Buckling tower and tower crane cooperative mounting and dismounting method based on steel box girder

Abstract

The invention provides a buckling tower and tower crane collaborative mounting and dismounting method based on a steel box girder, and relates to the technical field of tower crane mounting construction, and the method comprises the steps of steel box girder mounting, buckling tower base hoisting, tower crane mounting, buckling tower and tower crane mounting, buckling tower synchronous lifting, tower crane and buckling tower synchronous dismounting and the like. The installation and operation safety of the tower crane is ensured.

Description

Technical Field

[0001] This invention relates to the field of tower crane installation technology, specifically a method for the coordinated installation and dismantling of tower cranes based on steel box girders. Background Technology

[0002] Traditional design and construction of steel box girder bridges for plains and inland rivers typically employs installation on full-span scaffolding. However, this project, due to its ultra-large span (115+185+115) m steel box girder, faces challenges due to the inability to construct bridge piers at the site as a World Heritage Site, coupled with unsuitable surrounding environmental conditions. Therefore, the construction of this ultra-large span steel box girder bridge presents the following main problems: Traditional long-span steel truss arch bridges using the cable-stayed system have a clear and defined force transmission system for the members. The cable-stayed construction uses cable-stayed towers to horizontally offset the tension of the cables and directly transfer the vertical force to the permanent supports of the bridge via hinges. This long-span steel box girder bridge, where the scaffolding method cannot be used, generally employs cantilever assembly. However, steel box girders do not have the same stiffness as prestressed reinforced concrete box girders to overcome deformation over a certain span. To overcome the deformation of the cantilever section during the construction of long-span continuous steel box girder bridges, as well as to ensure closure accuracy and post-construction alignment control, a cable-stayed + cantilever assembly construction method is considered. The cable-stayed system requires tower cranes for vertical lifting, as the cable assembly and cable hanging processes require significant height.

[0003] The most crucial aspect of tower crane installation is the tower crane foundation. However, due to constraints such as cultural heritage preservation, environmental protection, and construction red lines, this project cannot place the tower crane foundation on the side of the bridge pier. Furthermore, the pier's foundation cap is relatively small to minimize impact on cultural relics, being approximately smaller than the width of the steel box girder's bottom plate. Therefore, based on a study of the stress characteristics and structural safety of the tower crane installation, placing the tower crane foundation on the tower crane's base, allowing the tower crane and tower crane to share the load and perform operations collaboratively, is a feasible option. Summary of the Invention

[0004] In view of the above-mentioned prior art, the present invention proposes a method for the coordinated installation and dismantling of tower cranes and tower clamps on steel box girders.

[0005] This invention provides a method for the coordinated installation and dismantling of tower cranes and tower clamps on steel box girders, comprising the following steps: S1. Install steel box girder: Install the large segment steel box girder of the side span and pier top using the scaffolding method, and install the tower clamping ear plate and wind cable ear plate in the corresponding segment of the steel box girder; S2. Lifting and installing the tower base: The tower base and the tower crane foundation are processed and lifted as a whole; a vertical damper is installed between the tower base and the tower ear plate on the steel box girder to ensure that the tower base can automatically keep the tower base and the tower crane foundation level when installed on the tower ear plate. S3. Tower Crane Installation: Install tower crane supports, standard tower crane sections, slewing mechanism, counterweight, and tower jib; after acceptance, jack up and add sections until the tower crane's lifting height is greater than the installation height of the wind cables. S4. Install the tower: Install the tower section by section using standard tower sections. After reaching the installation height of the tower wind cable, promptly tension and anchor the tower and the wind cable lugs on the steel box girder using the tower wind cable. S5. Tower crane and tower clamp raising: Raise the tower crane section by section and install the tower clamp sections simultaneously; install the support parallel connection between the tower crane struts and the tower clamp cross braces; complete the third tower clamp wind cable according to the progress of steel box girder segment assembly, and install the steel box girder to the closing hole; S6. Simultaneous dismantling of tower crane and tower clamp: During dismantling, the tower crane height is lowered simultaneously while the tower clamp segments are being dismantled.

[0006] Preferably, in S2, the tower crane foundation adopts a steel grid frame.

[0007] Preferably, in S4, the wind cable for the tower is made of connecting steel strand.

[0008] Compared to existing technologies, the beneficial effects of this invention are as follows: This invention proposes a method for the coordinated installation and dismantling of tower cranes and anchor towers on steel box girders. Although the cross-section of a steel box girder is large, its stiffness is much smaller than that of a prestressed reinforced concrete beam. Solving the problem of safe force transmission in the steel box girder is the key issue in the application of this method. To solve the problem of transferring the load of the tower crane on the foundation to the anchor tower base of the inclined cable-stayed structure, the working load of the tower crane is transferred to the permanent support of the bridge through the steel box girder as the force-bearing fulcrum via the anchor tower, hinge shaft, and anchor tower ear plate. The innovative design content of this invention is as follows: 1. The tower crane foundation is set on the tower base, and the tower frame and the steel box girder are hinged by the tower ear plate to ensure that the tower crane's operating load is applied to the steel box girder through the tower, thereby ensuring that the steel box girder only bears the vertical concentrated force and does not generate bending moment.

[0009] 2. Front and rear dampers were designed for the tower base and tower ear plate to support the tower base and adjust its level, ensuring the safety of tower crane installation and operation.

[0010] 3. Design a special steel grid frame foundation for tower cranes, tower base, tower ear plate, and hinge shaft. The steel grid frame for tower cranes also serves as a lateral connecting beam for the tower.

[0011] 4. When designing the tower crane structure and its horizontal bracing, consider that the tower crane's cross-sectional dimensions can be vertically passed through and horizontally connected to it using struts.

[0012] 5. The tower crane foundation is set on the tower base. The tower structure design takes into account the verticality of the tower and adds wind cables. By eliminating the need for a tower crane foundation and reducing the installation height of the tower crane, the overall cost of the inclined cable-stayed process is greatly reduced, saving project costs. Attached Figure Description

[0013] Figure 1 This is a construction diagram illustrating the method for the coordinated installation and dismantling of towers and tower cranes on steel box girders, as described in this embodiment of the invention.

[0014] Figure 2 , 3 This is a construction diagram of the hoisting and mounting tower base in an embodiment of the present invention.

[0015] Figure 4 This is a construction diagram illustrating the support connection between the tower crane strut and the tower brace in an embodiment of the present invention.

[0016] Among them, 1. Steel box girder; 2. Tower clamp ear plate; 3. Tower clamp base; 4. Tower crane foundation; 5. Damper; 6. Tower crane support; 7. Tower clamp wind cable; 8. Tower crane strut; 9. Tower clamp cross brace. Detailed Implementation

[0017] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0018] Example: Figures 1-4 The method for the coordinated installation and dismantling of tower cranes and tower clamps on steel box girders, as shown, includes the following steps: S1. Install steel box girder: Install the large segment steel box girder 1 of the side span and pier top using the scaffolding method, and install the tower clamping ear plate 2 and wind cable ear plate on the corresponding segment of the steel box girder 1.

[0019] S2. Lifting and hoisting the tower base: The tower base 3 and the tower crane foundation 4 are processed and hoisted as a whole; the tower crane foundation 4 adopts a steel grid frame, and a vertical damper 5 is installed between the tower base 3 and the tower ear plate 2 on the steel box beam 1 to ensure that the tower base 3 can automatically keep the tower crane foundation 4 level when it is installed on the tower ear plate 2.

[0020] S3. Install the tower crane: Install the tower crane support 6, the standard tower crane section, the slewing mechanism, the counterweight, and the tower arm; after acceptance, lift and add sections until the tower crane's lifting height is greater than the installation height of the tower cable 7.

[0021] S4. Install the tower: Install the tower section by section using standard sections. After reaching the installation height of the tower wind cable 7, promptly tension and anchor the tower and the wind cable lugs on the steel box girder 1 using the tower wind cable 7. The tower wind cable 7 uses connecting steel strands. Adjust the damper and cable force to ensure uniform force distribution and the levelness of the tower base.

[0022] S5. Tower crane and tower clamp are raised synchronously: the tower crane is raised section by section and the tower clamp section is installed synchronously; the support connection between the tower crane strut 8 and the tower clamp cross brace 9 is installed; the third tower clamp wind cable is completed according to the assembly progress of the steel box girder section, and the steel box girder 1 is installed into the closing hole; when adjusting the cross section of the closing hole before closing, pay attention to ensuring the verticality of the tower crane.

[0023] S6. Simultaneous dismantling of tower crane and tower clamp: During dismantling, the tower crane height is lowered simultaneously while the tower clamp segments are being dismantled.

[0024] In this embodiment, the tower crane foundation 4 is set on the tower crane base 3. The load of the tower crane's operation is directly transferred to the tower crane base 3 and then to the tower crane ear plate 2 of the steel box girder 1 through the tower crane hinge shaft, which can avoid the steel box girder structure bearing bending moment loads. In addition, the temporary tower crane measures of the inclined cable-stayed system are combined with the tower crane for installation and dismantling, forming a design scheme that combines temporary and permanent stress distribution and operation, achieving the most economical overall cost while meeting the safety requirements of the construction plan. Furthermore, the tower crane installed on the tower crane base 3 is horizontally connected to the tower crane at the tower crane horizontal brace, which increases the vertical structural stiffness and stability.

[0025] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent solutions made using the contents of the present invention specification, whether directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of the present invention.

Claims

1. A method for the coordinated installation and dismantling of tower cranes and tower clamps on steel box girders, characterized in that, Includes the following steps: S1. Install steel box girder: Install the large segment steel box girder of the side span and pier top using the scaffolding method, and install the tower clamping ear plate and wind cable ear plate in the corresponding segment of the steel box girder; S2. Lifting and installing the tower base: The tower base and the tower crane foundation are processed and lifted as a whole; a vertical damper is installed between the tower base and the tower ear plate on the steel box girder to ensure that the tower base can automatically keep the tower base and the tower crane foundation level when installed on the tower ear plate. S3. Tower Crane Installation: Install tower crane supports, standard tower crane sections, slewing mechanism, counterweight, and tower jib; after acceptance, jack up and add sections until the tower crane's lifting height is greater than the installation height of the wind cables. S4. Install the tower: Install the tower section by section using standard tower sections. After reaching the installation height of the tower wind cable, promptly tension and anchor the tower and the wind cable lugs on the steel box girder using the tower wind cable. S5. Tower crane and tower clamp raising: Raise the tower crane section by section and install the tower clamp sections simultaneously; install the support parallel connection between the tower crane struts and the tower clamp cross braces; complete the third tower clamp wind cable according to the progress of steel box girder segment assembly, and install the steel box girder to the closing hole; S6. Simultaneous dismantling of tower crane and tower clamp: During dismantling, the tower crane height is lowered simultaneously while the tower clamp segments are being dismantled.

2. The method for coordinated installation and dismantling of tower cranes and tower clamps on steel box girders as described in claim 1, characterized in that, In S2, the tower crane foundation adopts a steel grid frame.

3. The method for coordinated installation and dismantling of tower cranes and tower clamps on steel box girders as described in claim 1 or 2, characterized in that, In S4, the wind cable for the tower is made of connecting steel strand.

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