Reinforced soil wall for river revetment

Abstract

To provide a reinforced soil wall for river revetment which can prevent damage of a member for suppressing overturning and sliding of a wall surface material, when constructing a reinforced soil wall.SOLUTION: A reinforced soil wall 2 for river revetment includes: a revetment block 4 installed so as to face a river R; a suction-proof material 6 installed along a rear face 4d of the revetment block 4; a back-filling material 8 laid on the rear side of the suction-proof material 6; a frame material 10 installed on the rear side of the back-filling material 8; a reinforcement material 12 extending backward from the lower end of the frame material 10; and a metal fitting 14 which extends backward from an upper face 4a of the revetment block 4, and is made of metal. The metal fitting 14 has a vertical part 14a extending in a vertical direction, and a horizontal part 14b horizontally extending from the upper end of the vertical part 14a. An insertion hole is formed in the upper face 4a of the revetment block 4. The revetment block 4 and the metal fitting 14 are connected to each other by inserting the vertical part 14a of the metal fixing 14 into the insertion hole of the revetment block 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reinforced earth wall for riverbank protection. [Background technology]

[0002] Patent Document 1 below discloses a reinforced earth wall that can prevent the coping board from shifting. This reinforced earth wall includes a wall body, an embankment constructed behind the wall body, and a sheet-like reinforcing material buried within the embankment. The wall body includes a plurality of stacked precast concrete wall materials and a precast concrete coping board placed on the topmost wall material. The wall materials are provided with a first recess or a first protrusion, and the coping board is provided with a second protrusion or a second recess. In the reinforced earth wall, the second protrusion is inserted into the first recess from above, or the second recess is fitted into the first protrusion from above, thereby preventing the coping board from shifting.

[0003] The reinforced earth wall also includes a synthetic resin grid belt to prevent the wall material from tipping over or sliding. The grid belt is passed through fixing holes in the wall material and secured in a tensioned state by fixing pins. The fixing holes are formed in a pair of protrusions extending vertically on the rear surface of the wall material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-665 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned reinforced earth wall, there is a risk that the grid belt may be damaged during construction. Because the grid belt is made of synthetic resin, when the grid belt is passed through the fixing holes of the concrete wall material, the grid belt may rub against the inner surface of the fixing holes and be damaged. In addition, after the grid belt is passed through the fixing holes of the wall material, backfill material (crushed stone) is poured behind the wall material, and the grid belt may be damaged by the pouring of the backfill material. In addition, it is possible to attach protective members to the grid belt to prevent damage to the grid belt, but attaching protective members to all grid belts requires a great deal of effort.

[0006] Furthermore, because reinforced earth walls have high earthquake resistance, their use as river bank protection is being considered, but there is a problem in that conventional reinforced earth walls cannot be used for river bank protection. The facing materials used for reinforced earth walls are not able to withstand the impact of driftwood or boulders, and when reinforced earth walls are used for river bank protection, there is a concern that the fill material may be sucked out. Therefore, reinforced earth walls cannot be used for river bank protection if they remain in the conventional structure.

[0007] An object of the present invention is to provide a reinforced earth wall for river embankments that can prevent damage to members that prevent wall facing materials from tipping over and sliding when the wall is constructed. [Means for solving the problem]

[0008] According to the present invention, there is provided the following reinforced earth wall for river bank protection that solves the above-mentioned problems: "A reinforced earth wall for riverbank protection, Revetment blocks installed facing the river, a suction prevention material installed along the rear surface of the revetment block; A backfill material laid behind the suction prevention material; A frame material installed behind the backfill material; a reinforcing member extending rearward from the lower end of the frame member; a metal anchoring fitting extending rearward from the upper surface of the revetment block, The fixing fixture has a vertical portion extending in the up-down direction and a horizontal portion extending horizontally from an upper end of the vertical portion, An insertion hole into which the vertical portion of the anchoring fitting is inserted is formed on the upper surface of the revetment block, The vertical portion of the anchoring fitting is inserted into the insertion hole of the revetment block, thereby providing a reinforced earth wall for river revetment in which the revetment block and the anchoring fitting are connected.

[0009] Preferably, a recess extending rearward from the insertion hole is formed in the upper surface of the revetment block, and a portion of the horizontal portion of the anchoring fitting is accommodated in the recess. The horizontal portion of the anchoring fitting is desirably fastened to the upper surface of the revetment block via a fastener. The insertion hole of the revetment block may be formed 15 cm or more forward from the rear surface of the revetment block. It is preferable that the insertion depth of the vertical portion of the anchoring fitting into the insertion hole of the revetment block be 3 cm or more and 10 cm or less.

[0010] It is desirable that the frame member have a bottom portion and an upright portion extending upward from the front end of the bottom portion, and that the horizontal portion of the fastening metal fitting pass through the upright portion of the frame member.

[0011] A layer of crushed stone is preferably laid behind the frame member up to at least the same height as the predetermined water level of the river. The horizontal portion of the anchoring fitting may be fixed to the layer of crushed stone via a fastener. Additional anti-suction material may be provided along the rear surface of the frame member. [Effects of the Invention]

[0012] In the reinforced earth wall of the present invention, the anchoring fittings are made of metal, which prevents damage to the anchoring fittings when inserting their vertical portions into the insertion holes of the revetment blocks. Furthermore, in the reinforced earth wall of the present invention, the revetment blocks and the anchoring fittings are connected by inserting their vertical portions into insertion holes formed on the top surfaces of the revetment blocks. Therefore, the anchoring fittings can be connected to the revetment blocks after the backfill material has been laid, preventing damage to the anchoring fittings caused by the introduction of the backfill material. Therefore, according to the present invention, damage to the anchoring fittings that prevent the revetment blocks, which form the wall surface materials, from tipping and sliding can be prevented when constructing the reinforced earth wall. Furthermore, the reinforced earth wall of the present invention can be used for river bank protection because the revetment blocks prevent damage caused by collisions with driftwood and the like, and the suction prevention material prevents suction. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view of a reinforced earth wall for river bank protection according to the present invention. [Figure 2] FIG. 2 is a perspective view of the revetment block shown in FIG. 1. [Figure 3] Cross-sectional view taken along line III-III in Figure 2. [Figure 4] Cross-sectional view taken along line IV-IV in Figure 2. [Figure 5] FIG. 2 is a perspective view of the frame member shown in FIG. [Figure 6] FIG. 2 is a perspective view of the reinforcement member shown in FIG. 1. [Figure 7] FIG. 2 is a perspective view of the fastening fixture shown in FIG. [Figure 8] Schematic diagram showing the state after the revetment blocks and suction prevention materials have been installed. [Figure 9] 9 is a schematic diagram showing the state in which a frame material and additional anti-evacuation material have been installed from the state shown in FIG. 8. [Figure 10] 10 is a schematic diagram showing the state in which a reinforcing material has been installed following the state shown in FIG. 9. [Figure 11] A schematic diagram showing the state in which backfill material and a layer of crushed stone have been laid up to the height of the top surface of the installed revetment blocks, from the state shown in Figure 10. [Figure 12]12 is a schematic diagram showing the state in which the fixing fittings have been installed from the state shown in FIG. 11. [Figure 13] 13 is a schematic diagram showing the state in which revetment blocks are stacked from the state shown in FIG. 12 and backfill material and a crushed stone layer are laid up to the height of the top surfaces of the stacked revetment blocks. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, preferred embodiments of a reinforced earth wall for riverbank protection according to the present invention will be described with reference to the drawings.

[0015] (Reinforced earth wall 2) As shown in Figure 1, a reinforced earth wall 2 for protecting the bank of a river R comprises bank protection blocks 4, suction prevention material 6, backfill material 8, frame material 10, reinforcing material 12, and anchoring fittings 14. The reinforced earth wall 2 of this embodiment also comprises additional suction prevention material 16, a crushed stone layer 18, and embankment 20. As shown in Figures 1 and 2, the front of the reinforced earth wall 2 (the river R side) is the +X direction, the rear of the reinforced earth wall 2 is the -X direction, the width direction of the reinforced earth wall 2 is the Y direction (see Figure 2 for the positive and negative sides of the Y direction), the upper side is the +Z direction, and the lower side is the -Z direction. The X, Y, and Z directions are perpendicular to each other.

[0016] (Revetment Block 4) The revetment blocks 4 form the wall surface of the reinforced earth wall 2, and are installed in multiple units facing the river R. Specifically, multiple revetment blocks 4 are installed along the width direction (Y direction) of the reinforced earth wall 2, and are piled up at a predetermined gradient.

[0017] As shown in FIG. 2, the revetment block 4 is formed mainly from concrete into a trapezoidal columnar shape as a whole. The revetment block 4 has an upper surface 4a, a lower surface 4b, a front surface 4c, a rear surface 4d, and a pair of side surfaces 4e. In this embodiment, the upper surface 4a and the lower surface 4b are parallel, and the rear surface 4d and the pair of side surfaces 4e are perpendicular to the upper surface 4a and the lower surface 4b. On the other hand, the front surface 4c is inclined relative to the upper surface 4a and the lower surface 4b, specifically, inclined backward from the lower end to the upper end. The front surface 4c is the exposed surface facing the river R.

[0018] The dimensions of one revetment block 4 may be, for example, a back (X-direction dimension) of 35 cm to 100 cm, a width (Y-direction dimension) of 100 cm to 250 cm, and a height (Z-direction dimension) of 25 cm to 50 cm. The back is the X-direction dimension at the top end of the revetment block 4 (the X-direction dimension of the shortest part). The weight per square meter of the revetment block 4 is, for example, 805 kg / m 2 More than 2300kg / m 2 If the revetment block 4 has such dimensions and weight, damage to the reinforced earth wall 2 caused by collisions with driftwood and the like can be prevented.

[0019] 2 and 3, an insertion hole 22 is formed on the top surface 4a of the revetment block 4, into which the vertical portion 14a of the anchoring fitting 14, which will be described later, is inserted. The revetment block 4 and the anchoring fitting 14 are connected by inserting the vertical portion 14a of the anchoring fitting 14 into this insertion hole 22. The shape of the insertion hole 22 in a plan view (the shape when viewed from above) is rectangular, with the Y-direction dimension being greater than the X-direction dimension, corresponding to the shape of the plate-shaped anchoring fitting 14. In this embodiment, the insertion hole 22 is located in the middle of the revetment block 4 in the width direction (Y-direction). In this embodiment, one insertion hole 22 is provided, but multiple insertion holes 22 may be provided.

[0020] The insertion hole 22 is preferably formed at least 15 cm forward (in the +X direction) from the rear surface 4d of the revetment block 4, and the insertion depth of the vertical portion 14a of the anchoring fitting 14 into the insertion hole 22 is preferably 3 cm to 10 cm. This position and insertion depth of the insertion hole 22 allows the revetment block 4 and the anchoring fitting 14 to be firmly connected.

[0021] Preferably, a recess 24 extending rearward (in the -X direction) from the insertion hole 22 is formed in the upper surface 4a of the revetment block 4. The Z-direction dimension (depth) of the recess 24 is greater than the thickness of the horizontal portion 14b of the anchoring fitting 14, which will be described later. The Y-direction dimension (width) of the recess 24 is slightly greater than the width of the horizontal portion 14b of the anchoring fitting 14. The bottom surface 24a of the recess 24 is flat. In this embodiment, when the revetment block 4 and the anchoring fitting 14 are connected, part of the horizontal portion 14b of the anchoring fitting 14 is received in the recess 24, so that the upper surface of the horizontal portion 14b of the anchoring fitting 14 is positioned below the upper surface 4a of the revetment block 4. In other words, in this embodiment, the anchoring fitting 14 does not protrude upward from the upper surface 4a of the revetment block 4.

[0022] As shown in FIG. 3 , a cylindrical insert fitting 26 may be provided in the recess 24 behind the insertion hole 22. A female thread is formed on the inner circumferential surface of the insert fitting 26. The female thread of the insert fitting 26 fits into a fastener (not shown) for fastening the anchoring fitting 14 to the revetment block 4. The fastener may be, for example, a metal bolt. Then, by fastening the horizontal portion 14b of the anchoring fitting 14 to the upper surface 4a of the revetment block 4 via the fastener, the anchoring fitting 14 and the revetment block 4 are more firmly connected and displacement of the anchoring fitting 14 is prevented. Note that when the anchoring fitting 14 is fastened to the revetment block 4 via a fastener, it is preferable that the Z-direction dimension of the recess 24 be greater than the sum of the Z-direction dimension of the horizontal portion 14b of the anchoring fitting 14 and the Z-direction dimension of the fastener.

[0023] As shown in FIGS. 2 to 4 , a through hole 28 is formed in the revetment block 4 forward of the insertion hole 22, penetrating from the upper surface 4 a to the lower surface 4 b. The through hole 28 is formed as an elongated hole extending in the width direction (Y direction) (see FIG. 2 ). Upper and lower connecting bolts (not shown) are inserted into the through hole 28 to connect adjacent revetment blocks 4 vertically. As shown in FIGS. 2 and 4 , a pair of cylindrical insert fittings 30 are provided at the rear of the through hole 28 and above the revetment block 4, spaced apart in the width direction (Y direction). A female thread is formed on the inner peripheral surface of the insert fitting 30. The upper and lower connecting bolts are inserted into the through hole 28 from above the upper revetment block 4, and the upper and lower connecting bolts fit into the insert fittings 30 attached to the lower revetment block 4, thereby connecting adjacent revetment blocks 4 vertically. Although not shown, adjacent revetment blocks 4 in the Y direction are connected via left and right connecting bolts and connecting fittings.

[0024] (Suction prevention material 6) As shown in FIG. 1, the suction prevention material 6 is installed along the rear surface 4d of the revetment block 4. For convenience, in FIG. 1, the suction prevention material 6 is depicted as being separated from the rear surface 4d of the revetment block 4, but in reality, the suction prevention material 6 is installed so that it comes into contact with the rear surface 4d of the revetment block 4. The suction prevention material 6 may be formed in a strip shape from a synthetic fiber nonwoven fabric. The dimensions of the suction prevention material 6 may be, for example, a length of approximately 10 m to 30 m, a width of approximately 1 m to 3 m, and a thickness of approximately 10 mm to 20 mm. A plurality of suction prevention materials 6 are installed along the rear surface 4d of the revetment block 4, with the width direction of the suction prevention material 6 aligned with the Y direction.

[0025] (Backfill material 8) The backfill material 8 is laid behind the suction prevention material 6. The backfill material 8 may be single-grain crushed stone.

[0026] (Frame material 10) As shown in Figure 1, multiple frame materials 10 are installed behind the backfill material 8. Specifically, similar to the revetment blocks 4, multiple frame materials 10 are installed along the width direction (Y direction) of the reinforced earth wall 2, and multiple frame materials 10 are piled up at a predetermined gradient.

[0027] Referring to Figure 5, the frame material 10 is formed from a plurality of metal rods arranged in a grid pattern. The frame material 10 has a plurality of horizontal reinforcement bars 10a extending in the Y direction and a plurality of vertical reinforcement bars 10b intersecting the horizontal reinforcement bars 10a. The horizontal reinforcement bars 10a and the vertical reinforcement bars 10b are joined by welding or the like. However, the frame material used in the reinforced earth wall 2 is not limited to the frame material 10 made from a plurality of rods arranged together, and may be formed from, for example, expanded metal.

[0028] In the frame material 10 of this embodiment, the vertical reinforcement 10b is bent so that the cross section thereof transverse to the Y direction has an L-shape. That is, the frame material 10 has a bottom surface portion 10c and an upright portion 10d extending upward from the front end (the end portion in the +X direction) of the bottom surface portion 10c.

[0029] The bottom surface portion 10c of the frame material 10 is provided with a connecting portion 10e to which the reinforcing material 12 is connected. In this embodiment, the connecting portion 10e is formed by bending the vertical reinforcement 10b upward into a triangular shape. However, the shape of the connecting portion 10e is not limited to the above-mentioned shape as long as it is a shape to which the reinforcing material 12 can be connected.

[0030] The upright portion 10d of the frame material 10 extends upward from the front end of the bottom portion 10c, sloping backward. The Z-direction dimension of the upright portion 10d corresponds to the Z-direction dimension of two revetment blocks 4. A support portion 10f that supports the upper frame material 10 is provided at the upper end of the upright portion 10d. The support portion 10f is formed by bending each vertical reinforcement 10b so that it extends forward from the top and then upward. However, the shape of the support portion 10f is not limited to the above-mentioned shape as long as it can support the upper frame material 10.

[0031] (Reinforcement 12) As shown in Figure 1, multiple reinforcing members 12 are installed inside the reinforced earth wall 2 at intervals in the vertical direction, and extend rearward from the lower end (bottom surface portion 10c) of the frame member 10. The reinforcing members 12 are formed in a sheet shape from an appropriate synthetic resin such as polyolefin (e.g., polypropylene or polyethylene). As shown in Figure 6, the reinforcing members 12 are in the form of a mesh with a large number of rectangular openings 12a. However, the shape of the openings 12a of the reinforcing members 12 is not limited to rectangular, and may be other shapes such as square or triangular.

[0032] In this embodiment, when the reinforcing material 12 is installed, the orientation of the reinforcing material 12 is adjusted so that the longitudinal direction of the opening 12a of the reinforcing material 12 coincides with the X direction, and the opening 12a is fitted into the connecting portion 10e of the frame material 10. Then, a rod-shaped connecting tool (not shown) is inserted into the lower part of the connecting portion 10e along the Y direction, thereby connecting the reinforcing material 12 to the frame material 10.

[0033] (Fixing bracket 14) The anchoring fittings 14 prevent the revetment blocks 4, which form the wall surface, from tipping over or sliding. As shown in FIG. 1, the anchoring fittings 14 extend rearward from the upper surface 4a of the revetment blocks 4. Referring to FIG. 7, the anchoring fittings 14 can be formed by bending a flat metal (e.g., steel) plate. That is, the anchoring fittings 14 have a vertical portion 14a extending in the up-down direction and a horizontal portion 14b extending horizontally from the upper end of the vertical portion 14a, and have an L-shaped cross section in the Y direction. A first through-hole 14c is formed at the front end of the horizontal portion 14b, through which the fastener (not shown) for fastening the anchoring fitting 14 to the revetment blocks 4 passes. A second through-hole 14d is formed at the rear end of the horizontal portion 14b, through which a fastener 32 (see FIG. 1) for securing the anchoring fitting 14 to the crushed stone layer 18 or the embankment 20 passes. The fastener 32 may be, for example, a metal anchor pin.

[0034] (Additional anti-suction material 16) As shown in Figure 1, the additional suction prevention material 16 may be installed along the rear surface of the frame material 10. For convenience, Figure 1 shows the rear surface of the frame material 10 and the additional suction prevention material 16 separated from each other, but in reality the additional suction prevention material 16 is installed so that it is in contact with the rear surface of the frame material 10. The additional suction prevention material 16 may be formed in a strip shape from a synthetic nonwoven fabric. The additional suction prevention material 16 may also be a vegetation sheet made of synthetic nonwoven fabric with seeds attached.

[0035] Although not shown, a synthetic resin mesh sheet (not shown) may be installed between the rear surface of the frame material 10 and the front surface of the additional suction prevention material 16. The installation of the mesh sheet can prevent a decrease in the suction prevention effect if the additional suction prevention material 16 deteriorates. The mesh size of the mesh sheet is preferably small enough to prevent a decrease in the suction prevention effect. The mesh sheet may be made of polyolefin (e.g., polypropylene, polyethylene), etc. Furthermore, it is desirable for the mesh sheet to be integrated with the additional suction prevention material 16. This is because, if the mesh sheet and the additional suction prevention material 16 are integrated, the installation work of the mesh sheet and the additional suction prevention material 16 can be carried out simultaneously, improving workability.

[0036] (18 crushed stone layers, 20 embankments) The crushed stone layer 18 and the embankment 20 are laid behind the additional suction prevention material 16. It is advantageous that the crushed stone layer 18 is laid up to a height at least equal to a predetermined water level of the river R (for example, the planned high water level). This further enhances the effect of suppressing suction. The crushed stone layer 18 may be formed from single-grain crushed stone. Furthermore, the embankment 20 may be laid behind the additional suction prevention material 16 above the predetermined water level of the river R.

[0037] Next, a method for constructing the reinforced earth wall 2 as described above will be described.

[0038] (Installation process of the first layer of revetment blocks 4 and suction prevention material 6) First, as shown in Figure 8, the process of installing the first (lowest) tier of revetment blocks 4 and suction prevention material 6 is carried out. Although not shown, foundation work such as pouring concrete is carried out where the first tier of revetment blocks 4 will be installed. During the foundation work, not only the installation surface of the revetment blocks 4 but also the installation surface behind the revetment blocks 4 (the installation surface for the frame material 10, reinforcing material 12, etc.) is finished flat and level. After the foundation work is completed, multiple revetment blocks 4 are installed in a line in the Y direction facing the river R. Next, adjacent revetment blocks 4 in the Y direction are connected via left and right connecting bolts and connecting fittings. In addition, suction prevention material 6 is installed along the rear surfaces 4d of the multiple revetment blocks 4.

[0039] (Installation process of frame material 10 and additional suction prevention material 16) After the revetment blocks 4 and suction prevention material 6 have been installed, the process of installing the frame material 10 and additional suction prevention material 16 is carried out, as shown in Figure 9. As in Figure 1, the frame material 10 and the additional suction prevention material 16 are shown separated from each other in Figure 9, but in reality the additional suction prevention material 16 is installed so that it comes into contact with the rear surface of the frame material 10. The mesh sheet may also be installed between the rear surface of the frame material 10 and the front surface of the additional suction prevention material 16.

[0040] (Reinforcement material 12 laying process) After the frame member 10 and the additional suction prevention material 16 are installed, the step of laying the reinforcing material 12 is carried out, as shown in Figure 10. When laying the reinforcing material 12, the orientation of the reinforcing material 12 is adjusted so that the longitudinal direction of the opening 12a of the reinforcing material 12 coincides with the X direction, and the opening 12a at the front end of the reinforcing material 12 is fitted into the connecting portion 10e of the frame member 10. Next, a rod-shaped connecting tool (not shown) is inserted into the lower part of the connecting portion 10e along the Y direction to connect the reinforcing material 12 to the frame member 10. By laying the reinforcing material 12 in this manner, the pressure acting on the revetment block 4 from the crushed stone layer 18 or the embankment 20 can be reduced.

[0041] (Laying process of backfill material 8 and crushed stone layer 18) After laying the reinforcing material 12, a process is carried out in which backfill material 8 and crushed stone layer 18 are laid up to the height of the installed revetment blocks 4, as shown in Figure 11. The backfill material 8 is laid between the suction prevention material 6 and the frame material 10, and the crushed stone layer 18 is laid behind the frame material 10. Next, the backfill material 8 and crushed stone layer 18 are compacted using an appropriate compacting machine such as a plate compactor.

[0042] (Installation process of the fastening bracket 14) After the backfill material 8 and crushed stone layer 18 have been laid up to the height of the installed revetment blocks 4, the step of installing the anchoring fittings 14 is carried out, as shown in Figure 12. When installing the anchoring fittings 14, first, the horizontal portions 14b of the anchoring fittings 14 are made to pass through the suction prevention material 6, the upright portions 10d of the frame material 10, and the additional suction prevention material 16. At this time, notches are made in each of the suction prevention material 6 and the additional suction prevention material 16 to allow the anchoring fittings 14 to pass through. Then, the horizontal portions 14b of the anchoring fittings 14 are made to pass through the notches in the suction prevention material 6 and the additional suction prevention material 16, as well as through the opening in the vertical middle of the upright portions 10d of the frame material 10.

[0043] After the horizontal portion 14b of the anchoring fitting 14 has been passed through the suction prevention material 6, the opening in the upright portion 10d of the frame material 10, and the additional suction prevention material 16, the anchoring fitting 14 is connected to the revetment block 4. That is, the vertical portion 14a of the anchoring fitting 14 is inserted into the insertion hole 22 of the revetment block 4. This makes it possible to easily connect the anchoring fitting 14 to the revetment block 4.

[0044] In this embodiment, the vertical portion 14a of the anchoring fitting 14 is inserted into the insertion hole 22 of the revetment block 4, and part of the horizontal portion 14b of the anchoring fitting 14 is housed in the recess 24 of the revetment block 4. This prevents the anchoring fitting 14 from shifting out of position. Furthermore, because the upper surface of the anchoring fitting 14 is located lower than the upper surface 4a of the revetment block 4, even if there is no recess on the lower surface 4b of the revetment block 4 to prevent interference with the anchoring fitting 14, the anchoring fitting 14 will not be pinched between the upper and lower revetment blocks 4 when stacking the revetment blocks 4. Therefore, there is no need to worry about the presence of the anchoring fitting 14 when aligning the upper revetment block 4 with the lower revetment block 4. This allows the revetment blocks 4 to be stacked smoothly.

[0045] Once part of the horizontal portion 14b of the anchoring fitting 14 is accommodated in the recess 24, a fastener may be passed through the first through-hole 14c of the anchoring fitting 14 and the horizontal portion 14b may be fastened to the revetment block 4 via the fastener. This makes it possible to more firmly connect the revetment block 4 and the anchoring fitting 14 and also improves the effectiveness of preventing the anchoring fitting 14 from shifting out of position.

[0046] Furthermore, it is desirable to pass a fixing device 32 through the second through-hole 14d of the anchoring fitting 14 and drive the fixing device 32 into the crushed stone layer 18. This allows the horizontal portion 14b of the anchoring fitting 14 to be fixed to the crushed stone layer 18 via the fixing device 32, thereby firmly connecting the revetment block 4 to the crushed stone layer 18 via the anchoring fitting 14. That is, in addition to the frictional resistance between the crushed stone layer 18 and the anchoring fitting 14, the pull-out resistance of the fixing device 32 also adds to the strength of the revetment block 4 to the crushed stone layer 18.

[0047] (Installation process of second-tier revetment block 4) After the anchoring fittings 14 are installed, the second-tier revetment block 4 is installed on the top surface 4a of the first-tier revetment block 4, as shown in FIG. 13 . The position of the second-tier revetment block 4 is adjusted so that the through-holes 28 of the second-tier revetment block 4 are positioned above the insert fittings 30 of the first-tier revetment block 4, and the second-tier revetment block 4 is then placed on the top surface 4a of the first-tier revetment block 4. Next, upper and lower connecting bolts (not shown) are inserted into the through-holes 28 from above the second-tier revetment block 4, and the upper and lower connecting bolts are fitted into the insert fittings 30 attached to the first-tier revetment block 4. This connects the first-tier revetment block 4 and the second-tier revetment block 4 via the upper and lower connecting bolts. Similar to the first-tier revetment blocks 4, multiple second-tier revetment blocks 4 are also installed side by side in the Y direction, and adjacent second-tier revetment blocks 4 in the Y direction are connected via left and right connecting bolts and connecting fittings.

[0048] (Laying process of backfill material 8 and crushed stone layer 18) After the second tier of revetment blocks 4 is installed, backfill material 8 and crushed stone layer 18 are laid up to a height substantially equal to the height of the upper surface 4a of the second tier of revetment blocks 4, and the laid backfill material 8 and crushed stone layer 18 are compacted (see Figure 13).

[0049] The above steps are then repeated to construct the reinforced earth wall 2 shown in Figure 1. Note that in parts of the river R that are higher than a predetermined water level (for example, the planned high water level), embankment soil 20 may be laid instead of the crushed stone layer 18.

[0050] As described above, in the reinforced earth wall 2, because the anchoring fittings 14 are made of metal, damage to the anchoring fittings 14 can be prevented when the vertical portions 14a of the anchoring fittings 14 are inserted into the insertion holes 22 of the revetment blocks 4. Furthermore, in the reinforced earth wall 2, the revetment blocks 4 and the anchoring fittings 14 are connected by inserting the vertical portions 14a of the anchoring fittings 14 into the insertion holes 22 formed in the top surfaces 4a of the revetment blocks 4. Therefore, the anchoring fittings 14 can be connected to the revetment blocks 4 after the backfill material 8 and crushed stone layer 18 have been laid, preventing damage to the anchoring fittings 14 caused by the introduction of the backfill material 8, etc. Therefore, according to this embodiment, damage to the anchoring fittings 14, which prevent the revetment blocks 4, which form the wall materials, from tipping and sliding, can be prevented when constructing the reinforced earth wall 2.

[0051] In the reinforced earth wall 2 of this embodiment, the backfill material 8 is laid before the anchoring fittings 14 are installed, so the anchoring fittings 14 do not get in the way when laying the backfill material 8, making it easy to evenly lay the backfill material 8 behind the revetment blocks 4. In contrast, in the prior art described above, the grid belt is passed through the fixing holes in the wall material before the backfill material is poured behind the wall material, so the grid belt gets in the way when pouring the backfill material. As a result, gaps are likely to form below the grid belt, making it difficult to evenly lay the backfill material behind the wall material.

[0052] Furthermore, the reinforced earth wall 2 can be used for river bank protection, as the revetment blocks 4 prevent damage caused by collisions with driftwood and the like, and the suction prevention material 6 and additional suction prevention material 16 prevent suction. In this embodiment, a crushed stone layer 18, rather than embankment 20, is laid behind the frame material 10, at least up to the same height as the predetermined water level of the river R, further suppressing suction. [Explanation of symbols]

[0053] R:River 2: Reinforced earth wall 4: Revetment block 6: Anti-suction material 8: Backfill material 10: Frame material 12: Reinforcement material 14: Fixing bracket 14a: Vertical part 14b:Horizontal part 16: Additional anti-suction material 18: Crushed stone layer 22: Insertion hole 24: Recess 32: Fixtures

Claims

1. A reinforced earth wall for riverbank protection, Revetment blocks installed facing the river, a suction prevention material installed along the rear surface of the revetment block; A backfill material laid behind the suction prevention material; A frame material installed behind the backfill material; a reinforcing member extending rearward from the lower end of the frame member; a metal anchoring fitting extending rearward from the upper surface of the revetment block, The fixing fixture has a vertical portion extending in the up-down direction and a horizontal portion extending horizontally from an upper end of the vertical portion, An insertion hole into which the vertical portion of the anchoring fitting is inserted is formed on the upper surface of the revetment block, A reinforced earth wall for river bank protection in which the bank protection block and the anchoring fitting are connected by inserting the vertical portion of the anchoring fitting into the insertion hole of the bank protection block.

2. 2. A reinforced earth wall for river embankments as described in claim 1, wherein a recess extending rearward from the insertion hole is formed on the upper surface of the embankment block, and a portion of the horizontal portion of the anchoring fitting is accommodated in the recess.

3. 2. The reinforced earth wall for river bank protection according to claim 1, wherein the horizontal portion of the fixing fitting is fastened to the upper surface of the bank protection block via a fastener.

4. 2. The reinforced earth wall for river bank protection according to claim 1, wherein the insertion holes of the bank protection blocks are formed at least 15 cm forward from the rear surface of the bank protection blocks.

5. 2. The reinforced earth wall for river bank protection according to claim 1, wherein the insertion depth of the vertical portion of the fixing fitting into the insertion hole of the bank protection block is 3 cm to 10 cm.

6. The frame member has a bottom portion and an upright portion extending upward from a front end of the bottom portion, 2. The reinforced earth wall for riverbank protection according to claim 1, wherein the horizontal portions of the fastening fittings penetrate the upright portions of the frame members.

7. 2. The reinforced earth wall for river bank protection according to claim 1, wherein a crushed stone layer is laid behind said frame members up to a height at least equal to a predetermined water level of said river.

8. 8. The reinforced earth wall for river bank protection according to claim 7, wherein the horizontal portion of the anchoring fitting is fixed to the crushed stone layer via a fastener.

9. 2. The reinforced earth wall for riverbank protection according to claim 1, wherein an additional anti-suction material is installed along the rear surface of the frame material.

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