JP6904532B2 - Connecting structure of concrete blocks and how to remove the concrete blocks - Google Patents

Description

In the present invention, in a connecting portion of a structure in which blocks of precast concrete blocks are connected to each other and extended in the longitudinal direction, one side to the other side of the left and right side wall portions which are the front side or the back side of the continuous blocks in the structure. The present invention relates to a concrete block connecting structure capable of operating the connecting portion of the concrete block and a method for removing the concrete block.

There are various connecting structures in the structure in which the precast concrete blocks are connected and extended in the longitudinal direction. In the connecting structure of the concrete blocks shown in FIG. 7, the connecting plate is bridged to the adjacent concrete blocks, and the front side or the back side is provided. A plate fixing method of fixing with bolts and nuts from both surface sides of the left and right side wall portions on the side is often used as a simple means.

For example, in road construction, a concrete temporary guard rail block that separates the vehicle passage side and the construction area side is used, but at the time of installation, the vehicle is closed and both sides of the left and right side walls of the concrete temporary guard fence are constructed. It is possible to use it in the area for construction, but it is required to avoid vehicle closure at the time of removal, and in this situation the removal work using the vehicle traffic side is extremely dangerous. rice field.

There may be a dangerous area on either side of the left or right side wall of the concrete temporary guard fence, etc., and the removal of the connecting plate by the conventional plate fixing method as described above at the connecting part is a dangerous area. It had to go around to the side and remove the connecting plate, and in order to avoid the danger, it was necessary to take other measures.

Further, in Patent Document 1 described below, as shown in FIG. 8, adjacent blocks A are connected to each other by the above-mentioned connecting plate, and a joint plate C serving as a connecting plate is provided in a recess B of the block A. A technique is described in which a plurality of blocks A are connected and integrated by fitting and screwing a bolt into a through hole D provided in the recess B or tightening and fixing the block A with a nut. The recess B is a joint plate C. The joint plate C was formed to have a size capable of fitting the bolts, and the fitted joint plate C did not stay in the recess B even when the fixed state was released, but only dropped.

Japanese Patent No. 3951250

The present invention is a connecting structure of a concrete block in which the connecting portion can be operated only from the area on one side of the left and right side wall portions on the front side or the back side of the concrete blocks to be continuously installed. And a method for removing the concrete block.

The present invention is a connecting portion in which a concrete block composed of a concrete main body having an outer shape of a left and right side wall portion, an installation bottom portion, and an upper portion is extended in the longitudinal direction. A through hole is provided to form a connecting portion, and connecting portions of other concrete blocks having a similar shape are adjacent to each other, and a connecting plate is arranged across the left and right vertical portions of the connecting portion. In a connecting structure in which concrete blocks are connected to each other by fixing tightening bolts inserted through the through holes, bolt insertion holes are provided at both ends of the connecting plate arranged across the concrete blocks, and the left and right side walls are provided. A tightening bolt is inserted through the through hole from the connecting plate located on one side toward the connecting plate on the other side, and the connecting plate on the other side has a screwed portion on the surface side of the bolt insertion hole. Concrete that is integrally formed and the tip of the tightening bolt inserted from one side to the other side is fixed by the screwed portion, and the base end portion on the insertion side of the tightening bolt is fixed by the removable screwed portion. It features a block connection structure.

Further, the vertical portion is characterized by a connecting structure of concrete blocks provided at a plurality of positions in the vertical direction facing each other on the surface side of the end portions of the left and right side wall portions of the concrete block.

Further, the vertical portion on the side where the connecting plate integrally formed with the screwed portion is arranged forms a flat portion on which the connecting plate can rotate around one of the tightening bolts of the connecting plate. It features a block connection structure.

Further, the concrete block having a wide bottom side of the installation is a connection of concrete blocks formed by forming a vertical portion as a vertical notch by gradually deeply cutting out both the left and right side wall portions from the upper side to the lower side. It features a structure.

Further, in a connecting portion in which a concrete block composed of a concrete main body having an outer shape of a left and right side wall portion, an installation bottom portion, and an upper portion is extended in the longitudinal direction, the left and right vertical portions and the left and right side wall portions penetrate the end surface side of the left and right side wall portions. A through hole is provided to form a connecting portion, connecting portions of other concrete blocks having a similar shape are adjacent to each other, and a connecting plate is arranged across the left and right vertical portions of the connecting portion. In a connecting structure in which concrete blocks are connected to each other by fixing tightening bolts inserted through the through holes, bolt insertion holes are provided at both ends of the connecting plate arranged across the concrete blocks, and either the left or right side wall portion is provided. A tightening bolt is inserted through the through hole from the connecting plate located on one side toward the connecting plate on the other side, and the connecting plate on the other side integrally forms a screw portion on the surface side of the bolt insertion hole. Then, the tip of the tightening bolt inserted from one side to the other side is fixed by the screwed portion, and the base end portion on the insertion side of the tightening bolt is fixed by the detachable screwed portion of the concrete block. In the connecting structure, the tightening bolt of the connecting plate fixed by the detachable screwed part on either side of the left or right side wall of the concrete block on the side to be removed first is removed from the construction area side by releasing the screwed part. The tightening bolt of the concrete block to be removed later is left in a loosened state on the detachable side, and the connecting plate and the tightening bolt are left in the connecting part of the concrete block and the concrete on the side to be removed first. It features a method of removing a concrete block from which the block is removed.

In addition, the remaining connecting plate rotates counterclockwise around the remaining tightening bolt as the concrete block on the side to be removed first rises, and is removed together with the concrete block on the side to be removed later. It features a method of removing concrete blocks that will be used.

In the present invention, a plurality of concrete blocks are connected and installed along the longitudinal direction at the boundary between the vehicle passage side and the construction area side such as road construction, or the passage side and the ground side such as earth retaining work. By adopting a connecting structure in which the fixing of the connecting portion can be released only from one side of the continuous concrete block forming the boundary portion, the concrete block can be removed without wrapping around to the other side. It has become possible.

In addition, by making it possible to remove the installed concrete block from one side, the area on the other side can be maintained in a normal state. For example, if it is installed at the boundary of a road or passage, traffic It has become possible to carry out the work only from the safe construction area side without hindering or putting it in a dangerous state, and it has become possible to quickly remove the concrete block.

(A) Short sectional view of the concrete block, (b) Longitudinal front view of the concrete block. (A) Plan view of the connecting plate used for one side wall of the concrete block connecting part, (b) Same side view, (c) Connecting plate used for the other side side wall of the concrete block connecting part. Plan view, (d) same side view. (A) A plan sectional view of a connecting structure at an upper position of a concrete block, and (b) a plan sectional view of a connecting structure at a lower position of a concrete block. A front view of a side wall portion on one side showing a state in which concrete blocks are connected. (A), (b), (c) Schematic front view of a connecting portion on the side where a connecting plate is left, showing a state in which the concrete block is removed. (A) Short sectional view of another embodiment of the connecting portion of the concrete block, (b) Front view of the front side which is the one side side wall portion in the same connected state, and (c) The other side side wall portion. Front view on the back side. The front view of the conventional example of the connection part of a concrete block. Perspective view of another conventional example of the connection between blocks.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 5 are examples of a temporary guard fence block made of concrete, and FIG. 1A shows a cross-sectional view in the lateral direction thereof. The concrete temporary guard fence block 1 has a three-dimensional shape made of a concrete body having an outer shape consisting of a left side wall portion 2, a right side wall portion 3, an installation bottom portion 4, and an upper surface portion 5, and both ends in the longitudinal direction are shown in the figure. As shown in 1 (b), the upper left vertical for arranging the connecting plates formed on the left end wall portion 6, the right end wall portion 7, and the left and right side wall portions 2 and 3 on the left and right end wall portions 6 and 7 side. It is composed of parts 8, 8, upper right vertical parts 9, 9, lower left vertical parts 10, 10 and lower right vertical parts 11, 11, and in this embodiment, the entire cross-sectional shape is the installation bottom. It has a substantially isosceles trapezoid with four sides enlarged.

The concrete temporary guard fence block 1 is extended in the longitudinal direction to form a protective wall, but the left end wall portion 6 (left end wall portion 6) of the concrete temporary guard fence block 1 installed earlier is used. (When extending to the side), the right end wall portion 7 of the concrete temporary guard fence block 1a to be installed next is adjacent to each other and connected to each other, and the connection is repeated to continuously extend.

The upper left and right vertical portions 8 and 9 and the lower left and right vertical portions 10 and 11 provided on the left and right end wall portions 6 and 7 of the left side wall portion 2 and the right side wall portion 3 are the upper left and right and lower left and right connecting plates 12 and 13. , 14 and 15 are used as cutouts, and when the concrete temporary guard fence blocks 1 and 1a are installed adjacent to each other, the upper left and right vertical portions 8 and 9 and the lower left and right vertical portions 10 and 11 respectively. Since it is provided as a vertical notch at a height position corresponding to the left and right end wall portions 6 and 7, a continuous vertical portion is formed.

The upper left and right vertical portions 8 and 9 are formed as U-shaped groove-shaped notches having a size in which the connecting plates 12 and 13 are fitted or a size in which the connecting plates 12 and 13 can be rotated as described below. The left and right vertical portions 10 and 11 have a tapered cross-sectional triangular shape in which the lower side of the notch portion protrudes forward and gradually becomes deeper, and the connecting plates 14 and 15 have a size that allows rotation within the lower left and right vertical portions 10 and 11. The groove-shaped notch of. The upper left and right vertical portions 8 and 9 may be formed in the same manner as the lower left and right vertical portions 10 and 11. In the first embodiment, since the left and right side wall portions 2 and 3 having the width dimension on the installation bottom 4 side larger than the width dimension on the upper surface 5 side are inclined walls, the depth on the lower side becomes deeper by notching vertically. A step portion is formed in which the bottom 4 side projects forward.

In the connection at the left and right end wall portions 6 and 7, the upper left and right vertical portions 8 and 9 and the lower left and right vertical portions 10 of the adjacent concrete temporary guard fence blocks 1 and 1a are on the left side wall part 2 and the right side wall part 3. The upper left and right connecting plates 12 and 13 and the lower left and right connecting plates 14 and 15 are arranged and fixed at the positions of 11 so as to straddle both of them. Upper left and right through holes 16 that horizontally penetrate between the left and right side wall portions 2 and 3 in the lateral direction of the concrete block main body in order to fix the upper left and right connecting plates 12 and 13 and the lower left and right connecting plates 14 and 15. , 17, lower left and right through holes 18, 19 are formed, and upper left and right connecting plate tightening bolts 20, 21 and lower left and right connecting plate tightening bolts 22, 23 are inserted into the respective through holes 16, 17, 18, 19. Then, they shall be screwed and fixed to the upper left / right connecting plates 12, 13 and the lower left / right connecting plates 14, 15 respectively arranged in the upper left / right vertical portions 8, 9 and the lower left / right vertical portions 10, 11. become.

At the connecting portions of the left and right side wall end portions 6 and 7 of the adjacent concrete temporary guard fence blocks 1 and 1a, the two are firmly connected and fixed by the connecting plates 12, 13, 14 and 15 straddling the two.

2 (a), (b), (c), and (d) show connecting plates, and FIGS. 2 (a) and 2 (b) are upper left connecting plates 12 on the left wall portion 2 side on the vehicle passage side. , The front view and the side view of the lower left connecting plate 14 are shown, and the left connecting plate bolt insertion holes 24 and 25 are provided at both ends thereof, and the left connecting plate bolt insertion holes 24 on the outer surface of the upper and lower left connecting plates 12 and 14 are provided. The left and right nuts 26 and 27 to which the connecting plate tightening bolts are screwed at the positions of 25 are fixed by welding or the like.

2 (c) and 2 (d) are front views and side views of the upper right connecting plate 13 and the lower right connecting plate 15 of the right wall portion 3 on the construction area side, and the right connecting plate bolts are inserted into both ends thereof. Holes 28 and 29 are provided. No screwing means is provided in advance.

FIG. 3A shows a connecting portion provided on the upper side of the concrete temporary guard fence blocks 1 and 1a. In the upper left vertical portion 8 on the vehicle passage side, the upper side straddles between the upper left vertical portions 8. The left connecting plate 12 is arranged, the upper right connecting plate 13 is arranged between the upper right vertical portions 9 on the construction area side, and the upper left and right connecting plate tightening bolts 20 and 21 are placed in the upper left and right through holes 16 and 17 on the construction area side. The tip side thereof is passed through the left connecting plate bolt insertion holes 24 and 25 of the upper left connecting plate 12 and screwed into the left and right nuts 26 and 27 fixed to the upper left connecting plate 12 to the construction area side. Then, the upper left and right connecting plate tightening bolts 20 and 21 on the base end side protruding from the right connecting plate bolt insertion holes 28 and 29 of the upper right connecting plate 13 are screwed together with the detachable left and right nuts 30 and 31 which are separate bodies. And fix it.

FIG. 3B shows a connecting portion on the lower side of the concrete temporary guard fence block 1, but the lower left vertical portion 10 on the vehicle passage side straddles the lower left vertical portion 10 and lower. The side left connecting plate 14 is arranged, the lower right connecting plate 15 is arranged across the lower right vertical portion 11 on the construction area side, and the lower left and right connecting plate tightening bolts are arranged in the lower left and right through holes 18 and 19. 22 and 23 are inserted, and the tip side thereof is screwed into the left and right nuts 26 and 27 fixed to the lower left connecting plate 14 through the left connecting plate bolt insertion holes 24 and 25 of the lower left connecting plate 14. However, on the construction area side, the lower left and right connecting plate tightening bolts 22 and 23 on the base end side protruding from the right connecting plate bolt insertion holes 28 and 29 of the lower right connecting plate 15 are detachable left and right nuts. 30 and 31 are screwed and fixed.

FIG. 4 shows a front view of the left side wall portion 2 on the vehicle passage side in a state where the concrete temporary guard fence blocks 1, 1a, 1b, ... Are connected to each other. The right end wall portion 7 of the concrete temporary guard fence block 1a adjacent to the left end wall portion 6 is adjacent to the upper left vertical portion 8 and the lower left vertical portion 10 formed on the left and right end wall portions 6 and 7. Install a temporary guard rail block 1a made of concrete. As a result, the notch portion to be the vertical portion is arranged at a position where the notch portion communicates with each other, and the upper left connecting plate 12 and the lower left connecting plate 14 are fixed at the position. The upper and lower right connecting plates 13 and 15 are fixed in the same manner on the right side wall portion 3 side, which is the construction area side.

The case where the continuous concrete temporary guard fence blocks 1 and 1a are disassembled from each other is shown in FIGS. 5 (a), 5 (b) and 5 (c). In the upper connecting portion, the detachable left and right nuts 30 which are separate and are screwed into the upper left and right connecting plate tightening bolts 20 and 21 inserted into the upper left and right through holes 16 and 17 from the construction area side. By loosening 31, the tips of the upper left and right connecting plate tightening bolts 20 and 21 are removed from the nuts 26 and 27 fixed to the upper left connecting plate 12 on the vehicle passage side, and the fixed state of the upper left connecting plate 12 is released for construction. A person can reach out from the upper surface portion 5 side to remove the upper left connecting plate 12. As a result, the upper right connecting plate 13 on the construction area side can be removed by pulling out the upper left and right connecting plate tightening bolts 20 and 21 from the upper left and right through holes 16 and 17.

On the other hand, in the lower connecting portion, the lower left connecting plate tightening bolt 22 is first loosened from the detachable left nut 30 from the construction area side, so that the tip side of the lower left connecting plate tightening bolt 22 is on the right. The right side of the connecting plate 14 on the vehicle passage side is released from the nut 27, and the lower left connecting plate tightening bolt 22 can be pulled out from the lower left through hole 18. In this state, by slightly loosening the detachable right nut 31 of the lower right connecting plate tightening bolt 23 of the connecting plate 15, the lower right connecting plate tightening bolt 23 is fixed to the left nut 26 on the tip side. The condition becomes loose. In this state, when the concrete temporary guard fence block 1 is raised as shown in FIG. 5A, the lower left and right connecting plates 14 and 15 are screwed together with the lower right connecting plate tightening bolts 23 by nuts. Since it is still in the state of being removed, it comes into contact with the lower left and right vertical portions 10 and 11 of the concrete temporary guard fence block 1 on the side to be removed, and the lower right connecting plate is tightened by further raising. It rotates counterclockwise around the bolt 23.

In this state, when the concrete temporary guard fence block 1 to be removed is further raised, as shown in FIG. 5B, one end of the lower left and right connecting plates 14 and 15 on the movable side is the concrete. The temporary guard fence block 1 will stand up to the position of the outer corner of the lower end 32 of the lower left notch 10.

When the lower left and right connecting plates 14 and 15 are further raised from the state shown in FIG. 5B, the lower left and right connecting plates 14 and 15 are displaced from the position of the lower left notch 10. Depending on the tightened state of the lower right connecting plate tightening bolt 23, the standing state is maintained as it is, or as shown in FIG. 5C, the lower right connecting plate tightening bolt 23 rotates clockwise around the tightening bolt 23. Will be done. The lower left and right connecting plates 14 and 15 stay at the position of the lower right vertical portion 11 of the concrete temporary guard fence block 1a without falling.

By repeating the above removal method, it is possible to sequentially remove the concrete temporary guard rail blocks 1, 1a, 1b, ... Without having to go around to the vehicle passage side and remove the lower left and right connecting plates 14 and 15. It becomes.

The lower left and right connecting plates 14 and 15 can be easily removed after the concrete temporary guard fence blocks 1, 1a, 1b, ... Are removed and moved to a predetermined location.

In the above, the concrete block can be removed while the connecting plate of the concrete block to be removed later is left as the upper connecting portion is the same as the lower connecting portion. This method is adopted in the case of a connected structure of tall concrete blocks.

FIG. 6 shows another embodiment of a concrete temporary guard rail block for fall prevention. The concrete temporary guard fence block 41 is installed on the side wall side of the road on the front side of a place where cliffs and rocks are likely to occur or where deposits are likely to occur, and will be removed after the repair of the place. The concrete temporary guard fence block 41 is formed as a three-dimensional shape including a lower guard wall 42 installed on a road or the like and an upper guard fence 43 continuous with the lower guard wall 42.

The protective wall 42 is made of a massive concrete body having a weight and thickness capable of withstanding an impact caused by falling rocks or the like, the front side thereof is provided with a lower front vertical portion 44, and the back side is a lower back vertical portion. 45 is formed.

The guard fence 43 rises from the upper front side of the guard wall 42, has a thickness capable of withstanding the falling impact of obstacles such as rockfalls and other deposits, and their pressure, and the obstacles fall to the road side. It has a height to prevent this, and an upper front vertical portion 46 is provided on the front end edge portion thereof, and an upper back vertical portion 47 is formed on the back side.

The concrete temporary guard fence block 41 is a structure that forms an extended boundary portion by connecting a plurality of concrete blocks in the longitudinal direction.

A protective wall through hole 48 is formed by horizontally penetrating the block body from the lower front vertical portion 44 to the lower back vertical portion 45 of the protective wall 42 in the lateral direction, and similarly, the protective fence 43 is also on the upper side. A guard rail through hole 49 is formed by horizontally penetrating the block body in the lateral direction over the upper back vertical portion 47 from the front vertical portion 46.

A lower front connecting plate 50 and a lower back connecting plate 51 are arranged on the lower front vertical portion 44 and the lower back vertical portion 45, respectively, and the upper front vertical portion 46 and the upper back vertical portion 47 are respectively arranged. The upper front connecting plate 52 and the upper back connecting plate 53 will be arranged.

The configurations of the connecting plate tightening bolts 54, 55, 56, 57 inserted into the protective wall through hole 48 and the protective fence through hole 49, the configurations of the connecting plates 50 to 53, the configurations of the nuts 58, 59, 60, 61, etc. are as described above. It is the same as Example 1.

When the connecting structure in the connecting portion is released and the concrete block is removed, the concrete block can be removed by the same method as in the first embodiment.

At that time, since the back side on which the connecting plate of the concrete block is arranged is vertical, one side of the connecting plate is pivotally attached even if there is no configuration of the lower end portion with which the connecting plate abuts as in the first embodiment. The concrete block can be removed in this state.

In the case of the concrete temporary guard fence block for fall prevention, the height is often required. Therefore, the upper back connecting plate 53 should be removed by the same removal method as the lower back connecting plate 51. become.

1, 41 Concrete temporary guard rail block 2 Left side wall part 3 Right side wall part 4 Installation bottom part 5 Top surface part 6 Left end wall part 7 Right end wall part 8 Upper left vertical part 9 Upper right vertical part 10 Lower left vertical part 11 Lower side Right vertical part 12, 13 Upper left and right connecting plate 14, 15 Lower left and right connecting plate 16, 17 Upper left and right through hole 18, 19 Lower left and right through hole 20, 21 Upper left and right connecting plate Tightening bolt 22, 23 Lower left and right connecting plate Tightening bolts 24, 25 Left side connecting plate bolt insertion holes 26, 27 Left and right nuts 28, 29 Right side connecting plate bolt insertion holes 30, 31 Detachable left and right nuts 32 Lower end 42 Protective wall 43 Protective fence 44 Lower front vertical part 45 Lower Side back vertical part 46 Upper front vertical part 47 Upper back vertical part 48 Protective wall through hole 49 Protective fence through hole 50 Lower front connecting plate 51 Lower back connecting plate 52 Upper front connecting plate 53 Upper back connecting plate 54, 55, 56, 57 Connecting plate tightening bolts 58, 59, 60, 61 Nuts

Claims (5)

In a connecting portion in which a concrete block consisting of a concrete body having an outer shape of a left and right side wall portion, an installation bottom portion, and an upper portion is extended in the longitudinal direction, a penetration portion penetrating the left and right vertical portions and the left and right side wall portions on the surface side of the end portion of the left and right side wall portions. A hole is provided to form a connecting portion, a connecting portion of another concrete block having a similar shape is adjacent to the connecting portion, a connecting plate is arranged across the left and right vertical portions of the connecting portion, and the connecting plate is provided with each of the through holes. In a connecting structure in which concrete blocks are connected to each other by fixing tightening bolts inserted into the concrete blocks, bolt insertion holes are provided at both ends of the connecting plate arranged across the concrete blocks, and one of the left and right side wall portions is provided. A tightening bolt is inserted through the through hole from the connecting plate located at the position toward the connecting plate on the other side, and the connecting plate on the other side integrally forms a screw portion on the surface side of the bolt insertion hole. On the other hand the tip portion of the clamping bolt inserted from the side to the other side were fixed in該螺engagement portion, the proximal end portion comprising an insertion side of the clamping bolt Ri greens fixed by screwing of the detachable engagement portion The vertical portion on the side on which the connecting plate is integrally formed is characterized in that a flat portion on which the connecting plate can rotate around one of the tightening bolts of the connecting plate is formed. Connected structure of concrete blocks. The connecting structure of a concrete block according to claim 1, wherein the vertical portions are provided at a plurality of positions in the vertical direction facing each other on the surface side of the end portions of the left and right side wall portions of the concrete block. A claim that the concrete block having a wide installation bottom side is formed by forming a vertical portion as a vertical notch by gradually deeply notching both the left and right side wall portions from the upper side to the lower side. The connection structure of the concrete block according to 1 or 2. In a connecting portion in which a concrete block consisting of a concrete body having an outer shape of a left and right side wall portion, an installation bottom portion, and an upper portion is extended in the longitudinal direction, a penetration portion penetrating the left and right vertical portions and the left and right side wall portions on the surface side of the end portion of the left and right side wall portions. A hole is provided to form a connecting portion, a connecting portion of another concrete block having a similar shape is adjacent to the connecting portion, a connecting plate is arranged across the left and right vertical portions of the connecting portion, and the connecting plate is provided with each of the through holes. In a connecting structure in which concrete blocks are connected to each other by fixing tightening bolts inserted into the concrete blocks, bolt insertion holes are provided at both ends of the connecting plate arranged across the concrete blocks, and one of the left and right side wall portions is provided. A tightening bolt is inserted through the through hole from the connecting plate located at the position toward the connecting plate on the other side, and the connecting plate on the other side integrally forms a screw portion on the surface side of the bolt insertion hole. A concrete block connecting structure in which the tip of a tightening bolt inserted from one side to the other is fixed by the screwed portion, and the base end portion on the insertion side of the tightening bolt is fixed by a detachable screwed portion. In, the tightening bolt of the connecting plate fixed by the detachable screwed portion on either the left or right side wall of the concrete block on the side to be removed first is released from the screwed portion from the insertion side of the tightening bolt. The tightening bolt of the concrete block to be removed later is left in a loosened state on the detachable side, and the connecting plate and the tightening bolt are left in the connecting part of the concrete block on the side to be removed first. A method for removing a concrete block, which comprises removing the concrete block. The remaining connecting plate rotates counterclockwise around the remaining tightening bolt as the concrete block on the side to be removed first rises, and is removed together with the concrete block on the side to be removed later. The method for removing a concrete block according to claim 4, wherein the concrete block becomes.

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