JP2007270473A - Composite segment and composite segment joint structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite segment which ensures high rigidity even if the thickness thereof is thinned and the width thereof is extended. <P>SOLUTION: The arcuate composite segments 1 are connected to one another in plurality via joints in a tunnel circumferential direction and a tunnel axial direction along the inner surface of an excavated pit, to constitute a tunnel. Each synthetic segment 1 has at least two arcuate structural members 6, 6 embedded therein in a manner extending in the tunnel circumferential direction in parallel with each other, and a steel member 4 embedded therein in a manner extending in the tunnel axial direction. Herein a tensile force is introduced into the steel member 4, and both ends of the steel member 4 are fixed to the structural members 6, 6 by anchorage devices 5, 5, respectively, whereby prestress in the tunnel axial direction is applied to the composite segment. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a composite structure that forms a tunnel and a joint structure that joins adjacent composite segments in the tunnel axial direction.

  In recent years, there is an increasing demand for a thinner segment that reduces the thickness of the segment. When the segment is thinned, the diameter of the excavation pit excavated by the shield machine can be reduced, thereby reducing the size of the shield machine and reducing the amount of excavated soil, thereby reducing the cost.

  In recent years, there has been an increasing demand for widening the segment to increase the width of the segment (the dimension in the tunnel axis direction). If the segment is widened, the excavation distance per cycle becomes long, so that the tunnel excavation process can be shortened, and is particularly effective in the case of excavation in a long-distance tunnel.

On the other hand, as an inter-ring joint structure in a segment, a bolt-shaped male screw member provided at the joining end of one segment and a nut-like female screw member provided at the joining end of the other segment are screwed. There is a configuration in which a pair of segments adjacent to each other in the tunnel axis direction are joined together. The male screw member is attached to a fixing tool provided at the joining end of one segment, and the female screw member is attached to a fixing tool provided at the joining end of the other segment ( For example, see Patent Document 1.)
JP 2001-173385 A

However, when the segment is thinned, the segment tends to bend due to the earth pressure acting on the segment. In particular, in the case of a segment, it is necessary to consider bending in the tunnel circumferential direction, and it is necessary to maintain rigidity that allows bending in the tunnel circumferential direction.
Further, when the width of the segment is increased, bending tends to occur in the tunnel axis direction, and it is necessary to maintain an allowable rigidity in the tunnel axis direction.

  In addition, in the conventional inter-ring joint structure of the segment described above, it is necessary to screw the male screw member attached to one segment and the female screw member attached to the other segment. Has a problem that it takes a lot of work and the joint work is complicated.

The present invention has been made in consideration of the above-described conventional problems, and an object of the present invention is to provide a synthetic segment that can maintain high rigidity even if the synthetic segment is thinned and widened.
Another object of the present invention is to provide a joint structure of segments that can easily perform joints between rings of synthetic segments.

  The invention according to claim 1 is an arc-shaped composite segment that forms a tunnel by joining a plurality of joints in the tunnel circumferential direction and the tunnel axial direction along the inner surface of the excavation pit, and extends along the tunnel circumferential direction. At least two existing arc-shaped structural members are embedded in parallel, and a steel material extending along the tunnel axis direction is embedded, and a tensile force is introduced into the steel material, and the steel material Both ends are respectively fixed to the structural member by a fixing tool, so that prestress is applied in the tunnel axis direction.

  With such a configuration, the rigidity of the composite segment with respect to bending in the circumferential direction of the tunnel is improved by the rigidity of the structural member. Further, the steel material in which both ends are fixed to the structural member and the tensile force is introduced imparts prestress in the tunnel axis direction to the composite segment, and the rigidity of the composite segment with respect to bending in the tunnel axis direction is improved.

  Invention of Claim 2 is the joint structure of the composite segment which joins the composite segments described in Claim 1 in the tunnel axial direction, and is a composite of one of a pair of composite segments adjacent in the tunnel axial direction One fixing tool provided in the segment is provided with a male joint having a pin bolt, and the other fixing tool provided in the other synthetic segment has an insertion hole into which the pin bolt is inserted. A female joint having a wedge is provided, the pin bolt is inserted into the insertion hole, the pin bolt and the wedge are fitted and locked, and the pair of synthetic segments are jointed.

  With such a configuration, the wedge is gripped by the pin bolt inserted into the insertion hole, and the extraction of the pin bolt is restricted.

  According to the composite segment according to the present invention, the rigidity of the composite segment with respect to bending in the tunnel circumferential direction and the tunnel axial direction is improved, and high rigidity can be maintained even if the composite segment is thinned and widened.

  Further, according to the joint structure of the composite segment according to the present invention, the pin bolt provided in the fixing tool on the one composite segment side is only inserted into the insertion hole of the wedge provided in the fixing tool on the other composite segment side. Thus, the synthetic segments adjacent in the tunnel axis direction can be joined. Thus, since the inter-ring joint is a one-touch joint, the inter-ring joint can be easily operated.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a synthetic segment and a joint structure of synthetic segments according to the present invention will be described with reference to the drawings. In the following description, “front” and “front” are “front” and “front” in the direction of tunnel 2 tunneling, and are the left side in FIG. 1. Further, “rear” and “rear side” are “rear” and “rear side” in the tunnel 2 digging direction, and are the right side in FIG.

  FIG. 1 is a diagram showing a tunnel 2 composed of a plurality of segment pieces 1 (combined segments). As shown in FIG. 1, a tunnel 2 is constructed by assembling a plurality of curved plate-shaped segment pieces 1 into a cylindrical shape along the inner surface of an unillustrated excavation mine. At this time, the segment pieces 1 and 1 adjacent to each other in the circumferential direction of the tunnel 2 have inter-piece joint joints 1a and 1a (end faces of the segment piece 1 extending in the tunnel 2 axial direction) facing each other. It is connected by being joined via. Further, the segment pieces 1 and 1 adjacent to each other in the axial direction of the tunnel 2 have a plurality of opposing inter-ring joint surfaces 1b and 1b (end surfaces of the segment pieces 1 extending in the circumferential direction of the tunnel 2) (4 in FIG. 1). Are connected by being joined via an inter-ring joint 3... (Inter-ring joint structure).

  FIG. 2 is a diagram showing the segment piece 1. As shown in FIGS. 1 and 2, the segment piece 1 is a circular arc-shaped concrete member, and in its interior, two parallel steel frames 6 and 6 (structural members) such as H-shaped steel and A plurality of (four in FIG. 1) PC steel materials 4... (Steel materials) such as PC (prestressed concrete) steel wires and PC steel bars are embedded. The steel frames 6 and 6 are arc-shaped members extending along the circumferential direction of the tunnel 2, and are provided at both ends of the segment piece 1 on the side between the rings. The PC steel materials 4 are extended along the axial direction of the tunnel 2 and are installed between two parallel steel frames 6 and 6.

  Further, tensile forces are respectively introduced into the PC steel materials 4... And both ends of the PC steel materials 4... Penetrate through the steel frames 6 and 6 on both sides, and the steel frames are provided by the fixing tools 5 and 5. It is being fixed to the materials 6 and 6, respectively. Thereby, pre-stress in the tunnel biaxial direction is introduced to the segment piece 1, that is, the compressive force in the direction of the arrow shown in FIG. 2 (stress for canceling the tensile stress due to the external force) is applied in a planned manner. Yes. As a method of applying prestress to the segment piece 1, before placing the concrete of the segment piece 1, tension is applied to the PC steel material 4 placed in a mold (not shown) in advance, and tension is applied after the concrete is hardened. A pre-tensioning method is adopted in which pre-stress is introduced by loosening and the adhesion between the PC steel material 4 and the concrete of the segment piece 1.

FIG. 3 is an enlarged cross-sectional view of both end portions (front and rear end portions) of the segment piece 1 between the rings. As shown in FIG. 3, the PC steel material 4... Is a member in which at least both ends (the entire PC steel material 4 in FIG. 3) are formed in a male screw shape, and from one end between the rings of the segment piece 1. It extends to the other end part between the rings.
Moreover, the hole 6a for each inserting the edge part of several PC steel materials 4 ... is formed in the web of the steel frame materials 6 and 6 provided in the both ends of the ring piece side of the segment piece 1, respectively. Both ends of the PC steel material 4 are respectively penetrated into the steel frames 6 and 6.

  The fixing tool 5... Is a jig for fixing both ends of the PC steel material 4 to the steel frames 6, 6. Specifically, the fixing tool 5. It is comprised from the nut 8 arrange | positioned on the outer side, and the washer 9 interposed between the steel plate 7 and the nut 8. FIG. In the steel plate 7, a hole 7a corresponding to the hole 6a of the steel frame 6 is formed, and the end of the PC steel material 4 is inserted into the hole 7a. A nut 8 is screwed to the end of the PC steel material 4 protruding from the steel plate 7 via a washer 9. By tightening the nut 8, a tensile force is introduced into the PC steel material 4, and a reaction force is exerted on the steel plate 7. Prestress is given to the segment piece 1 by taking. In addition, the fixing tool 5 is formed with a tapered hole 1c constricted in a tapered shape on the end face between the rings of the segment piece 1 and the fixing tool 5 is provided in the circular hole 1c.

  As shown in FIGS. 1 and 2, a male joint 10 is provided on one fixing tool (rear fixing tool 5 a) provided at an end portion between the rings on one side (rear side) of the segment piece 1. A female joint 11 is provided on the other fixing tool (front fixing tool 5b) provided at the other ring front end of the segment piece 1 (front side).

As shown in FIG. 3, the male joint 10 includes a screwing portion 12 that is screwed into a tip portion of a male screw-like PC steel material 4 protruding from the nut 8 of the rear fixing tool 5 a, and a screwing portion 12. It is comprised from the pin volt | bolt 13 protrudingly provided by the front end surface (rear end surface).
The threaded portion 12 is a portion having a structure in which a female screw hole 12a opened on the base end side (front side) is formed and the distal end side (rear side) of the female screw hole 12a is closed. The pin bolt 13 is a cylindrical member extending in the axial direction of the tunnel 2, and the pin bolt 13 protrudes from the inter-ring joint surface 1 b of the segment piece 1. Further, on the outer peripheral surface of the pin bolt 13, a plurality of coaxial irregularities extending in the circumferential direction are formed continuously (saw-toothed) in the axial direction.

The female joint 11 includes a wedge 14, a holder 15 that holds the wedge 14, a urethane spring 16 that biases the wedge 14, and a case 17 that houses the urethane spring 16.
The wedge 14 is a hollow member having a tapered shape whose outer shape is narrowed to the front side, and an insertion hole 14a into which the pin bolt 13 is inserted. A plurality of coaxial irregularities extending in the circumferential direction are formed continuously (sawtooth) in the axial direction on the inner circumferential surface of the insertion hole 14a, and the coaxial irregularities formed on the inner circumferential surface of the insertion hole 14a. And the coaxial unevenness | corrugation formed in the outer peripheral surface of the pin bolt 13 has a shape which mutually meshes | engages.

  The holder 15 is a hollow member having a tapered shape whose inner peripheral shape is narrowed to the front side. In the tapered holder 15, a tapered wedge 14 is also inserted and stored. Yes. The wedge 14 is fitted to the holder 15 so as to be slidable in the axial direction. Further, the holder 15 and the wedge 14 (female joint 11) are arranged in the round hole 1c without protruding from the inter-ring joint surface 1b.

  The urethane spring 16 is a donut-shaped (annular) urethane member having a predetermined elasticity, and is in contact with the annular rear end surface (end-side end surface) of the wedge 14. The case 17 is a round plate-like member opened to the front side, the front end (the collar) of the case 17 is joined to the holder 15, and the rear end (bottom) of the case 17 is the front fixing tool 5b. It is joined to the nut 8. The case for storing the urethane spring may be integrally formed with the nut 8.

  FIG. 4 is a cutaway view showing the inter-ring joint 3 of the segment pieces 1, 1 ′ adjacent in the axial direction of the tunnel 2. As shown in FIG. 4, the inter-ring joint 3 includes the male joint 10 and the female joint 11 described above. That is, in the inter-ring joint 3, the pin bolt 13 of the male joint 10 provided on one newly installed segment piece 1 is inserted into the insertion hole 14 a of the female joint 11 of the other installed segment piece 1 ′. By inserting and locking the pin bolt 13 and the wedge 14 together, the segment pieces 1, 1 'adjacent in the axial direction of the tunnel 2 are joined together.

  Next, a method for jointing the segment pieces 1 and 1 ′ adjacent in the axial direction of the tunnel 2 will be described.

  As shown in FIG. 1, the segment piece 1 newly installed is arrange | positioned ahead of the segment piece 1 'installed previously. At this time, the newly installed segment piece 1 is arranged so as to be shifted by approximately half in the circumferential direction with respect to the previously installed segment piece 1 ′, and the joint piece 1... Has a zigzag joint. Arrange so that. In addition, the male joint 10 is attached to the rear fixing tool 5a of the newly installed segment piece 1, and the female joint 11 is attached to the front fixing tool 5b of the previously installed segment piece 1 '. deep.

  Then, as shown in FIG. 3, the newly installed segment piece 1 is moved rearward, and the inter-ring joining surface 1 b on the rear side of the newly installed segment piece 1 is changed to the previously installed segment piece 1 ′. By bringing the male joint 10 of the newly installed segment piece 1 into contact with the female joint 11 of the previously installed segment piece 1 ' The segment pieces 1, 1 'adjacent in the axial direction of the tunnel 2 are joined together. Specifically, after the pin bolt 13 of the male joint 10 is positioned in the insertion hole 14a of the female joint 11, the wedge 14 is inserted into the insertion hole 14a while being widened. At this time, as shown in FIG. 5A, the outer peripheral surface of the pin bolt 13 and the inner peripheral surface of the insertion hole 14a are hooked to each other by the coaxial irregularities, and are thus held by the holder 15 so as to be slidable in the axial direction. The wedge 14 is pressed against the urethane spring 16 by a force that is pushed rearward in the axial direction by the inserted pin bolt 13. When the wedge 14 is pressed against the urethane spring 16, as shown in FIG. 5B, the elastic reaction force of the urethane spring 16 causes a force that pushes the wedge 14 forward, and the wedge 14 is reduced in diameter. A force acts, the pin bolt 13 is gripped by the wedge 14, and the extraction of the pin bolt 13 is restricted. Further, when a pulling force is applied to the pin bolt 13, the inner peripheral surface of the insertion hole 14 a is caught by the outer peripheral surface of the pin bolt 13 due to the coaxial unevenness, and thus a force in the diameter reducing direction acts on the wedge 14. It is gripped more powerfully.

  According to the segment piece 1 having the above-described configuration, the rigidity of the segment piece 1 with respect to the bending in the circumferential direction of the tunnel 2 is improved by the rigidity of the steel frames 6 and 6, the tensile force is introduced, and both ends are The PC steel materials 4 fixed to the steel frames 6 and 6 respectively apply prestress to the segment piece 1 in the tunnel 2 axial direction, and the rigidity of the segment piece 1 against the bending of the tunnel 2 in the axial direction is improved. Thereby, even if the segment piece 1 is thinned and widened, high rigidity can be maintained.

  Further, according to the inter-ring joint 3 that joins the segment pieces 1 and 1 'adjacent to each other in the axial direction of the tunnel 2 described above, the pin bolt 13 provided on the rear side fixing tool 5a of the newly installed segment piece 1 is provided. The segment pieces 1, 1 ′ adjacent to each other in the axial direction of the tunnel 2 can be joined simply by being inserted into the insertion hole 14 a of the wedge 14 provided in the front fixing tool 5 b of the segment piece 1 ′ previously installed. Can do. Thus, since the inter-ring joint 3 becomes a one-touch joint, the work of the inter-ring joint 3 can be easily performed.

  Further, since the urethane spring 16 is interposed between the wedge 14 of the female joint 11 and the front fixing device 5b, the elastic reaction force of the urethane spring 16 causes a force in the direction of diameter reduction to act on the wedge 14, and the wedge. Since 14 pinches the pin bolt 13 strongly, the joint state of the segment pieces 1 and 1 ′ adjacent in the axial direction of the tunnel 2 can be reliably maintained.

  Further, when a shield machine (not shown) is dug with a jack (not shown), the reaction force of the jack (not shown) is taken at the inter-ring joint surface 1b on the front side of the segment piece 1, but the female joint 11 is indirectly connected to the ring. Since it does not protrude from the mating surface 1b, it does not obstruct the installation of a jack (not shown).

  As described above, the embodiments of the composite segment and the joint structure of the composite segment according to the present invention have been described. However, the present invention is not limited to the above-described embodiment and can be appropriately changed without departing from the scope of the present invention. is there. For example, in the above-described embodiment, pre-stress is applied to the segment piece 1 by applying tension to the PC steel material 4 arranged in advance in a mold (not shown) before placing the concrete of the segment piece 1. The segment piece of the pre-tension method to be applied is adopted, but the present invention embeds a sheath for inserting the PC steel material in the concrete of the segment piece, and inserts the PC steel material in the sheath after the concrete is hardened. It may be a post tension type segment piece that prestresses the segment piece by applying tension to the segment piece.

  Moreover, in above-mentioned embodiment, although the steel frame materials 6 and 6 which consist of H-section steel etc. are each embed | buried in the both ends of the ring piece side of the segment piece 1, this invention is structural members other than a steel frame. There may be. In the present invention, a structural member may also be provided in the central portion of the segment piece (synthetic segment), or three or more structural members may be embedded. Furthermore, in the present invention, structural members may be provided not only at both ends of the segment piece between the rings but also at both ends of the segment piece between the pieces.

In the above-described embodiment, the PC steel material 4 having both ends formed in a male screw shape is used. However, the present invention is a PC steel material having a structure in which male screw members are attached to both ends. May be.
In the above-described embodiment, the male joint 10 having the pin bolt 13 is provided at one end portion between the rings of the segment piece 1, and the pin bolt 13 is inserted into the other end portion between the rings. Although the female joint 11 having the wedge 14 is provided, the above-described male joint 10 and the female joint 11 do not have to be provided in the composite segment according to the present invention, and are joined by another joint structure. It may be a synthetic segment.
Further, in the above-described embodiment, the fixing device 5 using the nut 8 or the like is used. However, the present invention may be other fixing devices and does not depart from the gist of the present invention. In the range, the configuration in the above-described embodiment may be replaced with a known configuration.

It is the figure showing the tunnel which consists of a some synthetic segment for demonstrating embodiment of the synthetic | combination segment which concerns on this invention, and the joint structure of a synthetic segment. It is a figure showing the synthetic segment for demonstrating embodiment of the synthetic | combination segment which concerns on this invention, and the joint structure of a synthetic segment. It is a figure showing the ring segment side edge part of the synthetic segment for demonstrating embodiment of the synthetic | combination segment which concerns on this invention, and the joint structure of a synthetic segment. It is a figure showing the joint structure for demonstrating embodiment of the composite segment which concerns on this invention, and the joint structure of a composite segment. It is a figure showing the joint structure for demonstrating embodiment of the composite segment which concerns on this invention, and the joint structure of a composite segment.

Explanation of symbols

1, 1 'segment piece (synthetic segment)
2 Tunnel 3 Ring joint (joint structure)
4 PC steel (steel)
5, 5a, 5b Fixing tool 6 Steel frame (structural member)
10 Male Joint 11 Female Joint 13 Pin Bolt 14 Wedge 14a Insertion Hole

Claims (2)

A circular arc-shaped composite segment that is jointed together in the tunnel circumferential direction and the tunnel axial direction along the inner surface of the excavation pit to form the tunnel,
At least two arc-shaped structural members extending along the tunnel circumferential direction are embedded in parallel, and a steel material extending along the tunnel axis direction is embedded,
A composite segment, wherein a tensile force is introduced into the steel material, and both ends of the steel material are fixed to the structural member by a fixing tool, respectively, so that prestress is applied in the tunnel axis direction. . It is a joint structure of the composite segment which joins the composite segments described in claim 1 in the tunnel axial direction,
Of the pair of composite segments adjacent in the tunnel axis direction, one fixing tool provided in one composite segment is provided with a male joint having a pin bolt, and the other fixing tool provided in the other composite segment. Is provided with a female joint having a wedge formed with an insertion hole into which the pin bolt is inserted,
A joint structure of a composite segment, wherein the pin bolt is inserted into the insertion hole, the pin bolt and the wedge are fitted and locked, and the pair of composite segments are joined together.

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