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: In the cylindrical structure 100 constituting the foundation pile 1, the securing members 10 provided with the fastened components 20 fastened together with the circumferential flanges 113 and fixed to the liner plates 110 by the assembly bolts 120 fastening the circumferential flanges 113 of the liner plates 110 adjacent to each other in the width direction R and the reinforcing bar holding portions 30 disposed on the radially inner side Di of the fastened components 20 and holding the axial reinforcing bars 2 at positions close to the circumferential flanges 113 are assembled to the cylindrical structure 100 at predetermined intervals in the height direction H and the width direction R, and the axial reinforcing bars 2 are attached.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] This invention relates to a foundation structure constructed in a borehole formed by excavating the ground, and includes 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 inside of the cylindrical structure and extending in the depth direction; a mounting fixture assembled to the cylindrical structure and to which the axial reinforcing bars are attached; and an inner main body formed by hardening a solidifying material cast inside the cylindrical structure, and the mounting fixture is configured to fasten flanges of the liner plates together using fasteners, Circumferential direction a fastened portion that is fastened together with the flange and fixed to the liner plate; and a fastened portion that is disposed radially inside the fastened portion and Circumferential direction a reinforcing bar holding portion that holds the axial reinforcing bar at a position close to the flange, A retaining material is provided inside the liner plate along at least a portion of the circumferential direction and is a step reinforcement that holds the axial reinforcing bar. The reinforcing bar holding portion is configured to fix the retaining material and hold the axial reinforcing bar via the retaining material. The retaining material is formed in an arc shape, and a plurality of retaining materials are provided and arranged along the circumferential direction to form a circular or arc shape with a diameter smaller than the inner diameter of the liner plate. It is characterized by:

[0009] This invention also features a mounting fixture that includes a cylindrical structure that constitutes a foundation structure, in which liner plates are arranged circumferentially and in the depth direction along the wall surface of a borehole formed by excavating the ground, and multiple long axial reinforcing bars extending in the depth direction are arranged at predetermined intervals along the inside of the cylindrical structure that is assembled together, and a solidifying material poured inside the cylindrical structure hardens to form an inner main body portion.The mounting fixture is characterized by including a fastening portion that is fastened together with the flanges of the liner plates in the cylindrical structure and fixed to the liner plate by a fastening device that fastens the flanges, and a reinforcing bar holding portion that is positioned radially inward from the fastening portion and holds the axial reinforcing bars at a position close to the flange.

[0010] 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. The flanges of the liner plate include an axial flange extending in the depth direction, i.e., approximately in the direction in which the axial reinforcing bars extend, and a circumferential flange extending in the circumferential direction.

[0011] The reinforcing bar holding portion includes a configuration that directly holds the axial reinforcing bar and a configuration that indirectly holds the axial reinforcing bar via a separate member. The reinforcing bar holding portion refers to a reinforcing bar holding portion having a through hole penetrating in the depth direction, i.e., a holding portion through which the axial reinforcing bar can be inserted, or a holding portion formed by bending a wire, i.e., a holding portion that can be attached without insertion.

[0012] The retaining material is called so-called stepping reinforcement, and unlike structural reinforcement such as axial reinforcement which affects the strength of the foundation structure, it may be reinforcement used to arrange structural reinforcement in a predetermined position, or so-called hoop reinforcement, or it may be made of steel material etc. that is contained within the inner main body and does not affect the structure. The retaining material along at least a portion of the circumferential direction may be in the shape of an arc having a smaller diameter than the inner surface of the liner plate forming the cylindrical shape, or may be in the shape of a circle.

[0013] 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. In detail, the mounting fixture is fastened to the flange of the liner plate by the fastening portion and assembled to the liner plate, so that the desired number of axial reinforcing bars can be connected to predetermined circumferential positions on the tubular structure via the mounting fixture.

[0014] 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.

[0015] Therefore, the foundation structure and mounting fixtures can reduce the amount of labor required for reinforcement, thereby reducing the burden on workers at work sites using deep foundation construction methods to build foundation structures that can ensure the desired strength without compromising earthquake resistance or durability.

[0016] In addition, a retaining material is provided on the inside of the liner plate, running along at least a portion of the circumferential direction and holding the axial reinforcing bars, and the reinforcing bar holding portion is configured to fix the retaining material and hold the axial reinforcing bars via the retaining material, so that the axial reinforcing bars can be arranged at a predetermined position in the circumferential direction.

[0017] In more detail, when the axial reinforcing bar is directly held by the reinforcing bar holding portion arranged radially inside the fastened portion, the fastened portion is fastened by the fasteners arranged at a predetermined interval in the circumferential direction, and the circumferential position of the axial reinforcing bar directly held by the reinforcing bar holding portion is limited by the position of the fasteners.

[0018] In contrast, the retaining material along at least a portion of the circumferential direction is held by the rebar holding portion, and the axial rebar is held by binding it to the retaining material fixed to the rebar holding portion, so that the axial rebar can be arranged at a predetermined position in the circumferential direction regardless of the circumferential position of the fastener.

[0019] As an aspect of the present invention, the fastened portion may be formed in a plate shape arranged along the flange and fastened by a plurality of the fasteners. This invention allows the mounting fixture to be more stably fixed to the liner plate. Specifically, when the mounting fixture is fastened to the flange with one fastener, it is difficult to control the orientation of the rebar holding part, which is located radially inward of the fastened part. However, by fastening with multiple fasteners, the mounting fixture can be reliably fixed to the liner plate while controlling the orientation of the rebar holding part.

[0020] In another aspect of the present invention, the flanges may be arranged across the flanges of the adjacent liner plates. According to this invention, the axial reinforcing bars can be arranged radially inside the flanges of adjacent liner plates, thereby improving versatility.

[0021] Furthermore, when the fastening portion is positioned across the flanges of the liner plates adjacent in the circumferential direction, the shape retention between the liner plates assembled in the circumferential direction can be improved. More specifically, the liner plates are assembled in the circumferential direction to form a cylindrical shape, but the shape retention of the cylindrical shape at the joint portion where the circumferentially adjacent flanges are fastened together with fasteners is lower than that of other portions. However, by positioning the fastening portion across the flanges of the liner plates adjacent in the circumferential direction and fastening them together with fasteners, the shape retention of the cylindrical shape at the joint portion where the flanges are fastened together with fasteners can be improved. In particular, when the liner plates are assembled using a so-called grub joint, in which the positions of the circumferential joints of adjacent liner plates in the vertical direction are aligned, the shape retention of the circumferential joints will be lower than when the positions of the circumferential joints of adjacent liner plates in the vertical direction are different.However, by positioning the fastened portion across the flanges of adjacent liner plates in the circumferential direction and fastening them to the flanges with a fastening device, the tubular shape retention of the joints where the flanges are fastened together with the fastening device can be improved.

[0022] In another aspect of the present invention, the fastened portion may be disposed between flanges of adjacent liner plates. According to this invention, the liner plates are sandwiched between the flanges of the adjacent liner plates, thereby realizing a more stable mounting state.

[0023] In another aspect of the present invention, the reinforcing bar holding portion may be provided with a circumferential regulating portion that regulates the circumferential movement of the axial reinforcing bar, and the circumferential regulating interval by the circumferential regulating portion may be set wider than the diameter of the axial reinforcing bar.

[0024] According to this invention, the axial reinforcing bars can be arranged at predetermined positions in the circumferential direction. In more detail, even when the axial reinforcing bar is directly held by a reinforcing bar holding portion located radially inside the fastened portion, the circumferential restriction interval by the circumferential restriction portion that restricts the circumferential movement of the axial reinforcing bar is set wider than the diameter of the axial reinforcing bar, so the axial reinforcing bar can be arranged at a predetermined circumferential position regardless of the circumferential position of the fastening device.

[0025] Furthermore, the present invention is a method for constructing a foundation structure in a borehole formed by excavating the ground, comprising the steps of: a structure construction step of arranging liner plates in the circumferential and depth directions along the wall surface of the borehole and assembling them together to construct a cylindrical structure; a reinforcing bar arrangement 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 mounting fixtures assembled to the cylindrical structure; and a casting step of forming an inner main body by hardening a solidifying material cast inside the cylindrical structure, wherein in the reinforcing bar arrangement step, the mounting fixtures have fastening parts that fasten flanges of the liner plates together, Circumferential direction The reinforcing bar holding portion is fastened together with the flange and fixed to the liner plate, and is arranged radially inward from the fastened portion. Circumferential direction Holds the axial rebar in close proximity to the flange On the inside of the liner plate, a retaining material is provided along at least a part of the circumferential direction and is a step reinforcement that holds the axial reinforcing bar, and the reinforcing bar holding portion has the retaining material fixed thereto and holds the axial reinforcing bar via the retaining material, and the retaining material is formed in an arc shape, and a plurality of retaining materials are provided and arranged along the circumferential direction to form a circle or arc shape with a diameter smaller than the inner diameter of the liner plate. It is characterized by:

[0026] 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. In detail, the mounting fixture is fastened to the flange of the liner plate by the fastening portion and assembled to the liner plate, so that the desired number of axial reinforcing bars can be connected to predetermined circumferential positions on the tubular structure via the mounting fixture.

[0027] 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.

[0028] Therefore, this method of constructing foundation structures 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 can ensure the desired strength without compromising earthquake resistance or durability.

[0029] As another aspect of the present invention, in the structural body construction step, the fastened portion may be fastened together with the flange of the liner plate by the fastener. According to this invention, the mounting fixture can be fastened and assembled together with the flange during the process of assembling the liner plate in the depth direction, so that the construction of the cylindrical structure and the assembly of the mounting fixture can be carried out efficiently. [Effects of the Invention]

[0030] The present invention makes it possible to provide a foundation structure, a method for constructing a foundation structure, and mounting tools that can ensure the desired strength while reducing the burden on workers at a caisson foundation construction site. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 2 is a schematic perspective view of a foundation pile to which the mounting fixture of the first embodiment is attached. [Figure 2] FIG. 2 is a partially exploded perspective view of a foundation pile using the mounting fixture of the first embodiment. [Figure 3] FIG. 2 is an explanatory diagram of a foundation pile to which the mounting fixture of the first embodiment is attached. [Figure 4] 1 is a schematic side view of the state in which the mounting fixture and axial reinforcing bars of the first embodiment are mounted on a liner plate. FIG. [Figure 5] FIG. 10 is an explanatory diagram of a foundation pile to which a mounting fixture according to a second embodiment is attached. [Figure 6] FIG. 10 is an explanatory diagram of a foundation pile to which a mounting fixture according to a third embodiment is attached. [Figure 7] FIG. 10 is an explanatory diagram of a foundation pile to which a mounting fixture according to a fourth embodiment is attached. [Figure 8] FIG. 10 is a schematic side view of the state in which the mounting fixture and axial reinforcing bars of the fourth embodiment are mounted on a liner plate. [Figure 9] FIG. 10 is an explanatory diagram of a foundation pile to which a mounting fixture according to a fifth embodiment is attached. [Figure 10] FIG. 10 is a schematic side view of the state in which the mounting fixture and axial reinforcing bars of the fifth embodiment are mounted on a liner plate. [Figure 11] FIG. 10 is a schematic side view of the sixth embodiment of the mounting fixture and axial reinforcing bars mounted on a liner plate. [Figure 12] FIG. 13 is a schematic side view of the state in which the mounting fixture and axial reinforcing bars of the seventh embodiment are mounted on a liner plate. DETAILED DESCRIPTION OF THE INVENTION

[0032] 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.

[0033] 1 shows a schematic perspective view of a foundation pile 1 equipped with a fastener 10 of the first embodiment, Fig. 2 shows a partially exploded perspective view of the foundation pile 1 using the fastener 10 of the first embodiment, Fig. 3 shows an explanatory diagram of the foundation pile 1 equipped with the fastener 10 of the first embodiment, and Fig. 4 shows a schematic side view of the state in which the fastener 10 of the first embodiment and the axial reinforcing bar 2 are attached to a liner plate 110. In detail, Fig. 3(a) shows a plan view of the foundation pile 1 equipped with the fastener 10 of the first embodiment, and Fig. 3(b) shows an enlarged view of part a in Fig. 3(a).

[0034] 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 omitted. Also, the concrete body 3 is omitted from FIGS. 1 to 4. 4 shows an enlarged view of a part in the height direction of the cylindrical structure 100 constituting the foundation pile 1 and the axial reinforcing bars 2. In FIG.

[0035] 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 circumferential 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 12.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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 rows in the circumferential direction R to form a ring shape in plan view, with the axial flanges 112 of adjacent liner plates 110 in the circumferential direction R overlapping each other and fastened together with assembly bolts 120 in bolt holes 114 to form a single unit.

[0042] 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 with each other and fastened together by assembly bolts 120 in the bolt holes 114. At this time, the mounting fixture 10 is attached, the details of which will be described later.

[0043] 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.

[0044] The fixture 10 of the present invention is a jig for arranging a plurality of axial reinforcing bars 2 arranged at predetermined intervals in the circumferential direction R 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.

[0045] Specifically, the fixture 10 is attached to the liner plate 110 by being fastened together with the circumferential flanges 113 by assembly bolts 120 that fasten the circumferential flanges 113 of the liner plates 110 adjacent to each other in the height direction H.

[0046] The mounting fixture 10 is plate-shaped and formed into an arc-shaped band when viewed in a plane, and is equipped with a fastening portion 20 that is arranged radially outward Do and fixed to the liner plate 110, and a reinforcing bar holding portion 30 that is arranged radially inward Di from the fastening portion 20 and holds the axial reinforcing bar 2 in a position close to the circumferential flange 113.

[0047] The fastened portion 20 is formed in the same shape as the circumferential flange 113, and has a bolt hole 21 that penetrates with approximately the same diameter as the bolt hole 114 provided in the circumferential flange 113 and is provided in the same location as the bolt hole 114. The reinforcing bar holding part 30 is arranged on the radial inside Di of the fastened part 20, and has reinforcing bar holes 31 that penetrate in the height direction H for inserting the axial reinforcing bars 2 arranged at predetermined intervals. The reinforcing bar holes 31 are formed with a diameter slightly larger than the outer diameter of the axial reinforcing bars 2, and are provided at predetermined intervals in the circumferential direction R in accordance with the spacing of the axial reinforcing bars 2 arranged at predetermined intervals, and in a number corresponding to the number of axial reinforcing bars 2.

[0048] The mounting fixture 10 having the fastened portion 20 and reinforcing bar holding portion 30 configured in this manner is formed wider in the radial direction D than the circumferential flange 113 of the liner plate 110, so that when the radially outer side Do is aligned and stacked on the circumferential flange 113, the reinforcing bar holding portion 30 is configured to protrude radially inward Di from the circumferential flange 113.

[0049] A plurality of mounting fixtures 10 formed in the shape of an arcuate band in plan view are provided, and when these are joined together, a circular shape having the same outer diameter as the cylindrical tubular structure 100 can be formed. Furthermore, in this embodiment, the mounting fixture 10 formed in the shape of an arcuate band in plan view is formed to have the same arc length as the liner plate 110, but it may be formed to have a different arc length.

[0050] The fixture 10 configured in this manner is attached to the cylindrical structure 100 by being disposed between the circumferential flanges 113 of the liner plates 110 that are assembled adjacent to each other in the height direction H, as shown in FIG. Specifically, when assembling another liner plate 110 below an already assembled ring-shaped liner plate 110, the fastened portion 20 is positioned between the circumferential flange 113 on the lower side Hd of the already assembled liner plate 110 and the circumferential flange 113 on the upper side Hu of the liner plate 110 to be assembled.

[0051] At this time, the bolt holes 114 of the circumferential flange 113 and the bolt holes 21 of the fastened portion 20 are communicated in the height direction H, and the circumferential flange 113 on the lower side Hd of the already assembled liner plate 110, the fastened portion 20 of the mounting fixture 10, and the circumferential flange 113 on the upper side Hu of the liner plate 110 to be assembled are arranged in this order. Then, assembly bolts 120 are inserted through the bolt holes 114 of the circumferential flange 113 and the bolt holes 21 of the fastened portion 20, which communicate in the height direction H, and fastened, thereby assembling adjacent liner plates 110 in the height direction H and attaching the mounting fixture 10.

[0052] As described above, the reinforcing bar holding portions 30 of the mounting fixture 10 attached to the cylindrical structure 100 are disposed between the circumferential flanges 113 of the liner plates 110 that are assembled adjacent to each other in the height direction H, and protrude radially inward Di from the circumferential flanges 113 of the liner plates 110. By inserting the axial reinforcing bars 2 in the height direction H into the reinforcing bar holes 31 of the reinforcing bar holding portions 30 that protrude radially inward Di from the circumferential flanges 113 of the liner plates 110, the mounting fixture 10 can hold the axial reinforcing bars 2 at predetermined positions near the circumferential flanges 113 of the liner plates 110 that constitute the cylindrical structure 100.

[0053] As described above, the foundation pile 1 constructed in the borehole 201 formed by excavating the ground 200 includes a cylindrical structure 100 configured by arranging the liner plates 110 in the circumferential direction R and the height direction H along the wall surface of the borehole 201 and assembling them 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 mounting fixture 10 assembled to the cylindrical structure 100 and to which the axial reinforcing bars 2 are attached, and the cylindrical structure The fixture 10 is provided with a concrete body 3 formed by the hardening of a solidifying material poured inside the fixture 100, and the fixture 10 is fastened together with the circumferential flanges 113 by assembly bolts 120 that fasten the circumferential flanges 113 of adjacent liner plates 110, and is provided with a fastening portion 20 that is fixed to the liner plate 110, and a reinforcing bar holding portion 30 that is positioned radially inward Di from the fastening portion 20 and holds the axial reinforcing bar 2 at a position close to the circumferential flange 113.

[0054] Furthermore, in a method for constructing a foundation pile 1 in a borehole 201 formed by excavating the ground 200, the method includes a structure construction step of arranging liner plates 110 in the circumferential direction R and the height direction H along the wall surface of the borehole 201 and assembling them together to construct a cylindrical structure 100; a reinforcing bar arrangement step of attaching 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 to the mounting fixtures 10 assembled to the cylindrical structure 100; A pouring process is carried out to form a concrete body 3 by hardening a solidifying material poured inside the structure 100, and in the reinforcement process, the mounting fixture 10 is fastened together with the circumferential flanges 113 by assembly bolts 120 that fasten the circumferential flanges 113 of adjacent liner plates 110 to each other at the fastened portions 20, and is fixed to the liner plates 110, and the reinforcing bar holding portion 30, which is arranged radially inward Di from the fastened portions 20, holds the axial reinforcing bar 2 in a position close to the circumferential flange 113.

[0055] Therefore, it is possible to construct foundation piles 1 that can ensure the desired strength while reducing the burden on workers at work sites using the caisson foundation method. In detail, the mounting fixture 10 is fastened to the circumferential flange 113 of the liner plate 110 by the fastening portion 20 and assembled to the liner plate 110, so that the desired number of axial reinforcing bars 2 can be connected to predetermined positions in the circumferential direction R of the tubular structure 100 via the mounting fixture 10.

[0056] 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.

[0057] 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 reducing 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., ensuring the desired strength.

[0058] In addition, the construction method of the foundation pile 1 allows the mounting fixture 10 to be fastened and assembled together with the circumferential flange 113 during the process of assembling the liner plate 110 in the height direction H, so that the construction of the tubular structure 100 and the assembly of the mounting fixture 10 can be carried out efficiently.

[0059] In addition, the fastened portion 20 is formed in a plate shape arranged along the circumferential flange 113 and is fastened by multiple assembly bolts 120, so that the mounting fixture 10 can be fixed to the liner plate 110 more stably.

[0060] In detail, when the mounting fixture 10 is fastened together with the circumferential flange 113 using a single assembly bolt 120, it becomes difficult to control the orientation of the reinforcing bar holding portion 30, which is located radially inward Di from the fastened portion 20. However, by fastening using multiple assembly bolts 120, the mounting fixture 10 can be reliably fixed to the liner plate 110 while controlling the orientation of the reinforcing bar holding portion 30.

[0061] Furthermore, since the fastened portion 20 is positioned between the circumferential flanges 113 of the liner plates 110 adjacent to each other in the height direction H, it is sandwiched between the circumferential flanges 113 of the adjacent liner plates 110, thereby achieving a more stable mounting state.

[0062] The joint points of adjacent liner plates 110 in the circumferential direction R, i.e., the points where the axial flanges 112 of adjacent liner plates 110 in the circumferential direction R are fastened together by assembly bolts 120, and the space between the mounting fixtures 10 formed in the shape of an arc band in a planar view may be set at the same position in the circumferential direction R, but it is more preferable to set them at different positions.

[0063] In this way, by being arranged across the circumferential flanges 113 of adjacent liner plates 110, the axial reinforcing bars 2 can be arranged on the radially inner side Di of the circumferential flanges 113 of adjacent liner plates 110, thereby improving versatility.

[0064] Furthermore, when the fastened portion 20 is arranged across the axial flanges 112 of the liner plates 110 adjacent in the circumferential direction R, the shape retention between the liner plates 110 assembled in the circumferential direction R can be improved. More specifically, the liner plates 110 are assembled in the circumferential direction R to form a cylindrical shape, but the shape retention of the cylindrical shape at the joint portion where the axial flanges 112 adjacent in the circumferential direction R are fastened together with the assembly bolts 120 is lower than that of other portions. However, by arranging the fastened portion 20 across the axial flanges 112 of the liner plates 110 adjacent in the circumferential direction R and fastening them together with the circumferential flanges 113 with the assembly bolts 120, the shape retention of the cylindrical shape at the joint portion where the axial flanges 112 are fastened together with the assembly bolts 120 can be improved.

[0065] In particular, when the liner plates 110 are assembled using a so-called grub joint, in which the positions of the joint portions in the circumferential direction R of adjacent liner plates 110 in the height direction H are aligned, the shape retention of the joint portions in the circumferential direction R is lower than when the joint portions in the circumferential direction R of adjacent liner plates 110 in the height direction are assembled in different positions.However, by positioning the fastened portion 20 across the axial flanges 112 of adjacent liner plates 110 in the circumferential direction R and fastening them together with the circumferential flanges 113 with assembly bolts 120, the cylindrical shape retention of the joint portions where the axial flanges 112 are fastened together with the assembly bolts 120 can be improved.

[0066] (Second embodiment) The above-mentioned mounting fixture 10 has rebar holes 31 in the rebar holding portion 30 at a predetermined interval in the circumferential direction R, the number of which corresponds to the number of axial rebars 2. However, if multiple axial rebars 2 are arranged at predetermined intervals in the circumferential direction R depending on the strength of the foundation pile 1, multiple rebar holes 31 may be lined up and arranged at predetermined intervals in the circumferential direction R.

[0067] A mounting fixture 10a of the second embodiment will be described below with reference to FIG. 5 shows an explanatory diagram of the foundation pile 1 equipped with the fixture 10a of the second embodiment. In detail, Fig. 5(a) shows a plan view of the foundation pile 1 equipped with the fixture 10a of the second embodiment, and Fig. 5(b) shows an enlarged view of part b in Fig. 5(a). The concrete body 3 is not shown in Fig. 5.

[0068] The mounting fixture 10a of the second embodiment has two reinforcing bar holes 31 formed with a diameter slightly larger than the outer diameter of the axial reinforcing bars 2, adjacent to each other in the circumferential direction R, and the holes are arranged at a predetermined interval in the circumferential direction R, in a number corresponding to the number of axial reinforcing bars 2, depending on the spacing between the axial reinforcing bars 2 which are arranged at a predetermined interval.

[0069] The fixture 10a configured in this manner is attached to the cylindrical structure 100, similar to the fixture 10 described above, and by inserting the axial reinforcing bars 2 into each of the two reinforcing bar holes 31 of the axial reinforcing bars adjacent in the circumferential direction R, it is possible to hold two axial reinforcing bars 2 at predetermined positions near the circumferential flange 113 of the liner plate 110 that constitutes the cylindrical structure 100. Therefore, the foundation pile 1 equipped with the fixture 10a can achieve the same functions and effects as the foundation pile 1 equipped with the fixture 10. The number of reinforcing bar holes 31 is not limited to two, and may be set according to the number of axial reinforcing bars 2 required depending on the strength of the foundation pile 1.

[0070] (Third embodiment) A mounting fixture 10b according to a third embodiment will be described below with reference to FIG. Fig. 6 shows an explanatory diagram of the foundation pile 1 equipped with the fixture 10b of the third embodiment. In detail, Fig. 6(a) shows a plan view of the foundation pile 1 equipped with the fixture 10b of the third embodiment, and Fig. 6(b) shows an enlarged view of part c in Fig. 6(a). The concrete body 3 is not shown in Fig. 6.

[0071] The above-mentioned mounting fixture 10 and mounting fixture 10a are provided with a fastening portion 20 and a reinforcing bar holding portion 30, and a reinforcing bar hole 31 is provided in the reinforcing bar holding portion 30 for inserting the axial reinforcing bar 2, and the axial reinforcing bar 2 is inserted into the reinforcing bar hole 31 in the height direction H and held therein. In contrast to this, instead of a hole penetrating in a generally inverted L shape in plan view, a holding groove 32 in a generally inverted L shape in plan view may be provided as shown in FIG.

[0072] In detail, the retaining groove 32 is formed into a roughly inverted L-shape in a plan view by a radial groove 321 that runs along the radial direction D with the radial inner side Di open, and a circumferential groove 322 that extends from the end of the radial outer side Do of the radial groove 321 to one side in the circumferential direction R.

[0073] The radial groove 321 and the circumferential groove 322 are formed with a groove width slightly larger than the diameter of the axial reinforcing bar 2, and the circumferential groove 322 is formed so that its length in the circumferential direction R is longer than the diameter of the axial reinforcing bar 2. Therefore, by inserting the axial reinforcing bar 2 from the radial inside Di of the radial groove 321 and moving the circumferential groove 322 in the circumferential direction R, the axial reinforcing bar 2 can be placed at a predetermined position in the circumferential direction R.

[0074] In addition, the radially inner portion Di of the circumferential groove 322 in the arc-band-shaped reinforcing bar holding portion 30 functions as a radially inner regulating portion 331 that regulates the axial reinforcing bar 2 placed at a predetermined position in the circumferential groove 322 in the holding groove 32 from moving in the radially inner portion Di, and both sides of the circumferential groove 322 in the circumferential direction R function as circumferential regulating portions 332 that regulate the axial reinforcing bar 2 from moving in the circumferential direction R beyond a predetermined range.

[0075] As described above, the circumferential regulating portions 332 are arranged on both sides of the circumferential groove 322, which is formed to be longer than the diameter of the axial reinforcing bar 2, i.e., the circumferential regulating portions 332 are arranged at intervals longer than the diameter of the axial reinforcing bar 2.

[0076] The fixture 10b configured in this manner, like the fixture 10 described above, is attached to the cylindrical structure 100, and can be moved radially outward Do from the radial groove 321 of the reinforcing bar hole 31 to hold the axial reinforcing bar 2 at a desired position in the circumferential groove 322. Therefore, the foundation pile 1 equipped with the fixture 10b can achieve the same effects as the foundation pile 1 equipped with the fixture 10, as well as the effects of being able to hold the axial reinforcing bar 2 at a desired position in the circumferential groove 322 and being able to restrict movement from the desired position in the circumferential groove 322 to the radially inward Di and beyond the circumferential groove 322 in the circumferential direction R.

[0077] Furthermore, the reinforcing bar holding portion 30 of the mounting fixture 10b on the foundation pile 1 is provided with a circumferential regulating portion 332 that regulates the movement of the axial reinforcing bar 2 in the circumferential direction R, and the regulating interval in the circumferential direction R by the circumferential regulating portion 332 is set wider than the diameter of the axial reinforcing bar 2, so that the axial reinforcing bar 2 can be arranged at a predetermined position in the circumferential direction R.

[0078] In more detail, even when the axial reinforcing bar 2 is directly held by the reinforcing bar holding portion 30 arranged on the radially inner side Di of the fastened portion 20, the circumferential direction R restriction interval of the circumferential direction restriction portion 332 that restricts the movement of the axial reinforcing bar 2 in the circumferential direction R is set wider than the diameter of the axial reinforcing bar 2, so the main action and effect of the third embodiment can be achieved, that is, the axial reinforcing bar 2 can be arranged at a predetermined position in the circumferential direction R regardless of the circumferential direction R position of the assembly bolt 120.

[0079] Although the retaining groove 32 is formed to have a generally inverted L-shape in plan view by the radial groove 321 along the radial direction D with the radial inside Di open, and the circumferential groove 322 extending from the end of the radial outside Do of the radial groove 321 to one side in the circumferential direction R, the retaining groove 32 may be formed to have a generally inverted T-shape in plan view by forming the circumferential groove 322 to extend on both sides in the circumferential direction R with respect to the radial groove 321. Even in this case, it is possible to achieve the same functions and effects as the foundation pile 1 provided with the mounting fixture 10b having the retaining groove 32 formed in the generally inverted L-shape in plan view described above.

[0080] (Fourth embodiment) The above-described fastening fixture 10 of the first embodiment, fastening fixture 10a of the second embodiment, and fastening fixture 10b of the third embodiment are configured to include a fastened portion 20 and a rebar holding portion 30, and to hold the axial rebars 2 in multiple rebar holes 31 provided in the rebar holding portion 30. In contrast, the fastening fixture 10c of the fourth embodiment is configured to hold each of the axial rebars 2 in the rebar holding portions 30c, as shown in Figures 7 and 8.

[0081] Specifically, unlike the mounting fixtures 10, 10a, and 10b, which are composed of an arc-shaped fastened portion 20 and a reinforcing bar holding portion 30, the mounting fixture 10c is formed in a roughly inverted T-shape in plan view, with the fastened portion 20c having a roughly square shape in plan view with one bolt hole 21, and the reinforcing bar holding portion 30c having a roughly rectangular shape in plan view that is long in the circumferential direction R and is located radially inward Di of the fastened portion 20c.

[0082] Furthermore, a reinforcing bar hole 31c that is long in the circumferential direction R is provided in the reinforcing bar holding portion 30c of the fixture 10c. The reinforcing bar hole 31c is formed so that the groove width is one size larger than the diameter of the axial reinforcing bar 2, and the length in the circumferential direction R is longer than the diameter of the axial reinforcing bar 2. Therefore, the axial reinforcing bar 2 can be placed at a predetermined position in the circumferential direction R inside the reinforcing bar hole 31c.

[0083] A plurality of mounting fixtures 10c configured in this manner are provided so as to be spaced at predetermined intervals in the circumferential direction, and are stacked on the upper side Hu or lower side Hd of the circumferential flanges 113 stacked in the height direction H of the lower side Hd of the already assembled liner plate 110 and the upper side Hu of the liner plate 110 that is placed below it and is to be assembled, and fastened with assembly bolts 120 to attach the mounting fixtures 10c to the cylindrical structure 100. In this embodiment, the fastened portion 20c is stacked on the further upper side Hu of the circumferential flange 113 of the upper side Hu and fastened with the assembly bolts 120.

[0084] Then, the axial reinforcing bars 2 are inserted from the height direction H into the reinforcing bar holes 31c of the reinforcing bar holding portions 30c of the fixture 10c attached to the cylindrical structure 100, and the axial reinforcing bars 2 are arranged at predetermined positions in the circumferential direction R in the reinforcing bar holes 31c formed long in the circumferential direction R. At this time, it is more preferable to fix the positions of the axial reinforcing bars 2 relative to the reinforcing bar holding portions 30c by bundling, welding, etc. Therefore, the fixture 10c can arrange the axial reinforcing bars 2 at predetermined positions relative to the cylindrical structure 100.

[0085] In addition, in the reinforcing bar holding portion 30c, the radially inner portion Di of the reinforcing bar hole 31c functions as a radially inner regulating portion 331c that regulates the axial reinforcing bar 2 placed at a predetermined position in the reinforcing bar hole 31c from moving in the radially inner portion Di, and both sides of the circumferential direction R of the reinforcing bar hole 31c function as circumferential regulating portions 332c that regulate the axial reinforcing bar 2 from moving in the circumferential direction R beyond a predetermined range.

[0086] As described above, the circumferential regulating portions 332c are arranged on both sides of the reinforcing bar hole 31c, which is formed to be longer than the diameter of the axial reinforcing bar 2, i.e., the circumferential regulating portions 332c are arranged at intervals longer than the diameter of the axial reinforcing bar 2.

[0087] The foundation pile 1 having the mounting fixture 10c configured in this manner can achieve the same functions and effects as the above-mentioned mounting fixture 10, and can also achieve the same functions and effects as the foundation pile 1 having the mounting fixture 10b of the third embodiment.

[0088] In addition, similar to the mounting fixture 10, the fastening portion 20c of the mounting fixture 10c may be placed between the circumferential flange 113 of the existing liner plate 110 and the circumferential flange 113 of the liner plate 110 to be assembled, and fastened together with the circumferential flange 113 using an assembly bolt 120.

[0089] Furthermore, since the reinforcing bar hole 31c of the reinforcing bar holding portion 30c in the mounting fixture 10c is formed with a length in the circumferential direction R that is longer than the diameter of the axial reinforcing bar 2, multiple axial reinforcing bars 2 can be held in one mounting fixture 10c, that is, multiple axial reinforcing bars 2 can be inserted and held in the reinforcing bar hole 31c of one mounting fixture 10c.

[0090] (Fifth embodiment) A mounting fixture 10d according to the fifth embodiment will be described below with reference to FIGS. 9 shows an explanatory diagram of the foundation pile 1 equipped with the fixture 10d of the fifth embodiment. In detail, Fig. 9(a) shows a plan view of the foundation pile 1 equipped with the fixture 10d of the fifth embodiment, Fig. 9(b) shows an enlarged view of part e in Fig. 9(a), and Fig. 10 shows a schematic side view of the state in which the fixture 10d of the fifth embodiment and the axial reinforcing bars 2 are attached to the liner plate 110. The concrete body 3 is not shown in Figs. 9 and 10.

[0091] The fixture 10 of the first embodiment and the fixtures 10a to 10c of the second to fourth embodiments described above are configured to include fastened portions 20, 20c and rebar holding portions 30, 30c, and to directly hold the axial rebars 2 in the rebar holes 31, 31c in the rebar holding portions 30, 30c. In contrast, the fixture 10d of the fifth embodiment is configured to fix the fixing rebars 40 that fix the axial rebars 2, and to hold the fixing rebars 40 with the rebar holding portions 30d, as shown in Figures 9 and 10.

[0092] Specifically, unlike the mounting fixtures 10, 10a to 10c which are composed of arc-shaped fastened portions 20, 20c and reinforcing bar holding portions 30, 30c, the mounting fixture 10d is formed in an approximately rectangular shape in plan view that is long in the radial direction D, with the fastened portion 20c having an approximately square shape in plan view with one bolt hole 21 and the reinforcing bar holding portion 30d having an approximately square shape in plan view that is positioned radially inward Di of the fastened portion 20c.

[0093] Furthermore, the reinforcing bar holding portion 30d of the mounting fixture 10d holds an arc-shaped fixing reinforcing bar 40 that fixes the axial reinforcing bar 2. The fixing reinforcing bar 40 is a deformed reinforcing bar with a smaller diameter than the axial reinforcing bar 2 and is formed in an arc shape. A plurality of fixing reinforcing bars 40 are provided and connected along the circumferential direction R to form a circle with a diameter smaller than the inner diameter of the cylindrical structure 100.

[0094] Multiple mounting fixtures 10d configured in this manner are provided, spaced at predetermined intervals in the circumferential direction, and, like mounting fixture 10c, the fastened portion 20c is placed on the upper side Hu of the circumferential flange 113 stacked in the height direction H between the lower side Hd of the already assembled liner plate 110 and the upper side Hu of the liner plate 110 placed below it and to be assembled, and the bolt hole 21 of the fastened portion 20 and the bolt hole 114 of the circumferential flange 113 are connected in the height direction H, and the mounting fixture 10d is attached to the tubular structure 100 by fastening with an assembly bolt 120.

[0095] Furthermore, a fixed reinforcing bar 40 is placed near the end of the radially inner side Di of the reinforcing bar holding portion 30d of the mounting fixture 10d attached to the tubular structure 100 at a predetermined interval in the circumferential direction R, and fixed by welding or the like to attach the fixed reinforcing bar 40 to the mounting fixture 10d.

[0096] In this way, the fixed reinforcing bars 40 attached to the cylindrical structure 100 via the fixtures 10d form a circle near the inner surface of the cylindrical structure 100, and the axial reinforcing bars 2 are attached to the circular fixed reinforcing bars 40 by bundling or the like at predetermined positions. This allows the axial reinforcing bars 2 to be held via the fixed reinforcing bars 40. Therefore, the axial reinforcing bars 2 can be arranged at predetermined positions relative to the cylindrical structure 100 by the fixtures 10d that hold them via the fixed reinforcing bars 40.

[0097] In this way, the mounting fixture 10d is attached to the assembly bolts 120 arranged at a predetermined interval in the circumferential direction R, but the axial reinforcing bar 2 is fixed to the fixed reinforcing bar 40 held by the mounting fixture 10d, so that the axial reinforcing bar 2 can be held at any position in the circumferential direction R relative to the circular fixed reinforcing bar 40.

[0098] A foundation pile 1 having a mounting fixture 10d configured in this manner has the same functions and effects as the above-mentioned mounting fixture 10, and in addition, a fixed reinforcing bar 40 that runs along the circumferential direction R and holds the axial reinforcing bar 2 is provided inside the liner plate 110, and the reinforcing bar holding portion 30d is configured to have the fixed reinforcing bar 40 fixed thereto and to hold the axial reinforcing bar 2 via the fixed reinforcing bar 40, so that the axial reinforcing bar 2 can be arranged at a predetermined position in the circumferential direction R.

[0099] In detail, when the axial reinforcing bar 2 is directly held by the reinforcing bar holding portion 30d arranged on the radially inner side Di of the fastened portion 20c, the fastened portion 20c is fastened by assembly bolts 120 arranged at a predetermined interval in the circumferential direction R, and therefore the position in the circumferential direction R of the axial reinforcing bar 2 directly held by the reinforcing bar holding portion 30d is limited by the position of the assembly bolts 120.

[0100] In contrast, the fixed reinforcing bars 40 along the circumferential direction R are held by the reinforcing bar holding portion 30d, and the axial reinforcing bars 2 are held by being tied to the fixed reinforcing bars 40 fixed to the reinforcing bar holding portion 30d, thereby achieving the main action and effect of the mounting fixture 10d of the fifth embodiment, which is that the axial reinforcing bars 2 can be arranged at a predetermined position in the circumferential direction R regardless of the position of the assembly bolt 120 in the circumferential direction R.

[0101] Furthermore, the fixing rebars 40 only need to be located on the upper side Hu and lower side Hd of the axial rebars 2 in the height direction H, and since they are arrangement rebars, it does not matter if they are low in strength. Specifically, the fixing rebars 40 do not need to be as strong as the hoop rebars that restrain the outer periphery of multiple axial rebars 2 arranged circumferentially, and as long as they can arrange the axial rebars 2 in predetermined locations, the fixing rebars 40 may be thinner than the hoop rebars, and the number of fixing rebars arranged in the height direction H may be fewer. Furthermore, the fixing rebars 40 do not have to be circular, but may be arc-shaped. Furthermore, hoop rebars and circular fixing rebars 40 may be used together.

[0102] Furthermore, as long as the mounting fixture 10d can be fastened together with the circumferential flange 113 using the assembly bolts 120, the fastened portion 20c may be stacked on the lower side Hd of the circumferential flanges 113 stacked in the height direction H and fastened together with the assembly bolts 120, or, as with the mounting fixture 10, the fastened portion 20c may be placed between the circumferential flange 113 of the existing liner plate 110 and the circumferential flange 113 of the liner plate 110 to be assembled and fastened together with the circumferential flange 113 using the assembly bolts 120.

[0103] (Sixth embodiment) The above-mentioned mounting fixture 10d is configured to hold the fixed reinforcing bar 40 to the flat reinforcing bar holding portion 30d by welding or the like, but as shown in Figure 11, the radially inner side Di of the reinforcing bar holding portion 30d may be provided with a vertical wall 34 that restricts movement of the radially inner side Di of the fixed reinforcing bar 40.

[0104] The sixth embodiment of the fixture 10e will be described below with reference to Fig. 11. Fig. 11 shows a schematic side view of the fixture 10e of the sixth embodiment and the axial reinforcing bars 2 attached to the liner plate 110. The concrete body 3 is not shown in Fig. 11.

[0105] More specifically, as described above, the fixture 10e has a vertical wall 34 that protrudes from the end of the radially inner side Di of the reinforcing bar holding portion 30d toward the upper side Hu. The vertical wall 34 is formed so that the length in the height direction H is longer than the diameter of the axial reinforcing bar 2 .

[0106] Like fixture 10d, fixture 10e configured in this manner has fastened portions 20c disposed on the upper sides Hu of circumferential flanges 113 stacked in the height direction H, and is fastened to the circumferential flanges 113 with assembly bolts 120. By disposing the fixing reinforcing bars 40 on the radially outer sides Do of the vertical walls 34 of the reinforcing bar holding portions 30d of fixture 10e, it is possible to hold the fixing reinforcing bars 40 without fixing them to the reinforcing bar holding portions 30d by welding or the like, and to prevent the fixing reinforcing bars 40 from accidentally moving downwards Hd or radially inwards Di.

[0107] The foundation pile 1 provided with the fixture 10e and the fixing reinforcing bars 40 configured in this manner can achieve the same functions and effects as the foundation pile 1 provided with the fixture 10d and the fixing reinforcing bars 40 described above. Although it has been described that the fixed reinforcing bar 40 does not need to be fixed to the mounting fixture 10e by welding or the like, it is of course possible to fix the fixed reinforcing bar 40 to the reinforcing bar holding portion 30d of the mounting fixture 10e or the vertical wall 34 by welding, bundling or the like.

[0108] Furthermore, as with mounting fixture 10d, if mounting fixture 10e can be fastened together with circumferential flange 113 with assembly bolts 120, the fastened portion 20c may be stacked on the lower side Hd of the circumferential flanges 113 stacked in the height direction H and fastened together with assembly bolts 120, or, as with mounting fixture 10, the fastened portion 20c may be placed between the circumferential flange 113 of an existing liner plate 110 and the circumferential flange 113 of a liner plate 110 to be assembled, and fastened together with the circumferential flange 113 with assembly bolts 120.

[0109] Seventh embodiment The above-mentioned mounting fixture 10e is configured to have a vertical wall 34 at the end of the radially inner side Di of the flat reinforcing bar holding portion 30d, and to place the fixed reinforcing bar 40 on the radially outer side Do of the vertical wall 34, but as shown in Figure 12, a clip 35 for holding the fixed reinforcing bar 40 may also be provided on the radially inner side Di of the reinforcing bar holding portion 30d.

[0110] The seventh embodiment of the fixture 10f will be described below with reference to Fig. 12. Fig. 12 shows a schematic side view of the fixture 10f of the seventh embodiment and the axial reinforcing bars 2 attached to the liner plate 110. The concrete body 3 is not shown in Fig. 12.

[0111] More specifically, as described above, the fixture 10f includes the clip 35 that attaches and grips the fixed reinforcing bar 40 from the upper side Hu to the end portion on the radially inner side Di of the reinforcing bar holding portion 30d. The clip 35 is made of spring steel that is open on the upper side Hu and covers and grips about two-thirds of the outer periphery of the cross section of the axial reinforcing bar 2. The open end of the clip 35 is provided with a return portion 36 that guides the axial reinforcing bar 2 into the clip 35.

[0112] Like fastening fixture 10d, fastening fixture 10f configured in this manner has fastened portions 20c disposed on the upper sides Hu of circumferential flanges 113 stacked in the height direction H, and is fastened together with circumferential flanges 113 with assembly bolts 120. Then, by attaching fixing rebar 40 to the interior of clips 35 in reinforcing bar holding portions 30d of fastening fixture 10f through openings in the upper sides Hu, fixing rebar 40 can be held without fixing fixing rebar 40 to reinforcing bar holding portions 30d by welding or the like. Of course, the state in which fixing rebar 40 is held by clips 35 in reinforcing bar holding portions 30d of fastening fixture 10f may also be fixed by welding or the like. The foundation pile 1 provided with the fixture 10f and the fixing reinforcing bar 40 configured in this manner can achieve the same functions and effects as the foundation pile 1 provided with the fixtures 10d, 10e and the fixing reinforcing bar 40 described above.

[0113] Furthermore, as with mounting fixture 10d, if mounting fixture 10f can be fastened together with circumferential flange 113 using assembly bolts 120, the fastened portion 20c may be stacked on the lower side Hd of the circumferential flanges 113 stacked in the height direction H and fastened together with assembly bolts 120, or, as with mounting fixture 10, the fastened portion 20c may be placed between the circumferential flange 113 of an existing liner plate 110 and the circumferential flange 113 of a liner plate 110 to be assembled, and fastened together with the circumferential flange 113 using assembly bolts 120.

[0114] 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 circumferential 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 fixture is compatible with fixtures 10, 10a to 10f. The inner body part corresponds to the concrete body 3, The flange corresponds to a circumferential flange 113; The fastener corresponds to the assembly bolt 120, The fastened portions correspond to the fastened portions 20 and 20c, The inner diameter corresponds to the inner diameter Di, The reinforcing bar holding portions correspond to the reinforcing bar holding portions 30, 30c, and 30d, The retaining material is compatible with fixed rebar 40. The circumferential direction restricting portions correspond to the circumferential direction restricting portions 332 and 332c, but are not limited to those in the above embodiment.

[0115] Furthermore, the mounting fixture 10e of the sixth embodiment and the mounting fixture 10f of the seventh embodiment described above may be mounted upside down in the height direction H, or the fixed reinforcing bar 40 may be fixed to the underside of the reinforcing bar holding portion 30d of the mounting fixture 10d of the fifth embodiment. 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.

[0116] Furthermore, the above-mentioned mounting fixtures 10, 10a to 10f are attached to the tubular structure 100 by fastening the fastened portion 20 together with the circumferential flange 113 with the assembly bolts 120 that fasten the circumferential flange 113, but they may also be attached to the tubular structure 100 by fastening the fastened portion 20 together with the axial flange 112 with the assembly bolts 120 that fasten the axial flange 112.

[0117] Furthermore, the assembly bolts 120 that assemble the liner plates 110 that make up the above-mentioned cylindrical structure 100 in the height direction H are inserted from the lower side Hd to the upper side Hu, but they may also be inserted from the upper side Hu to the lower side Hd. [Explanation of symbols]

[0118] 1...Foundation piles 2...Axial reinforcement 3...Concrete body 10, 10a to 10f... Mounting fixture 20,20c…Connected part 30, 30c, 30d...Rebar holding section 40...Fixed rebar 100...Cylindrical structure 110...Liner plate 113... Circumferential flange 120...Assembly bolt 200...ground 201...Drilling hole 332,332c...Circumferential direction regulation part Di...Radial inner side H: Height R…Circumferential 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 mounting fixture that is assembled to the cylindrical structure 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 fastening portion that is fastened together with the flanges by a fastener that fastens the flanges of the liner plates together and is fixed to the liner plate; A reinforcing bar holding portion is provided, which is arranged radially inward from the fastened portion and holds the axial reinforcing bar at a position close to the flange. Foundation structure.

2. The fastened portion is The plate-shaped member is arranged along the flange and fastened by the plurality of fasteners. The foundation structure according to claim 1 .

3. The flanges of the adjacent liner plates are arranged across the flanges. The foundation structure according to claim 2 .

4. The fastened portion is disposed between the flanges of the adjacent liner plates The foundation structure according to claim 2 .

5. A retaining material is provided on the inner side of the liner plate along at least a part of the circumferential direction and for retaining the axial reinforcing bar, The reinforcing bar holding portion is The retaining material is fixed, and the axial reinforcing bar is held via the retaining material. The foundation structure according to any one of claims 1 to 4.

6. The reinforcing bar holding portion is A circumferential direction restricting portion is provided to restrict movement of the axial reinforcing bars in the circumferential direction, The circumferential restriction interval by the circumferential restriction portion is set wider than the diameter of the axial reinforcing bar. The foundation structure according to any one of claims 1 to 4.

7. 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 are arranged at predetermined intervals along the interior of the cylindrical structure and extend in the depth direction, and the long axial reinforcing bars are attached to the mounting fixtures assembled to the cylindrical structure; 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 fastening portion of the mounting fixture is fastened together with the flange by a fastener that fastens the flanges of the liner plate together, and is fixed to the liner plate, and the reinforcing bar holding portion, which is arranged radially inside the fastening portion, holds the axial reinforcing bar at a position close to the flange. How to build foundation structures.

8. In the structure construction step, The fastening portion is fastened together with the flange of the liner plate by the fastener. A method for constructing a foundation structure according to claim 7.

9. a cylindrical structure that constitutes a foundation, in which liner plates are 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 along the inside of the cylindrical structure that is constructed by assembling the liner plates together, and a solidifying material poured inside the cylindrical structure hardens to form an inner main body portion; and a fastening portion that is fastened together with the flanges of the liner plates by fastening devices that fasten the flanges together and is fixed to the liner plates; A reinforcing bar holding portion is provided, which is arranged radially inward from the fastened portion and holds the axial reinforcing bar at a position close to the flange. Mounting fixture.

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