JP2006291457A - Flexible joint mounting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure for easily mounting a flexible joint between a tip part of a shielded tunnel and a peripheral edge part of a pit mouth of an arrival shaft by easy work, without putting the periphery of the pit mouth in an unstable state. <P>SOLUTION: This flexible joint 10 mounting structure is arranged in an annular ring shape by interposing between the tip part 15a of the shielded tunnel 15 joined to the arrival shaft 12 and the peripheral edge part 13a of the pit mouth 13 of the arrival shaft 12, and absorbs relative positional dislocation between the tip part 15a of the tunnel 15 and the pit mouth 13. The flexible joint 10 is composed of a segment side fixing part 16 fixed to the tip part 15a of the tunnel 15, a pit mouth side fixing part 17 fixed to the peripheral edge 13a of the pit mouth 13, and a flexibly deformable part 18 arranged between the segment side fixing part 16 and the pit mouth side fixing part 17. The segment side fixing part 16 is fixed to a cutting end surface 19 of cutting a segment 14a on the tip of the tunnel 15 in a design fixing position of the segment side fixing part 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flexible joint mounting structure, and in particular, is disposed in an annular shape between a tip portion of a shield tunnel joined to a reaching shaft and a peripheral portion of a well shaft of the reaching shaft, The present invention relates to a flexible joint mounting structure for installing a flexible joint that absorbs a relative positional shift between a tip portion and a wellhead.

The shield tunnel construction method is arranged continuously between the starting shaft and the reaching shaft by performing the excavation work with the shield machine while obtaining the reaction force from the segments that are sequentially installed from the starting shaft to the reaching shaft. This is a method of forming a tunnel with many segments. In the shield tunnel method, a water stop mechanism is used to seal the gap between the wellhead formed in the start shaft and the reaching shaft and the outer peripheral surface of the tip of the shield tunnel, such as unequal subsidence and earthquakes. A flexible joint is provided to absorb the relative displacement between the tip of the shield tunnel, which is the joint to the start shaft and the final shaft, and the wellhead. (See, for example, Patent Document 1).
JP-A-11-324564

  A flexible joint for absorbing the relative displacement between the tip of the shield tunnel and the wellhead is generally fixed to the segment side fixing part fixed to the tip of the shield tunnel and the peripheral part of the wellhead. And a flexible deformation part arranged between the segment side fixing part and the well side fixing part, and in the tunnel axial direction from the well side fixing part to the segment side fixing part. It is designed and manufactured so that the dimension is a predetermined dimension. In the start shaft, the flexible joint adjusts the position of the first segment arranged at the rearmost end with respect to the wellhead, thereby changing the distance between the rear end of the shield tunnel and the wellhead. Therefore, it is possible to easily perform the operation of fixing the flexible joint between the rear end of the shield tunnel and the entrance of the start shaft.

  On the other hand, since it is difficult to adjust the position of the segment at the tip joined to the wellhead in the reaching shaft, the flexible joint is fixed between the tip of the shield tunnel and the wellhead of the reaching shaft. It takes a lot of time and effort. That is, the segment is generally allowed to have a manufacturing error of about 1 mm per ring and the thickness of the sealing material inserted between the segments is not constant. The position of the tip of the shaft of the reaching shaft is shifted mainly to the tip side from the design position. Therefore, it is possible to position and fix the flexible joint with the dimension in the tunnel axis direction between the tip of the segment displaced from the design position to the tip side and the peripheral edge of the wellhead as it is. become unable.

  For this reason, according to the prior art, after removing and removing the tip segment displaced to the tip side, cast the cast-in-place concrete so that the tip of the shield tunnel matches the fixing position of the segment side fixing portion. The method was adopted. In such a method, when the segment at the tip is removed, the backing material on the back side of the segment that also has a water stop function and a soil retaining function is in an open state. A lot of time and labor is required for the work of assembling and placing the cast concrete. Moreover, when the adjustment length by the cast-in-place concrete is 20 cm or less, for example, it is difficult to place the concrete, so it is necessary to remove another segment for the ring, and the surroundings of the wellhead are further unstable. At the same time, more time and labor will be required to construct the cast-in-place concrete.

  In addition, a method can be considered in which the tip segment joined to the wellhead of the reaching shaft is an adjustment segment formed by adjusting the length, and the tip of this adjustment segment is aligned with the fixed position of the segment side fixing part. It takes a lot of time and money to produce the segment, and the exact adjustment length by the adjustment segment is not known until the shield machine approaches the shaft, so the construction may be stopped for a long time .

  The present invention has been made paying attention to such a conventional problem, and can be performed by simple work without making the surroundings of the wellhead unstable and without requiring much time and labor. It is an object of the present invention to provide a flexible joint mounting structure that enables a flexible joint to be easily installed between the tip of a shield tunnel and the peripheral edge of a wellhead.

  The present invention is arranged in an annular shape interposed between the tip of the shield tunnel joined to the reach shaft and the peripheral edge of the entrance of the reach shaft, and the relative position between the tip of the shield tunnel and the well entrance A flexible joint mounting structure for installing a flexible joint that absorbs a misalignment, wherein the flexible joint includes a segment side fixing portion that is fixed to a tip portion of the shield tunnel; It consists of a wellhead side fixing part fixed to the peripheral part of the wellhead, and a flexible deformation part arranged between the segment side fixing part and the wellhead side fixing part, and the segment side fixing part is The above object is achieved by providing a flexible joint mounting structure in which a segment at the tip of a shield tunnel is fixed to a cut end surface cut at a fixing position of the segment side fixing portion. Than it is.

  According to the flexible joint attachment structure of the present invention, it is preferable that a wellhead ring is attached to a peripheral portion of the wellhead, and the wellhead-side fixing portion is fixed to the wellhead ring.

  Further, according to the flexible joint mounting structure of the present invention, the cut end surface is preferably a cut surface by a wall saw machine using a blade.

  Furthermore, according to the flexible joint attachment structure of the present invention, it is preferable that a hole-in anchor is attached to the cut end surface, and the segment side fixing portion is fixed to the cut end surface via the hole-in anchor.

  According to the flexible joint mounting structure of the present invention, the flexible joint can be connected to the shield tunnel by a simple operation without making the periphery of the wellhead unstable and without requiring much time and labor. It can install easily between the front-end | tip part of this and the peripheral part of the wellhead of a reaching shaft.

  The flexible joint mounting structure according to a preferred embodiment of the present invention is formed in the shield tunnel construction method, as shown in FIGS. 1 (a) and 1 (b), in which an opening is formed in the reaching shaft 12 to which the shield machine 11 reaches. When the tip 15a of the shield tunnel 15 formed by connecting the segment 14 to the formed wellhead 13 is joined, the tip 15a of the shield tunnel 15 and the peripheral portion 13a of the wellhead 13 of the reaching shaft 12 are connected. Is used when the flexible joint 10 is installed.

  Here, the flexible joint 10 has a relative displacement with respect to the wellhead 13 due to, for example, an earthquake or unequal settlement caused by the tip 15a of the shield tunnel 15 formed by the segment 14 arranged in a cylindrical ring shape. Even if it occurs, it is an annular joint member for joining the tip 15a of the shield tunnel 15 to the wellhead 13 in a state where such relative displacement can be absorbed. The flexible joint 10 has been developed to have various structures suitable for the diameter, construction method, geology, etc. of the shield tunnel 15, but as shown in FIG. The segment side fixing portion 16 fixed to the tip portion 15 a of the tunnel 15, the wellhead side fixing portion 17 fixed to the peripheral edge portion 13 a of the wellhead 13, and the segment side fixing portion 16 and the wellhead side fixing portion 17 are arranged. The flexible deformation portion 18 is deformed, and the deformation of the flexible deformation portion 18 allows the relative displacement of the distal end portion 15a of the shield tunnel 15 to the wellhead 13 to be absorbed.

  And the attachment structure of the flexible joint of this embodiment has the front-end | tip part 15a of the shield tunnel 15 joined to the arrival shaft 12, and the wellhead of the arrival shaft 12 as shown to FIG. 3 (a), (b). An attachment structure for installing a flexible joint 10 that is arranged in an annular shape so as to be interposed between the peripheral edge portion 13a of 13 and absorbs a relative positional shift between the tip portion 15a of the shield tunnel 15 and the wellhead 13. The flexible joint 10 includes a segment side fixing portion 16 fixed to the tip portion 15a of the shield tunnel 15, a wellhead side fixing portion 17 fixed to the peripheral portion 13a of the wellhead 13, and a segment side fixing portion. 16 and a flexible deformation portion 18 disposed between the well-portion-side fixing portion 17, and the segment-side fixing portion 16 segments the segment 14 a at the tip of the shield tunnel 15. It is adapted to be secured to the cutting end face 19 cut at a fixed position of the fixed portion 16.

  Further, according to the present embodiment, the wellhead ring 20 is attached to the peripheral edge portion 13 a of the wellhead 13, and the wellhead side fixing portion 17 of the flexible joint 10 is fixed to the wellhead ring 20. .

  According to the present embodiment, the reach shaft 12 is protected to a predetermined depth at which the shield tunnel 15 is to be constructed, with the periphery protected by the continuous wall 21 as a retaining wall made of a solidified material mixed with, for example, a cement-based solidified material. It is a vertical hole formed by excavation. Prior to arrival of the shield machine 11, a circular wellhead 13 having an inner diameter substantially equal to the outer diameter of the shield machine 11 is formed in the reach side of the continuous wall 21 before the shield machine 11 arrives. . Further, the wellhead ring 20 is fixed to the peripheral edge portion 13a of the wellhead 13 on the inner side surface of the continuous wall 21 by a fixing bolt or the like via a hole-in anchor 33 or the like, for example. The shield machine 11 moves forward so as to pass through the wellhead 13 and the wellhead ring 20, and the shield machine 11 reaches the reaching shaft 12 (see FIG. 1A).

  As shown in FIG. 2, the wellhead ring 20 is a known one that is attached to protect the peripheral portion 13 a of the wellhead 13 and to install a water stop structure for stopping the wellhead 13. The circular ring-shaped wellhead fixing plate 20a and the circular ring-shaped joint fixing plate 20b are connected together by a circular sleeve-shaped connection plate 20c so as to have a substantially U-shaped cross-sectional shape. By fixing the wellhead fixing plate 20a in close contact with the peripheral edge portion 13a of the wellhead 13, the wellhead ring 20 is firmly attached to the peripheral edge portion 13a of the wellhead 13, and the joint fixing plate 20b has the flexible joint 10 attached thereto. The wellhead side fixing part 17 is fixed as a unit by a fixing bolt or the like.

  Further, on the inner side surface of the connection plate 20 c of the wellhead ring 20, a waterstop member 22 including, for example, a waterstop seal 22 a and a waterstop tube 22 b is provided so as to be supported by the mounting rib 20 d and penetrates the wellhead 13. The gap between the outer peripheral surface of the shield machine 11 to be shielded and the segment 14a at the tip installed subsequently and the inner peripheral surface of the wellhead 13 is sealed by the water stop member 22, and the flexible joint 10 Until it is attached, the junction between the reaching shaft 12 and the shield tunnel 15 can be effectively stopped (see FIGS. 1 (a) and 3 (a)).

  The seal excavator 11 is a known shield excavator such as an earth pressure type, and includes a rotary cutter 11a at the tip and an outer body 11b behind the rotary cutter 11a. The shield machine 11 advances toward the reaching shaft 12 while obtaining the excavation reaction force from the segment 14 assembled in a ring shape inside the outer body 11b (see FIG. 1 (a)), and reaches through the wellhead 13. At the rear of the shield machine 11 leading to the vertical shaft 12, a segment 14a at the tip which is located inside the wellhead 13 and the wellhead ring 20 and constitutes the tip portion 15a of the shield tunnel 15 is left (see FIG. 1 (b)). In this embodiment, the flexible joint 10 is attached by being fixed to the cut end surface 19 of the segment 14a at the tip and the joint fixing plate 20b of the wellhead ring 20.

  As shown in FIG. 2, the flexible joint 10 includes a segment side fixing portion 16, a wellhead side fixing portion 17, and a flexible deformation portion 18. The segment-side fixing portion 16 is a circular ring-shaped plate member having a shape that follows the shape of the end surface (transverse section) of the segment 14a, and a plurality of bolts are fixed to the central portion in the radial direction at intervals in the circumferential direction. A hole 16a is provided. Further, a segment-side annular support rib 16b that protrudes perpendicularly from the radially outer portion of the segment-side fixing portion 16 toward the wellhead-side fixing portion 17 and supports the flexible deformation portion 18 is provided.

  The wellhead-side fixing portion 17 is a circular ring-shaped plate member having a width wider than the segment-side fixing portion 16 and having a width straddling the tunnel axial direction extension region of the end surface of the segment 14a and the joint fixing plate 20b of the wellhead ring 20. It is arranged in parallel with the segment side fixing part 16. Moreover, the wellhead side fixing | fixed part 17 is provided with the several bolt fixing hole 17a in the radial direction outer side part at intervals in the circumferential direction. Further, at the position facing the segment-side annular support rib 16b, a well-end ring-side annular support rib 17b that protrudes perpendicularly to the segment-side fixing portion 16 side and supports the flexible deformation portion 18 is provided.

  The flexible deformation portion 18 disposed between the well-end-side fixing portion 17 and the segment-side fixing portion 16 is formed of a rubber member such as a rubber seal as a flexible member and has a semicircular cross section. It consists of a flexible main body portion 18a and a presser flange portion 18b provided so as to protrude from both sides of the flexible main body portion 18a. The flexible deformation portion 18 clamps and fixes the holding flange portions 18b on both sides to the segment side annular support rib 16b and the wellhead ring side annular support rib 17b, respectively, via a pressing plate 23 that is pressed by a fastening bolt or the like. It is attached by. Accordingly, the flexible main body 18a can be easily flexibly deformed following the relative displacement between the segment side annular support rib 16b and the wellhead ring side annular support rib 17b. Further, a cover plate 24 is attached to the outer side in the radial direction of the flexible main body 18a, and a protective plate 25 is attached to the inner side in the radial direction so as to extend in the circumferential direction so as to cover the flexible main body 18a from both sides. Thus, the flexible deformation portion 18 is effectively protected.

  And the flexible joint 10 provided with the above-mentioned structure is made to correspond to the design position of the joint fixing plate 20b of the wellhead ring 20 and the design position of the front end surface of the segment 14a of the front end joined to the wellhead 13. The dimension L in the axial direction of the tunnel 15 between the wellhead side fixing portion 17 and the segment side fixing portion 16 is determined, and is preferably designed and manufactured in a factory or the like. Therefore, at the construction site in the reach shaft 12, as shown in FIG. 3A, the manufacturing error of the segment 14 in which a large number of distal end surfaces 26a of the distal segment 14a serving as the distal end surface of the shield tunnel 15 are arranged continuously. In addition, under the influence of the sealing material inserted between the adjacent segments 14, for example, in a state where the position is shifted to the tip side from the design fixing position 26, the wellhead side fixing portion 17 is attached to the joint fixing plate 20 b of the wellhead ring 20. The segment-side fixing portions 16 cannot be fixed to the distal end surface 26a of the distal segment 14a.

  Therefore, in this embodiment, the segment 14a at the tip of the shield tunnel 15 that is displaced toward the tip side is cut at a predetermined position, and the tunnel 15 is removed from the joint fixing plate 20b of the wellhead ring 20 attached to the peripheral edge portion 13a of the wellhead 13. A cut end face 19 is formed at the design fixing position of the segment side fixing portion 16 which is separated by a dimension L in the axial direction, and the segment side fixing of the flexible joint 10 is performed on the cut end face 19 as shown in FIG. The part 16 is fixed.

  Here, in FIG. 3A, the segment installed further on the tip side of the tip segment 14 a constituting the tip portion 15 a of the shield tunnel 15 is, for example, the shield machine 11 to remove the shield machine 11. Is a temporary assembly segment 27 that is used when pushing out to the inside of the reaching shaft 12, and this temporary assembly segment 27 is removed without constituting the shield tunnel 15 after the shield machine 11 is removed. . Further, after the outer body 11b of the shield machine 11 has passed, the gap between the segments 14 and 14a behind the water blocking member 22 and the natural ground or the continuous wall 21 is, for example, from bentonite mortar according to a conventional method. The backing material 30 is filled and solidified.

  According to the present embodiment, the work for cutting the segment 14a at the distal end displaced at the distal end side at the fixing position of the segment side fixing portion 16 is performed using a wall saw machine 28 as shown in FIG. 4A, for example. It can be easily performed by the wall saw method. The wall saw machine 28 is known as an apparatus capable of cutting a box culvert from the inside, for example, and can move up and down while rotating a blade 28b along a pair of hydraulic support rods 28a. Yes. Further, as shown in FIG. 4B, the wall saw machine 28 has a wall saw rail 29 attached in a string shape to the inner side surface of the segment 14a using a cut anchor 29a, a box-type spacer metal fitting 29b, a washer 29c, and the like. It can be slid and moved in the circumferential direction.

  Then, for example, in order to clearly indicate the fixing position of the segment side fixing portion 16, inking is performed in the circumferential direction on the inner peripheral surface of the segment 14a at the tip, and a cut anchor 29a is driven along the inking line. The wall saw rail 29 is fixed to the cut anchor 29a. Thereafter, a wall saw machine 28 is attached to the wall saw rail 29, the blade 28b is rotated along the hydraulic support rod 28a while the blade 28b is rotated, and the segment 14a is cut out along the hydraulic support rod 28a. By slidably moving the wall saw machine 28 along the circumferential direction 29, the segment 14 a is cut in the region where the wall saw rail 29 is attached. In addition, by repeating the operation from the placement of the cut anchor 29a to the cutting of the segment 14a by the blade 28b a plurality of times over the entire circumference as shown in FIG. The cutting end surface 19 cut along the fixing position of the segment side fixing portion 16 of the flexible joint 10 is easily and smoothly formed at the tip of the segment 14a at the tip.

  When the cut end face 19 is formed at the tip of the tip segment 14a, the water stop member 22 including the water stop seal 22a and the water stop tube 22b is removed as shown in FIG. In addition, a plurality of hole-in anchors 31 are punched at intervals in the circumferential direction at positions corresponding to the bolt fixing holes 16a formed in the segment side fixing portion 16 of the flexible joint 10 along the central portion of the cut end surface 19. Install and install. Thereafter, the bolt fixing hole 16a is aligned with the hole-in anchor 31, the segment-side fixing portion 16 of the flexible joint 10 is brought into close contact with the cut end surface 19 of the distal segment 14a, and fixed with a fixing bolt or the like. Further, the bolt fixing holes 17a of the wellhead side fixing portion 17 are brought into close contact with the bolt fixing holes of the joint fixing plate 20b of the wellhead ring 20, and are fixed by fixing bolts or the like. Furthermore, in the space | gap part of the front end side rather than the backing material 30 after removing the water stop member 22 surrounded by the attached flexible joint 10 and the wellhead ring 20, the expansible material which consists of foaming urethane etc., for example 32, the flexible joint mounting structure of this embodiment is provided.

  And according to the attachment structure of the flexible joint of this embodiment, without making the circumference | surroundings of the wellhead 13 an unstable state, and not requiring much time and labor, it is flexible by simple operation | work. The joint 10 can be easily installed between the front end portion 15 a of the shield tunnel 15 and the peripheral portion 13 a of the wellhead 13 of the reaching vertical shaft 12. That is, according to the present embodiment, it is not necessary to remove the tip segment 14a that is displaced to the tip side and to open the backing material 30 on the back side of the segment 14a. The function is not adversely affected, and it is possible to easily avoid the surrounding ground from becoming unstable. Further, for example, the cut end face 19 can be easily, accurately and quickly formed at the fixed position of the segment side fixing portion 16 using the above-described wall saw machine 28. It is possible to smoothly attach the flexible joint 10 without requiring installation work or production of an adjustment segment.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, it is not always necessary to attach a wellhead ring to the peripheral portion of the wellhead of the reaching shaft and fix the wellhead-side fixing portion of the flexible joint to the wellhead ring. For example, as shown in FIG. Without this, the wellhead side fixing portion 17 of the flexible joint 10 can be directly fixed to the peripheral edge portion 13a of the wellhead 13. Further, the cutting of the tip segment is not necessarily performed by a wall saw machine, and the segment side fixing portion is not necessarily fixed to the cutting end surface of the tip segment via the hole-in anchor.

(A) is a schematic cross-sectional view for explaining a situation in which a shield machine is made to reach a reaching shaft, and (b) is a diagram in which the tip of the shield tunnel is joined to the reaching shaft through the flexible joint mounting structure of the present invention. It is a schematic sectional drawing explaining a state. It is a principal part expanded sectional view explaining the structure of the attachment structure of the flexible joint which concerns on preferable one Embodiment of this invention. (A) And (b) is principal part sectional drawing explaining the construction condition of the attachment structure of the flexible joint which concerns on preferable one Embodiment of this invention. (A) is explanatory drawing of the wall saw machine which cut | disconnects the segment of a front-end | tip, (b) is explanatory drawing of the wall rail which slide-moves a wall saw machine. It is explanatory drawing of the construction condition at the time of cutting a segment with a wall saw machine, setting up in the circumferential direction. It is a schematic sectional drawing which illustrates other embodiment of the attachment structure of the flexible joint which fixed the wellhead side fixing | fixed part of the flexible joint directly to the peripheral part of the wellhead.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flexible joint 11 Shield machine 12 Reaching shaft 13 Wellhead 13a Peripheral edge part 14 Segment 14a Tip segment 15 Shield tunnel 15a Shield tunnel tip 16 Segment side fixing part 17 Wellhead side fixing part 18 Flexible deformation part 19 Cutting end face 20 Wellhead ring 22 Water stop member 26 Design fixing position 28 of segment side fixing part Wall saw machine 28b Blade 29 Wall saw rail 30 Backing material 31, 33 Hole-in anchor 32 Expansive material L Wellhead side fixing part and segment side Axial dimension of tunnel with fixed part

Claims (4)

A relative position shift between the tip of the shield tunnel and the wellhead is disposed between the tip of the shield tunnel joined to the reach and the peripheral edge of the wellhead of the reach shaft. A flexible joint mounting structure for installing a flexible joint that absorbs
The flexible joint includes a segment side fixing portion fixed to a tip portion of the shield tunnel, a wellhead side fixing portion fixed to a peripheral portion of the wellhead, the segment side fixing portion, and the wellhead side fixing portion. And a flexible deformation portion disposed between
The segment side fixing portion is a flexible joint mounting structure in which a segment at the tip of the shield tunnel is fixed to a cut end surface cut at a fixing position of the segment side fixing portion.   The flexible joint mounting structure according to claim 1, wherein a wellhead ring is attached to a peripheral portion of the wellhead, and the wellhead-side fixing portion is fixed to the wellhead ring.   The flexible joint mounting structure according to claim 1, wherein the cut end surface is a cut surface by a wall saw machine using a blade. The flexible joint mounting structure according to any one of claims 1 to 3, wherein a hole-in anchor is attached to the cut end face, and a segment side fixing portion is fixed to the cut end face via the hole in anchor.

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