JP6639240B2 - Retaining wall block and retaining wall and construction method of retaining wall - Google Patents

Description

  The present invention relates to a retaining wall block useful for constructing a retaining wall such as a block retaining wall, a retaining wall formed of the retaining wall block, and a method of constructing the retaining wall.

  The retaining wall is a structure for supporting the soil provided to prevent the collapse of the earth and sand, and is constructed on an unstable slope such as a slope of the soil for the purpose of securing land. Retaining walls are categorized into concrete retaining walls, reinforced soil retaining walls, and other special retaining walls, and general retaining walls are concrete retaining walls mainly composed of concrete. The types of concrete retaining walls are further classified into block pile retaining walls, gravity retaining walls (for example, leaning retaining walls, etc.), cantilever retaining walls (for example, L-shaped retaining walls, etc.).

  The concrete retaining wall is constructed, for example, by the following method. First, concrete blocks formed in the shape of a truncated pyramid are piled up sequentially in the vertical and horizontal directions along the ground surface, etc. (stacking process), and filler (gravel, concrete, etc.) is placed between adjacent concrete blocks in the vertical and horizontal directions. ) (Filling step).

  However, the concrete block alone cannot be piled up on its own, and needs to be piled up while being filled with a filler, so that the workability is low. Further, even if the filler is filled between the concrete blocks, the bonding strength between the concrete blocks is weak, and the seismic performance is not sufficient. In addition, in the stacking step and the stuffing step, the position of the concrete block must be accurately adjusted, which requires special skills and lowers working efficiency.

  The retaining wall block structure described in Japanese Patent Application Laid-Open No. 7-317085 (Patent Document 1) is interposed between a concrete block stacked along a covered surface and two concrete blocks vertically adjacent to each other. An embedding block is provided for surface-joining the two concrete blocks, and an uneven fitting portion is formed on a joint surface between the concrete block and the embedding block. The concrete block includes a front surface portion formed in a rectangular plate-like body, and a back surface portion formed in a substantially isosceles triangular pyramid shape protruding from the front surface portion toward the covered surface. The portion has a fitting protrusion or a fitting recess that can be fitted to the cylinder block. The hollow block has a shape similar to that of a concrete block, and has a surface formed in a rectangular plate-like body and a substantially isosceles triangular pyramid projecting forward from the surface. And a back surface. The document also describes that the stuffing block is made of resin (polystyrene foam). In the block structure of the document, the concrete block and the squeeze block can be stacked while being positioned with respect to each other, by fitting one fitting projection and the other fitting recess.

  However, in the block structure of Patent Literature 1, in the step of interposing the stuffing block between the two concrete blocks vertically adjacent to each other, the direction of the surface part of the concrete block and the surface part of the stuffing block are alternately changed. It is necessary to stack sequentially, the stacking operation is complicated, and the workability is low. In addition, the concrete block and the casing block are fitted to each other by fitting, and the fitting strength alone is not sufficient with the fitting alone. Further, since the concrete block and the squeeze block are fitted together, a retaining wall curved inward or outward with respect to the embraced surface cannot be constructed.

  The retaining wall block described in Japanese Patent Application Laid-Open No. 5-33355 (Patent Document 2) includes a flat plate block made of concrete and a back member made of polystyrene foam adhered integrally to the back side of the flat plate block. ing. With this back member, there is no need to fill the space between the retaining wall block and the ground with a filler (for example, framing stone or chestnut stone) after the retaining wall block is stacked, so that the labor required for the operation is reduced, and the operation time is reduced. Can be shortened. In addition, since the back member made of styrene foam is lightweight and does not contain moisture, the design standard itself is reduced, and the amount of material and the cost can be reduced.

  However, in the retaining wall block described in Patent Literature 2, since the polystyrene foam is adhered to the back side of the flat plate block, when used for a long period of time, the polystyrene foam is peeled off the flat block due to adhesion deterioration, and the flat block falls off. . Therefore, the retaining wall block is fragile, and the durability and stability of the retaining wall are poor. In addition, the styrofoam of the back member is exposed and dissolved when the organic solvent permeates, so that it does not function as the back member. In addition, in order to stably connect the fragile retaining wall blocks, for example, a step of connecting adjacent back members with U-shaped clamps is required, and the workability is low. Furthermore, even with the retaining wall block of Patent Literature 2, it is not possible to construct a retaining wall that is curved inward or outward with respect to the embraced surface.

JP-A-7-317085 (Claims, [0021] [0033] [0034] [0035] [0037] [0041]) JP-A-5-33355 (Claims: [0011] [0014] [0015])

  Accordingly, an object of the present invention is to provide a retaining wall block, a retaining wall, and a method for constructing the same, which are excellent in workability.

  Another object of the present invention is to provide a retaining wall block, a retaining wall, and a method for constructing the retaining wall, which have a sufficient compressive strength despite a small weight per unit volume.

  Still another object of the present invention is to provide a retaining wall block, a retaining wall, and a method for constructing the retaining wall which can maintain the stability of the retaining wall for a long time by strengthening the bonding force between adjacent blocks. is there.

  The inventor of the present invention has conducted intensive studies to achieve the above-described object, and as a result, has formed a projecting portion from the plate-shaped front portion with a height substantially equal to the plate-shaped front portion and a width smaller than the plate-shaped front portion. When the foamed plastic is housed in this protruding part, the blocks can be stably and easily stacked in the vertical and horizontal directions without special skills, and the workability is excellent, and the weight per unit volume is small. Nevertheless, it has sufficient compressive strength, can be hardened by placing concrete between adjacent blocks in the horizontal direction, can strengthen the bonding force between the blocks, and the stability of the retaining wall for a long time Have been found, and the present invention has been completed.

  That is, the block of the present invention, in the mounted state, a plate-shaped front portion capable of forming a retaining wall surface in a direction perpendicular to the mounting surface, and a projecting portion projecting from the back side of the plate-shaped front portion. Wherein the projecting portion has substantially the same height as the plate-shaped front portion and a width smaller than the plate-shaped front portion, and Foamed plastic is housed in the section.

  The projecting portion may be formed in a substantially rectangular parallelepiped or a substantially cubic shape. When formed in a substantially rectangular parallelepiped shape or a substantially cubic shape, the blocks can be stacked more stably in the vertical direction.

  The projecting portion may have a joining portion that is cast between the blocks adjacent in the lateral direction and joins with the hardened concrete, and the joining portion may have a concave portion or a convex portion. When such a concave portion or a convex portion is formed, the filling concrete and the concave portion or the convex portion form an engagement or fitting structure, and a bonding force between the block and the filling concrete can be further enhanced, The stability of the retaining wall can be further improved.

  At least both side surfaces of the plate-shaped front portion may have a curved surface that is convex toward the side portion. When the curved surfaces are formed on the both side surfaces, the blocks can be arranged by bringing the curved surfaces into contact with each other, so that a retaining wall curved inward or outward with respect to the covered surface can be formed.

  The present invention includes a retaining wall having a hardened block structure in which a plurality of the blocks are stacked vertically and horizontally on a mounting surface, and a space-filled concrete is cast between horizontally adjacent blocks. The retaining wall may be configured such that a reinforcing bar extends from a mounting surface between blocks adjacent in the lateral direction, and a filling concrete is cast between the blocks to be hardened. By joining the reinforcing steel with the filling concrete, the bonding force between the placing surface and the block structure can be strengthened. For example, a strong L-shaped (vertical) block retaining wall can be constructed.

  The present invention includes a method of constructing a retaining wall in which a plurality of the blocks are stacked vertically and horizontally on a mounting surface, and a space-filled concrete is poured between blocks adjacent in the horizontal direction and hardened.

  In the present invention, the “vertical direction” corresponds to the up-down direction, and the “horizontal direction” corresponds to the left-right direction.

  In the present invention, since the projecting portion has substantially the same height as the plate-shaped front portion and contains foamed plastic in the projecting portion, it does not require special skills and is stable. Blocks can be easily piled up in the vertical direction, and the workability is excellent. In addition, despite having a small weight per unit volume, it has a sufficient compressive strength. Further, since the protruding portion has a width smaller than the plate-shaped front portion, the concrete can be poured between the blocks adjacent in the lateral direction and hardened, and the bonding strength between the blocks can be strengthened. For this reason, the stability of the retaining wall can be maintained for a long time. When a concave portion or a convex portion is formed at the joint with the filling concrete, the stability of the retaining wall is further improved. In addition, when at least both side surfaces of the plate-shaped front portion are formed with curved surfaces protruding toward the side portion, the curved surfaces can be brought into contact with each other to arrange the block. Alternatively, an outwardly curved retaining wall can be formed.

FIG. 1 is a schematic rear perspective view showing an example of the retaining wall of the present invention. FIG. 2 is a schematic front perspective view of the retaining wall block of FIG. 1. FIG. 3 is a schematic rear perspective view showing another example of the block of the present invention. FIG. 4 is a schematic rear perspective view showing still another example of the block of the present invention. FIG. 5 is a schematic rear perspective view showing still another example of the block of the present invention. FIG. 6 is a schematic rear perspective view showing still another example of the block of the present invention. FIG. 7 is a schematic front perspective view showing still another example of the block of the present invention. FIG. 8 is a schematic rear perspective view showing another example of the retaining wall of the present invention. FIG. 9 is a schematic rear perspective view showing still another example of the retaining wall of the present invention.

  Hereinafter, an L-shaped (vertical) block storage wall will be described as an example of the retaining wall of the present invention with reference to FIGS. 1 and 2.

  The L-shaped block retaining wall (retaining wall) 1 shown in FIG. 1 is formed on a ground (not shown), and has a flat foundation surface 31 and a concrete foundation 30. A block structure 20 having a plurality of stacked retaining wall blocks 11, hardened filling concrete 10 cast between columns of laterally adjacent blocks 11, and laterally adjacent blocks 11 It includes a reinforcing bar 40 that extends from the mounting surface 31 and is hardened and filled with the concrete 10. When the reinforcing bars 40 anchored (fixed) to the concrete foundation 30 are joined to the filling concrete 10, the block structure 20 is integrated with the concrete foundation 30 to maintain stability. In addition, the part shown by the dotted line in the rebar 40 of FIG. 1 has shown in the concrete foundation 30 and the filling concrete 10.

  The block 11 has a plate-shaped front surface portion 12 that is a substantially square plate-shaped body extending in a direction perpendicular to the mounting surface 31, and protrudes from the back side of the plate-shaped front portion 12 to form a hollow substantially rectangular parallelepiped. A projecting portion 13 formed and having substantially the same height as the plate-shaped front portion 12 and a width smaller than that of the plate-shaped front portion 12, and a substantially rectangular parallelepiped independent shape accommodated in the hollow interior of the projecting portion 13. And a foamed plastic 14 having a cellular structure. The peripheral edge portion 22 of the plate-shaped front portion 12 projects forward, and a decorative surface (uneven surface) 18 is formed on the front surface of the plate-shaped front portion 12. The block 11 is a self-standing structure capable of stacking the plate-shaped front portions 12 in parallel in the vertical and horizontal directions, and the plate-shaped front portion 12 and the projecting portions 13 are integrally formed of concrete.

  In such a block 11, when the side surfaces 15 in the width direction of the plate-shaped front portion 12 are brought into contact with each other and the blocks 11 are laterally adjacent to each other, a space is formed between the blocks 11 where the concrete filling 10 can be poured. . The hardened concrete 10 that has been poured and hardened into this space is joined to both side surfaces 17 of the projecting portion 13. A substantially circular opening (recess) 19 is formed in the center area of the both side surfaces 17, and the concrete filling 10 enters the opening (recess) 19 to form an uneven engagement or fitting structure. . In the block 11 of FIG. 2, a part of the foamed plastic 14 accommodated in the projecting portion 13 is exposed by the opening (recess) 19, and the opening 19 is cast by filling the filling concrete 10. It may be at least partially closed or completely closed.

The protruding portion 13 shown in FIG. 2 has the same height as the plate-shaped front portion 12, forms a support portion (upper surface) 21 capable of supporting the vertically adjacent block 11, and reduces the weight per unit volume. Since it is possible, the blocks 11 can be stably and easily stacked in the vertical direction without requiring special skills, the workability is excellent, the labor required for the work can be reduced, and the economy is excellent. In addition, the block 11 can be transported and installed manually, and has an advantage that construction can be performed even in a narrow place where heavy equipment cannot enter. Further, since the foamed plastic 14 having a closed-cell structure is housed in the protruding portion 13, the block 11 has excellent compressive strength despite its small weight per unit volume, and the block 11 conforms to JIS A 5371. defined criteria (mass per construction area 1m ² 350kg / ^{m 2} or more, the compressive strength 18N / ^{m 2} or more (however, when the shape area of the surface of 2.236M ² from more than 0.135 m ^2, 21N / m ² or more)) can be ensured. In the present invention, the "1 m ² per mass 350 kg / ^{m 2} or more" includes the mass of Matsume concrete. In addition, since the foamed plastic 14 is accommodated in the protruding portion 13, the foamed plastic 14 does not detach or separate from the protruding portion 13, and has excellent durability for a long period of time and foaming. It has an advantage of suppressing penetration of an organic solvent or the like into the plastic 14.

  When the filling concrete 10 is cast into the space formed between the horizontally adjacent blocks 11 and hardened, the bonding force between the horizontally adjacent blocks 11 can be strengthened via the filling concrete 10. Furthermore, since the filling concrete 10 enters into the opening (recess) 19 to form a concave-convex engagement structure or a fitting structure, the block 11 can further strengthen the bonding force with the filling concrete 10 and stabilize the retaining wall. For example, it is preferably used as a retaining wall block that requires earthquake resistance. Further, if the width of the projecting portion 13 is smaller than that of the plate-shaped front portion 12, the width of the plate-shaped front portion 12 cannot be set up vertically in the vertical direction, and the worker may mistakenly mount the block 11. It also has the advantage that stacking in a vertical orientation can be prevented.

  The retaining wall 1 of FIG. 1 includes a plurality of blocks 11 stacked vertically and horizontally on a mounting surface 31 of a concrete foundation 30 (stacking process), and a space formed between the horizontally adjacent blocks 11 filled with concrete. 10 is cast and hardened (casting step). In the stacking step, the bottom surface of the block 11 (the bottom surface of the plate-shaped front portion 12 and the protruding portion 13) is moved to the upper surface of the lower block 11 (the top surface (the support portion 21) of the plate-shaped front portion 12 and the protruding portion 13). By stacking them on top of each other, columns can be formed. In the horizontal direction, the side surfaces 15 of the plate-shaped front part 12 can be overlapped with each other, and the blocks 11 can be adjacent to each other to form a row. The casting step may be performed between the blocks 11 that are horizontally adjacent to each other. However, when the columns are formed, the space in which the concrete filling 10 can be placed communicates in the vertical direction. The operation can be performed between the plurality of columns, and the operation time can be reduced.

  In addition, the plate-shaped front part 12 is not particularly limited as long as it can form a retaining wall surface in the mounting state in a direction perpendicular to the mounting surface 31. It is preferable that the plate-shaped front portion 12 can form a stable retaining wall surface if the sides adjacent in the vertical and horizontal directions can contact each other. As the plate-shaped front part 12, for example, a plate-shaped body such as a substantially square or a substantially rectangular shape such as a substantially rectangular shape or a substantially regular hexagonal shape can be exemplified. It is easy to pile up and is preferable from the viewpoint of workability.

  The peripheral surface including both side surfaces 15 of the plate-shaped front portion 12 is a flat surface in the block 11 of FIG. 2, but at least both side surfaces 15 have a curved surface that is convex toward the side direction (width direction). May have. For example, like the block 11A of FIG. 3, both sides of the plate-shaped front surface 12A may have a curved surface 15A that is convex toward the side. If the curved surfaces 15A are formed on the both side surfaces, the curved surfaces can be arranged in contact with each other, so that a retaining wall curved inward or outward with respect to the covered surface can be advantageously formed.

  It is not necessary to form a concave-convex surface 18 as a decorative surface on the front surface of the plate-shaped front portion 12. For example, instead of the concave-convex surface 18, a smooth surface, a convex surface, a rough surface (corrugated shape or the like), a porous surface, or the like is used. A decorative surface may be formed.

  The projecting portion 13 projects from the back side of the plate-shaped front portion 12 and has a height substantially equal to the height of the plate-shaped front portion 12 and a width smaller than the width of the plate-shaped front portion 12. Good. The protruding portion 13 is not limited to a substantially rectangular parallelepiped shape, and may be, for example, a prismatic shape such as a columnar shape (eg, a substantially cubic shape, a columnar shape having a substantially trapezoidal cross section, a substantially polygonal cross section (eg, a substantially hexagonal cross section)). Shape, a substantially cylindrical shape, a substantially semi-cylindrical shape, etc.), a substantially semi-frustoconical shape, or the like, workability such as portability, and stable contact of vertically adjacent blocks. It is preferably formed in a prismatic shape from the point of supporting, and more preferably in a substantially rectangular parallelepiped shape or a substantially cubic shape.

  In FIG. 2, the support portion 21 can be formed by the upper surface of the projecting portion 13, that is, one surface. However, if the block 11 can be supported in the vertical direction, at least one line contact, a plurality of point contacts, and a plurality of surface contacts are used. You may support it. For example, the support portion 21 formed by linear contact has a projecting portion formed in a substantially columnar shape (or a substantially elliptical column shape) whose axial direction is in the projecting direction (front-back direction) or at least the upper surface (or upper surface and bottom surface). And one or a plurality of chevron portions having a triangular cross section. The support portion 21 by a plurality of point contacts can be formed, for example, by a projecting portion having a plurality of regularly arranged conical shapes formed on the upper surface. As a form of the support portion 21 that can be brought into surface contact at a plurality of locations, for example, a concave groove is formed extending in the front-rear direction at least in the widthwise central portion of at least one of the upper surface (bottom surface) of the protruding portion 13 in FIG. 6 and a form of a protruding portion (a form in which a concave groove extends in the width direction) of FIG. 6 described later. The supporting portion 21 is preferably capable of one or more surface contact from the viewpoint of more stably supporting the adjacent block, and has a top surface having substantially the same size as the bottom surface as the protruding portion 13 in FIG. It is more preferably formed.

  Note that the projecting contact portion 13 is not limited to a form in which the foamed plastic 14 is surrounded by the projecting portion 13 as in the projecting portion 13 of FIG. In order to accommodate the foamed plastic 14 in the later protruding portion 13, a mounting recess or a mounting opening into which the foaming plastic 14 can be inserted or mounted is formed at an appropriate position (for example, the upper surface) of the protruding portion 13. Good.

  The projecting portion 13 is not limited to the projecting portion 13 of FIG. 2 as long as it can form a space in which the filling concrete 10 can be cast between the blocks 11 adjacent in the lateral direction. For example, a concave groove or the like may be formed in the longitudinal direction or the lateral direction at a central portion in the width direction of both side surfaces 17 of the projecting portion 13.

  The recesses 19 are not necessarily formed on both side surfaces (joining portions) 17, but are advantageous for further strengthening the bonding force between adjacent blocks. In addition, when the concave portions 19 are formed on both side surfaces (joining portions) 17, the operator can easily carry the concave portions 19 as a handle, which is advantageous because workability is improved. The concave portion 19 does not need to be formed by exposing the foamed plastic 14 as long as it can form an engagement or fitting structure with the filling concrete 10. Further, the concave portion 19 may be formed, for example, on one side surface of both side surfaces (joining portions) 17, may be formed in a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape (for example, a square shape). Instead of 19, a protruding portion (convex portion) may be formed. In addition, the concave portions formed on both side surfaces (joining portions) 17 are not limited to the opening portions (concave portions) 19. For example, the corners of the protruding portions 13 may be in any directions such as a vertical direction, a horizontal direction, and a height direction. May be formed to form a notch or a groove. For example, like the protruding portion 43 of the block 41 shown in FIG. 4, a corner on the back side of the upper surface of the protruding portion 13 in FIG. A pair of notches (recesses) 42 may be formed. Further, like the protruding portion 53 of the block 51 shown in FIG. 5, a corner portion on the back surface of the protruding portion 13 in FIG. A notch (recess) 52 may be formed. Further, like the protruding portion 63 of the block 61 shown in FIG. 6, the concave groove 62 may be formed in the widthwise central region of the upper and lower surfaces of the protruding portion 13 of FIG. Although FIGS. 5 and 6 illustrate a mode in which the notch 52 or the concave groove 62 is formed on the upper and lower surfaces of the projecting portion 13 in FIG. 2, the notch is formed only on one of the upper and lower surfaces. Alternatively, a concave groove may be formed.

The foamed plastic 14 has a closed cell structure from the viewpoint of having a sufficient compressive strength, and the type of the foamed plastic is not particularly limited, and examples thereof include foamed polyolefins such as foamed polyethylene, foamed polystyrene, foamed polyurethane, and the like. From the viewpoint of having excellent water resistance, foamed polystyrene is preferred. Further, the foamed plastic may be molded by an in-mold foaming method, or may be molded by an extrusion foaming method. The density (kg / m ³ ) of the foamed plastic is not particularly limited, but is, for example, 12 to ³⁰ kg / m ³ , preferably 15 to 27 kg / m ³ , and more preferably 18 to 25 kg / m ³ . In the present invention, the foamed plastic 14 is preferably high-density styrene foam of 18 to 25 kg / m ³ . The shape of the foamed plastic 14 is not particularly limited, and may be a shape conforming to the hollow shape of the projecting portion 13 so as to be accommodated in the hollow interior of the projecting portion 13.

  The block 11 may be provided with a pin insertion hole into which a pin for positioning can be inserted, for example, in order to prevent a displacement of the block 11 adjacent in the vertical direction. For example, as in a block 11B shown in FIG. 7, a configuration in which a pair of pin insertion holes 16 are formed near the center of the upper surface and the bottom surface of the plate-shaped front portion 12 may be employed.

  The filling concrete 10 of the block structure 20 is not limited to concrete, and may be formed of, for example, cement mortar.

  The retaining wall 1 is usually stably formed on a concrete foundation 30 having a flat surface.

  By joining the reinforcing bar 40 with the filling concrete 10, the bonding force between the concrete foundation 30 and the block structure 20 can be strengthened. For example, the L-shaped block retaining wall 1 as shown in FIG. This is advantageous because it is possible.

  The retaining wall of the present invention is not limited to the L-shaped block retaining wall, and may be, for example, a leaning block retaining wall. That is, the retaining wall formed by the plurality of blocks may extend in the vertical direction or may be inclined. For example, as in a retaining wall 1A shown in FIG. 8, the concrete foundation 30A may have a slope 31A, and the block structure 20 may be placed on the slope 31A. The plate-shaped front surface portion 12 of the block 11 can form a retaining wall surface in a direction perpendicular to the inclined surface even if the mounting surface is an inclined surface. In the retaining wall 1A in FIG. 8, for example, the back side of the block structure 20 is disposed along a ground-covered surface (not shown). The retaining wall 1A of FIG. 8 is the same as the retaining wall 1 shown in FIG.

  In addition, the retaining wall of the present invention may be a construction method in which the upper block is vertically aligned with the lower block and stacked, and the position of the upper block is shifted laterally with respect to the lower block. The blocks may be piled up in a stacking method for construction. For example, the retaining wall 1B shown in FIG. 9 is shown in FIG. 8 except that the side end of the upper block 11 is located at the center in the width direction of the lower block, and the lower block and the upper block are alternately stacked. It is the same as the retaining wall 1A.

  The block of the present invention has excellent workability, and various retaining walls, for example, excavation slopes, slopes of the ground, retaining walls and residential lands constructed for protection of slopes such as revetments of canals or rivers, The present invention can be suitably used for retaining walls used for construction of parks, earth retaining for road construction, and the like.

1, 1A, 1B ... Retaining wall 10 ... Filling concrete 11, 11A, 11B, 41, 51, 61 ... Block 12, 12A ... Plate-shaped front part 13, 43, 53, 63 ... Projecting part 14 ... Foamed plastic 15 , 15A ... curved surface (side surface)
16 ... pin insertion holes 17, 47, 57, 67 ... both side surfaces (joining part)
18: Uneven surface 19: Opening (recess)
Reference Signs List 20 block structure 21 support 22 peripheral edge 30, 30A concrete foundation 31, 31A mounting surface (inclined surface)
40 ... Reinforcing bar 42, 52 ... Notch (recess)
62 ... concave groove (recess)

Claims (7)

In the mounted state, it includes a plate-shaped front part that can form a retaining wall surface perpendicular to the mounting surface, and a protruding part that protrudes from the back side of this plate-shaped front part, and can be stacked vertically and horizontally Block for the retaining wall,
The plate-shaped front portion and the protruding portion are integrally formed,
The projecting portion is, at the same height and width less than the plate-like front portion and the plate-shaped front portion, projecting from said plate-shaped front portion, a support capable of supporting portion adjacent blocks in the vertical direction , Comprising a concave portion or a convex portion formed on the side surface ,
A block containing foamed plastic in the protruding portion.   The block according to claim 1, wherein the projecting portion is formed in a substantially rectangular parallelepiped or a substantially cubic shape. Both side surfaces of the projecting portion form a joint portion which is joined between the blocks adjacent in the lateral direction and joins with the hardened concrete, and a concave portion or a convex portion is formed in the joint portion. The block according to 1 or 2.   The block according to any one of claims 1 to 3, wherein at least both side surfaces of the plate-shaped front portion have a curved surface that is convex toward the side portion.   A plurality of blocks according to any one of claims 1 to 4, stacked vertically and horizontally on a mounting surface, and a block structure hardened by filling concrete between adjacent blocks in a horizontal direction. wall.   The retaining wall according to claim 5, wherein a reinforcing bar extends from a mounting surface between the horizontally adjacent blocks, and a filling concrete is cast between the blocks and hardened.   A method for constructing a retaining wall, comprising: stacking a plurality of blocks according to any one of claims 1 to 4 on a mounting surface in a vertical direction and a horizontal direction, placing concrete between adjacent blocks in a horizontal direction, and curing.

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