Foundation structure, construction method of foundation structure, and fixture

Abstract

To provide a foundation structure, a construction method of the foundation structure, and a fixture, capable of securing desired strength, while reducing a burden of a worker in a work site of a deep foundation construction method.SOLUTION: A fixture 10 provided with a liner holding part 20 for holding a circumferential flange 113 of a liner plate 110 in a cylindrical structure 100 constituting a foundation pile 1 and a reinforcement holding part 30 for holding an axial reinforcement 2 at a position close to the circumferential flange 113 is assembled to the cylindrical structure 100 at a predetermined interval in a height direction H and a width direction R, and the axial reinforcement 2 is mounted.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a foundation structure such as a foundation pile constructed by, for example, assembling liner plates in the vertical direction underground to form a cylindrical structure, arranging a plurality of reinforcing bars inside the structure, and pouring concrete into the structure, and a method for constructing the foundation structure. [Background technology]

[0002] For example, there is a deep foundation method in which a cylindrical structure is constructed by assembling a liner plate into a borehole excavated in the ground, and then multiple steel bars are placed inside the constructed cylindrical structure, and concrete is poured inside the cylindrical structure to construct foundation structures such as foundation piles.

[0003] Specifically, this method involves excavating the bottom of a borehole and assembling liner plates in a ring shape to protect the borehole walls, and repeating this process up to a specified depth to construct a shaft, after which concrete is poured to build a foundation structure.The method described in Patent Document 1 is one such method.

[0004] In the above-mentioned deep foundation method, as shown in Patent Document 1, for example, long axial reinforcing bars (also called main reinforcing bars) extending in the depth direction are arranged inside a cylindrical structure at predetermined intervals in the circumferential direction, and hoop reinforcing bars (also called tie bars) are wrapped around multiple axial reinforcing bars at predetermined intervals in the depth direction, and these are arranged before pouring the concrete, thereby constructing a reinforced concrete foundation structure with the desired strength.

[0005] However, within a hole surrounded by a cylindrical structure, multiple long axial reinforcing bars are arranged at a predetermined interval in the circumferential direction, and circular hoop reinforcing bars are arranged on the outer diameter side of them at a predetermined interval in the depth direction, and the reinforcing bar arrangement work of binding and integrating the axial reinforcing bars requires a lot of man-hours, which increases the burden on on-site workers. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2009-114649 A Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above-mentioned problems, the present invention aims to provide a foundation structure, a method for constructing a foundation structure, and mounting fixtures that can ensure the desired strength while reducing the burden on workers at deep foundation construction work sites. [Means for solving the problem]

[0008] The present invention relates to a foundation structure constructed in a borehole formed by excavating the ground, the foundation structure comprising: a cylindrical structure in which liner plates are arranged in the circumferential and depth directions along the wall surface of the borehole and assembled together; a plurality of long axial reinforcing bars arranged at predetermined intervals along the inside of the cylindrical structure and extending in the depth direction; a plurality of mounting fixtures assembled to the cylindrical structure at predetermined intervals in the depth direction and circumferential directions and to which the axial reinforcing bars are attached; and an inner main body portion formed by hardening a solidifying material cast inside the cylindrical structure, the mounting fixtures having liner holding parts that clamp flanges of the liner plates and reinforcing bar holding parts that hold the axial reinforcing bars in positions close to the flanges. The liner holding portion is configured as a clamp structure for clamping the flange. It is characterized by:

[0009] The present invention also provides a method for constructing a foundation structure in a borehole formed by excavating the ground, comprising a structure construction step of arranging liner plates in the circumferential and depth directions along the wall surface of the borehole and assembling them to construct a cylindrical structure; a reinforcement step of attaching a plurality of long axial reinforcing bars arranged at predetermined intervals along the inside of the cylindrical structure and extending in the depth direction to a plurality of mounting fixtures assembled to the cylindrical structure at predetermined intervals in the depth direction and circumferential direction; and a casting step of forming an inner main body by hardening a solidifying material cast inside the cylindrical structure, wherein in the reinforcement step, the mounting fixtures have liner holding parts that clamp flanges of the liner plates and reinforcing bar holding parts that hold the axial reinforcing bars in positions close to the flanges. The liner holding portion is configured to have a clamp structure for clamping the flange. It is characterized by:

[0010] Furthermore, the present invention provides a cylindrical structure that includes liner plates arranged in the circumferential and depth directions along the wall surface of a borehole formed by excavating the ground, and a plurality of long axial reinforcing bars extending in the depth direction are arranged at predetermined intervals inside the cylindrical structure that is assembled together, and a solidifying material poured inside the cylindrical structure hardens to form an inner main body, thereby forming a foundation structure. The cylindrical structure includes liner holding parts that clamp flanges of the liner plates and reinforcing bar holding parts that hold the axial reinforcing bars at positions close to the flanges, and is assembled to the cylindrical structure at predetermined intervals in the depth direction and the circumferential directions, and the axial reinforcing bars are attached. The liner holding portion is configured as a clamp structure for clamping the flange. It is characterized by being a mounting fixture.

[0011] The cylindrical structure may be a cylindrical structure in which the liner plates are assembled so that their circumferential connection positions do not coincide in the depth direction, a cylindrical structure in which the liner plates are assembled so that their circumferential connection positions coincide, or a cylindrical structure that is a combination of these. Note that the cylindrical structure may be a structure that is not only circular in plan view, but also elliptical, oval, or polygonal in plan view.

[0012] The liner holding portion refers to, for example, a liner holding portion with a clamp structure or a liner holding portion with a clip structure, and refers to a holding portion that can be attached to a flange or the like of a liner plate. The flanges of the liner plates include not only the connecting parts that connect the liner plates together but also the ribs that reinforce the liner plates. The flanges of the liner plates are classified into axial flanges that extend in the depth direction, i.e., roughly in the direction in which the axial reinforcing bars extend, and circumferential flanges that extend in the circumferential direction.

[0013] The above-mentioned reinforcing bar holding portion refers to a reinforcing bar holding portion made of a flat plate having a through hole penetrating in the depth direction, i.e., a holding portion through which axial reinforcing bars can be inserted, or, for example, a holding portion having a through hole formed by bending a wire rod, i.e., a holding portion that can be attached without insertion.

[0014] The clamp structure may be, for example, a structure consisting of a pair of flat plates facing each other across a flange, and a fixing bolt that screws into one of the flat plates and abuts against the flange through a through hole in the other flat plate.

[0015] This invention makes it possible to construct a foundation structure that can ensure the desired strength while reducing the burden on workers at a caisson foundation construction site. More specifically, the fixture is clamped and assembled to the flange of the liner plate, so that the desired number of axial reinforcing bars can be connected to predetermined circumferential positions of the tubular structure via the fixture.

[0016] At this time, the reinforcing bar holding portion of the fixture holds the axial reinforcing bar at a position close to the flange, so the fixture can restrict the axial reinforcing bar relative to the flange of the liner plate. This allows the foundation to function as a hoop reinforcement that wraps the tubular structure around the axial reinforcing bars, thereby reducing or eliminating the need for hoop reinforcement arranged at predetermined intervals in the depth direction of the foundation.

[0017] Therefore, the foundation structure, the method for constructing the foundation structure, and the mounting fixtures can reduce the labor required for reinforcement, thereby reducing the burden on workers at work sites using deep foundation construction methods to build foundation structures that do not compromise earthquake resistance or durability, i.e., that can ensure the desired strength.

[0018] In addition, the foundation construction method allows the mounting fixtures to be assembled to the flanges during the process of assembling the liner plates in the depth direction, making it possible to efficiently construct the cylindrical structure and assemble the mounting fixtures.

[0019] When the mounting fixture is attached to the circumferential flange, it can be attached at any position relative to the circumferential flange, and the axial reinforcing bars can be arranged at desired positions in the circumferential direction.

[0020] Although it has been described that the number of hoop reinforcements arranged at predetermined intervals in the depth direction of a foundation structure can be reduced or decreased, hoop reinforcements may also be used in combination.

[0021] Also, The liner holding portion is configured as a clamp structure for clamping the flange. This allows the liner holder to have a simple configuration, which prevents the fixture from becoming too large and improves the ease of assembling the fixture to the flange. As a result, the foundation structure can reduce the burden on workers at the caisson foundation construction site.

[0022] As another aspect of the present invention, two of the liner holding portions may be arranged side by side in the circumferential direction with an axial flange of the liner plate interposed therebetween. According to this invention, the mounting fixture can be attached across the axial flange, which is the circumferential connection point of the liner plate, so that the mounting fixture can be positioned at the circumferential position where the axial reinforcing bars are desired to be arranged.

[0023] This invention also is a foundation structure constructed in a borehole formed by excavating the ground, and is characterized in that it comprises a cylindrical structure in which liner plates are arranged circumferentially and in the depth direction along the wall surface of the borehole and assembled together, a plurality of long axial reinforcing bars arranged at predetermined intervals along the inside of the cylindrical structure and extending in the depth direction, a plurality of mounting fixtures assembled to the cylindrical structure at predetermined intervals in the depth direction and circumferential direction and to which the axial reinforcing bars are attached, and an inner main body portion formed by the hardening of a solidifying material poured inside the cylindrical structure, and the mounting fixtures are provided with a liner holding portion that clamps the flange of the liner plate and a reinforcing bar holding portion that holds the axial reinforcing bars at a position close to the flange, and the liner holding portion is configured as a clip structure that clamps the flange by a biasing force.

[0024] The present invention also provides a method for constructing a foundation structure in a borehole formed by excavating the ground, comprising a structure construction step of arranging liner plates in the circumferential and depth directions along the wall surface of the borehole and assembling them to construct a cylindrical structure; a reinforcement step of attaching a plurality of long axial reinforcing bars arranged at predetermined intervals along the interior of the cylindrical structure and extending in the depth direction to a plurality of fixtures assembled to the cylindrical structure at predetermined intervals in the depth and circumferential directions; and a casting step of forming an inner main body portion by hardening a solidifying material cast inside the cylindrical structure, wherein in the reinforcement step, the fixtures have liner holding portions that clamp flanges of the liner plates and reinforcing bar holding portions that hold the axial reinforcing bars at positions close to the flanges, and the liner holding portions have a clip structure that clamps the flanges by biasing force. It is characterized by:

[0025] Furthermore, this invention relates to a cylindrical structure that is constructed by arranging liner plates in the circumferential and depth directions along the wall surface of a borehole formed by excavating the ground, and assembling the liner plates together to form a cylindrical structure, and a plurality of long axial reinforcing bars extending in the depth direction are arranged at predetermined intervals along the inside of the cylindrical structure, and a solidifying material poured inside the cylindrical structure hardens to form an inner main body portion, thereby forming a foundation structure. The cylindrical structure is provided with liner holding parts that clamp flanges of the liner plates and reinforcing bar holding parts that hold the axial reinforcing bars at positions close to the flanges, and is assembled to the cylindrical structure at predetermined intervals in the depth direction and the circumferential direction, and the axial reinforcing bars are attached, and the liner holding parts are configured as clip structures that clamp the flanges by biasing force. It is characterized by being a mounting fixture. The clip structure has opposing portions sandwiching the flange, and clamps the flange by a biasing force acting on the opposing portions.

[0026] This invention allows the liner holder to have a simple configuration, which prevents the fixture from becoming too large and improves the ease of assembling the fixture to the flange. As a result, the foundation structure can reduce the burden on workers at the caisson foundation construction site.

[0027] In another aspect of the present invention, the liner holding portion may be integrally formed with a pair of approximately rod-shaped clamping portions facing each other across the flange, and an approximately ring-shaped annular connecting portion connecting the ends of the clamping portions. According to this invention, a biasing force can be generated in the pair of clamping portions with a simple configuration, and an increase in the size of the mounting fixture can be further suppressed.

[0028] In another aspect of the present invention, the liner holding portion may be integrally formed in an approximately triangular shape with an openable apex when viewed from the circumferential direction, by a pair of plate-shaped clamping plate portions facing each other across the flange and a connecting bottom portion connecting the ends of the clamping plate portions. According to this invention, a biasing force can be generated in the pair of clamping plate portions with a simple configuration, and an increase in the size of the mounting fixture can be further suppressed.

[0029] In another aspect of the present invention, the pair of clamping plate portions may be provided with a slit portion cut out from the top side of the approximately triangular shape toward the connecting bottom portion, the slit portion being large enough to allow the axial flange of the liner plate to be inserted. According to this invention, the mounting fixture can be attached across the axial flange, which is the circumferential connection point of the liner plate, so that the mounting fixture can be positioned at the circumferential position where the axial reinforcing bars are desired to be arranged.

[0030] As another aspect of the present invention, the reinforcing bar holding portion may be configured to hold the axial reinforcing bar and to be able to open the tip sides of the pair of clamping plate portions in the liner holding portion. According to this invention, the opening on the top side of the liner holding portion can be easily opened and closed, thereby improving the ease of assembling the mounting fixture to the flange.

[0031] The present invention also provides a foundation constructed in a borehole formed by excavating the ground, the foundation comprising: a cylindrical structure formed by arranging liner plates in the circumferential and depth directions along the wall surface of the borehole and assembling them together; a plurality of long axial reinforcing bars arranged at predetermined intervals along the interior of the cylindrical structure and extending in the depth direction; a plurality of mounting fixtures assembled to the cylindrical structure at predetermined intervals in the depth direction and circumferential directions and to which the axial reinforcing bars are attached; and an inner main body portion formed by hardening a solidifying material cast inside the cylindrical structure, the mounting fixtures having liner holding portions that clamp flanges of the liner plates and reinforcing bar holding portions that hold the axial reinforcing bars at positions close to the flanges, the reinforcing bar holding portions being formed in a shape having through holes that pass through along the depth direction, and the reinforcing bar holding portions having two through holes in the circumferential direction so that the interiors of the through holes are connected. .

[0032] The present invention also provides a method for constructing a foundation structure in a borehole formed by excavating the ground, the method comprising: a structure construction step of arranging liner plates in the circumferential and depth directions along the wall surface of the borehole and assembling them to construct a cylindrical structure; a reinforcement step of attaching a plurality of long axial reinforcing bars arranged at predetermined intervals along the interior of the cylindrical structure and extending in the depth direction to a plurality of mounting fixtures assembled to the cylindrical structure at predetermined intervals in the depth and circumferential directions; and a casting step of forming an inner main body by hardening a solidifying material cast inside the cylindrical structure, wherein in the reinforcement step, the mounting fixtures have liner holding parts that clamp flanges of the liner plates and reinforcing bar holding parts that hold the axial reinforcing bars at positions close to the flanges, and the reinforcing bar holding parts are formed in a shape having through holes that pass through along the depth direction, and the reinforcing bar holding parts are provided with two through holes in the circumferential direction so that the interiors of the through holes are connected. It is characterized by:

[0033] Furthermore, the present invention relates to a cylindrical structure constructed by excavating a ground and arranging liner plates in the circumferential and depth directions along the wall surface of the borehole, and assembling the liner plates to form a cylindrical structure, in which a plurality of long axial reinforcing bars extending in the depth direction are arranged at predetermined intervals along the inside of the cylindrical structure, and a solidifying material poured inside the cylindrical structure hardens to form an inner main body, thereby forming a foundation structure. The cylindrical structure is provided with liner holding parts that clamp flanges of the liner plates and reinforcing bar holding parts that hold the axial reinforcing bars at positions close to the flanges, and is assembled to the cylindrical structure at predetermined intervals in the depth direction and the circumferential direction, and the axial reinforcing bars are attached to the reinforcing bar holding parts, which are formed in a shape having through holes that pass through along the depth direction, and the reinforcing bar holding parts are provided with two through holes in the circumferential direction so that the insides of the through holes are connected. It is characterized by being a mounting fixture.

[0034] The reinforcing bar holding portion may be formed in a shape having a through hole that penetrates along the depth direction. According to this invention, the axial reinforcing bar can be held simply by inserting the axial reinforcing bar into the through hole along the depth direction.

[0035] Ma Ta, The reinforcing bar holding portion is provided with two through holes in the circumferential direction so that the insides of the through holes are in communication with each other. Because One fixture can hold two axial rebars, or the fixture can hold the lap splice of the axial rebars.

[0036] In another aspect of the present invention, the reinforcing bar holding portion may be cut out toward the liner holding portion and may be provided with a cutout portion that communicates with the through hole. According to this invention, the axial reinforcing bars can be inserted into the through holes in a direction intersecting the depth direction, thereby improving the ease of assembling the axial reinforcing bars to the mounting fixture.

[0037] As another aspect of the present invention, the reinforcing bar holding portion may be provided with a restricting portion that restricts the axial reinforcing bar from coming off through the notch portion. According to the present invention, for example, the axial reinforcing bar inserted into the through hole can be held without using a resilient reinforcing bar holding portion. [Effects of the Invention]

[0038] The present invention makes it possible to provide a foundation structure, a method for constructing a foundation structure, and mounting fixtures that can ensure the desired strength while reducing the burden on workers at a caisson foundation construction site. [Brief explanation of the drawings]

[0039] [Figure 1] FIG. [Figure 2] FIG. 2 is a schematic perspective view of the mounting fixture of the first embodiment. [Figure 3] Schematic side view of the mounting fixture and axial reinforcing bars attached to the liner plate. FIG. [Figure 4] FIG. 10 is an explanatory diagram illustrating the attachment of the mounting fixture and axial reinforcing bars to the liner plate. [Figure 5] FIG. 10 is an explanatory diagram illustrating the attachment of the mounting fixture and axial reinforcing bars to the liner plate. [Figure 6] FIG. 10 is a schematic perspective view of a mounting fixture according to a second embodiment. [Figure 7] 5A and 5B are explanatory views of mounting fixtures according to second and third embodiments. [Figure 8] FIG. 10 is an explanatory diagram of a mounting fixture according to a fourth embodiment. [Figure 9] FIG. 11 is a schematic perspective view of the state in which axial reinforcing bars are attached to a liner plate by the attachment fixture of the fifth embodiment. [Figure 10] FIG. 10 is a perspective view of a mounting fixture according to a fifth embodiment. [Figure 11] FIG. 10 is an explanatory diagram illustrating the attachment of the mounting fixture and axial reinforcing bars to the liner plate. [Figure 12] FIG. 13 is a schematic perspective view of the state in which axial reinforcing bars are attached to a liner plate by the attachment fixture of the sixth embodiment. [Figure 13] FIG. 13 is an exploded perspective view of a mounting fixture according to a sixth embodiment. [Figure 14] FIG. 10 is an explanatory diagram illustrating the attachment of the mounting fixture and axial reinforcing bars to the liner plate. [Figure 15] FIG. 13 is an explanatory view of another aspect of the mounting fixture of the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0040] An embodiment of the present invention will be described below with reference to the drawings. (First embodiment) The mounting fixture 10 of the first embodiment and the foundation pile 1 using the mounting fixture 10 will be described below with reference to FIGS.

[0041] In detail, Figure 1 shows a schematic oblique view of a foundation pile 1 using the mounting fixture 10 of the first embodiment, Figure 2 shows a schematic oblique view of the mounting fixture 10 of the first embodiment, Figure 3 shows a schematic side view of the mounting state of the mounting fixture 10 and axial reinforcing bars 2 to the liner plate 110, and Figures 4 and 5 show explanatory diagrams explaining the mounting of the mounting fixture 10 and axial reinforcing bars 2 to the liner plate 110.

[0042] In FIG. 1, the cylindrical structure 100 made up of the liner plate 110 and the front side of the foundation pile 1 are shown in a transparent state, and the axial reinforcing bars 2 on the front side are not shown. In addition, in FIG. 2, the axial reinforcing bars 2 attached to the fixture 10 are shown by dashed lines.

[0043] 3 and 4 show enlarged views of a part of the cylindrical structure 100 constituting the foundation pile 1 and the axial reinforcing bars 2 in the height direction. 4(a) shows a schematic side view of the state before the fixture 10 is attached to the liner plate 110, and FIG. 4(b) shows a schematic side view of the state before the axial reinforcing bars 2 are attached to the fixture 10 attached to the liner plate 110. Also, the concrete body 3 is not shown in FIGS. 1 and 3.

[0044] In addition, Figure 5(a) shows a schematic plan view of the state before the mounting fixture 10 is attached to the circumferential flange 113 across the axial flange 112 of the liner plate 110, and Figure 5(b) shows a schematic plan view of the state after the mounting fixture 10 has been attached to the circumferential flange 113 across the axial flange 112 of the liner plate 110.

[0045] Here, the depth direction of the cylindrical structure 100 in a state where the mounting fixture 10 is attached to the cylindrical structure 100 is referred to as the height direction H, the radial direction relative to the center of the cylindrical structure 100 in a plan view is referred to as the radial direction D, and the circumferential direction of the cylindrical structure 100 is referred to as the width direction R. The upper side of the height direction H is referred to as the upper side Hu, and the lower side is referred to as the lower side Hd. Furthermore, the side facing the radially outward in the radial direction D is referred to as the radially outward side Do, and the side facing the radially inward in the radial direction D is referred to as the radially inward side Di. Note that even when describing the mounting fixture 10 alone, the above directions are used, assuming a state where it is attached to the cylindrical structure 100. The same applies hereinafter to Figures 2 to 15.

[0046] The foundation pile 1 constructed using the mounting device 10 of this invention is a foundation structure constructed in a borehole 201 formed in the ground 200, and is composed of a cylindrical structure 100 made of a liner plate 110, axial reinforcing bars 2 arranged along the inner surface of the cylindrical structure 100, and a concrete body 3 poured inside the cylindrical structure 100.

[0047] Specifically, the ground 200 is excavated in a circular shape, and liner plates 110 are arranged circumferentially along the wall surface of the excavation hole to form a ring shape. Then, the ground 200 is further excavated, and below the existing liner plates 110 that have been assembled in a ring shape, further ground 200 is arranged circumferentially to form a ring shape, and assembled to the existing liner plates 110. This process is repeated to form a borehole 201 of a predetermined depth, and inside the borehole 201, the liner plates 110 are arranged in the circumferential direction and in the height direction H, and assembled together to form a cylindrical structure 100 (structure construction process). The ground 200 may be excavated by machine or by manual excavation.

[0048] In this way, axial steel bars 2 extending in the height direction H are attached and arranged at predetermined intervals along the inner surface of the cylindrical structure 100, which is configured along the inner surface of the excavation hole 201 of a predetermined depth, using mounting fixtures 10 described later (reinforcement arrangement process), and ready-mixed concrete is poured inside the cylindrical structure 100 (pouring process) to form the concrete body 3, and a foundation pile 1 made of reinforced concrete is constructed.

[0049] Next, the liner plate 110 that constitutes the cylindrical structure 100 will be described. The liner plate 110 is made of a corrugated thin steel plate having an arc-shaped configuration in plan view, and has flanges 111 (112, 113) for assembly on all four sides. The flanges 111 have a plurality of bolt holes 114 at predetermined intervals, through which assembly bolts 120 for assembly are inserted.

[0050] Of the assembly flanges 111 provided on the four sides of the corrugated thin steel plate that is arc-shaped when viewed from above, the flange that runs along the height direction H is called the axial flange 112, and the flange that runs along the arc, i.e., the circumferential direction, is called the circumferential flange 113.

[0051] In this way, liner plates 110, each having flanges 111 on all four sides of a corrugated, arc-shaped thin steel plate in plan view, are arranged in multiple circumferential directions to form a ring shape in plan view, with the axial flanges 112 of adjacent liner plates 110 in the circumferential direction overlapping each other and fastened together with assembly bolts 120 in bolt holes 114 to form a single unit.

[0052] As described above, the liner plates 110 are arranged in the height direction H, and the circumferential flanges 113 of the liner plates 110 adjacent to each other in the height direction H are overlapped and fastened together by assembly bolts 120 in the bolt holes 114 . The axial reinforcing bars 2 arranged at predetermined intervals along the inner surface of the cylindrical structure 100 formed by assembling the liner plates 110 configured in this manner are so-called deformed reinforcing bars, and are arranged with a diameter and number that corresponds to the required performance of the foundation pile 1.

[0053] The fixture 10 of the present invention is a jig for arranging a plurality of axial reinforcing bars 2, which are arranged at predetermined intervals in the circumferential direction, along the inner circumferential surface of the cylindrical structure 100. In other words, the fixture 10 is a jig for attaching the axial reinforcing bars 2 to the liner plates 110 that constitute the cylindrical structure 100 at predetermined positions.

[0054] Specifically, the fixture 10 is provided with a liner holding portion 20 that clamps the circumferential flange 113 of the flange 111 of the liner plate 110, and a reinforcing bar holding portion 30 that holds the axial reinforcing bar 2. The liner holding portion 20 is formed in an approximately triangular shape in side view with the apex, i.e., the end on the radially outer side Do, being openable, and is composed of a pair of plate-shaped clamping plate portions 21 facing each other across the circumferential flange 113, and a connecting bottom portion 22 that connects the ends of the radially inner side Di of the clamping plate portions 21 in the height direction H.

[0055] In addition, a slit portion 23 is provided in the center of the clamping plate portion 21 in the width direction R, the slit portion 23 being cut out from the tip toward the connecting bottom portion 22 and having a size that allows the axial flange 112 to be inserted therein. The liner holding portion 20 configured in this manner is configured so that the radial outer side Do of the clamping plate portion 21 can be opened in the height direction H, and is made of an elastic material that biases the clamping plate portion 21 in the closing direction when the clamping plate portion 21 is in the open state.

[0056] The reinforcing bar holding portion 30 is formed into a predetermined shape by bending a rod material, and comprises a fixing portion 31 extending along the clamping plate portion 21 of the liner holding portion 20, and a holding portion main body 32 protruding radially inward Di from the connecting bottom portion 22 and holding the axial reinforcing bar 2.

[0057] The fixing portions 31 extend from the radially outer side Do to the radially inner side Di of the clamping plate portion 21, and are arranged in pairs at a predetermined interval in the width direction R. The two fixing portions 31 thus provided are fixed to the surface of the clamping plate portion 21.

[0058] The holding portion body 32 protrudes from the ends of the two fixing portions 31 on the radially outer side Do toward the radially inner side Di along the inclination angle of the clamping plate portion 21, and forms a substantially circular shape. The holding portion body 32 formed in a substantially circular shape has a through hole with a diameter larger than that of the axial reinforcing bar 2 so that the axial reinforcing bar 2 can be inserted therethrough. The reinforcing bar holding portion 30 configured in this manner is provided for each of a pair of clamping plate portions 21 whose ends on the radially inner side Di are connected by the connecting bottom portion 22.

[0059] In the fixture 10 configured in this manner, a rebar holding portion 30 is provided for each of a pair of clamping plates 21 whose ends on the radially inner sides Di are connected by the connecting bottom 22, and a holding portion main body 32 protrudes radially inward Di from the clamping plates 21. In other words, the fixture 10, in which the holding portion main body 32 protrudes radially inward Di from the liner holding portion 20, constitutes a so-called double clip structure. Therefore, when an external force is applied so that the holding portion main body 32 protruding radially inward Di from the connecting bottom 22 approaches the liner holding portion 20 in the height direction H, the radially outer side Do of the clamping plate 21, which is made of an elastic material, opens in the height direction H against the biasing force (see FIG. 4(a)). Then, when the external force applied from the holding portion main body 32 is released, the clamping plates 21 close due to the biasing force of the liner holding portion 20.

[0060] As described above, the mounting fixture 10, which is made up of the liner holding portion 20 and the rebar holding portion 30, can be mounted by sandwiching the circumferential flange 113 of the liner plate 110, which is assembled in the height direction H, from the height direction H with the pair of clamping plate portions 21 of the liner holding portion 20. The mounting fixture 10 is attached to the circumferential flange 113 between the assembly bolts 120 that connect the liner plates 110 to each other in the height direction H.

[0061] Furthermore, the fixture 10 can hold the axial reinforcing bar 2 by inserting the axial reinforcing bar 2 into the holding portion main body 32 that protrudes radially inward Di from the connecting bottom portion 22 of the fixture 10 . Therefore, the axial reinforcing bar 2 can be held near the circumferential flange 113 of the liner plate 110 via the mounting fixture 10, which is attached by clamping the circumferential flange 113 of the liner plate 110 assembled in the height direction H from the height direction H with a pair of clamping plate portions 21 in the liner holding portion 20.

[0062] The mounting of the fixture 10 to the circumferential flange 113 of the liner plate 110 and the insertion of the axial reinforcing bars 2 into the retaining body 32 of the fixture 10 may be performed at any suitable timing and in any suitable order. Specifically, as shown in Fig. 4(a), the mounting of the fixture 10 to the circumferential flange 113 is performed after assembling a new liner plate 110 below the existing liner plate 110.

[0063] In order to attach the axial reinforcing bar 2 to the mounting fixture 10 which is mounted by clamping the circumferential flange 113 between a pair of clamping plate portions 21 from the height direction H, the axial reinforcing bar 2 is inserted from the height direction H into the holding portion main body 32 which is formed in an approximately circular shape, as shown in Figure 4(b).The axial reinforcing bar 2 may be inserted each time the mounting fixture 10 is mounted, or the axial reinforcing bar 2 may be inserted into the multiple mounting fixtures 10 all at once after multiple mounting fixtures 10 have been mounted in the height direction H.

[0064] In the above description, the mounting fixture 10 is attached to the circumferential flange 113 between the assembly bolts 120 that connect the liner plates 110 to each other in the height direction H, but as shown in Figure 5, the mounting fixture 10 may also be attached across the axial flange 112 that connects the liner plates 110 to each other in the circumferential direction.

[0065] Specifically, as shown in FIG. 5(a), the mounting fixture 10 is placed relative to the axial flange 112 that connects the liner plates 110 together in the circumferential direction. At this time, the mounting fixture 10 is placed so that the slits 23 provided in the clamping plate portions 21 of the mounting fixture 10 and the axial flange 112 face each other in the radial direction D. Then, as described above, the liner holding portions 20 of the mounting fixture 10 are attached to the circumferential flange 113 so that the liner holding portions 20 sandwich the circumferential flange 113 from the height direction H, and at this time, the mounting is performed so that the axial flange 112 is inserted into the slits 23 (see FIG. 5(b)). This allows the mounting fixture 10, which has the rebar holding portions 30 that hold the axial rebars 2, to be mounted across the axial flanges 112, which are the connecting portions between the liner plates 110 that connect each other in the circumferential direction to form the cylindrical structure 100.

[0066] As described above, the mounting fixture 10 is configured by arranging the liner plates 110 in the width direction R and height direction H along the wall surface of the borehole 201 formed by excavating the ground 200, and by arranging multiple long axial reinforcing bars 2 extending in the height direction H at predetermined intervals along the inside of the tubular structure 100 assembled together, and by disposing the solidifying material poured inside the tubular structure 100 to harden and form a concrete body 3, thereby forming the foundation pile 1. The mounting fixture 10 is provided with a liner holding portion 20 that clamps the circumferential flange 113 of the liner plate 110 in the tubular structure 100, and a reinforcing bar holding portion 30 that holds the axial reinforcing bars 2 at a position close to the circumferential flange 113, and is assembled to the tubular structure 100 at predetermined intervals in the height direction H and width direction R, and the axial reinforcing bars 2 are attached.

[0067] Furthermore, the foundation pile 1 constructed in the borehole 201 formed by excavating the ground 200 is provided with a cylindrical structure 100 in which liner plates 110 are arranged in the width direction R and the height direction H along the wall surface of the borehole 201 and assembled together, a plurality of long axial reinforcing bars 2 arranged at predetermined intervals along the inside of the cylindrical structure 100 and extending in the height direction H, a plurality of mounting fixtures 10 assembled to the cylindrical structure 100 at predetermined intervals in the height direction H and the width direction R and to which the axial reinforcing bars 2 are attached, and a concrete body 3 formed by the hardening of a solidifying material poured inside the cylindrical structure 100, and the mounting fixture 10 is provided with a liner holding portion 20 that clamps the circumferential flange 113 of the liner plate 110 and a reinforcing bar holding portion 30 that holds the axial reinforcing bars 2 in a position close to the circumferential flange 113.

[0068] In addition, the construction method of the foundation pile 1 constructed in the borehole 201 formed by excavating the ground 200 includes a structure construction process in which liner plates 110 are arranged in the width direction R and the height direction H along the wall surface of the borehole 201 and assembled together to construct the tubular structure 100, a reinforcement process in which long axial reinforcing bars 2 arranged at predetermined intervals along the inside of the tubular structure 100 and extending in the height direction H are attached to multiple mounting fixtures 10 assembled to the tubular structure 100 at predetermined intervals in the height direction H and width direction R, and a pouring process in which a concrete body 3 is formed by hardening a solidifying material poured inside the tubular structure 100, and in the reinforcement process, the liner holding portion 20 of the mounting fixture 10 clamps the circumferential flange 113 of the liner plate 110 in the height direction H, and the reinforcing bar holding portion 30 holds the axial reinforcing bar 2 at a position close to the circumferential flange 113.

[0069] As a result, the first effect of the mounting fixture 10 of the first embodiment is achieved, which is that it is possible to construct a foundation pile 1 that can ensure the desired strength while reducing the burden on workers at a caisson foundation construction work site. In detail, the mounting fixture 10 is clamped and assembled to the circumferential flange 113 of the liner plate 110, so that the desired number of axial reinforcing bars 2 can be connected via the mounting fixture 10 to any circumferential position on the tubular structure 100.

[0070] At this time, the reinforcing bar holding portion 30 of the mounting fixture 10 holds the axial reinforcing bar 2 at a position close to the circumferential flange 113, so that the mounting fixture 10 can restrict the axial reinforcing bar 2 relative to the circumferential flange 113 of the liner plate 110. This allows the foundation pile 1 to function as a hoop reinforcement that wraps the cylindrical structure 100 around the axial reinforcing bar 2. Therefore, the foundation pile 1 can reduce or lighten the number of hoop reinforcement bars arranged at predetermined intervals in the height direction H.

[0071] Therefore, the foundation pile 1, the construction method for the foundation pile 1, and the mounting fixture 10 can reduce the labor required for reinforcement, thereby achieving the first effect of the mounting fixture 10 of the first embodiment, which is to reduce the burden on workers at work sites using the deep foundation method to construct foundation piles 1 without compromising earthquake resistance or durability, i.e., to ensure the desired strength.

[0072] In addition, the construction method of the foundation pile 1 enables the mounting fixture 10 to be assembled to the circumferential flange 113 during the process of assembling the liner plate 110 in the height direction H, thereby achieving a second effect of the mounting fixture 10 of the first embodiment, in that the construction of the tubular structure 100 and the assembly of the mounting fixture 10 can be carried out efficiently.

[0073] In addition, since the reinforcing bar holding portion 30 is formed in a shape having a through hole that penetrates along the height direction H, a third effect of the mounting fixture 10 of the first embodiment is achieved, in that the axial reinforcing bar 2 can be held simply by inserting the axial reinforcing bar 2 into the through hole along the height direction H.

[0074] Furthermore, the liner holding portion 20 is configured with a clip structure that clamps the circumferential flange 113 with a biasing force. This allows the liner holding portion 20 to have a simple configuration, which prevents the mounting fixture 10 from becoming larger and improves the ease of assembling the mounting fixture 10 to the circumferential flange 113. Therefore, the foundation pile 1 achieves a fourth effect of the mounting fixture 10 of the first embodiment, which is that it can reduce the burden on workers at a work site using the caisson foundation method.

[0075] Furthermore, the liner holding portion 20 is integrally formed in an approximately triangular shape with an openable top when viewed from the width direction R, by a pair of plate-shaped clamping plate portions 21 facing each other across the circumferential flange 113, and a connecting bottom portion 22 connecting the ends of the clamping plate portions 21. Therefore, a spring force can be generated in the pair of clamping plate portions 21 with a simple configuration, thereby achieving a fifth effect of the mounting fixture 10 of the first embodiment, which is that the size of the mounting fixture 10 can be further prevented from increasing.

[0076] Furthermore, the reinforcing bar holding portion 30 holds the axial reinforcing bars 2 with the holding portion main body 32, and because the fixing portion 31 is fixed along the clamping plate portions 21, it is configured so that the reinforcing bar holding portion 30 can open the radially outer sides Do of the pair of clamping plate portions 21 in the liner holding portion 20. Therefore, by applying an external force to bring the holding portion main body 32, which protrudes radially inward Di from the liner holding portion 20, closer in the height direction H, the opening on the top side of the liner holding portion 20 can be easily opened and closed, thereby achieving a sixth effect of the mounting fixture 10 of the first embodiment, in that it is possible to improve the ease of assembling the mounting fixture 10 to the circumferential flange 113.

[0077] The pair of clamping plate portions 21 are provided with slit portions 23 cut out from the top side of the approximately triangular shape toward the connecting bottom portion 22, with a size that allows the axial flange 112 of the liner plate 110 to be inserted therein.

[0078] Therefore, the seventh effect of the mounting fixture 10 of the first embodiment is achieved, in that the mounting fixture 10 can be attached to the axial flange 112, which is the connection point of the liner plate 110 in the width direction R, and the mounting fixture 10 can be positioned at a position in the width direction R where the reinforcement of the axial reinforcing bars 2 is desired.

[0079] (Second embodiment) In the above-described mounting fixture 10, the holding portion main body 32 formed in a substantially circular shape is configured to protrude radially inward Di from the connecting bottom portion 22 of the liner holding portion 20. In contrast, the mounting fixture 10a of the second embodiment includes a holding portion main body 32a formed in a substantially C-shape with an opening on the radially inner side Di. The mounting fixture 10a of the second embodiment will be described below with reference to Figures 6 and 7.

[0080] FIG. 6 shows a schematic perspective view of a mounting fixture 10a of the second embodiment, and FIG. 7 shows an explanatory diagram of mounting to a liner plate 110. As shown in FIG. In FIG. 6, the axial reinforcing bars 2 attached to the fixture 10 are shown by dashed lines.

[0081] 7(a) shows the state in which the mounting fixture 10a and the axial reinforcing bars 2 have been attached to the liner plate 110, and FIG. 7(b) shows the state before the axial reinforcing bars 2 have been attached to the mounting fixture 10 attached to the liner plate 110. FIG. 7(c) shows the state in which the mounting fixture 10b and the axial reinforcing bars 2 of the third embodiment described below have been attached. In FIG. 7, the axial reinforcing bars 2 are shown by dashed lines. In the following description, the same components of the fixture 10a as those of the fixture 10 of the first embodiment described above will be denoted by the same reference numerals, and the description thereof will be omitted.

[0082] The liner holding portion 20a of the fixture 10a does not have the slit portion 23 in the clamping plate portion 21, but the clamping plate portion 21 and the connecting bottom portion 22 have the same structure as the fixture 10. The retaining portion body 32a of the reinforcing bar retaining portion 30a of the fixture 10a is substantially C-shaped with an opening 33 on the radially inner side Di, and a bent-back portion 34 is provided at the tip thereof.

[0083] The roughly C-shaped retaining portion main body 32a having the opening 33 is formed into a predetermined shape by bending a bar material, similar to the reinforcing bar retaining portion 30 described above, but has elasticity. Therefore, when an external force is applied to the tip of the holding portion main body 32a on which the bent portion 34 is formed so as to open in the width direction R, the opening 33 widens, and when the external force is released, the opening 33 returns to its original shape due to the biasing force of the holding portion main body 32a.

[0084] The fixture 10a configured in this manner is attached to the circumferential flange 113 of the liner plate 110, similar to the fixture 10 described above, and then, as shown in Fig. 7(b), the axial reinforcing bar 2 is pushed into the retaining body 32a through the opening 33 so as to widen the opening 33 relative to the retaining body 32a, causing the retaining body 32a to elastically deform in the direction of opening the opening 33. Then, when the axial reinforcing bar 2 passes through the opened opening 33, the biasing force causes the retaining body 32a to return to its original shape, and the axial reinforcing bar 2 can be attached inside the retaining body 32a (see Fig. 7(a)).

[0085] In addition to the first to sixth effects of the mounting fixture 10 of the first embodiment, the mounting fixture 10a of the second embodiment has the first effect of improving the ease of assembling the axial reinforcing bar 2 to the mounting fixture 10a, since the reinforcing bar holding portion 30a is cut out toward the liner holding portion 20a and has an opening 33 that communicates with the through hole, and therefore the axial reinforcing bar 2 can be inserted into the through hole from the radial direction D, which is a direction that intersects the height direction H.

[0086] (Third embodiment) In the above description of the mounting fixture 10, the reinforcing bar holding portion 30 is provided with one holding portion main body 32 and is configured so that the axial reinforcing bar 2 can be inserted through the through hole of the holding portion main body 32, but as shown in Figure 7(c), the mounting fixture 10b may also be provided with a reinforcing bar holding portion 30b having two holding portion main bodies 32b.

[0087] Specifically, fixture 10b is composed of liner retaining portion 20a of fixture 10a and rebar retaining portion 30b having two retaining portion bodies 32b. Note that liner retaining portion 20a constituting fixture 10b may be composed of liner retaining portion 20 having slit portion 23.

[0088] The reinforcing bar holding portion 30b having two holding portion bodies 32b is similar to the reinforcing bar holding portion 30 of the fixture 10 having one holding portion body 32, in that one holding portion body 32b is provided on the base end side of the two fixing portions 31 and the other holding portion body 32b is arranged in the width direction R. The reinforcing bar holding portion 30b configured in this manner forms a roughly figure-8 shape in plan view because the two holding portion bodies 32b share a portion of the circumferential direction. In this way, the fixture 10b having two holding portion bodies 32b can hold the axial reinforcing bars 2 in each of the two holding portion bodies 32b, thereby achieving the same effect as the fixture 10 described above and being able to hold two axial reinforcing bars 2 near the circumferential flange 113 of the liner plate 110.

[0089] In addition to the first to sixth effects of the mounting fixture 10 of the first embodiment, the mounting fixture 10b of the third embodiment has the first effect of the mounting fixture 10b of the third embodiment, in that the reinforcing bar holding portion 30b has two through holes in the width direction R so that the insides of the through holes are connected, so that one mounting fixture 10b can hold two axial reinforcing bars 2 and the lap joint points of the axial reinforcing bars 2 can be held by the mounting fixture 10b.

[0090] (Fourth embodiment) Furthermore, the retaining portion main body 32a in the above-mentioned mounting fixture 10a has an opening 33 and is configured so that the axial reinforcing bar 2 can be inserted through the opening 33, but the mounting fixture 10c of the fourth embodiment shown in Figure 8 has an opening 33c but also has a cover portion 35 that closes the opening 33c.

[0091] Fig. 8(a) shows a schematic plan view of the fixture 10c with the axial reinforcing bar 2 inserted into the reinforcing bar holding portion 30c, Fig. 8(b) shows a schematic cross-sectional view passing through the center of the reinforcing bar holding portion 30c with the cover portion 35 in the open state, and Fig. 8(c) shows a schematic cross-sectional view passing through the center of the reinforcing bar holding portion 30c with the cover portion 35 in the closed state. In Fig. 8, the axial reinforcing bar 2 is shown by a dashed line.

[0092] A fixture 10c of the fourth embodiment shown in FIG. 8 includes a liner holding portion 20a having the same structure as fixture 10a, and a reinforcing bar holding portion 30c having a holding portion main body 32c with an opening 33c. Similar to the reinforcing bar holding part 30 described above, the reinforcing bar holding part 30c includes a holding part body 32c on the radially inner side Di of two fixing parts 31 arranged in the width direction R at a predetermined interval.

[0093] In contrast to the holding portion main body 32a which is formed in a substantially C-shape with an opening 33 on the radially inner side Di, the holding portion main body 32c is formed in a substantially semicircular shape with an opening 33c which is wider than the opening 33.

[0094] A hinge portion 36 is provided at one end of the holding portion main body 32c, which is formed in a substantially semicircular shape, to pivotally connect a semicircular cover portion 35 that closes the opening 33c. The cover portion 35 connected to the holding portion main body 32c by the hinge portion 36 is one size larger than the holding portion main body 32c and has a cross-sectional shape that covers the other end of the holding portion main body 32c.

[0095] In addition, a cover portion 35 is formed in a cross-sectional shape that covers the other end of the holding portion main body 32c, and a locking portion 37 is provided at the other end of the holding portion main body 32c that is covered by the cover portion 35, to lock and maintain the cover portion 35 in a closed state.

[0096] In the mounting fixture 10c configured in this manner, similar to the above-described mounting fixture 10, when it is attached to the circumferential flange 113 of the liner plate 110, the cover portion 35 is opened with the hinge portion 36 as the pivot center, as shown in Figure 8(b), and the axial reinforcing bar 2 is placed through the opening 33c into the through hole inside the holding portion main body 32c.

[0097] Then, with the axial reinforcing bar 2 placed inside the holding portion main body 32c, the cover portion 35 is pivoted in the closing direction around the hinge portion 36 as the pivot center to close the opening 33c, and the inside of the cover portion 35 is engaged with the engaging portion 37 provided at the other end of the holding portion main body 32c, thereby maintaining the closed state with the cover portion 35 and allowing the axial reinforcing bar 2 to be held by the holding portion main body 32c.

[0098] In addition to the first to sixth effects of the mounting fixture 10 of the first embodiment, the mounting fixture 10c of the fourth embodiment has the first effect of the mounting fixture 10c of the fourth embodiment, in that the rebar holding portion 30c is provided with a cover portion 35 that prevents the axial rebar 2 from coming off through the opening 33, and therefore the mounting fixture 10c of the fourth embodiment has the first effect of being able to hold the axial rebar 2 inserted into the through hole even if the rebar holding portion 30c is not elastic.

[0099] (Fifth embodiment) Next, a mounting fixture 10d according to a fifth embodiment will be described with reference to FIGS. Fig. 9 shows a schematic perspective view of the state in which the axial reinforcing bars 2 are attached to the liner plate 110 by the attachment fixture 10d of the fifth embodiment, Fig. 10 shows a perspective view of the attachment fixture 10d of the fifth embodiment, and Fig. 11 shows an explanatory diagram for explaining the attachment of the attachment fixture 10d and the axial reinforcing bars 2 to the liner plate 110. The concrete body 3 is not shown in Fig. 9.

[0100] Specifically, FIG. 9 shows a partial schematic perspective view of a state in which a fixture 10d is attached to the cylindrical structure 100 and the axial reinforcing bars 2 are held by the fixture 10d, with the front side shown as transparent. Figure 11(a) shows a schematic cross-sectional view passing through the center of the fixture 10d before it is attached to the liner plate 110, and Figure 11(b) shows a schematic cross-sectional view passing through the center of the fixture 10d after it has been attached to the liner plate 110.

[0101] Unlike the above-described mounting fixtures 10, 10a to 10c which have a double clip structure, the mounting fixture 10d shown in Figures 9 to 11 is composed of a clip portion 20d which clamps the circumferential flange 113 from the height direction H, and a flat reinforcing bar holding portion 30d which is connected to the clip portion 20d and has an insertion hole 38.

[0102] The clip portion 20d is composed of two clip pieces 24 arranged at a predetermined interval in the height direction H, and an arc portion 25 having an approximately circular shape in side view and arranged radially inward Di of the clip pieces 24.

[0103] The two clip pieces 24 form a pair, and the tip surface of one clip piece 24 is provided with a guide surface 241 that is inclined toward the other clip piece 24.

[0104] The pair of clip pieces 24 face each other on the liner plates 110 adjacent in the height direction H, and are arranged at an interval narrower than the thickness of the circumferential flanges 113 that are overlapped therebetween. The radially inner ends Di of a pair of clip pieces 24, which are arranged at a distance narrower than the thickness of the circumferential flange 113 to be overlapped, are connected and integrated with an arc portion 25 which is approximately circular in side view.

[0105] The arc portion 25 connecting the base ends of the two clip pieces 24 is formed with a diameter wider than the distance between the two clip pieces 24 in the height direction H. Thus, the clip portion 20d, in which the two clip pieces 24 and the arc portion 25 are integrated, is formed into the above-mentioned shape using elastic round bar material. Therefore, when an external force is applied in a direction that opens the two clip pieces 24, the arc portion 25 bends and deforms, and when the external force is released, the elasticity of the round bar material causes the two clip pieces 24 to return to their original distance.

[0106] The reinforcing bar holding portion 30d is formed in a square shape in a plan view, and has an insertion hole 38 at the center in a plan view, through which the axial reinforcing bar 2 can be inserted. Note that the planar shape of the reinforcing bar holding portion 30d is not limited to a square shape, and it may be formed in any suitable shape. The reinforcing bar holding portion 30d configured in this manner is connected to the radially inner side Di of the arc portion 25 that is substantially circular in side view, and the clip portion 20d and the reinforcing bar holding portion 30d are integrated together.

[0107] As described above, the mounting fixture 10d, which is composed of the clip portion 20d and the reinforcing bar holding portion 30d, can be attached by clamping the circumferential flange 113 of the liner plate 110, which is assembled in the height direction H, from the height direction H using a pair of clip pieces 24 on the clip portion 20d.

[0108] Specifically, as shown in Figure 11(a), the tip surface of the clip piece 24 is positioned opposite the circumferential flange 113 between the assembly bolts 120 that connect the liner plates 110 in the height direction H.

[0109] When the mounting fixture 10d is attached to the circumferential flange 113 by inserting it from the radially inner side to the radially outer side, the pair of clip pieces 24, which are arranged at a distance narrower than the thickness of the overlapping circumferential flange 113, are guided to spread apart by the guide surface 241, causing the arc portion 25 to bend and deform, allowing the mounting to be completed.

[0110] Furthermore, by inserting the axial reinforcing bars 2 into the insertion holes 38 of the reinforcing bar holding portions 30d that protrude radially inward Di in the fixture 10d, the fixture 10d can hold the axial reinforcing bars 2. Therefore, the axial reinforcing bar 2 can be held near the circumferential flange 113 of the liner plate 110 via the mounting fixture 10d, which is attached by clamping the circumferential flange 113 of the liner plate 110 assembled in the height direction H from the height direction H with a pair of clip pieces 24 in the clip portion 20d.

[0111] The attachment of the fixture 10d to the circumferential flange 113 of the liner plate 110 and the insertion of the axial reinforcing bar 2 into the reinforcing bar holding portion 30d of the fixture 10d may be performed at an appropriate timing and in an appropriate order, similar to the fixture 10, etc.

[0112] In addition to the first to fourth effects of the mounting fixture 10 of the first embodiment and the first effect of the mounting fixture 10b of the third embodiment, the mounting fixture 10d of the fifth embodiment described above has the following advantage: the liner retaining portion 20 is integrally formed with a pair of approximately rod-shaped clip pieces 24 that face each other across the circumferential flange 113, and a approximately annular arc portion 25 that connects the ends of the clip pieces 24; therefore, a spring force can be generated in the pair of clip pieces 24 with a simple configuration, and the mounting fixture 10 can be further prevented from becoming larger.

[0113] In the above description of the mounting fixture 10d, the clip portion 20d is provided with a reinforcing bar holding portion 30d having one insertion hole 38, but the reinforcing bar holding portion 30d may be provided with two insertion holes 38. In this case, the two insertion holes 38 are arranged at a predetermined distance in the width direction R, so that the reinforcing bar holding portion 30d has a rectangular shape that is longer in the width direction R than in the radial direction D.

[0114] In this way, the mounting fixture 10d, which has a reinforcing bar holding portion 30d with two insertion holes 38, can hold an axial reinforcing bar 2 by inserting it into each of the two insertion holes 38, thereby achieving the same effect as the above-mentioned mounting fixture 10d and being able to hold two axial reinforcing bars 2 near the circumferential flange 113 of the liner plate 110.

[0115] (Sixth embodiment) Next, a mounting fixture 10e according to a sixth embodiment will be described with reference to FIGS. Figure 12 shows a schematic oblique view of the state in which axial reinforcing bars 2 are attached to a liner plate 110 using the mounting fixture 10e of the sixth embodiment, Figure 13 shows an exploded oblique view of the mounting fixture 10e of the sixth embodiment, Figure 14 shows an explanatory diagram explaining the attachment of the mounting fixture 10e and axial reinforcing bars 2 to the liner plate 110, and Figure 15 shows an explanatory diagram of another aspect of the mounting fixture 10e of the sixth embodiment.

[0116] 12 is a partial schematic perspective view of the state in which the fixture 10e is attached to the cylindrical structure 100 and the fixture 10e holds the axial reinforcing bars 2, with the front side being transparent. Also, the concrete body 3 is not shown in FIG.

[0117] Figure 14(a) shows a schematic cross-sectional view through the center of the fixture 10e before it is attached to the liner plate 110, and Figure 14(b) shows a schematic cross-sectional view through the center of the fixture 10e after it has been attached to the liner plate 110.

[0118] 15A is an explanatory diagram of another aspect of the mounting fixture 10e of the sixth embodiment, in which Fig. 15(a) is a schematic plan view of the mounting fixture 10e, Fig. 15(b) is a schematic plan view of the mounting fixture 10e when two holding portion bodies 32e are provided, Fig. 15(c) is a schematic plan view of the mounting fixture 10e, which has slits 23 for mounting across the axial flange 112, before being attached to the liner plate 110, and Fig. 15(d) is a schematic plan view of the mounting fixture 10e attached to the liner plate 110.

[0119] 12 to 15 differs from the above-described fasteners 10, 10a to 10c which have a double clip structure, and the clip-shaped fastener 10d, in that it is composed of a clamp portion 20e which clamps the circumferential flange 113 from the height direction H, and a flat reinforcing bar holding portion 30d which is connected to the clamp portion 20e and has an insertion hole 38. Reinforcing bar holding portion 30d has the same configuration as reinforcing bar holding portion 30d of the above-described fastener 10d, so a description thereof will be omitted.

[0120] The clamping portion 20e is composed of two flat fixing plates 26 (261, 262) arranged at a predetermined distance in the height direction H, a connecting plate 27 that connects the ends of the radially inner sides Di of the fixing plates 26 in the height direction H, a fixing nut 28 attached to the upper fixing plate 261 on the upper side Hu of the pair of fixing plates 26, and a fixing bolt 29 that threads into the fixing nut 28.

[0121] More specifically, the two fixing plates 26 constituting a pair have a generally square shape in plan view with a width approximately the same as that of the rebar holding portion 30d, and are arranged at a predetermined interval in the height direction H. The fixing plates 26 constituting a pair face each other on adjacent liner plates 110 in the height direction H, and are arranged at an interval wider than the thickness of the circumferential flanges 113 that are overlapped. For ease of explanation, of the fixing plates 26 constituting a pair, the fixing plate 26 arranged on the upper side Hu is referred to as the upper fixing plate 261, and the fixing plate 26 arranged on the lower side Hd is referred to as the lower fixing plate 262.

[0122] The upper fixing plate 261 is provided with a through hole 263 which is larger than the bolt hole of a fixing nut 28 described later and through which the bolt shank of the fixing bolt 29 passes in the height direction H. The lower fixing plate 262 is connected to the reinforcing bar holding portion 30d and is formed as if it were a single plate.

[0123] The connecting plate 27 is a plate material that connects the ends of the radially inner sides Di of the fixed plates 26 arranged at a predetermined interval in the height direction H, and as shown in Figure 14, the pair of fixed plates 26 and connecting plate 27 form a U-shape when viewed from the width direction R.

[0124] The fixing nut 28 is a nut that can be screwed onto a fixing bolt 29, which will be described later, and is fixed on the upper surface of the upper fixing plate 261 with the through hole 263 and the bolt hole arranged concentrically in the height direction H.

[0125] Fixing bolt 29 is a general bolt that is made up of a bolt head that is hexagonal in plan view and a cylindrical bolt shank 291 on which a screw thread is formed, and can be screwed onto fixing nut 28.

[0126] The bolt shaft portion 291 is formed to have a length sufficient to be threaded into the fixing nut 28 and allow its tip to pass through the through-hole 263 and abut against the upper surface of the lower fixing plate 262 . The clamp portion 20e configured in this manner is assembled by screwing the fixing bolt 29 into the fixing nut 28 fixed to the upper surface of the upper fixing plate 261.

[0127] As described above, the mounting fixture 10e, which is composed of the clamp portion 20e and the reinforcing bar holding portion 30d, can be attached by positioning the pair of fixing plates 26 in the clamp portion 20e so as to sandwich the circumferential flange 113 of the liner plate 110 assembled in the height direction H from the height direction H, and by screwing the fixing bolt 29 into the fixing nut 28.

[0128] Specifically, as shown in Figure 14(a), the tip surface of the fixing plate 26 is positioned to face the circumferential flange 113 between the assembly bolts 120 that connect the liner plates 110 to each other in the height direction H.

[0129] When the mounting fixture 10e is attached to the circumferential flange 113 by inserting it from the radially inner side toward the radially outer side, the pair of mounting plates 26, which are spaced apart at a distance wider than the thickness of the overlapping circumferential flanges 113, are positioned outside the circumferential flanges 113 in the height direction H. When the mounting bolt 29 is threaded into the mounting nut 28 in this state, the tip of the bolt shank 291 of the mounting bolt 29 passes through the through hole 263 of the upper mounting plate 261 and abuts against the upper surface of the circumferential flanges 113 that are overlapped in the height direction H. When the mounting bolt 29 is further threaded into the mounting nut 28, the mounting fixture 10e moves upward Hu relative to the circumferential flange 113, and the lower surface of the overlapping circumferential flanges 113 abuts against the upper surface of the lower mounting plate 262, thereby fixing and attaching the overlapping circumferential flanges 113 from both sides in the height direction H by the upper surface of the lower mounting plate 262 and the tip of the bolt shank 291 of the mounting bolt 29.

[0130] Furthermore, by inserting the axial reinforcing bars 2 into the insertion holes 38 of the reinforcing bar holding portions 30d that protrude radially inward Di in the fixture 10e, the fixture 10e can hold the axial reinforcing bars 2. Therefore, the axial reinforcing bar 2 can be held near the circumferential flange 113 of the liner plate 110 via the mounting fixture 10e, which is attached by clamping the circumferential flange 113 of the liner plate 110 assembled in the height direction H from the height direction H with a pair of fixing plates 26 in the clamp portion 20e.

[0131] The attachment of the fixture 10e to the circumferential flange 113 of the liner plate 110 and the insertion of the axial reinforcing bar 2 into the reinforcing bar holding portion 30d of the fixture 10e may be performed at an appropriate timing and in an appropriate order, similar to the fixture 10, etc.

[0132] In addition to the first to third effects of the mounting fixture 10 of the first embodiment and the first effect of the mounting fixture 10b of the third embodiment, the clamping portion 20e is configured with a clamping structure that clamps the circumferential flange 113, allowing the clamping portion 20e to have a simple configuration, preventing the mounting fixture 10e from becoming larger, and improving the ease of assembling the mounting fixture 10e to the circumferential flange 113. Therefore, the foundation pile 1 achieves the first effect of the mounting fixture 10e of the sixth embodiment, which is that it can reduce the burden on workers at a work site using the caisson foundation method.

[0133] In the above description of the mounting fixture 10e, as shown in Figure 15(a), the clamp portion 20e is provided with a reinforcing bar holding portion 30d having one insertion hole 38, but as shown in Figure 15(b), the reinforcing bar holding portion 30d may be provided with two insertion holes 38. In this case, since the two insertion holes 38 are arranged at a predetermined interval in the width direction R, the reinforcing bar holding portion 30d has a rectangular shape that is longer in the width direction R than in the radial direction D.

[0134] In this way, the mounting fixture 10e, which has a reinforcing bar holding portion 30d with two insertion holes 38, can hold an axial reinforcing bar 2 by inserting it into each of the two insertion holes 38, thereby achieving the same effect as the above-mentioned mounting fixture 10e and also achieving the first effect of the mounting fixture 10b of the third embodiment.

[0135] In addition, in the above description, the mounting fixture 10e is attached to the circumferential flange 113 between the assembly bolts 120 that connect the liner plates 110 to each other in the height direction H, but as shown in Figures 15(c) and (d), the mounting fixture 10e may also be attached across the axial flange 112 that connects the liner plates 110 to each other in the circumferential direction.

[0136] Specifically, as shown in Figure 15(c), the clamp portion 20e has two fixing nuts 28 and two fixing bolts 29 arranged at a predetermined interval in the width direction R, so that the fixing plate 26 and connecting plate 27 that make up the clamp portion 20e have a rectangular shape that is longer in the width direction R than in the radial direction D.

[0137] The upper fixing plates 261 are arranged at predetermined intervals in the width direction R on the rectangular upper fixing plates 261 that are longer in the width direction R than in the radial direction D. In addition, a slit portion 23 is provided in the center of the width direction R of the fixed plate 26, which has a rectangular shape that is longer in the width direction R than in the radial direction D, and is concave from the end on the radially outer side Do toward the radially inner side Di.

[0138] The fixture 10e configured in this manner is placed against the axial flange 112 that connects the liner plates 110 together in the circumferential direction. At this time, the fixture 10e is placed so that the slits 23 provided in the fixing plate 26 of the fixture 10e face the axial flange 112. Then, as described above, the clamping portions 20e of the fixture 10e are attached to the circumferential flange 113 so that the circumferential flange 113 is clamped and fixed by the clamping portions 20e from the height direction H. At this time, the fixture 10e is attached so that the axial flange 112 is inserted into the slits 23 (see FIG. 15(d)). This allows the fixture 10e, which has the rebar holding portions 30d that hold the concrete body 3, to be installed across the axial flanges 112, which are the connecting portions between the liner plates 110 that connect together in the circumferential direction to form the cylindrical structure 100.

[0139] In this way, the mounting fixture 10e, which has two fixing nuts 28 and two fixing bolts 29, can fix the circumferential flanges 113 on both sides of the axial flange 112 with the two fixing nuts 28 and two fixing bolts 29, and in addition to the same effect as the mounting fixture 10e described above, that is, the mounting fixture 10e can be mounted across the axial flange 112, two liner holding portions 20 are arranged side by side in the width direction R, sandwiching the axial flange 112 of the liner plate 110. Therefore, since the mounting fixture 10 can be mounted to the axial flange 112, which is the connecting point of the liner plate 110 in the width direction R, it has the effect of being able to position the mounting fixture 10 in the width direction R where the arrangement of the axial reinforcing bars 2 is desired.

[0140] As described above, in the configuration of the present invention and the correspondence between the configuration and the above-mentioned embodiment, the ground of the present invention corresponds to the ground 200, Similarly, The borehole corresponds to borehole 201; The foundation structure corresponds to foundation pile 1, The liner plate is compatible with liner plate 110. The circumferential direction corresponds to the width direction R, The depth direction corresponds to the height direction H, The cylindrical structure corresponds to the cylindrical structure 100, Axial reinforcement corresponds to axial reinforcement 2, The fixtures correspond to fixtures 10, 10a to 10e, The inner body part corresponds to the concrete body 3, The flange corresponds to a circumferential flange 113; The liner holding portions correspond to the liner holding portions 20, 20a to 20c, the clip portion 20d, and the clamp portion 20e. The reinforcing bar holding portions correspond to the reinforcing bar holding portions 30, 30a to 30d, The axial flange corresponds to the axial flange 112; The clamping portion corresponds to the clip piece 24, The annular connecting portion corresponds to the arc portion 25; The clamping plate portion corresponds to the clamping plate portion 21, The connecting bottom corresponds to the connecting bottom 22, The slit portion corresponds to the slit portion 23, The notches correspond to the openings 33 and 33c. The restricting portion corresponds to the cover portion 35, but is not limited to the above embodiment.

[0141] For example, the above-mentioned cylindrical structure 100 is assembled by shifting the connection positions of the liner plates 110 in the width direction R, i.e., the axial flanges 112, in the height direction H so that they do not coincide, but the liner plates 110 may also be assembled so that the connection positions of the liner plates 110 in the width direction R, i.e., the circumferential positions of the axial flanges 112, coincide, or a combination of these may be used.

[0142] Furthermore, the fixture 10d of the fifth embodiment and the fixture 10e of the sixth embodiment may be attached upside down in the height direction H. Furthermore, the above-mentioned mounting fixtures 10, 10a to 10e are attached by holding the circumferential flange 113 with the liner holding portions (20, 20a to 20e), but they may also be configured so that the axial flange 112 is held and attached with the liner holding portions (20, 20a to 20e) by orthogonally orienting the liner holding portions (20, 20a to 20e) with the reinforcing bar holding portions (30, 30a to 30e), or so that the reinforcing ribs provided on the liner plate 110 are held and attached with the liner holding portions (20, 20a to 20e). Furthermore, although the cylindrical structure 100 is formed to have a circular shape in a plan view, it may be formed to have, for example, an elliptical shape in a plan view, an oval shape in a plan view, or even a polygonal shape in a plan view. [Explanation of symbols]

[0143] 1...Foundation piles 2...Axial reinforcement 3...Concrete body 10, 10a to 10e... Mounting fixture 20, 20a to 20c...Liner holding section 20d...Clip part 20e...Clamp section 21...Holding plate part 22…Connection bottom 23...Slit section 24...Clip piece 25...Arc section 30, 30a to 30d...Rebar holding section 33,33c…Aperture 35...Cover part 100...Cylindrical structure 110...Liner plate 112...Axial flange 113... Circumferential flange 200...ground 201...Drilling hole H: Height W: Width direction

Claims

1. A foundation structure constructed in a borehole formed by excavating the ground, A cylindrical structure formed by arranging liner plates in the circumferential direction and the depth direction along the wall surface of the borehole and assembling them together; A plurality of long axial reinforcing bars are arranged at predetermined intervals along the inside of the cylindrical structure and extend in the depth direction; a plurality of mounting fixtures that are assembled to the cylindrical structure at predetermined intervals in the depth direction and the circumferential direction and to which the axial reinforcing bars are attached; an inner main body portion formed by hardening a solidification material cast inside the cylindrical structure; The mounting fixture is a liner holding portion that holds the flange of the liner plate; A reinforcing bar holding portion is provided to hold the axial reinforcing bar at a position close to the flange. Foundation structure.

2. The liner holding portion is A clamp structure configured to clamp the flange The foundation structure according to claim 1 .

3. The liner holding portion is Two axial flanges of the liner plate are arranged side by side in the circumferential direction. The foundation structure according to claim 2 .

4. The liner holding portion is A clip structure is configured to clamp the flange by biasing force. The foundation structure according to claim 1 .

5. The liner holding portion is a pair of substantially rod-shaped clamping portions facing each other with the flange in between; and a substantially annular connecting portion that connects the ends of the clamping portion. The foundation structure according to claim 4.

6. The liner holding portion is A pair of plate-shaped clamping plate portions facing each other with the flange interposed therebetween and a connecting bottom portion connecting the ends of the clamping plate portions are integrally formed in a substantially triangular shape with an openable top when viewed from the circumferential direction. The foundation structure according to claim 4.

7. The pair of clamping plate portions are A slit portion is provided in the approximately triangular shape, cut from the top side toward the connecting bottom portion, with a size that allows the axial flange of the liner plate to be inserted. The foundation structure according to claim 6.

8. The reinforcing bar holding portion is The axial reinforcing bars are held, and the tip sides of the pair of clamping plate portions in the liner holding portion are configured to be openable. The foundation structure according to claim 6.

9. The reinforcing bar holding portion is The substrate is formed in a shape having a through-hole penetrating along the depth direction. The foundation structure according to claim 1 .

10. The reinforcing bar holding portion is Two through holes are provided in the circumferential direction so that the insides of the through holes are in communication with each other. The foundation structure according to claim 9.

11. The reinforcing bar holding portion is A notch portion is provided which is cut out toward the liner holding portion and communicates with the through hole. The foundation structure according to claim 9.

12. The reinforcing bar holding portion is A restricting portion is provided to restrict the detachment of the axial reinforcing bar through the notch portion. The foundation structure according to claim 11.

13. A method for constructing a foundation structure constructed in a borehole formed by excavating the ground, comprising: a structure construction process in which liner plates are arranged in the circumferential direction and the depth direction along the wall surface of the borehole and assembled together to construct a cylindrical structure; a reinforcing bar arrangement process in which a plurality of long axial reinforcing bars arranged at predetermined intervals along the interior of the cylindrical structure and extending in the depth direction are attached to a plurality of mounting fixtures assembled to the cylindrical structure at predetermined intervals in the depth direction and the circumferential direction, respectively; a casting step of forming an inner main body portion by hardening a solidification material cast inside the cylindrical structure, In the reinforcement step, The mounting fixture has a liner holding portion that clamps the flange of the liner plate, and a reinforcing bar holding portion that holds the axial reinforcing bar at a position close to the flange. How to build foundation structures.

14. a liner holding portion for clamping the flanges of the liner plates in the cylindrical structure that constitutes a foundation structure constructed by arranging liner plates in the circumferential and depth directions along the wall surface of a borehole formed by excavating the ground, and arranging a plurality of long axial reinforcing bars extending in the depth direction at predetermined intervals along the inside of the cylindrical structure that is constructed by assembling the liner plates together, and hardening a solidifying material cast inside the cylindrical structure to form an inner main body portion; a reinforcing bar holding portion that holds the axial reinforcing bar at a position close to the flange, The axial reinforcing bars are attached to the cylindrical structure at predetermined intervals in the depth direction and the circumferential direction. Mounting fixture.

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