JP7808068B2 - Temporary equipment for installing invert blocks - Google Patents

Description

The present invention relates to temporary equipment used when installing invert blocks, and in particular to temporary equipment used when installing invert blocks in one area of a multi-lane road tunnel, while allowing vehicle traffic on the other area.

Multi-lane mountain road tunnels are tunnels formed by excavating rock or other free-standing, relatively stable ground. The excavated interior walls are covered with primary and secondary linings made of concrete or mortar. Specifically, after excavating the tunnel using blasting or other methods, a protective layer is formed on the interior walls of the mountain tunnel, preferably by spraying mortar or concrete onto the primary lining. Then, a known tunnel lining formwork, for example, is installed inside the protective layer formed by the primary lining. A concrete lining of a predetermined thickness is then formed as a secondary lining from the side walls to the upper arch-shaped portion of the tunnel. Furthermore, a bottom invert lining of a predetermined thickness is integrally formed in the transverse direction of the tunnel between the lower support sections of the pair of side walls of the previously formed lining extending from the side walls to the upper arch-shaped portion of the tunnel, thereby continuously covering the entire interior wall of the mountain tunnel with a secondary lining.

Mountain tunnels are formed by excavating relatively stable ground, so some tunnels constructed more than several decades ago, for example, omit the invert lining and only form a lining in the area from the tunnel's side wall to the upper arch-shaped section, forming a secondary lining. For such mountain tunnels that omit the invert lining, consideration is being given to forming a new invert lining to prevent future effects such as swelling of the base slab.

Furthermore, when forming a new invert lining for an existing mountain tunnel that was constructed several decades ago, for example, it is desirable to be able to carry out construction work in one area while ensuring access to the other area, without completely blocking traffic through the tunnel. Therefore, technology has been disclosed that allows the invert lining of a mountain tunnel to be constructed in each area on either side of the tunnel in the transverse direction (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2000-145390

The method of forming an invert in a mountain tunnel described in Patent Document 1 requires a great deal of work to install the multiple blocks that form the invert lining in one side area. Therefore, in Patent Application No. 2023-058334, for example, the applicant discloses technology that uses hexahedral blocks with curved upper and lower surfaces that follow the curved cross-sectional shape of the invert lining as the multiple blocks, allowing these multiple blocks to be efficiently installed in a continuous array vertically and horizontally. Furthermore, by filling the gaps between adjacent blocks with a filling and solidifying material and allowing it to harden, these multiple blocks are integrated, allowing the efficient formation of an invert structure that forms the invert lining in each side area of a mountain road tunnel.

On the other hand, when attempting to form an invert structure that constitutes an invert lining using multiple hexahedral blocks in one transverse side area of a multi-lane road tunnel while ensuring passage in the other side area, the work yard set up in one side area will be narrow. Therefore, to enable efficient construction without affecting passage in the other side area, further improvements will be needed, particularly in terms of the placement of heavy machinery used to lay the hexahedral blocks vertically and horizontally, and the means of transporting the blocks.

The present invention aims to provide temporary equipment for installing invert blocks that enables efficient installation of multiple hexahedral precast concrete blocks (PCa concrete blocks) that form invert structures in a narrow work yard set up on one side of a multi-lane road tunnel in the transverse direction, without affecting vehicle traffic on the other side, and that enables efficient construction of invert structures that are integrated with these PCa concrete blocks that are arranged in a row vertically and horizontally.

This invention relates to temporary invert block installation equipment used in the process of laying multiple invert blocks, made of PCa concrete blocks that constitute the invert section lining, in a work yard set up in one transverse area of a multi-lane road tunnel, while allowing vehicle passage in the other transverse area. The PCa concrete blocks are formed as hexahedral blocks with curved upper and lower surfaces so as to have a curved shape that follows the cross-sectional shape of the invert section lining. The PCa concrete blocks are installed in the invert section by being arranged side by side in the transverse direction of the tunnel, with a gap maintained between adjacent PCa concrete blocks, and are also installed in the invert section by being arranged side by side in the axial direction of the tunnel, with a gap maintained between adjacent PCa concrete blocks. When the PCa concrete blocks are laid out in the work yard in the one-side area, The above-mentioned objectives are achieved by providing temporary equipment for installing invert blocks in road tunnels, in which, when the base of the installation area has been leveled, a block lifting crane is movably installed in the space behind the laying start point of the installation area in the laying direction, and a block installation crane is movably installed in the space in the installation area toward the laying end point forward of the laying start point in the laying direction, and a block transport conveyor device is disposed on the top surface of the PCa concrete blocks that are installed sequentially in the installation area from the laying start point toward the forward laying end point, and extends from the laying start point to an area within the working radius of the block installation crane, and the block transport conveyor device is installed so that it can be added in the laying direction as the PCa concrete blocks are installed sequentially in the laying direction from the laying start point toward the laying end point.

Furthermore, it is preferable that the temporary equipment for installing inverted blocks of the present invention is arranged in the work yard in the one-side area so that the block lifting lifting machine and the block installation lifting machine can only rotate within an angle range that faces each other with their driver's seats facing each other.

Furthermore, when installing the invert block of the present invention, it is preferable that the angle range in which the driver's seats are opposed is an angle range in which the driver's seats can rotate left or right within 60 degrees from a position in which they face each other directly ahead.

Furthermore, in the temporary invert block installation equipment of the present invention, in the work yard in the one-side area, an auxiliary block lifting lifting machine is movably installed in the space behind the laying start end in the laying direction in the installation area, spaced apart from the block lifting lifting machine, and it is preferable that an auxiliary block transport conveyor device is installed extending from an area within the working radius of the auxiliary block lifting lifting machine to an area within the working radius of the block lifting lifting machine.

Furthermore, in the temporary equipment for installing inverted blocks of the present invention, it is preferable that the block lifting lifting machine and the auxiliary block lifting lifting machine are arranged in the work yard in the one-side area so that they can rotate only within the angle range in which the driver's seat is facing away from them.

Furthermore, it is preferable that the temporary equipment for installing inverted blocks of the present invention is configured so that, in the work yard in the one-side area, a transport vehicle loaded with the PCa concrete blocks moves in the laying direction with its loading platform facing forward in the laying direction in the space behind the auxiliary block lifting crane in the laying direction.

Furthermore, in the temporary equipment for installing invert blocks of the present invention, it is preferable that the block lifting lifting machine is a crawler crane and the block installation lifting machine is a backhoe.

Furthermore, in the temporary installation of invert blocks of the present invention, it is preferable that the block transport conveyor device is a roller conveyor, and the PCa concrete blocks are transported in the extension direction while placed on these roller conveyors.

The temporary invert block installation equipment of the present invention allows multiple hexahedral PCa concrete blocks that form the invert structure to be efficiently installed in a narrow work yard set up on one side of a multi-lane road tunnel in the transverse direction, without affecting vehicle traffic on the other side. This allows for efficient construction of the invert structure, which is made up of an integrated set of PCa concrete blocks arranged in a row and column.

1A and 1B are a schematic vertical cross-sectional view and a schematic plan view, respectively, illustrating temporary installation of an invert block according to a preferred embodiment of the present invention. This is a schematic cross-sectional view illustrating a mountain tunnel in which invert section structures are formed on both sides of the invert section in the transverse direction of the tunnel using temporary equipment during the installation of invert blocks in a preferred embodiment of the present invention. This is a schematic top view of Figure 1 viewed from the A-A direction, illustrating the state in which the invert section structure is formed on both sides over the entire area of the invert section in the transverse direction of the tunnel. This is a schematic cross-sectional view of a mountain tunnel that explains the state in which PCa concrete blocks are laid in one side area while allowing vehicles to pass in the other side area. 1 is a plan view of a main part illustrating temporary equipment when installing an invert block according to a preferred embodiment of the present invention. FIG. FIG. 2 is a longitudinal cross-sectional view of a main part illustrating a temporary installation when an invert block is installed according to a preferred embodiment of the present invention. This is a schematic top view of an invert structure provided in one side region in the transverse direction of the tunnel. 8 is a schematic cross-sectional view taken along CC in FIG. 7, showing the state before the filling solidification material is filled. This is an oblique view of the PCa concrete block that constitutes the invert structure. (a) is a top view of the PCa concrete block that constitutes the invert section structure, (b) is a transverse side view of (a) viewed from the right side, and (c) is an axial side view of (a) viewed from the front side. 1 is a schematic cross-sectional view of a PCa concrete block taken along a portion where a bolt insertion hole is formed, illustrating the bolt insertion hole. FIG. This is a simplified cross-sectional view illustrating the state in which filling solidification material has been filled into the gaps between the receiving base, the gaps between adjacent PCa concrete blocks, and the gaps below the bottom surface of the hexahedron shape. 1 is a schematic cross-sectional view of a PCa concrete block in the transverse direction along the portion where a filler injection hole is formed, illustrating the filler injection hole and the opening and closing valve. FIG. This is a schematic top view of the invert structure explaining the injection status of the filling solidification material. 1 is an explanatory diagram of the unevenness formed on the surface of the central portion of a PCa concrete block. FIG.

The temporary invert block installation equipment 70 according to a preferred embodiment of the present invention, shown in Figures 1(a) and (b), is used as temporary equipment for efficiently laying and arranging multiple hexahedral PCa concrete blocks 20 that form the invert structure 10 on both sides of the tunnel's transverse centerline C when forming a new invert structure 32 on the base 30a of an existing mountain tunnel 30 (see Figure 2), in continuation with the lining 31 that has been previously formed to cover the inner wall surface of the tunnel, from the side wall portions 31a on both sides to the upper arch-shaped portion 31b.

In this embodiment, the mountain tunnel 30 is a tunnel constructed, for example, several decades ago, and the ground to be excavated was stable. Therefore, at the time of construction, the lining 31 covering the tunnel inner wall surface was formed only from the side wall portions 31a on both sides to the upper arch-shaped portion 31b. However, over the years, concerns have arisen about the impact of swelling of the base portion 30a, so as shown in Figure 3, a new invert lining 32 is formed using invert structures 10 on both the left and right sides.

Furthermore, when forming a new invert lining 32 in an existing mountain tunnel 30, it is desirable to be able to carry out construction work while maintaining access to the passageway without completely blocking traffic through the tunnel. Therefore, in this embodiment, as shown in FIG. 4, the steps of forming the invert structure 10 are carried out in one side region 55A of the tunnel in the transverse direction, while maintaining access to the passageway 60 in the other side region 55B. The temporary invert block installation equipment 70 of this embodiment is provided as equipment to enable efficient, vertically and horizontally consecutive installation of the invert structure 10 constituting the invert lining 32 by integrating multiple hexahedral PCa concrete blocks 20 in one side region 55A of the transverse direction of a multi-lane road tunnel 30, without affecting vehicle traffic in the other side region 55B.

The temporary invert block installation equipment 70 of this embodiment is a temporary installation used in the process of installing multiple invert blocks made of PCa concrete blocks 20 that make up the invert section lining 32 by laying them vertically and horizontally on the invert section 33 in a work yard 71 set up in one transverse side area 55A of a road tunnel 30, which is a multi-lane mountain tunnel, as shown in Figures 1(a) and (b), while allowing vehicle traffic in the other side area 55B. The PCa concrete blocks 20 are installed in the invert section 33 by laying them vertically and horizontally on the invert section 33, while allowing vehicle traffic in the other side area 55B. The PCa concrete blocks 20 are installed in the work yard 71 set up in one transverse side area 55A of a road tunnel 30, which is a multi-lane mountain tunnel, as shown in Figures 7 to 10(a) to ( As shown in c), the PCa concrete blocks 20 are formed as hexahedral blocks having curved upper and lower surface portions 20a and 20b so as to have a curved shape that follows the cross-sectional shape of the invert section covering body 32, and are arranged in series in the transverse direction of the tunnel, with gaps 21b maintained between adjacent PCa concrete blocks 20, and are installed in the invert section 33, and are also arranged in series in the axial direction of the tunnel, with gaps 21b maintained between adjacent PCa concrete blocks 20, and are installed in the invert section 33. As also shown in Figures 5 and 6, in the work yard 71 of one side area 55A, when the base 72a of the laying area 72 where the PCa concrete blocks 20 are laid has been leveled, a block lifting crane 74 is movably installed in a space 73 rearward of the laying starting end 72b of the laying area 72 in the laying direction X, and a block installation crane 76 is movably installed in a space 75 in the laying area 72 on the side of the laying terminal end 72c forward of the laying starting end 72b in the laying direction X. The installation area 72 is also equipped with a block transport conveyor device 77, which is disposed on the top surface of the PCa concrete blocks 20 that are installed sequentially from the laying start end 72b toward the forward laying end 72c, and extends from the laying start end 72b to an area within the working radius of the block installation crane 76. This block transport conveyor device 77 is configured so that it can be added in the laying direction X as the PCa concrete blocks 20 are installed sequentially in the laying direction X from the laying start end 72b toward the laying end 72c.

In addition, in this embodiment, the block lifting lifting machine 74 and the block installation lifting machine 76 are preferably arranged in the work yard 71 of one side area 55A so that they can rotate only within an angular range that causes the driver's seats to face each other. Preferably, the angular range that causes the driver's seats to face each other is an angular range in which the driver's seats can rotate left and right within 60 degrees from a state in which the driver's seats face each other directly ahead.

Furthermore, in the temporary invert block installation facility 70 of this embodiment, as shown in Figures 1(a) and (b), preferably in the work yard 71 of one side area 55A, an auxiliary block lifting lifting machine 78 is movably installed in a space 73 rearward of the laying starting end 72b of the laying area 72 in the laying direction X, spaced further rearward from the block lifting lifting machine 74, and an auxiliary block transport conveyor device 79 is disposed extending from the area within the working radius of the auxiliary block lifting lifting machine 78 to the area within the working radius of the block lifting lifting machine 74.

Furthermore, in this embodiment, preferably in the work yard 71 of one side area 55A, the block lifting lifting machine 74 and the auxiliary block lifting lifting machine 78 are arranged so that they can rotate only within the angle range in which the driver's seat is facing away from them. Also preferably in the work yard 71 of one side area 55A, a truck, which is a transport vehicle 80 loaded with PCa concrete blocks 20, moves in the laying direction X with its loading platform facing forward in the laying direction X in the space behind the auxiliary block lifting lifting machine 78 in the laying direction X.

In this embodiment, as shown in Figures 7 and 8, the invert structure 10 formed in one side region 55A and the other side region 55B is formed by arranging a plurality of PCa concrete blocks 20 in series across the tunnel and in the invert section 33, with gaps 21a and 21b maintained between the blocks and the receiving bases 31c at the lower ends of adjacent side wall lining bodies 31a and between adjacent PCa concrete blocks 20, and by arranging the blocks in series across the tunnel and in the invert section 33, with gaps 21b maintained between adjacent PCa concrete blocks 20, and also in the axial direction of the tunnel. The block groups 20X and 10Y are then integrated by filling the gaps 21a between adjacent receiving bases 31c and the gaps 21b between adjacent PCa concrete blocks 20 with a filling solidification material 22 and allowing it to harden (see Figure 11).

That is, in this embodiment, the invert structure 10 is a structure of the invert section 33 using PCa concrete blocks 20 that is provided in at least one side region of the invert section 33 of a mountain tunnel 30 in the transverse direction of the tunnel and constitutes the invert section lining 32. As shown in Figures 9 and 10(a) to 10(c), the PCa concrete blocks 20 are each formed as a hexahedral block having a curved upper surface 20a and a curved lower surface 20b so as to have a curved shape that follows the cross-sectional shape of the invert section lining 32. These multiple PCa concrete blocks 20 are arranged in series in the transverse direction of the tunnel and installed in the invert section 33, with gaps 21a, 21b maintained between the receiving base portions 31c at the lower ends of adjacent side wall linings 31a and between adjacent PCa concrete blocks 20. They are also arranged in series in the axial direction of the tunnel and installed in the invert section 33, with gaps 21b maintained between adjacent PCa concrete blocks. As shown in Figures 2, 3, and 12, these multiple PCa concrete blocks 20 arranged in a row and column are integrated via filling and solidifying material 22 that has been filled and hardened in the gaps 21a between adjacent support portions 31c, the gaps 21b between adjacent PCa concrete blocks 20, and the gaps 21c below the hexahedral underside that communicate with these gaps 21a and 21b, and form at least a part of the invert section lining body 32, forming one side of the invert section lining body 32.

In this embodiment, the multiple PCa concrete blocks 20 are preferably formed to have similar hexahedral shapes with the same width x in the transverse direction of the tunnel, the same vertical width y in the axial direction of the tunnel, and the same height z (see Figures 9 and 10(a)-(c)). The multiple PCa concrete blocks 20 are arranged in a row and column, and are installed in the invert section 33 so that the gaps 21b, which are filled with filling solidification material 22 and extend axially between adjacent PCa concrete blocks 20 in the transverse direction of the tunnel, and the gaps 21b, which extend transversely between adjacent PCa concrete blocks 20 in the axial direction of the tunnel, are preferably arranged in a potato-like pattern that is linearly continuous (see Figures 3 and 7). The gaps 21a between adjacent receiving sections 31c and the gaps 21b between adjacent PCa concrete blocks, which are filled with filling solidification material 22, are preferably spaced approximately 15 to 30 mm apart.

In this embodiment, the multiple PCa concrete blocks 20 constituting the invert section structure 10 are arranged in a row in the transverse direction of the tunnel, with gaps 21a, 21b filled with filling solidification material 22 between the receiving bases 31c at the lower ends of adjacent side wall linings 31a and between adjacent PCa concrete blocks 20, as described above. They are also arranged in a row in the axial direction of the tunnel, with gaps 21b filled with filling solidification material 22 between adjacent PCa concrete blocks, and are installed in the invert section 33 in a row in both the vertical and horizontal directions. Furthermore, as shown in Figures 9 and 10(a)-(c), the PCa concrete blocks 20 are formed as hexahedral blocks with curved upper and lower surfaces 20a, 20b that are curved along the cross-sectional shape of the invert section lining 32, and have a pair of flat axially opposing surfaces 20c at the front and rear and a pair of flat laterally opposing surfaces 20d at the left and right. The upper surface portion 20a and lower surface portion 20b in cross section can be gently curved with a radius of curvature of, for example, approximately 14,000 mm to 145,000 mm.

Furthermore, each of these PCa concrete blocks 20 has bolt boxes 23 or female thread anchors 24 embedded and fixed to the four sides of the hexahedral top surface for connecting adjacent PCa concrete blocks 20 using bolt members (not shown). The bolt boxes 23 open to the top surface 20a of the PCa concrete block 20, and the female thread anchors 24 open to the upper ends of the axially facing surfaces 20c and the transversely facing surfaces 20d of the side surfaces. As shown in Figure 11, each PCa concrete block 20 has three bolt insertion holes 25 that penetrate the hexahedron in the vertical direction, located at each corner of an isosceles triangle (see Figure 10(a)). A female thread member 25a, into which a height adjustment bolt 26 is threaded, is fixed to each bolt insertion hole 25 below the vertical middle. A large trumpet-shaped recess 25b is formed from the portion where the female screw member 25a of each bolt insertion hole 25 is fixed, expanding in diameter upward and opening onto the upper surface 20a of the PCa concrete block 20, and a small trumpet-shaped recess 25c is formed from the portion where the female screw member 25a is fixed, expanding in diameter downward and opening onto the lower surface 20b of the PCa concrete block 20. Height adjustment bolts 26 are inserted into these bolt insertion holes 25 and screwed into the female screw members 25a, so that the height adjustment bolts 26 are attached with their lower ends 26a protruding movably from the lower surface 20b of the PCa concrete block 20. Furthermore, because the large and small trumpet-shaped recesses 25b and 25c have a trumpet shape that tapers toward the upper and lower openings, the box punching members attached to the box-shaped formwork for concrete pouring to form these trumpet-shaped recesses 25b and 25c can be smoothly removed after the concrete has hardened. From this perspective, it is preferable that the taper gradient of the large and small trumpet-shaped recesses 25b and 25c, which have a tapered trumpet shape that expands in diameter, be inclined by 10% or more with respect to the central axis of the bolt insertion and threaded hole 25.

As shown in Figure 10(a), the three bolt insertion and threaded holes 25 are formed on the top surface 20a of the PCa concrete block 20, preferably at each corner of an imaginary isosceles triangle (see dashed line) with the base positioned parallel to one axially opposing surface 20c and the apex positioned on the other axially opposing surface 20c.

In this embodiment, when viewed from the top side of the PCa concrete block 20, it is preferable that the center of gravity of the PCa concrete block 20 be located inside the area surrounded by an imaginary isosceles triangle, and it is particularly preferable that the center of gravity of the PCa concrete block 20 be located at the centroid of the imaginary isosceles triangle. This makes it possible to more stably and precisely adjust the height and tilt of the PCa concrete block 20 using the three height adjustment bolts 26, and also makes it possible to more stably support the PCa concrete block 20, whose height and tilt have been precisely adjusted, using the three height adjustment bolts 26.

Furthermore, as shown in Figures 12 and 13, some of these PCa concrete blocks 20, specifically the PCa concrete blocks 20', have filler injection holes 27 that penetrate the hexahedron in the vertical direction. Each filler injection hole 27 has a female threaded member 27a fixed to the vertical middle portion, to which the male threaded portion of an opening/closing valve member 28 is threaded. An upper horn-shaped recess 27b is formed, expanding in diameter upward from the portion where the female threaded member 27a is fixed and opening onto the upper surface 20a of the PCa concrete block 20'. Also, a lower horn-shaped recess 27c is formed, expanding in diameter downward from the portion where the female threaded member 27a is fixed and opening onto the lower surface 20b of the PCa concrete block 20'. The male threads of the valve member 28 are threaded into the female threads 27a of these filler injection holes 27, and the handle 28a is positioned above the upper surface 20a of the PCa concrete block 20'. This allows the valve member 28 to be detachably attached to the PCa concrete block 20' while the handle 28a can be opened and closed by working on the upper surface 20a of the PCa concrete block 20'. Furthermore, the upper and lower trumpet-shaped recesses 27b and 27c have a trumpet shape that tapers toward the upper and lower openings. This allows the box punching tools attached to the box-shaped formwork for concrete pouring to form these trumpet-shaped recesses 27b and 27c to be easily removed after the concrete has hardened. From this perspective, it is preferable that the taper gradient of these trumpet-shaped recesses 27b and 27c be at least 10% inclined relative to the central axis of the filler injection hole 27.

In this embodiment, the filler injection holes 27 that penetrate the hexahedral PCa concrete block 20' in the vertical direction can be preferably formed in the center of the top surface 20a of the PCa concrete block 20' (see Figure 10(a)). It is particularly preferable that the filler injection holes 27 be formed in the center of the central block 20B, which is located at the lowest position.

In addition, in this embodiment, spacer jigs 29a, 29b can be attached to each of the pair of flat axially opposing surfaces 20c and the pair of flat transversely opposing surfaces 20d, preferably of a hexahedral shape, of these PCa concrete blocks 20 (20') to maintain a predetermined gap 21b between the opposing surfaces 20c, 20d (see Figures 9, 10(b), and (c)). Preferably, multiple lifting jigs 29c are embedded and fixed to the hexahedral upper surface 20a to be used when lifting each PCa concrete block 20 (see Figures 9 and 10(a)).

In this embodiment, these PCa concrete blocks 20 are formed, for example, at a manufacturing factory, by pouring concrete into a box-shaped formwork assembled to conform to the above-mentioned predetermined hexahedron shape, allowing it to harden, and then demolding after a predetermined curing period. The resulting blocks are then formed into a hexahedron shape with a curved upper surface 20a and lower surface 20b, preferably measuring approximately 1,385 to 1,435 mm in width x, approximately 730 mm in length y, and approximately 500 mm in height z, and weighing approximately 1,300 kg. For example, by placing and supporting reinforcement bars inside the box-shaped formwork, the above-mentioned bolt boxes 23, female thread anchors 24, and box-punching members for the bolt insertion and threading holes 25 and filler injection holes 27 can be attached and embedded in the PCa concrete block 20 or temporarily fixed thereto. In this embodiment, the size, shape, weight, etc. of the PCa concrete blocks 20 used as invert blocks can be designed appropriately according to the capacity of the lifting equipment or other equipment that can be used in the work yard 71 of one side area 55A without affecting vehicle traffic in the other side area 55B. For example, the weight of the PCa concrete blocks 20 can preferably be 1,000 to 1,500 kg.

In addition, in this embodiment, the multiple PCa concrete blocks 20 are formed to have similar hexahedral shapes, which allows for efficient production by limiting the type of box formwork used. Furthermore, because the blocks are of similar weight, workability during lifting and transport is improved. Furthermore, since the blocks can be handled in the same way when lifting or installing them in the work yard 71 of one side area 55A, it becomes easier to precisely install each PCa concrete block 20 in a predetermined position, for example, by arranging them in a potato-like pattern. This also makes it possible to reduce manufacturing costs.

In this embodiment, as described above, the invert structure 10 is constructed in each of the pair of half regions 55A, 55B, with the regions on either side of the tunnel's transverse center being treated as a pair of half regions (see Figures 2 and 3). As described above, in the center of the tunnel's transverse direction in the invert section 33, multiple H-shaped steel beams 35 supporting retaining plate members 57 can be installed at a predetermined interval in the tunnel axial direction by driving them into the ground of the invert section 33 with the flange portions 35a aligned with the tunnel axial direction, to support the retaining plate members 57 that prevent the passageway 60 in the other half region 55B from being affected when the invert structure 10 is constructed in each half region 55A, 55B. For this reason, at the position where these H-shaped steel beams 35 are installed, a pair of PCa concrete blocks (central blocks) 20B adjacent in the axial direction of the tunnel at the center of the tunnel's transverse direction can have notched recesses 20e with rectangular cross-sections formed in the corners on both sides of the gap 21b between them (see Figure 8). These notched recesses 20e in the corners on both sides can form flange mounting recesses 10a for mounting one flange of the H-shaped steel beam 35 on the end face (central end face) 10B of each invert structure 10 on the central side of the tunnel's transverse direction, at the portion where the H-shaped steel beam 35 is installed.

That is, in the block groups 20X, 20Y (see FIG. 2) made up of a plurality of PCa concrete blocks 20 constituting the invert structure 10 of each side region 55A, 55B, the PCa concrete block 20 (central side block 20B) arranged in the portion where the H-shaped steel 35 is erected has a curved upper surface portion 20a and a lower surface portion 20b having a curved shape that follows the cross-sectional shape of the invert section covering body 32, and is formed as a hexahedral block having a pair of flat axial opposing surfaces 20c at the front and rear and a pair of flat transverse opposing surfaces 20d at the left and right (see FIGS. 10(a) to (c)), and at the corner portion between the axial opposing surfaces 20c and the transverse opposing surfaces 20d at any one location, as shown in FIG. 7, a notched recess 20e having a rectangular cross-sectional shape is cut out so as to have a side portion having a width of at least 1/2 the width of the flange portion 35a of the H-shaped steel 35, and is provided continuously from the upper surface portion 20a to the lower surface portion 20b. As a result, at the central ends of a pair of central blocks 20B that are adjacent in the axial direction of the tunnel at the section where the H-shaped steel 35 is erected, these cutout recesses 20e form flange mounting recesses 10a that can accommodate the flange portions of the H-shaped steel 35.

In this embodiment, as shown in Figures 7 and 8, the multiple PCa concrete blocks 20 that make up the invert section structure 10 have multiple transverse block rows 20D that include a base side block 20A arranged adjacent to the base portion 31c at the lower end of the side wall lining body 31a, a central side block 20B arranged on the transverse central side of the invert section, and one or more intermediate blocks 20C (in this embodiment, one intermediate block 20C) arranged between them. These PCa concrete blocks 20A, 20B, 20C are arranged in a row in the transverse direction of the tunnel, with gaps 21a, 21b maintained between adjacent base portions 31c and between adjacent PCa concrete blocks 20A, 20B, 20C, and also in the axial direction of the tunnel, with gaps 21b maintained between adjacent PCa concrete blocks 20A, 20B, 20C (transverse block rows 20D), and are installed in rows vertically and horizontally on the invert section 33. The multiple PCa concrete blocks 20A, 20B, and 20C used when constructing the invert structure 10 can be installed using the following method for installing PCa blocks in the invert section.

In other words, in this embodiment, the multiple PCa concrete blocks 20A, 20B, 20C of each transverse block row 20D arranged in a row across the tunnel are installed in the invert section 33 by installing the base-side block 20A adjacent to the base section 31c and temporarily fixing it using the temporary fixing means 36, as shown in Figure 8, and then installing the intermediate block 20C and the central block 20B adjacent to the temporarily fixed base-side block 20A.

For example, the base section side block 20A is installed adjacent to the base section 31c and temporarily fixed using the temporary fixing means 36, and then the intermediate section block 20C is installed adjacent to the temporarily fixed base section side block 20A. At the adjacent location between the installed intermediate section block 20C and the base section side block 20A, they are temporarily fixed using bolt members (not shown) via a bolt box 23 arranged on the upper surface 20a of at least one of the PCa concrete blocks 20A, 20C that is close to the transverse opposing surface 20d. The height and position of each PCa concrete block 20A, 20C are then adjusted, and the bolt members are then fully tightened. Next, the central block 20B is installed adjacent to the intermediate block 20C, and at the adjacent location between the installed central block 20B and the intermediate block 20C, they are temporarily fixed with bolts via a bolt box 23 arranged on the upper surface 20a of at least one of the PCa concrete blocks 20C, 20B that is close to the transverse opposing surface 20d. After adjusting the height and position of the central block 20B, the bolts are finally tightened, thereby installing the multiple PCa concrete blocks 20A, 20B, 20C of each transverse block row 20D connected in the transverse direction of the tunnel into the invert section 33.

In this embodiment, the temporary fixing means 36 that temporarily fixes the pedestal-side block 20A adjacent to the pedestal 31c preferably comprises a wire, chain, or other such cable 36b, both ends of which are secured to a locking member attached to a hole-in anchor 36a embedded in the pedestal 31c and to a locking member attached to a bolt box 23 or a lifting jig 29c provided on the pedestal-side block 20A. The wire, chain, or other such cable 36b may be provided with an extension/retraction adjustment means 36c, such as a turnbuckle, that adjusts the length between the locked ends. This makes it possible to adjust the width of the gap 21a maintained between the pedestal 31c and the adjacent pedestal-side block 20A.

In addition, in this embodiment, the height of each of the PCa concrete blocks 20A, 20B, and 20C can be adjusted using three height adjustment bolts 26 threaded into the bolt insertion holes 25 formed in the three locations described above, as shown in Figure 11. That is, each of the PCa concrete blocks 20A, 20B, and 20C has three bolt insertion holes 25 formed in the vertical direction, and a height adjustment bolt 26 is attached to each bolt insertion hole 25 in a manner that allows the lower end 26a to protrude downward from the underside 20b of the PCa concrete block 20A, 20B, and 20C. Prior to the process of filling the gaps 21a between adjacent receiving portions 31c of multiple PCa concrete blocks 20A, 20B, and 20C arranged vertically and horizontally with filling solidifying material 22, the gaps 21b between adjacent PCa concrete blocks 20A, 20B, and 20C, and the gaps 21c below the hexahedral undersides 20b that communicate with these gaps 21a and 21b (see Figure 12), the PCa concrete blocks 20A, 20B, and 20C are rotated from above to change the length by which the three height adjustment bolts 26 in each PCa concrete block 20A, 20B, and 20C protrude from the underside 20b of the PCa concrete block 20A, 20B, and 20C, thereby adjusting the height and inclination of each PCa concrete block 20A, 20B, and 20C.

As described above, in this embodiment, a nut member, preferably a female thread member 25a, is fixed to each bolt insertion hole 25 below the vertical middle. The height adjustment bolts 26 are threadedly attached to these nuts 25a, allowing the lower ends 26a of the height adjustment bolts 26 to protrude downward from the undersides 20b of the PCa concrete blocks 20A, 20B, and 20C. A tiltable ground adjuster 26b can be attached to the lower ends 26a of the height adjustment bolts 26. This allows the lower ends 26a of the height adjustment bolts 26 to be stably grounded on the ground, i.e., the filling bottom surface 26c, below the undersides 20b. The ground adjuster 26b can also be shaped so that when the height adjustment bolt 26 is retracted upward, the opening periphery of the bolt insertion hole 25 can be tapered to fit into the small trumpet-shaped recess 25c, which widens downward and is formed in the underside 20b of the PCa concrete blocks 20A, 20B, and 20C.

In this embodiment, the upper end 26d of the height adjustment bolt 26 is preferably formed to have a rectangular cross section. By engaging a rotation tool, such as an insert extension bar, with this upper end 26d and rotating the height adjustment bolt 26, the length of protrusion of the lower end 26a of the height adjustment bolt 26 from the lower surface 20b of the PCa concrete block 20A, 20B, or 20C can be easily adjusted by working above the upper surface 20a of the PCa concrete block 20A, 20B, or 20C. As described above, the bolt insertion hole 25 has a large trumpet-shaped recess 25b that expands upward from the portion where the nut member 25a, which is a female thread member, is secured, and opens to the upper surface 20a of the PCa concrete block 20A, 20B, or 20C. If the upper end 26d of the height adjustment bolt 26 protrudes from or is close to the upper surface 20a of the PCa concrete block 20A, 20B, or 20C after the lower end 26a is adjusted to contact the filling bottom surface 26c, preventing sufficient cover thickness from being secured above the upper end 26d when the large trumpet-shaped recess 25b is filled with finishing filler, the upper end 26d of the height adjustment bolt 26 can be cut to the required length in the large trumpet-shaped recess 25b. This ensures the desired cover thickness of the finishing filler, such as mortar, filled in the bolt insertion hole 25, preventing corrosion of the height adjustment bolt 26. The work of cutting the upper end 26d of the height adjustment bolt 26 can be performed smoothly because the large trumpet-shaped recess 25b, which expands in diameter, provides ample working space.

Furthermore, in this embodiment, in the invert section structure 10 using the above-mentioned PCa concrete blocks 20A, 20B, and 20C, the following PCa block connection structure 37 in the invert section structure can be adopted as the connection structure for connecting and arranging multiple PCa concrete blocks 20A, 20B, and 20C vertically and horizontally and installing them as a single unit on the invert section 33 while maintaining gaps 21b of a predetermined spacing width between adjacent PCa concrete blocks 20A, 20B, and 20C.

In other words, in this embodiment, as shown in Figures 7, 8, and 10(a) to (c), the PCa block connection structure 37 is configured such that transverse spacer jigs 29a (see Figure 10(b)) fixed to one of the transversely opposing surfaces 20d of adjacent PCa concrete blocks 20A, 20B, 20C facing each other in the transverse direction of the tunnel are interposed between the adjacent pairs of transversely opposing surfaces 20d, preferably in at least three locations, and the fastening force of bolt members (not shown) fastened in bolt boxes 23 arranged on the upper surface 20a of at least one of the PCa concrete blocks 20A, 20B, 20C adjacent to the transversely opposing surfaces 20d connects each pair of PCa concrete blocks 20A, 20B, 20C adjacent in the transverse direction of the tunnel, while maintaining a gap 21b of a predetermined spacing width between the transversely opposing surfaces 20d. Additionally, between each pair of axially opposing surfaces 20c of adjacent PCa concrete blocks 20A, 20B, and 20C in the tunnel axis direction, axial spacer jigs 29b (see Figure 10(c)) are fixed to one of the axially opposing surfaces 20c, preferably at at least three locations. The bolt boxes 23 are located on the upper surface 20a of at least one of the PCa concrete blocks 20A, 20B, and 20C adjacent to the axially opposing surfaces 20c. The fastening force of bolts (not shown) fastened by bolts is used to connect each pair of adjacent PCa concrete blocks 20A, 20B, and 20C in the tunnel axis direction, maintaining a predetermined gap 21b between the axially opposing surfaces 20c. The transverse spacer jigs 29a and axial spacer jigs 29b can also be attached to the transversely opposing surfaces 20d and axially opposing surfaces 20c at the locations where the bolt boxes 23 are installed.

In this embodiment, the transverse spacer jigs 29a and/or the axial spacer jigs 29b may be made of mortar blocks, preferably attached and fixed to one of the opposing surfaces 20c, 20d. The mortar block spacer jigs 29a, 29b may be removably attached to the opposing surfaces 20c, 20d and removed after the PCa concrete blocks 20A, 20B, 20C are fully tightened and connected. The transverse spacer jigs 29a and/or the axial spacer jigs 29b may also be made of male threaded members, preferably threaded into female threaded inserts embedded in one of the opposing surfaces 10c, 10d, so that the protruding length can be adjusted.

The transverse spacer jigs 29a and axial spacer jigs 29b, preferably arranged in at least three locations and secured to either one of the transverse opposing surfaces 20d or the axial opposing surface 20c, are preferably secured to at least two locations in the area below the center of gravity of the PCa concrete blocks 20A, 20B, and 20C. This makes it possible to stably and accurately form gaps 21a and 21b of the specified spacing in the area below the center of gravity, where it is difficult to confirm that the gaps 21a and 21b have been formed accurately, without using special equipment when installing the PCa concrete blocks 20A, 20B, and 20C.

The bolt members fastened in the bolt boxes 23 arranged on the upper surface 20a of at least one of the PCa concrete blocks 20A, 20B, 20C adjacent to the transverse opposing surface 20d, or the bolt members fastened in the bolt boxes 23 arranged on the upper surface 20a of at least one of the PCa concrete blocks 20A, 20B, 20C adjacent to the axial opposing surface 20c, may preferably be fastened across the bolt box 23 arranged on the upper surface 20a adjacent to the axial opposing surface 20c or transverse opposing surface 20d of one of the PCa concrete blocks 20A, 20B, 20C, and a female thread anchor 24 embedded in the axial opposing surface 20c or transverse opposing surface 20d of the other PCa concrete block 20A, 20B, 20C. Preferably, the bolt box 23 may be fastened across the bolt box 23 arranged on the top surface 20a adjacent to the axially opposing surface 20c or the transversely opposing surface 20d of one PCa concrete block 20A, 20B, 20C, and the bolt box 23 arranged on the top surface 20a adjacent to the axially opposing surface 20c or the transversely opposing surface 20d of the other PCa concrete block 20A, 20B, 20C.

In this embodiment, as shown in FIG. 12, the multiple PCa concrete blocks 20A, 20B, and 20C arranged in a row and column are integrated via the filling solidification material 22 that has been filled and hardened into the gaps 21a between adjacent receiving portions 31c, the gaps 21b between adjacent PCa concrete blocks 20A, 20B, and 20C, and the gaps 21c below the hexahedral undersides that communicate with these gaps, thereby constituting at least a portion of the invert section covering body 32. In this embodiment, the filling solidification material 22 is filled into the gaps 21a between adjacent receiving portions 31c, the gaps 21b between adjacent PCa concrete blocks 20A, 20B, and 20C, and the gaps 21c below the hexahedral undersides that communicate with these gaps 21a and 21b, using the following construction method.

In other words, in this embodiment, in order to fill the gaps 21a between adjacent receiving portions 31c of multiple PCa concrete blocks 20A, 20B, and 20C arranged in a row vertically and horizontally, the gaps 21b between adjacent PCa concrete blocks 20A, 20B, and 20C, and the gaps 21c below the hexahedral lower surface portions that communicate with these gaps 21a and 21b, the opening portions of the gaps 21a and 21b that open on the upper surface portions 20a, gable end surface portions 10A (see Figures 7 and 14), and center end surface portions 10B (see Figures 7 and 12) of multiple PCa concrete blocks 20A, 20B, and 20C arranged in a row vertically and horizontally are closed. 12 to 14, the filling material 22 is sequentially injected into the gaps 21a and 21b through the center-side filler injection holes 27d provided vertically through one or more of the plurality of center-side blocks 20B arranged in the axial direction of the tunnel, and through the pedestal-side filler injection holes 27e provided vertically through one or more of the plurality of pedestal-side blocks 20A arranged in the axial direction of the tunnel. Preferably, as shown in FIG. 14, the filling material 22 is injected first through the center-side filler injection hole 27d, then switched to the pedestal-side filler injection hole 27e, and further injected into the pedestal-side block 31c. After confirming that the filling material 22 has flowed out of the opening of the gap 21a between the pedestal-side block 20A and the pedestal-side block 31c held by the upper surface 20a of the pedestal-side block 20A, the filling of the filling material 22 is completed. It is also possible to inject the filling solidification material 22 using only the filling material injection hole 27d of the center side block 20B, without using the filling material injection hole 27e of the base side block 20A, and to finish filling the filling solidification material 22 once it has been confirmed that the filling solidification material 22 is flowing out from the opening of the gap 21a between the base 31c held by the upper surface 20a of the base side block 20A.

In addition, it is preferable to attach air vent hoses 42 (see Figure 12) that extend from appropriate positions and communicate with the gaps 21a, 21b, and 21d on the upper surfaces 20a to the band-shaped formwork 41a that closes the openings of the gaps 21a, 21b, and 21d on the upper surfaces 20a of multiple PCa concrete blocks 20A, 20B, and 20C arranged vertically and horizontally. This makes it possible to effectively vent air from the gaps 21a, 21b, and 21d via the air vent hoses 42 when the filling solidification material 22 is filled, and it is also possible to confirm that the filling solidification material 22 has been filled by seeing the filling solidification material 22 flow out of these air vent hoses 42.

The temporary invert block installation equipment 70 of this embodiment is used when constructing the above-mentioned invert section lining 10 in each of the transverse side regions 55A and 55B of the tunnel, as shown in Figures 1(a), (b), and 4. For example, in one side region 55A, while ensuring passage on the passageway 60 in the other side region 55B, multiple invert blocks made of PCa concrete blocks 20 that make up the invert section lining 32 are installed in a vertical and horizontal line on the invert section 33. This equipment allows multiple hexahedral PCa concrete blocks to be efficiently installed in a vertical and horizontal line without affecting vehicle traffic in the other side region 55B.

5 and 6, in this embodiment, in the work yard 71 of one side area 55A, with the base 72a of the laying area 72 where the PCa concrete blocks 20 are laid being leveled as described above, a block lifting crane 74 is movably installed in a space 73 rearward of the laying starting end 72b in the laying area 72 in the laying direction X, and a block installation crane 76 is movably installed in a space 75 in the laying area toward the laying end 72c forward of the laying starting end 72b in the laying direction X. Also, a block transport conveyor device 77 is installed on the top surface of the PCa concrete blocks 20 sequentially laid in the laying area 72 from the laying starting end 72b toward the forward laying end 72c, and extends from the laying starting end 72b to an area within the working radius of the block installation crane 76. This block transport conveyor device 77 is designed to add blocks as needed in the laying direction X as the PCa concrete blocks 20 are sequentially placed in the laying direction X from the laying start end 72b to the laying end 72c.

In this embodiment, the block lifting lifting machine 74 is preferably a crawler crane, and the block installation lifting machine 76 is preferably a backhoe. A roller conveyor can preferably be used as the block transport conveyor device 77. In the space 73 behind the laying start end 72b in the laying direction X of the laying area 72, the PCa concrete block 20 lifted by the block lifting lifting machine 74 can be placed on the roller conveyor 77, preferably with the curved underside 20b as the placement surface and the pair of flat axially opposing surfaces 20c aligned along the extension direction of the roller conveyor 77. As a result, each PCa concrete block 20 moves while rotating the multiple rollers of the roller conveyor 77, allowing it to be transported smoothly and stably to the portion of the space 75 adjacent to the block installation lifting machine 76 on the laying end end 72c side in the laying direction X.

In this embodiment, the truck, which is the vehicle 80 (see Figure 1) transporting the PCa concrete blocks 20, can move from the rear to the work yard 71, preferably on the lane of one side area 55A, without crossing into the work yard 71 from the other side area 55B, so as not to affect traffic in the other side area 55B. The PCa concrete blocks 20 loaded on the moving truck 80 can be unloaded into the work yard 71 by a block lifting crane 74. The unloaded PCa concrete blocks 20 can be lifted appropriately, for example, by the block lifting crane 74, and sequentially lowered and placed on the end of the roller conveyor 77 installed on the top surface of the laid PCa concrete blocks 20, on the side of the laying starting end 72b in the laying direction X. The PCa concrete block 20 placed on the starting end 72b of the roller conveyor 77 can be pushed out, for example by hand, by a worker and moved smoothly along the roller conveyor 77 to an area within the working radius of the block installation lifting machine 76, which is installed in the space 75 on the terminal end 72c of the laying direction X, in front of the block lifting lifting machine 74 on the starting end 72b side.

In the space 75 at the laying end 72c of the laying area 72 in the work yard 71, where the block installation lifting machine 76 is installed, the block installation lifting machine 76, which is positioned with its driver's seat facing the block lifting lifting machine 74, can lift up PCa concrete blocks 20 that have been transported to the adjacent area along the roller conveyor 77, and install them sequentially at designated positions in the laying area 72 without rotating 180 degrees, preferably by a rotation angle of no more than 60 degrees to the left or right, while keeping the driver's seat facing the block, so as not to affect vehicle traffic in the other area on either side. Furthermore, the block transport conveyor device 77 can be added as needed in the laying direction X as the PCa concrete blocks 20 are sequentially placed in the laying direction X toward the laying starting end 72b. Therefore, by repeating the same operation while moving the block installation lifting machine 76 back while still facing it, it is possible to efficiently install multiple PCa concrete blocks 20 in a row, vertically and horizontally, with the driver's seat facing the block lifting lifting machine 74.

As a result, the temporary invert block installation equipment 70 of this embodiment allows the multiple hexahedral PCa concrete blocks 20 that form the invert structure 10 to be efficiently arranged and installed in a row vertically and horizontally in a narrow work yard 71 set up in one transverse side area 55A of a multi-lane road tunnel without affecting vehicle traffic in the other side area 55B, making it possible to efficiently construct the invert structure 10, which is an integrated unit of these PCa concrete blocks 20 arranged in a row vertically and horizontally.

In this embodiment, as shown in FIGS. 1A and 1B, in the work yard 71 of the one side area 55A, a space 73 on the rear side of the laying starting end 92b of the laying area 72 in the laying direction X is provided, spaced further rearward of the block lifting crane 74,
An auxiliary block lifting lifting machine 78, preferably a crawler crane, is movably installed, and an auxiliary block transport conveyor device 79, preferably a roller conveyor, is disposed extending from the area within the working radius of the auxiliary block lifting lifting machine 78 to the area within the working radius of the block lifting lifting machine 74. In the work yard 71 in one side area 55A, the block lifting lifting machine 74 and the auxiliary block lifting lifting machine 78 are preferably positioned so that they can rotate only within the angle range in which the driver's seat is turned away. This allows the auxiliary block lifting lifting machine 78 to unload PCa concrete blocks 20 loaded on a truck without increasing the rotational width, or to lift them as needed and place them on the end of the auxiliary block transport conveyor device 79 on the laying start end 72b side. Furthermore, the PCa concrete blocks 20 transported via the auxiliary block transport conveyor device 79 to the area adjacent to the block lifting lifting machine 74 can be lifted by the block lifting lifting machine 74, with the driver's seat facing away from the driver, without increasing the swing width, and can be successively lowered onto the end of the roller conveyor 77 installed on the upper surface of the laid PCa concrete blocks 20, on the side of the laying starting end 72b. This makes it possible to more efficiently install the multiple hexahedral PCa concrete blocks 20 that form the invert section structure 10 in a continuous vertical and horizontal arrangement without affecting vehicle traffic in the other side region 55B.

Furthermore, in this embodiment, in the work yard 71 of one side area 55A, a transport vehicle 80, such as a truck, loaded with PCa concrete blocks 20 moves in the laying direction X with its loading platform facing forward in the laying direction X, preferably in the space behind the auxiliary block lifting lifting machine 78 in the laying direction X. Using the auxiliary block lifting lifting machine 78, the PCa concrete blocks 20 loaded on the truck 80 can be unloaded without increasing the swing width, or lifted as needed and placed at the end of the auxiliary block transport conveyor device 79 on the laying starting end 72b side. This makes it possible to install PCa concrete blocks 20 in the work yard 71 of one side area 55A without having to rotate heavy machinery such as the block installation lifting machine 76, block lifting lifting machine 74, and auxiliary block lifting lifting machine 78 180 degrees. Furthermore, because the transport vehicle 80 loaded with PCa concrete blocks 20 moves to the work yard 71 with its loading platform facing forward in the laying direction X, work can be carried out efficiently in one side area 65A without having to move the transport vehicle 80 sideways from the other side area 55B.

In this embodiment, the temporary equipment 70 for installing the invert blocks can also be used in a work yard set up in the other side area 55B that has become the new one-side area, while ensuring vehicle passage in the one-side area 55A where construction has been completed, when the other side area 55B of a multi-lane road tunnel such as a mountain tunnel 30 is used as the new one-side area, and the one-side area 55A where construction of the invert section structure 10 has been completed is used as the other side area, and the invert section structure 10 is installed in the other side area 55B that has become the new one-side area. In other words, when the area above the invert structure 10 formed in one side region 55A is backfilled to restore the passage and ensure vehicle passage, and then the other side region 55B is used as a new side region to construct the invert structure 10, the temporary invert block installation equipment 70 of this embodiment can be used as equipment to efficiently install multiple PCa concrete blocks 20 laid out vertically and horizontally without affecting vehicle passage in the other side region.

In this embodiment, the invert section structures 10 formed in one side region 55A and the other side region 55B are integrated to form the invert section structure 50 across the entire transverse area, which constitutes the invert section covering body 32, as shown in Figures 2 and 3.

In other words, the invert section structure 50 covering the entire transverse area is a structure using PCa concrete blocks 20A, 20B, and 20C that is provided throughout the entire transverse area of the tunnel in the invert section 33 of the mountain tunnel and constitutes the invert section lining body 32, and each of the PCa concrete blocks 20A, 20B, and 20C is formed as a hexahedral block having curved upper surface 20a and lower surface 20b so as to have a curved shape that follows the cross-sectional shape of the invert section lining body 32, as described above. 2 and 3, in each of the tunnel's transverse side regions 55A and 55B, a plurality of PCa concrete blocks 20A, 20B, and 20C are arranged in series in the transverse direction of the tunnel and installed in the invert section 33, with gaps 21a and 21b maintained between the receiving bases 31c at the lower ends of adjacent side wall linings 31a and between adjacent PCa concrete blocks. Also, in the axial direction of the tunnel, adjacent PCa concrete blocks 20A, 20B, and 20C are arranged in series in the invert section 33, with gaps 21b maintained between them. This forms a first-side block group 20X and an second-side block group 20Y. Furthermore, a gap 51 is maintained between the first-side block group 20X and the second-side block group 20Y in the central portion of the tunnel's transverse direction. The multiple PCa concrete blocks 20A, 20B, 20C arranged vertically and horizontally in the one-side block group 20X and the other-side block group 20Y are integrated to form the invert section covering body 32 via the filling solidification material 22 that has been filled and hardened in the gaps 21a between adjacent receiving portions 31c, the gaps 21b between adjacent PCa concrete blocks 20A, 20B, 20C, the gaps 51 between the one-side block group 20X and the other-side block group 20Y, and the gaps 21c below the hexahedral underside that communicate with these gaps 21a, 21b and gaps 51.

In addition, in this embodiment, the gaps 21a between adjacent receiving base portions 31c filled with filling solidification material 22 and the gaps 21b between adjacent PCa concrete blocks 20A, 20B, and 20C preferably have a spacing width of 15 to 30 mm, and the gap portion 51 between one side block group 20X and the other side block group 20Y preferably has a spacing width of 100 to 130 mm.

Furthermore, in this embodiment, the multiple PCa concrete blocks 20A, 20B, 20C arranged in a row vertically and horizontally in the one-side block group 20X and the other-side block group 20Y are installed in the invert section 33 in a potato-like arrangement, with the gaps 21b extending axially between adjacent PCa concrete blocks in the transverse direction of the tunnel and the gaps extending transversely between adjacent PCa concrete blocks in the axial direction of the tunnel filled with filling solidification material 22, preferably both arranged linearly and continuously.

Furthermore, in this embodiment, it is preferable that the central side surface of the PCa concrete block (central side block) 20B located closest to the center of one side block group 20X, which faces the gap portion 51, and the central side surface of the PCa concrete block (central side block) 20B located closest to the center of the other side block group, are formed with irregularities 52 to improve adhesion with the filling solidification material 22, as shown in Figure 15, for example.

The unevenness 52 that improves adhesion with the filling solidification material 22 can also be formed on the lateral opposing surfaces 20d across the maintained gaps 21a, 21b of each PCa concrete block 20 that are arranged in series across the tunnel and installed in the invert section 33, preferably with gaps 21a, 21b maintained between the receiving base portions 31c at the lower ends of adjacent side wall lining bodies 31a and adjacent PCa concrete blocks 20. The unevenness 52 that improves adhesion with the filling solidification material 22 can also be formed on the axial opposing surfaces 20c across the maintained gaps 21b of each PCa concrete block 20 that are arranged in series across the tunnel and installed in the invert section 33, preferably with gaps 21b maintained between the PCa concrete blocks 20.

In addition, in this embodiment, it is preferable that the PCa concrete block (central block) 20B located most centrally of the one-side block group 20X and the PCa concrete block (central block) 20B located most centrally of the other-side block group 20Y are connected via long bolt members (not shown). This makes it possible to ensure the installation accuracy of the one-side block group 20X and the other-side block group 20Y, as well as to ensure the shear strength of the portion between these block groups 20X and 20Y.

In this embodiment, the invert structure 50 for the entire transverse area of the tunnel described above can be formed by the following construction method. That is, in this embodiment, the construction method for the invert structure 50 involves arranging multiple PCa concrete blocks 20A, 20B, and 20C in a row in the transverse direction of the tunnel in one side region 55A of the tunnel, while maintaining gaps 21a and 21b between the blocks and the receiving base 31c at the lower end of the adjacent side wall lining body 31a and between the blocks and adjacent PCa concrete blocks 20A, 20B, and 20C, and installing them in the invert section 33. Also, gaps 21b are maintained between adjacent PCa concrete blocks 20A, 20B, and 20C in the axial direction of the tunnel. and a step of filling and hardening a filling solidification material 22 into the gaps 21a between the adjacent receiving base portions 31c of the plurality of PCa concrete blocks 20A, 20B, 20C of the one side block group 20X arranged in a row and row, the gaps 21b between the adjacent PCa concrete blocks 20A, 20B, 20C, and the gaps 21c below the lower surface portions of the hexahedrons communicating with the gaps 21a, 21b, and 21c, respectively; and a step of filling and hardening a filling solidification material 22 into the gaps 21a between the adjacent receiving base portions 31c of the plurality of PCa concrete blocks 20A, 20B, 20C of the one side block group 20X arranged in a row and row, and the gaps 21b between the adjacent PCa concrete blocks 20A, 20B, 20C, and the gaps 21c below the lower surface portions of the hexahedrons communicating with the gaps 21a, 21b, and 21c, respectively, of the plurality of PCa concrete blocks 20A, 20B, 20C in the other side region 55B in the transverse direction of the tunnel. A step of forming the other side block group 20Y by arranging the PCa concrete blocks 20A, 20B, 20C in a row in the transverse direction of the tunnel and installing them in the invert section 33 while maintaining gaps 21a, 21b between them and the receiving base section 31c at the lower end of the adjacent side wall lining body 31a and between them and the adjacent PCa concrete blocks 20A, 20B, 20C, and also by arranging the PCa concrete blocks 20A, 20B, 20C in a row in the axial direction of the tunnel and installing them in the invert section 33 while maintaining gaps 21b between them and the adjacent PCa concrete blocks 20A, 20B, 20C, The process includes a step of filling and hardening filling solidification material 22 into the gaps 21a between adjacent support portions 31c of multiple PCa concrete blocks 20A, 20B, 20C, the gaps 21b between adjacent PCa concrete blocks 20A, 20B, 20C, and the gaps 21c below the hexahedral undersides that communicate with these, as well as into the gaps 51 between one side block group 20X and the other side block group 20Y. This makes it easy to form the invert structure 50 that is provided across the entire transverse area of the tunnel and that constitutes the invert lining 32.

The present invention is not limited to the above-described embodiments and can be modified in various ways. For example, the block lifting lifting machine and auxiliary block lifting lifting machine do not necessarily have to be crawler cranes; other types of heavy lifting equipment such as tow trucks, crawler trucks, and Unic vehicles can be used. The block transport conveyor device and auxiliary block transport conveyor device do not necessarily have to be roller conveyors; they can be other types of conveyor-type transport devices that can be extended in the extension direction. Electric transport devices can also be used.

10 Inverted structure 20, 20' PCa concrete block (inverted block)
21a Gap between the support portion 21b Gap between adjacent PCa concrete blocks 21c Gap below the underside portion 21d Gap between the existing invert portion structure 22 Filling solidification material 23 Bolt box 24 Female thread anchor 25 Bolt insertion screw hole 26 Height adjustment bolt 27 Filling material injection hole 28 Opening and closing valve member 30 Mountain tunnel (road tunnel)
30a Bottom panel portion 31 Lining body 31a Side wall portion (side wall lining body)
31b Arch-shaped portion 31c Support portion 32 Invert portion lining body 33 Invert portion 35 H-shaped steel 36 Temporary fixing means 37 PCa block connection portion structure 42 Air vent hose 50 Invert portion structure 51 across the entire area of the tunnel in the transverse direction Space portion 55A between one side block group and the other side block group One side area 55B Other side area 60 Passageway 70 Temporary equipment 71 for installing invert blocks Work yard 72 Laying area 72a Base portion 72b Starting end of laying 72c End of laying 73 Space behind the starting end of laying in the laying area 74 Block lifting lifting machine (crawler crane)
75 Space at the end of the laying in the laying area 76 Lifting machine for installing blocks (backhoe)
77 Block transport conveyor device 78 Auxiliary block lifting lifting machine 79 Auxiliary block transport conveyor device 80 Transport vehicle (truck)
X Laying direction

Claims (8)

A method for installing invert blocks, which is used in a process of installing a plurality of invert blocks made of PCa concrete blocks constituting an invert section covering body, in a work yard set up in one transverse area of a multi-lane road tunnel while allowing vehicle traffic in the other transverse area, comprising:
The PCa concrete blocks are formed as hexahedral blocks having curved upper and lower surfaces so as to have a curved shape that follows the cross-sectional shape of the invert section lining body, and are arranged in series in the transverse direction of the tunnel while maintaining a gap between adjacent PCa concrete blocks, and are also arranged in series in the axial direction of the tunnel while maintaining a gap between adjacent PCa concrete blocks, and are also arranged in series in the invert section,
In the work yard in the one-side area, with the base of the laying area where the PCa concrete blocks are to be laid being leveled, a block lifting lifting machine is movably installed in a space behind the laying start end in the laying direction of the laying area, and a block installation lifting machine is movably installed in a space in the laying area towards the laying end terminal end forward of the laying start end in the laying direction, and a block transport conveyor device is provided on the top surface of the PCa concrete blocks that are successively laid in the laying area from the laying start end towards the forward laying end, extending from the laying start end to an area within the working radius of the block installation lifting machine.
The block transport conveyor device is provided so that it can be added in the laying direction as the PCa concrete blocks are sequentially placed in the laying direction from the laying start end to the laying end,
The method for installing invert blocks in a road tunnel is as follows: the unloaded PCa concrete blocks are lifted by the block lifting crane and successively lowered and placed on the end of the block transport conveyor device installed on the upper surface of the laid PCa concrete blocks, which is closer to the starting end of the laying direction in the laying direction; the placed PCa concrete blocks are then manually pushed out and moved along the block transport conveyor device to an area within the working radius of the block installation crane, where they are lifted by the block installation crane and placed successively at predetermined positions in the laying area. The invert block installation method described in claim 1, wherein the block lifting lifting machine and the block installation lifting machine in the work yard in the one-side area are configured to rotate only within an angle range that faces each other with their driver's seats facing each other. The method for arranging the invert blocks described in claim 2, wherein the angle range within which the driver's seats are opposed is an angle range within which the driver's seats can rotate left or right within 60 degrees from a state in which they face each other directly ahead. In the work yard in the one-side area, an auxiliary block lifting lifting machine is movably installed in a space rearward of the laying start end of the laying area in the laying direction, spaced apart from the block lifting lifting machine, and an auxiliary block transport conveyor device is disposed extending from an area within the working radius of the auxiliary block lifting lifting machine to an area within the working radius of the block lifting lifting machine,
3. A method for arranging inverted blocks as described in claim 1 or 2, wherein the PCa concrete blocks are lifted using the auxiliary block lifting lifting machine and placed on the end of the auxiliary block transporting conveyor device near the starting end of laying, and then transported via the auxiliary block transporting conveyor device to a section adjacent to the block lifting lifting machine, and the transported PCa concrete blocks are lifted by the block lifting lifting machine and successively lowered onto the end of the block transporting conveyor device near the starting end of laying. The invert block installation method described in claim 4, wherein the block lifting lifting machine and the auxiliary block lifting lifting machine in the work yard in the one-side area are configured to rotate only within the angle range in which the driver's seat is turned away. The invert block installation method described in claim 4, wherein a transport vehicle loaded with the PCa concrete blocks moves in the laying direction with its loading platform facing forward in the laying direction in the space behind the auxiliary block lifting lifting machine in the work yard in one side area. The invert block installation method according to claim 1 or 2, wherein the block lifting lifting machine is a crawler crane and the block installation lifting machine is a backhoe. The invert block installation method according to claim 1 or 2, wherein the block transport conveyor device is a roller conveyor, and the PCa concrete blocks are transported in the extension direction while placed on these roller conveyors.