Columnar structure demolition method

Abstract

To provide a hollow columnar structure demolition method without requiring installation of a heavy machine at a high place like apex of the hollow columnar structure such as chimney or a tall heavy machine reaching the high place.SOLUTION: When a columnar structure is demolished by cutting part by part from a top end of a wall surface of the columnar structure, the top end part of the wall surface in plan view is divided into a first area and a second area. The columnar structure is demolished by alternately repeating a first step group to cut a cut part on the wall surface of the first area while supporting the cut part and lower the cut part by a lifting machine installed so as to apply load on the second area, and a second step group to cut the cut part on the wall surface of the second area while supporting the cut part and lower the cut part by a lifting machine installed so as to apply load on the first area.SELECTED DRAWING: Figure 15

Description

[Technical Field]

[0001] This invention relates to the demolition of hollow columnar structures such as chimneys. [Background technology]

[0002] Patent Document 1 discloses a chimney demolition system for demolishing chimneys. This chimney demolition system uses a crushing vehicle suspended from a wire rope hanging from the top of the chimney to crush a portion of the top of the chimney. A pulley is provided on a portion of the wall surface of the top of the chimney, and the crushing vehicle is connected to one end of a wire extending downward from the pulley, with the other end of the wire connected to the bottom of the chimney. The crushing vehicle uses a crushing means at the end of an arm to crush an area of ​​the wall surface of the top of the chimney that is radially opposite the side on which the pulley is installed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7381782 Summary of the Invention [Problem to be solved by the invention]

[0004] The demolition system in Patent Document 1 has the problem that it requires heavy machinery such as a crushing vehicle to be installed at a high place such as the top of the chimney, which makes the work time-consuming and dangerous. On the other hand, there are few tall heavy machinery that can reach high places, and arranging them is time-consuming and costly.

[0005] Therefore, the object of this invention is to provide a method for demolishing hollow columnar structures that does not require the installation of heavy machinery at high places such as the top of hollow columnar structures such as chimneys, or the use of tall heavy machinery that can reach high places. [Means for solving the problem]

[0006] One aspect of the present invention is a method for dismantling a columnar structure, in which an erected hollow columnar structure is dismantled by cutting part by part from the top end of its wall using a lifting machine equipped with a wire and a lifting part attached to the wire, the method comprising the steps of: a first erection step of erecting a load-bearing beam on the wall corresponding to the first region when the wall of the columnar structure is divided into a first region and a second region in a plan view such that the first region and the second region are alternately arranged; a first installation step of installing a fixed beam to which a lifting machine is fixed on the load-receiving beam; a first fixing step of fixing the lifting machine to the fixed beam and arranging it at the first position; a first locking step of locking the lifting part of the lifting machine fixed at the first position to the suspended part provided on the wall surface of the second area; a first cutting step of cutting a part of the wall surface to include an upper end of the wall surface of the second area and the suspended part; and locking the part of the wall surface of the second area cut in the first cutting step to the suspended part locked to the suspended part included in the part of the wall surface. a first lowering step of lowering the load-receiving beam by the lifting machine, a first removing step of removing the fixed beam from the load-receiving beam, a first removing step of removing the load-receiving beam from the wall surface corresponding to the first area, a second erecting step of erecting the load-receiving beam on the wall surface corresponding to the second area, a second installing step of installing a fixed beam to which the lifting machine is fixed on the load-receiving beam so that the lifting machine is disposed at a second position where the lifting part can be engaged with a suspending part provided on the wall surface of the first area, and a second fixing step of arranging the fixed beam at a position indicated by the arrow A; a second locking step of locking the lifting part of the lifting machine fixed at the second position to the suspended part provided on the wall surface of the first area; a second cutting step of cutting a part of the wall surface to include an upper end of the wall surface of the first area and the suspended part; a second lowering step of lowering the part of the wall surface of the first area cut in the second cutting step by the lifting machine having the lifting part locked to the suspended part included in the part of the wall surface; and a second removal step of removing the fixed beam from the load-receiving beam.and a second removal step of removing the load-bearing beam from the wall surface corresponding to the second area, wherein a first step group consisting of the first erection step, the first installation step, the first fixing step, the first locking step, the first cutting step, the first lowering step, the first removal step, and the first removal step, and a second step group consisting of the second erection step, the second installation step, the second fixing step, the second locking step, the second cutting step, the second lowering step, the second removal step, and the second removal step are alternately repeated. [Effects of the Invention]

[0007] When dismantling an erected hollow columnar structure by cutting part by part from the top of its wall, the upper end of the wall, as viewed in plan, is divided into a first area and a second area, and the first process group involves using a lifting machine installed so that the load is applied to the second area to support the cut part on the wall of the first area, cut the cut part, and lower it; and the second process group involves using a lifting machine installed so that the load is applied to the first area to support the cut part on the wall of the second area, cut the cut part, and lower it.This eliminates the need to install heavy machinery at high altitudes or to use tall heavy machinery that can reach high altitudes. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front view of a chimney 1 according to the present embodiment. [Figure 2] FIG. 1 is a front view of a chimney 1 according to the present embodiment. [Figure 3] FIG. 1A is a front view of the chimney 1 according to this embodiment, and FIGS. 1B to 1E are plan views of the chimney 1 according to this embodiment. [Figure 4] FIG. 1 is a front view of a chimney 1 according to the present embodiment. [Figure 5] FIG. 1 is a front view of a chimney 1 according to the present embodiment. [Figure 6] FIG. 4 is a flowchart showing a method for dismantling the inner cylinder 2 according to the present embodiment. [Figure 7] FIG. 2 is a plan view of the outer cylinder 3 according to the present embodiment. [Figure 8] (A) is a front view of the upper end of the outer tube 3 according to this embodiment, (B) is a view of the outer tube 3 according to this embodiment as seen from the arrow AA in Figure 8(A), and (C) is a view of the outer tube 3 according to this embodiment as seen from the arrow BB in Figure 8(A). [Figure 9] (A) is a front view of the upper end of the outer tube 3 according to this embodiment, (B) is a plan view of the outer tube 3 according to this embodiment, and (C) is a side view of the upper end of the outer tube 3 while going around the outer tube 3. [Figure 10] (A) is a front view of the upper end of the outer tube 3 according to this embodiment, (B) is a view of the outer tube 3 according to this embodiment as seen from the arrow AA in Figure 10(A), and (C) is a view of the outer tube 3 according to this embodiment as seen from the arrow BB in Figure 10(A). [Figure 11] (A) is a front view of the upper end of the outer tube 3 according to this embodiment, (B) is a plan view of the outer tube 3 according to this embodiment, and (C) is a side view of the upper end of the outer tube 3 while going around the outer tube 3. [Figure 12] FIG. 2 is a front view of the outer cylinder 3 according to the present embodiment. [Figure 13] FIG. 2 is a front view of the outer cylinder 3 according to the present embodiment. [Figure 14] FIG. 2 is a front view of the outer cylinder 3 according to the present embodiment after disassembly. [Figure 15] FIG. 4 is a flowchart showing a first disassembly method for the outer cylinder 3 according to the present embodiment. [Figure 16] FIG. 10 is a flowchart showing a second disassembly method for the outer cylinder 3 according to the present embodiment. [Figure 17] (A) is a side view of the bracket 52 attached to the outer tube 3 of this embodiment, (B) is a front view of the upper end of the outer tube 3 of this embodiment, (C) is a view of the outer tube 3 of this embodiment as seen from the arrow AA in Figure 17(B), and (D) is a view of the outer tube 3 of this embodiment as seen from the arrow BB in Figure 17(B). [Figure 18] 2 is a front view of the upper end portion of the outer cylinder 3 according to this embodiment. [Figure 19]19(A) is a front view of the upper end portion of the outer cylinder 3 according to this embodiment, and (B) is a view of the outer cylinder 3 according to this embodiment as seen from the arrow AA in FIG. 19(A). [Figure 20] (A) is a front view of the upper end of the outer tube 3 according to this embodiment, (B) is a view of the outer tube 3 according to this embodiment as seen from the arrow AA in Figure 20(A), and (C) is a view of the outer tube 3 according to this embodiment as seen from the arrow BB in Figure 20(A). [Figure 21] 2 is a front view of the upper end portion of the outer cylinder 3 according to this embodiment. [Figure 22] 2 is a front view of the upper end portion of the outer cylinder 3 according to this embodiment. [Figure 23] 2 is a front view of the upper end portion of the outer cylinder 3 according to this embodiment. [Figure 24] 2 is a front view of the upper end portion of the outer cylinder 3 according to this embodiment. [Figure 25] 10A to 10G are transition diagrams showing an example of the operation of the jack 20 according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

[0010] The following describes the dismantling of a double-structure chimney 1, shown in Figure 1, which includes an outer cylinder 3 and an inner cylinder 2 located inside the outer cylinder 3. The outer cylinder 3 is a hollow cylindrical structure with walls made of reinforced concrete, approximately 120 m high, and weighs approximately 2,300 tons. The wall thickness is 200 to 550 mm. The inner cylinder 2, on the other hand, has an exhaust section 2a that exhausts smoke, an induction section 2b that takes in flue gas emitted from a thermal power plant or the like and directs it to the exhaust section 2a, and an IDF (Induced Draft Fan) 2c that draws the smoke taken in by the induction section 2b to the exhaust section 2a. The inner cylinder 2 weighs approximately 100 tons, and the wall thickness is 12 to 16 mm. The chimney 1 is erected on a foundation 4.

[0011] In this embodiment, a jack-type lifting machine 20 (hereinafter sometimes referred to as "jack 20") shown in Figure 25 is used. The jack 20 has a wire W and an anchor 25 attached to the wire W, and can raise or lower the object to be lifted by lifting or lowering the wire W with the anchor 25 engaged with a suspended part such as a hook or a lifting piece provided on the object to be lifted. The specific operation of the jack 20 will be described later.

[0012] [1. How to disassemble the inner cylinder 2] First, a method for dismantling the inner cylinder 2 will be described with reference to Figures 2 to 6. In this embodiment, the case where the inner cylinder 2 has a discharge section 2a, a guide section 2b, and an IDF 2c will be described, but this dismantling method can also be applied to other columnar structures (for example, a structure in which the discharge section 2a continues from the top to the bottom). Below, the description will be made according to the flowchart in Figure 6.

[0013] [1.1. Mobile lifting scaffold installation process (Step S11)] As shown in Figure 2, a mobile climbing scaffolding consisting of a mast 10 and a scaffolding 11 that rises and falls while being guided by the mast 10 is assembled along the outer wall surface of the outer cylinder 3. The mast 10 has a height from the ground to near the top end of the chimney 1, and the scaffolding is circular in plan view and rises and falls along the outer periphery of the outer cylinder 3. This allows workers and cargo such as beams and jacks 20 used for demolition to be moved up and down along the chimney 1, and allows, for example, workers to attach and remove brackets 52 (described later) at any height on the outer wall surface of the outer cylinder 3.

[0014] [1.2. Jack installation process (Step S12)] As shown in Figure 3(B) , the chimney 1 in plan view has a double wall structure consisting of the inner tube 2 and the outer tube 3. In this process, a jack 20, a load-bearing beam 17, and a jack fixing beam 18 are placed on scaffolding 11 on the ground, and the scaffolding 11 is raised to the top of the chimney 1.

[0015] Next, a bracket crane (not shown) installed on the scaffolding 11 is used to install load-bearing beams 17 on the wall surface of the outer cylinder 3. Specifically, for example, as shown in FIG. 3(B), when the circular wall surface of the outer cylinder 3 in plan view is divided into four by dotted lines, two load-bearing beams 17 are placed in each region, as shown in FIG. 3(C), parallel to the tangent line that touches the center of the arc formed by dividing the circular wall surface of the outer cylinder 3 into four. Note that the number of divisions of the circular wall surface of the outer cylinder 3 is not limited to "4" and may be other numbers. Furthermore, the number of load-bearing beams 17 placed in each region is not limited to "2" and may be other numbers.

[0016] Next, as shown in Figure 3(D), two jack fixing beams 18 are erected on the load-receiving beams 17 in adjacent regions, for a total of four positions. The jack fixing beams 18 are erected so that, when the jack 20 is fixed to the jack fixing beams 18, anchors 25 (an example of a "hanging part") provided at the ends of the wires W extending downward of the jack 20 can be engaged with hanging pieces provided on the wall surface of the outer cylinder 3. Note that the number of jack fixing beams 18 erected on the load-receiving beams 17 in adjacent regions is not limited to "two" and may be any number.

[0017] Next, as shown in Figures 3(A) and (E), two jacks 20 are fixed to each of the four jack fixing beams 18, for a total of eight jacks 20. The number of jacks 20 fixed to the jack fixing beams 18 is not limited to two and may be any number. The number of jacks 20 to be installed is calculated based on the mass of the inner cylinder 2 to be lifted and the rated load of the jacks 20 (15 tons in this embodiment). It is also preferable to arrange the jacks 20 so that the load is evenly distributed across each jack 20.

[0018] By this step, the jack 20 can be installed so that a load is applied to the wall surface of the outer cylinder 3.

[0019] [1.3. Locking step (step S13)] In this process, workers use existing scaffolding along the discharge section 2a of the inner cylinder 2 to attach hanging pieces for engaging the anchors 25 of the jacks 20 to the outer wall surface of the discharge section 2a. The hanging positions of the hanging pieces are below each of the jacks 20 installed in the jack installation process. Furthermore, the height position of the hanging pieces is preferably close to the upper end of the inner cylinder 2, since if they are located lower than the center of gravity of the inner cylinder 2, the inner cylinder 2 will become unstable when suspended by the jacks 20. Note that the hanging pieces may be installed on the inner cylinder 2 before dismantling the inner cylinder 2, such as during construction of the inner cylinder 2, thereby eliminating the need to install the hanging pieces during dismantling.

[0020] Next, the anchor 25 of the jack 20 is engaged with the lifting piece. This operation is performed for each jack 20. With the anchor 25 of the jack 20 engaged with the lifting piece, the wire is pulled up and tensioned, allowing the jack 20 to bear the load of the inner tube 2.

[0021] [1.4. Opening Step (Step S14)] In this step, as shown in FIG. 4, an opening 3a is made in the wall surface at the bottom of the outer cylinder 3 using a cutting machine (not shown).

[0022] [1.5. Cutting Process (Step S15)] In this process, the load of the inner cylinder 2 is supported by the jack 20, and the lower part of the inner cylinder 2 (IDF2c in FIG. 4) is cut (and / or crushed) by a cutting machine. For example, the lower end of the inner cylinder 2 is cut off by about 2 m. As a result, the inner cylinder 2 is suspended in mid-air by the jack 20.

[0023] [1.6. Removal step (step S16)] In this step, the debris produced in the cutting step is removed from the outer cylinder 3 through the opening 3a.

[0024] [1.7. Lowering process (step S17)] In this step, as shown in FIG. 5, the wire W of the jack 20 is lowered (jacked down) to lower the lower end of the inner cylinder 2 suspended in mid-air to the ground or near the ground.

[0025] [1.8. Judgment step (step S18)] In this step, it is determined whether the inner cylinder 2 can be removed from the opening 3a. If the inner cylinder 2 can be removed from the opening 3a (step S18: YES), the process proceeds to step S19. On the other hand, if the inner cylinder 2 cannot be removed from the opening 3a (step S18: NO), the process proceeds to step S15.

[0026] That is, the cutting step (step S15), removal step (step S16), and lowering step (step S17) are repeated to cut the inner cylinder 2 from its lower end until the remaining portion of the inner cylinder 2 is large enough to be removed from the opening 3a. In the cutting step performed when repeating the steps, for example, the lower end of the inner cylinder 2 is cut (and / or crushed) at a length of about 2 m, and in the subsequent removal step, the cut portion of the inner cylinder 2 is removed outside the outer cylinder 3.

[0027] [1.9. Final Removal Process (Step S19)] In this step, the remaining part of the inner cylinder 2 is removed from the opening 3a. When this step is completed, the method for dismantling the inner cylinder 2 is completed.

[0028] As explained above, the method for dismantling the inner cylinder 2 of this embodiment is a method for dismantling the inner cylinder 2 (an example of an "inner columnar structure") in a chimney 1 (an example of a "double structure") in which the inner cylinder 2 and the outer cylinder 3 (an example of "two hollow columnar structures") are installed in a double structure, and includes a jack installation process (an example of an "installation process") in which a jack 20 (an example of a "lifting machine") equipped with a wire W and an anchor 25 (an example of a "lifting part") attached to the wire W is installed at the upper end of the outer cylinder 3 (an example of an "outer columnar structure"); The process includes a locking step of locking the anchor 25 of the jack 20 to the hanging piece (an example of a "suspended part"), a cutting step of cutting the lower end of the inner tube 2 through an opening formed in the lower part of the outer tube 3 while the load of the inner tube 2 is supported by the jack 20, a removal step of removing the rubble produced by the cutting step from the opening 3a to the outside of the outer tube 3, and a lowering step of lowering the inner tube 2 with the jack 20, and after the jack installation step, locking step, cutting step, removal step and lowering step are performed in order, the cutting step, removal step and lowering step are repeated in order.

[0029] Therefore, according to the method for dismantling the inner tube 2 of this embodiment, the load of the inner tube 2 is supported by a jack 20 installed at the upper end of the outer tube 3 erected outside the inner tube 2, and the inner tube 2 is dismantled by repeatedly cutting the lower end of the inner tube 2 and lowering the inner tube 2. This eliminates the need to perform cutting or crushing operations at a high altitude, such as at the upper end of the inner tube 2, and prevents the debris generated by cutting or crushing from falling.

[0030] [2. How to disassemble the outer cylinder 3] Next, we will explain a method for dismantling the outer cylinder 3. In this embodiment, we will explain a method for dismantling the outer cylinder 3 in a chimney 1 consisting of an inner cylinder 2 and an outer cylinder 3, but the dismantling method described below can also be applied to a single hollow columnar structure such as an outer cylinder 3 that does not have an inner cylinder 2.

[0031] In the following, as methods for dismantling the outer cylinder 3, a first dismantling method and a second dismantling method will be described.

[0032] [2.1. First method for dismantling the outer tube 3] A first dismantling method for the outer tube 3 will be described with reference to Figures 7 to 15. Figure 7 is a diagram showing the wall surface of the outer tube 3 in a plan view. In the first dismantling method, the wall surface of the outer tube 3 is divided into first and second regions, with the first and second regions arranged alternately, and the installation locations of the load-bearing beams 31 and fixed beams 33, which will be described later, are determined. In this embodiment, the first and second regions are divided into four locations each, but it is sufficient that there is at least one first region and one second region each. Below, the method will be described with reference to the flowchart in Figure 15.

[0033] [2.1.1. First erection process (step S31)] In this step, as shown in Figures 8(A) and (B), a load-bearing beam 31 is erected on the wall surface of the outer cylinder 3 corresponding to the first region (see Figure 7) (the wall surface of the outer cylinder 3 may be indicated by the symbol "3"). The load-bearing beam 31 has a lattice shape and bears the load of the fixed beam 33, jack 20, etc. that are installed on the load-bearing beam 31. In this embodiment, since there are four first regions, the load-bearing beams 31 are erected in a lattice shape, but the load-bearing beams 31 are erected according to the number of first regions. When there is one first region, for example, the load-bearing beams 31 are erected from one end of the first region to the other.

[0034] [2.1.2. First installation step (step S32)] In this step, a fixed beam 33 to which the jack 20 is fixed is installed relative to the load-receiving beam 31. At this time, as shown in Figures 8(A) and 8(C), the fixed beam 33 is installed so that the jack 20 is disposed at a position (an example of a "first position") where the anchor 25 of the jack 20 can be engaged with a hanging piece (described later) provided on the wall surface 3 of the second area.

[0035] [2.1.3. First Fixation Step (Step S33)] In this step, as shown in Figures 8(A)-(C), the jack 20 is fixed to the fixed beam 33 and positioned so that the anchor 25 of the jack 20 can be engaged with the hanging piece. As a result, the jack 20 is positioned in the second region of the wall surface 3 in a plan view. In this embodiment, four jacks 20 are positioned.

[0036] [2.1.4. First locking step (step S34)] In this process, first, a hole is drilled in the wall surface 3 of the second region below the jack 20 disposed in the second region, and a hanging piece is attached to the hole on the inside of the wall surface 3. As shown in Figures 9(A) and (B), the attachment position of the hanging piece is preferably at or above the center of the cut portion 3p (the mesh pattern portion in Figure 9(A)) on the wall surface 3 that will be cut in the first cutting process described below. The range of the cut portion 3p extends downward from the upper end of the wall surface 3 of the second region and includes the attachment position of the hanging piece. The lower limit of the range of the cut portion 3p is set based on the mass of the cut portion 3p and the rated load of the jack 20, etc. In this embodiment, four hanging pieces are provided. The hanging pieces may be attached to the outer tube 3 before dismantling the outer tube 3, such as during construction, thereby eliminating the need to attach the hanging pieces during dismantling.

[0037] Next, the anchor 25 of the jack 20, which is placed in a position where the anchor 25 can be locked to the hanging piece provided on the wall surface 3 of the second area, is engaged with the hanging piece. As a result, when the cut portion 3p is cut in the first cutting step described below, the cut portion 3p will not fall because it is connected to the jack 20.

[0038] [2.1.5. First Cutting Process (Step S35)] In this step, the wall surface 3 is cut by a cutting machine at the cut portions 3p including the upper end portion of the wall surface 3 in the second region and the hanging piece. In this embodiment, four cut portions 3p are cut.

[0039] [2.1.6. First Lowering Step (Step S36)] In this step, the cut portions 3p cut in the first cutting step are lowered by a jack 20 equipped with anchors 25 engaged with the hanging pieces included in the cut portions 3p. In this embodiment, four cut portions 3p are lowered. The cut portions 3p can be lowered on either the inside or outside of the outer tube 3, but lowering the inside prevents damage to the outside of the outer tube 3 in the unlikely event that the anchors 25 come off the hanging pieces, as the cut portions 3p fall inside the outer tube 3.

[0040] [2.1.7. First Removal Process (Step S37)] In this step, the jack 20 is removed from the fixed beam 33, and the fixed beam 33 fixed in the first fixing step is removed from the load-receiving beam 31.

[0041] [2.1.8. First Removal Process (Step S38)] In this step, the load-bearing beam 31 erected in the first erection step is removed from the wall surface 3 corresponding to the first region.

[0042] As explained above, by carrying out the first installation step through the first removal step, the outer cylinder 3 is in a state in which the cut portion 3p of Fig. 9(A) is eliminated. In other words, when the upper end portion of the outer cylinder 3 is viewed from the side while going around the outer cylinder 3, it has a rectangular wave shape as shown in Fig. 9(C) (the second region of the outer cylinder 3 has a concave shape, and the first region of the outer cylinder 3 has a convex shape).

[0043] [2.1.9. Second erection process (step S39)] In this process, as shown in Figures 10(A) and (B), a load-bearing beam 31 is erected (in the concave portion of Figure 9(C)) on the wall surface of the outer cylinder 3 corresponding to the second region (see Figure 7). The load-bearing beam 31 has a lattice shape and bears the load of the fixed beam 33, jack 20, etc. that are installed on the load-bearing beam 31. In this embodiment, since there are four second regions, the load-bearing beams 31 are erected in a lattice shape, but the load-bearing beams 31 are erected according to the number of second regions. When there is one second region, for example, the load-bearing beams 31 are erected from one end of the second region to the other.

[0044] [2.1.10. Second installation process (step S40)] In this process, as shown in Figures 10(A) and (C), a fixed beam 33 to which the jack 20 is fixed is installed on the load-bearing beam 31 so that the jack 20 is positioned at a position (an example of a "second position") where the anchor 25 of the jack 20 can be engaged with the hanging piece provided on the wall surface 3 of the second area.

[0045] [2.1.11. Second Fixation Step (Step S41)] In this step, as shown in Figures 10(A)-(C), the jack 20 is fixed to the fixed beam 33 and positioned so that the anchor 25 of the jack 20 can be engaged with the hanging piece. As a result, the jack 20 is positioned in the first region of the wall surface 3 in a plan view. In this embodiment, four jacks 20 are positioned.

[0046] [2.1.12. Second locking step (step S42)] In this process, holes are first drilled in the wall surface 3 of the first region below the jacks 20 arranged in the first region, and hanging pieces are attached to the holes. As shown in Figures 11(A) and (B), the attachment position of the hanging pieces is preferably at or above the center of the cut portion 3q (the mesh-patterned portion in Figure 11(A)) on the wall surface 3 that will be cut in the second cutting process described below. The range of the cut portion 3q extends downward from the upper end of the wall surface 3 of the first region and includes the attachment position of the hanging pieces. The lower limit of the range of the cut portion 3q is set based on the mass of the cut portion 3q and the rated load of the jacks 20, etc. In this embodiment, four hanging pieces are provided. The hanging pieces may be attached to the outer tube 3 before dismantling the outer tube 3, such as during construction, thereby eliminating the need to attach the hanging pieces during dismantling.

[0047] Next, the anchor 25 of the jack 20, which is placed in a position where the anchor 25 can be locked to the hanging piece provided on the wall surface 3 of the first area, is engaged with the hanging piece. As a result, when the cut portion 3q is cut in the second cutting step described below, the cut portion 3q will not fall because it is connected to the jack 20.

[0048] [2.1.13. Second Cutting Process (Step S43)] In this step, the wall surface 3 of the first region is cut by a cutting machine at the cut portion 3q including the upper end portion and the hanging piece. In this embodiment, four cut portions 3q are cut.

[0049] [2.1.14. Second Lowering Step (Step S44)] In this step, the cut portions 3q cut in the second cutting step are lowered by a jack 20 equipped with anchors 25 engaged with the hanging pieces included in the cut portions 3q. In this embodiment, four cut portions 3q are lowered. The cut portions 3q can be lowered on either the inside or outside of the outer tube 3, but lowering the inside prevents damage to the outside of the outer tube 3 if the anchors 25 come off the hanging pieces, as the cut portions 3q fall inside the outer tube 3.

[0050] [2.1.15. Second Removal Process (Step S45)] In this step, the jack 20 is removed from the fixed beam 33, and the fixed beam 33 fixed in the second fixing step is removed from the load-receiving beam 31.

[0051] [2.1.16. Second Removal Process (Step S46)] In this step, the load-bearing beam 31 erected in the second erection step is removed from the wall surface 3 corresponding to the second region.

[0052] As explained above, by carrying out the second installation step through the second removal step, the cut portion 3q of the outer cylinder 3 shown in Fig. 11(A) is eliminated. That is, the first region of the outer cylinder 3 becomes concave, and the second region of the outer cylinder 3 becomes convex, and when the upper end of the outer cylinder 3 is viewed from the side around the outer cylinder 3, it has a rectangular wave shape (the first region of the outer cylinder 3 becomes concave, and the second region of the outer cylinder 3 becomes convex).

[0053] [2.1.17. First Determination Step (Step S47)] In this step, it is determined whether the outer cylinder 3 can be dismantled by heavy machinery J on the ground. That is, it is determined whether the height of the outer cylinder 3 at that time is a height that can be dismantled by heavy machinery J on the ground. At this time, if it can be dismantled by heavy machinery J on the ground (step S47: YES), the process proceeds to step S51. On the other hand, if it cannot be dismantled by heavy machinery J on the ground (step S47: NO), the process proceeds to step S48.

[0054] [2.1.18. First Step Group Repeat Step (Step S48)] In this process, the first process group consisting of the first erection process, first installation process, first fixing process, first locking process, first cutting process, first lowering process, first removal process, and first removal process is repeated, and then the process proceeds to step S49. Note that the lower limit of the range of the cut portion 3n (the symbol 3n is used to generally represent the "cut portion" of the wall surface 3) is, for example, such that in the first first cutting process, the wall surface 3 is cut so that the mass of the cut portion 3n is about 35% of the rated load of the jack 20, and in the second or subsequent first cutting processes and the first or subsequent second cutting processes, the wall surface 3 is cut so that the mass of the cut portion 3n is about 70% of the rated load of the jack 20. As a result, the upper end of the outer tube 3 alternates between a state in which the first region is convex and the second region is concave (see Figure 9(C)) and a state in which the first region is concave and the second region is convex (see Figure 11(C)), and the process of placing the jack 20 in the concave portion and cutting the convex portion can be repeated.

[0055] [2.1.19. Second Determination Step (Step S49)] In this step, the same determination as in the first determination step is made. At this time, if the demolition can be performed using heavy equipment J on the ground (step S49: YES), the process proceeds to step S51. On the other hand, if the demolition cannot be performed using heavy equipment J on the ground (step S49: NO), the process proceeds to step S50.

[0056] [2.1.20. Second Process Group Repeating Step (Step S50)] In this process, the second process group consisting of the second erection process, second installation process, second fixing process, second locking process, second cutting process, second lowering process, second removal process, and second removal process is repeated, and then step S47 is carried out.

[0057] That is, after step S46, the first process group and the second process group are alternately repeated to cut the outer cylinder 3 from the upper end until the outer cylinder 3 reaches a height that can be dismantled by heavy equipment J on the ground (for example, about 20 m).

[0058] [2.1.21. Remaining Processing Step (Step S51)] In this step, the remaining portion of the outer cylinder 3 is dismantled by heavy machinery J on the ground, as shown in Fig. 13. When this step is completed, the outer cylinder 3 is dismantled as shown in Fig. 14, and the method for dismantling the outer cylinder 3 is completed.

[0059] As explained above, the first dismantling method of the outer cylinder 3 of this embodiment is a method of dismantling the outer cylinder 3, in which the outer cylinder 3 (an example of an "upright hollow columnar structure") is cut and dismantled part by part from the upper end of its wall using a jack 20 (an example of a "lifting machine") equipped with a wire W and an anchor 25 (an example of a "lifting part") attached to the wire W. When the wall surface of the outer cylinder 3 in plan view is divided into first and second areas such that the first and second areas are alternately arranged, the first dismantling method includes a first erection step of erecting a load-receiving beam 31 on the wall surface corresponding to the first area, and a second erection step of erecting a load-receiving beam 31 on the wall surface corresponding to the first area using the jack 20. a first installation step of installing a fixed beam 33 to which the jack 20 is fixed on the load-receiving beam 31 so that the fixed beam 33 is located at a first position where the anchor 25 can be locked to a hanging piece (an example of a "hanging portion") provided on the wall surface of the second region; a first fixing step of fixing the jack 20 to the fixed beam 33 and locating the jack 20 at the first position; a first locking step of locking the anchor 25 of the jack 20 fixed at the first position to a hanging piece provided on the wall surface of the second region; a first cutting step of cutting a cut portion 3p (an example of a "part of the wall surface") so as to include the upper end of the wall surface of the second region and the hanging piece; and a cutting step of cutting the cut portion 3p of the second region cut in the first cutting step. a first lowering step of lowering the cut portion 3p by a jack 20 having an anchor 25 engaged with a hanging piece included in the cut portion 3p; a first removal step of removing the fixed beam 33 from the load-receiving beam 31; a first removal step of removing the load-receiving beam 31 from the wall surface corresponding to the first region; a second installation step of erecting the load-receiving beam 31 on the wall surface corresponding to the second region; a second installation step of installing the fixed beam 33 to which the jack 20 is fixed on the load-receiving beam 31 so that the jack 20 is located at a second position where the anchor 25 can be engaged with the hanging piece provided on the wall surface of the first region; a second fixing step of fixing the jack 20 to the fixed beam 33 and arranging it in a second position; a second locking step of locking the anchor 25 of the jack 20 fixed at the second position to a hanging piece provided on the wall surface of the first area; a second cutting step of cutting a cut portion 3q (an example of a "part of the wall surface") so as to include the upper end of the wall surface of the first area and the hanging piece; a lowering step of lowering the cut portion 3q of the first area cut in the second cutting step by the jack 20 having the anchor 25 locked to the hanging piece included in the part of the wall surface; and a second removal step of removing the fixed beam 33 from the load-receiving beam 31.and a second removal step of removing the load-bearing beam 31 from the wall surface corresponding to the second region, and a first process group consisting of a first erection process, a first installation process, a first fixing process, a first locking process, a first cutting process, a first lowering process, a first removal process, and a first removal process, and a second process group consisting of a second erection process, a second installation process, a second fixing process, a second locking process, a second cutting process, a second lowering process, a second removal process, and a second removal process are alternately repeated.

[0060] Therefore, according to the first dismantling method of the outer tube 3 of this embodiment, when the outer tube 3 is dismantled by cutting it part by part from the upper end of its wall, the upper end of the wall in a plan view is divided into a first region and a second region, and the first process group in which the cut portion 3p on the wall surface of the first region is cut and lowered while supported by a jack 20 installed so that a load is applied to the second region, and the second process group in which the cut portion 3q on the wall surface of the second region is cut and lowered while supported by a jack 20 installed so that a load is applied to the first region, are alternately repeated to carry out the dismantling, thereby eliminating the need to install heavy machinery at a high place or to use tall heavy machinery that can reach high places.

[0061] [2.2. Second method for dismantling the outer tube 3] In the second dismantling method, as shown in FIGS. 17(A)-(D), a plurality of brackets 52 (hereinafter, the brackets are designated by the reference numerals "52" or "52" with an alphabetical character (e.g., "52A")) are horizontally arranged around the outer wall of the outer cylinder 3. As shown in FIG. 17(B), an assembly frame 60 (hereinafter, the assembly frame is designated by the reference numerals "60" or "60" with an alphabetical character (e.g., "60A")) is installed on the brackets 52. The assembly frame 60 includes a lower frame 61 placed on the brackets 52 and an upper frame 63 supported by supports 62 attached to the lower frame 61 and attached above the lower frame 61. A jack 20 is attached to the upper frame 63. In the second dismantling method, these brackets are used to cut the wall surface 3 one portion at a time from the upper end to dismantle the outer cylinder 3. This will be described below with reference to the flowchart in FIG. 16.

[0062] [2.2.1. Bracket installation process (step S71)] In this step, as shown in Figures 17(A)-(D), multiple brackets 52 (eight in Figure 17) are installed horizontally on the outer wall surface of the outer cylinder 3. At this time, it is preferable to install the brackets 52 so that they are spaced evenly apart. The brackets 52 include horizontal portions 52a and support portions 52b, and the horizontal portions 52a and support portions 52b are joined by bolts 53 to upper and lower mounting brackets 51 that penetrate the wall surface 3 and are fixed to the wall surface. In this way, the brackets 52 are attached to the wall surface 3.

[0063] [2.2.2. Assembly Platform Installation Process (Step S72)] In this step, the assembly stand 60 is installed so that the lower stand 61 is placed on the multiple brackets 52 installed in the bracket installation step (step S71). Jacks 20 are attached to the upper stand 63. In this embodiment, four jacks 20 are attached. As shown in Figures 17(B) and (C), the lower stand 61 is composed of multiple (eight in Figure 17) lower beams 61a placed on the brackets 52. Also, as shown in Figures 17(B) and (D), the upper stand 63 is composed of multiple (eight in Figure 17) upper beams 63a supported by struts 62.

[0064] [2.2.3. Locking Process (Step S73)] In this process, first, a hole is drilled in the wall 3 below the jack 20 attached to the upper platform 63, and a hanging piece is attached to the hole on the inside of the wall 3. As shown in FIG. 18, the hanging piece is preferably attached at or above the center of the cut portion 3r (the mesh-patterned portion in FIG. 18) on the wall 3 that will be cut in the cutting process described below. The range of the cut portion 3r extends downward from the upper end of the wall 3 and includes the attachment position of the hanging piece. The lower limit of the range of the cut portion 3r is set so that the mass of the cut portion 3r is approximately 70% of the rated load of the jack 20. In this embodiment, four hanging pieces are provided. The hanging pieces may be attached to the outer tube 3 before dismantling the outer tube 3, such as during construction, thereby eliminating the need to attach the hanging pieces during dismantling. In the assembly stand installation step (step S72), the assembly stand 60 is installed so that the mounting position of the jack 20 is higher than the height of the hanging piece.

[0065] Next, the anchor 25 of the jack 20, which is disposed in a position where the anchor 25 can be engaged with the hanging piece provided on the wall surface 3 and is attached to the upper platform 63, is engaged with the hanging piece. As a result, when the cutting portion 3r is cut in the cutting step described below, the cutting portion 3r will not fall because it is connected to the jack 20.

[0066] [2.2.4. Cutting Process (Step S74)] In this step, the wall surface 3 is cut by a cutting machine at cutting portions 3r including the upper end portion of the wall surface 3 and the hanging piece. In this embodiment, the wall surface 3 is cut so that there are four cutting portions 3r.

[0067] [2.2.5. Lowering process (step S75)] In this step, the cut portions 3r cut in the cutting step (step S74) are lowered by the jack 20 equipped with anchors 25 engaged with the hanging pieces included in the cut portions 3r. In this embodiment, four cut portions 3r are lowered.

[0068] [2.2.6. Judgment step (step S76)] In this step, it is determined whether the outer cylinder 3 can be dismantled by heavy machinery J on the ground. That is, it is determined whether the height of the outer cylinder 3 at that time is a height (for example, about 20 m) that can be dismantled by heavy machinery J on the ground. At this time, if it can be dismantled by heavy machinery J on the ground (step S76: YES), the process proceeds to step S77. On the other hand, if it cannot be dismantled by heavy machinery J on the ground (step S76: NO), the process proceeds to step S71. That is, steps S71 to S75 are repeated until the height of the outer cylinder 3 reaches a height that can be dismantled by heavy machinery J on the ground, and the outer cylinder 3 is cut from the upper end.

[0069] [2.2.7. Repeat process]

[0070] When steps S71 to S75 are repeated multiple times, in the second and subsequent bracket installation steps (step S71), multiple new brackets 52 are installed horizontally at positions lower than the positions of the brackets 52 installed in the previous bracket installation step, and the assembled platform installation step (step S72) is performed using the installed brackets 52. In other words, a new assembled platform 60 is installed so that the lower platform 61 of the new assembled platform 60 is placed on the newly installed brackets 52.

[0071] [2.2.8. Remaining Processing Step (Step S77)] In this step, the remaining portion of the outer cylinder 3 is dismantled by heavy machinery J on the ground (see FIG. 13). After this step is completed, the outer cylinder 3 is dismantled (see FIG. 14), and the method for dismantling the outer cylinder 3 is completed.

[0072] As described above, the second dismantling method of the outer cylinder 3 of this embodiment is a method of dismantling the outer cylinder 3 (an example of an "upright hollow columnar structure") by cutting and dismantling the wall surface of the outer cylinder 3 one portion at a time from the upper end using an assembly platform 60 including a lower platform 61 placed on brackets 52 provided on the outer wall surface of the outer cylinder 3 and an upper platform 63 supported by struts 62 provided on the lower platform 61 and provided above the lower platform 61, and a jack 20 (an example of a "lifting machine") equipped with wire W and anchors 25 (an example of a "hanging part") provided on the wire W and attached to the upper platform 63, the method including a bracket installation step of installing a plurality of brackets 52 horizontally on the outer wall surface of the outer cylinder 3, and a bracket installation step of installing the lower platform 61 on the plurality of brackets 52 installed in the bracket installation step. a locking step of locking anchors 25 of jacks 20 attached to upper racks 63 to hanging pieces (an example of a "hanging portion") provided on the wall surface; a cutting step of cutting cut portion 3r (an example of a "portion of the wall surface") so as to include the upper end of the wall surface and the hanging pieces; and a lowering step of lowering cut portion 3r cut in the cutting step by jacks 20 equipped with anchors 25 locked to hanging pieces included in cut portion 3r. These steps are repeated multiple times in this order, and when repeated multiple times, in the second and subsequent bracket installation steps, multiple brackets 52 are newly installed horizontally in a position lower than the position of the brackets 52 installed in the previous bracket installation step, and the installed brackets 52 are used to perform the assembly rack installation step.

[0073] Therefore, according to the second dismantling method of the outer tube 3 of this embodiment, when the outer tube 3 is dismantled by cutting it part by part from the upper end of its wall, a bracket 52 is provided on the outer wall surface of the outer tube 3, an assembly stand 60 with a jack 20 attached is placed on the bracket 52, and the cut portion 3r at the upper end of the wall is supported by the jack 20, and the cut portion 3r is repeatedly cut and lowered to be dismantled, thereby eliminating the need to install heavy machinery at a high place or to use tall heavy machinery that can reach high places.

[0074] [2.3. Specific example of the second method for dismantling the outer tube 3] As described above, in the second disassembly method, the assembly stand 60 is placed on the brackets 52, the cutting is performed while the cutting portion 3r is engaged with the jack 20 attached to the upper stand 63, and the cut portion 3r is lowered. These steps are repeated, and at this time, the brackets 52 and the assembly stand 60 are lowered in their installation positions as the upper end of the outer cylinder 3 is repeatedly cut and the height of the outer cylinder 3 decreases. Below, specific examples of the process of lowering the installation positions of the brackets 52 and the assembly stand 60 will be described as specific example 1 and specific example 2.

[0075] [2.3.1. Example 1] In the second or subsequent assembly platform installation process (step S72) performed when steps S71 to S75 are repeated, as shown in FIG. 19, the lower platform 61A of the assembly platform 60A installed in the previous assembly platform installation process is used as the upper platform 63B of a new assembly platform 60B (constructed below the assembly platform 60A), the lower platform 61B of the new assembly platform 60B is newly installed on the multiple brackets 52B newly installed in the bracket installation process (step S71) (see FIG. 19(B)), and pillars 62B of the new assembly platform 60B are provided on the lower platform 61B of the new assembly platform 60B, and the upper platform 63B of the new assembly platform 60B is supported by the pillars 62B of the new assembly platform 60B. In addition, in order to compensate for errors in the mounting position of the newly installed bracket 52B, the length of the support 62B is set so that there is a gap between the upper end of the support 62B and the upper stage base 63B, and a manual hydraulic jack 69 is placed in this gap so that the load of the upper stage base 63B is supported by the lower stage base 61B via the hydraulic jack 69.

[0076] Then, the jack 20 attached to the upper platform 63A of the assembly platform 60A installed in the previous assembly platform installation process is replaced by manual labor or a hoist or the like installed on the scaffolding 11 to the upper platform 63B of the new assembly platform 60B, and the upper platform 63A and support pillar 62A of the assembly platform 60A installed in the previous assembly platform installation process are removed.

[0077] In this way, in specific example 1, a new bracket 52B is set at a position lower than the previous bracket 52A, and the installation positions of the bracket 52 and the assembly stand 60 are lowered by repeating the process of rearranging the new assembly stand 60B so that the lower stand 61A of the previous assembly stand 60A becomes the upper stand 63B of the new assembly stand 60B.

[0078] As described above, in the specific example 1 of the second disassembly method for the outer cylinder 3 of this embodiment, in the second and subsequent assembly frame installation steps performed when steps S71 to S75 are repeated multiple times, the lower frame 61A installed in the previous assembly frame installation step is used as the upper frame 63B of the new assembly frame 60B, and the lower frame 61B of the new assembly frame 60B is newly installed on the multiple brackets 52B newly installed in the bracket installation step, and the new assembly frame 60B is installed. A support column 62B of a new assembly platform 60B is provided on the lower platform 61B of platform 60B, and an upper platform 63B of the new assembly platform 60B is supported by the support column 62B of the new assembly platform 60B. The jack 20 attached to the upper platform 63A of the assembly platform 60A installed in the previous assembly platform installation process is replaced with the upper platform 63B of the new assembly platform 60B, and the upper platform 63A and support column 62A of the assembly platform 60A installed in the previous assembly platform installation process are removed.

[0079] Therefore, according to specific example 1 of the second dismantling method for the outer tube 3 of this embodiment, as the upper end of the outer tube 3 is repeatedly cut to reduce the height of the outer tube 3, the brackets 52 are attached to progressively lower positions, and when the assembly stand 60 is reinstalled to progressively lower positions, the previous lower stand 61A is reused as the new upper stand 61B, thereby reducing the time required to install the new assembly stand 60B.

[0080] [2.3.2. Example 2] In Example 2, as shown in FIG. 20 , telescopic columns 72 are used instead of the columns 62. The telescopic columns 72 may have, for example, a maximum total length of 4.8 m, a minimum total length of 4.8 m, a stroke of 3 m, and a load capacity of 600 kg per column. First, as shown in FIG. 20(A), multiple brackets 52P are arranged horizontally, and then multiple brackets 52Q are arranged horizontally below them. Furthermore, multiple brackets 52R are arranged horizontally below them. The height positions of the brackets 52P, 52Q, and 52R are set according to the height of the cut portion 3s. For example, bracket 52P is arranged below the cut portion 3s, including the upper end of the wall surface 3.

[0081] The lower stage 61 of the assembly stage 60 is placed on a plurality of brackets 52Q. The telescopic support 72 adjusts the degree of telescoping so that the upper stage 63 is at a position (for example, higher than the upper end of the wall surface 3) where the cut portion 3s can be lifted and supported by the jack 20 attached to the upper stage 63. The arrangement of the lower beams 61a of the lower stage 61 and the upper beams 63a of the upper stage 63 is as shown in Figures 20(B) and (C).

[0082] Then, as shown in FIG. 21, after the hanging piece and the anchor 25 are engaged (step S73), the wall surface 3 is cut by a cutting machine at a cutting portion 3s including the upper end of the wall surface 3 and the hanging piece (step S74), and the cutting portion 3s is lowered (step S75).

[0083] Next, as shown in FIG. 22, the telescopic support 72 is retracted (for example, to 3 m), and the upper stage 63 is placed on the bracket 52P, and the upper stage 63 supports the weight of the assembly stage 60.

[0084] Next, as shown in FIG. 23, after removing the bracket 52Q, the telescopic support 72 is extended (for example, to 3 m), and the lower stage 61 is placed on the bracket 52R, and the lower stage 61 supports the weight of the assembly stage 60.

[0085] Next, as shown in Fig. 24, bracket 52P is removed and bracket 52Q is attached in its previous position. This returns the assembly to the state shown in Fig. 20, and by repeating this process, assembly platform 60 moves downward on wall surface 3 like an inchworm.

[0086] That is, in specific example 2, in the second and subsequent assembly platform installation processes that are performed when steps S71 to S75 are repeated multiple times, the telescopic support 72 is extended and retracted, and the assembly platform 60 is moved downward while the load is alternately transferred between the upper platform 63 and the lower platform 61 using brackets that are installed in multiple stages.

[0087] As described above, in specific example 2 of the second disassembly method for the outer tube 3 of this embodiment, the support is an extendable support 72 (an example of an "extendable support"), and in the second or subsequent assembly platform installation process performed when steps S71 to S75 are repeated multiple times, the extendable support 72 is extended and the lower platform 61 is placed on the multiple brackets 52R newly installed in the bracket installation process, and then the extendable support 72 is retracted and the upper platform 63 is lowered.

[0088] Therefore, according to specific example 2 of the second dismantling method for the outer tube 3 of this embodiment, as the upper end of the outer tube 3 is repeatedly cut to lower the height of the outer tube 3, the brackets 52 are attached to progressively lower positions, and when the assembly stand 60 is reinstalled to progressively lower positions, the lower stand 61 and the upper stand 63 are lowered sequentially using the telescopic support 72, thereby shortening the time required to lower the position of the assembly stand 60, and also, since there is no need to create a separate assembly stand, the number of beams used for the assembly stand 60 can be minimized.

[0089] [3. Jack 20 Configuration and Operation]

[0090] The configuration and operation of the jack 20 will be outlined using Figure 25. The jack 20 has a first grip 22 and a second grip 23 that hold a wire W having an anchor 25 attached to its tip, and a hydraulic jack 21 that pushes the first grip 22 upward. The hydraulic jack 21 has a cylinder 21a and a piston 21b. The jack 20 is controlled by a control device (not shown).

[0091] The control device controls the first grip 22 and the second grip 23 to either a gripping state (referred to as a "closed state") or a non-gripping state (referred to as an "open state") regarding the gripping state of the wire W.

[0092] Next, a procedure will be described when the jack 20 pulls the wire W upward. First, as shown in Figure 25(A), in the initial state, the first grip 22 and the second grip 23 are controlled to be in a closed state. At this time, the load of the wire W is applied to the second grip 23.

[0093] 25(B), the control device opens the second grip 23. As a result, the load of the wire W is applied to the first grip 22.

[0094] 25(C), the control device jacks up the hydraulic jack 21 (extends the piston 21b from the cylinder 21a), thereby pulling the wire W upward by the amount of extension of the piston 21b from the cylinder 21a.

[0095] Next, in order to jack down the hydraulic jack 21, the control device closes the second grip 23 as shown in Fig. 25(D) and then opens the first grip 22 as shown in Fig. 25(E). This causes a transition from a state in which the load of the wire W is applied to the first grip 22 to a state in which the load of the wire W is applied to the second grip 23.

[0096] Next, the control device jacks down the hydraulic jack 21 as shown in FIG. 25(F).

[0097] Next, the control device closes the first grip 22 as shown in Fig. 25(G), which places the jack 20 in the same state as shown in Fig. 25(A) (however, the positions at which the first grip 22 and the second grip 23 grip the wire W are different).

[0098] Thereafter, by repeating the steps of FIGS. 25(A) to 25(G), the wire W can be continuously pulled up. [Explanation of symbols]

[0099] 1: Chimney 2: Inner cylinder 2a: Discharge section 2b: Induction part 3: Outer cylinder (wall) 3a:Aperture 3n: Cutting part 3p: Cutting part 3q: Cutting part 3r: Cutting part 3s: Cutting part 4: Basics 10: Mast 11: Scaffolding 17: Load-bearing beam 18: Jack fixed beam 20: Jack-type lifting machine (jack) 21: Hydraulic jack 21a: Cylinder 21b: Piston 22: First grip 23: Second grip 25: Anchor 31: Load-bearing beam 33: Fixed beam 51: Mounting bracket 52: Bracket 52A: Bracket 52B: Bracket 52C: Bracket 52P: Bracket 52Q: Bracket 52R: Bracket 52a:Horizontal part 52b: Support part 53: Bolt 60: Assembly stand 60A: Assembly stand 60B: Assembly stand 61: Stand 61A: Mounting stand 61B: Stand 61a: Lower beam 62: Strut 62A: Strut 62B: Post 63: Stand 63A: Mounting stand 63B: Stand 63a: Upper beam 69: Hydraulic jack 72: Telescopic column J: Heavy equipment W: Wire

Claims

[Claim 1] A method for dismantling a columnar structure, comprising the steps of: cutting an upright hollow columnar structure part by part from the upper end of its wall surface using a lifting machine having a wire and a lifting part attached to the wire; a first erection step of erecting a load-bearing beam on the wall surface corresponding to the first region when the wall surface of the columnar structure in a plan view is divided into a first region and a second region such that the first region and the second region are alternately arranged; a first installation step of installing a fixed beam to which the lifting machine is fixed on the load-receiving beam so that the lifting machine is disposed at a first position where the lifting part can be engaged with a suspended part provided on a wall surface of the second area; a first fixing step of fixing the lifting machine to the fixed beam and disposing the lifting machine at the first position; a first locking step of locking the lifting part of the lifting machine fixed at the first position to the suspended part provided on the wall surface of the second area; a first cutting step of cutting a portion of the wall surface so as to include an upper end portion of the wall surface of the second region and the suspended portion; a first lowering step of lowering the portion of the wall surface of the second region cut in the first cutting step by the lifting machine having the lifting part engaged with the suspended part included in the portion of the wall surface; a first removal step of removing the fixed beam from the load-receiving beam; a first removal step of removing the load-bearing beam from the wall surface corresponding to the first region; a second erection step of erecting a load-bearing beam on the wall surface corresponding to the second region; a second installation step of installing a fixed beam to which the lifting machine is fixed on the load-receiving beam so that the lifting machine is disposed at a second position where the lifting part can be engaged with a suspended part provided on the wall surface of the first area; a second fixing step of fixing the lifting machine to the fixed beam and disposing the lifting machine at the second position; a second locking step of locking the lifting portion of the lifting machine fixed at the second position to the suspended portion provided on the wall surface of the first area; a second cutting step of cutting a portion of the wall surface so as to include an upper end portion of the wall surface of the first region and the suspended portion; a second lowering step of lowering the portion of the wall surface of the first region cut in the second cutting step by the lifting machine having the lifting part engaged with the suspended part included in the portion of the wall surface; a second removal step of removing the fixed beam from the load-receiving beam; a second removal step of removing the load-bearing beam from the wall surface corresponding to the second region; Including, A method for dismantling a columnar structure, characterized by alternately repeating a first group of steps consisting of the first erection step, the first installation step, the first fixing step, the first locking step, the first cutting step, the first lowering step, the first detachment step, and the first removal step, and a second group of steps consisting of the second erection step, the second installation step, the second fixing step, the second locking step, the second cutting step, the second lowering step, the second detachment step, and the second removal step.

Images