Support and protection work joint structure

Abstract

This invention provides a shoring connection structure that is easy to install, shortens the construction period, and offers excellent construction quality. [Solution] When constructing a widened section of a mountain tunnel, where the diameter of the section gradually increases from the standard section of the section, a support structure is provided in which arch-shaped support structures 1,1 of different diameters, which are provided at predetermined intervals before and after the tunnel in the direction of travel TF, are connected using a plurality of connecting means provided at intervals in the circumferential direction of the support structures. The connecting means comprises tubular connecting members 3,3 provided on the front and rear support structures, and a rod-shaped connecting member 2 connected to the front and rear tubular connecting members 3,3. One hook portion 2b of the rod-shaped connecting member 2 is inserted into the opening 3h of the rear tubular connecting member, and the other hook portion 2b of the rod-shaped connecting member 2 is inserted into the opening 3h of the front tubular connecting member, so that the center line 2C of the shaft portion 2a of the rod-shaped connecting member 2 and the center line 3C of the pipe of the tubular connecting member 3 are perpendicular to each other.

Description

Technical Field

[0001] The present invention relates to a support connection structure for connecting front and rear supports provided at a predetermined interval before and after in the advancing direction of a tunnel when constructing an enlarged cross-section cavity portion formed so that the diameter of the cavity portion gradually increases from a standard cross-section cavity portion in the construction of a mountain tunnel.

Background Art

[0002] Conventionally, in the construction of mountain tunnels, the ground exposed by excavation is supported by supports to stabilize the ground. That is, an arch-shaped steel support is arranged along the cross-sectional shape of the tunnel cavity portion formed by excavation. In the construction of a mountain tunnel, when constructing a standard cross-section cavity portion with a standard cross-sectional diameter, arch-shaped supports are installed at a predetermined interval along the extension direction of the tunnel. At this time, in order to prevent the supports from falling over and improve stability, the supports located before and after along the extension direction of the tunnel are connected to each other using a plurality of connecting means provided at intervals in the circumferential direction of the supports. The connecting means includes a tubular connecting member called a sheath tube provided on the front and rear supports provided at a predetermined interval before and after in the advancing direction of the tunnel, and a rod-shaped connecting member called a connecting piece connected to the front and rear tubular connecting members provided on the front and rear supports and corresponding to each other (see Patent Document 1). As shown in Fig. 4(a), a tubular connecting member 3 called a sheath tube is a tubular member of a predetermined length extending straight with openings 3h, 3h opening at both end faces 3e, 3e, and is constituted by, for example, a steel pipe having a circular cross-section and extending straight and hollow. As shown in Figure 4(b), the tubular connecting member 3 is attached to the support structure 1 by welding 3w or the like, such that the center line 3C of the pipe extends in direction A along the arch of the support structure 1. The arched support structure 1 is, for example, made of H-shaped steel material with a web 1a and flanges 1b and 1c, and the tubular connecting member 3 is welded, for example, to the inner surface 1cu of the flange 1c located on the ground side. As shown in Figure 4(c), the rod-shaped connecting member 2, called a connecting member, is provided on the front and rear supports 1,1 and is a rod-shaped member comprising a straight shaft portion 2a with a length corresponding to the distance between the centerlines 3C, 3C of the corresponding front and rear tubular connecting members 3, 3, and hook portions 2b, 2b provided at both ends of the shaft portion 2. In other words, the rod-shaped connecting member 2 is provided such that hook portions 2b, 2b extend in the same direction from both ends of the shaft portion 2a, and is constructed of, for example, a steel rod with a circular cross-section such that the center line 2C of the shaft portion 2a and the center line 2CF of the hook portion 2b are perpendicular to each other. Specifically, it is constructed of a steel rod with a circular cross-section formed in a concave shape such that the angle between the center line 2C of the shaft portion 2a and the center line 2CF of the hook portion 2b is 90 degrees. Then, by inserting one hook portion 2b of the rod-shaped connecting member 2 into the opening 3h that opens at the end 3e of the tubular connecting member 3 provided on the rear support structure 1, and inserting the other hook portion 2b of the rod-shaped connecting member 2 into the opening 3h that opens at the end 3e of the tubular connecting member 3 provided on the front support structure 1, the front and rear support structures 1,1 are connected. In other words, a connecting means is formed by connecting the rod-shaped connecting member 2 and the front and rear tubular connecting members 3, 3, and the front and rear supports 1, 1 are connected by a plurality of connecting means provided at intervals in the circumferential direction of the support 1, resulting in a support structure connection. Furthermore, in the construction of mountain tunnels, when a standard section of a standard cross-sectional cavity and a widened section of a cavity with a larger cross-sectional diameter than the standard section are configured to be continuous, the cavity with a larger diameter than the standard section is gradually excavated from the end face (terminal face) of the standard section, and arch-shaped supports corresponding to the size of the cavity are erected at predetermined intervals along the length of the tunnel. In other words, when constructing a widened section of a tunnel where the cross-sectional shape gradually increases, the same-shaped supports are not always placed parallel to each other at predetermined intervals along the length of the tunnel. Instead, as shown in Figure 5, arch-shaped supports 1,1… with different diameters corresponding to the diameter of the cavity are erected at predetermined intervals along the length of the tunnel (front-to-back direction) TF. However, as shown in Figure 5, in a configuration in which arch-shaped supports 1,1… of different diameters corresponding to the size of the cavity are erected at predetermined intervals along the length direction (front-to-back direction) TF of the tunnel, for example, if the same number of tubular connecting members 3,3… are provided at equal intervals on each arch-shaped support 1,1… of different diameters corresponding to the size of the cavity, then the hook portion 2b of the rod-shaped connecting member 2 cannot be inserted into either the opening 3h of the corresponding front and rear tubular connecting members 3,3 provided on the front and rear supports 1,1. Conventionally, when gradually excavating a cavity with a diameter larger than the cross-sectional diameter of the standard-section cavity from the end face (terminal face) of the standard-section cavity, and erecting arch-shaped supports 1,1... corresponding to the size of the cavity at predetermined intervals along the length direction of the tunnel, for example, as shown in Figure 5, the supports 1,1 at the front and rear were connected by welding 2w to the rod-shaped supports 2, without using tubular connecting members 3. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-112863 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, when adopting a support structure connection system in which a rod-shaped connecting member 2 and a support structure 1 are joined by welding 2w, as shown in Figure 5, when installing the front support structure 1 in a predetermined position relative to the rear support structure 1 installed on the tunnel entrance side, the connection position (welding position) of the rod-shaped connecting member 2 is not determined for the front support structure 1 installed on the tunnel entrance side. Therefore, it is necessary to constantly check the position using measuring means such as an optical distance meter while installing the front support structure 1 in a predetermined position, and it is also necessary to weld the rod-shaped connecting member 2 and the support structure 1 on site, which presents challenges in terms of construction. The present invention has been made in view of the above-mentioned problems, and provides a support structure connection structure that is easy to construct, shortens the construction period, and has excellent construction quality, when constructing a widened section of a mountain tunnel where the diameter of the section of the section gradually increases from the standard section of the [Means for solving the problem]

[0005] The support structure connection structure according to the present invention is a support structure connection structure that connects arch-shaped support structures of different diameters, provided at predetermined intervals before and after the standard cross-section cavity of a mountain tunnel, using a plurality of connecting means provided at intervals in the circumferential direction of the support structure, when constructing a widened cross-section cavity of a mountain tunnel where the diameter of the cavity gradually increases from the standard cross-section cavity. The connecting means comprises a tubular connecting member provided on the front and rear support structures and a rod-shaped connecting member provided on the front and rear support structures and connected to the corresponding front and rear tubular connecting members. The tubular connecting member is provided so that the center line of the pipe extends in the direction along the arch of the support structure, and the rod-shaped connecting part The material has a straight shaft portion with a length corresponding to the distance between the centerlines of the respective front and rear tubular connecting members, and hook portions provided extending in the same direction from both ends of the shaft portion, configured such that the centerline of the shaft portion and the centerline of the hook portion are perpendicular to each other. The connecting means is characterized in that one hook portion of the rod-shaped connecting member is inserted into an opening that opens on the end face of the rear tubular connecting member, and the other hook portion of the rod-shaped connecting member is inserted into an opening that opens on the end face of the front tubular connecting member, so that the centerline of the shaft portion of the rod-shaped connecting member and the centerline of the tube of the tubular connecting member are perpendicular to each other. Furthermore, the tubular connecting member is made of a hollow steel pipe with a circular cross-section, and the rod-shaped connecting member is made of a steel rod with a circular cross-section. The rod-shaped connecting member and the tubular connecting member are connected by the hook portion of the rod-shaped connecting member being fitted into the opening of the tubular connecting member. According to the support structure of the present invention, when constructing a widened section of a mountain tunnel where the diameter of the section gradually increases from the standard section of the section, arch-shaped supports corresponding to the size of the section are erected at predetermined intervals before and after the length of the tunnel, and these supports are connected. This support structure is easy to construct, shortens the construction period, and provides a support structure with excellent construction quality. [Brief explanation of the drawing]

[0006] [Figure 1](a) is a perspective view showing the shoring connection structure, and (b) is a plan view of (a) (an embodiment). [Figure 2] A plan view (embodiment) showing one connecting means for linking the front and rear shoring structures. [Figure 3] Cross-sectional view AA of Figure 2 (embodiment). [Figure 4] (a) is a perspective view showing a tubular connecting member, (b) is a diagram showing a tubular connecting member welded to a support structure, and (c) is a perspective view showing a rod-shaped connecting member. [Figure 5] (a) is a perspective view showing the shoring connection structure, and (b) is a plan view of (a) (conventional example). [Modes for carrying out the invention]

[0007] The support structure according to this embodiment is a support structure that, when constructing a widened section of a mountain tunnel where the diameter of the section gradually increases from the standard section of the section, connects arch-shaped support structures 1, 1... of different diameters, which are provided at predetermined intervals before and after the tunnel in the direction of travel TF, using a plurality of connecting means provided at intervals in the circumferential direction of the support structure 1.

[0008] As shown in Figure 1(a), the support structure 1 is an arch-shaped steel support structure with its upper part formed in a curved shape corresponding to the cross-sectional diameter of the widened cross-sectional cavity and having legs on both sides. For example, it is formed by connecting multiple steel members to create an arch shape. The arched support structure 1 is composed of H-shaped steel members with a web 1a and flanges 1b and 1c, as shown in Figure 3, for example.

[0009] As shown in Figure 1, the connecting means consists of tubular connecting members 3,3 called sheath pipes, which are provided on the support structures 1,1 erected before and after the tunnel in the direction of travel TF, and rod-shaped connecting members 2 called connecting members, which are provided on the front and rear support structures 1,1 and connected to the corresponding front and rear tubular connecting members 3,3.

[0010] The tubular connecting member 3 and the rod-shaped connecting member 2 are the same as those shown in Figure 4. That is, as shown in Figure 4(a), the tubular connecting member 3 is a straight, predetermined length tubular member with openings 3h, 3h on both end faces 3e, 3e, and is made of, for example, a straight, hollow steel pipe with a circular cross-section. The tubular connecting member 3 is attached, for example, to the inner surface 1cu of the flange 1c of the support structure 1 (the flange located on the wall (ground) side of the tunnel cavity) by welding 3w or the like, as shown in Figures 2 and 3, such that the center line 3C of the pipe extends in direction A along the arch of the support structure 1 (see Figure 4(b)). Specifically, as shown in Figure 3, the rear tubular connecting member 3 is welded to the inner surface 1cu near the front (face) edge of the flange 1c of the support structure 1 erected on the rear side (port side), and the front tubular connecting member 3 is welded to the inner surface 1cu near the rear (port side) edge of the flange 1c of the support structure 1 erected on the front side (face side), and these front and rear tubular connecting members 3, 3 are connected by a rod-shaped connecting member 2. Furthermore, as shown in Figure 4(c), the rod-shaped connecting member 2 is a rod-shaped member comprising a straight shaft portion 2a, which is provided on the front and rear supports 1,1 and has a length corresponding to the distance c (see Figure 3) between the respective centerlines 3C, 3C of the front and rear tubular connecting members 3, 3, and hook portions 2b, 2b provided at both ends of the shaft portion 2. In other words, the rod-shaped connecting member 2 is a rod-shaped member comprising a straight shaft portion 2a provided on the front and rear supports 1,1 and having a length corresponding to the distance between the front and rear tubular connecting members 3,3 that correspond to each other, and hook portions 2b, 2b provided at both ends of the shaft portion 2. In other words, the rod-shaped connecting member 2 is provided with hook portions 2b, 2b extending in the same direction from both ends of the shaft portion 2a, and is made of a steel material with a circular cross-section formed in a concave shape, for example, such that the center line 2C of the shaft portion 2a and the center line 2CF of the hook portion 2b are perpendicular to each other (see Figure 4(c)). Furthermore, the shaft diameter of the hook portion 2b and the diameter of the opening 3h are set so that the hook portion 2b of the rod-shaped connecting member 2 can be inserted into the opening 3h of the tubular connecting member 3 in a fitted state.

[0011] Figure 2 is a plan view seen from above of one connecting means for connecting the front and rear support works 1, 1, which is provided on the front and rear support works 1, 1 and is located on the same plane as one end face 3e, 3e of each of the corresponding tubular connecting members 3, 3. As can be seen from the plan view of Figure 2, one hook portion 2b of the rod-shaped connecting member 2 is inserted and attached in a fitted state into an opening 3h that opens at an end portion 3e of the rear tubular connecting member 3 provided on the rear support work 1, and the other hook portion 2b of the rod-shaped connecting member 2 is inserted and attached in a fitted state into an opening 3h that opens at an end portion 3e of the front tubular connecting member 3 provided on the front support work 1, so that the center line 2C of the shaft portion 2a of the rod-shaped connecting member 2 and the center line 3C of the tubular connecting member 3 are orthogonal to each other. That is, in a plan view seen from a direction orthogonal to the plate surface of the flange 1c of the support work 1, in the state where the front and rear support works 1, 1 are connected by the connecting means, as shown in Figure 2, the angle α formed by the center line 2C of the shaft portion 2a of the rod-shaped connecting member 2 and the center line 3C of the tubular connecting member 3 is configured to be 90 degrees.

[0012] Figure 3 is a cross-sectional view taken along the line A-A of Figure 2. In the design stage, as shown in Figure 3, since the horizontal distance a between the front and rear tubular connecting members 3, 3 corresponding to each other and the vertical distance b between the front and rear tubular connecting members 3, 3 corresponding to each other can be calculated, the length c of the shaft portion 2a of the rod-shaped connecting member 2 was calculated based on the Pythagorean theorem.

[0013] In other words, in the embodiment, when the front and rear support works 1, 1 are built in at predetermined positions, the one end faces 3e, 3e of the front and rear tubular connecting members 3, 3 provided on the front and rear support works 1, 1 that constitute each connecting means are configured to be located on the same plane. Then, each hook portion 2b, 2b of the rod-shaped connecting member 2 is inserted into the openings 3h, 3h that open to one end surface 3e, 3e located on the same plane from the same direction along the center lines 3C, 3C of the front and rear tubular connecting members 3, 3. As shown in FIG. 2, the angle α formed by the center line 2C of the shaft portion 2a of the rod-shaped connecting member 2 and the center lines 3C, 3C of the front and rear tubular connecting members 3, 3 is configured to be 90 degrees.

[0014] That is, in the embodiment, the rod-shaped connecting member 2 and the front and rear tubular connecting members 3, 3 are connected such that the angle α formed by the center line 2C of the shaft portion 2a of the rod-shaped connecting member 2, which constitutes each connecting means for connecting the front and rear support timbers 1, 1, and the center line 3C of the tubular connecting member 3 is 90 degrees. When the front and rear support timbers 1, 1 are connected by each connecting means, the front support timber 1 (face side) is installed at a predetermined position with respect to the rear support timber 1 (shaft mouth side) built in, and the front and rear support timbers 1, 1 are in a state of being connected by each connecting means. Therefore, compared with the conventional support timber connection structure, it has become possible to provide a support timber connection structure that is easy to construct, can shorten the construction period, and has excellent construction quality.

[0015] In other words, in the support timber connection structure according to the embodiment in which arch-shaped support timbers 1, 1... corresponding to the size of the cavity are built in at predetermined intervals in the front and rear directions of the tunnel extension direction TF and the front and rear support timbers 1, 1 are connected, in the front and rear support timbers 1, 1, the connection positions of the rod-shaped connecting member 2 are determined by the front and rear tubular connecting members 3, 3. Therefore, when installing the support structure 1 on the front side (facing side) relative to the support structure 1 installed on the rear side (port side) in the extension direction TF of the tunnel, one hook portion 2b of the rod-shaped connecting member 2 is inserted into the opening 3h of the rear tubular connecting member 3 in a fitted state and installed, and the other hook portion 2b of the rod-shaped connecting member 2 is inserted into the opening 3h of the front tubular connecting member 3 in a fitted state and installed, so that the center line 2C of the shaft portion 2a of the rod-shaped connecting member 2 and the center lines 3C, 3C of the front and rear tubular connecting members 3, 3 are perpendicular to each other, the support structure 1 on the front side (facing side) is installed so that the support structure 1 on the front side (facing side) is installed in the predetermined position relative to the support structure 1 on the rear side (port side), thus making construction easier and ensuring construction quality. Furthermore, since it is no longer necessary to erect the front (pit entrance side) support structure 1 in the predetermined position using measuring means such as an optical rangefinder, as in the conventional method, the workload and management burden associated with erecting the front (pit entrance side) support structure 1 in the predetermined position can be reduced. Furthermore, the conventional process of welding the rod-shaped connecting member 2 to the support structure 1 is eliminated. Therefore, compared to conventional shoring connection structures, it is now possible to provide a shoring connection structure that is easier to construct, shortens the construction period, and offers superior construction quality.

[0016] In other words, in the support structure according to the embodiment, at the design stage, the size of each support structure 1,1..., the installation position of each support structure 1,1..., the installation position of the tubular connecting member 3 for each support structure 1,1..., the length of the shaft portion 2a and hook portion 2b of the rod-shaped connecting member 2, etc., can be determined. Furthermore, during on-site construction, by connecting the front and rear support structures 1,1 with a plurality of connecting means provided at intervals in the circumferential direction of the support structure 1, the front support structure 1 (face side) can be accurately installed in a predetermined position relative to the rear support structure 1 (pit entrance side). Therefore, in the support structure according to this embodiment, construction is made easier, construction quality can be ensured, and the need for measuring means such as optical distance meters is eliminated, thereby reducing the workload and management burden, the construction period can be shortened, and construction costs can be reduced.

[0017] Furthermore, in the specification of this invention, "orthogonal" includes not only exact 90 degrees but also angles near 90 degrees. That is, in the specification of this invention, "orthogonal" also includes "approximately orthogonal".

[0018] Furthermore, in the embodiments, examples were given of a steel rod with a circular cross-section being used as the rod-shaped connecting member 2 and a hollow steel pipe with a circular cross-section being used as the tubular connecting member 3, but the cross-sectional shapes of the rod-shaped connecting member 2 and the tubular connecting member 3 are not particularly limited.

[0019] Furthermore, in the embodiment, an example was given in which the tubular connecting member 3 is attached by welding to the inner surface 1cu of the flange 1c of the support structure 1 (the flange located on the wall (ground) side of the tunnel cavity). However, the location and method of attaching the tubular connecting member 3 to the support structure 1 are not particularly limited. In other words, as long as the center line 2C of the shaft portion 2a of the rod-shaped connecting member 2 and the center lines 3C, 3C of the pipes of the tubular connecting members 3, 3 are perpendicular to each other, the location where the tubular connecting member 3 is attached to the support structure 1 is not particularly limited, nor is the method of attaching the tubular connecting member 3 to the support structure 1 particularly limited. [Explanation of Symbols]

[0020] 1. Support structure, 2. Rod-shaped connecting member, 2a. Shaft portion of rod-shaped connecting member, 2b Hook portion of rod-shaped connecting member, 2C Center line of shaft portion of rod-shaped connecting member, 2CF Center line of the hook portion of the rod-shaped connecting member, 3 Tubular connecting member, 3C Centerline of the pipe of the tubular connecting member, 3e End face of the tubular connecting member, 3h Opening of the tubular connecting member.

Claims

1. In constructing a widened section of a mountain tunnel, where the diameter of the section gradually increases from the standard section of the section, a support structure is provided in which arch-shaped support structures of different diameters, provided at predetermined intervals at the front and rear of the tunnel in the direction of travel, are connected using a plurality of connecting means provided at intervals in the circumferential direction of the support structures. The connecting means comprises tubular connecting members provided on the front and rear supports, and rod-shaped connecting members provided on the front and rear supports and connected to the corresponding front and rear tubular connecting members. The tubular connecting member is installed so that the centerline of the pipe extends in a direction along the arch of the support structure. The rod-shaped connecting member has a straight shaft portion with a length corresponding to the distance between the centerlines of the respective front and rear tubular connecting members, and hook portions provided extending in the same direction from both ends of the shaft portion, configured such that the centerline of the shaft portion and the centerline of the hook portion are perpendicular to each other. The connecting means is characterized in that one hook portion of a rod-shaped connecting member is inserted into an opening that opens on the end face of a rear tubular connecting member, and the other hook portion of the rod-shaped connecting member is inserted into an opening that opens on the end face of a front tubular connecting member, so that the center line of the shaft portion of the rod-shaped connecting member and the center line of the tube of the tubular connecting member are perpendicular to each other, thereby connecting the rod-shaped connecting member and the front and rear tubular connecting members.

2. The tubular connecting member is made of a hollow steel pipe with a circular cross-section. The rod-shaped connecting member is made of a steel rod with a circular cross-section. The support structure according to claim 1, characterized in that the rod-shaped connecting member and the tubular connecting member are connected by the hook portion of the rod-shaped connecting member being inserted into the opening of the tubular connecting member in a fitted state.

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