Connection method of composite steel tube concrete column and steel beam and an integral external reinforcement ring connection node

Abstract

The invention discloses a connection method of a composite steel tube concrete column and a steel beam and an integral external reinforcement ring connection node, including square steel tubes, round steel tubes, concrete, H-shaped steel beams, integral external reinforcement rings and other structural components. The node of the invention enables the plastic deformation of the steel frame beam-column node to occur only at the non-node core of the beam end, while the main structural components such as the steel frame beam-column are always kept within the elastic range, and no damage occurs after the earthquake. The integral external reinforcement ring is a prefabricated structure, which saves support parts during construction, is convenient for construction, saves construction time, is economical and practical, and is easy to operate.

Description

Technical Field

[0001] The patent type of the present invention belongs to the field of energy dissipation and shock absorption of engineering structures, and relates to nodes, and specifically to an integral external reinforcement ring steel tube concrete column-beam node. Background Art

[0002] CFST columns and steel beams are often connected in the form of nodes. In the actual earthquake resistance of engineering structures, nodes are very critical parts, and the seismic performance of node parts is one of the main focuses of research. Therefore, it is necessary to ensure that the nodes have high bearing capacity and deformation capacity to meet the seismic requirements of "strong nodes, weak components".

[0003] Based on the research on building beam-column nodes, it can be found that in the steel tube concrete column-steel beam node connection, the bearing capacity of the node is easily reduced after the connection, the initial stiffness is low, plastic deformation is easy to occur early in the force process, the energy dissipation capacity is poor, and the column in the node area is prone to stress concentration and shear failure. Therefore, it is necessary to find a new node connection method to overcome the above problems. Summary of the invention

[0004] In view of the defects and shortcomings of the prior art, the purpose of the present invention is to provide a connection method for a composite steel tube concrete column and a steel beam and an integral external reinforcement ring connection node to solve the technical problems of low bearing capacity and easy shear failure of the current steel tube concrete column-steel beam node.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for connecting a composite steel tube concrete column and a steel beam, the composite steel tube concrete column comprises an outer square steel tube and an inner round steel tube, the inner round steel tube is sleeved inside the outer square steel tube, the space between the outer square steel tube and the inner round steel tube and inside the inner round steel tube are filled with concrete, the steel beam is an H-shaped steel beam, comprising a web and an upper flange and a lower flange connected to the web, the composite steel tube concrete column and the steel beam are connected at the node by an external reinforcement ring, the external reinforcement ring comprises a first reinforcement ring, a second reinforcement ring and two outer rib ring plates, the first reinforcement ring and the second reinforcement ring have the same structure, both are regular octahedron structures, the first reinforcement ring and the second reinforcement ring are hollow inside; the first reinforcement ring and the second reinforcement ring are connected into a whole by two outer rib ring plates;

[0007] When connecting a composite concrete-filled steel tubular column and an H-shaped steel beam, the outer strengthening ring is sleeved on the outer square steel tube, and the first strengthening ring and the second strengthening ring are welded at the contact with the outer square steel tube of the composite concrete-filled steel tubular column; meanwhile, the web of the H-shaped steel beam is inserted into the outer square steel tube of the composite concrete-filled steel tubular column in a direction parallel to the plane where the outer ribbed ring plate is located, and the contact between the web and the outer square steel tube is welded, and the upper flange and the lower flange are respectively welded to the first strengthening ring and the second strengthening ring.

[0008] Specifically, inserting the web of the H-shaped steel beam into the outer square steel tube of the composite concrete-filled steel tubular column in a direction parallel to the plane where the outer ribbed ring plate is located specifically includes cutting off the upper flange and the lower flange of the H-shaped steel beam, only retaining the web, and the cutting-off length is not less than the depth of the web inserted into the square steel tube; a reserved hole is processed on the outer side of the square steel tube, and the height and width of the reserved hole are respectively the same as the height and width of the web, and the web of the H-shaped steel beam is inserted into the outer square steel tube of the composite concrete-filled steel tubular column through the reserved hole in a direction parallel to the plane where the outer ribbed ring plate is located.

[0009] Furthermore, the structures of the first strengthening ring and the second strengthening ring satisfy that D / B is 1.85 - 2.38, B / t d is 6 - 12, h / t d does not exceed 22, where D is the side length of the square steel tube, B is the outer extension length of the first strengthening ring or the second strengthening ring along the direction of the H-shaped steel beam, t d is the thickness of the first strengthening ring or the second strengthening ring, and h is the height of the H-shaped steel beam.

[0010] Furthermore, the structure of the H-shaped steel beam satisfies that b f / t f is 15.4 - 19.2, where b f is the width of the upper flange or the lower flange of the H-shaped steel beam, and t f is the thickness of the upper flange or the lower flange of the H-shaped steel beam.

[0011] In addition, the cutting-off length b of the upper flange or the lower flange of the H-shaped steel beam satisfies 0.65h < b < 0.85h, where h is the height of the H-shaped steel beam;

[0012] the distance a from the weakened area of the upper flange or the lower flange of the H-shaped steel beam to the end of the H-shaped steel beam ranges from 0.1b f + B < a < 0.2b f + B, where B is the outer extension length of the first strengthening ring or the second strengthening ring along the direction of the H-shaped steel beam;

[0013] the weakened depth c of the upper flange or the lower flange of the H-shaped steel beam ranges from 0.13b f < c < 0.26b f .

[0014] The present invention also discloses an integral external reinforcement ring connection node, which is used for connecting a composite steel tube concrete column with a steel beam, wherein the steel beam is an H-shaped steel beam, including a web and an upper flange and a lower flange connected to the web, and is characterized in that the external reinforcement ring includes a first reinforcement ring, a second reinforcement ring and an outer rib ring plate, the first reinforcement ring or the second reinforcement ring is a regular octahedral structure, a square groove is processed in the first reinforcement ring and the second reinforcement ring, and the first reinforcement ring and the second reinforcement ring are connected to form a whole through two outer rib ring plates; the structure of the first reinforcement ring and the second reinforcement ring satisfies that D / B is 1.85-2.38, B / t d 6~12,h / t d Not more than 22, where D is the side length of the square steel tube, B is the extension length of the first reinforcement ring or the second reinforcement ring along the steel beam direction, t d is the thickness of the first reinforcement ring or the second reinforcement ring, and h is the height of the steel beam.

[0015] Specifically, during the connection, the outer reinforcement ring is put on the compound steel tube concrete column, and the first reinforcement ring and the second reinforcement ring are welded to the contact position of the compound steel tube concrete column; at the same time, the web of the H-shaped steel beam is inserted into the compound steel tube concrete column in a direction parallel to the plane where the outer rib ring plate is located, and the web is welded to the contact position of the compound steel tube concrete column, and the upper flange and the lower flange are respectively welded to the contact position of the first reinforcement ring and the second reinforcement ring.

[0016] Optionally, the axial compression ratio of the connection node between the composite steel tube concrete column and the steel beam is 0.3 to 0.5.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) According to the connection method of the present invention, when an earthquake occurs, the node enters the elastic stage and the stress-strain curve rises rapidly. Before the stress-strain curve of the beam-column structural member reaches the elastic-plastic stage, the non-node core area of ​​the beam end at the node has reached the plastic stage and has obvious deformation, dissipating energy, successfully transferring plasticity and avoiding stress concentration in the node core area, which would cause brittle fracture.

[0019] (2) According to the connection method of the present invention, the composite steel tube concrete column can better limit the stress performance of the core concrete. It has a high bearing capacity, and its maximum bearing capacity can reach 6583kN. The ductility coefficient is 1.52, showing good ductility performance, slow stiffness degradation rate, and high seismic performance. It can meet the design requirements of the structure under dynamic loads and can be used in areas with high seismic fortification intensity.

[0020] (3) The integral external reinforcement ring connection node of the present invention can strengthen the stiffness of the node, improve the bearing capacity of the node, and enable the plastic hinge of the node to move significantly outward. At the same time, it can consume a part of the seismic energy. The presence of the reinforcement ring can make the energy consumption coefficient of the node reach 3.191, showing good energy consumption performance.

[0021] (4) In addition, the integral external reinforcement ring connection node of the present invention is an integrated structure and is prefabricated in a factory. During the construction of the building structure, the construction speed can be accelerated. During construction, the steel beam does not need to be welded with support parts, but can be directly placed in the middle of the integral external reinforcement ring for welding, which is convenient for construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the integral external reinforcement ring connection node of the present invention.

[0023] Figure 2 It is a cross-sectional view of the integral outer reinforcement ring connection node of the present invention.

[0024] Figure 3 It is a front view of the integral outer reinforcement ring structure of the integral outer reinforcement ring connection node of the present invention.

[0025] Figure 4 This is a cross-sectional view of the composite steel tube concrete column structure of the integral external reinforcement ring connection node of the present invention.

[0026] Figure 5 This is a cross-sectional view of the H-shaped steel beam structure of the integral external reinforcement ring connection node of the present invention.

[0027] Figure 6 It is an elevation view of the integral external reinforcement ring connection node of the present invention.

[0028] Figure 7 It is a plan view of the middle steel pipe in the integral outer reinforcement ring connection node of the present invention.

[0029] The meaning of the numbers in the attached drawings: 1-complex steel tube concrete column, 2-external reinforcement ring, 3-steel beam, 4-first reinforcement ring, 5-second reinforcement ring, 6-outer square steel tube, 7-concrete in the outer square steel tube, 8-inner round steel tube, 9-concrete in the inner round steel tube, 10-outer rib ring plate, 11-web plate, 12-upper flange, 13-reserved holes, 14-lower flange, D is the side length of the outer square steel tube, C is the diameter of the inner round steel tube, t c is the outer square steel tube wall thickness, t b is the wall thickness of the inner circular steel tube, A is the vertical extension length of the reinforcing ring and the steel beam, B is the extension length of the reinforcing ring along the steel beam direction, t a The thickness of the outer rib ring plate of the reinforcing ring, t dis the thickness of the first reinforcement ring, h is the height of the steel beam, b f is the upper or lower flange of the steel beam, t f is the height of the upper or lower flange of the steel beam, t w is the web thickness.

[0030] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0031] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0032] The composite steel tube concrete column and steel beam connection method of the present invention mainly involves components including a steel tube concrete column and an H-shaped steel beam, one end of the H-shaped steel beam is connected to the column of the composite steel tube concrete column by an integral external reinforcement ring, wherein the composite steel tube concrete column is composed of a square steel tube, concrete in the square steel tube, a round steel tube and concrete in the round steel tube (wherein the concrete in the square tube and the round steel tube are both concrete with a strength grade of C60), the integral external reinforcement ring is prefabricated by combining an upper reinforcement ring, a lower reinforcement ring and an outer rib ring plate, the H-shaped steel beam removes the upper flange and the lower flange by a corresponding length according to the length B of the upper outer reinforcement ring and the lower outer reinforcement ring in the integral external reinforcement ring, and only retains the web in the H-shaped steel beam (wherein the outer reinforcement ring is an octagon, and the specific size of the octagon is determined according to the column ring diameter length ratio D / B), when connected, The prefabricated integral outer reinforcement ring is inserted into the corresponding position of the compound steel tube concrete column and welded around the compound steel tube concrete column; then the H-shaped steel beam is inserted between the upper and lower outer reinforcement rings, a part of the web of the H-shaped steel beam is inserted into the reserved hole of the square steel tube reserved in the outer layer, and is welded with the reserved hole of the outer square steel tube; then the upper flange and the lower flange of the H-shaped steel beam are respectively welded and fixed to the upper reinforcement ring and the lower reinforcement ring in the integral outer reinforcement ring, wherein the height and width of the reserved hole in the square steel tube are consistent with the height and width of the web of the H-shaped steel beam, the position of the reserved hole is in the middle position of the square steel tube, and the flange of the H-shaped steel beam is not welded with the outer square steel tube of the compound steel tube concrete column, mainly to reduce the initial stiffness of the node connection, so that the node has sufficient deformation energy dissipation capacity when an earthquake occurs.

[0033] The inventors' research found that when the column-ring diameter-to-length ratio varies from 1.52 to 3.33, the failure mode of the joint is plastic hinge failure at the beam end. As the column-ring diameter-to-length ratio increases, the bearing capacity, energy dissipation coefficient, and secant stiffness of the joint all gradually decrease, and the hysteresis curve becomes less plump; when the column-ring diameter-to-length ratio is 1.52, the stress and initial stiffness in the joint core area are very large, and the seismic performance of the joint is not ideal. Therefore, the column-ring diameter-to-length ratio D / B should be in the range of 1.85 to 2.38.

[0034] At the same time, the research also found that when the length-to-thickness ratio of the integral external strengthening ring is not greater than 24, the failure mode of the joint is plastic hinge failure at the beam end. As the length-to-thickness ratio of the integral external strengthening ring decreases, the maximum stress in the joint core area gradually decreases, the equivalent plastic strain at the plastic hinge of the beam end gradually increases, the maximum stress and equivalent plastic strain of the integral external strengthening ring gradually decrease, the bearing capacity changes insignificantly, the ductility coefficient and initial stiffness become larger and larger, and the energy dissipation coefficient first increases and then decreases. Therefore, the length-to-thickness ratio B / t of the integral external strengthening ring d should be in the range of 6 to 12.

[0035] Further research found that when the beam flange width-to-thickness ratio is 23.1, due to the excessive thickness of the beam flange, stress concentration is likely to occur at the strengthening ring, the initial stiffness is relatively large, and the ductility performance of the joint is poor; when the beam flange width-to-thickness ratio is less than 11.5, the ultimate bearing capacity of the joint is small and the energy dissipation capacity is not good. Therefore, the beam flange width-to-thickness ratio b f / t f should be in the range of 15.4 to 19.2. When the beam-strengthening ring height-to-thickness ratio varies from 11 to 25, as the beam-strengthening ring height-to-thickness ratio increases, the maximum stress and equivalent plastic strain of the joint gradually increase, the initial stiffness and ultimate bearing capacity become larger and larger, and the energy dissipation coefficient first increases and then decreases; however, when the beam-strengthening ring height-to-thickness ratio is greater than 25, stress concentration will occur at the joint, the plumpness of the hysteresis curve of the joint is not good, the initial stiffness is too large, and the ductility performance and energy dissipation performance are poor. Therefore, the beam-strengthening ring height-to-thickness ratio h / t d should be less than 22.

[0036] The influence of the beam end weakening length and the distance from the weakening area to the beam end on the seismic performance of the joint is relatively small, but too small weakening length and the distance from the weakening area to the beam end will lead to stress concentration. Therefore, the weakening length b is taken as 0.65h < b < 0.85h, and the distance a from the beam flange weakening area to the beam end is taken as 0.1b f +B < a < 0.2b f +B. The influence of the beam flange weakening depth on the seismic performance of the joint is relatively large. As the beam flange weakening depth increases, the ductility performance and energy dissipation capacity of the joint increase, while the stiffness and bearing capacity decrease; when the weakening depth is too large, the deformation of the weakening area is very large and the bearing capacity drops linearly. Therefore, the beam flange weakening depth c is taken as: 0.13b f < c < 0.26b fBeam flange weakening is a way of node weakening. The weakening length b, the distance a between the beam flange weakening area and the beam end, and the beam flange weakening depth c are all weakening parameters that limit the weakening size. The research on these parameters has been mature. As a preferred solution, the present invention further limits the size range of the parameters to avoid the weakening length and the distance between the weakening zone and the beam end being too small. It should be clear that the limitation of these parameters is not a necessary technical feature of the technical solution of the present invention.

[0037] Embodiment 1:

[0038] According to the connection method of the composite steel tube concrete column and the steel beam, the present embodiment provides an integral external reinforcement ring connection node for connecting the composite steel tube concrete column and the steel beam, the steel beam is an H-shaped steel beam, including a web and an upper flange and a lower flange connected to the web, the outer reinforcement ring includes a first reinforcement ring, a second reinforcement ring and an outer rib ring plate, the first reinforcement ring or the second reinforcement ring is a regular octahedral structure, and a square groove is processed in the first reinforcement ring and the second reinforcement ring, the first reinforcement ring and the second reinforcement ring are connected to form a whole through two outer rib ring plates; the structure of the first reinforcement ring and the second reinforcement ring satisfies D / B of 1.85 to 2.38, B / t d 6~12,h / t d Not more than 22, where D is the side length of the square steel tube, B is the extension length of the first reinforcement ring or the second reinforcement ring along the steel beam direction, t d is the thickness of the first reinforcement ring or the second reinforcement ring, and h is the height of the steel beam.

[0039] In this embodiment, the material of the H-beam column or I-beam is Q235 steel, the cross-sectional size of the square steel tube in the compound steel tube concrete column is 500mm×500mm, the wall thickness is 16mm, the diameter size of the round steel tube is 266mm, the wall thickness is 12mm, the cross-sectional size of the I-beam is HW350mm×488mm, the thickness of the web and flange are 14mm and 22mm respectively, the weld adopts E40 welding rod, the grade of square steel tube concrete and round steel tube concrete is C60, the thickness of the upper and lower reinforcing rings of the integral outer reinforcing ring is 30mm, the thickness of the outer rib of the reinforcing ring is 16mm, the overhanging length of the reinforcing ring in the direction perpendicular to the beam is 240mm, and the overhanging length of the reinforcing ring along the beam is 240mm.

[0040] The axial compression ratio of the connection node between the composite steel tube concrete column and the steel beam is 0.3 to 0.5. The axial compression ratio refers to the ratio of the design value of the axial pressure to the product of the full cross-sectional area of ​​the node and the design value of the axial compressive strength of the concrete. The range of the axial compression ratio is limited in order to better control the ductility.

[0041] According to tests, the integral external reinforcing ring connection node of the present invention can make the energy consumption coefficient of the node reach 3.191, showing good energy consumption performance.

[0042] The construction method of the integral outer reinforcement ring connection node of this embodiment is as follows: first, the first reinforcement ring and the second reinforcement ring 4 and 5 are connected by two outer rib ring plates 10, and prefabricated in the factory to form an integral outer reinforcement ring 2. During construction, the prefabricated integral outer reinforcement ring 2 is first inserted into the corresponding position of the compound steel tube concrete column 1, and welded around the compound steel tube concrete column 1; then the H-shaped steel beam 3 is inserted between the upper and lower outer reinforcement rings 4 and 5, and a part of the web of the H-shaped steel beam 3 is inserted into the reserved hole 13 of the square steel tube 6 reserved in the outer layer, and welded with the outer square steel tube 6; then the upper flange 12 and the lower flange 14 of the H-shaped steel beam 3 are respectively welded and fixed with the upper and lower reinforcement rings 4 and 5 in the integral outer reinforcement ring 2, and the upper flange 12 and the lower flange 14 of the H-shaped steel beam 3 are not welded with the outer square steel tube 6 of the compound steel tube concrete column 1, and the connection between the compound steel tube concrete column and the steel beam is completed.

Claims

1. A connection method for a composite concrete-filled steel tubular column and an H-shaped steel beam. The composite concrete-filled steel tubular column includes an outer square steel tube and an inner circular steel tube. The inner circular steel tube is sleeved inside the outer square steel tube. Concrete is filled between the outer square steel tube and the inner circular steel tube and inside the inner circular steel tube. The H-shaped steel beam includes a web, an upper flange, and a lower flange connected to the web. It is characterized in that: At the joint of the composite concrete-filled steel tubular column and the H-shaped steel beam, an external strengthening ring is used for connection. The external strengthening ring includes a first strengthening ring, a second strengthening ring, and two external ribbed ring plates. The first strengthening ring and the second strengthening ring have the same structure and are both regular octagon structures. The inside of the first strengthening ring and the second strengthening ring is hollow. The first strengthening ring and the second strengthening ring are connected into a whole by two external ribbed ring plates. When connecting the composite concrete-filled steel tubular column and the H-shaped steel beam, the external strengthening ring is sleeved on the outer square steel tube, and the contact parts of the first strengthening ring and the second strengthening ring with the outer square steel tube of the composite concrete-filled steel tubular column are welded. At the same time, the web of the H-shaped steel beam is inserted into the outer square steel tube of the composite concrete-filled steel tubular column in a direction parallel to the plane where the external ribbed ring plate is located, and the contact part of the web and the outer square steel tube is welded. The upper flange and the lower flange are respectively welded to the first strengthening ring and the second strengthening ring. The structures of the first reinforcement ring and the second reinforcement ring satisfy D / B of 1.85 to 2.38, B / t d 6~12,h / t d Not more than 22, where D is the side length of the square steel tube, B is the overhanging length of the first reinforcement ring or the second reinforcement ring along the H-beam direction, t d is the thickness of the first reinforcement ring or the second reinforcement ring, and h is the height of the H-beam; The structure of the H-beam meets b f / t f is 15.4~19.2, among which b f is the width of the upper or lower flange of the H-beam, t f is the thickness of the upper or lower flange of the H-beam; The cutting length b of the upper flange or the lower flange of the H-shaped steel beam satisfies 0.65h < b < 0.85h, where h is the height of the H-shaped steel beam. The distance a between the upper flange or lower flange weakened area of ​​the H-beam and the end of the H-beam is in the range of 0.1b f +B <a<0.2b f +B, B is the overhanging length of the first reinforcement ring or the second reinforcement ring along the direction of the H-beam; The weakening depth c of the upper flange or lower flange of the H-beam is in the range of 0.13b f <c<0.26b f .

2. The method for connecting a composite steel tube concrete column and a steel beam according to claim 1, characterized in that: Inserting the web of the H-shaped steel beam into the outer square steel tube of the composite concrete-filled steel tubular column in a direction parallel to the plane where the external ribbed ring plate is located specifically includes cutting off the upper flange and the lower flange of the H-shaped steel beam, only retaining the web, and the cutting length is not less than the depth of the web inserted into the square steel tube. A reserved hole is processed on the outside of the square steel tube, and the height and width of the reserved hole are respectively the same as the height and width of the web. The web of the H-shaped steel beam is inserted into the outer square steel tube of the composite concrete-filled steel tubular column through the reserved hole in a direction parallel to the plane where the external ribbed ring plate is located.

3. An integral external reinforcement ring connection node, used for connecting a composite steel tube concrete column (1) with a steel beam (3), the steel beam being an H-shaped steel beam, comprising a web (11) and an upper flange (12) and a lower flange (14) connected to the web (11), the composite steel tube concrete column (1) being a square steel tube, characterized in that: The outer reinforcement ring (2) comprises a first reinforcement ring (4), a second reinforcement ring (5) and an outer rib ring plate (10); the first reinforcement ring (4) or the second reinforcement ring (5) is a regular octagonal structure; a square groove is processed in the first reinforcement ring (4) and the second reinforcement ring (5); the first reinforcement ring (4) and the second reinforcement ring (5) are connected to form a whole through two outer rib ring plates (10); the structure of the first reinforcement ring (4) and the second reinforcement ring (5) satisfies that D / B is 1.85 to 2.38, and B / t d 6~12,h / t d Not more than 22, where D is the side length of the square steel tube, B is the extension length of the first reinforcement ring (4) or the second reinforcement ring (5) along the steel beam (3), t d is the thickness of the first reinforcement ring (4) or the second reinforcement ring (5), and h is the height of the steel beam (3); The structure of the H-beam meets b f / t f is 15.4~19.2, among which b f is the width of the upper or lower flange of the H-beam, t f is the thickness of the upper or lower flange of the H-beam; The cutting length b of the upper flange or the lower flange of the H-shaped steel beam satisfies 0.65h < b < 0.85h, where h is the height of the H-shaped steel beam. The distance a between the upper flange or lower flange weakened area of ​​the H-beam and the end of the H-beam is in the range of 0.1b f +B <a<0.2b f +B, B is the overhanging length of the first reinforcement ring or the second reinforcement ring along the direction of the H-beam; The weakening depth c of the upper flange or lower flange of the H-beam is in the range of 0.13b f <c<0.26b f .

4. The integral external reinforcement ring connection node according to claim 3, characterized in that: During connection, the external strengthening ring (2) is sleeved on the composite concrete-filled steel tubular column (1), and the contact parts of the first strengthening ring (4) and the second strengthening ring (5) with the composite concrete-filled steel tubular column (1) are welded. At the same time, the web (11) of the H-shaped steel beam is inserted into the composite concrete-filled steel tubular column (1) in a direction parallel to the plane where the external ribbed ring plate (10) is located, and the contact part of the web (11) and the composite concrete-filled steel tubular column (1) is welded. The upper flange (12) and the lower flange (14) are respectively welded to the contact parts of the first strengthening ring (4) and the second strengthening ring (5).

5. The integral external reinforcement ring connection node according to claim 3, characterized in that: The axial compression ratio of the connection joint of the composite concrete-filled steel tubular column (1) and the steel beam (3) is 0.3 - 0.5.

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