Steel structure splicing joint

Abstract

The utility model relates to a steel structure splicing joint which comprises a first steel beam, a second steel beam, a plurality of high-strength bolts and a plurality of base plates. A first end plate is arranged on the first steel beam, a plurality of first connecting holes are formed in the first end plate, a second end plate is arranged on the second steel beam, a plurality of second connecting holes are formed in the second end plate, a plurality of third connecting holes are formed in the base plate, and the high-strength bolts sequentially penetrate through the first connecting holes, the second connecting holes and the third connecting holes. The nominal diameter d1 of the first connecting hole and the nominal diameter d2 of the second connecting hole meet the following relation: 1.2 d1 < = d2 < = 2d1, and the nominal diameter d1 of the first connecting hole is equal to the nominal diameter d3 of the third connecting hole. According to the utility model, the problem that the stress on the end plate is not uniformly distributed due to the forced displacement of the connecting holes in the mounting process can be avoided, the problem that the bolts are difficult to be aligned with the holes due to the position offset of the connecting holes in the multi-time dismounting process is solved, and the reusability of the first steel beam and the second steel beam is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of prefabricated steel structures, in particular to a steel structure splicing joint. Background Technique

[0002] The prefabricated steel structure system is a housing unit or component manufactured according to unified and standard building component specifications, and is a building produced by transporting to the construction site for assembly after prefabrication in the factory. The steel structure has good machining performance, is easy to assemble, and the assembled building has the characteristics of light weight, high strength, energy conservation and environmental protection, fast construction speed and high industrialization degree. Developing prefabricated steel structures is an urgent requirement for green buildings and building industrialization in China.

[0003] Currently, the most commonly used splicing joint in light steel structures is the traditional end plate connection joint with "double-row bolt arrangement". Such joints can be applied to light steel structure buildings with relatively small forces, such as small steel structure factories; while the most commonly used splicing joint in civil steel structures is the "fully bolted splicing joint". This type of joint generally uses double splints to connect the originally disconnected flanges and webs through high-strength bolts, which has a certain weakening effect on the cross-section of the original component, and the number of bolts is often huge, and the construction and installation are relatively cumbersome. Therefore, the traditional steel structure splicing joint has the disadvantages of weak bearing capacity, many bolts, inconvenient disassembly and assembly, and poor reusability.

[0004] To ensure the reusability of reusable steel structures, improve the disassembly and reinstallation efficiency, and achieve true repeatable functions, it is of great significance to propose a reusable steel structure splicing joint and reuse method with greater bearing capacity, which can adapt to rapid on-site assembly, digest the cumulative errors expected to occur after multiple disassembly and assembly, and is green, low-carbon and environmentally friendly. Content of the Utility Model

[0005] The purpose of the utility model is to overcome the defects of the above-mentioned existing technologies and provide a steel structure splicing joint to ensure the reusability of the steel structure and improve the disassembly and installation efficiency.

[0006] The purpose of the utility model can be realized by the following technical solutions:

[0007] A steel structure splicing joint includes a first steel beam, a second steel beam, a plurality of high-strength bolts and a plurality of backing plates;

[0008] A first end plate is provided on the first steel beam, and a plurality of first connection holes are provided on the first end plate. A second end plate is provided on the second steel beam, and a plurality of second connection holes are provided on the second end plate. A third connection hole is provided on the backing plate. The first end plate and the second end plate are arranged in a stacked manner relative to each other. The high-strength bolts sequentially pass through the first connection holes, the second connection holes, and the third connection hole, and the high-strength bolts correspond to the first connection holes, the second connection holes, the third connection hole, and the backing plate one by one;

[0009] The nominal diameter d1 of the first connection hole and the nominal diameter d2 of the second connection hole satisfy the following relationship: 1.2d1 ≤ d2 ≤ 2d1, and the nominal diameter d1 of the first connection hole is equal to the nominal diameter d3 of the third connection hole.

[0010] In one embodiment, both the length L and the width B of the backing plate satisfy the following relationship: L ≥ 3d2, B ≥ 3d2; the thickness H of the backing plate satisfies the following relationship: H ≥ 0.6h, where h is the thickness of the second end plate.

[0011] In one embodiment, both the first steel beam and the second steel beam are I-shaped steel beams. The I-shaped steel beam includes a web and two flange plates connected to both ends of the web, and the two flange plates are arranged opposite to each other in a first direction.

[0012] In one embodiment, the length directions of the first end plate and the second end plate are parallel to the first direction. The length of the first end plate is greater than the dimension of the first steel beam in the first direction, and the length of the second end plate is greater than the dimension of the second steel beam in the first direction.

[0013] In one embodiment, a first stiffening rib is provided on the part of the first end plate extending beyond the first steel beam in the first direction, and a second stiffening rib is provided on the part of the second end plate extending beyond the second steel beam in the first direction.

[0014] In one embodiment, the width direction of the first end plate and the second end plate is a second direction, and the second direction is perpendicular to the first direction. The width of the first end plate is greater than the dimension of the first steel beam in the second direction, and the width of the second end plate is greater than the dimension of the second steel beam in the second direction.

[0015] In one embodiment, a third stiffening rib is provided on the part of the first end plate extending beyond the first steel beam in the second direction, and a fourth stiffening rib is provided on the part of the second end plate extending beyond the second steel beam in the second direction.

[0016] In one embodiment, there are four third stiffening ribs, which are respectively connected to the flange plates of the first steel beam, and there are four fourth stiffening ribs, which are respectively connected to the flange plates of the second steel beam.

[0017] In one embodiment, both the first end plate and the second end plate are I-shaped end plates, and the arrangement direction of the I-shaped end plates is the same as that of the I-shaped steel beam.

[0018] In one embodiment, the first connection holes are distributed at positions on the first end plate on both sides of the flange plate, and one row of the first connection holes along the width direction of the first end plate is respectively provided on both sides of the flange plate;

[0019] When the distance D between two rows of the first connection holes between the two flange plates satisfies the following relationship: D≥20d1, one more row of the first connection holes is added to the part between the two rows of the first connection holes on the first end plate;

[0020] The positions of the second connection holes correspond to those of the first connection holes one by one.

[0021] Compared with the prior art, the utility model has the following advantages:

[0022] 1. For the above steel structure splicing joint, the first steel beam and the second steel beam are respectively provided with the first end plate and the second end plate. The first end plate, the second end plate and the backing plate are connected by high-strength bolts to realize the fixed connection of the first steel beam and the second steel beam; since the diameter of the second connection holes on the second end plate is much larger than that of the first connection holes on the first end plate, and the diameter of the third connection holes on the backing plate is equal to that of the first connection holes, the high-strength bolts can pass through the first end plate and the second end plate first and then connect the backing plate. Therefore, during the installation process, the first connection holes and the second connection holes do not need to be completely aligned to complete the installation of the high-strength bolts, solving the problem of difficult bolt hole alignment, avoiding the forced displacement of the connection holes during the installation process, which may cause uneven stress distribution on the end plate and reduce the safety. At the same time, it can also avoid the problem of difficult bolt hole alignment caused by the position deviation of the connection holes during multiple disassembly and assembly processes, improving the reuse performance of the first steel beam and the second steel beam.

[0023] 2. For the above steel structure splicing joint, the length L and width B of the backing plate are limited to be greater than or equal to 3 times the diameter of the second connection holes, and the thickness of the backing plate is limited to be greater than or equal to 0.6 times the thickness of the end plate. Therefore, the backing plate can completely cover the second connection holes, and the strength of the backing plate is also sufficient to make up for the influence of the large hole diameter on the strength of the second end plate, effectively improving the bearing capacity of the second end plate, optimizing the yield line form, delaying the development of its plastic deformation, and improving the elastic bearing capacity of the joint.

[0024] 3. For the above steel structure splicing joint, by restricting the lengths of the first end plate and the second end plate to be greater than the dimension of the first steel beam and the second steel beam in the first direction, the connection reliability of the first steel beam and the second steel beam in the first direction is enhanced. Moreover, the first stiffening rib and the second stiffening rib are provided at the protruding parts of the first end plate and the second end plate, further improving the strength of the protruding parts of the first end plate and the second end plate and further enhancing the bearing capacity of the splicing joint.

[0025] 4. In the second direction, further restrict the widths of the first end plate and the second end plate to be greater than the dimensions of the first steel beam and the second steel beam, and directly set the third stiffening rib connected to the flange of the first steel beam and the fourth stiffening rib connected to the flange of the second steel beam, effectively improving the strength and bearing capacity of the first end plate and the second end plate in terms of width.

[0026] 5. At the same time, the shapes of the first end plate and the second end plate match the shapes of the first steel beam and the second steel beam. By adopting I-shaped end plates and I-shaped steel beams, the steel consumption can be reduced while ensuring the structural stability of the connection node, and the damage probability during the transportation and installation of the first end plate and the second end plate can be decreased.

[0027] 6. The distribution pattern of the first connection holes on the first end plate, that is, two columns of first connection holes are distributed on both sides of each flange. And when the distance between the two flanges is too large, an additional column of first connection holes can be added, minimizing the number of openings on the first end plate and the second end plate and fully ensuring the connection strength of the first end plate and the second end plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a perspective view of the steel structure splicing joint in the present utility model.

[0029] Figure 2 is a cross-sectional view of the steel structure splicing joint in the present utility model.

[0030] Figure 3 is a cross-sectional view of the first steel beam and the second steel beam in the present utility model.

[0031] Figure 4 is a top view of the second steel beam in the present utility model.

[0032] Reference numerals: 100, steel structure splicing joint; 10, first steel beam; 11, first end plate; 111, first stiffening rib; 112, third stiffening rib; 12, first connection hole; 13, web; 14, flange; 20, second steel beam; 21, second end plate; 211, second stiffening rib; 212, fourth stiffening rib; 22, second connection hole; 30, high-strength bolt; 40, backing plate; 41, third connection hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The present utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present utility model, and the detailed implementation manners and specific operation processes are given. However, the protection scope of the present utility model is not limited to the following embodiments.

[0034] A steel structure splicing joint 100 will be described in detail below in conjunction with the accompanying drawings.

[0035] As Figures 1 to 4 shown, in one embodiment, a steel structure splicing joint 100 is provided, which includes a first steel beam 10, a second steel beam 20, a plurality of high-strength bolts 30, and a plurality of backing plates 40;

[0036] Among them, a first end plate 11 is provided on the first steel beam 10, a plurality of first connection holes 12 are provided on the first end plate 11, a second end plate 21 is provided on the second steel beam 20, a plurality of second connection holes 22 are provided on the second end plate 21, a plurality of third connection holes 41 are provided on the backing plate 40, the first end plate 11 and the second end plate 21 are arranged in a stacked and opposite manner, the high-strength bolts 30 sequentially pass through the first connection holes 12, the second connection holes 22, and the third connection holes 41, and the high-strength bolts 30 correspond to the first connection holes 12, the second connection holes 22, the third connection holes 41, and the backing plate 40 one by one;

[0037] And, the nominal diameter d1 of the first connection hole 12 and the nominal diameter d2 of the second connection hole 22 satisfy the following relationship: 1.2d1 ≤ d2 ≤ 2d1, and the nominal diameter d1 of the first connection hole 12 is equal to the nominal diameter d3 of the third connection hole 22.

[0038] For the above-mentioned steel structure splicing joint 100, the first end plate 11 and the second end plate 21 are respectively provided on the first steel beam 10 and the second steel beam 20, and the first end plate 11, the second end plate 21, and the backing plate 40 are connected by high-strength bolts 30 to realize the fixed connection of the first steel beam 10 and the second steel beam 20; since the diameter of the second connection holes 22 on the second end plate 21 is much larger than the diameter of the first connection holes 12 on the first end plate 11, and the third connection holes 41 on the backing plate 40 are equal in diameter to the first connection holes 12, the high-strength bolts 30 can pass through the first end plate 11 and the second end plate 21 first and then connect the backing plate 40. Therefore, during the installation process, the first connection holes 12 and the second connection holes 22 do not need to be completely aligned, and the installation of the high-strength bolts 30 can be completed, solving the problem of difficult bolt hole alignment, avoiding the forced displacement of the connection holes during the installation process, which may cause uneven stress distribution on the end plate and reduce the safety, and at the same time, it can also avoid the problem of difficult bolt hole alignment caused by the displacement of the connection hole positions during multiple disassembly and assembly processes, improving the reuse performance of the first steel beam 10 and the second steel beam 20.

[0039] Specifically, in one embodiment, the length L and width B of the backing plate 40 both satisfy the following relationships: L ≥ 3d2, B ≥ 3d2; the thickness H of the backing plate 40 satisfies the following relationship: H ≥ 0.6h, where h is the thickness of the second end plate 21. For the above steel structure splicing joint 100, restricting the length L and width B of the backing plate 40 to be greater than or equal to 3 times the diameter of the second connection hole 22 and restricting the thickness of the backing plate 40 to be greater than or equal to 0.6 times the end plate thickness, so the backing plate 40 can completely cover the second connection hole 22, and the strength of the backing plate 40 is also sufficient to compensate for the influence of the large hole diameter on the strength of the second end plate 21, effectively improving the bearing capacity of the second end plate 21, optimizing the yield line form, delaying the development of its plastic deformation, and improving the elastic bearing capacity of the joint.

[0040] Further, in one embodiment, the nominal diameter d1 of the first connection hole 12 is 14 mm to 33 mm.

[0041] Specifically, as Figure 1 shown, in one embodiment, both the first steel beam 10 and the second steel beam 20 are I-shaped steel beams. The I-shaped steel beam includes a web 13 and two flange plates 14 connected to both ends of the web 13. The two flange plates 14 are arranged opposite to each other in the first direction.

[0042] Further, as Figure 4 shown, in one embodiment, the length directions of the first end plate 11 and the second end plate 21 are parallel to the first direction. The length of the first end plate 11 is greater than the dimension of the first steel beam 10 in the first direction, and the length of the second end plate 21 is greater than the dimension of the second steel beam 20 in the first direction.

[0043] Further, as Figure 1 and Figure 4 shown, in one embodiment, the part of the first end plate 11 extending beyond the first steel beam 10 in the first direction is provided with a first stiffening rib 111, and the part of the second end plate 21 extending beyond the second steel beam 20 in the first direction is provided with a second stiffening rib 211. For the above steel structure splicing joint 100, by restricting the lengths of the first end plate 11 and the second end plate 21 to be greater than the dimensions of the first steel beam 10 and the second steel beam 20 in the first direction, the connection reliability of the first steel beam 10 and the second steel beam 20 in the first direction is stronger, and the first stiffening rib 111 and the second stiffening rib 211 are provided at the extending parts of the first end plate 11 and the second end plate 21, further improving the strength of the extending parts of the first end plate 11 and the second end plate 21 and further improving the bearing capacity of the splicing joint.

[0044] In this specific embodiment, there are two first stiffening ribs 111, which are respectively connected to the side walls of the two flange plates 14 of the first steel beam 10; there are two second stiffening ribs 211, which are respectively connected to the two flange plates 14 of the second steel beam 20.

[0045] Specifically, as Figure 4As shown, in one embodiment, the width direction of the first end plate 11 and the second end plate 21 is the second direction, the second direction is perpendicular to the first direction, the width of the first end plate 11 is greater than the dimension of the first steel beam 10 in the second direction, and the width of the second end plate 21 is greater than the dimension of the second steel beam 20 in the second direction.

[0046] Specifically, as Figure 1 and Figure 4 shown, in one embodiment, the part of the first end plate 11 extending beyond the first steel beam 10 in the second direction is provided with a third stiffening rib 112, and the part of the second end plate 21 extending beyond the second steel beam 20 in the second direction is provided with a fourth stiffening rib 212.

[0047] Furthermore, as Figure 1 and Figure 4 shown, in one embodiment, there are four third stiffening ribs 112, which are respectively connected to both ends of the flange 14 of the first steel beam 10, and there are four fourth stiffening ribs 212, which are respectively connected to both ends of the flange 14 of the second steel beam 20.

[0048] In the second direction, by further restricting the widths of the first end plate 11 and the second end plate 21 to be greater than the dimensions of the first steel beam 10 and the second steel beam 20, and directly arranging the third stiffening rib 112 connected to the flange 14 of the first steel beam 10 and the fourth stiffening rib 212 connected to the flange 14 of the second steel beam 20, the strength and load-bearing capacity of the first end plate 11 and the second end plate 21 in the width direction are effectively improved.

[0049] Specifically, as Figure 4 shown, in one embodiment, both the first end plate 11 and the second end plate 21 are I-shaped end plates, and the arrangement directions of the I-shaped end plates are the same as those of the I-shaped steel beams. At the same time, the shapes of the first end plate 11 and the second end plate 21 match the shapes of the first steel beam 10 and the second steel beam 20. Using I-shaped end plates and I-shaped steel beams can reduce the steel consumption while ensuring the stability of the connection node structure, and reduce the damage probability during the transportation and installation of the first end plate 11 and the second end plate 21.

[0050] Specifically, as Figure 4 shown, in one embodiment, the first connection holes 12 are distributed at positions on both sides of the flange 14 of the first end plate 11, and one row of first connection holes 12 along the width direction of the first end plate 11 is respectively provided on both sides of the flange 14;

[0051] When the distance D between the two rows of first connection holes 12 between the two flanges 14 satisfies the following relationship: D≥20d1, an additional row of first connection holes 12 is added to the part between the two rows of first connection holes 12 on the first end plate 11;

[0052] The positions of the second connection holes 22 correspond one-to-one with those of the first connection holes 12, that is, the second connection holes 22 are distributed on the second end plate 21 at positions on both sides of the wing plate 14. One row of second connection holes 22 along the width direction of the second end plate 21 is provided on each side of the wing plate 14; when the distance D between the two rows of second connection holes 22 between the two wing plates 14 satisfies the following relationship: D≥20d1, an additional row of second connection holes 22 is added to the portion between the two rows of second connection holes 22 on the second end plate 21.

[0053] Generally, D≥400, and an additional row of second connection holes 22 is added to the portion between the two rows of second connection holes 22 on the second end plate 21.

[0054] The distribution pattern of the first connection holes 12 on the first end plate 11 is that two rows of first connection holes 12 are distributed on each side of each wing plate 14. And when the distance between the two wing plates 14 is too large, an additional row of first connection holes 12 can be added, so that the number of openings on the first end plate 11 and the second end plate 21 is minimized, and the connection strength of the first end plate 11 and the second end plate 21 is fully ensured.

[0055] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0056] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0057] In the present utility model, unless otherwise clearly stipulated and defined, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the internal communication between two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0058] In the present utility model, unless otherwise clearly stipulated and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature is at a higher horizontal level than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature is at a lower horizontal level than the second feature.

[0059] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0060] The preferred specific embodiments of the present utility model have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present utility model without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present utility model through logical analysis, reasoning or limited experiments on the basis of the prior art shall fall within the protection scope determined by the claims.

Claims

1. A steel structure splicing node, characterized in that: It comprises a first steel beam (10), a second steel beam (20), a plurality of high-strength bolts (30) and a plurality of pads (40); The first steel beam (10) is provided with a first end plate (11), and the first end plate (11) is provided with a plurality of first connection holes (12); the second steel beam (20) is provided with a second end plate (21), and the second end plate (21) is provided with a plurality of second connection holes (22); the pad (40) is provided with a plurality of third connection holes (41); the first end plate (11) and the second end plate (21) are relatively stacked and arranged; the high-strength bolts (30) pass through the first connection holes (12), the second connection holes (22) and the third connection holes (41) in sequence; the high-strength bolts (30) correspond to the first connection holes (12), the second connection holes (22), the third connection holes (41) and the pad (40) in one-to-one correspondence; The nominal diameter d1 of the first connecting hole (12) and the nominal diameter d2 of the second connecting hole (22) satisfy the following relationship: 1.2d1≤d2≤2d1, and the nominal diameter d1 of the first connecting hole (12) and the nominal diameter d3 of the third connecting hole (41) are equal.

2. A steel structure splicing node according to claim 1, characterized in that: The length L and width B of the pad (40) both satisfy the following relationship: L≥3d2, B≥3d2; the thickness H of the pad (40) satisfies the following relationship: H≥0.6h, where h is the thickness of the second end plate (21).

3. A steel structure splicing node according to claim 1, characterized in that: The first steel beam (10) and the second steel beam (20) are both I-beams, and the I-beams include a web (13) and two wing plates (14) connected to both ends of the web (13), and the two wing plates (14) are arranged opposite to each other along a first direction.

4. A steel structure splicing node according to claim 3, characterized in that: The length directions of the first end plate (11) and the second end plate (21) are parallel to the first direction; the length of the first end plate (11) is greater than the first direction dimension of the first steel beam (10); and the length of the second end plate (21) is greater than the first direction dimension of the second steel beam (20).

5. A steel structure splicing node according to claim 4, characterized in that: A portion of the first end plate (11) extending out of the first steel beam (10) in the first direction is provided with a first stiffening rib (111), and a portion of the second end plate (21) extending out of the second steel beam (20) in the first direction is provided with a second stiffening rib (211).

6. A steel structure splicing node according to claim 3, characterized in that: The width direction of the first end plate (11) and the second end plate (21) is the second direction, the second direction is perpendicular to the first direction, the width of the first end plate (11) is greater than the second direction dimension of the first steel beam (10), and the width of the second end plate (21) is greater than the second direction dimension of the second steel beam (20).

7. A steel structure splicing node according to claim 6, characterized in that: A portion of the first end plate (11) extending out of the first steel beam (10) in the second direction is provided with a third stiffening rib (112), and a portion of the second end plate (21) extending out of the second steel beam (20) in the second direction is provided with a fourth stiffening rib (212).

8. A steel structure splicing node according to claim 7, characterized in that: There are four third stiffening ribs (112) and they are respectively connected to the wing plates (14) of the first steel beam (10); there are four fourth stiffening ribs (212) and they are respectively connected to the wing plates (14) of the second steel beam (20).

9. A steel structure splicing node according to claim 3, characterized in that: The first end plate (11) and the second end plate (21) are both I-shaped end plates, and the I-shaped end plates and the I-shaped steel beam are arranged in the same direction.

10. A steel structure splicing node according to claim 9, characterized in that: The first connection holes (12) are distributed on the first end plate (11) at positions on both sides of the wing plate (14), and a row of the first connection holes (12) along the width direction of the first end plate (11) is respectively provided on both sides of the wing plate (14); When the distance D between the two rows of the first connection holes (12) between the two wing plates (14) satisfies the following relationship: D ≥ 20d1, an additional row of the first connection holes (12) is added to the portion between the two rows of the first connection holes (12) on the first end plate (11); The position of the second connection hole (22) corresponds one-to-one to the first connection hole (12).

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