Earth retaining materials and structures

Abstract

To provide an earth retaining member and an earth retaining structure capable of securing strength of a connection part in the circumferential direction.SOLUTION: An earth retaining member has a body whose cross-sectional shape perpendicular to the first direction is worked in a wave shape and plate-like vertical flange parts set at both ends of the first direction of the body. The vertical flange parts are connected with each other by bolts to form an earth retaining structure. The body has lateral flange parts which are formed at both ends in the width direction of the main body perpendicular to the first direction and are formed with connection holes penetrating through a face perpendicular to the width direction. In a cross section perpendicular to the first direction, a section modulus Z1 of the body when a neutral axis of the cross section of the body is parallel to the width direction, and in a cross section perpendicular to the width direction of the main body, a section modulus Z2 when the neutral axis of the cross section of the vertical flange is parallel to the thickness direction of the body are defined. When a factor based on a bearing area ratio of the bolts fastened to the vertical flange part is assumed as K, and a factor determined according to the number of set bolts set to the vertical flange part is assumed as α, the section modulus Z2 satisfies a relation of 2Z2×K×α>Z1 ... (1).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a structure of an earth retaining member that constitutes an earth retaining structure constructed on the ground. [Background technology]

[0002] Traditionally, civil engineering structures such as shafts for constructing the foundations of structures, underground collection wells, and retaining walls on slopes have been constructed by connecting retaining members to form walls in a ring or horseshoe shape (U-shape or C-shape).

[0003] This type of earth retaining structure has the advantage that each of the earth retaining members is lightweight and can be easily constructed by hand, even in mountainous areas where large heavy machinery cannot be used. For example, when constructing a vertical shaft, workers can enter the shaft and connect the earth retaining members.

[0004] For example, the earth retaining structure disclosed in Patent Document 1 is constructed by combining multiple earth retaining members to form a ring-shaped body, and then connecting multiple such rings in the central axial direction of the ring-shaped body. The multiple earth retaining members are arranged in a staggered pattern to ensure the strength of the entire earth retaining structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-193741 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, for example, earth retaining structures using earth retaining members such as liner plates are sometimes used when forming small foundations, handholes or manholes in railways because the earth retaining members are easy to handle. In this case, the earth retaining structure is formed from a single-stage annular body formed by connecting multiple earth retaining members. An earth retaining structure formed by connecting multiple earth retaining members only in the circumferential direction is a structure in which the earth retaining members are simply connected to each other with connecting members such as bolts, and when a load is applied from the outside due to earth pressure, etc., there is a problem that deformation occurs at the vertical flanges at the ends of each earth retaining member because there are no members above or below the annular body to support the load.

[0007] The earth retaining structure disclosed in Patent Document 1 is constructed by connecting a plurality of annular bodies in the central axis direction of the annular bodies. The vertical flanges arranged at the circumferential ends of the earth retaining members constituting the annular bodies are shifted in the circumferential direction so that the vertical flanges of the liner plates are not aligned in the central axis direction of the annular bodies. However, depending on the size of the shaft in which the earth retaining structure is arranged, due to the circumferential length dimension of the earth retaining members constituting the annular bodies, the vertical flanges may be aligned in the central axis direction of the earth retaining structure or may be arranged close to each other even if they are not aligned in the central axis direction, and there is a problem that the strength of the earth retaining structure is partially reduced in such areas.

[0008] The present invention is devised to solve the above-mentioned problems, and provides an earth-retaining member and an earth-retaining structure that can ensure the strength of the connecting parts that connect the circumferential direction of the earth-retaining structure. [Means for solving the problem]

[0009] The earth retaining member according to the present invention is a plurality of earth retaining members connected in a first direction to form an earth retaining unit, the earth retaining member comprising a main body having a corrugated cross section perpendicular to the first direction, and flat plate-shaped vertical flange portions installed at both ends of the main body in the first direction, and the vertical flange portions are connected to each other with bolts to form an earth retaining structure, the main body comprises horizontal flange portions formed at both ends in the width direction of the main body perpendicular to the first direction, and each horizontal flange portion has a connecting hole penetrating a surface perpendicular to the width direction, and the section modulus Z of the main body when the neutral axis of the cross section of the main body is parallel to the width direction in a cross section perpendicular to the first direction is 1 and a section modulus Z when the neutral axis of the cross section of the vertical flange portion is parallel to the thickness direction of the body in a cross section perpendicular to the width direction of the body. 2 When the coefficient based on the bearing area ratio of the bolts fastened to the vertical flange portion is K and the coefficient determined according to the number of bolts installed on the vertical flange portion is α, The section modulus Z 2 teeth, 2Z 2 ×K×α>Z 1 ... (1) Satisfy the relationship.

[0010] In addition, the retaining structure of the present invention includes the retaining unit formed by connecting the vertical flange portions of the retaining members with the bolts. Effect of the Invention

[0011] According to the present invention, by setting the thickness of the vertical flange of the earth retaining member according to the section modulus of the cross-sectional shape of the main body, the strength of the axial connection part when bolted can be ensured to be the same as that of the main body. Therefore, the earth retaining structure formed using the earth retaining member can suppress partial reduction in strength due to the arrangement of the earth retaining member, and the degree of freedom in installation is improved. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an oblique view of an earth retaining structure 100 according to embodiment 1. [Diagram 2]1 is a cross-sectional view of an earth retaining member 10 according to a first embodiment. [Diagram 3] 1 is a cross-sectional view of an earth retaining member 10 according to a first embodiment. [Figure 4] FIG. 4 is a perspective view of the retaining member 10 of FIG. 3. [Diagram 5] 2 is a perspective view of a corner member 30 of the earth retaining structure 100 according to embodiment 1. FIG. [Figure 6] 2 is a perspective view of a corner member 30 of the earth retaining structure 100 according to embodiment 1. FIG. [Figure 7] 3 is a layout diagram of welds 36 of a reinforcing member 32 of a corner member 30 according to the first embodiment. FIG. [Figure 8] 4 is a schematic diagram illustrating a test for evaluating the strength of the axial connection portion 11 of the earth retaining structure 100 according to embodiment 1. FIG. [Figure 9] 1 is a schematic diagram of a test for evaluating the strength of the earth-retaining member 10 of the earth-retaining structure 100 of embodiment 1. FIG. [Figure 10] FIG. 10 is a graph showing the relationship between the load F and the deformation of the test specimen shown in FIGS. 8 and 9. [Figure 11] 10 is an explanatory diagram of a modified example of the arrangement of the reinforcing member 32 of the corner member 30 and the welded portions 36 of the reinforcing member 32 according to the first embodiment. FIG. [Figure 12] 10 is an explanatory diagram of a modified example of the arrangement of the reinforcing member 32 of the corner member 30 and the welded portions 36 of the reinforcing member 32 according to the first embodiment. FIG. [Figure 13] 1 is an oblique view of an earth retaining structure 200 according to a second embodiment. FIG. [Figure 14] 13 is a front view of a modified example of the corner member 230 of the earth retaining structure 200 according to embodiment 2. FIG. [Figure 15] A bottom view of the retaining structure 200 of embodiment 2. [Figure 16] 4 is a cross-sectional view of a modified example of the corner member 30 according to the first embodiment. FIG. [Figure 17] 1 is an example of an earth retaining structure 100 according to embodiment 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an earth retaining structure 100 according to an embodiment will be described with reference to the drawings. In the following drawings including FIG. 1, the relative dimensional relationship and shape of each component may differ from the actual ones. In addition, in the following drawings, the same reference numerals are used to denote the same or equivalent objects, and this applies throughout the entire specification. In addition, to facilitate understanding, terms indicating directions (e.g., up, down, left, right, front, rear, front and back, etc.) are used as appropriate, but these notations are for the convenience of explanation and do not limit the arrangement, direction or orientation of devices, instruments, parts, etc.

[0014] Embodiment 1 [Earth retaining structure 100] FIG. 1 is a perspective view of an earth retaining structure 100 according to the first embodiment. The earth retaining structure 100 is, for example, a civil engineering structure such as a vertical shaft for constructing the foundation of a structure or a drainage well constructed underground, and is constructed inside a vertical hole formed by excavating the ground 92. The earth retaining structure 100 shown in FIG. 1 is, for example, a structure for forming a relatively small foundation in the ground 92, and is composed of a single-stage earth retaining unit 50 formed by connecting a plurality of earth retaining members 10 in a rectangular shape with corner members 30 in a plan view. In the following description, the outside of the earth retaining structure 100 is called the ground 92, and the inside is called the space portion 93. In the first embodiment, the earth retaining structure 100 is rectangular from the viewpoint of the direction perpendicular to the ground 92, i.e., the z direction, but is not limited to a rectangle. The earth retaining structure 100 may be formed, for example, in a circular, oval, elliptical, rectangular, or oval ring shape in a plan view. The retaining structure 100 can also be formed into a semi-annular shape such as an arc shape, a horseshoe shape, or a U-shape in plan view. When the retaining unit 50 is a semi-annular shape, the central axis C of the retaining unit 50 passes through the center of gravity of the retaining unit 50 in plan view and is an axis extending perpendicularly to the ground 92 on which the retaining unit 50 is installed. The x and y directions shown in the figure are directions along the surface of the ground 92 on which the retaining structure 100 is installed, and the z direction is the depth direction of the shaft and the height direction of the retaining structure. In the first embodiment, the retaining structure 100 is formed by one layer of the retaining unit 50, but the retaining unit 50 may be formed by stacking and connecting them in the height direction.

[0015] The retaining unit 50 shown in FIG. 1 is installed along the excavation wall surface 95 (see FIG. 3) of a vertical shaft formed by excavating the ground 92 in a substantially rectangular shape when a relatively small foundation such as a foundation supporting a station platform is to be installed. In this case, in the case of a small foundation, the depth of the vertical shaft is relatively shallow, and only one layer of the retaining members 10 can be arranged in the z direction. Therefore, the retaining unit 50 is formed by connecting multiple retaining members 10 in the circumferential direction using connecting members 40 such as bolts and nuts. In addition, since each side of the rectangular retaining structure 100 in FIG. 1 is short, two retaining members 10 are arranged on each side, and the multiple retaining members 10 are connected by corner members 30. Note that the retaining unit 50 is not limited to one having two retaining members 10 arranged on each side, and may have one retaining member 10 arranged on each side, two or more retaining members 10 on each side, or may be composed of only corner members 30.

[0016] The corner members 30 are configured so that the retaining members 10 can be connected to both ends, and connect two retaining members 10 arranged in intersecting directions. Here, the direction in which the multiple retaining members 10 are connected in the retaining unit 50, which is an annular body, is referred to as the first direction. The first direction is the circumferential direction around the central axis C of the retaining unit 50, and in the case of the retaining unit 50 in Figure 1, it is the direction along each side of the rectangle.

[0017] The earth-retaining unit 50 has axial connecting portions 11 that connect the earth-retaining members 10 and the corner members 30. The axial connecting portions 11 also connect the earth-retaining members 10 to each other.

[0018] [Earth retaining material 10] 2 and 3 are cross-sectional views of the retaining member 10 according to the first embodiment. FIG. 2 and FIG. 3 show a cross section perpendicular to the first direction, which is the circumferential direction of the retaining unit 50, and show an example of a cross section (xz cross section or yz cross section) along the central axis of the retaining unit 50 of the retaining structure 100 shown in FIG. 1. The main body 14 of the retaining member 10 shown in FIG. 2 has a sine curve-shaped waveform in a cross section perpendicular to the first direction. The main body 14 of the retaining member 10 shown in FIG. 3 has a rectangular wave shape with rounded corners in the cross section, and parallel surfaces are formed on the outside and inside of the retaining structure 100. The retaining structure 100 shown in FIG. 1 is composed of the retaining member 10 and the corner member 30 having the cross-sectional shape of the main body 14 shown in FIG. 3 as an example, but the cross-sectional shape of the main body 14 can be changed to another wave shape.

[0019] The retaining members 10 shown in Figures 2 and 3 have different cross-sectional shapes and different corrugated shapes of the main body 14, but each has a horizontal flange portion 13 formed at both ends in the z direction, allowing other retaining members 10 to be connected in the z direction. The horizontal flange portion 13 has a connecting hole 13a to which a connecting member 40 is applied. A plurality of connecting holes 13a are formed in the horizontal flange portion 13, and are arranged at equal intervals in the first direction. In addition, a corrugated portion is formed between the two horizontal flange portions 13. The connecting hole 13a provided in the horizontal flange portion 13 and penetrating in the z direction is sometimes called a second connecting hole 13a.

[0020] 2 is corrugated in the shape of a sine curve, and is capable of resisting loads due to earth pressure from the ground 92. Because the body 14 is corrugated, it has greater strength and rigidity against loads acting in the thickness direction of the earth retaining member 10 than if it were formed with a simple flat cross-sectional shape.

[0021] The trapezoidally corrugated body 14 of the retaining member 10 shown in FIG. 3 includes a protruding portion 16 protruding inward of the retaining unit 50, and outer wall portions 17 and 18 protruding outward of the retaining unit 50 in the cross section of FIG. 3. The outer wall portion 18 connecting the protruding portion 16 and the horizontal flange portion 13 is referred to as the first outer wall portion 18, and the outer wall portion 17 connecting two adjacent protruding portions 16 is referred to as the second outer wall portion 17. In the cross-sectional shape of the body 14 of the retaining member 10 according to the first embodiment, a plurality of protruding portions 16 are provided, but only one may be provided. For example, two protruding portions 16 are provided in FIG. 3, but only one may be provided in the center in the z direction.

[0022] The convex portion 16 has an inner wall portion 16a having a surface perpendicular to the surface of the horizontal flange portion 13 in cross section. The inner wall portion 16a and the outer wall portions 17 and 18 are formed substantially parallel to each other. The inner wall portion 16a and the outer wall portions 17 and 18 are connected by a web portion 15. The web portion 15 has a surface extending in the y (x) direction in the cross section of FIG. 3 and is slightly inclined with respect to the y (x) direction. The inclination direction of the web portion 15 is such that, when the main body 14 is viewed from the central axis C of the retaining unit 50, the open end of the valley portion of the corrugated shape is wide and the valley bottom is narrow. By being configured in this way, the main body 14 is easy to release from the mold when performing plastic processing for corrugation, making it easy to manufacture.

[0023] In addition, the web portion 15 is formed at an angle close to parallel to the y(x) axis in FIG. 3, so that the width in the z direction of the inner wall portion 16a and the outer wall portions 17 and 18 is wider. As a result, the retaining member 10 has a higher rigidity when a bending moment is applied in the thickness direction. For example, the retaining member 10 shown in FIG. 3 has a larger dimension in the y(x) direction than the retaining member 10 shown in FIG. 2, and has a higher rigidity against a load applied in the y(x) direction. When the retaining member 10 of the retaining structure 100 in FIG. 1 is loaded in the surface direction of the main body 14, that is, in the y(x) direction, a bending moment is applied to the retaining member 10 in the y(x) direction. At this time, the section modulus of the retaining member 10 with respect to the neutral axis N of bending is larger when the width of the inner wall portion 16a, the outer wall portions 17 and 18 farther from the neutral axis N is wider. Therefore, by configuring the web portion 15 at an angle close to parallel to the y (x) axis, the width dimension in the z direction of the inner wall portion 16a and the outer wall portions 17 and 18 becomes wider, and the strength and rigidity against bending load in the y (x) direction of the earth retaining member 10 increases. Specifically, the web portion 15 is set at an angle of 0° to 20°, and more preferably 0° to 3°, with respect to the direction perpendicular to the inner wall portion 16a or the outer wall portions 17 and 18.

[0024] 3, the inner wall portion 16a and the outer wall portions 17 and 18 are formed with the same plate thickness as the web portion 15, but the plate thickness may be made thicker than that of the web portion 15. By configuring in this manner, the cross-sectional areas of the inner wall portion 16a and the outer wall portions 17 and 18 farther from the neutral axis N become larger, and the section modulus of the earth retaining member 10 can be further increased.

[0025] 2 and 3, both ends in the z direction of the earth retaining member 10 are formed with horizontal flanges 13. The horizontal flanges 13 are formed perpendicular to the z direction, and have connecting holes 13a in their flat portions. The horizontal flanges 13 are parallel to the x and y directions, and have surfaces to which the connecting members 40 can be attached.

[0026] FIG. 4 is a perspective view of the retaining member 10 of FIG. 3. The retaining member 10 has vertical flanges 19 at both ends in the first direction, which is the circumferential direction of the retaining unit 50. The vertical flanges 19 are plate-shaped members and are joined to the end faces of the main body 14 in the first direction by welding. The length of the vertical flanges 19 in the z direction is substantially the same as the length of the main body 14 in the width direction, i.e., the z direction. The vertical flanges 19 have connecting holes 19a penetrating the plate surface. The connecting holes 19a provided in the vertical flanges 19 penetrating the first direction (x (y) direction) may be referred to as first connecting holes 19a. As shown in FIG. 1, the connecting holes 19a are holes for passing connecting members 40 such as bolts and nuts when connecting the retaining member 10 to another retaining member 10 or a corner member 30 in the circumferential direction of the retaining unit 50.

[0027] The connecting holes 19a are provided in accordance with the wave shape of the main body 14, and specifically, are arranged side by side in the y (x) direction of each of the outer wall portions 17 and 18 of the main body 14. Moreover, the connecting holes 19a are arranged further inward of the earth-retaining unit 50 than the outer wall portions 17 and 18. This configuration enables a worker to perform the connecting work of the earth-retaining members 10 from the inside of the shaft in which the earth-retaining structure 100 is installed.

[0028] The structure of the vertical flange portion 19 is the same even if the cross-sectional shape of the main body 14 is a sine curve shape as shown in Fig. 2. That is, in the case of an earth-retaining member 10 having the cross-sectional shape shown in Fig. 2, the connecting holes 19a are arranged at positions corresponding to the outer wall portions 17b and 18, which are valleys when the earth-retaining member 10 is viewed from the inside of the earth-retaining unit 50. In the case of an earth-retaining member 10 having the cross-sectional shape shown in Fig. 2, four connecting holes 19a are arranged in the vertical flange portion 19. Also, in the case of an earth-retaining member 10 having the cross-sectional shape shown in Fig. 3, three connecting holes 19a are arranged in the vertical flange portion 19.

[0029] [Corner member 30] 5 and 6 are perspective views of the corner member 30 of the earth-retaining structure 100 according to the first embodiment. The corner member 30 includes an angle member 31 that is L-shaped when viewed from the z direction, a main body 14 having the same structure as the main body 14 of the earth-retaining member 10, and a vertical flange portion 19 joined to an end face of the main body 14 in the first direction (circumferential direction). The two main bodies 14 are joined to both ends of the angle member 31 and arranged in a direction perpendicular to each other. The corner member 30 is configured to connect the earth-retaining member 10 to the vertical flange portion 19, forming a corner of the earth-retaining structure 100. In the first embodiment, the corner member 30 connects two earth-retaining members 10 so that they are perpendicular to each other, but they may be connected at an angle other than a right angle.

[0030] The body 14 of the corner member 30 has the same shape as the body 14 of the retaining member 10 except for its length in the first direction, and may be formed into a sinusoidal waveform as shown in Fig. 2. The length of the body 14 can be changed as appropriate.

[0031] The angle member 31 is formed in an L-shape when viewed from the z direction, and has a shape in which the flat plate portions 33 are connected at right angles. The flat plate portions 33 are plate-shaped and extend in the z direction. One end face of the main body 14 is joined to the flat plate portions 33 by welding or the like. The reinforcing member 32 is joined to the tip portions 35 of the two flat plate portions 33 of the angle member 31. The reinforcing member 32 is a plate-shaped member and extends in the z direction as shown in Figs. 5 and 6. The reinforcing member 32 is disposed so as to connect the tip portions 35 of the angle members 31 to each other, thereby suppressing deformation of the tip portions 35 of the flat plate portions 33 in a direction opening from each other.

[0032] FIG. 7 is a layout diagram of the welded portion 36 of the reinforcing member 32 of the angle member 30 according to the first embodiment. The reinforcing member 32 is welded to the tip portions 35 of the two flat plate portions 33. The welded portion 36 includes a plurality of welded portions 36a, 36b, and 36c. The welded portion 36 of the reinforcing member 32 is divided into a plurality of portions and arranged, thereby reducing the manufacturing cost due to welding and suppressing deformation due to welding. In addition, the flat plate portion 33 of the angle member 31 is deformed so that the two flat plate portions 33 open when a load applied to the main body 14 joined to the flat plate portion 33 is transmitted. The welded portion 36 of the reinforcing member 32 may be provided at a location where the tip portions 35 of the two flat plate portions 33 are pulled and deformed so as to open. When the main body 14 receives a load from the ground 92, the outer wall portions 17 and 18 of the main body 14 are joined to the tip portion 35 of the flat plate portion 33 of the angle member 31, and therefore pull the tip portion 35 of the angle member 31, deforming the two tip portions 35 so as to open. Therefore, as shown in FIG. 7, the welded portion 36 is disposed at a position in the z direction corresponding to the outer wall portions 17 and 18 of the main body 14. Specifically, the welded portions 36a and 36c are disposed so that at least a part of them is parallel to the outer wall portion 18 in the circumferential direction of the earth retaining unit 50, i.e., in the first direction. Also, the welded portion 36b is disposed so that at least a part of them is parallel to the outer wall portion 17 in the circumferential direction of the earth retaining unit 50, which is an annular body, i.e., in the first direction.

[0033] In other words, weld 36a is positioned so as to at least partially overlap region a1 shown in Fig. 3 in the z direction. Desirably, weld 36a is positioned so as to overlap region aa1 in Fig. 3. Weld 36b is positioned so as to at least partially overlap region a2 shown in Fig. 3 in the z direction. Desirably, weld 36b is positioned so as to overlap region aa2 in Fig. 3. Weld 36c is positioned so as to at least partially overlap region a3 shown in Fig. 3 in the z direction. Desirably, weld 36c is positioned so as to overlap region aa3 in Fig. 3.

[0034] The welded portion 36a may be disposed so as to include the entire region a1 shown in FIG. 3, but if it is disposed so as to overlap at least a portion of the region a1, the load from the outer wall portion 18 can be transmitted to the reinforcing member 32 via the welded portion 36a. The welded portion 36b and the region a2, and the welded portion 36c and the region a3 are disposed in the same manner as the relationship between the welded portion 36a and the region a1. The welded portion 36 may overlap the region B, but the portion of the reinforcing member 32 corresponding to the region B may not be welded. The regions a1 to a4 and aa1 to aa4 shown in FIG. 2 and FIG. 3 may be collectively referred to as region A. At least a portion of the welded portion 36 in the z direction is disposed in the region A in the z direction, i.e., in the height direction (z direction) of the angle member 31. Region A is the range in which the portion of the corrugation of main body 14 that protrudes beyond the neutral line of the corrugation of the retaining member toward the side where the free end of the plate-shaped portion of the angle member is located is located in a height direction perpendicular to the first direction of each of the two retaining members.

[0035] [Vertical flange part 19] The vertical flange portion 19 of the retaining member 10 according to the first embodiment has a section modulus Z of the main body 14 when the neutral axis N of the cross section of the main body 14 is parallel to the width direction (z direction) in a cross section perpendicular to the first direction (x (y) direction) of the main body 14. 1 The thickness h is determined according to the above. The earth-retaining structure 100 is installed in a vertical shaft formed in the ground 92, and receives the earth pressure of the ground 92, so that a load is applied from the outside to the inside of the earth-retaining structure 100. At this time, the earth-retaining member 10 receives a load in the opposite direction, y (x) direction, as shown in Figures 2 and 3. The load is applied to the main body 14, and not only does it generate a bending moment in the main body 14 with the first direction (x (y) direction in Figures 2 and 3) as the longitudinal direction, but it may also deform so that the axial connecting portion 11 formed by connecting the vertical flange portions 19 of the two earth-retaining members 10 opens.

[0036] FIG. 8 is a schematic diagram for explaining a test for evaluating the strength of the axial coupling portion 11 of the earth-retaining structure 100 according to the first embodiment. FIG. 9 is a schematic diagram for explaining a test for evaluating the strength of the earth-retaining member 10 of the earth-retaining structure 100 according to the first embodiment. Since the earth-retaining structure 100 receives a load from the surrounding ground 92, the strength of the axial coupling portion 11 and the earth-retaining member 10 is evaluated by assuming that the load F from the y(x) direction shown in FIG. 8 and FIG. 9 is the load from the ground 92. When the thickness h of the vertical flange portion 19 is relatively thin, the strength of the axial coupling portion 11 is weaker than the strength of the main body 14. For this reason, the conventional earth-retaining structure 100 is designed so that the earth-retaining members 10 are arranged in a staggered manner, and the axial coupling portions 11 are arranged in a dispersed manner. On the other hand, in the earth-retaining structure 100 according to the first embodiment, the thickness h of the vertical flange portion 19 of the earth-retaining member 10 is set to the section modulus Z of the main body 14. 1 In order to set the strength of the axial connecting portion 11 in accordance with the load, the strength of the axial connecting portion 11 is made equal to the strength of the main body 14.

[0037] Specifically, as shown in FIG. 8, when the neutral axis n perpendicular to the thickness h of the vertical flange portion 19 is defined, the section modulus of the vertical flange portion 19 is Z 2 Let K be the bearing area ratio of the bolt, which is the connecting member 40, and α be the coefficient. 2Z 2 ×K×α>Z 1 ... (1) The thickness h of the vertical flange portion 19 is set so as to satisfy the relationship. The coefficient α is α=2J, where J is the number of bolts installed in the vertical flange portion 19. The bearing area ratio K of the connecting member 40 is the area ratio when the bearing area of ​​M16, which is the standard used in the earth retaining structure 100, is set to 1.

[0038] In FIG. 8, when the dimension of the vertical flange portion 19 in the y (x) direction is the width b and the dimension in the x (y) direction is the thickness h, the section modulus Z of the vertical flange portion 19 is 2 teeth, Z 2 =bh 2 / 6 ··· (2) It is expressed as:

[0039] In the test shown in Fig. 8, the test specimen 100A has the axial connector 11 disposed at the center, and supports S disposed at an interval LS. A load F is applied to two positions symmetrically with the axial connector 11 at the center. The load F is applied to two positions, separated by an interval LF. At this time, when the load F is increased, the axial connector 11 of the test specimen 100A deforms so as to open in the direction of the arrow p, and the test specimen 100A bends in the x (y) direction.

[0040] In the test shown in FIG. 9, the test specimen 100B has the center of the retaining member 10 in the first direction (x(y) direction) positioned at the center of the distance LS between the fulcrums S. A load F is then applied to positions symmetrically on either side of the center of the retaining member 10. The load F applied to the two points is positioned with a distance LF between them, similar to the evaluation of the axial connecting portion 11. At this time, if the load F is increased, the retaining member 10 of the test specimen 100B bends in the y(x) direction.

[0041] FIG. 10 is a diagram showing the relationship between the load F and the deformation of the specimens shown in FIG. 8 and FIG. 9. Case 1 shown in FIG. 10 shows the relationship between the load F and the deformation of the specimen 100B shown in FIG. 9. In case 1, the cross-sectional shape of the main body 14 of the specimen 100B is the shape shown in FIG. 3. The retaining member 10 with the cross-sectional shape shown in FIG. 3 is set to a plate thickness t=3.2 mm, a width W in the z direction=500 mm, and a thickness dimension H in the y (x) direction of 100 mm. A load F is applied to the specimen 100B set to the above dimensions, and the load at which it yields is the strength criterion P. The load F at the end point of the proportional part of the curve of case 1 in FIG. 10 is the yield point of the specimen 100B shown in FIG. 9, that is, the strength criterion P indicates the strength of the main body 14 of the retaining member 10 with the cross-sectional shape shown in FIG. 3. Therefore, if the strength of the axial connecting portion 11 is set to exceed the strength standard P in the test shown in Figure 9, the retaining structure 100 can ensure that each portion has a strength equal to or greater than that of the main body 14 of the retaining member 10, regardless of the arrangement of the axial connecting portion 11.

[0042] Case 2 shown in Fig. 10 is a specimen 100A in which the thickness of the vertical flanges 19 is set to h = 16 mm and the width to b = 100 mm, and the connecting member 40 is an M20 hexagonal bolt (JIS B 1180 Annex JA) that connects two vertical flanges 19. Note that the cross-sectional shape of the main body 14 of the specimen 100A in Case 2 is a rectangular wave shape as shown in Fig. 3, and the plate thickness t = 3.2 mm. At this time, the yield point of the specimen 100A exceeds the strength criterion P.

[0043] At this time, the section modulus Z of the vertical flange portion 19 2 From the above formula (2), it is 4267 [mm 3 ]. The section modulus Z of the main body 14 shown in FIG. 1 is 76460 [mm 3 The bearing area ratio K of the M20 hexagonal bolt to the M16 hexagonal bolt used as the connecting member 40 is 1.55, and the number of hexagonal bolts connecting the vertical flange portion 19 is three, so the coefficient α is 6 (see Table 1 below). Therefore, applying these to the above formula (1), we get 2Z 2 ×K×α=2×4267×1.55×6=79366 (rounded to the nearest whole number)>Z 1 = 76460, which satisfies the above equation (1).

[0044] In addition, when the thickness h of the vertical flange portion 19 of the test specimen 100A of Case 2 shown in FIG. 10 is changed to h = 19 mm, the section modulus Z of the vertical flange portion 19 is 2 From the above formula (2), it is 6017 [mm 3 ] (rounded off to the nearest whole number. This corresponds to test piece 4 in Table 1, which will be described later). The hexagonal bolt used as the connecting member 40 satisfies the relationship in the above formula (1) even for M18. The bearing area ratio K of the M18 hexagonal bolt to the M16 hexagonal bolt is 1.21. Therefore, applying these to the above formula (1), we get 2Z 2 ×K×α=2×6017×1.21×6=87367 (rounded to the nearest whole number)>Z 1 8 is performed using the test specimen 100A having such specifications, the yield point exceeds the strength criterion P.

[0045] The specimen 100A of Case 3 shown in FIG. 10 is a comparative example, in which the thickness h of the vertical flange portion 19 is set to h = 4 mm (corresponding to specimen 1 in Table 1 described later). In addition, the cross-sectional shape of the body 14 of the specimen 100A in Case 3 is a rectangular wave shape as shown in FIG. 3, and the plate thickness t = 3.2 mm. In this case, the section modulus Z of the vertical flange portion 19 is 2 From the above formula (2), it is 267 [mm 3 When an M16 hexagonal bolt is applied to the test piece 100A in Case 3, 2Z 2 ×K×α=2×267×1×6=3204 <Z 1 = 76460, which does not satisfy the above formula (1). The specimen 100A of Case 3 yields and deforms without exceeding the strength criterion P, as shown by the curve of Case 3 in Figure 10. Even if the bolt of the specimen 100A of Case 3 is changed to, for example, M20, the 2Z 2 ×K×α=4966 (rounded off to the nearest whole number) <Z 1 Therefore, the above formula (1) is not satisfied. Therefore, for example, when the earth-retaining structure 100 shown in Fig. 1 receives a load from the ground 92, the earth-retaining structure 100 deforms from the axial connecting parts 11, and therefore the axial connecting parts 11 must be reinforced. Furthermore, when the earth-retaining structure 100 is formed by connecting a plurality of earth-retaining units 50 in the axial direction, it is necessary to ensure that the axial connecting parts 11 of adjacent earth-retaining units 50 are not arranged in a straight line in the axial direction.

[0046] [Table 1]

[0047] The above Table 1 is a summary of the results of the test shown in Figure 8 conducted on specimens with different cross-sectional shapes of the main body, dimensions of the vertical flange portion, and specifications of the fastening bolts. The bottom row of Table 1 shows the experimental results when the test shown in Figure 8 was conducted on each specimen, and judges whether or not the yield point was exceeded when the test shown in Figure 9 was conducted on a specimen of main body 4 with the same cross-sectional shape. Test specimens that exceeded the yield point are indicated with an "O".

[0048] For example, the test specimen 2 shown in Table 1 is a test specimen 3 of Case 2 in FIG. 10, in which the bolts fastening the vertical flange portion 19 are changed. The vertical flange portion 19 of the test specimen 2 is fastened by an M16 bolt. When the test shown in FIG. 8 is performed using the test specimen 100A having such specifications, the yield point does not exceed the strength criterion P. In other words, the axial connecting portion 11 formed by the vertical flange portion 19 of the test specimen 2 has a lower strength than the main body 14 in the test shown in FIG. 9. Therefore, the retaining structure 100 having the axial connecting portion 11 corresponding to the test specimen 2 is easily deformed from the axial connecting portion 11 when subjected to a load such as earth pressure from the outside. Therefore, the retaining structure 100 needs to reinforce the axial connecting portion 11 or to arrange the retaining members 10 in a staggered manner.

[0049] On the other hand, as in the case of the retaining member 10 of the retaining structure 100 of embodiment 1, by setting the thickness h of the vertical flange portion 19 to satisfy the above formula (1), the axial connecting portion 11 can be ensured to have strength equal to or greater than that of the main body 14 of the retaining member 10.

[0050] The retaining member 10 of the retaining structure 100 according to the first embodiment is made of a general structural rolled steel plate having a thickness of 2.7 to 7.0 mm in the cross-sectional shape shown in Figures 2 and 3, and bolts of M16 to M24 are used as the connecting members 40. For example, in the retaining member 10 having the vertical flange portion 19 with a thickness h of 22 mm shown in Table 1 (specimen 5 in Table 1), even an M16 bolt can ensure strength of the axial connecting portion 11 equal to or greater than that of the main body 14.

[0051] Test results of specimens 6 and 7 in Table 1 are shown for the case where the cross-sectional shape of the earth-retaining member 10 of the earth-retaining structure 100 according to the first embodiment is as shown in FIG. 2. Specimen 6 in Table 1 is a specimen in which the cross-sectional shape of the earth-retaining member 10 is given a sine curve waveform as shown in FIG. 2, the thickness h of the vertical flange portion 19 is 3.2 mm, and the vertical flange portion 19 is fastened at four points with M16 bolts. That is, in specimen 6, M16 bolts are arranged in sections a1, a2, a3, and a4, respectively, to connect the vertical flange portions 19 together. Specimens 6 and 7 have a plate thickness t of 2.7 mm in the cross section of the main body 14.

[0052] In specimen 6, 2Z 2 ×K×α=1360<23000, which does not satisfy the relationship of formula (1) above. The result of the test shown in FIG. 8 using specimen 6 does not exceed the yield point when the test shown in FIG. 9 was performed using the earth-retaining member 10 with the cross-sectional shape shown in FIG. 3, and is therefore marked "X." For this reason, the earth-retaining structure 100 formed by the earth-retaining member 10 and axial connecting portion 11 of specimen 6 is prone to deformation from the axial connecting portion 11 when subjected to a load such as external earth pressure. On the other hand, in specimen 7, the thickness h of the vertical flange portion 19 was set to 12 mm and the bolts were M18, so that the 2Z 2 ×K×α=23232>23000, which satisfies the relationship of formula (1) above. The results of the test shown in Fig. 8 using specimen 7 exceed the yield point when the test shown in Fig. 9 was performed using earth-retaining member 10 having the cross-sectional shape shown in Fig. 3. Therefore, the earth-retaining structure 100 formed by the earth-retaining member 10 and axial connecting parts 11 of specimen 7 can ensure that the axial connecting parts 11 have a strength equivalent to that of the main body 14 of earth-retaining member 10 when subjected to a load such as external earth pressure.

[0053] As described above, the relationship of the above formula (1) is also established for the retaining member 10 having a different cross-sectional shape. The plate thickness t of the cross-sectional shape of the main body 14 is usually set in the range of 2.7 mm to 7.0 mm, but may be set to be greater than 7.0 mm. The cross-sectional shape of the main body 14 according to the first embodiment has a width W=500 mm in the z direction, and although there are four positions where bolts can be placed as shown in FIG. 2 and three positions where bolts can be placed as shown in FIG. 3, the number of positions where bolts can be placed may be, for example, two, depending on the waveform. The bolts connecting the vertical flange portions 19 are preferably installed at the portions where the waveform of the main body 14 of the retaining member 10 protrudes outward. In the first embodiment, the cross-sectional shape of the main body 14 can be set to, for example, W=750 mm or 1000 mm by changing the width W in the z direction. Even if the width W and plate thickness t are changed, by setting the dimensions of the vertical flange portion 19 so as to satisfy the above formula (1), the axial connecting portion 11 can be ensured to have a strength equivalent to that of the main body 14 of the retaining member 10.

[0054] In addition, in the retaining structure 100 according to the first embodiment, the corner member 30 also has a vertical flange portion 19, and is formed by connecting the vertical flange portion 19 of the retaining member 10 to the vertical flange portion 19. The axial connection portion 11 formed by connecting the corner member 30 of the retaining structure 100 according to the first embodiment and the retaining member 10 can also ensure strength so that the yield point exceeds the reference strength P, as with the test specimen 100A of case 2 shown in FIG. 10, by setting the dimensions of the vertical flange portion 19 so as to satisfy the relationship of the above formulas (1) and (2). Therefore, in the retaining structure 100, the axial connection portion 11 between the corner member 30 and the retaining member 10 can ensure strength equal to or greater than that of the main body 14 of the retaining member 10. Therefore, in the case of the retaining structure 100 shown in FIG. 1, the retaining unit 50 can ensure the required strength at any position.

[0055] FIG. 17 is an example of the retaining structure 100 according to the first embodiment. FIG. 17(a) shows a plan view, and FIG. 17(b) shows a central cross-sectional view. The retaining member 10 constituting the retaining structure 100 according to the first embodiment is configured so that the thickness of the vertical flange portion 19 satisfies the above formula (1), so that when a load such as earth pressure is applied from the outside of the retaining structure 100, the axial connecting portion 11 has a strength equivalent to that of the main body 14. Therefore, when the retaining units 50 are stacked in the axial direction, the retaining structure 100 has sufficient strength even if the axial connecting portions 11 are connected in the axial direction. The axial connecting portions 11 shown in FIG. 17(b) are all arranged to be connected in the axial direction, but this is one example, and the retaining structure 100 may have a portion where the axial connecting portions 11 are connected in the axial direction.

[0056] [Variations] Fig. 11 is an explanatory diagram of a modified example of the arrangement of the reinforcing member 32 and the welded portion 36 of the reinforcing member 32 of the corner member 30 according to the first embodiment. The corner member 30A according to the modified example is configured such that both ends in the z direction of the reinforcing member 32A of the corner member 30 shown in Fig. 7 are shorter than the length of the angle member 31 in the z direction. Although both ends of the reinforcing member 32A are shorter than the angle member 31, the range of the welded portion 36 in the z direction is such that at least a part of the welded portions 36a to 36c are positioned in the region A, so that the reinforcing member 32A has a strength substantially equivalent to that of the corner member 30 shown in Fig. 7. According to the corner member 30A in Fig. 11, the reinforcing member 32A can be made smaller, so that the weight can be reduced and the material used can also be reduced.

[0057] Fig. 12 is an explanatory diagram of a modified example of the arrangement of the reinforcing member 32 of the angle member 30 according to the first embodiment and the welded portion 36 of the reinforcing member 32. In the angle member 30B shown in Fig. 12, the reinforcing member 32 is divided into a plurality of reinforcing members 32a to 32c, and the welded portions 36a to 36c are arranged on each of them. The plate surfaces of the plurality of reinforcing members 32a to 32c face the connection portion of the flat plate portion 33 of the angle member 31. In other words, each of the reinforcing members 32a to 32c is arranged so that the plate surface is along the z direction. By being configured in this manner, the reinforcing members 32a to 32c can further reduce the amount of material used, can be made lighter, and can efficiently improve the strength of the angle member 30.

[0058] In the corner member 30B, the reinforcing members 32a-32c and the welded parts 36a-36c are arranged at three positions in the z direction, but the number of them to be arranged is not limited. For example, if the cross-sectional shape of the main body 14 is a sine curve as shown in FIG. 2 and there are four parts protruding from the neutral axis N to the y(x) side in the cross-sectional shape perpendicular to the first direction, the reinforcing members 32 or the welded parts 36 may be arranged at four positions in accordance with the regions a1-a4. Also, for example, if there are two parts protruding from the neutral axis N to the y(x) side in the cross-sectional shape of the main body 14, the reinforcing members 32 or the welded parts 36 may be arranged at two positions corresponding to the protruding parts. Note that the number of the reinforcing members 32 or the welded parts 36 does not need to match the number of parts protruding from the neutral axis N to the y(x) side in the cross-sectional shape of the main body 14, and it is sufficient to install only the number necessary to ensure strength in the region A.

[0059] The earth retaining structure 100 may be formed in a circular, oval, elliptical, rectangular, or oval ring shape in plan view, for example. The earth retaining structure 100 may also be formed in a semi-ring shape such as an arc shape, horseshoe shape, or U-shape in plan view. The earth retaining structure 100 described in the first embodiment has corners, but in the case of a shape without corners such as a circle, the earth retaining structure 10 is formed by connecting the earth retaining members 10 without using the corner members 30, and the strength of the axial connecting portion 11 can be ensured by setting the vertical flange portion 19 so as to satisfy the above formulas (1) and (2).

[0060] Fig. 16 is a cross-sectional view of a modified example of the corner member 30 according to the first embodiment. Fig. 16 shows a cross section perpendicular to the z-direction. In the first embodiment, the corner member 30 is formed by joining the main body 14 to two flat plate portions 33 of an L-shaped angle member 31, but in the corner member 30, the angle member 31 is replaced with a steel pipe 131 having a rectangular cross section. The corner member 30 is formed by joining the main body 14 to each of two adjacent faces of the steel pipe 131 having a rectangular cross section.

[0061] That is, the steel pipe 131 having a rectangular cross section has the main body 14 having a corrugated cross section welded to two adjacent flat plate portions 33, and a flat plate portion 134 is further joined to the tip portions 35 of the two flat plate portions 33 to form a tube shape. A reinforcing member 32 may be arranged on a diagonal line connecting the tip portions 35 inside the steel pipe 131. The reinforcing member 32 is fixed inside the steel pipe 131. By arranging the reinforcing member 32 on a diagonal line connecting the tip portions 35, deformation in the direction in which the tip portions 35 approach each other can be suppressed. In addition, the reinforcing member 32 can also suppress deformation in the direction in which the tip portions 35 move away from each other by being partially welded and fixed inside the steel pipe 131.

[0062] As a modification of the corner member 30, the interior 38 of the steel pipe 131 may be filled with a filler such as concrete instead of the reinforcing member 32. By filling the interior 38 of the steel pipe 131 with concrete, deformation of the steel pipe 131 can be suppressed, and the steel pipe 131 can be strengthened without the reinforcing member 32. Note that the steel pipe 131 has a rectangular cross-sectional shape and is therefore relatively strong even without the reinforcing member 32 and the filler, and therefore can be used as the corner member 30 without being reinforced.

[0063] 11, 12 and 16 can also be applied to the earth-retaining structure 100 shown in Fig. 17. In this case, if the vertical flange portion 19 that connects the corner member 30A and the earth-retaining member 10 is designed to satisfy the above formula (1), the strength of the axial connecting portion 11 can be ensured. Therefore, even if the axial connecting portions 11 are arranged continuously in the axial direction of the earth-retaining structure 100 as in the axial connecting portions 11 in Fig. 17, the strength of the earth-retaining structure 100 will not be reduced partially.

[0064] Embodiment 2 An explanation will be given of an earth retaining structure 200 according to the second embodiment. The earth retaining structure 200 is obtained by modifying the structure of the corner member 30 constituting the earth retaining structure 100 according to the first embodiment. Note that components having the same functions and actions as those in the first embodiment are given the same reference numerals and their explanation will be omitted.

[0065] 13 is a perspective view of an earth-retaining structure 200 according to embodiment 2. The earth-retaining structure 200 is configured in a rectangular shape, with one earth-retaining member 10 placed on each side and connected by corner members 230. As in embodiment 1, the dimensions of the vertical flange portions 19 of the earth-retaining members 10 are set so as to satisfy the relationship between the above formulas (1) and (2).

[0066] [Corner piece 230] The angle member 230 according to the second embodiment includes an angle member 231 that is L-shaped when viewed from the z direction. The angle member 231 is configured by connecting two flat plate portions 233, and the two flat plate portions 233 are arranged in a perpendicular positional relationship. The longitudinal direction of the flat plate portion 233 extends in the z direction. A connecting hole 239 is provided in the flat plate portion 233, and is configured to be able to connect the vertical flange portion 19 of the retaining member 10.

[0067] The angle member 230 includes a reinforcing member 232 disposed between two flat plate portions 233 of the angle member 231 and joined by welding. The reinforcing member 232 is a plate-like body whose shape is aligned with the inside of an L-shape in accordance with the cross-sectional shape of the angle member 231 and whose surface is oriented perpendicularly to the z-direction. The reinforcing member 232 has, for example, a triangular or substantially triangular shape in a plan view. The reinforcing member 232 counters loads in the directions in which the two flat plate portions 233 of the angle member 231 widen and narrow, and reinforces the angle member 231. In FIG. 13, the reinforcing members 232 are disposed between the connecting holes 239 and provided at two locations, but the installation locations can be changed as appropriate depending on the required strength.

[0068] 14 is a front view of a modified example of the angle member 230 of the retaining structure 200 according to embodiment 2. The reinforcing member 232 is provided at a position corresponding to the outer wall portions 17 and 18 of the main body 14, thereby being able to support the force transmitted from the outer wall portions 17 and 18, and the strength of the angle member 231 can be efficiently improved.

[0069] The reinforcing member 232 may be disposed in a range corresponding to any one of the regions a1, a2, and a3 shown in Fig. 3, and is preferably disposed in the range of the regions aa1, aa2, and aa3. That is, the reinforcing member 232 may be disposed in the region A. In this case, both the reinforcing member 232 and the flat plate portion 233 may be disposed in each of the regions A. Note that the reinforcing member 232 and the flat plate portion 233 do not need to be disposed in all of the multiple regions A, and are disposed according to the required strength.

[0070] FIG. 15 is a bottom view of the retaining structure 200 according to the second embodiment. In the retaining structure 200 according to the second embodiment, the corner member 230 is composed of the angle member 231, and the retaining member 10 and the corner member 230 are connected by the connecting member 40. Therefore, welding and processing can be reduced when manufacturing each member constituting the corner member 230. In addition, the vertical flange portion 19 of the retaining member 10 connected to the corner member 230 satisfies the relationship of the above formulas (1) and (2) as in the first embodiment. In addition, the corner member 230 has the angle member 231 reinforced by the reinforcing member 232, and strength and rigidity are ensured. Therefore, the axial connecting portion 11 formed by connecting the corner member 230 to the retaining structure 100 also has a strength equal to or greater than that of the main body 14 of the retaining member 10, as in the axial connecting portion 11 according to the first embodiment. Therefore, the retaining structure 200 can ensure sufficient strength of the axial connecting portion 11 with the retaining member 10 while reducing the amount of processing of each member constituting the corner member 230.

[0071] The retaining structure 200 according to the second embodiment has one retaining member 10 arranged on each side, but may have two or more retaining members 10 on each side. When multiple retaining members 10 are arranged on each side, the dimensions of the vertical flange portions 19 are determined so as to satisfy the above formulas (1) and (2), as with the axial connecting portions 11 described in the first embodiment, and the axial connecting portions 11 of adjacent retaining members 10 are ensured to have a strength equal to or greater than that of the main body 14 of the retaining members 10 against the load from the ground 92 side.

[0072] [Variations] The structure in which the reinforcing member 232 is welded to the angle member 31 of the second embodiment with the surface facing the height direction (z direction) may be applied to the angle member 30 of the first embodiment. In this case, the reinforcing members 232 are arranged in accordance with the corrugations of the main body 14, and may be arranged in, for example, a1 to a4 and aa1 to aa4 shown in FIG. 2 or FIG. 3. That is, the reinforcing members 232 are arranged in the region A. When the reinforcing member 232 of the second embodiment is applied to the angle member 30 of the first embodiment, the angle member 30 has the main body 14, so that the angle member 31 does not have a connecting hole 239 as in the angle member 230 of the second embodiment, and there is an advantage that the degree of freedom in the arrangement of the reinforcing member 232 is high.

[0073] 14, the reinforcing member 232 is joined by welding to the inside of the flat plate portion 33 of the angle member 31. The range of the welded portion 36 between the reinforcing member 232 and the flat plate portion 33 is located in a portion on the tip portion 35 side of the flat plate portion 33, but it may extend over the entire area where the reinforcing member 232 and the flat plate portion 33 are in contact. The reinforcing member 232 may have the welded portion 36 on both the top and bottom surfaces, or only on one surface.

[0074] The reinforcing member 232 may be, for example, a steel bar. In this case, the reinforcing member 232 is welded to connect the tip portion 35 of the flat plate portion 33. The reinforcing member 332 is also disposed in the region A, thereby efficiently strengthening the angle member 31 of the corner member 330. Furthermore, since the provision of the reinforcing member 32 can suppress deformation of the flat plate portion 33, the strength of the axial connecting portion 11 formed by the flat plate portion 33 and the vertical flange portion 19 of the earth retaining member 10 can be ensured in the same manner as described in the first embodiment.

[0075] In the earth-retaining structure 200 according to the second embodiment, the earth-retaining units 50 can also be stacked and connected in the axial direction of the earth-retaining structure 200. In the case of the earth-retaining structure 200 shown in FIG. 13, when the earth-retaining units 50 are stacked in the axial direction, the axial connecting parts 11 between the corner members 230 and the earth-retaining members 10 are inevitably arranged continuously in the axial direction. However, because the vertical flange parts 19 of the earth-retaining members 10 satisfy the above formula (1), the axial connecting parts 11 of the earth-retaining structure 200 according to the second embodiment can ensure a strength equal to or greater than that of the main body 14. As a result, the earth-retaining structure 200 does not require any special reinforcement of the axial connecting parts 11.

[0076] The configurations shown in the above embodiments are merely examples, and the embodiments and their modified examples can be combined together. For example, the same earth retaining structure may include earth retaining members 10 having vertical flange portions 19 with different thicknesses h, or may include corner members 30 with different structures. The above embodiments can also be combined with other known techniques, and part of the configuration can be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0077] 1 case, 2 case, 3 case, 10 retaining member, 11 axial connection portion, 13 horizontal flange portion, 13a (second) connection hole, 13b tip portion, 14 main body, 15 web portion, 16 convex portion, 16a inner wall portion, 16b apex, 17 (second) outer wall portion, 17b outer wall portion, 18 (first) outer wall portion, 19 vertical flange portion, 19a (first) connection hole, 30 corner member, 30A corner member, 30B corner member, 31 angle member, 32 reinforcing member, 32A reinforcing member, 32a reinforcing member, 32b reinforcing member, 32c reinforcing member, 33 flat plate portion, 34 flat plate portion, 35 tip portion, 36 welded portion, 36a welded portion, 36b welded portion, 36c welded portion, 37 upper end, 38 Interior, 40 connecting member, 43 clamping section, 50 earth retaining unit, 92 ground, 93 space, 95 excavation wall, 100 earth retaining structure, 100A test specimen, 100B test specimen, 131 steel pipe, 134 flat plate section, 200 earth retaining structure, 230 corner member, 231 angle member, 232 reinforcing member, 233 flat plate section, 235 tip section, 239 connecting hole, 330 corner member, 332 reinforcing member, A area, C central axis, H thickness dimension, K bearing area ratio, N neutral axis, P reference strength, S support, Z 1 Section Modulus, Z 2 Section modulus, h thickness, n neutral axis, p arrow, t plate thickness.

Claims

1. A plurality of earth retaining members are connected in a first direction to form an earth retaining unit, A main body having a corrugated cross-sectional shape perpendicular to the first direction; and a flat vertical flange portion provided on both ends of the main body in the first direction, A retaining member that forms an earth retaining structure by connecting the vertical flange portions with bolts, The body includes: A horizontal flange portion is formed on each of both ends in a width direction of the main body perpendicular to the first direction, and a connecting hole is formed through the horizontal flange portion in a plane perpendicular to the width direction, In a cross section perpendicular to the first direction, the section modulus Z of the body when the neutral axis of the cross section of the body is parallel to the width direction １ and a section modulus Z when the neutral axis of the cross section of the vertical flange portion is parallel to the thickness direction of the body in a cross section perpendicular to the width direction of the body. ２ When a coefficient based on a bearing area ratio of the bolts fastened to the vertical flange portion is K and a coefficient determined according to the number of bolts installed on the vertical flange portion is α, The section modulus Z ２ teeth, 2Z ２ ×K×α>Z １ ・・・ (1) An earth retaining member that satisfies the above relationship.

2. The body includes: A corrugated portion is provided between the two horizontal flange portions, the corrugated portion being formed by corrugating a plate, The wave processing unit is A convex portion formed protruding toward the inside of the retaining unit; The retaining member according to claim 1 , further comprising: a first outer wall portion connecting the convex portion and the lateral flange portion.

3. The body includes: A corrugated portion is provided between the two horizontal flange portions, the corrugated portion being formed by corrugating a plate, The wave processing unit is The retaining member according to claim 1 , having a sine curve-shaped waveform in a cross section perpendicular to the first direction.

4. An earth retaining structure comprising an earth retaining unit formed by connecting the vertical flange portions of the earth retaining members described in any one of claims 1 to 3 with the bolts.

5. The retaining unit includes: Including a plurality of earth retaining units; The plurality of earth retaining units include The retaining structure according to claim 4 , which is formed by connecting the horizontal flange portions of the retaining members to each other.

6. Each of the plurality of earth retaining units is The vertical flange portion is connected to an axial connecting portion by the bolt, Among the plurality of earth retaining units, two earth retaining units arranged adjacent to each other are The retaining structure according to claim 5 , wherein the axial connecting portions are arranged side by side in the width direction of the main body of the retaining member.

7. The bolts connecting the vertical flange portions are Hexagonal bolts of M16 or larger. The coefficient K is The retaining structure according to any one of claims 4 to 6, wherein K is defined as A2 / A1, where A1 is the bearing area of ​​an M16 hexagonal bolt and A2 is the bearing area of ​​the bolt.

8. The coefficient α is The retaining structure according to any one of claims 4 to 7, wherein α is defined as 2J when the number of bolts connecting the two vertical flange portions is J.

Images