JP2003301614A - Demolishing method of concrete structure and plasma shock wave injector used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a demolishing method for a concrete structure capable of reducing energy consumption required for demolition of the concrete structure, miniaturizing a device and effectively demolishing it with a little energy in a short time. <P>SOLUTION: In the demolishing method for a concrete structure 2, a part of internally existing reinforcements or steel frames is exposed out of the concrete structure 2 and shock waves simultaneously or stepwise generated by plasma discharging or blasting are imparted in two directions of the axial direction C and the direction D orthogonal to the axis to the same reinforcements 3 or the steel frame with every time interval. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete structure by imparting a shock wave such as plasma discharge or blasting to a material having a high elastic modulus such as a reinforcing bar or a steel frame which is inherent as a skeleton. The present invention relates to a method of effectively disassembling a structure with a small amount of energy in a short time, and a device for applying a shock wave by plasma used in the dismantling method. Therefore, the present invention can be applied to not only ordinary existing structures but also aged concrete structures that require attention to access by workers, such as dismantling of an aged nuclear power plant.

[0002]

2. Description of the Related Art A method for electrically dismantling a concrete structure is shown in FIG.
The exposed reinforcing bar 3 is used as one electrode 11 and an energy supply circuit 13 is connected between the other electrode 12 and the other electrode 12 so that electric energy can be supplied in a short time to discharge the concrete portion by impact force such as vaporization of water. Method for destroying the
No. 18648) or as shown in FIG. 9, the rebar 3 exposed by piercing is used as one electrode 14, and the rebar 3 is discharged by being discharged between the electrode 14 and the discharge end 16 inserted into the hole 15 reaching the electrode 14.
There is a method (Japanese Patent Laid-Open No. 8-218649) of disassembling the concrete structure 2 by melting and vaporizing the concrete. Further, as shown in FIG. 10, a shock wave generated by inserting the electrolyte solution and the probe 19 into the hole 18 formed in the bedrock 17 and causing discharge at the tip of the probe 19 and causing the electrolyte solution to become plasma by this discharge energy. There is a method of destroying the bedrock 17 etc.

[0003]

Among these conventional techniques, in the above-mentioned and the method by electric discharge, the problem is to break the concrete first, and after the electric discharge, the concrete is separated from the reinforcing bar, the steel frame and the like. However, the adhesive force between the reinforcing bar and the concrete is large, the separation between the two is not performed efficiently, and the recycling efficiency of the concrete-based and reinforcing-bar-crushed materials is poor.

Further, even in the above method using plasma discharge, the subject is to break the rock, probably because it is a problem to break the rock (corresponding to the concrete in the above). However, since concrete has a lower elastic modulus and a higher viscous resistance than rebar and steel frame,
Since the ability to absorb breaking energy is greater than that of reinforcing bars and steel frames, the concrete itself is not efficiently dismantled, and the dismantling time is long. However, in the above-mentioned conventional techniques, how to destroy concrete efficiently has been studied as a research subject, and therefore, how to increase the breaking energy has been a problem. Therefore, in the conventional technique, the size of the device becomes large, the amount of energy consumption increases, and the cost increases.

Therefore, the present invention provides a method for reducing the energy consumption required for destruction of a concrete structure to reduce the size of the apparatus, effectively dismantling with a small amount of energy and in a short time, and a shock wave imparting apparatus used therefor. It is intended to be provided.

[0006]

The present invention reduces the energy consumption required for the destruction of concrete structures,
In order to reduce the size of the device, impact energy is applied not to concrete but to reinforcing bars and steel frames that have a larger elastic coefficient and less impact energy loss than concrete. The applied impact energy emits a shock wave into the concrete around the reinforcing bar and the steel frame, and the tensile stress of the shock wave cuts the edge of the bond between the reinforcing bar system and the concrete, causing cracks in the concrete itself.

[0007] Specifically, the invention of claim 1 is a method for dismantling a concrete structure, in which a part of the internal reinforcing bar or steel frame is exposed from the concrete structure, and the exposed reinforcing bar or steel frame is exposed. A method for dismantling a concrete structure in which shock waves are applied simultaneously or stepwise in the two directions of the axial direction and the direction perpendicular to the axis was adopted.

The invention of claim 2 provides the method for disassembling a concrete structure according to claim 1, wherein the shock wave is generated by plasma discharge or blasting.

In the invention of claim 3, the application of the shock wave in the axial direction of the rebar or the steel frame is performed on the same rebar or the steel frame with a time interval provided therebetween. The demolition method of the concrete structure was used.

According to a fourth aspect of the present invention, a shock wave generator is provided.
An existing construction machine used for dismantling, specifically, a nibler, an excavator excavator, or a giant breaker, is mounted on the tip of the working part, and a shock wave is repeatedly applied to the dismantled part to weaken the dismantled part. The method for dismantling a concrete structure was used.

According to a fifth aspect of the present invention, the tip of the electrode of the plasma discharge is attached so as to cover a hollow body having a closed tip, and the space formed by the tip of the electrode and the hollow body in the hollow body. The part was a device for applying a shock wave by plasma for dismantling a concrete structure containing an insulator.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram for clarifying the features of the present invention. The horizontal axis represents the amount of destruction of concrete, and the greater the amount to the right, the greater the amount of destruction. The vertical axis is
It shows the amount of energy required to destroy concrete, and shows that the higher the amount, the more energy is required. In this FIG. 1, 45 goes up from the origin.
The thin line (A) that extends at a certain degree indicates the direction of conventional technology development, and will increase the amount of energy required to destroy a concrete block of a certain size, that is, the breaking force for concrete of high strength. Direction (for example, measures to enhance the destructive force in plasma discharge).

The thick line (B) extending downward from the point indicating 500 kj of this thin line is the one required by the present invention, and is intended to break concrete having high strength with a smaller breaking force. It indicates that the direction is to. For example, it is an attempt to destroy concrete, which conventionally requires an energy amount of 500 kj, with an energy of 300 kj or less. In other words, it qualitatively shows that the concrete structure can be dismantled efficiently and in a short time.

FIG. 2 was prepared to explain the point of the present invention in which the concrete structure 2 is destroyed by such a smaller destructive force. Although it is described that all the reinforcing bars 3 are exposed from the concrete structure 2, this was created in order to explain the direction of the shock wave applied to the reinforcing bars 3 in an easy-to-understand manner. , The reinforcing bar 3 is not entirely exposed. FIG. 2 shows that a shock wave is applied in two directions, that is, in the reinforcing bar axis direction C and in a direction D perpendicular to the reinforcing bar axis (hereinafter referred to as “reinforcing bar axis perpendicular direction D”).

FIG. 3 shows a state in which a shock wave is imparted to the reinforcing bar 3 from the shock wave applying device 1 by plasma in the axial direction C of the reinforcing bar, and FIG. 5 is shown in FIG. In order to apply a shock wave in the direction D at right angles,
2 shows a state in which two excavation holes 4 have been drilled in the concrete structure 2 until the exposed portion is exposed.

In FIG. 3, the applying device 1 for applying a shock wave in the axial direction C of the reinforcing bar has a plasma electrode rod 6 inserted into a hollow steel cylinder 5 having a closed lower end. It is fixed and inserted into the excavation hole 7 drilled until the upper end 3a of the reinforcing bar 3 appears from the concrete of the concrete structure 2 and brought into contact with the upper end 3a of the reinforcing bar 3. Water 8, which is an insulating liquid having a relatively large insulating property, is placed in the hollow cylindrical body 5, and the plasma electrode rod 6
The rear end portion (the upper portion in FIG. 3) of the hollow cylindrical body 5 on the side where is inserted is in a sealed state so that water 8 as an insulating liquid does not leak.

FIG. 4 shows an applying device 1 for applying this shock wave.
The thickened disk-shaped rebar contact body 9 that comes into contact with the rebar 3 is provided at the outer end of the hollow cylindrical body 5. In the embodiment of this embodiment, the hollow cylindrical body 5
Is firmly fixed to the plasma electrode rod 6 and cannot be easily removed. Since the hollow cylindrical body 5 and the plasma electrode rod 6 are substantially integrated, if a plurality of excavation holes 4 and 7 exposing the reinforcing bar 3 are provided in advance,
The hollow cylindrical body 5 and the plasma electrode rod 6 are substantially integrated with each other, and a plurality of these drill holes 4, 7 are provided in advance.
The shock waves can be easily applied by sequentially inserting the shock waves into the.

FIG. 6 shows an applicator 1a for more effectively applying a shock wave in the direction D perpendicular to the axis of the reinforcing bar. The reinforcing bar 3 is grasped as a reinforcing bar contact body provided at the tip of the hollow cylindrical body 5a. A gripping tool 9a for a reinforcing bar formed in a substantially Y shape is provided for easy operation. FIG. 7 shows an example of the plasma electrode rod 6 (for example, Japanese Patent Laid-Open No. 2001-303880). 6c, an outer conductor non-magnetic material portion 6d, and an outer conductor magnetic material portion 6e are provided respectively, and the cable 6f is led out from the rear end portion of the plasma electrode rod 6, and such a known one can be used.

Next, a method of destroying the concrete structure 2 using the method of the embodiment of the present embodiment and the applying device 1 will be described. First, in the concrete structure 2, as shown in FIG.
The excavation hole 7 for imparting a shock wave in the rebar axis direction C and the excavation hole 4 for imparting a shock wave in the direction D perpendicular to the rebar axis are provided. The former is provided with a drill hole 7 as shown in FIG. 3, and the latter is provided with a plurality of drill holes 4 as shown in FIG.

Next, the plasma electrode rod 6 and the hollow cylindrical body 5
The applying device 1 for applying a shock wave composed of and is inserted into the excavation hole 4 or 7, and the rebar contact body 9 of the applying device 1 is brought into contact with the rebar 3, and then plasma discharge is performed, and the shock wave is applied to the rebar 3. Give. This operation is repeated for the plurality of drill holes 4, 7. Although water 8 is filled in advance in the hollow cylindrical body 5, the water 8 is vaporized every time plasma discharge occurs, so it is not shown in the figure, but it can be replenished at any time.

In order to apply shock waves to both the reinforcing bar axis direction C and the reinforcing bar axis direction D at the same time, two shock wave applying devices 1 may be used. 30 for normal primary rock fracture
0kj or more is required, and recently 500kj
Although a plasma discharge device capable of discharging the above energy has been developed, the energy emitted from the plasma electrode rod 6 in the embodiment of this embodiment may be 150 to 200 kj. In addition, an existing construction machine used for dismantling a concrete structure, specifically, the shock wave imparting device 1 is mounted on the tip of a shovel or the like, which is a working part of a nibler, excavator excavator, giant breaker, or the like. It is also possible to adopt a method of making the dismantled portion fragile by repeatedly applying.

Above, as an example of applying a shock wave to the reinforcing bar,
Although the explanation has been given by taking the shock wave by plasma as an example, it is also possible to give a shock wave by blasting as another example. In the present invention, as described above, less energy than the conventional one,
That is, since the intended purpose can be achieved with a small shock wave, the destructive ability of blasting may be such that energy of 150 to 200 kj is applied as in the case of the shock wave of plasma. The blasting is performed by inserting the blasting into the same excavation holes 7 to 4 as shown in FIGS. 3 and 5. For blasting, a commercial product for construction having a shape that can be easily inserted into the excavation holes 7 to 4 may be used, and for the blasting method, a method generally used for rock crushing may be used.

In the above embodiment, only the case where the shock wave is applied to the reinforcing bar 3 is described, but the shock wave may be applied to the steel frame in addition to the reinforcing bar 3. Further, although the shock wave imparting apparatus 1 by plasma is specifically described, the shock wave imparting apparatus 1 by plasma is not limited to this.

As the concrete structure,
Not limited to ordinary existing structures, workers are safe, including old concrete buildings at thermal power plants, dams at hydroelectric power stations, incidental equipment, and aged concrete buildings at nuclear power plants. It can also be applied at work sites where care must be taken. In particular,
In dismantling an aged concrete building in a nuclear power plant, it is necessary to work while paying attention to the radiation exposure of workers so that the same worker does not work continuously, but according to the method of this invention, Since the working time can be shortened as compared with the conventional one, the work can be performed efficiently. Further, in the case of dismantling in a nuclear power plant, when the shock wave imparting device 1 of the present invention is attached to an existing construction machine, a radiation protection plate is laid around the driver's seat of the construction machine. It is preferable to take measures.

[0025]

According to each of the first to fourth aspects of the invention, in order to reduce the energy consumption, impact energy is applied not to concrete but to a reinforcing bar or a steel frame having an elastic coefficient larger than that of concrete. . This allows
Since impact energy is absorbed by concrete and the reduced impact energy is not transmitted to the reinforcing bar system, more impact energy is transmitted to the reinforcing bars and steel frames than before, and then the reinforcing bars and steel frames are transferred to the concrete. Will be transmitted to. Then, due to the tensile stress of the shock wave applied to the reinforcing bar system and the concrete, the edge of the adhesion between the reinforcing bar system and the concrete occurs, and the concrete itself also cracks. Concrete that is no longer attached to the reinforcing bar system becomes brittle and can be easily dismantled, so that the separation of the reinforcing bar system and concrete can be done efficiently and in a short time.

According to the invention of claim 5, a hollow cylindrical body having a closed tip is attached to the tip of the electrode for plasma discharge, and a space formed by the tip of the electrode for plasma discharge in the hollow cylinder. Since the liquid is filled with a highly insulating liquid, plasma discharge is reliably performed, and a shock wave can be easily applied to the reinforcing bar or the steel frame.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the features of the present invention.

FIG. 2 is an explanatory diagram showing a direction in which a shock wave is applied to a reinforcing bar existing in a concrete structure according to the embodiment of the present invention.

FIG. 3 shows a state in which a shock wave is applied by making a hole in a concrete structure to expose the upper end of the reinforcing bar and bringing a shock wave applying device close to the exposed upper end of the reinforcing bar in the embodiment of the present invention. FIG.

FIG. 4 is a partial cross-sectional view of a shock wave imparting device according to an embodiment of the present invention.

FIG. 5 is a perspective view of a concrete structure in which holes are drilled and the reinforcing bars are exposed in order to apply a shock wave in a direction perpendicular to the axis of the reinforcing bars in the embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of another applying device according to the embodiment of the present invention.

FIG. 7A is a side sectional view of a plasma electrode rod described in JP 2001-303880 A. (B)
The figure is a cross-sectional view of the plasma electrode rod.

FIG. 8 is a sectional view showing a procedure for breaking a concrete structure described in JP-A-8-218648.

FIG. 9 is a cross-sectional view showing a procedure for breaking a concrete structure described in JP-A-8-218649.

FIG. 10 is an explanatory diagram of a plasma crushing device that destroys rocks and the like.

[Explanation of Codes] 1 Applying device 2 Concrete structure 3 Reinforcing bar 5 Hollow cylindrical body 6 Plasma electrode rod 8 Water C Reinforcing bar axial direction D Reinforcing bar orthogonal direction

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akira Kataoka             1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo East             Inside Kyoden Electric Co., Ltd. (72) Inventor Yuji Tokunaga             4-833 Shibaura, Minato-ku, Tokyo Co., Ltd.             KANDENKO (72) Inventor Masayuki Iguchi             4-833 Shibaura, Minato-ku, Tokyo Co., Ltd.             KANDENKO (72) Inventor Yukio Yoshii             1-6-1, Otemachi, Chiyoda-ku, Tokyo             Inside the Nuclear Power Company F-term (reference) 2E176 AA01 DD31 DD53

Claims (5)

[Claims] 1. A method for dismantling a concrete structure,
A part of the internal reinforcing bar or steel frame is exposed from the concrete structure, and shock waves are applied to the exposed reinforcing bar or steel frame in two directions, the axial direction and the direction perpendicular to the axis, simultaneously or stepwise. A method for dismantling a concrete structure, characterized by: 2. The method of dismantling a concrete structure according to claim 1, wherein the shock wave is generated by plasma discharge or blasting. 3. A shock wave in the axial direction of the reinforcing bar or the steel frame is applied to the same reinforcing bar or steel frame at a time interval, according to any one of claims 1 and 2. Method for dismantling the described concrete structure. 4. A shock wave generator is mounted on the tip of the action part of an existing construction machine used for dismantling, and shock waves are repeatedly applied as in claim 1 to weaken the dismantled part, and the concrete structure is constructed by the construction machine. Dismantling method for concrete structure, characterized by dismantling. 5. The tip of the electrode of the plasma discharge is attached so as to cover a hollow body having a closed tip, and the space formed by the tip of the electrode and the hollow body in the hollow body is insulated. An apparatus for applying a shock wave by plasma for dismantling a concrete structure, characterized in that the body is housed.