JP5096819B2 - Demolition method of concrete frame - Google Patents

Description

  The present invention relates to a method for dismantling a concrete body that dismantles the concrete body.

In nuclear power plants, nuclear fuel reprocessing facilities, medical radiation utilization facilities, etc., parts contaminated by the radioactivity of concrete frames may be removed.
Conventionally, when dismantling such a concrete frame, a method of hanging using a crusher such as a breaker has been generally performed.

  However, the suspended work by the crusher of the part contaminated by radioactivity generates a large amount of dust contaminated by radioactivity, so installation of exhaust equipment to prevent exposure of workers, etc., and replacement of exhaust filters There was a problem that labor and cost for ensuring safety such as frequency increased.

In addition, the handling of the lifting equipment by wearing radiation protective clothing is not workable and unsuitable for contamination of a large area due to manual work.
In addition, there was a problem that secondary radioactive waste such as radiation protective clothing and exhaust filters were frequently generated.

In addition, the waste generated from the demolition of the concrete frame needs to be disposed in a sealed state in a disposal container such as a drum can, but the waste that has been crushed into a glass is filled only by about 60%. I couldn't. Since the cost of such waste disposal is converted per disposal container, the conventional dismantling method with a low waste filling rate has been expensive.
Furthermore, since the machine used for dismantling the concrete frame having a high contamination concentration is disposed of in principle, there is a problem that the cost is increased due to the purchase and disposal of a large crusher.

For this reason, a number of methods for decomposing concrete with little generation of dust have been developed and put into practical use as methods for decomposing concrete frames contaminated by radioactivity.
For example, in Patent Document 1, a vertical hole is formed along a boundary portion between a contaminated portion on the surface side of a side wall that is partially radioactively contaminated and a back side portion that is not radioactively contaminated, and this vertical hole is formed. Using a wire saw, a cut surface is formed in the vertical direction by a wire saw, and then a horizontal cut surface is formed by a wire saw. A dismantling method for removing the mass is disclosed.

  Note that the conventional method of dismantling the concrete frame is not limited to removing the part contaminated by radioactivity. For example, when repairing a crack or a stripped part generated in the concrete frame, a part of the concrete frame is partially removed. It can also be applied to the removal.

Japanese Patent Laid-Open No. 5-19697

However, in the conventional dismantling method, it is necessary to form a cut surface over the entire length in the vertical direction in the concrete frame, and it is difficult to remove only the desired part, so the construction range is inevitably widened, It took time and effort.
Moreover, many uncontaminated parts around the contaminated part are dismantled, and the amount of waste disposed as radioactive waste increases. Therefore, there has been a problem that the cost for disposal increases.
Also, because it is removed in the vertical direction, the cutting range is limited in terms of structural strength, and a temporary support structure is required, so it is difficult to cope with radioactive contamination over a large area range. Had problems.

In addition, since it is disassembled into a relatively large lump, secondary crushing is required and time consuming to accommodate in a disposal container such as a drum can.
Furthermore, since a plurality of machines such as a machine and a wire saw are required for drilling the vertical holes, there is a problem that the cost for purchasing and disposal increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to propose a method for dismantling a concrete frame that is excellent in workability, safety, and economy.

In order to solve the above-mentioned problems, the present invention provides a cutting step of cutting a mesh-shaped cut into a removal region set in a concrete frame to divide the removal region into a plurality of blocks, and a dismantling step of removing the block A method of dismantling the concrete frame, comprising: a peripheral notch formed so that the mesh-shaped notch surrounds the outer periphery of the removal region; and an in-edge notch formed inside the peripheral notch; In the incision step, at least one side of the peripheral incision is formed by a groove with a step so that the groove width on the surface side of the first incision is on the bottom side. In the dismantling step, the first cut and the second cut are widened by widening the groove width of the second cut that is an in-edge cut formed along the first cut. It is characterized in that removing the block between the serial second cut.

  According to such a method for dismantling a concrete body, since a mesh-shaped cut is made in the removal region and the subdivided blocks are removed, it is possible to dismantle in a state where generation of dust is suppressed. Therefore, safety is ensured and workability is excellent.

Further, since it is possible to partially disassemble the concrete frame without penetrating it, the present invention can be applied to a removal range over a large area range without requiring a temporary support structure or the like.
Moreover, since it is subdivided into a mesh shape and removed, the removal range can be limited to the minimum, and the amount of waste can be minimized.

  Also, since the groove on the front side of the first notch is thick, it is easy to widen the groove width of the second notch, and as a result, it is possible to easily apply the force in the first notch direction to the block. It becomes. Thereby, it becomes possible to cause a shear fracture at the base of the block, and the block can be easily removed.

  In addition, since the waste generated by dismantling is disassembled into finely divided blocks, it can be packed regularly in a disposal container, and chips (dust) are placed in the gap between the waste and the disposal container. It becomes possible to make the filling rate of the disposal container close to 100%. Therefore, it is possible to minimize the cost required for waste disposal.

  Furthermore, since the machine used for dismantling the concrete frame (the machine to be purchased and disposed of) is only a simple machine such as a concrete cutter, the equipment cost is low.

  In the dismantling process, a groove width of the second cut may be widened by inserting a wedge into the second cut.

  Further, in the disassembling step, an expansion agent may be injected into the second cut and the groove width of the second cut may be widened by an expansion force of the expansion agent.

According to such a method for dismantling the concrete body, since static crushing is used, when dismantling the removal area, it becomes possible for a worker to wait at a remote location, causing collapse of concrete blocks and dust scattering. The risk due to such as is reduced.
Further, by adjusting the depth at which the expansion agent is injected, removal at a desired depth is possible, so that the amount of waste disposal can be minimized.

  In the method of dismantling the concrete frame, if the second cut is formed by a stepped groove, for example, when the groove width of the second cut is widened by using a wedge or the like, the step is used by the force of the lever. , Dismantling can be performed more easily. Moreover, it becomes possible to insert a wedge to the back of a notch | incision, and it becomes possible to perform a disassembly work more easily.

  In addition, it is preferable to form the stepped groove by using a two-blade cutter formed by combining blades having different diameters, because the operation can be easily performed.

  According to the method for demolishing a concrete frame of the present invention, the concrete frame can be partially disassembled by a method that is superior in workability, safety, and economy as compared with a conventional demolition method.

  Preferred embodiments of the present invention will be described with reference to the drawings. In the description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted.

<First Embodiment>
In the present embodiment, a description will be given of a case where a removal region 2 including a contaminated portion 3 contaminated by radioactivity is removed from a radiation shielding wall which is a concrete case 1 by the method for dismantling a concrete case of the present invention (see FIG. 1). ).

  In the method of dismantling the concrete frame according to the present embodiment, a mesh-shaped cut (peripheral cut 10 and in-edge cut 20) is made in the removal region 2 set in the concrete frame 1, and the removal region 2 is divided into a plurality of blocks 30. , 30,... And a dismantling process for removing these blocks 30, 30,... (See FIGS. 1 and 2).

  In the cutting process, mesh-shaped cuts (peripheral cut 10 and in-edge cut 20) are formed in the rectangular removal region 2 including the contaminated portion 3. The size of the mesh formed in the cutting process (the size of the block 30) is not limited, but is large enough to allow the worker to safely remove the block 30 in the disassembly process described later. Say it. In the present embodiment, the removal region 2 is formed in a rectangular shape, but the shape of the removal region is not limited and can be set as appropriate.

First, vertical and horizontal peripheral edge cuts 10 are formed in the concrete housing 1 so as to surround the outer periphery of the removal region 2 in a rectangular shape (see FIG. 1A).
Here, in the present embodiment, of the peripheral notches 10 formed so as to surround the removal region 2, the lower peripheral peripheral notch 10 is defined as the first notch 11. The first notch 11 is not limited to the peripheral notch 10 on the lower side.

As shown in FIG. 3 (a), the peripheral notch 10 is formed by using a two-blade cutter C formed by combining cutter blades C1 and C2 having different diameters, thereby forming a groove on the surface side. The groove is formed with a step so that the width is larger than the groove width on the bottom side. The cutter blades C1 and C2 of the cutter C are rotated about the same axis by the power of the motor C3.
In this embodiment, all the peripheral incisions 10 are formed to have a wide groove width by using the two-blade cutter C, but at least one side (the first incision 10) has a wide groove width. It only has to be.

  Here, in this embodiment, the two-blade cutter C is used for forming the peripheral edge notch 10 in order to increase the groove width, but the configuration of the cutter C is not limited to this. The diameters of the cutter blades C1 and C2 may be set as appropriate. However, in this embodiment, the radius of the large cutter blade C1 is larger than the radius of the small cutter blade C2 of the main bars arranged in the concrete frame. Use a reinforcing bar diameter + 2-5 mm larger. By using such a cutter C, a stepped groove avoiding the main bars is formed, and the reinforcing bar cutting load is reduced.

Next, as shown in FIG. 1 (a), a plurality of vertical cuts 22 (edge cuts 20) are formed at predetermined intervals in the removal region 2 surrounded by the peripheral cuts 10, 10,.
The vertical cut 22 is formed using a single-blade cutter, and is formed with a groove width narrower than the groove width of the peripheral cut 10.

Subsequently, as shown in FIG. 1 (b), a second cut 21 (edge cut 20) is formed in the removal region 2 in parallel with the first cut 11. By forming the second cuts 21, a plurality of lowermost blocks 30, 30,... Are formed. The second cuts 21 do not necessarily have to be parallel as long as they are formed along the first cuts 11.
In this embodiment, similarly to the first notch 11, the second notch 21 is formed by using a two-blade cutter C formed by combining blades C1 and C2 having different diameters. The groove is formed with a stepped groove so that the groove width is larger than the groove width on the bottom side (see FIG. 3B).

  In the dismantling process, the blocks 30, 30,... Formed by the mesh-shaped cuts (the peripheral cut 10 and the in-edge cut 20) formed in the cutting process are removed.

As shown in FIG. 3 (b), the block 30 is removed by inserting a wedge 41 into the second cut 21, expanding the groove width of the second cut 21, and using the first cut 11 and the second cut 21. This is performed by applying a downward load P to the sandwiched block 30.
Here, a step is formed in the second cut 21, and the groove width on the surface side of the second cut 21 is larger than the groove width on the bottom side, so that the wedge 41 is grooved (second cut 21). It can be inserted to the back. Further, the downward load P can be efficiently applied by utilizing the principle of the lever by the step of the groove of the second cut 21.

  When a downward load is applied to the block 30 formed between the first notch 11 and the second notch 21, a shear fracture S occurs at the root as shown in FIG. And as shown in FIG.3 (c), the block 30 can be isolate | separated from the concrete housing 1 in the root, and can be removed.

  In the dismantling process, as shown in FIG. 1C, removal is performed for each block 30, and the lowermost block 30 is all removed.

As shown in FIG. 2A, when the removal of the lowermost block 30 is completed, a second cut 21 parallel to the first cut 11 is formed, and second blocks 30, 30,... Are formed. (Cutting process).
Then, the second block is removed by the same method as the lowest step (disassembly step).

By repeating the cutting process and the dismantling process as many times as necessary, all the blocks 30 in the removal area 2 are removed as shown in FIG.
The disassembly process of the uppermost block 30 is performed by inserting a wedge 41 into the upper peripheral notch 10. In addition, the construction procedure is not limited to the above-described procedure. For example, after forming the second cuts 21 (transverse cuts) for the required number of steps, the block 30 may be removed for each step.

  As described above, according to the method for dismantling a concrete frame according to the first embodiment, the blocks 30 formed by subdividing the removal region 2 are individually removed, so that they can be transported by human power. Can be disassembled. In addition, generation of dust can be suppressed. Therefore, safety during work is ensured and workability is excellent.

Moreover, since it can be demolished with a desired thickness without penetrating the concrete housing 1, it can be applied to a removal range over a large area range without requiring a temporary support structure or the like.
Further, since the blocks are subdivided into a plurality of blocks 30, 30,... And removed, the removal range can be limited to a minimum, and the amount of waste can be minimized.

  Further, since the cutting width of the first notch 11 is formed thick, it is easy to apply a force in the first notch 11 direction to the block 30 by widening the groove width of the second notch 21. Thereby, a shear fracture can be caused at the base of the block 30, and the block 30 can be easily removed.

  Further, since the second notch 21 is formed in a groove having a step, it is possible to insert the wedge 41 to the back of the groove and apply the load P to the base of the block 30. Further, if the step formed in the second notch 21 is used, the downward load P can be applied only by inserting a wedge formed in a tapered shape.

  Further, the block 30 can be regularly packed in a disposal container such as a drum can. Further, by filling the gap formed between the blocks 30 and the disposal container with the chips (dust) generated with the formation of the cuts 10 and 20, the filling rate of the disposal container is as close as possible to 100%. It becomes possible.

  Moreover, since only the cutter C is sufficient as the machine used for dismantling the concrete frame 1, the equipment cost is low.

<Second Embodiment>
In the present embodiment, a case will be described in which the removal region 2 including the contaminated portion 3 contaminated by radioactivity is removed from the radiation shielding wall which is the concrete casing 1 by the method for dismantling the concrete casing of the present invention (see FIG. 4). ).

  In the method of dismantling the concrete frame according to the present embodiment, a mesh-shaped cut (peripheral cut 10 and in-edge cut 20) is made in the removal region 2 set in the concrete frame 1, and the removal region 2 is divided into a plurality of blocks 30. , 30,... And a dismantling process for removing these blocks 30, 30,... (See FIGS. 4 and 5).

  In the cutting process, mesh-shaped cuts (peripheral cut 10 and in-edge cut 20) are formed in the rectangular removal region 2 including the contaminated portion 3. The size of the mesh formed in the cutting process (the size of the block 30) is not limited, but is large enough to allow the worker to safely remove the block 30 in the disassembly process described later. Say it. In the present embodiment, the removal region 2 is formed in a rectangular shape, but the shape of the removal region is not limited and can be set as appropriate.

First, vertical and horizontal peripheral edge notches 10 are formed in the concrete housing 1 so as to surround the outer periphery of the removal region 2 in a rectangular shape (see FIG. 4A).
Here, in the present embodiment, of the peripheral notches 10 formed so as to surround the removal region 2, the lower peripheral peripheral notch 10 is defined as the first notch 11. The first notch 11 is not limited to the peripheral notch 10 on the lower side.

In addition, as shown in FIG. 6A, the peripheral notch 10 is formed by using a two-blade cutter C formed by combining cutter blades C1 and C2 having different diameters, thereby forming a groove on the surface side. The groove is formed with a step so that the width is larger than the groove width on the bottom side.
In this embodiment, all the peripheral incisions 10 are formed to have a wide groove width by using the two-blade cutter C, but at least one side (the first incision 10) has a wide groove width. It only has to be.

  Here, the configuration of the cutter C used to form the peripheral notch 10 is the same as that shown in the first embodiment, and thus detailed description thereof is omitted.

Next, as shown in FIG. 4 (a), a vertical cut 22 and a horizontal cut (second cut 21) are formed in the removal region 2 surrounded by the peripheral cuts 10, 10,. Divided into a plurality of blocks 30, 30,.
The in-edge cut 20 (vertical cut 22 and horizontal cut) is formed using a single-blade cutter, and is formed with a groove width narrower than the groove width of the peripheral cut 10.

  Subsequently, as shown in FIG. 4B and FIG. 6A, a bottomed dismantling hole 23 is formed by a drill D at the intersection of the second cut 21 and the vertical cut 22 which are the lowermost horizontal cuts. .

  In the dismantling process, the blocks 30, 30,... Formed by the mesh-shaped cuts (the peripheral cut 10 and the in-edge cut 20) formed in the cutting process are removed.

  As shown in FIG. 6B, the block 30 is removed by filling the dismantling hole 23 with the crushing agent 42, expanding the groove width of the second cut 21 by the expansion force to the crushing agent 42, And a downward load P is applied to the block 30 sandwiched between the second cuts 21.

  Since the downward load P acts when the crushing agent 42 expands, a shear fracture S occurs at the base of the block 30. Then, as shown in FIGS. 4C and 6C, the block 30 is separated from the concrete casing 1 at the base thereof, and the lowermost block 30 is all removed.

When the removal of the lowermost block 30 is completed, as shown in FIG. 5A, a disassembly hole 23 is formed by a drill D at the intersection of the second cut 21 and the vertical cut 22 in the second row from the bottom (cut) Process).
Then, the crushing agent 42 is filled in the dismantling hole 23 by the same method as in the lowermost step, and the second-stage blocks 30, 30, ... are removed (disassembly step).

As shown in FIG. 5B, all the blocks 30 in the removal region 2 are removed by repeating the formation of the disassembly hole 23 and the disassembly process in the cutting process as many times as necessary.
The uppermost block 30 may be disassembled by forming the dismantling hole 23 in the upper peripheral notch 10 and filling the crushing agent 42. In addition, the construction procedure is not limited to the above-described procedure. For example, after all the dismantling holes 23, 23,... Are formed, the blocks 30, 30,.

  As described above, according to the method for dismantling a concrete frame according to the second embodiment, since static crushing by the crushing material 42 is used, when dismantling the removal range 2, an operator waits at a remote position. It becomes possible to be. For this reason, the danger associated with collapse of concrete blocks, dust scattering, etc. is reduced.

  Further, by adjusting the depth of the dismantling hole 23, removal at a desired depth can be easily performed, and the amount of waste disposal can be minimized.

  Since the effect by the method of dismantling the concrete frame according to the other second embodiment is the same as the contents shown in the first embodiment, detailed description thereof is omitted.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and it goes without saying that the above-described constituent elements can be appropriately changed in design without departing from the spirit of the present invention.
For example, in each of the above embodiments, the radiation shielding wall having a contaminated portion contaminated by radioactivity has been described with reference to the case where the contaminated portion is removed by the method of dismantling the concrete casing of the present invention. The concrete frame to which the method is applied is not limited and can be applied to any concrete structure.

  The concrete frame to be demolished is not limited to one made of reinforced concrete, and may be a concrete frame made of unreinforced concrete, for example.

In each of the above embodiments, the peripheral cut is formed by a stepped groove, but the shape of the groove is not limited.
Similarly, the cross-sectional shape of the second cut is not limited.
Moreover, you may form in-edge notch by the groove | channel with a level | step difference.

  In the first embodiment, the wedge width is used to widen the groove width of the second cut, but the method of widening the groove width of the second cut is not limited.

  In the second embodiment, the dismantling hole is formed and the dismantling hole is filled with the expansion agent. However, the incision in the edge is directly filled with the expansion agent, and the expansion force of the expansion agent causes the edge. It is good also as a structure which widens the groove width of an inner notch.

(A)-(c) is a perspective view which shows each work process of the demolition method of the concrete frame which concerns on 1st Embodiment. (A)-(b) is a perspective view which shows each work process of the demolition method of the concrete frame which concerns on 1st Embodiment. It is an expanded sectional view which shows each work process of the demolition method of the concrete frame shown in FIG.1 and FIG.2, (a) is a cutting process, (b) is a demolition process, (c) shows the condition after demolition. Yes. (A)-(c) is a perspective view which shows each work process of the demolition method of the concrete frame which concerns on 2nd Embodiment. (A)-(b) is a perspective view which shows each work process of the demolition method of the concrete frame which concerns on 2nd Embodiment. It is an expanded sectional view which shows each operation process of the demolition method of the concrete frame shown in FIG.4 and FIG.5, (a) is a cutting process, (b) is a demolition process, (c) shows the condition after demolition. Yes.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Concrete frame 2 Removal area 10 Perimeter cut 11 First cut 20 Inner cut 21 Second cut C cutter C1, C2 Cutter blade

Claims (5)

A cutting step of making a mesh-like cut into the removal region set in the concrete frame and dividing the removal region into a plurality of blocks;
A demolition step of removing the block, and a demolition method of the concrete frame,
A peripheral notch formed so that the mesh-shaped notch surrounds the outer periphery of the removal region, and an in-edge notch formed inside the peripheral notch,
In the incision step, the groove width on the surface side of the first notch is larger than the groove width on the bottom side by forming a first notch that is at least one side of the peripheral notch by a groove with a step . Formed to be large,
In the dismantling step, removing the block between the first notch and the second notch by widening the groove width of the second notch that is an in-edge notch formed along the first notch. A method for dismantling a concrete frame, characterized by   2. The method for demolishing a concrete frame according to claim 1, wherein a wedge is inserted into the second cut to widen a groove width of the second cut in the disassembling step.   2. The method of dismantling a concrete frame according to claim 1, wherein in the dismantling step, an expansion agent is injected into the second cut and the groove width of the second cut is widened by an expansion force of the expansion agent. The method for dismantling a concrete frame according to claim 2 , wherein the second cut is formed by a groove having a step.   The method of disassembling a concrete frame according to claim 4, wherein the second cut is formed by using a two-blade cutter obtained by combining blades having different diameters.

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