Wire saw method

Abstract

To propose a wire saw method capable of suppressing generation of dust at the time of cutting a structure.SOLUTION: The periphery of a structure 1 which is a cutting object is surrounded with a pipe body 200. The pipe body 200 comprises a body pipe 210 and an elastic layer 220 covering the body pipe 210, and is pressed against the structure 1. Thereby, the elastic layer 220 elastically deforms. A wire saw 400 surrounds the structure 1 in a state of penetrating the pipe body 200. By rotating the wire saw 400 in that state around the structure 1, the structure 1 is cut together with the pipe body 200. The dust generated in the process of cutting the structure 1 can reach the inside of the pipe body 200 but stays in the pipe body 200, so that it is less likely to flow out to the outside environment.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a wire saw method for dismantling a structure using a wire saw. [Background technology]

[0002] There are many methods for demolishing structures (which in this application includes buildings), one of which is the wire saw method, which uses a wire saw (generally a wire with a continuous diamond tip attached). The wire saw method cuts a structure by rotating an endless wire saw around the structure to be cut while applying tension to the wire saw. The wire saw method has the advantage that it can cut even structures with complex shapes, as long as the structure can be run over with the wire saw, and large structures such as bridges, dams, and chimneys. Another advantage of the wire saw method is that it generates relatively little vibration and noise during construction, making it possible to cut structures of various constructions, such as reinforced concrete, marble, and brick. Summary of the Invention [Problem to be solved by the invention]

[0003] Although the wire saw method offers such advantages, there are still areas that need improvement. The wire saw method produces dust when cutting the structure. Depending on the type of structure, harmful substances (e.g. asbestos) may be contained inside, so the dust produced by the wire saw method may be mixed with harmful substances. Considering these points, it is preferable to carry out wire saw construction while suppressing the generation of dust.

[0004] There are two types of wire sawing: dry and wet. Simply put, the former is a method in which the wire saw is kept dry while cutting the structure, and the latter is a method in which the wire saw is wet with water while cutting the structure. The dry method has the advantage that it does not use water, and therefore eliminates the labor and cost of preparing water and treating the wastewater. However, it has the disadvantage that the wire saw becomes hot and easily cuts, so it takes a long time to cut the structure and is more likely to generate dust. In the wet method, the wire saw is wetted with water while cutting the structure, so the wire saw does not get too hot, the time required to cut the structure can be shortened, and dust is not easily generated by being caught in the water. However, the wet method requires the effort and cost of preparing water and disposing of the wastewater. In particular, when the cutting point of the structure is at a high altitude, such as more than 100m above ground, it may be practically impossible to raise the water to that height, and in such cases, the wet method may not be possible at all.

[0005] As described above, when comparing the dry construction method and the wet construction method from the viewpoint of suppressing the generation of dust, the wet construction method is superior. However, the wet method also has the disadvantages mentioned above, and there are cases where it cannot be used at all depending on the conditions.

[0006] An object of the present invention is to propose a wire saw method that can suppress the generation of dust when cutting a structure, and that can be applied to both dry and wet methods. [Means for solving the problem]

[0007] In order to solve the above problems, the inventors of the present application propose the following invention. The present invention is a wire saw method in which an endless wire saw is wound around a structure to be cut, and the wire saw is rotated around the structure while applying tension to the structure, thereby cutting the structure. Up to this point, the method is the same as the conventional wire saw method, or may be the same as the conventional wire saw method. In the wire saw method of the present invention, a tube body having a main tube, which is a long, bendable tube, and an elastic layer made of an elastic material covering the outer surface of the main tube, is attached to the structure in a state in which the elastic layer is pressed against the periphery of the structure and so as to surround the periphery of the structure, and the wire saw is passed through the main tube in the tube body to cut the structure together with the main tube. In the wire saw method of the present invention, a tubular body is used, and the wire saw is passed through the tubular body and rotated around the structure while applying tension, thereby cutting the structure together with the tubular body. Here, the tube body includes a main tube, which is a bendable long tube, and an elastic layer that covers the outer circumferential surface of the main tube. The bendable main tube can be made of, for example, resin, more specifically, polyvinyl chloride. The elastic layer is made of an elastic material and is capable of elastic deformation. The elastic layer can be made of, for example, rubber, a resin (for example, urethane) sponge, or urethane. In the wire saw method of the present invention, as described above, the wire saw cuts the structure together with the tube. Here, on both sides of the cut in the structure made by the wire saw passing, the elastic layer of the tube pressed against the surface of the structure is in close contact with the structure without any gaps. Therefore, although dust generated by cutting the structure with the wire saw may enter the tube (more specifically, into the internal space of the main tube) through the cut in the tube (elastic layer and main tube) cut by the wire saw, it does not leak out from the tube to the outside, at least except at both ends of the tube. Therefore, the wire saw method of the present invention can suppress the generation of dust when cutting a structure. This effect is the same whether the wire saw method is a wet method or a dry method. Even in the case of a dry method, the ability to suppress the generation of dust when cutting a structure is an effect that is difficult to obtain with conventional wire saw methods. Of course, when the wire saw method of the present invention is applied as a wet method, dust generation can be suppressed more than when it is applied as a dry method, but as already mentioned, the wet method has the disadvantages of being time-consuming and costly, and may not be usable in some cases. If a stronger effect of suppressing dust generation is desired despite these disadvantages, it is also possible to apply the wire saw method of the present invention as a wet method.

[0008] In the wire saw method of the present application, air may be sucked from within the main tube of the tubular body while the wire saw is rotating around the structure. As described above, in the wire saw method of the present application, dust generated by cutting the structure with the wire saw enters the tube surrounding the structure, more specifically, the space inside the main tube contained in the tube. Therefore, by sucking the air inside the main tube, the dust present in the space inside the main tube can be sucked in together with the air, and the leakage of dust to the outside of the tube can be more effectively suppressed.

[0009] In the wire saw method according to the present invention, as described above, the tube is attached to the structure. The method of attaching the tube to the structure is basically free as long as the following two conditions are met: the elastic layer of the tube is pressed against the periphery of the structure, and the tube surrounds the periphery of the structure. For example, it is possible to pre-attach fasteners to each of a number of positions on the structure along the planned path of the pipe around the structure, and then attach the pipe to the structure via the fasteners. The use of fasteners such as those described above allows the tube to be easily attached to the structure. When the pipe is attached to the structure via a fastener, the wire saw method according to the present invention can be further modified as follows. In other words, the fixture may be configured to include a fixture main body capable of fixing to the structure and capable of locking the tube, and a pressing body movable from a position far from the structure to a position close to the structure and attachable to the fixture main body. When attaching the tube to the structure, the fixture main body may be attached to the structure, the tube may be locked to the fixture main body, and the pressing body may be attached to the fixture main body while moving it from a position far from the structure to a position close to the structure, thereby attaching the tube to the structure in a state in which the elastic layer is pressed against the periphery of the structure.

[0010] There is no particular limit to the type of structure to be cut by the wire saw method of the present application. For example, it may be a bridge, a chimney, a building, an apartment building, etc. In addition, the cutting position of the structure using the wire saw method of the present application may be at a high place, for example, 100 m or more above ground. When cutting a structure using a wire saw at such a high place, it is often very difficult to use a wet method because it is difficult to raise a certain amount of water from the ground to that height or the cost is likely to be excessive. In such a case, the wire saw method of the present application, which can be implemented as a dry method, is likely to be effective. Of course, as already mentioned, it is possible to use a wet method even at such a high place. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a side view including a partial perspective view of a structure being dismantled using a wire saw method in one embodiment and a lifting scaffold used in dismantling the structure. [Diagram 2] FIG. 1 is a plan view including a partial perspective view of a structure being dismantled using a wire saw method in one embodiment and a lifting scaffolding used to dismantle the structure. [Diagram 3] FIG. 2 is a cross-sectional view of the tube shown in FIG. [Figure 4] FIG. 4 is a diagram showing a method of attaching the pipe body to a structure. [Diagram 5]3 is an enlarged plan view including a partially perspective view showing the power unit and its periphery in FIG. 2. [Figure 6] FIG. 11 is a plan view showing a process of cutting a structure using a wire saw. [Figure 7] FIG. 4 is an enlarged side view showing the vicinity of the tube body during the wire sawing process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0013] In this embodiment, a case will be described in which the structure 1 is cut by carrying out a wire saw method. FIG. 1 shows a side view including the structure 1 in a state where the wire saw method is being performed, and FIG. 2 shows a plan view of the same.

[0014] The structure 1 to be cut in this embodiment is, but is not limited to, a chimney. The structure to be cut by the wire saw method is of course not limited to a chimney, and may be a bridge, which is an example of a structure, or a building such as a condominium. A chimney, which is an example of structure 1, is cylindrical, with a diameter of about 4 m, but is not limited to this, and has a height from the ground of 200 m or more, more specifically about 240 m, but is not limited to this. The thickness in the diametrical direction of structure 1, which is a chimney, is about 0.1 m, but is not limited to this. The walls of a chimney, which is an example of a structure 1, are basically made of reinforced concrete, although this is not limited to this. However, the walls have a multi-layer structure, and among these layers there is a layer made of asbestos for the purpose of fire and heat resistance. Therefore, the dust generated when the wire saw method is carried out will inevitably contain asbestos, so scattering of the dust should be avoided as much as possible. The wire saw method in this embodiment is carried out for the purpose of demolishing a chimney, which is an example of a structure 1. The chimney, which is an example of a structure 1, is cut by the wire saw method, for example, every 10 m in the height direction, starting from the top, but in this embodiment, virtually horizontally. Therefore, in order to cut the structure 1, which is a chimney, the wire saw method is carried out multiple times at 10 m intervals in the height direction of the structure 1, and at least the first multiple times of these are carried out at a height of more than 200 m above the ground.

[0015] Since the structure 1, which is a chimney, is high-rise, a scaffold is required for workers to work at a high altitude in order to carry out the wire saw method for demolishing the structure 1. Although not limited to this, in this embodiment, a mobile climbing scaffold 100 is used when demolishing the structure 1. However, if the structure 1 is not high-rise and workers are not required to perform the work, neither the mobile climbing scaffold 100 nor a general scaffold is required. The mobile climbing scaffold 100 used in this embodiment may be a known or well-known one, or may be a commercially available one. For example, the climbing scaffold 100 used in this embodiment may be a Skanclimber SC6000 (trademark) which is rented out by Nishio Rent-All Co., Ltd. in Japan. The climbing scaffold 100 comprises a mast 110 and a deck 120. The mast 110 is a column that extends vertically in the up-down direction, has sufficient strength to support the deck 120, and is firmly fixed to the ground. The mast 110 is formed, for example, by connecting small masts that extend in the up-down direction. The deck 120 is attached to the mast 110 and can be raised and lowered freely relative to the mast 110, and can be stopped at an appropriate height on the mast 110. The deck 120 includes a deck plate 121 made of a metal plate. A hole is drilled in the middle of the longitudinal direction of the deck plate 121, and the mast 110 penetrates the hole. The deck plate 121 is designed to maintain a horizontal position regardless of the relative position of the deck 120 to the mast 110. With the deck 120 located on the ground, various tools, devices, etc. required for carrying out the wire saw method are placed on the deck plate 121, and a worker is placed on the deck plate 121, and in this state, the deck 120 can be raised along the mast 110 and stopped at an appropriate position. In other words, the mobile lifting scaffold 100 used in this embodiment can function as if it were an elevator, and by using such a lifting scaffold 100, various tools, devices, etc. and a worker can be safely and quickly moved to a high place. The deck plate 121 has strength, shape, and size that make such a thing possible. In this embodiment, the deck plate 121 has a rectangular shape in plan view, although this is not limited thereto. A lifting device 122 is provided on, for example, the underside of the deck plate 121 for raising and lowering the deck 120 along the mast 110 and releasably fixing the deck 120 to the mast 110. An operator can operate the lifting device 122 by operating an operating device (not shown). By operating the lifting device 122, an operator can move the deck 120 up and down relative to the mast 110 and can stop the deck 120 at any height. A fall prevention fence 123 is provided around the deck plate 121 to prevent workers from falling.

[0016] Although not limited thereto, the deck 120 of this embodiment is provided with an arm plate 124. The arm plate 124 is a metal plate and has a substantially rectangular shape in a plan view. The arm plate 124 is a scaffold for workers to work on, and has a strength, shape, and width sufficient for the workers to work on it. Four arm plates 124 are attached to mounting parts 125 provided at both ends of the deck plate 121 in the longitudinal direction. The arm plates 124 attached to the mounting parts 125 are hinge-connected by hinges 126. Adjacent arm plates 124 are connected to each other by hinges 126 at both ends of the longitudinal direction. As a result, the four arm plates 124 attached to one mounting part 125 in a series can be extended from one mounting part 125 by the hinges 126 while taking any shape such as a straight line or a curved line. The shape formed by the four arm plates 124 attached to one mounting part 125 can be arbitrarily changed by an operator, for example, by using the above-mentioned operating device. The four arm plates 124 attached to the other mounting part 125 in series are similarly configured and have the same functions. Although not limited to this, the arm plates 124 in this embodiment are also provided with fall prevention fences 123 to prevent the operator from falling, but this is omitted from FIG. 2. 2, the arm plate 124 is extended from the mounting portion 125 so as to surround the chimney structure 1. In this manner, a worker can perform necessary work at any position surrounding the chimney structure 1 by moving to an appropriate position on the deck plate 121 or the arm plate 124.

[0017] The deck 120 is stopped at an appropriate height of the mast 110, and the arm plate 124 is deformed into a shape that surrounds the periphery of the structure 1, thereby bringing the lifting scaffold 100 into the state shown in Figures 1 and 2. In this state, a worker performs a wire saw method to cut the structure 1 horizontally at the height where the deck 120 is stopped. In this embodiment, the opening at the top end of the structure 1, which is a chimney, is closed with the lid 2 at an appropriate timing before the wire saw, which will be described later, starts to rotate around the structure 1 in the wire saw method, as will be described later. The work of closing the opening with the lid 2 may be performed using the climbing scaffold 100. In addition, the lid 2 may be any type as long as it can close the opening. This lid 2 is intended to more efficiently suppress leakage of dust into the external environment caused by the structure 1 being a chimney when the wire saw method is performed, as will be described later. Therefore, if the structure 1 is not a chimney, the lid 2 is basically unnecessary, and even if leakage of dust into the external environment is permitted to a certain extent, the lid 2 is not necessary.

[0018] When carrying out the wire saw method, first, the pipe body 200 is attached so as to surround the periphery of the structure 1 horizontally. 3 shows a cross section of the tube 200. The tube 200 comprises a main tube 210, which is a long, bendable tube, and an elastic layer 220 that covers the outer circumferential surface of the main tube 210. The cross section of the tube 200 is uniform over its entire length. In this embodiment, the main body tube 210 has a cylindrical shape. However, the main body tube 210 does not have to be cylindrical as long as it is tubular enough to allow the wire saw, which will be described later, to pass through it. The main body tube 210 is long and bendable. However, the main body tube 210 or the tube 200 does not have to be a single piece over its entire length, and may be divided into several pieces in the length direction. The main body tube 210 is bendable. This is because the tube 200 needs to be aligned along the path of the wire saw. The main body tube 210 is made of a material that allows it to be bent. For example, the main body tube 210 can be made of a resin, such as polyvinyl chloride. The elastic layer 220 is for elastically deforming the tube 200 when the tube 200 is pressed against the structure 1 as described below, thereby making the tube 200 adhere closely to the structure 1 without any gaps. As long as this is possible, the elastic layer 220 may be made of any material. The elastic layer 220 is made of an elastic material, and may be made of, for example, rubber, a resin (e.g., urethane) sponge, or urethane.

[0019] The pipe 200 is attached to the structure 1. The method of attaching the pipe 200 to the structure 1 is basically free as long as the following two conditions are satisfied: the elastic layer 220 of the pipe 200 is pressed against the surface surrounding the structure 1, and the pipe 200 surrounds the periphery of the structure 1. Although not limited thereto, in this embodiment, fixtures 300 are used to attach tube 200 to structure 1. By fixing a plurality of fixtures 300 to the outer surface of structure 1 along the path along which the wire saw is to be disposed, the path of the wire saw, or the path of tube 200 that guides the wire saw therein, can be easily and correctly set. As shown in Fig. 4, the fixture 300 in this embodiment includes a fixture body 310 and a pressing body 320, although this is not limited thereto. The fixture body 310 and the pressing body 320 can be tied together with a string-like body such as a thin wire to prevent the pressing body 320 from falling off, and although not shown in the figures, this is done in this embodiment. Figs. 4(A-1) and (B-1) are side views for explaining a method of attaching the pipe body 200 to the structure 1 using the fixture 300, and Figs. 4(A-2) and (B-2) are plan views of the same. Figs. 4(A-1) and (A-2) and Figs. 4(B-1) and (B-2) each show the same thing. Both the fixing body 310 and the pressing body 320 can be made of metal, for example, although this is not necessarily the case in this embodiment. The fixing device main body 310 can be fixed to the structure 1. The fixing device main body 310 can lock the tube 200 while being fixed to the structure 1. On the other hand, the pressing body 320 can be attached to the fixing device main body 310 and can move relative to the fixing device main body 310 attached to the structure 1. More specifically, the pressing body 320 can move, for example, move in parallel, from a position far from the structure 1 to a position close to the structure 1. When the pressing body 320 moves to a position close to the structure 1, the pressing body 320 presses the tube 200 against the surrounding surface of the structure 1. As a result, the elastic layer 220 of the tube 200 is elastically deformed and comes into close contact with the surrounding surface of the structure 1.

[0020] Fixing device main body 310 in this embodiment includes body 311 bent into an L-shape in side view, and rib 312 which is a plate used to fix fixing device main body 310 to structure 1. The method for fixing rib 312 to structure 1 can be determined appropriately, but for example, rib 312 can be fixed to structure 1 by screwing a screw that has penetrated a hole provided in rib 312 into structure 1. When the rib 312 is fixed to the outer peripheral surface of the structure 1, a groove is formed between the body 311, which is bent into an L-shape in side view, and the outer peripheral surface of the structure 1. The width of the groove is such that the pipe body 200 can be inserted into the groove. The pipe body 200 is inserted into the groove (FIGS. 4(A-1) and (A-2)). On the other hand, a hole (not shown) is drilled in the vertical portion of the body 311 when the fixing device main body 310 is attached to the structure 1, and the pressing body 320 is inserted into the hole. The left side of the pressing body 320 in Fig. 4(A-1), i.e., the end portion facing the structure 1 or the pipe 200, forms an inclined surface 321 that slopes from the upper left to the lower right in Fig. 4(A-1). In the state shown in Figs. 4(A-1) and (A-2), the inclined surface 321 of the pressing body 320 does not touch the pipe 200 inserted in the above-mentioned groove formed by the structure 1 and the body 311 of the fixing device main body 310, or at least does not press the pipe 200 against the structure 1. From this state, pressing body 320 is moved relative to structure 1; in this embodiment, it is moved in parallel toward the left side of Fig. 4. Then, inclined surface 321 of pressing body 320 comes into contact with tube 200, and applies a force pressing tube 200 toward the lower left in Fig. 4(B-1). When pressing body 320 is further moved toward the left side of Fig. 4, inclined surface 321 of pressing body 320 presses tube 200 against structure 1 and the upper surface of the horizontal part of body 311 of fixing device main body 310. Then, the part of elastic layer 220 of tube 200 that is in contact with structure 1 and the upper surface of the horizontal part of body 311 of fixing device main body 310 is elastically deformed and crushed (Figs. 4(B-1) and (B-2)).

[0021] The tubular body 200 is arranged to surround the structure 1 horizontally, basically all around (see FIG. 2). The reason why it is "basically" is that a part of the wire saw 400 exposed from the tubular body 200 is necessary in order to combine the wire saw 400 with a power unit 500 (described later) which is a device for rotating the wire saw 400 (described later). In this embodiment, there is a small portion of the structure 1 facing the deck 120 where the pipe body 200 is not present. Except for this portion, the pipe body 200 surrounds the structure 1 in a continuous manner when viewed from above.

[0022] Next, the wire saw 400 and the power unit 500 are set. The wire saw 400 is placed in a state of going around the structure 1 in the same manner as in the case of a normal wire sawing method. The wire saw 400 itself may be the same as the wire saw used in the normal wire sawing method. Naturally, the wire saw 400 may be a known or well-known one, and a commercially available one is sufficient. In general, the wire saw 400 is a wire to which diamond tips are continuously attached. In this embodiment, the wire saw 400 is placed in a state of being appropriately tensioned before being rotated around the structure 1 by the power unit 500. In addition, although not limited thereto, the wire saw 400 in this embodiment is stretched substantially horizontally at all portions. The wire saw 400 is positioned to surround the structure 1, as in the case of a normal wire saw method, but when performing the wire saw method of the present invention, the wire saw 400 is positioned to penetrate the space within the main tube 210 contained in the tube body 200. However, a part of the wire saw 400 is exposed from the tube 200. Since it is necessary to pass the power unit 500 through the part of the wire saw 400 exposed from the tube 200, it is necessary to expose a part of the wire saw 400 from the tube 200. The power unit 500 is a device whose main function is to provide the wire saw 400 with a driving force for rotating around the structure 1. The wire saw 400 rotates around the structure 1 by the driving force provided by the power unit 500. Although not limited to this, the wire saw 400 in this embodiment rotates around the structure 1 in a counterclockwise direction this time as indicated by the arrow X1 in FIG. 2. Of course, the rotation direction of the wire saw 400 may be either direction, and the rotation direction may be reversed midway if necessary. In order to create a portion of the wire saw 400 that is exposed from the tube 200, the tube 200 does not go completely around the structure 1. In other words, the tube 200 is not present in an area required to expose the wire saw 400.

[0023] The power plant 500 will now be described in detail. Please refer to Fig. 5, which shows an enlarged view of the power plant 500 and its surroundings in Fig. 2. The power plant 500 includes a case 510. The case 510 is airtight and contains components described below inside. Although not limited to this, an opening 511 is provided in the portion of the case 510 in this embodiment that faces the structure 1. However, the periphery of the opening 511 is made airtight with the structure 1 by taking appropriate measures such as sealing the periphery with adhesive tape after adhering it to the structure 1. Holes (not shown) are drilled on both sides of the portion of the case 510 that is closer to the structure 1. Through these two holes, one end and the other end of the tube 200 reach the inside of the case 510. Airtightness is also maintained between the edges of these holes and the outer surface of the tube 200 by taking appropriate measures. Pulleys 521, 522, and 523 are present inside case 510. Of these, only pulley 523 is essential. Pulley 521 is for changing the traveling direction of wire saw 400 emerging from pulley 523 toward main tube 210 included in tubular body 200. Pulley 522 is for changing the traveling direction of wire saw 400 emerging from main tube 210 of tubular body 200 toward pulley 523. Wire saw 400 is run around pulleys 521 and 522, and in this embodiment, although this is not necessarily the case, it rotates by the force received from wire saw 400. In other words, pulleys 521 and 522 are not connected to a power generating device, which will be described later. On the other hand, pulley 523 is connected to a power generating device (not shown) included in power unit 500, and is a pulley that rotates counterclockwise in this case in Figures 2 and 5 by the power received from the power generating device. Wire saw 400 is run around pulley 523, and receives a propulsive force from the rotating pulley 523. When the pulley 523 starts to rotate, it moves in the direction of the arrow X2 in the figure at an appropriate speed. This movement may be continuous or not. This movement may be controlled manually by an operator or may be automated, for example, by computer control. In addition, as a mechanism for moving the pulley 523 in the direction of the arrow X2, since the movement direction of the pulley 523 may be linear, a known or well-known appropriate mechanism, such as a rack-and-pinion mechanism, a slider-crank mechanism, or a heart-cam mechanism, may be adopted. Pulley 523, which has started to rotate, is moved in the direction of arrow X2 in order to gradually shorten the length of the portion of wire saw 400 that is located closer to structure 1 than pulleys 521 and 523. As a result, structure 1 is gradually cut from the portion farthest from pulleys 521 and 523 toward pulleys 521 and 523. Power units having a function of moving pulley 523 that provides a driving force to wire saw 400, and further power units having pulleys 521, 522 for changing the traveling direction of wire saw 400, have been widely used in conventional wire sawing methods, and are publicly known or well-known and commercially available. Therefore, those parts of power unit 500 can be diverted from those of publicly known or well-known or commercially available power units.

[0024] Although not limited to this, this embodiment also has a mechanism for sucking up dust generated when the structure 1 is cut by rotating the wire saw 400, thereby preventing leakage into the external environment. The mechanism is realized by equipment centered on the suction device 600. The suction device 600 is a device that sucks in air by negative pressure. As described later, dust that has accumulated inside the main tube 210 of the tube body 200 is sucked into the suction device 600 together with the air. The suction device 600 may be any device that can suck in dust together with the air and store the sucked in dust inside without letting it flow out to the outside. It goes without saying that such devices are publicly known or well known, and are commercially available. As the suction device 600, any suitable device that is publicly known or well known, or commercially available, may be adopted. In this embodiment, branch pipes 211, which are pipes communicating with main pipe 210 inside pipe 200, are provided near both ends of pipe 200. A base end of connecting pipe 212, which is a pipe whose tip is connected to intake pipe 610, which is a pipe connected to intake device 600, is connected to branch pipe 211. As a result, dust inside main pipe 210 flows together with air through connecting pipe 212 as shown by arrow Y1, and is sucked into intake device 600 via intake pipe 610. In this embodiment, the base end of an intake pipe 610, which is a pipe whose tip is connected to the intake device 600, is connected to the case 510 of the power unit 500. As a result, dust inside the case 510 of the power unit 500 flows together with air through the intake pipe 610 as indicated by the arrow Y2, and is sucked into the intake device 600 via the intake pipe 610, as described below.

[0025] In this manner, the setting of the wire saw 400 and the power unit 500 is completed. Note that Figures 1, 2 and 5 show the state in which the setting of the wire saw 400 and the power unit 500 has been completed. In this state, the worker starts the power generating device of the power device 500. Then, in accordance with the power from the power generating device, the pulley 523 starts to rotate counterclockwise in FIG. When pulley 523 rotates, wire saw 400 also starts to rotate counterclockwise in Fig. 2. Appropriate tension is applied to wire saw 400. Therefore, the portion of wire saw 400 passing through inside tubular body 200 or main tube 210 of tubular body 200 starts to cut the inside of main tube 210 (the side closer to the central axis of structure 1, which is the chimney). Fig. 6(A) shows the structure 1 and wire saw 400 at this time as viewed from above. In the power unit 500, the pulley 523 gradually moves in the direction of the arrow X2. As a result, the length of the portion of the wire saw 400 that is located closer to the structure 1 than the pulley 521 and the pulley 523 gradually shortens (FIGS. 6B and 6C). In the process, the wire saw 400 cuts the structure 1 together with the tube 200 .

[0026] The wire saw 400 first cuts the inside of the main tube 210 of the tube 200, then cuts the elastic layer 220, and proceeds toward the inside of the structure 1 while cutting away the structure 1 (FIG. 7). As wire saw 400 advances from tube 200 toward the inside of structure 1, incisions 801, 802, and 803 are created following the advance of wire saw 400. In Figure 7, incision 801 is an incision in main tube 210 of tube 200, incision 802 is an incision in elastic layer 220 of tube 200, and incision 803 is an incision in structure 1. Of these, notch 801 in main tube 210 of tube 200 and notch 803 in structure 1 may not become blocked, but notch 802 in elastic layer 220 of tube 200 will tend to become blocked by deformation of elastic layer 220 because elastic layer 220 is made of an elastic material and because elastic layer 220 is pressed against structure 1 as tube 200 is pressed against structure 1. While the structure 1 is being cut by the wire saw 400, dust is generated from the structure 1. However, the dust basically remains in the structure 1, for example, in the incision 803 in the structure 1, because the incision 802 made in the elastic layer 220 is about to close. However, if the incision 802 in the elastic layer 220 is not closed sufficiently, the dust may pass through the incisions 801 and 802 and reach the internal space of the main tube 210 of the tube 200. However, the dust remains in the internal space of the main tube 210 and does not go out from the main tube 210, so there is little risk of leakage. In addition, since the upper end of the structure 1, which is a chimney, is closed by the lid 2, the dust that reaches the internal space of the structure 1 is confined by the wall of the structure 1 itself and does not leak out at least from the upper opening. In addition, while the structure 1 is being cut by the wire saw 400, the suction device 600 draws in air from the space within the main tube 210 of the tubular body 200. Therefore, dust that has reached the space within the main tube 210 of the tubular body 200 is sucked into the suction device 600 together with the air via the branch pipe 211, the connecting pipe 212, and the suction pipe 610. On the other hand, dust that has reached the inside of the case 510 of the power unit 500 by adhering to the wire saw 400, for example, is sucked into the suction device 600 together with the air via the suction pipe 610. Therefore, dust generated while the structure 1 is being cut by the wire saw 400 does not leak into the external environment, or even if it does leak, the amount of dust is kept extremely small.

[0027] In this manner, the cutting of the topmost portion of the structure 1 is completed. The cut topmost portion of the structure 1 is lowered to the ground by an appropriate method. As described above, the structure 1 is cut from top to bottom at 10 m intervals. Therefore, the deck 120 of the lifting scaffold 100 is lowered by about 10 m, a new lid 2 is placed on the top of the new structure 1 created by cutting the structure 1, and the wire saw method is carried out again in the same manner as described above. By repeating this process, the entire structure 1 in its height direction is dismantled.

[0028] In the above example, the wire saw method was performed as a dry method. However, the wire sawing method may be performed as a wet method. When performing the wire sawing method as a wet method, water may be sprayed onto the wire saw 400 immediately before it enters the main tube 210 of the tube 200 (for example, the wire saw 400 in the area surrounded by the dashed line marked with the symbol Z in FIG. 5). The water can be stored, for example, in a water tank (not shown) attached to the power unit 500. There is no particular limitation on the method for spraying water on the wire saw 400. Naturally, this can be achieved by using publicly known or well-known techniques. [Explanation of symbols]

[0029] 1 structure 2 lid 100 Lifting scaffold 110 Mast 120 Deck 121 Deck Board 200 Body 210 Main tube 211 Branch pipe 212 Connecting pipe 220 Elastic layer 300 Fixtures 310 Fixture body 320 Pressing body 400 Wire Saw 500 power plant 521 Pulley 522 Pulley 523 Pulley 600 Intake system 610 Intake pipe

Claims

1. A wire saw method for cutting a structure by rotating an endless wire saw around a structure to be cut while applying tension to the structure, the wire saw comprising: a tube body having a main tube, which is a long, bendable tube, and an elastic layer made of an elastic material covering the outer circumferential surface of the main tube, is attached to the structure in a state in which the elastic layer is pressed against the periphery of the structure and in a manner surrounding the periphery of the structure, and the wire saw is passed through the main tube of the tube body to cut the structure together with the main tube; Wire saw method.

2. Aspirating air within the body tube of the tube while the wire saw rotates around the structure. The wire saw method according to claim 1.

3. The main body tube is made of polyvinyl chloride. The wire saw method according to claim 1.

4. The elastic material constituting the elastic layer is rubber, a resin sponge, or urethane. The wire saw method according to claim 1.

5. attaching fixtures to the structure in advance at each of a plurality of positions along a planned path of the pipe around the structure, and attaching the pipe to the structure via the fixtures; The wire saw method according to claim 1.

6. the fixture is configured to include a fixture body capable of being fixed to the structure and capable of locking the pipe, and a pressing body that is attachable to the fixture body and movable from a position far from the structure to a position close to the structure, When the pipe body is attached to the structure, Attaching the fixture body to the structure; The pipe is engaged with the fixing device main body, The pressing body is attached to the fixing device main body while being moved from a position far from the structure to a position close to the structure, so that the pipe body is attached to the structure in a state in which the elastic layer is pressed against the periphery of the structure. The wire saw method according to claim 5.

7. It is a dry construction method. The wire saw method according to claim 1.

8. The cutting position in the structure is 100 m or more above the ground. The wire saw method according to claim 1.

9. The structure is a chimney. The wire saw method according to claim 1 or 8.

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