Tunnel formwork device

Abstract

The present invention provides a tunnel formwork device that can easily and reliably prevent displacement of the left and right side frames of the lining formwork. [Solution] The structure comprises a base frame 1 extending in the longitudinal direction of the tunnel, a lining formwork 2 supported by the base frame 1 and extending in the longitudinal direction of the tunnel while maintaining a predetermined distance from it and curving in a substantially semi-circular cross-section along the inner circumference of the tunnel T, a base plate 3 installed on the tunnel bottom surface T1 and extending in the longitudinal direction of the tunnel, and jack members 35 installed between both side edges of the base plate 3 and both side frames 22 of the lining formwork 2.

Description

Technical Field

[0001] The present invention relates to a tunnel formwork device, and particularly to a structure of a tunnel formwork device that prevents displacement of a lining formwork during concrete placement.

Background Art

[0002] The lining formwork of a tunnel formwork device extends in the longitudinal direction of the tunnel while curving into a substantially semi-circular arc cross-section at a predetermined interval along the inner circumference of the tunnel. When placing lining concrete into the space formed between the lining formwork and the inner circumference of the tunnel, the formwork is displaced under a large lateral pressure, resulting in a problem that the thickness of the placed concrete is not uniform at this part.

[0003] Therefore, in the case of a structure in which the lining formwork is supported by a base frame having a portal frame, for example, in the tunnel formwork device disclosed in Patent Document 1, side beams extending downward from the left and right ends of the top beam of the portal frame are greatly deflected and deformed in the direction of receiving the lateral pressure of the concrete in advance before concrete placement, so that even when receiving the lateral pressure during concrete placement, the two side beams do not deform further, and the displacement of the left and right side frames of the lining formwork supported by the two side beams is prevented.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above conventional displacement prevention structure, it is difficult to adjust the amount of deformation of the deflection deformation. Therefore, it takes time and effort for the adjustment and the adjustment tends to be insufficient, making it difficult to reliably prevent the displacement of the left and right side frames of the lining formwork.

[0006] Therefore, the present invention aims to solve these problems by providing a tunnel formwork device that can easily and reliably prevent displacement of the left and right side frames of the lining formwork. [Means for solving the problem]

[0007] To achieve the above objective, the first invention comprises a base frame (1) extending in the longitudinal direction of the tunnel, a lining formwork (2) supported by the base frame (1) and extending in the longitudinal direction of the tunnel while curving in a substantially semi-circular cross-section along the inner circumference of the tunnel (T) at a predetermined distance from it, a base body (3) installed on the tunnel bottom surface (T1) and extending in the longitudinal direction of the tunnel, and support rods (35) erected between both side edges of the base body (3) and both side frames (22) of the lining formwork (2).

[0008] In this first invention, since both side frames are supported by support rods sandwiching a base placed on the tunnel bottom surface, the side frames are reliably maintained in their predetermined positions without being displaced inward against the lateral pressure during concrete pouring.

[0009] In this second invention, a pier (6) for vehicle traffic is provided in an upper space (S2) away from the base (3), extending in the longitudinal direction of the tunnel.

[0010] According to this second invention, even during concrete pouring and curing, work vehicles can pass through the pier in the longitudinal direction of the tunnel. Furthermore, even if the pier vibrates when vehicles pass through, since the pier is located in an upper space away from the base, the vibrations of the pier are not transmitted from the base through the support rods to the side frame, and therefore do not adversely affect the poured secondary lining concrete.

[0011] In this third invention, the base frame (1) is movable in the longitudinal direction of the tunnel, and when it is moved, the erected state of the support rod (35) is released, and the base (3) is pulled upward by the lifting means (5) provided on the base frame (1).

[0012] In this third invention, the tunnel formwork device can be quickly moved after the concrete pouring and curing are completed.

[0013] The symbols in parentheses above are for reference only, indicating the correspondence with the specific means described in the embodiments described later. [Effects of the Invention]

[0014] As described above, the tunnel formwork device of the present invention makes it possible to easily and reliably prevent displacement of the left and right side frames of the lining formwork. [Brief explanation of the drawing]

[0015] [Figure 1] This is an overall front view of a tunnel formwork installation device installed inside a tunnel, illustrating one embodiment of the present invention. [Figure 2] This is an overall side view of the main parts of the tunnel formwork device. [Figure 3] This is a plan view of the circuit board and the pier located above it. [Figure 4] This is an overall side view of the circuit board. [Figure 5] This is an overall front view of the tunnel formwork installation device installed inside the tunnel for use during movement. [Figure 6] This is an overall side view of the pier during movement. [Modes for carrying out the invention]

[0016] The embodiments described below are merely examples, and various design improvements made by those skilled in the art without departing from the spirit of the present invention are also included within the scope of the present invention.

[0017] Figure 1 shows a cross-section of a tunnel T on which the tunnel formwork device E of the present invention is installed. The tunnel formwork device E includes a base frame 1, which has a portal frame 11. The portal frame 11 is composed of a horizontal ceiling beam 111 and side beams 112 extending downward from the left and right ends of the ceiling beam 111. Multiple portal frames 11 are provided at multiple locations along the longitudinal direction of the tunnel (Figure 2), and these are connected by vertical beams 12.

[0018] On both sides of the base frame 1 in the tunnel width direction, column supports 13 (Fig. 1) are provided at appropriate positions in the tunnel longitudinal direction, and the wheels 131 at the lower ends of the column supports 13 are located on the rails 14 laid in the tunnel longitudinal direction on the tunnel bottom surface (inverted concrete). Thereby, the base frame 1 (i.e., the tunnel formwork device E) is movable in the tunnel longitudinal direction.

[0019] As shown in Fig. 1, a lining formwork 2 is provided supported by the base frame 1. The lining formwork 2 as a whole extends in the tunnel longitudinal direction while curving in a substantially semi-arc shape in cross section at a predetermined interval along the inner circumference of the once-lined tunnel T. That is, the top frame 21 at the central top of the lining formwork 2 is supported by a pair of left and right jack members 15 provided on the top beam 111 of the portal frame 11 so as to be movable up and down, and side frames 22 are rotatably connected to both ends of the top frame 21, respectively. Invert frames 23 are further rotatably connected to the lower ends of the respective side frames 22. The side frames 22 and the invert frames 23 are connected to the base frame 1 by jack members 41 that are extensible and contractible at appropriate positions.

[0020] With such a structure, secondary lining concrete C is placed in the placement space S formed in a substantially semi-arc shape in cross section on the outer periphery of the lining formwork 2 (see Fig. 5). After the placement and curing of the secondary lining concrete C, as shown in Fig. 5, the top frame 21 is lowered and the side frames 22 and the invert frames 23 are rotated inward, so that the lining formwork 2 is separated from the secondary lining concrete C.

[0021] In FIG. 1, within an internal space S2 formed below the portal frame 1, a plate-shaped base body (hereinafter referred to as a substrate) 3 is provided on the tunnel bottom surface T1. The substrate 3 is a rectangular frame body that extends in the longitudinal direction of the tunnel with a length approximately the same as that of the lining frame body 2 and a constant width (FIGS. 3 and 4). On both side ends of a plurality of cross members 31 extending in the tunnel width direction, longitudinal members 32 extending in the longitudinal direction of the tunnel are respectively positioned. Such a substrate 3 is provided with connecting pieces 33 (FIG. 3) at both ends of the cross members 31 at a plurality of locations in the longitudinal direction. One end of a jack member 35 as a support rod body is detachably connected to each connecting piece 33. The other end of the jack member 35 is detachably connected to the side frame 22 (FIG. 1).

[0022] When secondary lining concrete C is placed in the placing space S1 (FIG. 1), a large lateral pressure from the concrete C acts on the side frame 22 rotatably connected to the top frame 21. Here, in this embodiment, since the left and right side frames 22 are structured such that they are respectively connected to both side edges of the substrate 3 by the jack members 35 with the substrate 3 placed on the tunnel bottom surface T1, the side frame 22 is surely maintained at a predetermined position without being displaced inward against the large lateral pressure.

[0023] In addition, suspension rings 34 are provided at a plurality of locations (three locations in this embodiment) in the longitudinal direction of the longitudinal members 32 on both sides of the substrate 3 (FIG. 4). A suspension hook 51 at the lower end of a wire hanging from an electric hoist 5 as a lifting means provided on the top beam 111 of the portal frame body 11 is locked to these suspension rings 34 (FIG. 1).

[0024] Above the substrate 3, a trestle 6 for vehicle passage is installed (FIG. 1). The trestle 6 is composed of a main body 61 (FIG. 2) and inclined plates 62 rotatably connected to both longitudinal ends of the main body 61. As shown in FIG. 3, the main body 61 has the same shape as the substrate 3 and is a rectangular shape with a slightly shorter width. It is horizontally supported above the substrate 3 at a distance therefrom by its own legs 611 (FIG. 2). The inclined plates 62 are inclined from the base end side connected to the main body 61 toward the tunnel bottom surface T1 as shown in FIG. 2 during use.

[0025] As a result, even during the curing of the secondary lining concrete C, a work vehicle V (Figure 2) can pass through the pier 6 into the internal space S2 below the gate formwork 11 (Figure 1). Furthermore, even if the pier 6 vibrates when this vehicle passes, as described above, the pier 6 is located above and spaced apart from the base plate 3, so the vibration of the pier 6 is not transmitted to the base plate 3 or to the side frame 22 connected to the base plate 3 via the jack member 35, thus preventing adverse effects on the poured secondary lining concrete C. In addition, frames 63 extending outward from both ends in the longitudinal direction of the pier body 61 are provided (Figure 2), and the hooks 641 at the lower end of the wires hanging down from the chain hoist 64 provided at the tip of each frame are locked to the tip of each ramp plate 62.

[0026] When the secondary lining concrete C has been poured and cured and the tunnel formwork device E is to be moved to the next concrete pouring position, as shown in Figure 5, the jack member 35 (Figure 1) is removed, the entire lining formwork 2 is lowered, and the side frames 22 and invert frames 23 are rotated inward to separate the top frame 11, side frames 22, and invert frames 23 from the inner circumference of the secondary lining concrete C. Then, the base plate 3 is lifted up by the electric hoist 5 together with the pier 6 located above it. At this time, the ramp plates 62 at both ends of the pier 6 are lifted and rotated by the chain block 64 to a horizontal position, as shown in Figure 6.

[0027] In the above embodiment, the tunnel formwork device E is designed to be movable in the longitudinal direction of the tunnel, but it is not necessarily required to be movable. In the above embodiment, a pier was provided above the substrate, but a pier is not necessarily required. Furthermore, the side frames are not necessarily limited to those that are rotatably connected to the top frame; they may also be integrated with the top frame. In the above embodiment, the base frame has a gate-shaped frame structure, but the structure of the base frame is not particularly limited. [Explanation of symbols]

[0028] 1...Base frame, 11...Gate frame, 2...Lining formwork, 22...Side frame, 3...Base body, 35...Jack member (support rod), 5...Electric hoist (lifting means), 6...Pier, S2...Internal space, T...Tunnel, T1...Tunnel bottom.

Claims

1. A tunnel formwork device comprising: a base frame extending in the longitudinal direction of the tunnel; a lining formwork supported by the base frame and extending in the longitudinal direction of the tunnel while curving in a substantially semi-circular cross-section at a predetermined distance from the inner circumference of the tunnel; a base body installed on the bottom surface of the tunnel and extending in the longitudinal direction of the tunnel; and support rods erected between the side edges of the base body and the side frames of the lining formwork.

2. The tunnel formwork apparatus according to claim 1, wherein a pier for vehicle traffic extending in the longitudinal direction of the tunnel is provided in the space above the substrate, away from the substrate.

3. The tunnel formwork device according to claim 1, wherein the base frame is movable in the longitudinal direction of the tunnel, and when moved, the erected state of the support rods is released, and the base is lifted upward by a lifting means provided on the base frame.

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