A method of dismantling a support platform

Abstract

This application relates to a method for dismantling a support platform, comprising: fixing a steel bridge deck to the bottom of a pier; dividing multiple columns into first columns and second columns, and staggering the first and second columns; removing the top pads of the first columns, and lowering the distribution beams and Bailey beams at the top of the first columns onto the first columns; removing the top pads of the second columns, and lowering the distribution beams and Bailey beams at the top of the second columns onto the second columns; dismantling the Bailey beams and distribution beams; lowering the entire steel bridge deck onto the first and second columns; and dismantling the steel bridge deck. This invention changes the dismantling sequence of the steel bridge deck, distribution beams, and Bailey beams. The Bailey beams and distribution beams are dismantled first, followed by the steel bridge deck. All components—the Bailey beams, distribution beams, and steel bridge deck—are lowered onto the first and second columns before dismantling, reducing the lifting and dismantling height of the steel bridge deck, distribution beams, and Bailey beams, simplifying the dismantling process, and improving safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bridge construction, in particular to a support platform dismantling method. BACKGROUND

[0002] In the process of bridge construction, before the construction of the bridge deck, the support platform needs to be dismantled. The traditional method generally uses a tower crane to dismantle the platform from above, which needs to hoist and dismantle the steel bridge deck, distribution beam and Bailey beam from top to bottom. The construction is complex and the safety is low. SUMMARY

[0003] The embodiments of the present application provide a support platform dismantling method to solve the problem of low safety in hoisting and dismantling the steel bridge deck, distribution beam and Bailey beam from top to bottom when dismantling the platform in the related art.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a support platform dismantling method, comprising: fixing a steel bridge deck at the bottom end of a pile cap; dividing a plurality of columns into first columns and second columns, and staggering the first columns and the second columns; removing the top end pad of the first column, and lowering the distribution beam and the Bailey beam at the top end of the first column onto the first column; removing the top end pad of the second column, and lowering the distribution beam and the Bailey beam at the top end of the second column onto the second column; removing the Bailey beam and the distribution beam; lowering the steel bridge deck as a whole onto the first column and the second column; and removing the steel bridge deck.

[0005] In some embodiments, a reserved hole is formed in the steel bridge deck, and a pre-buried pipe corresponding to the position of the reserved hole is arranged on the pile cap.

[0006] The steel bridge deck is fixed at the bottom end of the pile cap, and the specific steps include: fixing the connecting structure with the steel bridge deck after passing through the pre-buried pipe and the reserved hole.

[0007] In some embodiments, the top end pad of the first column is removed, and the specific steps include: using the support structure on one side of the first column to hold the distribution beam; cutting and removing the top end pad of the first column to form a lowering space between the top end of the first column and the distribution beam.

[0008] In some embodiments, the top end pad of the second column is removed, and the specific steps include: using the support structure on one side of the second column to hold the distribution beam; cutting and removing the top end pad of the second column to form a lowering space between the top end of the second column and the distribution beam.

[0009] In some embodiments, the support structure includes a continuous jack; or, the pre-set distance is 300-400 mm.

[0010] In some embodiments, the distribution beam and Bailey beam at the top of the first column are lowered onto the first column. The specific steps include: lowering the distribution beam and Bailey beam at the top of the first column; releasing the limiting structure between the steel bridge deck and the Bailey beam; and temporarily welding the distribution beam to the top of the first column.

[0011] In some embodiments, the distribution beam and Bailey beam at the top of the second column are lowered onto the second column. The specific steps include: lowering the distribution beam and Bailey beam at the top of the second column; releasing the limiting structure between the steel bridge deck and the Bailey beam; and temporarily fixing the distribution beam to the top of the second column.

[0012] In some embodiments, the specific steps in dismantling the Bailey beams and distribution beams include: dragging the Bailey beams out in sections to the lifting area and then lifting them away; dragging out the distribution beams at the top of the first column and the top of the second column; and lifting the distribution beams away.

[0013] In some embodiments, after the Bailey beam is pulled out in sections to the lifting area and lifted away, and before the distribution beams at the top of the first and second columns are pulled out, the step further includes: releasing the temporary weld between the distribution beams and the tops of the first and second columns.

[0014] In some embodiments, the specific steps in dismantling the steel bridge deck include: cutting the steel bridge deck into sections; sliding and dragging the cut steel bridge deck sections to the lifting area; and lifting the steel bridge deck away from the lifting area.

[0015] The beneficial effects of the technical solution provided in this application include:

[0016] This application provides a method for dismantling a support platform, which changes the dismantling sequence of the steel bridge deck, distribution beam, and Bailey bridge beam. The Bailey bridge beam and distribution beam are dismantled first, followed by the steel bridge deck. The Bailey bridge beam, distribution beam, and steel bridge deck are all lowered onto the first and second columns before dismantling. This reduces the height of the steel bridge deck, distribution beam, and Bailey bridge beam during hoisting and dismantling, making the dismantling of the steel bridge deck, distribution beam, and Bailey bridge beam simpler and improving safety. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 The Bailey beam and distribution beam placement process provided in this application embodiment is as follows:

[0019] Figure 2 The second process for lowering the Bailey beam and distribution beam provided in the embodiments of this application;

[0020] Figure 3 The third step in the process of lowering the Bailey beam and distribution beam provided in the embodiments of this application;

[0021] Figure 4 This is a schematic diagram of the overall structure provided for an embodiment of this application;

[0022] Figure 5 This is a schematic diagram of the Bailey beam lifting structure provided in an embodiment of this application;

[0023] Figure 6 A flowchart illustrating the support platform dismantling method provided in this application embodiment.

[0024] In the diagram: 1. Pier; 2. Steel bridge deck; 3. First column; 4. Second column; 5. Pad block; 50. Cutting line; 6. Bailey beam; 7. Distribution beam; 8. Connecting structure; 9. Supporting structure; 90. Continuous jack; 91. Pad plate; 10. Lowering space; 11. Tower crane; 12. Connection system. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] This application provides a method for dismantling a support platform, which can solve the problem of low safety in related technologies where steel bridge decks, distribution beams, and Bailey beams are hoisted and dismantled from top to bottom during platform dismantling.

[0027] See Figures 1 to 6 This application provides a method for dismantling a support platform, which includes:

[0028] 101: Fix the steel bridge deck 2 to the bottom end of the pier cap 1;

[0029] 102: Divide multiple columns into first column 3 and second column 4, and arrange the first column 3 and second column 4 alternately;

[0030] 103: Remove the top pad 5 of the first column 3, and lower the distribution beam 7 and Bailey beam 6 at the top of the first column 3 onto the first column 3;

[0031] 104: Remove the top pad 5 of the second column 4, and lower the distribution beam 7 and Bailey beam 6 at the top of the second column 4 onto the second column 4;

[0032] 105: Remove Bailey beam 6 and distribution beam 7;

[0033] 106: Lower the steel bridge deck 2 as a whole onto the first column 3 and the second column 4;

[0034] 107: Remove the steel bridge deck 2.

[0035] This application changes the dismantling sequence of the steel bridge deck 2, distribution beam 7, and Bailey bridge 6. The Bailey bridge 6 and distribution beam 7 are removed first, followed by the steel bridge deck 2. The Bailey bridge 6, distribution beam 7, and steel bridge deck 2 are all lowered onto the first column 3 and the second column 4 before being dismantled. This reduces the height of the hoisting and dismantling of the steel bridge deck 2, distribution beam 7, and Bailey bridge 6, making the dismantling method simpler and improving safety.

[0036] Before dismantling the support platform, the steel bridge deck 2 is fixed to the bottom of the pier 1. Multiple columns are divided into first columns 3 and second columns 4, with the first columns 3 and second columns 4 staggered. Steps 101 and 102 can be performed by either constructing step 101 first and then step 102, or by constructing step 102 first and then step 101. Dividing the multiple columns into first columns 3 and second columns 4, and staggering them, means that within the construction area, if the first column along the longitudinal direction of the bridge is designated as first column 3, then the second column is designated as second column 4, the third column as first column 3, and so on for the remaining columns; similarly, if the first column along the longitudinal direction of the bridge is designated as second column 4, then the second column is designated as first column 3, the third column as second column 4, and so on for the remaining columns.

[0037] In steps 103 and 104, step 103 can be performed first, i.e., first removing the top pad 5 of the first column 3 and lowering the distribution beam 7 and Bailey beam 6 from the top of the first column 3 onto the first column 3; then step 104 can be performed, i.e., removing the top pad 5 of the second column 4 and lowering the distribution beam 7 and Bailey beam 6 from the top of the second column 4 onto the second column 4. Alternatively, step 104 can be performed first, removing the top pad 5 of the second column 4 and lowering the distribution beam 7 and Bailey beam 6 from the top of the second column 4 onto the second column 4; then step 103 can be performed, i.e., removing the top pad 5 of the first column 3 and lowering the distribution beam 7 and Bailey beam 6 from the top of the first column 3 onto the first column 3.

[0038] Furthermore, the steel bridge deck 2 is provided with reserved holes, and the pier 1 is provided with embedded pipes corresponding to the positions of the reserved holes.

[0039] Specifically, to facilitate the fixing of the steel bridge deck 2 to the bottom of the pier cap 1, holes are drilled in the steel bridge deck 2 before the pier cap 1 is poured. During the pouring of the pier cap 1, reserved holes are set on the pier cap 1 so that the reserved holes correspond to the holes on the steel bridge deck 2. The location and number of reserved holes can be set according to the bridge length and construction conditions; this embodiment does not limit this. For example, three rows of reserved holes are set along the longitudinal direction of the downstream pier cap 1, with six reserved holes in each row, for a total of 18 holes; two rows of reserved holes are set along the longitudinal direction of the upstream pier cap 1, with six reserved holes in each row, for a total of 12 holes. After the reserved holes are set, embedded pipes are installed in the reserved holes.

[0040] Therefore, the steel bridge deck 2 is fixed to the bottom of the pier 1. The specific steps include: passing the connecting structure 8 through the pre-embedded pipe and the reserved hole and then fixing it to the steel bridge deck 2.

[0041] The connecting structure 8 includes threaded steel bars, with both ends anchored to the top surface of the pier cap 1 (tower base) and the steel bridge deck 2, respectively. The steel bridge deck 2 is then locked in place by tensioning, ensuring it is tightly attached to the bottom of the pier cap 1. This embodiment does not limit the size of the threaded steel bars; for example, a 9m long, 32mm diameter precision-rolled threaded steel bar can be used. The specific dimensions of the threaded steel bars are determined based on the bridge conditions.

[0042] In this embodiment, taking construction step 103 first and construction step 104 as an example, after dividing the multiple columns into first column 3 and second column 4, the distribution beam 7 and Bailey beam 6 are decomposed so that the distribution beam 7 and Bailey beam 6 on the first column 3 are separated from the distribution beam 7 and Bailey beam 6 on the second column 4.

[0043] Based on the above embodiments, in this embodiment, the top pad 5 of the first column 3 is removed, and the specific steps include:

[0044] 201: The distribution beam 7 is supported by the support structure 9 on one side of the first column 3;

[0045] 202: Cut and remove the top pad 5 of the first column 3 so that a lowering space 10 is formed between the top of the first column 3 and the distribution beam 7.

[0046] Before the steel bridge deck 2 is locked in place by the connecting structure 8, a support structure 9 is installed within a preset distance on one side of the first column 3. This support structure 9 is designed to move the Bailey beam 6 and the steel bridge deck 2 upwards as a whole; however, in this embodiment, the support structure 9 is used to support the distribution beam 7. Since the entire bridge load is applied to the column segment, the pad 5 of the distribution beam 7 at the top of the first column 3 needs to be cut and removed along the cutting line 50 on the pad 5, transferring the bridge load to the second column 4, and then supporting the distribution beam 7, which has lost the support of the pad 5, through the support structure 9. In this embodiment, the support structure 9 includes a continuous jack 90, which is installed on the connecting system 12 next to the first column 3. The preset distance between the continuous jack 90 and the first column 3 is 300mm-400mm. By setting the continuous jack 90 to support the distribution beam 7 instead of the first column 3 and the pad 5, the bridge is kept in balance. Furthermore, the support structure 9 also includes a pad 91, which is installed on the connecting system 12. The continuous jack 90 is installed on the pad 91. Multiple pads 91 can be set along the height direction of the bridge.

[0047] Furthermore, the distribution beam 7 and Bailey beam 6 at the top of the first column 3 are lowered onto the first column 3. The specific steps include:

[0048] 301: Lower the distribution beam 7 and Bailey beam 6 at the top of the first column 3;

[0049] 302: Release the restraining structure between the steel bridge deck 2 and the Bailey beam 6;

[0050] 303: Temporarily weld the distribution beam 7 to the top of the first column 3.

[0051] A limiting structure is installed between the steel bridge deck 2 and the Bailey beam 6. When the distribution beam 7 and the Bailey beam 6 are lowered, the limiting structure moves together with the Bailey beam 6 to maintain balance during the lowering process. When the distribution beam 7 and the Bailey beam 6 at the top of the first column 3 are lowered, the continuous jack 90 retracts. When the top of the continuous jack 90 is on the same horizontal plane as the top of the first column 3, the bottom end of the distribution beam 7 is in contact with the top of the first column 3, and the Bailey beam 6 separates from the steel bridge deck 2. At this time, the height of the distribution beam 7 and the Bailey beam 6 at the top of the first column 3 has been reduced. Then, the limiting structure on the Bailey beam 6 is removed to release the restriction between the steel bridge deck 2 and the Bailey beam 6. Next, the distribution beam 7 is welded to the top of the first column 3 so that the distribution beam 7 can remain stable when the Bailey beam 6 is removed.

[0052] After lowering the distribution beam 7 and Bailey beam 6 from the top of the first column 3 onto the first column 3, remove the top pad 5 of the second column 4. The specific steps include:

[0053] 401: The distribution beam 7 is supported by the support structure 9 on one side of the second column 4;

[0054] 402: Cut and remove the top pad 5 of the second column 4 to create a lowering space 10 between the top of the second column 4 and the distribution beam 7.

[0055] Similarly, before the steel bridge deck 2 is locked by the connecting structure 8, a support structure 9 is already installed within a preset distance on one side of the second column 4. However, in this embodiment, the support structure 9 is used to support the distribution beam 7. When the pad 5 is cut, the pad 5 of the distribution beam 7 at the top of the second column 4 is cut and removed along the cutting line 50 on the pad 5. In this embodiment, the support structure 9 includes a continuous jack 90. ​​The continuous jack 90 is installed on the connecting system 12 next to the second column 4, so that the distance between the continuous jack 90 and the second column 4 is within a preset distance. By setting the continuous jack 90 to support the distribution beam 7 instead of the second column 4 and the pad 5, the bridge is kept balanced. Furthermore, the support structure 9 also includes a pad plate 91. The pad plate 91 is installed on the connecting system 12, and the continuous jack 90 is installed on the pad plate 91. Multiple pad plates 91 can be set along the height direction of the bridge.

[0056] Furthermore, the distribution beam 7 and Bailey beam 6 at the top of the second column 4 are lowered onto the second column 4. The specific steps include:

[0057] 501: Lower the distribution beam 7 and Bailey beam 6 at the top of the second column 4;

[0058] 502: Release the restraining structure between the steel bridge deck 2 and the Bailey beam 6;

[0059] 503: Temporarily fix the distribution beam 7 to the top of the second column 4.

[0060] In this embodiment, a limiting structure is set between the steel bridge deck 2 and the Bailey beam 6. When the distribution beam 7 and the Bailey beam 6 are lowered, the limiting structure moves together with the Bailey beam 6 to maintain balance during the lowering process. When the distribution beam 7 and the Bailey beam 6 are lowered onto the second column 4, the continuous jack 90 retracts as the distribution beam 7 and the Bailey beam 6 at the top of the second column 4 are lowered. When the top of the continuous jack 90 is on the same horizontal plane as the top of the second column 4, the bottom end of the distribution beam 7 is attached to the top end of the second column 4, and the Bailey beam 6 separates from the steel bridge deck 2. At this time, the height of the distribution beam 7 and the Bailey beam 6 at the top of the second column 4 has been reduced. Then, the limiting structure on the Bailey beam 6 is removed to release the restriction between the steel bridge deck 2 and the Bailey beam 6. Next, the distribution beam 7 is welded to the top end of the second column 4 so that the distribution beam 7 can remain stable when the Bailey beam 6 is removed.

[0061] Based on the above embodiments, in this implementation, after the distribution beam 7 and Bailey beam 6 at the top of the first column 3 and the second column 4 are lowered, the Bailey beam 6 and the distribution beam 7 are removed. The specific steps for removing the Bailey beam 6 and the distribution beam 7 include:

[0062] 601: Pull out the 6-section Bailey beam to the lifting area and then lift it away;

[0063] 602: Drag out the distribution beam 7 from the top of the first column 3 and the top of the second column 4;

[0064] 603: Lift the distribution beam 7 away.

[0065] Because the Bailey beam 6 is quite long overall, it needs to be disassembled before being pulled out in sections. The disassembly length of the Bailey beam 6 is determined according to the actual situation. In this embodiment, the Bailey beam 6 is disassembled into 9m or 12m sections before being pulled out in sections. Using the distribution beam 7 (the ribs of the distribution beam 7 have holes for easy connection of the chain hoist) and the chain hoist, the Bailey beams 6 of the first column 3 and the second column 4 are pulled out sequentially along the longitudinal direction of the bridge towards the mid-span side. Each Bailey beam 6 is pulled to the lifting area and then lifted off. The lifting area is located outside the pier cap 1.

[0066] After the Bailey beam 6 sections are pulled out to the lifting area and lifted away, before pulling out the distribution beam 7 at the top of the first column 3 and the top of the second column 4, the steps also include: removing the temporary welding between the distribution beam 7 and the top of the first column 3 and the top of the second column 4, then setting a reaction seat on the column and placing the distribution beam 7 on the reaction seat, and then using a chain hoist to pull the distribution beam 7 out from the centerline of the bridge along the transverse direction and lift it away.

[0067] After the steel bridge deck 2 is lowered onto the first column 3 and the second column 4, it needs to be removed. Based on the above embodiment, in this embodiment, the specific steps for removing the steel bridge deck 2 include:

[0068] 701: Cut the steel bridge deck into two sections;

[0069] 702: Slide and pull the cut steel bridge deck sections 2 out to the lifting area;

[0070] 703: Lift the steel bridge deck 2 away from the lifting area.

[0071] Using a continuous jack 90, threaded steel bars, and a PLC logic control system, the steel bridge panel 2 is lowered synchronously onto the first column 3 and the second column 4. Then, the steel bridge panel 2 is cut into sections. The cut steel bridge panel 2 is then slid out in sections towards the centerline of the bridge using a chain hoist and the steel strand at the top of the pier 1. Finally, it is lifted away from the lifting area.

[0072] Therefore, through the synchronized operation of jacks and the PLC logic control system, Bailey beam 6, distribution beam 7, and steel bridge deck 2 were lowered. This made the entire lowering process safe and controllable, increased the dismantling speed of the pier cap 1 support platform, and reduced safety risks.

[0073] With this solution, only one truck crane and two tower cranes are needed to complete the dismantling of Bailey beam 6, distribution beam 7 and steel bridge deck 2. The number of large-scale mechanical equipment used is small, the operability is high, the safety risks during the platform dismantling process are reduced, the investment in on-site construction equipment is reduced, and the manpower and material resources consumed during the dismantling of the support platform are also reduced.

[0074] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0075] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0076] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for dismantling a support platform, characterized in that, It includes: The steel bridge deck (2) is fixed to the bottom of the pier (1). The steel bridge deck (2) has a reserved hole, and the pier (1) has a pre-embedded pipe corresponding to the position of the reserved hole. The steel bridge deck (2) is fixed to the bottom of the pier (1). The specific steps include: the connecting structure (8) is passed through the pre-embedded pipe and the reserved hole and then fixed to the steel bridge deck (2). The multiple columns are divided into a first column (3) and a second column (4), and the first column (3) and the second column (4) are arranged alternately; Remove the top pad (5) of the first column (3), and lower the distribution beam (7) and Bailey beam (6) at the top of the first column (3) onto the first column (3). The specific steps include: using the support structure (9) on one side of the first column (3) to support the distribution beam (7); cutting and removing the top pad (5) of the first column (3) so that a lowering space (10) is formed between the top of the first column (3) and the distribution beam (7); the support structure (9) includes a continuous jack (90); Remove the top pad (5) of the second column (4), and lower the distribution beam (7) and Bailey beam (6) at the top of the second column (4) onto the second column (4). The specific steps include: using the support structure (9) on one side of the second column (4) to support the distribution beam (7); cutting and removing the top pad (5) of the second column (4) to create a lowering space (10) between the top of the second column (4) and the distribution beam (7). Remove Bailey beam (6) and distribution beam (7); The steel bridge deck (2) is lowered as a whole onto the first column (3) and the second column (4); The specific steps of dismantling the steel bridge deck (2) include: cutting the steel bridge deck (2) into sections; sliding and dragging the cut steel bridge deck (2) sections to the lifting area; and lifting the steel bridge deck (2) away from the lifting area.

2. The method for dismantling the support platform as described in claim 1, characterized in that: The distribution beam (7) and Bailey beam (6) at the top of the first column (3) are lowered onto the first column (3). The specific steps include: Lower the distribution beam (7) and Bailey beam (6) at the top of the first column (3); Release the restraining structure between the steel bridge deck (2) and the Bailey beam (6); The distribution beam (7) is temporarily welded to the top of the first column (3).

3. The method for dismantling the support platform as described in claim 2, characterized in that: The distribution beam (7) and Bailey beam (6) at the top of the second column (4) are lowered onto the second column (4). The specific steps include: Lower the distribution beam (7) and Bailey beam (6) at the top of the second column (4); Release the restraining structure between the steel bridge deck (2) and the Bailey beam (6); Temporarily weld the distribution beam (7) to the top of the second column (4).

4. The method for dismantling the support platform as described in claim 3, characterized in that, The specific steps involved in dismantling the Bailey beam (6) and the distribution beam (7) include: The Bailey beam (6) was pulled out in sections to the lifting area and then lifted away; Drag out the distribution beam (7) from the top of the first column (3) and the top of the second column (4); Lift the distribution beam (7) away.

5. The method for dismantling the support platform as described in claim 4, characterized in that, After the Bailey beam (6) is pulled out in sections to the lifting area and then lifted away, before the distribution beam (7) at the top of the first column (3) and the top of the second column (4) is pulled out, the steps further include: Release the temporary welding between the distribution beam (7) and the top of the first column (3) and the top of the second column (4).

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