A vertical manufacturing method for a complex octagonal variable cross-section space inclined steel member

Abstract

The present invention relates to a method for vertically fabricating a complex octagonal variable cross-section space-inclined steel member. Computer-aided BIM three-dimensional modeling lofting, numerical control cutting, laser marking, and high-precision positioning and assembly tooling measures are adopted to control the fabrication quality of the steel member; when the overall assembly of the steel member is carried out, the "vertical method" assembly scheme is adopted. The ground line of the steel member is accurately laid out on a special horizontal assembly platform, and then each wall panel unit is successively assembled and positioned along the ground line from one side to the other along the space-inclined angle direction of the steel member, and a reliable positioning and support device is adopted to ensure the accuracy of the position of each wall panel unit of the steel member and the stability of the structure. A temporary locking device is arranged near the top and bottom box openings before the welding of the steel member. After the assembly and welding of the steel member are completed, only the top port is designed with a secondary trimming process. Based on the horizontal ring baseline of the member, a level is used to release the secondary trimming line at the top of the steel member and flame cutting is carried out along the line to ensure that the height and top port flatness of the finished steel member meet the requirements.

Description

Technical Field

[0001] The present invention relates to a vertical manufacturing method for complex octagonal variable cross-section space inclined steel members, belonging to the technical field of steel bridge manufacturing. Background Art

[0002] The existing traditional technologies for complex octagonal variable cross-section space inclined steel members mainly have the following problems: (1) Fabrication of the panel unit components that make up the steel member: Conventionally, CAD lofting, numerical control cutting, manual scribing, and simple fixture positioning and assembly are used. The fabricated geometric dimension accuracy is poor and the efficiency is low, seriously affecting the overall assembly quality of the subsequent steel member; (2) The overall assembly of the steel member conventionally adopts the "horizontal position method" assembly scheme, that is, horizontal horizontal assembly. The existing problems are as follows: ① Since the space angles of the steel member are complex, when horizontally assembled, the linear change of the jig is large. Each steel member needs to be individually designed and fabricated with different bottom jigs to control the linearity and elevation, and the jig fabrication and installation amount is large; ② When assembling, a separate support inner jig needs to be designed and installed to position the top three panel unit components. The internal space is small, and the design and installation of the assembly inner jig is difficult; ③ The steel member is an octagonal variable cross-section space structure. When horizontally assembled, it is very difficult to accurately control the geometric dimensions of the top and bottom box openings and the relative angular relationship of each panel unit component; After the overall assembly and welding of the steel member, secondary cutting processes need to be designed for both the top and bottom ports, and a total station or API needs to be used for setting out during secondary cutting. The difficulty is high, the error probability is high, and the workload is large. Summary of the Invention

[0003] Design Purpose: To avoid the deficiencies in the background art, aiming at the shortcomings and deficiencies of the existing traditional technologies for the fabrication of complex octagonal variable cross-section space inclined steel members, a vertical manufacturing method for complex octagonal variable cross-section space inclined steel members with advanced technology, good feasibility, high efficiency, and obvious cost reduction and efficiency increase is designed.

[0004] Design Scheme: With the continuous improvement of the urbanization level, urban steel bridge products are increasingly characterized by diverse cross-section forms, complex space angles, high manufacturing precision requirements, and great manufacturing difficulty. This method relies on the steel bridge tower column of the project, which is a variable cross-section space inclined octagonal structure. The central axis of the steel tower column is in space, with an included angle of 62.2° with the longitudinal bridge projection and an included angle of 76.8° with the transverse bridge. The axis length of the steel tower column is 87.445m, and the cross-section gradually changes from 5.2m X 8.5m to 3.2m X 4m. The steel tower column is divided into multiple individually fabricated steel members along the height direction in the factory. This steel member has the characteristics of complex structure, large cross-section change, small construction space, and large space inclination angle.

[0005] In order to implement the above design scheme, in the method design of the present invention: First, measures such as computer BIM three-dimensional modeling lofting, numerical control cutting, laser marking, and high-precision positioning and assembly tooling are adopted to control the manufacturing quality of the panel unit components included in the steel component. Then, when the steel component is assembled integrally, the "erect position method" assembly scheme is adopted. First, the ground line of the steel component (the position line of each panel unit component of the steel component on the platform) is accurately laid out on a special horizontal assembly platform. Then, along the spatial inclination angle direction of the steel component, each panel unit component is sequentially assembled and positioned along the ground line from one side to the other side, and a reliable positioning and support device is adopted to ensure the accuracy of the position of each panel unit component of the steel component and the stability of the structure. A temporary locking device is set near the top and bottom box openings before the steel component is welded to prevent the change of the geometric dimensions of the steel component box opening caused by welding deformation. After the steel component is assembled and welded, only the top end is designed with a secondary cutting process. Using a level, the secondary cutting line of the top end of the steel component can be set based on the horizontal ring baseline of the component, and flame cutting is carried out along the line. While ensuring that the height and top opening flatness of the finished steel component meet the requirements, the operation is simple, not easy to make mistakes, and the manufacturing efficiency is high.

[0006] Compared with the background technology, the present invention has the following advantages: First, for the panel unit components included in the steel component, computer BIM three-dimensional modeling lofting, numerical control cutting, laser marking, and high-precision tooling for accurate positioning and assembly are all adopted. The manufacturing accuracy of the panel unit components is high, and the overall assembly quality of the steel component is guaranteed. Second, the "erect position method" assembly scheme is adopted for the overall assembly of the steel component, which is safe, reliable, high in efficiency, low in manufacturing cost, and high in geometric dimension accuracy. Third, after the steel component is assembled and welded, only the top port is designed with a secondary cutting process, without the need for secondary cutting at both the top and bottom ports. Moreover, the secondary cutting line can be accurately set only by using a level. While ensuring that the height and top and bottom opening flatness of the finished steel component meet the requirements, the operation is simple, not easy to make mistakes, and the manufacturing efficiency is high. Fourth, by adopting this manufacturing technical scheme, the manufacturing difficulty of the complex octagonal variable cross-section space-inclined steel component is greatly reduced (the manufacturing accuracy is easy to control, the method is simple, and it is not easy to make mistakes), the manufacturing efficiency is greatly improved (compared with the existing technology, the manufacturing efficiency is increased by at least 50%), the welding deformation and the geometric accuracy of the steel component are effectively controlled (compared with the existing technology, the welding deformation and the geometric accuracy deviation are controlled within the range required by the specification standards (it is very difficult to meet the standards by traditional methods)), the manufacturing cost is reduced (compared with the existing technology, the cost is reduced by 40%), and the safety is good (anti-tipping supports are set to ensure no tipping; each panel unit is supported on the platform, with good stability; the overall center of gravity is relatively low; the assembly sequence design takes into account the sequence, ensuring that there will be no tipping between each other). Description of the Drawings

[0007] Figure 1 It is a schematic diagram of an octagonal variable cross-section space-inclined steel component.

[0008] Figure 2It is a flow chart of the manufacturing method of an octagonal variable cross-section space inclined steel member. Embodiment

[0009] Example 1: Refer to the appendix Figure 1 and 2 . A vertical manufacturing method for a complex octagonal variable cross-section space inclined steel member,

[0010] The NO1 steel member is lofted by computer BIM three-dimensional modeling;

[0011] For the NO2, each wall panel unit part is numerically controlled for blanking, and the position line of the stiffening rib is laser marked;

[0012] For the NO3, the assembly of each wall panel unit part (using a high-precision positioning assembly tooling);

[0013] For the NO4, the ground sample line (the assembly position line of each wall panel unit part) of the steel member is accurately laid out on a special horizontal assembly platform;

[0014] For the NO5, design the assembly sequence of the steel member, and sequentially assemble and place each wall panel unit part along the ground sample line from one side to the other side along the space inclination angle direction of the steel member (using a reliable positioning support device);

[0015] For the NO6, after the assembly of the steel member is completed, a temporary locking device is set at the top and bottom box openings, and then the steel member is welded;

[0016] For the N7, after the welding of the steel member is completed, the temporary locking device at the box opening is removed. Then, the secondary trimming tangent line at the top end of the steel member is set based on the horizontal ring baseline (using a high-precision instrument);

[0017] For the N8, accurately flame cut the top port along the secondary trimming tangent line at the top port;

[0018] For the N9, conduct finished product inspection of the steel member. Including: geometric dimensions of the top and bottom port cross-sections, flatness of the top and bottom port cross-sections, height of the steel member.

[0019] For the N10, the manufacturing of the steel member is completed.

[0020] In order to ensure the implementation effect of this technology, the following measures are taken for control:

[0021] Strictly control the manufacturing quality of each wall panel unit part of the steel member, and adopt measures such as computer BIM three-dimensional modeling lofting, numerical control blanking, laser marking, and high-precision positioning assembly tooling for control to ensure that the geometric dimension accuracy deviation of the wall panel unit part manufacturing is ≤1mm;

[0022] Strictly control and detect the flatness of the top surface of the vertical assembly platform of the steel member and the bearing capacity requirements of the platform to ensure that the flatness of the top surface of the assembly platform is ≤0.5mm;

[0023] Strictly control the layout accuracy of the position lines of each wall panel unit of the steel members on the assembly platform to ensure that the deviation of the position lines ≤ 0.3 mm;

[0024] Strictly control the geometric dimension accuracy of the finished steel members. After the steel members are assembled and welded, adopt the secondary cutting process at the top end to ensure that the height deviation ≤ 0.5 mm and the flatness of the top box opening ≤ 0.5 mm.

[0025] The vertical position method belongs to the well-known technology and has been applied in steel shell towers (steel-concrete composite structure towers, such as: the Fifth Nanjing Yangtze River Bridge, Dongguan Binhai Bay Bridge, Zhengzhou Anlu Yellow River Bridge), but it is rarely applied in pure steel towers (no concrete pouring is carried out inside, such as: the Third Nanjing Yangtze River Bridge, Changtai Yangtze River Bridge, both adopt the horizontal position method for assembly). Whether to choose the horizontal position or the vertical position mainly depends on the structure and construction characteristics of the steel members themselves, and comprehensively consider and evaluate their respective advantages and disadvantages from aspects such as cost, construction period, and difficulty of quality control. The horizontal position method is a relatively traditional assembly method and is suitable for large steel members with regular cross-sections, small linear changes, and perpendicular internal partitions and wall panels.

[0026] According to the spatial inclined structure and construction characteristics of the steel members, the overall scheme selected for the assembly of the steel members is: starting from the outward inclined side, assemble forward in turn ( Figure 1 , assemble from right to left), this scheme has relatively high assembly efficiency, less use of tooling, and guaranteed precision control. At the same time, during the process, the assembly sequence of adjacent wall panels needs to be considered one by one, with the principle that the previously assembled wall panel does not interfere with the assembly of the subsequent wall panel. ) And adopt installation positioning support devices (mainly accurately adjust and position the inclination angle of each wall panel) and temporary locking devices for the top and bottom box openings (after the assembly of each wall panel of the steel member is completed, install a locking device at the box opening (that is: temporarily fix the box opening with angle steel, see Figure 2 -NO6), fix the box opening to ensure that the position of the box opening no longer changes) measures to assemble and position each wall panel unit (assemble each wall panel in turn according to the previously designed assembly sequence).

[0027] The secondary cutting process is a well-known technology and is a commonly used technology for controlling the manufacturing accuracy of steel structures. In the traditional process, secondary cutting is required at both ends of the top and bottom box openings of the steel members. What this application involves is: only secondary cutting is required at one end of the top opening of the steel member, because with vertical assembly, the bottom opening is already on a reliable horizontal platform, and the flatness control of the bottom opening is already guaranteed.

[0028] It should be understood that: although the above embodiments have made relatively detailed written descriptions of the design concept of the present invention, these written descriptions are only simple written descriptions of the design concept of the present invention, rather than 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 vertical manufacturing method for complex octagonal variable-section space inclined steel members, characterized by: (1) When manufacturing the wall panel unit components that make up the steel member, computer BIM three-dimensional modeling lofting, numerical control cutting, laser marking, and high-precision positioning and assembly tooling are adopted. That is, the assembly angles of each wall panel and the transverse ribs are obtained in advance in the model, and then according to the different angular relationships between the transverse ribs and the wall panel units, specific triangular templates are made to control the assembly angle between the transverse ribs and the wall panel. When assembling the wall panel unit, with the transverse rib position line on the wall panel part as the reference, the angle template is fixed in advance to ensure the accurate position and firm fixation of the angle template. Then, the transverse ribs are assembled and positioned along the transverse rib position line on the wall panel, and the spatial assembly angle is controlled by the angle template. (2) The "vertical method" is adopted for the assembly of the steel member. Before assembly, the assembly platform is inspected. The flatness of the platform top surface is ≤0.5 mm and the bearing capacity of the platform is ≥20 KN / m², ensuring that the flatness of the platform top surface and the bearing capacity of the platform meet the requirements, and guaranteeing the flatness of the bottom port of the steel member. (3) The position lines of each wall panel unit component of the steel member are arranged on the assembly platform, mainly controlling the planar dimensions of the octagon at the bottom port of the steel member. First, the theoretical assembly position lines of each wall panel are drawn on the platform according to the theoretical contour dimension data, that is, the theoretical contours of the bottoms of the eight wall panels, which serve as the reference for placing each wall panel unit during actual assembly. Each wall panel unit bottom port is positioned and fixed according to the reference, which can effectively ensure the sectional dimensions of the bottom port. After the steel member is assembled, the position deviation of the bottom ports of each wall panel is ≤0.5 mm. (4) According to the spatial inclined structure and construction characteristics of the steel member, the overall assembly plan for the steel member is selected as follows: starting from the outward inclined side, assemble forward in sequence. At the same time, the assembly sequence of adjacent wall panels needs to be considered one by one, with the principle that the previously assembled wall panel does not interfere with the assembly of the subsequent wall panel, and an installation and positioning support device is adopted to accurately adjust and position the inclination angle of each wall panel; top and bottom box mouth temporary locking device: after the assembly of each wall panel of the steel member is completed, a locking device is installed at the box mouth to fix the box mouth, ensuring that the position of the box mouth no longer changes, and each wall panel is assembled in sequence according to the previously designed assembly sequence. (5) After the steel member is assembled and welded, only the top box mouth is preset with a secondary cutting process, which can control the finished height of the steel member and the flatness of the box mouth, and the bottom port does not need to be designed with secondary cutting. The geometric dimension accuracy deviation of the wall panel unit component manufacturing is ≤1 mm; The flatness of the top surface of the steel member assembly platform is ≤0.5 mm; The position line deviation of each wall panel unit component of the steel member arranged on the assembly platform is ≤0.5 mm; After the steel member is assembled and welded, the accuracy deviation of the setting of the top secondary cutting line is ≤0.3 mm; Strictly control the manufacturing quality of each wall panel unit component of the steel member: the geometric dimension deviation of the length and width of each wall panel unit component is ≤1 mm; the assembly angle deviation of the transverse ribs on the wall panel unit is ≤0.1°. Computer BIM three-dimensional modeling lofting, numerical control cutting, laser marking, and high-precision positioning and assembly tooling measures are adopted to control it, ensuring that the geometric dimension accuracy deviation of the wall panel unit component manufacturing is ≤1 mm.

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