Penetrating anchor wrapping type story-adding steel column connecting joint and building story-adding structure

Abstract

The invention provides an anchor penetrating outer wrapping type story-adding steel column connecting joint and a building story-adding structure. The connecting joint comprises a story-adding steel column, a steel reinforcement framework and an outer wrapping concrete layer. The steel bar framework comprises a plurality of plate penetrating longitudinal bars and a plurality of stirrups, and the plate penetrating longitudinal bars surround the peripheral side of the frame beam-column joint at intervals and are distributed on the outer sides of the corners of the frame beam-column joint. The multiple stirrups are fixed to the peripheries of the multiple plate penetrating longitudinal bars in a surrounding mode. The bottom end of each plate-penetrating longitudinal rib is bent to form a horizontal bent section, and the horizontal bent sections of the two opposite plate-penetrating longitudinal ribs are in lap joint with each other and are fixedly connected with each other. The outer wrapping concrete layer wraps the peripheral areas of the storey-adding steel columns and the reinforcement cage, so that the storey-adding steel columns, the reinforcement cage and the reinforced concrete frame form an overall stress structure. According to the connecting joint provided by the embodiment of the invention, the structural reliability of connection between the connecting joint and an existing frame beam column joint can be effectively improved, so that the overall stress reliability and construction feasibility of the connecting joint are improved, and the structural service life is prolonged.

Description

Technical Field

[0001] This application relates to the field of architecture, and in particular to an anchor-supported external steel column connection node and building addition structure. Background Technology

[0002] When adding floors to existing buildings, the connection nodes between the steel column addition structure and the existing reinforced concrete frame main structure are the core load-bearing parts of the entire addition structure. Current technology typically uses rebar anchoring and concrete pouring to connect the existing reinforced concrete frame to the upper steel column addition. This method has the following drawbacks: Firstly, directly applying the existing reinforced concrete column extension anchoring structure cannot meet the installation requirements of the column base plate of the addition steel column. It also makes it difficult to effectively transfer horizontal shear force between the addition steel column and the existing reinforced concrete frame, and easily leads to conflicts between rebar arrangement and steel component positions, making on-site construction difficult. Secondly, the above solution causes significant damage to the beam-column joints and frame beams of the existing reinforced concrete frame during construction, easily compromising the structural integrity of the original structure. It also suffers from indirect force transmission paths, poor bonding performance between the old and new concrete interfaces, and a tendency to crack and detach later on. It cannot meet the long-term safety and durability requirements of the addition structure and is difficult to adapt to the complex construction needs of adding floors to existing buildings.

[0003] Therefore, when adding floors to an existing reinforced concrete frame structure, how to improve the structural reliability of the connection nodes between the added steel columns and the existing structure, so as to improve the overall stress reliability, construction feasibility and service life of the added structure, has become a key technical challenge. Summary of the Invention

[0004] The anchor-supported outer layer steel column connection node provided in this application embodiment can effectively improve the structural reliability of the connection between the connection node and the existing frame beam-column node, thereby improving the overall stress reliability, construction feasibility and structural service life of the connection node.

[0005] A first aspect of this application provides an anchored, externally encased layered steel column connection node, comprising: an additional steel column, a reinforcing cage, and an outer concrete layer. The additional steel column extends vertically, and its bottom end is used to connect to the top of a frame beam-column node of a reinforced concrete frame. The reinforced concrete frame includes multiple reinforced concrete frame beams and reinforced concrete columns, and the intersection of the tops of the multiple reinforced concrete frame beams and the reinforced concrete columns constitutes the frame beam-column node. The reinforcing cage includes multiple through-slab longitudinal bars and multiple stirrups. Each through-slab longitudinal bar extends vertically from the bottom of the frame beam-column node to a target height position of the additional steel column, and the multiple through-slab longitudinal bars are spaced around the outer periphery of the frame beam-column node and distributed on the outer side of each corner of the frame beam-column node. Multiple stirrups are spaced apart vertically, each stirrup surrounding and fixed to the outer periphery of multiple through-slab longitudinal reinforcement bars; furthermore, the bottom end of each through-slab longitudinal reinforcement bar is bent to form a horizontal bend, and the horizontal bends of two through-slab longitudinal reinforcement bars arranged opposite each other along a first direction perpendicular to the vertical direction are overlapped and fixedly connected. An outer concrete layer covers the outer periphery of the added steel column and the reinforcing cage, making the added steel column, the reinforcing cage, and the reinforced concrete frame an integral load-bearing structure.

[0006] The anchored external-enclosed steel column connection node provided in this application is a connection node structure used for building structural modification or addition. When adding floors to an existing reinforced concrete frame, additional steel columns are added upwards at the intersection of existing reinforced concrete columns and reinforced concrete frame beams to support the new floors. The additional steel column is the vertical load-bearing member of the newly added floor, and its bottom end is connected to the top of the existing frame beam-column joint. The steel reinforcement cage serves as the force transmission medium. Multiple through-slab longitudinal bars are vertically extending steel bars that surround the frame beam joint and are spaced apart at its corners. Furthermore, the horizontally bent sections of two opposing through-slab longitudinal bars overlap and are fixed at the bottom of the frame beam-column joint. Multiple stirrups are spaced vertically around the outer periphery of the multiple through-slab longitudinal bars and are fixedly connected to them. The multiple through-slab longitudinal bars and multiple stirrups together form an integral steel cage structure. The outer concrete layer is a concrete structure poured around the added steel columns and the reinforcing cage. The outer concrete layer encloses the added steel columns, the reinforcing cage, and the existing reinforced concrete frame into a whole. It fills the gaps, provides bonding force, and enables the new and old structures to work together to form a unified load-bearing system.

[0007] Because existing reinforced concrete frame beams and columns typically contain dense reinforcing bars, evenly distributing the longitudinal reinforcement bars through the slabs across the entire beam-column joint area may cause positional conflicts with the reinforcing bars, leading to construction difficulties and even affecting the feasibility of the design. Concentrating the longitudinal reinforcement bars through the slabs at the four corners of the beam-column joint effectively avoids the existing reinforcing bars within the structure, thus alleviating positional conflicts and facilitating on-site construction.

[0008] At the bottom of the frame beam-column joint, opposing through-slab longitudinal reinforcement bars are paired and welded together via horizontal bends. This construction integrates two through-slab reinforcement bars into a single unit, allowing them to better cooperate in bearing loads and fully utilize the structural strength. Simultaneously, the through-slab longitudinal reinforcement bars extend downwards from the outside of the added steel column and are bent and anchored at the bottom of the frame beam-column joint, facilitating the direct transfer of upper loads to the stress area at the bottom of the frame beam-column joint, resulting in a simple force transmission path. Given the limited space at the bottom of the frame beam, the welded connection provides reliable anchorage, reducing the risk of pull-out of the through-slab longitudinal reinforcement bars due to insufficient anchorage length, thereby improving the connection reliability and ensuring that it forms an effective integrated load-bearing system with the outer concrete layer.

[0009] The anchored external-encased steel column connection node provided in this application, through the coordinated design of the added steel column, the steel reinforcement cage and the outer concrete layer, combined with the structural design of the longitudinal reinforcement through the slab arranged at the corner of the frame beam-column node and the horizontal bending section of the opposite longitudinal reinforcement through the slab welded at the bottom of the frame beam-column node, can effectively improve the structural reliability of the connection node and the existing frame beam-column node, thereby improving the overall stress reliability, construction feasibility and structural service life of the anchored external-encased steel column connection node.

[0010] In one possible implementation, the horizontally bent sections of two opposing longitudinal reinforcing bars are fixedly connected by single-sided welding, with the length of the welded area being greater than or equal to 10 times the diameter of the longitudinal reinforcing bar. Alternatively, the horizontally bent sections of two opposing longitudinal reinforcing bars are fixedly connected by double-sided welding, with the length of the welded area being greater than or equal to 5 times the diameter of the longitudinal reinforcing bar.

[0011] By adopting the above scheme, the two separate longitudinal bars that pass through the slab can be connected by welding to form a continuous force transmission path at the bottom of the frame beam-column joint, so that they can work together as an integral load-bearing component. Setting the length range of the welding area can ensure the strength of the weld, further improve the ultimate load-bearing capacity of the longitudinal bars that pass through the slab, and improve the reliability of the connection.

[0012] In one possible implementation, the multiple stirrups include multiple first stirrups and multiple second stirrups. The multiple first stirrups are spaced apart in the vertical direction and located above the reinforced concrete frame. The multiple second stirrups are located below the added steel columns. Multiple stirrup holes are formed on each reinforced concrete frame beam, and each second stirrup passes through the corresponding stirrup hole on each reinforced concrete frame beam. The second stirrups surround the periphery of multiple through-slab longitudinal reinforcement bars.

[0013] Using the above scheme, in the area above the reinforced concrete frame beam, multiple first stirrups and multiple through-slab longitudinal bars are tied or connected together to form an integral reinforcement cage. This effectively constrains the outer concrete layer in this area, improving its integrity, density, and crack resistance, and enhancing the deformation characteristics and durability of the structure under stress. In the area where the reinforced concrete frame beam is located, by pre-drilling stirrup holes in the beam and inserting second stirrups through them, the interruption of stirrups caused by beam obstruction is reduced, ensuring the continuity of the second stirrups. This further enhances the structural integrity and load-bearing reliability of the connection between the anchored outer-layer steel column and the beam.

[0014] In one possible implementation, the steel reinforcement cage also includes multiple structural longitudinal bars, which are spaced around the outer periphery of the frame beam-column joint and spaced apart from multiple through-slab longitudinal bars. At least one structural longitudinal bar is provided on some or all of the reinforced concrete frame beams. Each structural longitudinal bar extends vertically from the top end face of the reinforced concrete frame beam to the target height position of the added steel column. Each stirrup located above the reinforced concrete frame surrounds and is fixed to the outer periphery of the multiple through-slab longitudinal bars and the multiple structural longitudinal bars.

[0015] Using the above scheme, the structural longitudinal reinforcement is placed in the corresponding area above the reinforced concrete frame beam to meet the spacing limits and structural requirements of the stirrups in the reinforced concrete column. Because the longitudinal reinforcement passing through the slab is concentrated at the four corners of the frame beam-column joint, the central area of ​​the reinforced concrete frame beam will lack longitudinal reinforcement. If stirrups are directly installed using only the longitudinal reinforcement passing through the slab, the stirrup spacing may be too large, failing to effectively restrain the concrete and thus affecting the load-bearing performance, crack resistance, and overall ductility of the outer concrete layer. By adding structural longitudinal reinforcement, reliable intermediate support points can be provided for the stirrups, allowing them to be evenly and rationally distributed along the outer perimeter of the frame beam-column joint, effectively reducing the stirrup spacing, ensuring the restraining effect of the stirrups on the outer concrete layer, and improving the stiffness, integrity, and load-bearing safety of the frame beam-column joint area.

[0016] In one possible implementation, the through-anchored external steel column connection node further includes a column base plate and multiple installation anchors. The column base plate is fixedly connected to the bottom end of the added steel column. Multiple installation holes are formed on the column base plate. Multiple connection grooves are formed at the top of the frame beam-column node. The multiple installation anchors correspond one-to-one with the multiple installation holes and one-to-one with the multiple connection grooves. Each installation anchor passes through the installation hole of the column base plate and is anchored in the corresponding connection groove of the frame beam-column node.

[0017] The above-mentioned scheme involves installing column base plates at the bottom of the added steel columns, with corresponding installation holes and connection slots at the column base plates and the frame beam-column joints. Anchor bolts are then used to achieve alignment and connection between the column base plates and the frame beam-column joints, enabling rapid positioning and temporary fixation of the added steel columns, thus improving on-site construction efficiency and installation accuracy. The anchor bolts are primarily used for positioning and temporary fixation of the added steel columns, serving a positioning function during the installation phase. During normal structural use and under load, they do not participate in the transmission of vertical or horizontal loads or other internal forces, and do not bear the main force transmission function. This separates the installation positioning from the main force transmission path, ensuring clear structural stress and reliable joint safety.

[0018] In one possible implementation, structural adhesive is used to fill the space between the outer wall of the anchor bolt and the inner wall of the connecting groove.

[0019] Using the above method, the structural adhesive can fill the gap between the anchor bolt and the connecting groove, so that the anchor bolt is tightly integrated with the existing reinforced concrete structure, thereby improving the anchoring reliability and integrity of the anchor bolt.

[0020] In one possible implementation, the anchored external layer steel column connection node also includes a shear key, which is fixedly connected to the bottom surface of the column base plate. A mating groove is formed at the top of the frame beam-column node, and the shear key is embedded in the mating groove.

[0021] Using the above scheme, the shear key is embedded in the mating groove at the top of the frame beam-column joint, which can effectively bear and transfer the horizontal shear force at the column base, improving the shear resistance and lateral displacement resistance of the connection joint under horizontal loads and seismic action. The horizontal shear force is transferred to the shear key through the added steel column and column base plate, and then directly transferred to the existing reinforced concrete column structure below. The shear force transfer path is short and the stress distribution is clear, avoiding excessive concentration of shear force on the installation anchor bolts or other non-shear components, and ensuring the safety and reliability of the joint under stress.

[0022] In one possible implementation, a grouting layer is formed between the column base plate and the top end face of the frame beam-column joint, and the grouting layer is a micro-expansion concrete layer.

[0023] Using the above method, local gaps and poor contact are prone to occur on the top surface of the concrete at the column base plate and the frame beam-column joint. The grouting layer is used to fill the gaps between them. By controlling the thickness of the grouting layer, the verticality and horizontality of the added steel column can be corrected, reducing the installation difficulty of the added steel column and improving the positioning accuracy of the column base plate. The micro-expansion concrete layer can be poured and filled to fill the space between the top end face of the column base plate and the frame beam-column joint, reducing phenomena such as hollowness or separation, and enhancing the overall structural reliability of the connection joint.

[0024] In one possible implementation, multiple studs are provided on the outer periphery of the added steel column. The studs are arranged in an array in the circumferential and height directions of the added steel column. One end of each stud is fixedly connected to the side wall of the added steel column, and the other end is anchored in the outer concrete layer.

[0025] By adopting the above scheme, the setting of multiple studs can enhance the overall connection between the added steel column and the outer concrete layer. The arrayed studs can form a uniform internal constraint on the outer concrete layer, ensuring the long-term structural integrity of the outer concrete layer, improving the overall load-bearing capacity of the connection node, and enhancing the crack resistance of the outer concrete layer.

[0026] The second aspect of this application also provides a building addition structure, including: a reinforced concrete frame and an anchored external steel column connection node provided in the first aspect and any implementation thereof, wherein the anchored external steel column connection node is fixedly connected to the reinforced concrete frame to form an integral load-bearing structure.

[0027] The building addition structure provided in this application embodiment, by applying the through-anchored external steel column connection node provided in the first aspect and any implementation thereof, the through-anchored external steel column connection node is stably and fixedly connected to the reinforced concrete frame. The two work together to form an integrated load-bearing structure, which can effectively improve the load-bearing capacity, seismic performance and long-term service life of the building after the addition of floors. Attached Figure Description

[0028] Figure 1 This is a front view of a reinforced concrete frame according to an embodiment of this application;

[0029] Figure 2 This is a top view of a reinforced concrete frame according to an embodiment of this application;

[0030] Figure 3 This is a front sectional view of the connection node between the anchored externally wrapped steel column and the reinforced concrete frame according to an embodiment of this application.

[0031] Figure 4 for Figure 3 A cross-sectional schematic diagram of CC;

[0032] Figure 5 for Figure 3 Schematic diagram of the cross section of DD;

[0033] Figure 6 for Figure 3 A cross-sectional diagram of the EE;

[0034] Figure 7 This is a schematic diagram of the column base plate and the installation of anchor bolts in the anchor-supported external layered steel column connection node according to an embodiment of this application.

[0035] Figure 8 This is a schematic diagram of the structure of the layered steel column in the anchor-supported layered steel column connection node according to an embodiment of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] 100. Connect nodes;

[0038] 10. Additional steel column; 11. Column base plate; 111. Mounting hole; 12. Anchor bolt installation; 13. Shear key; 14. Grouting layer; 15. Stud;

[0039] 20. Reinforcing steel cage; 21. Through-slab longitudinal reinforcement; 211. Horizontal bend section; 212. Welding area; 22. Stirrups; 221. First stirrup; 222. Second stirrup; 23. Structural longitudinal reinforcement;

[0040] 30. External concrete layer;

[0041] 40. Reinforced concrete frame; 41. Reinforced concrete frame beam; 411. Transverse beam; 412. Longitudinal beam; 42. Reinforced concrete column; 43. Frame beam-column joint; 431. Connection groove; 432. Fitting groove;

[0042] A. Vertical direction; B. First direction. Detailed Implementation

[0043] When adding floors to existing buildings, the connection nodes between the steel column addition structure and the existing reinforced concrete frame main structure are the core load-bearing parts of the entire addition structure. Current technology typically uses rebar anchoring and concrete pouring to connect the existing reinforced concrete frame to the upper steel columns. This method has the following drawbacks: Firstly, directly applying the existing reinforced concrete column extension anchoring structure cannot meet the installation requirements of the column base plate of the addition steel column. It also makes it difficult to effectively transfer horizontal shear force between the addition steel column and the existing reinforced concrete frame, and easily leads to conflicts between rebar arrangement and steel component positions, making on-site construction difficult. Secondly, the above solution causes significant damage to the beam-column joints and frame beams of the existing reinforced concrete frame during construction, easily compromising the structural integrity of the original structure. It also suffers from indirect force transmission paths, poor bonding performance between the old and new concrete interfaces, and a tendency to crack and detach later on. It cannot meet the long-term safety and durability requirements of the addition structure and is difficult to adapt to the complex construction needs of adding floors to existing buildings.

[0044] Therefore, when adding floors to an existing reinforced concrete frame structure, how to improve the structural reliability of the connection nodes between the added steel columns and the existing structure, so as to improve the overall stress reliability, construction feasibility and service life of the added structure, has become a key technical challenge.

[0045] To address the aforementioned technical problems, this application provides a building addition structure, comprising: a reinforced concrete frame and an anchored external steel column connection node, wherein the anchored external steel column connection node is fixedly connected to the reinforced concrete frame to form an integral load-bearing structure.

[0046] This embodiment also provides an anchor-supported external steel column connection node for connecting an existing reinforced concrete frame structure with a newly added steel column structure, which effectively improves the structural reliability of the connection between the connection node and the existing reinforced concrete frame, thereby improving the overall stress reliability, construction feasibility and service life of the connection node.

[0047] Specifically, the reinforced concrete frame refers to the existing reinforced concrete frame described above. For example... Figure 1 and Figure 2As shown, the reinforced concrete frame 40 includes multiple reinforced concrete frame beams 41 and reinforced concrete columns 42. The intersection of the tops of the multiple reinforced concrete frame beams 41 and reinforced concrete columns 42 is the frame beam-column node 43. The reinforced concrete column 42 is the vertical load-bearing member of the entire reinforced concrete frame 40, mainly bearing axial pressure, bending moment, and shear force. The column body is internally reinforced with reinforcing steel to ensure compressive, shear, and ductile performance. Its top supports the existing reinforced concrete frame beams 41. The reinforced concrete frame beams 41 are horizontal load-bearing members, connecting the various reinforced concrete columns 42, transferring floor loads to the frame columns, and forming rigid joints with the columns to jointly resist horizontal loads. Multiple reinforcing steel bars are installed within the beams to ensure bending and shear bearing capacity. The frame beam-column node 43 is the core area where beams and columns intersect, and is the stress concentration and most complex part. It bears the transmission and conversion of beam-end bending moment and shear force with column-end axial force and bending moment. The node area has dense reinforcement and is the weak point of the existing frame structure, as well as the core construction area for adding floors.

[0048] The anchored external steel column connection node serves as a connection node when adding floors to an existing building. The anchored external steel column connection node is stably and fixedly connected to the frame beam-column joint of the existing reinforced concrete frame, so that the anchored external steel column connection node and the existing reinforced concrete frame together form an integrated whole load-bearing structure, which can effectively improve the load-bearing capacity, seismic performance and long-term service life of the building after the addition of floors.

[0049] The following section, in conjunction with the accompanying drawings, introduces the structure and corresponding functions of each part of the anchor-supported, externally-encased steel column connection node.

[0050] like Figure 3 and Figure 4 As shown, the anchored external-encased additional steel column connection node 100 includes: an additional steel column 10, a steel reinforcement cage 20, and an external concrete layer 30. The additional steel column 10 extends vertically in the direction A, and its bottom end is used to connect to the top of the frame beam-column node 43 of the reinforced concrete frame 40. At the intersection of the existing reinforced concrete column 42 and the reinforced concrete frame beam 41, an additional steel column 10 is added upwards to support the new floor. The additional steel column 10 is the vertical load-bearing member of the newly added upper floor, and its bottom end is connected to the top of the existing frame beam-column node 43.

[0051] like Figure 3 and Figure 4As shown, the reinforcing cage 20 includes multiple through-slab longitudinal bars 21 and multiple stirrups 22. Each through-slab longitudinal bar 21 extends vertically in direction A from the bottom of the frame beam-column node 43 to the target height of the added steel column 10, and the multiple through-slab longitudinal bars 21 are spaced around the outer periphery of the frame beam-column node 43 and distributed on the outer side of each corner of the frame beam-column node 43. The multiple stirrups 22 are spaced apart in the vertical direction A, and each stirrup 22 surrounds and is fixed to the outer periphery of the multiple through-slab longitudinal bars 21. The reinforcing cage 20 serves as a force transmission medium, and the multiple through-slab longitudinal bars 21 are steel bars extending in the vertical direction A, surrounding the frame beam-column node 43 and spaced apart at its corners.

[0052] The longitudinal reinforcement bars 21 are arranged at the four corners of the frame beam-column joint 43, which can avoid the reinforcing bars inside the existing reinforced concrete frame beam 41. It should be noted that the existing reinforced concrete frame beam 41 usually has a relatively dense reinforcing bar. If the longitudinal reinforcement bars 21 are evenly distributed throughout the entire frame beam-column joint 43, they will inevitably conflict with the reinforcing bars inside the reinforced concrete frame beam 41, causing difficulties in construction and even affecting the feasibility of the plan. By concentrating the longitudinal reinforcement bars 21 at the four outer corners of the frame beam-column joint 43, the reinforcing bars form a concentrated stress area at the four corners of the frame beam-column joint 43, which can more evenly bear the load from all directions. It can also avoid the reinforcing bars inside the existing reinforced concrete frame beam 41, thereby alleviating the positional conflict and facilitating on-site construction. The number of longitudinal reinforcement bars arranged at each corner is set according to the actual structure calculation. This application embodiment does not limit the number of longitudinal reinforcement bars.

[0053] Furthermore, combined Figure 3Each longitudinal reinforcement bar 21 has a horizontal bend 211 formed at its bottom end. Two longitudinal reinforcement bars 21 with opposite horizontal bends 211 arranged along the first direction B are overlapped and fixedly connected. The first direction B is perpendicular to the vertical direction A. The longitudinal reinforcement bars 21 extend vertically downwards from the outside of the target height position of the added steel column 10, extending to the outside of the existing reinforced concrete frame beam 41, and then bend horizontally after reaching the bottom of the frame beam-column node 43, forming a horizontal bend 211. The horizontal bends 211 of two opposite longitudinal reinforcement bars 21 are welded together at the bottom of the frame beam-column node 43. Multiple stirrups 22 are spaced apart on the outer periphery of the multiple longitudinal reinforcement bars 21 in the vertical direction A and fixedly connected to the longitudinal reinforcement bars 21. The multiple longitudinal reinforcement bars 21 and the multiple stirrups 22 together form an integral steel cage structure. At the bottom of the frame beam-column node 43, opposite longitudinal reinforcement bars 21 are welded together through the horizontal bends 211. This structure connects two through-slab reinforcement bars into one, allowing them to better cooperate in bearing loads and fully utilize the structural strength. Simultaneously, the through-slab longitudinal reinforcement 21 extends downwards from the outside of the added steel column 10 and is bent and anchored at the bottom of the frame beam-column joint 43, facilitating the direct transfer of upper loads to the stress area at the bottom of the frame beam-column joint 43, resulting in a simple force transmission path. Given the limited space at the bottom of the frame beam, the welded connection provides reliable anchorage, reducing the risk of the through-slab longitudinal reinforcement 21 being pulled out due to insufficient anchorage length. This improves the connection reliability of the through-slab longitudinal reinforcement 21, ensuring it forms an effective integrated load-bearing system with the outer concrete layer 30.

[0054] like Figure 3 As shown, the outer concrete layer 30 covers the outer periphery of the added steel column 10 and the reinforcing cage 20, making the added steel column 10, the reinforcing cage 20, and the reinforced concrete frame 40 an integral load-bearing structure. The outer concrete layer 30 is a concrete structure cast around the added steel column 10 and the reinforcing cage 20. The outer concrete layer 30 encapsulates the added steel column 10, the reinforcing cage 20, and the existing reinforced concrete frame 40 into a whole. It fills the gaps, provides bonding force, and enables the new and old structures to work together to form a unified load-bearing system. The specific material of the outer concrete layer is not limited. In one possible implementation, a micro-expansion agent can be incorporated into the outer reinforced concrete layer to enhance the bonding strength between the outer concrete layer 30 and other structures, thereby further improving the overall mechanical properties of the connection node 100.

[0055] In summary, the through-anchored external-encased steel column connection node 100, through the coordinated design of the added steel column 10, the steel reinforcement skeleton 20 and the outer concrete layer 30, combined with the structural design of the longitudinal reinforcement 21 through the slab arranged at the corner of the frame beam-column node 43 and the horizontal bending section 211 of the opposite longitudinal reinforcement 21 welded at the bottom of the frame beam-column node 43, can effectively improve the structural reliability of the connection node 100 and the existing frame beam-column node 43, thereby improving the overall stress reliability, construction feasibility and structural service life of the through-anchored external-encased steel column connection node 100.

[0056] The extension length of the longitudinal reinforcement 21 through the slab, i.e., the length of the horizontal bend 211, needs to be adjusted according to the beam height to ensure that the horizontal bend 211 can be reliably anchored at the bottom of the frame beam-column joint 43. To ensure the anchorage reliability of the longitudinal reinforcement 21 through the slab, the anchorage length and bending radius of the horizontal bend 211 at the bottom of the frame beam-column joint 43 are set to meet the requirements for reinforcement anchorage performance in the current national standard "Code for Design of Concrete Structures" (GB50010). Specific values ​​can be calculated and determined based on factors such as the diameter of the reinforcement, the concrete strength grade, and the seismic resistance level; this application embodiment does not limit this. The bending radius of the longitudinal reinforcement 21 through the slab meets the requirements of the reinforcement processing specification. The specific structure of the longitudinal reinforcement 21 through the slab is not limited. In one possible implementation, the angle between the horizontal bend 211 and the vertical direction A is 90 degrees, which facilitates construction and the connection of two opposing longitudinal reinforcements 21 through the slab. In other possible implementations, the angle between the horizontal bend 211 and the vertical direction A is 135 degrees. At an angle of 135 degrees, the bend has better anchoring performance, which is especially suitable for seismic design.

[0057] Furthermore, the connection method of the horizontal bends of the two opposing longitudinal reinforcement bars is not limited. For example... Figure 3 As shown, in one possible implementation, the horizontally bent segments 211 of two opposing through-plate longitudinal reinforcements 21 are fixedly connected by single-sided welding, and the length of the welding area 212 is greater than or equal to 10 times the diameter of the through-plate longitudinal reinforcement 21. Single-sided welding is simple to construct and suitable for scenarios with relatively open spaces.

[0058] Alternatively, the horizontally bent sections 211 of the two opposing longitudinal reinforcement bars 21 can be fixedly connected by double-sided welding, with the length of the welding area 212 being greater than or equal to five times the diameter of the longitudinal reinforcement bar 21. The double-sided welding area 212 is shorter and suitable for situations where the bottom space of the frame beam-column joint 43 is limited. The specific choice can be made according to the actual working conditions, and this embodiment does not impose any restrictions on this.

[0059] Therefore, by welding, the two separate through-slab longitudinal reinforcement bars 21 can form a continuous force transmission path at the bottom of the frame beam-column joint 43, enabling them to work collaboratively as a whole load-bearing component. Setting the length range of the welding area 212 ensures the strength of the weld, further enhancing the ultimate load-bearing capacity of the through-slab longitudinal reinforcement bars 21 and improving the reliability of the connection. Simultaneously, the welding connection can provide reliable anchorage even in situations with limited space at the bottom of the frame beam-column joint 43, preventing reinforcement pull-out damage due to insufficient anchorage length.

[0060] Furthermore, such as Figure 4 As shown, and in combination Figure 3 It is understood that, in one possible implementation, the steel reinforcement cage 20 also includes a plurality of structural longitudinal bars 23, which are spaced around the outer periphery of the frame beam-column node 43 and spaced apart from a plurality of through-slab longitudinal bars 21. At least one structural longitudinal bar 23 is provided on part or all of the reinforced concrete frame beam 41. Each structural longitudinal bar 23 extends from the top end face of the reinforced concrete frame beam 41 in the vertical direction A to the target height position of the added steel column 10. Each stirrup 22 located above the reinforced concrete frame 40 surrounds and is fixed to the outer periphery of the plurality of through-slab longitudinal bars 21 and the plurality of structural longitudinal bars 23.

[0061] Both the through-slab longitudinal reinforcement 21 and the structural longitudinal reinforcement 23 are longitudinal reinforcing bars, extending vertically in direction A, used to bear the axial pressure, tensile stress, and bending moment in the area of ​​the connection node 100. The structural longitudinal reinforcement 23 is set in the corresponding area above the reinforced concrete frame beam 41 to meet the leg spacing limits and structural requirements of the stirrups 22 in the reinforced concrete column 42. Since the through-slab longitudinal reinforcement 21 is concentrated at the four corners of the frame beam-column node 43, the middle area of ​​the reinforced concrete frame beam 41 will lack longitudinal reinforcement. If the stirrups 22 are directly set by relying solely on the through-slab longitudinal reinforcement 21, the leg spacing of the stirrups 22 may be too large, failing to effectively restrain the concrete, thus affecting the stress performance, crack resistance, and overall ductility of the outer concrete layer 30. By adding structural longitudinal reinforcement 23, reliable intermediate support points can be provided for stirrup 22, enabling stirrup 22 to be evenly and reasonably arranged along the outer periphery of frame beam-column node 43, effectively reducing the spacing of stirrup 22 legs, ensuring the restraining effect of stirrup 22 on the outer concrete layer 30, and improving the stiffness, integrity and stress safety of the frame beam-column node 43 area.

[0062] In the vertical direction A, the area without reinforced concrete frame beam 41 and the area with reinforced concrete frame beam 41 are respectively provided with first stirrup 221 and second stirrup 222. For example... Figure 3 and Figure 4As shown, in one possible implementation, the multiple stirrups 22 include multiple first stirrups 221 and multiple second stirrups 222. The multiple first stirrups 221 are spaced apart in the vertical direction A and located above the reinforced concrete frame 40.

[0063] The first stirrup 221 is placed above the reinforced concrete frame beam 41, i.e., in the area without the reinforced concrete frame beam 41. Multiple first stirrups 221 are tied or welded to the outside of the through-slab longitudinal reinforcement 21 and the structural longitudinal reinforcement 23, forming a reinforcing cage together with the through-slab longitudinal reinforcement 21 and the structural longitudinal reinforcement 23. The multiple first stirrups 221 are evenly distributed along the vertical direction A at a certain spacing, which can restrain the outer concrete layer 30, improve the compressive bearing capacity and ductility of the connection node 100, enhance the integrity and crack resistance of the connection node 100, and improve the deformation characteristics and durability of the structure during stress.

[0064] like Figures 3-5 As shown, multiple second stirrups 222 are located below the added steel columns 10. Multiple stirrup holes are formed on each reinforced concrete frame beam 41, and each second stirrup 222 passes through the corresponding stirrup hole on each reinforced concrete frame beam 41. The second stirrups 222 surround the outer perimeter of multiple through-slab longitudinal reinforcements 21. The multiple second stirrups 222 are evenly distributed at a certain spacing in the vertical direction A. In the area where the reinforced concrete frame beam 41 is located, by pre-processing stirrup holes on the beam body, and ensuring the drilling positions avoid the original stressed reinforcement inside the reinforced concrete frame beam 41, small drilling equipment can be used for construction, minimizing the impact on the original reinforced concrete frame beam 41 structure. The second stirrups 222 are passed through the stirrup holes, and after both ends of the second stirrups 222 extend out of the beam body, they are tied and connected to the through-slab longitudinal reinforcements 21 and structural longitudinal reinforcements 23, forming a complete stirrup system 22. The arrangement of the second stirrup 222 can reduce the interruption of the stirrup 22 due to the obstruction of the beam, reduce the damage to the reinforced concrete frame beam 41, and also ensure the continuity of the second stirrup 222, thereby enhancing the structural integrity and stress reliability of the connection between the anchored outer layer steel column connection node 100 and the beam.

[0065] It should be noted that the specific parameters of the stirrups are not limited. The diameter and spacing of the stirrups are determined based on stress calculations. Those skilled in the art can design according to actual conditions and specific needs, and this application does not impose specific limitations on this. When the building at the connection node is located in a seismic fortification zone, the stirrups can be appropriately densified in the core stress zone of the connection node.

[0066] In summary, the addition of stirrups can further enhance the integrity and durability of the connection nodes, optimize the collaborative performance of the new and old structures, and improve the seismic performance of the connection nodes.

[0067] It should be noted that the existing reinforced concrete frame beams and columns are the original reinforced concrete structures of the building, and their cross-sectional dimensions and reinforcement details are determined according to the original design. The cross-sectional dimensions of the added steel columns, the number and diameter of the longitudinal reinforcement bars passing through the slab, and the spacing of the stirrups are all determined based on calculations of the actual construction structure. Those skilled in the art can design according to the actual engineering conditions, and this application does not limit this aspect.

[0068] like Figure 4 As shown, and in combination Figure 3 Understandably, in one possible implementation, the reinforced concrete frame beams 41 are divided into two types: transverse beams 411 and longitudinal beams 412. The transverse beams 411 extend along the first direction B, while the longitudinal beams 412 are arranged perpendicular to the transverse beams 411. Their intersection forms a regular frame beam-column node 43, providing a precise placement carrier for the through-slab longitudinal reinforcement 21 and structural longitudinal reinforcement 23. The through-slab longitudinal reinforcement 21 is concentrated at the four corners of the frame beam-column node 43, with a total of twelve bars, three at each corner. One through-slab longitudinal reinforcement 21 is placed on each side of each transverse beam 411 or each longitudinal beam 412, forming a symmetrical four-corner pattern. The number of structural longitudinal bars 23 is set to four. The four structural longitudinal bars 23 are respectively set in the upper area of ​​the transverse beam 411 and the longitudinal beam 412. Each structural longitudinal bar 23 is arranged in the middle position of the two through longitudinal bars 21 on both sides of the transverse beam 411 or the longitudinal beam 412, filling the gap in the spacing of the through longitudinal bars 21, so as to meet the limit value of the stirrup 22 leg spacing.

[0069] The above arrangement is only an example to help those skilled in the art understand the arrangement of the longitudinal reinforcement bars and structural reinforcement bars. In other possible implementations, the number of longitudinal reinforcement bars and structural reinforcement bars can be flexibly adjusted according to the size of the frame beam-column joint, the stress calculation results, and the seismic structural requirements. This application does not limit this.

[0070] The connection structure between the added steel column and the existing reinforced concrete frame is not limited. For example... Figure 6 and Figure 7 As shown, and in combination Figure 3 It is understood that, in one possible implementation, the through-anchored external layered steel column connection node 100 also includes a column base plate 11 and a plurality of installation anchors 12. The column base plate 11 is fixedly connected to the bottom end of the layered steel column 10. A plurality of installation holes 111 are formed on the column base plate 11. A plurality of connection grooves 431 are formed at the top of the frame beam-column node 43. The plurality of installation anchors 12 correspond one-to-one with the plurality of installation holes 111 and one-to-one with the plurality of connection grooves 431. Each installation anchor 12 passes through the installation hole 111 of the column base plate 11 and is anchored in the corresponding connection groove 431 of the frame beam-column node 43.

[0071] Specifically, a column base plate 11 is provided at the bottom of the added steel column 10. The column base plate 11 is made of steel plate and welded to the bottom of the added steel column 10. Multiple through-plate longitudinal reinforcements 21 and multiple structural reinforcements are arranged at equal intervals along the perimeter of the column base plate 11, with the vertical sections of the through-plate longitudinal reinforcements 21 extending downwards close to the edge of the column base plate 11. Anchor bolts 12 are used for structural positioning. The bottom end of the anchor bolt 12 is anchored to the top of the existing frame beam-column joint 43, and the top end of the anchor bolt 12 passes through the mounting hole 111 on the column base plate 11 and is fixedly connected to the column base plate 11 by fasteners. To prevent loosening, spring washers can be added between the fasteners and the column base plate 11. The anchor bolts 12 are only used for temporary fixing and positioning of the added steel column 10 during the construction phase. After the outer concrete layer 30 is poured and formed, the main load is borne by the through-plate longitudinal reinforcements 21. Since the anchor bolts 12 do not bear the main load, the number of holes is small and the depth is shallow, resulting in minimal damage to the original structure. Compared with conventional rebar installation methods, this design can effectively reduce the amount of rebar installation work and the damage to the original structure. The anchor bolts 12 can be directly anchored into the existing frame beam-column joint 43, or anchored into the transition section formed by the outer concrete layer 30. This application embodiment does not impose any limitations on this. Those skilled in the art will understand that vent holes can also be provided on the column base plate to ensure that air at the bottom of the column can be smoothly discharged during concrete pouring, avoiding the formation of voids. After pouring, these voids can be sealed with cement mortar of the same strength grade.

[0072] Therefore, by setting a column base plate 11 at the bottom of the added steel column 10, and setting mounting holes 111 and connecting grooves 431 corresponding to the column base plate 11 and the frame beam-column node 43, and using installation anchors 12 to achieve the alignment and connection between the column base plate 11 and the frame beam-column node 43, the placement and temporary fixing of the added steel column 10 can be completed quickly, improving on-site construction efficiency and installation accuracy. The installation anchors 12 are mainly used for the positioning and temporary fixing of the added steel column 10, undertaking the positioning function during the installation stage. During normal use and stress of the structure, they do not participate in the transmission of internal forces such as vertical loads and horizontal loads, and do not undertake the main force transmission function, thereby realizing the separation of installation positioning and main force transmission path, ensuring clear structural stress and safe and reliable node.

[0073] It should be noted that, as Figure 3 As shown, in one possible implementation, structural adhesive (not shown in the figure) fills the gap between the outer wall of the anchor bolt 12 and the inner wall of the connecting groove 431. The structural adhesive can fill the gap between the anchor bolt 12 and the connecting groove 431, so that the anchor bolt 12 is tightly bonded to the existing reinforced concrete structure as a whole, thereby improving the anchoring reliability and integrity of the anchor bolt 12.

[0074] To enhance the connection strength between the added steel column 10 and the frame beam-column joint 43, shear keys 13 are provided on the bottom surface of the column base plate 11 to resist horizontal shear forces. Figure 6 and Figure 7 As shown, and in combination Figure 3 It is understood that, in one possible implementation, the anchored external-enclosed steel column connection node 100 also includes a shear key 13. The shear key 13 is fixedly connected to the bottom surface of the column base plate 11. A fitting groove 432 is formed at the top of the frame beam-column node 43, and the shear key 13 is embedded in the fitting groove 432. The shear key 13 is made of steel plate and welded to the bottom surface of the column base plate 11. The shear key 13 is anchored in the existing frame beam-column node 43. Through the bearing pressure of its sidewall and the concrete of the existing frame beam-column node 43, the shear key 13 directly transfers the horizontal shear force generated at the bottom of the added steel column 10 to the existing reinforced concrete column 42. The shear force transfer path is short and the stress is clear, which greatly improves the shear performance and lateral displacement resistance of the connection node 100 under horizontal loads and seismic action. This structure can also effectively reduce the shear load on the installation anchor bolt 12, allowing the installation anchor bolt 12 to mainly undertake the functions of structural positioning and auxiliary anchoring, realizing a clear division of labor for the shear resistance of the shear key 13, the bending resistance of the through-plate longitudinal reinforcement 21, and the positioning of the installation anchor bolt 12 within the connection node 100, thus comprehensively improving the overall stress performance of the connection node 100.

[0075] Therefore, the shear key 13 is embedded in the mating groove 432 at the top of the frame beam-column joint 43, which can effectively bear and transfer the horizontal shear force at the column base, improving the shear resistance and lateral displacement resistance of the connection joint 100 under horizontal loads and seismic action. The horizontal shear force is transferred to the shear key 13 through the added steel column 10 and the column base plate 11, and then directly transferred to the existing reinforced concrete column 42 structure below by the shear key 13. The shear force transfer path is short and the force is clear, avoiding excessive concentration of shear force on the installation anchor bolts 12 or other non-shear components, ensuring the safety and reliability of the joint under stress.

[0076] The specific structural parameters of shear key 13 are not limited. For example... Figure 3 As shown, in one possible implementation, the depth of the shear key 13 embedded in the mating groove 432 in the vertical direction A is not less than 50mm, so as to ensure that the shear key 13 has sufficient bearing contact area with the existing concrete, to ensure the stability and reliability of horizontal shear force transmission, and to further improve the shear bearing capacity of the connection node 100.

[0077] like Figure 3As shown, in one possible implementation, a grouting layer 14 is formed between the column base plate 11 and the top end face of the frame beam-column node 43. The grouting layer 14 is a micro-expansion concrete layer. The grouting layer 14 is formed by pouring micro-expansion concrete. Since the concrete top surfaces of the column base plate 11 and the frame beam-column node 43 are prone to local gaps and poor contact, the grouting layer 14 is used to fill the gaps between them. By controlling the thickness of the grouting layer 14, the verticality and horizontality of the added steel column 10 can be corrected, reducing the installation difficulty of the added steel column 10 and improving the positioning accuracy of the column base plate 11. The micro-expansion concrete layer can pour and fill the space between the column base plate 11 and the top end face of the frame beam-column node 43, reducing phenomena such as hollowness or detachment, and enhancing the overall structural reliability of the connection node 100.

[0078] The thickness of the grouting layer 14 should not be too small. If the thickness of the grouting layer 14 is too small, the micro-expansion concrete cannot fill the narrow gaps smoothly, which can easily lead to problems such as grout leakage, insufficient grout, hollow areas, and voids. The grouting layer 14 cannot form a complete load-bearing layer, and the top surface of the column base plate 11 and the existing frame beam-column joint 43 will be partially suspended, resulting in uneven vertical load transfer and local stress concentration. For example, setting the thickness of the grouting layer 14 to 50mm can ensure that the micro-expansion concrete can be poured smoothly and vibrated to ensure compaction, completely filling all gaps between the column base plate 11 and the top surface of the existing frame beam-column joint 43, eliminating the risk of hollow areas, achieving a complete and tight fit between the two, and ensuring uniform vertical load transfer. In other possible implementations, the thickness of the grouting layer 14 can also be other dimensions, and this application embodiment does not limit this.

[0079] The specific structure of the additional steel column 10 is not limited. For example... Figure 6 and Figure 8 As shown, and in combination Figure 3 It is understood that, in one possible implementation, a plurality of studs 15 are provided on the outer periphery of the added steel column 10. The plurality of studs 15 are arranged in an array in the circumferential and height directions of the added steel column 10. One end of each stud 15 is fixedly connected to the side wall of the added steel column 10, and the other end is anchored in the outer concrete layer 30.

[0080] The additional steel column 10 can be a square column structure filled with concrete to enhance its vertical bearing capacity and stiffness. Multiple studs 15 are arrayed on the four side walls of the steel column. The arrangement of these studs 15 strengthens the overall connection between the additional steel column 10 and the outer concrete layer 30. The arrayed studs 15 provide uniform internal constraint to the outer concrete layer 30, ensuring its long-term structural integrity, improving the overall bearing capacity of the connection node 100, and enhancing the crack resistance of the outer concrete layer 30.

[0081] In other possible implementations, the additional steel column 10 can be an I-beam (not shown in the figure), with studs 15 welded to the flanges or web of the additional steel column 10 to ensure the cooperative working ability of the steel section and the outer concrete layer 30. The additional steel column 10 can also be other structures, which are not limited in this embodiment.

[0082] The following combination Figures 1-3 The specific construction steps for the anchor-supported outer layer steel column connection node 100 during construction are explained below:

[0083] First, the interface treatment is carried out on the beam-column joint 43 area of ​​the existing reinforced concrete frame beam 41 and reinforced concrete column 42, by roughening and applying an interface agent. Next, the measurement and layout are carried out to determine the installation position of the anchor bolt 12. The connecting groove 431 is drilled at the top of the existing beam-column joint 43, and the anchor bolt 12 is installed. The drilling position must be avoided by using a rebar detector to avoid the original stressed rebar in the existing reinforced concrete frame 40 to ensure the quality of rebar installation.

[0084] Shear keys 13 are pre-welded to the bottom surface of the column base plate 11. At the same time, a matching groove 432 is chiseled at the corresponding position at the top of the existing frame beam-column node 43. The groove depth of the matching groove 432 matches that of the shear key 13. Subsequently, the added steel column 10 is initially positioned. The elevation and level of the column base plate 11 are adjusted by adjusting the nuts on the anchor bolts 12, so that a 50mm gap is reserved between the bottom surface of the column base plate 11 and the top end face of the existing frame beam-column node 43. This gap is used for subsequent filling with micro-expansion concrete to form a grouting layer 14, ensuring that the area under the column base plate 11 is completely filled without any voids.

[0085] After the column base plate 11 is leveled and positioned, the reinforcement cage 20 is tied. First, the through-slab longitudinal bars 21 and structural longitudinal bars 23 are tied. The through-slab longitudinal bars 21 extend vertically downward from the outside of the target height position of the added steel column 10 according to the design requirements, extending to the outside of the existing reinforced concrete frame beam 41 and then bending horizontally after reaching the bottom of the frame beam-column joint 43 to form a horizontal bend section 211. The two horizontal bend sections 211 of the through-slab longitudinal bars 21 are connected by double-sided welding at the bottom of the frame beam-column joint 43. At the same time, the first stirrup 221 and the second stirrup 222 are set according to the position. The second stirrup 222 needs to be installed after drilling stirrup holes in the existing reinforced concrete frame beam 41 with a small drilling machine. The drilling position should avoid the original stressed reinforcement in the beam. After the steel reinforcement cage 20 passes inspection, formwork is erected, outer concrete is poured, vibrated to ensure compaction, and cured to form an outer concrete layer 30. The outer concrete is poured and shaped to wrap the column base plate 11 of the added steel column 10, the exposed part of the anchor bolt 12, the studs 15, and the upper part of the longitudinal reinforcing bars, forming an integral outer reinforced concrete transition section, and finally forming an integral through-anchored outer-wrapped added steel column connection node 100.

[0086] The added-story structure formed through the above construction steps achieves a reliable connection between the added steel column 10 and the existing reinforced concrete frame 40 through the connection node 100. This connection node 100 has a simple force transmission path, effectively transferring the vertical loads, horizontal loads, and seismic forces from the superstructure, ensuring the safety and stability of the added-story structure. Simultaneously, this construction process causes minimal damage to the original structure, and the construction quality is easy to control, exhibiting good economic efficiency and applicability. By adopting the aforementioned connection node 100, the building added-story structure effectively solves technical problems such as difficulty in connecting the added steel column 10 to the reinforced concrete frame 40, significant damage from rebar installation, and indirect force transmission.

[0087] The above description illustrates the implementation of this application through specific embodiments. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Although the description of this application is presented in conjunction with some embodiments, this does not mean that the features of this application are limited to this embodiment. On the contrary, the purpose of describing the application in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of this application. To provide a thorough understanding of this application, many specific details are included in the above description. This application may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this application, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0088] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0089] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0090] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0091] In the description of this application, it should be understood that "electrical connection" can be understood as physical contact and electrical conduction between components.

[0092] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A type of anchor-supported, multi-layered steel column connection node, characterized in that, include: An additional steel column is provided, which extends vertically and whose bottom end is used to connect to the top of a beam-column joint of a reinforced concrete frame. The reinforced concrete frame includes multiple reinforced concrete frame beams and reinforced concrete columns, and the intersection of the top of the multiple reinforced concrete frame beams and the top of the reinforced concrete columns is the beam-column joint. The steel reinforcement cage includes multiple through-slab longitudinal bars and multiple stirrups. Each through-slab longitudinal bar extends vertically from the bottom of the frame beam-column joint to the target height of the added steel column. The multiple through-slab longitudinal bars are spaced around the outer periphery of the frame beam-column joint and distributed on the outer side of each corner of the frame beam-column joint. The multiple stirrups are spaced vertically, and each stirrup surrounds and is fixed to the outer periphery of the multiple through-slab longitudinal bars. Furthermore, the bottom end of each through-slab longitudinal bar is bent to form a horizontal bend. The horizontal bends of two through-slab longitudinal bars arranged opposite each other along a first direction are overlapped and fixedly connected. The first direction is perpendicular to the vertical direction. An outer concrete layer covers the outer periphery of the added steel column and the reinforcing steel frame, so that the added steel column, the reinforcing steel frame and the reinforced concrete frame form an integral load-bearing structure.

2. The anchor-supported outer-layer steel column connection node as described in claim 1, characterized in that, The two opposing horizontally bent segments of the through-plate longitudinal reinforcement are fixedly connected by single-sided welding, and the length of the welded area is greater than or equal to 10 times the diameter of the through-plate longitudinal reinforcement; or, The two opposing horizontally bent sections of the through-plate longitudinal reinforcement are fixedly connected by double-sided welding, and the length of the welding area is greater than or equal to 5 times the diameter of the through-plate longitudinal reinforcement.

3. The anchor-supported, externally-encased steel column connection node as described in claim 1, characterized in that, The plurality of stirrups includes a plurality of first stirrups and a plurality of second stirrups, wherein the plurality of first stirrups are spaced apart in the vertical direction and are located above the reinforced concrete frame; The plurality of second stirrups are located below the added steel columns. Each of the reinforced concrete frame beams has a plurality of stirrup holes. Each second stirrup passes through the corresponding stirrup hole on each of the reinforced concrete frame beams. The second stirrups surround the periphery of the plurality of through-slab longitudinal reinforcement bars.

4. The anchor-supported, externally-encased steel column connection node as described in claim 1, characterized in that, The steel reinforcement cage also includes a plurality of structural longitudinal bars, which are spaced around the outer periphery of the frame beam-column joint and spaced apart from the plurality of through-slab longitudinal bars. At least one of the structural longitudinal bars is provided on some or all of the reinforced concrete frame beams. Each structural longitudinal bar extends vertically from the top end face of the reinforced concrete frame beam to the target height position of the added steel column. The stirrups located above the reinforced concrete frame surround and are fixed to the outer periphery of the plurality of through-slab longitudinal bars and the plurality of structural longitudinal bars.

5. The anchor-supported outer-layer steel column connection node as described in claim 1, characterized in that, The through-anchored external-enclosed steel column connection node also includes a column base plate and multiple installation anchors. The column base plate is fixedly connected to the bottom end of the steel column. Multiple installation holes are formed on the column base plate. Multiple connection grooves are formed at the top of the frame beam-column node. The multiple installation anchors correspond one-to-one with the multiple installation holes and one-to-one with the multiple connection grooves. Each installation anchor passes through the installation hole of the column base plate and is anchored in the connection groove corresponding to the frame beam-column node.

6. The anchor-supported, externally-encased steel column connection node as described in claim 5, characterized in that, Structural adhesive is used to fill the space between the outer wall of the anchor bolt and the inner wall of the connecting groove.

7. The anchor-supported, externally-encased steel column connection node as described in claim 5, characterized in that, The anchor-supported, multi-layered steel column connection node also includes a shear key, which is fixedly connected to the bottom surface of the column base plate. A mating groove is formed at the top of the frame beam-column node, and the shear key is embedded in the mating groove.

8. The anchor-supported, externally-encased steel column connection node as described in claim 5, characterized in that, A grouting layer is formed between the column base plate and the top end face of the frame beam-column joint, and the grouting layer is a micro-expansion concrete layer.

9. The through-anchored, externally-encased steel column connection node as described in any one of claims 1-8, characterized in that, Multiple studs are provided on the outer periphery of the added steel column. The multiple studs are arranged in an array in the circumferential and height directions of the added steel column. One end of each stud is fixedly connected to the side wall of the added steel column, and the other end is anchored in the outer concrete layer.

10. A building addition structure, characterized in that, include: The reinforced concrete frame and the anchor-supported outer layer steel column connection node as described in any one of claims 1-9, wherein the anchor-supported outer layer steel column connection node is fixedly connected to the reinforced concrete frame to form an integral load-bearing structure.

Images