Frame column and superposed beam connecting joint and construction method thereof

Abstract

The invention discloses a frame column and superposed beam connecting joint and a construction method thereof. The novel connecting joint mainly comprises a superposed beam, a frame column, a connecting cover plate and a post-pouring part. The frame column comprises a steel pipe column and a steel pipe concrete column, the composite beam is placed on a lower connecting ring plate of the steel pipe column, a composite beam bottom embedded steel plate is connected with the column lower connecting ring plate in a welded mode, and a composite beam top embedded steel plate is connected with a steel column upper connecting ring plate or a steel column wall plate in a welded mode through a connecting cover plate. And concrete, ultra-high performance concrete or grouting materials are poured into gaps between the superposed beam ends and the steel columns to form a whole. Compared with the prior art, reliable force transmission of the beam top rib and the bottom rib in a joint area is achieved through welded connection of the superposed beam embedded steel plate and the frame column, machining and construction links such as steel pipe column wall trepanning, reinforcement and beam top rib penetrating are effectively reduced, the technology is simplified, and efficiency is improved. The connecting joint of the frame column and the superposed beam is clear in force transmission path, simple in structure and convenient to construct, and has performance and construction advantages.

Description

Technical Field

[0001] The invention belongs to the field of building technology, relates to precast concrete buildings, and particularly relates to a connection node between a frame column and a composite beam and a construction method thereof. Background Art

[0002] Concrete-filled steel tube columns have many advantages in engineering. In terms of mechanical properties, they can give full play to the advantages of steel and concrete materials, effectively reduce the cross-sectional size of components, and improve the practical performance of buildings. In addition, there are advantages such as no need for formwork in construction. The advantages of precast concrete in processing and construction efficiency and cost are obvious, and the economic and social benefits it brings make this technology widely used in the construction industry.

[0003] The beam-column node connection is the key technology of the steel tube column-concrete beam structure. The existing node connections can be divided into rigid connection, hinged connection and semi-rigid connection. For rigid connection, the common practice is to extend the top reinforcement of the concrete beam into the steel tube column to enhance the stiffness and bearing capacity of the node, so as to transmit larger bending moments and shear forces. However, this method is difficult to construct, and it is necessary to drill holes in the steel pipe and ensure the accurate position of the concrete beam reinforcement, which is difficult to apply in practice. In addition, for concrete composite beams, when the top reinforcement is threaded on site, the construction difficulty is increased due to problems such as the length of the reinforcement and high-altitude operations. Other forms of connection nodes generally have problems such as complex node structure and difficult construction, and most of them are semi-rigid connections with complex force performance, and none of them solve the problem of difficulty in threading the top reinforcement of composite beams. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a connection node between a frame column and a composite beam and a construction method thereof, so as to optimize the node structure, avoid the many problems caused by the opening of steel pipes in frame columns and the reinforcement construction of concrete composite beams, improve construction efficiency and simplify the design method.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A connection node between a frame column and a composite beam, which is realized as follows:

[0007] A beam top embedded steel plate is arranged at the top of the beam end of the composite beam, and a beam bottom embedded steel plate is arranged at the bottom of the beam end. The top reinforcement of the composite beam is welded to the beam top embedded steel plate, and the bottom reinforcement is welded to the beam bottom embedded steel plate to achieve stress transfer.

[0008] Connect the ring plate under the welded column on the outer wall of the steel pipe of the frame column;

[0009] The composite beam is placed on the connecting ring plate under the column, the embedded steel plate at the bottom of the beam is connected to the connecting ring plate under the column by welding, and the embedded steel plate at the top of the beam is connected to the outer wall of the steel pipe by connecting the cover plate or by welding the connecting cover plate to the connecting plate on the column, so as to realize the effective force transmission of the composite beam steel bar in the node area and avoid the opening of the pipe wall of the steel pipe;

[0010] The post-cast part is formed by pouring between the beam end of the composite beam and the pipe wall of the steel pipe.

[0011] That is, the top of the connection node of the present invention can adopt two structures. The first structure is that the embedded steel plate on the top of the beam and the outer wall of the steel pipe are welded and connected through the connection cover plate and the connection plate on the column, which is realized as follows:

[0012] A column upper connecting plate is welded to the outer wall of the steel pipe of the frame column, wherein the radial dimension of the column lower connecting ring plate is greater than the radial dimension of the column upper connecting plate;

[0013] The connecting cover plate is placed on the top of the embedded steel plate on the top of the beam and the top of the connecting plate on the column, and is welded to the embedded steel plate on the top of the beam and the top of the connecting plate on the column by fillet welds. When the weld size does not meet the connection strength requirement, a notch is opened on the plate surface of the cover plate, and the connection is performed by combining plug welding and fillet weld connection.

[0014] In addition, the second structure can be adopted, that is, the embedded steel plate on the top of the beam is directly welded to the outer wall of the steel pipe through the connecting cover plate. In this case, the outer wall of the steel pipe does not need to be welded with the connecting plate on the column, which is realized as follows:

[0015] One end of the connecting cover plate is welded to the top of the embedded steel plate on the top of the beam, and the other end is directly connected to the outer wall of the steel pipe by groove butt welding. An inner ring plate is arranged on the inner wall of the steel pipe corresponding to the connection position of the connecting cover plate to ensure reliable force transmission in the core area of ​​the node.

[0016] In the present invention, the strength of the embedded steel plate on the top of the beam and the connecting cover plate must be determined according to the design requirements to ensure that the cross-sectional bearing capacity in the node connection area is greater than the cross-sectional bearing capacity of each part of the composite beam body, so that the plastic hinge at the beam end is generated in the area outside the range of the embedded steel plate on the top of the beam.

[0017] In one embodiment, the two sides of the embedded steel plate at the bottom of the beam are connected to the connecting ring plate under the column by fillet welds. When the weld size does not meet the connection strength requirement, the size of the embedded steel plate at the bottom of the beam is increased along the width direction of the beam section, and a second groove is opened in the part of the embedded steel plate at the bottom of the beam that exceeds the beam width area, and the connection is performed by combining plug welding connection and fillet weld connection.

[0018] In one embodiment, the top reinforcement is welded to the top surface of the pre-embedded steel plate at the top of the beam, and a portion for welding to the connecting cover plate is reserved on the top surface of the pre-embedded steel plate at the top of the beam close to the frame column; the bottom reinforcement is welded to the top surface of the pre-embedded steel plate at the bottom of the beam.

[0019] In one embodiment, the prefabricated beam body is provided with stirrup one outside the range of the embedded steel plate at the top of the beam and the embedded steel plate at the bottom of the beam, and stirrup two is provided within the range; the constraint area of ​​stirrup one includes the top reinforcement, the bottom reinforcement and the core concrete therebetween, and stirrup two is located between the embedded steel plate at the top of the beam and the embedded steel plate at the bottom of the beam and constrains the concrete therebetween; additional short bars are arranged below the embedded steel plate at the top of the beam and above the embedded steel plate at the bottom of the beam, and the additional short bars are parallel to the long direction of the beam, extending from the constraint area of ​​stirrup two to the constraint area of ​​stirrup one.

[0020] In one embodiment, a plurality of vertical stiffening plates are welded to the outer wall of the steel pipe. The stiffening plates are located between the connecting plates on the columns and the connecting ring plates under the columns and are welded to the connecting plates on the columns and the connecting ring plates under the columns at the same time. The beam ends of the composite beams are located between adjacent stiffening plates and are spaced apart from the stiffening plates to provide space for welding operations.

[0021] In one embodiment, the steel tube is filled with concrete to form a concrete-filled steel tube column.

[0022] The present invention also provides a construction method for the connection node between the frame column and the composite beam, comprising the following steps:

[0023] Step 1, completing the welding of the steel pipe, the connection plate on the column and the connection ring plate under the column in the frame column, or completing the welding of the steel pipe, the connection plate on the column and the connection ring plate under the column in the factory;

[0024] Step 2: Complete the binding of the composite beam reinforcement cage in the factory, weld the bottom reinforcement and the embedded steel plate at the bottom of the beam, fix the embedded steel plate at the top of the beam, and weld the top reinforcement and the embedded steel plate at the top of the beam;

[0025] Step 3: Support the formwork and complete the pouring of the composite beam. During the concrete pouring process, the top embedded steel plate needs to be protected to prevent concrete contamination.

[0026] Step 4: At the construction site, after the frame columns are positioned and hoisted and fixed, the composite beams are placed on the connecting ring plates under the columns, positioned and welded to form a whole; the connecting cover plates are placed, one end is welded to the embedded steel plate on the top of the beam, and the other end is welded to the connecting plate on the column, or directly welded to the steel pipe column wall.

[0027] Step 5: After the on-site formwork is supported, pour the post-cast parts of the nodes and the overlapping layers in sequence.

[0028] In one embodiment, in step 3, the prefabricated beam body of the composite beam is cast within the range of the embedded steel plate at the top of the beam to the bottom surface of the embedded steel plate at the top of the beam, and is cast outside the range of the embedded steel plate at the top of the beam to the elevation of the bottom surface of the composite layer. The bottom surface of the embedded steel plate at the top of the beam is higher than the bottom surface of the composite layer, which can be achieved by casting twice.

[0029] Compared with the prior art, the present invention realizes a new connection node form at the beam end by arranging embedded steel plates on the top and bottom of the beam and welding them to the main reinforcement of the beam; and arranging a connecting cover plate to rigidly connect the composite beam and the frame column by welding, thereby realizing reliable transmission of the bending moment in the node area.

[0030] The present invention welds the top reinforcement of the composite beam and the pre-embedded steel plate on the top of the beam into one body, and when the composite beam is cast, the pre-embedded steel plate on the top of the beam and the beam body are concreted into one body, thereby further improving the construction efficiency.

[0031] The node structure of the present invention is simple and the force transmission path is clear, which solves the application pain points of the existing rigid connection nodes between frame columns and composite beams. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a three-dimensional schematic diagram of the connection node between the frame column and the composite beam of the present invention.

[0033] Figure 2 It is a three-dimensional schematic diagram of the welding node between the frame column and the composite beam in an example of the present invention.

[0034] Figure 3 It is a three-dimensional schematic diagram of the composite beam end structure in an example of the present invention.

[0035] Figure 4 This is a three-dimensional schematic diagram of the connection node top in the example of the present invention when the second structure is adopted.

[0036] Figure 5 It is a three-dimensional schematic diagram of the post-casting part in the example of the present invention.

[0037] In the figure:

[0038] 1-composite beam; 11-prefabricated beam body; 12-embedded steel plate on top of beam; 13-embedded steel plate on bottom of beam; 131-side wall of steel plate; 132-slot 2; 14-top reinforcement; 15-bottom reinforcement; 16-stirrup 1; 17-stirrup 2; 18-staff reinforcement; 2-frame column; 21-steel pipe; 22-connecting plate on column; 23-connecting ring plate under column; 24-stiffening plate; 25-inner ring plate; 3-connecting cover plate; 31-slot 1; 4-post-cast part. DETAILED DESCRIPTION

[0039] The specific technical solutions of the present invention are described below in conjunction with the accompanying drawings and embodiments.

[0040] refer to Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the present invention is a connection node between a frame column and a composite beam, and provides a rigid node form of a composite beam 1 and a frame column 2. In the present invention, the composite beam 1 generally refers to a prefabricated composite beam, including a prefabricated part 11 and a steel bar part thereof, and the frame column 2 generally refers to a steel frame column, including a steel pipe 21, and may further include concrete and grouting materials poured in the steel pipe 21.

[0041] To achieve welding between beams and columns, the present invention provides two structures.

[0042] In the first structure, a beam top embedded steel plate 12 and a beam bottom embedded steel plate 13 are provided at the beam end of the composite beam 1, which are respectively used to connect with the frame column 2. Among them, the beam top embedded steel plate 12 is located at the top of the beam end of the composite beam 1, and is preferably a horizontal steel plate. The beam bottom embedded steel plate 13 is located at the bottom of the beam end of the composite beam 1, and is also preferably a horizontal steel plate.

[0043] The specific arrangement of the beam top embedded steel plate 12 is to weld it to the top reinforcement 14 of the composite beam 1 to achieve stress transfer. The specific arrangement of the beam bottom embedded steel plate 13 is to weld it to the bottom reinforcement 15 of the composite beam 1 to achieve stress transfer. As is known, the top reinforcement 14 and the bottom reinforcement 15 are known structures of the composite beam 1, and their arrangement parameters can refer to the existing construction specifications.

[0044] The frame column 2 of the present invention includes a steel pipe 21. In order to achieve connection with the embedded steel plate 12 on the top of the beam and the embedded steel plate 13 on the bottom of the beam, the present invention welds a column upper connecting plate 22 and a column lower connecting ring plate 23 on the outer wall of the steel pipe 21. Obviously, the column upper connecting plate 22 is located above the column lower connecting ring plate 23. In the prior art, if a double-layer plate is set, the beam is often extended between the double-layer plates, which brings difficulty to the construction to a certain extent. In order to avoid this problem, the present invention designs the radial dimension of the column lower connecting ring plate 23 to be larger than the radial dimension of the column upper connecting plate 22. At this time, the composite beam 1 is placed on the column lower connecting ring plate 23, and the column lower connecting ring plate 23 contacts the embedded steel plate 13 at the bottom of the beam, and a reliable connection is achieved by welding. The top surface of the embedded steel plate 12 on the top of the beam is designed to be flush with the top surface of the column upper connecting plate 22. After the ends of the two are in contact, a reliable connection is achieved by welding through the upper connecting cover plate 3.

[0045] In the second structure of the present invention for realizing the connection between beams and columns, there is no need to set the connection plate 22 on the column, but the connection cover plate 3 is directly welded to the beam top embedded steel plate 12 and the column wall of the steel pipe 21. The column side adopts the groove butt weld.

[0046] Through the above two structures and connection methods, effective force transmission of the steel bars of the composite beam 1 in the node domain can be finally achieved, and no holes need to be opened in the wall of the steel pipe 21, which reduces the construction steps and reduces the construction difficulty.

[0047] In order to meet the node requirements, it is obvious that after completing the above-mentioned welding connection, it is necessary to cast between the beam end of the composite beam 1 and the tube wall of the steel tube 21 to form a post-cast part 4, and finally form a complete and reliable beam-column connection node.

[0048] It can be seen that compared with the prior art, the present invention realizes reliable force transmission between the top reinforcement 14 and the bottom reinforcement 15 in the node area by arranging a pre-buried steel plate at the end of the composite beam 1 and welding it to the frame column 2, effectively reducing the processing and construction links such as opening holes in the steel pipe column wall, reinforcement, and beam top reinforcement penetration, simplifying the process, and improving efficiency. The connection node between the frame column and the composite beam of the present invention has a clear force transmission path, simple structure, and convenient construction, and has both performance and construction advantages.

[0049] In a further embodiment of the present invention, after the connecting cover plate 3 is placed on the top of the beam top embedded steel plate 21 and the column connecting plate 22, it is specifically welded to the beam top embedded steel plate 21 and the column connecting plate 22 in the form of fillet welds. The fillet welds can provide good shear and tensile strength and are highly flexible. When the second structure is adopted without setting the column connecting plate 22, the connecting cover plate 3 and the beam top embedded steel plate 21 are still welded in the form of fillet welds, and are connected to the column wall of the steel pipe 21 by groove welding. Compared with the reinforcement construction, the difficulty of the two structures is greatly reduced. At the same time, since the fillet weld has certain requirements on the size, when the weld size does not meet the connection strength requirements, the present invention opens a notch 31 on the plate surface of the connecting cover plate 3, performs plug welding at the notch 31, and connects by combining plug welding connection with fillet weld connection. The strength of the embedded steel plate 12 on the top of the beam and the connecting cover plate 3 is determined according to the design requirements to ensure that the cross-sectional bearing capacity at the node connection is greater than the bearing capacity of each cross-section in the beam body of the composite beam 1. Under the action of load, the bending moment of the beam body cross-section reaches the limit bending moment first, causing the plastic hinge to appear in the beam body.

[0050] Preferably, the notch 31 is simultaneously provided on the connecting cover plate 3 corresponding to the portion of the beam top embedded steel plate 21 and the column connecting plate 22 .

[0051] Similarly, in a further embodiment of the present invention, after the composite beam 1 is placed on the column connection ring plate 23, the two sides of the beam bottom embedded steel plate 13 are welded to the column bottom connection ring plate 23 in the form of fillet welds. To this end, preferably, the width of the beam bottom embedded steel plate 13 is not less than the beam width, and its steel plate side wall 131 is exposed to achieve fillet weld welding with the column bottom connection ring plate 23. Similarly, when the weld size does not meet the connection strength requirements of the beam bottom embedded steel plate 13 and the column bottom connection ring plate 23, the size of the beam bottom embedded steel plate 13 along the beam cross-section width direction is increased, and a second notch 132 is opened in the portion of the beam bottom embedded steel plate 13 that exceeds the beam width area, and plug welding construction is performed at the second notch 132, and the connection is performed in the form of a combination of plug welding connection and fillet weld connection.

[0052] In a further embodiment of the present invention, the specific arrangement form of the beam top embedded steel plate 12 and the beam bottom embedded steel plate 13 of the present invention in the composite beam 1. The top reinforcement 14 of the composite beam 1 is welded to the top surface of the beam top embedded steel plate 12, and the length of the top reinforcement 14 is less than the beam length, that is, it is necessary to leave a blank plate surface on the top surface of the beam top embedded steel plate 12 in the direction close to the frame column 2, and the blank plate surface is used as the part welded to the connecting cover plate 3. The bottom reinforcement 15 is welded to the top surface of the beam bottom embedded steel plate 13, so the length of the bottom reinforcement 15 can be unlimited, for example, it can be equal to the beam length.

[0053] In traditional composite beam structures, stirrups are often directly and evenly arranged. Since the present invention designs a special beam end structure, the stirrups are also adjusted accordingly. Specifically, in the prefabricated beam body 11 of the composite beam 1, stirrups 16 and stirrups 2 17 are designed respectively. Among them, stirrups 1 16 are located outside the range of the beam top embedded steel plate 12 and the beam bottom embedded steel plate 13, and the constrained area includes the top reinforcement 14, the bottom reinforcement 15 and the core concrete therebetween. Stirrups 2 17 are located within the range of the beam top embedded steel plate 12 and the beam bottom embedded steel plate 13, specifically between the beam top embedded steel plate 12 and the beam bottom embedded steel plate 13, and constrain the concrete therebetween. At the same time, since the length of the steel bars at the ends of the beam is insufficient, the present invention adds short bars 18 below the embedded steel plate 12 at the top of the beam and above the embedded steel plate 13 at the bottom of the beam. The added short bars 18 are parallel to the long direction of the beam and are within the constraint area of ​​the stirrup 17. A portion of the short bars 18 may also extend into the constraint area of ​​the stirrup 16.

[0054] In a further embodiment of the present invention, in order to further improve the strength of the node structure, the present invention also welds a number of vertical stiffening plates 24 on the outer wall of the steel pipe 21, and each stiffening plate 24 is located between the column connecting plate 22 and the column connecting ring plate 23. Its side wall is welded to the outer wall of the steel pipe 21, the top edge is welded to the column connecting plate 22, and the bottom edge is welded to the column connecting ring plate 23. A space is formed between adjacent stiffening plates 24, and the space should be sufficient to allow the beam end of the composite beam 1 to be inserted, and there is still space for welding operations after insertion.

[0055] In a further embodiment of the present invention, concrete may be filled in the steel tube 21 to form a steel tube concrete column. That is, the frame column 2 of the present invention may be a steel structure or a steel-concrete structure.

[0056] In a further embodiment of the present invention, the material of the post-cast part 4 can be concrete, ultra-high performance concrete or high-strength grouting material, which is cast in the space enclosed by the steel pipe 21, the stiffening plate 24, the beam body 11 and the connecting ring plate 23 under the column, and is the part formed by on-site construction.

[0057] In a further embodiment of the present invention, when the second structure is adopted without setting the connecting plate 22 on the column, the connecting cover plate 3 is directly welded to the groove of the column wall of the steel pipe 21. In order to further enhance the structural strength, an inner ring plate 25 should be set on the inner wall of the steel pipe 21. The inner ring plate 25 and the connecting cover plate 3 are at the same height, and the two correspond to each other inside and outside the steel pipe 21 to ensure reliable force transmission in the core area of ​​the node.

[0058] The construction method of the connection node between the frame column and the composite beam of the present invention mainly comprises the following steps:

[0059] Step 1, completing the welding of the steel pipe 21, the column connection plate 22 (if any) and the column lower connection ring plate 23 in the frame column 2 in the factory;

[0060] Step 2, completing the binding of the steel cage of the composite beam 1 in the factory, welding the bottom reinforcement 15 and the pre-embedded steel plate 13 at the bottom of the beam, fixing the pre-embedded steel plate 12 at the top of the beam, and welding the top reinforcement 14 and the pre-embedded steel plate 12 at the top of the beam;

[0061] Step 3, support the formwork and complete the pouring of the composite beam 1. During the pouring of concrete, the top embedded steel plate needs to be protected to prevent concrete contamination.

[0062] Furthermore, in this step, the prefabricated beam body 11 of the composite beam 1 is cast within the range of the embedded steel plate 12 on the top of the beam to the bottom surface of the embedded steel plate 12 on the top of the beam, and is cast outside the range of the embedded steel plate 12 on the top of the beam to the bottom elevation of the composite layer 41. The bottom surface of the embedded steel plate 12 on the top of the beam is higher than the bottom surface of the composite layer 41, which can be achieved by casting twice, thereby forming a step structure at the end of the beam.

[0063] Step 4, at the construction site, after positioning and hoisting the frame column 2, place the composite beam 1 on the column connection ring plate 23, and weld it to form a whole after positioning; place the connection cover plate 3, when the structure 1 is adopted, one end of it is welded to the embedded steel plate 12 on the top of the beam, and the other end is welded to the connection plate 22 on the column, when the structure 2 is adopted, it is directly welded to the column wall of the steel pipe 21. Further, in this step, when the composite beam 1 falls, it needs to avoid the range of the connection plate 22 on the column, and the length of the weld between the connection ring plate 23 under the column and the embedded steel plate 13 at the bottom of the beam needs to be ensured. When the size of the connection ring plate 23 under the column is large, measures such as stiffening plates 24 and stiffening ribs should be added at the lower connection ring plate 23.

[0064] Step 5, after on-site formwork, cast the node post-cast part 4 and the superimposed layer 41 in sequence.

[0065] Furthermore, in this step, before supporting the formwork, the gaps between the adjacent prefabricated beams 11 and the connecting ring plates 23 under the columns are sealed with a caulking agent or a cover plate to prevent leakage of mortar.

[0066] The present invention solves the problem of difficulty in threading top reinforcement during on-site construction. The top reinforcement is pre-buried in the factory prefabrication stage and cast integrally with the beam at the end to form partial full prefabrication; the remaining parts use composite beams and are cast later with the prefabricated floor slabs to form an integral structure.

Claims

1. The connection node between the frame column and the composite beam is characterized by: A beam top embedded steel plate (12) is arranged at the top of the beam end of the composite beam (1), and a beam bottom embedded steel plate (13) is arranged at the bottom of the beam end; the top reinforcement (14) of the composite beam (1) is welded to the beam top embedded steel plate (12), and the bottom reinforcement (15) is welded to the beam bottom embedded steel plate (13), so as to realize stress transfer; A ring plate (23) is connected under the outer wall welding column of the steel pipe (21) of the frame column (2); The composite beam (1) is placed on the column lower connecting ring plate (23), the beam bottom embedded steel plate (13) is connected to the column lower connecting ring plate (23) by welding, the beam top embedded steel plate (12) is connected to the outer wall of the steel pipe (21) by connecting cover plate (3) or by connecting cover plate (3) and column upper connecting plate (22) by welding, so as to realize effective force transmission of the composite beam (1) steel bar in the node area and avoid opening of the pipe wall of the steel pipe (21); A post-cast part (4) is cast between the beam end of the composite beam (1) and the tube wall of the steel tube (21).

2. The connection node between the frame column and the composite beam according to claim 1, characterized in that: The beam top embedded steel plate (12) is welded to the outer wall of the steel pipe (21) via a connecting cover plate (3), which is achieved as follows: One end of the connection cover plate (3) is welded to the top of the beam top embedded steel plate (21), and the other end is directly connected to the outer wall of the steel pipe (21) by groove butt welding, and an inner ring plate (25) is arranged on the inner wall of the steel pipe (21) at a position corresponding to the connection position of the connection cover plate (3) to ensure reliable force transmission in the core area of ​​the node.

3. The connection node between the frame column and the composite beam according to claim 1, characterized in that: The beam top embedded steel plate (12) and the outer wall of the steel pipe (21) are welded and connected to the column connecting plate (22) via the connecting cover plate (3), which is achieved as follows: A column upper connecting plate (22) is welded to the outer wall of a steel pipe (21) of a frame column (2), wherein the radial dimension of the column lower connecting ring plate (23) is greater than the radial dimension of the column upper connecting plate (22); The connecting cover plate (3) is placed on the top of the beam top embedded steel plate (21) and the column connecting plate (22), and is welded to the beam top embedded steel plate (21) and the column connecting plate (22) respectively by fillet welds. When the size of the weld does not meet the connection strength requirement, a notch (31) is opened on the plate surface of the cover plate (3), and the connection is performed by a combination of plug welding connection and fillet weld connection.

4. The connection node between the frame column and the composite beam according to claim 2 or 3, characterized in that: The strength of the beam top embedded steel plate (12) and the connection cover plate (3) is determined according to design requirements to ensure that the cross-sectional bearing capacity in the node connection area is greater than the cross-sectional bearing capacity of each part of the composite beam (1), so that the plastic hinge at the beam end is generated in the area outside the range of the beam top embedded steel plate (12).

5. The connection node between the frame column and the composite beam according to claim 3, characterized in that: The prefabricated beam body (11) is provided with stirrup one (16) outside the range of the beam top embedded steel plate (12) and the beam bottom embedded steel plate (13), and stirrup two (17) is provided within the range; the restraining area of ​​stirrup one (16) includes the top reinforcement (14), the bottom reinforcement (15) and the core concrete therebetween, and stirrup two (17) is located between the beam top embedded steel plate (12) and the beam bottom embedded steel plate (13) and restrains the concrete therebetween; additional short reinforcement (18) is arranged below the beam top embedded steel plate (12) and above the beam bottom embedded steel plate (13), and the additional short reinforcement (18) is parallel to the beam length direction and extends from the restraining area of ​​stirrup two (17) to the restraining area of ​​stirrup one (17).

6. The connection node between the frame column and the composite beam according to claim 3, characterized in that: The outer wall of the steel pipe (21) is further welded with a plurality of vertical stiffening plates (24), the stiffening plates (24) being located between the column connection plates (22) and the column lower connection ring plates (23) and being welded to the column connection plates (22) and the column lower connection ring plates (23) at the same time, the beam end of the composite beam (1) being located between adjacent stiffening plates (24) and being spaced apart from the stiffening plates (24) to provide a space for welding operation.

7. The connection node between the frame column and the composite beam according to any one of claims 1 to 6, characterized in that: The two sides of the beam bottom embedded steel plate (13) are connected to the column bottom connection ring plate (23) by fillet welds. When the size of the weld does not meet the connection strength requirement, the size of the beam bottom embedded steel plate (13) along the beam cross-section width direction is increased, and a second notch (132) is provided in the portion of the beam bottom embedded steel plate (13) that exceeds the beam width area, and the connection is performed in a combination of plug welding connection and fillet weld connection.

8. The connection node between the frame column and the composite beam according to claim 1, characterized in that: The top reinforcement (14) is welded to the top surface of the beam top embedded steel plate (12), and a portion for welding to the connecting cover plate (3) is reserved on the top surface of the beam top embedded steel plate (12) in the direction close to the frame column (2); the bottom reinforcement (15) is welded to the top surface of the beam bottom embedded steel plate (13).

9. The construction method of the connection node between the frame column and the composite beam according to any one of claims 1 to 8, characterized in that: The steps include: Step 1, completing the welding of the steel pipe (21) in the frame column (2) and the connecting ring plate (23) under the column, or completing the welding of the steel pipe (21), the connecting plate (22) on the column and the connecting ring plate (23) under the column in the factory; Step 2, completing the binding of the steel cage of the composite beam (1) in the factory, welding the bottom reinforcement (15) and the pre-embedded steel plate (13) at the bottom of the beam, fixing the pre-embedded steel plate (12) at the top of the beam, and welding the top reinforcement (14) and the pre-embedded steel plate (12) at the top of the beam. Step 3, supporting the formwork and completing the casting of the composite beam (1); Step 4, at the construction site, after positioning and hoisting the frame column (2), the composite beam (1) is placed on the connecting ring plate (23) under the column, and welded to form a whole after positioning; a connecting cover plate (3) is placed, one end of which is welded to the embedded steel plate (12) on the top of the beam, and the other end is welded to the connecting plate (22) on the column, or directly welded to the column wall of the steel pipe (21). Step 5, after the on-site formwork is supported, the node post-casting part (4) and the superimposed layer (41) are cast in sequence.

10. The connection node between the frame column and the composite beam according to claim 1, characterized in that: In the step 3, the prefabricated beam body (11) of the composite beam (1) is cast within the range of the beam top embedded steel plate (12) to the bottom surface of the beam top embedded steel plate (12), and is cast outside the range of the beam top embedded steel plate (12) to the bottom surface elevation of the composite layer (41), and the bottom surface of the beam top embedded steel plate (12) is higher than the bottom surface of the composite layer (41).

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