Earth retaining wall and method for constructing earth retaining wall

Abstract

To provide a method for constructing concrete blocks and an earth retaining wall which use arrangement parts of suspension materials of concrete blocks as a part of a drain passage, and thereby can quickly construct an earth retaining wall.SOLUTION: There is provided an earth retaining wall 100 in which concrete blocks 10 having block pars 12 formed into rectangular shapes by concrete, and suspension materials 14 embedded in a state of projecting from the upper surfaces of the block parts 12 are arranged in a width direction and a height direction. The concrete block 10 at N-th (N is integer of 2 or greater) stage is arranged at a position of sandwiching the suspension materials 14 in the concrete block 10 arranged at (N-1)th stage by the block parts 12.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an earth retaining wall and a method for constructing an earth retaining wall. [Background technology]

[0002] The structure of an earth retaining wall using concrete blocks is known. For example, a structure such as that disclosed in Patent Document 1 (JP Patent Publication No. 2013-11153) is known as an earth retaining wall.

[0003] The retaining wall disclosed in Patent Document 1 employs a method in which two types of concrete blocks, large and small, are placed offset in one direction (up, down, left, right) and then integrated to speed up construction. This gives each concrete block a vertical slope, minimizing the slope ratio when laying the retaining wall and reducing the construction area of ​​the wall. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-11153 A (paragraphs 0004-0006, Figures 1, 3-4, etc.) Summary of the Invention [Problem to be solved by the invention]

[0005] In temporary restoration work following landslides, etc., there is a trend to use larger concrete blocks to construct earth-retaining walls, as it is desirable to progress the work quickly in case of a secondary landslide. However, even though it is temporary restoration work, it is necessary to lay drainage paths at appropriate intervals in the earth-retaining walls, so there is an issue that simply making the concrete blocks larger does not speed up the construction of the earth-retaining walls. [Means for solving the problem]

[0006] Therefore, the present invention is intended to solve the above-mentioned problems, and its object is to provide a method for constructing concrete blocks and retaining walls that enables the rapid construction of an earth-retaining wall by utilizing the installation parts of the hanging materials for hoisting the concrete blocks as part of the drainage path of the earth-retaining wall.

[0007] As a result of intensive research by the present inventors to solve the above problems, the present invention has come up with the following configuration: That is, the present invention is an earth-retaining wall formed by arranging concrete blocks in the width and height directions, each block having a block portion formed in a rectangular parallelepiped shape from concrete and a hanging material embedded in a state protruding from the top surface of the block portion, characterized in that the concrete block in the Nth (N is an integer of 2 or more)th tier is arranged in such a manner that the block portion sandwiches the hanging material in the concrete block arranged in the (N-1)th tier.

[0008] This makes it possible to quickly construct the retaining wall by using the installation areas for the hanging materials used to hoist the concrete blocks as part of the drainage path of the retaining wall.

[0009] In addition, it is preferable that the front of the concrete block arranged on the Nth tier is set back toward the rear side relative to the front of the concrete block arranged on the (N-1)th tier, and that a slip prevention portion is arranged on the upper surface of the concrete block arranged on the (N-1)th tier.

[0010] This prevents the retaining wall from shifting out of position due to earth pressure.

[0011] There is also an invention for a method of constructing an earth-retaining wall by arranging concrete blocks in the width and height directions, the concrete blocks having a block portion formed in a rectangular parallelepiped shape from concrete and a hanging material embedded in a state protruding from the top surface of the block portion, the method comprising the steps of: arranging a plurality of the concrete blocks in the width direction on the original ground; and arranging an Nth tier of the concrete blocks (N is an integer of 2 or more) in the width direction on the top surface of the block portion of each of the concrete blocks, the steps being repeated until a predetermined number of tiers is reached, and the step of arranging the Nth tier of the concrete blocks in the width direction is a step of arranging the hanging material of the (N-1)th tier of the concrete blocks while clamping it in the width direction with the block portion of the Nth tier of the concrete blocks.

[0012] This makes it possible to quickly construct the retaining wall by using the installation areas for the hanging materials used to hoist the concrete blocks as part of the drainage path of the retaining wall.

[0013] In addition, it is preferable that the process of arranging the Nth tier concrete block in the width direction is a process of arranging the concrete block in a position set back to a rear position from the front position of the block portion of the (N-1)th tier concrete block, and further includes a process of arranging a slip prevention portion on the upper surface of the concrete block arranged in the (N-1)th tier.

[0014] This prevents the retaining wall from shifting out of position due to earth pressure.

[0015] It is also preferable that the method further comprises the step of laying a suction prevention sheet and backfill material on the rear side of the concrete block after the step of arranging the concrete block in the width direction.

[0016] This allows for better drainage on the rear side of the retaining wall. Effect of the Invention

[0017] By adopting the configuration of the retaining wall and the construction method of the present invention, the installation area of ​​the hanging materials for lifting the concrete blocks can be used as part of the drainage path of the retaining wall, making it possible to construct the retaining wall quickly. [Brief description of the drawings]

[0018] [Figure 1] 2A and 2B are a front view and a side view, respectively, of a concrete block used in constructing an earth retaining wall in this embodiment. [Diagram 2] FIG. 2 is a flow chart showing the general steps of a method for constructing an earth retaining wall in this embodiment. [Diagram 3] This is a front view showing an example of the state in which a concrete block in this embodiment is placed on the original ground (the state in which the first layer of an earth retaining wall is placed). [Figure 4] This is a side view showing the first layer of concrete blocks after they have been placed and backfilled. [Diagram 5] 1 is a front view showing an example of the arrangement of a second tier of concrete blocks in this embodiment. FIG. [Figure 6] This is a side view showing the second layer of concrete blocks being placed and backfill material being filled in. [Figure 7] 1 is a front view showing an example of the arrangement of a third tier of concrete blocks in this embodiment. FIG. [Figure 8] This is a side view showing the state after the third row of concrete blocks has been placed, backfill material has been filled, and anti-slip sections have been placed. [Figure 9] 1A is a front view and FIG. 1B is a side view showing a modified example of a concrete block. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of an earth retaining wall 100 according to the present invention will be specifically described with reference to the drawings. FIG. 1 is a front view (A) and a side view (B) of a concrete block 10 used to construct an earth retaining wall 100 in this embodiment. The concrete block 10 has a block portion 12 made of concrete and a hanging member 14 protruding from the upper surface of the block portion 12. In this embodiment, the block portion 12 is exemplified as being formed in a cubic shape, but the block portion 12 can also be formed in a rectangular parallelepiped shape with different vertical, horizontal and height dimensions. The block portion 12 preferably has a length dimension of 1 meter or more in each of its vertical, horizontal and height dimensions, but the length dimension of the block portion 12 is not particularly limited. The block portion 12 may be either reinforced concrete or unreinforced concrete. In addition, the concrete used can be so-called leftover concrete left over from a construction site.

[0020] The hanging member 14 in this embodiment is formed by bending a reinforcing bar. As shown in Fig. 1(B), a U-shaped portion 14A is formed in the middle of the reinforcing bar in the longitudinal direction, and the hanging member 14 is formed by embedding the portion other than the U-shaped portion 14A in the block portion 12 with only the U-shaped portion 14A protruding from the upper surface of the block portion 12. In this embodiment, the hanging member 14 is formed by bending a D22 size deformed reinforcing bar, but the hanging member 14 is not limited to a D22 size deformed reinforcing bar.

[0021] Next, a method for constructing an earth retaining wall 100 using the concrete blocks 10 shown in FIG. 1 will be described with reference to a flow diagram shown in FIG. 2. In the present embodiment, the earth retaining wall 100 will be described in a form constructed by stacking the concrete blocks 10 in three layers in the height direction as shown in FIGS. 3 to 8. The builder uses a construction machine (not shown) to shape the original ground G in the construction area where the earth retaining wall 100 is to be constructed (S-1). The builder uses the construction machine to arrange the concrete blocks 10 in the width direction, aligned at intervals equal to the width dimension (diameter dimension) of the hanging material 14, as shown in FIG. 3 (S-2). At this time, the concrete blocks 10 (block parts 12) adjacent to each other in the width direction are arranged with a gap 20 equal to the width dimension of the hanging material 14.

[0022] In addition, it is preferable to lay the suction prevention sheet 30 with its lower end sandwiched between the original ground G and the concrete block 10 (S-3). Furthermore, it is more preferable to lay foundation crushed stones (not shown). The suction prevention sheet 30 is laid in a state in which a required length of one end side is sandwiched between the original ground G and the lower surface of the block portion 12 and aligned along the back side of the block portion 12. As shown in FIG. 4, the upper end of the suction prevention sheet 30 is at least higher than the upper surface height of the block portion 12 of the first concrete block 10. The concrete block 10 is arranged so that the state shown in FIG. 1(A) is the same as the state when the earth retaining wall 100 is viewed from the front.

[0023] After laying the erosion prevention sheet 30 on the back surface of the first layer of concrete blocks 10, the builder uses construction machinery to fill the gap between the back surface of the block portion 12 of the first layer of concrete blocks 10 and the original ground G with backfill material 40 (S-4). By filling the gap with backfill material 40, the erosion prevention sheet 30 can be brought into close contact with the back surface of the block portion 12. Next, the builder places the second layer of concrete blocks 10 in a stacked state on top of the first layer of concrete blocks 10 as shown in Figure 5 (S-5). After the second tier of concrete blocks 10 has been installed, it is preferable to use an adhesive or the like to bond the protruding portion of the suction prevention sheet 30 extending from the top surface of the block portion 12 of the first tier of concrete blocks 10 shown in Figure 4 (the upper end portion of the suction prevention sheet 30 on the lower tier side) to the lower end portion of the suction prevention sheet 30 added in the height direction (not shown), so that the suction prevention sheet 30 is extended and protrudes from the top surface of the block portion 12 of the second tier of concrete blocks 10, as shown in Figure 6 (S-6).

[0024] The second concrete block 10 is arranged in the width direction of the earth retaining wall 100 with the hanging members 14 of the first concrete block 10 sandwiched between the block parts 12 from both sides in the width direction. By arranging the hanging members 14 of the first concrete block 10 in the width direction on the side surfaces of the block parts 12 of the second concrete block 10 in this way, a gap 20 having the diameter dimension of the deformed reinforcing bar forming the hanging members 14 is formed between the block parts 12 of the concrete blocks 10 adjacent in the width direction in the second stage. Since both side surfaces and the bottom surface of this gap 20 are the outer surfaces of the block parts 12, the gap 20 can be used as a drainage path. According to this form, although the hanging members 14 are present in the drainage path, drainage can be achieved without any problem as long as it is from the back surface of the earth retaining wall 100. In addition, if the retaining wall 100 is constructed for temporary restoration purposes, it eliminates the need to install a separate drainage path in the retaining wall 100, and since the hanging material 14 is preserved, it becomes easier to remove the concrete blocks 10 when the retaining wall 100 is demolished, which is advantageous in that it enables rapid construction and removal work.

[0025] Then, in the same manner as when filling the backing material 40 into the back of the block part 12 of the concrete block 10 in the first stage, filling the backing material 40 into the back side of the block part 12 of the concrete block 10 in the second stage (S-7) is performed as shown in FIG. 6. Then, the builder extends the suction prevention sheet 30 in the same manner as in the first stage (S-8). Then, the builder installs the concrete block 10 in the third stage (S-9) as shown in FIG. 7 in the same procedure as the procedure for installing the concrete block 10 in the second stage. It is preferable that the concrete blocks 10 in the second and third stages are installed in a state where they are set back from the front position of the concrete block 10 installed below, as shown in FIG. 6 and FIG. 8. Then, the builder installs the backing material 40 into the back side of the block part 12 of the concrete block 10 in the third stage (S-10). Then, the builder performs upper end processing (S-11) such as cutting off the upper end of the suction prevention sheet 30 protruding from the upper surface of the block portion 12 of the third layer of concrete block 10 as necessary.

[0026] After arranging a plurality of concrete blocks 10 in the required range in the width direction and height direction in this way, the builder arranges (S-12) a slip prevention part 50 on the top surface of the (N-1)th concrete block 10 to prevent the Nth concrete block 10 from slipping toward the front side, as shown in FIG. 8. The slip prevention part 50 is formed by an anchor material 52 driven into the exposed top surface of the (N-1)th concrete block 10 and concrete 54 in which the anchor material 52 is embedded and integrated with the front surface of the Nth concrete block 10. An anchor recess (not shown) for inserting the anchor material 52 can be arranged in advance on the top surface of the concrete block 10. The slip prevention part 50 can be arranged after the concrete blocks 10 of each stage are arranged, or can be arranged all at once after all the concrete blocks 10 of all stages are arranged. If the slippage prevention portion 50 is formed with an upper limit within the range of the width dimension of the block portion 12 of the concrete block 10, drainage from the back surface of the retaining wall 100 will not be impeded. The process of installing the slippage prevention portion 50 can be replaced with the process of processing the upper end portion of the suction prevention sheet 30.

[0027] In this manner, the retaining wall 100 can be constructed using the concrete blocks 10 (END). According to the method for constructing the retaining wall 100 in this embodiment, the retaining wall 100 can be quickly constructed and dismantled, which is particularly advantageous when applied to the retaining wall 100 for disaster recovery. It is sufficient that the retaining wall 100 is constructed by stacking at least two or more layers of concrete blocks 10.

[0028] In this embodiment, the hanger 14 is exemplified in which the builder forms a U-shaped portion 14A in the middle of the length of the rebar, and only the U-shaped portion 14A is embedded in the block portion 12, but the hanger 14 is not limited to this form. As shown in Fig. 9, it is also possible to adopt a hanger 14 in which a hook portion 14B is formed at one end of the rebar, the hook portion 14B is projected from the top surface of the block portion 12, and the portion other than the hook portion 14B is embedded in the block portion 12.

[0029] In the above embodiment, a configuration is shown in which a plurality of first-stage concrete blocks 10 are arranged in the width direction of the earth retaining wall 100 at intervals 20 that are the same width as the diameter of the hanging members 14, but the present invention is not limited to this configuration. If the diameter of the hanging members 14 is significantly smaller than the width of the block portion 12, it is also possible to adopt a configuration in which the first-stage concrete blocks 10 are arranged in close contact with each other in the width direction.

[0030] In the above embodiment, the upper end of the suction prevention sheet 30 protruding from the upper surface of the block portion 12 of the (N-1)th concrete block 10 and the lower end of the suction prevention sheet 30 additionally disposed in the height direction are bonded by an adhesive or the like, but the present invention is not limited to this embodiment. It is also possible to adopt a configuration in which one suction prevention sheet 30 is used for the entire range of the earth retaining wall 100 in the height direction.

[0031] In addition, in this embodiment, an example is shown in which the suction prevention sheet 30 and the backfill material 40 are respectively laid on the back side of the retaining wall 100, but this is not limited to this example. It is also possible to adopt a form in which the laying of at least one of the suction prevention sheet 30 and the backfill material 40 is omitted.

[0032] In addition, by laying a filter material such as crushed stone or a synthetic resin mat in the gaps (drainage path portions) between the block portions 12 of the concrete blocks 10 adjacent to each other in the width direction in the retaining wall 100, the gaps (drainage path portions) can be prevented from being filled up with soil and sand, overgrowth of weeds, etc.

[0033] Furthermore, it is also possible to adopt a form in which the above-described embodiments and the modified examples described in each embodiment are appropriately combined. [Explanation of symbols]

[0034] 10: Concrete block 12: Block section, 14: Hanging material, 14A: U-shaped section, 14B: Hook section 20: Gap 30: Anti-absorption sheet 40: Backfill material 50: Anti-slip part 52: Anchor material, 54: Concrete 100: Earth retaining wall G: Original ground

Claims

1. A retaining wall formed by arranging concrete blocks having a block portion formed in a rectangular parallelepiped shape by concrete and a suspension member embedded in a state of protruding from the upper surface of the block portion in the width direction and the height direction, wherein the concrete block at the Nth (N is an integer of 2 or more) stage is arranged in a state of sandwiching the suspension member in the concrete block arranged at the (N-1)th stage by the block portion. The retaining wall is characterized by this.

2. The front surface of the concrete block arranged at the Nth stage is set back to the back side from the front surface of the concrete block arranged at the (N-1)th stage, The retaining wall according to claim 1, characterized in that a displacement preventing portion is arranged on the upper surface of the concrete block arranged at the (N-1)th stage.

3. A method for constructing a retaining wall formed by arranging concrete blocks having a block portion formed in a rectangular parallelepiped shape by concrete and a suspension member embedded in a state of protruding from the upper surface of the block portion in the width direction and the height direction, a step of arranging a plurality of the concrete blocks in the width direction on the original ground, repeatedly executing the step of arranging the concrete block at the Nth (N is an integer of 2 or more) stage in the width direction on the upper surface of the block portion of each of the concrete blocks until the number of stages reaches a preset number, The step of arranging the concrete block at the Nth stage in the width direction is a step of arranging while sandwiching the suspension member in the concrete block at the (N-1)th stage with the block portion in the concrete block at the Nth stage in the width direction. The method for constructing a retaining wall is characterized by this.

4. The step of arranging the concrete block at the Nth stage in the width direction is a step of arranging at a position set back to the back side from the front position of the block portion of the concrete block at the (N-1)th stage, The method for constructing a retaining wall according to claim 3, further comprising a step of arranging a displacement preventing portion on the upper surface of the concrete block arranged at the (N-1)th stage.

5. The method for constructing a retaining wall according to claim 3 or 4, further comprising a step of laying a suction prevention sheet and a backfill material on the back side of the concrete block after the step of arranging the concrete blocks in the width direction.

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