JP3654896B1 - How to install concrete blocks - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete block installation method and an installation tool which can improve working efficiency and can be applied to a concrete block of a general shape and which is not affected by the levelness of the installation surface.
SOLUTION: A first flat plate 35 is installed on the upper surface of a base 31 of the foundation concrete 19, and a powder 36 such as lime is laid on the upper surface of the first flat plate 35. Next, fine powder balls 23 for sandblasting, for example, are scattered on the powder 36 and are held on the first flat plate 35 via the powder 36. Then, a second flat plate 37 similar to the first flat plate 35 is placed on the fine steel ball 23, and a precast concrete block 39 to be installed on the upper surface of the second flat plate 37 is placed. When the precast concrete block 39 is moved in the horizontal direction in this state, the resistance caused by the movement is reduced by the action of the fine steel balls 23 that are not likely to fall off by the powder 36.
[Selection] Figure 5

Description

  The present invention relates to a method and an installation tool for a concrete block, and more particularly to an installation method and an installation tool for a concrete block related to installation and horizontal movement of a precast concrete block such as a box culvert.

  11 is a schematic view of a concrete block installation method disclosed in, for example, Patent Document 1, FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11, and FIG. 13 is a “Y” portion in FIG. It is an enlarged view.

  Referring to these drawings, box culverts 61 a to 61 c having a hollow center, which is one of precast concrete blocks, are sequentially connected to foundation concrete 19. The box culvert 61d that is hooked and caught by the wire 18 is suspended near the box culvert 61c from above. Then, it is drawn in the direction indicated by the horizontal arrow, and moves to a connected state like box culvert 61a to box culvert 61c.

  In order to reduce the frictional resistance with the foundation concrete 19 during the horizontal movement, the lower part of the box culvert 61 has a special shape. That is, as shown in FIG. 13, a protrusion 62 protruding downward is formed on the lower surface of the box culvert 61, and a steel plate 63 is attached to the surface of the protrusion 62. On the other hand, a guide rail 65 made of I-type steel is embedded in the foundation concrete 19, and a plurality of steel balls 66 are arranged on the upper surface thereof.

  With the box culvert 61 and the foundation concrete 19 thus formed, the box culvert 61 is installed on the foundation concrete 19 so that the protrusion 62 is positioned on the guide rail 65. When the box culvert 61 is moved in the horizontal direction in this state, resistance to movement in the horizontal direction is reduced by the bearing effect of the steel ball 66, and the box culverts 61 can be smoothly connected.

  Usually, after the box culvert 61 is drawn to a connected state, in order to secure a mutual seal between them, a compacting operation is performed to draw them together, and these are integrated. Thereafter, the flowable ready-mixed concrete is poured between the lower portion of the box culvert 61 and the upper surface of the foundation concrete 19 to fix the box culvert 61 to the foundation concrete 19.

  Furthermore, as shown in Patent Document 2, there has been proposed a method in which a first flat plate is installed on the upper surface of the foundation of the foundation concrete 19, and an adhesive such as water glue is applied to the upper surface of the first flat plate. . That is, for example, fine sand balls 23 for sandblasting are disposed in the adhesive so as to be held by the adhesive. Then, a second flat plate similar to the first flat plate is placed on the fine steel ball, and a precast concrete block to be placed on the upper surface of the second flat plate is placed. When the precast concrete block is moved in the horizontal direction in this state, the resistance caused by the movement is reduced by the action of the fine steel balls that are not likely to drop off from the first flat plate by the adhesive.

Japanese Patent Laid-Open No. 2000-293938 JP 2002-235363 A

  In the concrete block installation method as described in Patent Document 1, it is necessary to finish the box culvert 61 into a special shape by providing the projection 62 at the lower portion of the box culvert 61 as described above. Therefore, it is disadvantageous in terms of cost compared with the normal box culvert 61.

  Moreover, since it is necessary to embed the guide rail 65 in the foundation concrete 19 in order to arrange | position the steel ball 66, the operation | work will be troublesome and cost will increase as a result. Further, since the steel balls 66 are arranged on the upper surface of the guide rail 65, if the level of the guide rail 65 is not ensured, the steel balls 66 are not arranged uniformly as a whole and may be biased in one direction. . For this reason, it is difficult to adopt this construction method when the installation surface of the box culvert 61 is a horizontal surface and is an inclined surface.

  On the other hand, if it is a method like said patent document 2, since a hard ball does not move by the holding | maintenance property of an adhesive, since it can implement even on the inclined surface, it is convenient. However, since the pressure-sensitive adhesive has to be applied in advance, the work efficiency may be reduced. Also, water glue or the like is used as the adhesive, but it cannot be said that it is easy to handle due to its adhesiveness. Moreover, this adhesive is essentially unnecessary when the movement of the concrete block is completed, but it tends to remain due to its properties.

  The present invention has been made to solve the above-described problems. A concrete block installation method that can be applied to a concrete block having a general shape and that is not affected by the levelness of the installation surface, while improving work efficiency. The purpose is to provide.

  In order to achieve the above object, the invention according to claim 1 is a method for installing a concrete block, in which a flat plate-like first flat plate is installed at a predetermined position on a foundation concrete, and the outer surfaces of a plurality of hard balls A step of attaching the powder to at least a part of the step, a step of arranging a plurality of hard spheres with the powder attached on the first flat plate, a step of installing a flat plate-like second flat plate on the hard ball, A concrete block placed on the second flat plate and moved in a substantially horizontal direction.

  If comprised in this way, a hard ball will be hold | maintained on the 1st flat plate by the powder which adhered, and a concrete block will be mounted on the foundation concrete in the state via the hard ball hold | maintained at the powder.

  As described above, in the first aspect of the invention, the concrete block is placed on the foundation concrete with the hard ball interposed therebetween, so the concrete block moves in the horizontal direction without requiring a special shape. The resistance to is reduced. Further, since the arranged hard spheres are held by the powder adhering to at least a part of the outer surface thereof, there is no risk of inadvertent movement regardless of the level of the first flat plate, and stable installation work is possible. . In addition, since it is a powder, its handling becomes easy, and furthermore, the hard ball can be held on the first flat plate simply by placing the hard ball with the powder previously attached to at least a part of its outer surface, so the amount of powder used Can be further suppressed and work efficiency is improved.

  FIG. 1 is a schematic view showing a method of installing a concrete block according to the first embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is “X” in FIG. FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG. 3.

  With reference to these drawings, a pair of guide rails 21a and 21b is installed on the foundation concrete 19, and a box culvert 16a to a box culvert 16c, which is one of the precast concrete blocks, are disposed between them. Are installed sequentially. The guide rail 21a and the guide rail 21b are embedded in the foundation concrete 19 and are fixed on the anchor 25 whose level is adjusted. Therefore, the box culvert 16 is installed in a state where the level of the guide rail 21a and the guide rail 21b is ensured.

Powder 26 made of lime, for example, is laid on the upper surface of the horizontal member 27 of the guide rail 21b. 4 to 12 mm) 23 is dispersed and arranged (3 to 100 per 100 cm ² ).

  In this embodiment, the box culvert 16 locked by the wire 18 is suspended at a certain position, and is moved to a predetermined position in the horizontal direction. Therefore, the powder 26 is laid on almost the entire upper surface of the horizontal member 27, and similarly, the fine steel balls 23 are arranged at random or at predetermined intervals over the entire area of the powder 26. The powder easily adheres to the horizontal member 27 due to its characteristics, and the fine steel balls 23 are held by the powder 26. Therefore, after the placement, the fine steel balls 23 are placed at other positions from above the horizontal member 27. There is no fear of moving.

  A predetermined number of flat plates 22 corresponding to the lower surface of the box culvert 16 are prepared, and are disposed above the fine steel balls 23 at a position where the box culvert 16 is suspended. In this state, the box culvert 16 is suspended on the flat plate 22. Thus, the box culvert 16 is installed on the horizontal member 27 with the fine steel ball 23 interposed therebetween.

  Next, the suspended box culvert 16 is moved in the horizontal direction using a winch, a wire or the like (not shown). At this time, as shown in FIG. 4, the box culvert 16 moves with respect to the horizontal member 27 through the fine steel balls 23 together with the flat plate 22, and thus resistance to movement is reduced. At this time, the powder 26 only holds the fine steel balls 23 and does not serve as resistance when the fine steel balls 23 roll. As a result, it is possible to move the box culvert 16 smoothly. In addition, the lower corner part 29 with respect to the advancing direction of the flat plate 22 shown by the arrow in FIG. 4 is rounded so that the fine steel ball 23 is not shaved when moving.

  In this movement, the vertical member 28 of the guide rail 21 serves as a guide, and the box culvert 16 can be stably moved horizontally. In this manner, the box culvert 16a to the box culvert 16d are sequentially drawn and connected to each other, and are further compacted in order to secure a seal of these connecting portions. Even in this compacting operation, the box culvert 16 moves smoothly by the action of the fine steel balls 23.

  When the compaction of the box culvert 16a to the box culvert 16d is completed, ready-mixed concrete or mortar having fluidity is poured between the lower portion of the box culvert 16a to the box culvert 16d and the upper surface of the foundation concrete 19 in this state. 16a-box culvert 16d is fixed to foundation concrete 19, and the installation operation is completed.

  FIG. 5 is a schematic process diagram illustrating a method for installing a concrete block according to a second embodiment of the present invention, which is a method for installing a concrete block on a foundation formed on foundation concrete. .

  Referring to the drawing, as shown in (1) of FIG. 5, a flat plate-like first flat plate 35 such as an iron plate is formed on a base 31 formed on the foundation concrete 19 and adjusted in the level of the upper surface thereof. Is placed. The base 31 is not necessarily formed, and the first flat plate 35 may be directly disposed on the foundation concrete 19.

  Next, as shown in (2) of FIG. 5, a powder 36 having adhesion such as lime is spread on the upper surface of the first flat plate 35 from above, and a thickness of, for example, about 1 mm is applied to almost the entire surface of the first flat plate 35. Now lay. On this powder 36, for example, a plurality of fine steel balls 23 used for sandblasting are dropped and arranged so as to be scattered almost uniformly. Note that the size of the fine steel balls 23 and the degree of distribution thereof are the same as those in the first embodiment. As a result, as shown in FIG. 5 (3), the fine steel balls 23 are held by the powder 36, and there is no possibility of inadvertent movement with respect to the first flat plate 35. Therefore, the initial distribution state of the fine steel balls 23 on the powder 36 is maintained.

  Next, as shown in (4) of FIG. 5, a second flat plate 37 made of a flat plate-like iron plate having substantially the same shape as the first flat plate 35 is installed so as to cover the fine steel balls 23. Although the powder 36 holds the fine steel ball 23 at the position, it does not prevent the fine steel ball 23 from rotating. As a result, the first flat plate 35 and the second flat plate 37 can be easily moved on each other's surface via the fine steel balls 23. Even if the powder 36 scatters at this stage, there is no problem because the fine steel balls 23 are already held between the first flat plate 35 and the second flat plate 37. In this manner, the fine steel balls 23 are sandwiched between the first flat plate 35 and the second flat plate 37, and a precast concrete block 39 to be installed is placed thereon as shown in FIG. 5 (5).

  For this reason, the resistance caused by the movement of the precast concrete block 39 in the horizontal direction is reduced by the action of the fine steel balls 23, so that the movement in the horizontal direction can be adjusted smoothly. Thus, the installation adjustment work of the precast concrete block 39 is completed. After this operation is finished, even if the powder 36 is scattered by the wind or the like and completely disappears, there is no problem because the role of the fine hard sphere 3 is already finished. Thereafter, the ready-mixed concrete is poured between the precast concrete block 39 and the foundation concrete 19 as usual, and these are fixed.

  FIG. 6 shows an example of the mounting state when the foundation concrete 19 is inclined in the case where the height adjusting bracket is used at the lower part of the concrete block in the method for installing the concrete block shown in FIG. FIG.

  Referring to the figure, in this example, the precast concrete block 39 is not placed directly on the second flat plate 37, but the second flat plate is interposed via a height adjustment fitting 41 attached to the lower surface of the precast concrete block 39. 37. The first flat plate 35 has an inclination of about 8 degrees at the maximum, but the powder 36 is kept attached to the first flat plate 35. Therefore, the initial arrangement interval of the fine steel balls 23 is maintained. The height adjusting bracket 41 has a function of changing a protruding length of a bolt screwed to both sides thereof by rotating a central nut. Further, the height adjusting bracket 41 may be used by turning it upside down, or an upper bolt screwed into a nut having the same shape as that of the lower one may be used.

  Therefore, in this example, after the precast concrete block 39 is adjusted to a predetermined height from the foundation concrete 19, the height adjusting bracket 41 is adjusted so as to match the distance between the lower surface of the precast concrete block 39 and the second flat plate 37. . In this state, the head of the bolt below the height adjustment fitting 41 is brought into contact with the second flat plate 37.

  When the height adjustment of the precast concrete block 39 with respect to the foundation concrete 19 is completed, the precast concrete block 39 is then moved by a predetermined amount in the direction of the arrow as shown in FIG. In this case, the height adjustment fitting 41 attached to the lower surface of the precast concrete block 39 is easily moved in the direction of the arrow with respect to the first flat plate 35 integrally with the second flat plate 37. In this case, the upper surface of the base 31 is inclined. However, since the fine steel balls 23 are held by the powder 36 attached to the first flat plate 35, there is a possibility that the inclination may move with respect to the first flat plate 35. Absent. Therefore, since the fine steel balls 23 are held at the positions where they are initially arranged, the second flat plate 37 is guaranteed to move stably with respect to the first flat plate 35.

  When the adjustment and movement of the precast concrete block 39 in the height direction and the horizontal direction are completed in this way, ready-mixed concrete or mortar is poured between the lower part of the precast concrete block 39 and the upper surface of the foundation concrete 19, and the precast concrete block 39 39 is fixed to the foundation concrete 19 in that state, and the installation work is completed. Also in the example of FIG. 6, the base 31 is not necessarily formed, and the first flat plate 35 may be disposed directly on the foundation concrete 19.

  FIG. 7 is a schematic process diagram illustrating a method for installing a concrete block according to a third embodiment of the present invention, which is a method for installing a concrete block on a foundation formed on foundation concrete. .

  Referring to the drawing, as shown in (1) of FIG. 7, a flat plate-like first flat plate 35 such as an iron plate is formed on a base 31 formed on the foundation concrete 19 and adjusted in the level of the upper surface thereof. Is placed. The base 31 is not necessarily formed, and the first flat plate 35 may be directly disposed on the foundation concrete 19.

  Next, as shown in (2) of FIG. 7, a plurality of fine steel balls 23 used for sandblasting, for example, are arranged on the upper surface of the first flat plate 35 so as to be scattered almost uniformly. Note that the size of the fine steel balls 23 and the degree of distribution thereof are the same as those in the first embodiment. Next, the powder 36 having adherence such as lime is spread on the first flat plate 35 from above with the fine steel ball 23 as the center. The amount of the powder is preferably at least about 1 to 2 mm around the fine steel ball 23. As a result, as shown in FIG. 7 (3), the fine steel ball 23 is held by the powder 36 adhering to the periphery thereof, and there is no possibility of inadvertent movement with respect to the first flat plate 35. Therefore, the initial distribution state of the fine steel balls 23 on the first flat plate 35 is maintained.

  Next, as shown in FIG. 7 (4), a second flat plate 37 made of a flat plate-like iron plate having substantially the same shape as the first flat plate 35 is installed so as to cover the fine steel balls 23. Although the powder 36 holds the fine steel ball 23 in this position, it does not prevent its rotational movement because it is only attached to the fine steel ball 23. As a result, the first flat plate 35 and the second flat plate 37 can be easily moved on each other's surface via the fine steel balls 23. Even if the powder 36 scatters at this stage, there is no problem because the fine steel balls 23 are already held between the first flat plate 35 and the second flat plate 37. In this manner, the fine steel balls 23 are sandwiched between the first flat plate 35 and the second flat plate 37, and a precast concrete block 39 to be installed is placed thereon as shown in FIG.

  For this reason, the resistance caused by the movement of the precast concrete block 39 in the horizontal direction is reduced by the action of the fine steel balls 23, so that the movement in the horizontal direction can be adjusted smoothly. Thus, the installation adjustment work of the precast concrete block 39 is completed. After this operation is finished, even if the powder 36 mainly adhering to the fine steel balls 23 is scattered by the wind or the like and disappears completely, there is no problem because the role of the powder 36 is already finished. . Thereafter, the ready-mixed concrete is poured between the precast concrete block 39 and the foundation concrete 19 as usual, and these are fixed.

  FIG. 8 is a schematic process diagram illustrating a method for installing a concrete block according to a third embodiment of the present invention, in which fine hard balls are arranged on a flat plate placed on a foundation concrete block.

  Referring to the figure, as shown in (1) of FIG. 8, the storage case 51 is filled with the powder 36 so as to be almost full. Next, as shown in (2) of FIG. 8, a plurality of fine steel balls 23 are put into the powder 36 in the housing case 51 and mixed. The size of the fine steel ball 23 is the same as that according to the first embodiment. Then, the fine steel balls 23 are taken out from the powder 36 and arranged at a desired interval on a flat plate 53 made of a steel plate or the like used as an installation tool as shown in (3) of FIG. The arrangement interval of the fine steel balls 23 is the same as that according to the first embodiment. The fine steel ball 23 taken out from the housing case 53 is in a state where the powder 36 is attached to at least a part of its outer surface. Therefore, the fine steel ball 23 is held on the flat plate 53 via the powder 36 and does not move from the position where it was initially arranged.

  Hereinafter, as in the previous embodiments, when a flat plate or the like is placed on the fine steel ball 23 and a concrete block to be moved further upward is installed in this state, the horizontal movement is similarly smooth. Adjustment is possible.

  FIG. 9 is a schematic plan view of a concrete block installation device according to a fifth embodiment of the present invention, and FIG. 10 is a sectional view taken along line XX of FIG.

  Referring to these drawings, the installation tool according to this embodiment includes a rectangular flat plate-shaped first flat plate 35, powder 36 such as lime laid on the upper surface of first flat plate 35, and powder 36. A plurality of fine steel balls 23 for sandblasting arranged so as to be scattered over almost the entire area, a second flat plate 37 having a rectangular flat plate shape arranged on the fine steel balls 23, and each corner portion of the first flat plate 35 It is comprised from the corner piece 43a-the corner piece 43d of planar view L shape attached to. Note that the size of the fine steel balls 23 and the degree of distribution thereof are the same as those in the first embodiment. Further, the powder 36 may be laid so as to be spread over the entire upper surface of the first flat plate 35, but at least a part of the outer surface of the fine steel ball 23 by the method as described in the previous embodiments. It is sufficient that the holding function can be exhibited by adhering to the upper surface of the first flat plate 35 in the vicinity thereof.

  The height H of the corner pieces 43 a to 43 d from the first flat plate 35 is set to be smaller than the distance L between the upper surface of the second flat plate 37 attached to the fine steel ball 23 and the upper surface of the first flat plate 35. Has been. Further, as shown in FIG. 9, the size of the second flat plate 37 in plan view is set to be a predetermined amount smaller than the rectangular shape defined by the inner surface positions of the corner pieces 43a to 43d.

  When in use, the state shown in FIG. 9 and FIG. 10 is taken as it is to the concrete block installation place, and the first flat plate 35 is installed at a predetermined position on the foundation concrete. And the concrete block which is not shown in figure is installed so that the bottom face of the concrete block which should be installed in the upper surface of the 2nd flat plate 37 may be mounted. In this case, since the lower surface of the concrete block does not contact the upper surfaces of the corner pieces 43a to 43d, the concrete block can be easily moved in the horizontal direction via the second flat plate 37.

  Since the second flat plate 37 is surrounded by the corner pieces 43a to 43d as shown in FIG. 9, the movement of the second flat plate 37 is limited only within the range. Therefore, if the first flat plate 35 is set at a predetermined position and the horizontal adjustment margin of the concrete block placed thereon is set within a movable range of the second flat plate 37, the second flat plate 37 is set. It becomes easy to confirm the correctness of the installed state of the concrete block depending on the moving state of this, and the usefulness increases. That is, when the second flat plate 37 is not yet moved even in a state in which the second flat plate 37 is in contact with any one or two of the corner pieces 43a to 43d, the concrete block is not installed at the correct position. This means that it is a measure of the quality of the installation. It should be noted that this installation tool is more convenient since it can be managed immediately after use, with the fine steel balls 23 and powder 36 removed, and can be used immediately if they are set.

  In addition, in said embodiment, although the concrete block of general shape is made into object, it cannot be overemphasized that it can apply similarly to the concrete block of the special shape shown in the prior art example.

  In the above embodiment, hard balls made of fine steel balls are used. However, the present invention is not limited to this, and hard balls made of hard materials such as ceramics and plastics may be used similarly.

  Furthermore, in the above embodiment, lime is used as the powder for holding the fine steel balls. However, as long as it adheres to at least a part of the outer surface of the fine steel balls and can hold it on a flat plate. In addition to lime as powder, for example, cement, earth, sand, gravel, concrete powder, glass powder, brick powder, shell powder, wheat flour and other grain powder, potato starch, rice husk powder, paper powder, slag, aluminum pieces, ceramic pieces Further, it may be a powder such as a steel frame, a metal piece, a plastic piece, a rubber piece, a fine granular material, or a mixture thereof. In this case, in the case of a fine granular material, the average outer diameter is preferably 0.1 mm or less, and more preferably 0.01 mm or less.

  Furthermore, in the above embodiment, the steel ball is used as an example of a sphere for sandblasting, but it goes without saying that other steel balls or granular spheres may be used.

  Furthermore, in the above embodiment, the precast concrete block is applied to the box culvert, but besides this, not only the arch culvert but also the water tank, garage, L-shaped retaining wall, waterway, gutter, retaining wall block, etc. Needless to say, it can be applied to the above.

  Furthermore, in the above embodiment, the flat plate uses an iron plate, but instead of this, another metal plate, a reinforced plastic plate, a reinforced cement concrete material, a rubber plate, or the like may be used.

  Furthermore, in the above embodiment, the fine steel ball is sandwiched between two flat plates. However, depending on the condition of the bottom surface of the concrete block to be installed and the weight of the concrete block being light, the concrete block is directly placed on the fine steel ball. It is also possible to use it without using the upper flat plate. In this case, the diameter of the fine steel ball is preferably about 12 mm. And if the board equivalent to an upper flat plate is embedded in the lower surface of a concrete block, there will exist the same effect as said embodiment. In this case, if the L-shaped steel is embedded so as to surround the outer corner of the lower surface of the concrete block, it is possible to move more stably together with the protective effect of the concrete block from the vertical member of the guide rail.

  Furthermore, in said 1st Embodiment, although the cross-section L-shaped steel materials are used as a guide rail, it replaces with this and other shapes, such as a mere flat plate formed in the moving direction, and L-shaped steel materials, are changed. Steel materials may be used.

  In the second embodiment described above, a height adjusting bracket is used as a modification thereof, but this bracket is used for the horizontal member of the L-shaped guide rail shown in the first embodiment. When the height is adjusted by attaching to the lower surface, and the fine adjustment is performed by attaching a fine steel ball and a flat plate to the upper surface of the horizontal member, the usability is further improved.

It is the figure which showed the outline of the installation method of the concrete block by 1st Embodiment of this invention. It is sectional drawing of the II-II line of FIG. FIG. 3 is an enlarged view of an “X” portion in FIG. 2. It is an expanded sectional view of the IV-IV line of FIG. It is the figure which showed the schematic process of the installation method of the concrete block by 2nd Embodiment of this invention. It is the figure which showed the modification of the installation method by the process shown in FIG. It is the figure which showed the general | schematic process of the installation method of the concrete block by the 3rd Embodiment of this invention. It is the figure which showed the general | schematic process regarding the preparation stage about the installation method of the concrete block by 4th Embodiment of this invention. It is the top view which showed schematic structure of the installation tool of the concrete block by the 5th Embodiment of this invention. It is sectional drawing of the XX line of FIG. It is the figure which showed the outline of the installation method of the conventional concrete block. It is sectional drawing of the XII-XII line of FIG. FIG. 13 is an enlarged view of a “Y” portion in FIG. 12.

Explanation of symbols

16 ... Box culvert 19 ... Basic concrete 22 ... Flat plate 23 ... Fine steel ball 26, 36 ... Powder 27 ... Horizontal member 35 ... First flat plate 37 ... Second flat plate 39 ... Precast concrete block Or an equivalent part is shown.

Claims (1)

A concrete block installation method,
Installing a flat plate-like first flat plate at a predetermined position on the foundation concrete, and attaching powder to at least a part of the outer surfaces of the plurality of hard balls;
Arranging the plurality of hard spheres to which the powder is attached on the first flat plate;
Installing a flat plate-like second flat plate on the hard sphere;
Placing the concrete block on the second flat plate and moving the concrete block in a substantially horizontal direction.

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