Coupling metal fitting and method for coupling earth retaining members

Abstract

The present invention provides a coupling metal fitting for mutually coupling flanges of adjacent earth retaining members in which a plurality of coupling holes are formed in the flanges, the coupling metal fitting comprising a coupling metal fitting body portion, an insertion portion to be inserted into a coupling hole formed in a flange, and a clamping portion to clamp an edge of a flange together with the coupling metal fitting body portion. The insertion portion is formed so as to be inclined by a prescribed angle to the direction of extension of the coupling metal fitting body portion so that the lateral edge of a step portion joining the coupling metal fitting body portion and the insertion portion abuts the opening edge of a coupling hole when the coupled adjacent flanges are displaced relative to each other in the radial direction of a drilled hole, and such that the angle between the insertion portion and the step portion is an acute angle. A leading end portion of the insertion portion contacts a flange when the insertion portion is attached to said flange and flanges are coupled to each other.

Description

Connecting fittings and method for connecting earth retaining members

[0001] The present disclosure relates to a connecting fitting for connecting earth retaining members having flanges to each other and a method for connecting earth retaining members.

[0002] A conventional connecting fitting is known in which a plurality of earth-retaining members, each having a flange with a connecting hole formed therein, are arranged along the inner wall surface of an excavation hole and the flanges of adjacent earth-retaining members are butted together to connect them (see, for example, Patent Document 1). This connecting fitting includes a plate-shaped connecting fitting main body and an insertion portion formed by bending one end edge of the connecting fitting main body toward one side of the connecting fitting main body in an L-shape and inserted into the connecting hole formed in the flange. This connecting fitting also includes a clamping portion formed by bending the other end edge of the connecting fitting main body toward one side of the connecting fitting main body in a U-shape and clamping the edges of the butted flanges together with the connecting fitting main body. The connecting fitting also includes insertion portions formed between the connecting fitting main body and the clamping portion for inserting the edges of two flanges.

[0003] The insertion portion of the connecting fitting disclosed in Patent Document 1 is inclined at a predetermined angle relative to the extension direction of the connecting fitting body so that the side edge of the step connecting the connecting fitting body and the insertion portion abuts against the opening edge of the connecting hole when adjacent connected flanges are displaced relative to each other in the radial direction of the borehole. The connecting fitting has an insertion portion inserted into the connecting holes of two overlapping flanges, the overlapping flanges are inserted into the insertion portion, and the edges of the two flanges are clamped between the connecting fitting body and the clamping portion, thereby fastening and connecting the two flanges. However, multiple earth-retaining members arranged along the inner wall surface of the borehole are subjected to radial earth pressure from the ground toward the borehole, which can cause relative radial displacement of adjacent earth-retaining members above and below the borehole. The connecting fitting disclosed in Patent Document 1 resists this relative displacement using the insertion portion and the step.

[0004] Japanese Patent Application Laid-Open No. 2023-124175

[0005] When the connecting fitting of Patent Document 1 fastens two flanges, the connecting fitting has a height allowance in the step portion relative to the flanges, so the insertion portion and the flanges do not come into contact. When the connecting fitting of Patent Document 1 fastens two flanges, the portion that fastens and connects the two flanges is the insertion portion, and only the portion between the connecting fitting main body and the clamping portion that sandwich the two overlapping flanges. It is desired that the connecting fitting of Patent Document 1 further improve the fastening strength of the two overlapping flanges and increase the bearing strength of the structure.

[0006] The present disclosure aims to solve the above-mentioned problems and to provide a method for connecting a connecting fitting and an earth retaining member that can further improve the fastening strength of two stacked flanges and increase the strength of the structure.

[0007] The connecting fitting according to the present disclosure is a plurality of earth retaining members arranged along the inner wall surface of an excavation hole, and is a connecting fitting that connects the flanges of adjacent earth retaining members together in a butt-together state when the flanges of the adjacent earth retaining members have flanges with multiple connecting holes formed therein. The connecting fitting comprises a plate-shaped connecting fitting main body, an insertion portion formed by bending one end edge of the connecting fitting main body toward one side of the connecting fitting main body in an L-shape and inserted into at least one connecting hole formed in the flange, and an insertion portion formed by bending the other end edge of the connecting fitting main body toward one side of the connecting fitting main body in a U-shape. and a clamping portion that clamps the end edges of the butted flanges together with the connecting fixture main body portion, and the insertion portion is formed at a predetermined angle with respect to the extension direction of the connecting fixture main body portion so that when the connected adjacent flanges are displaced relative to each other in the radial direction of the drilling hole, the side edge of the step portion connecting the connecting fixture main body portion and the insertion portion abuts against the opening edge of the connecting hole, and is formed so that the angle between the insertion portion and the step portion is an acute angle, and when attached to the flanges and connecting the flanges together, the tip of the insertion portion abuts against the flanges.

[0008] The method of connecting earth retaining members disclosed herein comprises connecting fittings of the above-described configuration, earth retaining members arranged in plurality along the inner wall surface of an excavation hole, the earth retaining members having flanges with multiple connecting holes formed therein, and bolts and nuts for fastening the flanges of adjacent earth retaining members together while the flanges of the adjacent earth retaining members are butted together, and bolts and nuts are attached to at least two of the multiple connecting holes in the flanges, and connecting fittings are attached to connecting holes other than the connecting holes to which the bolts and nuts are attached, thereby fastening the flanges of adjacent earth retaining members together.

[0009] The connecting fitting and method for connecting earth-retaining members according to the present disclosure are configured so that the angle between the insertion portion and the step portion is an acute angle, and the tip of the insertion portion abuts the flange when attached to the flange to connect the flanges. The connecting fitting contacts the overlapping flanges at two points: the clamping portion and the connecting fitting main body, and the tip of the insertion portion, thereby holding down the two overlapping flanges. Therefore, the connecting fitting can improve the fastening strength of the two flanges compared to a configuration in which the tip of the insertion portion does not contact the flanges and the two overlapping flanges are fastened only by the clamping portion and the connecting fitting main body. Furthermore, the connecting fitting fastens the two flanges using the entire connecting fitting, thereby improving the strength of the structure compared to a configuration in which the tip of the insertion portion does not contact the flanges and the two overlapping flanges are fastened only by the clamping portion and the connecting fitting main body.

[0010] 10 is a perspective view schematically showing an example of an earth-retaining structure according to embodiment 1. FIG. 11 is a perspective view showing an example of an earth-retaining member constituting the earth-retaining structure according to embodiment 1. FIG. 12 is a longitudinal cross-sectional view of the earth-retaining member shown in FIG. 2. FIG. 13 is an explanatory diagram showing a state in which adjacent earth-retaining members are connected by a connecting fitting. FIG. 14 is a perspective view showing a different form of an earth-retaining member constituting the earth-retaining structure according to embodiment 1. FIG. 15 is a longitudinal cross-sectional view of the earth-retaining member shown in FIG. 5. FIG. 16 is a perspective view showing a connecting fitting according to embodiment 1. FIG. 17 is a plan view showing a connecting fitting according to embodiment 1. FIG. 18 is a bottom view showing a connecting fitting according to embodiment 1. FIG. 19 is an explanatory diagram schematically showing a state in which horizontal flanges of earth-retaining members are connected with ..., and earth pressure is acting on the earth-retaining members. FIG. 10 is a side view of the connecting fitting as seen from the direction of arrow AL in FIG. 8. FIG. 11 is a side view of another aspect of the connecting fitting as seen from the direction of arrow AL in FIG. 8. FIG. 12 is a conceptual diagram showing the relationship between the protrusion and the horizontal flange in the vicinity of the connecting hole when the connecting fitting according to embodiment 1 is attached to the horizontal flange. 1 is a conceptual diagram showing another relationship between the protrusion and the horizontal flange near the connecting hole when the connecting fitting of embodiment 1 is attached to the horizontal flange. FIG. 2 is a side view of the step portion and insertion portion of the connecting fitting of embodiment 1. FIG. 3 is an explanatory diagram showing the procedure for connecting the horizontal flanges of the earth-retaining member with the connecting fitting of embodiment 1. FIG. 4 is an explanatory diagram showing a modified example of the connecting fitting of embodiment 1. FIG. 5 is a perspective view of the connecting fitting of embodiment 2. FIG. 6 is a perspective view of the modified example 1 of the connecting fitting of embodiment 2. FIG. 7 is a perspective view of the modified example 2 of the connecting fitting of embodiment 2. FIG. 8 is a conceptual diagram showing a method of connecting earth-retaining members using the connecting fitting of embodiment 3. FIG. 9 is another conceptual diagram showing a method of connecting earth-retaining members using the connecting fitting of embodiment 3.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that in the following drawings, including FIG. 1, the relative dimensional relationships and shapes of the components may differ from those in reality. In addition, in the following drawings, components with the same reference numerals are the same or equivalent, 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.

[0012] Embodiment 1. Figure 1 is a perspective view that schematically shows an example of an earth-retaining structure 300 according to Embodiment 1. Figure 2 is a perspective view that shows an example of an earth-retaining member 200 that constitutes the earth-retaining structure 300 according to Embodiment 1. Figure 3 is a vertical cross-sectional view of the earth-retaining member 200 shown in Figure 2. Figure 4 is an explanatory diagram that shows a state in which adjacent earth-retaining members 200 are connected by a connecting fitting 100.

[0013] 1 to 4, the connecting fitting 100 according to the first embodiment is used to connect a plurality of soil-retaining members 200 arranged along the inner wall surface of an excavation hole. The connecting fitting 100 connects adjacent soil-retaining members 200, each having a vertical flange 202 with a plurality of connecting holes 202a formed therein, by butting the vertical flanges 202 of the adjacent soil-retaining members 200 together. The connecting fitting 100 also connects adjacent soil-retaining members 200, each having a horizontal flange 203 with a plurality of connecting holes 203a formed therein, by butting the horizontal flanges 203 of the adjacent soil-retaining members 200 together.

[0014] The retaining members 200, each having a vertical flange 202 with a connecting hole 202a formed therein and a horizontal flange 203 with a connecting hole 203a formed therein, are placed along the inner wall surface of a vertical borehole formed by excavating the ground. The connecting fittings 100 connect the vertical flanges 202 and the horizontal flanges 203 of adjacent retaining members 200 together while butting them against each other. First, the configuration of a retaining structure 300 constructed using the retaining members 200 will be described with reference to Figures 1 to 4.

[0015] [Earth-retaining structure 300] The earth-retaining structure 300 is, for example, a vertical shaft for constructing the foundation of an architectural structure or a drainage well constructed underground. The earth-retaining structure 300 is formed in a circular cylindrical shape in a plan view. The earth-retaining structure 300 is constructed by stacking annular structures 301 in multiple stages along the axial direction of a vertical borehole formed by excavating the ground, as shown in Figure 1.

[0016] Each structure 301 constituting the earth-retaining structure 300 is formed by arranging a plurality of earth-retaining members 200 having the same section modulus in a ring shape. As shown in Figures 2 and 3 as an example, the earth-retaining members 200 are so-called liner plates whose corrugated cross sections are formed in a sine curve shape.

[0017] [Soil-retaining member 200] The soil-retaining member 200 is formed in a rectangular shape in a side view seen in the radial direction of the borehole, and in an arc-shaped shape in a plan view seen in the axial direction of the borehole. The soil-retaining member 200 is not limited to an arc-shaped configuration in a plan view, and may be, for example, a linear configuration in a plan view or another shape depending on the shape of the earth-retaining structure 300 to be constructed. In Figures 2 and 3, the longitudinal direction of the soil-retaining member 200, which is the circumferential direction of the borehole, is shown as the longitudinal direction X, the transverse direction, which is the axial direction of the borehole, is shown as the transverse direction Y, and the depth direction, which is the radial direction of the borehole, is shown as the depth direction D.

[0018] As shown in Figures 2 and 3, the retaining wall member 200 comprises a corrugated steel plate 201, vertical flanges 202 provided at both ends of the corrugated steel plate 201 in the longitudinal direction X, and horizontal flanges 203 provided at both ends of the corrugated steel plate 201 in the short direction Y.

[0019] The corrugated steel plate 201 is formed in a wave-like shape with alternating peaks and valleys along the short direction Y, and the peaks and valleys of the wave are formed to extend along the long direction X. The corrugated steel plate 201 of the illustrated earth-retaining member 200 is arc-shaped in a plan view. The thickness of the corrugated steel plate 201 is, for example, approximately 2.7 mm to 7 mm. Note that the corrugated steel plate 201 is not limited to the arc-shaped shape shown in the figure, and may be, for example, linear in a plan view or another shape depending on the shape of the earth-retaining structure 300 to be constructed.

[0020] The vertical flanges 202 are flat plate-shaped members formed by welding plates to both end edges of the corrugated steel plate 201 in the longitudinal direction X. The thickness of the vertical flanges 202 is determined according to the strength and rigidity required for the earth-retaining structure 300. The vertical flanges 202 are flat plate-shaped portions of the earth-retaining member 200 that extend in the short direction Y and the depth direction D.

[0021] The vertical flange 202 has multiple connecting holes 202a formed along the vertical direction (short direction Y) for fastening the vertical flanges 202 of adjacent retaining members 200 on the left and right sides arranged in the circumferential direction θ of the excavation hole (see Figure 4) and connecting adjacent retaining members 200.

[0022] As shown in Figure 4, adjacent soil-retaining members 200 on the left and right are connected by butting their vertical flanges 202 together and using connecting fittings 100 inserted through the connecting holes 202a. The number of connecting holes 202a shown in the figure is an example and is not limited to this. Bolts may be inserted into the connecting holes 202a instead of connecting fittings 100. Adjacent soil-retaining members 200 on the left and right may have connecting fittings 100 or bolts inserted into each of the multiple connecting holes 202a, and the vertical flanges 202 may be fastened together using the connecting fittings 100, bolts, and nuts.

[0023] 2 and 3, the corrugated steel plate 201 has horizontal flanges 203 formed by bending both edges of the corrugation at both ends in the short side direction Y. The horizontal flanges 203 are flat portions formed substantially perpendicular to the axial direction of the borehole. The horizontal flanges 203 are flat portions of the retaining member 200 that extend in the longitudinal direction X and the depth direction D.

[0024] The horizontal flanges 203 are formed with a plurality of connecting holes 203a along the longitudinal direction X for fastening the horizontal flanges 203 of adjacent vertically stacked earth retaining members 200 stacked in the axial direction of the borehole together and connecting adjacent earth retaining members 200. The multiple connecting holes 203a are formed in the horizontal flanges 203 so as to be arranged along the circumferential direction of the borehole.

[0025] As shown in Figure 4, vertically adjacent earth retaining members 200 butt their horizontal flanges 203 together and are connected by connecting fittings 100 inserted into the connecting holes 203a. The number of connecting holes 203a shown in the figure is an example and is not limited to this. Bolts may be inserted into the connecting holes 203a instead of connecting fittings 100. Vertically adjacent earth retaining members 200 may have connecting fittings 100 or bolts inserted into each of the multiple connecting holes 203a, and the horizontal flanges 203 may be fastened together using the connecting fittings 100, bolts, and nuts.

[0026] The earth-retaining structure 300 is not limited to a circular configuration in plan view. For example, the earth-retaining structure 300 may be constructed in a rectangular configuration in plan view. In this case, the earth-retaining members 200 are used in a linear or L-shaped configuration in plan view, depending on the shape of the earth-retaining structure 300 to be constructed. Furthermore, the earth-retaining members 200 are not limited to the configurations shown in Figures 2 and 3, and may have other configurations.

[0027] FIG. 5 is a perspective view showing a different form of the earth-retaining member 200 constituting the earth-retaining structure 300 according to the first embodiment. FIG. 6 is a longitudinal cross-sectional view of the earth-retaining member 200 shown in FIG. 5. For example, the corrugated steel plate 201 of the earth-retaining member 200 shown in FIGS. 5 and 6 is a corrugated steel plate that has been bent so that the corrugated cross section has a square wave shape. An example of a square wave shape is a trapezoidal wave shape with rounded corners. The earth-retaining member 200 shown in FIGS. 5 and 6 is, for example, composed of three peaks and two valleys, but the number of peaks and valleys is not limited to the number shown. Note that the peaks and valleys are formed to be approximately parallel.

[0028] FIG. 7 is a perspective view of the connecting fitting 100 according to the first embodiment. FIG. 8 is a plan view of the connecting fitting 100 according to the first embodiment. FIG. 9 is a bottom view of the connecting fitting 100 according to the first embodiment. FIG. 10 is an explanatory diagram that schematically shows the state in which the horizontal flanges 203 of the earth-retaining members 200 are connected using the connecting fitting 100 according to the first embodiment. FIG. 11 is an explanatory diagram that schematically shows the state in which the horizontal flanges 203 of the earth-retaining members 200 are connected using the connecting fitting 100 according to the first embodiment, with earth pressure P acting on the earth-retaining members 200. Next, the connecting fitting 100 according to the first embodiment will be described with reference to FIGS. 7 to 11 . Note that the following description will focus on an example in which the connecting fitting 100 is used to connect horizontal flanges 203, but the connecting fitting 100 can also be used to connect vertical flanges 202.

[0029] [Connecting fitting 100] The connecting fitting 100 according to the first embodiment is a fitting formed by bending a metal sheet. The connecting fitting 100 is made of, for example, iron or plated iron. Note that the material of the connecting fitting 100 is not limited to iron, and metals other than iron may be used as long as they function as connecting fittings. The workability and strength of a plated connecting fitting 100 are equivalent to those of an unplated connecting fitting 100. If the connecting fitting 100 is plated, the plating is hot-dip galvanized or hot-dip zinc-aluminum alloy plating. If the plating is high-strength hot-dip zinc-aluminum alloy plating, the connecting fitting 100 can reduce peeling of the plating due to friction during hammering, etc.

[0030] Plated connecting fittings 100 are used, for example, in permanent use. Permanent use refers to use in long-term structures (not temporary) such as drainage wells, and the liner plates that make up the earth retaining members 200 are, for example, zinc-plated. When using earth retaining members 200 in drainage wells, it is advisable to use connecting fittings 100 that are plated with plating that has excellent corrosion resistance, and if they are painted, the corrosion resistance will be further improved.

[0031] As shown in FIGS. 7 to 11, the connecting fitting 100 comprises a connecting fitting main body 1, an insertion portion 2, and a clamping portion 3.

[0032] 7 to 11 , the connecting fitting main body 1 is plate-shaped and is formed so as to extend long from the excavation hole side toward the natural ground side when the connecting fitting 100 is connected to the retaining member 200. When viewed in a plan view perpendicular to the plate surface of the connecting fitting main body 1, the connecting fitting main body 1 is formed in a shape that roughly follows the shape of a parallelogram.

[0033] At one longitudinal end of the connecting fitting main body 1, an insertion portion 2 is formed at a corner on the acute angle side of a parallelogram, and a narrowed portion 8 is formed at a corner on the obtuse angle side of the parallelogram. That is, the insertion portion 2 is formed at one longitudinal edge 10 of the connecting fitting main body 1. Also, the connecting fitting main body 1 has a clamping portion 3 formed at the other longitudinal end extending from the borehole side toward the natural ground side. That is, the clamping portion 3 is formed at the other longitudinal edge 11 of the connecting fitting main body 1.

[0034] As shown in FIG. 8 , the connecting fitting body 1 is formed so as to be inclined toward the insertion portion 2 with respect to a direction perpendicular to the extension direction of the clamping portion 3 in a plan view. In other words, the connecting fitting body 1 is formed at an angle so as to be inclined toward the insertion portion 2 with respect to the insertion direction of the clamping portion 3 into the flange. As shown in FIG. 10 , when the horizontal flanges 203 of adjacent earth-retaining members 200 are connected to each other, the connecting fitting body 1 is formed so as to be inclined in the circumferential direction θ of the excavated hole, which is the direction in which the horizontal flanges 203 extend, with respect to the radial direction r of the excavated hole. This is to increase the contact area between the connecting fitting body 1 and the horizontal flanges 203 and ensure a strong connection. Furthermore, ease of insertion of the insertion portion 2 into the connecting hole 203a is also taken into consideration.

[0035] As shown in Figure 8, in a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body 1, when the longitudinal direction of the connecting fitting main body 1 is defined as the distance between the clamping portion 3 and the step portion 20, the connecting fitting main body 1 has two side edges that run along the longitudinal direction of the connecting fitting main body 1. Of the two side edges, the first side edge 1a is formed to be longer than the second side edge 1b. When seen in a direction perpendicular to the plate surface of the connecting fitting main body 1, in a direction perpendicular to the extension direction of the step portion 20, the first side edge 1a has a tapered portion 8 that is recessed in an arc toward the clamping portion 3 and the step portion 20 on the opposite side of the insertion portion 2, with the step portion 20 between them.

[0036] 8 , in a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body 1, the length of the step portion 20 in the direction in which the step portion 20 extends is defined as the width W of the step portion 20, and the shortest distance between the second side edge 1 b and the first side edge 1 a of the tapered portion 8 is defined as the shortest distance LS. The connecting fitting 100 is formed so that the shortest distance LS between the second side edge 1 b and the first side edge 1 a of the tapered portion 8 is longer than the width W of the step portion 20.

[0037] 7 to 11, the connecting fitting main body 1 has a first side edge 1a and a second side edge 1b along the longitudinal direction, one of which, the second side edge 1b, is formed to be inclined in a substantially linear manner, while the other, first side edge 1a, is formed so as to narrow towards the insertion portion 2 by a tapered portion 8. The width of one edge 10 of the connecting fitting main body 1 on the side where the insertion portion 2 is formed is shorter than the width of the other edge 11 on the side where the clamping portion 3 is formed. This is to correspond to the dimensions of the insertion portion 2 that is inserted into the connecting hole 203a formed in the horizontal flange 203.

[0038] By making the width dimension of the other end edge 11 of the connecting fitting main body 1 longer than the dimension of the one end edge 10, the clamping portion 3 can be formed long along the end edge 203b of the horizontal flange 203 (see Figure 4), and the end edges 203b of the two horizontal flanges 203 can be firmly clamped by the clamping portion 3.

[0039] The connecting fitting body 1 is provided with a protrusion 12 formed by embossing near the insertion portion 2. That is, the connecting fitting body 1 has the protrusion 12 formed so as to partially rise and protrude near the step portion 20. Next, an example of the protrusion 12 is shown.

[0040] As shown in Figure 8, when viewed in a direction perpendicular to the plate surface of the connecting fitting main body 1, the protrusion portion 12 is formed at a position closer to the step portion 20 than the narrowed portion 8 in a direction perpendicular to the extension direction of the step portion 20.

[0041] 8 and 9, the length of the step portion 20 in the direction in which the step portion 20 extends in a plan view perpendicular to the plate surface of the connecting fitting main body 1 is defined as the width W of the step portion 20. As shown in Figures 8 and 9, in the connecting fitting 100, the protrusion 12 is formed within the range of the width W of the step portion 20 of the connecting fitting main body 1 located in a direction intersecting the direction in which the step portion 20 extends.

[0042] 8 and 9, in a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body 1, the central portion of the length of the step portion 20 in the direction in which the step portion 20 extends is defined as the step center portion 20c. An imaginary line passing through the step center portion 20c in a direction perpendicular to the direction in which the step portion 20 extends is defined as the imaginary line VL. In this case, the connecting fitting 100 is formed so that the protrusion 12 of the connecting fitting main body 1 is located on the imaginary line VL.

[0043] The step central portion 20c is the central portion of the width W between the side edges 20a and 20b of the step portion 20 in a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body 1. The direction perpendicular to the extending direction of the step portion 20 is the direction along the protruding direction of the insertion portion 2 in a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body 1.

[0044] As shown in FIG. 10 , the protrusion 12 is formed so that at least a portion thereof is positioned above the connecting hole 203 a of the horizontal flange 203 when the connecting fitting 100 is attached to the horizontal flange 203 .

[0045] As shown in Figure 11, when adjacent connected horizontal flanges 203 are displaced relative to one another in the radial direction r of the drilled hole, a load acts on the stepped portion 20, providing resistance, but the connecting fitting 100 itself, consisting of the insertion portion 2 and the connecting fitting main body 1, deforms (rotates) around the stepped portion 20 as an axis. This is because the upper and lower horizontal flanges 203 are misaligned, causing twisting above and below the stepped portion 20. Therefore, with conventional connecting fittings, there is a risk that the connecting fitting main body will twist.

[0046] The shortest distance LS of the connecting fitting main body 1 of the connecting fitting 100 is longer than the width W of the stepped portion 20. The connecting fitting 100 also has a protrusion 12 formed to partially protrude and rise near the stepped portion 20. Therefore, the clip width of the connecting fitting 100 is increased to increase rigidity, and the protrusion 12 is positioned near the stepped portion 20 where twisting is likely to occur, making the connecting fitting 100 less prone to twisting. As a result, even if the relative displacement of the lateral flange 203 increases, the connecting fitting 100 itself does not deform, contributing to improving the strength of the entire structure.

[0047] Fig. 12 is a side view of the connecting fitting 100 as viewed in the direction of arrow AL in Fig. 8. Fig. 13 is a side view of another embodiment of the connecting fitting 100 as viewed in the direction of arrow AL in Fig. 8. As shown in Fig. 12, the protrusion 12 is formed on the plate surface 1c of the connecting fitting main body 1 opposite the side on which the insertion portion 2 is arranged, so as to protrude in the direction opposite to the insertion portion 2. As shown in Fig. 13, the protrusion 12 may be formed on the plate surface 1d of the connecting fitting main body 1 on the side on which the insertion portion 2 is arranged, so as to protrude toward the side on which the insertion portion 2 is arranged.

[0048] The protrusions 12 are formed in a convex shape on the plate surface of the connecting fitting main body 1, improving the rigidity of the connecting fitting main body 1 and the strength of the connecting fitting 100. In the connecting fitting 100 shown in Figure 13, the insertion portion 2, the connecting fitting main body 1, the clamping portion 3, and the protrusions 12 abut against the lateral flange 203, and each portion resists the relative displacement of the lateral flange 203, improving the strength of the entire structure of the connecting fitting 100.

[0049] Figure 14 is a conceptual diagram showing the relationship between the protrusion 12 and the horizontal flange 203 in the vicinity of the connecting hole 203a when the connecting fitting 100 according to embodiment 1 is attached to the horizontal flange 203. Figure 15 is a conceptual diagram showing another relationship between the protrusion 12 and the horizontal flange 203 in the vicinity of the connecting hole 203a when the connecting fitting 100 according to embodiment 1 is attached to the horizontal flange 203. Figures 14 and 15 are conceptual diagrams of the connecting hole 203a of the horizontal flange 203 and the connecting fitting 100 viewed from the insertion portion 2 side.

[0050] As shown in Figure 13, when the protrusion 12 is formed so as to protrude on the plate surface 1d of the connecting fitting main body 1 on the side where the insertion portion 2 is located, the horizontal flange 203 and the protrusion 12 have the following relationship.

[0051] The protrusion 12 protruding from the side where the insertion portion 2 shown in Fig. 13 is arranged is formed so as to come into contact with the plate surface of the horizontal flange 203 when the connecting fitting 100 is attached to the horizontal flange 203, as shown in Fig. 14. Alternatively, the protrusion 12 protruding from the side where the insertion portion 2 shown in Fig. 13 is arranged is formed so as to be inserted into the connecting hole 203a of the horizontal flange 203 when the connecting fitting 100 is attached to the horizontal flange 203, as shown in Fig. 15.

[0052] 8 , the connecting fitting main body 1 has, on the plate surface opposite the side where the clamping portion 3 is located, a marking portion 15 that serves as a mark for the fitting position of the horizontal flange 203 when the edge of the horizontal flange 203 is clamped by the connecting fitting main body 1 and the clamping portion 3. The connecting fitting 100 is attached to the horizontal flange 203 so that the horizontal flange 203 is positioned at least at the position of the marking portion 15.

[0053] It is desirable that connecting fitting 100 be attached to horizontal flange 203 so that horizontal flange 203 is inserted deeper than marking portion 15. It may not be clear how far connecting fitting 100 needs to be fitted into horizontal flange 203 to exert strength, and by marking connecting fitting 100, it is possible to clarify the fitting position of connecting fitting 100 into horizontal flange 203 that will provide sufficient strength.

[0054] 7 to 11 , the insertion portion 2 is formed by bending one end edge 10 of the connecting fitting main body 1 in an L-shape toward one side of the connecting fitting main body 1, and is inserted into at least one or more connecting holes 203a formed in the horizontal flange 203. The insertion portion 2 is formed so as to be inclined from the direction in which the connecting fitting main body 1 extends toward the circumferential direction θ of the drilled hole (see FIGS. 4 and 10 ), which is also the direction in which the horizontal flange 203 extends.

[0055] As shown in Fig. 11 , the insertion portion 2 is formed at a predetermined angle with respect to the extension direction of the linking fitting main body 1 so that when adjacent connected horizontal flanges 203 are displaced relative to each other in the radial direction r of the drilled hole, the side edge 20a or 20b of the step portion 20 connecting the linking fitting main body 1 and the insertion portion 2 abuts against the opening edge of the connecting hole 203a. As an example, the insertion portion 2 shown in Fig. 10 extends along a tangential direction to the circumferential direction θ of the drilled hole. In a plan view in which the plate surface of the linking fitting main body 1 faces, the linking fitting 100 is formed so that the angle between the extension direction of the linking fitting main body 1 and the protruding direction of the insertion portion 2 is an obtuse angle.

[0056] The connecting fitting 100 is formed so that, in a state in which the connecting fitting main body 1 interconnects the horizontal flanges 203 of adjacent earth retaining members 200, the horizontal flanges 203 extend in a direction inclined relative to the radial direction r of the excavation hole. Furthermore, the connecting fitting 100 is formed so that the insertion portion 2 is tilted from the extension direction of the connecting fitting main body 1 toward the extension direction of the horizontal flanges 203.

[0057] The connecting fitting 100 has a step portion 20 that forms a portion connecting the connecting fitting main body 1 and the insertion portion 2. The step portion 20 extends in a direction in which the plate surface of the connecting fitting main body 1 faces the connecting fitting main body 1. The angle between the step portion 20 and the connecting fitting main body 1 is, for example, 90 degrees or an angle close to 90 degrees, but is not limited to these angles. One end of the step portion 20 is connected to the connecting fitting main body 1, and the other end of the step portion 20 is connected to the insertion portion 2. The insertion portion 2 is formed at the end of the step portion 20 and extends in a direction in which the plate surface of the step portion 20 faces. The insertion portion 2 extends so as to extend outward relative to the connecting fitting main body 1.

[0058] The step portion 20 is disposed so that the direction from one side edge 20a to the other side edge 20b is along the radial direction r and is oriented in a direction substantially perpendicular to the width direction of the U-shaped opening of the clamping portion 3. As shown in Fig. 10, the insertion portion 2 is configured so that the displacement L1 until the side edge 20a or 20b of the step portion 20 abuts against the opening edge of the connecting hole 203a is shorter than the length L2 in the radial direction r over which the lateral flange 203 is clamped by the clamping portion 3. The tip portion 2a of the insertion portion 2 is inclined so as to abut against the surface of the lateral flange 203 when inserted into the connecting hole 203a.

[0059] FIG. 16 is a side view of the stepped portion 20 and insertion portion 2 of the connecting fitting 100 according to the first embodiment. As shown in FIG. 16 , the angle between the insertion portion 2 and the stepped portion 20 is defined as angle α. The connecting fitting 100 is formed so that the angle α between the insertion portion 2 and the stepped portion 20 is an acute angle. Because the connecting fitting 100 is formed so that the angle α between the insertion portion 2 and the stepped portion 20 is an acute angle, when the connecting fitting 100 is attached to the horizontal flanges 203 and connects the horizontal flanges 203, the tip end 2a of the insertion portion 2 abuts against the horizontal flanges 203. The angle α between the insertion portion 2 and the stepped portion 20 is preferably greater than 65 degrees and less than 90 degrees. Furthermore, the angle α is preferably greater than 80 degrees and less than 90 degrees, with 85 degrees being optimal and desirable. The angle α is the bending angle of the insertion portion 2.

[0060] (Clamping portion 3) As shown in Fig. 7 , the clamping portion 3 is formed by bending the other end edge 11 of the connecting fitting main body 1 toward one side of the connecting fitting main body 1 in a U-shape, and clamps the edges 203b of the two butted horizontal flanges 203 together with the connecting fitting main body 1. An insertion portion 30 for inserting the edges 203b of the two horizontal flanges 203 is formed between the clamping portion 3 and the connecting fitting main body 1. The two butted horizontal flanges 203 are inserted by inserting their edges 203b into the insertion portion 30, as shown in Fig. 10 , and are clamped between the clamping portion 3 and the connecting fitting main body 1.

[0061] The clamping portion 3 is bent so that the spacing between the insertion portions 30 is smaller than the thickness of the two overlapping horizontal flanges 203. This configuration of the clamping portion 3 is intended to firmly clamp the two horizontal flanges 203. In addition, as shown in FIG. 7 , the tip end 3 a of the clamping portion 3 is formed so that the spacing between the insertion portions 30 is wider. This configuration of the clamping portion 3 is intended to make it easier to insert the two horizontal flanges 203 into the insertion portion 30.

[0062] 12 and 13 , in a side view of the connecting fitting 100 seen in the direction in which the clamping portion 3 extends, the clamping portion 3 has a mountain-shaped portion 31 at a position facing the connecting fitting main body 1. The mountain-shaped portion 31 is formed by being bent in a mountain-like manner so as to approach the connecting fitting main body 1 in a side view of the connecting fitting 100 seen in the direction in which the clamping portion 3 extends.

[0063] If the part of the mountain-shaped portion 31 closest to the connecting fitting main body 1 is defined as the apex portion 31a, then the marker portion 15 (see FIG. 8) is formed at a position opposite the apex portion 31a in the direction perpendicular to the plate surface of the connecting fitting main body 1. As shown in FIGS. 12 and 13 , in a side view of the connecting fitting 100 seen in the direction in which the clamping portion 3 extends, if an imaginary line perpendicular to the plate surface of the connecting fitting main body 1 is defined as an imaginary line VL1, then it is desirable that the apex portion 31a and the marker portion 15 be located on the imaginary line VL1.

[0064] Figure 17 is an explanatory diagram showing the procedure for connecting the horizontal flanges 203 of the earth-retaining members 200 with the connecting fitting 100 according to embodiment 1. Figures 17(A) to 17(C) show the procedure for connecting the horizontal flanges 203 of the earth-retaining members 200 using the connecting fitting 100. To connect adjacent upper and lower horizontal flanges 203 using the connecting fitting 100 configured as described above, first, as shown in Figure 17(A), the insertion portions 2 are inserted into the two connecting holes 203a of the overlapping horizontal flanges 203.

[0065] Next, as shown in Figure 17 (B), with the insertion portion 2 abutting against the surface of one of the horizontal flanges 203, the clamping portion 3 is rotated around the insertion portion 2 toward the edge 203b of the horizontal flange 203.

[0066] 17(C), the clamping portion 3 is struck with, for example, a hammer to insert the edges 203b of the two horizontal flanges 203 into the insertion portion 30. At this time, the tip 3a of the clamping portion 3 is formed so that the spacing between the insertion portions 30 is wide, so that the edges 203b of the two horizontal flanges 203 can be smoothly inserted into the insertion portion 30.

[0067] In this way, the connecting fitting 100 has the insertion portion 2 inserted into the connecting hole 203a abutting against the surface of one of the two overlapping horizontal flanges 203, and the edge 203b of the two horizontal flanges 203 inserted into the insertion portion 30 is clamped between the connecting fitting main body 1 and the clamping portion 3. The connecting fitting 100 connects adjacent upper and lower horizontal flanges 203 by at least the insertion portion 2, the connecting fitting main body 1, and the clamping portion 3.

[0068] Figure 18 is an explanatory diagram showing a modified example of the connecting fitting 100 according to embodiment 1. As shown in Figure 18, the length L3 by which the insertion portion 2 protrudes from the connecting fitting main body 1 is preferably longer than the diameter of the connecting hole 203a. This prevents the insertion portion 2 from slipping out of the connecting hole 203a even if adjacent retaining members 200 are relatively displaced in the circumferential direction θ, and the connected state of the horizontal flanges 203 can be maintained.

[0069] [Effects of the connecting fitting 100] The connecting fitting 100 is formed so that the angle between the insertion portion 2 and the step portion 20 is an acute angle, and when attached to the lateral flanges 203 to connect the lateral flanges 203, the tip 2a of the insertion portion 2 abuts against the lateral flanges 203. The connecting fitting 100 contacts the overlapping lateral flanges 203 at two points: the clamping portion 3 and the connecting fitting main body 1, and the tip 2a of the insertion portion 2, thereby holding down the two overlapping lateral flanges 203. Therefore, the connecting fitting 100 can improve the fastening strength of the two overlapping lateral flanges 203 compared to a configuration in which the tip 2a of the insertion portion 2 does not come into contact with the lateral flanges 203 and the connecting fitting main body 1 only, and the two overlapping lateral flanges 203 are fastened together. Furthermore, the connecting fitting 100 can improve the structural strength by fastening the two lateral flanges 203 using the entire connecting fitting 100, compared to a configuration in which there is no contact between the insertion portion 2 and the lateral flanges 203 and the two lateral flanges 203 are fastened only using the clamping portion 3 and the connecting fitting main body portion 1.

[0070] As shown in Figure 11, when multiple soil-retaining members 200 are arranged along the inner wall surface of a borehole, they may be subjected to earth pressure P in a radial direction r from the natural ground toward the borehole, causing vertically adjacent soil-retaining members 200 to be displaced relative to each other in the radial direction r of the borehole. Consider the case where horizontal flanges 203 are connected to each other using a connecting fitting whose insertion portion extends along an extension of the direction in which the connecting fitting body extends. With such a connecting fitting, if the relative displacement between vertically adjacent soil-retaining members 200 is large, the force of the edge 203b of one of the horizontal flanges 203 coming off the insertion portion 30 of the connecting fitting may cause the insertion portion of the connecting fitting to come out of the connecting hole.

[0071] 10 and 11 , in the connecting fitting 100 according to the first embodiment, the insertion portion 2 is formed at a predetermined angle with respect to the extension direction of the connecting fitting main body 1 so that when adjacent connected lateral flanges 203 are relatively displaced in the radial direction r of the borehole due to earth pressure P in the radial direction r from the natural ground toward the borehole, the side edge 20a or 20b of the step portion 20 connecting the connecting fitting main body 1 and the insertion portion 2 abuts against the opening edge of the connecting hole 203a. Furthermore, the connecting fitting 100 is configured so that the displacement L1 until the side edge 20a or 20b of the step portion 20 abuts against the opening edge of the connecting hole 203a is shorter than the length L2 in the radial direction r over which the lateral flanges 203 are clamped by the clamping portion 3.

[0072] Therefore, as shown in Figure 11, in the connecting fitting 100 of embodiment 1, even if earth pressure P in the radial direction r from the ground side toward the excavation hole acts on the retaining member 200 and the adjacent horizontal flanges 203 above and below are displaced relative to each other in the radial direction r of the excavation hole, the side edge 20a or 20b of the step portion 20 of the connecting fitting 100 will abut against the opening edge of the connecting hole 203a before the end edge 203b of the horizontal flange 203 comes off the insertion portion 30 of the connecting fitting 100, so the insertion portion 2 will not come out of the connecting hole 203a and the connected state of the adjacent horizontal flanges 203 above and below can be maintained.

[0073] Furthermore, when the horizontal flanges 203 of adjacent earth-retaining members 200 are connected to each other, the connecting fitting main body 1 is formed to be inclined in the direction in which the horizontal flanges 203 extend with respect to the radial direction r of the excavation hole. The insertion portion 2 is formed to be inclined from the direction in which the connecting fitting main body 1 extends toward the direction in which the horizontal flanges 203 extend. With this configuration, even if adjacent horizontal flanges 203 are relatively displaced in the radial direction r of the excavation hole, the side edge 20a or 20b of the stepped portion 20 abuts against the opening edge of the connecting hole 203a before the end edge 203b of the horizontal flange 203 comes out of the insertion portion 30 of the connecting fitting 100. Therefore, the connecting fitting 100 can maintain the connected state of vertically adjacent horizontal flanges 203 without the insertion portion 2 coming out of the connecting hole 203a.

[0074] Furthermore, the angle α between the insertion portion 2 and the step portion 20 is preferably greater than 65 degrees and less than 90 degrees. Furthermore, the angle α is preferably greater than or equal to 80 degrees and less than 90 degrees, with 85 degrees being optimal and desirable. The angle α of the connecting fitting 100 is formed at 85 degrees, which improves workability and strength compared to when the angle α is not formed at 85 degrees. Here, the inventors conducted experiments in which the insertion portion 2 was machined so that the angle α was 65 degrees, 85 degrees, and 90 degrees, and confirmed the workability and strength for each angle α. When the angle α was 65 degrees, the insertion portion 2 hit the flanges, making it difficult to sandwich the two flanges between the clamping portion 3 and the connecting fitting main body 1. Therefore, the angle α should be greater than 65 degrees. When the angle α is 85 degrees, the ease of clamping the two flanges using the clamping portion 3 and the connecting fixture main body portion 1 is improved compared to when the angle α is 65 degrees, and the strength of the connecting fixture 100 is also improved compared to when the angle α is 65 degrees.

[0075] When the angle α is 90 degrees, the tip 2a of the insertion portion 2 does not come into contact with the horizontal flange 203 when the connecting fitting 100 is attached to the overlapping flanges. When the angle α is 85 degrees, the tip 2a of the insertion portion 2 comes into contact with the horizontal flange 203 when the connecting fitting 100 is attached to the overlapping flanges. Therefore, when the angle α is 85 degrees, the fastening strength of the two flanges is improved compared to when the angle α is 90 degrees, and the bearing strength of the connecting fitting 100 is improved. As described above, in a comparison of workability, bearing strength, etc. when the angle α is 65 degrees, 85 degrees, and 90 degrees, the angle α of 85 degrees was optimal in terms of workability, bearing strength, etc.

[0076] Additionally, the connecting fitting main body 1 has a protrusion 12 formed to partially bulge and protrude near the step portion 20. The rigidity of the connecting fitting main body 1 of the connecting fitting 100 is improved by having the protrusion 12. Furthermore, the rigidity of the connecting fitting main body 1 is further improved by providing the protrusion 12 near the step portion 20. By positioning the protrusion 12 closer to the tip end on the insertion portion 2 side, the rigidity of the connecting fitting main body 1 itself can be increased, and deformation of the connecting fitting 100 can be suppressed.

[0077] Furthermore, when viewed in a direction perpendicular to the plate surface of the connecting fitting main body 1, the protrusion 12 is formed in a position closer to the step portion 20 than the narrowed portion 8 in a direction perpendicular to the extension direction of the step portion 20. The connecting fitting 100 is designed to be less prone to twisting when the upper and lower horizontal flanges 203 are misaligned, as the protrusion 12 is located near the step portion 20 where twisting is likely to occur. As a result, the connecting fitting 100 itself does not deform even if the horizontal flanges 203 are subject to significant relative displacement, which contributes to improving the strength of the entire structure.

[0078] Furthermore, the protrusion 12 is formed within the range of the width W of the step portion 20 of the connecting fitting main body 1, which is located in a direction perpendicular to the extension direction of the step portion 20 in a plan view. By forming the connecting fitting 100 in this configuration, the protrusion 12 is formed near the step portion 20. The connecting fitting 100 has a structure in which the protrusion 12 is located near the step portion 20, where twisting is likely to occur when the upper and lower lateral flanges 203 are misaligned, making the connecting fitting 100 less likely to twist. As a result, even if the relative displacement of the lateral flanges 203 increases, the connecting fitting 100 itself does not deform, which contributes to improving the strength of the entire structure.

[0079] Furthermore, when an imaginary line VL is defined as a virtual line passing through the step center portion 20c in a direction perpendicular to the extension direction of the step portion 20 in a plan view, the protrusion 12 is formed to be located on the imaginary line VL. By being formed with this configuration, the connecting fitting 100 has the protrusion 12 formed near the step portion 20. By locating the protrusion 12 near the step portion 20, where twisting is likely to occur when the upper and lower horizontal flanges 203 are misaligned, the connecting fitting 100 is structured to be less susceptible to twisting. As a result, even if the horizontal flanges 203 are subject to significant relative displacement, the connecting fitting 100 itself does not deform, contributing to improving the strength of the entire structure.

[0080] Furthermore, the protrusion 12 is formed so that when the connecting fitting 100 is attached to the horizontal flange 203, at least a portion of it is positioned above the connecting hole 203a of the horizontal flange 203. By forming the connecting fitting 100 in this configuration, the protrusion 12 is formed near the step portion 20. The connecting fitting 100 has a structure in which the protrusion 12 is located near the step portion 20, where twisting is likely to occur when the upper and lower horizontal flanges 203 are misaligned, making the connecting fitting 100 less likely to twist. As a result, even if the relative displacement of the horizontal flanges 203 increases, the connecting fitting 100 itself does not deform, which contributes to improving the strength of the entire structure.

[0081] Furthermore, the protrusion 12 is formed on the plate surface of the connecting fitting main body 1 opposite the side on which the insertion portion 2 is arranged, so as to protrude in the direction opposite to the insertion portion 2. Alternatively, the protrusion 12 is formed on the plate surface of the connecting fitting main body 1 on the side on which the insertion portion 2 is arranged, so as to protrude toward the side on which the insertion portion 2 is arranged. By having the protrusion 12 of this configuration, the rigidity of the connecting fitting main body 1 of the connecting fitting 100 is improved.

[0082] Furthermore, the protrusions 12 are formed so as to come into contact with the plate surfaces of the horizontal flanges 203 when the connecting fitting 100 is attached to the horizontal flanges 203. As shown in Figure 14, when the protrusions 12 come into contact with the plate surfaces of the horizontal flanges 203, the protrusions 12 become the part of the connecting fitting 100 that resists relative displacement of the horizontal flanges 203, thereby improving the strength of the entire structure of the connecting fitting 100. The connecting fitting 100 comes into contact with the overlapping horizontal flanges 203 at three points: the clamping portion 3 and the connecting fitting main body 1, the tip end 2a of the insertion portion 2, and the protrusions 12, and holds down the two overlapping horizontal flanges 203.

[0083] Therefore, by having this configuration, the connecting fitting 100 can improve the fastening strength of the two overlapping lateral flanges 203 compared to a configuration in which the two overlapping lateral flanges 203 are fastened only by the clamping portion 3 and the connecting fitting main body 1. Furthermore, by having this configuration, the connecting fitting 100 can improve the strength of the structure because the two lateral flanges 203 are fastened by the entire connecting fitting 100 compared to a configuration in which the two lateral flanges 203 are fastened only by the clamping portion 3 and the connecting fitting main body 1.

[0084] Furthermore, the protrusion 12 is formed so that it can be inserted into the connecting hole 203a of the horizontal flange 203 when the connecting fitting 100 is attached to the horizontal flange 203. As shown in Figure 15, when the protrusion 12 is inserted into the connecting hole 203a of the horizontal flange 203, the protrusion 12 acts as a part that resists relative displacement of the horizontal flange 203, thereby improving the strength of the entire structure of the connecting fitting 100. When the protrusion 12 is inserted into the connecting hole 203a of the horizontal flange 203, the protrusion 12 abuts against the edge of the connecting hole 203a when the horizontal flange 203 is displaced relative to the horizontal flange 203, making it difficult for the connecting fitting 100 to come out of the connecting hole 203a.

[0085] Furthermore, when the length of the step portion 20 in the direction in which the step portion 20 extends in a plan view is defined as the width W of the step portion 20, the shortest distance LS between the second side edge 1b and the first side edge 1a of the tapered portion 8 is longer than the width W of the step portion 20. By forming the shortest distance LS of the linking fitting main body 1 to be longer than the width W of the step portion 20, the linking fitting 100 has increased rigidity of the linking fitting main body 1 itself compared to a case not having this configuration, and deformation of the linking fitting 100 can be suppressed.

[0086] The connecting fitting main body 1 has, on the plate surface opposite the side where the clamping portion 3 is located, a marker portion 15 that serves as a mark for the fitting position for inserting the lateral flange 203 when the edge of the lateral flange 203 is clamped between the connecting fitting main body 1 and the clamping portion 3. There are cases where it is not clear how far the connecting fitting 100 needs to be inserted into the lateral flange 203 to exert strength. The connecting fitting 100 is marked with the marker portion 15, which clarifies the fitting position for the connecting fitting 100 into the lateral flange 203 where sufficient strength can be exerted. In other words, by having the marker portion 15, the connecting fitting 100 can clearly indicate the position for inserting the lateral flange 203 into the insertion portion 30 (see FIG. 7 ), and can also clearly indicate the depth to which the lateral flange 203 should be inserted into the insertion portion 30.

[0087] Furthermore, in a side view of the connecting fitting 100 seen in the direction in which the clamping portion 3 extends, the clamping portion 3 has a mountain-shaped portion 31 at a position facing the connecting fitting main body 1. The mountain-shaped portion 31 is formed by being bent in a mountain shape so as to approach the connecting fitting main body 1 in a side view of the connecting fitting 100. If the part of the mountain-shaped portion 31 closest to the connecting fitting main body 1 is defined as the apex portion 31a, the mark portion 15 is formed at a position facing the apex portion 31a in the direction perpendicular to the plate surface of the connecting fitting main body 1. The apex portion 31a of the mountain-shaped portion 31 is the portion that clamps the horizontal flange 203 that is overlapped together with the connecting fitting main body 1.

[0088] The linking fitting 100 has the marker portion 15 formed in a position opposite the apex portion 31a, thereby clarifying the fitting position of the linking fitting 100 into the lateral flange 203 where sufficient strength can be exerted. In other words, by having the marker portion 15 in this position, the linking fitting 100 can clarify the position where the lateral flange 203 is to be inserted into the insertion portion 30 (see FIG. 7 ), and can also clarify the depth to which the lateral flange 203 is to be inserted into the insertion portion 30.

[0089] Embodiment 2. Figure 19 is a perspective view showing a connecting fitting 101 according to embodiment 2. The connecting fitting 101 according to embodiment 2 will be described with reference to Figure 19. Note that components having the same functions and actions as the connecting fitting 100 described in embodiment 1 will be assigned the same reference numerals and their description will be omitted. Using Figure 19, the configuration of embodiment 2 will be described, focusing on the differences from embodiment 1, and configurations not described in embodiment 2 are the same as embodiment 1.

[0090] The connecting fitting 101 according to the second embodiment includes a reinforcing portion 4 that abuts against the opening edge of the connecting hole 203a and makes surface contact with it, instead of the side edge 20a or the side edge 20b of the step portion 20. As an example, the reinforcing portion 4 shown in Fig. 19 is configured such that a steel plate is attached to the side edge 20a and the side edge 20b of the step portion 20 by welding.

[0091] The steel plate of the reinforcing portion 4 is triangular so as not to interfere with the insertion of the insertion portion 2 into the connecting hole 203a. The shape and size of the steel plate are not limited to the configuration shown in the figure, and may be modified as appropriate depending on the size of the connecting hole 203a and the size of the insertion portion 2. The reinforcing portion 4 may also be configured such that the steel plate is attached by welding or the like to the flat portion of the stepped portion 20 or to the connecting fitting main body 1, so that the reinforcing portion 4, together with the side edge 20a or 20b of the stepped portion 20, abuts against the opening edge of the connecting hole 203a and makes surface contact.

[0092] Fig. 20 is a perspective view showing Modification 1 of the connecting fitting 101 according to Embodiment 2. The reinforcing portion 5 shown in Fig. 20 is formed by bending a portion from the side edge 20a and the side edge 20b of the step portion 20 toward the connecting fitting main body 1 side.

[0093] Fig. 21 is a perspective view showing Modification 2 of the connecting fitting 101 according to Embodiment 2. The reinforcing portion 6 shown in Fig. 21 is formed by bending a portion downward from a part of the first side edge 1a and a part of the second side edge 1b of the connecting fitting main body 1.

[0094] Figure 22 is a perspective view showing a third modified example of the connecting fitting 101 according to the second embodiment. The reinforcing portion 7 shown in Figure 22 has a curved shape that follows the opening edge of the connecting hole 203a. The reinforcing portion 7 is configured by attaching a reinforcing member made of steel having a curved surface, such as a semicircular, columnar, or cylindrical shape, to the side edges 20a and 20b of the stepped portion 20 or to the flat surface of the stepped portion 20 by welding or the like. Note that the reinforcing portion 7 may also be formed by bending a curved shape from the side edge 20a or 20b of the stepped portion 20 toward the connecting fitting main body 1. The reinforcing portion 7 is not limited to the above configuration as long as it has a curved shape that follows the opening edge of the connecting hole 203a.

[0095] The reinforcing portions are not limited to the configurations of the reinforcing portions 4 to 7 shown in Figures 19 to 22. The reinforcing portions 4 to 7 may have other configurations as long as they can be in surface contact with the opening edge of the connecting hole 203a and can distribute the stress acting on the opening edge.

[0096] [Operation and effect of connecting fitting 100] Connecting fitting 100 further includes a reinforcing portion 4 that abuts against and makes surface contact with the opening edge of connecting hole 203a, instead of side edge 20a or 20b of step portion 20. Alternatively, connecting fitting 100 further includes a reinforcing portion 4 that abuts against and makes surface contact with the opening edge of connecting hole 203a, together with side edge 20a or 20b of step portion 20.

[0097] If the side edges 20a and 20b of the step portion 20 abut against the opening edge of the connecting hole 203a and stress is concentrated on a portion of the opening edge, there is a risk of cracks occurring through the opening edge in the horizontal flange 203. The connecting fitting 101 according to the second embodiment is provided with a reinforcing portion 4 that comes into surface contact with the opening edge of the connecting hole 203a, and therefore the reinforcing portion 4 can distribute the stress acting on the opening edge, thereby preventing cracks from occurring in the horizontal flange 203.

[0098] Furthermore, the reinforcing portion 4 is configured by attaching a steel plate to the side edge 20a or the side edge 20b of the step portion 20. The connecting fitting 101 according to the second embodiment is provided with the reinforcing portion 4 that is in surface contact with the opening edge of the connecting hole 203a, and therefore the reinforcing portion 4 can distribute the stress acting on the opening edge, thereby preventing cracks from occurring in the horizontal flange 203.

[0099] Furthermore, the reinforcing portion 5 is formed by bending a portion from the side edge 20a and the side edge 20b of the step portion 20. The connecting fitting 101 shown in Figure 20 is equipped with a reinforcing portion 5 that comes into surface contact with the opening edge of the connecting hole 203a, as well as the side edge 20a or the side edge 20b of the step portion 20. Therefore, the connecting fitting 101 having the reinforcing portion 5 can distribute the stress acting on the opening edge with the reinforcing portion 5, and can prevent cracks from occurring in the horizontal flange 203.

[0100] Furthermore, the reinforcing portion 6 is formed by bending a portion from the first side edge 1a and the second side edge 1b of the connecting fixture main body 1. The connecting fixture 101 shown in Figure 21 is equipped with a reinforcing portion 6 that comes into surface contact with the opening edge of the connecting hole 203a, as well as the side edge 20a or 20b of the step portion 20. Therefore, the connecting fixture 101 having the reinforcing portion 6 can distribute the stress acting on the opening edge with the reinforcing portion 6, thereby preventing cracks from occurring in the lateral flange 203.

[0101] Furthermore, the reinforcing portion 7 has a curved shape that fits along the edge of the connecting hole 203 a. The connecting fitting 101 shown in Figure 22 can bring the reinforcing portion 7 into surface contact with the connecting hole 203 a so that it fits along the edge of the opening of the connecting hole 203 a, so that the reinforcing portion 7 can further distribute the stress acting on the opening edge.

[0102] Embodiment 3. Figure 23 is a conceptual diagram showing a method of connecting soil-retaining members 200 using a connecting fitting 100 according to embodiment 3. Figure 24 is another conceptual diagram showing a method of connecting soil-retaining members 200 using a connecting fitting 100 according to embodiment 3. Figure 23 shows the connection of soil-retaining members 200 adjacent in the vertical direction, and Figure 24 shows the connection of soil-retaining members 200 adjacent in the circumferential direction. A method of connecting soil-retaining members 200 using a connecting fitting 100 according to embodiment 3 will be described with reference to Figures 23 and 24. Components having the same functions and actions as those of the connecting fitting 100 described in embodiments 1 and 2 will be denoted by the same reference numerals and their description will be omitted. In the following description of the method of connecting soil-retaining members 200, the fastening of horizontal flanges 203 is described, but the description of fastening horizontal flanges 203 may also be applied to fastening vertical flanges 202.

[0103] The method for connecting earth retaining members 200 comprises a plurality of earth retaining members 200 arranged along the inner wall surface of an excavation hole, the earth retaining members 200 having horizontal flanges 203 with multiple connecting holes 203a formed therein, and the connecting fitting 100 according to embodiment 1 or 2. The method for connecting earth retaining members 200 using the connecting fitting 100 also comprises fixing members 60 such as bolts 61 and nuts 62 that fasten the horizontal flanges 203 of adjacent earth retaining members 200 together while the horizontal flanges 203 are butted against each other.

[0104] The fixing member 60 is, for example, a bolt 61 and a nut 62, but is not limited to the bolt 61 and the nut 62, and may be any other member that can fasten the overlapping horizontal flanges 203 in the same manner as the bolt 61 and the nut 62.

[0105] In the method of connecting earth retaining members 200 using connecting fittings 100 according to the third embodiment, bolts 61 and nuts 62 are attached to at least two of the connecting holes 203a in the horizontal flanges 203. In addition, in the method of connecting earth retaining members 200, connecting fittings 100 are attached to the connecting holes 203a other than the connecting holes 203a to which the bolts 61 and nuts 62 are attached, thereby fastening the horizontal flanges 203 of adjacent earth retaining members 200 together.

[0106] In the method of connecting earth-retaining members 200 using connecting fittings 100 according to embodiment 3, bolts 61 and nuts 62 are attached to the connecting holes 203a located at least on both ends of the horizontal flanges 203 out of the multiple connecting holes 203a in the horizontal flanges 203. In addition, in the method of connecting earth-retaining members 200 using connecting fittings 100 according to embodiment 3, connecting fittings 100 are attached to the connecting holes 203a other than the connecting holes 203a into which the bolts 61 and nuts 62 are attached out of the multiple connecting holes 203a in the horizontal flanges 203.

[0107] In the method of connecting soil-retaining members 200 using connecting fittings 100 according to the third embodiment, the horizontal flanges 203 of adjacent soil-retaining members 200 are fastened together by bolts 61 and nuts 62, and by connecting fittings 100. In the method of connecting soil-retaining members 200 according to the third embodiment, the horizontal flanges 203 are fastened together at least at both longitudinal ends of the soil-retaining members 200 by bolts 61 and nuts 62. In the method of connecting soil-retaining members 200 according to the third embodiment, the horizontal flanges 203 are fastened together by connecting fittings 100 in areas other than those fastened together by bolts 61 or the like.

[0108] As shown in Figure 23, when vertically adjacent soil-retaining members 200 are connected with a circumferential offset, both ends of each soil-retaining member 200 are fastened with bolts 61 and nuts 62, and therefore both ends and the central portion of each soil-retaining member 200 are also fastened with bolts 61 and nuts 62. For example, in the case shown in Figure 23, both ends of the lateral flanges 203 of each soil-retaining member 200 and the connecting holes 203a in the central portion are fastened with bolts 61 and nuts 62. In the case shown in Figure 4, both ends of the lateral flanges 203 of each soil-retaining member 200 and the connecting holes 203a in the next central portion are fastened with bolts 61 and nuts 62.

[0109] 24 , when connecting circumferentially adjacent earth retaining members 200, bolts 61 and nuts 62 are attached to at least two of the connecting holes 202a of the vertical flanges 202. In addition, in the method for connecting earth retaining members 200, connecting fittings 100 are attached to connecting holes 202a other than the connecting holes 202a to which the bolts 61 and nuts 62 are attached, thereby fastening the vertical flanges 202 of adjacent earth retaining members 200 together.

[0110] In the method of connecting earth-retaining members 200 using connecting fittings 100 according to embodiment 3, bolts 61 and nuts 62 are attached to the connecting holes 202a located at least at both the upper and lower ends of the vertical flanges 202 out of the plurality of connecting holes 202a in the vertical flanges 202. In the method of connecting earth-retaining members 200 using connecting fittings 100 according to embodiment 3, connecting fittings 100 are attached to the connecting holes 202a other than the connecting holes 202a into which the bolts 61 and nuts 62 are attached out of the plurality of connecting holes 202a in the vertical flanges 202.

[0111] In the method of connecting soil-retaining members 200 using connecting fittings 100 according to the third embodiment, the vertical flanges 202 of adjacent soil-retaining members 200 are fastened together by bolts 61 and nuts 62, and by connecting fittings 100. In the method of connecting soil-retaining members 200 according to the third embodiment, the vertical flanges 202 are fastened together at least at both ends of the soil-retaining members 200 in the vertical direction by bolts 61 and nuts 62. In the method of connecting soil-retaining members 200 according to the third embodiment, the vertical flanges 202 are fastened together by connecting fittings 100 in areas other than those fastened with bolts 61 or the like. In the method of connecting soil-retaining members 200 using connecting fittings 100 according to the third embodiment, the bolts 61 and connecting fittings 100 are used in combination, and the connecting fittings 100 can be attached either upward or downward.

[0112] [Function and effect of the method for connecting earth-retaining members 200] In the method for connecting earth-retaining members 200 using connecting fittings 100, bolts 61 and nuts 62 are attached to at least two of the multiple connecting holes 203a in the horizontal flanges 203. Furthermore, in the method for connecting earth-retaining members 200 using connecting fittings 100, connecting fittings 100 are attached to the multiple connecting holes 203a in the horizontal flanges 203 other than the connecting holes 203a to which the bolts 61 and nuts 62 are attached. In the method for connecting earth-retaining members 200 using connecting fittings 100, the horizontal flanges 203 of adjacent earth-retaining members 200 are fastened together by the bolts 61 and nuts 62 and the connecting fittings 100.

[0113] The horizontal flanges 203 of adjacent earth retaining members 200 may all be fastened together using connecting fittings 100, or bolts 61 may also be used where appropriate. Connecting fittings 100 are generally made of iron, and so may be subject to deformation if repeatedly attached and detached from horizontal flanges 203, etc. Using spring steel or the like instead of ordinary steel as the material for connecting fittings 100 would allow the shape to be maintained, but would be expensive. On the other hand, bolts 61 are easy to remove and use when positioning during construction.

[0114] Therefore, in the method of connecting the earth retaining members 200, if conventional bolts 61 are used in situations where the fixing members 60, etc. are to be removed, and connecting fittings 100 are used otherwise, construction speed will improve by roughly 50%, and overall workability will be improved. In the method of connecting the earth retaining members 200, the bolts 61 and nuts 62 are used to fine-tune the positions of the lateral flanges 203 and position them, and connecting fittings 100 can be used to simply and quickly fasten the lateral flanges 203 together.

[0115] Furthermore, in a method of connecting earth-retaining members 200 using connecting fittings 100, bolts 61 and nuts 62 are attached to the connecting holes 203a located at both ends of the multiple connecting holes 203a in the horizontal flanges 203. In a method of connecting earth-retaining members 200 using connecting fittings 100, connecting fittings 100 are attached to the connecting holes 203a in the horizontal flanges 203 other than the connecting holes 203a to which the bolts 61 and nuts 62 are attached. In other words, in a method of connecting earth-retaining members 200 using connecting fittings 100, the horizontal flanges 203 are fastened to each other at both circumferential ends of the horizontal flanges 203 by bolts 61 and nuts 62, and the horizontal flanges 203 are fastened to each other by connecting fittings 100 in parts other than those fastened by bolts 61, etc.

[0116] In the method for connecting the earth-retaining members 200, the horizontal flanges 203 can be reliably positioned by fastening both circumferential ends of the horizontal flanges 203 with bolts 61 and nuts 62, which have strong fastening force. In the method for connecting the earth-retaining members 200, the horizontal flanges 203, whose positioning is ensured by the bolts 61 and nuts 62, can be easily and quickly fastened to each other using the connecting fittings 100. Note that the effect of connecting adjacent horizontal flanges 203 described above can also be applied to connecting adjacent vertical flanges 202 with the connecting fittings 100 and bolts 61 attached to the multiple connecting holes 202a.

[0117] While the linking fittings 100 and 101 have been described above based on the embodiments, the linking fittings 100 and 101 are not limited to the configurations of the above-described embodiments. For example, the linking fittings 100 and 101 are not limited to the components described above, and may include other components. In short, the linking fittings 100 and 101 include the range of design modifications and application variations that would normally be made by a person skilled in the art, as long as they do not deviate from the technical concept.

[0118] DESCRIPTION OF SYMBOLS 1 Connecting fitting main body, 1a First side edge, 1b Second side edge, 1c Plate surface, 1d Plate surface, 2 Insertion portion, 2a Tip portion, 3 Clamping portion, 3a Tip portion, 4 Reinforcement portion, 5 Reinforcement portion, 6 Reinforcement portion, 7 Reinforcement portion, 8 Squeezing portion, 10 One end edge, 11 Other end edge, 12 Protrusion portion, 15 Mark portion, 20 Step portion, 20a Side edge, 20b Side edge, 20c Step center portion, 30 Insertion portion, 31 Mountain-shaped portion, 31a Apex portion, 60 Fixing member, 61 Bolt, 62 Nut, 100 Connecting fitting, 101 Connecting fitting, 200 Earth retaining member, 201 Corrugated steel plate, 202 Vertical flange, 202a Connection hole, 203 Horizontal flange, 203a Connection hole, 203b Edge, 300 earth retaining structure, 301 structure, AL arrow, D depth direction, L1 displacement, LS shortest distance, P earth pressure, VL virtual line, VL1 virtual line, X longitudinal direction, Y lateral direction, r radial direction, α angle, θ circumferential direction.

Claims

1. A soil retaining member arranged in plurality along the inner wall surface of an excavation hole, and a connecting fitting for connecting the flanges of adjacent soil retaining members in a state where the flanges are abutted against each other, the soil retaining member having a plurality of connecting holes, the connecting fitting comprising: a plate-shaped connecting fitting main body; an insertion portion formed by bending L-shaped from one end edge of the connecting fitting main body portion to one surface side of the connecting fitting main body portion and inserted into at least one of the connecting holes formed in the flange; and a clamping portion formed by bending U-shaped from the other end edge of the connecting fitting main body portion to the one surface side of the connecting fitting main body portion and clamping the edge of the abutted flange together with the connecting fitting main body portion. The insertion portion is inclined at a predetermined angle with respect to the extending direction of the connecting fitting main body portion such that when the connected adjacent flanges are displaced relative to each other in the radial direction of the excavation hole, the side edge of the stepped portion connecting the connecting fitting main body portion and the insertion portion abuts against the opening edge of the connecting hole. The angle between the insertion portion and the stepped portion is formed to be an acute angle, and the connecting fitting is attached to the flange and the tip of the insertion portion abuts against the flange in a state where the flanges are connected to each other.

2. The connecting fitting according to claim 1, wherein the angle between the insertion portion and the stepped portion is greater than 65 degrees and less than 90 degrees.

3. The connecting fitting according to claim 1, wherein the angle between the insertion portion and the stepped portion is 80 degrees or more and less than 90 degrees.

4. The connecting fitting according to claim 1, wherein the angle between the insertion portion and the stepped portion is 85 degrees.

5. The connecting fitting according to any one of claims 1 to 4, wherein the connecting fitting main body portion has a protruding portion formed to partially bulge and protrude near the stepped portion.

6. When the longitudinal direction of the connecting fitting main body is the direction between the clamping portion and the stepped portion, the connecting fitting main body has, in a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body, two side edges along the longitudinal direction of the connecting fitting main body. Among the two side edges, the first side edge is formed longer than the second side edge. In a direction perpendicular to the extending direction of the stepped portion, the first side edge has a constricted portion that is arcuately recessed toward the clamping portion and the stepped portion side on the opposite side of the insertion portion across the stepped portion. The protrusion is formed at a position closer to the stepped portion than the constricted portion in a direction perpendicular to the extending direction of the stepped portion when seen in a direction perpendicular to the plate surface of the connecting fitting main body. The connecting fitting according to claim 5.

7. In a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body, when the length of the stepped portion in the extending direction of the stepped portion is defined as the width of the stepped portion, the protrusion is formed within the range of the width of the stepped portion of the connecting fitting main body located in a direction intersecting the extending direction of the stepped portion. The connecting fitting according to claim 5 or 6.

8. In a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body, when the central portion of the length of the stepped portion in the extending direction of the stepped portion is defined as the stepped center portion and a virtual straight line passing through the stepped center portion in a direction perpendicular to the extending direction of the stepped portion is defined as a virtual line, the protrusion is formed so as to be located on the virtual line. The connecting fitting according to any one of claims 5 to 7.

9. The protrusion is formed such that at least a part thereof is located on the connecting hole of the flange when attached to the flange. The connecting fitting according to any one of claims 5 to 8.

10. The protrusion is formed to protrude on the plate surface of the connecting fitting main body on the side opposite to the side where the insertion portion is arranged, on the side opposite to the insertion portion. The connecting fitting according to any one of claims 5 to 9.

11. The protrusion is formed to protrude on the side where the insertion portion is arranged on the plate surface of the connecting fitting main body on the side where the insertion portion is arranged. The connecting fitting according to any one of claims 5 to 9.

12. The connecting fitting according to claim 11, wherein the protrusion is formed so as to be in contact with the plate surface of the flange when attached to the flange.

13. The connecting fitting according to claim 11, wherein the protrusion is formed so as to be inserted into the connecting hole of the flange when attached to the flange.

14. When the longitudinal direction of the connecting fitting main body is the direction between the clamping portion and the step portion, in a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body, the connecting fitting main body has two side edges along the longitudinal direction of the connecting fitting main body. Among the two side edges, the first side edge is formed longer than the second side edge. In a direction perpendicular to the extending direction of the step portion, the first side edge has a constriction portion that is arcuately recessed toward the clamping portion and the step portion side on the opposite side of the insertion portion across the step portion. In a plan view seen in a direction perpendicular to the plate surface of the connecting fitting main body, when the length of the step portion in the extending direction of the step portion is defined as the width of the step portion, the shortest distance between the second side edge and the first side edge of the constriction portion is formed longer than the width of the step portion. The connecting fitting according to claim 5.

15. The connecting fitting according to any one of claims 1 to 14, wherein the connecting fitting main body has a marking portion on the plate surface on the side opposite to the side where the clamping portion is disposed, which serves as a mark for the fitting position of the flange when the edge of the flange is clamped by the connecting fitting main body and the clamping portion.

16. In a side view seen in the extending direction of the clamping portion, the clamping portion has a mountain-shaped portion at a position facing the connecting fitting main body. The mountain-shaped portion is formed by being bent in a mountain-fold shape so as to approach the connecting fitting main body in a side view seen in the extending direction of the clamping portion. When the portion closest to the connecting fitting main body among the mountain-shaped portions is defined as the apex portion, in a direction perpendicular to the plate surface of the connecting fitting main body, the marking portion is formed at a position facing the apex portion. The connecting fitting according to claim 15.

17. The connecting fitting main body portion is formed to be inclined in a direction in which the flange extends with respect to the radial direction of the excavation hole in a state where the flanges of the adjacent earth retaining members are connected to each other, and the insertion portion is formed to be inclined from the direction in which the connecting fitting main body portion extends and further in the direction in which the flange extends. The connecting fitting according to any one of claims 1 to 16.

18. The connecting fitting according to any one of claims 1 to 17, further comprising a reinforcing portion that abuts against and is in surface contact with the opening edge of the connecting hole instead of or together with the side edge of the step portion.

19. The connecting fitting according to claim 18, wherein the reinforcing portion is configured by attaching a steel plate to the side edge of the step portion.

20. The connecting fitting according to claim 18, wherein the reinforcing portion is formed by bending a part from the side edge of the step portion or the side end edge of the connecting fitting main body portion.

21. The connecting fitting according to any one of claims 18 to 20, wherein the reinforcing portion has a shape curved along the opening edge of the connecting hole.

22. A method for connecting earth retaining members, comprising the connecting fitting according to any one of claims 1 to 17, the earth retaining members arranged in plurality along the inner wall surface of the excavation hole and having flanges formed with a plurality of connecting holes, and bolts and nuts for fastening the flanges to each other in a state where the flanges of the adjacent earth retaining members are butted against each other. At least two or more of the plurality of connecting holes in the flange are provided with the bolts and the nuts, and the connecting fitting is attached to the connecting holes other than the connecting holes to which the bolts and the nuts are attached, and the flanges of the adjacent earth retaining members are fastened.

23. The method for connecting earth retaining members according to claim 22, wherein the bolts and the nuts are attached to the connecting holes located at at least both ends of the flange, and the connecting fitting is attached to the connecting holes other than the connecting holes to which the bolts and the nuts are attached, and the flanges of the adjacent earth retaining members are fastened.

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