Bottom-corner concrete structure decomposition-removal method

Abstract

To provide a bottom-corner concrete structure decomposition-removal method that makes a bottom-corner concrete structure, which is continuously arranged at the side edge part of a pavement body formed at the bottom of a tunnel, not affect the use of existing facility structures.SOLUTION: A bottom-corner concrete structure decomposition-removal method comprises a hole-linked groove drilling process to form a vertical-direction hole-linked groove 41, a pressure-applying hole drilling process to form a pressure-applying hole 43 in which a power jack 45 is mounted for pressing, a disconnect process in which a concrete block 44 is disconnected from a foundation part 52 including a sidewall structure 51a and a base concrete layer (passage base part) 22a, a pull-out process to pull out the concrete block 44, and a lift-up removal process in which the concrete block 44 is lifted up and removed.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a method for dismantling and removing a bottom corner concrete structure, and in particular to a method for dismantling and removing a bottom corner concrete structure that is provided along the side edge of a pavement formed at the bottom of a mountain tunnel, and is used when dismantling and removing the bottom corner concrete structure for repair. [Background technology]

[0002] For example, in mountain road tunnels, the pavement is formed at the bottom of the tunnel with a predetermined thickness, and on the outside of the sides, structures for passages for inspectors to carry out inspections or waterway structures are sometimes formed out of concrete along the side edges of the pavement as bottom concrete structures whose upper surfaces are at the same level as the pavement surface. In construction work to repair these bottom concrete structures together with the pavement, or to remove them together with the pavement and, for example, to build a new invert structure at the bottom of the tunnel, it may be necessary to remove the bottom concrete structures in advance while continuing to use the pavement.

[0003] For example, in a mountain tunnel for a road, in order to remove a bottom concrete structure formed on the outside along the side edge of an existing pavement in advance while continuing to use the pavement, it is preferable to divide the bottom concrete structure into multiple blocks and remove them by lifting them upward (see, for example, Patent Document 1).

[0004] In the method for removing concrete structures described in Patent Document 1, the concrete blocks to be demolished are divided into pieces of a size (weight) that can be lifted and removed by a crane while separating them from the foundation ground. Mounting holes for attaching hydraulic jacks are formed in designated positions in the concrete blocks using a core boring machine, and the hydraulic jack is set in the formed mounting holes and pressure is applied to divide the concrete blocks to be demolished. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-105980 Summary of the Invention [Problem to be solved by the invention]

[0006] The method of removing concrete structures described in Patent Document 1 can be implemented when there is a free surface around or to the side of the concrete block to be demolished that allows the divided blocks to be moved laterally, and a work space that allows various types of work to be performed.However, if, for example, the bottom concrete structure is formed continuously with the existing pavement and work can only be done from the top surface of these, it is difficult to divide the bottom concrete structure into multiple blocks or to lift and remove the divided blocks.

[0007] Furthermore, for example, when existing equipment structures such as piping equipment structures are installed along the length of the tunnel on the sidewalls of a concrete tunnel lining that covers the inner periphery of a mountain tunnel, removing the bottom concrete structure at the corner where the tunnel lining sidewall structure and the foundation join, which is formed in the area below the existing equipment structures, becomes an obstacle, making the removal difficult. For this reason, it is desirable to be able to smoothly remove the bottom concrete structure at the corner formed in the area below the existing equipment structures without affecting the use of the existing equipment structures.

[0008] The present invention aims to provide a method for removing bottom concrete structures in mountain tunnels, which enables the removal of bottom concrete structures formed in continuity with the pavement along the side edge portions of the pavement formed at the bottom of the tunnel by dividing them into multiple blocks without affecting the use of existing facility structures. [Means for solving the problem]

[0009] The present invention provides a method for dismantling and removing a bottom corner concrete structure, which is used when dismantling and removing a bottom corner concrete structure made of concrete, which is formed in a lower region of an existing facility structure, supported by a side wall structure and extending in the longitudinal direction of the side wall structure, at a joint corner between the side wall structure and a foundation, in a process separate from the side wall structure and the foundation, and which extends in the longitudinal direction of the side wall structure, while avoiding contact with the existing facility structure. In this method, a side end face of the bottom corner concrete structure opposite to the face in contact with the side wall structure, in a region away from the region directly below the existing facility structure, is opened as a working end face, and work is carried out from the working end face side in a removal construction span set as a region having a predetermined extension in the longitudinal direction of the bottom corner concrete structure, and a plurality of core holes are drilled at one end of the working end face in the region of the removal construction span in the longitudinal direction of the bottom corner concrete structure, a connecting hole groove drilling step for forming a vertical connecting hole groove by connecting the upper surface of the concrete structure to the foundation portion and drilling holes laterally toward the side wall structure with a core drilling device; a pressure hole drilling step for forming a pressure hole for attaching a power jack to press the pressure hole by drilling one or more core holes laterally toward the side wall structure with a core drilling device at the other end of the length direction of the bottom corner concrete structure at the working end face in the region of the removal construction span; A cutting process is performed by attaching a war jack and applying a pressing force toward the vertical connecting hole groove to push out the concrete block made of the bottom corner concrete structure in the area of ​​the removal construction span, thereby cutting off the side portion of the concrete block from the side wall structure and cutting off the bottom portion from the foundation part; a pulling out process is performed by pulling out the cut-off concrete block to a position away from the side wall structure so that it can avoid the existing facility structure; and then, the pulled out concrete block isThe above object has been achieved by providing a method for dismantling and removing a bottom corner concrete structure, which includes a lifting and removal step in which the structure is lifted up using a sling.

[0010] Furthermore, in the method for dismantling and removing a bottom corner concrete structure of the present invention, it is preferable that in the connecting hole groove drilling process and the pressure hole drilling process, holes are drilled using a core drilling device to a depth that does not reach the side wall structure, thereby forming the vertical connecting hole groove and the pressure hole.

[0011] Furthermore, in the method for dismantling and removing a bottom corner concrete structure of the present invention, it is preferable that the side wall structure is a side wall structure made of a concrete tunnel lining that covers the inner surface of a mountain tunnel, the existing equipment structure extending along the length of the side wall structure is a piping equipment structure, and the concrete bottom corner structure formed at the corner where the side wall structure and the foundation part join is a corner structure made of a bottom concrete structure that is provided along the side edge of a pavement formed at the bottom of the tunnel. [Effects of the Invention]

[0012] According to the method for dismantling and removing bottom corner concrete structures of the present invention, in mountain tunnels, bottom corner concrete structures formed in continuity with the pavement along the side edge portions of the pavement formed at the bottom of the tunnel can be divided into multiple blocks and removed without affecting the use of existing facility structures. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view illustrating a main part of a bottom corner concrete structure to be removed by a method for dismantling and removing a bottom corner concrete structure according to a preferred embodiment of the present invention. [Figure 2] 10(a) and 10(b) are cross-sectional views of the main part illustrating a cutter cutting step. [Figure 3]FIG. 10 is a cross-sectional view of a main part illustrating a transverse core drilling step. [Figure 4] FIG. 10 is a schematic plan view illustrating the transverse core drilling step and the longitudinal core drilling step. [Figure 5] FIG. 10 is a cross-sectional view of a main part illustrating a lifting and removal process. [Figure 6] FIG. 10 is a perspective view illustrating the lifting and removal process. [Figure 7] FIG. 10 is a cross-sectional view of a main part illustrating the hole drilling process of the method for dismantling and removing a bottom corner concrete structure. [Figure 8] FIG. 10 is a simplified front view illustrating the edge cutting process of the method for dismantling and removing a bottom corner concrete structure. [Figure 9] FIG. 10 is a cross-sectional view of a main part illustrating the pulling-out process of the method for dismantling and removing a bottom corner concrete structure. [Figure 10] FIG. 1 is a side view illustrating a known cutter machine. [Figure 11] FIG. 10 is an explanatory diagram of a portion that is left uncut in a cutter cutting step. [Figure 12] FIG. 1 is a side view illustrating a known core drilling device. DETAILED DESCRIPTION OF THE INVENTION

[0014] A preferred embodiment of the method for removing a bottom concrete structure according to the present invention is used in a mountain tunnel 50 for a road tunnel having a horseshoe-shaped cross section, for example, to remove a pavement 25 formed at the bottom of the tunnel 50 together with a bottom concrete structure 20 provided along its side edges, as shown in Fig. 1. This method is used, for example, in construction work to add a new bottom invert lining between the lower ends of both sidewall portions 51a of a concrete tunnel lining 51 covering the inner periphery of the tunnel 50, to remove the bottom concrete structure 20 in advance, preferably while continuing to use the pavement 25, while appropriately restricting road traffic on the pavement 25. In this embodiment, the bottom concrete structure 20 formed along the side edges of the pavement 25 at the bottom of the tunnel 50 can be divided into multiple concrete blocks by working from above, allowing for smoother removal.

[0015] The method for removing a bottom concrete structure in this embodiment is a removal method used when removing and renovating a bottom concrete structure 20 that is provided along the side edge portion of a pavement 25 formed at the bottom of a mountain tunnel 50, and as shown in Figure 1, the bottom concrete structure 20 is formed between the lower end inner surface portion 51b of a tunnel lining 51 that covers the inner surface of the mountain tunnel 50 and the side end surface portion 25a of the pavement 25. 2(a) and (b) to FIG. 6, the method for removing the bottom concrete structure of this embodiment includes a cutter cutting process (see FIGS. 2(a) and (b)) in which two or more rows of cutter grooves 11a, 11b, 11c, including a cutter groove 11a formed at the boundary with the pavement 25, are provided in the bottom concrete structure 20 in the region of a removal construction span S having a predetermined extension in the axial direction X of the tunnel 50 (see FIG. 4), extending in the longitudinal direction along the axial direction X of the tunnel 50, and cutting from the top surface 20a of the bottom concrete structure 20 to a depth reaching the foundation portion 52 using a cutter machine 30 (see FIG. 10); and a cutter cutting process (see FIGS. 2(a) and (b)) in which a plurality of core holes 12 are connected in the transverse direction Y along the width direction of the tunnel 50 at least at both ends of the removal construction span S in the axial direction X of the tunnel 50, so as to extend from the top surface 20a of the bottom concrete structure 20 to the foundation portion 52. The process includes a transverse core drilling process (see Figures 3 and 4) in which a core is drilled to a depth of 100 mm using a core drilling device 31 (see Figure 12) to form a transverse connecting hole groove 13; a cutting process (not shown) in which a power jack (not shown) is attached to the inside of the transverse connecting hole groove 13 formed at one end of the tunnel 50 in the axial direction X in the area of ​​the removal construction span S, and a pressing force is applied in the axial direction X of the tunnel 50 to cut off the bottom portion of the concrete block 14 (see Figure 6) made of the bottom concrete structure surrounded by the pair of left and right cutter grooves 11a, 11b, 11c and the pair of front and rear transverse connecting hole grooves 13 from the foundation portion 52; and a lifting and removal process (see Figures 5 and 6) in which the concrete block 14, whose bottom portion has been cut off from the foundation portion 52, is removed by slinging it, preferably with a wire member 34.

[0016] In this embodiment, the pavement 25 formed at the bottom of the tunnel 50 is a pavement structure used as a roadway, having a thickness of, for example, about 450 mm, and consisting of a roadbed layer, for example, about 300 mm thick, which is preferably laid and compacted on the roadbed that constitutes the foundation portion 52, and an asphalt layer, for example, about 150 mm thick, which is laid and compacted on the roadbed layer. On the side of the pavement 25, between the side wall portion 51 a of the tunnel lining 51 and the lower end inner peripheral surface portion 51 b, a bottom concrete structure 20 is installed in the axial direction X of the tunnel 50 along the side edge of the pavement 25 in a separate process from the construction of the tunnel lining 51 and the pavement 25, and is formed continuously with the side wall portion 51 a of the tunnel lining 51 and the pavement 25. The bottom concrete structure 20 is composed of a water channel section 21 on the pavement 25 side, which is formed by connecting and installing multiple precast concrete water channel blocks in the axial direction X of the tunnel 50, and a passage base section 22, which is formed by pouring cast-in-place concrete between the lower end inner surface section 51b of the side wall section 51a of the tunnel lining body 51 and the water channel section 21.

[0017] The waterway section 21 is formed by placing and integrating a plurality of waterway blocks in a connected state in the axial direction X of the tunnel 50 on the upper surface of a base concrete layer 21a formed, for example, with a thickness of about 100 mm on a foundation section 52 including a foundation ground, a sand layer, and a crushed stone layer, so that the waterway section 21 has a thickness (height) of about 450 mm from the base concrete layer 21a. The passage base section 22 is formed by further pouring cast-in-place concrete on the base concrete layer 22a, which is about 100 mm thick and formed on the foundation section 52 including a foundation ground, a sand layer, and a crushed stone layer, so that the waterway section 21 has a thickness (height) of about 450 mm from the base concrete layer 21a. The waterway section 21 and the passage base section 22, which together with the base concrete layers 21a and 22a form the bottom concrete structure 20, are preferably formed so that their upper surfaces are at the same level as the pavement surface of the pavement 25. On the upper surface of the passage base portion 22, on the water channel portion 21 side, a drainage groove 22b is formed by box-cutting out the groove so as to extend in the axial direction X of the tunnel 50.

[0018] In this embodiment, support bracket members 53 made of, for example, angle iron are attached to the inner surface of side wall portions 51a of a tunnel lining 51 that covers the inner circumferential surface of the tunnel 50 at a predetermined height position above the bottom concrete structure 20 so as to protrude inward. The support bracket members 53 are attached at multiple locations at predetermined intervals in the axial direction X of the tunnel 50. A piping equipment structure 54 is supported by these multiple support bracket members 53 and is provided extending in the axial direction X of the tunnel 50, which is the length direction of the side wall portions 51a.

[0019] As a result, in this embodiment, in the bottom concrete structure 20, a concrete portion (bottom corner concrete structure) 40 (see FIG. 7) located at the corner where the side wall portion (side wall structure) 51a of the tunnel lining 51 joins with the foundation portion 52 of the passage base 22, which is formed in the area below the existing equipment structure, piping equipment structure 54, is considered to be difficult to remove because the existing piping equipment structure 54 becomes an obstacle. In this embodiment, by implementing a method for dismantling and removing a bottom corner concrete structure, which will be described later, it is possible to smoothly remove the bottom corner concrete structure 40 at the joining corner formed in the area below the existing equipment structure without affecting the use of the existing equipment structure 54.

[0020] In this embodiment, the cutter cutting step in the method for removing a bottom concrete structure can be performed using a cutter machine 30, preferably a known cutter device known as a paving cutter, capable of forming cut grooves with a depth of, for example, about 500 to 600 mm, as shown in Figure 10. In the cutter cutting step, as shown in Figures 2(a), (b), and 4, cutter grooves 11a, 11b, and 11c can be formed from one end to the other end of a predetermined removal construction span S having a predetermined construction length of, for example, several tens of meters in the longitudinal direction, which is the axial direction X of the tunnel 50, using the cutter machine 30 to a depth of, for example, about 500 to 600 mm, from the upper surface 20a of the bottom concrete structure 20 to the foundation portion 52. In this embodiment, the cutter grooves 11a, 11b, 11c formed in the bottom concrete structure 20 are formed as three rows of cutter grooves 11a, 11b, 11c, including the cutter groove 11a formed at the boundary with the pavement 25. The three rows of cutter grooves 11a, 11b, 11c include the cutter groove 11a formed in the water channel portion 21 near the boundary with the pavement 25 at the boundary between the pavement 25 and the water channel portion 21, the cutter groove 11b formed in the water channel portion 21 near the boundary between the passage base portion 22 and the water channel portion 21, and the cutter groove 11c formed in the central portion of the passage base portion 22, away from the portion directly below the existing facility structure. By forming the cutter groove 11a at the boundary with the pavement 25 on the water channel portion 21 side near the boundary, it is possible to effectively prevent, for example, the side edge surface portion 25a of the pavement 25 from being disturbed by the cutter groove 11a during cutting.

[0021] Here, because the cutter blade 30a of the cutter machine 30 has a disk shape, if the cutting by the cutter machine 30 is stopped at both ends of the set removal construction span S, for example, before the adjacent removal construction span S' so that the cutter groove 11c in the center part of the passage base 22 does not penetrate into the adjacent removal construction span S', in the region of the removal construction span S before the adjacent removal construction span S', as shown in FIG. 11, the cutter groove 11c does not reach from the upper surface 20a of the bottom concrete structure 20 to the foundation part 52, resulting in an uncut portion (see the shaded area in FIG. 11). In such a case, in this embodiment, preferably, by performing the longitudinal core drilling process described later on the cutter groove 11c formed in the center part of the passage base 22, it is possible to form a dividing groove extending to the foundation part 52, including, for example, the foundation ground, sand layer, or crushed stone layer below the base concrete layer 22a of the passage base 22, even in the region before the adjacent removal construction span S'.

[0022] Furthermore, for example, by using a cutter machine 30 to enter the area of ​​the adjacent removal construction span S' and continuing to cut the cutter groove 11c for the required length, preferably a length that exceeds the radius of the cutter blade, it is possible to form a cutter groove 11c that reaches the foundation portion 52 below the base concrete layer 22a in the area of ​​the removal construction span S just before the adjacent removal construction span S'.

[0023] The transverse core drilling step in the method for removing a bottom concrete structure of this embodiment can be carried out using a core drilling device 31, preferably a known core drilling machine capable of drilling cores with an inner diameter of, for example, about 100 to 200 mm, as shown in Figure 12. In the transverse core drilling step, as shown in Figures 3 and 4, a cutter machine 30 is used to form multiple core holes 12 at least at one end and the other end of a predetermined removal construction span S having a predetermined construction length, from the upper surface 20a of the bottom concrete structure 20 to a depth reaching the foundation portion 52 including the foundation ground, sand layer, and crushed stone layer. In this embodiment, the core holes 12 can be formed in a total of six locations, with parts of them overlapping each other in the transverse direction Y of the tunnel 50, for example, three locations between the cutter groove 11c in the central portion of the passage base portion 22 and the boundary line between the water channel portion 21 and the passage base portion 22, and three locations between the boundary line between the water channel portion 21 and the passage base portion 22 and the boundary line between the water channel portion 21 and the pavement 25. This makes it possible to form a transverse connected hole groove 13 made up of six core holes 12 that are continuous in the transverse direction Y of the tunnel 50 between the cutter groove 11a in the boundary portion with the pavement 25 and the cutter groove 11c in the central portion of the passage base portion 22.

[0024] The transverse connecting grooves 13 do not necessarily need to be formed continuously between the cutter groove 11a at the boundary between the pavement 25 and the waterway 21 and the cutter groove 11b at the boundary between the passage base 22 and the waterway 21, and between the cutter groove 11b at the boundary between the passage base 22 and the waterway 21 and the cutter groove 11c at the center of the passage base 22, at both ends of the removal construction span S. It is sufficient that the transverse connecting grooves 13 are formed continuously between these at either one end or the other end of the removal construction span S. In other words, when a power jack (not shown) is attached inside the transverse connecting grooves 13 to apply a pressing force in the axial direction X of the tunnel 50 during the bottom edge cutting process, a free surface for pushing and moving the concrete block 14 only needs to be secured in the transverse connecting groove 13 opposite the transverse connecting groove 13 to which the power jack is attached.

[0025] Furthermore, in this embodiment, the preset removal construction span S has a considerable construction length, for example, several tens of meters, in the axial direction X of the tunnel 50. For this reason, it is preferable to form a transverse connecting hole groove 13 by drilling a plurality of interconnected core holes 12 with a core drilling device 31 in the middle part of the axial direction X of the tunnel 50 between the transverse connecting hole grooves 13 formed at each end of the axial direction X of the tunnel 50 in the region of the removal construction span S by an intermediate region core drilling process. The transverse connecting hole grooves 13 formed by the intermediate region core drilling process can be formed in one or more locations in the region between the transverse connecting hole grooves 13 at both ends of the removal construction span S, at a pitch of, for example, about 2 m in the axial direction X of the tunnel 50, by the same method as in the transverse core drilling process for forming these transverse connecting hole grooves 13. The transverse connecting hole groove 13 formed by the intermediate region core drilling process does not necessarily have to be formed continuously between the cutter groove 11a at the boundary between the pavement 25 and the water channel section 21 and the cutter groove 11b at the boundary between the passage base section 22 and the water channel section 21, and between the cutter groove 11b at the boundary between the passage base section 22 and the water channel section 21 and the cutter groove 11c in the central section of the passage base section 22; there may be portions between these where the transverse connecting hole groove 13 is not formed.

[0026] As a result, in the bottom edge cutting process, by attaching a power jack (not shown) inside the transverse connecting hole groove 13 and applying a pressing force in the axial direction X of the tunnel 50, when pushing out and moving the concrete blocks 14, it is possible to push out the blocks 14 one by one, for example, with a length of about 2 m, thereby making it possible to cut the edge smoothly.

[0027] Furthermore, in this embodiment, as described above, when forming the cutter groove 11c, particularly in the central portion of the passage base portion 22, if cutting by the cutter machine 30 is stopped before the adjacent removal construction span S' so as not to allow the cutter groove 11c to penetrate into the adjacent removal construction span S', it is preferable to further include a longitudinal core drilling process in which, as shown in Figure 4, a longitudinal connecting hole groove 16 made of a plurality of connected core holes 15 is drilled by a core drilling device 31 in an overlapping manner on the cutter groove 11c in the portion close to these ends, so as to be continuous with the transverse connecting hole groove 13 formed at at least one end (in this embodiment, both ends) of the removal construction span S area.

[0028] As a result, at both ends of the set removal construction span S, cutting by the cutter machine 30 is stopped just before the adjacent removal construction span S' so that the cutter groove 11c does not penetrate into the adjacent removal construction span S'.Even if the depth of the cutter groove 11c does not reach the foundation part 52 in the area of ​​the removal construction span S just before the adjacent removal construction span S' as shown in Figure 11, resulting in an uncut part, by forming a longitudinal connecting hole groove 16 in the area just before such adjacent removal construction span S' by the longitudinal core drilling process, it is possible to reliably form a dividing groove that reaches, for example, the foundation part 52 below the base concrete layer 22a of the passage base part 22.

[0029] The edge-cutting step in the method for removing a bottom concrete structure according to this embodiment can be performed using a power jack, preferably a hydraulic jack known as a hydraulic jack. The bottom edge-cutting step can be performed by attaching a power jack (not shown) to the transverse connecting grooves 13 formed in the removal span S, which are formed continuously between the cutter groove 11a at the boundary between the pavement 25 and the channel 21 and the cutter groove 11b at the boundary between the passage base 22 and the channel 21, or between the cutter groove 11b at the boundary between the passage base 22 and the channel 21 and the cutter groove 11c at the center of the passage base 22, as free surfaces. The power jack applies a pressing force in the axial direction X of the tunnel 50 toward the transverse connecting grooves 13 that have become free surfaces. This makes it possible to easily cut off the edges of the bottom concrete structures of the portions surrounded by the pair of left and right cutter grooves 11a, 11b, 11c and the pair of front and rear transverse connecting hole grooves 13 as divided concrete blocks 14 (see Figure 6) in the portion between the cutter groove 11a at the boundary between the pavement 25 and the water channel portion 21 and the cutter groove 11b at the boundary between the passage base portion 22 and the water channel portion 21, and in the portion between the cutter groove 11b at the boundary between the passage base portion 22 and the water channel portion 21 and the cutter groove 11c in the central portion of the passage base portion 22, and to extrude these bottom portions toward the free surface side by cutting them into divided concrete blocks 14 (see Figure 6).

[0030] Furthermore, if the transverse connecting hole grooves 13 formed by the intermediate region core drilling process are formed at multiple locations, for example at a pitch of about 2 m, between the transverse connecting hole grooves 13 formed at both ends of the removal construction span S, it is possible to sequentially attach a power jack (not shown) to the transverse connecting hole groove 13 formed by the intermediate region core drilling process closest to the transverse connecting hole groove 13 at one end that has become the free surface, and apply a pressing force to the transverse connecting hole groove 13 that has become the free surface, thereby making it possible to extrude each of the divided concrete blocks 14. In other words, the transverse connecting hole groove 13 after the power jack has been attached and extruded from the concrete block 14 becomes a new free surface, and by attaching a power jack to the next transverse connecting hole groove 13 and applying a pressing force, it is possible to extrude the concrete block 14 sequentially while cutting its edge from the foundation portion 52.

[0031] The lifting and removal step in the method for removing a bottom concrete structure of this embodiment can be performed using, for example, a backhoe 32, which can also be used as a heavy lifting machine, and a dump truck 33, as shown in Figures 5 and 6. The lifting and removal step can be easily performed by, for example, attaching a lifting jig to the concrete block 14 via a hole-in anchor, and slinging the concrete block 14 by engaging a wire member 34 with the lifting jig, and then lifting the concrete block 14 with the bucket 32a of the backhoe 32 installed on the upper surface of the pavement 25. Each divided concrete block 14 is then loaded onto the bed of the dump truck 33 for transport. The concrete block 14 severed from the foundation portion 52 in the edge severing step can be removed individually, or multiple concrete blocks 14 can be severed from the foundation portion 52 and then removed all at once.

[0032] As a result, according to the method for removing a bottom concrete structure of this embodiment, in a mountain tunnel 50, the bottom concrete structure 20 formed continuously along the side edge portion of the pavement 25 formed at the bottom of the tunnel 50 can be easily removed by dividing it into multiple concrete blocks 14 by working from the top surface of the structure.

[0033] In addition, in this embodiment, after removing the bottom concrete structure 20 between the cutter groove 11a at the boundary between the pavement 25 and the waterway section 21 and the cutter groove 11b at the boundary between the passage base section 22 and the waterway section 21, and the bottom concrete structure 20 between the cutter groove 11b at the boundary between the passage base section 22 and the waterway section 21 and the cutter groove 11c in the central section of the passage base section 22, within the set removal construction span S using the above-mentioned bottom concrete structure removal method, the remaining bottom concrete structure 20 between the cutter groove 11c in the central section of the passage base section 22 and the lower end inner surface section 51b of the tunnel lining body 51 can be easily removed using the following method for dismantling and removing bottom corner concrete structures.

[0034] In this embodiment, as described above, the side wall portion 51a of the tunnel lining 51 covering the inner surface of the tunnel 50 has a piping equipment structure 54, which is an existing equipment structure, provided at a predetermined height position above the bottom concrete structure 20, extending in the axial direction X of the tunnel 50, which is the length direction of the side wall portion 51a. For this reason, as shown in Figure 7, when removing the bottom concrete structure 20 between the central cutter groove 11c and the lower end inner surface 51b of the tunnel lining 51, which is the bottom corner concrete structure 40 located at the corner where the side wall portion (side wall structure) 51a of the tunnel lining 51 and the foundation portion 52 below the base concrete layer 22a of the passage base 22 join, the piping equipment structure 54 would be an obstacle, making removal difficult. However, by implementing the following method of dismantling and removing the bottom corner concrete structure, it is possible to smoothly remove such bottom corner concrete structure 40 without affecting the use of the existing piping equipment structure 54.

[0035] That is, in this embodiment, the bottom concrete structure 20 between the cutter groove 11a at the boundary between the pavement 25 and the water channel section 21 and the cutter groove 11b at the boundary between the passage base section 22 and the water channel section 21, and the bottom concrete structure 20 between the cutter groove 11b at the boundary between the passage base section 22 and the water channel section 21 and the cutter groove 11c in the central section of the passage base section 22 are removed, so that the side end face opposite to the face in contact with the side wall structure 51a of the bottom corner concrete structure 40 in the part away from the part directly below the existing piping equipment structure 54 is left open as a working end face 40a. The method for demolishing and removing the bottom corner concrete structure is carried out by working from the working end face 40a side, as shown in Figures 7 to 9, over a removal construction span S" of, for example, a length of about 2m, which is set as an area with a predetermined extension in the axial direction X of the tunnel, which is the length direction of the side wall structure 51a. The method for demolishing and removing the bottom corner concrete structure includes a connecting hole groove drilling step for forming vertical connecting hole grooves 41, a pressure hole drilling step for forming pressure holes 43 to which power jacks 45 are attached and applied pressure, a cutting step for cutting the concrete blocks 44 from the side wall structure 51a and the foundation part 52 below the base concrete layer 22a, a pulling out step for pulling out the concrete blocks 44, and a lifting and removal step for lifting and removing the concrete blocks 44.

[0036] In the connecting hole groove drilling process, a plurality of core holes 42 are connected vertically from the top surface of the bottom corner concrete structure 40 to the foundation part 52 below the base concrete layer 22a at one end of the length of the bottom corner concrete structure 40 at the working end face 40a in the area of ​​the removal construction span S", and then drilled horizontally toward the side wall structure 51a using a core drilling device 31 similar to the core drilling machine shown in Figure 12 above, thereby forming a vertical connecting hole groove 41 (see Figures 7 and 8).

[0037] In the pressure hole drilling process, one or more core holes are drilled laterally toward the side wall structure 51a at the other end of the length of the bottom corner concrete structure 40 at the working end face 40a in the removal construction span S" area using a core drilling device 31 similar to the core drilling machine shown in Figure 12 above, to form pressure holes 43 to which a power jack 45 is attached and pressed (see Figures 7 and 8).

[0038] In the edge-cutting process, a power jack 45 is attached inside the formed pressurized hole 43, and a pressing force is applied toward the vertical connecting hole groove 41, thereby pushing out the concrete block 44 made of the bottom corner concrete structure 40 in the area of ​​the removal construction span S", thereby cutting off the side portion of the concrete block 44 from the side wall structure 51a and cutting off the bottom portion from the foundation portion 52 below the base concrete layer 22a (see Figure 8).

[0039] In the pulling-out process, the concrete blocks 44 that have been cut in the cutting process are pulled out, for example, using a support stand 46 or a chain block 47 installed on the upper surface of the pavement 25, to a position away from the side wall structure 51a where they can avoid the existing equipment structure, i.e., the piping equipment structure 54 (see Figure 9).

[0040] In the lifting and removal process, after the concrete block 44 is pulled out in the pulling-out process, the same backhoe 32 and dump truck 33 (see Figures 5 and 6) as described above are used, and the pulled-out concrete block 44 is hoisted and removed using a sling.

[0041] This makes it possible to smoothly remove the bottom corner concrete structure 40, which is the bottom concrete structure of the joint corner portion formed in the area below the piping equipment structure 54, which is an existing equipment structure, without affecting the use of the piping equipment structure 54.

[0042] In this embodiment, in the connecting hole groove drilling step and the pressurizing hole drilling step, the core holes 42, 43 are preferably drilled by the core drilling device 31 to a depth that does not reach the side wall structure 51a, thereby forming the vertical connecting hole groove 41 and the pressurizing hole 43. This makes it possible to avoid damaging the existing side wall structure 51a made of the side wall portion of the concrete tunnel lining 51 that covers the inner surface of the tunnel 50.

[0043] The present invention is not limited to the above-described embodiment and various modifications are possible. For example, the method for removing a concrete structure at the bottom of a tunnel according to the present invention does not need to include a longitudinal core drilling step in which a plurality of adjacent core holes are formed on the cutter groove so as to be continuous with the transverse connecting hole groove formed at at least one end of the removal span. Furthermore, in addition to being used as a method for removing concrete structures at the bottom corners of mountain tunnels for road tunnels with a horseshoe-shaped cross section, the present invention can also be used as a method for removing structures such as concrete that make up the floor of a building with walls and floors when existing facility structures are present on the walls. [Explanation of symbols]

[0044] 10. Tunnel workstation for mini bench cut construction method 11a, 11b, 11c Cutter groove 12 Core hole 13 Transverse connecting hole groove 14 Concrete Block 15 Core hole 16 Longitudinal connecting hole groove 20 Bottom concrete structure 20a Top part 21 Waterway section 21a Base concrete layer (waterway section) 22 Passage base 22a Base concrete layer (passage base) 22b Drainage groove 25 Pavement 25a Side end surface 30 Cutter Machine 30a cutter blade 31 Core drilling equipment 32 Back Four 32a Bucket 33 Dump Truck 34 Wire material 40 Bottom corner concrete structure 40a Working end surface 41 Vertical connecting hole groove 42 Core hole 43 Pressurization hole (core hole) 44 Concrete Block 45 Power Jack 46 Support stand 47 Chain Block 50 Mountain Tunnel 51 Tunnel lining 51a Side wall part (side wall structure) 51b Lower end inner peripheral surface 52 Basic part 53 Support bracket member 54 Piping equipment structures (existing equipment structures) X Axial direction of the tunnel Y tunnel crossing direction S, S', S” Removal construction span

Claims

1. A method for dismantling and removing a bottom corner concrete structure, which is used when dismantling and removing a bottom corner concrete structure made of concrete, which is formed in a lower region of an existing facility structure supported by a side wall structure and extending in the length direction along the side wall structure at a joint corner between the side wall structure and a foundation portion in a process separate from that of the side wall structure and the foundation portion, and which extends in the length direction along the side wall structure, while avoiding contact with the existing facility structure, The concrete structure is then laid out in a manner that allows it to be easily removed. The concrete structure is then laid out in a manner that allows it to be easily removed. The concrete structure is then laid out in a manner that allows it to be easily removed. a connecting hole groove drilling process in which a plurality of core holes are connected vertically from the top surface of the bottom corner concrete structure to the foundation portion at one end of the length direction of the working end face in the area of ​​the removal construction span, and a core drilling device is used to drill holes horizontally toward the side wall structure, thereby forming a vertical connecting hole groove; A pressure hole drilling process in which one or more core holes are drilled laterally toward the side wall structure by a core drilling device at the other end of the length direction of the bottom corner concrete structure at the working end face in the area of ​​the removal construction span, thereby forming a pressure hole to which a power jack is attached and pressed; A cutting process is performed by attaching a power jack to the inside of the formed pressurized hole and applying a pressing force toward the vertical connecting hole groove to push out the concrete block made of the bottom corner concrete structure in the area of ​​the removal construction span, thereby cutting off the side portion of the concrete block from the side wall structure and cutting off the bottom portion from the foundation part; a pulling-out process of pulling out the cut concrete block away from the side wall structure to a position where the cut concrete block can avoid the existing facility structure; The concrete block is then removed by lifting it up with a sling.

2. A method for dismantling and removing a bottom corner concrete structure as described in claim 1, wherein in the connecting hole groove drilling process and the pressure hole drilling process, holes are drilled using a core drilling device to a depth that does not reach the side wall structure, thereby forming the vertical connecting hole groove and the pressure hole.

3. The method for dismantling and removing a bottom corner concrete structure according to claim 1 or 2, wherein the side wall structure is a side wall structure made of a concrete tunnel lining that covers the inner surface of a mountain tunnel, the existing equipment structure extending along the length of the side wall structure is a piping equipment structure, and the concrete bottom corner structure formed at the corner where the side wall structure joins the foundation is a corner structure made of a bottom concrete structure that is provided along the side edge of a pavement formed at the bottom of the tunnel.

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