JP2016094796A - Demolition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a demolition method that enables efficient demolition of an underground concrete structure.SOLUTION: A pile 1 in ground 3 is drilled downward from an upper end, and an approximately vertical hole 5 is formed to a bottom of the pile 1. A detonating fuse 7 is inserted into the hole 5 and arranged in such a manner as to continue to a bottom of the hole almost throughout the length of the hole 5, and water is poured into the hole 5. Subsequently, concrete of the pile 1 is crushed by blasting of the detonating fuse 7; the ground 3 is excavated to the bottom of the pile 1; and debris 15 after the blasting is removed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for demolishing an underground concrete structure.

  Conventional methods of dismantling underground concrete piles include a method of breaking and crushing concrete with a breaker, nibra, or other demolition machine, or breaking the concrete into small blocks with a wall saw, wire saw, etc. Depending on the situation, there was a method of dismantling by further secondary crushing.

  In recent years, there has also been known an MB (microblasting) method in which a large number of holes are formed by drilling in concrete, and a blast wire is installed in each hole for blasting (see Patent Documents 1 and 2). Furthermore, Patent Document 3 describes a method of performing blasting by placing explosives or the like in multiple stages in a hole after drilling a vertical hole in concrete.

JP 2011-157807 A JP 2013-087413 A JP-A-5-247939

  When dismantling using a breaker or nibler, the noise and vibration are large and the generation time is long. In addition, since a large amount of dust is generated, a large amount of water is required for dust countermeasures. Further, in the case of a large-diameter pile or the like, it takes time to disassemble one member. Similarly, when disassembling with a wall saw or wire saw, it takes time to disassemble, and a large amount of water is required to prevent dust. In addition, the cost is high, and there is a problem that a separate heavy machine for lifting the cut block is required. In the case of secondary crushing, the cost and construction period are further increased. In addition, in these methods, the excavation of the ground is stopped halfway, and the piles are once exposed to the ground and then dismantled.

  In the MB method, it is common to drill using a drill with a small diameter of about 24 mm to form a small diameter hole, but such drills currently have a very long drilling length that can be drilled at once. No (for example, about 1.8m). Therefore, when dismantling a concrete pile constructed deep underground, it was necessary to disassemble it in several times. In addition, since a large number of holes are drilled at a fine pitch, and a small amount of explosive lines are installed in each hole for blasting, drilling requires a work period, and for the processing and installation of explosive lines, and to prevent blowout It takes a lot of work to put sand in. Furthermore, the concrete blast after blasting may become large, in which case secondary crushing is required.

  In the method of Patent Document 3, since the explosive is discontinuously installed in the hole, the force is not evenly applied to the pile to be demolished, and the vicinity of the explosive is finely crushed, but the other parts are sufficiently crushed. There is a possibility that it may remain as a large block, and there is a problem in that secondary crushing is required. Moreover, since the detonator is used for each of the explosives arranged in multiple stages in the hole, the cost is increased, and it takes time to install the tamping material between each explosive and the explosive. If the tamping material is omitted to create a void, the shock wave at the time of explosive blasting will not propagate well.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a dismantling method that can dismantle an underground concrete structure efficiently.

  The present invention for achieving the above-described object is a method for dismantling an underground concrete structure, comprising a step of drilling a hole in a substantially vertical direction from the upper end of the concrete structure to a predetermined depth, and a linear crushing Disposing the agent continuously over substantially the entire length of the hole, filling the hole with liquid, crushing the concrete of the concrete structure with the crushing agent, and excavating the ground to the predetermined depth And a step of removing the crushed concrete.

The hole is preferably formed by drilling at a time to the bottom of the concrete structure.
The liquid is preferably water.
The concrete structure is, for example, a pile.

  In the present invention, after a hole in a substantially vertical direction is drilled in a concrete structure, a linear crushing agent is continuously arranged to the bottom of the hole to fill the hole with liquid. Then, the concrete is crushed with a crushing agent, and the glass is removed simultaneously with excavation of the ground. Thereby, in this invention, compared with the dismantling method using a breaker, a nibler, etc., since blasting is completed in an instant, generation of noise, vibration, and dust can be greatly suppressed. Compared to the dismantling method, the construction period and cost can be reduced. In addition, the concrete can be crushed and made fine enough without excavating the ground, and then the ground can be removed simultaneously with excavating heavy equipment such as backhoes, so that the construction efficiency is high and the process is not compressed. .

  Further, in the present invention, unlike the method using the multistage arrangement of explosives described above, the crushing agent is arranged in a balanced manner in the vertical direction of the concrete structure by continuously arranging the crushing agent over substantially the entire length of the hole. Since only one chemical work is required and only one detonator is required, the construction efficiency is high and the cost is low. In addition, in the present invention, since the liquid is filled in the hole, the sand filling work is unnecessary, and the construction efficiency is high even compared with the MB method described above, and the liquid is an inelastic body, so the force to crush the concrete is weakened. There is nothing. Furthermore, the pressure of the liquid is larger at the bottom of the hole than at the top of the hole, and the propagation efficiency of the force for crushing the concrete is improved. Accordingly, the concrete can be finely crushed even in a deep underground place where the restraint force due to earth pressure is large. As a result, the concrete of the concrete structure can be evenly and finely crushed most efficiently with the minimum amount of charge.

  Also, in the present invention, unlike the MB method, the diameter of the hole is increased, and the amount of the crushing agent that can be drilled to the bottom of the concrete structure at once using a drilling machine with a long drilling length that can be drilled at one time. Can be increased. As a result, the entire concrete of the concrete structure can be crushed at a time with a small number of perforations, and can be made fine enough to eliminate or reduce secondary crushing.

  In the present invention, water can be used as the liquid injected into the holes. When water is used, it is relatively easy to obtain at any site and injection is easy. The present invention is also particularly suitable for dismantling piles that are often built deep into the ground among concrete structures.

  ADVANTAGE OF THE INVENTION According to this invention, the dismantling method which can dismantle an underground concrete structure efficiently can be provided.

Diagram showing drilling of pile 1 The figure which shows about arrangement | positioning and water injection of the explosive wire 7 to the hole 5 Figure showing concrete crushing of pile 1 The figure shown about the excavation of the ground 3 and the removal of the glass 15 Diagram showing another example of dismantling method Diagram showing another example of dismantling method

  Hereinafter, an embodiment of a disassembly method of the present invention will be described based on the drawings.

  This embodiment demonstrates the example which disassembles the pile 1 shown in FIG. 1 as an underground concrete structure. The pile 1 is an existing pile in the ground 3 and is constructed by embedding a reinforcing bar rod (not shown) as a reinforcing bar inside the concrete. 1A is a view of a vertical section of the pile 1, and FIG. 1B is a view of a plane of the pile head. The same applies to FIG. 2 described later.

(1. Drilling of pile 1)
In this embodiment, when disassembling the pile 1, as shown in FIG. 1A, first, the hole 1 is drilled in a substantially vertical direction from the upper end of the pile 1 to the bottom. The hole 5 is formed over substantially the entire length of the pile 1 to a predetermined depth at the bottom of the pile 1.

  As shown in FIG. 1B, in the present embodiment, three holes 5 are formed in the pile 1. Each hole 5 is formed in the range inside the reinforcing bar rod (not shown) in the pile 1, for example. Further, the diameter of the hole 5 is, for example, in the range of about φ50 mm to φ100 mm, and is larger than that in the MB method. If there is a large hole diameter, there is a drilling machine having a large drilling length (for example, the maximum depth at which the drill is inserted into the concrete) that can be drilled at one time. In this embodiment, such a long distance (for example, 10 m) The hole 5 to the bottom of the pile 1 is drilled at a time using a drilling machine capable of drilling a degree).

(2. Arrangement and water injection of explosive wire 7 in hole 5)
In this invention, a linear crushing agent is arrange | positioned in the hole 5, and the concrete of the pile 1 is crushed by this. The crushing agent is a high-energy substance such as an explosive, an explosive, or a non-explosive crushing agent, and generates an explosion shock wave or gas pressure by ignition (detonation), thereby crushing the object. When an explosive is used as a crushing agent, an explosion shock wave is generated, and when an explosive or non-explosive crushing agent is used, a gas pressure is generated.

In the present embodiment, an explosive wire 7 shown in FIG. 2A is used as a linear crushing agent. The explosive wire 7 is formed by waterproofing an explosive as a core and covering it with paper and thread, and the upper and lower ends are closed with a tape or the like to stop water. As shown in FIG. 2A, the explosive wire 7 is inserted into the hole 5 and arranged so as to continue to the bottom of the hole over substantially the entire length of the hole 5. In the present embodiment, one or a plurality of explosive wires 7 are bundled and used according to the amount of charge necessary for finely crushing the concrete of the pile 1. For example, the explosive wire 7 is used to charge 200 g of charge per 1 m ³ of pile concrete. The upper end of the explosive wire 7 is located slightly below the upper end of the hole 5, and a blasting detonator (not shown) is attached. A leg wire (not shown) is connected to the detonator.

  In this way, the explosive wire 7 is disposed and water is poured into the hole 5 to fill the water 13 (liquid) up to the upper end of the hole 5.

(3. Concrete crushing of pile 1)
Thereafter, the leg of the explosive wire 7 is connected to a blasting device (not shown), and the explosive wire 7 of each hole 5 is blasted. In the present embodiment, the explosion lines 7 of each hole 5 are blasted almost simultaneously. Then, a shock wave is generated from the explosive wire 7 arranged continuously over substantially the entire length of the hole 5, and propagates through the water 13 to the surrounding pile 1.

  Here, as shown in FIG. 3 (a), earth pressure P is applied to the pile 1 from the periphery, and at the bottom of the pile 1, the earth pressure P is large, and a large restraining force is applied to the concrete so that it is difficult to be crushed. . However, in this embodiment, the water 13 is injected into the hole 5, and the water pressure increases as it goes to the bottom of the hole 5. Therefore, the water 13 at the bottom of the hole 5 behaves more like a rigid body with respect to the propagation of the shock wave, and the energy of the shock wave is efficiently propagated and becomes a force for crushing the concrete of the pile 1. Thereby, even at the bottom of the pile 1 having a large restraining force due to the earth pressure P, the concrete is crushed to the same extent as the top of the pile 1, and as a result, the concrete is crushed evenly as a whole.

  FIG. 3B shows a state in which the concrete of the pile 1 is crushed as described above. As shown in the figure, in this embodiment, the entire concrete of the pile 1 is cracked, and is finely divided and crushed. The crushed concrete also peels off from the reinforcing bars of the reinforcing bar rod (not shown).

(4. Excavation of ground 3 and removal of glass 15)
Thereafter, as shown in FIG. 4A, the ground 3 is excavated by using a heavy excavator such as the backhoe 17 and the crushed concrete glass 15 is removed. The finely crushed glass 15 can be taken out manually and taken out along with excavated soil by the backhoe 17, and a weight breaking machine for secondary crushing is not necessary. The exposed reinforcing bars (not shown) of the pile 1 are bent or cut as necessary.

  When the ground 3 is excavated to a predetermined depth at the bottom of the pile 1 as shown in FIG. 4 (b) and the glass 15 is removed, the dismantling operation is completed.

  As described above, in the present embodiment, after the hole 5 in the substantially vertical direction is drilled in the pile 1, the explosive wire 7 is inserted into the hole 5 and continuously disposed to the bottom of the hole 5. Fulfill. Then, the concrete of the pile 1 is crushed by blasting the detonation wire 7 and the glass 15 is removed simultaneously with the excavation of the ground 3. As a result, in this embodiment, compared to a disassembly method using a breaker, nibbler, or other dismantling machine, the blasting is completed in an instant, so the generation of noise, vibration, and dust can be greatly suppressed. Compared with the dismantling method using a wire saw, the construction period and cost can be reduced. Moreover, the concrete of the pile 1 in the ground 3 can be crushed and sufficiently fine without excavating the ground 3, and then the ground 15 can be removed simultaneously with excavating the ground 3 using a heavy excavator such as the backhoe 17. Therefore, construction efficiency is high and there is no pressure on the process.

  Further, in the present embodiment, unlike the method using the multistage arrangement of explosives described above, the explosives are arranged in a balanced manner in the vertical direction of the pile 1 by continuously arranging the explosive wires 7 over substantially the entire length of the hole 5. In addition, it is easy to fix the explosive wire 7. In addition, since the charging operation is performed only once and a detonator or the like is only required in one place, the construction efficiency is high and the cost is low. Moreover, in this embodiment, since the water 13 is filled in the hole 5, sand filling work is unnecessary, and the construction efficiency is higher than the MB method described above, and the water 13 can be obtained relatively easily at any site and can be easily injected. It is. Further, since the water 13 is an inelastic body, the force of the shock wave is not weakened. Furthermore, at the bottom of the hole, the effect of improving the propagation efficiency of shock waves due to water pressure can be expected, and concrete can be finely crushed even in deep underground locations where the restraint force due to earth pressure is large. As a result, the concrete of the pile 1 can be evenly and finely crushed most efficiently with the minimum amount of charge.

  Further, in this embodiment, unlike the MB method, the diameter of the hole 5 is increased, and a boring machine having a large drilling length that can be drilled at once can be drilled all the way to the bottom of the pile 1 and installed in one hole 5. The amount of line 7 can be increased. As a result, the entire concrete of the pile 1 can be crushed at a time with a small number of perforations, and can be made fine enough to eliminate or reduce secondary crushing.

  However, the present invention is not limited to this. For example, although the explosive wire 7 is used in the present embodiment, the present invention is not limited to this, and other crushing agents can be arranged in a linear shape and used as necessary. Moreover, although the example which disassembles the pile 1 was demonstrated in this embodiment, if it is an underground concrete structure, a disassembly object will not be specifically limited, The other concrete structure with reinforcement or unreinforced may be sufficient. However, the pile 1 is often constructed deep into the ground, and the method of the present embodiment is particularly suitable for dismantling such a pile 1. Further, water having a specific gravity adjusted may be poured into the holes 5, and various liquids can be injected into the holes 5 instead of water.

  Also, if the pile is longer than the drilling length that can be drilled at once with a drilling machine, the hole 5 is drilled to a predetermined depth in the middle of the pile 1 'as shown in FIG. After crushing the concrete of the pile 1 by blasting the wire 7, the ground 3 is excavated to the predetermined depth and the glass 15 is removed as shown in FIG. 5 (b), and this series of operations is repeated thereafter. It is also possible to disassemble the entire pile 1 ′.

  In addition, the arrangement of the holes 5 such as the number of holes and the plane position, or the amount of charge per hole by the explosive wire 7 depends on the size and shape of the concrete structure to be demolished, the structure type, the amount of reinforcing bars, etc. Thus, it can be determined appropriately so that the force is applied evenly to the concrete and crushed into the target fine glass 15, and is not particularly limited. For example, with respect to the arrangement of the holes 5, as shown in FIG. 6, a plurality of holes 5 are formed at intervals along each of inner and outer concentric circles (see the dotted line in FIG. 6) centered on the center of the plane of the pile 1. In this case, for example, after blasting the outer explosive line 7, the inner explosive line 7 is blasted. Thereby, after crushing the outer concrete (from the outer explosive wire 7) so as to be pushed outward, the inner concrete can be broken so as to be pushed outward as well.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

1; pile 3; ground 5; hole 7; explosive wire 13; water 15;

Claims (4)

A method for dismantling underground concrete structures,
Drilling a substantially vertical hole from the upper end of the concrete structure to a predetermined depth;
Arranging a linear crushing agent so as to be continuous over substantially the entire length of the hole, and filling the liquid in the hole;
Crushing the concrete of the concrete structure with the crushing agent;
Excavating the ground to the predetermined depth and removing the crushed concrete;
A disassembling method comprising:   The dismantling method according to claim 1, wherein the hole is formed by drilling to the bottom of the concrete structure at a time.   The disassembling method according to claim 1 or 2, wherein the liquid is water.   The dismantling method according to any one of claims 1 to 3, wherein the concrete structure is a pile.

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