earth retaining structure

Abstract

This invention provides an earth retaining structure with reinforcing rings that can reduce manufacturing costs even when it has curved sections. [Solution] The earth retaining structure comprises a plurality of structures and one or more H-shaped steels arranged between vertically adjacent structures among the plurality of structures, which reinforce the strength of the plurality of structures. The plurality of structures are composed of a plurality of earth retaining panels that constitute the wall surface of the plurality of structures arranged in a ring, and have curved portions that constitute a curved shape when viewed in the direction of the hole axis. One or more reinforcing rings have a ring curved portion that is formed in a curved shape along the curved portion in the portion facing the curved portion in the direction of the hole axis, and the ring curved portion is composed of a plurality of straight portions arranged in a line along the curved portion, and each of the plurality of straight portions is formed in a straight line when viewed in the direction of the hole axis.

Description

Technical Field

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[0001] The present disclosure relates to a retaining structure using a retaining panel and a reinforcing ring that form the wall surface of a hollow structure constructed, for example, underground.

Background Art

[0002] Conventionally, there has been known a retaining structure constructed by assembling retaining panels made of corrugated steel sheets in an excavation hole formed by excavating the ground (see, for example, Patent Document 1). The retaining structure is constructed by stacking, in the hole axis direction, a structure formed by annularly arranging a plurality of retaining panels along the wall surface of the excavation hole. The retaining panels constituting the retaining structure are used, for example, for blocking the ground, for a shaft for constructing the foundation of the structure, for a sump well constructed underground, or for a retaining wall on a slope.

[0003] Generally, in a retaining structure having a rectangular shape in plan view, stress concentrates at the corner portions, and the generated bending moment at the corner portions becomes larger than that at the straight portions. In a retaining structure having a rectangular shape in plan view, in order to secure a cross-section corresponding to the stress generated at the corner portions, there has been a problem that it is uneconomical because the plate thickness of the retaining panels of the entire retaining structure, the pitch of the reinforcing rings, and the size of the steel materials are determined according to the stress generated at the corner portions. A retaining structure such as that in Patent Document 1 is intended to reduce the generated bending moment at the intersection portion by providing an arcuate liner plate and a reinforcing ring having a curved surface both inside and outside at the intersection portion where the straight portions intersect, and to achieve cost reduction by downsizing as a whole.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The reinforcing ring described in Patent Document 1 is constructed from arc-shaped steel sections, where the corners of a rectangular earth-retaining structure, when viewed from above, are curved on both the inner and outer sides. However, constructing a reinforcing ring from arc-shaped steel sections with curved surfaces on both the inner and outer sides requires processing of the steel sections using various devices, such as bending with a large bending machine or processing using a high-frequency induction heating device, which results in high manufacturing costs.

[0006] This disclosure aims to solve the above-mentioned problems and provides an earth retaining structure that can suppress manufacturing costs even when it has curved parts, such as arc-shaped parts, in an earth retaining structure having a reinforcing ring. [Means for solving the problem]

[0007] The earth retaining structure according to this disclosure is a cylindrical earth retaining structure constructed in an excavated hole formed by excavating the ground, comprising: a plurality of cylindrical structures constructed by stacking a plurality of layers along the axis of the hole; and one or more H-shaped steel rings arranged between vertically adjacent structures among the plurality of structures to reinforce the strength of the plurality of structures, wherein the plurality of structures are constructed by arranging a plurality of earth retaining panels that constitute the wall surface of the plurality of structures in a ring shape, and have curved portions that constitute a curved part when viewed in the direction of the axis of the hole, and one or more reinforcing rings have a ring curve portion that is formed in a curved shape along the curve portion in the part facing the curve portion in the direction of the axis of the hole, and the ring curve portion is composed of a plurality of straight portions arranged in a line along the curve portion, and each of the plurality of straight portions is formed in a straight line when viewed in the direction of the axis of the hole. [Effects of the Invention]

[0008] According to this disclosure, in an earth retaining structure having a reinforcing ring, the manufacturing cost can be reduced even if the earth retaining structure has a curved portion. [Brief explanation of the drawing]

[0009] [Figure 1]This is a schematic front view showing the earth retaining structure according to Embodiment 1. [Figure 2] This is a schematic plan view showing an example of the configuration of an earth retaining structure according to Embodiment 1. [Figure 3] This is a schematic elevation view showing an example of the configuration of an earth retaining structure according to Embodiment 1. [Figure 4] This is a perspective view showing an example of a retaining wall panel according to Embodiment 1. [Figure 5] This is a perspective view showing another example of the earth retaining panel according to Embodiment 1. [Figure 6] This is a longitudinal cross-sectional view showing a retaining wall panel according to Embodiment 1. [Figure 7] This is a schematic plan view showing an example of the configuration of an earth retaining panel according to Embodiment 1. [Figure 8] This is a schematic plan view showing another example of the configuration of the earth retaining panel according to Embodiment 1. [Figure 9] This is a schematic plan view showing another example of the configuration of the earth retaining panel according to Embodiment 1. [Figure 10] This is a longitudinal cross-sectional view showing another example of the earth retaining panel according to Embodiment 1. [Figure 11] This is a schematic perspective view showing a reinforcing ring used in the earth retaining structure according to Embodiment 1. [Figure 12] This is a schematic plan view showing a reinforcing ring used in the earth retaining structure according to Embodiment 1. [Figure 13] This is a conceptual diagram showing a joint plate in an earth retaining structure according to Embodiment 1. [Figure 14] This is a schematic plan view showing the connection between the reinforcing ring and the retaining panel in the retaining structure according to Embodiment 1. [Figure 15] This is a conceptual diagram showing the connection between the reinforcing ring and the retaining panel in the retaining structure according to Embodiment 1, viewed in the circumferential direction. [Figure 16] This is a schematic diagram showing an enlarged view of the ring-shaped curved portion of the reinforcing ring that constitutes the earth retaining structure according to Embodiment 1. [Figure 17]It is a conceptual diagram showing an example of the main straight line part constituting the ring curve part of FIG. 16. [Figure 18] It is a conceptual diagram showing an example of the end straight line part constituting the ring curve part of FIG. 16. [Figure 19] It is an enlarged schematic diagram of another example of the ring curve part of the reinforcing ring constituting the earth retaining structure according to Embodiment 1. [Figure 20] It is a conceptual diagram showing an example of the main straight line part constituting the ring curve part of FIG. 19. [Figure 21] It is a conceptual diagram showing an example of the end straight line part constituting the ring curve part of FIG. 19. [Figure 22] It is an enlarged schematic diagram of the ring curve part of the first other configuration example in the reinforcing ring constituting the earth retaining structure according to Embodiment 1. [Figure 23] It is an enlarged schematic diagram of the ring curve part of the second other configuration example in the reinforcing ring constituting the earth retaining structure according to Embodiment 1. [Figure 24] It is an enlarged schematic diagram of the ring curve part of the third other configuration example in the reinforcing ring constituting the earth retaining structure according to Embodiment 1. [Figure 25] It is an enlarged schematic diagram of the ring curve part of the fourth other configuration example in the reinforcing ring constituting the earth retaining structure according to Embodiment 1. [Figure 26] It is an enlarged schematic diagram of the ring curve part of the fifth other configuration example in the reinforcing ring constituting the earth retaining structure according to Embodiment 1. [Figure 27] It is an enlarged schematic diagram of the ring curve part of the sixth other configuration example in the reinforcing ring constituting the earth retaining structure according to Embodiment 1. [Figure 28] It is a plan view schematically showing an example of the curved part of the earth retaining structure according to Embodiment 2. [Figure 29] It is a plan view showing an example of the earth retaining panel constituting the curved part of the earth retaining structure according to Embodiment 2. [Figure 30] It is a plan view showing the connection state of the earth retaining panels constituting the curved part of the earth retaining structure according to Embodiment 2. [Figure 31]This is a schematic elevation view showing an example of the configuration of an earth retaining structure according to Embodiment 2. [Figure 32] This is a plan view showing an example of a reinforcing ring for an earth retaining structure according to Embodiment 2. [Figure 33] This is a plan view showing another example of a reinforcing ring for an earth retaining structure according to Embodiment 2. [Figure 34] This is a schematic plan view showing an example of the configuration of an earth retaining structure related to the comparative example. [Modes for carrying out the invention]

[0010] The earth-retaining structure according to the embodiment will be described below with reference to the drawings. Note that in the following drawings, including Figure 1, the relative dimensions and shapes of each component may differ from those of the actual components. Also, in the following drawings, components with the same reference numerals are the same or equivalent, and this is consistent throughout the entire specification. In addition, terms indicating direction (e.g., up, down, left, right, front, back, front and back, etc.) will be used as appropriate to facilitate understanding, but these notations are for the convenience of explanation and do not limit the arrangement, direction, and orientation of devices, equipment, or parts.

[0011] Embodiment 1. [Earth retaining structure 200] Figure 1 is a schematic front view showing the earth retaining structure 200 according to Embodiment 1. Figure 2 is a schematic plan view showing an example of the configuration of the earth retaining structure 200 according to Embodiment 1. Figure 3 is a schematic elevation view showing an example of the configuration of the earth retaining structure 200 according to Embodiment 1. The dashed line in Figure 1 indicates the excavation hole 301. In Figure 2, the reinforcing ring 50, which will be described later, is made transparent to show the positional relationship between the reinforcing ring 50 and the earth retaining panel 100. The earth retaining structure 200 will be explained using Figures 1 to 3.

[0012] The earth retaining structure 200 is constructed, for example, when constructing civil engineering structures such as the foundation of a structure, a shaft for constructing a sewer, or a water collection well constructed underground. The earth retaining structure 200 is a cylindrical structure constructed in an excavation hole 301 formed by excavating the ground 300.

[0013] The retaining wall structure 200 is formed in a rectangular tubular shape, for example, as shown in Figures 1 and 2. That is, the retaining wall structure 200 is formed in a roughly rectangular shape in plan view, as shown in Figure 2, for example. The retaining wall structure 200 shown in Figure 2 has four corners 250 that form the corner sections. The retaining wall structure 200 may also be formed in a circular shape in plan view. For example, the retaining wall structure 200 may be formed in a cylindrical shape. Alternatively, the retaining wall structure 200 may be formed in an oval, elliptical, or horseshoe-shaped tubular form in plan view.

[0014] The earth retaining structure 200 comprises a plurality of cylindrical structures 201 and one or more reinforcing rings 50 that reinforce the strength of the plurality of structures 201. The earth retaining structure 200 has a structure in which annular structures 201 are connected in the axial direction, as shown in Figure 1. The earth retaining structure 200 is constructed by stacking a plurality of annular structures 201 in multiple layers along the axis of the hole in an excavation hole 301 formed by excavating the ground 300. In Figure 1, the earth retaining structure 200 has a structure in which seven layers of structures 201 are stacked along the axial direction, but the number of layers of structures 201 can be any number and is not limited to seven layers.

[0015] The earth retaining structure 200 has multiple structural elements 201 in the axial direction, and the multiple structural elements 201 are connected continuously in the axial direction to form the structure. The earth retaining structure 200 is formed by combining multiple earth retaining panels 100 that constitute the structural elements 201 in the horizontal and vertical directions. The earth retaining structure 200 has multiple earth retaining panels 100, and the multiple earth retaining panels 100 are combined to form a cylindrical shape.

[0016] [Structure 201] Structure 201 is a structure that covers the excavated surface underground. Structure 201 is formed in an annular shape when viewed in the axial direction and is formed as a cylindrical body overall. Structure 201 is formed in a roughly rectangular shape, for example, a square shape with rounded corners, etc. Structure 201 may also be called an annular body. Structure 201 may be formed in a circular shape when viewed in plan. For example, structure 201 may be formed in a cylindrical shape. Alternatively, structure 201 may be formed in an oval, elliptical, or horseshoe-shaped cylindrical shape when viewed in plan.

[0017] Each structure 201 constituting the earth retaining structure 200 is constructed by connecting multiple earth retaining panels 100, and is formed by connecting the longitudinal ends of the earth retaining panels 100. Each of the multiple structures 201 constituting each stage of the earth retaining structure 200 is constructed by arranging multiple earth retaining panels 100 in a ring when viewed in the direction of the hole axis. That is, the structure 201 is composed of multiple earth retaining panels 100 arranged in the circumferential direction. The structure 201 is constructed by arranging multiple earth retaining panels 100 in a ring and connecting adjacent earth retaining panels 100 to each other.

[0018] As shown in Figure 2, the multiple structures 201 are constructed by arranging multiple earth retaining panels 100 that constitute the wall surface of the multiple structures 201 in a ring shape, and have curved sections 211 that form a curved shape when viewed in the direction of the hole axis.

[0019] The curved section 211 constitutes the side wall of the corner portion where a virtual extension 100c of a straight retaining panel 100 intersects with a virtual extension 100c of another straight retaining panel 100 in a plurality of retaining panels 100 arranged in a ring.

[0020] The curved portion 211 of the structure 201 constitutes the corner portion 250 of the earth retaining structure 200 described above. In other words, the curved portion 211 constitutes the portion located at the four corners of the substantially rectangular earth retaining structure 200 when viewed in the direction of the hole axis. The straight earth retaining panel 100 is, for example, the first earth retaining panel 101 described later (see Figure 4). The curved portion 211 of the earth retaining structure 200 in Embodiment 1 may include, for example, the second earth retaining panel 102 described later (see Figure 5).

[0021] The retaining wall structure 200 and the structural structure 201 are formed with different sizes of retaining wall panels 100 depending on their installation positions in the circumferential direction. Depending on the installation location and installation method, the retaining wall structure 200 and the structural structure 201 may be formed with the same size of retaining wall panels 100 depending on their installation positions in the circumferential direction.

[0022] The earth retaining structure 200 is constructed by stacking multiple cylindrical structures 201 in multiple layers along the axis of the hole. In the earth retaining structure 200, structures 201 adjacent to the earth retaining structure 200 in the axial direction are assembled in such a way that the positions of the earth retaining panels 100 constituting the structures 201 are offset in the longitudinal direction of the earth retaining panels 100, as shown in Figure 3, for example. In the earth retaining structure 200 shown in Figure 3, the earth retaining panels 100 constituting the structures 201 are constructed in a staggered arrangement. However, the arrangement of the earth retaining panels 100 is not limited to a staggered arrangement.

[0023] [Construction of earth retaining structure 200] As shown in Figure 1, in one example of a construction method for the earth retaining structure 200, first, an excavation hole 301 for constructing the earth retaining structure 200 is formed in the ground 300. The excavation hole 301 is formed with an outer diameter that is, for example, about 20 cm larger than the outer diameter of the earth retaining structure 200. In this example, the excavation hole 301 is formed to extend in the vertical direction, but it is not limited to being formed to extend in that direction, and may be inclined with respect to the vertical direction, for example.

[0024] The retaining wall panels 100 are arranged in a ring along the wall surface of the excavated hole 301 to assemble the structure 201. The structure 201 is assembled by arranging the retaining wall panels 100 sequentially along the circumferential direction of the wall surface of the excavated hole 301 and connecting adjacent retaining wall panels 100 on the left and right with connecting members such as bolts and nuts (not shown in the illustration).

[0025] The retaining wall panel 100 of the upper structure 201 and the retaining wall panel 100 of the lower structure 201 are connected by a connecting member 56 (see Figure 15), which will be described later. Note that the connecting member 56 is not limited to bolts and nuts, but may also be a clip-shaped member. As shown in Figures 2 and 3, the retaining wall structure 200 has a reinforcing ring 50 between the retaining wall panel 100 of the upper structure 201 and the retaining wall panel 100 of the lower structure 201.

[0026] The reinforcing ring 50 is sandwiched between the retaining wall panel 100 of the upper structure 201 and the retaining wall panel 100 of the lower structure 201, and is fixed together with the retaining wall panel 100 of the upper structure 201 and the retaining wall panel 100 of the lower structure 201 by a connecting member 56 (see Figure 15).

[0027] Depending on the height position in the direction of the hole axis, the retaining structure 200 may have portions where there is no reinforcing ring 50 between the retaining panel 100 of the upper structure 201 and the retaining panel 100 of the lower structure 201. In other words, depending on the height position in the direction of the hole axis, the retaining structure 200 may have portions where the retaining panel 100 of the upper structure 201 and the retaining panel 100 of the lower structure 201 are directly fixed to each other.

[0028] The retaining wall structure 200 is arranged such that the upper retaining wall panels 100 and the lower retaining wall panels 100 are staggered in the circumferential direction. This makes it possible to suppress variations in strength and rigidity at each position of the retaining wall structure 200 in the circumferential direction. However, if the connecting plates 20 (see Figure 4), which will be described later, are made sufficiently thick, the retaining wall panels 100 may be installed continuously in the axial direction without being staggered. In this way, the structure 201 is stacked in multiple layers along the axial direction to construct a part of the retaining wall structure 200.

[0029] The construction method for the earth retaining structure 200 may further include the following steps: After the uppermost structure 201 is fixed to the ground 300 with a grid (not shown in the figure), the excavated holes 301 outside the structure 201 are backfilled with excavated soil. The means for fixing the uppermost structure 201 to the ground 300 is not limited to a grid, and concrete may be used, for example.

[0030] In the construction method for the earth retaining structure 200, the structure 201 is assembled while the ground is excavated, and the excavation is continued to a predetermined depth. After the uppermost structure 201 is fixed in place with a crisscross pattern, earth retaining panels 100 are placed along the circumferential direction of the wall surface of the excavation hole 301 at the lower end of the upper structure 201. The placed earth retaining panels 100 are connected to the upper earth retaining panels 100 with bolts and nuts, and are also connected to the earth retaining panels 100 adjacent to them on the left and right with bolts and nuts.

[0031] The earth retaining structure 200 is constructed by building another structure 201 beneath the lower structure 201 in this manner. After that, concrete or mortar is filled between the earth retaining panel 100 and the excavation hole 301 as backfill material. The earth retaining structure 200 is constructed by stacking multiple annular structures 201 in vertical excavation holes 301 formed by excavating the ground 300, along the axis direction of the excavation hole 301.

[0032] [Earth retaining panel 100] Figure 4 is a perspective view showing an example of the retaining wall panel 100 according to Embodiment 1. Figure 5 is a perspective view showing another example of the retaining wall panel 100 according to Embodiment 1. Figure 6 is a longitudinal cross-sectional view showing the retaining wall panel 100 according to Embodiment 1. The retaining wall panel 100 will be described using Figures 4 to 6.

[0033] In the retaining wall panel 100, the longitudinal direction of the retaining wall panel 100 is defined as the first direction X, the short direction of the retaining wall panel 100 is defined as the second direction Z, and the thickness direction of the retaining wall panel 100 is defined as the third direction Y. The first direction X may also be referred to as the left-right width direction of the retaining wall panel 100, and the second direction Z may also be referred to as the up-down width direction of the retaining wall panel 100. In this case, in the second direction Z, the Z1 side is the upper side and the Z2 side is the lower side. Furthermore, the first direction X may also be referred to as the circumferential direction of the retaining wall structure 200 and the structure 201, and the second direction Z may also be referred to as the axial direction or hole axis direction of the retaining wall structure 200 and the structure 201.

[0034] The third direction Y is perpendicular to the first direction X and the second direction Z, and is perpendicular to the retaining panel 100 in the retaining structure 200 and the structure 201. The third direction Y is also the thickness direction of the retaining structure 200 and the structure 201, for example, the radial direction. Furthermore, when the retaining panel 100 is installed in the excavation hole 301 (see Figure 1), in the third direction Y, the Y1 side is the ground side and the Y2 side is the inside of the shaft.

[0035] The retaining wall panels 100 are installed in excavated holes 301 (see Figure 1) formed by excavating the ground 300 and are used to construct a cylindrical retaining wall structure 200. The retaining wall panels 100 are a general term for, for example, the first retaining wall panels 101 which are formed in a straight line in plan view and the second retaining wall panels 102 which are formed in a curved line in plan view, as described later.

[0036] Of the retaining wall panels 100, the first retaining wall panel 101 is formed in a rectangular shape when viewed in the third direction Y, which is the thickness direction of the retaining wall panel 100, as shown in Figure 4, and in a straight line when viewed in the second direction Z, which is the width direction of the retaining wall panel 100. The first retaining wall panel 101 is formed in a rectangular parallelepiped shape as a whole. The first retaining wall panel 101 is a retaining wall panel 100 that constitutes the straight portion of the retaining wall structure 200.

[0037] Of the retaining wall panels 100, the second retaining wall panel 102 is formed in a curved shape when viewed in the second direction Z, as shown in Figure 5. As shown in Figure 5, the second retaining wall panel 102 is formed in a rectangular shape when viewed in the third direction Y, which is the thickness direction of the retaining wall panel 100, and in an arc shape when viewed in the second direction Z, which is the vertical width direction of the retaining wall panel 100. The second retaining wall panel 102 is formed in an arc shape when viewed in the second direction Z, and as a whole, it is formed in a curved shape.

[0038] The second retaining panel 102 is a retaining panel 100 that constitutes the curved portion of the retaining structure 200. In the retaining structure 200 according to Embodiment 1, the second retaining panel 102 is a retaining panel 100 that constitutes the corner portion 250 (see Figure 2) of the retaining structure 200 which is formed in a rectangular tube shape. As shown in Figure 2, the retaining structure 200 has a configuration that includes a first retaining panel 101 which is formed in a straight line in plan view and a second retaining panel 102 which is formed in a curved shape in plan view.

[0039] The first retaining panel 101 and the second retaining panel 102 differ only in their shape when viewed from above; their basic configuration is the same. Therefore, in the following description, the first retaining panel 101 and the second retaining panel 102 will be referred to as retaining panel 100. Note that retaining panel 100 may be a liner plate with a configuration other than the first retaining panel 101 and the second retaining panel 102 described above, as long as it has the configuration of retaining panel 100 as described below.

[0040] As shown in Figures 4 to 6, the earth retaining panel 100 comprises a main body portion 10 formed such that the corrugated outer surface portion 17 and inner surface portion 16, which will be described later, extend along a first direction X which is the longitudinal direction, and a pair of connecting plates 20 provided at both ends of the main body portion 10 in the first direction X.

[0041] <Main body 10> The main body portion 10 is a member with a corrugated shape in the second direction Z. The main body portion 10 is a steel plate whose cross-sectional shape perpendicular to the first direction X, which is the longitudinal direction, is formed in a corrugated shape. The main body portion 10 may also be called a corrugated steel plate. The main body portion 10 is provided between a pair of connecting plates 20. The main body portion 10 is formed to extend in the first direction X.

[0042] The main body 10 of the earth retaining panel 100 is made of, for example, a so-called liner plate. The liner plate has a corrugated cross-section formed in a sine curve shape. As shown in Figure 6, the corrugation of the main body 10 has a cross-sectional shape perpendicular to the first direction X that is formed in a sine curve shape. The main body 10 has a thickness of, for example, 2.7 mm to 7 mm. Note that the said thickness of the main body 10 is just an example and is not limited to this thickness.

[0043] The main body portion 10 has at least one outer surface portion 17, at least one inner surface portion 16, and a plurality of intermediate wall portions 15. The main body portion 10 only needs to have a sine wave-shaped cross-section, and the number of outer surface portions 17, inner surface portions 16, and intermediate wall portions 15 in the main body portion 10 is not limited to the illustrated example.

[0044] The outer surface portion 17 constitutes the side portion of the main body portion 10 facing the ground in the excavated hole 301 (see Figure 1). In other words, the outer surface portion 17 constitutes the side portion of the main body portion 10 facing the outside of the shaft. In the main body portion 10 shown in Figures 4 to 6, multiple outer surface portions 17 are arranged in a second direction Z perpendicular to the first direction X. An opening 19 is formed in the portion of adjacent outer surface portions 17.

[0045] The outer surface portion 17 of the central part shown in Figures 4 to 6 is provided between two inner surface portions 16 in the vertical width direction of the earth retaining panel 100. In the second direction Z, the outer surface portion 17 of the central part is provided between the inner surface portions 16 adjacent to the multiple inner surface portions 16 in the second direction Z, and constitutes the side portion of the main body portion 10 located on the cylindrical outside of the earth retaining structure 200 relative to the multiple inner surface portions 16.

[0046] The inner surface portion 16 constitutes the side portion of the main body portion 10 facing the inside of the shaft. The inner surface portion 16 faces the inside of the cylinder of the earth retaining structure 200. The inner surface portion 16 constitutes the side portion of the main body portion 10 located on the inside of the cylinder of the earth retaining structure 200 relative to the outer surface portion 17. In the main body portion 10 shown in Figures 4 to 6, multiple inner surface portions 16 are arranged in a second direction Z perpendicular to the first direction X.

[0047] The inner surface portion 16 shown in Figures 4 to 6 is provided between two outer surface portions 17 in the vertical width direction of the earth retaining panel 100. In the second direction Z perpendicular to the first direction X, the inner surface portion 16 is provided between the outer surface portions 17 adjacent to the multiple outer surface portions 17 in the second direction Z, and constitutes the side portion of the main body portion 10 located on the cylindrical side of the earth retaining structure 200 relative to the multiple outer surface portions 17.

[0048] When viewed in the first direction X, the outer surface portion 17 and the inner surface portion 16 are formed to be located on imaginary lines that are substantially parallel to each other. As shown in Figure 6, the main body portion 10 is composed of, for example, four outer surface portions 17 and three inner surface portions 16, and the outer surface portions 17 and the inner surface portions 16 are arranged in parallel in the second direction Z.

[0049] In the main body 10, when the ground side of the excavation hole 301 (see Figure 1) is made into a wave-shaped peak and the inside of the shaft is made into a valley, the outer surface 17 constitutes the wave-shaped peak and the inner surface 16 constitutes the wave-shaped valley.

[0050] Each of the multiple intermediate wall portions 15 extends in a third direction Y, which is perpendicular to the first direction X and the second direction Z, connecting the outer surface portion 17 and the inner surface portion 16, as shown in Figure 6. The intermediate wall portion 15 is a plate-like portion and is formed to extend, for example, in the first direction X, the second direction Z, and the third direction Y. The main body portion 10 is formed with the intermediate wall portions 15 connecting the outer surface portion 17 and the inner surface portion 16 slightly inclined with respect to the horizontal direction.

[0051] The main body portion 10 is provided continuously with the outer surface portions 17 located at both ends of the second direction Z, among a plurality of outer surface portions 17, and further has a pair of lateral flange portions 13 used for connecting with an adjacent earth retaining panel 100 in the second direction Z.

[0052] The main body 10 has transverse flange portions 13 at both ends in the second direction Z, which is the vertical width direction, formed by bending the edges of the corrugated shape. The transverse flange portions 13 are formed by bending the upper and lower edges of the main body 10 so as to protrude into the interior of the borehole. The transverse flange portions 13 are flat plate-like portions formed substantially perpendicular to the parallel direction of the outer surface portion 17 and inner surface portion 16 of the corrugated shape. The transverse flange portions 13 are formed in a flat plate shape and are formed to extend in the first direction X and the third direction Y.

[0053] As shown in Figure 6, the lateral flange portion 13 is formed to extend in the third direction Y in its cross-sectional shape, and is formed to extend from the outer surface portion 17 to the inner surface portion 16. The tip of the lateral flange portion 13 faces in the opposite direction to the wall surface 303 of the excavation hole 301 (see Figure 1) in the earth retaining structure 200.

[0054] The lateral flange portion 13 has multiple connecting holes 13a formed therein, which are used to connect the main body portions 10 of adjacent earth retaining panels 100 stacked vertically in the axial direction of the excavation hole 301 (see Figure 1). The multiple connecting holes 13a are formed along the first direction X, which is the width direction of the earth retaining panel 100 from left to right.

[0055] The main body portions 10 of adjacent retaining wall panels 100 are connected by fastening the shafts of bolts inserted through connecting holes 13a with nuts, with the lateral flange portions 13 abutted together. Note that the means for connecting the lateral flange portions 13 of adjacent main body portions 10 are not limited to bolts and nuts; for example, connecting devices such as clips may also be used. Furthermore, while the number of connecting holes 13a shown in Figure 4 is shown as 10 as an example, this is merely an example and the number is not limited to these figures.

[0056] As shown in Figure 3, in the retaining wall structure 200 of Embodiment 1, the retaining wall panel 100 of the upper structure 201 and the retaining wall panel 100 of the lower structure 201 are joined with their ends in the width direction offset from each other. In the retaining wall structure 200 according to Embodiment 1, the retaining wall panel 100 located on the upper side and the retaining wall panel 100 located on the lower side are joined with, for example, an offset of half the length in the width direction in the circumferential direction. As a result, the retaining wall structure 200 can suppress variations in rigidity at each position in the circumferential direction.

[0057] However, the amount by which the upper and lower retaining panels 100 are shifted is not limited to half the length in the width direction, but can also be shifted by the pitch of the multiple connecting holes 13a formed in the lateral flange portion 13. For example, the retaining panel 100 in Figure 4 has 10 connecting holes 13a formed in the lateral flange portion 13, but the connecting holes 13a of the lower retaining panel 100 may be shifted by 1 to 5 pitches relative to the upper retaining panel 100 when connecting them. Note that the retaining structure 200 does not necessarily have to be joined with the upper retaining panel 100 and the lower retaining panel 100 shifted relative to each other in the circumferential direction.

[0058] <Connecting plate 20> The connecting plates 20 are flat plate-shaped members and are spaced apart from each other in the first direction X. While the connecting plates 20 are formed in a rectangular shape when viewed in the first direction X, their shape is not limited to a rectangular shape. The connecting plates 20 are welded to both ends of the main body 10 in the first direction X, which is the longitudinal direction of the main body 10. The thickness of the connecting plates 20 is determined according to the required strength and rigidity of the earth retaining structure 200.

[0059] The connecting plate 20 has multiple joint connection holes 21 formed therein for connecting adjacent earth retaining panels 100 arranged circumferentially around the excavation hole 301 (see Figure 1). The multiple joint connection holes 21 are formed along the second direction Z, which is the vertical width direction of the earth retaining panel 100.

[0060] Adjacent retaining wall panels 100 are connected by butting their connecting plates 20 together and fastening the shafts of bolts inserted through the joint connection holes 21 with nuts. The means of connecting the connecting plates 20 of adjacent retaining wall panels 100 are not limited to bolts and nuts; for example, connecting devices such as clips may also be used. In Figure 4, the number of joint connection holes 21 is shown as four, but the number of joint connection holes 21 shown is just an example and is not limited to this.

[0061] Figure 7 is a schematic plan view showing an example of the configuration of the retaining wall panel 100 according to Embodiment 1. Figure 8 is a schematic plan view showing another example of the configuration of the retaining wall panel 100 according to Embodiment 1. Figure 9 is a schematic plan view showing another example of the configuration of the retaining wall panel 100 according to Embodiment 1. The shapes of the retaining wall panel 100 and the retaining wall structure 200 will be explained using Figures 2 and 7 to 9.

[0062] The retaining wall panels 100 are connected in the circumferential direction by connecting adjacent connecting plates 20 to each other. The retaining wall panels 100 are formed in a straight line in plan view, for example, as shown in Figures 7 and 4. Alternatively, the retaining wall panels 100 are formed in an arc shape in plan view, for example, as shown in Figures 8 and 5. Alternatively, the retaining wall panels 100 are formed to have a straight portion and an arc shape in plan view, as shown in Figure 9.

[0063] The retaining wall structure 200 according to Embodiment 1 is formed by combining retaining wall panels 100 as shown in Figures 7 to 9, and the retaining wall structure 200 as shown in Figure 2 is formed in a rectangular tubular shape with curved portions in plan view, such as the corners 250. That is, as an example, the retaining wall structure 200 is formed in a substantially rectangular shape in plan view, as shown in Figure 2. The retaining wall structure 200 uses retaining wall panels 100 that have curved portions in plan view, as shown in Figures 8 and 9, so that the corners 250 are formed in an arc shape.

[0064] Figure 10 is a longitudinal cross-sectional view showing another example of the earth retaining panel 100 according to Embodiment 1. The main body 10 of the earth retaining panel 100 may be composed of, for example, a so-called plank plate. The plank plate has a corrugated cross-section formed in a rectangular shape.

[0065] Since plank plate retaining panels 100 can ensure sufficient strength, it is generally not necessary to install reinforcing rings 50 on the retaining structure 200 composed of plank plates. However, the retaining panels 100 that make up the retaining structure 200 may include, for example, plank plate retaining panels 100 shown in Figure 10 and liner plate retaining panels 100 shown in Figure 4, depending on the depth. In such cases, the retaining structure 200 may require reinforcing rings 50 in the portion that makes up the liner plate retaining panels 100. Therefore, depending on the installation conditions, the retaining panels 100 shown in Figure 10 may be used as the retaining panels 100 for the retaining structure 200.

[0066] Alternatively, the earth retaining structure 200 may be constructed using plank plate earth retaining panels 100 and reinforcing rings 50. In the earth retaining structure 200, if the rigidity of the plank plate earth retaining panels 100 alone is insufficient, the reinforcing rings 50 may be used in combination. That is, the earth retaining structure 200 may be constructed using plank plate earth retaining panels 100, liner plate earth retaining panels 100, and reinforcing rings 50 together, or using plank plate earth retaining panels 100 and reinforcing rings 50 together, etc.

[0067] As shown in Figure 10, the waveform of the main body 10 may be formed in a rectangular wave shape with a cross-sectional shape perpendicular to the first direction X, for example, or it may be any other shape. The main body 10 is constructed by bending a rolled steel sheet into a rectangular wave shape, for example, so that the waveform cross-section is rectangular. In Embodiment 1, the rectangular wave shape may be, for example, a trapezoidal wave shape with rounded corners.

[0068] When viewed in the first direction X, the outer surface portion 17 and the inner surface portion 16 are formed to be located on imaginary lines that are substantially parallel to each other. In the main body portion 10 shown in Figure 10, the outer surface portion 17 and the inner surface portion 16 form surfaces that are parallel to each other on the outside and inside of the wall structure.

[0069] It is desirable that the main body portion 10 is formed with an intermediate wall portion 15 connecting the outer surface portion 17 and the inner surface portion 16, which is slightly inclined with respect to the horizontal direction, so that the bottom of the valley of the inner surface portion 16 becomes narrower.

[0070] Because the intermediate wall portion 15 is slightly inclined, the retaining wall panel 100 is formed such that, as shown in Figure 10, the distance D1 between adjacent outer surface portions 17 in the second direction Z is greater than the length D2 of the portion constituting the inner surface portion 16. In the main body portion 10, when the portions of adjacent outer surface portions 17 are made into openings 19, the size of the openings 19 in the second direction Z is formed to be greater than the length of the inner surface portion 16.

[0071] The retaining wall panel 100 is made easier to manufacture by slightly inclining the intermediate wall portion 15, which makes it easier to demold the main body portion 10 when plastic deformation is performed on the main body portion 10 for corrugation. When the width of the main body portion 10 in the second direction Z is kept constant, reducing the inclination angle of the intermediate wall portion 15 connecting the outer surface portion 17 and the inner surface portion 16 with respect to the horizontal direction makes the width of the outer surface portion 17 and the inner surface portion 16 in the second direction Z wider than when the inclination angle is increased.

[0072] By reducing the inclination angle of the intermediate wall portion 15 with respect to the horizontal direction, the width of the outer surface portion 17 and the inner surface portion 16 in the second direction Z becomes wider than when the inclination angle of the intermediate wall portion 15 is increased, and the rigidity when a bending moment is applied in the planar direction increases. This is because the section modulus when the main body portion 10 is bent in the third direction Y increases as the width of the outer surface portion 17 and the inner surface portion 16 increases. The inclination angle of the intermediate wall portion 15 of the main body portion 10 with respect to the horizontal direction is set to 0° or more and 30° or less, and more preferably to 0° or more and 10° or less. Note that the inclination angle of the intermediate wall portion 15 is preferably within the above range, but is not limited to this range.

[0073] The outer surface portion 17 and the inner surface portion 16 are formed with the same thickness as the intermediate wall portion 15, but they may be thicker than the intermediate wall portion 15. By configuring the earth retaining panel 100 in this way, the cross-sectional area of ​​the outer surface portion 17 and the inner surface portion 16, which are farther from the neutral axis N, is increased, and the section modulus of the main body portion 10 can be further increased.

[0074] [Reinforcement Ring 50] Figure 11 is a schematic perspective view showing the reinforcing ring 50 used in the earth retaining structure 200 according to Embodiment 1. Figure 12 is a schematic plan view showing the reinforcing ring 50 used in the earth retaining structure 200 according to Embodiment 1. The reinforcing ring 50 will be explained using Figures 2, 11 and 12, etc.

[0075] As the depth of the excavation hole 301 increases, the earth pressure from the ground side increases, and the earth retaining panels 100 alone may not have sufficient rigidity. Also, regardless of the depth, the earth pressure may be high depending on the soil conditions, etc. Furthermore, as the depth in the direction of the hole axis increases, the self-weight of the upper structure 201 acts on the lower structure 201. For this reason, in places where rigidity needs to be increased, such as in deep areas, the earth retaining structure 200 has its rigidity increased by inserting H-shaped steel called reinforcing rings 50 between adjacent earth retaining panels 100.

[0076] The reinforcing ring 50 is an H-shaped steel beam positioned between two adjacent structures 201, and it reinforces the strength of the multiple structures 201. As shown in Figure 2, the reinforcing ring 50 is formed in an annular shape when viewed in the direction of the hole axis. The reinforcing ring 50 is composed of multiple divided components 55, and these components 55 are connected to each other by joint plates 60.

[0077] The partial components 55 of the reinforcing ring 50 are H-shaped steel, as shown in Figures 11 and 12. The partial components 55 are formed in a straight line in a plan view, or in a curved shape in a plan view. The partial components 55 are formed in a straight or curved shape depending on their position in the circumferential direction. The partial components 55 are a part of the reinforcing ring 50 in the circumferential direction, and the collective term for the partial components 55 is the reinforcing ring 50.

[0078] The reinforcing ring 50 has a plate-shaped web 51 and a pair of plate-shaped flange portions 52 provided at both ends of the web 51 in the thickness direction of the multiple earth retaining panels 100 when viewed in the direction of the hole axis. The reinforcing ring 50 has an H-shaped cross section perpendicular to the first direction X, formed by the web 51 and the pair of flange portions 52.

[0079] The web 51 is made of steel and is formed in a flat plate shape extending in the first direction X and the third direction Y of the retaining wall panel 100. The plate surface constituting the web 51 is oriented in the direction of the hole axis, which is the second direction Z of the retaining wall panel 100. The web 51 is elongated in the first direction X of the retaining wall panel 100. As shown in Figure 12, the web 51 has a plurality of ring-shaped holes 51a formed therein.

[0080] The ring holes 51a are through holes and are formed to be aligned along the first direction X of the retaining wall panel 100. In the second direction Z, which is the axial direction of the hole, the ring holes 51a are formed opposite the connecting holes 13a of the lateral flange portion 13. In Figure 12, 10 ring holes 51a are formed in the web 51, but the number of ring holes 51a is not limited to the illustrated example.

[0081] A pair of flange portions 52 are provided at both ends of the web 51 in a third direction Y, which is the thickness direction of the retaining wall panel 100. The pair of flange portions 52 are made of steel and are formed in a flat plate shape extending in the first direction X and the second direction Z of the retaining wall panel 100. The plate surfaces constituting the flange portions 52 are oriented in the third direction Y of the retaining wall panel 100. The pair of flange portions 52 are elongated in the first direction X of the retaining wall panel 100.

[0082] The pair of flange portions 52 include a first flange portion 52c positioned on the ground side and a second flange portion 52b positioned on the tunnel side. The first flange portion 52c and the second flange portion 52b are positioned facing each other via the web 51 in the third direction Y.

[0083] The first flange portion 52c and the second flange portion 52b have a plurality of flange holes 52a through which the second connecting member 57, described later, is inserted. The flange holes 52a are provided at both ends of the first flange portion 52c and the second flange portion 52b in the first direction X of the earth retaining panel 100. The flange holes 52a are through holes. In Figure 11, four flange holes 52a are formed at each end of the first flange portion 52c and the second flange portion 52b, but the number of flange holes 52a is not limited to the example shown.

[0084] Figure 13 is a conceptual diagram showing a joint plate 60 in an earth retaining structure 200 according to Embodiment 1. As shown in Figure 13, the joint plate 60 that connects adjacent circumferentially adjacent component parts 55 is formed in a plate shape. The joint plate 60 is, for example, a steel plate. The joint plate 60 has a plurality of joint holes 60a through which a second connecting member 57, which will be described later, is inserted. The joint holes 60a are through holes. In Figure 13, eight joint holes 60a are formed in the joint plate 60, but the number of joint holes 60a is not limited to the example shown.

[0085] Figure 14 is a schematic plan view showing the connection between the reinforcing ring 50 and the retaining panel 100 in the retaining structure 200 according to Embodiment 1. Figure 15 is a conceptual diagram showing the connection between the reinforcing ring 50 and the retaining panel 100 in the retaining structure 200 according to Embodiment 1, viewed in the circumferential direction. In addition, in Figure 14, a part of the reinforcing ring 50 is made transparent to show a part of the retaining panel 100 in order to clarify the positional relationship between the reinforcing ring 50 and the retaining panel 100. The connection state between the reinforcing ring 50 and the retaining panel 100 will be explained using Figures 14 and 15.

[0086] As shown in Figures 14 and 15, the retaining structure 200 has the ends of multiple retaining panels 100 arranged in the space enclosed by the web 51 and a pair of flange portions 52, in the direction of the hole axis. The lateral flange portions 13 of the multiple retaining panels 100 are fixed to the web 51 of the reinforcing ring 50.

[0087] The reinforcing ring 50 is positioned with its web 51 sandwiched between the horizontal flange portions 13 of the upper and lower earth retaining panels 100. The reinforcing ring 50 is attached to the earth retaining panels 100 by fastening the web 51 and the upper and lower horizontal flange portions 13 with a connecting member 56. The connecting member 56 is, for example, a bolt 56a and a nut 56b as shown in Figure 15.

[0088] The bolt 56a is inserted through the connecting hole 13a of the lateral flange portion 13 and the ring hole portion 51a formed in the web 51 of the reinforcing ring 50. The web 51 and the lateral flange portions 13 positioned above and below the web 51 are fastened together by the bolt 56a and the nut 56b attached to the bolt 56a. The reinforcing ring 50 and the earth retaining panels 100 positioned above and below the reinforcing ring 50 are fastened together and fixed together by connecting members 56 such as the bolt 56a and the nut 56b.

[0089] The joint plate 60 is positioned so as to straddle the ends of the partial components 55 of the reinforcing ring 50 that are butted in the circumferential direction (first direction X), and is in contact with the flange portion 52 of the partial components 55, and is fixed to the flange portion 52 of each partial component 55 by the second connecting member 57. The partial components 55 of the reinforcing ring 50 that are butted in the circumferential direction (first direction X) are fixed and connected to each other by the joint plate 60 and the second connecting member 57. The second connecting member 57 is, for example, a second bolt 57a and a second nut 57b as shown in Figure 15.

[0090] The second bolt 57a is inserted through the joint hole 60a of the joint plate 60 and the flange hole 52a formed in the flange portion 52 of the reinforcing ring 50. The joint plate 60 and the flange portion 52 of the reinforcing ring 50 are fastened together by the second bolt 57a and the second nut 57b attached to the second bolt 57a. Adjacent parts 55 of the reinforcing ring 50 are connected and fixed to each other by a second connecting member 57, such as the second bolt 57a and the second nut 57b, and the joint plate 60.

[0091] As shown in Figure 2, the reinforcing ring 50 has a curved ring portion 50A that is formed in a curved shape along the curved portion 211 in the portion facing the curved portion 211 in the direction of the hole axis. The earth retaining structure 200 has an annular reinforcing ring 50 as shown in Figure 2, and the annular reinforcing ring 50 has a curved ring portion 50A that constitutes the curved part. Because the reinforcing ring 50 has a curved ring portion 50A, when viewed in the direction of the hole axis, it is formed in a substantially rectangular shape with rounded corners.

[0092] The ring-curved portion 50A constitutes the portion in the annularly formed reinforcing ring 50 where a virtual extension portion 100c of a straight portion intersects with a virtual extension portion 100c of another straight portion. The ring-curved portion 50A of the reinforcing ring 50 constitutes the corner portion 250 of the earth retaining structure 200 described above. In other words, when viewed in the direction of the hole axis, the ring-curved portion 50A constitutes the portion located at the four corners of the roughly rectangular earth retaining structure 200. The bending angle of the portion constituting the ring-curved portion 50A is, for example, 90°.

[0093] [An example of the ring-shaped curved section 50A of the reinforcing ring 50] Figure 16 is a schematic, enlarged view of the ring-curved portion 50A of the reinforcing ring 50 that constitutes the earth-retaining structure 200 according to Embodiment 1. Figure 17 is a conceptual diagram showing an example of the main straight portion 151 that constitutes the ring-curved portion 50A in Figure 16. Figure 18 is a conceptual diagram showing an example of the end straight portion 152 that constitutes the ring-curved portion 50A in Figure 16. In Figure 16, a part of the reinforcing ring 50 is made transparent to show a part of the earth-retaining panel 100 in order to clarify the positional relationship between the reinforcing ring 50 and the earth-retaining panel 100. Figures 16 to 18 are plan views of the ring-curved portion 50A as seen in the direction of the hole axis. The ring-curved portion 50A will be explained using Figures 16 to 18.

[0094] The ring curved section 50A shown in Figure 16 is an example of the configuration of the straight sections 150 that constitute the ring curved section 50A when the arc radius is 2000 mm, and the number of straight sections 150 and the number of ring holes 51a are not limited to those shown. The ring curved section 50A is composed of a plurality of straight sections 150 arranged in a line along the curved section 211 of the structure 201. Each of the plurality of straight sections 150 is formed in a straight line when viewed in the direction of the hole axis.

[0095] The ring-shaped curved section 50A is formed in a curved shape by arranging multiple straight sections 150, which are straight in a plan view, to follow the curved section 211. In other words, the ring-shaped curved section 50A is formed in an arc shape by arranging multiple straight sections 150, which are straight in a plan view, to follow the curved section 211.

[0096] Multiple straight sections 150, when connected to each other, constitute a curved or arc-shaped ring-shaped section 50A. More precisely, multiple straight sections 150, when connected to each other, constitute a pseudo-curved or pseudo-arc-shaped ring-shaped section 50A.

[0097] Multiple straight sections 150 are arranged along the first direction X of the retaining panel 100, which is the circumferential direction of the retaining structure 200. The multiple straight sections 150 arranged along the circumferential direction are fixed to each other, for example, by welding. The ring curve section 50A is arranged such that the axial direction of each of the multiple straight sections 150 is aligned with the curve section 211. That is, the ring curve section 50A is arranged such that the longitudinal direction of each of the multiple straight sections 150 is aligned with the curve section 211. Note that the connection between the straight sections 150 may be by means other than welding, such as connection by joint plates.

[0098] In addition to welding, the reinforcing ring 50 may also be created by press forming. The multiple straight sections 150 arranged along the circumferential direction may be formed by bending an H-shaped steel beam with a press, rather than connecting the individual straight sections 150 later by welding or the like. For example, when creating two main straight sections 151 as shown in Figure 16, bending the central part of an H-shaped steel beam with a press that is the length of two sections will produce the same shape as if they were joined by welding. When forming the reinforcing ring 50, if a long H-shaped steel beam is pressed in several places, the boundaries of adjacent straight sections 150 will be bent, and the ring curved section 50A can be formed into a pseudo-arc shape by the multiple straight sections 150 arranged along the circumferential direction.

[0099] The ring-shaped curved section 50A is formed in an arc shape when viewed in the direction of the hole axis. The multiple straight sections 150 have two end straight sections 152 located at both ends of the ring-shaped curved section 50A, and multiple main straight sections 151 arranged between the two end straight sections 152.

[0100] Here, when viewed in the direction of the hole axis, the length of the longest portion of each of the two end straight portions 152 in the circumferential direction of the multiple structures 201 is defined as the end straight portion length L2. Also, when viewed in the direction of the hole axis, the length of each of the multiple main straight portions 151 in the circumferential direction of the multiple structures 201 is defined as the main straight portion length L1, which is the length of the longest portion of each of the multiple main straight portions 151. The end straight portions 152 and the main straight portions 151 are formed such that the end straight portion length L2 is shorter than the main straight portion length L1. The length of the longest portion is, for example, the length of the first flange portion 52c located on the outer circumference side relative to the second flange portion 52b.

[0101] In the ring-shaped curved section 50A shown in Figures 16 to 18, the multiple main straight sections 151 consist of nine main straight sections 151. Therefore, the ring-shaped curved section 50A shown in Figures 16 to 18 is composed of two end straight sections 152 and nine main straight sections 151.

[0102] The reinforcing ring 50 has multiple ring holes 51a formed therein, which are used to connect with multiple structures 201. As shown in Figures 16 to 18, of the multiple ring holes 51a, there is one ring hole 51a formed in each of the two end straight sections 152. Also, of the multiple ring holes 51a, there are two ring holes 51a formed in each of the nine main straight sections 151.

[0103] As shown in Figure 17, both ends 150a of the main straight section 151 in the first direction X are formed to be inclined with respect to the first direction X and the third direction Y in a plan view. As shown in Figure 18, at least one end 150a of the end straight section 152 in the first direction X is formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Because the ends 150a are formed to be inclined in a plan view, the multiple connected straight sections 150 constitute a pseudo-arc-shaped ring curve section 50A.

[0104] Figure 19 is an enlarged schematic diagram of another example of the ring curved portion 50A of the reinforcing ring 50 constituting the earth retaining structure 200 according to Embodiment 1. Figure 20 is a conceptual diagram showing an example of the main straight portion 151 constituting the ring curved portion 50A in Figure 19. Figure 21 is a conceptual diagram showing an example of the end straight portion 152 constituting the ring curved portion 50A in Figure 19. In Figure 19, a part of the reinforcing ring 50 is made transparent to show a part of the earth retaining panel 100 in order to clarify the positional relationship between the reinforcing ring 50 and the earth retaining panel 100. Figures 19 to 21 are plan views of the ring curved portion 50A as seen in the direction of the hole axis. The ring curved portion 50A will be explained using Figures 19 to 21.

[0105] The ring curved section 50A shown in Figure 19 is, for example, another example of the configuration of the straight section 150 that constitutes the ring curved section 50A when the arc radius is 2000 mm, and the number of straight sections 150 and the number of ring holes 51a are not limited to those shown.

[0106] In the ring-shaped curved section 50A shown in Figures 19 to 21, the multiple straight sections 150 consist of two end straight sections 152 located at both ends of the ring-shaped curved section 50A, and multiple main straight sections 151 positioned between the two end straight sections 152. In the ring-shaped curved section 50A shown in Figures 19 to 21, the multiple main straight sections 151 are four main straight sections 151. Therefore, the ring-shaped curved section 50A shown in Figures 19 to 21 is composed of two end straight sections 152 and four main straight sections 151.

[0107] The reinforcing ring 50 has multiple ring holes 51a formed therein, which are used to connect with multiple structures 201. As shown in Figures 19 to 21, of the multiple ring holes 51a, there are two ring holes 51a formed in each of the two end straight sections 152. Also, of the multiple ring holes 51a, there are four ring holes 51a formed in each of the four main straight sections 151. Furthermore, in the ring curved section 50A shown in Figures 19 to 21, the end straight sections 152 and the main straight sections 151 are formed such that the length L2 of the end straight section is shorter than the length L1 of the main straight section.

[0108] Note that the number of straight sections 150 shown in Figures 16 to 21 is just an example and is not limited to the illustrated example. Also, the number of ring holes 51a and connecting holes 13a shown in Figures 16 to 21 is just an example and is not limited to the illustrated example.

[0109] Figure 22 is an enlarged schematic diagram of the ring curve portion 50A of a first alternative configuration example in the reinforcing ring 50 that constitutes the earth retaining structure 200 according to Embodiment 1. In order to clarify the positional relationship between the reinforcing ring 50 and the earth retaining panel 100, a part of the reinforcing ring 50 is made transparent to show a part of the earth retaining panel 100. Figure 22 is a plan view of the ring curve portion 50A as seen in the direction of the hole axis. In the first alternative configuration example shown in Figure 22, for example, the arc radius of the ring curve portion 50A is formed to be larger than the arc radius of the ring curve portion 50A shown in Figure 16.

[0110] The ring curved section 50A shown in Figure 22 is, for example, an example of the configuration of the straight section 150 that constitutes the ring curved section 50A when the arc radius is 2500 mm, and the number of straight sections 150 and the number of ring holes 51a are not limited to the numbers shown.

[0111] The ring-shaped curved section 50A is formed in an arc shape when viewed in the direction of the hole axis. The multiple straight sections 150 have eight main straight sections 151 and one second straight section 153. The second straight section 153 is located, for example, in the central part of the ring-shaped curved section 50A in the circumferential direction. In the ring-shaped curved section 50A shown in Figure 22, four main straight sections 151 are arranged on each side of the second straight section 153. In the ring-shaped curved section 50A shown in Figure 22, the main straight sections 151 constitute both ends of the ring-shaped curved section 50A.

[0112] Here, when viewed in the direction of the hole axis, the length of the longest part of the second straight section 153 in the circumferential direction of the multiple structures 201 is defined as the second straight section length L3. The main straight section 151 and the second straight section 153 are formed such that the second straight section length L3 is shorter than the main straight section length L1. The length of the longest part is, for example, the length of the first flange section 52c located on the outer circumference side relative to the second flange section 52b (see Figure 20).

[0113] The reinforcing ring 50 has multiple ring holes 51a formed therein, which are used to connect with multiple structures 201. As shown in Figure 22, of the multiple ring holes 51a, three are formed in each of the eight main straight sections 151. In addition, of the multiple ring holes 51a, one is formed in the second straight section 153.

[0114] As shown in Figure 22, both ends of the main straight section 151 in the first direction X are formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Similarly, both ends of the second straight section 153 in the first direction X are formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Because both ends of the main straight section 151 and the second straight section 153 are formed to be inclined in a plan view, the multiple connecting straight sections 150 constitute a pseudo-arc-shaped ring curve section 50A.

[0115] Figure 23 is an enlarged schematic diagram of the ring curve portion 50A of a second alternative configuration example in the reinforcing ring 50 constituting the earth retaining structure 200 according to Embodiment 1. In order to clarify the positional relationship between the reinforcing ring 50 and the earth retaining panel 100, a portion of the reinforcing ring 50 is made transparent to show a portion of the earth retaining panel 100. Figure 23 is a plan view of the ring curve portion 50A as seen in the direction of the hole axis. In the second alternative configuration example shown in Figure 23, for example, the arc radius of the ring curve portion 50A is formed to be larger than the arc radius of the ring curve portion 50A shown in Figure 16.

[0116] The ring curved section 50A shown in Figure 23 is, for example, another example of the configuration of the straight section 150 that constitutes the ring curved section 50A when the arc radius is 2500 mm, and the number of straight sections 150 and the number of ring holes 51a are not limited to the numbers shown.

[0117] In the ring-shaped curved section 50A shown in Figure 23, the multiple straight sections 150 consist of two end straight sections 152 located at both ends of the ring-shaped curved section 50A, and multiple main straight sections 151 positioned between the two end straight sections 152. In the ring-shaped curved section 50A shown in Figure 23, the multiple main straight sections 151 consist of seven main straight sections 151. Therefore, the ring-shaped curved section 50A shown in Figure 23 is composed of two end straight sections 152 and seven main straight sections 151.

[0118] The reinforcing ring 50 has multiple ring holes 51a formed therein, which are used to connect with multiple structures 201. As shown in Figure 23, of the multiple ring holes 51a, there are two ring holes 51a formed in each of the two end straight sections 152. Also, of the multiple ring holes 51a, there are three ring holes 51a formed in each of the seven main straight sections 151. In addition, in the ring curved section 50A shown in Figure 23, the end straight sections 152 and the main straight sections 151 are formed such that the length L2 of the end straight section is shorter than the length L1 of the main straight section.

[0119] As shown in Figure 23, both ends of the main straight section 151 in the first direction X are formed to be inclined with respect to the first direction X and the third direction Y in a plan view. As shown in Figure 23, at least one end of the end straight section 152 in the first direction X is formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Because the ends of the main straight section 151 and the end straight section 152 are formed to be inclined in a plan view, the multiple connecting straight sections 150 constitute a pseudo-arc-shaped ring curve section 50A.

[0120] Figure 24 is an enlarged schematic diagram of the ring curve portion 50A of a third alternative configuration example in the reinforcing ring 50 constituting the earth retaining structure 200 according to Embodiment 1. In order to clarify the positional relationship between the reinforcing ring 50 and the earth retaining panel 100, a portion of the reinforcing ring 50 is made transparent to show a portion of the earth retaining panel 100. Figure 24 is a plan view of the ring curve portion 50A as seen in the direction of the hole axis. In the third alternative configuration example shown in Figure 24, for example, the arc radius of the ring curve portion 50A is formed to be smaller than the arc radius of the ring curve portion 50A shown in Figure 16.

[0121] The ring curved section 50A shown in Figure 24 is, for example, an example of the configuration of the straight section 150 that constitutes the ring curved section 50A when the arc radius is 1500 mm, and the number of straight sections 150 and the number of ring holes 51a are not limited to the numbers shown.

[0122] In the ring-shaped curved section 50A shown in Figure 24, the multiple straight sections 150 are five main straight sections 151, and the ring-shaped curved section 50A is composed of these five main straight sections 151. The reinforcing ring 50 has multiple ring holes 51a formed therein, which are used for connecting with multiple structures 201. As shown in Figure 24, of the multiple ring holes 51a, there are three ring holes 51a formed in each of the five main straight sections 151.

[0123] As shown in Figure 24, at least one end of the main straight section 151 in the first direction X is formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Because the ends of the main straight section 151 are formed to be inclined in a plan view, the multiple connected straight sections 150 constitute a pseudo-arc-shaped ring curve section 50A.

[0124] Figure 25 is an enlarged schematic diagram of the ring curve portion 50A of a fourth alternative configuration example in the reinforcing ring 50 constituting the earth retaining structure 200 according to Embodiment 1. In order to clarify the positional relationship between the reinforcing ring 50 and the earth retaining panel 100, a portion of the reinforcing ring 50 is made transparent to show a portion of the earth retaining panel 100. Figure 25 is a plan view of the ring curve portion 50A as seen in the direction of the hole axis. In the fourth alternative configuration example shown in Figure 25, for example, the arc radius of the ring curve portion 50A is formed to be smaller than the arc radius of the ring curve portion 50A shown in Figure 16.

[0125] The ring curved section 50A shown in Figure 25 is, for example, another example of the configuration of the straight section 150 that constitutes the ring curved section 50A when the arc radius is 1500 mm, and the number of straight sections 150 and the number of ring holes 51a are not limited to those shown.

[0126] The ring curved section 50A is formed in an arc shape when viewed in the direction of the hole axis. The multiple straight sections 150 have six main straight sections 151, one second straight section 153, and two end straight sections 152. The second straight section 153 is located, for example, in the central part of the ring curved section 50A in the circumferential direction. The end straight sections 152 are located at both ends of the ring curved section 50A in the circumferential direction. In the ring curved section 50A shown in Figure 25, three main straight sections 151 are located on each side of the second straight section 153. In the ring curved section 50A shown in Figure 25, the main straight sections 151 are located between the end straight sections 152 and the second straight sections 153.

[0127] The main straight section 151 and the second straight section 153 are formed such that, in the circumferential direction, the length L3 of the second straight section 153 is shorter than the length L1 of the main straight section 151. Furthermore, the main straight section 151 and the end straight section 152 are formed such that, in the circumferential direction, the length L2 of the end straight section 152 is shorter than the length L1 of the main straight section 151.

[0128] The reinforcing ring 50 has multiple ring holes 51a formed therein, which are used to connect with multiple structures 201. As shown in Figure 25, of the multiple ring holes 51a, there are two ring holes 51a formed in each of the six main straight sections 151. Also, of the multiple ring holes 51a, there is one ring hole 51a formed in the second straight section 153. Also, of the multiple ring holes 51a, there is one ring hole 51a formed in each of the two end straight sections 152.

[0129] As shown in Figure 25, both ends of the main straight section 151 in the first direction X are formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Similarly, both ends of the second straight section 153 in the first direction X are formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Furthermore, at least one end of the end straight section 152 in the first direction X is formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Because the ends of the main straight section 151, the second straight section 153, and the end straight section 152 are formed to be inclined in a plan view, the multiple connected straight sections 150 constitute a pseudo-arc-shaped ring curve section 50A.

[0130] Figure 26 is an enlarged schematic diagram of the ring curve portion 50A of a fifth alternative configuration example in the reinforcing ring 50 constituting the earth retaining structure 200 according to Embodiment 1. In order to clarify the positional relationship between the reinforcing ring 50 and the earth retaining panel 100, a portion of the reinforcing ring 50 is made transparent in Figure 26 to show a portion of the earth retaining panel 100. Figure 26 is a plan view of the ring curve portion 50A as seen in the direction of the hole axis. In the ring curve portion 50A of the fifth alternative configuration example shown in Figure 26, for example, the arc radius of the ring curve portion 50A is formed to be smaller than the arc radius of the ring curve portion 50A shown in Figure 16 and the arc radius of the ring curve portion 50A shown in Figure 24.

[0131] The ring curved section 50A shown in Figure 26 is, for example, an example of the configuration of the straight section 150 that constitutes the ring curved section 50A when the arc radius is 1000 mm, and the number of straight sections 150 and the number of ring holes 51a are not limited to the numbers shown.

[0132] In the ring-shaped curved section 50A shown in Figure 26, the multiple straight sections 150 are five main straight sections 151, and the ring-shaped curved section 50A is composed of these five main straight sections 151. The reinforcing ring 50 has multiple ring holes 51a formed therein, which are used for connecting with multiple structures 201. As shown in Figure 26, of the multiple ring holes 51a, there are two ring holes 51a formed in each of the five main straight sections 151.

[0133] As shown in Figure 26, at least one end of the main straight section 151 in the first direction X is formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Because the end of the main straight section 151 is formed to be inclined in a plan view, the multiple connected straight sections 150 constitute a pseudo-arc-shaped ring curve section 50A.

[0134] Figure 27 is an enlarged schematic diagram of the ring curve portion 50A of a sixth alternative configuration example in the reinforcing ring 50 constituting the earth retaining structure 200 according to Embodiment 1. In order to clarify the positional relationship between the reinforcing ring 50 and the earth retaining panel 100, a portion of the reinforcing ring 50 is made transparent to show a portion of the earth retaining panel 100. Figure 27 is a plan view of the ring curve portion 50A as seen in the direction of the hole axis. In the sixth alternative configuration example shown in Figure 27, for example, the arc radius of the ring curve portion 50A is formed to be smaller than the arc radius of the ring curve portion 50A shown in Figure 16 and the arc radius of the ring curve portion 50A shown in Figure 24.

[0135] The ring curved section 50A shown in Figure 27 is, for example, an example of the configuration of the straight section 150 that constitutes the ring curved section 50A when the arc radius is 1000 mm, and the number of straight sections 150 and the number of ring holes 51a are not limited to the numbers shown.

[0136] In the ring-shaped curved section 50A shown in Figure 27, the multiple straight sections 150 consist of two end straight sections 152 located at both ends of the ring-shaped curved section 50A, and multiple main straight sections 151 positioned between the two end straight sections 152. In the ring-shaped curved section 50A shown in Figure 27, the multiple main straight sections 151 are four main straight sections 151. Therefore, the ring-shaped curved section 50A shown in Figure 27 is composed of two end straight sections 152 and four main straight sections 151.

[0137] The reinforcing ring 50 has multiple ring holes 51a formed therein, which are used to connect with multiple structures 201. As shown in Figure 27, of the multiple ring holes 51a, there is one ring hole 51a formed in each of the two end straight sections 152. Also, of the multiple ring holes 51a, there are two ring holes 51a formed in each of the four main straight sections 151. In addition, in the ring curved section 50A shown in Figure 27, the end straight sections 152 and the main straight sections 151 are formed such that the length L2 of the end straight section is shorter than the length L1 of the main straight section.

[0138] As shown in Figure 27, both ends of the main straight section 151 in the first direction X are formed to be inclined with respect to the first direction X and the third direction Y in a plan view. As shown in Figure 27, at least one end of the end straight section 152 in the first direction X is formed to be inclined with respect to the first direction X and the third direction Y in a plan view. Because the ends of the main straight section 151 and the end straight section 152 are formed to be inclined in a plan view, the multiple connecting straight sections 150 constitute a pseudo-arc-shaped ring curve section 50A.

[0139] Note that the number of straight sections 150 shown in Figures 22 to 27 is just an example and is not limited to the illustrated example. Also, the number of ring holes 51a and connecting holes 13a shown in Figures 22 to 27 is just an example and is not limited to the illustrated example.

[0140] [Effects of earth retaining structure 200] The earth retaining structure 200 is a cylindrical earth retaining structure constructed in an excavated hole 301 formed by excavating the ground 300. The earth retaining structure 200 comprises multiple cylindrical structures 201 that are stacked in multiple layers along the axis of the hole. The earth retaining structure 200 also comprises one or more reinforcing rings 50, which are H-shaped steels placed between vertically adjacent structures 201, and which reinforce the strength of the multiple structures 201.

[0141] The multiple structures 201 are constructed by arranging multiple earth retaining panels 100 that constitute the wall surface of the multiple structures 201 in a ring shape, and have curved sections 211 that form a curved shape when viewed in the direction of the hole axis.

[0142] The reinforcing ring 50 has a curved ring portion 50A formed in a curved shape that follows the curved portion 211 in the portion facing the curved portion 211 in the direction of the hole axis. The curved ring portion 50A is composed of a plurality of straight portions 150 arranged in a line along the curved portion 211, and each of the plurality of straight portions 150 is formed in a straight line when viewed in the direction of the hole axis.

[0143] As described above, the ring-shaped curved section 50A is composed of a plurality of straight sections 150 arranged in a line along the curved section 211, and each of the plurality of straight sections 150 is formed in a straight line when viewed in the direction of the hole axis. Constructing the ring-shaped curved section 50A of the earth retaining structure 200 is easy as it only requires connecting a plurality of straight sections 150 cut to a specific length to each other by welding or other means.

[0144] For example, a reinforcing ring composed of curved arc-shaped steel sections on both the inner and outer circumferences requires processing of the steel sections using various devices, such as large bending machines or processing using high-frequency induction heating devices, which results in high manufacturing costs. In contrast, the construction of the ring curved section 50A is easy to manufacture, requiring only the connection of multiple straight sections 150 cut to a specific length by welding or other means, and thus reducing manufacturing costs compared to processing the steel sections using bending machines or high-frequency induction heating devices. Therefore, in an earth retaining structure 200 having a reinforcing ring 50, manufacturing costs can be reduced even if the earth retaining structure 200 has a curved section.

[0145] Furthermore, the curved section 211 constitutes the side wall of the corner portion where a virtual extension 100c of a straight retaining panel 100 intersects with a virtual extension 100c of another straight retaining panel 100 in a plurality of retaining panels 100 arranged in a ring.

[0146] The retaining wall structure 200 has curved sections 211 of multiple structural elements 201 and a ring-shaped curved section 50A of a reinforcing ring 50 at the corner where a virtual extension 100c of a straight retaining wall panel 100 intersects with a virtual extension 100c of another straight retaining wall panel 100. The curved sections 211 and the ring-shaped curved section 50A are formed in a curved shape in plan view. With this configuration, the retaining wall structure 200 can reduce the bending moment generated at the intersection where two straight sections intersect at the corner where a virtual extension 100c of a straight retaining wall panel 100 intersects with another straight retaining wall panel 100. Therefore, the retaining wall structure 200 can reduce manufacturing costs and reduce the bending moment generated at the intersection where two straight sections intersect.

[0147] Furthermore, in the earth retaining structure 200, the ends of multiple earth retaining panels 100 in the direction of the hole axis are arranged in the space surrounded by the web 51 and a pair of flange portions 52. The multiple earth retaining panels 100 are fixed to the web 51. With this configuration, the earth retaining structure 200 can ensure strength compared to the case where there is no reinforcing ring 50, and the bending moment generated at the intersection where linear portions intersect can be reduced.

[0148] Furthermore, the ring-shaped curved section 50A is formed in an arc shape when viewed in the direction of the hole axis. The multiple straight sections 150 have two end straight sections 152 located at both ends of the ring-shaped curved section 50A, and multiple main straight sections 151 positioned between the two end straight sections 152. The two end straight sections 152 and the multiple main straight sections 151 are formed such that the length L2 of the end straight sections is shorter than the length L1 of the main straight sections. With this configuration, the retaining structure 200 can be easily manufactured by forming the ring-shaped curved section 50A in an arc shape by connecting multiple straight sections 150 cut to a specific length to each other by welding or other means. In addition, with this configuration, the retaining structure 200 can reduce the bending moment generated at the intersections where the straight sections intersect.

[0149] Furthermore, the multiple main straight sections 151 consist of nine main straight sections 151, and the ring curved section 50A consists of two end straight sections 152 and nine main straight sections 151. In addition, the multiple straight sections 150 consist of the number shown in Figures 22 to 27, depending on the size of the arc radius of the ring curved section 50A. According to the inventor's verification, by configuring the ring curved section 50A in this configuration, the retaining structure 200 can align the ring hole 51a of the reinforcing ring 50 with the connecting hole 13a of the retaining panel 100 that constitutes the curved section 211. Therefore, by configuring the ring curved section 50A in this configuration, the retaining structure 200 can stack the reinforcing ring 50 and the multiple retaining panels 100 in the direction of the hole axis. By configuring the ring curved section 50A of the earth retaining structure 200 in this manner, misalignment of the stacking of the reinforcing ring 50 and the multiple earth retaining panels 100 in the hole axis direction can be suppressed, thereby ensuring the overall strength of the structure.

[0150] Furthermore, the reinforcing ring 50 has multiple ring holes 51a formed therein, which are used for connecting with multiple structures 201. Of the multiple ring holes 51a, each of the two end straight sections 152 has one ring hole 51a. Also, of the multiple ring holes 51a, each of the nine main straight sections 151 has two ring holes 51a. In addition, the number of ring holes 51a in the multiple straight sections 150 is determined by the size of the arc radius of the ring curve section 50A, as shown in Figures 22 to 27.

[0151] According to the inventor's verification, by configuring the ring curved section 50A of the earth retaining structure 200 in this manner, the ring hole 51a of the reinforcing ring 50 and the connecting hole 13a of the earth retaining panel 100 that constitute the curved section 211 can be aligned. Therefore, by configuring the ring curved section 50A of the earth retaining structure 200 in this manner, the reinforcing ring 50 and multiple earth retaining panels 100 can be stacked in the direction of the hole axis.

[0152] By configuring the ring curved section 50A of the earth retaining structure 200 in this manner, the ring hole 51a can be formed in the central part of the reinforcing ring 50 in the third radial direction Y. Therefore, by configuring the ring curved section 50A of the earth retaining structure 200 in this manner, the structural balance of the structure is improved. With this configuration, the earth retaining structure 200 can suppress misalignment in the stacking direction of the reinforcing ring 50 and the multiple earth retaining panels 100 in the hole axis direction, thereby ensuring the overall strength of the structure.

[0153] Furthermore, the multiple main straight sections 151 consist of four main straight sections 151, and the ring curved section 50A consists of two end straight sections 152 and four main straight sections 151. According to the inventor's verification, by configuring the ring curved section 50A of the earth retaining structure 200 in this configuration, the ring hole 51a of the reinforcing ring 50 and the connecting hole 13a of the earth retaining panel 100 that constitutes the curved section 211 can be aligned. Therefore, by configuring the ring curved section 50A of the earth retaining structure 200 in this configuration, the reinforcing ring 50 and the multiple earth retaining panels 100 can be stacked in the direction of the hole axis. With this configuration, the earth retaining structure 200 has fewer connection points between the main straight sections 151 compared to, for example, the case where there are nine main straight sections 151 as shown in Figure 16, making it easier to manufacture.

[0154] Furthermore, the reinforcing ring 50 has multiple ring holes 51a formed therein, which are used for connecting with multiple structures 201. Of the multiple ring holes 51a, there are two ring holes 51a formed in each of the two end straight sections 152. Also, of the multiple ring holes 51a, there are four ring holes 51a formed in each of the four main straight sections 151.

[0155] According to the inventor's verification, by configuring the ring curved section 50A of the earth retaining structure 200 in this manner, the ring hole 51a of the reinforcing ring 50 and the connecting hole 13a of the earth retaining panel 100 that constitute the curved section 211 can be aligned. Therefore, by configuring the ring curved section 50A of the earth retaining structure 200 in this manner, the reinforcing ring 50 and multiple earth retaining panels 100 can be stacked in the direction of the hole axis.

[0156] Furthermore, each of the multiple earth retaining panels 100 has a pair of connecting plates 20, which are flat plate-shaped members spaced apart from each other in a first direction X, and a main body portion 10 provided between the connecting plates 20 of the pair, with a cross-sectional shape perpendicular to the first direction X formed in a corrugated shape. By having this configuration, the earth retaining structure 200, which has earth retaining panels 100 made of so-called corrugated steel plates, can reduce the bending moment generated at the intersection where straight portions intersect, and can also suppress manufacturing costs.

[0157] Embodiment 2. Figure 28 is a schematic plan view showing an example of a curved section 211 of the earth retaining structure 200 according to Embodiment 2. Figure 29 is a plan view showing an example of an earth retaining panel 100 constituting the curved section 211 of the earth retaining structure 200 according to Embodiment 2. Figure 30 is a plan view showing the connected state of the earth retaining panels 100 constituting the curved section 211 of the earth retaining structure 200 according to Embodiment 2.

[0158] Components having the same function and operation as the earth retaining structure 200 according to Embodiment 1 are denoted by the same reference numerals and their descriptions are omitted. Hereinafter, the configuration of Embodiment 2 will be described using Figures 28 to 30, focusing on the differences from Embodiment 1. Components not described in Embodiment 2 are the same as those in Embodiment 1. The earth retaining structure 200 according to Embodiment 2 further specifies the configuration of the earth retaining panel 100 in the curved section 211 of the structure 201.

[0159] Of the multiple retaining panels 100, the multiple retaining panels 100 that constitute the curved section 211 of the multiple structures 201 are made up of multiple straight panels 170. The curved section 211 is made up of multiple straight panels 170 arranged in a line along the circumferential direction of the multiple structures 201. Each of the multiple straight panels 170 is formed in a straight line when viewed in the direction of the hole axis. The straight panels 170 are formed in a straight line in a plan view, such as the first retaining panel 101 described above, and are not formed in a curved line in a plan view, such as the second retaining panel 102 (see Figures 4-5).

[0160] Of the multiple earth retaining panels 100, the multiple earth retaining panels 100 that constitute the curved portion 211 of the multiple structures 201 are configured as follows. That is, the straight panel 170 is configured as follows. As shown in Figures 29 and 30, in the straight panel 170, at least one of the pair of connecting plates 20 is provided so as to be inclined with respect to the first direction X when viewed in the second direction Z. More specifically, as shown in Figures 29 and 30, at least one of the connecting plates 20 in the first direction X of the straight panel 170 is formed so as to be inclined with respect to the first direction X and the third direction Y in a plan view.

[0161] The curved section 211 is formed by arranging multiple straight panels 170, which are straight in a plan view, in a continuous manner along the circumferential direction of the structure 201. In other words, the curved section 211 is formed by arranging multiple straight panels 170, which are straight in a plan view, in a continuous manner along the circumferential direction of the structure 201.

[0162] The curved section 211 is arranged such that the axial direction of each of the multiple straight panels 170 aligns with the curved section 211. In other words, the curved section 211 is arranged such that the longitudinal direction of each of the multiple straight panels 170 aligns with the curved section 211.

[0163] Multiple straight panels 170 are connected to each other to form a curved or arc-shaped curved section 211. More precisely, multiple straight panels 170 are connected to each other to form a pseudo-curved or pseudo-arc-shaped curved section 211.

[0164] Multiple straight panels 170 are arranged along a first direction X, which is the circumferential direction of the earth retaining structure 200 and the structural body 201. In the multiple straight panels 170 arranged along the circumferential direction of the earth retaining structure 200 and the structural body 201, adjacent straight panels 170 on the left and right are connected by butting connecting plates 20 together and fastening the shafts of bolts inserted through joint connection holes 21 (see Figure 4) with nuts.

[0165] The means for connecting the connecting plates 20 of adjacent straight panels 170 on the left and right are not limited to bolts and nuts; for example, connectors such as clips may be used. Furthermore, multiple straight panels 170 arranged along the circumferential direction of the earth retaining structure 200 and the structure 201 may be fixed to each other by welding.

[0166] Figure 31 is a schematic elevation view showing an example of the configuration of the earth retaining structure 200 according to Embodiment 2. Note that Figure 31 is a schematic representation for the purpose of explaining the earth retaining structure 200, and does not precisely show the shape and position of each member, and may differ from Figure 28, etc.

[0167] As shown in Figure 31, in the earth retaining structure 200 according to Embodiment 2, in the multiple structures 201, the straight panels 170 formed of the same shape are arranged at the same position in the circumferential direction of the multiple structures 201. That is, in the earth retaining structure 200 according to Embodiment 2, in the multiple structures 201, the straight panels 170 formed of the same shape are arranged so as to be connected in the direction of the hole axis.

[0168] Furthermore, in the earth retaining structure 200, if a staggered arrangement of earth retaining panels 100 is not adopted, and in order to ensure the strength of the joint portion against bending due to earth pressure, for example, the plate thickness of the axial joint could be increased, or the connecting bolts could be changed to stronger ones.

[0169] Figure 32 is a plan view showing an example of a reinforcing ring 50 of an earth retaining structure 200 according to Embodiment 2. Figure 33 is a plan view showing another example of a reinforcing ring 50 of an earth retaining structure 200 according to Embodiment 2. Figure 33 shows the straight section 150 at the end portion of the ring curved section 50A, while Figure 32 shows the straight section 150 located between the straight sections 150 located at both ends in the circumferential direction of the ring curved section 50A.

[0170] As shown in Figure 32, the reinforcing ring 50 may be constructed as a single component 155 by pre-fixing multiple straight sections 150 by welding or the like. In Figure 32, the component 155 of the reinforcing ring 50 is composed of four straight sections 150, but the number of straight sections 150 that make up the component 155 is not limited to four.

[0171] As with component 155, the combination of straight sections 150 of a certain width in the circumferential direction may be formed, for example, by cutting an H-shaped steel beam of a certain length to a specific length to form the straight sections 150, then connecting the straight sections 150 to each other by welding or the like, and then shaping them by press working or the like.

[0172] As shown in Figures 28 and 31, adjacent components 155 of the earth retaining structure 200 may be fixed and connected by joint plates 60, or they may be fixed and connected by other means such as welding. Alternatively, adjacent components 155 of the earth retaining structure 200 and the straight section 150 may be fixed and connected by joint plates 60, or they may be fixed and connected by other means such as welding, as shown in Figures 28 and 31.

[0173] Note that the number of straight panels 170 and straight sections 150 shown in Figures 16 to 21 is just an example and is not limited to the illustrated example. Also, the number of ring holes 51a and connecting holes 13a shown in Figures 16 to 21 is just an example and is not limited to the illustrated example.

[0174] [Effects of earth retaining structure 200] The curved section 211 of the earth retaining structure 200 according to Embodiment 2 is composed of a plurality of straight panels 170 arranged in a line along the circumferential direction of a plurality of structures 201. Each of the plurality of straight panels 170 is formed in a straight line when viewed in the direction of the hole axis. With this configuration, the earth retaining structure 200 can form the corners in a curved shape, thereby reducing the bending moment generated at the corners. Furthermore, with this configuration, the earth retaining structure 200 does not require the manufacture of earth retaining panels 100 that are curved in plan view, making processing easier and reducing manufacturing costs compared to the case where earth retaining panels 100 that are curved in plan view are used.

[0175] Furthermore, in the earth retaining structure 200 according to Embodiment 2, in the multiple structural elements 201, the straight panels 170 formed of the same shape are arranged at the same position in the circumferential direction of the multiple structural elements 201. That is, in the earth retaining structure 200 according to Embodiment 2, in the multiple structural elements 201, the straight panels 170 formed of the same shape are arranged so as to be connected in the direction of the hole axis.

[0176] Figure 34 is a schematic plan view showing an example of the configuration of a retaining wall structure 200L related to a comparative example. Figure 34 shows the retaining wall panel 100L as viewed in the direction of the hole axis. In Figure 34, the retaining wall panel 100L shown by the dashed line indicates a panel that is positioned adjacent to or below the retaining wall panel 100L shown by the solid line. The retaining wall structure 200L in Figure 34 shows a case where the retaining wall panels 100L are arranged in a staggered pattern. That is, in the retaining wall structure 200L in Figure 34, the retaining wall panel 100L located above and the retaining wall panel 100L located below are offset in the circumferential direction.

[0177] As shown in Figure 34, when the retaining panels 100L are arranged in a staggered pattern in the retaining structure 200L, the positions of the connecting holes 13a of the vertically arranged retaining panels 100L become misaligned, making it impossible to connect the vertically arranged retaining panels 100L to each other. Therefore, it is difficult to manufacture a retaining structure like the one shown in Figure 34 because the vertically arranged retaining panels 100L cannot be connected to each other.

[0178] In the retaining wall structure 200 according to Embodiment 2, as shown in Figure 31, in the multiple structures 201, the straight panels 170 formed of the same shape are arranged at the same position in the circumferential direction of the multiple structures 201. Therefore, in the retaining wall structure 200 according to Embodiment 2, the positions of the connecting holes 13a of the vertically arranged retaining wall panels 100 can be aligned, and the vertically arranged retaining wall panels 100 can be connected to each other in the depth direction.

[0179] Furthermore, in the earth retaining structure 200 according to Embodiment 2, as shown in Figure 31, in the multiple structures 201, among the multiple straight panels 170, the straight panels 170 formed of the same shape are arranged so as to be connected in the direction of the hole axis. Therefore, in the earth retaining structure 200 according to Embodiment 2, the positions of the connecting holes 13a of the earth retaining panels 100 arranged vertically can be aligned, and the earth retaining panels 100 arranged vertically can be connected to each other in the depth direction.

[0180] Furthermore, in the earth retaining structure 200 according to Embodiment 2, the pair of connecting plates 20 of the earth retaining panels 100 that constitute the curved portion 211 of the multiple structural elements 201 are configured as follows: Of the pair of connecting plates 20, at least one of the connecting plates 20 is provided so as to be inclined with respect to the first direction X when viewed in the second direction Z.

[0181] In the retaining wall structure 200, the connecting plates 20 of the multiple retaining wall panels 100 that make up the curved section 211 are formed at an inclination in plan view, so that the multiple connecting retaining wall panels 100 can form a pseudo-arc-shaped curved section 211. Furthermore, because the connecting plates 20 are inclined, the retaining wall structure 200 can form joints between the retaining wall panels 100 so that they are connected in the direction of the hole axis, and vertical joints can be formed at the same position in the circumferential direction.

[0182] The retaining wall structure 200 can have vertical joints formed at the same position in the circumferential direction, thereby aligning the positions of the connecting holes 13a and the ring holes 51a. The retaining wall structure 200 according to Embodiment 2 can align the positions of the connecting holes 13a of the retaining wall panels 100 arranged vertically, and the retaining wall panels 100 arranged vertically can be connected to each other.

[0183] The configurations shown in the above embodiments are examples only, and can be combined with other known technologies. Furthermore, parts of the configuration can be omitted or modified without departing from the spirit of the invention. Each of the above embodiments 1 and 2 can be implemented in combination with each other.

[0184] The earth retaining structure 200 described above may also include combinations of the features shown in the following appendices 1 to 10. These combinations are shown below. [Note 1] A cylindrical earth retaining structure constructed in an excavated hole formed by excavating the ground, Multiple cylindrical structures are constructed by stacking them in multiple layers along the axis of the hole, Among the plurality of structures, an H-shaped steel beam is placed between adjacent structures vertically, and comprises one or more reinforcing rings that reinforce the strength of the plurality of structures. Equipped with, The aforementioned plurality of structures are The plurality of earth retaining panels that constitute the wall surface of the plurality of structures are arranged in a ring, and when viewed in the direction of the hole axis, they have curved portions that constitute a curved shape. The one or more reinforcing rings mentioned above are In the axial direction of the hole, the portion facing the curved portion has a ring-shaped curved portion that is formed in a curved shape along the curved portion, The aforementioned ring-shaped curved portion is It is composed of a plurality of straight sections arranged in a line along the aforementioned curved section, Each of the aforementioned multiple straight sections is A retaining structure formed in a straight line when viewed in the direction of the hole axis. [Note 2] The aforementioned curved section is The retaining wall structure described in Appendix 1, wherein, in a plurality of retaining walls arranged in a ring, the side wall of the corner portion where the virtual extension portion of a straight retaining wall panel intersects with the virtual extension portion of another straight retaining wall panel. [Note 3] The one or more reinforcing rings mentioned above are The web is a plate-like part, When viewed in the axial direction of the hole, a pair of plate-shaped flange portions are provided at both ends of the web in the thickness direction of the plurality of earth retaining panels, It has, The ends of the plurality of earth retaining panels in the direction of the hole axis are arranged in the space enclosed by the web and the pair of flange portions. The aforementioned multiple earth retaining panels are A retaining structure as described in Appendix 1 or 2, fixed to the aforementioned web. [Note 4] The aforementioned ring-shaped curved portion is When viewed in the axial direction of the hole, it is formed in an arc shape. The aforementioned multiple straight sections are, The two straight end portions located at both ends of the ring-shaped curved portion, A plurality of main straight sections are arranged between the two end straight sections, It has, When viewed in the direction of the hole axis, the length of each of the two end straight sections in the circumferential direction of the plurality of structures is defined as the length of the longest portion of each of the two end straight sections. When viewed in the direction of the hole axis, the length of each of the multiple main straight sections in the circumferential direction of the multiple structures, with the length of the longest part of each of the multiple main straight sections defined as the main straight section length, The two end straight sections and the plurality of main straight sections are, A retaining structure according to any one of the appendices 1 to 3, wherein the length of the end straight section is formed to be shorter than the length of the main straight section. [Note 5] When, among the plurality of earth retaining panels, the plurality of earth retaining panels that constitute the curved portion of the plurality of structures are made into a plurality of straight panels, The aforementioned curved section is It is composed of a plurality of straight panels arranged in a line along the circumferential direction of the plurality of structures, Each of the aforementioned plurality of linear panels is A retaining structure described in any one of the appendices 1 to 4, which is formed in a straight line when viewed in the direction of the hole axis. [Note 6] In the aforementioned plurality of structures, Among the plurality of straight panels, the straight panels formed in the same shape are earth-retaining structures as described in Appendix 5, which are arranged at the same position in the circumferential direction of the plurality of structures. [Note 7] In the aforementioned plurality of structures, The earth retaining structure described in Appendix 5 or 6, wherein the straight panels, among the plurality of straight panels, are formed to be continuous in the direction of the hole axis. [Note 8] Each of the aforementioned multiple earth retaining panels is A flat plate-shaped member, comprising a pair of connecting plates spaced apart from each other in a first direction, A main body portion is provided between the pair of connecting plates, and has a cross-sectional shape perpendicular to the first direction that is formed in a corrugated shape, A retaining structure described in any one of the appendices 1 to 4, which has the following characteristics. [Note 9] Each of the aforementioned multiple earth retaining panels is A flat plate-shaped member, comprising a pair of connecting plates spaced apart from each other in a first direction, A main body portion is provided between the pair of connecting plates, and has a cross-sectional shape perpendicular to the first direction that is formed in a corrugated shape, A retaining structure described in any one of the appendices 5 to 8, which has the following characteristics. [Note 10] Among the plurality of earth retaining panels, the pair of connecting plates that constitute the plurality of earth retaining panels in the portion that constitutes the curved part of the plurality of structures, Of the pair of connecting plates, at least one of the connecting plates is The earth retaining structure described in Appendix 9 is provided so as to be inclined with respect to the first direction when viewed in a second direction perpendicular to the first direction. [Explanation of Symbols]

[0185] 10 Main body, 13 Side flange, 13a Connecting hole, 15 Intermediate wall, 16 Inner surface, 17 Outer surface, 19 Opening, 20 Connecting plate, 21 Joint connecting hole, 50 Reinforcement ring, 50A Ring curved section, 51 Web, 51a Ring hole, 52 Flange section, 52a Flange hole, 52b Second flange section, 52c First flange section, 55 Partial component, 56 Connecting member, 56a Bolt, 56b Nut, 57 Second connecting member, 57a Second bolt, 57b Second nut, 60 Joint plate, 60a Joint hole, 100 Retaining wall panel, 100L Retaining wall panel, 100c Extension section, 101 First retaining wall panel, 102 Second retaining wall panel, 150 Straight section, 150a End section, 151 Main straight section, 152 End straight section, 153 Second straight section, 155 Components, 170 Straight panel, 200 Retaining structure, 200L Retaining structure, 201 Structure, 211 Curved section, 250 Corner section, 300 Ground, 301 Excavation hole, 303 Wall surface.

Claims

1. A cylindrical earth retaining structure constructed in an excavated hole formed by excavating the ground, Multiple cylindrical structures are constructed by stacking them in multiple layers along the axis of the hole, Among the plurality of structures, an H-shaped steel beam is placed between adjacent structures vertically, and comprises one or more reinforcing rings that reinforce the strength of the plurality of structures. Equipped with, The aforementioned plurality of structures are The plurality of earth retaining panels that constitute the wall surface of the plurality of structures are arranged in a ring, and when viewed in the direction of the hole axis, they have curved portions that constitute a curved shape. The one or more reinforcing rings mentioned above are In the axial direction of the hole, the portion facing the curved portion has a ring-shaped curved portion that is formed in a curved shape along the curved portion, The aforementioned ring-shaped curved portion is It is composed of a plurality of straight sections arranged in a line along the aforementioned curved section, Each of the aforementioned multiple straight sections is A retaining structure formed in a straight line when viewed in the direction of the hole axis.

2. The aforementioned curved section is The retaining wall structure according to claim 1, wherein, in the plurality of retaining walls arranged in a ring, the side wall of the corner portion where the virtual extension portion of a straight retaining wall panel intersects with the virtual extension portion of another straight retaining wall panel.

3. The one or more reinforcing rings mentioned above are The web is a plate-like part, When viewed in the axial direction of the hole, a pair of plate-shaped flange portions are provided at both ends of the web in the thickness direction of the plurality of earth retaining panels, It has, The ends of the plurality of earth retaining panels in the direction of the hole axis are arranged in the space enclosed by the web and the pair of flange portions. The aforementioned multiple earth retaining panels are The earth retaining structure according to claim 1 or 2, which is fixed to the aforementioned web.

4. The aforementioned ring-shaped curved portion is When viewed in the axial direction of the hole, it is formed in an arc shape. The aforementioned multiple straight sections are, The two straight end portions located at both ends of the aforementioned ring-shaped curved portion, A plurality of main straight sections are arranged between the two end straight sections, It has, When viewed in the direction of the hole axis, the length of each of the two end straight sections in the circumferential direction of the plurality of structures is defined as the length of the longest portion of each of the two end straight sections. When viewed in the direction of the hole axis, the length of each of the multiple main straight sections in the circumferential direction of the multiple structures, with the length of the longest part of each of the multiple main straight sections defined as the main straight section length, The two end straight sections and the plurality of main straight sections are, The earth retaining structure according to claim 1 or 2, wherein the length of the end straight section is formed to be shorter than the length of the main straight section.

5. When, among the plurality of earth retaining panels, the plurality of earth retaining panels that constitute the curved portion of the plurality of structures are made into a plurality of straight panels, The aforementioned curved section is It is composed of a plurality of straight panels arranged in a line along the circumferential direction of the plurality of structures, Each of the aforementioned plurality of linear panels is The earth retaining structure according to claim 1 or 2, which is formed in a straight line when viewed in the direction of the hole axis.

6. In the aforementioned plurality of structures, The earth retaining structure according to claim 5, wherein the straight panels formed of the same shape are arranged at the same position in the circumferential direction of the plurality of structures.

7. In the aforementioned plurality of structures, The earth retaining structure according to claim 5, wherein, among the plurality of straight panels, the straight panels formed in the same shape are formed to be connected in the direction of the hole axis.

8. Each of the aforementioned multiple earth retaining panels is A flat plate-shaped member, comprising a pair of connecting plates spaced apart from each other in a first direction, A main body portion is provided between the pair of connecting plates, and has a cross-sectional shape perpendicular to the first direction that is formed in a wave shape, A retaining structure according to claim 1 or 2, having the following features.

9. Each of the aforementioned multiple earth retaining panels is A flat plate-shaped member, comprising a pair of connecting plates spaced apart from each other in a first direction, A main body portion is provided between the pair of connecting plates, and has a cross-sectional shape perpendicular to the first direction that is formed in a wave shape, The earth retaining structure according to claim 5, having the following features.

10. Among the plurality of earth retaining panels, the pair of connecting plates that constitute the plurality of earth retaining panels in the portion that constitutes the curved part of the plurality of structures, Of the pair of connecting plates, at least one of the connecting plates is The earth retaining structure according to claim 9, which is provided so as to be inclined with respect to the first direction when viewed in a second direction perpendicular to the first direction.

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