EP4636199A1

EP4636199A1 - Method for dismantling construction structure

Info

Publication number: EP4636199A1
Application number: EP23918416.1A
Authority: EP
Inventors: Masayuki Kanemasu; Akihito Suzuki; Takehiko Hirata; Yukio Takeuchi; Makoto Nishigaki; Shuho Tsubota
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2023-01-27
Filing date: 2023-01-27
Publication date: 2025-10-22
Also published as: EP4636199A4; JPWO2024157454A1; WO2024157454A1

Abstract

This method for dismantling a construction structure that has a columnar support object extending from a reference surface and has an upper structure provided to an upper part of the columnar support object comprises: a step for laying a cable between the upper structure and the reference surface; a step for lowering a component generated by dismantling the upper structure along the cable to the reference surface; and a step for collapsing the columnar support object from the end on the reference surface side. In the step for lowering the component to the reference surface, the lowering speed is controlled by a braking mechanism.

Description

Technical Field

The present disclosure relates to a method for dismantling a construction structure.

Background Art

For example, as a technique for dismantling a construction structure such as a chimney, a technique described in PTL 1 below is known. In the technique according to PTL 1 below, the wire is unwound in a state where a pair of long arms is aligned on the side of the chimney, so that the chimney can be collapsed while the load of the chimney is borne by the arms.

Citation List

Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No. 2000-213183

Summary of Invention

Technical Problem

However, in the above-described technique, since the long arm needs to be additionally provided, an increase in the cost of the dismantling work and a prolongation of the construction period are problems. Further, since the collapsing speed when the construction structure is collapsed only by unwinding of the wire is controlled, there is also a problem in that the collapsing speed becomes excessive.
The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide a method for dismantling a construction structure allowing dismantling work to proceed more inexpensively and easily. Solution to Problem
In order to solve the above problems, a method for dismantling a construction structure according to the present disclosure is a method for dismantling a construction structure that has a columnar support object extending from a reference surface and has an upper structure provided to an upper part of the columnar support object according to the present disclosure, the method includes a step of laying a cable between the upper structure and the reference surface, a step of lowering a component generated by dismantling the upper structure to the reference surface in a state where the component is suspended on the cable, and a step of collapsing the columnar support object from an end part on a reference surface side, in which in the step of lowering the component to the reference surface, a lowering speed is controlled by a braking mechanism.
A method for dismantling a construction structure according to the present disclosure is a method for dismantling a construction structure having a columnar support object extending from a reference surface and an upper structure provided to an upper part of the columnar support object, the method including a step of attaching a thrust device that generates a thrust toward the reference surface to the construction structure, and a step of collapsing the construction structure from an end part on a reference surface side while controlling a collapsing speed by using the thrust of the thrust device.
A method for dismantling a construction structure according to the present disclosure is a method for dismantling a construction structure having a columnar support object extending from a reference surface and an upper structure provided to an upper part of the columnar support object, the method including a step of preventing scattering of sludge by generating a water flow flowing around the columnar support object in water, the reference surface being a seabed, a lakebed, or a riverbed, and a step of collapsing the construction structure while the water flow is generated.

Advantageous Effects of Invention

According to the present disclosure, it is possible to provide a method for dismantling a construction structure allowing the dismantling work to proceed more inexpensively and easily.

Brief Description of Drawings

Fig. 1 is a schematic view showing an example of a construction structure according to a first embodiment of the present disclosure.
Fig. 2 is a flowchart showing each step of a method for dismantling a construction structure according to the first embodiment of the present disclosure.
Fig. 3 is an explanatory view showing a state during dismantling in the method for dismantling a construction structure according to the first embodiment of the present disclosure.
Fig. 4 is an explanatory view showing a step of collapsing a columnar support object in the method for dismantling a construction structure according to the first embodiment of the present disclosure.
Fig. 5 is a view showing a modification example of the cable used in the method for dismantling a construction structure according to the first embodiment of the present disclosure.
Fig. 6 is a flowchart showing each step of a method for dismantling a construction structure according to a second embodiment of the present disclosure.
Fig. 7 is an explanatory view showing a state during dismantling in the method for dismantling a construction structure according to the second embodiment of the present disclosure.
Fig. 8 is a view showing a state where the method for dismantling a construction structure according to the second embodiment of the present disclosure is applied to a wind turbine, and is a view showing a step of dismantling the upper structure.
Fig. 9 is a flowchart showing each step of a method for dismantling a construction structure according to a third embodiment of the present disclosure.
Fig. 10 is an explanatory view showing a state during dismantling in the method for dismantling a construction structure according to the third embodiment of the present disclosure.

Description of Embodiments

Hereinafter, a method for dismantling a construction structure 1 according to a first embodiment of the present disclosure will be described with reference to Figs. 1 to 4.

(Configuration of Construction Structure)

As shown in Fig. 1, a construction structure 1 according to the present embodiment is a structure having a shape of a tower extending from a water bottom (reference surface 2) of the ocean, a lake, or a river to the water. More specifically, examples thereof include an offshore lighthouse, an oil field drilling rig, and the like. In the following description, the construction structure 1 will be described as including a columnar support object 11 and an upper structure 12 in a schematic manner. The columnar support object 11 is fixed to the water bottom and has a columnar shape extending in the up-down direction from the water bottom to the water surface. The upper structure 12 is provided at an upper end part of the columnar support object 11. That is, the columnar support object 11 is provided to support the weight of the upper structure 12.

(Method for Dismantling Construction Structure 1)

Next, a method for dismantling the construction structure 1 will be described with reference to Figs. 2 to 4. As shown in Fig. 2, the method for dismantling includes step S1 of generating a water flow F, step S2 of laying the cable 3, step S3 of dismantling the upper structure 12, step S4 of attaching a flying object 51 to a component 13 generated by the dismantling, step S5 of lowering the component 13 along the cable 3, step S6 of collapsing the columnar support object 11, and step S7 of stopping the water flow F.
As shown in Fig. 3, in step S1, a water flow F flowing around the columnar support object 11 is generated by the water flow generation device 4 installed in the water. This is to prevent sludge or the like on the water bottom from being scattered, or chips from being dispersed, when the columnar support object 11 is collapsed in a subsequent step S6 or the columnar support object 11 is processed by cutting or machining. Specifically, a large pump, a water flow F fan, or the like is considered as the water flow generation device 4. In addition, devices that locally promote convection with a heater to generate a water flow, devices that generate a water flow with a magnetic force, and the like can be given as examples. In addition, in order to restrict the flowing direction of the water flow F, it is also possible to install, for example, a plate-shaped member to sandwich the columnar support object 11. It is also possible to adopt a method of preventing the sludge from being scattered by laying a dust-proof net or the like on the water bottom by omitting step S1.
In step S2, the cable 3 is laid between the upper structure 12 and the ground or a work ship. A metal wire is preferable as the cable 3. The cable 3 is laid obliquely with respect to the horizontal direction such that the height of the cable 3 gradually decreases from the upper structure 12 toward the ground or a work ship. As long as the environmental conditions permit, the gentler the inclination angle of the cable 3, the more preferable it is.
Next, in step S3, the upper structure 12 is dismantled for each component 13. Subsequently, in step S4, the flying object 51 as the braking mechanism 5 is attached to the component 13. The flying object 51 is a drone or a multicopter capable of flying without a pilot, and can hover or move in the air in a state where the component 13 is suspended on the airframe. In this state, the component 13 is placed on the cable 3. That is, the weight of the component 13 is borne by the support from below by the cable 3 and the support from above by the flying object 51. It is not always necessary to attach the flying object 51 to the component 13, and self-weight of the flying object 51 may be used. In this case, an example is considered in which the inclination of the cable 3 is controlled to control the falling speed of the component 13.
Thereafter, in step S5, the component 13 is caused to slide on the cable 3 and is lowered toward the ground or the work ship while the flying object 51 moves along the cable 3. In this case, the moving speed of the flying object 51 is controlled such that the effective speed becomes constant or is a predetermined reference speed or less. That is, the flying object 51 serves as a brake when the component 13 is lowered. Steps S3 to S5 are sequentially repeated for each of all the components 13 configuring the upper structure 12. As described above, the upper structure 12 is dismantled, and only the columnar support object 11 remains.
Subsequently, in step S6, as shown in Fig. 4, the columnar support object 11 is cut in the vicinity of the end part on the water bottom side and is caused to collapse under self-weight. In addition, it is also possible to adopt a method of controlling the collapsing speed by using a thrust device operated by a flying object 51 such as a drone or by water pressure in addition to the self-weight of the columnar support object 11. In this case, the water flow F generated in step S1 suppresses the scattering of the sludge or the dust on the water bottom. In addition, step S1 can also be executed immediately before step S6. Finally, the water flow generation device 4 is stopped in step S7 to stop the water flow F. As described above, all steps of the method for dismantling the construction structure 1 are completed.

(Effects of Action)

Here, in the method for dismantling according to the related art, it was common to dismantle the construction structure 1 by using lifting equipment such as a crane. Therefore, an increase in work cost and a prolongation of a construction period were problems. In addition, it was common to pull the columnar support object 11 with a large number of wires or the like while performing work when the columnar support object 11 was to collapse. For this reason, it was difficult to control the collapsing speed, and the efficiency and safety of work were impaired. In addition, when the columnar support object 11 was collapsed in the water, sludge or the like on the water bottom was stirred up, causing an environmental load, which was also one of the problems. Therefore, in the present embodiment, each of the above-described methods is adopted.
According to the above method, the dismantling work can be carried out simply by using the cable 3 and the braking mechanism 5 without using expensive lifting equipment such as a crane. In this manner, it is possible to reduce the cost and time for transporting the lifting equipment to the work site and the personnel cost of the operator, and the like. Therefore, it is possible to realize reduction of the work cost and shortening of the construction period. Further, since the component 13 is lowered while the lowering speed is controlled by the braking mechanism 5, the lowering speed can be arbitrarily adjusted. For example, when the large and heavy component 13 is lowered, it is possible to lower the large and heavy component 13 at a lower speed in order to ensure safety. On the contrary, when the small and lightweight component 13 is lowered, it is possible to lower the small and lightweight component 13 at a higher speed with emphasis on work efficiency. In this way, according to the above method, it is possible to significantly improve the efficiency of work.
Further, according to the above method, since the flying object 51 that can freely move in the air is used as the braking mechanism 5, the lowering speed of the component 13 can be more precisely and freely controlled. In addition, since the flying object 51 can also hover in the air, the lowering of the component 13 can be freely stopped and restarted. In this manner, it is possible to make the safety during the lowering work more reliable. In addition, it is also possible to transport the component 13 from the ground to the air.
Further, according to the above method, when the columnar support object 11 is collapsed in the water, the water flow F is generated in advance in the water, so that it is possible to prevent the sludge or the like on the water bottom from being stirred up. In addition, the dust and debris generated due to the collapse can be accumulated at any location by the water flow F. Accordingly, since the work range is limited when the dust is recovered later, it is possible to achieve both improvement in work efficiency and cost reduction. In this manner, according to the above method, it is possible to smoothly proceed with the dismantling work while minimizing the environmental load.
The first embodiment of the present disclosure has been described above. Various changes or improvements can be made to the above method without departing from the concept of the present disclosure. For example, in the first embodiment, an example in which the component 13 is lowered along a single cable 3 has been described. However, as shown in Fig. 5 as a modification example, it is also possible to lay the cable 3 in duplicate. Accordingly, the weight of the component 13 can be more stably borne by the cable 3, and thus the efficiency and safety of the work can be further improved. In addition, provided that conditions such as cost permit, it is also possible to lay the cable 3 in triplicate. Furthermore, it is also possible to install a plurality of the cables 3 in a plurality of directions from the upper structure 12. In this manner, it is possible to proceed with the dismantling work more efficiently. In addition, a thrust device that generates thrust toward the reference surface 2 side can also be used instead of the flying object 51 as the braking mechanism 5. Examples of the thrust device referred to here include a device that pumps up water from underwater and jets the water toward the reference surface 2 side, or the like. The component 13 is lowered while being supported from below by the thrust, so that the lowering speed can be freely controlled. In addition, since water around the work site is used as the medium to be jetted, it is also possible to realize reductions in cost and environmental load. In addition, a movable pulley can also be used as the braking mechanism 5.

Next, a second embodiment of the present disclosure will be described with reference to Figs. 6 to 8. The same configurations as those of the first embodiment will be assigned with the same reference numerals, and detailed description thereof will be omitted. In addition, in the present embodiment, unlike the first embodiment, the construction structure 1 on the ground will be described as an example. Specifically, as the construction structure 1 on the ground, a building, a house having a tower shape, a chimney, a steel tower, or the like can be given as an example. In any case, it is assumed that the upper structure 12 and the columnar support object 11 are schematically configured to form the construction structure 1.
As shown in Fig. 6, the method for dismantling the construction structure 1 according to the present embodiment includes step S21 of attaching the thrust device 52 to the upper end of the columnar support object 11, step S22 of laying the cable 3 between the upper structure 12 and the ground or the like, step S23 of dismantling the upper structure 12 for each component 13, step S24 of attaching the flying object 51 to the component 13, step S25 of lowering the component 13, step S26 of driving the thrust device 52, and step S27 of collapsing the columnar support object 11.
In step S21, as shown in Fig. 7, the thrust device 52 is attached to the upper end or the side surface of the columnar support object 11. As the thrust device 52, for example, a device that pumps up water and jets the water toward the reference surface 2 side, a small jet engine, or the like can be considered. Further, it is desirable that the thrust device 52 has a nozzle capable of freely changing the thrust direction in a range of 360°. Step S21 may be executed immediately before step S26, which will be described later.
In step S22, as in the first embodiment, the cable 3 is laid between the upper structure 12 and the ground. A metal wire is preferable as the cable 3. The cable 3 is laid obliquely with respect to the horizontal direction such that the height of the cable 3 gradually decreases from the upper structure 12 toward the ground. As long as the environmental conditions permit, the gentler the inclination angle of the cable 3, the more preferable it is.
Next, in step S23, the upper structure 12 is dismantled for each component 13. Subsequently, in step S24, the flying object 51 as the braking mechanism 5 is attached to the component 13. The flying object 51 is a drone or a multicopter capable of flying without a pilot, and can hover or move in the air in a state where the component 13 is suspended on the airframe. In this state, the component 13 is placed on the cable 3. That is, the weight of the component 13 is borne by the support from below by the cable 3 and the support from above by the flying object 51.
Thereafter, in step S25, the component 13 is caused to slide on the cable 3 and is lowered toward the ground while the flying object 51 moves along the cable 3. In this case, the moving speed of the flying object 51 is controlled such that the effective speed becomes constant or is a predetermined reference speed or less. That is, the flying object 51 serves as a brake when the component 13 is lowered. Steps S23 to S25 are sequentially repeated for all the components 13 constituting the upper structure 12. As described above, the upper structure 12 is dismantled, and only the columnar support object 11 remains.
Thereafter, in step S26, the above-described thrust device 52 is driven to generate thrust toward the reference surface 2 side. In subsequent step S27, as shown in Fig. 7, the columnar support object 11 is cut in the vicinity of the end part on the water bottom side and is caused to collapse under self-weight. In this case, the weight of the columnar support object 11 is supported from below by the thrust generated by the thrust device 52.

(Effects of Action)

According to the above method, when the columnar support object 11 is collapsed, the columnar support object 11 can be collapsed while the weight of the columnar support object 11 is borne on the reference surface 2 side by the thrust generated by the thrust device 52. In this manner, it is possible to precisely control the collapsing speed or direction of the columnar support object 11. On the contrary, it is also possible to set the thrust direction of the thrust device 52 to a direction opposite to the collapsing direction. In this case, the collapsing speed can be further increased, and the work can be completed more quickly. In addition, after a cut is made in the columnar support object 11 and the operator is moved away, it is also possible to start the collapse by the thrust of the thrust device 52. Therefore, the safety of the operator can be more reliably ensured.
Further, according to the above method, the dismantling work can be carried out simply by using the cable 3 and the braking mechanism 5 without using expensive lifting equipment such as a crane. In this manner, it is possible to reduce the cost and time for transporting the lifting equipment to the work site and the personnel cost of the operator, and the like. Therefore, it is possible to realize reduction of the work cost and shortening of the construction period. Further, since the component 13 is lowered while the lowering speed is controlled by the braking mechanism 5, the lowering speed can be arbitrarily adjusted. For example, when the large and heavy component 13 is lowered, it is possible to lower the large and heavy component 13 at a lower speed in order to ensure safety. On the contrary, when the small and lightweight component 13 is lowered, it is possible to lower the small and lightweight component 13 at a higher speed with emphasis on work efficiency. In this way, according to the above method, it is possible to significantly improve the efficiency of work.
Further, according to the above method, since the flying object 51 that can freely move in the air is used as the braking mechanism 5, the lowering speed of the component 13 can be more precisely and freely controlled. In addition, since the flying object 51 can also hover in the air, the lowering of the component 13 can be freely stopped and restarted. In this manner, it is possible to make the safety during the lowering work more reliable.
The second embodiment of the present disclosure has been described above. Various changes or improvements can be made to the above method without departing from the concept of the present disclosure. For example, as shown in Fig. 8, the above-described method for dismantling can also be applied to a wind turbine 60. As an example, the wind turbine 60 includes a columnar support object 11, a nacelle 61, and a propeller 62. The nacelle 61 and the propeller 62 constitute the upper structure 12. By sequentially dismantling the nacelle 61 and the propeller 62, and finally collapsing the columnar support object 11, the same actions and effects as those described above can be obtained.

Subsequently, a third embodiment of the present disclosure will be described with reference to Figs. 9 and 10. The same configurations as those of each of the embodiments described above will be assigned with the same reference signs, and detailed description thereof will be omitted.
In the present embodiment, as shown in Fig. 10, a wind turbine 60 (an offshore wind turbine as an example) installed on the water is targeted for the dismantling work. The wind turbine 60 includes a columnar support object 11, a nacelle 61, and a propeller 62. The nacelle 61 and the propeller 62 constitute the upper structure 12. The nacelle 61 is internally provided with devices such as a generator and a lubrication device connected to a shaft of the propeller 62. The lower end of the columnar support object 11 is fixed to the water bottom.
As shown in Fig. 9, the method for dismantling according to the present embodiment includes step S31 of generating a water flow F in the water, step S32 of attaching the thrust device 52 to the upper structure 12, step S33 of driving the thrust device 52, step S34 of cutting the columnar support object 11, and step S35 of collapsing the columnar support object 11.
In step S31, a water flow F flowing around the columnar support object 11 is generated by the water flow generation device 4 installed in the water. This is to prevent sludge or the like on the water bottom from scattering when the columnar support object 11 is collapsed in the subsequent Step S35. Specifically, a large pump, a water flow F fan, or the like is considered as the water flow generation device 4. In addition, in order to restrict the flowing direction of the water flow F, it is also possible to install a plate-shaped member to sandwich the columnar support object 11.
In step S32, as an example, the thrust device 52 is mounted on the rear side of the nacelle 61 (that is, the side opposite to the propeller 62). As the thrust device 52, for example, a device that pumps up water and jets the water toward the reference surface 2 side, a small jet engine, or the like can be considered. Further, it is desirable that the thrust device 52 has a nozzle capable of freely changing the thrust direction in a range of 360°.
In step S33, the thrust device 52 is driven to generate thrust toward the reference surface 2 (water bottom) side. In subsequent step S34, the columnar support object 11 is cut in the vicinity of the end part on the water bottom side, and the entire wind turbine 60 (construction structure 1) is caused to collapse under self-weight (step S35). In this case, the weight of the construction structure 1 is supported from below by the thrust generated by the thrust device 52. That is, the collapsing speed is controlled by the magnitude of the thrust. Finally, the water flow F is stopped in step S36. As described above, the dismantling of the construction structure 1 is completed.

(Effects of Action)

Here, in the method for dismantling according to the related art, it was common to dismantle the construction structure 1 by using lifting equipment such as a crane. Therefore, an increase in work cost and a prolongation of a construction period were problems. In addition, it was common to pull the columnar support object 11 with a large number of wires or the like while performing work when the columnar support object 11 was to collapse. For this reason, it was difficult to control the collapsing speed, and the efficiency and safety of work were impaired. In addition, when the columnar support object 11 was collapsed in the water, sludge or the like on the water bottom was stirred up, causing an environmental load, which was also one of the problems. In particular, since a large amount of lubricant flows inside the nacelle 61 of the wind turbine 60, there was a concern that the lubricant may leak into the water when the nacelle 61 is submerged in the water. In addition, although the lubricant is removed before the work, there was a concern that a certain amount of grease that cannot be completely removed may be present. Therefore, in the present embodiment, each of the above-described methods is adopted.
According to the above method, when the construction structure 1 is collapsed, the construction structure 1 can be collapsed while the weight of the construction structure 1 is borne on the reference surface 2 side by the thrust generated by the thrust device 52. In this manner, it is possible to precisely control the collapsing speed of the construction structure 1. On the contrary, it is also possible to set the thrust direction of the thrust device 52 to a direction opposite to the collapsing direction. In this case, the collapsing speed can be further increased, and the work can be completed more quickly.
Further, according to the above method, when the construction structure 1 is collapsed in the water, the water flow F is generated in advance in the water, so that it is possible to prevent the sludge or the like on the water bottom from being stirred up. In addition, dust, grease, or the like generated due to the collapse can be accumulated at any location by the water flow F. Accordingly, since the work range is limited when the dust is recovered later, it is possible to achieve both improvement in work efficiency and cost reduction. In this manner, according to the above method, it is possible to smoothly proceed with the dismantling work while minimizing the environmental load.
The third embodiment of the present disclosure has been described above. Various changes or improvements can be made to the above method without departing from the concept of the present disclosure.

The method for dismantling the construction structure 1 described in each embodiment is understood as follows, for example.

(1) A method for dismantling a construction structure 1 according to a first aspect is a method for dismantling a construction structure 1 that has a columnar support object 11 extending from a reference surface 2 and an upper structure 12 provided to an upper part of the columnar support object 11, the method including: a step of laying a cable 3 between the upper structure 12 and the reference surface 2; a step of lowering a component 13 generated by dismantling the upper structure 12 to the reference surface 2 while the component is suspended on the cable 3; and a step of collapsing the columnar support object 11 from an end part on a reference surface 2 side, in which in the step of lowering the component 13 to the reference surface 2, a lowering speed is controlled by a braking mechanism 5.
According to the above method, the dismantling work can be carried out simply by using the cable 3 and the braking mechanism 5 without using lifting equipment such as a crane. In this manner, it is possible to realize reduction of the work cost and shortening of the construction period. Further, since the component 13 is lowered while the lowering speed is controlled by the braking mechanism 5, the lowering speed can be arbitrarily adjusted. In this manner, the efficiency of the work can be further improved.
(2) A method for dismantling a construction structure 1 according to a second aspect is the method for dismantling a construction structure 1 according to (1), in which the braking mechanism 5 is a flying object 51 capable of lifting the component 13.
According to the above method, since the flying object 51 that can freely move in the air is used as the braking mechanism 5, the lowering speed of the component 13 can be more precisely and freely controlled.
(3) A method for dismantling a construction structure 1 according to a third aspect is the method for dismantling a construction structure 1 according to (1), in which the braking mechanism 5 is a thrust device 52 that is provided in the component 13 and that generates thrust toward the reference surface 2 side.
According to the above method, the component 13 can be supported with a relatively large force, by generating thrust on the reference surface 2 side by using the thrust device 52. In this manner, it is possible to further stabilize the lowering speed of the component 13.
(4) A method for dismantling a construction structure 1 according to a fourth aspect is the method for dismantling a construction structure 1 according to any one of (1) to (3), in which in the step of collapsing the columnar support object 11, a thrust device 52 that is provided in the columnar support object 11 and that generates thrust toward the reference surface 2 side is used to control a collapsing speed.
According to the above method, when the columnar support object 11 is collapsed, the columnar support object 11 can be collapsed while the weight of the columnar support object 11 is borne on the reference surface 2 side by the thrust generated by the thrust device 52. In this manner, it is possible to precisely control the collapsing speed of the columnar support object 11.
(5) A method for dismantling a construction structure 1 according to a fifth aspect is the method for dismantling a construction structure 1 according to any one of (1) to (4), in which the reference surface 2 is a seabed, a lakebed, or a riverbed, and in the step of collapsing the columnar support object 11, a water flow F flowing around the columnar support object 11 is generated in water from before to after the columnar support object 11 is collapsed to prevent scattering of sludge.
According to the above method, when the columnar support object 11 is collapsed in the water, the water flow F is generated in advance, so that it is possible to prevent the sludge or the like on the water bottom from being stirred up. In addition, the dust and debris generated due to the collapse can be accumulated at any location by the water flow F. In this manner, it is possible to smoothly proceed with the dismantling work while minimizing the environmental load.
(6) A method for dismantling a construction structure 1 according to a sixth aspect is a method for dismantling a construction structure 1 having a columnar support object 11 extending from a reference surface 2 and an upper structure 12 provided to an upper part of the columnar support object 11, the method including a step of attaching a thrust device 52 that generates thrust toward the reference surface 2 to the construction structure 1, and a step of collapsing the construction structure 1 from an end part on a reference surface 2 side while controlling a collapsing speed by using the thrust of the thrust device 52.
According to the above method, when the construction structure 1 is collapsed, the construction structure 1 can be collapsed while the weight of the construction structure 1 is borne on the reference surface 2 side by the thrust generated by the thrust device 52. In this manner, it is possible to precisely control the collapsing speed of the construction structure 1.
(7) A method for dismantling a construction structure 1 according to a seventh aspect is a method for dismantling a construction structure 1 having a columnar support object 11 extending from a reference surface 2 and an upper structure 12 provided to an upper part of the columnar support object 11, the method including: a step of preventing scattering of sludge by generating a water flow F flowing around the columnar support object 11 in water, the reference surface 2 being a seabed, a lakebed, or a riverbed; and a step of collapsing the construction structure 1 while the water flow F is generated.

According to the above method, when the construction structure 1 is collapsed in the water, the water flow F is generated in advance, so that it is possible to prevent the sludge or the like on the water bottom from being stirred up. In addition, the dust and debris generated due to the collapse can be accumulated at any location by the water flow F. In this manner, it is possible to smoothly proceed with the dismantling work while minimizing the environmental load.

Industrial Applicability

According to the method for dismantling a construction structure, it is possible to more inexpensively and easily proceed with dismantling work.

Reference Signs List

1: construction structure
2: reference surface
3: cable
4: water flow generation device
5: braking mechanism
11: columnar support object
12: upper structure
13: component
51: flying object
52: thrust device
60: wind turbine
61: nacelle
62: propeller
F: water flow

Claims

A method for dismantling a construction structure that has a columnar support object extending from a reference surface and an upper structure provided to an upper part of the columnar support object, the method comprising:
a step of laying a cable between the upper structure and the reference surface;

a step of lowering a component generated by dismantling the upper structure to the reference surface while the component is suspended on the cable; and

a step of collapsing the columnar support object from an end part on a reference surface side,

wherein in the step of lowering the component to the reference surface, a lowering speed is controlled by a braking mechanism.
The method for dismantling a construction structure according to Claim 1,
wherein the braking mechanism is a flying object capable of lifting the component.
The method for dismantling a construction structure according to Claim 1,
wherein the braking mechanism is a thrust device that is provided in the component and that generates thrust toward the reference surface side.
The method for dismantling a construction structure according to any one of Claims 1 to 3,
wherein in the step of collapsing the columnar support object, a thrust device that is provided in the columnar support object and that generates thrust toward the reference surface side is used to control a collapsing speed.
The method for dismantling a construction structure according to Claim 1,
wherein the reference surface is a seabed, a lakebed, or a riverbed, and in the step of collapsing the columnar support object, a water flow flowing around the columnar support object is generated in water from before to after the columnar support object is collapsed to prevent scattering of sludge.
A method for dismantling a construction structure having a columnar support object extending from a reference surface and an upper structure provided to an upper part of the columnar support object, the method comprising:
a step of attaching a thrust device that generates thrust toward the reference surface to the construction structure; and

a step of collapsing the construction structure from an end part on a reference surface side while controlling a collapsing speed by using the thrust of the thrust device.
A method for dismantling a construction structure having a columnar support object extending from a reference surface and an upper structure provided to an upper part of the columnar support object, the method comprising:
a step of preventing scattering of sludge by generating a water flow flowing around the columnar support object in water, the reference surface being a seabed, a lakebed, or a riverbed; and

a step of collapsing the construction structure while the water flow is generated.