JP4172887B2 - Cutting method by wire sawing - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a cutting method suitable for cutting a concrete structure by wire sawing, particularly for horizontal cutting in water.
[0002]
[Prior art]
As shown in FIG. 1, a concrete structure is generally cut by wire sawing by attaching a guide pulley 2 to the cut portion of the concrete structure 1 as shown in FIG. Next, the endless wire saw 3 is placed over the concrete structure 1 via the drive pulley and guide pulley 2 of the wire saw drive device, and the wire saw 3 is circulated and driven by the drive pulley. This is performed by making a cut in the concrete structure 1 and retracting the wire saw driving device from the concrete structure so that the wire saw-3 does not become slack with the cutting.
[0003]
In horizontal cutting by such a construction method, as the cutting progresses, the cutting gap 4 narrows due to the weight of the concrete structure above the cut surface, and the wire saw tends to break into the concrete structure and be crushed. It is. In order to solve this problem, a wedge-shaped spacer 5 as shown in FIG. 2 is driven into the cutting gap to maintain the cutting gap 4.
[0004]
[Problems to be solved by the invention]
When the wedge-shaped spacer as described above is wide and has a large contact area with the cut surface, the frictional resistance with the concrete structure becomes large and the driving becomes difficult. Therefore, it is necessary to use a narrow one, but it is necessary to drive a large number of spacers in order to withstand the weight of the concrete structure. There are disadvantages such as being difficult to use and driving.
[0005]
Moreover, as shown in FIG. 2, when the concrete structure is approaching or in contact with the obstacle, the spacer cannot be driven from the obstacle side.
An object of this invention is to provide the cutting method by the wire saw which can eliminate said problem.
[0006]
[Means for solving problems]
The invention according to claim 1 is a cutting method for cutting a concrete structure by pressing an endless wire saw against the concrete structure and circulatingly running it. Cutting core formed by wire sawing by using a core drill consisting of a cylindrical body to be rotated and a grinding part provided at the tip of the body with a substantially same outer diameter as the main body, and rotating the core drill. Drilling work is stopped at the stage where a suitable amount of holes have been drilled, and the core drill body is partly or entirely left on the concrete structure and mounted at several points in the cutting gap. It is characterized by that.
[0007]
According to the present invention, the core drill receives the weight of the concrete structure above the cutting gap, but the contact area between the core drill and the concrete structure can be larger than the wedge-shaped spacer, so the number of core drills used can be reduced compared to the wedge-shaped spacer. it can.
As shown in FIG. 1, the wire saw is cut by a method in which the wire saw 3 is stretched over the concrete structure 1. As shown in FIG. 3, the guide hole 7 is formed in the concrete structure 6 and the guide pulley 8. There is a method of pushing the concrete structure 6 between the guide holes with a wire saw 9 between the guide pulleys 8.
[0008]
The present invention is applicable to any of the above methods.
The present invention is suitable for horizontally cutting a concrete structure, but is more particularly suitable for horizontally cutting an underwater concrete structure.
Accordingly, the invention described in claim 2 is characterized in that the cutting method of the invention described in claim 1 is performed on an underwater concrete structure.
[0009]
When cutting concrete structures on the ground, it is necessary to inject cooling water into the cutting gap for cooling, lubrication, and chip discharge. Even if the wire saw breaks, there is less danger of scattering compared to the work on the ground and it is safe, and there are adverse effects such as contamination of the work environment due to dust like cutting work on the ground Less, vibration and noise at the time of cutting can be reduced, and if the concrete structure after cutting is underwater, it will be lightened by buoyancy, so it can be easily removed and removed, compared with driving a wedge-shaped spacer There are advantages such as easy work and less work.
[0010]
According to a third aspect of the present invention, there is provided a cylindrical main body that is rotationally driven by a motor in a cutting method for cutting a concrete structure by pressing an endless wire saw against the concrete structure and causing the rod to circulate. Using a first core drill provided at the tip and made of a grinding part having a diameter larger than that of the main body, the core drill is driven to rotate to drill deeply into the planned cutting surface of the concrete structure. After removing the cylindrical core edged with the surrounding concrete structure with the core drill, wire sawing is performed on the planned cutting surface, and then the grinding part has the same outer diameter as the main body. The core drill is pushed deeply into the hole from which the core has been removed, and then rotated to drive the concrete structure. Things were some or all of the second core drill an appropriate amount perforated stage Sonoma ゝ left behind, characterized in that attached to the concrete structure by.
[0011]
The invention according to claim 4 is a cutting method for cutting a concrete structure by pressing an endless wire saw against the concrete structure and circulatingly running it, and is rotated by a motor when cutting by wire sawing has progressed to some extent. Drilling work toward the cutting gap formed by wire sawing by using a first core drill which is provided at the tip of the main body and which is provided at the tip of the main body and which has a grinding part having a diameter larger than that of the main body. Then, after removing the first core drill and removing the cylindrical core cut off from the surrounding concrete structure by the core drill, the grinding part has a substantially same outer diameter as the main body. The core drill was pushed deeply into the hole from which the core was removed, and then rotated. Characterized in that attached to the concrete structure of the concrete structure with a suitable amount of drilling stages to a part or all of the second core drill Sonoma ゝ left behind Te.
[0012]
According to invention of Claim 3 and 4, a 2nd core drill can be made to reach deeply toward the other side from one side of a concrete structure. Therefore, it is effective when the concrete structure contacts or approaches the obstacle, and there is not enough space between the concrete structure and the obstacle for drilling with a core drill. A second core drill can be attached to maintain the cutting gap.
[0013]
As shown in FIG. 4, the core drill usually has an adapter 11 that is detachably fixed to a shaft that is rotationally driven by a motor, a cylindrical main body 12 that is screwed into the adapter 11, and a larger diameter than the main body 12. And is constituted by a grinding part 13 made of a diamond tip fixed to the front end of the main body, or a structure in which the adapter 11 shown in FIG. 4 is integrally formed with the main body 15 as shown in FIG.
[0014]
The second core drill according to the third and fourth aspects of the present invention is the core drill shown in FIGS. 4 and 5, wherein the grinding portion 13 is configured to have substantially the same outer diameter as that of the main body 12 or 15. When the part or the whole is attached to the concrete structure and left behind, the main body 12 is removed from the adapter 11, the main body 12 is removed from the shaft together with the adapter 11, or the main body 15 is removed from the shaft.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 6 shows a state where the cutting of the concrete structure 21 by wire sawing has progressed to some extent, using a core drill 22 in which the grinding part has substantially the same outer diameter as the main body, and rotating the core drill 22 to thereby form the cutting gap 23. An example in which drilling is performed at several places and the core drill 22 is left as it is and attached to the concrete structure 21 is shown.
[0016]
7 and 8 show a state in which the cutting gap 23 is held by the core drill 22.
FIG. 9 shows an example where there is an obstacle 26 near the concrete structure 25 and the above work cannot be performed from the obstacle side. Using the first core drill shown in FIG. 5, a drilling operation is performed deeply toward the obstacle 26 from the opposite side of the obstacle 26 to the cutting gap 27, and the first core drill is once rounded by the drill. Remove with the core. Thereafter, the grinding part is pushed into a hole 29 formed by removing the core using a second core drill 28 having substantially the same outer diameter as that of the main body, and the concrete structure is cut in an appropriate amount and left to be attached. . Then, before and after this, the cutting work 27 on the near side and the right side is similarly cut by the second core drill 28 and is left behind and attached to the concrete structure.
[0017]
In the above-described example, the drilling operation by the first and second core drills is performed at a stage where the cutting by the wire sawing has progressed to some extent, but in another example, the drilling operation by the first core drill is performed before the cutting operation by the wire sawing. Is performed on the surface to be cut and wire sawing is performed after removing the core drill and core. Then, when the cutting by wire sawing has progressed to some extent, the second core drill is pushed into the hole from which the core has been removed, and after cutting an appropriate amount, it is left behind and attached to the concrete structure.
[0018]
FIG. 10 and FIG. 11 show an example of the case where the wire is sawed. When the cut to the concrete structure 30 has progressed to some extent, the second core drill 31 performs a drilling operation into the cutting gap 32, and the concrete is cut. Install it by leaving it on the structure (Fig. 10). When the push-cutting further proceeds, the first core drill shown in FIG. 4 or 5 is used to drill the cutting gap 32 deep into the concrete structure, and the first core drill and the core are once taken out. Thereafter, the second core drill 31 is pushed into the hole 33 from which the core has been removed, cut to an appropriate amount, and left behind on the concrete structure for attachment.
[0019]
【The invention's effect】
According to the first aspect of the present invention, the core drill is easily attached to the concrete structure by a drilling operation, and is more in contact with the concrete structure than a conventional wedge-shaped spacer that is driven to maintain a cutting gap. Since the area can be widened, the number of core drills used can be reduced, and the amount of work can be reduced to facilitate the work.
[0020]
According to the second aspect of the present invention, it is not necessary to inject cooling water during cutting by wire sawing, and even if the wire saw may break during cutting, it is due to scattering compared to work on the ground. Low risk and safety, less adverse effects such as contamination of the work environment due to dust such as cutting work on the ground, vibration and noise during cutting can be reduced, and the concrete structure after cutting is underwater Since the weight is reduced by buoyancy, the work can be easily carried out and removed, and compared with driving a wedge-shaped spacer, the work is easy and the number of work can be reduced.
[0021]
According to the third and fourth aspects of the present invention, it is possible to attach the core drill to the concrete structure and maintain the cutting gap by using the core drill even in a place where there is an obstacle and the drilling operation cannot be performed by the core drill. .
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a cutting method using wire sawing.
FIG. 2 is a cross-sectional view of a conventional example in which a wedge-shaped spacer is driven into a cutting gap.
FIG. 3 is a schematic view of a pressing method using wire sawing.
FIG. 4 is a cross-sectional view of a core drill.
FIG. 5 is a cross-sectional view showing another example of a core drill.
FIG. 6 is a schematic view of a cutting method by wire sawing using a core drill.
FIG. 7 is a cross-sectional view with a core drill attached.
8 is a cross-sectional view taken along line AA in FIG.
FIG. 9 is a schematic diagram showing an example when there is an obstacle.
FIG. 10 is a schematic diagram in the case of a press-cutting method.
FIG. 11 is a schematic diagram showing a state when cutting further proceeds.
[Explanation of symbols]
11..Adapter 12, 15..Main body 13..Grinding part 21, 25..Concrete structures 22, 28, 31..Core drills 23, 27, 32..Cutting gap 26..Obstacles 29, 33 .. Hole

Claims (4)

A cylindrical body that is driven to rotate by a motor at the stage where cutting by wire sawing has progressed to some extent in a cutting method of cutting a concrete structure by pressing an endless wire saw against a concrete structure and circulating it. And using a core drill consisting of a grinding part provided at the tip of the main body with substantially the same outer diameter as the main body, performing a drilling operation toward a cutting gap formed by wire sawing by rotating the core drill, By wire sawing, the drilling operation is stopped when an appropriate amount has been drilled, and the core drill body is partly or entirely left on the concrete structure and mounted at multiple points in the cutting gap. Cutting method. A cutting method by wire sawing, wherein the cutting method according to claim 1 is performed on an underwater concrete structure. In a cutting method that cuts a concrete structure by pushing an endless wire saw against the concrete structure and circulating it, a cylindrical main body that is driven to rotate by a motor, and a tip that is larger than the main body. A first core drill composed of a grinding part having a diameter is used, and the core drill is rotationally driven to drill deeply into the planned cutting surface of the concrete structure. Then, the first core drill is once extracted, and the core drill After removing the cylindrical core edged with the concrete structure, wire sawing is performed on the planned cutting surface, and then a second core drill whose grinding part has substantially the same outer diameter as the main body is used. A stage where a concrete structure is perforated in an appropriate amount by pushing it deeply into the hole from which the core has been removed and then rotating it. In cutting method by sawing, characterized in that attaching a part or all of the second core drill Sonoma ゝ left behind to concrete structures. In a cutting method of cutting a concrete structure by pressing an endless wire saw against a concrete structure and circulating it, a cylindrical body rotated by a motor when cutting by wire sawing has progressed to some extent Using the first core drill provided at the tip of the main body and having a grinding part having a diameter larger than that of the main body, the core drill is rotationally driven and drilled deeply into the cutting gap formed by wire sawing. After extracting the core drill of No. 1 and removing the columnar core cut off from the surrounding concrete structure by the core drill, the second core drill whose grinding part has substantially the same outer diameter as the main body is used. Push the core deeply into the hole from which the core has been removed, and then rotate it to rotate the concrete structure. Cleavage method by ear sawing, characterized in that attaching an appropriate amount perforated stage by some or all of the second core drill Sonoma ゝ left behind concrete structure.

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