Connecting joint of prestressed steel reinforced concrete composite beam and concrete filled steel tubular column

Abstract

The invention discloses a connecting joint of a prestressed steel reinforced concrete composite beam and a concrete filled steel tubular column. The connecting joint comprises a beam joint with a first profile steel connecting piece and a column joint with a second profile steel connecting piece. The first profile steel connecting piece is provided with a pair of first flange plates embedded into the end of the beam joint in a non-full-length mode and a first web between the first flange plates. The section, embedded into the end of the beam joint, of the first web extends towards the midspan of the beam to form an extending section with the section height gradually decreased. The second profile steel connecting piece comprises a pair of transverse stiffening plates in the column joint section steel pipe and a second web plate between the transverse stiffening plates; the second web horizontally extends out of a section steel pipe to be connected with the first web in an aligned mode, second flange plates are arranged on the upper plate edge and the lower plate edge of the extending section of the second web respectively, and the upper second flange plate and the lower second flange plate are connected with the upper first flange plate and the lower first flange plate in an aligned mode respectively. According to the connecting joint, through the variable cross-section height extension section, the rigidity of the beam end is in smooth transition, rigidity sudden change is avoided, stress concentration is reduced, joint ductile deformation and energy dissipation performance are improved, and the overall anti-seismic performance of the structure is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building components, in particular to a prestressed steel reinforced concrete composite beam and a concrete-filled steel tube column connection node. BACKGROUND

[0002] Steel reinforced concrete composite beams (SRC beams) as a kind of efficient structural components, by combining steel and concrete two materials organically, give full play to the advantages of high bearing capacity, good ductility of steel beam and large rigidity, fire resistance and durability of concrete beam. This kind of composite structure not only can significantly improve the bearing capacity and rigidity of the component, but also can effectively improve the seismic performance of the structure, so it has been widely used in modern high-rise buildings, large-span space structures and important infrastructure projects.

[0003] The traditional SRC beam design usually adopts the construction method of arranging profile steel along the whole length of the beam inside the concrete beam. This design concept is embodied in many patent technologies. For example, the first profile steel connecting piece arrangement scheme disclosed in the "wave-shaped steel-concrete composite beam" with the patent number ZL201910179952.7, and the T-shaped steel application method shown in the "prestressed steel seat type T-shaped steel reinforced concrete composite beam" with the patent number ZL201310499946.2. In these traditional structures, the connection node between the beam end and the column is the key part of the whole structure system, and its mechanical properties will directly determine the seismic safety and use reliability of the overall structure.

[0004] However, in the current widely used steel-concrete composite structure (SRC) beam technology system, the connection node between the beam end and the reinforced concrete column as the key part of the structure force transmission still faces many technical problems to be solved in practical engineering application: Firstly, there is obvious defect in stiffness transition. The design of traditional through profile steel suddenly terminating at the beam end section height will cause the stiffness of the concrete beam section height to the node core zone to change sharply. This stiffness mutation not only will produce significant stress concentration phenomenon in the node area, but also will seriously affect the ductility deformation capacity and energy dissipation performance of the node, and then reduce the overall seismic performance of the structure.

[0005] Secondly, the node structure is too complex. In the beam end area, especially the anchoring treatment of longitudinal steel bars needs to take various construction measures, including steel bar perforation, bending and other intensive operations. These complex construction requirements not only increase the construction difficulty, but also easily affect the reliability of the node due to the difficulty in ensuring the construction quality.

[0006] Thirdly, the reliability of the connection mode is prominent. The traditional connection mode often relies on anchorage, welding or bolt connection of steel bars, which is difficult to guarantee long-term stability and durability in the node parts with complex stress and high deformation requirement. Especially under the action of extreme load such as earthquake, the damage of the connection part often becomes one of the main reasons for structural failure. SUMMARY

[0007] In view of the above problems, the present application aims to provide a prestressed steel reinforced concrete composite beam and concrete filled steel tube column connection joint, which has good mechanical properties and reliable connection mode, and can solve the problems of traditional SRC beam connection joint. In the stiffness transition, the beam end stiffness is smoothly transitioned through the two-section steel connecting piece and the variable cross-section height extension section, avoiding stiffness mutation, reducing stress concentration, improving the ductility deformation and energy dissipation performance of the joint, and enhancing the overall seismic performance of the structure. In terms of joint construction, the first and second steel connecting pieces and the beam and column joint construction steps are clear and orderly, reducing the complex construction measures of traditional beam longitudinal steel anchorage, reducing the construction difficulty, improving the controllability of construction quality, and ensuring the reliability of the joint. In terms of reliability of connection mode, the beam and column joint site connection steps are reasonable, first temporary fixation, then high-strength bolt connection for shear connection, and then welding for bending connection and corrosion and fireproofing treatment, which can adapt to complex stress joints, ensure the stability and durability of the connection part. In addition, prestressed tendons are pre-tensioned to apply prestress to the beam concrete, improve the bearing and crack resistance of the beam, and make the connection joint performance more superior to meet the demand of modern building structure.

[0008] To achieve the above purpose, the present application discloses a prestressed steel reinforced concrete composite beam and concrete filled steel tube column connection joint, which comprises a beam joint with a first steel connecting piece and a column joint with a second steel connecting piece, and the key lies in that: the first steel connecting piece comprises a pair of non-lengthwise embedded end parts of the beam joint, a first flange plate for receiving the upper and lower longitudinal bars, and a first web plate arranged between the two; the embedded end part of the first web plate extends towards the beam span direction, and forms an extension section with gradually decreasing cross-section height; the extension section is used to build a transition area with continuous and smooth change of bending stiffness in the beam body; the second steel connecting piece comprises a pair of transverse stiffening plates with grouting holes arranged in the segment steel pipe of the column joint, and a second web plate arranged between the two; the second web plate extends out of the segment steel pipe and is connected with the first web plate in alignment; the upper and lower edges of the second web plate extending out of the segment steel pipe are respectively provided with a second flange plate for receiving the segment steel pipe; the upper and lower second flange plates are connected with the upper and lower first flange plates in alignment, respectively.

[0009] Further, at least part of the cross-section height of the extension section changes linearly or nonlinearly.

[0010] Further, the overall cross-section height of the extension section is linearly changed, and the upper and lower plate edges are inclined and extended to be relatively close to each other to form a wedge-shaped structure.

[0011] Further, the first type steel connecting piece and the beam joint are constructed according to the following steps: A1: determining the embedding depth of the first type steel connecting piece, the stop position of the flange, the extension length of the web, and the gradient slope according to the construction requirements; A2: in a prefabrication factory or a construction site, welding the first flange plate and the first web according to the construction requirements, and cutting and processing the extension section of the first web to form a transition zone with gradually reduced cross-section height; A3: embedding the first flange plate and the first web in place; A4: welding an upper steel pad plate at each upper longitudinal reinforcement of the beam joint, and welding a lower steel pad plate at each lower longitudinal reinforcement of the beam joint; A5: vertically welding the lower steel pad plate after the welding of the lower longitudinal reinforcement is completed to the lower first flange plate of the first type steel connecting piece to form a continuous fillet weld, and vertically welding the upper steel pad plate after the welding of the upper longitudinal reinforcement is completed to the upper first flange plate to form a continuous fillet weld; A6: arranging a high-strength prestressed steel wire bundle at the bottom of the beam joint, and performing tensioning and temporary anchoring according to the pretensioning process; A7: supporting end formworks and side formworks to enclose a pouring cavity for the beam body concrete of the beam joint; A8: arranging stirrups and other structural reinforcements to build a reinforcement framework of the beam joint; A9: pouring the beam body concrete of the beam joint, and curing to a specified strength; A10: after the beam body concrete reaches the specified strength, releasing the tension of the high-strength prestressed steel wire bundle by the adhesion force to transmit the prestress to the beam body concrete.

[0012] Further, in step A1, the first flange plate of the first type steel connecting piece stops embedding at a distance of from the end face of the beam joint; and the first web continues to extend by an extension section with a length of to form a transition zone with a gradient slope of for the upper and lower edges, and the geometric parameters satisfy the relationship （Ⅰ） :

[0013] In the formula: the net span of the beam joint; the distance from the stop embedding end of the first flange plate to the end of the beam joint; the extension section length; total length from the beam joint end to the end of the extension section; initial height of the extension section; total height of the beam joint section; web height at the end of the extension section; remaining section height at the end of the extension section; web extension coordinate with positive direction pointing to the beam span direction, and origin at the position where the first flange plate stops embedding; extension section gradual slope; ratio of the extension length of the extension section to the position where the first flange plate stops embedding; ratio of the minimum embedding depth of the first flange plate to the span; ratio of the residual height of the extension section to the initial height of the web; ratio of the residual height of the extension section to the height of the beam joint; span utilization coefficient, ; adjustment factor of the gradual slope of the load response; monotonic increasing function about the uniform load ; maximum bending moment design value at the beam span; steel yield strength; design value of the uniform load on the beam.

[0014] Further, in step A3, the beam end steel plate is installed at the position where the embedding of the first flange plate and the first web plate stops, and the first flange plate and the first web plate are embedded in place with the beam end steel plate as the reference; in step A7, the beam end steel plate serves as the end formwork of the beam body concrete pouring cavity.

[0015] Further, in step A4, the waist steel backing plate is welded at each waist rib of the beam joint; in step A5, the waist steel backing plate with the completed waist rib is vertically welded to the first web plate or / and the beam end steel plate to form a continuous fillet weld.

[0016] ​Further, in step A8, the spacing of the stirrups in the embedded part of the first steel connecting member is smaller than the spacing of the stirrups in other parts; a through slot is also reserved on a section of the slab surface at the end of the first web embedded beam joint, which is used for arranging the tie bars between the web stirrups of the beam joint.

[0017] Further, the second steel connecting member and the column joint are constructed according to the following steps: B1: The segment steel pipe of the column joint is manufactured in a prefabrication factory, the position and the extension length of the embedded second steel connecting member in the column are determined; B2: Two transverse stiffening plates are welded at the accurate positions on the inner wall of the segment steel pipe, and the transverse stiffening plates are provided with grouting holes; B3: The upper and lower second flange plates of the second steel connecting member are respectively aligned with the upper and lower transverse stiffening plates, and then the second web of the second steel connecting member is inserted between the two transverse stiffening plates through the slot on the wall of the segment steel pipe; B4: The second web is extended to a section of the segment steel pipe and is subjected to full penetration groove welding with the inner wall of the segment steel pipe and the two transverse stiffening plates; and the second flange plate is subjected to continuous fillet welding with the outer wall of the segment steel pipe; B5: The segment steel pipe is hoisted on site, the column body concrete is poured in the segment steel pipe, and the grouting holes of the transverse stiffening plates are filled densely.

[0018] Further, the beam joint and the column joint are connected on site according to the following steps: C1: When the beam joint is hoisted, the first steel connecting member protruding at the end of the beam joint is roughly aligned with the second steel connecting member protruding on the column joint, and the first web of the first steel connecting member and the second web of the second steel connecting member are both provided with fixing holes in the exposed parts; C2: The first web and the second web are temporarily fixed by using installation bolts or part of high-strength bolts in cooperation with connecting plates, and the position and the elevation of the beam joint are adjusted to the design position; C3: The high-strength bolts are used to replace the installation bolts, and the bolts are subjected to initial tightening and final tightening according to the design requirements, so that the shear connection of the first web and the second web is completed; C4: The butt joints of the upper and lower first flange plates and the second flange plates are welded on site, and the bending connection is completed; C5: The necessary corrosion and fireproof treatment is performed on the joint area.

[0019] Compared with the prior art, the significant effects of the present application are: (1) After the first steel connector is embedded to a predetermined depth at the end of the beam node, its flange stops penetrating, while the web continues to extend a distance toward the mid-span of the beam. In the extended section, its cross-sectional height gradually decreases in a linear or nonlinear manner, eventually forming a small residual cross-sectional height. This design constructs a stiffness buffer / transition zone, the core objective of which is to achieve a continuous and smooth transition of the flexural stiffness of the beam node cross-sectional height from the pure concrete region to the region containing the complete steel section, avoiding stress concentration caused by abrupt changes and delaying crack propagation. In this region, cracks in the beam concrete appear later and are more dispersed and finer, which helps to maintain the contribution of concrete and makes the overall stiffness degradation more gradual. At the same time, this design can also improve hysteresis performance. The smoother stiffness change and reduced stress concentration help to obtain a fuller hysteresis curve with less pinching effect, which means that the structure has a stronger energy dissipation capacity and a smaller degree of stiffness / strength degradation.

[0020] (2) In the structural design of the beam joint, the first type of steel connector adopts a non-continuous design, which not only simplifies the overall structure of the beam joint, but also avoids the complexity brought about by the continuous arrangement of steel along the beam in the traditional design. This design not only significantly reduces the amount of steel used and lowers the cost, but also makes the assembly and welding work in the construction process simpler and more efficient. At the same time, due to the simple and clear structure of the first type of steel connector, the error and uncertainty in the construction process are greatly reduced, and the reliability of the joint and the safety of the overall structure are improved. On the other hand, the present invention uses the first flange plate to bear the stress of the longitudinal reinforcement of the beam joint, which simplifies the detailed design of the beam joint end and reduces the cumbersome construction of dense openings on the first flange plate or complex bending of the reinforcement. This simple structural design not only reduces the construction difficulty and improves the construction efficiency, but also reduces the potential reliability hazards of the joint caused by construction quality problems. In addition, the through groove reserved on the first web plate provides convenience for the through arrangement of tie bars, further enhancing the connection performance of the joint.

[0021] (3) Regarding the connection method, this invention further optimizes the connection design to ensure the reliability and efficiency of the connection method. The connection between the first type of steel connector and the beam node and the second type of steel connector adopts a strategy combining multiple fixing methods. On the one hand, the first flange plate of the first type of steel connector is welded and fixed to the longitudinal reinforcement of the beam node with the help of steel pads. This rigid connection method can provide a stable force transmission path and ensure the integrity and coordination of the structure under stress. On the other hand, fixing holes are opened in the exposed parts of the first web and the second web for installing high-strength bolts. This bolt connection method not only facilitates quick on-site installation, positioning and error adjustment, but also has the ability to slip and deform, which can dissipate some seismic energy and meet the seismic performance requirements. In addition, the first flange plate and the second flange plate are aligned and welded after the bolts are tightened to ensure the tightness of the connection and the final stiffness.

[0022] (4) In terms of prestress introduction, the present application applies prestress to the beam body concrete by means of the pre-tensioned high-strength prestressed steel wire bundle, which effectively enhances the bearing capacity and crack resistance of the entire beam joint. The prestressed steel wire bundle can ensure that the concrete beam body can bear stress uniformly after the prestress is applied, thereby improving the overall stability and durability of the structure. In addition, the application of prestress technology further optimizes the mechanical properties of the beam joint, making it better adapt to various complex working conditions and extreme load conditions.

[0023] (5) Regarding the column joint, the transverse stiffening plate and the second web extension welding method is adopted: two transverse stiffening plates with grouting holes are arranged in the segment steel pipe, the height of which is the same as the upper and lower second flange plates, and the second web extension is welded on the inner pipe wall of the segment steel pipe and the two transverse stiffening plates. This approach provides strong bending, shearing and anti-pulling anchoring effect for the extended steel segment, ensuring that the bending moment and shear force of the beam joint can be effectively transmitted to the column core area. This method significantly enhances the integrity, stiffness and bearing capacity of the column joint core area. The transverse stiffening plate plays a restraining role on the core column concrete, improving its strength and deformation capacity. The grouting holes on the transverse stiffening plate can ensure that the concrete pouring of the joint core area is dense, avoiding the occurrence of cavities.

[0024] (6) regarding construction, the construction process of the application strictly follows scientific and reasonable steps, and clear quality control and technical requirements are provided at each link to ensure the construction quality and performance of the entire connection joint. In the construction of the beam joint, each step is closely connected. From determining the geometric parameters of the first type steel connecting piece to welding, embedding, arranging steel bars, pouring concrete, and applying prestress, etc., all are demonstrated by practice. Especially in determining the geometric parameters of the first type steel connecting piece, through calculation and use of relevant relationship formula, it is ensured that it can build a transition area with continuous and smooth change of bending stiffness in the beam body, thereby avoiding the generation of stress concentration and cracks. In the aspect of steel bar arrangement, the spacing of stirrups at different positions is reasonably adjusted, and a through groove is reserved on the first web for penetrating tie bars, which further enhances the connection performance and overall stability of the joint. In the construction of the column joint, from the production of segmented steel pipes in the prefabrication factory to the determination of the position and extension length of the second type steel connecting piece, to the steps of welding, hoisting and pouring concrete, etc., the construction is rigorous and standardized. Especially in the installation process of the second type steel connecting piece, through positioning and welding process, it is ensured that it can provide reliable anchoring effect for the bending moment and shear force transmission of the beam joint, while enhancing the integrity, stiffness and bearing capacity of the core area of the column joint. In the on-site connection process of the beam joint and the column joint, temporary fixation is carried out first, and then the position and elevation are adjusted, and then high-strength bolts are used to complete the shear connection, and finally welding and corrosion and fireproofing treatment are carried out. This reasonable connection step can adapt to complex stress conditions and ensure the stability and durability of the connection part. In addition, effective quality control can be implemented at each link in the entire construction process, thereby ensuring the reliability of the joint and the safety of the overall structure. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, a brief introduction will be given below to the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0026] Figure 1 is the overall structure schematic diagram of the connection joint in embodiment one (one); Figure 2 is the overall structure schematic diagram of the connection joint in embodiment one (two); Figure 3 is the assembly relationship schematic diagram of the first type steel connecting piece and the second type steel connecting piece in embodiment one; Figure 4 is the steel bar skeleton structure schematic diagram of the beam joint in embodiment one; Figure 5 is the end structure schematic diagram (one) of the beam joint in embodiment one; Figure 6 is an end configuration schematic diagram of the beam joint in Example One (two); Figure 7 is an end configuration schematic diagram of the beam joint in Example One (three); Figure Label: 1-First type steel connecting piece, 2-Beam joint, 3-Second type steel connecting piece, 4-Column joint, 5-Connecting plate, 6-High-strength bolt; 101-First flange plate, 102-First web plate, 103-Extension section, 104-Upper steel backing plate, 105-Lower steel backing plate, 106-Waist steel backing plate, 107-Beam end steel plate, 108-Tunnel; 201-Longitudinal reinforcement, 202-Prestressed steel wire bundle, 203-Waist reinforcement, 204-Tie reinforcement, 205-Tie reinforcement, 206-Beam body concrete; 301-Lateral stiffening plate, 302-Second web plate, 303-Second flange plate; 401-Section steel pipe. DETAILED DESCRIPTION

[0027] The embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0028] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, in the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0029] Figures 1 to 3The first embodiment of the present application is shown: a prestressed steel reinforced concrete composite beam and a concrete filled steel tube column connecting joint, including a beam joint 2 with a first steel connecting piece 1, and a column joint 4 with a second steel connecting piece 3, the first steel connecting piece 1 includes a pair of non-length embedded in the beam joint 2 end, and the first flange plate 101 that receives the upper and lower longitudinal reinforcement 201, and the first web 102 between them; the first web 102 embedded in the beam joint 2 end of the section extends towards the beam span direction, and forms an extension section 103 with gradually decreasing cross-sectional height; the extension section 103 is used to build a transition area with continuous and smooth change of bending stiffness in the beam body; the second steel connecting piece 3 includes a pair of transverse stiffening plates 301 with grouting holes in the segment steel pipe 401 of the column joint 4, and the second web 302 between them; the second web 302 extends out of the segment steel pipe 401 and is connected with the first web 102 in alignment; the second flange plate 303 that receives the segment steel pipe 401 is also provided at the upper and lower plate edges of the second web 302 extending out of the segment steel pipe 401; the upper and lower second flange plates 303 are connected in alignment with the upper and lower first flange plates 101 respectively.

[0030] In this embodiment, at least part of the cross-sectional height of the extension section 103 changes linearly or nonlinearly. In this embodiment, preferably, the overall cross-sectional height of the transition section changes linearly, and the upper and lower plate edges are inclined to extend and relatively close to each other to form a wedge-shaped structure. This wedge-shaped structure design further enhances the smoothness of the transition area, making the change of bending stiffness more uniform, thereby further optimizing the seismic performance of the structure. In other embodiments, the overall cross-sectional height of the transition section can also change nonlinearly, or in a combination of linear and nonlinear changes, to meet specific engineering requirements or optimize structural performance. In addition, the design of cross-sectional height using nonlinear change, or a combination of nonlinear and linear changes, may involve more complex geometry and manufacturing process. But in some cases, compared with linear change, this design can provide superior performance. For example, under certain dynamic response or load conditions, it can more effectively disperse stress and energy.

[0031] Please refer to Figures 4 to 7 In specific implementation, the first steel connecting piece 1 and the beam joint 2 are constructed according to the following steps: A1: Determine the embedding depth, flange stop position, web extension length and gradient of the first steel connecting piece 1 according to the construction requirements; A2: In the prefabrication factory or construction site, weld the first flange plate 101 and the first web 102 according to the construction requirements, and cut and process the extension section 103 of the first web 102 to form a transition area with gradually decreasing cross-sectional height; A3: Embed the first flange plate 101 and the first web plate 102 in place; A4: Weld the upper steel pad plate 104 at each upper longitudinal reinforcement 201 of the beam joint 2, and weld the lower steel pad plate 105 at each lower longitudinal reinforcement 201 of the beam joint 2; A5: Perpendicularly weld the lower steel pad plate 105, which has completed the welding of the lower longitudinal reinforcement 201, to the lower first flange plate 101 of the first profile steel connector 1 to form a continuous fillet weld; perpendicularly weld the upper steel pad plate 104, which has completed the welding of the upper longitudinal reinforcement 201, to the upper first flange plate 101 to form a continuous fillet weld; A6: Arrange the high-strength prestressed steel wire bundle 202 at the bottom of the beam joint 2, and perform tensioning and temporary anchoring according to the pretensioning process; A7: Set up end formworks and side formworks to form a pouring cavity for the beam body concrete 206 of the beam joint 2; A8: Arrange stirrups 204 and other construction reinforcements to build the reinforcement framework of the beam joint 2; A9: Pour the beam body concrete 206 of the beam joint 2 and maintain it to the specified strength; A10: After the beam body concrete 206 reaches the specified strength, release the tension of the pretensioning high-strength prestressed steel wire bundle 202, so that it transmits the prestress to the beam body concrete 206 through the bonding force.

[0032] During construction, the quality of each step must be strictly controlled. In step A1, when determining various dimensional parameters, precise engineering calculations and actual site conditions must be combined to ensure that the first steel connector 1 can perfectly fit the beam node 2. In step A2, during welding and cutting, welding quality must be guaranteed to avoid problems such as incomplete welding and missing welding. The surface of the transition zone after cutting should be flat and smooth to ensure its mechanical properties. In step A3, when embedding the first flange plate 101 and the first web plate 102, professional hoisting equipment and positioning tools must be used to ensure accurate embedding position and control the deviation within a very small range. In steps A4 and A5, when welding the steel pads, the welding process requirements must be strictly followed, and the welding current, voltage, and welding speed must be controlled to ensure the strength and quality of the weld. For the arrangement of the high-strength prestressed steel bar bundle 202 in step A6, its position must be accurate and its arrangement must be neat. Tensioning and temporary anchoring must be carried out according to the standard process of pre-tensioning, and the magnitude and uniformity of the tension force must be precisely controlled. When setting up the formwork in step A7, the formwork must be installed firmly and level to prevent deformation or grout leakage during concrete pouring. In step A8, when arranging the stirrups 204 and other structural reinforcement, ensure that the spacing, quantity, and binding quality of the reinforcement meet design requirements to create a stable reinforcement skeleton for beam node 2. In step A9, when pouring the beam concrete 206 for beam node 2, use layered pouring and vibration compaction to ensure the density and integrity of the concrete. During concrete curing, take appropriate curing measures based on ambient temperature and humidity to ensure the concrete reaches the specified strength. In step A10, when releasing the pre-tensioned high-strength prestressed steel reinforcement bundles 202, operate slowly and evenly to avoid excessive prestress loss or cracks in the beam concrete 206 due to excessively fast release speed. Simultaneously, throughout the entire construction process, professional quality inspection personnel should conduct strict quality inspection and acceptance at each step to ensure that the construction quality of the connection nodes meets design and specification requirements.

[0033] In a specific application, in step A1, the first flange plate 101 of the first steel connector 1 is located at a distance from the end face of the beam node 2. The insertion stops at the point where it stops; the first web 102 continues to extend its length. The extension segment 103 forms a gradient slope at both the upper and lower edges. The transition region, whose geometric parameters satisfy the relation （Ⅰ） :

[0034] In the formula: Clear span of beam node 2; The distance between the end of the first flange plate 101 and the end of the beam node 2; Length of extension segment 103 Total length from beam node 2 end to extension segment 103 end Initial height of extension segment 103 Total height of beam node 2 section Height of web at flange stop position Remaining section height at extension segment 103 end Web extension coordinate, positive direction points to beam span direction, origin at first flange plate 101 stop embedding position Extension segment 103 tapering slope Extension segment 103 extension length and first flange embedding stop position ratio First flange plate 101 minimum embedding depth and span ratio Extension segment 103 residual height and web initial height ratio Extension segment 103 residual height and beam node 2 height ratio Span utilization coefficient Tapering slope adjustment factor of load response Monotonic increasing function about uniform load Maximum bending moment design value of beam node 2 at span Steel yield strength Uniform load design value on beam The application of the above geometric parameter relationship formula has important significance in actual engineering. When determining these parameters, factors such as the net span of the beam node 2 and the design value of the uniform load borne by the beam node 2 need to be considered comprehensively. By calculating and using these relationship formulas, the first type steel connector 1 can be accurately determined with reasonable geometric parameters, so as to ensure that it can play the best mechanical performance in the beam body.

[0035]

[0036] ​​​For example, when the net span of beam joint 2 is large or the design value of the uniform load borne is high, the embedded depth of first flange plate 101 and the length of extension section 103 should be appropriately increased according to the relationship to ensure that beam joint 2 has sufficient bending capacity and stability. At the same time, the adjustment of the gradient slope also needs to be accurately calculated according to the actual situation to ensure that the bending stiffness change in the transition area meets the design requirements.

[0037] The relationship is verified by taking a standard floor frame beam of a high-rise office building as an example （Ⅰ） . 1. Design input parameters : Net span of beam joint 2 (structural axis spacing minus support width); Section height of beam joint 2 (structural construction drawing size); Design value of uniform load (combination value of dead load and live load); Maximum bending moment at midspan (structural analysis software calculation result); Yield strength of steel (measured value of Q390 grade steel); Starting height of extension section 103 (specification parameter of HN550x200 steel).

[0038] 2. Coefficient value explanation

[0039] 3. Parameter calculation process (1) Determine the stop embedding position of first flange plate 101 : ; Value: ; Explanation: meet seismic anchoring ; meet bending moment transmission .

[0040] (2) Determine the extension length of the web : ; Explanation: coefficient achieves efficient transition of short extension section 103 (3) Determine the total length from the end of beam joint 2 to the end of extension section 103 : ; Check constraints: ; (4) Determine the stiffness adjustment coefficient : ; Note: Logarithmic function response load strength, corresponding to the moderate slope of the gradual change; (5) Determine the unilateral cutting slope : ; Note: Slope and load are positively correlated , inversely related to span; (6) Determine the web height function : ; Key points: ; ; (7) Determine the residual section height : ; Check constraints: ; (8) Total length of shaped steel : ; The outer extension of the end of beam joint 2 is 200mm long for column joint 4 connection: .

[0041] 4. Extension section 103 cutting rules: Upper plate edge cutting line: ; Lower plate edge cutting line: .

[0042] 5. Beam joint 2 construction implementation and zoning: |← Left section of shaped steel coverage area →|← Middle concrete area →|← Right section of shaped steel coverage area →| 0 ────── 3055mm ──────── 4945mm ────────8000mm; The first flange plate 101 and the first web 102 in the beam joint 2 are complete areas: 0 ~ 2350mm (flange + web); Extension section 103 gradual change area: 2350 ~ 3055 mm (extension section 103 section height 550 → 469 mm); Middle concrete area: 3055 ~ 4945 mm (pure concrete section); Symmetry: Two segments of the coverage area are equal in length (each 3055 mm), and the midpoints are aligned.

[0043] 6. Implementation effect: (1) The stress concentration coefficient is reduced from 2.8 in traditional design to 1.5; (2) The amount of steel used is saved by 28% (compared to the full-length arrangement); (3) The construction time of the node is reduced by 35%; (4) The rotation capacity of the plastic hinge is improved to 0.032 rad (to meet the seismic requirements in high intensity areas).

[0044] In subsequent engineering design, the design scheme of beam node 2 can be further optimized based on construction experience and results. For example, the coefficients in the geometric parameter relationship can be adjusted according to different engineering requirements and load conditions to achieve better mechanical properties and economic benefits. New materials can also be tried to improve the quality and performance of beam node 2.

[0045] In this embodiment, in step A3, the beam end steel plate 107 is installed at the cutoff position of the embedding of the first flange plate 101 and the first web plate 102, and the first flange plate 101 and the first web plate 102 are embedded in place based on the beam end steel plate 107, which can better ensure the accuracy and stability of the embedding position. The installation of the beam end steel plate 107 needs to be strictly in accordance with the design requirements, and the flatness, perpendicularity and other deviations need to be controlled within a very small range to ensure that it can provide accurate positioning for the embedding of the first flange plate 101 and the first web plate 102. In step A7, the beam end steel plate 107 serves as an end formwork for the pouring cavity of the beam body concrete 206, effectively avoiding the cumbersome process of traditional formwork installation and improving the construction efficiency. The beam end steel plate 107 is closely combined with the beam body concrete 206, enhancing the integrity and stability of the beam node 2. In the subsequent use process, the beam end steel plate 107 can also play a certain protective role to prevent the end of the beam body from being damaged by external forces.

[0046] In specific implementation, in step A4, a waist steel backing plate 106 is welded at each waist rib 203 of the beam node 2; in step A5, the waist steel backing plate 106 that has completed the welding of the waist rib 203 is vertically welded to the first web plate 102 or / and the beam end steel plate 107 to form a continuous fillet weld. This welding method can significantly enhance the connection strength between the waist rib 203 and the first web plate 102 and the beam end steel plate 107, thereby improving the overall stability of the beam node 2. During the welding process, attention should be paid to controlling the welding quality to avoid problems such as virtual welding and missed welding. The size and shape of the continuous fillet weld should be strictly constructed in accordance with the design requirements to ensure that it meets the relevant standards.

[0047] In specific applications, in step A8, the spacing between the stirrups 204 in the embedded part of the first steel connector 1 is smaller than that in other parts; a through slot 108 is also reserved on a section of the slab surface at the end of the embedded beam joint 2, which is used to arrange the tie bars 205 through the web bars 203 of the beam joint 2. Such arrangement of stirrups 204 can effectively enhance the restraint effect of the embedded part of the first steel connector 1, improve the shear capacity and overall stability of this area. The reserved through slot 108 and the arrangement of tie bars 205 further strengthen the connection and cooperative work capacity of the internal steel bars of the beam joint 2, so that the beam joint 2 can better transmit and disperse forces when bearing loads, avoiding damage caused by local stress concentration.

[0048] During construction, the size and position of the reserved through slot 108 require high precision and must be strictly constructed according to the design drawings. The size of the through slot 108 should ensure that the tie bars 205 can be smoothly penetrated, and there is enough gap between the tie bars 205 and the web bars 203 to ensure the convenience of construction operation and the effective anchoring of the tie bars 205. At the same time, the material and specifications of the tie bars 205 also need to meet the design requirements, and the performance indicators such as tensile strength and elongation should meet the force requirements of the beam joint 2 under different working conditions.

[0049] In actual engineering, the construction quality of the beam joint 2 also needs to be strictly detected and accepted. In addition to checking the binding quality and welding quality of the steel bars, the strength and compactness of the concrete also need to be detected. Non-destructive testing methods such as ultrasonic method and rebound method can be used to detect the internal quality of the concrete to ensure that the construction quality of the beam joint 2 meets the design requirements. The appearance quality of the beam joint 2 also needs to be carefully checked to ensure that the surface is flat, crack-free, and free of honeycomb and pitted defects. During the acceptance process, it is necessary to strictly evaluate according to relevant standards and specifications, and for parts that do not meet the requirements, timely rectification must be carried out until the qualified standard is reached.

[0050] In addition, the arrangement and tensioning of the high-strength prestressed steel wire bundle 202 in step A6 is a key step to ensure that the beam joint 2 has sufficient prestress. When arranging, the position of each steel wire bundle is accurately measured and marked. During tensioning, professional tensioning equipment is used and operated by experienced operators, and the tensioning force is strictly controlled according to the standard process of the pretensioning method to avoid problems such as cracks or deformation of the beam body caused by uneven tensioning force. When arranging the stirrup 204 and other construction steel bars in step A8, in addition to ensuring that the spacing, quantity and binding quality of the steel bars meet the design requirements, attention should also be paid to the anchoring length and overlapping method of the steel bars. Suitable anchoring length and correct overlapping method can ensure that the steel bars fully exert their strength when subjected to stress, further improving the stability of the steel reinforcement skeleton of the beam joint 2. When pouring the beam body concrete 206 of the beam joint 2 in step A9, layered pouring and vibration compaction are important measures to ensure the quality of the concrete. The pouring thickness of each layer of concrete should be moderate, and the vibration time should be sufficient to ensure that there are no gaps and bubbles in the concrete. At the same time, attention should be paid to the pouring sequence to avoid phenomena such as concrete segregation. During the concrete curing stage, scientific and reasonable curing measures should be taken according to the actual environmental temperature and humidity conditions. For example, in a high-temperature and dry environment, the pouring frequency should be increased or a moisture-retaining material should be used to cover the surface of the concrete to prevent the water on the surface of the concrete from evaporating too quickly and causing cracks; in a low-temperature environment, insulation measures should be taken to ensure that the concrete can reach the specified strength at a suitable temperature. When releasing the pretensioning high-strength prestressed steel wire bundle 202 in step A10, slow and uniform operation is the key. Too fast release speed will result in excessive loss of prestress, affecting the mechanical properties of the beam joint 2. During the release process, the deformation of the beam body should be monitored in real time, and once an abnormality is found, the release should be stopped immediately and appropriate treatment measures should be taken.

[0051] Please refer to Figure 3 In a specific application scenario, the second steel connecting piece 3 and the column joint 4 are constructed according to the following steps: B1: The segment steel pipe 401 of the column joint 4 is manufactured in the prefabrication factory, and the position and extension length of the second steel connecting piece 3 embedded in the column are determined; B2: Two transverse stiffening plates 301 are welded at the precise positions on the inner wall of the segment steel pipe 401, and the transverse stiffening plates 301 are provided with grouting holes; B3: Ensure that the upper and lower second flange plates 303 of the second steel connecting piece 3 are aligned with the upper and lower two transverse stiffening plates 301, respectively, and then insert the second web plate 302 of the second steel connecting piece 3 between the two transverse stiffening plates 301 through the slot opening formed on the wall of the segment steel pipe 401; B4: The second web plate 302 is extended to a section of the segmental steel pipe 401 and is full penetration groove welded with the inner pipe wall of the segmental steel pipe 401 and the two transverse stiffening plates 301; the second flange plate 303 is continuously fillet welded with the outer pipe wall of the segmental steel pipe 401; B5: The segmental steel pipe 401 is hoisted on site, the column body concrete is poured into the segmental steel pipe 401, and it is ensured that the grouting holes of the transverse stiffening plates 301 are filled densely.

[0052] After the above construction steps are completed, the connection quality of the second steel connecting piece 3 and the column joint 4 needs to be strictly checked. First, the appearance of the full penetration groove welding and continuous fillet welding is checked to see if there are defects such as incomplete weld, porosity, and slag inclusion. For the welds in question, further detection is carried out by non-destructive testing methods such as ultrasonic testing or radiographic testing to ensure that the welding quality meets the design requirements. After the column body concrete is poured, the strength of the concrete is detected. Concrete test blocks can be reserved during the pouring process, and then the compressive strength test is carried out under standard curing conditions. At the same time, the internal quality of the column body concrete is detected by non-destructive testing methods such as ultrasonic method to check if there are internal defects. For the grouting holes on the transverse stiffening plates 301, it is checked whether they are filled densely by concrete. Preliminary judgment can be made by knocking, and if abnormal sound is found, detailed inspection is carried out by drilling core taking method. If the grouting is not dense, measures such as pressure grouting should be taken to deal with it in time.

[0053] As shown in FIG. 1, the beam joint 2 and the column joint 4 are connected on site according to the following steps: Figures 1 to 3 C1: When hoisting the beam joint 2, the first steel connecting piece 1 protruding from the end of the beam joint 2 is roughly aligned with the second steel connecting piece 3 protruding from the column joint 4, and the first web plate 102 of the first steel connecting piece and the second web plate 302 of the second steel connecting piece are both provided with fixing holes in the exposed part; C2: First, temporarily fix the first web plate 102 and the second web plate 302 with installation bolts or part of high-strength bolts 6 in cooperation with the connecting plate 5, adjust the position and elevation of the beam joint 2 to the design position; C3: Replace the installation bolts with high-strength bolts 6, and perform initial tightening and final tightening according to the design requirements to complete the shear connection of the first web plate 102 and the second web plate 302; C4: The butt joints of the upper and lower first flange plates 101 and the second flange plates 303 are respectively welded on site to complete the bending connection; C5: The necessary corrosion and fireproofing treatment is carried out on the joint area.

[0054] ​After the on-site connection of beam joints 2 and column joints 4 is completed, comprehensive quality acceptance work needs to be carried out. For the connection of high-strength bolts 6, it is necessary to check whether the tightening torque of the bolts meets the design requirements, and a torque wrench can be used for spot checking. At the same time, check whether the number of exposed threads of the bolts meets the specified requirements to ensure the reliability of the connection. For the butt joints welded on site, in addition to the appearance inspection to check whether the weld surface is smooth and free of cracks and other defects, further detection of the surface quality of the welds is required using methods such as magnetic powder detection or penetration detection, and for the welds of important parts, ultrasonic detection or radiographic detection is required to detect the internal quality. The quality of corrosion and fireproofing treatment is also crucial. Check whether the thickness of the corrosion-resistant coating is uniform and whether there are phenomena such as missing coating and sagging, and use a coating thickness gauge to measure. The thickness and performance of the fireproof coating should meet the design standards, and the fire resistance limit and other performance of the fireproof coating can be evaluated through spot detection. In the subsequent use process, a regular monitoring and maintenance mechanism should be established. Regularly check the connection parts of beam joints 2 and column joints 4 to observe whether there is deformation, loosening, corrosion, etc. Strain gauges and other monitoring equipment can be used to monitor the stress state of the joints in real time to discover potential safety hazards in a timely manner. For problems found during monitoring, take appropriate measures in a timely manner, such as tightening loose bolts and repairing corroded parts, to ensure the long-term stability and safety of the connection of beam joints 2 and column joints 4.

[0055] In summary, after the first steel connector 1 is embedded into the end of the beam joint 2 to a predetermined depth, the flange stops deepening, while the web continues to extend in the direction of the beam span for a certain distance. In the extension section 103, the cross-sectional height gradually decreases in a linear or nonlinear manner, and finally forms a smaller residual cross-sectional height. This design builds a stiffness buffer / transition zone, the core goal of which is to ensure that the flexural stiffness of the beam joint 2 cross-sectional height continuously and smoothly transitions from the pure concrete area to the complete steel area, avoiding stress concentration caused by sudden changes and delaying crack development. In this area, the cracks in the beam concrete 206 appear later, are more dispersed and fine, which is conducive to maintaining the contribution of the concrete and making the overall stiffness degradation more gradual. At the same time, this design can also improve the hysteretic performance. The more gradual stiffness change and reduced stress concentration help to obtain a more complete hysteretic curve with less pinching effect, which means that the structure has stronger energy dissipation capacity and smaller stiffness / strength degradation. In the design of the beam joint 2, the first steel connector 1 adopts a non-full-length design, which not only simplifies the overall structure of the beam joint 2, but also avoids the complexity brought by the full-length arrangement of the steel in the traditional design. This design not only greatly reduces the use of steel and the cost, but also makes the assembly and welding work in the construction process more simple and efficient. At the same time, due to the simple and clear structure of the first steel connector 1, the error and uncertainty in the construction process are greatly reduced, improving the reliability of the joint and the safety of the overall structure. On the other hand, the first steel connector 1 simplifies the detail design of the end of the beam joint 2 by bearing the stress of the longitudinal reinforcement 201 of the beam joint 2 through the first flange plate 101, reducing the complex structure of dense holes or complex bending of the reinforcement on the first flange plate 101. This simple design not only reduces the construction difficulty and improves the construction efficiency, but also reduces the potential joint reliability problems caused by construction quality problems. In addition, the through slot 108 reserved on the first web 102 provides convenience for the penetration arrangement of the tie reinforcement 205, further enhancing the connection performance of the joint. In terms of connection method, the invention further optimizes the connection design to ensure the reliability and efficiency of the connection method. The connection between the first steel connector 1, the beam joint 2 and the second steel connector 3 adopts a combination of multiple fixing methods. On the one hand, the first flange plate 101 of the first steel connector 1 is welded and fixed with the longitudinal reinforcement 201 of the beam joint 2 through steel pads. This rigid connection method can provide a stable force transmission path to ensure the integrity and synergy of the structure under stress. On the other hand, fixed holes are provided on the exposed parts of the first web 102 and the second web 302 for installing high-strength bolts 6. This bolt connection method not only facilitates quick installation, positioning and error adjustment on site, but also has slip deformation capability to dissipate part of the seismic energy, meeting the seismic performance requirements. In addition, the first flange plate 101 and the second flange plate 303 are aligned and welded after being fastened by bolts, ensuring the tightness and final stiffness of the connection.In terms of prestress introduction, the application applies prestress to the beam body concrete 206 by means of the pre-tensioned high-strength prestressed steel wire bundle 202, thereby effectively enhancing the bearing capacity and crack resistance of the entire beam joint 2. The prestressed steel wire bundle 202 can ensure that the concrete beam body can bear stress uniformly after the prestress is applied, thereby improving the overall stability and durability of the structure. In addition, the application of the prestressed technology further optimizes the mechanical properties of the beam joint 2, enabling it to better adapt to various complex working conditions and extreme load conditions. As for the column joint 4, the transverse stiffening plate 301 is extended and welded with the second web plate 302: two transverse stiffening plates 301 with grouting holes are arranged in the segment steel pipe 401, the height of the transverse stiffening plate is the same as that of the upper and lower second flange plate 303, and the extended section 103 of the second web plate 302 is welded on the inner wall of the segment steel pipe 401 and the two transverse stiffening plates 301. This approach provides strong bending, shearing and anti-pulling anchoring effect for the extended steel segment, ensuring that the bending moment and shear force of the beam joint 2 can be effectively transmitted to the column core area. This approach significantly enhances the integrity, stiffness and bearing capacity of the core area of the column joint 4. The transverse stiffening plate 301 plays a restraining role on the core column concrete, improving its strength and deformation capacity. The grouting holes on the transverse stiffening plate 301 can ensure that the concrete in the joint core area is densely poured to avoid cavities. In terms of construction, the construction process of the application strictly follows scientific and reasonable steps, and clear quality control and technical requirements are provided at each link to ensure the construction quality and performance of the entire connecting joint. In the construction of the beam joint 2, each step is closely connected. From determining the geometric parameters of the first steel connecting piece 1 to welding, embedding, arranging steel bars, pouring concrete and applying prestress, etc., all are demonstrated by practice. Especially when determining the geometric parameters of the first steel connecting piece 1, through calculation and the use of relevant relationship formulas, it is ensured that it can construct a transition area with continuous and smooth change of bending stiffness in the beam body, thereby avoiding stress concentration and crack generation. In terms of steel bar arrangement, the spacing of stirrups 204 at different positions is reasonably adjusted, and a through slot 108 is reserved on the first web plate 102 for the penetration of tie bars 205, which further enhances the connection performance and overall stability of the joint. In the construction of the column joint 4, from the production of the segment steel pipe 401 in the prefabrication factory to the determination of the position and extension length of the second steel connecting piece 3, and then to the steps of welding, hoisting and pouring concrete, etc., the construction is rigorous and standardized. Especially in the installation process of the second steel connecting piece 3, through positioning and welding process, it is ensured that it can provide reliable anchoring effect for the bending moment and shear force transmission of the beam joint 2, while enhancing the integrity, stiffness and bearing capacity of the core area of the column joint 4. In the on-site connection process of the beam joint 2 and the column joint 4, temporary fixation is performed first, the position and elevation are adjusted, then high-strength bolts 6 are used to complete the shear connection, and finally welding and corrosion and fireproofing treatment are performed. This reasonable connection step can adapt to complex stress conditions and ensure the stability and durability of the connection part.In addition, during the whole construction process, each link can implement effective quality control, thereby guaranteeing the reliability of the node and the safety of the overall structure.

[0056] The above only discloses one preferred embodiment of the present application, and of course cannot limit the scope of the present application, and those skilled in the art can understand that all or part of the above-mentioned processes can be implemented, and equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1. A connection node between a prestressed steel-concrete composite beam and a steel-concrete composite column, comprising a beam node with a first steel connector and a column node with a second steel connector, characterized in that: The first type of steel connector includes a pair of non-continuous first flange plates embedded in the end of the beam node and supporting the upper and lower longitudinal reinforcements thereon, and a first web plate disposed between the two. A section of the first web plate embedded in the end of the beam node extends toward the mid-span of the beam and forms an extension section with a gradually decreasing cross-sectional height. This extension section is used to construct a transition region in the beam body where the bending stiffness changes continuously and smoothly. The second type of steel connector includes a pair of transverse stiffening plates with grouting holes disposed in the segmental steel pipe of the column node, and a second web plate disposed between the two. The second web plate extends horizontally out of the segmental steel pipe and is aligned and connected with the first web plate. At the upper and lower edges of the section of the second web plate extending out of the segmental steel pipe, second flange plates supporting the segmental steel pipe are respectively provided. The upper and lower second flange plates are aligned and connected with the upper and lower first flange plates, respectively.

2. The connection node between the prestressed steel-concrete composite beam and the steel-concrete composite column according to claim 1, characterized in that: At least a portion of the cross-sectional height of the extension section varies linearly or nonlinearly.

3. The connection node between the prestressed steel-concrete composite beam and the steel-concrete composite column according to claim 2, characterized in that: The overall cross-sectional height of the extension section varies linearly, with its upper and lower edges extending obliquely and converging relatively to form a wedge-shaped structure.

4. The connection node between the prestressed steel-concrete composite beam and the steel-concrete composite column according to any one of claims 1-3, characterized in that: The first steel connector and the beam joint are constructed according to the following steps: A1: Determine the embedding depth, flange stopping position, web extension length, and gradient slope of the first type of steel connector according to construction requirements; A2: At the prefabrication plant or construction site, the first flange plate and the first web plate are welded according to the construction requirements, and the extension section of the first web plate is cut and processed to form a transition zone with a gradually decreasing cross-sectional height. A3: Insert the first flange plate and the first web plate into place; A4: Weld an upper steel plate to each upper longitudinal reinforcement bar of the beam joint, and weld a lower steel plate to each lower longitudinal reinforcement bar of the beam joint. A5: The lower steel plate with the lower longitudinal ribs already welded is vertically welded to the first flange plate at the bottom of the first steel connector to form a continuous fillet weld; the upper steel plate with the upper longitudinal ribs already welded is vertically welded to the first flange plate at the top to form a continuous fillet weld. A6: Arrange high-strength prestressed steel wire bundles at the bottom of the beam joint, and tension and temporarily anchor them according to the pre-tensioning process; A7: Erect end formwork and side formwork to enclose and form the concrete pouring cavity for the beam joint; A8: Arrange stirrups and other structural reinforcement to build the steel reinforcement cage for the beam joint; A9: Pour concrete into the beam joint and cure it to the specified strength; A10: After the concrete of the beam reaches the specified strength, the pre-tensioned high-strength prestressed steel bar bundles are released so that the prestress can be transferred to the concrete of the beam through the bond force.

5. The connection node between the prestressed steel-concrete composite beam and the steel-concrete composite column according to claim 4, characterized in that: In step A1, the first flange plate of the first steel connector is located at a distance from the beam node end face. The insertion stops at the point where the first web plate continues to extend. The extended segment forms a gradient slope at both the upper and lower edges. The transition region, whose geometric parameters satisfy the relation （Ⅰ） : ； In the formula: Clear span of beam joint; The distance between the end of the first flange plate and the end of the beam node; Extension length; The total length from the end of the beam node to the end of the extension; Starting height of the extension section; Total height of beam node section; Distance from the wing edge stopping position Web height at the location; The remaining cross-sectional height at the end of the extension section; The web extension coordinates are positively directed towards the mid-span of the beam, with the origin located at the point where the first flange plate stops embedding. Gradual slope in the extension segment; The ratio of the extension length of the extension section to the first flange insertion stop position; The ratio of the minimum embedment depth of the first flange to the span; The ratio of the residual height of the extension section to the initial height of the web; The ratio of the residual height of the extension section to the height of the beam joint; Span utilization coefficient ; Gradual slope adjustment factor for load response; Regarding uniformly distributed loads A monotonically increasing function; Design value of maximum bending moment at mid-span of beam joint; steel yield strength; Design value of uniformly distributed load on beam.

6. The connection node between the prestressed steel-concrete composite beam and the steel-concrete composite column according to claim 4, characterized in that: In step A3, the beam end steel plate is installed at the cut-off position where the first flange plate and the first web plate are embedded, and the first flange plate and the first web plate are embedded in place using the beam end steel plate as a reference; in step A7, the beam end steel plate serves as the end template for enclosing the concrete pouring cavity of the beam.

7. The connection node between the prestressed steel-concrete composite beam and the steel-concrete composite column according to claim 4, characterized in that: In step A4, a web steel pad is welded at each web reinforcement of the beam node; in step A5, the web steel pads of the completed web reinforcements are vertically welded to the first web plate and / or the beam end plate to form a continuous fillet weld.

8. The connection node between the prestressed steel-concrete composite beam and the steel-concrete composite column according to claim 5, characterized in that: In step A8, the spacing of the stirrups tied in the embedded part of the first steel connector is smaller than the spacing of the stirrups in other parts; a through groove is also reserved on a section of the plate at the end of the first web embedded in the beam node, which is used to arrange tie bars through the web reinforcement of the beam node.

9. The connection node between the prestressed steel-concrete composite beam and the steel-concrete composite column according to claim 4, characterized in that: The second type of steel connector and the column joint are constructed according to the following steps: B1: Prefabricate the segmental steel pipes of the column joint in the prefabrication plant, and determine the position and extension length of the second type of steel connector embedded in the column; B2: Weld two transverse stiffening plates at precise positions on the inner wall of the segmental steel pipe. Grouting holes are pre-drilled on the transverse stiffening plates. B3: Ensure that the second flange plates of the upper and lower sections of the second steel connector are aligned with the upper and lower transverse stiffening plates respectively, and then insert the second web plate of the second steel connector between the two transverse stiffening plates through the slot opened on the pipe wall of the segment steel pipe. B4: The second web plate is extended to a section of the segmental steel pipe and is fully penetrated and beveled to the inner wall of the segmental steel pipe and the two transverse stiffening plates; the second flange plate is continuously filled-in welded to the outer wall of the segmental steel pipe. B5: On-site hoisting of segmental steel pipes, pouring column concrete inside the segmental steel pipes, ensuring that the grouting holes through the transverse stiffening plates are filled tightly.

10. The connection node between the prestressed steel-concrete composite beam and the steel-concrete composite column according to claim 9, characterized in that: The beam joint and the column joint are connected on-site according to the following steps: C1: When hoisting the beam node, roughly align the first steel connector extending outward at the end of the beam node with the second steel connector extending outward on the column node. The first web of the first steel connector and the second web of the second steel connector are both reserved with fixing holes in their exposed parts. C2: First, use mounting bolts or some high-strength bolts in conjunction with connecting plates to temporarily fix the first and second web plates, and adjust the position and elevation of the beam nodes to the design position; C3: Replace the mounting bolts with high-strength bolts, and perform initial and final tightening according to design requirements to complete the shear connection between the first and second web plates; C4: The butt joints of the upper and lower first flange plates and the second flange plates are welded on site to complete the bending connection; C5: Perform necessary anti-corrosion and fireproofing treatment on the node area.

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