Construction method of nonlinear hyperbolic box beam canopy

Abstract

The application discloses a kind of nonlinear hyperbolic box beam canopy manufacturing construction method, belongs to steel structure construction technical field.Step includes, box beam blanking, wing web roll forming, secondary assembly, welding and component all-around vertical integral pre-assembly.Advantages are that device is simple to make, ensures quality while improving processing and manufacturing precision, efficiency.Thereby the on-site installation efficiency of hyperbolic box beam canopy is improved, and component size precision is improved.Green construction is realized, and the requirement of personnel safe operation is realized.

Description

Technical Field

[0001] This invention belongs to the field of steel structure construction technology, and in particular provides a method for fabricating and constructing a nonlinear hyperboloid box girder canopy, which is applicable to the fabrication and construction of steel structure hyperboloid box girders. Background Technology

[0002] With the continuous improvement of the construction industry's requirements for spatial form and aesthetics, nonlinear hyperboloid steel structure canopies, with their unique streamlined appearance and spatial stress advantages, are increasingly widely used in large public buildings such as airports, train stations, and commercial complexes. Hyperboloid box girders, as the core load-bearing components of this type of canopy, exhibit a three-dimensional nonlinear geometric shape, placing extremely high demands on manufacturing precision, installation positioning, and load-bearing performance.

[0003] However, existing fabrication and construction technologies for hyperboloid box girders have significant shortcomings in practical applications. Traditional methods rely on manual measurement and experience-based judgment for controlling the geometric accuracy of complex curved surfaces, lacking efficient and precise digital modeling and processing technologies. This results in large component processing errors, making it difficult to meet design requirements. In terms of forming processes, segmented processing and on-site splicing are commonly used, which are cumbersome and inefficient, preventing mass production of components and severely impacting construction progress. Furthermore, the lack of reliable positioning and calibration methods during installation easily leads to component installation deviations, affecting the overall load-bearing performance and structural stability of the canopy. In addition, existing technologies also face technical bottlenecks in areas such as welding deformation control and component transportation protection, making it difficult to meet the high-precision and high-efficiency engineering requirements of modern architecture for hyperboloid steel structure canopies.

[0004] Therefore, there is an urgent need for a construction method that can solve key problems such as the control of geometric precision of complex curved surfaces, efficient forming and precise installation, so as to meet the engineering requirements of modern buildings for hyperboloid steel structure canopies. Summary of the Invention

[0005] The purpose of this invention is to provide a method for fabricating and constructing a nonlinear hyperboloid box girder canopy, which can effectively solve the problems of fabrication accuracy and installation positioning of curved spatial steel structures. It is applicable to the fabrication and construction of nonlinear hyperboloid box girder steel structures.

[0006] The main technologies of this invention include: box girder cutting, flange and web plate rolling, secondary assembly, welding, and all-round vertical pre-assembly of components. The specific operation steps are as follows: 1. Box Girder Cutting: Based on the detailed construction drawings and the plotting diagrams of individual components, CAD layout was used. During layout, due to the different radii of curvature of the box girder, to save material waste, the girder was divided into sections based on the overall detailed plotting diagram. Flange 1 and Web 2 were divided into three sections for layout. A 20mm allowance was added to the end plates during the layout (as a welding shrinkage allowance), while no allowance was added to the middle plate. The component layout data was input into a laser cutting machine for steel plate cutting. Semi-automatic cutting was used for the web beveling. This achieved rapid cutting, improved efficiency, and ensured the cutting accuracy and surface cutting quality of Flange 1 and Web 2.

[0007] 2. Rolling: The wings and webs of the hyperboloid box girder are rolled using a W11-30*3000 three-roll symmetrical rolling machine. Before rolling, positioning and rolling observation lines are marked on the wings and webs (Note: the observation lines are the lines connecting the inner and outer arc length bisectors), and a 50mm allowance is left at the ends. Then, the parallelism of the upper and lower rollers of the rolling machine is adjusted, and a center line is marked on the lower roller. When rolling the wings and webs, the center line on the lower roller must be parallel to the positioning lines and rolling observation lines on the wings and webs. If they are not parallel, twisting and inaccurate rotation angle dimensions will occur. At the same time, during the rolling process, the radius of curvature is checked using an arc template with a chord length of 1000mm. The gap between the web and the template must not exceed 3mm. The gap for wing 1 must not exceed 2mm. For areas with drastic curvature changes, variable radius rolling is achieved by adjusting the pressure of the upper roller (accuracy ±0.1mm), and the pressure value of the rolling machine is recorded simultaneously during the process (controlled within the range of 200-300kN).

[0008] 3. Secondary assembly and welding of components: To ensure the accuracy of the hyperbolic box girder, a hyperbolic box girder assembly jig device is used; Based on the surface parameters of the box girder, the height of the support column 8 is adjusted to form a reference surface of the jig that matches the design surface on the base 7, and the coordinates of each positioning point are calibrated with a total station (deviation ≤ 2mm).

[0009] 4. All-around vertical pre-assembly: (1) Assembly Unit Division. The main and secondary box girder beams are pre-assembled on a hard cement floor using a jig. The box girder canopy is divided into three units based on its curvature radius for overall pre-assembly.

[0010] (2) Pre-assembly process. First, assemble the main and secondary beams in the first unit. After acceptance, assemble the first unit and the second unit. After acceptance, dismantle all components of the first unit. Then assemble the second unit and the third unit. After all components are assembled and accepted, dismantle the whole unit. Make a record of component relocation during dismantling.

[0011] The advantages of this invention are that the device is simple to manufacture, ensuring quality while improving processing accuracy and efficiency. This improves the on-site installation efficiency of hyperboloid box girder canopies and enhances component dimensional accuracy. It also achieves the requirements of green construction and safe operation for personnel. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the segmented unfolding and blanking of the web of the nonlinear hyperboloid box girder described in this invention.

[0013] Figure 2 This is a schematic diagram of the process for rolling the flange of a W11-30*3000 three-roll symmetrical plate rolling machine.

[0014] Figure 3 This is a schematic diagram of a hyperbolic box-type assembly jig device.

[0015] Figure 4 This is a schematic diagram showing the division of pre-assembled units for a box girder canopy.

[0016] Figure 5 This is a flowchart illustrating the process of pre-assembling a fully vertical structure.

[0017] In the figure, 1 is the wing plate; 2 is the web plate; 3 is the positioning line; 4 is the rolling observation line; 5 is the lower roller of the rolling machine; 6 is the arc template; 7 is the assembly jig base; 8 is the adjustable support column; 9 is the positioning template; 10 is the pre-assembly unit dividing line; 11 is the main and secondary beam interface; 12 is the relocation mark; and 13 is the segment line. Detailed Implementation

[0018] The specific implementation of this invention adopts the following steps: 1. Box Girder Cutting: Based on the detailed construction drawings of the refined design, a 1:1 solid model of each box girder component is created using CAD software, generating a plotting diagram containing 3D coordinate information. For different curvature radii of the box girder, the flange 1 and web 2 are divided into three sections for unfolding according to the principle of "segmented fitting and reduced loss": 20mm allowance is reserved for each end plate during rolling (to compensate for rolling and welding shrinkage deformation), while the middle plate is unfolded according to the theoretical surface without any allowance. During unfolding, the positioning line 3 (centerline) and bevel direction of the plates are simultaneously marked to ensure subsequent assembly accuracy. Cutting: The unfolded data (including plate dimensions, bevel angle, and hole coordinates) is input into a fiber laser cutting machine, and the steel plate is cut using a nitrogen-protected cutting process. The bevel of web 2 (e.g., a 45° V-shaped bevel) is processed using a semi-automatic flame cutting machine, with the surface roughness controlled at Ra≤25μm and the edge perpendicularity deviation ≤1mm. After cutting, the plates are numbered and labeled with "upper flange", "lower web" and installation direction. The deviation between the measured dimensions and the theoretical values ​​is recorded simultaneously (allowable error ±1.5mm).

[0019] 2. Wing and Web Plate Rolling: Before rolling, use a W11-30*3000 three-roll symmetrical plate rolling machine to pre-calibrate the parallelism of the upper and lower rolls (error ≤ 0.5mm / m). Draw the center line on the surface of the lower roll as a reference line. Draw positioning lines 3 (plate centerline) and rolling observation lines 4 (a spiral line formed by connecting points with 10 equal divisions of the inner and outer arc lengths) on the surfaces of wing plate 1 and web plate 2. Leave a 50mm heading allowance at the ends of the plate (for equipment clamping during rolling). During curved surface forming control, align the plate positioning line 3 with the center line of the lower roll of the plate rolling machine. Monitor the plate feed direction in real time through the observation line 4 to ensure that the two are parallel to avoid twisting. A segmented, progressive rolling process is adopted: the initial feed is controlled at 1 / 5 of the plate width. For every 100mm of length rolled, the radius of curvature is checked using an arc-shaped template 6 with a chord length of 1000mm. The gap between the web 2 and the template must not exceed 3mm, and the gap between the flanges 1 must not exceed 2mm. For areas with drastic curvature changes, variable radius rolling is achieved by adjusting the downward pressure of the upper roller (accuracy ±0.1mm). During the process, the pressure value of the rolling machine is recorded simultaneously (controlled within the range of 200-300kN).

[0020] 3. Secondary Assembly and Welding of Components: The assembly jig is constructed using a hyperbolic box-type assembly jig device, including a steel base 7, adjustable support columns 8 (with screw jacks, adjustment accuracy ±1mm), and positioning templates 9 (curved surface profile prefabricated according to the design model). Based on the curved surface parameters of the box girder, the height of the support columns 8 is adjusted to form a jig reference surface on the base 7 that matches the designed curved surface, and the coordinates of each positioning point are calibrated using a total station (deviation ≤2mm); Assembly and welding process: (1) Base plate positioning: Place the lower flange 1 on the jig, fix the two ends and the mid-span position through the positioning template 9, and adjust its flatness (≤3mm / 2m). (2) Web plate assembly: Erect web plate 2, use the side mold of the jig for positioning, ensure the perpendicularity of the web plate and the flange (deviation ≤ h / 250, where h is the beam height), and use positioning pins for temporary fixation; (3) Top plate closure: hoist the upper flange 1, adjust the bevel gap with the web plate 2 (8±1mm), and weld it after clamping it with a clamp; (4) Welding sequence: Symmetrical welding is adopted. First, weld the inner welds of the web and flange (weld in 2 layers, each layer thickness ≤4mm). After flipping the component, weld the outer welds. After welding, perform UT flaw detection (Level II qualified). After welding, flame straighten the component (heating temperature 600-800℃) to control the straightness of the beam ≤L / 1000 (L is the beam length) and the torsional deformation ≤5mm / m.

[0021] 4. All-around vertical pre-assembly: (1) Assembly Unit Division. Based on the curvature radius distribution of the canopy steel structure, it is divided into three pre-assembly units along the span direction (unit dividing line 10 is located where the curvature changes gently), and each unit contains 3-5 main and secondary beams. A steel frame is erected on a hard cement ground, with a frame height of 500mm and an elevation error of ≤2mm for each support point.

[0022] (2) Pre-assembly process. (1) First unit assembly: Lay out the first unit on the jig at a 1:1 scale, hoist the main and secondary beams in the first unit in sequence, temporarily connect node 11 with high-strength bolts, use a total station to check the coordinates of each control point (X, Y, Z deviation ≤ 3mm), and mark the node position after adjustment; (2) Unit docking assembly: After the first unit is accepted, remove all components of the unit (retain the jig positioning mark), hoist the second unit components and align them with the jig reference point, repeat the above inspection steps, and ensure that the interface error between units is ≤ 2mm; (3) Overall forming acceptance: After the assembly of all units is completed, the overall curved surface line is inspected (using a 5m chord length for inspection, gap ≤ 5mm), the relative position data of each component is recorded, and a pre-assembly report is generated. After the pre-assembly is qualified, a relocation mark 12 (including unit number, installation coordinates, and interface direction) is marked on the surface of the component, and it is classified, packaged and transported to the site.

Claims

1. A method for fabricating and constructing a nonlinear hyperboloid box girder canopy, characterized in that, The specific construction steps are as follows: 1) Box girder cutting: According to the construction details, the single component is laid out using CAD. Based on the overall large detail drawing, it is divided into sections. The flange (1) and web (2) are divided into three sections for cutting. When the drawing is unfolded, the end plates are rolled with a 20mm allowance as the welding shrinkage allowance. The middle plate is not added. The component unfolding data is input into the laser cutting machine for steel plate cutting. The bevel of the web (2) is cut semi-automatically, which realizes rapid cutting and improves efficiency, ensuring the cutting accuracy and surface cutting quality of the flange (1) and web (2). 2) Rolling: The wings and webs of the hyperboloid box girder are rolled using a W11-30*3000 three-roll symmetrical rolling machine. Before rolling, the positioning and rolling observation lines (4) are marked on the wings and webs. The observation lines are the lines connecting the inner and outer arc lengths. A 50mm head allowance is left at the ends. Then, the parallelism of the upper and lower rollers of the rolling machine is adjusted, and the center line is marked on the lower roller. When rolling the wings (1) and webs (2), the center line on the lower roller is parallel to the positioning line (3) and the rolling observation line (4) on the wings and webs (2). At the same time, during the rolling process, the radius of curvature is checked with an arc template (6) with a chord length of 1000mm. The gap between the webs (2) and the template shall not be greater than 3mm. The gap must not exceed 2mm. For areas with drastic curvature changes, variable radius rolling can be achieved by adjusting the upper roller's downward pressure accuracy to ±0.1mm. During the process, the pressure value of the rolling machine is recorded simultaneously and controlled within the range of 200-300kN. 3) Secondary assembly and welding of components: A hyperbolic box-type assembly jig device is used to ensure the accuracy of the hyperbolic box-type beam; Based on the surface parameters of the box girder, by adjusting the height of the support column (8), a reference surface of the frame that matches the design surface is formed on the base (7), and the coordinate deviation of each positioning point is calibrated with a total station to be ≤2mm; 4) All-around vertical pre-assembly: Assembly Unit Division: The main and secondary beams of the box girder are pre-assembled on a hard cement floor using a jig. The box girder canopy is divided into three units based on its curvature radius for overall pre-assembly. Pre-assembly process: First, assemble the main and secondary beams in the first unit. After acceptance, assemble the first unit and the second unit. After acceptance, dismantle all components of the first unit. Then assemble the second unit and the third unit. After all components are assembled and accepted, dismantle the whole unit. Make component relocation markings (12) during dismantling.

2. The method for fabricating and constructing a nonlinear hyperboloid box girder canopy according to claim 1, characterized in that, The assembly and welding process in step 3) includes: Bottom plate positioning: Place the lower flange (1) on the jig, fix the two ends and the mid-span position through the positioning template (9), and adjust its flatness to ≤3mm / 2m; Web plate assembly: Erect the web plate (2), use the side mold of the jig for positioning, and ensure that the verticality deviation between the web plate (2) and the flange (1) is ≤h / 250, where h is the beam height, and use positioning pins for temporary fixation; Top plate closure: hoist the upper wing plate (1), adjust the bevel gap with the web plate (2) to 8±1mm, and weld it after clamping it with a clamp; Welding sequence: Symmetrical welding is adopted. First, weld the inner welds of the web and flange in two layers, with each layer having a thickness of ≤4mm. After flipping the component, weld the outer welds. Perform UT flaw detection after welding. After welding, flame straighten the component with a heating temperature of 600-800℃, control the straightness of the beam to ≤L / 1000, where L is the beam length, and the torsional deformation to ≤5mm / m.

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