A steel reinforced concrete column and a concrete filled steel tube column connecting structure and a method for installing the same

Abstract

The application discloses a kind of steel reinforced concrete column and steel pipe concrete column connecting structure and its installation method, comprising: upper steel pipe concrete column, transition zone and lower cross steel reinforced concrete column, upper steel pipe concrete column includes first rectangular steel frame, transition zone includes the second rectangular steel frame of first rectangular steel frame fixed connection, first cross steel partition is vertically arranged in second rectangular steel frame, and the upper end of second cross steel partition of lower cross steel reinforced concrete column is fixedly connected with the lower end of first cross steel partition;First cross steel partition is provided with upper stiffener and lower stiffener.This application forms the through three-dimensional force transmission framework of " lower second cross steel partition to transition zone first cross steel partition to upper first rectangular steel frame", and vertical axial force, horizontal shear force and bending moment are continuously and uniformly transmitted by steel member, so that the seismic energy dissipation capacity of joint is significantly improved, and the use requirement in high-intensity seismic fortification zone is satisfied.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a connection structure and installation method for steel-concrete composite columns and steel-concrete composite columns. Background Technology

[0002] With the comprehensive advancement of new building industrialization, prefabricated construction, dual-carbon and low-carbon construction, and high-quality development of super high-rise buildings in China's construction industry, steel-concrete composite structures have become the mainstream load-bearing system for super high-rise office buildings, commercial complexes, large-span industrial plants, and mixed-use buildings with high and low-rise buildings, thanks to their core advantages such as high load-bearing capacity, light weight, excellent seismic performance, and fast construction speed.

[0003] Currently, a clear trend of layered construction has emerged in engineering practice: the lower part of the building uses cross-shaped steel-concrete composite columns, while the upper part uses steel-concrete composite columns, with the two components complementing each other. The lower cross-shaped steel-concrete composite columns have an internal cross-shaped steel frame encased in reinforced concrete, resulting in high cross-sectional stiffness and outstanding torsional and eccentric load resistance. The outer surface of the column is consistent with that of ordinary concrete columns, facilitating the close integration of walls and pipelines. The cross-shaped steel provides balanced multi-directional stress, adapting to conditions of large axial compression at the bottom and complex horizontal seismic shear forces. At the same time, the outer concrete encasing directly restrains the steel frame, providing superior fire resistance and corrosion resistance. The outer steel pipes of the upper steel-concrete composite columns can serve as permanent formwork and temporary load-bearing components. The high precision of factory prefabrication and the fast on-site assembly speed, combined with the reinforcement effect of the steel pipes on the core concrete, result in lower self-weight and significantly reduce the vertical load on the upper floors.

[0004] However, while layered composite structures can address multiple requirements related to load-bearing capacity, construction, and architectural space, current national standards and standard atlases only specify independent joint structures for cruciform steel-concrete composite columns and steel-concrete composite columns, lacking standardized transition joints for the vertical connection of "lower cruciform steel column + upper steel-concrete composite column". Due to the significant differences in the steel-concrete synergistic load-bearing mechanisms of the two types of components, vertical transition joints have become a core technical bottleneck restricting the large-scale promotion of hybrid composite structures.

[0005] Currently, there is no standardized construction method in the industry for connecting the lower cruciform steel-concrete column to the upper steel-concrete composite column. Design institutes and construction units can only adopt two temporary transition solutions: Solution 1 uses a short steel pipe directly sleeved on the top of the cruciform steel column. The flanges and webs of the cruciform steel extend into the inner cavity of the steel pipe and are fully welded to the inner wall of the steel pipe to form a connection. The side wall of the steel pipe is perforated to insert longitudinal reinforcing bars, and the joint area is integrally poured with concrete. Solution 2 adds an outer concrete transition layer with a variable diameter. The lower cruciform steel extends upward to the top of the transition layer, and the upper steel-concrete composite column rests on the top end plate of the transition layer. The vertical pressure and shear force are indirectly transmitted by the concrete of the transition layer, and the stirrups are densely packed throughout the transition layer.

[0006] Industry measurement and test data show that vertical variable cross-section transition nodes in composite structures are weak points where stress concentration and plastic damage preferentially occur under seismic loading. Existing temporary transition structures generally suffer from problems such as force transmission faults, loose concrete pouring, uncontrollable welding quality of internal cavities, and difficulty in avoiding reinforcement. In high-intensity seismic fortification areas, defects such as steel pipe buckling, steel reinforcement weld cracking, and concrete interface delamination are prone to occur, which cannot meet the current mandatory requirements for long-term durability.

[0007] Chinese patent CN219033576U discloses a novel connection node between a steel-concrete composite column and a steel-concrete composite section column. It includes a steel-concrete composite column, a steel-concrete composite section column, and a steel beam. The lower end of the steel-concrete composite section column is inserted into the upper end of the steel-concrete composite column, and a connecting plate is provided at the intersection of the steel-concrete composite column and the steel-concrete composite section column. One end of the connecting plate is connected to the steel-concrete composite section column, and the other end of the connecting plate is connected to the steel-concrete composite column. The steel beam is connected at the intersection of the steel-concrete composite column and the steel-concrete composite section column. However, this patent has the following defects in its implementation: (1) The connection direction of the scheme is that the steel-concrete composite column is below and the steel-concrete composite column is above, while the present invention is aimed at the vertical transition node where the lower cross-shaped steel-concrete composite column connects to the upper steel-concrete composite column. The column arrangement directions of the two are completely opposite, and there are essential differences in the force transmission path and the force characteristics of the node. The prior art cannot solve the technical problems in the engineering scenario targeted by the present invention.

[0008] (2) This scheme relies on the connecting plate as the main force transmission component. The load of the upper steel column needs to be transferred to the connecting plate first, and then transferred to the lower steel pipe column by the connecting plate. This is an indirect force transmission mode, and there is an obvious discontinuity in the force transmission path. At the same time, the steel column needs to be concealed and welded in a narrow space when inserted into the inner cavity of the steel pipe. It is difficult to fully inspect the quality of the weld. Under the action of seismic cyclic load, the weld of the connecting plate is prone to stress concentration and low-cycle fatigue failure.

[0009] (3) The scheme does not set up any dedicated concrete diversion and exhaust channels. The closed cavity formed by inserting the steel column into the steel pipe makes it difficult for air to be discharged during pouring, which easily leads to defects such as hollowing, honeycombing and concrete delamination. At the same time, the steel pipe sidewall needs to be perforated to insert longitudinal steel bars, which damages the integrity and continuity of the steel pipe wall and weakens the confinement effect of the steel pipe on the core concrete. Summary of the Invention

[0010] The purpose of this invention is to provide a connection structure and installation method for steel-concrete composite columns and steel-concrete composite columns, in order to solve the above-mentioned problems in the prior art.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a connection structure between a steel-concrete composite column and a steel-tube concrete column, comprising: an upper steel-tube concrete column, the upper steel-tube concrete column including a vertically arranged first rectangular steel frame, wherein multiple studs are provided on the inner sidewalls of the rectangular steel frame; a transition zone, the transition zone including a second rectangular steel frame corresponding to the first rectangular steel frame, the second rectangular steel frame being fixedly connected to the first rectangular steel frame, wherein a first cross-shaped steel partition is vertically arranged inside the second rectangular steel frame, the upper edge of the first cross-shaped steel partition corresponding to the bottom end of the first rectangular steel frame of the upper steel-tube concrete column, and the four outer edges of the first cross-shaped steel partition being fixedly connected to the inner wall of the second rectangular steel frame; and a lower cross-shaped steel-concrete column, the lower cross-shaped steel-concrete column including a second cross-shaped steel partition, the upper end of the second cross-shaped steel partition being correspondingly arranged and fixedly connected to the first cross-shaped steel partition, the lower cross-shaped steel-concrete column further including a ring of longitudinal reinforcing bars arranged around the second cross-shaped steel partition, the longitudinal reinforcing bars continuously extending upwards. The longitudinal reinforcing bars are arranged vertically along the outer wall of the second rectangular steel frame in the transition zone. The upper ends of the longitudinal reinforcing bars are flush with the upper ends of the second rectangular steel frame. A predetermined spacing is maintained between the longitudinal reinforcing bars and the outer wall surface of the second rectangular steel frame in the transition zone. Multiple layers of reinforced stirrups and tie bars are arranged around the outer side of the longitudinal reinforcing bars. The multiple layers of tie bars connect the longitudinal reinforcing bars in different directions. The reinforced stirrups and tie bars also maintain a predetermined spacing with the outer wall surface of the steel pipe shell in the transition zone. A template is set around the outer side of the reinforced stirrups. The upper end of the template is flush with the upper end of the longitudinal reinforcing steel bars; stiffening ribs, upper stiffening ribs and lower stiffening ribs are fixedly installed on the first cross-shaped steel partition. The lower stiffening ribs are located at the lower end of the first cross-shaped steel partition near the edge, and the upper stiffening ribs are located at the uppermost edge of the first cross-shaped steel partition. The outer edges of the upper stiffening ribs and the lower stiffening ribs are fixedly connected to the second rectangular steel frame. Concrete overflow outlets are opened on all four sides of the second rectangular steel frame at the position between the lower stiffening ribs and the lower edge of the first cross-shaped steel partition.

[0012] In a preferred embodiment, the first cross-shaped steel partition includes a cross-shaped web and four wing plates. The cross-shaped web is composed of two intersecting first and second webs fixedly connected together. The four wing plates are vertically arranged at the four outer edges of the cross-shaped web. The second cross-shaped steel partition has the same cross-shaped web and wing plate cross-sectional structure as the first cross-shaped steel partition. The cross-shaped webs of the first and second cross-shaped steel partitions correspond one-to-one with each other in the vertical projection direction. The wing plates of the first and second cross-shaped steel partitions correspond one-to-one with each other in the vertical projection direction.

[0013] In a preferred embodiment, both the upper and lower stiffening ribs are horizontally arranged flat plate members. The flat plate surfaces of the upper and lower stiffening ribs have cross-shaped through cuts corresponding to the cross-shaped web of the first cross-shaped steel partition. The upper and lower stiffening ribs are horizontally fitted around the periphery of the cross-shaped web of the first cross-shaped steel partition through the cross-shaped through cuts. The edges of the cross-shaped through cuts of the upper and lower stiffening ribs are fixedly connected to the corresponding positions of the cross-shaped web of the first cross-shaped steel partition. The outer peripheral edges of the upper and lower stiffening ribs are fixedly connected to the inner wall of the second rectangular steel frame.

[0014] In a preferred embodiment, the upper stiffening rib and the lower stiffening rib are respectively divided into upper left plate, upper right plate, lower left plate, and lower right plate by a cross-shaped through cut. Grouting holes are provided at the connection points of the upper left plate, upper right plate, lower left plate, and lower right plate with the center point of the cross-shaped web of the first cross-shaped steel partition. Four ventilation holes are provided on the upper left plate, upper right plate, lower left plate, and lower right plate of the upper and lower stiffening ribs, and the four ventilation holes are located in the middle of the upper left plate, upper right plate, lower left plate, and lower right plate. Vibration holes are provided on the upper left plate, upper right plate, lower left plate, and lower right plate, and the four vibration holes are located at the four corners of the second rectangular steel frame. Two overflow holes are provided on the upper left plate, upper right plate, lower left plate, and lower right plate, and the two overflow holes on the upper left plate, upper right plate, lower left plate, and lower right plate are located at the connection points of the cross-shaped web of the first cross-shaped steel partition and the second rectangular steel frame.

[0015] In a preferred embodiment, the upper left plate, upper right plate, lower left plate, and lower right plate of the upper stiffening rib are identical in specifications, shape, opening position, and opening size to the upper left plate, upper right plate, lower left plate, and lower right plate of the lower stiffening rib.

[0016] In a preferred embodiment, two concrete overflow outlets are provided on each side of the second rectangular steel frame, and the two concrete overflow outlets are symmetrically arranged on both sides of the wing plate of the first cross-shaped steel partition corresponding to that side; the concrete overflow outlets are semi-circular openings, and the chord length of the semi-circular openings is equal to the width of the wing plate of the first cross-shaped steel partition.

[0017] In a preferred embodiment, the lower cross-shaped steel-concrete column includes the original concrete structure and a post-cast zone. The post-cast zone is located above the original concrete structure and is equipped with longitudinal reinforcing bars. The longitudinal reinforcing bars surround the second cross-shaped steel partition and are arranged vertically along the outer wall of the second rectangular steel frame of the transition zone. The upper end of the longitudinal reinforcing bars is flush with the upper end of the second rectangular steel frame. A predetermined distance is maintained between the longitudinal reinforcing bars and the outer wall surface of the second rectangular steel frame of the transition zone. Multiple layers of reinforced stirrups and tie bars are also arranged around the outside of the longitudinal reinforcing bars. The multiple layers of tie bars are tied between the longitudinal reinforcing bars in different directions. The reinforced stirrups and tie bars are also maintained at a predetermined distance from the outer wall surface of the steel pipe shell of the transition zone. A template is provided around the outside of the reinforced stirrups. The upper end of the template is flush with the upper end of the longitudinal reinforcing bars. Concrete is poured into the post-cast zones of the upper steel pipe concrete column, the transition zone, and the lower cross-shaped steel-concrete column.

[0018] This invention also discloses an installation method for a connection structure between a steel-concrete composite column and a steel-tube concrete column, comprising the following steps: S1: Prefabricate the upper steel-concrete composite column and the integrated steel component of the transition zone to fix the first rectangular steel frame and the second rectangular steel frame together. Fix the first cross-shaped steel partition plate inside the second rectangular steel frame and fix the upper stiffening rib and lower stiffening rib on the first cross-shaped steel partition plate. Weld studs around the inner wall of the first rectangular steel frame. Open concrete overflow outlets on the four sides of the second rectangular steel frame below the lower stiffening ribs. S2: On-site construction of the second cross-shaped steel diaphragm of the lower cross-shaped steel-concrete column to the design elevation, and binding longitudinal reinforcing bars, denser stirrups and tie bars around the second cross-shaped steel diaphragm. The upper end of the longitudinal reinforcing bars is reserved to the top elevation of the transition zone. S3: Hoist the integrated steel component as a whole to the top of the second cross-shaped steel partition, and adjust the component's axis, elevation, and verticality so that the lower end of the first cross-shaped steel partition is aligned with the upper end of the second cross-shaped steel partition. S4: The lower end of the first cross-shaped steel partition is butt-welded to the upper end of the second cross-shaped steel partition to form a rigid connection; S5: Set up a formwork around the outside of the longitudinal reinforcing bars, with the top of the formwork flush with the top of the longitudinal reinforcing bars. S6: Concrete is poured integrally from the top of the first rectangular steel frame downwards. The concrete flows downwards through the grouting holes on the upper and lower stiffening ribs. The air inside the second rectangular steel frame is discharged upwards through the vent holes. The vibrator is inserted through the vibration hole to perform vibration operation. The concrete flows into the outer area of ​​the second cross-shaped steel partition through the concrete overflow outlets on all four sides of the second rectangular steel frame located below the lower stiffening ribs. S7: Remove the formwork after the concrete reaches the design strength and begin curing.

[0019] In a preferred embodiment, in S4, the full penetration butt welding adopts a layered and segmented symmetrical welding process. Before welding, the welding bevels at the lower end of the first cross-shaped steel partition and the upper end of the second cross-shaped steel partition are cleaned and rusted and preheated to 100℃~150℃. During the welding process, symmetrical welding is performed to offset the welding thermal stress. After the welding is completed, the weld is visually inspected and subjected to ultrasonic non-destructive testing. In S5, the formwork is continuously and enclosedly supported along the outer wall of the second rectangular steel frame. A predetermined distance is maintained between the formwork and the outer wall surface of the second rectangular steel frame. This distance is consistent with the distance between the longitudinal reinforcing bars, the dense stirrups, and the tie bars relative to the outer wall surface of the second rectangular steel frame, so that the post-poured concrete forms a uniform and continuous concrete protective layer between the formwork and the second rectangular steel frame.

[0020] In a preferred embodiment, in S6, a layered continuous pouring method is adopted. After pouring 500mm of height, an immersion vibrator is used for compaction. The vibrator is inserted into the interior of the second rectangular steel frame through the vibration holes on the upper and lower stiffening ribs, and moves slowly along the inner walls of the first and second rectangular steel frames. The vibrator avoids the weld seam. During the pouring process, the concrete filling status is observed in real time through the vent holes on the upper and lower stiffening ribs until the concrete surface is stable and the air bubbles are completely expelled.

[0021] Compared with the prior art, the present invention has the following features and beneficial effects: 1. This invention establishes a transition zone, in which a first cross-shaped steel partition is vertically installed inside the second rectangular steel frame of the transition zone. The lower end of the first cross-shaped steel partition is aligned and fixedly connected to the upper end of the second cross-shaped steel partition of the lower cross-shaped steel-concrete column. The four outer edges of the first cross-shaped steel partition are fixedly connected to the inner wall of the second rectangular steel frame. The upper end of the first cross-shaped steel partition corresponds to the bottom end of the first rectangular steel frame of the upper steel-concrete column, forming a continuous three-dimensional force transmission skeleton from the lower second cross-shaped steel partition to the first cross-shaped steel partition in the transition zone to the upper first rectangular steel frame. Vertical axial force, horizontal shear force, and bending moment are continuously and uniformly transmitted by the steel components, avoiding the force transmission fault problem caused by indirect force transmission through local welds or outer concrete in the prior art. This significantly improves the seismic energy dissipation capacity of the nodes and meets the requirements for use in high-intensity seismic fortification zones.

[0022] 2. This invention fixes upper and lower stiffening ribs on the first cross-shaped steel partition, dividing the upper and lower stiffening ribs into upper left, upper right, lower left, and lower right plates respectively. Grouting holes, venting holes, vibration holes, and overflow holes are opened on each plate. During concrete pouring, the concrete flows downward through the grouting holes on the upper and lower stiffening ribs, while the air inside the second rectangular steel frame is discharged upward through the venting holes. The vibrator is inserted through the vibration hole for vibration operation, and the concrete flows into the outer area of ​​the second cross-shaped steel partition through the concrete overflow ports located below the lower stiffening ribs on all four sides of the second rectangular steel frame. This forms a four-in-one pouring system of "flow guidance, air ventilation, vibration, and overflow", ensuring that the concrete inside the second rectangular steel frame in the transition zone and the post-poured area of ​​the lower cross-shaped steel-concrete column are simultaneously filled and compacted. This structurally eliminates defects such as internal voids, honeycombing, and concrete interface delamination, and significantly improves the joint's impermeability, corrosion resistance, and freeze-thaw resistance.

[0023] 3. In this invention, the longitudinal reinforcing bars are continuously arranged vertically along the outer wall of the second rectangular steel frame in the transition zone, and a predetermined distance is maintained between them and the outer wall surface of the second rectangular steel frame. There is no need to open any holes in the side wall of the second rectangular steel frame for the reinforcing bars to pass through. The continuous confinement effect of the second rectangular steel frame on the core concrete is fully preserved, avoiding the cross-sectional weakening and stress concentration hazards caused by opening holes in the side wall of the steel pipe for reinforcing bars in the prior art, and ensuring that the load-bearing performance of the steel-concrete composite column is not reduced.

[0024] 4. In this invention, the transition zone and the first rectangular steel frame of the upper steel-concrete composite column are prefabricated as an integral steel component. The first cross-shaped steel partition, upper stiffening rib, and lower stiffening rib are all prefabricated and installed in the factory. On-site, only the lower end of the first cross-shaped steel partition and the upper end of the second cross-shaped steel partition need to be fully penetrated and welded. The welding is carried out under open conditions, which has strong visibility and avoids the problem of uncontrollable weld quality caused by welding in the narrow cavity of the steel pipe in the prior art. After the steel component is welded and accepted, the node construction can be completed by pouring concrete integrally from the top of the first rectangular steel frame downwards. This eliminates the cumbersome process of layered formwork, multiple pouring and segmented curing, effectively shortening the construction cycle and reducing the input of labor and machinery. Attached Figure Description

[0025] The present invention will now be described in further detail with reference to the accompanying drawings.

[0026] Figure 1 This is a structural elevation view of the present invention; Figure 2 This is a cross-sectional view of the present invention at point A1-A1; Figure 3 This is a cross-sectional view of section A3-A3 of the present invention.

[0027] Figure reference numerals: 1 - Upper steel-concrete composite column, 2 - First rectangular steel frame, 3 - Stud, 4 - Transition zone, 5 - Second rectangular steel frame, 6 - First cross-shaped steel diaphragm, 7 - Lower cross-shaped steel-concrete composite column, 8 - Second cross-shaped steel diaphragm, 9 - Longitudinal reinforcing bars, 10 - Dense stirrups, 11 - Tie bars, 12 - Upper stiffening rib, 13 - Lower stiffening rib, 14 - Concrete overflow port, 15 - Cross-shaped web, 16 - Wing plate, 17 - Upper left plate, 18 - Upper right plate, 19 - Lower left plate, 20 - Lower right plate, 21 - Grouting hole, 22 - Vent hole, 23 - Vibration hole, 24 - Overflow hole. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention. Example

[0029] See the examples. Figure 1 As shown in Figure 3, a connection structure between a steel-concrete composite column and a steel-concrete composite column of the present invention includes an upper steel-concrete composite column 1. The upper steel-concrete composite column 1 includes a vertically arranged first rectangular steel frame 2, and multiple studs 3 are provided on the inner sidewalls of the rectangular steel frame.

[0030] The transition zone 4 includes a second rectangular steel frame 5 corresponding to the first rectangular steel frame 2. The second rectangular steel frame 5 is fixedly connected to the first rectangular steel frame 2. A first cross-shaped steel partition 6 is vertically arranged inside the second rectangular steel frame 5. The upper edge of the first cross-shaped steel partition 6 corresponds to the bottom end of the first rectangular steel frame 2 of the upper steel pipe concrete column 1. The four outer edges of the first cross-shaped steel partition 6 are fixedly connected to the inner wall of the second rectangular steel frame 5.

[0031] The lower cross-shaped steel-concrete column 7 includes a second cross-shaped steel partition 8, the upper end of which is correspondingly and fixedly connected to the first cross-shaped steel partition 6.

[0032] Stiffening ribs: An upper stiffening rib 12 and a lower stiffening rib 13 are fixedly installed on the first cross-shaped steel partition 6. The lower stiffening rib 13 is located at the lower end of the first cross-shaped steel partition 6 near the edge, and the upper stiffening rib 12 is located at the uppermost edge of the first cross-shaped steel partition 6. The outer edges of the upper stiffening rib 12 and the lower stiffening rib 13 are fixedly connected to the second rectangular steel frame 5. Concrete overflow outlets 14 are opened on all four sides of the second rectangular steel frame 5 at the position between the lower stiffening rib 13 and the lower edge of the first cross-shaped steel partition 6.

[0033] By setting a transition zone 4, a first cross-shaped steel partition 6 is vertically installed inside the second rectangular steel frame 5 of the transition zone 4. The lower end of the first cross-shaped steel partition 6 is fixedly connected to the upper end of the second cross-shaped steel partition 8 of the lower cross-shaped steel-concrete column 7, the four outer edges of the first cross-shaped steel partition 6 are fixedly connected to the inner wall of the second rectangular steel frame 5, and the upper edge of the first cross-shaped steel partition 6 corresponds to the bottom end of the first rectangular steel frame 2 of the upper steel-concrete column 1. This forms a continuous three-dimensional force transmission skeleton from the second cross-shaped steel partition 8 to the first cross-shaped steel partition 6 to the first rectangular steel frame 2. The vertical axial force, horizontal shear force, and bending moment are continuously and uniformly transmitted by the steel components, avoiding the force transmission discontinuity problem caused by indirect force transmission through local welds or outer concrete in the prior art.

[0034] By opening functional holes on the upper stiffening rib 12 and the lower stiffening rib 13, and opening concrete overflow outlets 14 on the four sides of the second rectangular steel frame 5, it is ensured that the post-poured concrete can be densely filled. At the same time, the upper steel pipe concrete column 1 and the transition zone 4 can be prefabricated as an integrated steel component, which only needs to be hoisted and aligned on site, resulting in high construction efficiency and strong quality control.

[0035] Furthermore, the first cross-shaped steel partition 6 includes a cross-shaped web 15 and four wing plates 16. The cross-shaped web 15 is composed of two intersecting first webs and second webs fixedly connected together. The four wing plates 16 are respectively vertically arranged at the four outer edges of the cross-shaped web 15. The second cross-shaped steel partition 8 has the same cross-shaped web 15 and wing plate 16 cross-sectional structure as the first cross-shaped steel partition 6. The cross-shaped web 15 of the first cross-shaped steel partition 6 and the cross-shaped web 15 of the second cross-shaped steel partition 8 correspond to each other in the vertical projection direction. Each wing plate 16 of the first cross-shaped steel partition 6 and each wing plate 16 of the second cross-shaped steel partition 8 correspond to each other in the vertical projection direction.

[0036] By setting the first cross-shaped steel partition 6 as a combination of a cross-shaped web 15 and four flanges 16, and making it completely consistent with the cross section of the second cross-shaped steel partition 8, and ensuring that the cross-shaped web 15 and each flange 16 of the upper and lower partitions correspond and overlap in the vertical projection direction, it is ensured that the vertical force transmitted by the lower second cross-shaped steel partition 8 is transmitted to the first cross-shaped steel partition 6 without eccentricity, avoiding local stress concentration and eccentric force due to cross section misalignment, and ensuring that the force transmission path is direct and continuous.

[0037] Furthermore, both the upper stiffening rib 12 and the lower stiffening rib 13 are horizontally arranged flat plate members. The flat plate surfaces of the upper stiffening rib 12 and the lower stiffening rib 13 have cross-shaped through cuts corresponding to the positions of the cross-shaped web 15 of the first cross-shaped steel partition 6. The upper stiffening rib 12 and the lower stiffening rib 13 are horizontally fitted around the periphery of the cross-shaped web 15 of the first cross-shaped steel partition 6 through the cross-shaped through cuts. The edges of the cross-shaped through cuts of the upper stiffening rib 12 and the lower stiffening rib 13 are fixedly connected to the corresponding positions of the cross-shaped web 15 of the first cross-shaped steel partition 6. The outer peripheral edges of the upper stiffening rib 12 and the lower stiffening rib 13 are fixedly connected to the inner wall of the second rectangular steel frame 5.

[0038] By opening cross-shaped through-cuts on the upper stiffening rib 12 and the lower stiffening rib 13 and fitting them around the cross-shaped web 15 of the first cross-shaped steel partition 6, and fixing each edge of the cut to the cross-shaped web 15 and the outer peripheral edge to the inner wall of the second rectangular steel frame 5, the stiffening ribs, the first cross-shaped steel partition 6 and the second rectangular steel frame 5 form a rigid whole, effectively restraining the local buckling deformation of the connection part, and evenly distributing the concentrated load transmitted from the upper part to the four walls of the second rectangular steel frame 5, avoiding local crushing or instability caused by load concentration, and significantly improving the bearing capacity of the node.

[0039] Furthermore, the upper stiffening rib 12 and the lower stiffening rib 13 are respectively divided into upper left plate 17, upper right plate 18, lower left plate 19, and lower right plate 20 by a cross-shaped through cut. Grouting holes 21 are provided at the connection points between the upper left plate 17, upper right plate 18, lower left plate 19, and lower right plate 20 and the center point of the cross-shaped web 15 of the first cross-shaped steel partition 6. Four ventilation holes 22 are provided on the upper left plate 17, upper right plate 18, lower left plate 19, and lower right plate 20 of the upper stiffening rib 12 and the lower stiffening rib 13. The four ventilation holes 22 are located on the upper left plate 17. The upper right plate 18, lower left plate 19, and lower right plate 20 are located in the middle. Vibration holes 23 are provided on the upper left plate 17, upper right plate 18, lower left plate 19, and lower right plate 20. The four vibration holes 23 are located at the four corners of the second rectangular steel frame 5. Two overflow holes 24 are provided on the upper left plate 17, upper right plate 18, lower left plate 19, and lower right plate 20. The two overflow holes 24 on the upper left plate 17, upper right plate 18, lower left plate 19, and lower right plate 20 are located at the connection position between the cross-shaped web 15 of the first cross-shaped steel partition 6 and the second rectangular steel frame 5.

[0040] By dividing the upper stiffening rib 12 and lower stiffening rib 13 into upper left plate 17, upper right plate 18, lower left plate 19 and lower right plate 20, and opening grouting holes 21, venting holes 22, vibration holes 23 and overflow holes 24 on each plate, a four-in-one concrete pouring system of "flow guidance - air ventilation - vibration - overflow" is formed. Grouting holes 21 provide the main channel for concrete to flow downward, venting holes 22 ensure that the internal air is completely discharged and avoids air cavitation, vibration holes 23 provide the vibrator with an insertion channel to the core area of ​​the node and ensure sufficient vibration and compaction, and overflow holes 24 allow the concrete to flow smoothly to the outer area of ​​the second cross-shaped steel partition 8 and ensure synchronous filling of the post-pouring area. The four functional holes work together to completely solve the pouring difficulties caused by the staggered obstruction of steel components in the core area of ​​the node from a structural point of view, ensuring that the concrete is filled with no dead corners and is dense, and eliminating hollow and honeycomb defects.

[0041] Furthermore, the upper left plate 17, upper right plate 18, lower left plate 19, and lower right plate 20 of the upper stiffening rib 12 are identical in specifications, shape, opening position, and opening size to the upper left plate 17, upper right plate 18, lower left plate 19, and lower right plate 20 of the lower stiffening rib 13.

[0042] The specifications, shape, opening position, and opening size of each plate of the upper stiffening rib 12 and the lower stiffening rib 13 are completely consistent. This ensures that the grouting holes 21, venting holes 22, vibration holes 23, and overflow holes 24 on the upper and lower stiffening ribs are vertically aligned and connected. This allows the concrete to flow smoothly downwards along the grouting holes 21, and the internal air to be continuously discharged upwards along the venting holes 22. The vibrator can be inserted vertically into the vibration holes 23 without obstruction, forming a vertically connected channel for guiding, venting, and vibrating. This avoids the concrete flow being obstructed or the venting being poor due to misalignment of the openings in the upper and lower layers, and greatly improves the smoothness and density of the pouring.

[0043] Furthermore, each side of the second rectangular steel frame 5 has two concrete overflow ports 14, which are symmetrically arranged on both sides of the wing plate 16 of the first cross-shaped steel partition 6 corresponding to that side; the concrete overflow ports 14 are semi-circular openings, and the chord length of the semi-circular opening is equal to the width of the wing plate 16 of the first cross-shaped steel partition 6.

[0044] By opening two concrete overflow ports 14 on each side of the second rectangular steel frame 5 and symmetrically arranging them on both sides of the wing plate 16 of the first cross-shaped steel partition 6 corresponding to that side, the concrete filling the interior of the second rectangular steel frame 5 can flow simultaneously and evenly into the outer area of ​​the second cross-shaped steel partition 8 from both sides of the wing plate 16, avoiding uneven filling of the outer concrete caused by unilateral overflow. The overflow ports are semi-circular openings with a chord length consistent with the width of the wing plate 16, ensuring sufficient flow area of ​​the overflow channel. At the same time, the semi-circular openings have no sharp corners and low stress concentration, which will not significantly weaken the load-bearing performance of the second rectangular steel frame 5.

[0045] Furthermore, the lower cross-shaped steel-concrete column 7 includes the original concrete structure and a post-cast zone. The post-cast zone is located above the original concrete structure and is equipped with longitudinal reinforcing bars 9. The longitudinal reinforcing bars 9 surround the second cross-shaped steel partition 8 and are arranged vertically along the outer wall of the second rectangular steel frame 5 in the transition zone 4. The upper end of the longitudinal reinforcing bars 9 is flush with the upper end of the second rectangular steel frame 5, and a certain distance is maintained between the longitudinal reinforcing bars 9 and the outer wall surface of the second rectangular steel frame 5 in the transition zone 4. At a predetermined spacing, multiple layers of reinforced stirrups 10 and tie bars 11 are arranged around the outer side of the longitudinal reinforcing bars 9. The multiple layers of tie bars are tied between the longitudinal reinforcing bars 9 in different directions. The reinforced stirrups 10 and tie bars 11 also maintain a predetermined spacing with the outer wall surface of the steel pipe shell of the transition zone 4. A template is provided around the outer side of the reinforced stirrups 10. The upper end of the template is flush with the upper end of the longitudinal reinforcing bars 9. Concrete is poured in the post-cast areas of the upper steel pipe concrete column 1, the transition zone 4 and the lower cross-shaped steel concrete column 7.

[0046] By arranging the longitudinal reinforcing bars 9 along the outer wall of the second rectangular steel frame 5 and maintaining a predetermined distance from the steel pipe wall, it is not necessary to open any holes in the side wall of the second rectangular steel frame 5 for the reinforcing bars to pass through, thus fully preserving the continuous confinement effect of the second rectangular steel frame 5 on the core concrete.

[0047] The lower cross-shaped steel-concrete column 7 is set as the original concrete structure and the post-cast zone, and the upper steel-concrete column 1, the transition zone 4 and the post-cast zone of the lower cross-shaped steel-concrete column 7 are cast as one unit. The post-cast concrete completely wraps and solidifies the upper ends of the first rectangular steel frame 2, the second rectangular steel frame 5, the first cross-shaped steel partition 6, the second cross-shaped steel partition 8 and the lower part of the longitudinal reinforcing steel 9 into a whole. It forms a continuous wrapping inside the second rectangular steel frame 5 and outside the second cross-shaped steel partition 8, so that the steel components and concrete form a tight bond and interlocking, ensuring that the steel and concrete in the joint area work together to resist external loads. At the same time, the setting of the post-cast zone ensures that the original concrete structure below is not disturbed by the joint construction, and guarantees the integrity and load-bearing performance of the hardened concrete of the lower column. Example

[0048] The present invention also provides an installation method for a connection structure between a steel-concrete composite column and a steel-concrete composite column, the steps of which are as follows: S1: Prefabricate the upper steel-concrete composite column 1 and the transition zone 4 into an integrated steel component, so that the first rectangular steel frame 2 and the second rectangular steel frame 5 are fixedly connected as one unit. Fix the first cross-shaped steel partition 6 inside the second rectangular steel frame 5, and fix the upper stiffening rib 12 and the lower stiffening rib 13 on the first cross-shaped steel partition 6. Weld studs 3 around the inner wall of the first rectangular steel frame 2. Open concrete overflow outlets 14 on the four sides of the second rectangular steel frame below the lower stiffening ribs 13.

[0049] S2: On-site construction of the second cross-shaped steel partition 8 of the lower cross-shaped steel-concrete column 7 to the design elevation, and binding longitudinal reinforcing bars 9, dense stirrups 10 and tie bars 11 around the second cross-shaped steel partition 8. The upper end of the longitudinal reinforcing bars 9 is reserved to the top elevation of the transition zone 4.

[0050] S3: Hoist the integrated steel component as a whole to the top of the second cross-shaped steel partition 8, and adjust the component's axis, elevation, and verticality so that the lower end of the first cross-shaped steel partition 6 is aligned with the upper end of the second cross-shaped steel partition 8.

[0051] S4: The lower end of the first cross-shaped steel partition 6 and the upper end of the second cross-shaped steel partition 8 are fully penetrated butt welded to form a rigid connection. The full penetration butt weld adopts a layered and segmented symmetrical welding process. Before welding, the welding bevels of the lower end of the first cross-shaped steel partition 6 and the upper end of the second cross-shaped steel partition 8 are cleaned and rusted and preheated to 100℃~150℃. During the welding process, symmetrical welding is performed to offset the welding thermal stress. After the welding is completed, the weld is visually inspected and subjected to ultrasonic non-destructive testing.

[0052] S5: A formwork is installed outside the longitudinal reinforcing bars 9, with the upper end of the formwork flush with the upper end of the longitudinal reinforcing bars 9. The formwork is continuously and closedly supported along the outer wall of the second rectangular steel frame 5. A predetermined distance is maintained between the formwork and the outer wall surface of the second rectangular steel frame 5. This distance is consistent with the distance between the longitudinal reinforcing bars 9, the stirrups 10, and the tie bars 11 relative to the outer wall surface of the second rectangular steel frame 5, so that the post-poured concrete forms a uniform and continuous concrete protective layer between the formwork and the second rectangular steel frame 5.

[0053] S6: Concrete is poured integrally from the top of the first rectangular steel frame 2 downwards. The concrete flows downwards through the grouting holes 21 on the upper stiffening rib 12 and the lower stiffening rib 13. The air inside the second rectangular steel frame 5 is discharged upwards through the vent holes 22. The vibrator is inserted through the vibration hole 23 to perform vibration operation. The concrete flows into the outer area of ​​the second cross-shaped steel partition 8 through the concrete overflow outlets 14 on all four sides of the second rectangular steel frame 5 located below the lower stiffening rib 13, so that the post-cast area of ​​the upper steel pipe concrete column 1, the transition area 4 and the lower cross-shaped steel concrete column 7 are poured into one piece at one time.

[0054] A layered continuous pouring method is adopted. After pouring 500mm of height, an immersion vibrator is used for compaction. The vibrator is inserted into the interior of the second rectangular steel frame 5 through the vibration holes 23 on the upper stiffening rib 12 and the lower stiffening rib 13, and moves slowly along the inner wall of the first rectangular steel frame 2 and the second rectangular steel frame 5. The vibrator avoids the weld seam. During the pouring process, the concrete filling status is observed in real time through the vent holes 22 on the upper stiffening rib 12 and the lower stiffening rib 13 until the concrete liquid surface is stable and the air bubbles are completely discharged.

[0055] S7: Remove the formwork after the concrete reaches the design strength and begin curing.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A connection structure between a steel-concrete composite column and a steel-tube concrete column, characterized in that, include: The upper steel-concrete composite column (1) includes a vertically arranged first rectangular steel frame (2), and multiple studs (3) are provided on the inner sidewalls of the rectangular steel frame. The transition zone (4) includes a second rectangular steel frame (5) corresponding to the first rectangular steel frame (2). The second rectangular steel frame (5) is fixedly connected to the first rectangular steel frame (2). A first cross-shaped steel partition (6) is vertically arranged inside the second rectangular steel frame (5). The upper edge of the first cross-shaped steel partition (6) corresponds to the bottom end of the first rectangular steel frame (2) of the upper steel pipe concrete column (1). The four outer edges of the first cross-shaped steel partition (6) are fixedly connected to the inner wall of the second rectangular steel frame (5). The lower cross-shaped steel-concrete column (7) includes a second cross-shaped steel partition (8), the upper end of which is correspondingly and fixedly connected to the first cross-shaped steel partition (6). Stiffening ribs: An upper stiffening rib (12) and a lower stiffening rib (13) are fixedly provided on the first cross-shaped steel partition (6). The lower stiffening rib (13) is located at the lower end of the first cross-shaped steel partition (6) near the edge. The upper stiffening rib (12) is located at the uppermost edge of the first cross-shaped steel partition (6). The outer edges of the upper stiffening rib (12) and the lower stiffening rib (13) are fixedly connected to the second rectangular steel frame (5). Concrete overflow outlets (14) are opened on all four sides of the second rectangular steel frame (5) at the position between the lower stiffening rib (13) and the lower edge of the first cross-shaped steel partition (6).

2. The connection structure between a steel-concrete composite column and a steel-tube concrete column according to claim 1, characterized in that, The first cross-shaped steel partition (6) includes a cross-shaped web (15) and four wing plates (16). The cross-shaped web (15) is composed of two cross-shaped webs and a second web, which are fixedly connected. The four wing plates (16) are respectively vertically arranged at the four outer edges of the cross-shaped web (15). The second cross-shaped steel partition (8) has the same cross-shaped web (15) and wing plate (16) cross-sectional structure as the first cross-shaped steel partition (6). The cross-shaped web (15) of the first cross-shaped steel partition (6) and the cross-shaped web (15) of the second cross-shaped steel partition (8) are correspondingly superimposed in the vertical projection direction. Each wing plate (16) of the first cross-shaped steel partition (6) and each wing plate (16) of the second cross-shaped steel partition (8) are correspondingly superimposed in the vertical projection direction.

3. The connection structure between a steel-concrete composite column and a steel-tube concrete column according to claim 2, characterized in that, The upper stiffening rib (12) and the lower stiffening rib (13) are both horizontally arranged flat plate components. The flat plate surfaces of the upper stiffening rib (12) and the lower stiffening rib (13) are provided with cross-shaped through cuts corresponding to the cross-shaped web plate (15) of the first cross-shaped steel partition (6). The upper stiffening rib (12) and the lower stiffening rib (13) are horizontally fitted around the cross-shaped web plate (15) of the first cross-shaped steel partition (6) through the cross-shaped through cuts. The edges of the cross-shaped through cuts of the upper stiffening rib (12) and the lower stiffening rib are fixedly connected to the corresponding positions of the cross-shaped web plate (15) of the first cross-shaped steel partition (6). The outer peripheral edges of the upper stiffening rib (12) and the lower stiffening rib (13) are fixedly connected to the inner wall of the second rectangular steel frame (5).

4. The connection structure between a steel-concrete composite column and a steel-tube concrete column according to claim 3, characterized in that, The upper stiffening rib (12) and the lower stiffening rib (13) are respectively the upper left plate (17), the upper right plate (18), the lower left plate (19) and the lower right plate (20) with the cross-shaped through cut as the boundary. Grouting holes (21) are opened at the positions where the upper left plate (17), the upper right plate (18), the lower left plate (19) and the lower right plate (20) are connected to the center point of the cross-shaped web plate (15) of the first cross-shaped steel partition (6). The upper left plate (17), upper right plate (18), lower left plate (19), and lower right plate (20) of the upper stiffening rib (12) and the lower stiffening rib (13) are each provided with four ventilation holes (22), which are located in the middle of the upper left plate (17), upper right plate (18), lower left plate (19), and lower right plate (20). Vibration holes (23) are provided on the upper left plate (17), upper right plate (18), lower left plate (19) and lower right plate (20), and the four vibration holes (23) are located at the four corners of the second rectangular steel frame (5); Two overflow holes (24) are provided on the upper left plate (17), upper right plate (18), lower left plate (19) and lower right plate (20). The two overflow holes (24) on the upper left plate (17), upper right plate (18), lower left plate (19) and lower right plate (20) are located at the connection position between the cross-shaped web (15) of the first cross-shaped steel partition (6) and the second rectangular steel frame (5).

5. The connection structure between a steel-concrete composite column and a steel-tube concrete column according to claim 4, characterized in that, The upper left plate (17), upper right plate (18), lower left plate (19), and lower right plate (20) of the upper stiffening rib (12) are identical in specifications, shape, opening position, and opening size to the upper left plate (17), upper right plate (18), lower left plate (19), and lower right plate (20) of the lower stiffening rib (13).

6. The connection structure between a steel-concrete composite column and a steel-tube concrete column according to claim 5, characterized in that, The second rectangular steel frame (5) has two concrete overflow ports (14) on each side. The two concrete overflow ports (14) are symmetrically arranged on both sides of the wing plate (16) of the first cross-shaped steel partition (6) corresponding to that side. The concrete overflow port (14) is a semi-circular opening, and the chord length of the semi-circular opening is equal to the width of the wing plate (16) of the first cross-shaped steel partition (6).

7. The connection structure between a steel-concrete composite column and a steel-tube concrete column according to claim 6, characterized in that, The lower cross-shaped steel-concrete column (7) includes the original concrete structure and the post-cast area. The post-cast area is located above the original concrete structure and is equipped with longitudinal reinforcing bars (9). The longitudinal reinforcing bars (9) surround the second cross-shaped steel partition (8). The longitudinal reinforcing bars (9) extend upwards continuously along the outer wall of the second rectangular steel frame (5) of the transition area (4) and are arranged vertically. The upper end of the longitudinal reinforcing bars (9) is flush with the upper end of the second rectangular steel frame (5). The longitudinal reinforcing bars (9) and the outer wall surface of the second rectangular steel frame (5) of the transition area (4) maintain a pre-stressed distance. At a fixed spacing, multiple layers of reinforced stirrups (10) and tie bars (11) are arranged around the outside of the longitudinal reinforcing bars (9). The multiple layers of tie bars are tied between the longitudinal reinforcing bars (9) in different directions. The reinforced stirrups (10) and tie bars (11) also maintain a predetermined spacing with the outer wall surface of the steel pipe shell of the transition zone (4). A template is provided around the outside of the reinforced stirrups (10). The upper end of the template is flush with the upper end of the longitudinal reinforcing bars (9). Concrete is poured in the post-cast areas of the upper steel pipe concrete column (1), the transition zone (4) and the lower cross-shaped steel concrete column (7).

8. An installation method for a connection structure between a steel-concrete composite column and a steel-concrete composite column as described in any one of claims 1-7, characterized in that: Includes the following steps: S1: Prefabricate the upper steel-concrete composite column (1) and the transition zone (4) into an integrated steel component, so that the first rectangular steel frame (2) and the second rectangular steel frame (5) are fixedly connected as one unit, the first cross-shaped steel partition (6) is fixedly installed inside the second rectangular steel frame (5), and upper stiffening ribs (12) and lower stiffening ribs (13) are fixedly installed on the first cross-shaped steel partition (6); studs (3) are welded around the inner wall of the first rectangular steel frame (2); concrete overflow outlets (14) are opened on the four sides of the second rectangular steel frame (5) below the lower stiffening ribs (13). S2: On-site construction of the second cross-shaped steel partition (8) of the lower cross-shaped steel concrete column (7) to the design elevation, and tie longitudinal reinforcing bars (9), dense stirrups (10) and tie bars (11) around the second cross-shaped steel partition (8). The upper end of the longitudinal reinforcing bars (9) is reserved to the top elevation of the transition zone (4); S3: The integrated steel component is hoisted to the top of the second cross-shaped steel partition (8), and the component axis, elevation and verticality are adjusted so that the lower end of the first cross-shaped steel partition (6) is aligned with the upper end of the second cross-shaped steel partition (8). S4: The lower end of the first cross-shaped steel partition (6) and the upper end of the second cross-shaped steel partition (8) are fully penetrated and butt welded to form a rigid connection; S5: A template is set up on the outside of the longitudinal reinforcing bar (9), and the upper end of the template is flush with the upper end of the longitudinal reinforcing bar (9); S6: Concrete is poured integrally from the top of the first rectangular steel frame (2) downwards. The concrete flows downwards through the grouting holes (21) on the upper stiffening rib (12) and the lower stiffening rib (13). The air inside the second rectangular steel frame (5) is discharged upwards along the vent holes (22). The vibrator is inserted through the vibration hole (23) to perform vibration operation. The concrete flows into the outer area of ​​the second cross-shaped steel partition (8) through the concrete overflow port (14) on all four sides of the second rectangular steel frame (5) located below the lower stiffening rib (13). This makes the post-casting area of ​​the upper steel pipe concrete column (1), the transition area (4) and the lower cross-shaped steel concrete column (7) poured into one piece at one time. S7: Remove the formwork after the concrete reaches the design strength and begin curing.

9. The installation method of the connection structure between a steel-concrete composite column and a steel-tube concrete column according to claim 8, characterized in that, In S4, the full penetration butt welding adopts a layered and segmented symmetrical welding process. Before welding, the welding bevels of the lower end of the first cross-shaped steel partition (6) and the upper end of the second cross-shaped steel partition (8) are cleaned and rusted and preheated to 100℃~150℃. During the welding process, symmetrical welding is performed to offset the welding thermal stress. After the welding is completed, the weld is visually inspected and ultrasonic non-destructive testing is performed. In S5, the template is continuously and closedly supported along the outer wall of the second rectangular steel frame (5), and a predetermined distance is maintained between the template and the outer wall surface of the second rectangular steel frame (5). This distance is consistent with the distance between the longitudinal reinforcing bars (9), the dense stirrups (10), and the tie bars (11) relative to the outer wall surface of the second rectangular steel frame (5), so that the post-cast concrete forms a uniform and continuous concrete protective layer between the template and the second rectangular steel frame (5).

10. The installation method of the connection structure between a steel-concrete composite column and a steel-tube concrete column according to claim 8, characterized in that, In S6, a layered continuous pouring method is adopted. After pouring 500mm of height, an immersion vibrator is used for compaction. The vibrator is inserted into the interior of the second rectangular steel frame (5) through the vibration holes (23) on the upper stiffening rib (12) and the lower stiffening rib (13), and moves slowly along the inner wall of the first rectangular steel frame (2) and the second rectangular steel frame (5). The vibrator avoids the weld position. During the pouring process, the concrete filling status is observed in real time through the vent holes (22) on the upper stiffening rib (12) and the lower stiffening rib (13) until the concrete liquid surface is stable and the air bubbles are completely discharged.

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