular cross section is rotated to excavate the natural ground 25. It is not limited. For example, the circular cross-sectional shape may be excavated by rotating the cutter face plate 3 including only the central cutter 17 from which the side cutter 18 has been cut in advance. Alternatively, the side cutters 18 may be attached to both sides of the central cutter 17, and the cutter face plate 3 integrated into a circular cross-sectional shape may be driven to swing to excavate the circular cross-sectional shape.

  Furthermore, in the said embodiment, although the shield machine 1 was remodeled from a substantially circular cross-sectional shape to a substantially rectangular cross-sectional shape, the shape after remodeling is not restricted to this. By changing the shape of the cutter face plate or the copy cutter or changing the swing angle, it is possible to remodel the shield machine to excavate an irregular cross-sectional shape such as a polygon or an ellipse.

  In the above embodiment, the upstream tunnel is described as the first tunnel 2a, and the downstream tunnel is described as the second tunnel 2b. However, the present invention is not limited to this. For example, both the first tunnel 2a and the second tunnel 2b may be an uplink tunnel or a downlink tunnel, or may be a tunnel having both upper and lower lines.

  In the above embodiment, the shield machine 1 is modified from the substantially circular cross-sectional shape to the substantially rectangular cross-sectional shape in the work space 27. However, the shield machine 1 is a parent-child shield (see FIGS. 10 to 12). ) And the child shield machine 35 formed in a substantially rectangular cross-sectional shape in the work space 27 is started from the parent shield machine 36 formed in a substantially circular cross-sectional shape. Can drill. In this case, the child shield machine 35 is provided with a modified cutter face plate 37 having a modified cross-sectional shape. When the circular cross section is excavated, the deformed cutter face plate 37 is driven to rotate, and during the modified cross section excavation, the deformed cutter face plate 37 is driven to swing. I will let you.

It is the front view which showed suitable embodiment of the shield machine which concerns on this invention. It is side surface sectional drawing which showed suitable embodiment of the shield machine based on this invention. It is the rear view which showed suitable embodiment of the shield machine which concerns on this invention. It is the front view which showed the state after the division | segmentation of the shield machine which concerns on this invention. It is the rear view which showed the state after the division | segmentation of the shield machine which concerns on this invention. It is the front view which showed the shield machine which excavates between a 1st tunnel and a 2nd tunnel. It is side surface sectional drawing which showed the excavation state of the shield machine which concerns on this invention. It is the front view which showed the shield machine which reached | attained work space. It is side surface sectional drawing which showed the excavation state of the shield machine which concerns on this invention. It is sectional drawing which showed the parent-child shield machine. It is the front view which showed the parent-child shield machine. It is sectional drawing which showed the parent-child shield machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield machine 2a 1st tunnel 2b 2nd tunnel 3 Cutter face plate 16 Shield frame 17 Central cutter 18 Side cutter 21 Central frame 22 Side frame 25 Ground mountain 26 New tunnel 27 Work space 29 Opposite part 31 (of new tunnel) Connection part

Claims (10)

  In a tunnel excavation method in which a new tunnel is excavated and constructed between a first tunnel and a second tunnel provided at a predetermined interval, a cutter face plate having a substantially circular cross-sectional shape at the front portion in the advancing direction, and a rear side thereof After starting a shield excavator with a shield frame having a substantially circular cross-sectional shape from the ground, excavating the natural ground to build a new tunnel, after approaching between the first tunnel and the second tunnel, The shield face machine and the sides of the shield frame of the shield machine are separated from each other, and modified to a shield machine having a cutter face plate and a shield frame having an irregular cross-sectional shape. Excavation between the two tunnels and connecting the first tunnel and the second tunnel together to construct the connection part of the new tunnel with a different cross-sectional shape Tunnel method drilling, characterized in that as.   In a tunnel excavation method in which a new tunnel is excavated and constructed between a first tunnel and a second tunnel provided at a predetermined interval, a cutter face plate having a substantially circular cross-sectional shape at the front portion in the advancing direction, and a rear side thereof After starting a shield excavator with a shield frame having a substantially circular cross-sectional shape from the ground, excavating the natural ground to build a new tunnel, after approaching between the first tunnel and the second tunnel, The shield face machine and the sides of the shield frame of the shield machine are separated from each other, and modified to a shield machine having a cutter face plate and a shield frame having an irregular cross-sectional shape. Excavation between the two tunnels, the first tunnel and the second tunnel are connected to each other, and the connection part of the new tunnel with a different cross-sectional shape is constructed Later, the side of the shield machine and the side of the shield frame of the shield machine were attached to each other, and the shield machine was modified to a shield machine with a substantially circular cross-section cutter face plate and a shield frame. A tunnel excavation method characterized in that it is constructed.   The cutter face plate is driven to rotate when excavating a circular section close to the first tunnel and the second tunnel from a natural ground, and is driven to swing when excavating an irregular section excavating between the first tunnel and the second tunnel. The tunnel excavation method according to claim 1 or 2.   The tunnel excavation method according to any one of claims 1 to 3, wherein the modified cross-sectional shape exhibited by the cutter face plate and the shield frame of the shield machine is a substantially rectangular shape having arc-shaped portions on the top and bottom.   The tunnel excavation machine according to any one of claims 1 to 4, wherein the shield excavation machine is remodeled in a work space previously formed by a chemical injection or the like in the vicinity of the first tunnel and the second tunnel. Drilling method.   The facing portions of the first tunnel and the second tunnel facing each other are formed in advance with a material that can be excavated by a shield machine, and the cutter face plate and the shield frame having the irregular cross-sectional shape are formed between the first tunnel and the second tunnel. The excavation of a tunnel according to any one of claims 1 to 5, wherein when excavating with the shield machine provided, the opposing portion formed of the excavable material of the first tunnel and the second tunnel is excavated together with a natural ground. Method.   A cutter face plate that can be deformed into a modified cross-sectional shape by separating both sides from the substantially circular cross-sectional shape, and both sides thereof from the substantially circular cross-sectional shape when the cutter face plate located behind the cutter face plate is deformed into a deformed cross-sectional shape. A shield machine having a shield frame which is cut off at a part and deformable into a deformed cross-sectional shape.   The shield frame is provided at the center of the shield width direction and mounts various equipment for the shield machine, and is separated from the center frame when it is disposed on both sides of the shield frame and deformed from a substantially circular cross-sectional shape to an irregular cross-sectional shape. The shield machine according to claim 7, further comprising a side frame.   The cutter face plate includes a center cutter provided in the center of the shield width direction, and a side cutter that is disposed on both sides of the cutter face plate and is separated from the center cutter when deformed from a substantially circular cross-sectional shape to an irregular cross-sectional shape. The shield machine according to claim 7 or 8. The shield machine according to any one of claims 7 to 9, wherein the cutter face plate is driven to rotate during excavation of a circular cross section and is driven to swing during excavation of an irregular cross section.

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