A method for manufacturing a small-radius flat curve steel box beam U rib plate unit

Abstract

The application discloses a kind of small-radius flat curve steel box girder U rib plate unit manufacturing method, it is related to steel box girder manufacturing technical field, comprising the following steps: S1: based on the theoretical flat curve in the design drawing of steel box girder is plane lofting;S2: the intersection of partition plate position line and U rib theoretical position line is obtained as the positioning point of U rib;S3: select the two positioning points of adjacent on the same U rib and carry out line connection, to determine the actual length of U rib, butt joint seam position and installation layout line;S4: the intersection of partition plate position line and the theoretical plate edge line of panel is intersection, as the control point of panel contour, control point is connected with straight line, as the actual contour line of panel;S5: according to U rib installation layout line and the actual contour line of panel, the assembly of U rib and panel is carried out, welding, and finally profile is cut out once.The application solves the technical problem that quality is difficult to guarantee when the bridge of small-radius flat curve radius in the prior art is manufactured.

Description

Technical Field

[0001] This invention relates to the field of steel box girder manufacturing technology, and in particular to a method for manufacturing U-rib plate units of small-radius horizontal curve steel box girders. Background Technology

[0002] Since the Ministry of Transport issued the "Guiding Opinions on Promoting the Construction of Steel Structure Bridges on Highways" in 2016, the application of steel structure bridges in new and expanded highway projects has become increasingly widespread. Among these, ramp bridge steel box girders, due to their alignment requirements, often face complex situations where horizontal curves overlap with longitudinal curves. This complexity is particularly pronounced when the radius of the horizontal curve is small, posing a severe challenge to the fabrication of steel box girders, especially the top and bottom plate units with U-shaped stiffeners (U-ribs). Due to their inherent cross-sectional shape, U-ribs have inherent difficulties in resisting and adapting to horizontal bending deformation.

[0003] In engineering practice, for bridges with small horizontal curve radii, the industry typically adopts the following approach: For bridges with small horizontal curve radii (usually referring to a single beam segment with a plane sag > 50mm): The U-ribs are often treated by dividing the long U-ribs into fixed-length short segments. Multiple short U-ribs are then joined end-to-end to form a broken line approximating the design curve, achieving "replacing a curve with a fold." The panel outline (including longitudinal butt joints and free edges) is strictly determined according to the design arc radius, and is usually directly cut as a whole using a CNC cutting machine, resulting in a fan-shaped panel. However, the above process has drawbacks. Using multiple short U-ribs to splice into a broken line significantly increases the number of butt welds. This not only increases the welding workload and material waste, but also directly affects the installation accuracy of the U-ribs due to the difficulty in controlling cumulative errors. Panel fabrication requires secondary curved edge cutting, making quality control difficult. Summary of the Invention

[0004] The purpose of this invention is to provide a method for manufacturing U-rib plate units of steel box girders with small radius horizontal curves, which solves the technical problem that it is difficult to guarantee the quality when manufacturing bridges with small horizontal curve radii in the prior art.

[0005] This application discloses a method for fabricating U-rib plate units of small-radius horizontal curve steel box girders, including the following steps: S1: Based on the theoretical horizontal curve in the design drawing of the steel box girder, perform planar layout to determine the theoretical edge line of the panel, the theoretical position line of the U-rib, and the position line of the partition plate arranged radially along the panel. S2: Obtain the intersection of the partition position line and the theoretical position line of the U-rib, and use it as the positioning point of the U-rib; S3: Select two adjacent positioning points on the same U-rib and connect them with a line, and extend the line to the position of the bisection point of the distance between two adjacent partitions, so as to determine the actual length of the U-rib, the position of the butt joint and the installation layout line; S4: The intersection point of the partition position line and the theoretical edge line of the panel is taken as the control point of the panel outline. The control points are connected by straight lines to form a multi-segment broken line along the arc direction, which is used as the actual outline of the panel. S5: Based on the U-rib installation layout in step S3 and the actual outline of the panel in step S4, assemble and weld the U-rib to the panel, and finally cut out the outline in one go.

[0006] This application adopts the layout concept of positioning U-ribs with partition slots to determine the layout of U-ribs. At the same time, it adopts the top and bottom plate unit broken line method and edge cutting process, which saves an edge cutting process and trimming workload, and improves the manufacturing accuracy of the plate unit.

[0007] Based on the above technical solution, the present application can be further improved as follows: Furthermore, in step S3, the U-ribs are installed in a straight-curved arrangement. The advantage of this step is that it ensures a smooth connection while minimizing gaps.

[0008] Furthermore, the butt joint of the U-rib is defined by the following steps: Connect the positioning points on two adjacent partitions on the same U-rib with straight lines and extend them until they intersect. The intersection point is the U-rib butt joint. The advantage of this step is that it facilitates the subsequent assembly of the U-rib.

[0009] Furthermore, in step S4, when the difference in elevation between the line connecting adjacent control points and the edge line of the theoretical plate meets the preset accuracy requirements, the connection method of adjacent control points is adopted, or the connection method of crossing one or more control points is adopted to reduce the number of segments of the formed broken line. The beneficial effect of this step is that it facilitates subsequent cutting.

[0010] Furthermore, if it is a cross-point connection, the same point should be selected on the two plate units on both sides of the same butt joint to connect the lines. The advantage of this step is that it can reduce the number of segments of the broken line by using cross-point connections.

[0011] Furthermore, the specific content of step S5 is as follows: S501: Use CNC laser scribing to scribing U-rib installation layout lines, actual panel outline lines, and partition position lines on the steel plate; S502: Assemble the U-ribs and perform welding; S503: Repair welding deformation and adjust the outline according to the longitudinal and transverse baselines; S504: A semi-automatic trolley is used to precisely cut the edge contour and bevel along the actual outline of the panel. The advantage of this step is that it cuts in one go, reducing the processing difficulty and ensuring the quality of the final product.

[0012] Furthermore, the steel box girder is a steel box girder with a horizontal curve radius of less than 300m.

[0013] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. In the layout stage, this application uses partition slots to position U-ribs. The partitions are arranged radially, and at least two partition slots are used to position U-ribs. The U-ribs are straight instead of curved, and the U-rib joints are located between the partitions to ensure the consistency of the partition slot positions. This allows the partition units to be mass-produced and minimizes the U-rib joints, avoiding the internal stress generated by the flame bending of the U-ribs, which would exacerbate the welding deformation of the plate units.

[0014] 2. This application adopts a top and bottom plate unit broken line method and edge trimming process. The intersection of the partition plate position line and the theoretical plate edge line is used as the control point to form a broken line. The broken line replaces the curve. The laser scribing program is used to accurately scribing the line. Then, the U-shaped ribs are assembled. After welding and finishing, a semi-automatic carriage is used to accurately trim the edge along the broken line. This abandons the conventional process of adding material according to the curve strip process and trimming the edge after assembly and welding. This saves one trimming process and finishing work, avoids the risk of high difficulty and difficulty in quality control of the secondary trimming of the arc type, and improves the manufacturing accuracy of the plate unit. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic flowchart illustrating a method for fabricating a U-rib plate unit for a small-radius horizontal curve steel box girder according to a specific embodiment of the present invention. Figure 2 This is a schematic diagram of the U-rib plate unit of the small-radius horizontal curve steel box girder according to a specific embodiment of the present invention; Figure 3 This is a schematic diagram of the positioning U-rib in a method for fabricating a small-radius horizontal curve steel box girder U-rib plate unit according to a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the overall layout of control points in a method for fabricating a small-radius horizontal curve steel box girder U-rib plate unit according to a specific embodiment of the present invention; Figure 5 This is a schematic diagram of a single control point plate in a method for fabricating a U-rib plate unit of a small-radius horizontal curve steel box girder according to a specific embodiment of the present invention; Figure 6 This is a schematic diagram of laser scribing in a method for fabricating a small-radius horizontal curve steel box girder U-rib plate unit according to a specific embodiment of the present invention; Detailed Implementation The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention. It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0017] In the description of this application, it should be understood that the terms "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present 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, and therefore should not be construed as a limitation of the present invention.

[0018] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific embodiments.

[0019] Example: like Figure 1-6 As shown in the embodiment of this application, a method for manufacturing U-rib plate units of small-radius horizontal curve steel box girders is disclosed. The design is based on the structural characteristics of the top and bottom plate units of small-radius horizontal curve U-rib steel box girders. Since the plane sag of the steel box girder is large, the U-ribs in the plate unit cannot be straightened or flame-bent in the existing process, and the butt joints of the inner panels of the segments cannot be divided in a straight line. This application can ensure the manufacturing accuracy of the plate unit and the finished segment.

[0020] This application employs a partition slot positioning U-rib, with the partitions arranged radially. At least two partition slots are used to position the U-ribs, which are straight rather than curved. The U-rib butt joints are located between the partitions to ensure consistent partition slot positions, allowing for mass production of partition units and minimizing U-rib butt joints. This avoids internal stress generated during flame bending of the U-ribs, which could exacerbate welding deformation of the plate units. Simultaneously, this application uses a zigzag method for top and bottom plate units (panels) followed by edge trimming. The intersection of the partition position line and the theoretical plate edge line is used as control points to form a zigzag line, replacing curves. A laser scribing program is used for precise scribing, followed by assembly of the U-ribs. After welding and finishing, a semi-automatic carriage precisely trims the edges along the zigzag line. This eliminates the conventional method of adding material according to a curved strip process and then trimming after welding, saving a trimming step and finishing work. It also avoids the risks of difficult secondary trimming of curved surfaces and the difficulty in quality control, thus improving the manufacturing accuracy of the plate units.

[0021] The specific steps for this application are as follows: S1: Based on the theoretical horizontal curve in the design drawing of the steel box girder, perform planar layout to determine the theoretical edge line of the panel, the theoretical position line of the U-rib, and the position line of the partition plate arranged radially along the panel. The steel box girder is a small radius steel box girder. S2: Obtain the intersection of the partition position line and the theoretical position line of the U-rib, and use it as the positioning point of the U-rib; S3: Select two adjacent positioning points on the same U-rib and connect them with a line, and extend the line to the position of the bisection point of the distance between two adjacent partitions, so as to determine the actual length of the U-rib, the position of the butt joint and the installation layout line; S4: The intersection point of the partition position line and the theoretical edge line of the panel is taken as the control point of the panel outline. The control points are connected by straight lines to form a multi-segment broken line along the arc direction, which is used as the actual outline of the panel. S5: Based on the U-rib installation layout in step S3 and the actual outline of the panel in step S4, assemble and weld the U-rib to the panel, and finally cut out the outline in one go.

[0022] In step S3, the installation layout of the U-rib is a straight-curved arrangement. In this application, the U-rib is laid out in plan according to the theoretical line shape. The positioning point is determined by the intersection of the partition position line and the theoretical position line of the U-rib. The line connecting two adjacent positioning points is extended to the two equal division points of the partition spacing, thereby determining the length of the U-rib and the actual layout. This application can use the slots of two partitions to position the U-rib, or within the tolerance range, the line connecting the slots of three partitions can be used to position the U-rib. The U-rib is straight with some curves. The U-rib butt joint is set between the partitions to ensure the consistency of the partition slot positions, reduce the number of partition parts, and ensure smooth butt joint while minimizing the number of gaps.

[0023] The butt joint of the U-rib is defined by the following steps: Connect the positioning points on two adjacent partitions on the same U-rib with straight lines and extend them until they intersect. The intersection point is the U-rib butt joint. This intersection point is generally located in the middle of the two partitions. Draw all the straight lines in sequence, which are the actual positioning lines for the U-rib installation. In step S4, when the difference in elevation between the line connecting adjacent control points and the edge line of the theoretical plate meets the preset accuracy requirements, the connection method of adjacent control points is adopted, or the connection method of crossing one or more control points is adopted to reduce the number of segments of the formed broken line, reduce the number of times the trolley track changes direction, and facilitate subsequent edge cutting.

[0024] Specifically, if it is a cross-point connection, the same point should be selected on the two plate units on both sides of the same butt joint; otherwise, the mismatch of the plate edge contours will lead to uneven width of the butt joint and affect the weld quality.

[0025] The specific content of step S5 is as follows: S501: Use CNC laser scribing to scribing U-rib installation layout lines, actual panel outline lines, and partition position lines on the steel plate; S502: Assemble the U-ribs and perform welding; S503: Repair welding deformation and adjust the outline according to the longitudinal and transverse baselines; S504: A semi-automatic trolley is used to precisely cut the edge contour and bevel along the actual contour line of the panel.

[0026] The steel box girder is a steel box girder with a horizontal curve radius of less than 300m.

[0027] Further explanation is provided regarding this application: The U-rib butt welding process of this application greatly reduces the number of U-rib butt welds, thereby reducing quality risks and construction workload; and it eliminates the U-rib flame bending process, reducing the internal stress of the U-rib, significantly improving the control of plate unit structure deformation and box assembly accuracy, while also improving assembly efficiency.

[0028] The unchanged slot spacing and the distance between the slot and the plate edge in this application reduce the types of partition drawings, improve the efficiency of drawing and document preparation, and reduce the risk of errors. At the same time, this allows the partition units to be mass-produced, improving the production efficiency by about 20%. It also increases the interchangeability of partitions in the final assembly stage, reduces the time for picking parts in the final assembly, reduces the time occupied by lifting equipment, and improves the final assembly efficiency by about 20%.

[0029] This application uses a partition slot to position the U-rib, forming parallel broken line segments. Compared to conventional bending of U-ribs, which can only be welded using a semi-automatic trolley, this process can be achieved by a gantry multi-nozzle automatic welding machine, greatly improving welding efficiency. This application assembles and welds on the steel plate material, maximizing the constraint of welding deformation of the plate unit. Simultaneously, the broken line edges are more conducive to trimming and cutting, ensuring the manufacturing accuracy of the curved plate unit.

[0030] This application uses the intersection of the partition position line and the plate edge line as the control point to ensure the matching of the butt welds between adjacent plate units and to ensure the consistency of the weld gap.

[0031] This application reduces the material preparation process. Extensive welding on curved panels can affect the curvature. This avoids a larger amount of trimming work for curved panel units, reduces the difficulty of edge cutting, and also speeds up the turnover efficiency.

[0032] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification. In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for fabricating U-rib plate units of small-radius horizontal curve steel box girders, characterized in that, Includes the following steps: S1: Based on the theoretical horizontal curve in the design drawing of the steel box girder, perform planar layout to determine the theoretical edge line of the panel, the theoretical position line of the U-rib, and the position line of the partition plate arranged radially along the panel. S2: Obtain the intersection of the partition position line and the theoretical position line of the U-rib, and use it as the positioning point of the U-rib; S3: Select two adjacent positioning points on the same U-rib and connect them with a line, and extend the line to the position of the bisection point of the distance between two adjacent partitions, so as to determine the actual length of the U-rib, the position of the butt joint and the installation layout line; S4: The intersection point of the partition position line and the theoretical edge line of the panel is taken as the control point of the panel outline. The control points are connected by straight lines to form a multi-segment broken line along the arc direction, which is used as the actual outline of the panel. S5: Based on the U-rib installation layout in step S3 and the actual outline of the panel in step S4, assemble and weld the U-rib to the panel, and finally cut out the outline in one go. In step S3, the installation layout line of the U-rib is arranged in a straight and curved manner. The butt joint of the U-rib in S3 is defined by the following steps: Connect the positioning points on two adjacent partitions on the same U-rib with straight lines and extend them until they intersect. The intersection point is the U-rib butt joint. In step S4, when the difference in elevation between the line connecting adjacent control points and the edge line of the theoretical plate meets the preset accuracy requirements, the connection method of adjacent control points is adopted, or the connection method of crossing one or more control points is adopted to reduce the number of segments of the formed broken line. The specific content of step S5 is as follows: S501: Use CNC laser scribing to scribing U-rib installation layout lines, actual panel outline lines, and partition position lines on the steel plate; S502: Assemble the U-ribs and perform welding; S503: Repair welding deformation and adjust the outline according to the longitudinal and transverse baselines; S504: A semi-automatic trolley is used to precisely cut the panel edge contour and bevel along the outline of the panel.

2. The method for fabricating the U-rib plate unit of a small-radius horizontal curve steel box girder according to claim 1, characterized in that, If it is a cross-point connection, the same point should be selected on the two plate units on both sides of the same butt joint.

3. The method for fabricating the U-rib plate unit of a small-radius horizontal curve steel box girder according to claim 1 or 2, characterized in that, The steel box girder is a steel box girder with a horizontal curve radius of less than 300m.

Images