Steel structure box beam column pure bolting joint capable of pre-adding reverse bending moment

Abstract

The utility model discloses a steel structure box type beam column pure bolting joint capable of pre-adding reverse bending moment, a box type beam and a column are bolted through angle steel, the box type beam comprises a beam upper flange and a beam lower flange, and the box type beam comprises a bracket, a first base plate and a second base plate. The corbel is arranged below the box beam, the end face of the first end of the corbel makes contact with the column, the first base plate is fixedly connected with the second end of the corbel and makes contact with the beam lower flange, the second base plate is fixedly connected with the beam lower flange and is in bolted connection with the corbel, and the second base plate is fixedly connected with the beam lower flange and is in bolted connection with the corbel. The thickness of the second base plate is smaller than that of the first base plate. The bracket, the first base plate and the second base plate are additionally arranged, so that the effect of pre-adding the reverse bending moment is achieved, the deflection and stress of the box beam after bearing can be reduced, and the bearing limit of the box beam is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of bolted nodes, in particular to a pure bolted node for a steel structure box beam column capable of pre-adding reverse bending moment. Background Art

[0002] When connecting steel box beams and columns, the box beams and columns are connected using pure bolts. Besides using end-plate joints, another approach is to first transition the box section to an H-section in the node area and then connect according to the H-section. However, the transition to an H-section reduces the lateral stiffness and torsional resistance of the beam in the node area. Due to the significant difference in mechanical properties between box and H-sections, the length of the H-section of the beam needs to be kept as short as possible. The limit is that it can meet the angle steel connection requirements at the web ends. In this way, the difference in cross-sectional performance can be almost ignored.

[0003] After the box section transitions to an H-section, the existing connection method generally uses angle steel brackets to connect the upper and lower flanges of the beam to the column respectively. This method is not convenient for installing partitions in the central area where the column flange or web is subjected to vertical compression or tension, causing large bending deformation of the column web or flange, thereby weakening the node stiffness. At the same time, the bracket and the beam flange are connected in a simple shear manner. When the beam section height is low and the bending moment is large, a large restraint force is required on the beam flange to withstand the corresponding bending moment. The beam flange needs to be installed with a large number of bolts to achieve connection strength. This requires that the length of the H-section cannot be too short, resulting in reduced mechanical properties. Therefore, this connection method is not suitable for scenarios with large bending moments. Utility Model Content

[0004] The purpose of the utility model is to provide a steel structure box beam-column pure bolt connection node capable of pre-adding reverse bending moment, so as to solve the problems mentioned in the above background technology.

[0005] In order to solve the above technical problems, the utility model provides a pure bolted connection node of a steel structure box beam and column that can be pre-applied with reverse bending moment. The box beam and the column are bolted by angle steel. The box beam includes an upper flange and a lower flange of the beam, which includes a corbel, a first pad and a second pad. The corbel is arranged below the box beam, and the end face of the first end thereof is in contact with the column. The first pad is fixedly connected to the second end of the corbel and is in contact with the lower flange of the beam. The second pad is fixedly connected to the lower flange of the beam and is bolted to the corbel. The thickness of the second pad is less than that of the first pad.

[0006] Furthermore, the box beam also includes two webs, which are symmetrically installed between the upper flange and the lower flange of the beam to form a box structure, and the distance between the ends of the two webs gradually decreases from the inside to the outside until they are close to each other.

[0007] Furthermore, the corbel is an H-shaped corbel, and the corbel comprises an upper corbel flange and a lower corbel flange, and a corbel rib is provided between the upper corbel flange and the lower corbel flange.

[0008] Furthermore, a beam rib is provided inside the box beam, and the beam rib is connected to the inner wall of the box beam.

[0009] Furthermore, the angle steel includes a first angle steel and two second angle steels, the first side of the first angle steel is bolted to the column, the second side of the first angle steel is bolted to the upper flange of the beam, the two second angle steels are respectively located on the outside of the two web ends, the first side of the second angle steel is bolted to the column, and the second side of the second angle steel is bolted to the web end.

[0010] Furthermore, a connecting ear plate parallel to the web is fixedly installed on the column, and the number of the first angle steels is two, and the two first angle steels are arranged on both sides of the connecting ear plate. The first side of the first angle steel is bolted to the connecting ear plate, and the second side of the first angle steel is bolted to the upper flange of the beam.

[0011] Furthermore, the thickness of the first pad is 1-2 mm thicker than that of the second pad.

[0012] The beneficial effects of the present invention are as follows: the present invention achieves the effect of pre-applying reverse bending moment by adding a corbel, a first pad and a second pad, thereby reducing the deflection and stress of the box beam after bearing load and improving the bearing limit of the box beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the three-dimensional structure of the first embodiment of the present utility model.

[0014] Figure 2 This is a rear structural schematic diagram of the first embodiment of the present invention.

[0015] Figure 3 This is a schematic diagram of the three-dimensional structure of the second embodiment of the present utility model.

[0016] Figure 4 This is a rear structural schematic diagram of the second embodiment of the present invention.

[0017] Figure 5 This is a schematic diagram of the deflection of the box beam before and after loading according to an embodiment of the utility model.

[0018] Among them: 1. Box beam; 2. Column; 3. Corbel; 4. First pad; 5. Second pad; 6. First angle steel; 7. Second angle steel; 8. Connecting ear plate.

[0019] 11. Beam upper flange; 12. Beam lower flange; 13. Web; 14. Beam rib; 21. Stiffener; 31. Corbel upper flange; 32. Corbel lower flange; 33. Corbel rib; 61. Angle steel rib. DETAILED DESCRIPTION

[0020] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiment described is only one embodiment of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] In order to make the objectives, technical solutions and advantages of this application clearer, this application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] In the following description, references to "one embodiment," "an embodiment," "an example," "an example," etc. indicate that the embodiment or example described may include certain features, structures, characteristics, properties, elements, or limitations, but not every embodiment or example necessarily includes the certain features, structures, characteristics, properties, elements, or limitations. In addition, repeated use of the phrase "according to one embodiment of the present application" may refer to the same embodiment, but does not necessarily refer to the same embodiment.

[0023] like Figure 1-5 As shown, the utility model discloses a pure bolted connection node of a steel structure box beam 1 and a column 2 capable of pre-applying reverse bending moment. The box beam 1 and the column 2 are bolted together by angle steel. The box beam 1 includes an upper beam flange 11 and a lower beam flange 12, and includes a corbel 3, a first pad 4, and a second pad 5. The corbel 3 is arranged below the box beam 1, and the end face of its first end contacts the column 2. The first pad 4 is fixedly connected to the second end of the corbel 3 and contacts the lower beam flange 12. The second pad 5 is fixedly connected to the lower beam flange 12 and bolted to the corbel 3. The thickness of the second pad 5 is less than that of the first pad 4. In this embodiment, the first pad 4 is welded to the corbel 3, and the second pad 5 is welded to the lower beam flange 12. The threaded ends of the high-strength bolts pass through the lower beam flange 12, the second pad 5, and the corbel 3 in sequence.

[0024] To address the weak moment-bearing capacity of the beam-end connection structure, a corbel 3 of appropriate length is added to the bottom of the box beam. The first pad 4 is welded to the corbel 3, and the second pad 5 is welded to the lower beam flange 12 to strengthen the lower beam flange 12. This also facilitates the distinction between the upper and lower surfaces of the beam in the construction area. The installation contact surfaces of the first pad 4 and the second pad 5, as well as the corresponding areas of the box beam 1 or the corbel 3, are treated with friction surfaces.

[0025] The thickness of the second pad 5 is less than that of the first pad 4. This ensures that the contact point between the box beam 1 and the corbel 3 does not shift toward the column 2 end as the corbel 3 and box beam 1 deform, making node calculations simpler and more accurate. Furthermore, when the high-strength bolts on the lower flange 12 of the beam are tightened on-site to bring the box beam 1 into close contact with the second pad 5, a bending moment is generated at the end of the box beam 1. This bending moment is in the opposite direction to the bending moment generated by the box beam 1 under vertical load. By applying this reverse bending moment, the deflection of the box beam 1 under load can be reduced.

[0026] That is, the addition of the corbel 3, the first pad 4 and the second pad 5 turns the entire structure into a typical lever system. A pressure several times greater than the external force of the system will be generated at the fulcrum (the first pad 4). After the contact surface between the box beam 1 and the first pad 4 is treated as a friction surface, obvious static friction will be generated to constrain the horizontal movement of the box beam 1.

[0027] The utility model achieves the effect of pre-adding reverse bending moment by adding the corbel 3, the first pad 4 and the second pad 5, thereby reducing the deflection and stress of the box beam 1 after bearing load and improving the bearing limit of the box beam 1.

[0028] In one embodiment, the box beam 1 also includes two webs 13, which are symmetrically installed between the upper flange 11 and the lower flange 12 of the beam to form a box structure. Since the mechanical properties of the box section and the H-section are significantly different, it is necessary to control the length of the H-section of the beam as much as possible. The shorter the better. The limit is that as long as it can meet the angle steel connection requirements of the ends of the webs 13, the cross-sectional performance differences can be almost ignored, thereby simplifying the calculation process. The distance between the ends of the two webs 13 gradually decreases from the inside to the outside until they are close together. That is, after they are close together, the cross-section of the box beam 1 changes from box-shaped to H-shaped, which makes it easier to use angle steel to connect the column 2 and the end of the web 13 with high-strength bolts, while controlling the length of the H-section and retaining the torsional stiffness of the box beam 1 to the greatest extent, making it more stable and safe when bearing external loads.

[0029] In one embodiment, the corbel 3 is an H-shaped corbel 3, comprising an upper corbel flange 31 and a lower corbel flange 32, with a corbel rib 33 disposed between the upper and lower corbel flanges 31, 32. The corbel 3 also includes a corbel web, with the corbel rib 33 connecting the corbel web, the upper and lower corbel flanges 31, 32. In this embodiment, the first and second shims 4, 5 are both disposed above the upper corbel flange 31, with high-strength bolts connecting the beam lower flange 12, the second shim 5, and the upper corbel flange 31. The corbel rib 33 distributes and transfers loads, preventing damage caused by excessive local stress.

[0030] In one embodiment, a beam rib 14 is provided inside the box beam 1, and the beam rib 14 is connected to the inner wall of the box beam 1 to prevent the web 13 of the box beam 1 from being compressed and unstable.

[0031] In the embodiment, reinforcing ribs 21 may also be added inside the column 2 to prevent the web of the column 2 from becoming unstable due to compression.

[0032] In one embodiment, the angle steel includes a first angle steel 6 and two second angle steels 7. The first side of the first angle steel 6 is bolted to the column 2, and the second side of the first angle steel 6 is bolted to the upper flange 11 of the beam. The two second angle steels 7 are respectively located outside the ends of the two webs 13. The first side of the second angle steel 7 is bolted to the column 2, and the second side of the second angle steel 7 is bolted to the ends of the webs 13. In other words, the first angle steel 6 is responsible for connecting the column 2 and the upper flange 11 of the beam, while the two second angle steels 7 respectively connect the column 2 and the ends of the two webs 13. Both the first angle steel 6 and the second angle steel 7 can withstand the axial, vertical, and lateral forces of the beam, and restrain the displacement and torsion of the beam end.

[0033] That is, when it is necessary to withstand a large positive bending moment in the direction of the main axis of the beam and a large secondary axis bending moment, the connection structure of the upper and lower flanges at the end of the box beam 1 and the connection structure at the web 13 can be combined to withstand the shear force in the same direction, and the system efficiency is significantly improved; and when the positive bending moment of the main axis is too large and the number of bolts is insufficient, it is only necessary to increase the number of bolts between the angle steel of the upper flange 11 of the beam and the column 2, without extending the length of the H-section at the end of the beam; this can also significantly improve the node's ability to withstand the axial force and torque of the box beam 1.

[0034] In one embodiment, a connecting lug 8 parallel to the web 13 is fixedly mounted on the column 2. Two first angle steels 6 are provided on either side of the connecting lug 8. The first side of each first angle steel 6 is bolted to the connecting lug 8, and the second side of each first angle steel 6 is bolted to the beam upper flange 11. At the beam upper flange 11, connecting lugs 8 parallel to the web 13 of the box beam 1 can be welded to the column 2 in the factory. First angle steels 6 are used to connect the connecting lugs 8 to the beam upper flange 11 on either side. This configuration is also applicable to situations where the beam has vertical supports.

[0035] In one embodiment, the thickness of the first pad 4 is 1-2 mm thicker than that of the second pad 5 .

[0036] The design ideas of this utility model are as follows:

[0037] Example 1: A first angle steel 6 is connected to the column 2 and the upper beam flange 11 via high-strength bolts. An angle steel rib 61 is installed in the middle of the first angle steel to further strengthen the load-bearing structure of the first angle steel 6, making it more stable and capable of withstanding greater loads. Two second angle steels 7 are connected to the ends of the column 2 and the two webs 13 via high-strength bolts. The corbel 3 is positioned below the lower beam flange 12, with the first pad 4 in contact with it. High-strength bolts connect the lower beam flange 12, the second pad 5, and the upper corbel flange 31.

[0038] Example 2: A connecting ear plate 8 parallel to the web 13 of the box beam 1 is welded on the column 2, and two first angle steels 6 are arranged on both sides of the connecting ear plate 8 to be connected to the upper flange 11 of the beam with the first angle steel 6 respectively. Two second angle steels 7 are connected to the ends of the column 2 and the two webs 13 by high-strength bolts. The corbel 3 is arranged below the lower flange 12 of the beam, the first pad 4 is in contact with the lower flange 12 of the beam, and high-strength bolts are used to connect the lower flange 12 of the beam, the second pad 5 and the upper flange 31 of the corbel.

[0039] In addition, in practical applications, the form of the node can be appropriately changed. For example, when the cross-section of column 2 is also a closed cross-section, the web 13 of the box beam 1 only needs to be connected with a single-side angle steel. The angle steel is connected to the box beam 1 through high-strength bolts and welded to column 2 in the factory.

[0040] The installation sequence for the node components is as follows: After placing both ends of the box beam 1 on the corbels 3 and adjusting their positions, pre-tighten the high-strength bolts at the lower flanges 12 of the box beam 1, ensuring that the lower flange 12 is in close contact with the second pad 5 and then connected to the upper flange 31 of the corbel. Deformation of the beam ends generates a reverse bending moment, aligning the remaining bolt holes at the beam ends. Then, install the web 13 and the upper flange connection structure, and tighten all high-strength bolts in sequence. At this point, the pre-applied reverse bending moment is shared by all bolts at the beam ends, eliminating the need to worry about partial deformation of the lower flange due to bolt pull after the beam is subjected to external loads.

[0041] The addition of the corbel 3, the first pad 4 and the second pad 5 transforms the entire structure into a typical lever system. At the fulcrum (the first pad 4), a pressure several times greater than the external force of the system is generated. After the contact surface of the box beam 1 and the first pad 4 is treated with friction, a significant static friction force is generated to constrain the horizontal movement of the box beam 1. When it is necessary to withstand a large positive bending moment in the direction of the main axis of the beam and a large bending moment in the secondary axis, the connection structure of the upper and lower flanges of the box beam 1 end and the connection structure at the web 13 are combined to withstand the shear force in the same direction, which significantly improves the efficiency of the system. Moreover, when the positive bending moment of the main axis is too large and the number of bolts is insufficient, it is only necessary to increase the number of bolts between the angle steel of the upper flange 11 of the beam and the column 2, without extending the length of the H-section at the end of the beam. This can also significantly improve the node's ability to withstand the axial force and torque of the box beam 1.

[0042] The utility model achieves the effect of pre-adding reverse bending moment by adding the corbel 3, the first pad 4 and the second pad 5, thereby reducing the deflection and stress of the box beam 1 after bearing load and improving the bearing limit of the box beam 1.

[0043] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A steel structure box beam-column pure bolted connection capable of pre-applying reverse bending moment, wherein the box beam and column are bolted together by angle steel, and the box beam comprises an upper flange and a lower flange, and is characterized by: It includes a corbel, a first pad and a second pad. The corbel is arranged below the box beam, and the end face of its first end is in contact with the column. The first pad is fixedly connected to the second end of the corbel and in contact with the lower flange of the beam. The second pad is fixedly connected to the lower flange of the beam and bolted to the corbel. The thickness of the second pad is less than that of the first pad.

2. A steel structure box beam-column pure bolted connection capable of pre-applying reverse bending moment according to claim 1, characterized in that: The box beam further comprises two webs, which are symmetrically mounted between the upper flange and the lower flange of the beam to form a box structure. The distance between the ends of the two webs gradually decreases from the inside to the outside until they are tightly attached.

3. The steel structure box beam-column pure bolted connection node capable of pre-applying reverse bending moment according to claim 1, characterized in that: The corbel is an H-shaped corbel, comprising an upper corbel flange and a lower corbel flange, and a corbel rib is provided between the upper corbel flange and the lower corbel flange.

4. The steel structure box beam-column pure bolted connection node capable of pre-applying reverse bending moment according to claim 1, characterized in that: A beam rib is provided inside the box beam, and the beam rib is connected to the inner wall of the box beam.

5. The steel structure box beam-column pure bolted connection node capable of pre-applying reverse bending moment according to claim 2, characterized in that: The angle steel includes a first angle steel and two second angle steels, the first side of the first angle steel is bolted to the column, the second side of the first angle steel is bolted to the upper flange of the beam, the two second angle steels are respectively located on the outside of the two web ends, the first side of the second angle steel is bolted to the column, and the second side of the second angle steel is bolted to the web end.

6. The steel structure box beam-column pure bolted connection node capable of pre-applying reverse bending moment according to claim 5, characterized in that: A connecting ear plate parallel to the web is fixedly installed on the column, and the number of the first angle steels is two. The two first angle steels are arranged on both sides of the connecting ear plate. The first side of the first angle steel is bolted to the connecting ear plate, and the second side of the first angle steel is bolted to the upper flange of the beam.

7. The steel structure box beam-column pure bolted connection node capable of pre-applying reverse bending moment according to claim 1, characterized in that: The thickness of the first pad is 1-2 mm thicker than that of the second pad.

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