JPH10249847A - Horizontally cutting method for concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an executing efficiency of horizontally cutting. SOLUTION: The concrete structure 10 is horizontally cut by a wire saw 12 from one end side toward the other end side. At the stage of exceeding a position of a center of gravity G at a cutting position of the saw 12 at an outer peripheral side of the structure 10, an interleaving material 14 to become a hinge fulcrum is inserted into a cutting gap 16 the saw 12. When the material 14 is installed, the saw 12 is circularly fed to proceed the horizontal cutting to complete the cutting and separating of the structure 10, the cut and separated upper part side is placed on the material 14. Since nothing is provided at the starting side of cutting, this part is brought into contact with a lower part side of the structure 10. At this time, an inserting position of the material 14 becomes one hinge fulcrum. This material 44 to become one hinge fulcrum is installed between the position G and an uncut site 18 in the gap 16, and hence a moment M operating in the case of separating the structure 10 by the saw 12 becomes a direction for pressing the starting side down.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for horizontally cutting a concrete structure, and more particularly to an improved technique for horizontally cutting a concrete structure using a wire saw.

[0002]

2. Description of the Related Art As a method of dismantling and removing a concrete structure, a technique of cutting a concrete structure with a wire saw has recently attracted attention in terms of construction efficiency, noise, and measures against dust.

In this type of construction method, a wire saw is used in which diamond beads are fitted with a spacer interposed between wire ropes, and tension is introduced into the wire saw.
It is circulated and cut by friction generated between the diamond bead and the concrete.

[0004] When a concrete structure is horizontally cut using a wire saw, the upper load of the cut and separated portion is applied to the wire saw at the end of cutting, which makes it difficult to travel and the upper side sinks. is expected.

[0005] Japanese Patent Publication No. 7-18261 discloses a method of horizontally cutting underwater in which wedge-shaped spacers are sequentially driven into gaps cut by a wire saw to avoid the above-mentioned inconvenience. However,
The horizontal cutting method disclosed in this publication has technical problems described below.

[0006]

That is, according to the horizontal cutting method disclosed in the above publication, the spacers are sequentially driven into the cutting gap of the wire saw generated as the cutting progresses. The driving work is
Stopping the running of the wire saw and performing underwater work by the diver, and repeating this multiple times greatly reduces the efficiency of the cutting work.

[0007] In this case, the underwater work of the diver is performed in a state where the water is polluted by friction-cut concrete dust due to the circulation running of the wire saw and the see-through works only, so that the work efficiency is further reduced. It was a cause, and the improvement was strongly demanded.

Further, even if the spacers are sequentially driven into the cutting gap, it is not always possible to prevent the upper load from being applied to the wire saw at the end of cutting. FIG.
1 schematically shows a horizontal cutting method disclosed in the above publication.

In FIG. 1A, reference numeral 1 denotes a columnar concrete structure to be cut, and this concrete structure 1 is horizontally cut by a wire saw 2 in water. Reference numeral 3 denotes a gap generated as the cutting of the wire saw 2 proceeds, and reference numeral 4 denotes a wedge-shaped spacer driven into the gap 3.

In such a horizontal cutting method, when the wedge-shaped spacer 4 is driven into the gap 3 at the initial stage of cutting when the cutting by the wire saw 2 does not reach the center of gravity G of the structure 1, the position of the wire saw 2 becomes larger than the center of gravity G. The fulcrum will be located on the cutting start side.

In such a state, the cutting proceeds, and the end of the cutting is reached. When the upper side is cut off and separated, the moment M acting as shown in FIG. However, there is a problem in that the wire saw 2 is pressed in a direction in which the side from which the wire saw 2 is to be pulled out is pressed downward, which makes it difficult to pull out the wire saw.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and an object of the present invention is to reduce the underwater work of a diver as much as possible and to use a wire saw when cutting and separating. An object of the present invention is to provide a method for horizontal cutting of a concrete structure which does not hinder the escape of the concrete.

[0013]

In order to achieve the above object, the present invention relates to a method of winding a wire saw around an outer periphery of a concrete structure, introducing tension to the wire saw, and circulating the wire structure so that the concrete structure can be circulated at one end. In the method of cutting horizontally from the other end side, at least at the outer peripheral side of the concrete structure, at the stage where the horizontal cutting position by the wire saw exceeds the center of gravity position of the concrete structure, in the cutting gap of the wire saw An interposer serving as one hinge fulcrum is arranged between the position of the center of gravity and the uncut portion. According to this configuration, since only the interposition material serving as one hinge fulcrum is installed, even when the underwater concrete structure is horizontally cut, the underwater work by the diver can be extremely reduced. In addition, since the interleaving material serving as one hinge fulcrum is installed between the position of the center of gravity in the cutting gap of the wire saw and the uncut portion, a moment acting when the concrete structure is cut and separated by the wire saw starts cutting. Side is pressed downward, and as a result, a moment acts in a direction in which the cutting end side rotates upward, so that the wire saw can be easily pulled out. Such a horizontal cutting method can be applied to not only a concrete structure constructed in the air but also a columnar concrete structure constructed in water. The concrete structure has a columnar shape with a circular cross section, and in a rectangular coordinate system whose origin is the center of gravity of the concrete structure, the horizontal cutting position by the wire saw is at least on the outer peripheral side of the concrete structure. At a stage beyond the position, a pair of the inserts can be installed at positions symmetrical with respect to the position of the center of gravity. According to this configuration, since the pair of interleaving members are installed at positions symmetrical with respect to the center of gravity of the concrete structure to be cut, this can be used as one hinge fulcrum.

[0014]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 3 show one embodiment of a method for horizontally cutting a concrete structure according to the present invention. The horizontal cutting method shown in the figure is a case where it is applied to horizontal cutting of a columnar concrete structure 10 having a circular cross section.

When the columnar concrete structure 10 is horizontally cut, the wire saw 12 is placed on the line to cut the structure 10.
Is wound. The wire saw 12 is provided with guide pulleys at appropriate locations, and is horizontally circulated and traveled on the planned cutting line.

At this time, a predetermined tension is introduced into the wire saw 12 by, for example, retracting the driving device or suspending the weight. The running of the wire saw 12 causes the concrete structure 10 to be horizontally cut from one end to the other end (in FIG. 2, from the left end to the right end).

In the process of horizontal cutting of the concrete structure 10, in the case of the present embodiment, as shown in FIG. 2, the cutting position by the wire saw 12 on the outer peripheral side of the concrete structure 10 is the center of gravity of the concrete structure 10. At a stage beyond the position G, the interposer 14 serving as one hinge fulcrum is inserted into the cutting gap 16 of the wire saw 12.

The interposer 14 is inserted between the position G of the center of gravity of the concrete structure 10 and the uncut portion 18 (the portion indicated by hatching in FIG. 2).

The interposer 14 is made of a plate-like or rod-like steel material slightly thinner than the thickness of the cutting gap 16 and is inserted without being driven into the cutting gap 16. In the case of the present embodiment, a pair of interposers 14 are inserted and installed at positions that are symmetrical about the X axis with respect to the orthogonal coordinates X and Y with the center of gravity G of the concrete structure 10 as the origin.

When the pair of interposers 14 are installed at such positions, when the upper side of the concrete structure 10 is cut and separated, the upper surfaces of the interposers 14 abut at a position parallel to the Y-axis. One hinge fulcrum.

After the interleaving material 14 is installed, the horizontal cutting proceeds by the circulation running of the wire saw 12, and when the cutting and separating of the concrete structure 10 is completed, the cut and separated upper side is placed on the interleaving material 14. At the same time, on the cutting start side,
Since nothing is provided, this portion abuts against the lower side of the concrete structure 10.

At this time, in the case of this embodiment, the interposer 1
4 is used as one hinge fulcrum, and the insert 14 serving as one hinge fulcrum is installed between the center of gravity position G and the uncut portion 18 within the cutting gap 16 of the wire saw 12. The moment M acting when the concrete structure 10 is cut and separated by 12 is
This is the direction in which the cutting start side is pressed downward.

As a result, the moment M acts in a direction in which the cutting end side pivots upward and the moment M acts in a direction in which the cutting gap 16 opens, so that the wire saw 12 can be easily pulled out.

Further, in the case of this embodiment, since only one pair of interleaving members 14 serving as one hinge fulcrum is installed, even when the underwater concrete structure 10 is cut horizontally, the underwater work by the diver is required. Is required only once, and the underwater work is extremely reduced, and the construction efficiency can be improved.

FIG. 4 shows another embodiment of the method for horizontally cutting a concrete structure according to the present invention. The same or corresponding portions as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted. In addition, only the characteristic points will be described below.

In the embodiment shown in the figure, the concrete structure 10a to be cut is a columnar body having a rectangular cross section, and is cut horizontally so that the cut surface is parallel to one end surface of the concrete structure 10a. .

When cutting horizontally in such a state, guide pulleys 20 are respectively installed on two opposing side surfaces of the concrete structure 10a, and the wire saw 12 hung on the guide pulleys 20 is parallelized with the guide pulleys 20. Move.

As the cutting of the wire saw 12 progresses, the cutting position of the wire saw 12 is changed to the concrete structure 10.
At a stage beyond the position G of the center of gravity of a, the interposer 14a serving as one hinge fulcrum is inserted into the cutting gap 16 of the wire saw 12.

The insert 14a is made of the concrete structure 10
It is inserted and installed between the center of gravity G of a and the uncut portion 18 (the portion shown by hatching in FIG. 4).

The interposer 14a is made of a single plate-like or rod-like steel material that is slightly thinner than the thickness of the cutting gap 16, and is inserted without being driven into the cutting gap 16.
When the interposer 14a is inserted and installed in this manner, the same operation and effect as in the above embodiment can be obtained.

In the above embodiment, a columnar object installed in water is exemplified as the concrete structure 10 to be horizontally cut. However, the present invention is not limited to this, and may be installed in the air. It may be a concrete structure.

The columnar material may be solid or hollow, and may be applied to a wall-shaped concrete structure.

[0033]

As described in detail in the above embodiments, according to the horizontal cutting method according to the present invention, underwater work of the diver is reduced as much as possible, and when the diver is cut off and separated, the obstacle of the wire saw coming out is obstructed. Therefore, the construction efficiency can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a method for horizontally cutting a concrete structure according to the present invention during cutting.

FIG. 2 is an explanatory plan view of FIG. 1;

FIG. 3 is a side view of the horizontal cutting method for a concrete structure according to the present invention at the end of cutting.

FIG. 4 is an explanatory plan view showing another embodiment of the method for horizontally cutting a concrete structure according to the present invention during cutting;

FIG. 5 is a side view showing the middle of cutting and the end of cutting in the conventional method for horizontally cutting a concrete structure.

[Explanation of symbols]

 10, 10a Concrete structure 12 Wire saw 14, 14a Insert material 16 Cutting gap 18 Uncut part

Claims (3)

[Claims] 1. A method of horizontally cutting the concrete structure from one end to the other end by winding a wire saw around the outer periphery of the concrete structure, introducing tension to the wire saw and circulating the wire saw, At least at the outer peripheral side of the structure, at the stage where the horizontal cutting position by the wire saw exceeds the center of gravity of the concrete structure, one hinge fulcrum is provided between the center of gravity and the uncut portion in the cutting gap of the wire saw. A horizontal cutting method for a concrete structure, comprising the steps of: 2. The method for horizontally cutting a concrete structure according to claim 2, wherein the concrete structure is a columnar concrete structure constructed underwater. 3. The concrete structure has a columnar shape with a circular cross-section, and in a rectangular coordinate system whose origin is the center of gravity of the concrete structure, the horizontal cutting position by the wire saw is at least on the outer peripheral side of the concrete structure. 3. The method for horizontally cutting a concrete structure according to claim 1, wherein a pair of the interposers is installed at positions symmetrical with respect to the position of the center of gravity at a stage beyond the position of the center of gravity.