Manufacturing process of box steel truss bevel u rib

Abstract

This invention relates to a manufacturing process for the beveled U-ribs of box girder steel trusses. By setting beveled ends of the U-ribs and controlling the precision of the U-rib hole group along the beveled ends, this process solves the problem of controlling the butt joint gap of bolted U-ribs in curved bridge roof units, while ensuring accuracy requirements and improving production efficiency. After manufacturing the bolted U-ribs for curved bridge roof units using straight sections, the two butt joint U-rib sides are made into parallel bevels. Simultaneously, by adjusting the plate edge distance of the U-rib bolt holes, the bolt holes of the two limbs of the beveled U-ribs are aligned in both the horizontal and vertical planes, standardizing the spacing of the bolt holes. Advantages: First, this invention effectively solves the connection problem of bolted U-ribs in curved bridge roof units; second, it not only fully meets the accuracy requirements of U-rib manufacturing but, more importantly, meets the geometric and quality requirements, improving production efficiency and possessing high practical and promotional value; third, it serves as a good reference for the subsequent manufacturing of similar beveled U-ribs.

Description

Technical Field

[0001] This invention relates to a manufacturing process for the inclined U-ribs of box girder steel trusses, which solves the problem of controlling the butt joint gap of bolted U-ribs in curved bridge top plate units by setting the inclined edge of the U-rib and controlling the precision of the U-rib hole group through the inclined edge, while ensuring the precision requirements and improving the production efficiency. It belongs to the field of cross-sea bridge component structure manufacturing. Background Technology

[0002] In existing cross-sea bridges, the U-rib bolted connections are all straight-edge bolted connections (see...). Figure 7 Because the steel beam box girder is a variable cross-section curved bridge, the top plate unit docking ring is an inclined side. If the connecting edge of the two U-ribs at the ring is made into a straight edge as in the conventional U-rib, the U-rib gap requirement cannot be guaranteed. Summary of the Invention

[0003] Design objective: To overcome the shortcomings of the prior art, this paper designs a manufacturing process for the U-ribs of box girder bevels. By setting the beveled ends of the U-ribs and controlling the precision of the U-rib hole group through the beveled ends, this process can solve the problem of controlling the butt joint gap of the bolted U-ribs of the top plate unit of the curved bridge, while ensuring the accuracy requirements and improving the production efficiency.

[0004] Design Scheme: Since the approach bridge steel box girder of the cross-sea steel bridge is a curved bridge, and the top plate unit uses bolted U-ribs for connection, after the plate unit is replaced by a straight line, the butt joint ring is beveled. To ensure the required U-rib gap at the ring joint, if the two U-ribs are straight at their butt joint edges, the distances from the two U-rib limbs to the top plate end will be inconsistent, resulting in a gap at one end of the U-rib butt joint ring being larger than the other, making it impossible to guarantee the required U-rib gap. Therefore, this invention designs the process at the curved bridge plate unit ring joint (see...) Figure 1 The two U-rib end faces are beveled to ensure a 10mm gap between the two U-ribs and to guarantee the accuracy of the holes in the two limbs of the U-rib. This is achieved by beveling the U-rib's mating edge, making the bent U-rib parallel to the edge of the top plate's mating ring, thus achieving better practical results and ensuring the required U-rib gap accuracy. Simultaneously, after beveling the U-rib, the accuracy of the holes in the two limbs of the U-rib becomes a key control point. For conventional straight-edge U-ribs, the distance between the holes at the U-rib end and the edge of the U-rib plate is a fixed value. For beveled U-ribs, if the distance between the holes at the end and the edge of the U-rib plate is kept fixed, each row of holes will be misaligned. Therefore, after ensuring the shortest hole distance at the beveled edge, the distance of other hole groups from the beveled end is changed to ensure the holes are flush and to guarantee drilling accuracy.

[0005] 1. Optimization of U-rib drilling process with beveled edges: such as Figure 2 As shown. Layout diagram of U-rib hole group ( Figure 6In this case, the distance between the end bolt holes and the hypotenuse of the U-rib is a fixed value, and each row of U-rib holes is misaligned vertically. If drilling is performed in this manner, misalignment will occur within a single U-rib hole group, and misalignment will also occur between different U-ribs. In this situation, it is impossible to use a fixed drilling template for batch drilling of the U-ribs. Furthermore, due to the variation in hole spacing, a fixed splicing plate cannot be used when connecting beam segments, which is extremely detrimental to manufacturing accuracy and production efficiency. However, with an optimized hole arrangement for the U-ribs, after ensuring the hole spacing on the shorter of the two hypotenuses of the U-rib, and using this bolt hole as a reference, the end bolt holes can be aligned vertically by changing the edge distances of other end holes. This allows for batch drilling of the U-ribs using a drilling template, improving drilling efficiency, ensuring uniformity of U-rib hole spacing, and improving drilling and connection accuracy.

[0006] 2. Setting of the U-rib bevel: (1) The overall principle is to set the bevel while ensuring the U-rib gap at the ring opening. Figure 3 Taking the U-rib with beveled edge as an example, since the beveled edge values ​​at both ends of the U-rib are different, if the beveled edge is cut and manufactured according to the theoretical value, the direction of the U-rib must be distinguished, which will increase the workload again. Therefore, within the allowable error range, the two beveled edge values ​​are optimized to be flame-cut at 18mm, and the cutting edge data is unified, which improves the production efficiency. (2) Because the number of U-ribs is large, in order to improve the production efficiency, the straight edge is uniformly cut when cutting the material, and then the beveled U-ribs are manufactured according to the process of drilling → bending → cutting the beveled edge. When cutting the beveled edge, a special template is used for cutting, see Figure 4 .

[0007] Compared with the prior art, this invention has several advantages: first, it effectively solves the problem of connecting U-ribs bolted to the top plate of curved bridges; second, it not only fully meets the requirements for U-rib manufacturing precision, but more importantly, it meets the requirements for geometric dimensions and quality, improving production efficiency and having extremely high practical and promotional value; and third, it serves as a good reference for the subsequent manufacturing of similar inclined U-ribs. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of a U-rib bolted to a bevel.

[0009] Figure 2 This is the optimized layout diagram of the U-rib hole group.

[0010] Figure 3 This is a schematic diagram of a hypotenuse U-rib.

[0011] Figure 4 This is a schematic diagram of the U-rib bevel cutting.

[0012] Figure 5 This is a schematic diagram of a beveled flame cutting template.

[0013] Figure 6 This is a diagram showing the arrangement of the U-rib hole group.

[0014] Figure 7 This is a schematic diagram of the background technology. Implementation

[0015] Example 1: Refer to Appendix Figure 1-5 Fabrication process of U-ribs on the inclined side of the box girder, (1) Optimization of drilling process for U-ribs on the inclined side: such as Figure 5 As shown, the diagram illustrates the arrangement of U-rib holes before optimization. In this case, the distance between the end bolt holes and the hypotenuse of the U-rib is fixed, and each horizontal row of U-rib holes is vertically misaligned. If drilling is performed in this manner, misalignment occurs not only within a single U-rib hole group but also between holes in different U-ribs. This makes it impossible to use a fixed drilling template for batch drilling of the U-ribs. Furthermore, due to variations in hole spacing, fixed splicing plates cannot be used when connecting beam segments, severely impacting manufacturing accuracy and production efficiency. This invention optimizes the above situation by designing each horizontal row of holes in the U-rib to be vertically flush. This allows the use of a standard template for drilling the hole groups, such as... Figure 3 and Figure 4 As shown. The optimized hole arrangement, after ensuring the hole spacing on the shorter side of the two limbs of the inclined U-rib, uses this bolt hole as a reference (see...). Figure 3 and Figure 4 ), when changing the edge distance of other end holes (see Figure 3 and Figure 4 Based on the reference hole group, adjust the other end bolt holes so that the other bolt holes are in the same vertical row as the reference hole group. In this way, the drilling template can be used to drill the U-rib in batches, which improves the drilling efficiency and ensures the uniformity of the U-rib hole spacing, thus improving the drilling and connection accuracy. (2) Setting the U-rib bevel: 1) The overall principle is to set the bevel on the basis of ensuring the U-rib gap at the ring opening. Figure 3 Taking the U-rib with its beveled side as an example, since the beveled side values ​​at both ends of the U-rib are different, if the beveled side is cut and manufactured according to the theoretical value, the direction of the U-rib must be distinguished, which further increases the workload. Therefore, within the allowable error range, the middle value of the two beveled sides, 16mm and 20mm, is taken (see...). Figure 3 and Figure 4 The process has been optimized to flame cut at 18mm, standardizing the cutting edge data and improving production efficiency. (See attached image) Figure 5 .

[0016] Practice has proven that the beveled U-rib manufacturing process of this invention can fully meet the requirement that the edge distance of the U-rib manufacturing hole is greater than 50mm. More importantly, it meets the geometrical accuracy requirement of a 10mm gap between the two U-ribs at the annular opening, improving production efficiency and possessing extremely high practical and promotional value. It also serves as a valuable reference for the subsequent manufacturing of similar beveled U-ribs.

[0017] It should be understood that although the above embodiments provide a relatively detailed textual description of the design concept of the present invention, these textual descriptions are merely simple textual descriptions of the design concept of the present invention, and not limitations on the design concept of the present invention. Any combination, addition, or modification that does not exceed the design concept of the present invention falls within the protection scope of the present invention.

Claims

1. A manufacturing process for the U-ribs on the inclined side of a steel box girder, characterized by: After the U-ribs for the top plate of the curved bridge are made by replacing the curve with a straight one, the two U-rib sides are made into parallel bevels. At the same time, by adjusting the plate edge distance of the U-rib bolt holes, it is ensured that the bolt holes of the two limbs of the beveled U-rib are aligned in both the horizontal and vertical planes, and the hole spacing of the bolt holes used for the beveled U-rib bolting is standardized.

2. The manufacturing process of the U-ribs on the inclined side of the steel box girder according to claim 1, characterized in that: (1) Drilling process of U-ribs with beveled side: U-rib hole group arrangement; After ensuring the hole spacing of the bolt holes on the shorter side of the two limbs of the U-rib with beveled side, take the bolt holes on the shorter side as the reference, and on the basis of changing the hole edge spacing of the bolt holes at other ends, make the bolt holes at the ends in the same vertical row. (2) Setting the U-rib bevel: On the basis of ensuring the gap of the U-rib at the ring opening, the bevel is set. Within the allowable error range, the midpoint of the two bevel values ​​at both ends of the U-rib is taken for flame cutting, and the cutting data is unified. When cutting the material, the straight edge is cut in a unified manner, and then the beveled U-rib is made according to the process of drilling → bending → cutting the bevel.

3. The manufacturing process of the U-rib on the inclined side of the steel box girder according to claim 2, characterized in that: in When cutting the bevel, a bevel flame cutting template is used. The bevel value of the bevel flame cutting template is determined according to the bevel of the U-rib. After the U-rib and the bevel flame cutting template are bent, the bevel of the U-rib is cut according to the bevel flame cutting template.

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