Earth retaining wall support structure

Abstract

To provide a support structure of an earth retaining wall that is applicable even when a gap between an earth retaining wall and a boundary line of a site on which the earth retaining wall is constructed is relatively narrow.SOLUTION: A support structure 12 comprises: tensioned ground anchors 20 that are arranged with intervals from each other along an earth retaining wall 10, extend vertically underground, and have heads 20a that protrude above the ground; and a plurality of metal fittings 22 arranged on the ground with intervals from each other along the earth retaining wall. Each metal fitting comprises: a first flat plate portion 24 being in contact with the ground surface and having one end and the other end; an inclined plate portion 26 extending diagonally upward from the first flat plate portion; and a second flat plate portion 28 provided with a hole. Each metal fitting is fastened to the head of the ground anchor at one end of the first flat plate portion, and is in contact with a head of a core material of the earth retaining wall at the other end of the first flat plate portion. The second flat plate portion surrounds the head of the core material of the earth retaining wall that passes through the hole, at the hole.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a support structure for an earth retaining wall. [Background technology]

[0002] Conventionally, a support structure for an earth retaining wall has been proposed, which includes a plurality of tensioned ground anchors that are installed around the earth retaining wall and extend vertically underground to prevent the earth retaining wall, which includes a plurality of core members, from collapsing, and metal fittings that receive the tension of each ground anchor and apply a bending moment to each core member of the earth retaining wall.

[0003] The metal fitting consists of a straight, horizontal arm member, and its both ends are fixed to the head of the ground anchor that protrudes above ground and the head of the core material of the earth retaining wall that protrudes above ground, respectively. In this way, the core material of the earth retaining wall receives the bending moment and bends toward the back of the earth retaining wall, thereby preventing the earth retaining wall from collapsing.

[0004] However, under ground conditions where the ground on which the earth retaining wall is to be constructed is soft and therefore the lateral pressure acting on the wall is relatively large, it is necessary to make the arm member relatively long in order to obtain a relatively large bending moment. However, depending on the size of the gap between the earth retaining wall and the boundary line of the site, it may be difficult to ensure the arm member length necessary to obtain the required bending moment. Furthermore, to resolve this issue, it may be necessary to reduce the size of the earth retaining wall to be constructed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-136922 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a support structure for an earth retaining wall that is applicable even when the distance between the earth retaining wall and the boundary line of the site on which the earth retaining wall is constructed is relatively narrow. [Means for solving the problem]

[0007] The present invention relates to a support structure for an earth retaining wall that includes a plurality of core members that are installed underground at intervals from one another and have heads that protrude above ground.

[0008] In one embodiment, the support structure comprises a plurality of tensioned ground anchors arranged at intervals along the earth retaining wall, extending vertically underground and having heads protruding above ground, and a plurality of metal fittings arranged at intervals along the earth retaining wall, each metal fitting comprising a first flat plate portion having one end and another end that contacts the ground surface, an inclined plate portion extending diagonally upward from the first flat plate portion, and a second flat plate portion having a hole and extending from the tip of the inclined plate portion parallel to the first flat plate portion. One end of each metal fitting is fixed to the head of the ground anchor, the other end of each first flat plate portion abuts against the head of a core material of the earth retaining wall, and the second flat plate portion surrounds the head of the core material of the earth retaining wall that passes through the hole in its hole.

[0009] According to one embodiment of the present invention, one end of each metal fitting's first plate portion receives the tension of each ground anchor and receives a vertically downward tensile force, and the second plate portion located above the first plate portion of each metal fitting abuts against the head of each core material passing through its hole. As a result, each core material is subjected to a bending moment at its head that causes it to deflect toward the ground behind the earth retaining wall. As a result, the earth retaining wall is prevented from collapsing to the side opposite the ground. In addition, the other end of the first plate portion abutting against the head of each core material at a position below the second plate portion functions to limit the range of deflection of each core material to the head of each core material. As a result, the portion of each core material located below the head is maintained in a vertically extended state.

[0010] In one embodiment of the present invention, the magnitude of the bending moment depends on the length of the inclined plate portion of the metal fitting, and the length of the inclined plate portion depends on the inclination angle of the inclined plate portion relative to the first flat plate portion. Therefore, it is possible to set the bending moment to a required magnitude regardless of the length between the two ends of the first flat plate portion of the metal fitting. As a result, even if the gap between the earth retaining wall and the boundary line between the site on which the earth retaining wall is to be constructed and the adjacent land is relatively narrow, the metal fitting can be installed between them, and the support structure can be applied to the earth retaining wall.

[0011] The first flat plate portion of the metal fitting may have a hole formed at one end thereof, and the head of the ground anchor may be passed through the hole and fixed to the one end.

[0012] A support structure for an earth retaining wall according to another embodiment of the present invention comprises a plurality of ground anchors similar to the plurality of ground anchors in the first embodiment, a plurality of metal fittings connected to each other, and a tension transmission structure. Here, the plurality of connected metal fittings are arranged on the ground along the earth retaining wall at intervals from each other so that the heads of the ground anchors are located between two adjacent metal fittings. Like the metal fittings in the first embodiment, each metal fitting comprises a first flat plate portion having one end and the other end that contacts the ground surface, an inclined plate portion extending diagonally upward from the first flat plate portion, and a second flat plate portion having a hole formed therein and extending from the tip of the inclined plate portion parallel to the first flat plate portion. The multiple metal fittings connected to each other receive the tension of the ground anchor via the tension transmission structure at one end of their first flat plate portions, and are abutted at the other end of their first flat plate portions against the heads of the multiple core materials of the retaining wall, and their second flat plate portions each surround the heads of the multiple core materials of the retaining wall that pass through their holes.

[0013] In another embodiment of the present invention, the multiple metal fittings receive a vertically downward tensile force at one end of their first plate portion via the tension transmission structure, receiving the tension of the multiple ground anchors. As in the first embodiment, the multiple metal fittings receive the tensile force, and the second plate portion located above the first plate portion of the multiple metal fittings abuts against the heads of the core members passing through its holes. As a result, the multiple core members are subjected to a bending moment at their heads that causes them to deflect toward the ground behind the earth retaining wall. As a result, the earth retaining wall is prevented from collapsing to the side opposite the ground. Also, as in the first embodiment, the other end of the first plate portion abutting against the heads of the core members at a position below the second plate portion functions to limit the range of deflection of each core member to the heads of each core member. As a result, the portions of each core member below the heads are maintained in a vertically extended state.

[0014] In this other embodiment of the present invention, as in the first embodiment, the magnitude of the bending moment depends on the length of the inclined plate portion of the metal fitting, and the length of the inclined plate portion depends on the inclination angle of the inclined plate portion relative to the first flat plate portion. Therefore, it is possible to set the bending moment to a required magnitude regardless of the length between the two ends of the first flat plate portion of the metal fitting. Furthermore, this also makes it possible to install the metal fitting between the earth retaining wall and the boundary line between the site on which the earth retaining wall is to be constructed and the neighboring land, even when the gap between these two is relatively narrow, and it is possible to apply a support structure to the earth retaining wall.

[0015] The tension transmission structure may comprise a pair of elongated members arranged on one end of the first flat plate portions of the plurality of metal fittings and extending across the one end, and a plurality of pedestals arranged on both elongated members, each pedestal being fixed to the head of a respective ground anchor.

[0016] In the one embodiment and the other embodiment, the inclination angle of the inclined plate portion relative to the first flat plate portion of the metal fitting is preferably set to any angle within a range of 45 degrees to 60 degrees. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a plan view showing a support structure of an earth retaining wall according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. [Figure 3] FIG. 10 is a plan view showing a support structure for an earth retaining wall according to another embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0018] 1 and 2, a support structure (one support structure) of an earth retaining wall 10 according to one embodiment is generally indicated by the reference numeral 12. Also, in FIGS. 3 and 4, a support structure (another support structure) of an earth retaining wall 10 according to another embodiment is generally indicated by the reference numeral 14.

[0019] The illustrated earth retaining wall 10 has an overall rectangular planar shape. However, the earth retaining wall to be supported may have planar shapes other than the rectangular shape, such as a polygon, a circle, or a straight line. The illustrated earth retaining wall 10 comprises side wall portions 10a extending along each side of the rectangle. The earth retaining wall 10 includes a plurality of core members 16 arranged at intervals along each side wall portion 10a and extending vertically through the ground (underground) E. Each core member 16 has a head portion 16a protruding above ground. In the illustrated example, the core members 16 are made of H-shaped steel, and sheet piles 18 that, together with the H-shaped steel, form the earth retaining wall 10 are placed between a pair of flanges of one H-shaped steel and a pair of flanges of the other H-shaped steel of two adjacent H-shaped steels.

[0020] Both the first support structure 12 and the second support structure 14 include a plurality of tensioned ground anchors 20 arranged at intervals along the earth retaining wall 10, more specifically along each side wall portion 10a, and extending vertically underground E, and a plurality of metal fittings 22 arranged at intervals along the earth retaining wall 10, more specifically along each side wall portion 10a. In the illustrated example, the earth retaining wall 10 is surrounded by the plurality of ground anchors 20 and the plurality of metal fittings 22. Like the core material 16, each ground anchor 20 has a head portion 20a that protrudes above ground (see FIGS. 2 and 4).

[0021] The plurality of metal fittings 22 of one support structure 12 are arranged corresponding to the plurality of ground anchors 20 (see FIG. 1).

[0022] In contrast, the multiple metal fittings 22 of the other support structure 14 are connected to each other at the tips of their second flat plate portions 28 (described later) via connecting members 23 such as H-shaped steel, and are arranged so that the heads 20a of the ground anchors 20 are located between two adjacent metal fittings 22 (see Figures 3 and 4). In addition to the multiple ground anchors 20 and the multiple metal fittings 22 connected to each other, the other support structure 14 also includes a tension force transmission structure 25. The tension force transmission structure 25 will be described in detail later.

[0023] Each metal fitting 22 comprises a first flat plate portion 24 that contacts the ground surface S, an inclined plate portion 26, and a second flat plate portion 28. In the illustrated example, the first flat plate portion 24, the inclined plate portion 26, and the second flat plate portion each have a rectangular planar shape. The first flat plate portion 24 has one end portion 24a and the other end portion 24b that face each other. The inclined plate portion 26 extends diagonally upward from the first flat plate portion 24, in the illustrated example, from a position approximately midway between the end portions 24a, 24b. The second flat plate portion 28 extends from the tip of the inclined plate portion 26 in parallel to the first flat plate portion 24. A rectangular hole 28a is provided through the second flat plate portion 28 in the illustrated example.

[0024] 1 and 2, in one support structure 12, each metal fitting 22 is fixed to the head 20a of the ground anchor 20 at one end 24a of its first flat plate portion 24, and is abutted against the head 16a of the core material 16 of the earth retaining wall 10 at the other end 24b of the first flat plate portion 24, and the second flat plate portion 28 surrounds the periphery of the head 16a of the core material 16 of the earth retaining wall 10, which passes through the hole 28a in the second flat plate portion 22. In the illustrated example, the first flat plate portion 24 has a hole 30 formed in its one end 24a, and the head 20a of the ground anchor 20 passes through the hole 30 and is fixed to the one end 24a. The head 20a of the ground anchor 20 is protected by a cap 32 placed over it.

[0025] According to one support structure 12, each metal fitting 22 receives a tension force from each ground anchor 20 at one end 24a of its first flat plate portion 24, resulting in a vertically downward tensile force, and the second flat plate portion 28 located above the first flat plate portion 24 of each metal fitting 22 abuts against the head 16a of each core material 16 passing through its hole 28a. As a result, each core material 16 is subjected to a bending moment at its head 16a that causes it to deflect toward the ground E behind the earth retaining wall 10. As a result, the earth retaining wall 10 is prevented from collapsing to the side opposite the ground E. In addition, the other end 24b of the first flat plate portion 24 abutting against the head 16a of each core material 16 at a position below the second flat plate portion 28 functions to limit the range of deflection of each core material 16 to the head 16a of each core material 16. This allows the portion 16b of each core 16 located below the head 16a to be maintained in a vertically extended state.

[0026] In one support structure 12, the magnitude of the bending moment depends on the length of the inclined plate portion 26 of the metal fitting 22 (the length from the point where it connects to the first flat plate portion 24 to the point where it connects to the second flat plate portion 28), and the length of the inclined plate portion 26 depends on the inclination angle θ of the inclined plate portion 26 with respect to the first flat plate portion 24, and therefore the length between the first and second flat plate portions 24, 28. Therefore, it is possible to set the bending moment to a required magnitude regardless of the length between the end portions 24a, 24b of the first flat plate portion 24 of the metal fitting 22, i.e., the length in the extension direction of the flat plate portion 24 (the left-right direction as viewed in Figure 2). For this reason, even if the distance D between the earth retaining wall 10 and the boundary line L between the site on which the earth retaining wall 10 is to be constructed and the adjacent land is relatively narrow, the metal fitting 22 can be installed therebetween, and the support structure 12 can be applied to the earth retaining wall 10.

[0027] In contrast, in another support structure 14, as shown in Figures 3 and 4, multiple metal fittings 22 connected to each other each receive the tension of the ground anchor 20 at one end 24a of their first flat plate portions 24 via a tension transmission structure 25, and each abut against the heads 16a of multiple core materials 16 of the retaining wall 10 at the other end 24b of their first flat plate portions 24, and each second flat plate portion 28 surrounds the heads 16a of the multiple core materials 16 that pass through their respective holes 28a.

[0028] In the other support structure 14, as in the first support structure 12, the magnitude of the bending moment depends on the length of the inclined plate portion 26 of the metal fitting 22, and the length of the inclined plate portion 26 depends on the inclination angle θ of the inclined plate portion 26 with respect to the first flat plate portion 24. This makes it possible to set the bending moment to a required magnitude regardless of the length between the end portions 24a, 24b of the first flat plate portion 24 of the metal fitting 22. Furthermore, this makes it possible to install the metal fitting 22 between the earth retaining wall 10 and the boundary line L between the site on which the earth retaining wall 10 is to be constructed and the adjacent land even when the distance D therebetween is relatively narrow, making it possible to apply another support structure 14 to the earth retaining wall 10.

[0029] The tension transmission structure shown in the figure comprises a pair of long members 34, for example made of H-shaped steel, that are placed on one ends 24a of the first flat plate portions 24 of the multiple metal fittings 22 and extend across these one ends 24a, and a plurality of pedestals 36 made of flat plates that are placed on both long members 34. Each pedestal 36 is fixed to the head 20a of each ground anchor 20.

[0030] In the first support structure 12 and the second support structure 14, the inclination angle θ of the inclined plate portion 26 relative to the first flat plate portion 24 of the metal fitting 22 is preferably set to any angle within the range of 45 degrees to 60 degrees. [Explanation of symbols]

[0031] 10 Mountain retaining wall 12. One support structure 14 Other supporting structures 16 Core material of earth retaining wall 16a Core head 20 Ground anchor 20a Ground anchor head 22 Metal fittings 24 First flat part of metal fitting 24a, 24b One end and the other end of the first flat plate portion 26 Inclined plate part of metal fittings 28 Second flat part of metal fitting 28a Hole in the second flat part of the bracket 34 Long members 36 Pedestal

Claims

1. A support structure for an earth retaining wall including a plurality of core members arranged at intervals from each other, extending vertically underground, and having heads protruding above ground, a plurality of tensioned ground anchors arranged at intervals along the retaining wall, extending vertically into the ground and having heads protruding above ground; a plurality of metal fittings arranged on the ground at intervals along the retaining wall, each of the metal fittings comprising a first flat plate portion having one end and the other end in contact with the ground surface, an inclined plate portion extending obliquely upward from the first flat plate portion, and a second flat plate portion having a hole formed therein and extending from the tip of the inclined plate portion parallel to the first flat plate portion; A support structure for an earth retaining wall, in which each metal fitting is fixed to the head of the ground anchor at one end of its first flat plate portion, abuts against the head of the core material of the earth retaining wall at the other end of its first flat plate portion, and its second flat plate portion surrounds the periphery of the head of the core material of the earth retaining wall that passes through the hole.

2. 2. The earth retaining wall support structure according to claim 1, wherein the first flat plate portion of the metal fitting has a hole formed at one end thereof, and the head of the ground anchor is passed through the hole and fixed to the one end thereof.

3. A support structure for an earth retaining wall including a plurality of core members arranged at intervals from each other, extending vertically underground, and having heads protruding above ground, a plurality of tensioned ground anchors arranged at intervals along the retaining wall, extending vertically into the ground and having heads protruding above ground; a plurality of metal fittings connected to each other and arranged on the ground along the retaining wall at intervals and with the head of the ground anchor located between two adjacent metal fittings, each metal fitting comprising a first flat plate portion having one end and the other end in contact with the ground surface, an inclined plate portion extending diagonally upward from the first flat plate portion, and a second flat plate portion having a hole formed therein and extending from the tip of the inclined plate portion parallel to the first flat plate portion; and a tension transmission structure, A support structure for an earth retaining wall, in which a plurality of metal fittings each receive the tension of the ground anchor via the tension transmission structure at one end of their first flat plate portions, and abut against the heads of a plurality of core materials of the earth retaining wall at the other end of their first flat plate portions, and the second flat plate portions each surround the periphery of the heads of a plurality of core materials of the earth retaining wall that pass through their holes.

4. 4. The support structure for an earth retaining wall according to claim 3, wherein the tension transmission structure comprises a pair of elongated members arranged on one end of the first flat plate portions of the plurality of metal fittings and extending across said one end, and a plurality of pedestals arranged on both elongated members, each pedestal being fixed to a head of a respective ground anchor.

5. The supporting structure of the retaining wall according to any one of claims 1 to 4, wherein the inclination angle of the inclined plate portion relative to the first flat plate portion of the metal fitting is set to any one within the range of 45 degrees to 60 degrees.

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