Construction method of overhead platform steel structure

Abstract

The application discloses a high-level platform steel structure construction method, and belongs to the technical field of high-level platform construction. The high-level platform steel structure construction method comprises the following steps: (1) site treatment: selecting a prefabrication site near a high-level bearing column, filling the pits and depressions of the ground of the prefabrication site, simultaneously shoveling the protrusions of the ground, finally tamping the ground to make the ground flat and solid, and then erecting a beam plate full-frame scaffold on the high-level bearing column; (2) prefabricating a platform steel structure: assembling and welding a steel structure on the prefabrication site according to drawings, so that the steel structure forms a platform steel structure on the prefabrication site, 2 permanent lifting points are arranged on the right outer and left outer of a truss of the platform steel structure, 2 permanent lifting points are arranged at a distance of 2.4 m from the right inner of the truss, and 2 permanent lifting points are arranged at the left end of the truss, the application can fully guarantee the safety during construction, can accurately control the installation position of the high-level platform steel structure, and guarantees the installation quality of the high-level platform steel structure.

Description

Technical Field

[0001] This invention relates to the field of elevated platform construction technology, and more particularly to a construction method for steel structures of elevated platforms. Background Technology

[0002] Currently, the main forms of bridge construction in China are prestressed concrete structures and steel truss and steel box girder structures. Steel pipe concrete structures and steel pipe truss structures are also widely used in existing bridge construction projects. Although the above-mentioned bridge structures each have many advantages and are suitable for different bridge construction environments, they also have some significant drawbacks. However, all of the above-mentioned bridge structures require the construction of elevated platforms.

[0003] A search revealed that Chinese patent number CN102168418B discloses a construction method for an offshore elevated platform. Although the elevated platform is easy to build and does not present any technical difficulties, its construction process has low safety and it is also impossible to accurately control the installation quality of the steel structure of the elevated platform. Summary of the Invention

[0004] The purpose of this invention is to address the deficiencies in the existing technology by proposing a construction method for elevated platform steel structures.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The construction method for the steel structure of an elevated platform is as follows:

[0007] (1) Site preparation: Select a prefabrication site near the elevated load-bearing column, fill in the pits and depressions on the ground of the prefabrication site, level the raised parts of the ground, and finally compact the ground to make the ground flat and firm. Then erect a full-span scaffolding for beams and slabs on the elevated load-bearing column.

[0008] (2) Prefabricated platform steel structure: According to the drawings, the steel structure is assembled and welded on the prefabrication site so that the steel structure forms a platform steel structure on the prefabrication site. Two permanent suspension points are set on the right and left outer sides of the truss of the platform steel structure, and two permanent suspension points are set at 2.4 meters inside the right side of the truss. Two permanent suspension points are set on the left side of the truss.

[0009] (3) Pre-inspection: Check whether the permanent lifting point in step (2) is stable, then install the corbel anchor plate on the elevated load-bearing column, and at a distance of 5-6m from the outside of the crash barrier. At the same time, make the corbel anchor plate wrap around the top of the crash barrier. Meanwhile, check whether the various indicators of the crane are normal, check whether the wire rope buckle is tightened, and check whether the installation of the safety wire rope buckle meets the requirements.

[0010] (4) Trial lifting: Install loads on the truss of the platform steel structure, and then connect the permanent lifting point of the platform steel structure to the crane through steel wire ropes. The platform steel structure is lifted 100mm off the ground by the crane. At the same time, ordinary workers on both sides use towing ropes to hold the platform steel structure to prevent it from swinging until the truss is kept horizontal.

[0011] (5) Lifting: After the trial lift is successful, the platform steel structure is lifted by a crane. During the lift, two general workers use ropes on both sides of the other end to control the platform steel structure and keep it in a certain direction to prevent it from touching the elevated load-bearing column. When the platform steel structure is close to the elevated load-bearing column, the signalman above the elevated load-bearing column directs the signalman below the elevated load-bearing column, and the signalman below directs the crane operator, so that the lifting position of the platform steel structure can be accurately controlled and the platform steel structure is ready to be in place.

[0012] (6) Welding and re-inspection: After the platform steel structure is prepared, the permanent suspension points on the truss of the platform steel structure are connected to the wind-resistant suspension points on the elevated load-bearing columns, and then the welding and anchoring are carried out. After the welding is completed, the load on the truss is removed, and then the weld inspection instrument is used to detect whether the welding points of the truss are qualified. The qualified welding points are marked as A, and the unqualified welding points are marked as B. B is reworked and inspected a second time until all welding points are qualified.

[0013] (7) Post-processing: Remove the steel wire ropes on the platform steel structure truss, drive the crane away from the construction site, and then dismantle the full-span scaffolding of the beams and slabs.

[0014] Furthermore, the erection process of the full-span scaffolding for beams and slabs described in step (1) is as follows:

[0015] S1. Erect uprights and horizontal bars, and at the same time, erect longitudinal and transverse ground bracing at the bottom of the uprights. Then insert U-bracing at the top of the uprights to form a prefabricated full-span scaffold.

[0016] S2. Vertical and horizontal scissor bracing are installed on the precast full-span scaffold. When the width-to-height ratio of the precast full-span scaffold is ≥4, horizontal reinforcement layers are installed at the top and bottom of the precast full-span scaffold. If the distance between the top and bottom horizontal reinforcement layers is ≥16m, horizontal reinforcement layers are added every 8 to 12m to form a beam-slab full-span scaffold.

[0017] Furthermore, the horizontal sweeping rod is located below the vertical sweeping rod, and the center of the sweeping rod is ≤200mm above the working surface.

[0018] Furthermore, the length of the U-shaped support extending out of the upright is 150-200mm, and the length of the U-shaped support inserted into the upright is ≥150mm.

[0019] Furthermore, in step (3), the anchor bolts of the corbel anchor plate are grade 8.8 anchor bolts with a diameter of 22mm, the anchor plate is made of 12mm thick Q235B steel with a diameter of 400mm, and the anchor bolts of the corbel anchor plate are arranged in 3 rows and 2 columns with a spacing of 100mm.

[0020] Furthermore, the crane mentioned in step (4) is a 25T crane.

[0021] Furthermore, the welding method for welding anchoring in step (6) is plasma arc welding, with the following conditions: current 220A, voltage 20V, welding speed 260mm / min, and shielding gas flow rate 30L / min.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. This invention reduces safety hazards by leveling and compacting the ground, checking the stability of permanent lifting points, verifying the normal operation of the crane, inspecting the tightness of wire rope clips, and ensuring the installation of safety wire rope clips meets requirements. Then, loads are installed on the truss of the platform steel structure, and the crane lifts the platform steel structure 100mm off the ground. Simultaneously, workers on both sides use tow ropes to hold the platform steel structure in place to prevent swaying until the truss is kept horizontal, achieving the goal of safe hoisting and fully guaranteeing safety during the construction process.

[0024] 2. This invention uses a signalman above the elevated load-bearing column to direct a signalman below the column, who in turn directs the crane operator. This allows for precise control of the lifting position of the platform steel structure, connecting the permanent lifting points on the truss of the platform steel structure to the wind-resistant lifting points on the elevated load-bearing column. Welding and anchoring are then performed. After welding, the load on the truss is removed, and a weld inspection instrument is used to check the weld points. Qualified weld points are marked as A, and unqualified weld points are marked as B. Weld points B are reworked and inspected a second time until all weld points are qualified. This achieves precise control of the installation position of the elevated platform steel structure and ensures the installation quality of the elevated platform steel structure. Attached Figure Description

[0025] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0026] Figure 1 This is a schematic diagram of the construction process of the elevated platform steel structure construction method proposed in this invention. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0028] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0029] Example 1:

[0030] Please see Figure 1 This invention provides a technical solution: a construction method for a steel structure of an elevated platform, the steps of which are as follows:

[0031] (1) Site preparation: Select a prefabrication site near the elevated load-bearing column, fill in the pits and depressions on the ground of the prefabrication site, level the raised parts of the ground, and finally compact the ground to make the ground flat and firm. Then erect a full-span scaffolding for beams and slabs on the elevated load-bearing column.

[0032] (2) Prefabricated platform steel structure: According to the drawings, the steel structure is assembled and welded on the prefabrication site so that the steel structure forms a platform steel structure on the prefabrication site. Two permanent suspension points are set on the right and left outer sides of the truss of the platform steel structure, and two permanent suspension points are set at 2.4 meters inside the right side of the truss. Two permanent suspension points are set on the left side of the truss.

[0033] (3) Pre-inspection: Check whether the permanent lifting point in step (2) is stable, then install the corbel anchor plate on the elevated load-bearing column, and at a distance of 5-6m from the outside of the crash barrier. At the same time, make the corbel anchor plate wrap around the top of the crash barrier. Meanwhile, check whether the various indicators of the crane are normal, check whether the wire rope buckle is tightened, and check whether the installation of the safety wire rope buckle meets the requirements.

[0034] (4) Trial lifting: Install the load on the truss of the platform steel structure, and then connect the permanent lifting point of the platform steel structure to the crane through the wire rope. The platform steel structure is lifted 100mm off the ground by the crane. At the same time, ordinary workers on both sides use towing ropes to pull the platform steel structure to prevent it from swinging until the truss is kept horizontal.

[0035] Specifically, to ensure construction safety, a prefabrication site was selected near the elevated load-bearing columns. The ground was then leveled and compacted. Full-span scaffolding for beams and slabs was then erected on the elevated load-bearing columns. Simultaneously, steel structures were assembled and welded on the prefabrication site according to the drawings, forming a platform steel structure. Two permanent lifting points were installed on the outer right and left sides of the truss of the platform steel structure, and two more permanent lifting points were installed 2.4 meters inside the right side of the truss. Two more permanent lifting points were installed on the inner left side of the truss. The permanent lifting points were then inspected. To ensure stability, the crane's various indicators are checked for normality. The wire rope clips are inspected for tightness, and the installation of safety wire rope clips is verified to meet requirements. Loads are then installed on the platform's steel truss, and the permanent lifting points of the platform's steel structure are connected to the crane via wire ropes. The crane then lifts the platform's steel structure 100mm off the ground. Simultaneously, workers on both sides use tow ropes to hold the platform's steel structure in place to prevent swaying, until the truss remains horizontal, achieving the goal of safe hoisting and fully guaranteeing safety during construction.

[0036] Example 2:

[0037] Please see Figure 1 The present invention provides a technical solution: a construction method for a steel structure of an elevated platform, which further includes: (5) hoisting: after the trial hoisting is successful, the steel structure of the platform is hoisted by a crane. During hoisting, two ordinary workers use ropes on both sides of the other end to control the steel structure of the platform and keep it in a certain direction to prevent it from touching the elevated load-bearing column. When the steel structure of the platform is close to the elevated load-bearing column, the signalman above the elevated load-bearing column directs the signalman below the elevated load-bearing column, and the signalman below directs the crane driver, so that the hoisting position of the steel structure of the platform can be accurately controlled and the steel structure of the platform is ready to be in place.

[0038] (6) Welding and re-inspection: After the platform steel structure is prepared, the permanent suspension points on the truss of the platform steel structure are connected to the wind-resistant suspension points on the elevated load-bearing columns, and then the welding and anchoring are carried out. After the welding is completed, the load on the truss is removed, and then the weld inspection instrument is used to detect whether the welding points of the truss are qualified. The qualified welding points are marked as A, and the unqualified welding points are marked as B. B is reworked and inspected a second time until all welding points are qualified.

[0039] (7) Post-processing: Remove the steel wire ropes on the platform steel structure truss, drive the crane away from the construction site, and then dismantle the full-span scaffolding of the beams and slabs.

[0040] Specifically, during the installation of the elevated platform steel structure, a crane is used to lift the steel structure. Two workers control the structure with ropes at either end, maintaining its orientation to prevent it from touching the elevated load-bearing columns. When the platform steel structure approaches the columns, a signalman above the columns directs a signalman below, who in turn directs the crane operator. This precise control of the lifting position allows for the connection of the permanent lifting points on the truss to the wind-resistant lifting points on the load-bearing columns, followed by welding and anchoring. After welding, the loads on the truss are removed, and a weld inspection instrument is used to check the weld points. Qualified weld points are marked as A, and unqualified weld points as B. Welds B are reworked and inspected a second time until all weld points are qualified. This process ensures precise control over the installation position of the elevated platform steel structure and guarantees its installation quality.

[0041] The working principle and usage process of this invention are as follows: A prefabrication site is selected near the elevated load-bearing columns, the ground is leveled and compacted, and then a full-span scaffolding for beams and slabs is erected on the elevated load-bearing columns. Simultaneously, the steel structure is assembled and welded on the prefabrication site according to the drawings, forming a platform steel structure. Two permanent lifting points are set on the outer right and outer left sides of the truss of the platform steel structure, and two permanent lifting points are set 2.4 meters inside the right side of the truss. Two permanent lifting points are also set on the inner left side of the truss. The permanent lifting points are then checked. To ensure stability, the crane's various indicators are normal, the wire rope clips are tightened, and the installation of the safety wire rope clips meets the requirements. Loads are then installed on the platform's steel truss, and the permanent lifting points of the platform's steel structure are connected to the crane via wire ropes. The crane then lifts the platform's steel structure 100mm off the ground. Meanwhile, workers on both sides use towing ropes to hold the platform's steel structure in place to prevent swaying until the truss remains horizontal, achieving the goal of safe hoisting and fully guaranteeing safety during the construction process.

[0042] After the above operations are completed, the platform steel structure is lifted by a crane. During the lifting process, two workers control the platform steel structure with ropes on both sides to maintain its orientation and prevent it from touching the elevated load-bearing columns. When the platform steel structure is close to the elevated load-bearing columns, the signalman above the column directs the signalman below, who in turn directs the crane operator. This ensures precise control of the lifting position of the platform steel structure, allowing the permanent lifting points on the truss of the platform steel structure to be connected to the wind-resistant lifting points on the elevated load-bearing columns. Welding and anchoring are then carried out. After welding, the load on the truss is removed, and a weld inspection instrument is used to check whether the weld points of the truss are qualified. Qualified weld points are marked as A, and unqualified weld points are marked as B. B weld points are reworked and inspected a second time until all weld points are qualified. This achieves the goal of accurately controlling the installation position of the elevated platform steel structure and ensuring the installation quality of the elevated platform steel structure, thus completing the operation.

[0043] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A construction method for steel structures of elevated platforms, characterized in that, The construction steps for the steel structure of the elevated platform are as follows: (1) Site preparation: Select a prefabrication site near the elevated load-bearing column, fill in the pits and depressions on the ground of the prefabrication site, and at the same time level the raised parts of the ground. Finally, compact the ground to make the ground flat and firm, and then erect a full-span scaffolding for beams and slabs on the elevated load-bearing column. (2) Prefabricated platform steel structure: According to the drawings, the steel structure is assembled and welded on the prefabrication site so that the steel structure forms a platform steel structure on the prefabrication site. Two permanent suspension points are set on the right and left sides of the truss of the platform steel structure, and two permanent suspension points are set 2.4 meters inside the right end of the truss and two permanent suspension points are set inside the left end of the truss. (3) Pre-inspection: Check whether the permanent lifting point in step (2) is stable, then install the corbel anchor plate on the elevated load-bearing column, and at a distance of 5-6m from the outside of the crash barrier. At the same time, make the corbel anchor plate wrap around the top of the crash barrier. Meanwhile, check whether the various indicators of the crane are normal, check whether the wire rope buckle is tightened, and check whether the installation of the safety wire rope buckle meets the requirements. (4) Trial lifting: Install loads on the truss of the platform steel structure, and then connect the permanent lifting point of the platform steel structure to the crane through steel wire ropes, so that the platform steel structure is lifted 100mm off the ground by the crane. At the same time, ordinary workers on both sides use towing ropes to pull the platform steel structure to prevent it from swinging until the truss is kept horizontal. (5) Lifting: After the trial lifting is successful, the platform steel structure is lifted by a crane. During the lifting, two general workers use ropes on both sides of the other end to control the platform steel structure and keep it in a certain direction to prevent it from touching the elevated load-bearing column. When the platform steel structure is close to the elevated load-bearing column, the signalman above the elevated load-bearing column directs the signalman below the elevated load-bearing column, and the signalman below directs the crane operator, so that the lifting position of the platform steel structure can be accurately controlled and the platform steel structure is ready to be in place. (6) Welding and re-inspection: After the platform steel structure is prepared, the permanent suspension points on the truss of the platform steel structure are connected to the wind-resistant suspension points on the elevated load-bearing columns, and then the welding and anchoring are carried out. After the welding is completed, the load on the truss is removed, and then the weld inspection instrument is used to detect whether the welding points of the truss are qualified. The qualified welding points are marked as A, and the unqualified welding points are marked as B. B is reworked and inspected a second time until all welding points are qualified. (7) Post-processing: Remove the steel wire ropes on the steel structure truss of the platform, drive the crane away from the construction site, and then dismantle the full-span scaffolding of the beams and slabs; The specific process of erecting the full-span scaffolding for beams and slabs described in step (1) is as follows: S1. Erect uprights and horizontal bars, and at the same time, erect longitudinal and transverse ground bracing at the bottom of the uprights. Then insert U-bracing at the top of the uprights to form a prefabricated full-span scaffold. S2. Vertical and horizontal scissor bracing are installed on the precast full-span scaffold. When the width-to-height ratio of the precast full-span scaffold is ≥4, horizontal reinforcement layers are installed at the top and bottom of the precast full-span scaffold. If the spacing between the top and bottom horizontal reinforcement layers is ≥16m, horizontal reinforcement layers are added every 8 to 12m to form a beam-slab full-span scaffold. The horizontal sweeping bar is located below the vertical sweeping bar, and the center of the sweeping bar is ≤200mm above the working surface; The length of the U-shaped bracket extending out of the upright is 150-200mm, and the length of the U-shaped bracket inserted into the upright is ≥150mm; The anchor bolts of the corbel anchor plate mentioned in step (3) are 8.8 grade anchor bolts with a diameter of 22mm. The anchor plate is made of 12mm thick Q235B steel with a diameter of 400mm. The anchor bolts of the corbel anchor plate are arranged in 3 rows and 2 columns with a spacing of 100mm. The crane used in step (4) is a 25T crane; The welding method for the welding anchor described in step (6) is plasma arc welding, with the following conditions: current 220A, voltage 20V, welding speed 260mm / min, and shielding gas flow rate 30L / min.

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