PC steel wire insertion device for shield tunneling.

Abstract

The present invention provides a PC steel wire insertion device that allows for the efficient and labor-saving insertion of PC steel wires into sheath pipes continuously embedded in a segment ring. [Solution] The device is composed of a lower divided weight body 20 equipped with a single drive roller 25 and an upper divided weight body 30 equipped with two driven rollers 35, and has a considerable weight that allows it to obtain the reaction force when inserting the PC steel strand 4 through its own weight. The lower divided weight body 20 has a rectangular curved mounting bottom portion 21 that is curved with the same radius of curvature as the inner circumferential surface of the segment ring 1. With the PC steel strand 4 sandwiched between the single drive roller 25 and the two driven rollers 35, the drive roller 25 is rotated to feed the sandwiched PC steel strand 4 toward the sheath pipe 3 with its end opening facing the notch portion 53.

Description

Technical Field

[0002] ,

[0004] , , , , ,

[0003]

[0001] The present invention relates to a PC steel wire inserting device for a shield tunnel method, and particularly relates to a device used for inserting a PC steel wire into a sheath tube from a notch provided in a concrete segment ring in which the sheath tube has been embedded in advance, for example, a PC steel wire inserting device for an internal water pressure resistant shield tunnel method.

Background Art

[0002] As a shield tunnel method, for example, the internal water pressure resistant shield tunnel method is a method in which a pressure water that generates water pressure due to the head difference with the water level of the stored water stored in a shaft is filled into a shield tunnel communicating with a shaft used as a temporary water storage facility such as rainwater. By doing so, a circumferential prestress (pre-compressive force) is introduced in advance into the segment ring so that it can withstand the circumferential tensile load applied by the water pressure to the segment ring that constitutes the shield tunnel. In addition, the internal water pressure resistant shield tunnel method inserts PC steel wires into a sheath tube continuously embedded in the segment ring in the circumferential direction, and uses a known tensioning device such as a center hole jack, for example. In a state where prestress is applied to the inserted PC steel wires, preferably, both ends of the PC steel wires are fixed to a known fixing fitting such as an X anchor, so that a compressive force is introduced in advance in the circumferential direction of the segment ring to be able to withstand the circumferential tensile load due to the internal water pressure.

[0003] In such an internal water pressure resistant shield tunnel method, the operation of inserting PC steel wires into the sheath tube embedded in the segment ring has conventionally been performed manually by workers. However, when the weight of each PC steel wire becomes as large as, for example, about 10 kg, it requires a great deal of labor to insert the PC steel wires manually. Therefore, there has been a demand for the development of a device that can perform such an operation of inserting PC steel wires smoothly and efficiently with less labor. <00000​​On the other hand, various devices have been developed for inserting PC steel wires into sheath pipes pre-embedded in concrete structures, for example, when constructing prestressed concrete structures (see, for example, Patent Documents 1 and 2). The PC steel wire automatic feeding device described in Patent Document 1 is used when inserting PC steel wires into sheath pipes pre-embedded in precast concrete members in a construction method that connects and integrates multiple precast concrete members, such as precast floor slabs, in a continuous manner. The PC steel wire automatic feeding device of Patent Document 1 has a rubber drive roller and a guide roller positioned parallel to the drive roller. Clamping grooves are formed on the circumferential surfaces of the drive roller and the guide roller, facing each other, and the PC steel wires are clamped in these clamping grooves. The PC steel wires are fed out by rotating the guide roller while pressing it against the drive roller. In the process of connecting multiple precast concrete members together using PC steel strands, the PC steel strand automatic feeding device is positioned and fixed on the upper surface of a flat precast concrete member, preferably in such a position that the PC steel strands are fed in a straight line relative to the sheath pipe.

[0005] Furthermore, the PC steel wire insertion machine described in Patent Document 2 is used to insert PC steel wires vertically downward from above the concrete structure to apply prestress, for example, in concrete structures such as above-ground PC tanks for LNG. The PC steel wire insertion machine of Patent Document 2 has a pair of upper and lower feed rollers with concave curved surfaces formed around their entire circumference, and moves the PC steel wire by passing it between the two feed rollers and feeding it in one direction by rotation. The PC steel wire insertion machine of Patent Document 2 is also installed on a flat dedicated stand and includes a guide section that guides the direction of the PC steel wire, which is fed out horizontally from the feed rollers, for example, to vertically downward, and a pressure adjustment section that applies pressure to at least one of the upper and lower feed rollers so that they are close together. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 9-67933 Public Relations [Patent Document 2] Japanese Patent Publication No. 2011-89368 Public Relations [Overview of the project] [Problems that the invention aims to solve]

[0007] However, while the PC steel wire automatic feeding device described in Patent Document 1 and the PC steel wire insertion machine described in Patent Document 2 enable efficient feeding of PC steel wires, including PC steel wire strands, towards sheath pipes embedded in precast concrete members or concrete structures with minimal effort, when installed on the top surface of a flat precast concrete member or on a flat dedicated stand, these conventional PC steel wire insertion devices are difficult to use as they are, for example, in the internal water pressure-resistant shield tunneling method when inserting PC steel wires circumferentially into the sheath pipes of assembled segment rings, because the working space inside the shield tunnel is narrow and the arc-shaped inner surface of the segment ring needs to be used as a working platform. For these reasons, there is a need to develop a new insertion device that has been improved to be suitable for construction inside a shield tunnel, enabling efficient and smooth insertion of PC steel wires into sheath pipes continuously embedded circumferentially in segment rings with minimal effort.

[0008] The present invention aims to provide a PC steel wire insertion device for shield tunneling that enables the efficient and smooth insertion of PC steel wires into sheath pipes continuously embedded in the circumferential direction within a segment ring in a shield tunnel, with minimal effort. [Means for solving the problem]

[0009] The present invention relates to a shield tunneling method in which, after assembling a segment ring using concrete segments with pre-embedded sheath pipes, PC steel wires are inserted through notches provided in the assembled segment ring and tensioned and fixed to introduce prestress in the circumferential direction of the segment ring, and the present invention relates to a PC steel wire insertion device used when inserting the PC steel wires into the embedded sheath pipes, comprising a lower divided weight body equipped with one drive roller and an upper divided weight body equipped with two driven rollers, and having a considerable weight that, when placed on the segment ring, can obtain the reaction force when inserting the PC steel wires by its own weight, the lower divided weight body has a rectangular planar shape with a predetermined width and length, and has a curved mounting bottom portion that is curved in the longitudinal direction with a radius of curvature similar to that of the inner circumferential surface of the segment ring, and has a rotation axis parallel to the width direction of the curved mounting bottom portion. The above objective is achieved by providing a PC steel wire insertion device for internal water pressure-resistant shield tunneling, wherein a rotatable drive roller is mounted on the upper part, and two driven rollers, rotatable about an axis of rotation parallel to the rotation axis of the drive roller, are mounted on the lower part of the upper divided weight body so as to be positioned on both sides of the drive roller in the longitudinal direction of the curved mounting bottom surface, and the lower divided weight body and the upper divided weight body are connected by connecting pressing means so as to be stacked vertically, so that the PC steel wire can be extended in the longitudinal direction of the curved mounting bottom surface and clamped between the one drive roller and the two driven rollers while applying pressing force, and by rotating the drive roller with the PC steel wire clamped, the clamped PC steel wire is fed towards the sheath pipe with its end opening facing the notch.

[0010] Furthermore, it is preferable that the PC steel wire insertion device for shield tunneling according to the present invention has urethane rubber attached to the curved mounting bottom surface.

[0011] Furthermore, in the PC steel wire insertion device for shield tunnel construction according to the present invention, it is preferable that the drive roller is made of a metal roller member having a V-shaped cross-sectional groove formed on its outer circumference.

[0012] Furthermore, it is preferable that the PC steel wire insertion device for shield tunneling according to the present invention uses a urethane rubber roller member in which a clamping groove with an arc-shaped cross-section is formed on the outer circumference as the driven roller.

[0013] Furthermore, it is preferable that the PC steel wire insertion device for shield tunneling according to the present invention comprises a long bolt member and a nut member, which are stretched and fastened between a lower fastening flange having screw holes, which is provided extending laterally from both sides of the lower divided weight body in the PC steel wire feeding direction, and an upper fastening flange having through holes, which is provided extending laterally from both sides of the upper divided weight body in the PC steel wire feeding direction. [Effects of the Invention]

[0014] According to the PC steel wire insertion device for shield tunnel construction of the present invention, the work of inserting PC steel wires into sheath pipes continuously embedded in the circumferential direction of segment rings within a shield tunnel can be performed efficiently and smoothly with less effort. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic cross-sectional view illustrating a shield tunnel in which a PC steel wire insertion device for shield tunneling, according to a preferred embodiment of the present invention, is used. [Figure 2] This is a schematic cross-sectional view illustrating the process of inserting PC steel wires using a PC steel wire insertion device for shield tunneling according to a preferred embodiment of the present invention. [Figure 3]A PC steel wire insertion device for shield tunneling according to a preferred embodiment of the present invention is described below, where (a) is a front view and (b) is a cross-sectional view along AA in (a). [Figure 4] A preferred embodiment of the present invention describes a PC steel wire insertion device for shield tunneling, where (a) is a side view of Figure 3(a) viewed from the left, and (d) is a cross-sectional view of the hydraulic motor and motor fixing plate portion along BB in (a). [Figure 5] This is a schematic cross-sectional view illustrating a method for inserting PC steel wires into a segment ring using a PC steel wire insertion device for shield tunneling according to a preferred embodiment of the present invention. [Figure 6] Figure 5 is an inner circumferential view of the segment ring along CC, illustrating the method of inserting PC steel wires into the segment ring using a PC steel wire insertion device. [Figure 7] This is a schematic cross-sectional view of the main parts along DD in Figure 5, illustrating a method for inserting PC steel wires into a segment ring using a PC steel wire insertion device for shield tunneling according to a preferred embodiment of the present invention. [Modes for carrying out the invention]

[0016] A preferred embodiment of the present invention, the PC steel wire insertion device 10 for shield tunnel construction, as shown in Figures 1 and 2, is used in a shield tunnel 50, for example, with an inner diameter of about 4 m, which is preferably formed by a slurry shield tunneling method and serves as a temporary rainwater storage facility during heavy rains. The device is used to insert PC steel wires, preferably PC steel strands 4 (see Figure 2), into the sheath pipes 3 (see Figure 2) that are continuously embedded in the circumferential direction of each assembled segment ring 52, after assembling each ring of segment rings 52 made of concrete segments 51 with sheath pipes 3 (see Figure 2) embedded in advance, in the direction of the feed-out direction X. The PC steel wire insertion device 10 of this embodiment is a device that enables the continuous and efficient insertion of PC steel wire strands 4 into the sheath pipe 3 embedded in the circumferential direction of the assembled segment ring 52 with minimal effort, in a shield tunnel construction method that pre-introduces circumferential prestress into the segment ring 52 so as to resist the circumferential tensile load applied to the segment ring 52 by water pressure, for example by filling the inside with pressurized water from rainwater that generates considerable water pressure.

[0017] And the PC steel wire insertion device 10 of the present embodiment is an insertion device used when inserting the PC steel wire 4 into the embedded sheath pipe 3 in the shield tunneling method. After assembling the segment ring 52 with the concrete segments 51 in which the sheath pipe 3 is embedded in advance, the PC steel wire 4, preferably the PC steel wire, is inserted from the notch 53 provided in the assembled segment ring 52 and tension-fixed to introduce prestress in the circumferential direction of the segment ring 52. For example, in the internal water pressure-resistant shield tunneling method, as shown in FIGS. 3(a), (b) and FIGS. 4(a), (b), it is composed of a lower divided weight body 20 having a single driving roller 25 and an upper divided weight body 30 having a pair of driven rollers 35. When placed on the segment ring 52, it has a corresponding weight of about 72 kg, for example, so that the reaction force when inserting the PC steel wire 4 can be obtained by its own weight. Further, the lower divided weight body 20 has a curved mounting bottom surface portion 21 having a rectangular planar shape and curved with the same radius of curvature as the inner peripheral surface of the segment ring 52, and a driving roller 25 rotatable about a driving rotation axis 24 parallel to the width direction W of the curved mounting bottom surface portion 21 is attached to the upper part. On the upper divided weight body 30, a pair of driven rollers 35 rotatable about a fixed rotation axis 34 parallel to the driving rotation axis 24 of the driving roller 25 are attached to the lower part in a state where they can be arranged on both sides sandwiching the driving roller 25 in the length direction L of the curved mounting bottom surface portion 21. The lower divided weight body 20 and the upper divided weight body 30 are connected so as to be stacked vertically via the connecting pressing means 40, so that the PC steel wire 4 can be extended in the length direction L of the curved mounting bottom surface portion 21 and sandwiched between the single driving roller 25 and the pair of driven rollers 35 with a pressing force applied. By rotating the driving roller 25 with the PC steel wire 4 sandwiched, the sandwiched PC steel wire 4 is sent out toward the sheath pipe 3 with an end opening facing the notch 53.

[0018] Also, in the present embodiment, the connecting pressing means 40 is preferably provided so as to project laterally from the side portions on both sides in the feeding direction X of the PC steel wire 4 in the lower divided weight body 20, and is provided between the lower fastening flange 41 having a screwing hole 41a and the upper fastening flange 42 having a through hole 42a provided so as to project laterally from the side portions on both sides in the feeding direction X of the PC steel wire 4 in the upper divided weight body 30, and is fastened by the long bolt member 43a and the nut member 43b which are each spanned and fastened.

[0019] In the present embodiment, as described above, the PC steel wire inserting device 10 includes the lower divided weight body 20 having a single driving roller 25, the upper divided weight body 30 having a pair of driven rollers 35, and the connecting pressing means 40 for connecting the lower divided weight body 20 and the upper divided weight body 30 so as to be vertically overlapped.

[0020] The lower segmented weight body 20 has a rectangular planar shape having a predetermined width and length, a curved mounting bottom portion 21 that is curved in the longitudinal direction with a radius of curvature similar to that of the inner circumferential surface of the segment ring 52, a base portion 22 integrally joined to the upper side of the curved mounting bottom portion 21, a pair of upright support plate portions 23 that are erected from one side region of the width direction W of the curved mounting bottom portion 21 on the base portion 22 (see Figure 3(b)), a drive rotation shaft 24 that is rotatably supported on the upper part of these upright support plate portions 23 via bearings or the like and is arranged to extend parallel to the width direction W of the curved mounting bottom portion 21, and a drive roller 25 that is integrally joined to the drive rotation shaft 24 in the region between the pair of upright support plate portions 23 so as to pass through the drive rotation shaft 24 and is rotatable together with the drive rotation shaft 24. Furthermore, the drive roller 25 is rotated together with the drive rotation shaft 24 by the drive of the hydraulic motor 26, as the drive rotation shaft 24 is connected to the hydraulic motor 26 via a known chain coupling 29 in the region opposite to the drive roller 25, with the central upright support plate portion 23 in between. The hydraulic motor 26 is attached to the base portion 22 in the region opposite to the pair of upright support plate portions 23 in the width direction W of the curved mounting bottom surface portion 21, and is fixed to the motor fixing plate portion 27 which is erected parallel to the upright support plate portion 23, so that it protrudes on the opposite side from the upright support plate portion 23. The hydraulic motor 26 can rotate the drive rotation shaft 24 and the drive roller 25 by engaging the motor rotation shaft 26a, which rotatably penetrates and protrudes from the motor fixing plate portion 27, with the chain coupling 29.

[0021] The curved mounting base portion 21, which constitutes the lower segmented weight body 20, is located at the very bottom of the lower segmented weight body 20 and is the portion that allows the lower segmented weight body 20 to be placed on the inner surface of the segment ring 52 in a state of close contact with the arc-shaped curved inner surface of the segment ring 52. The curved mounting base portion 21 is curved in the length direction L, which is the longer side direction, with a radius of curvature similar to that of the inner surface of the segment ring 52, which has an inner diameter of, for example, about 4 m, and has a rectangular planar shape with a short side of about 300 mm and a long side of about 500 mm. The curved mounting base portion 21 is curved in the longitudinal direction L, which is also the feeding direction X of the PC steel strand 4, with a radius of curvature similar to that of the inner circumferential surface of the segment ring 52. This makes it possible to easily and smoothly install the PC steel wire insertion device 10 at a predetermined position on the inner circumferential surface of the segment ring 52, preferably by manual operation while the PC steel wire insertion device 10 is suspended, so that the feeding direction X of the PC steel strand 4 coincides with the circumferential direction of the segment ring 52, which is the direction in which the sheath pipe 3 embedded in the segment ring 52 extends. Preferably, for example, urethane rubber 21b is attached to the bottom surface 21a of the curved mounting base portion 21, which is the mounting surface on the segment ring 52. This makes it possible to more effectively prevent the PC steel wire insertion device 10 from shifting when a reaction force is applied to the PC steel wire insertion device 10 installed at a predetermined position on the inner circumferential surface of the segment ring 52 during the insertion of the PC steel strand 4. The thickness of the urethane rubber 21b can be, for example, 10 mm, but is not limited to this. On the upper side of the curved mounting base portion 21, opposite to the bottom surface 21a to which the urethane rubber 21b is attached, a base portion 22 is provided, which is integrally joined to it.

[0022] The base portion 22 is composed of, for example, three support plates 22a that extend in the longitudinal direction L and are arranged parallel to each other on the upper surface of the curved mounting bottom portion 21, and a base top plate 22b that is joined to these support plates 22a so as to connect their flat upper surfaces and cover the upper surfaces of the support plates 22a. The pair of upright support plates 23 that are erected from the base top plate 22b and rotatably support the drive rotation shaft 24 are integrally joined and provided, and the motor fixing plate 27 that supports and fixes the hydraulic motor 26 is integrally fixed and provided.

[0023] The pair of upright support plate sections 23 are made of horizontally elongated rectangular metal plate members and are preferably positioned in one side region in the width direction W of the base plate top plate 22b, directly above the support plate 22a of the base section 22, and are attached in an upright position from the base plate top plate 22b such that the long side is parallel to the length direction L of the curved mounting bottom surface section 21. Lower fastening flanges 41, which have screw holes 41a formed therein and constitute a connecting pressing means 40 described later, are provided on both sides of the upright support plate section 23 in the long side direction, extending laterally and straddling the pair of upright support plate sections 23. Furthermore, a cylindrical rod-shaped drive rotation shaft 24 is rotatably supported by these pair of upright support plate sections 23, with one end protruding towards the hydraulic motor 26, and is attached to the upper central part of the upright support section 23 so as to be parallel to the width direction W of the curved mounting bottom surface section 21. A drive roller 25, which is integrally joined to the drive rotating shaft 24, is positioned in the space between these pair of upright support plate sections 23.

[0024] The drive roller 25 is preferably made of a metal disc-shaped roller member with a V-shaped cross-sectional groove 25a formed on its outer circumference. The V-shaped cross-sectional shape of the groove 25a formed on the outer circumference of the drive roller 25 makes it easier to grip the PC steel strand 4, and allows for more efficient transmission of the force fed by the rotation of the drive roller 25. The angle between the two sides of the V-shape is preferably, for example, 90°.

[0025] As shown in Figures 4(a) and (b), the motor fixing plate portion 27, which is erected from the base plate top plate 22b, is made of a metal plate member having a vertically elongated, approximately pentagonal front shape with its upper edge cut in a V-shape, and the fixing base plate portion 27a is fixed to it at a right angle to its bottom edge. By fastening and fixing the fixing base plate portion 27a to the upper surface of the base plate top plate 22b by overlapping it, for example by bolting, the motor fixing plate portion 27 is positioned parallel to the pair of vertical support plate portions 23 in the area opposite to the pair of vertical support plate portions 23 in the width direction W of the base plate top plate 22b, and is provided in an erect state from the base plate top plate 22b. The known chain coupling 29 described above is provided in the portion between the motor fixing plate portion 27 and the vertical support plate portion 23 on the motor fixing plate portion 27 side for transmitting the rotational driving force from the hydraulic motor 26 to the drive rotation shaft 24. On the outer surface of the motor fixing plate portion 27, which is the side opposite to the chain coupling 29, the hydraulic motor 26 is fixed so as to protrude at a right angle, with the motor rotation shaft 26a protruding towards the chain coupling 29 (see Figure 3(b)).

[0026] The hydraulic motor 26 can be a known hydraulic motor, preferably having a rated pressure of 8.5 MPa, a rated output torque of 470 N°m, a rated flow rate of 57 L / min, a rated rotational speed of 138 rpm, a brake torque of 200 N°m, and a brake release pressure of 2.0 MPa. The hydraulic motor 26 is fixed to the side of the motor fixing plate portion 27 opposite to the chain coupling 29, for example, by bolt connection via a connecting flange 26b attached to the base end face, in a state that protrudes outward.

[0027] Furthermore, in this embodiment, on the upper part of the motor fixing plate portion 27, which is erected and attached from the base top plate 22b of the base portion 22, in the area above the portion to which the hydraulic motor 26 is attached, three suspension holes 28 are formed along the upper edge portion which is cut in a V-shape, in the upper central portion and on both sides one step lower than this.As will be described later, when the PC steel wire insertion device 10 is lifted up or lowered and positioned to face a predetermined direction on the inner circumferential surface of the segment ring 52, the tip locking portions of linear members 57a such as wires or chains extending from an electric winch 57, or linear members 58a extending from a lever block (registered trademark) 58, are locked into these suspension holes 28, as shown in Figures 1 and 5. These linear members 57a such as wires or chains extending from an electric winch 57, or linear members 58a extending from a lever block (registered trademark) 58, are attached to a support frame 56a such as an I-beam, which is supported by the shield tunneling machine 55 and installed inside it. This allows the PC steel wire insertion device 10 to be suspended from the support frame 56 via linear members 57a and 58a, and the suspended PC steel wire insertion device 10 can be moved up and down by, for example, an electric winch 57, and can also be moved to any position in the front, back, left, or right by, for example, pulling it in the left or right direction by a lever block (registered trademark) 58 or pushing it out in the front or back direction by a worker. Here, the hydraulic motor 26 protrudes from the motor fixing plate portion 27 on the opposite side from the pair of upright support plate portions 23, the drive rotation shaft 24 and the drive roller 25, which makes it possible to set the center of gravity of the PC steel wire insertion device 10 preferably to the portion of the motor fixing plate portion 27, making it possible to lift and lower the PC steel wire insertion device 10 in a more stable state, and to install it more smoothly in a predetermined position facing in the circumferential direction.

[0028] The upper divided weight body 30, which together with the lower divided weight body 20 constitutes the PC steel wire insertion device 10, is composed of an upper base body 33 having a U-shaped cross-section, which consists of a top plate 31 having a horizontally elongated rectangular flat planar shape, and a pair of horizontally elongated rectangular side-shaped extension support plate portions 32 attached to each other, extending downward from the edges along the long sides of both sides of the top plate 31; a pair of left and right fixed rotating shafts 34 that are positioned in the portion between the pair of extension support plate portions 32 of the upper base body 33, with both ends fixedly supported by these extension support plate portions 32, and extending parallel to the width direction W of the top plate 31; and a pair of driven rollers 35 that are positioned in the central portion between the pair of extension support plate portions 32 and are rotatably supported and attached to the pair of fixed rotating shafts 34, and rotate around these fixed rotating shafts 34.

[0029] Furthermore, a gripping fitting 36, formed by bending a reinforcing bar into a U-shape, for example, is attached to the top surface of the top plate 31 of the upper base portion 33 in an upright position by joining its lower end to the top plate 31 by welding or the like. By gripping the gripping fitting 36, it becomes easier to connect the upper divided weight 30 to the lower divided weight 20 by overlapping it on top of the lower divided weight 20, with the PC steel strand 4 sandwiched between the clamping groove 25a of the drive roller 25 of the lower divided weight 20 and the clamping groove 35a of the pair of driven rollers 35 of the upper divided weight 30.

[0030] The pair of extended support plate sections 32 of the upper base section 33 are made of horizontally elongated rectangular metal plate members and are positioned directly above each of the pair of upright support plate sections 23 that rise from the base section 22 of the lower divided weight section 20 when the upper divided weight section 30 is connected so as to overlap the lower divided weight section 20. Upper fastening flanges 42, which have through holes 42a formed in them and constitute the connecting pressing means 40 described later, are provided on both sides of the extended support plate section 32 in the direction of the long side, extending laterally and straddling the pair of extended support plate sections 32. Furthermore, a pair of fixed rotating shafts 34, which are cylindrical rods, are mounted with their ends supported on both sides by these pair of extended support plate sections 32, as described above, and are arranged parallel to the width direction W of the top plate 31. In the portion between these pair of extended support plate sections 32, driven rollers 35 are mounted, as described above, so as to be rotatably supported on the pair of fixed rotating shafts 34 via bearings or the like.

[0031] Each of the pair of driven rollers 35 is made of a urethane rubber roller member, preferably having a clamping groove 35a with an arc-shaped cross-section formed on its outer circumference. Because each driven roller 35 is made of a urethane rubber roller member, it deforms along the outer shape of the PC steel strand 4, making it easier for the driven roller 35 to adhere closely to the PC steel strand 4, thereby more effectively preventing the PC steel strand 4 from slipping. Preferably, the radius of curvature of the clamping groove 35a with an arc-shaped cross-section is larger than the radius of curvature of the outer surface of the PC steel strand 4 being fed out.

[0032] The pair of driven rollers 35 rotate around a fixed rotation axis 34, which is arranged parallel to the drive rotation axis 24 of the drive roller 25, when the upper divided weight body 30 is connected so as to overlap the lower divided weight body 20. The pair of driven rollers 35 are positioned on both sides of the drive roller 25, above it, in the longitudinal direction L of the curved mounting base portion 21 and the top plate 31. As a result, by rotating the drive roller 25 with the PC steel strand 4 sandwiched in the gap between the drive roller 25 and the pair of driven rollers 35, the sandwiched PC steel strand 4 can be fed in the feeding direction X toward the notch portion 53 facing the end opening 3a of the sheath pipe 3 (see Figure 2). When the PC steel strand 4 is fed out, the PC steel strand 4 is guided by the driven roller 35 on the downstream side in the feeding direction X so as not to bend upward, and preferably is fed out in a straight line or while curving downward, so that the PC steel strand 4 can be inserted more smoothly toward the end opening 3a of the sheath pipe 3 which is preferably facing the notch 53 formed in the segment ring 52 via the X anchor 61.

[0033] The connecting and pressing means 40, which together with the lower divided weight body 20 and the upper divided weight body 30 constitute the PC steel wire insertion device 10, preferably consists of a lower fastening flange 41 having screw holes 41a, which is provided on both sides of the lower divided weight body 20 in the PC steel wire feed direction X, and an upper fastening flange 42 having through holes 42a, which is provided on both sides of the upper divided weight body 30 in the PC steel wire feed direction X, respectively, and fastened between them, as shown in Figures 3(a) and 4(a).

[0034] In other words, the connecting and pressing means 40, consisting of a long bolt member 43a and a nut member 43b, is configured such that, for example, the upper male threaded portion of the long bolt member 43a is inserted through the through hole 42a of the upper fastening flange 42, and the lower male threaded portion is screwed into the screw hole 41a of the lower fastening flange 41. The nut member 43b is then tightened from above onto the portion of the upper male threaded portion that protrudes above the upper fastening flange 42, thereby fastening it to the upper fastening flange 42. This makes it possible to connect the lower divided weight body 20 and the upper divided weight body 30 as a single unit by stacking them vertically, with the PC steel strand 4, which is inserted in the gap between the drive roller 25 and the pair of driven rollers 35, sandwiched between these rollers 25 and 35. Furthermore, by increasing or decreasing the amount of tightening by the nut member 43b, for example, the pressing force when the PC steel strand 4 is sandwiched between the drive roller 25 and the pair of driven rollers 35 can be adjusted as appropriate. The connecting and pressing means 40 does not necessarily have to consist of a long bolt member 43a and a nut member 43b; it may also be a one-touch connecting and pressing means consisting of a clamp member, a buckle member, or the like.

[0035] To perform the work of inserting PC steel wires 4 into sheath pipes 3 embedded in the circumferential direction of segment rings 52, using the PC steel wire insertion device 10 for shield tunneling according to this embodiment, which has the above-described configuration, in the working space inside the shield tunnel 50, using the arc-shaped inner surface of the segment rings 52 as a working platform, the PC steel wire insertion device 10 is suspended so as to be able to move up and down from an electric winch 57 attached to a support frame 56 made of, for example, I-beams 56a, which is supported by the shield tunneling machine 55 and installed inside it.

[0036] Here, the support frame 56 is composed of a pair of I-beams 56a positioned in the central part of the circular hollow cross-section of the skin plate 55a, which is the outer shell of the shield tunneling machine 55. The support frame 56, including the pair of I-beams 56a, is provided in a state where it extends out to the rear of the skin plate 55a by being supported at one end by a support member (not shown) that supports, for example, a known erector device 60 (see Figure 1) installed inside the shield tunneling machine 55 to assemble the segment ring 52. In this way, the support frame 56 can advance in the excavation direction as a whole unit together with the skin plate 55a and the erector device 60 as the shield tunneling machine 55 excavates. A suspension frame 62 is fixed to the support frame 56 so as to be erected between the pair of I-beams 56a in the working area of ​​the rear end of the skin plate 55a in the excavation direction where the erector device 60 is located, and an electric winch 57 is attached to the central part of this suspension frame 62.

[0037] In this embodiment, for example, the locking tip of the linear member 57a extending downward from the electric winch 57 is preferably locked into the suspension hole 28 in the upper central part of the motor fixing plate 27, thereby enabling the PC steel wire insertion device 10 to be suspended from the suspension frame 62 in a balanced manner while being able to be raised and lowered by the electric winch 57.

[0038] Furthermore, in this embodiment, with the PC steel wire insertion device 10 suspended from the suspension frame 62, for example as shown in Figure 7, the PC steel wire insertion device 10 can be easily and smoothly installed at a predetermined position on the inner circumferential surface of the segment ring 52, with the length L of the curved mounting bottom surface 21 facing the circumferential direction, by manually lowering the PC steel wire insertion device 10 while pushing it in a predetermined direction. Furthermore, as shown in Figure 5, if the PC steel wire insertion device 10 is to be installed in the area between the lowest part of the circular cross-section of the segment ring 52 and one side end, a considerable distance to the side from the portion directly below the electric winch 57, it is considered difficult to lift it up manually by a worker. Therefore, by lifting it up with a lever block (registered trademark) 58 locked to the I-beam 56a on the side of the electric winch 57 and then lowering it, it becomes possible to easily and smoothly install the PC steel wire insertion device 10 in a predetermined position in the area between the lowest part of the circular cross-section of the segment ring 52 and one side end, a distance to the side from the portion directly below the electric winch 57 on the inner circumferential surface of the segment ring 52, with the length L of the curved mounting base portion 21 facing the circumferential direction.

[0039] As shown in Figure 2, the PC steel wire insertion device 10 is installed at the lowest position of the circular cross-section of the segment ring 52, with the feeding direction X, which is the length direction L of the curved mounting base portion 21, facing the circumferential direction of the segment ring 52. To insert the PC steel strand 4 into the sheath pipe 3 through the notch portion 53 formed in the region between the lowest position of the circular cross-section of the segment ring 52 and one side end, the PC steel strand 4 is sandwiched in the gap between the drive roller 25 of the lower divided weight body 20 and the pair of driven rollers 35 of the upper divided weight body 30 in the installed PC steel wire insertion device 10. The operation of sandwiching the PC steel strand 4 is performed, for example, by loosening the tightening of the nut member 43b of the connecting pressing means 40 and lifting the upper divided weight body 30, thereby widening the gap between the drive roller 25 of the lower divided weight body 20 and the pair of driven rollers 35 of the upper divided weight body 30. The PC steel strand 4 is inserted through the widened gap and positioned so that it is sandwiched between the V-shaped clamping groove 25a of the drive roller 25 and the arc-shaped clamping groove 35a of the pair of driven rollers 35. Then, the lifted upper divided weight body 30 is placed on top of the lower divided weight body 20 and the nut member 43b is tightened, making it possible to sandwich the PC steel strand 4 between the clamping groove 25a of the drive roller 25 and the clamping groove 35a of the pair of driven rollers 35 with a predetermined pressing force.

[0040] Once the PC steel strand 4 is sandwiched between the drive roller 25 and a pair of driven rollers 35 of the PC steel wire insertion device 10, the hydraulic motor 26 is driven to rotate the drive roller 25. This allows the sandwiched PC steel strand 4 to be fed towards the X anchor 61, a known anchoring fitting that connects to the end opening 3a of the sheath pipe 3 embedded in the segment ring 52, which is fixed integrally in the concrete of the intermediate anchor base 53a in the notch 53 formed in the region between the lowest part of the circular cross-section of the segment ring 52 and one side end.

[0041] Here, the notch 53 formed on the inner circumferential surface of the segment ring 52 has a pair of ship-bottom shaped notches 53b that extend circumferentially along the inner circumferential surface of the segment ring 52, on both sides of the intermediate anchor base 53a to which the X anchor 61 is fixed. In addition, the X anchor 61 is embedded and fixed in the concrete of the intermediate anchor base 53a with one of each pair of open end faces facing the rear end face of the ship-bottom shaped notches 53b, and the other of each pair of open end faces connected to the end opening 3a of the sheath pipe 3 embedded in the segment ring 52.

[0042] The PC steel strands 4, fed from the PC steel wire insertion device 10 toward the notch 53, are inserted into one open end face of the X anchor 61, which is positioned facing one of the bottom-shaped notches 53b of the notch 53. After being further pushed in, they are inserted into the sheath pipe 3, which is connected to the other open end face of the X anchor 61. The PC steel strands 4 inserted into the sheath pipe 3 are then inserted along the sheath pipe 3 embedded in the segment ring 52, making one full rotation in the circumferential direction of the segment ring 52. After this, their tip is pushed out from the open end face of the X anchor 61 facing the other bottom-shaped notch 53b, extending outwards and protruding toward the other bottom-shaped notch 53b.

[0043] Subsequently, the tip of the PC steel strand 4 protruding from the other bottom-shaped notch 53b is pulled along with the base end of the PC steel strand 4 that remains uninserted into the X anchor 61 in the other bottom-shaped notch 53b using a known pulling device such as a center hole jack. This introduces circumferential prestress (pre-compression force) to the segment ring 52, and the known anchoring fixture is then used to anchor it to the X anchor 61, which is a known anchoring fitting. This makes it possible to effectively reinforce the shield tunnel 50 so that it can withstand circumferential tensile loads due to internal water pressure, for example, when the shield tunnel 50 is used as a temporary water storage facility for rainwater, by introducing prestress in the circumferential direction of the segment ring 52.

[0044] As a result, with the PC steel wire insertion device 10 for shield tunneling according to this embodiment, the work of inserting PC steel wire strands 4, which are PC steel wires, into sheath pipes 3 that are continuously embedded in the segment ring 52 in the circumferential direction within the shield tunnel 50 can be performed efficiently and smoothly with less effort. Furthermore, by introducing prestress in the circumferential direction of the segment ring 52, it becomes possible to effectively reinforce the shield tunnel 50 so that it can withstand circumferential tensile loads such as those caused by internal water pressure.

[0045] Furthermore, in this embodiment, as shown in Figure 6, for example, each segment ring 52 assembled using concrete segments 51 has a plurality of sheath pipes 3, with four rows of sheath pipes 3 extending continuously in the circumferential direction, arranged in multiple rows at predetermined intervals in the axial direction of the tunnel 50, from the tunnel entrance side to the tunnel face side. The notches 53 into which the PC steel wire strands 4 are inserted are, for example, positioned as a first position for the first and third rows of sheath pipes 3 from the tunnel entrance side, preferably at the bottom of the circular cross-section of the segment ring 52, and positioned as a second position for the second and fourth rows of sheath pipes 3 from the tunnel entrance side, preferably between the bottom of the circular cross-section of the segment ring 52 and one side end, and are arranged alternately in an alternating pattern with circumferential positioning.

[0046] For a segment ring 52 in which multiple rows and multiple locations of sheath tubes 3 and notches 53 are arranged in this manner, it becomes possible to efficiently insert PC steel strands 4, which are PC steel wires, into each sheath tube 3 by following the procedure below.

[0047] In other words, in this embodiment, the hollow interior of the rear end portion of the circular cross-section skin plate 55a constituting the shield tunneling machine 55 is used as the working area. As shown in Figure 1, the PC steel wire insertion device 10 is lifted to the central portion of the skin plate 55a by an electric winch 57 attached to the central portion of the suspension frame 62. The erector device 60 is rotated circumferentially, and the segment gripping portion 60a is moved radially, while one segment ring 52 is assembled using multiple concrete segments 51. After one ring is assembled using the segment ring 52, the erector device 60 is preferably rotated circumferentially to retract the segment gripping portion 60a upward, and the PC steel wire insertion device 10, which had been lifted to the central portion of the skin plate 55a, is lowered. Then, for example, the PC steel wire insertion device 10 is used to insert the PC steel strands 4 into the first row of sheath pipes 3 on the tunnel entrance side.

[0048] Since the notch 53 in the first row of sheath tubes 3 is preferably located at the lowest point of the circular cross-section of the segment ring 52 (see Figure 6), as shown in Figure 5, the PC steel wire insertion device 10 can be raised to the area between the lowest point of the circular cross-section of the segment ring 52 and one side end using a lever block (registered trademark) 58 that is locked to the I-beam 56a on the side of the electric winch 57, and then lowered while finely adjusting the position mainly in the front-rear direction by a worker, and adjusting the orientation so that the feeding direction X matches the circumferential direction of the segment ring 52, the PC steel wire insertion device 10 can be installed in the area between one side end and the lowest point of the circular cross-section of the segment ring 52, with the curved mounting bottom surface 21 of the PC steel wire insertion device 10 in close contact with the inner circumferential surface that curves in the circumferential direction of the segment ring 52.

[0049] Subsequently, the nut member 43b of the connecting pressing means 40 is loosened, and with the upper divided weight body 30 slightly lifted, the PC steel strand 4 is passed through the gap between the drive roller 25 and the pair of driven rollers 35. Then, the nut member 43b is tightened again to sandwich the PC steel strand 4 between them with a predetermined pressing force, and the hydraulic motor 26 is rotated to feed and insert the PC steel strand 4 into the sheath pipe 3 which is continuously embedded in the segment ring 52 in the circumferential direction. Once the PC steel strand 4 is inserted, the PC steel strand 4 inserted into the sheath pipe 3 is pulled at the notch 53 using a known pulling device, thereby introducing circumferential prestress (pre-compression force) to the segment ring 52 as described above, and the end of the PC steel strand 4 can be fixed to the X anchor 61 placed in the notch 53 via a fixing jig.

[0050] After inserting the PC steel strands 4 into the first row of sheath pipes 3 and fixing their ends while applying tensile force, the PC steel wire insertion device 10 is moved again to the lowest point of the circular cross-section of the segment ring 52 and suspended, for example, using a lever block (registered trademark) 58 and an electric winch 57. Then, preferably by manually pushing it out, the PC steel wire insertion device 10 is lowered while making fine adjustments to the axial position of the tunnel 50. This allows the PC steel wire insertion device 10 to be installed on the extension of the second row of sheath pipes 3, preferably at the lowest point of the circular cross-section of the segment ring 52, with the curved mounting base 21 in close contact with the curved inner surface of the segment ring 52. Since the notch 53 in the second row of sheath tubes 3 is preferably located in the region between one side end and the bottom of the circular cross-section of the segment ring 52, the PC steel strand 4 can be inserted into the sheath tube 3, which is continuously embedded in the segment ring 52 in the circumferential direction, through the notch 53 located in the region between one side end and the bottom of the circular cross-section of the segment ring 52, by rotating the hydraulic motor 26 with the PC steel strand 4 sandwiched between the drive roller 25 and the pair of driven rollers 35 of the installed PC steel wire insertion device 10. Furthermore, while applying tensile force, the end of the inserted PC steel strand 4 can be fixed to the X anchor 61 located in the notch 53 via a fixing jig.

[0051] After inserting the PC steel wire strands 4 into the second row of sheath pipes 3 and fixing the ends of the PC steel wire strands 4 to which tensile force has been applied, the PC steel wire insertion device 10 is moved back to the lowest part of the circular cross-section of the segment ring 52 and suspended, for example, using a lever block (registered trademark) 58 or an electric winch 57. Then, by manual labor by workers and using the lever block (registered trademark) 58 or electric winch 57, the device is pulled up again to the area between one side end and the lowest part of the circular cross-section of the segment ring 52. From this state, for example, by repeating the same work as described above, it becomes possible to insert the PC steel wire strands 4 into the third and fourth rows of sheath pipes 3, apply tensile force to each sheath pipe 3, and fix the ends of the PC steel wire strands 4 to which tensile force has been applied in the notches 53, thereby introducing circumferential prestress (pre-compression force) to the segment ring 52.

[0052] Therefore, according to this embodiment, in a shield tunneling method in which a segment ring 52 is assembled using concrete segments 51 in which sheath pipes 3 are embedded in advance, and then PC steel wires 4 are inserted through notches 53 provided in the assembled segment ring 52 and tensioned and anchored to introduce prestress in the circumferential direction of the segment ring 52, the method for inserting PC steel wires 4 into the embedded sheath pipes 3 is a PC steel wire insertion device 10, wherein the sheath pipes 3 are continuously embedded in the circumferential direction of the segment ring 52 and are arranged in multiple rows at predetermined intervals in the axial direction. The PC steel wire insertion device 10 is composed of a lower divided weight body 20 and an upper divided weight body 30, and when placed on the segment ring 52, it has a considerable weight that can obtain the reaction force when inserting the PC steel wires 4 by its own weight, and the lower divided weight body 20 has a curved mounting bottom portion 21 that is curved with a radius of curvature similar to that of the inner circumferential surface of the segment ring 52.According to this embodiment, the PC steel wire insertion device 10 is suspended by an electric winch 57, which is a lifting device installed in the central part of the circular hollow cross-section of the shield tunneling machine 55. The suspended PC steel wire insertion device 10 is lowered while being positioned, and the PC steel wire insertion device 10 is installed on the inner surface of the segment ring 52 so that the feeding direction X matches the circumferential direction of the row of sheath pipes 3 in which the notches 53 are arranged. The PC steel wire 4 is sandwiched between the drive roller 25 and driven roller 35 of the installed PC steel wire insertion device 10, and the hydraulic motor 26 is rotated to insert the PC steel wire 4 into the notches 53. The method for inserting PC steel wires using the PC steel wire insertion device 10 is implemented, which includes an insertion step of feeding the PC steel wire towards the sheath pipe 3 facing the opening 3a and inserting it into the sheath pipe 3, and a reinstallation step of lifting the PC steel wire insertion device 10 with the lifting device 57 after inserting the PC steel wire 4 into the sheath pipe 3, lowering the lifted PC steel wire insertion device 10 with the lifting device 57, lowering the suspended PC steel wire insertion device 10 while positioning it, and reinstalling the PC steel wire insertion device 10 on the inner surface of the segment ring 52 so that the feeding direction X matches the circumferential direction of the next row of sheath pipes 3 where the notches 53 are located.

[0053] It should be noted that the present invention is not limited to the above embodiments and can be modified in various ways. For example, it is not necessarily required that urethane rubber be attached to the curved mounting bottom surface, and the clamping groove on the outer circumference of the drive roller does not necessarily need to have a V-shaped cross-section. The driven roller does not have to be made of a roller member made of urethane rubber. [Explanation of Symbols]

[0054] 3. Sheath tube 3a End opening 4PC steel strands (PC steel wire) 10 PC steel wire insertion device 20 Lower split weight body 21 Curved mounting base 21a Bottom 21b Urethane rubber 22 Base 22a Support plate 22b Base Plate 23 Standing support plate section 24 Drive Rotating Shaft 25 drive rollers 25a, 35a pinch groove 26 Hydraulic motor 26a Motor Rotation Shaft 26b Joint flange 27 Motor fixing plate section 27a Fixed bottom plate part 28 Hanging holes 29 Chain Coupling 30 Upper split weight body 31 Top plate 32 Extension support plate part 33 Upper base 34 Fixed Rotating Shaft 35 Driven roller 36 Gripping hardware 40 Connecting pressing means 41 Lower clamping flange 41a Screw hole 42 Upper fastening flange 42a through hole 43a Long bolt member 43b Nut component 50 Shield Tunnel 51 segments 52 Segment Ring 53 Notch 53a Intermediate anchor base 53b Bottom shape notch 55 Shield tunneling machine 55a Skin Plate 56 Support frame 56a I-beam 57 Electric winch 57a, 58a Linear members 58 Lever Block (Registered Trademark) 60 Erecta equipment 61 X-Anchor 62 Hanging Frames W (width direction) L (Length direction) X Sending direction

Claims

1. In a shield tunneling method in which a segment ring is assembled using concrete segments with pre-embedded sheath pipes, and then PC steel wires are inserted through notches in the assembled segment ring and tensioned to introduce prestress in the circumferential direction of the segment ring, the present invention relates to a PC steel wire insertion device used when inserting the PC steel wires into the embedded sheath pipes, It is composed of a lower segmented weight body equipped with one drive roller and an upper segmented weight body equipped with two driven rollers, and when placed on the segment ring, it has a considerable weight that allows it to obtain the reaction force when inserting the PC steel wire through its own weight. The lower segmented weight body has a rectangular planar shape having a predetermined width and length, and a curved mounting base portion that is curved in the longitudinal direction with a radius of curvature similar to that of the inner circumferential surface of the segment ring, and the drive roller, which is rotatable about a rotation axis parallel to the width direction of the curved mounting base portion, is mounted on the upper part. The upper divided weight body has two driven rollers mounted at its lower part, which are rotatable around a rotation axis parallel to the rotation axis of the drive roller, so that they can be positioned on both sides of the drive roller in the longitudinal direction of the curved mounting bottom surface. The lower divided weight body and the upper divided weight body are connected by a connecting pressing means so as to be stacked vertically, thereby allowing the PC steel wire to be extended in the longitudinal direction of the curved mounting bottom surface and sandwiched between the one-wheeled drive roller and the two-wheeled driven rollers while applying pressing force. A PC steel wire insertion device for shield tunneling, wherein the PC steel wire is clamped in place, and the drive roller is rotated to feed the clamped PC steel wire toward the sheath pipe, which has its end opening facing the notch.

2. The PC steel wire insertion device for shield tunnel construction according to claim 1, wherein urethane rubber is attached to the curved mounting bottom surface.

3. The PC steel wire insertion device for shield tunnel construction according to claim 1 or 2, wherein the drive roller is made of a metal roller member having a V-shaped cross-sectional groove formed on its outer circumference.

4. The PC steel wire insertion device for shield tunnel construction according to claim 1 or 2, wherein the driven roller is a roller member made of urethane rubber having a clamping groove with an arc-shaped cross-section formed on its outer circumference.

5. The PC steel wire insertion device for shield tunnel construction according to claim 1 or 2, wherein the connecting pressing means consists of a long bolt member and a nut member that are stretched and fastened between a lower fastening flange having screw holes, which is provided extending laterally from both sides of the lower divided weight body in the PC steel wire feeding direction, and an upper fastening flange having through holes, which is provided extending laterally from both sides of the upper divided weight body in the PC steel wire feeding direction.

Images