A method for connecting a secondary box steel beam to a primary box steel beam

Abstract

The present application relates to the technical field of building construction, in particular to a method for connecting a secondary box-shaped steel beam with a primary box-shaped steel beam, a short box-shaped beam is arranged on the primary box-shaped steel beam, then according to the stress state of the structure, the end of the short box-shaped beam and the secondary box-shaped steel beam is made into a pair of flush openings or misaligned openings according to the design requirements for butt welding, which meets the design and related specification requirements, the joint is easy to butt, and all welding forms are used in the construction process, the connection is more reliable, the internal force is smoothly transmitted, the construction is simple and convenient, the construction period can be shortened, the construction cost can be reduced, the accumulation of field welds and factory welds and the production of layered tearing and other phenomena can be effectively prevented, and the stability of the box-shaped beam connection structure is ensured.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically a method for connecting a secondary box-type steel beam to a main box-type steel beam. Background Technology

[0002] With the development of the construction industry, steel structures have become one of the main load-bearing structural systems in modern building engineering. Steel structure construction is more in line with the requirements of building industrialization and environmental protection. Steel structures are made of a single material, facilitating the formation of optimal load-bearing sections. Components are easy to process and industrially manufacture and install. Large components or modular assembly is possible, resulting in high production efficiency, short construction cycles, and less wet work during construction. Pollution is also lower, perfectly aligning with my country's building industrialization and technological policies. For some important load-bearing components, box-section steel beams are increasingly used due to space and stress constraints. Since the cross-section of box-section steel beams can meet large span requirements and some special design space needs, how to quickly complete the connection between box-section steel beams on-site has become a primary technical issue for designers and on-site construction workers.

[0003] Currently, there is no unified and perfect method for connecting box-type steel beams to each other. Generally, the following two methods are adopted:

[0004] First, the secondary box-type steel beams are directly butted together with the main box-type steel beams using a bevel welding method.

[0005] 2. The upper and lower flanges of the secondary box girder are butted with the bevels of the main box girder, and the web of the secondary box girder is bolted together.

[0006] This connection method requires pre-drilling holes in the upper flange of the secondary box girder before bolting can be performed. After the bolts on the web plate are installed, the pre-drilled holes in the upper flange of the secondary box girder must be sealed.

[0007] In the two methods described above, if the cross-sectional dimensions are large and the plate thickness is thick, the welded box-type connection will cause accumulation of weld seams between the field and the factory. If the plate thickness is greater than or equal to 40mm, the connection interface will produce damage such as lamellar tearing, which seriously affects the stability and rigidity of the structure. Summary of the Invention

[0008] The present invention aims to solve the above problems and thereby provide a method for connecting secondary box-type steel beams and main box-type steel beams.

[0009] The technical solution adopted by the present invention to solve the aforementioned problem is as follows:

[0010] A method for connecting a secondary box girder to a primary box girder involves the following steps: Before both the primary and secondary box girder beams leave the factory, a short box girder is integrally formed on the primary box girder at the connection point with the secondary box girder. The cross-sectional dimensions of the short box girder are the same as those of the secondary box girder to be connected. Upon arrival at the construction site, based on the stress conditions of the secondary box girder to be connected, the ends of the short box girder are either flush-cut or staggered in a "Z" shape. The conditions are divided into two cases: bearing static load and bearing dynamic load. When bearing static load, the connection port is processed into a flush joint, and when bearing dynamic load, the connection port is processed into a staggered joint. The connection end faces of the secondary box girder and the short box girder to be connected are also made into corresponding flush joints or reverse staggered joints to facilitate the alignment of the secondary box girder with the short box girder. The main box girder is installed in place, and then the secondary box girder is lifted by a crane, and the secondary box girder is aligned with the short box girder and welded.

[0011] The present invention, which adopts the above technical solution, has the following prominent features compared with the prior art:

[0012] This invention involves setting a short box girder on the main box girder. Then, based on the stress state of the structure and according to design requirements, the ends of the short box girder and the secondary box girder are made into pairs with either flush or staggered joints for butt welding. This meets design and relevant specification requirements, facilitates joint connection, and uses welding throughout the construction process, resulting in more reliable connections, smooth transmission of internal forces, and simple and convenient construction. It can shorten the construction period, reduce construction costs, and effectively prevent the accumulation of welds between the field and factory welds, as well as the occurrence of lamellar tearing, thus ensuring the stability of the box girder connection structure.

[0013] As a preferred embodiment, a further technical solution of the present invention is:

[0014] When the height of the secondary box girder to be connected to the main box girder is equal to the height of the main box girder, T-shaped reinforcing flanges are provided on the upper and lower sides of the main box girder. These reinforcing flanges are fully welded to both the main box girder and the short box girder. Supporting webs are provided inside the main box girder, located at opposite positions on the two webs of the short box girder. The thickness and width of these supporting webs are the same as those of the webs of the short box girder. When the height of the secondary box girder to be connected to the main box girder is less than the height of the main box girder... The upper flange of the short box girder is flush with the upper flange of the main box girder, and a T-shaped reinforcing flange is fully welded above the upper flange. Supporting webs are installed inside the main box girder at the opposite positions of the two webs of the short box girder. At the same time, a lower flange support plate is installed inside the main box girder at the same height as the lower flange of the short box girder. The thickness and width of the supporting web are the same as those of the web of the short box girder, and the thickness and width of the lower flange support plate are the same as those of the lower flange of the short box girder.

[0015] During the butt welding process between the secondary box girder and the short box girder, pre-reserved welding holes are made on the secondary box girder. The location of the pre-reserved welding holes varies depending on the width of the secondary box girder. When the width of the secondary box girder is less than 500mm, the pre-reserved welding holes are made on the web plate on one side of the secondary box girder; when the width of the secondary box girder is greater than or equal to 500mm, the pre-reserved welding holes are made on the upper flange plate of the secondary box girder. After the welding is completed and the inspection is qualified, the pre-reserved welding holes are sealed.

[0016] After the secondary box girder and the short box girder are aligned, positioning plates are welded on the interface of the opposite upper flange plate or the interface of the opposite lower flange plate. The positioning plates are placed upright and welded to the secondary box girder and the short box girder respectively.

[0017] When the width of the secondary box girder is less than 500mm, the positioning plate is located on the interface of the opposite upper flange plate; when the width of the secondary box girder is greater than or equal to 500mm, the positioning plate is located on the interface of the opposite lower flange plate.

[0018] The bottom of the positioning plate, above the interface, has solder holes.

[0019] The butt welds between the upper and lower flange plates of the secondary box girder and the short box girder are all V-shaped welds. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cross-sectional structure of the box-type steel beam according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the main structure of the connection between the narrow box girder and the main box girder in an embodiment of the present invention when the box girder is subjected to static load;

[0022] Figure 3 This is a top view of the connection between the narrow box girder and the main box girder in an embodiment of the present invention when the box girder is subjected to static load.

[0023] Figure 4 This is a schematic diagram of the main structure of the connection between the narrow box girder and the main box girder in an embodiment of the present invention when the box girder is subjected to dynamic loads;

[0024] Figure 5 This is a top view of the connection between the narrow box girder and the main box girder in an embodiment of the present invention when the box girder is subjected to dynamic loads.

[0025] Figure 6 This is a schematic diagram of the main structure of the connection between the secondary box girder and the main box girder when the secondary box girder is wider and subjected to static load according to an embodiment of the present invention.

[0026] Figure 7This is a top view of the connection between the secondary box girder and the main box girder when the secondary box girder is wider and subjected to static load, according to an embodiment of the present invention.

[0027] Figure 8 This is a schematic diagram of the main structure of the connection between the secondary box girder and the main box girder when the secondary box girder is wider and subjected to dynamic loads according to an embodiment of the present invention.

[0028] Figure 9 This is a top view of the connection between the secondary box girder and the main box girder in an embodiment of the present invention when the secondary box girder is wider and subjected to dynamic loads;

[0029] Figure 10 This is a schematic diagram of the main box girder structure when the height of the secondary box girder is less than the height of the main box girder according to an embodiment of the present invention;

[0030] Figure 11 This is a top view of the main box girder structure when the height of the secondary box girder is less than the height of the main box girder according to an embodiment of the present invention;

[0031] The markings in the figure are as follows: main box girder 1, secondary box girder 2, short box girder 3, strong flange plate 4, positioning plate 5, upper flange plate 1-1, lower flange plate 1-2, web plate 1-3, supporting web plate 1-4, lower flange support plate 1-5, reserved welding hole 2-1, and through welding hole 5-1. Implementation

[0032] The present invention will be further described below with reference to embodiments, which are intended only to provide a better understanding of the invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0033] See Figures 1-11 A method for connecting a secondary box girder to a main box girder is disclosed. The box girder consists of an upper flange plate 1-1, a lower flange plate 1-2, and two web plates 1-3. Before the main box girder 1 and the secondary box girder 2 leave the factory, a short box girder 3 is integrally formed on the main box girder 1 at the connection position with the secondary box girder 2. The cross-sectional dimensions of the short box girder 3 are the same as those of the secondary box girder 2 to be connected. After arriving at the construction site, according to the stress conditions of the secondary box girder 2 to be connected, the ends of the short box girder 3 are made flush or "Z" shaped. The secondary box girder 2 is designed with a staggered joint in the shape of the letter "T". The stress conditions are divided into two categories: static load and dynamic load. When subjected to static load, the connection ends are machined to be flush; when subjected to dynamic load, the connection ends are machined to be staggered. The connection ends of the secondary box girder 2 and the short box girder 3 are also made to be flush or staggered in the opposite direction to facilitate alignment between the secondary box girder 2 and the short box girder 3. The main box girder 1 is installed in place, and then a crane is used to lift the secondary box girder 2, aligning it with the short box girder 3 and completing the welding.

[0034] When the height of the secondary box girder 2 to be connected to the main box girder 1 is equal to the height of the main box girder 1, T-shaped reinforcing flanges 4 are provided on the upper and lower sides of the main box girder 1. The reinforcing flanges 4 are fully welded to the main box girder 1 and the short box girder 3. Supporting webs 1-4 are provided inside the main box girder 1 and at opposite positions on the two webs 1-3 of the short box girder 3. The thickness and width of the supporting webs 1-4 are the same as those of the webs of the short box girder 3. The height of the secondary box girder 2 to be connected to the main box girder 1 is less than the height of the main box girder 1. At the same time, the upper flange plate of the short box girder 3 is flush with the upper flange plate of the main box girder 1, and a T-shaped reinforcing flange plate 4 is fully welded above the upper flange plate. Supporting web plates 1-4 are set in the main box girder 1 at the relative positions of the two web plates of the short box girder 3. At the same time, lower flange support plates 1-5 are set in the main box girder 1 at the same height as the lower flange plate of the short box girder 3. The thickness and width of the supporting web plates 1-4 are the same as those of the web plates of the short box girder 3, and the thickness and width of the lower flange support plates 1-5 are the same as those of the lower flange plates of the short box girder 3.

[0035] During the butt welding process between the secondary box girder 2 and the short box girder 3, a reserved welding hole 2-1 is provided on the secondary box girder 2. The reserved welding hole 2-1 is located in different positions depending on the width of the secondary box girder 2. When the width of the secondary box girder 2 is less than 500mm, the reserved welding hole 2-1 is located on the web plate on one side of the secondary box girder 2, which facilitates welding construction from one side. When the width of the secondary box girder 2 is greater than or equal to 500mm, the reserved welding hole 2-1 is located on the upper flange plate of the secondary box girder 2. Personnel can enter the reserved welding hole 2-1 to weld the box girder. After the welding is completed and the inspection is qualified, the reserved welding hole is sealed.

[0036] After the secondary box girder 2 and the short box girder 3 are aligned, positioning plates 5 are welded to the corresponding upper flange plate joints or the corresponding lower flange plate joints. The positioning plates 5 are placed upright and welded to the secondary box girder 2 and the short box girder 3 respectively. The secondary box girder 2 and the short box girder 3 are positioned and fixed. After the positioning plates 5 are fixed at both ends of the secondary box girder 2, the positioning plates 5 at both ends can bear the self-weight and construction load of the secondary box girder 2. Then the crane hook rope can be removed, and the crane can carry out the hoisting of the next component, thus speeding up the construction efficiency.

[0037] When the width of the secondary box girder 2 is less than 500mm, the positioning plate 5 is located on the interface of the opposite upper flange plate. When the width of the secondary box girder 2 is greater than or equal to 500mm, the positioning plate 5 is located on the interface of the opposite lower flange plate.

[0038] A welding hole 5-1 is provided at the bottom of the positioning plate 5 and above the interface to ensure that the joint weld can be continuously welded.

[0039] The butt welds between the upper and lower flange plates of the secondary box girder 2 and the short box girder 3 are all V-shaped welds; the lower flange plate is flat welded by pre-reserved welding holes 2-1, avoiding overhead welding of the lower flange, which can ensure welding quality, speed up welding, and reduce welding difficulty.

[0040] During construction, when the width of the secondary box girder 2 is less than 500mm, the reserved welding hole 2-1 is opened on the web plate on one side of the secondary box girder 2. After the secondary box girder 2 and the short box girder 3 are aligned, the personnel are positioned on one side of the reserved welding hole 2-1 to carry out welding construction. The two ends of the secondary box girder 2 are fixed to the short box girder 3 on both sides on the upper flange plate through the positioning clamp plate 5. Then, the positioning clamp plate 5 at both ends can be used to bear the self-weight of the secondary girder and the construction load, and the crane hook rope can be removed. The crane can then carry out the hoisting of the next component, which speeds up the construction efficiency. Then, the upper flange plate, lower flange plate and web plates on both sides of the secondary box girder 2 are welded in sequence. After the welding is completed and the inspection is qualified, the reserved welding hole is sealed. The sealing plate is welded with a backing plate. After the inspection is completed and qualified, the secondary box girder 2 is ready.

[0041] The width of the secondary box girder 2 is greater than or equal to 500mm. When the width is wider, the reserved welding hole 2-1 is opened on the upper flange plate of the secondary box girder 2. After the secondary box girder 2 and the short box girder 3 are aligned, personnel can enter the reserved welding hole 2-1 to carry out welding construction on the box girder. The two ends of the secondary box girder 2 are fixed to the short box girder 3 on both sides on the lower flange plate through the positioning clamps 5. Then, the positioning clamps at both ends can be used to bear the self-weight of the secondary girder and the construction load, and the crane hook rope can be removed. The crane can then lift the next component, which speeds up the construction efficiency. After that, the lower flange plate and the web plates on both sides of the secondary box girder are welded in sequence. After the welding is completed and the inspection is qualified, the reserved welding hole is sealed. The sealing plate is welded with a backing plate. After the inspection is completed and qualified, the secondary box girder is ready.

[0042] This invention involves setting a short box girder on the main box girder. Then, based on the stress state of the structure and according to design requirements, the ends of the short box girder and the secondary box girder are made into pairs with either flush or staggered joints for butt welding. This meets design and relevant specification requirements, facilitates joint connection, and uses welding throughout the construction process, resulting in more reliable connections, smooth transmission of internal forces, and simple and convenient construction. It can shorten the construction period, reduce construction costs, and effectively prevent the accumulation of welds between the field and factory welds, as well as the occurrence of lamellar tearing, thus ensuring the stability of the box girder connection structure.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent changes made based on the description and drawings of the present invention are included within the scope of the present invention.

Claims

1. A method for connecting a secondary box girder to a main box girder, characterized in that: Before the main box girder and the secondary box girder leave the factory, a short box girder is integrally formed on the main box girder and at the connection position with the secondary box girder. The cross-sectional dimensions of the short box girder are the same as the cross-sectional dimensions of the secondary box girder that needs to be connected. Upon arrival at the construction site, based on the stress conditions of the secondary box girder to be connected, the ends of the short box girder are either flush or staggered in a "Z" shape. The stress conditions of the secondary box girder are divided into two cases: bearing static load and bearing dynamic load. When bearing static load, the connection ends are processed to be flush; when bearing dynamic load, the connection ends are processed to be staggered. The connection end faces of the secondary box girder and the short box girder to be connected are also made to be flush or staggered in the opposite direction to facilitate the alignment of the secondary box girder with the short box girder. The main box girder is installed in place, and then a crane is used to lift the secondary box girder, align the secondary box girder with the short box girder, and complete the welding. When the height of the secondary box girder to be connected to the main box girder is equal to the height of the main box girder, T-shaped reinforcing flanges are provided on the upper and lower sides of the main box girder. These reinforcing flanges are fully welded to both the main box girder and the short box girder. Supporting webs are provided inside the main box girder, located at opposite positions on the two webs of the short box girder. The thickness and width of these supporting webs are the same as those of the webs of the short box girder. When the height of the secondary box girder to be connected to the main box girder is less than the height of the main box girder... The upper flange of the short box girder is flush with the upper flange of the main box girder, and a T-shaped reinforcing flange is fully welded above the upper flange. A supporting web is set inside the main box girder at the opposite position of the two webs of the short box girder. At the same time, a lower flange support plate is set inside the main box girder at the same height as the lower flange of the short box girder. The thickness and width of the supporting web are the same as those of the web of the short box girder, and the thickness and width of the lower flange support plate are the same as those of the lower flange of the short box girder. During the butt welding process between the secondary box girder and the short box girder, pre-reserved welding holes are made on the secondary box girder. The location of the pre-reserved welding holes varies depending on the width of the secondary box girder. When the width of the secondary box girder is less than 500mm, the pre-reserved welding holes are made on the web plate on one side of the secondary box girder; when the width of the secondary box girder is greater than or equal to 500mm, the pre-reserved welding holes are made on the upper flange plate of the secondary box girder. After the welding is completed and the inspection is qualified, the pre-reserved welding holes are sealed. After the secondary box girder and the short box girder are aligned, positioning plates are welded to the corresponding upper flange plate joints or the corresponding lower flange plate joints. The positioning plates are placed upright and welded to the secondary box girder and the short box girder respectively. When the width of the secondary box girder is less than 500mm, the positioning plates are located on the corresponding upper flange plate joints. When the width of the secondary box girder is greater than or equal to 500mm, the positioning plates are located on the corresponding lower flange plate joints. Welded holes are opened at the bottom of the positioning plates and above the joints.

2. The method for connecting a secondary box girder and a main box girder according to claim 1, characterized in that: The butt welds between the upper and lower flange plates of the secondary box girder and the short box girder are all V-shaped welds.

Images