JPH08177391A - Segment for constructing curved tunnel - Google Patents

Abstract

PURPOSE: To maintain a proper sealing performance by establishing an external shape for securing proper seal clearance between rear shield internal surface and segment external surface, so as to keep a proper interference for a seal used to hermetically close a cavity resulting from a difference between shield inner diameter and segment outer diameter. CONSTITUTION: A difference between the lateral outer diameter L1 of an elliptical segment 10b and the inner diameter ϕD of a rear shield 6 is established, so as to give a proper interference value for a wire brush 11 along the left side A1 and right side B1 of a bending direction. Thereafter, the lateral outermost length of the segment 10b is taken at L1 for a proper seal interference. Also, the longitudinal outermost length H1 thereof is taken as equal to L0 for keeping proper clearance, provided that L0 is the outer diameter of a circular segment 10 for a linear tunnel. Then, the segment 10b with the length L1 as a minor axis and the length H1 orthogonal with a bending direction as a major axis is used, thereby providing a proper seal interference for maintaining a seal performance between the outer diameter of the segment 10b and the inner diameter of the shield 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curved tunnel construction segment, and more particularly to a curved tunnel construction segment for constructing a sharp curve tunnel.

[0002]

2. Description of the Related Art Conventionally, as a method for constructing a curved portion of a shield tunnel, for example, "Japanese Patent Laid-Open No. 63-142191" has been proposed. This is, as shown in FIG. 8, a step of lining a curved construction portion with a reduced diameter segment 50 having an outer diameter smaller than that of the normal segment 51 used for the straight construction portion, and the reduced diameter segment 50 and the ordinary diameter. Between the segment 51 and the segment 51, there is a step of interposing a deformed segment 52 in which one joint end face 52a coincides with the normal segment 51 and the other joint end face 52b coincides with the reduced diameter segment 50. In addition, Tm is a shield machine.

[0003]

However, the following problems occur in the above conventional technique. In order to prevent the trailing edge of the segment and the shield shield machine Tm from sticking to the inner diameter of the rear shield during curve construction, the outer diameter of the segment 50 is reduced to secure a necessary tail clearance between the rear shield and the segment 50. The tail clearance in the direction perpendicular to the bending direction is increased by the reduction of the outer diameter of the segment 50. As a result, the tightening margin of the tail seal attached to the rear shield in the direction perpendicular to the bending direction of the excavator is reduced, and an accident such as water leakage occurs. Therefore, since there is a limit to the reduction of the outer diameter of the segment 50, there is a problem that the radius of curvature of the bending tunnel is restricted.

The present invention has been made in view of the above problems, and in order to give a proper tightening margin to the entire circumference of the seal installed on the inner diameter of the rear shield, the entire distance between the inner surface of the rear shield and the outer peripheral surface of the segment. Since the outer shape of the segment is set so as to secure an appropriate seal clearance around the circumference, the segment and the inner diameter of the rear shield are prevented from curling even during curved construction, preventing accidents such as water leakage and using the conventional segment. The purpose is to provide a segment that can reduce the curvature of a tunnel that can be constructed from time to time.

[0005]

In order to achieve the above object, the curved tunnel construction segment according to the present invention covers the tunnel excavated by the shield machine and also serves as a reaction force of the shield machine. In the segment, it is installed in the rear shield inner diameter part of the shield machine at the time of curved construction, and in order to secure an appropriate tightening margin of the seal that seals between the rear shield inner diameter part and the segment outer peripheral surface, the rear shield inner surface And the outer peripheral surface of the segment are formed in an outer shape for ensuring an appropriate seal clearance.

The outer shape of the cross section of the segment orthogonal to the tunnel construction planning line is an elliptical shape having a minor axis in the bending direction of the shield machine and a long axis in the direction perpendicular to the bending direction, The direction opposite to the center of curvature is a semi-circle, and the part of the curved tunnel on the center of curvature is formed by a curve or arc that smoothly follows this semi-circle. Even if the flat shape is shorter than the maximum length in the direction perpendicular to, the part on the side opposite to the center of curvature of the curved tunnel is a curve or an arc centered on the side of the center of curvature of the curved tunnel, while the part on the side of the center of curvature of the curved tunnel is Is a curve or an arc having a center on the side opposite to the center of curvature of the curve tunnel, and is formed by a curve or arc that smoothly connects these curves or arcs. De maximum length in the direction of the excavator is bent may be a shorter flat shape than the maximum length of the direction perpendicular to the direction of bending.

In the curved tunnel construction segment, a gap between the segment outer peripheral surface on the side of the center of curvature of the curved tunnel and the inner surface of the rear shield and a gap between the outer peripheral surface of the segment on the side opposite to the center of curvature of the curved tunnel and the inner surface of the rear shield are set. In consideration of the interference between the outer peripheral surface of the foremost segment and the inner surface of the rear shield, and the interference between the rear end portion of the inner surface of the rear shield and the outer peripheral surface of the segment, and the proper tightening margin of the seal attached to the rear shield. It may be set, and in the curved tunnel construction segment, the clearance between the rear shield inner surface and the segment outer peripheral surface, or the interference between the front segment outer peripheral surface and the rear shield inner surface, which is almost the same as during straight running, , And the center of curvature of the curved tunnel, which is set in consideration of the interference between the rear end of the inner surface of the rear shield and the outer peripheral surface of the segment. Set the clearance between the outer peripheral surface of the segment and the inner surface of the rear shield, the clearance between the outer peripheral surface of the segment on the side opposite to the center of curvature of the curved tunnel and the inner surface of the rear shield, and the appropriate tightening margin of the seal attached to the rear shield at the front end. It may be set to an appropriate value at an almost intermediate position between the seal and the last seal.

[0008]

The segment for constructing a curved tunnel according to the present invention having the above-described structure acts as follows. As in the conventional case, the tunnel excavated by the shield machine is lined, and the excavation reaction force of the shield machine is received. In addition, a segment having an appropriate seal clearance between the rear shield inner diameter and the segment outer diameter so as to provide a proper interference for sealing between the seal installed on the rear shield inner diameter portion of the shield machine and the segment outer diameter. Since the outer diameter is formed, it is possible to secure good sealing performance and seal durability over the entire inner circumference of the rear shield.

The outer shape of the segment cross section orthogonal to the tunnel construction planning line is an elliptical cross section having a minor axis in the bending direction of the shield machine and a major axis in the direction orthogonal to the bending direction, or the center of curvature of a curved tunnel. The part on the side opposite to is a semicircle, and the part on the side of the center of curvature of the curved tunnel is continuous with this semicircle, and is formed by a curve or arc that smoothly continues to that semicircle. Set the flat shape that the maximum length becomes shorter than the maximum length in the direction perpendicular to the bending direction, or the outer diameter of the segment cross section, center the curve on the side opposite to the curvature center of the curved tunnel, or the curvature center side of the curved tunnel. The curved center of the curved tunnel is curved, or the curved center of the curved tunnel is opposite to the curved center of the curved tunnel. If the flat shape is formed by a curved line or an arc that connects to the shield shield machine, the maximum length in the bending direction of the shield machine is shorter than the maximum length in the direction perpendicular to the bending direction. Good sealability and seal durability can be ensured.

Since the clearance between the outer peripheral surface of the segment and the inner surface of the rear shield hardly changes even during the construction of the curved tunnel, it can be set to a value substantially the same as that during the straight construction. The gap between the outer shape of the segment on the side of the center of curvature of the curved tunnel and the rear shield, and the gap between the outer peripheral surface of the segment on the side opposite to the side of the center of curvature of the curved tunnel and the inner surface of the rear shield are the outer peripheral surface of the segment at the front end and the inner surface of the rear shield. Interference with the
When considering the interference between the rear end of the inner surface of the rear shield and the outer peripheral surface of the segment and the proper tightening margin of the seal attached to the rear shield, or when installing multiple seals on the rear shield, , It is possible to prevent the segment and the rear shield from being damaged due to the interference between the outer peripheral surface of the segment and the inner surface of the rear shield by ensuring an appropriate clearance of the seal at an approximately intermediate position between the frontmost seal and the rearmost seal. The performance of the seal can be secured.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a curved tunnel construction segment according to the present invention will be described in detail below with reference to the drawings. 1A and 1B are views showing a first embodiment of a segment for curved tunnel construction according to the present invention, which is applied to a single-stage middle-break shield machine, in which FIG. 1A is a longitudinal sectional view, and FIG. 1B is a lateral sectional view. 2 is
FIG. 2 is a diagram showing a second embodiment of a curved tunnel construction segment according to the present invention, which is applied to a two-stage center-break shield machine.
(A) is a vertical cross-sectional view, (B) is a horizontal cross-sectional view, FIG. 3 is a diagram showing a third embodiment of a segment for curved tunnel construction according to the present invention, which is applied to a two-stage middle-break shield machine. (A)
Is a longitudinal sectional view, (B) is a lateral sectional view, FIG. 4 is a lateral sectional view showing a fourth embodiment of a curved tunnel construction segment according to the present invention, and FIG. 5 is a curved tunnel construction segment according to the present invention. FIG. 6A is a cross-sectional view showing another embodiment of the above, in which FIG.
(B) is a cross-sectional view of a segment for a curved tunnel construction that is flat in the vertical direction.

6A and 6B are views for explaining the principle for determining the outer shape of the segment for constructing a curved tunnel according to the present invention. FIG. 6A is a vertical sectional view when traveling straight, and FIG. 6B is a vertical sectional view when bending. FIG. 7 and FIG. 7 are cross-sectional views of FIG.
6A is a view taken in the direction of arrow P in FIG. 6B, and FIG.
It is a Q arrow line view in (B).

Next, the principle for determining the outer shape of the curved tunnel construction segment according to the present invention will be described with reference to FIGS. 6 and 7. In FIG. 6 (A), 6 is a rear shield, 10 is a segment for lining an excavated tunnel, and the segment 10a at the foremost end gives a reactive force to the shield machine. Reference numeral 11 is a wire brush that seals between the outer diameter of the segment 10 and the one-stage wire brush 1.
1a and a two-step wire brush 11b. When S1 is the inner diameter of the rear shield and S2 is the outer diameter of the segment, the clearance d1 during straight running is expressed as follows. d1 = (S1-S2) / 2

In FIG. 6 (B), the bending angle of the central axis of the shield with respect to the central axis of the segment is θ, and the cross section of the shield perpendicular to the axis passing through the intersection O between the central axis of the segment 10 and the central axis of the rear shield 6. If the length of the major axis of the segment in S is S3, the clearance d2 during curve construction is expressed as follows. From d2 = (S1−S3) / 2, S3 = S2 / cos θ, d2 = (S1−S2 / cos θ) / 2 ∴d1> d2, that is, d1−d2 = (S2 / cos θ−S2) / 2 =
If the segment length S3 is reduced in the bending direction of the shield machine by twice ((1-cos θ) / 2cos θ) S2, the same clearance d1 as when straight line can be obtained. Of course, this is the clearance at the position passing through the center O, as shown in the figure. However, in reality, A,
Since the reduction ratio of the segment diameter and the bending center are set so as to secure an appropriate clearance that can satisfy the sealing performance at the positions B, C, and D, it is not always necessary that d1 = d2, but of course d1> d2 As can be seen from the above, the segment diameter S3 in the bending direction must be reduced.

The above will be described with reference to FIG. Figure 7
FIG. 6A is a view as seen from the arrow P in FIG. 6B. Since the segment outer diameter in the bending direction (horizontal direction) during curve construction is S3, the clearance d2 with the rear shield inner diameter S1 is straight during construction. Is smaller than the clearance d1.
This reduction amount is (d1 −d2) = (S2 / cos θ−S2)
/ 2 = ((1-cos θ) / 2cos θ) S2. Therefore, if a circular segment with an outer diameter S2 is used so that the clearance in the bending direction (left-right direction) is d1, the segment outer diameter in the direction perpendicular to the bending direction (up-down direction) is S2a, and the clearance with the rear shield inner diameter S1 is Is d1a, and d1a> d1. Therefore, the sealing performance may be deteriorated and the water may not be stopped. Therefore, in FIG. 7A, the segment outer diameter in the bending direction (horizontal direction) and the segment outer diameter in the direction perpendicular to the bending direction (vertical direction) are both S.
If a segment of 2 is used, a clearance of d1 can be maintained. This will be described with reference to FIG. 7B which is a view taken in the direction of arrow Q in FIG. 6B. The maximum segment length in the left-right direction is S2a (short axis) so that the clearance in the bending direction (left-right direction) is d1. If an elliptical segment 10b with a maximum segment length in the vertical direction of S2 (long axis) is used so that the clearance in the direction perpendicular to the bending direction (vertical direction) is d1, the elliptical segment 10b
A good sealing performance can be obtained over the entire outer circumference of the curved tunnel construction as in the straight construction.

In the above, the outer diameter shape of the segment where the clearance at the intermediate position in the axial direction of the two-stage seal is constant even when the curved tunnel is constructed was examined. However, since the seals 11 generally have two or more stages, the seals 11 in each stage are made to have a proper clearance as much as possible, or the outer peripheral surface of the frontmost segment 10a and the rear shield 6 are secured.
Front tail clearance G to avoid interference with the inner surface of the
1 and the rear tail clearance G2 for avoiding the interference between the rear end portion of the rear shield 6 and the outer peripheral surface of the segment, it is necessary to deform the outer shape of the segment. Although the center of bending is set to the point O, it is actually moved and adjusted appropriately.

FIG. 1 is a view showing a first embodiment of the present invention applied to a single-stage middle-break shield excavator. The middle-break shield excavator 1 has a concave shape installed at the rear end of the front shield 2. The spherical bearing 7a and the convex spherical bearing 7b installed at the front end portion of the rear shield 6 are connected in a bendable manner by a spherical bearing 7. A cutter head 3 for excavating the tunnel 4 is rotatably attached to the front end portion of the front shield 2, and a copy cutter 5 is attached to the cutter head 3 so as to be retractable in the radial direction. A shield jack 8 is fixed to the front end of the rear shield 6 via a bracket 6a.
A spreader 9 is connected to the piston rod 8a of FIG. The excavated tunnel 4 is lined by the segment 10b, and the spreader 9 is brought into contact with the segment 10a at the foremost end to extend the piston rod 8a of the shield jack 8 so that the medium-break shield excavator 1 is provided. Gives digging reaction force. Further, the rear end of the rear shield 6 has two stages of wire brushes 11a, 11a.
The wire brush 11 constituted by b is attached, and water is stopped between the wire brush 11 and the outer peripheral surface of the segment 10b.

Next, the operation of FIG. 1 will be described. Between the front shield 2 and the rear shield 6, a plurality of known articulate jacks (not shown) are installed at equal intervals on the circumference. Due to the difference in the amount of extension of each articulate jack, The rear shield 6 bends around the spherical bearing 7. In the thus-bent single-stage middle-break shield excavator 1, the shield jack 8 fixed to the rear shield 6 obtains the excavation reaction force from the frontmost segment 10a via the spreader 9, and the cutter head 3 cuts the ground. While excavating, excavate the curved tunnel 4. When excavating the curved tunnel 4, the inside of the curved tunnel 4 in the bending direction is over excavated by the copy cutter 5 that can freely project and retract in the radial direction of the cutter head 3 to advance the shield machine 1 with a single-step break. Also, the rear shield 6
The wire brush 11 including the one-step wire brush 11a and the two-step wire brush 11b installed at the rear end of the oval segment 10b stops the water between the outer diameter of the elliptical segment 10b and the inner diameter of the rear shield 6.

FIG. 1B, which is a sectional view taken along line AA of FIG.
In, the clearance between the outer diameter L1 of the elliptical segment 10b in the lateral direction (within the bending surface) and the inner diameter φD of the rear shield 6 is defined by the bending direction left side (IN side) A1 and the bending direction right side (OUT side) B1. The tightening margin of the wire brush 11 is set to an appropriate value. Elliptical segment 1 at this time
The lateral outer diameter L1 of 0b is the outer diameter L of the circular segment 10 for straight tunnel as described in FIGS. 7 and 8.
It must be smaller than 0. At this time, if the circular segment 10 of L1 is used, the circular segment 10
The clearance C1 between the outer diameter in the vertical direction (the direction perpendicular to the bending surface) (L1 shown by the chain double-dashed line, which indicates the above-mentioned conventional technique) and the inner diameter φD of the rear shield 6, is the outside of the circular segment 10 for straight tunnels. Proper clearance D1 when the diameter is L0
Get bigger. Therefore, there is a problem that the sealing performance between the outer diameter of the circular segment 10 and the inner diameter of the rear shield 6 is deteriorated, and muddy water or the like enters the rear shield 6. Further, since there is no member that restricts the relative position of the shield machine 1 in the curved tunnel 4, the clearance C1
May eccentric by up to twice the maximum C1, which significantly reduces the sealing performance between the outer diameter of the circular segment 10 and the inner diameter of the rear shield 6. Therefore, circular segment 1
When the outer diameter of 0 is reduced from L0 to L1, there is a limit to the reduction ratio, and due to the interference between the outer peripheral surface of the circular segment 10 and the inner surface of the rear shield 6, there is a limit to the curvature of the curved tunnel that can be constructed.

Therefore, in the present embodiment, the outermost length in the lateral direction (in the plane of the bending direction) of the segment is L1, which is a proper seal tightening margin, and the outermost length H1 in the longitudinal direction of the segment (direction perpendicular to the bending direction) is , H1 = L0 in order to maintain the proper clearance D1 when the outer diameter L0 of the circular segment 10 for straight tunnel is maintained. That is, the length L1 in the bending direction is the minor axis, and the length H1 in the direction perpendicular to the bending direction is H1.
An elliptical segment 10b whose major axis is (= L0) is used. If this elliptical segment 10b is used, a proper seal tightening margin can be obtained over the entire outer diameter of the elliptical segment 10b even during construction of a curved tunnel. Therefore, the outer diameter of the elliptical segment 10b and the inner diameter of the rear shield 6 can be increased. The sealing performance between can be secured. Further, it becomes possible to sufficiently secure the front tail clearance and the rear tail clearance as shown in FIGS. 7 and 8, and it is possible to reduce the curvature of the curved tunnel that can be constructed. Further, since the inclination angle between the elliptical segment 10b and the rear shield 6 can be made larger than that of the conventional reduced circular segment 10, if the curvatures of the curved tunnels are the same, the inclination angle between the rear shield 6 and the front shield 2 can be increased. Since it can be reduced, the amount of excess digging by the copy cutter can be reduced.

FIG. 2 is a view showing a second embodiment of the present invention, which is applied to a two-stage intermediate-break shield excavator.
12186 ", two-step broken center shield shield machine 1
Is configured as follows. Middle break shield machine 1
A cutter head 3 for excavating a tunnel 4 is rotatably attached to a front end of a cutter support device 13 that is bendably attached to the cutter support device 13. Is installed.
Convex spherical bearing 17a formed on the cutter support device 13
And a concave spherical bearing 17b installed at the front end portion of the front shield 12 constitute a spherical bearing 17, and the cutter support device 13 and the front shield 12 are flexibly connected. Further, the spherical spherical bearing 7 is constituted by the concave spherical bearing 7 a installed at the rear end of the front shield 12 and the convex spherical bearing 7 b installed at the front end of the rear shield 6, and the front shield 12 and the rear shield 6 are formed. And are flexibly connected. Therefore, the cutter support device 13 has the bending center O1 with respect to the rear shield 6 by the two spherical bearings 7 and 17.
Since it can be bent in two steps up to 13 degrees and 7 minutes, then up to 20 degrees, it is possible to construct a sharp curve tunnel.
In addition, the rear end of the rear shield 6 has a two-stage wire brush 1
A wire brush 11 composed of 1a and 11b is attached to stop water from the outer peripheral surface of the segment 10b. Incidentally, the operation of the rear shield 6 to excavate by taking the excavation reaction force from the foremost end segment 10a is similar to that of the first embodiment, and therefore its explanation is omitted. In this embodiment, an elliptical segment 10b is used in which the outer diameter L2 in the lateral direction (in the bending plane) of the circular segment 10 for straight tunnel is reduced by E2 from the left and right. That is, there is a relation of L0-L2 = 2E2.

Next, the operation of FIG. 2 will be described. Between the rear shield 6 and the front shield 12, and the front shield 12
A plurality of well-known articulate jacks (not shown) are installed at equal intervals on the circumference between the cutter support device 13 and the cutter support device 13, and the spherical bearing 7 and the spherical surface 7 are formed due to the difference in the extension amount of each articulate jack. Bearing 1
Due to 2, it bends around the bending center O1. The two-stage middle-break shield excavator 1 bent in this way has a rear shield 6
The excavation reaction force is obtained from the segment 10b by the shield jack similar to that shown in FIG. 1, and the curved tunnel 4 is excavated while excavating the natural ground by the cutter head 3. O2 is the center of curvature of the bending tunnel, and the curved tunnel 4
Is excavated with a curvature R that is smaller than that of a shield machine with a single-stage break. As described above, when it becomes possible to construct a sharp curve tunnel, it becomes necessary to further consider the front tail clearance G1 and the rear tail clearance G2 as shown in FIG. When excavating the curved tunnel 4, the inside of the shield excavator 1 in the bending direction is overexposed by the copy cutter 5 that can freely project and retract in the radial direction of the cutter head 3 to excavate the shield excavator 1 in two steps. There is.
At the rear end of the rear shield 6, a wire brush 11 similar to that shown in FIG. 1 is used to seal between the outer peripheral surface of the elliptical segment 10b and the inner surface of the rear shield 6 to prevent intrusion of muddy water or the like.

FIG. 2B, which is a sectional view taken along line AA of FIG. 2A.
In the lateral direction of the elliptical segment 10b (in the bending plane)
The clearance between the outside diameter L2 of the rear shield 6 and the inside diameter φD of the rear shield 6 is the left side in the bending direction (IN side) A2 and the right side in the bending direction (OU
(T side) B2 so that the tightening margin of the wire brush 11 becomes an appropriate value. At this time, the lateral outer diameter L2 of the elliptical segment 10b needs to be made smaller than the outer diameter L0 of the straight-line tunnel circular segment 10 as described in FIGS. 7 and 8. Therefore, when a circular segment 10 having an outer diameter L2 is used, the outer diameter (L indicated by a chain double-dashed line) in the longitudinal direction (direction perpendicular to the bending direction) of the circular segment 10 is
2 shows the above conventional technology) and the inner diameter φ of the rear shield 6
The clearance C2 with D is larger than the proper clearance D2 when the outer diameter L0 of the circular segment 10 for straight tunnel is large. Therefore, there is a problem that the sealing performance between the outer diameter of the circular segment 10 and the inner diameter of the rear shield 6 is deteriorated, and muddy water or the like enters the rear shield 6. Also, the first
Similar to the embodiment, when the outer diameter of the circular segment 10 is reduced from L0 to L1, there is a limit to the reduction rate, and due to the interference between the outer peripheral surface of the elliptical segment 10b and the inner surface of the rear shield 6, it is possible to construct a curved tunnel. There is a limit to the curvature of.

Therefore, in this embodiment, the outermost length in the lateral direction (bending direction) of the elliptical segment 10b is set to L2 which is a proper sealing margin, and the outermost length in the vertical direction (direction perpendicular to the bending direction) of the elliptical segment 10b is set. The outer length H2 is set to H2 = L0 in order to maintain an appropriate clearance D2 when the outer diameter L0 of the straight-line tunnel circular segment 10 is maintained. That is, the elliptical segment 10b having the length L2 in the bending direction as the minor axis and the length H2 (= L0) in the direction perpendicular to the bending direction as the major axis is used. If this elliptical segment 10b is used, the elliptical segment 10 can be used even during curved construction.
Since a proper seal tightening margin can be obtained over the entire outer circumference of b, the sealing performance between the outer diameter of the elliptical segment 10b and the inner diameter of the rear shield 6 can be secured. Further, the curvature of the curved tunnel can be reduced as compared with the conventional reduced circular segment 10 and the amount of overdue by the copy cutter can be reduced as compared with the conventional reduced circular segment 10 as in the first embodiment. The other points are the same as those in the first embodiment, and the description thereof will be omitted.

FIG. 3 is a diagram showing a third embodiment of the present invention applied to the two-stage middle-break shield excavator of FIG. 2. The same parts as those in FIG. Is omitted. In this embodiment, with respect to the outer diameter L0 of the circular segment 10 for straight tunnel, the outermost length L3 of the deformed segment 10c in the lateral direction (in the bending direction plane) is aligned on the right side (OUT side), and only the left side (IN side) is E3. A reduced profile segment 10c is used. That is, L0-L3 =
The relationship is E3. The operation of FIG. 3 is similar to that of FIG.

FIG. 3B, which is a sectional view taken along line AA of FIG.
At the clearance between the outer diameter L3 of the deformed segment 10c in the lateral direction (inside the bending direction plane) and the inner diameter φD of the rear shield 6, the bending direction left side (IN side) A3 and the bending direction right side (OUT side) B3 are The tightening margin of the wire brush 11 is set to an appropriate value. Deformed segment 10 at this time
The outermost lateral length L3 of c is the outer diameter L of the circular segment 10 for straight tunnel as described in FIGS. 7 and 8 above.
It must be smaller than 0. Therefore, if a circular segment 10 having an outer diameter L3 is used, the circular segment 10
The clearance C3 between the outer diameter in the vertical direction (the direction perpendicular to the bending direction) (L3 shown by the chain double-dashed line indicates the above-mentioned conventional technique) and the inner diameter φD of the rear shield 6 is the outside of the circular segment 10 for straight tunnels. Proper clearance D when the diameter is L0
Greater than 3. Therefore, there is a problem that the sealing performance between the outer diameter of the circular segment 10 and the inner diameter of the rear shield 6 is deteriorated, and muddy water or the like enters the rear shield 6. Also,
As in the first embodiment, the outer diameter of the circular segment 10 is L0.
When reducing from L1 to L1, there is a limit to the reduction rate, and due to the interference between the outer surface of the reduced segment and the inner surface of the rear shield 6,
There is a limit to the curvature of the curved tunnel that can be constructed. The other points are the same as those in the first embodiment, and the description thereof will be omitted.

Therefore, in this embodiment, the outermost length in the lateral direction (in the plane of the bending direction) of the deformed segment 10c is set to L3, which is a proper sealing surface pressure, and the outside of the segment 10 in the longitudinal direction (the direction perpendicular to the bending direction). The diameter H3 is set to H3 = L0 in order to maintain an appropriate clearance D3 when the outer diameter L0 of the straight tunnel circular segment 10 is maintained. That is, the right side in the lateral direction of the odd-shaped segment 10c (OUT side)
L31 is a circular arc with a radius R3, and the left side (IN
The side) has a minor axis radius of L32 and a major axis of irregular segment 10c.
Outermost length H3 (= L0) in the vertical direction (direction perpendicular to the bending direction)
) The deformed segment 10c which is a semi-ellipse part is used.
If this deformed segment 10c is used, an appropriate sealing surface pressure can be obtained on the entire outer circumference of the deformed segment 10c during curved construction, so that the sealing performance between the outer diameter of the deformed segment 10c and the inner diameter of the rear shield 6 is improved. improves.
Further, the curvature of the bending tunnel can be reduced as compared with the conventional reduced circular segment 10 and the amount of overdue by the copy cutter can be reduced as compared with the conventional reduced circular segment 10 as in the first embodiment. Other than that, the description is omitted because it is the same as the second embodiment.

FIG. 4 is a view showing the outer diameter of the deformed segment 10d of the fourth embodiment according to the present invention, and is a view corresponding to FIG. 3 (B). In FIG. 4, the outer diameter L4 of the deformed segment 10d in the lateral direction (inside the bending direction) and the inner diameter φ of the rear shield 6 are shown.
The clearance between the wire brush 11 and the left side in the bending direction (IN side) A4 and the right side in the bending direction (OUT side) B4 are
Make sure that the tightening margin of is set to an appropriate value. The lateral outer diameter L4 of the deformed segment 10d at this time is, as described in FIGS. 7 and 8, the circular segment 1 for straight tunnels.
It is necessary to reduce the outer diameter L0 from 0. Therefore, if a circular segment 10 having an outer diameter L4 in the lateral direction of the deformed segment 10d is used, the outer diameter (L4 shown by a chain double-dashed line) in the longitudinal direction (direction perpendicular to the bending direction) of the circular segment 10 is Clearance C4 between the rear shield 6 and the inner diameter φD of the rear shield 6 is an appropriate clearance D4 when the outer diameter L0 of the circular segment 10 for a straight tunnel.
Get bigger. Therefore, as in FIG. 2, the sealing performance between the outer diameter of the odd-shaped segment 10d and the inner diameter of the rear shield 6 is reduced, so that muddy water enters the rear shield 6 or the outer diameter of the odd-shaped segment 10d is changed from L0 to L0. When reducing to L1, there is a limit to the reduction rate, and due to the interference between the outer peripheral surface of the deformed segment 10d and the inner surface of the rear shield 6, there is a limit to the curvature of the curved tunnel that can be constructed.

Therefore, the outer diameter H4 of the deformed segment 10d in the vertical direction (the direction perpendicular to the bending direction) is set to H4 = L0 in order to maintain the proper clearance D4 when the outer diameter L0 of the straight-line tunnel circular segment 10 is maintained. . Further, the right side (OUT side) and the left side (IN side) of the deformed segment 10d in the horizontal direction are arcuate portions having a radius R4, and the outermost length of the deformed segment 10d in the vertical direction (direction perpendicular to the bending direction) is H4.
A deformed segment 10d in which arcuate portions on the right side (OUT side) and the left side (IN side) in the lateral direction of the deformed segment 10d are smoothly joined so that (= L0) is used.
If this deformed segment 10d is used, an appropriate seal tightening margin can be obtained over the entire outer circumference of the deformed segment 10d during curved construction.
The sealing performance between the outer diameter of the rear shield and the inner diameter of the rear shield 6 is improved. Further, the curvature of the curved tunnel can be reduced as compared with the conventional reduced circular segment 10 and the amount of over-digging due to the copy cutter can be reduced as compared with the conventional reduced circular segment 10 as in the first embodiment.
Other than that, the description is omitted because it is the same as the second embodiment. In the above, in the first to fourth embodiments, the construction of the curved tunnel that bends in the left-right direction has been described, but the construction of the curved tunnel that bends in the up-down direction is exactly the same, and therefore description thereof will be omitted.

In addition, regarding the outer shapes of the segments 10e and 10f, when constructing a curved tunnel in the left-right direction, as shown in FIG. 5A, the upper portion has a radius R5a and the lower portion has a radius R5a, and they are joined by a straight line. When flattening the left-right direction with a simple shape or when constructing a curved tunnel in the up-down direction, as shown in FIG. 5B, the left side (IN side) in the left-right direction is the radius R5b and the right side (OUT side). ) Is a radius R5c, and the top and bottom can be flattened with a shape that smoothly joins between them. 5A shows an embodiment in which the horizontal direction is flattened, and FIG. 5B is an embodiment in which the vertical direction is flattened. However, by rotating each of them by 90 degrees, FIG. 5A shows the vertical direction. 5B can also be applied to the construction of the curved tunnel of FIG. 5B.

[0031]

As described in detail above, according to the configuration of the present invention, the following effects can be obtained. (1) The outer shape of the segment cross section orthogonal to the tunnel construction planning line is an elliptical cross section, or a part opposite to the center of curvature is a semicircle, and the part on the side of the center of curvature is formed by a smoothly continuous curve to this semicircle. By forming a flat shape or a flat shape that smoothly connects two arcs so as to secure an appropriate seal clearance between the rear shield inner diameter surface and the segment outer peripheral surface, the rear shield inner diameter can be simplified. While ensuring good sealing performance over the entire circumference of the surface,
The durability of the seal can also be improved. Also, when installing multiple seals on the rear shield, if the seal clearance is set to an appropriate value at approximately the middle position between the frontmost seal and the rearmost seal, the sealability of all seals will be improved. And durability can be guaranteed on average. (2) Since the outer shape of the segment cross section orthogonal to the tunnel construction planning line is formed so as to secure an appropriate seal clearance between the rear shield inner diameter surface and the segment outer peripheral surface,
The curvature of the curve tunnel that can be constructed can be made smaller than that of the conventional reduced circular segment. Further, if the curvatures of the curved tunnels are the same, the amount of overburden can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a segment for curved tunnel construction according to the present invention, which is applied to a single-stage middle-break shield machine, in which (A) is a longitudinal sectional view and (B) is a lateral sectional view. .

2A and 2B are views showing a second embodiment of a segment for curved tunnel construction according to the present invention, which is applied to a two-stage middle-break shield machine, in which (A) is a longitudinal sectional view and (B) is a lateral sectional view. is there.

FIG. 3 is a view showing a third embodiment of a curved tunnel construction segment according to the present invention, which is applied to a two-stage middle-break shield machine, in which (A) is a longitudinal sectional view and (B) is a transverse sectional view. is there.

FIG. 4 is a transverse cross-sectional view showing a fourth embodiment of a bending tunnel construction segment according to the present invention.

FIG. 5 is a cross-sectional view showing another embodiment of the curved tunnel construction segment according to the present invention, in which (A) is a horizontal sectional view of the curved tunnel construction segment which is flat in the left-right direction;
[Fig. 3] is a cross-sectional view of a curved tunnel construction segment that is flat in the vertical direction.

6A and 6B are diagrams showing the principle for determining the outer shape of a curved tunnel construction segment according to the present invention, in which FIG. 6A is a vertical cross-sectional view during straight-line construction, and FIG. 6B is a vertical cross-sectional view during curved construction. is there.

7 is a diagram showing a cross-sectional view in FIG. 6, in which (A) is a view on arrow P in FIG. 6 (B), and (B) is a view on arrow Q in FIG. 6 (B).

FIG. 8 is a diagram showing a conventional technique.

[Explanation of symbols]

1 ... Middle break shield machine, 2 ... Front shield,
3 ... Cutter head, 4 ... Curved tunnel,
5 ... Copy cutter, 6 ... Rear shield,
6a ・ ・ Bracket, 7,17 ・ ・ Spherical bearing,
7b, 17a ... Convex spherical bearings, 7a, 17b ...
Concave spherical bearing, 8 ... Shield jack, 8a
・ Piston rod, 9 ・ ・ Spreader, 10 ・
・ Circular segment 10a ...
10b ... Elliptical segment, 10c, 10d, 10
e, 10f ... Deformed segment, 11 ... Wire brush, 11a ... Single-stage wire brush, 11b.
・ Two-step wire brush, 12 ・ ・ Front shield, 13 ・
-Cutter head support device.

Claims (7)

[Claims] 1. A lining of a tunnel excavated by a shield machine, and a segment which receives a reaction force of the shield machine, is installed in the inner diameter portion of the shield after the shield machine when a curved tunnel is constructed. In order to ensure a proper tightening margin of the seal that seals between the inner diameter of the rear shield and the outer peripheral surface of the segment, the outer shape of the rear shield is formed to ensure an appropriate seal clearance between the inner peripheral surface of the segment and the outer peripheral surface of the segment. A curved tunnel construction segment. 2. The curved tunnel construction segment according to claim 1, wherein the outer shape of the segment cross section orthogonal to the tunnel construction plan line has a minor axis in the direction in which the shield machine bends, and is perpendicular to the direction in which it bends. A segment for curved tunnel construction characterized by having an elliptical shape with a long axis in the. 3. The curved tunnel construction segment according to claim 1, wherein the outer shape of the segment cross section orthogonal to the tunnel construction planning line is a semi-circle on the side opposite to the curvature center of the curved tunnel, and the curvature center of the curved tunnel. The side part is formed by a smoothly continuous curve or arc in this semicircle,
A segment for curved tunnel construction characterized by having a flat shape such that the maximum length in the bending direction of the shield machine is shorter than the maximum length in the direction perpendicular to the bending direction. 4. The curved tunnel construction segment according to claim 1, wherein the outer shape of the segment cross section orthogonal to the tunnel construction planning line is a curve on the side opposite to the curvature center of the curved tunnel, or the curvature center side of the curved tunnel. Is a circular arc whose center is on the other hand, and the part on the side of the center of curvature of the curved tunnel is a curve, or an arc whose center is on the side opposite to the center of curvature of the curved tunnel, and a curve or circular arc that smoothly connects those curves or arcs. A segment for curved tunnel construction, which is formed and has a flat shape in which the maximum length in the bending direction of the shield machine is shorter than the maximum length in the direction perpendicular to the bending direction. 5. The curved tunnel construction segment according to any one of claims 1 to 4, wherein the outer shape of the segment cross section orthogonal to the tunnel construction plan line is the inner surface of the rear shield and the outer circumferential surface of the segment. A curved tunnel construction segment that has the same clearance as straight line construction. 6. The curved tunnel construction segment according to any one of claims 1 to 4, wherein a gap between a segment outer peripheral surface on a curvature center side of the curved tunnel and a rear shield inner surface, and a curved tunnel Considering the gap between the segment outer peripheral surface on the side opposite to the center of curvature and the rear shield inner surface, considering the interference between the front segment outer peripheral surface and the rear shield inner surface, and the interference between the rear shield inner surface rear end and the segment outer surface, A segment for curved tunnel construction characterized by being set in consideration of an appropriate tightening margin of the seal attached to the rear shield. 7. In the curved tunnel construction segment according to at least any one of claims 2 to 4, the clearance of claim 5 and claim 6 is provided between the seal at the frontmost end and the seal at the rearmost end. A segment for curved tunnel construction characterized by having an appropriate clearance at approximately the middle position.