Method for dismantling a portal structure and method for manufacturing a portal structure

Abstract

Regarding the demolition of a portal structure having a beam section and two leg sections provided at each end of the beam section, the aim is to reduce costs and improve the flexibility of setting the construction period by not using large heavy machinery to raise and lower the portal structure itself. [Solution] First jacks are installed on jack beams provided along the longitudinal direction of the beam at both ends of the beam section, and the wires of each first jack are suspended and connected to the beam section. Then, both ends of the beam section are cut, dividing the portal structure into a first structural section corresponding to the central part of the beam section to which each wire is connected, and two second structural sections consisting of beam end sections and leg sections corresponding to the ends of the beam section. The first structural section is then lowered and dismantled using the first jacks, and the second structural sections are also dismantled.

Description

Technical Field

[0001] The present invention relates to the disassembly and manufacture of a portal structure having a beam portion and leg portions respectively joined to lower portions of both ends of the beam portion.

Background Art

[0002] One example of a portal structure is a goliath crane. A goliath crane is a huge portal crane mainly used in shipyards for ship construction, repair, etc., and has two leg portions called swing legs and rigid legs, and a girder installed between them. Traveling devices are provided at lower ends of the swing legs and the rigid legs, and they travel on rails laid in the shipyard. Also, a lifting device capable of traveling on the girder is provided on the girder, and thereby parts of a ship or the like can be lifted and transported.

[0003] By the way, when disassembling a goliath crane due to its lifespan or the like, a disassembly method different from that of ordinary buildings has been sought due to its large size. Among these, Patent Document 1 discloses a disassembly method for a goliath crane. Specifically, a temporary beam is installed between both legs at an intermediate height position of the swing legs and the rigid legs, then the girder is removed, then the upper part above the temporary beam installation positions of both leg portions is cut off and removed, then the temporary beam is removed from both leg portions and removed, and then the lower parts of the remaining both leg portions are removed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the demolition method described in Patent Document 1, a temporary beam is erected between the swaying leg and the rigid leg at an intermediate height, which increases the number of steps required for the installation and removal of the temporary beam. Furthermore, these steps require large heavy machinery to raise and lower the heavy temporary beam between the intermediate height of the swaying leg and the rigid leg and the ground. However, large heavy machinery is expensive to use and has a limited usage period, resulting in higher demolition costs and reduced flexibility in setting the construction period.

[0006] Another dismantling method involves moving the Goliath crane to the seaward side of the dock and dismantling it using a large crane ship prepared at sea; however, this method also tends to be costly.

[0007] Furthermore, the construction of such massive portal structures is not only difficult to dismantle, but the use of large heavy machinery to lift and lower heavy parts during its manufacture is also costly and limited in duration, resulting in high manufacturing costs and reduced flexibility in setting construction schedules.

[0008] Therefore, the object of this invention is to provide a method for dismantling a portal structure that does not require large heavy machinery to lift and lower ultra-heavy objects such as portal structures, thereby reducing dismantling costs and increasing the flexibility of setting the construction period, and a method for manufacturing a portal structure that does not require large heavy machinery to lift and lower ultra-heavy objects such as portal structures, thereby reducing manufacturing costs and increasing the flexibility of setting the construction period. [Means for solving the problem]

[0009] One embodiment of a method for dismantling a portal structure is a method for dismantling a portal structure having a beam section and two leg sections provided at each end of the beam section, wherein jack beams are provided along the longitudinal direction of the beam section at each end of the beam section, and the first jacks are installed on the jack beams; and the first jack installation step is to install the first jacks on the jack beams; and the first wire connection step is to hang down the wires of each of the first jacks and connect them to the beam section. The invention is characterized by comprising: a beam cutting step, which involves cutting both ends of the beam to divide the portal structure into a first structural section corresponding to the central part of the beam to which each of the wires is connected, and two second structural sections consisting of beam end sections corresponding to the ends of the beam and the leg sections; a first structural section lowering step, which involves lowering the first structural section using the first jack; a first structural section dismantling step, which involves dismantling the first structural section after the first structural section lowering step; and a second structural section dismantling step, which involves dismantling the second structural section.

[0010] One embodiment of a method for manufacturing a portal structure is a method for manufacturing a portal structure which comprises a beam section and two leg sections provided at both ends of the beam section, and involves joining a first structural section corresponding to the central part of the beam section and two second structural sections consisting of beam section ends corresponding to the ends of the beam section and the leg sections, and is characterized by including a first jack installation step of providing jack beams, on which first jacks capable of raising and lowering objects via wires are installed, along the longitudinal direction at each end of the beam section and installing the first jacks on the jack beams; a second structural section assembly step of assembling two second structural sections which include the leg sections to which the beam section ends having the first jacks installed in the first jack installation step are joined at the top; and a beam section joining step of hanging and connecting the wires of each first jack to the first structural section positioned between each of the second structural sections, raising the first structural section with each first jack, and joining the beam section ends of each of the second structural sections to both ends of the first structural section. [Effects of the Invention]

[0011] According to one method for dismantling a portal structure, the beam is cut while supporting the first structural section corresponding to the central part of the beam using first jacks installed at both ends of the beam, thereby dividing the portal structure into a first structural section and a second structural section corresponding to the ends and legs of the beam. After lowering the first structural section with jacks, the first and second structural sections are dismantled separately. This method does not require large heavy machinery to lift and lower extremely heavy objects such as portal structures, thus reducing dismantling costs and increasing flexibility in setting the construction period.

[0012] According to one embodiment of the manufacturing method for a portal structure, two second structural parts, each including a leg with a beam end on which a first jack is installed joined to the top, are assembled. The wires of each first jack are suspended and connected to the first structural part corresponding to the central beam section located between the second structural parts. The first structural parts are then raised using the first jacks, and the beam ends of each second structural part are joined to both ends of the first structural part to manufacture the portal structure. Since this method does not require large heavy machinery to raise and lower the portal structure itself, manufacturing costs can be reduced and the flexibility of setting the construction period can be increased. [Brief explanation of the drawing]

[0013] [Figure 1] (A) is a front view showing an example of the Goliath crane 1 according to this embodiment, (B) is a left side view thereof, (C) is a right side view thereof, and (D) is a top view thereof. [Figure 2] This is a schematic diagram showing the Goliath Crane 1 divided into a first structural section and a second structural section. [Figure 3] This is a front view of the Goliath crane 1 for explaining the frame construction process and other aspects according to this embodiment. [Figure 4] This is a plan view of the Goliath crane 1 for explaining the frame construction process and other aspects according to this embodiment. [Figure 5] (A) and (B) are left side views of the Goliath crane 1 for illustrating the frame construction process and the like according to this embodiment. [Figure 6] (A) and (B) are right side views of the Goliath crane 1 for illustrating the frame construction process and the like according to this embodiment. [Figure 7] (A)-(D) are diagrams showing an example of a cutting line 50A when cutting the gusset part 4 of the Gorilla screen 1 according to this embodiment. [Figure 8] (A) is a front view of the Gorilla screen 1 for explaining the first structure part lowering process and the like according to this embodiment, (B) is a left side view thereof, (C) is a right side view thereof, and (D) is a plan view thereof. [Figure 9] (A) is a front view of the Gorilla screen 1 for explaining the repeating process and the like according to this embodiment, (B) is a left side view thereof, (C) is a right side view thereof, and (D) is a plan view thereof. [Figure 10] (A) is a front view of the Gorilla screen 1 for explaining the pedestal removal process and the like according to this embodiment, (B) is a left side view thereof, (C) is a right side view thereof, and (D) is a plan view thereof. [Figure 11] This is a flowchart showing an example of a disassembly method for the Gorilla screen 1 according to this embodiment. [Figure 12] This is a flowchart showing an example of a manufacturing method for the Gorilla screen 1 according to this embodiment.

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of a disassembly method and a manufacturing method for a portal structure according to the present invention will be described with reference to the drawings. Note that the portal structure is a structure having a beam part and leg parts respectively joined to the lower parts of both ends of the beam part. In addition, in this embodiment, a disassembly method and a manufacturing method for a Gorilla screen 1 which is an example of a portal structure will be described.

[0015] [1. Outline of Gorilla Screen 1] First, the outline of the Gorilla screen 1 will be described using FIGS. 1(A)-(D).

[0016] The Goliath crane 1 has rocking legs 2 and rigid legs 3, and a girder part 4 horizontally installed between the upper ends of the rocking legs 2 and the rigid legs 3. For example, it is a huge portal structure with a height of about 90 meters, a width of about 200 meters, and a total weight of about 6500 tons.

[0017] The rocking legs 2 are joined to the girder part 4 via a joint (not shown) that can slide and rotate with respect to the girder part 4, absorbing the expansion and contraction of the girder part 4 and the deviation of the gauge span (width) of the left and right running rails, etc., to prevent derailment. On the other hand, the rigid legs 3 are rigidly joined to the girder part 4, transmitting the horizontal force acting in the longitudinal direction of the girder part 4 to the running rails to prevent overturning.

[0018] The Goliath crane 1 is arranged such that the rocking legs 2 and the rigid legs 3 straddle the dock of the shipyard, and each traveling device of the rocking legs 2 and the rigid legs 3 uses rails (not shown) laid along the dock to move the Goliath crane 1. Further, on the girder part 4, a trolley 5 is provided as a lifting device capable of traveling on the girder part 4. The trolley 5, for example, lifts the parts P outside the ship S and transports them onto the ship S inside the dock, or vice versa.

[0019] [2. Disassembly method of the Goliath crane 1] Next, referring to FIGS. 2 - FIGS. 11, the disassembly method of the Goliath crane 1 according to the present embodiment will be described. In the present embodiment, as shown in FIG. 2, the Goliath crane 1 is cut along the cutting lines 50A and 50B, and is disassembled by dividing it into a first structural part (the central part of the girder part 4, sometimes referred to as the central part 4A of the girder part, and since the central part 4A of the girder part and the first structural part are the same, each is assigned the symbol 4A) corresponding to the central part of the girder part 4, and two second structural parts 6A and 6B (sometimes collectively referred to as the second structural part 6) on the left and right of the first structural part 4A. The second structural part 6A consists of the end part of the girder part 4 (sometimes referred to as the end part 4B of the girder part) and the rocking legs 2, and the second structural part 6B consists of the end part of the girder part 4 (sometimes referred to as the end part 4C of the girder part) and the rigid legs 3. In FIG. 2, the illustration of the trolley 5 is omitted.

[0020] In Figures 3-6, 8, and 9, the jack stands 11A-11D, etc., are depicted transparently for illustrative purposes. In Figure 5(A), the depiction of the anti-tipping wires 36A-36D is omitted (the same applies to (B) in Figures 8-10), while in Figure 5(B), the anti-tipping wires 36A and 36D are depicted, but the depiction of the jack stands 11A and 11D and the anti-tipping wires 13A-13H is omitted. In Figure 6(A), the depiction of the anti-tipping wires 36A-36D is omitted (the same applies to (C) in Figures 8-10), while in Figure 6(B), the anti-tipping wires 38B and 38C are depicted, but the depiction of the jack stands 11B and 11C and the anti-tipping wires 15A-15H is omitted. Furthermore, in Figures 8(B) and 8(C), the depiction of the second structural parts 6A and 6B is omitted in order to clarify the first structural part 4A. Also, in Figures 9(B), 9(C), 10(B), and 10(C), the illustration of the anti-tipping wires 21 and 31 and anchors 23 and 33 is omitted for clarity.

[0021] [2.1. Frame Construction Process (Step S11 in Figure 11)] First, the frame construction process will be explained with reference to Figures 3-6. In the frame construction process, jack frames 11A-11D (sometimes referred to collectively as jack frame 11) are constructed near both legs of the rocking leg section 2 and the rigid leg section 3. In this embodiment, as shown in Figure 4, jack frames 11A-11D are constructed at a total of four locations: the front and rear sides of the rocking leg section 2 and the front and rear sides of the rigid leg section 3. The jack frames 11 are made higher than the height of the Goliath crane 1. The jack frames 11 have a basic structure similar to that of a typical scaffold and are constructed using steel frame members, etc.

[0022] A jack 25 for the rocking leg section is installed on the upper surface of each of the jack bases 11A and 11D, and similarly, a jack 35 for the rigid leg section is installed on the upper surface of each of the jack bases 11B and 11D. The jack 25 for the rocking leg section and the jack 35 for the rigid leg section are jacks that can raise and lower objects via the wires 41 and 42 for the second structural section, respectively, and can raise, lower, and stop (stop raising and lowering) an object connected to the wire (the same applies to the other jacks in this application). In the girder section cutting process described later (step S15 in Figure 11), the Goliath crane 1 is divided into a first structural section 4A and second structural sections 6A and 6B by cutting both ends of the girder section 4. Then, the jacks 25 for the swinging legs and the jacks 35 for the rigid legs are appropriately placed on each jack stand 11A-11D in a number that is sufficient to lift the entire load of each second structural part 6, in order to support the load of the second structural part 6A and the second structural part 6B, respectively.

[0023] To prevent tipping, one end of anti-tipping wires 13A-13D is connected to the upper end of the jack base 11A, and the other end of the anti-tipping wires 13A-13D is fixed to an anchor (not shown) installed in the ground. Similarly, anti-tipping wires 15A-15D are attached to the jack base 11B, anti-tipping wires 15E-15H are attached to the jack base 11C, and anti-tipping wires 13E-13H are attached to the jack base 11D. In this way, the anti-tipping wires 13A-13H and 15A-15H (sometimes collectively referred to as anti-tipping wires 13 and 15) connect the jack base 11 to the anchor, thereby preventing the jack base 11 from tipping over when the load of the second structural part 6, etc., is supported by the swinging leg jack 25 or rigid leg jack 35 installed on the upper part of the jack base 11. Note that, as long as the jack base 11 does not tip over, one end of the anti-tipping wires 13 and 15 may be connected to a part other than the upper end of the jack base 11, or the other end may be connected to a fixed object other than an anchor installed in the ground.

[0024] Furthermore, in this embodiment, one end of anti-tipping wires 36A-36D is connected to the upper end of the girder section end 4B to prevent tipping, and the other end of the anti-tipping wires 36A-36D is gripped by anti-tipping jacks 37A-37D fixed to the ground. Similarly, one end of anti-tipping wires 38A-38D is connected to the upper end of the girder section 4 on the rigid leg section 3 side to prevent tipping, and the other end of the anti-tipping wires 38A-38D is gripped by anti-tipping jacks 39A-39D fixed to the ground. In this way, the anti-tipping wires 36A-36H and 38A-38H (sometimes collectively referred to as anti-tipping wires 36 and 38) connect the girder section 4 to the ground, thereby preventing the Goliath crane 1 from tipping over. Furthermore, the anti-tipping jacks 37A-37D and 39A-39D not only grip the anti-tipping wires 36 and 38, but can also change the gripping position of the anti-tipping wires 36 and 38. Therefore, as will be described later, even when the second structural parts 6A and 6B descend, the tension of the anti-tipping wires 36 and 38 can be maintained by changing the gripping position of the anti-tipping wires 36 and 38.

[0025] [2.2. Wire connection process for the second structural section (Step S12 in Figure 11)] Next, the wire connection process for the second structural section will be described. In the wire connection process for the second structural section, the wire 41 for the second structural section is connected to the girder end 4B of the second structural section 6A, and the wire 42 for the second structural section is connected to the girder end 4C of the second structural section 6B, thereby applying tension to the wires. For example, the wires are connected by providing a suspension fitting on the object to be connected and hooking the suspension hook at the end of the wire to the suspension fitting.

[0026] [2.3. Installation process for jacks for the girder section (Step S13 in Figure 11)] Next, the process for installing jacks for the girder section will be described. In the process for installing jacks for the girder section, a jack beam 16 is installed at the end 4B of the girder section along the longitudinal direction of the girder section 4, and a girder section jack 17 is installed on the jack beam 16. In addition, a jack beam 26 is installed at the end 4C of the girder section along the longitudinal direction of the girder section 4, and a girder section jack 27 is installed on the jack beam 26.

[0027] More specifically, two jack beams 16 and 26 are provided on the upper surface of the end of the girder section 4, and jack mounting beams 12 and 14 are erected on the upper surfaces of the jack beams 16 and 26, respectively. At this time, the jack mounting beams 12 and 14 are positioned on the inner side of the jack beam 16 when the girder section 4 is viewed from the front (the right side of the jack beam 16 and the left side of the jack beam 26 in Figure 3), and girder section jacks 17 and 27 are installed on the jack mounting beams 12 and 14, respectively. As a result, the girder section jacks 17 and 27 are installed on the inner side of the jack beams 16 and 26 when the girder section 4 is viewed from the front, and the girder section jacks 17 and 27 can lower the first structural section 4A, which is divided in the girder section cutting process (step S15 in Figure 11), via the girder section wires 18 and 28.

[0028] Furthermore, anchor jacks 19 and 29 are installed on the upper surfaces of the jack beams 16 and 26, respectively. The anchor jacks 19 and 29 are positioned on the outer parts of the jack beams 16 and 26 when the girder section 4 is viewed from the front (the left side of jack beam 16 and the right side of jack beam 26 in Figure 3). The anchor jacks 19 and 29 are capable of raising and lowering anti-tipping wires 21 and 31, respectively, to prevent the Goliath crane 1 or any part thereof from tipping over during demolition work. One end of the anti-tipping wires 21 and 31 is gripped (fixed) to the anchor jacks 19 and 29, and the other end is fixed to anchors 23 and 33 fixed to the ground. In other words, the anti-tipping wires 21 and 31 connect the outer parts of the jack beams 16 and 26 to the anchors 23 and 33 other than the Goliath crane 1. This prevents the Goliath crane 1 or any part thereof from tipping over during demolition work (especially while the first structural section is being lowered). Furthermore, the anchor jacks 19 and 29 not only grip the anti-tipping wires 21 and 31, but can also change the gripping position of the anti-tipping wires 21 and 31. As will be described later, even when the girder section 4 is lowered, the tension of the anti-tipping wires 21 and 31 can be maintained by changing the gripping position of the anti-tipping wires 21 and 31.

[0029] [2.4. Wire connection process for the first structural part (Step S14 in Figure 11)] Next, the wire connection process for the first structural part will be described. In the wire connection process for the first structural part, the girder wire 18 of the girder jack 17 is connected to the hanging girder section 4, and the girder wire 28 of the girder jack 27 is also connected to the hanging girder section 4, thereby applying tension to the girder wires 18 and 28. For example, the connection of the girder wires 18 and 28 is made by providing a hanging fitting at the bottom of the girder section 4 and hooking the hanging hooks at the ends of the girder wires 18 and 28 to the hanging fitting.

[0030] [2.5. Girder section cutting process (Step S15 in Figure 11)] Next, the girder section cutting process will be explained. In the girder section cutting process, both ends of the girder section 4 are cut, dividing the Goliath crane 1 into a first structural section 4A to which the wires 18 and 28 for each girder section are connected, and second structural sections 6A and 6B. The trolley 5 is fixed to the first structural section 4A.

[0031] More specifically, the girder section 4 is cut along the cutting lines 50A and 50B shown in Figure 3. As shown in Figure 7(A), when the girder section 4 is viewed from the front, one end of the cutting line 50A is at point 51 on the upper surface 4X of the girder section 4, which is on the central side of the girder section 4 (right side in the figure) beyond the right end of the jack beam 16, and the other end of the cutting line 50A is at point 52 on the lower surface 4Y of the girder section 4, which is outside the part to which the girder section wire 18 is connected (left side in the figure). The reason that point 51, one end of the cutting line 50A, is on the central side of the girder section 4 (right side in the figure) beyond the right end of the jack beam 16 is that the jack beam 16 obstructs the cutting of the girder section 4 outside the right end of the jack beam 16 (left side in the figure). Furthermore, point 52, which is the other end of the cutting line 50A, is located outside (to the left in the figure) of the part to which the girder wire 18 is connected, because the first structural part is supported and lowered by the girder jack 27 via the girder wire 18 hanging down from the girder jack 17. Note that although Figure 7(A) shows the cutting line 50A on the rocking leg 2 side, the cutting line 50B on the rigid leg 3 side is similar except that it is symmetrical.

[0032] Here, a modified example of the cutting line 50A will be described. The girder section 4 may also be cut along the cutting line 50A as shown in Figures 7(B) and (C). In both cases, one end of the cutting line 50A is at point 51 on the upper surface 4X of the girder section 4 when viewed from the front, which is on the central side (right side in the figure) of the right end of the jack beam 16, and the other end is at point 52 on the lower surface 4Y of the girder section 4 when viewed from the front, which is outside (left side in the figure) of the part to which the girder section wire 18 is connected. Note that Figures 7(B) and (C) show the cutting line 50A on the rocking leg section 2 side, but the cutting line 50B on the rigid leg section 3 side is similar except that it is symmetrical.

[0033] [2.6. First structural section lowering process (Step S16 in Figure 11)] Next, the process of lowering the first structural section will be described. In the process of lowering the first structural section, as shown in Figure 8, the first structural section 4A is lowered to the ground via the girder wires 18 and 28 using the girder jacks 17 and 27. The trolley 5 is also lowered together with the first structural section 4A.

[0034] [2.7. Dismantling process of the first structural part (Step S17 in Figure 11)] Next, the process of dismantling the first structural section will be described. In the process of dismantling the first structural section, the first structural section 4A is dismantled using demolition heavy machinery (not shown) or the like. At this time, the trolley 5 is removed from the first structural section 4A, dismantled if it is not needed, and preserved if it is to be reused. This makes it possible to dismantle the huge first structural section 4A on the ground without using large heavy machinery to lift or lower the first structural section 4A itself. The rubble generated by the dismantling is loaded onto transport vehicles (not shown) and removed.

[0035] [2.8. Cutting process of the second structural part (Step S18 in Figure 11)] Next, the process of cutting the second structural section will be described. In the process of cutting the second structural section, a demolition heavy machine (not shown) is used to cut a portion of the lower end of each second structural section 6A and 6B. At this time, each second structural section 6 is supported by the load from the jacks 25 for the rocking legs and the jacks 35 for the rigid legs via the wires 41 and 42 for the second structural section, so even if a portion of the lower end of each second structural section 6 is cut, each second structural section 6 will not fall.

[0036] [2.9. Repeated Process (Step S19 in Figure 11)] Next, the repeating process will be explained. In the repeating process, the second structural section cutting process (step S18 in Figure 11) and the second structural section lowering process (step S20 in Figure 11) are repeated until the dismantling of the second structural section 6 is completed (step S19: YES). Specifically, if the dismantling of the second structural section 6 is not completed (step S19: NO), the process proceeds to the subsequent second structural section lowering process (step S20 in Figure 11), then to the second structural section cutting process (step S18 in Figure 11), and then back to the repeating process. On the other hand, if the dismantling of the second structural section 6 is completed (step S19: YES), the process proceeds to the frame removal process (step S21 in Figure 11), which will be described later.

[0037] [2.10. Lowering process of the second structural section (Step S20 in Figure 11)] Next, the process of lowering the second structural section will be described. In the process of lowering the second structural section, the jacks 25 for the rocking legs and 35 for the rigid legs lower the second structural sections 6A and 6B, respectively, via the wires 41 and 42 for the second structural section until their lower ends touch the ground. Alternatively, the sections may be lowered to a height where the lower ends can be cut off with demolition machinery, even if they do not touch the ground completely.

[0038] In this way, by repeatedly cutting and lowering the second structural section 6, the second structural section 6 is dismantled sequentially from the bottom up, and when the rocking leg section 2 and rigid leg section 3 of each second structural section 6 are dismantled, it will look like Figure 9. Furthermore, when the girder section ends 4B and 4C of each second structural section 6 are dismantled, it will look like Figure 10. As a result, the first structural section 4A and each second structural section 6 are dismantled, and the Goliath crane 1 is dismantled.

[0039] Furthermore, the second structural part 6 can be dismantled by repeating steps S18-S20 in Figure 11 until the dismantling of the second structural part 6 is completed. The dismantling of the second structural part 6 involves a frame construction step (step S11 in Figure 11), a second structural part wire connection step (step S12 in Figure 11), a second structural part cutting step (step S18 in Figure 11), a repeating step (step S19 in Figure 11), and a second structural part lowering step (step S20 in Figure 11). In other words, the dismantling process for the second structural part of the present invention includes a frame construction step, a second structural part wire connection step, a second structural part cutting step, a repeating step, and a second structural part lowering step.

[0040] [2.11. Frame Removal Process (Step S21 in Figure 11)] Next, the frame removal process will be explained. As shown in Figure 10, after the dismantling of the Goliath crane 1 is completed, in the frame removal process, all the jacks 25 for the swinging legs and jacks 35 for the rigid legs are lowered to the ground from the jack frame 11, and the jack frame 11 is dismantled and removed. In addition, the jack beams 16, 26, the jack mounting beams 12, 14, the girder jacks 17, 27, and the anchor jacks 19, 29, etc. are dismantled and removed.

[0041] As described above, the method for dismantling the Goliath crane 1 of this embodiment (an example of the "gantry structure" of the present invention) is a method for dismantling the Goliath crane 1 having a girder section 4 (an example of the "beam section" of the present invention) and swinging leg sections 2 and rigid leg sections 3 (an example of the "two leg sections" of the present invention) provided at both ends of the girder section 4, wherein jack beams 16 and 26 are provided along the longitudinal direction of the girder section 4, respectively, on which girder section jacks 17 and 27 (an example of the "first jack" of the present invention) that can raise and lower objects via girder section wires 18 and 28 are installed, and a girder section jack installation step (step S13 in Figure 11) (an example of the "first jack installation step" of the present invention) is performed in which the girder section jacks 17 and 27 are installed on the jack beams 16 and 26, and each girder section The process includes: a first structural wire connection step (step S14 in Figure 11) (an example of the "first wire connection step" of the present invention) in which the wires 18 and 28 for the girder section of jacks 17 and 27 are lowered and connected to the girder section 4; a girder section cutting step (step S15 in Figure 11) (an example of the "beam section cutting step" of the present invention) in which both ends of the girder section 4 are cut to divide the Goliath crane 1 into a first structural section 4A to which the wires 18 and 28 for the girder section are connected, and second structural sections 6A and 6B; a first structural section lowering step (step S16 in Figure 11) in which the first structural section 4A is lowered using the girder section jacks 17 and 27; a first structural section dismantling step (step S17 in Figure 11) in which the first structural section 4A is dismantled after the first structural section lowering step; and a second structural section dismantling step in which the second structural section 6 is dismantled.

[0042] Furthermore, the second structural dismantling process involves constructing a jack stand 11 (an example of the "stand" in the present invention) near the rocking leg 2 and the rigid leg 3, respectively, on which rocking leg jacks 25 and rigid leg jacks 35 (an example of the "second jack" in the present invention) are installed via wires 41 and 42 for the second structural part, and then connecting the wires 41 and 42 for the second structural part of the rocking leg jack 25 and rigid leg jack 35 to the second structural parts 6A and 6B respectively. The invention includes a second structural wire connection step (step S12 in Figure 11) (an example of the "second wire connection step" of the present invention), a second structural cutting step (step S18 in Figure 11) in which the lower ends of each second structural part 6 are cut and removed, a second structural lowering step (step S20 in Figure 11) in which each second structural part 6 is lowered using a jack 25 for the rocking leg and a jack 35 for the rigid leg, and a repeating step (step S19 in Figure 11) in which the second structural part 6 is dismantled by repeating the second structural cutting step and the second structural lowering step.

[0043] Therefore, according to the dismantling method of the Goliath crane 1 of this embodiment, the girder section 4 is cut while the first structural section 4A is supported by girder section jacks 17 and 27 installed at both ends of the girder section 4, thereby dividing the Goliath crane 1 into the first structural section 4A and the second structural sections 6A and 6B. After the first structural section 4A is lowered using the girder section jacks 17 and 27, the first structural section 4A and the second structural sections 6A and 6B are dismantled respectively. As a result, large heavy machinery is not required to raise and lower the Goliath crane 1, dismantling costs can be reduced and the flexibility of setting the construction period can be increased.

[0044] Furthermore, in the method for dismantling the Goliath crane 1 of this embodiment, when cutting the girder section 4 in the girder section cutting process, the cutting lines 50A and 50B are such that, when the girder section 4 is viewed from the front, one end is at point 51 on the upper surface 4X of the girder section 4, which is closer to the center of the girder section 4 than the respective jack beams 16 and 26, and the other end is at point 52 outside the part of the girder section 4 to which the respective girder section wires 18 and 28 are connected. This makes it possible to cut the girder section 4 without the jack beams 16 and 26 getting in the way, and while the load of the first structural section 4A is supported by the girder section wires 18 and 28.

[0045] Furthermore, in the method for dismantling the Goliath crane 1 of this embodiment, in the step of installing the jacks for the girder section, the outer parts of the jack beams 16 and 26 when the girder section 4 is viewed from the front are connected to fixed objects other than the Goliath crane 1 with anti-tipping wires 21 and 31. More specifically, anchor jacks 19 and 29 (an example of the "anti-tipping jacks" of the present invention) that can raise and lower objects via the anti-tipping wires 21 and 31 are provided on the outer parts of the jack beams 16 and 26, and the anti-tipping wires 21 and 31 are connected to anchors 23 and 33 (an example of the "fixed objects" of the present invention) that are fixed to the ground. This prevents the second structural section 6 from tipping over when the load of the first structural section 4A is supported by the girder section jacks 17 and 27.

[0046] [3. Manufacturing method of Goliath Crane 1] Next, the manufacturing method of the Goliath crane 1 according to this embodiment will be described with reference to Figures 2-10 and 12. The manufacturing method of the Goliath crane 1 according to this embodiment basically involves manufacturing the Goliath crane 1 by following the reverse procedure of the dismantling method of the Goliath crane 1 described above. In the manufacturing method according to this embodiment, as shown in Figure 2, the girder section 4 is divided into the central girder section 4A and the end girder sections 4B and 4C before manufacturing, and the girder section 4 is formed by joining the end girder sections 4B and 4C to both ends of the central girder section 4A during the manufacturing process. Therefore, joining is required at the joining lines 50A and 50B (in the dismantling method of the Goliath crane 1 described above, reference numerals 50A and 50B were described as "cutting lines," but in the description of the manufacturing method of the Goliath crane 1, reference numerals 50A and 50B are described as "joining lines"). For example, the joining portion of the central girder section 4A and the joining portions of the end girder sections 4B and 4C may be processed so that they can be joined to each other. For example, if bolt and nut connections are to be made, flanges for bolt and nut connections may be formed in advance, or if welding is to be done, the joint parts may be processed to facilitate welding. The rocking leg section 2 includes multiple rocking leg and leg members divided in the height direction, and the rocking leg section 2 is assembled by joining these together. Similarly, the rigid leg section 3 includes multiple rigid leg and leg members divided in the height direction, and the rigid leg section 3 is assembled by joining these together.

[0047] Next, referring to the flowchart in Figure 12, we will explain the manufacturing process of the Goliath crane 1.

[0048] [3.1. Frame Construction Process (Step S51 in Figure 12)] The frame construction process is the same as the frame construction process for the dismantling method of Goliath Crane 1 (step S11 in Figure 11), so the explanation is omitted. However, the jack frame 11 is constructed at the location where Goliath Crane 1 will be assembled.

[0049] [3.2. Wire connection process for the second structural section (Step S52 in Figure 12)] Next, the wire connection process for the second structural section will be described. In the wire connection process for the second structural section, the wire 41 for the second structural section of the jack 25 for the swinging leg section is connected to the end 4B of the girder section, and the wire 42 for the second structural section of the jack 35 for the rigid leg section is connected to the end 4C of the girder section, thereby applying tension to the wires. For example, the wires are connected by providing a suspension fitting on the object to be connected and hooking the suspension hook at the end of the wire to the suspension fitting.

[0050] [3.3. Installation process for jacks for the girder section (Step S53 in Figure 12)] Next, the process for installing the jacks for the girder section will be described. In the process for installing the jacks for the girder section, as shown in Figure 9, a jack beam 16 is installed on the ground at the end 4B of the girder section along the longitudinal direction of the girder section 4, and a girder section jack 17 is installed on the jack beam 16. In addition, a jack beam 26 is installed at the end 4C of the girder section along the longitudinal direction of the girder section 4, and a girder section jack 27 is installed on the jack beam 26.

[0051] More specifically, two jack beams 16 and 26 are provided on the upper surfaces of the girder section ends 4B and 4C, respectively, and jack mounting beams 12 and 14 are erected on the upper surfaces of the jack beams 16 and 26, respectively. At this time, the jack mounting beams 12 and 14 are positioned on the inner side of the jack beams 16 and 26 when the completed girder section 4 is viewed from the front (the right side of jack beam 16 and the left side of jack beam 26 in Figure 9(A)), and girder section jacks 17 and 27 are installed on top of the jack mounting beams 12 and 14, respectively. As a result, the girder section jacks 17 and 27 are installed on the inner side of the jack beams 16 and 26 when the girder section 4 is viewed from the front, and the first structural section 4A can be raised by the girder section jacks 17 and 27 via the girder section wires 18 and 28.

[0052] Furthermore, anchor jacks 19 and 29 are installed on the upper surfaces of the jack beams 16 and 26, respectively. The anchor jacks 19 and 29 are positioned on the outer parts of the jack beams 16 and 26 when the completed girder section 4 is viewed from the front (the left side of jack beam 16 and the right side of jack beam 26 in Figure 9(A)). The anchor jacks 19 and 29 are capable of raising and lowering anti-tipping wires 21 and 31, respectively, to prevent the Goliath crane 1 or any part thereof from tipping over during manufacturing. One end of the anti-tipping wires 21 and 31 is gripped (fixed) to the anchor jacks 19 and 29, and the other end is fixed to anchors 23 and 33 fixed to the ground. In other words, the anti-tipping wires 21 and 31 connect the outer parts of the jack beams 16 and 26 to the anchors 23 and 33 other than the Goliath crane 1. This prevents the Goliath crane 1 or any part thereof from tipping over during manufacturing operations (especially while the first structural part 4A is being raised).

[0053] [3.4. Second structural section raising process (Step S54 in Figure 12)] Next, the process of raising the second structural section will be described. In the process of raising the second structural section, the girder section end 4B is raised and stopped by the jack 25 for the rocking leg section via the wire 41 for the second structural section. At this time, the girder section end 4B is raised and stopped to a height at which the rocking leg section / leg member to be joined next can be joined. Also, the girder section end 4C is raised and stopped by the jack 35 for the rigid leg section via the wire 42 for the second structural section. At this time, the girder section end 4C is raised and stopped to a height at which the rigid leg section / leg member to be joined next can be joined.

[0054] [3.5. Leg Joining Process (Step S55 in Figure 12)] Next, the leg joining process will be explained. In the leg joining process, the rocking leg section / leg member and the rigid leg section / leg member are joined to the lower part of the girder section ends 4B and 4C, respectively. Specifically, with the upward movement of the girder section end 4B stopped, the rocking leg section / leg member to be joined next is joined according to a predetermined joining sequence. If the rocking leg section / leg member to be joined is the uppermost rocking leg section / leg member, it is joined to the girder section end 4B. If the rocking leg section / leg member to be joined is a rocking leg section / leg member other than the uppermost leg member of rocking leg section 2, it is joined to the rocking leg section / leg member immediately above it that has already been joined.

[0055] Similarly, when the upward movement of the girder end 4C has stopped, the next rigid leg member to be joined is joined based on a predetermined joining sequence. If the rigid leg member to be joined is the uppermost rigid leg member, it is joined to the girder end 4C. If the rigid leg member to be joined is a rigid leg member other than the uppermost leg member of the rigid leg 3, it is joined to the rigid leg member immediately above it that has already been joined.

[0056] [3.6. Repeated Process (Step S56 in Figure 12)] Next, the repeating process will be explained. In the repeating process, the second structural section raising process (step S54) and the leg joining process (step S55) are repeated for each second structural section 6 until all leg members (rocking leg section / leg member and rigid leg section / leg member) are joined (step S56:NO). This completes the second structural section 6.

[0057] [3.7. Wire connection process for the first structural part (Step S57 in Figure 12)] Next, the first structural wire connection process will be described. In the first structural wire connection process, the girder wires 18 and 28 of the girder jacks 17 and 27 are suspended and connected to the first structural 4A located between each of the second structural 6.

[0058] [3.8. First structural unit raising process (Step S58 in Figure 12)] Next, the process of raising the first structural section will be described. In the process of raising the first structural section, the first structural section 4A is raised and stopped using the girder section jacks 17 and 27. At this time, the first structural section 4A is raised to the same height as the girder section ends 4B and 4C and then stopped. The trolley 5 is fixed to the first structural section 4A and is raised together with the first structural section 4A.

[0059] [3.9. Girder section joining process (Step S59 in Figure 12)] Next, the girder section joining process will be explained. In the girder section joining process, the girder section ends 4B and 4C of the second structural sections 6A and 6B are joined to both ends of the first structural section 4A by aligning their respective joining lines 50A and 50B. Conventional methods such as bolt and nut joining or welding can be used for joining. This completes the Goliath crane 1.

[0060] [3.10. Frame Removal Process (Step S60 in Figure 12)] Next, the frame removal process will be explained. As shown in Figure 3, after the manufacturing of the Goliath crane 1 is completed, in the frame removal process, all the jacks 25 for the swinging legs and jacks 35 for the rigid legs are lowered to the ground from the jack frame 11, and the jack frame 11 is dismantled and removed.

[0061] As described above, the manufacturing method of the Goliath crane 1 of this embodiment (an example of the "gantry structure" of the present invention) has a girder section 4 (an example of the "beam section" of the present invention), and a swinging leg section 2 and a rigid leg section 3 (an example of the "two leg sections" of the present invention) provided at both ends of the girder section 4, and a first structural section 4A corresponding to the central part of the girder section 4A (an example of the "central part of the beam section" of the present invention), a second structural section 6A consisting of a girder section end section 4B (an example of the "beam section end section" of the present invention) and a swinging leg section 2, and girder A manufacturing method for producing a Goliath crane 1 by joining a second structural part 6B consisting of a girder end 4C (an example of the "beam end" of the present invention) and a rigid leg part 3, wherein jack beams 16, 26 are provided along the longitudinal direction of each girder end 4B, 4C, on which girder jacks 17, 27 (an example of the "first jack" of the present invention) that can raise and lower objects via girder wires 18, 28 are installed, and the girder jacks 17, 27 are installed on the jack beams 16, 26 - A jack installation process for the girder section (step S53 in Figure 12) (an example of the "first jack installation process" of the present invention), a second structural section assembly process in which the second structural section 6A includes a swing leg section 2 to which the girder section end 4B having a girder section jack 17 installed in the girder section jack installation process is joined at the top, and the second structural section 6B includes a rigid leg section 3 to which the girder section end 4C having a girder section jack 27 is joined at the top, and the first structural section is positioned between each of the second structural sections 6. The process includes a first structural wire connection step (step S57 in Figure 12), a first structural raising step (step S58 in Figure 12), and a girder joining step (step S59 in Figure 12) (an example of the "beam joining step" of the present invention), in which the girder wires 18 and 28 of the girder jacks 17 and 27 for each girder section are suspended and connected to 4A, the girder wires 18 and 28 of the girder jacks 17 and 27 for each girder section are raised by the girder jacks 17 and 27, and the girder ends 4B and 4C of the second structural sections 6 are joined to both ends of the first structural section 4A.

[0062] Furthermore, each of the rocking leg section 2 and the rigid leg section 3 includes a plurality of leg members divided in the height direction, and the second structural assembly process is a frame construction process (step S51 in Figure 12) (an example of the "frame construction process" of the present invention) in which a jack frame 11 ("an example of the "frame" of the present invention") is installed on which rocking leg jacks 25 and rigid leg jacks 35 that can raise and lower objects via wires 41 and 42 for the second structural section are installed, and each girder section end 4B, 4 has girder section jacks 17 and 27 installed in the girder section jack installation process. The invention includes a second structural wire connection step (step S52 in Figure 12) (an example of the "connection step" of the present invention) in which the wires 41 and 42 of the second structural parts of the jacks 25 for the rocking legs and jacks 35 for the rigid legs are connected to C respectively, and a leg joining step (step S55 in Figure 12) in which the girder end parts 4B and 4C are repeatedly raised and stopped using the jacks 25 for the rocking legs and jacks 35 for the rigid legs respectively, and each time the rise of the girder end parts 4B and 4C is stopped, the respective leg members are joined below the girder end parts 4B and 4C.

[0063] Therefore, according to the manufacturing method of the Goliath crane 1 of this embodiment, the Goliath crane 1 is manufactured by assembling a second structural part 6A which includes a swinging leg part 2 to which a girder end part 4B on which a girder jack 17 is installed is joined at the top, and another second structural part 6B which includes a rigid leg part 3 to which a girder end part 4C on which a girder jack 27 is installed is joined at the top, and then connecting the girder wires 18 and 28 to the first structural part 4A which is positioned between the second structural parts 6, raising the first structural part 4A with the girder jacks 17 and 27, and joining the girder end parts 4B and 4C of the second structural parts 6 to both ends of the first structural part 4A. Since this does not require large heavy machinery to raise and lower the Goliath crane 1, manufacturing costs can be reduced and the flexibility of setting the construction period can be increased.

[0064] Furthermore, in the manufacturing method of the Goliath crane 1 of this embodiment, when joining the central part 4A of the girder section and the end parts 4B and 4C of the girder section in the girder section joining process, the joining lines 50A and 50B, when the girder section 4 is viewed from the front, have one end at point 51 on the upper surface 4X of the girder section 4, which is closer to the center of the girder section 4 than the respective jack beams 16 and 26, and the other end at point 52 on the girder section 4, which is further outside the part to which the respective girder section wires 18 and 28 are connected. In this way, by setting point 51, which is one end of the joining lines 50A and 50B, on the upper surface 4X of the girder section 4, which is closer to the center of the girder section 4 than the respective jack beams 16 and 26, the contact surface of the girder section end parts 4B and 4C becomes larger when installing the jack beams 16 and 26, allowing the first structural section 4A to be raised stably. Furthermore, by setting point 52, which is the other end of the connecting wires 50A and 50B, outside the portion where the girder wires 18 and 28 of the girder section 4 are connected, a portion can be provided where the girder wires 18 and 28 support the load of the first structural section 4A.

[0065] Furthermore, in the manufacturing method of the Goliath crane 1 of this embodiment, before the girder section joining process, the outer portions of the jack beams 16 and 26 when the girder section 4 is viewed from the front are connected to fixed objects other than the Goliath crane 1 with anti-tipping wires 21 and 31. More specifically, anchor jacks 19 and 29 (an example of the "anti-tipping jacks" of the present invention) that can raise and lower objects via the anti-tipping wires 21 and 31 are provided on the outer portions of the jack beams 16 and 26, and the anti-tipping wires 21 and 31 are connected to anchors 23 and 33 (an example of the "fixed objects" of the present invention) that are fixed to the ground. This prevents the second structural section 6 from tipping over when the load of the first structural section 4A is supported by the girder section jacks 17 and 27. [Explanation of Symbols]

[0066] 1: Goliath Crane 2: Rocking leg part 3: Rigid leg 4: Girder section 4A: Center of the girder section 4B: End of girder section 4C: End of girder section 4X:Top surface 4Y: Bottom surface 5: Trolley 6A:Second structural part 6B:Second structural part 11: Jack stand 11A-11D: Jack stand 12: Beam for jack mounting 13: Anti-tip wire 13A-13H: Anti-tipping wire 14: Beam for jack mounting 15: Anti-tip wire 15A-15H: Anti-tipping wire 16: Jack beam 17: Jack for girder section 18: Wire for the girder section 19: Anchor jack 21: Anti-tip wire 23: Anchor 25: Jack for the swinging leg section 26: Jack beam 27: Jack for girder section 28: Wire for the girder section 29: Anchor jack 31: Anti-tipping wire 33: Anchor 35: Jack for rigid leg section 36A-36D: Anti-tip wire 37A-37D: Anti-tipping jack 38A-38D: Anti-tipping wire 39A-39D: Anti-tipping jack 41: Wire for the second structural part 42: Wire for the second structural part 50A: Cutting wire or joining wire 50B: Cutting line or joining line 51: point 52: point P: Parts S :Ship

Claims

1. A method for dismantling a portal structure having a beam and two legs provided at both ends of the beam, Jack beams are provided along the longitudinal direction of the beam, each having a first jack installed at both ends of the beam, which is capable of raising and lowering an object via a wire. The first jack installation step involves installing the first jack on the jack beam. A first wire connection step involves hanging the wires of each of the first jacks and connecting them to the beam section, A beam cutting step, in which both ends of the beam section are cut, thereby dividing the portal structure into a first structural section corresponding to the central part of the beam section to which each of the wires is connected, and two second structural sections consisting of beam end sections and leg sections corresponding to the ends of the beam section, A first structural member lowering step in which the first structural member is lowered by the first jack, Following the first structural section lowering process, there is a first structural section dismantling process in which the first structural section is dismantled, A second structural dismantling step for dismantling the aforementioned second structural part, A method for dismantling a portal structure, characterized by including the following:

2. A method for dismantling a portal structure according to claim 1, When cutting the end of the beam in the beam cutting process, the cutting line is, when the beam is viewed from the front, One end of the cutting line is on the upper surface of the beam and is on the central side of the beam, rather than the jack beam provided at the end of the beam. A method for dismantling a portal structure, characterized in that the other end of the cutting line is on the lower surface of the beam and outside the portion of the beam to which the wire is connected.

3. A method for dismantling a portal structure according to claim 1, A method for dismantling a gantry structure, characterized in that, in the first jack installation step, the outer portion of the jack beam when the beam is viewed from the front is connected to fixed objects other than the gantry structure with a wire for preventing tipping.

4. A method for dismantling a portal structure according to claim 3, A method for dismantling a portal structure, characterized in that, in the first jack installation step, an anti-tipping jack capable of raising and lowering an object via the anti-tipping wire is provided on the outer part of the jack beam, and the anti-tipping wire is connected to the fixed object fixed to the ground.

5. A method for dismantling a portal structure according to any one of claims 1 to 4, The second structural dismantling process is as follows: A frame construction step involves constructing a frame near the legs, on which a second jack capable of raising and lowering an object via a wire is installed. A second wire connection step involves connecting the wire of the second jack to the second structural part, A second structural cutting step involves cutting and removing the lower end of the second structural part, A second structural lowering step in which the second structural part is lowered by the second jack, A repeating process of dismantling the second structural part by repeating the second structural part cutting process and the second structural part lowering process, Includes, A method for dismantling a portal structure, characterized in that the second structural dismantling step is performed on two of the second structural parts.

6. A method for manufacturing a portal structure, comprising a beam section and two leg sections provided at both ends of the beam section, wherein a first structural section corresponding to the central part of the beam section and two second structural sections consisting of beam section ends and the leg sections corresponding to the ends of the beam section are joined together to manufacture the portal structure, A jack beam is provided along the longitudinal direction at each end of the beam section, on which a first jack capable of raising and lowering an object via a wire is installed, and a first jack installation step is performed in which the first jack is installed on the jack beam. A second structural assembly step involves assembling two second structural parts, each including the leg portion to which the end portion of the beam section having the first jack installed in the first jack installation step is joined at the top; A beam joining step is performed in which the wires of each first jack are suspended and connected to the first structural part positioned between each of the second structural parts, the first structural part is raised by each of the first jacks, and the beam ends of each of the second structural parts are joined to both ends of the first structural part, A method for manufacturing a portal structure, characterized by including the following:

7. A method for manufacturing a portal structure according to claim 6, When joining the beam ends of the first structural part and the second structural part in the beam joining process, the joining line, when viewed from the front, One end of the aforementioned connection line is on the upper surface of the beam portion, and is located on a point closer to the center of the beam portion than the jack beam provided at the end of the beam portion. A method for manufacturing a portal structure, characterized in that the other end of the connecting line is located on the lower surface of the beam portion, outside the portion of the beam portion to which the wire is connected.

8. A method for manufacturing a portal structure according to claim 7, A method for manufacturing a portal structure, characterized in that, before the beam joining process, the outer portion of the jack beam when the beam is viewed from the front and fixed objects other than the portal structure are connected with anti-tipping wires.

9. A method for manufacturing a portal structure according to claim 8, A method for manufacturing a portal structure, characterized in that, before the beam joining process, an anti-tipping jack capable of raising and lowering an object via the anti-tipping wire is provided on the outer part of the jack beam, and the anti-tipping wire is connected to the fixed object fixed to the ground.

10. A method for manufacturing a portal structure according to any one of claims 6 to 9, Each of the aforementioned legs includes a plurality of leg members divided in the height direction, The second structural assembly process is as follows: A frame construction process involves constructing a frame equipped with a second jack that can raise and lower objects via a wire, A connection step of connecting the wire of the second jack to the beam end having the first jack installed in the first jack installation step, The process involves repeatedly raising and stopping the beam end using the second jack, and each time the beam end stops rising, joining the leg member to the lower part of the beam end; Includes, A method for manufacturing a portal structure, characterized in that the assembly step of the second structural part is performed on two of the second structural parts.

Images