Metal fittings embedded in tunnel lining concrete

Abstract

To provide an embedded metal fitting that can be installed at an optimum position on the inner periphery of lining concrete regardless of the opening position of an inspection hatch of a tunnel center. [Solution] The embedded fitting 2 for tunnel lining concrete comprises a flat plate portion 21, an anchor portion 22 provided on one side of the flat plate portion 21 and embedded in the tunnel lining concrete, and a connecting portion 231 provided on the other side of the flat plate portion 21 to which a pulling device 6 extending outward from within an attachment opening F2 provided in the form F of the tunnel center T is connected.

Description

[Technical Field]

[0001] The present invention relates to an embedded metal fitting that is embedded in the lining concrete that covers the inner surface of a tunnel. [Background technology]

[0002] The inner periphery of a tunnel is covered with a predetermined thickness of secondary concrete lining. In order to install various equipment and components such as ventilation systems, lighting equipment, and cables inside the concrete-covered tunnel, it is necessary to expose embedded metal fittings at appropriate locations on the tunnel's inner periphery.

[0003] Here, Patent Document 1 proposes a system in which a slide frame is erected at an angle between an inspection hatch that opens on the outer periphery of the tunnel center form and a support frame inside the center, and embedded metal fittings are fixed to an inspection window that is movable along the slide frame, which is then transported and installed to the inspection hatch.With this type of transport structure, by pouring lining concrete into the concrete pouring space between the outer periphery of the form and the tunnel natural ground (or primary lining concrete), the embedded metal fittings exposed on the inner periphery of the lining concrete can be efficiently installed without requiring excessive effort. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2020-197038 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as mentioned above, the embedded fittings used in the conventional transport structure are designed to be fixed to an inspection window that can be moved along a slide frame to an inspection hatch, and therefore can only be installed in locations that correspond to the inspection hatches that open into the form, which are limited in number and location, making it difficult to install them in the optimal locations for the above-mentioned equipment and components installed inside the tunnel.

[0006] Therefore, the present invention aims to solve such problems and to provide an embedded metal fitting that can be installed in the optimal position on the inner circumference of the lining concrete, regardless of the opening position of the tunnel center inspection hatch. [Means for solving the problem]

[0007] In order to achieve the above object, the embedding metal fitting (2) for tunnel lining concrete of the first invention comprises a flat plate portion (21), an anchor portion (22) provided on one side of the flat plate portion (21) and embedded in the tunnel lining concrete, and a connecting portion (231) provided on the other side of the flat plate portion (21) to which a pulling device (6) extending outward from within an attachment opening (F2) provided in the form (F) of the tunnel center (T) is connected.

[0008] The embedded fitting of the first invention can be installed in the optimal position on the inner periphery of the lining concrete regardless of the opening position of the tunnel center inspection hatch by connecting a retracting device that extends outward from within the mounting opening provided in the form to its connecting part and retracting and fixing the embedded fitting to the outer surface of the form.

[0009] In the metal fitting (2) for embedding in tunnel lining concrete according to the second invention, the anchor portion (22) is composed of at least one rod body erected on one surface of the flat plate portion (21).

[0010] In the embedding metal fitting (2) for tunnel lining concrete of the third invention, a guide protrusion (23) is provided on the other surface of the flat plate portion (21), and the side surface (23a) of the guide protrusion (23) is inclined outward toward its base end.

[0011] In the embedded fitting of the third invention, even if the positions of the embedded fitting and the mounting opening are slightly misaligned when the fitting is pulled in by the pulling-in tool, the inclined side of the guide protrusion abuts against the edge of the mounting opening and guides the guide protrusion into the mounting opening, so that the embedded fitting is attached to the mounting opening without being significantly misaligned.

[0012] In the embedding metal fitting (2) for tunnel lining concrete according to the fourth invention, a screw hole (231) is provided in the end face of the guide projection (23) to form the connecting portion.

[0013] The fifth invention is a pulling-in device (6) used for the embedded metal fitting (2) of the tunnel lining concrete of the fourth invention, which is provided with a screw member (61) that is threadedly connected to the screw hole (231) through the mounting opening (F2), and the embedded metal fitting (2) is fixed to the outer peripheral surface of the form (F) by a pressing member (62) that is pressed against its back by a nut (612) that is threaded onto the screw member (61).

[0014] The symbols in parentheses above indicate, for reference, the correspondence with specific means described in the embodiments to be described later. [Effects of the Invention]

[0015] As described above, the tunnel lining concrete embedding metal fitting of the present invention can be installed at the optimum position on the inner circumference of the lining concrete, regardless of the opening position of the tunnel center inspection hatch. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a front view of a tunnel center equipped with a transport device. [Figure 2] FIG. 1 is a partial plan view of the tunnel center form. [Figure 3] FIG. 1 is a side view of the longitudinal end of the tunnel center. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 6 is a cross-sectional view corresponding to FIG. 5 in a state where the parallel link is raised. [Figure 9] FIG. 7 is a cross-sectional view corresponding to FIG. 6 in a state where the parallel link is raised. [Figure 10] 1A and 1B are a cross-sectional view and a plan view of an embedded metal fitting. [Figure 11] A cross-sectional view of the inner periphery of the tunnel outside the foam, taken along the longitudinal direction of the tunnel. [Figure 12] This is a plan view of the reinforcing bars arranged on the inner periphery of the tunnel outside the form. [Figure 13] This is a cross-sectional view along the longitudinal direction of the tunnel of the inner periphery of the tunnel outside the foam, with embedded fittings temporarily fixed. [Figure 14] A cross-sectional view showing the state in which the temporarily fixed embedded metal fitting has been pulled into the mounting hole in the foam. [Figure 15] FIG. 2 is a side view of the embedded fitting and the pull-in tool. [Figure 16] This is a partial cross-sectional side view of the embedded metal fittings pulled into the outer periphery of the foam and fixed using a pulling tool. [Figure 17] This is a plan view from inside the form showing the embedded metal fittings pulled into and fixed to the outer periphery of the form using a pulling tool. DETAILED DESCRIPTION OF THE INVENTION

[0017] The embodiments described below are merely examples, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

[0018] FIG. 1 shows a front view of a tunnel center T equipped with a transport device 1 of the present invention. The tunnel center T is equipped with a portal-shaped gantry T1, which is movable in the longitudinal direction of the tunnel (front-to-back direction in the figure) using a known structure (not shown). A circular arc-shaped form (not shown) that follows the inner periphery of the tunnel N natural ground (hereinafter simply referred to as the tunnel) is supported by a frame on the gantry T1. In the figure, L indicates the outer periphery of the form when the lining concrete is poured. Note that reinforcing bars (not shown) are arranged in the space S between the outer periphery L and the inner periphery of the tunnel N (i.e., the space for pouring the lining concrete).

[0019] On the outer periphery of the form, embedded metal fittings 2 transported by a transport device 1 (described later) are installed in multiple positions in the circumferential direction. Figure 2 shows a partial plan view of form F, with embedded metal fittings 2 arranged in multiple positions at approximately equal intervals along the longitudinal direction of the tunnel (left and right direction in Figure 2). In the figure, F1 is an inspection hatch provided in the form.

[0020] The following describes in detail the conveying device 1 that conveys the embedded fittings 2. The conveying device 1 is equipped with a rail member 11, which, as shown in Figure 1, is curved in an arc shape at a position inward from the outer periphery line L of the form F, maintaining a fixed distance from the outer periphery line L. As shown in Figure 3, this rail member 11 is positioned outward from the longitudinal ends of the form F, and the inner periphery of the rail member 11 is fixed to and supported on both ends of cross beams T2 (Figure 1) that serve as a frame supported by a gantry T1.

[0021] A conveyance table 3 is positioned on the rail member 11. In this embodiment, a pair of conveyance tables 3 having the same structure are provided, and each is capable of moving along the semicircular arcs on the left and right sides of the rail member 11. A plan view of the conveyance table 3 is shown in FIG. 4, and a side view thereof is shown in FIG. 5. Also, FIG. 6 shows a cross-sectional view taken along line VI-VI in FIG. 4, and FIG. 7 shows a cross-sectional view taken along line VII-VII in FIG. 4.

[0022] The conveyance platform 3 is equipped with a drive unit 31, which is provided with a motor 311 that rotates a sprocket 313 (FIG. 6) in both forward and reverse directions via a speed reduction mechanism 312. The sprocket 313 is engaged with a chain 315 that is stretched around the outer periphery of the rail member 11. The drive unit 31 is provided with guide rollers 314 at the front, rear, left, and right positions as shown in FIG. 4, and each guide roller 314 is provided in pairs at the top and bottom as shown in FIG. 7, and sandwiches both upper and lower edges of the rail member 11 between them. This positions the conveyance platform 3 on the rail member 11 and enables it to move along the rail member 11, and it can move up and down on the semicircular arc of the rail member 11 in response to the forward and reverse rotation of the motor 311.

[0023] In this embodiment, the conveying table 3 is provided with a rectangular plate-shaped platform 32 (FIG. 4). A rectangular opening 321 is formed in the plate surface of the platform 32, and the left and right positions in the width direction of the underside are supported by parallel links 41, 42 (FIG. 6) that constitute the movement mechanism 4. The base end of the upper link 41 of the parallel links is bent downward, and the bent portion is supported by a rotation shaft, and the bent end is rotatably connected to the base end of the lower link 42. The tip of a horizontally extending drive screw 44 is connected to a female screw member 43 (FIG. 6) that is rotatably provided on this connecting portion.

[0024] With this structure, when a manual tool or an electric tool such as a ratchet wrench is attached to the base end of the drive screw 44 and rotated, the female thread member 43 of the connecting part moves along the drive screw 44 toward its base end, and in response, the parallel links 41, 42 rise up as shown in Figures 8 and 9, and the platform 32 is lifted outward from the arc of the rail member 11 while maintaining its posture, and is moved outward from the outer circumferential line L of the form.

[0025] Figure 10 shows an example of an embedded metal fitting 2 transported by the transport device 1. Figure 10(1) is a cross-sectional view of the embedded metal fitting 2, and Figure 10(2) is a plan view of the embedded metal fitting 2 viewed from below. The embedded metal fitting 2 has a rectangular flat plate portion 21, and multiple anchor rods 22 (eight in this embodiment) with slightly larger diameter tips are erected on the outer edge of the surface of the flat plate portion 21. A truncated pyramidal guide protrusion 23 with inclined side surface 23a is formed on the inner periphery of the back surface of the flat plate portion 21. A screw hole 231 is provided in the center of the guide protrusion 23 as a connecting portion, and a screw hole 211 is also provided on the surface of the flat plate portion 21 at the same position as the screw hole 231.

[0026] When placing such an embedded metal fitting 2 on the platform 32 of the conveyor 3, the conveyor 3 is moved downward along the rail member 11 until the platform 32 approaches an upright position, and the lower edge of the flat plate portion 21 of the embedded metal fitting 2, which is suspended in an upright position by a hoisting tool, is engaged with a hook-shaped engaging member 322 (Fig. 5) formed on the side edge of the platform 32, and in this state the back surface of the embedded metal fitting 2 is aligned with the plate surface of the platform 32. If necessary, the periphery of the flat plate portion 21 of the embedded metal fitting 2 and the platform 32 can be clamped in an appropriate position with a clamp 33.

[0027] As already mentioned, reinforcing bars R are arranged outside the outer periphery L of the form between it and the tunnel N (Fig. 11), and in this embodiment, tubular retaining fittings R1 (a pair in this embodiment) for temporarily fixing the embedded fittings 2 are provided at required positions on the reinforcing bars R arranged in a grid pattern as shown in Fig. 12. The inner diameter of this retaining fitting R1 is larger than the outer diameter of the anchor rod body 22 of the embedded fitting 2 (Fig. 10).

[0028] The embedded metal fitting 2 on the platform 32, which is transported by the conveyor 3 and raised by the moving mechanism 4 to the required position, is temporarily fastened to the retaining metal fittings R1 as shown in FIG. 13. This temporary fastening is achieved by passing two anchor rods 22 of the embedded metal fitting 2, one of which is symmetrically positioned across the guide protrusion 23, through each retaining metal fitting R1, attaching an eyebolt 51 to the threaded hole 211 (FIG. 10) on the surface of the embedded metal fitting 2, and threading a wire rope 52 through the eyebolt 51 to suspend the embedded metal fitting 2 via the rebar R as shown in FIG. 13. The base end of the wire rope 52 is fixed within reach of the inspection window F1 (FIG. 2) of the form F, which will later be moved and expanded to the pouring state. To further secure the temporary fastening, the two anchor rods 22 may be threaded, and flat washers 53 with a larger diameter than the retaining metal fittings R1 may be attached to their outer peripheries as shown in FIG. 13.

[0029] In this state, the tunnel center T is moved appropriately to expand the form F to the state where the lining concrete is poured (Fig. 14), and the guide protrusion 23 of the temporarily fixed embedded metal fitting 2 is inserted into the mounting opening F2 previously provided in the form F. This is actually performed as follows.

[0030] Figure 15 As shown in Fig. 16, the tip of the eyebolt 61 of the retracting tool 6 is screwed into the screw hole 231 of the guide protrusion 23 of the temporarily fixed embedded fitting 2 from the tunnel center T side through the mounting opening F2 of the form F. Then, the other hook (not shown) of a lever block (registered trademark) with one hook engaged with a frame or the like inside the tunnel center T is engaged with the base end ring portion 611 of the eyebolt 61, and the embedded fitting 2 is retracted into the mounting opening F2 by operating the lever. During this retraction, even if the embedded fitting 2 and the mounting opening F2 are slightly misaligned, the inclined side surface 23a of the guide protrusion 23 abuts against the edge of the mounting opening F2 to guide the guide protrusion 23 into the mounting opening F2, so that the embedded fitting 2 is fitted into the mounting opening F2 without being significantly misaligned (Figs. 16 and 17).

[0031] In this state, the long retaining piece 62, the center of which is fitted onto the outer periphery of the threaded portion of the eyebolt 61, is pressed against the plate wall F3 protruding from the opposite periphery of the mounting opening F2 by rotating the nut 612 attached to the back, whereby the embedded fitting 2 is fixed with its flat portion 21 pressed against the outer periphery of the form F. At this point, the wire rope 52 is cut near the inspection window F1 (Figure 14). Also, the hook of the lever block (registered trademark) engaged with the base end ring portion 611 of the eyebolt 61 is released.

[0032] After each embedded metal fitting 2 has been fitted into the specified mounting opening F2 using this procedure, lining concrete is poured into the pouring space S formed outside the form. After pouring, the nut 612 is turned back and rotated, the eyebolt 61 is released from the threaded hole 231 of the guide projection 23, and the pulling device 6 is removed. After the concrete has cured, the form F is reduced in diameter to release it from the concrete surface, and the tunnel center T is moved, whereupon the embedded metal fittings 2 are embedded in appropriate locations on the lining concrete surface (inner surface) with their flat plate portions 21 exposed on the surface.

[0033] In the above embodiment, the rail members are installed in the tunnel center, but instead, the rail members may be installed on an independent moving device such as a dedicated carriage. In the above embodiment, the embedded metal fitting 2 has multiple anchor rods 22 erected on the flat plate portion 21 to form the anchor portion, but the number and arrangement of the anchor rods are merely examples. Also, the anchor portion does not necessarily have to be composed of anchor rods, and other structures can be used. In the above embodiment, the flat plate portion 21 of the embedded metal fitting 2 is provided with a guide protrusion 23, which is then provided with a screw hole 231 as a connecting portion, but this does not necessarily have to be provided on the guide protrusion 23, and the guide protrusion 23 itself does not necessarily have to be provided. Note that the connecting portion does not necessarily have to be configured as a screw hole 231. In the above embodiment, an installation opening F2 is provided through which the embedded fitting 2 is pulled in toward the form F using a pulling-in device 6 for installation, but the structure of the installation portion does not necessarily have to use the above installation opening F2. In the above embodiment, the rail member 11 is provided on the tunnel center T and moves integrally with the movement of the tunnel center T, but the rail member 11 may also be moved by a separate moving mechanism. [Explanation of symbols]

[0034] 1...conveying device, 11...rail member, 2...embedded metal fittings, 3...conveying platform, 32...loading platform, 4...moving mechanism, 6...pulling device, F...form, F2...mounting opening (mounting part), N...tunnel, R...reinforcing bar, T...tunnel center, T2...cross beam (frame).

Claims

1. 1. A tunnel lining concrete embedding fixture comprising: a flat plate portion; an anchor portion provided on one side of the flat plate portion and embedded in the tunnel lining concrete; and a connecting portion provided on the other side of the flat plate portion and to which a retraction device extending outward from within an attachment opening provided in a tunnel center form is connected, wherein the tunnel lining concrete embedding fixture is detachably temporarily fastened to a reinforcing bar arranged in the concrete pouring space outside the tunnel center, and the retraction device extending outward from within the attachment opening is connected to the connecting portion, and is pulled into the attachment opening and fixed to the outer peripheral surface of the form.

2. 2. The metal fitting for embedding in tunnel lining concrete according to claim 1, wherein the anchor portion is formed of at least one rod body erected on one surface of the flat plate portion.

3. 3. An embedding metal fitting for tunnel lining concrete according to claim 1 or 2, wherein a guide protrusion is provided on the other surface of the flat plate portion, and the side surface of the guide protrusion is inclined outward toward its base end.

4. 4. The embedding metal fitting for tunnel lining concrete according to claim 3, wherein a screw hole is provided on the end surface of the guide projection to form the connecting portion.

5. A pulling-in device to be used for embedded metal fittings in tunnel lining concrete as described in claim 4, comprising a screw member that is threadedly connected to the screw hole through the mounting opening, and the embedded metal fitting is fixed to the outer peripheral surface of the form by a pressing member whose back is pressed by a nut that is screwed into the screw member.

6. An installation structure for an embedded metal fitting for tunnel lining concrete, comprising: a flat plate portion; an anchor portion provided on one side of the flat plate portion and embedded in the tunnel lining concrete; and a connecting portion provided on the other side of the flat plate portion to which a retraction device extending outward from within an attachment opening provided in the form of the tunnel center is connected, wherein the retraction device extending outward from within the attachment opening is connected to the connecting portion of the embedded metal fitting which is detachably temporarily fixed to a reinforcing bar arranged in the concrete pouring space outside the tunnel center, thereby retracting the embedded metal fitting into the attachment opening and fixing it to the outer peripheral surface of the form.

7. The installation structure for embedded fittings in tunnel lining concrete described in Claim 6, wherein the retraction device is provided with a screw member that is screwed into a screw hole provided in the connecting part through the mounting opening, and the embedded fitting is fixed to the outer surface of the form by a pressing member whose back is pressed by a nut screwed into the screw member.

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