Hollow interlayer steel pipe concrete structure and construction method

Abstract

The invention belongs to the technical field of hollow sandwich steel tube concrete, and discloses a hollow sandwich steel tube concrete structure and a construction method.The structure comprises an upper column and a lower column which are the same in structure, the upper column and the lower column are each of a hollow sandwich structure, the upper column and the lower column are connected through an inter-column adapter, and the inter-column adapter comprises an adapter outer steel tube; an adapter inner steel pipe is arranged in the adapter outer steel pipe, and the adapter outer steel pipe and the adapter inner steel pipe are connected through an adapter stiffening rib; the first end plate of the adapter is connected with the end plate of the upper column; the second end plate of the adapter is connected with the end plate of the lower column; a through hole is formed in the side face of the adapter outer steel pipe. The components can be prefabricated in advance, and the construction quality can be guaranteed. According to the design of the inter-column adapter, connection can be conducted according to the situation that the cross sections of the upper column and the lower column are not consistent in size.

Description

Technical Field

[0001] This invention belongs to the field of hollow sandwich steel tube concrete technology, specifically relating to a hollow sandwich steel tube concrete structure and construction method. Background Technology

[0002] Currently, the splicing of hollow steel tube concrete columns mainly falls into the following categories: 1. Direct welding method; 2. Flange connection method; 3. Through bolt connection method; 4. Hybrid connection method combining flange connection and direct welding. Direct welding method: After aligning the inner and outer steel tubes of the upper and lower columns, a full penetration weld is used for connection. The core concrete needs to be poured from the top or through a pre-drilled hole after welding. Disadvantages: 1) Welding quality relies excessively on manual skills. Full penetration welds are prone to defects such as incomplete welds and porosity, requiring 100% non-destructive testing, making the process complex and costly. 2) The high temperature generated during welding can cause local deformation of the steel tubes, affecting their coordination with the core concrete, requiring subsequent correction. 3) On-site welding operations are greatly affected by weather and pose safety and environmental hazards such as fire and smoke. 4) It is only suitable for situations where the inner and outer steel tube cross-sections of the upper and lower columns are the same, and is not applicable when the cross-sections of the inner and outer steel tubes are different, thus having limitations. Flange connection method: Flanges are welded to the inner and outer steel tubes respectively, and the inner and outer flanges of the upper and lower columns are fastened together with high-strength bolts. Disadvantages: This method is only suitable for situations where the cross-sections of the inner and outer steel pipes of the upper and lower columns are the same. It is not applicable when the cross-sections of the inner and outer steel pipes are different, thus having limitations. Through-bolt connection method: Bolts pass through the inner and outer steel pipes of the upper and lower columns (bolt holes need to be pre-drilled), directly connecting and fixing the columns in series. Disadvantages: 1) Only suitable for components with small diameters and simple stress. 2) Through-bolts penetrate the inner and outer steel pipes, weakening the steel pipe cross-section, and the bolt holes easily become stress concentration points, reducing fatigue resistance. Flange connection + direct welding hybrid connection method: External flange bolts achieve rapid positioning and installation, while internal steel pipes are welded to ensure the core area rigidity. Disadvantages: 1) Involves both bolt installation and welding operations, resulting in multiple overlapping processes, a more complex construction process, and potential delays in the connection between processes. 2) Different internal and external connection methods lead to different stress paths, requiring more complex node design and calculations; otherwise, stress imbalances such as "external rigidity and internal flexibility" or "internal rigidity and external flexibility" can easily occur.

[0003] Chinese patent publication number CN215671419U, entitled "A Hollow-core Steel-tube Concrete Structure and Its Joint Node," includes a connector for a hollow-core steel-tube concrete column. The connector comprises a main plate, multiple first stiffening ribs and second stiffening ribs. A through hole is located at the center of the main plate, with a diameter less than or equal to the inner diameter of the inner steel tube of the hollow-core steel-tube concrete column. The first and second stiffening ribs are sequentially and spaced apart around the through hole on the main plate. One end of the first stiffening rib is located outside the outer steel tube, and the other end passes through a first slot and connects to the inner steel tube. The second stiffening rib is entirely located outside the outer steel tube. A connection hole is provided on the main plate, located on the outside of the outer steel tube. This patent uses ordinary flanges and stiffening ribs, only strengthening the internal structure, and cannot solve the connection problem of hollow-core steel-tube concrete columns requiring grouting. Summary of the Invention

[0004] To overcome the problems existing in the prior art, the present invention aims to provide a hollow-core steel-tube concrete structure and its construction method. The upper and lower columns are connected by inter-column joints, which can be prefabricated in the factory, ensuring construction quality. Furthermore, the design of the inter-column joints can accommodate connections where the cross-sectional sizes of the upper and lower columns are different. This invention relies on the overall force transmission through the joints, resulting in a longer force transmission path, reducing stress concentration and preventing or delaying node slippage and residual deformation.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a hollow sandwich steel tube concrete structure, comprising: an upper column and a lower column with identical structures, both of which are hollow sandwich structures. Each hollow sandwich structure includes: an outer steel tube containing an inner steel tube, the inner and outer steel tubes being connected by stiffening ribs; an end plate connected to the end of the outer steel tube, and the end of the inner steel tube connected to the end plate; the upper and lower columns are connected by an inter-column adapter, the inter-column adapter including an outer steel tube containing an inner steel tube, the outer and inner steel tubes being connected by stiffening ribs; a first end plate and a second end plate connected to the top and bottom of the outer steel tube, respectively; the first end plate connected to the end plate of the upper column; the second end plate connected to the end plate of the lower column; and a through hole on the side of the outer steel tube.

[0006] Optionally, a set of opposite sides of the outer steel pipe are provided with steel pipe positioning holes; the steel pipe positioning holes on both sides are in corresponding positions, and the two corresponding steel pipe positioning holes are connected by a tie rod.

[0007] Optionally, the pull rod is an L-shaped rod, and the two pull rods are interlocked with each other.

[0008] Optionally, one end of the pull rod extends into the outer steel pipe and is connected to another pull rod at a corresponding position, while the other end extends out from the positioning hole of the steel pipe, and a pull rod fastener is installed at the extended end.

[0009] Optionally, a side end plate is provided at the steel pipe positioning hole of the outer steel pipe, and the side end plate is provided with an end plate positioning hole corresponding to the position of the steel pipe positioning hole.

[0010] Optionally, one end of the outer steel pipe is provided with several steel pipe slots, and the stiffening ribs are installed in the steel pipe slots.

[0011] Optionally, the stiffening rib includes a trapezoidal plate and a rectangular plate connected to each other, the rectangular plate of the stiffening rib is connected to the inner steel pipe, and the trapezoidal plate of the stiffening rib is engaged in the steel pipe seam and extends out from the steel pipe seam.

[0012] Optionally, both the outer steel pipe and the inner steel pipe of the adapter are hollow frustum-shaped.

[0013] Optionally, the end plate of the upper column is connected to the first end plate of the adapter by fasteners; the end plate of the lower column is connected to the second end plate of the adapter by fasteners.

[0014] Secondly, the present invention provides a construction method for a hollow sandwich steel tube concrete structure, comprising the following steps: The upper column, lower column, and inter-column joint were prefabricated separately. Fill the space between the inner and outer steel pipes of the lower column with concrete. After the concrete has hardened, flip the lower column over. Connect the second end plate of the adapter at the bottom of the column adapter to the end plate of the lower column; Connect the first end plate of the adapter at the top of the column adapter to the end plate of the upper column; Fill the through hole on the side of the outer steel pipe of the adapter with grout; fill the space between the inner and outer steel pipes of the upper column with concrete.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a hollow sandwich steel tube concrete structure in which the columns are connected by inter-column adapters. The inter-column adapters can be prefabricated in the factory, and the upper and lower columns can also be prefabricated in the factory, so the construction quality can be guaranteed. The factory-prefabricated, integrated inter-column adapters serve as the key hubs for the upper and lower columns.

[0016] The column-to-column joint design of this invention can connect columns with different cross-sectional sizes. At the column base, stiffening ribs are inserted between the outer and inner steel pipes. Since the column base is located in the plastic hinge region, the stiffening ribs allow the plastic hinge to develop slowly, strengthening the constraint of the outer and inner steel pipes on the concrete, thus ensuring the full utilization of the component's load-bearing capacity and enhancing its ductility. Under seismic loading, if the joint fails, only the affected component needs to be replaced, simplifying the reinforcement and replacement process and saving costs. This invention relies on the overall force transmission of the joint, resulting in a longer force transmission path, reducing stress concentration and preventing or delaying joint slippage and residual deformation.

[0017] Furthermore, during installation, the present invention only requires fasteners to align and connect the upper and lower columns using the column-to-column adapter, resulting in a high degree of assembly, a short construction period, and guaranteed precision.

[0018] Furthermore, the installation of this invention allows for fully prefabricated construction, resulting in a short cycle, cost savings, and guaranteed installation accuracy. The concrete can be poured in the factory, ensuring high-quality pouring and consistent concrete construction, thereby maximizing the performance of the entire component.

[0019] Furthermore, during installation, the present invention enables the connection between the adapter and the upper and lower columns to be seamless, thus eliminating the influence of residual welding stress.

[0020] Furthermore, this invention enables the connection of the crossbeam via tie rods. The L-shaped rods are rotated and snapped together in pairs, ensuring a quick and secure connection of the crossbeam. Moreover, by connecting the crossbeam to the side end plate, the strength of the connection is guaranteed, preventing deformation.

[0021] This invention enables factory-based, standardized production, fundamentally guaranteeing construction quality and efficiency. It transforms component production from on-site manual labor to factory assembly line manufacturing. Both the inter-column adapter and the upper and lower columns can be prefabricated in the factory according to precise design drawings, achieving a high degree of standardization and modularization. This invention provides a flexible and efficient variable cross-section connection solution, enhancing the adaptability and economy of structural design. In high-rise buildings or complex structures, column cross-section dimensions need to be changed to accommodate load variations on different floors; the adapter of this invention provides an efficient solution. Compared to traditional variable cross-section treatments requiring complex on-site transition welding, the construction method of this invention is more convenient, safer, and offers more significant overall benefits. The structure of this invention employs an integral force transmission mechanism, improving the mechanical properties of the nodes and the durability of the structure. Loads are transferred through the integral structure of the adapter, resulting in a longer and continuous force transmission path, allowing stress to be evenly distributed throughout the node area, effectively avoiding dangerous stress concentrations at welds, bolt holes, or abrupt changes in cross-section. By optimizing the force transmission path and internal structure, the nodes possess higher initial stiffness and bearing capacity. Under cyclic loads such as earthquakes, this effectively avoids or significantly delays node slippage and buckling, ensuring strong node characteristics under major earthquakes and improving the overall seismic toughness of the structure. Simultaneously, by avoiding stress concentration, the fatigue life of the node area is significantly improved, reducing maintenance needs due to accumulated local damage, thereby enhancing the long-term durability and reliability of the entire building structure. In this invention, the column base stiffening ribs are arranged continuously between the inner and outer steel tube walls. Under cyclic loads, plastic hinges tend to first form and develop in the column base area. The stiffening ribs can slow down the expansion rate of plastic hinges and enhance the restraint effect of the inner and outer steel tubes on the core concrete, thus ensuring the full utilization of the component's ultimate bearing capacity and significantly improving its ductility. Attached Figure Description The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings: Figure 1 This is a schematic diagram of the inner steel pipe according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the outer steel pipe according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the stiffening ribs according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the end plate according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the side end plate according to an embodiment of the present invention; Figure 6This is a schematic diagram of the crossbeam according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the pull rod according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the tie rod assembly according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the pull rod extending in according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the pull rod rotation locking according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 12 This is a schematic diagram of the steel pipe inside the adapter according to an embodiment of the present invention; Figure 13 This is a schematic diagram of the outer steel pipe of the adapter according to an embodiment of the present invention; Figure 14 This is a schematic diagram of the adapter end plate according to an embodiment of the present invention; Figure 15 This is a schematic diagram of the outer steel pipe of the lower column according to an embodiment of the present invention; Figure 16 This is a schematic diagram of the lower column stiffening rib in an embodiment of the present invention; Figure 17 This is a schematic diagram of the lower column end plate according to an embodiment of the present invention; Figure 18 This is a schematic diagram of the outer steel pipe of the upper column according to an embodiment of the present invention; Figure 19 This is a schematic diagram of the upper column end plate according to an embodiment of the present invention; Figure 20 This is a schematic diagram of the adapter end plate installation according to an embodiment of the present invention; Figure 21 The stress cloud diagrams are for embodiments of the present invention, wherein (a) is a stress cloud diagram of direct splicing between columns; and (b) is a splicing stress cloud diagram of columns directly using the column-to-column adapter of the present invention. Figure 22 This is an embodiment of the present invention. Figure 21 The corresponding load-displacement curve diagram.

[0022] Among them, 1. Inner steel pipe; 2. Outer steel pipe; 21. Steel pipe seam; 22. Steel pipe positioning hole; 3. Stiffening rib; 4. End plate; 5. Side end plate; 51. End plate positioning hole; 6. Crossbeam; 7. Tie rod; 71. Connector; 8. Fastener; 30. Inter-column adapter; 301. Inner steel pipe of adapter; 302. Stiffening rib of adapter; 303. Outer steel pipe of adapter; 304. First end plate of adapter; 305. Second end plate of adapter. Two end plates; 10. Upper column; 101. Inner steel pipe of upper column; 102. Outer steel pipe of upper column; 1021. Steel pipe seam of upper column; 1022. Positioning hole of steel pipe of upper column; 103. Stiffening rib of upper column; 104. End plate of upper column; 20. Lower column; 201. Inner steel pipe of lower column; 202. Outer steel pipe of lower column; 2021. Steel pipe seam of lower column; 2022. Positioning hole of steel pipe of lower column; 203. Stiffening rib of lower column; 204. End plate of lower column. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0024] Therefore, the following detailed description of embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0025] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, they are only for the convenience of describing the present invention 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, and therefore should not be construed as a limitation of the present invention.

[0026] When an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments. The use of the term "horizontal" does not imply that the component is required to be absolutely horizontal, but rather that it may be slightly tilted. "Horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0027] It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification and appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0029] The present invention will now be described in detail with reference to the accompanying drawings.

[0030] like Figure 11As shown, a hollow sandwich steel tube concrete structure of the present invention includes: an upper column 10 and a lower column 20 with identical structures, both of which are hollow sandwich structures. Each hollow sandwich structure includes: an outer steel tube 2, within which an inner steel tube 1 is disposed, the inner steel tube 1 and the outer steel tube 2 being connected by stiffening ribs 3; an end plate 4 is connected to the end of the outer steel tube 2, and the end of the inner steel tube 1 is connected to the end plate 4; the upper column 10 and the lower column 20 are connected by an inter-column adapter 30, the inter-column adapter 30 including: An adapter outer steel pipe 303 is provided, and an adapter inner steel pipe 301 is provided inside the adapter outer steel pipe 303. The adapter outer steel pipe 303 and the adapter inner steel pipe 301 are connected by an adapter stiffening rib 302. The top and bottom ends of the adapter outer steel pipe 303 are respectively connected to an adapter first end plate 304 and an adapter second end plate 305. The adapter first end plate 304 is connected to the end plate 4 of the upper column 10. The adapter second end plate 305 is connected to the end plate 4 of the lower column 20. A through hole is opened on the side of the adapter outer steel pipe 303.

[0031] The outer steel tube 2 provides effective lateral restraint to the internal concrete, placing the concrete in a triaxial compressive stress state, thus improving its compressive strength and deformation capacity (plasticity). Simultaneously, the inner steel tube 1 is also supported by the concrete, making it less prone to local buckling. The outer steel tube 2 bears most of the tensile stress generated by the bending moment, while the internal concrete primarily bears the compressive stress. This combination allows the component to maintain high strength while exhibiting good plastic deformation capacity under enormous loads, avoiding brittle failure. Therefore, it possesses extremely high load-bearing capacity and excellent ductility. Due to its ductility and energy dissipation capacity, under accidental loads such as earthquakes, explosions, or impacts, it can absorb a large amount of energy, undergoing significant deformation without sudden collapse, providing crucial protection for life and property.

[0032] Because the material of hollow-core steel-concrete composite structures is distributed around the perimeter of the cross-section, the moment of inertia of the cross-section is greatly increased, resulting in high bending and torsional stiffness. This effectively resists lateral forces (such as wind loads and seismic action) and torque, controlling structural deformation. Compared with solid steel-concrete composite structures, it significantly reduces the self-weight of the structure while achieving similar or higher bending capacity and stiffness. This is beneficial for the foundation design of large-span structures, high-rise buildings, and bridges, and can reduce foundation costs. Simultaneously, the outer steel tube itself serves as both a load-bearing structure and a permanent formwork for pouring concrete, eliminating the procedures and costs of formwork erection and dismantling, simplifying the construction process, and shortening the construction period. With the same amount of steel and concrete, the hollow-core cross-section has a larger outer diameter than the solid cross-section, thus providing a larger moment of inertia, making it more efficient under bending and compression. Therefore, hollow-core steel-concrete composite components integrate high load-bearing capacity, high stiffness, superior energy dissipation capacity, lightweight and high strength, convenient construction, and good durability, making them an extremely high-performance composite material component.

[0033] The column-to-column connection of this invention utilizes an inter-column adapter 30. This adapter 30 can be prefabricated in the factory, as can the upper column 10 and lower column 20, ensuring construction quality. The design of the inter-column adapter 30 allows for connection even when the cross-sectional sizes of the upper column 10 and lower column 20 are inconsistent. At the column base, stiffening ribs 3 are inserted between the outer steel pipe 2 and the inner steel pipe 1. Located in the plastic hinge region, the stiffening ribs 3 allow the plastic hinge to develop slowly, strengthening the constraint effect of the outer steel pipe 2 and inner steel pipe 1 on the concrete, thereby ensuring the full utilization of the component's load-bearing capacity and enhancing ductility. Under seismic loading, if a node fails, only the affected component needs to be replaced, simplifying the reinforcement and replacement process and saving costs.

[0034] The column base area is the main formation site of plastic hinges. The stiffening ribs 3 of this invention are arranged through the outer steel pipe 2 and the inner steel pipe 1. This structure can delay the development of plastic hinges while enhancing the restraining effect of the outer steel pipe 2 and the inner steel pipe 1 on the sandwiched concrete, ensuring the full utilization of the component's load-bearing capacity and significantly improving its ductility. Under seismic loading, even if the joint is damaged, only local components need to be replaced or reinforced, making construction convenient and economical.

[0035] Example 1 like Figures 1 to 11As shown in this embodiment, a hollow sandwich steel tube concrete structure includes: an upper column 10 and a lower column 20 with identical structures. Both the upper column 10 and the lower column 20 are hollow sandwich structures. The hollow sandwich structure includes: an outer steel tube 2, an inner steel tube 1 disposed in the outer steel tube 2, and the inner steel tube 1 and the outer steel tube 2 are connected by stiffening ribs 3; an end plate 4 is connected to the end of the outer steel tube 2; and the end of the inner steel tube 1 is connected to the end plate 4.

[0036] The upper column 10 and the lower column 20 are connected by an inter-column adapter 30. The inter-column adapter 30 includes an outer steel pipe 303 and an inner steel pipe 301. The outer steel pipe 303 and the inner steel pipe 301 are connected by a stiffening rib 302. The top and bottom ends of the outer steel pipe 303 are respectively connected to a first end plate 304 and a second end plate 305. The first end plate 304 is connected to the end plate 4 of the upper column 10. The second end plate 305 is connected to the end plate 4 of the lower column 20. A through hole is provided on the side of the outer steel pipe 303.

[0037] Optionally, two through holes are provided on each inclined surface of the outer steel pipe 303 of the adapter.

[0038] The outer steel pipe 2 has a set of opposite side openings for steel pipe positioning holes 22; the steel pipe positioning holes 22 on both sides are in corresponding positions, and the two corresponding steel pipe positioning holes 22 are connected by a tie rod 7.

[0039] Optionally, in this embodiment, there are six steel pipe positioning holes 22 on each side of the outer steel pipe 2, arranged in two columns. Optionally, the steel pipe positioning holes 22 are vertical strip holes.

[0040] like Figures 7 to 10 As shown, the pull rod 7 is an L-shaped rod, and the two pull rods 7 are interlocked with each other.

[0041] Specifically, one end of the pull rod 7 has a connector 71, and the pull rod 7 and the connector 71 form an L-shaped rod. The two pull rods 7 are connected by the connector.

[0042] One end of the pull rod 7 extends into the outer steel pipe 2 and is connected to another pull rod at a corresponding position. The other end extends out from the positioning hole 22 of the steel pipe, and a pull rod fastener 8 is installed on the extended end.

[0043] Specifically, the tie rod fastener 8 is a nut.

[0044] A side end plate 5 is provided at the steel pipe positioning hole 22 of the outer steel pipe 2, and an end plate positioning hole 51 corresponding to the position of the steel pipe positioning hole 22 is provided on the side end plate 5.

[0045] The outer steel pipe 2 has several steel pipe slots 21 at one end, and the stiffening ribs 3 are installed in the steel pipe slots 21. The stiffening ribs 3 include trapezoidal plates and rectangular plates that are connected to each other. The rectangular plates of the stiffening ribs 3 are connected to the inner steel pipe 1, and the trapezoidal plates of the stiffening ribs 3 are engaged in the steel pipe slots 21 and extend out of the steel pipe slots 21.

[0046] like Figures 12 to 14 As shown, both the outer steel pipe 303 and the inner steel pipe 301 of the adapter are hollow quadrangular frustum shapes.

[0047] Specifically, the stiffening rib 302 of the adapter is a trapezoidal plate; the slope of the outer steel pipe 303 of the adapter is greater than the slope of the inner steel pipe 301 of the adapter. Optionally, there are four stiffening ribs 302, and the middle of each slope of the inner steel pipe 301 of the adapter is connected to the outer steel pipe 303 of the adapter through one stiffening rib 302. Optionally, the area of ​​the first end plate 304 is greater than the area of ​​the second end plate 305 of the adapter.

[0048] The end plate 4 of the upper column 10 is connected to the first end plate 304 of the adapter by fasteners; the end plate 4 of the lower column 20 is connected to the second end plate 305 of the adapter by fasteners.

[0049] Optionally, mounting holes are provided on the end plate 4 of the upper column 10, the end plate 4 of the lower column 20, the first end plate 304 of the adapter, and the second end plate 305 of the adapter.

[0050] Optionally, the fastener installed in the mounting hole is a bolt, and the mounting hole is a threaded hole.

[0051] Optionally, the end plate 4 of the upper column 10 is connected to the first end plate 304 of the adapter by fasteners; the end plate 4 of the lower column 20 is connected to the second end plate 305 of the adapter by fasteners.

[0052] Optionally, the cross-sectional dimension of the outer steel pipe 2 of the upper column 10 is smaller than the cross-sectional dimension of the outer steel pipe 2 of the lower column 20. Further, the cross-sectional dimension of the end plate 4 of the upper column 10 is smaller than the cross-sectional dimension of the end plate 4 of the lower column 20. Optionally, the cross-sectional dimension of the first end plate 304 of the adapter is the same as the cross-sectional dimension of the end plate 4 of the upper column 10, and the cross-sectional dimension of the second end plate 305 of the adapter is the same as the cross-sectional dimension of the end plate 4 of the lower column 20.

[0053] Example 2 A construction method for a hollow steel-tube concrete structure includes the following steps: The upper column 10, the lower column 20, and the inter-column adapter 30 were prefabricated respectively. Fill the space between the inner steel pipe 1 and the outer steel pipe 2 of the lower column 20 with concrete. After the concrete has solidified, flip the lower column 20 over. Connect the second end plate 305 of the adapter at the bottom of the column adapter 30 to the end plate 4 of the lower column 20. Connect the first end plate 304 of the adapter at the top of the inter-column adapter 30 to the end plate 4 of the upper column 10. Grouting material is filled into the through hole on the side of the outer steel pipe 303 of the adapter; concrete is filled between the inner steel pipe 1 and the outer steel pipe 2 of the upper column 10.

[0054] Optionally, the prefabrication steps for the upper column 10 and the lower column 20 are as follows: The stiffening rib 3 is installed in the steel pipe seam 21, and the stiffening rib 3 is welded to the outer wall of the inner steel pipe 1; and the stiffening rib 3 is welded to the outer steel pipe 2. The end plate 4 is welded to the inner steel pipe 1, the outer steel pipe 2 and the stiffening rib 3.

[0055] Optionally, before filling the space between the inner steel pipe 1 and the outer steel pipe 2 of the upper column 10 with concrete, the first end plate 304 of the inter-column adapter 30 is connected to the end plate 4 of the upper column 10. Then, the side end plate 5 is placed at the steel pipe positioning holes 22 on both sides of the outer steel pipe 2, aligning the steel pipe positioning holes 22 with the end plate positioning holes 51. A tie rod 7 is inserted into each steel pipe positioning hole 22 of the outer steel pipe 2 of the upper column 10, with the two corresponding tie rods 7 aligned. By rotation, the connectors 71 of the L-shaped tie rods 7 are hooked together, completing the snap-fit ​​connection. The side end plate 5, tie rods 7, and outer steel pipe 2 are then fixed using tie rod fasteners 8. A crossbeam 6 is connected to the side end plate 5.

[0056] Currently, the methods for connecting hollow steel tube concrete beams and columns include the insertion plate-through tie rod with end plate connection method, the through bolt-reinforcing cage collaborative connection method, and the traditional outer ring plate connection method.

[0057] The insert plate-through tie rod connection method with end plate requires strict matching in the welding positioning of the insert plate and the inner steel pipe, as well as the pre-drilled holes for the through tie rod. Excessive dimensional deviation can prevent the end plate from tightly fitting the outer steel pipe, reducing the overall integrity of the joint. Furthermore, the staggered arrangement of the insert plate and tie rod within the interlayer can hinder the pouring and vibration of the interlayer concrete, easily leading to defects such as voids and honeycombing, affecting the joint's load-bearing capacity. This method is only suitable for rectangular hollow interlayer steel pipe concrete columns, exhibiting poor compatibility with round-within-round or square-within-square cross-sections, thus lacking versatility. The full penetration bevel welding of the steel beam flange and end plate must be completed on-site. Welding quality is greatly affected by the construction environment, and welding stress tends to concentrate at the connection between the end plate and the outer steel pipe, easily leading to brittle cracking.

[0058] Through bolt-reinforcing cage co-connection method: The through bolt needs to pass through both the inner and outer steel pipes at the same time. The hole will significantly weaken the effective load-bearing section of the steel pipe. Especially in the area of ​​bolt hole group, stress concentration is easy to occur, which reduces the shear and compressive strength of the column.

[0059] Traditional connection method for outer ring plates: Full welding of the outer ring plate to the outer steel pipe easily generates significant residual welding stress, especially at the corner joint between the ring plate and the steel pipe, where stress concentration is prominent. Under repeated loading, this can easily lead to brittle fracture and poor seismic performance. When adding an inner ring plate inside the inner steel pipe, the operating space is limited, and the welding quality is difficult to inspect. If the inner ring plate is not welded firmly, it cannot effectively restrain the interlayer concrete, and the concrete in the joint area is prone to local crushing under pressure. On-site welding involves a large amount of work and a long construction period, which is difficult to meet the needs of modern industrialized construction and rapid assembly.

[0060] This invention enables beam-column structural connection through the crossbeam 6, and has the following advantages: 1) By adopting prefabricated construction technology, components can be prefabricated in the factory in a standardized manner in advance, and only assembly work is required on site. This greatly reduces the time for wet work and process connection on site, and the construction cycle is significantly shortened compared with traditional technology. It can fully meet the technical requirements and schedule goals of modern building industrialization and rapid assembly.

[0061] 2) The node construction abandons the design of weld seams, completely avoids the manual welding operation on site, and eliminates the quality risks such as welding deformation and weld seam defects from the root. The geometric accuracy and mechanical properties of the nodes can be strictly controlled through the factory production process, and the construction quality is reliably guaranteed.

[0062] 3) The structural force transmission path is clear and well-defined. The vertical and horizontal loads borne by the steel beams are efficiently and evenly transferred to the steel columns through the mechanical interlocking of the end plates and matching connectors, which conforms to the seismic design principle of strong nodes and weak members and ensures the overall stability of the structure.

[0063] 4) Sufficient space is reserved in the node area for concrete pouring. During the pouring process, the concrete can flow smoothly and fully fill the gaps between components. Combined with vibration operation, it can effectively avoid pouring defects such as honeycomb and voids, and significantly improve the density and molding quality of concrete pouring.

[0064] 5) The node has convenient repair and reinforcement characteristics. If damage occurs during the use stage, there is no need to dismantle the main structure on a large scale. Only the damaged transition component needs to be replaced to quickly restore the load-bearing capacity of the node, which greatly reduces the later maintenance cost and construction difficulty.

[0065] Example 3 like Figures 18-19 As shown, in this embodiment, the upper column 10 includes an inner steel pipe 101, an outer steel pipe 102, stiffening ribs 103, and an end plate 104. The outer steel pipe 102 has a steel pipe seam 1021 and a positioning hole 1022.

[0066] like Figures 15 to 17As shown, in this embodiment, the lower column 20 includes an inner steel pipe 201, an outer steel pipe 202, stiffening ribs 203, and an end plate 204. The outer steel pipe 202 has a lower column steel pipe slot 2021 and a lower column steel pipe positioning hole 2022.

[0067] like Figure 20 As shown, in this embodiment, the first end plate 304 of the inter-column adapter 30 is connected to the upper column end plate 104; the second end plate 305 of the adapter is connected to the lower column end plate 204.

[0068] Optionally, in this embodiment, the inner steel pipe 1, the outer steel pipe 2, the stiffening rib 3, the end plate 4, and the inter-column adapter 30 are all made of steel.

[0069] Optionally, in this embodiment, the inner steel pipe 1, outer steel pipe 2, stiffening rib 3, end plate 4, and inter-column adapter 30 are all made of Q235 steel, Q355 steel, Q390 steel, Q420 steel, or Q460 steel.

[0070] Optionally, in this embodiment, the fasteners on the tie rod fastener 8 and the end plate 4 are friction-type high-strength bolts.

[0071] Example 4 In this embodiment, the inter-column adapter 30 in Embodiment 3 is taken as an example.

[0072] Figure 21 (a) is a stress contour plot of the column-to-column direct splice joint. The stress distribution characteristics of the contour plot clearly show that a significant stress concentration phenomenon occurred at the splice position where the cross-section of the member changes abruptly. Affected by this stress concentration effect, the outer steel pipe of the upper column undergoes obvious local buckling deformation, and the core concrete inside it suffers crush damage due to the high pressure stress, forming a characteristic plastic hinge zone in this weak stress area; while the overall stress level of the lower column is in a low state, and the stress distribution is relatively uniform. This phenomenon fully indicates that the column-to-column direct splice member has experienced premature failure due to local instability, and the overall load-bearing capacity of the member has not been fully utilized, and the mechanical properties have not been effectively utilized.

[0073] Figure 21(b) Stress cloud diagram of the column-to-column transition joint. The diagram shows that the transition joint effectively optimizes the force transmission path in the joint area, ensuring a smooth and uniform stress transition from top to bottom, effectively avoiding stress concentration. Simultaneously, the presence of the column transition joint 30 maintains good coordination and consistency in the deformation of the upper column 10 and the lower column 20, resulting in good overall structural synergy. No obvious plastic hinge area appears in the joint area, and the stress distribution in various parts of the outer steel pipe 2 and the transition joint's outer steel pipe 303 is more uniform and reasonable, effectively controlling the stress level. These stress distribution and deformation characteristics clearly demonstrate that the column splicing connection method using the column transition joint 30 can effectively improve the stress state of the column splicing joint, significantly enhance the overall structural performance of the component, and fully and effectively utilize the column's load-bearing potential and mechanical properties.

[0074] Figure 22 The load-displacement curves compare two connection types: direct column-to-column splicing and column-to-column transition joint splicing. As can be seen from the curves, during the elastic stress stage, the load-displacement curve slope of the column-to-column transition joint splicing member with the column-to-column transition joint 30 is significantly greater than that of the direct column-to-column splicing member. This indicates that the transition joint splicing member possesses greater initial stiffness and stronger resistance to deformation during the elastic stage. Furthermore, the peak load of the transition joint splicing member is significantly higher, demonstrating its superior ultimate bearing capacity. During the curve decline phase after the load reaches its peak, the load-displacement curve of the column-to-column transition joint splicing member is flatter, indicating a slower rate of bearing capacity degradation and a more stable degradation process. This means that the member can maintain good bearing performance even after entering the plastic stage, possessing a higher structural safety reserve.

[0075] Unless otherwise specified, the equipment components involved in the above embodiments are all conventional equipment components, and the structural settings, working methods or control methods involved are all conventional settings, working methods or control methods in the art unless otherwise specified.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A hollow sandwich steel tube concrete structure, characterized in that, include: The upper column (10) and lower column (20) are structurally identical, both of which are hollow sandwich structures. The hollow sandwich structure includes: an outer steel pipe (2), an inner steel pipe (1) inside the outer steel pipe (2), and the column base of the inner steel pipe (1) and the column base of the outer steel pipe (2) are connected by stiffening ribs (3); an end plate (4) is connected to the end of the column base of the outer steel pipe (2), and the end of the column base of the inner steel pipe (1) is connected to the end plate (4); the upper column (10) and lower column (20) are connected by an inter-column adapter (30), the inter-column adapter (30) including an adapter. An outer steel pipe (303) is provided inside the outer steel pipe (303) of the adapter, and an inner steel pipe (301) of the adapter is provided inside the outer steel pipe (303) of the adapter. The outer steel pipe (303) and the inner steel pipe (301) of the adapter are connected by an adapter stiffening rib (302). The top and bottom ends of the outer steel pipe (303) of the adapter are respectively connected to a first end plate (304) of the adapter and a second end plate (305) of the adapter. The first end plate (304) of the adapter is connected to the end plate (4) of the upper column (10). The second end plate (305) of the adapter is connected to the end plate (4) of the lower column (20). A through hole is provided on the side of the outer steel pipe (303) of the adapter.

2. The hollow sandwich steel tube concrete structure according to claim 1, characterized in that, The outer steel pipe (2) has a set of opposite sides with steel pipe positioning holes (22); the steel pipe positioning holes (22) on both sides are in corresponding positions, and the two corresponding steel pipe positioning holes (22) are connected by a tie rod (7).

3. A hollow sandwich steel tube concrete structure according to claim 2, characterized in that, The pull rod (7) is an L-shaped rod, and the two pull rods (7) are interlocked.

4. A hollow sandwich steel tube concrete structure according to claim 2, characterized in that, One end of the pull rod (7) extends into the outer steel pipe (2) and is connected to another pull rod at a corresponding position. The other end extends out from the positioning hole (22) of the steel pipe, and the extended end is equipped with a pull rod fastener (8).

5. A hollow sandwich steel tube concrete structure according to claim 2, characterized in that, A side end plate (5) is provided at the steel pipe positioning hole (22) of the outer steel pipe (2), and an end plate positioning hole (51) corresponding to the position of the steel pipe positioning hole (22) is provided on the side end plate (5).

6. A hollow sandwich steel tube concrete structure according to claim 1, characterized in that, The outer steel pipe (2) has several steel pipe slots (21) at one end, and the stiffening ribs (3) are installed in the steel pipe slots (21).

7. A hollow sandwich steel tube concrete structure according to claim 6, characterized in that, The stiffening rib (3) includes a trapezoidal plate and a rectangular plate connected to each other. The rectangular plate of the stiffening rib (3) is connected to the inner steel pipe (1). The trapezoidal plate of the stiffening rib (3) is engaged in the steel pipe seam (21) and extends out from the steel pipe seam (21).

8. A hollow sandwich steel tube concrete structure according to claim 1, characterized in that, Both the outer steel pipe (303) and the inner steel pipe (301) of the adapter are hollow truncated quadrangular shapes.

9. A hollow sandwich steel tube concrete structure according to claim 1, characterized in that, The end plate (4) of the upper column (10) is connected to the first end plate (304) of the adapter by fasteners; the end plate (4) of the lower column (20) is connected to the second end plate (305) of the adapter by fasteners.

10. A construction method for a hollow sandwich steel tube concrete structure as described in any one of claims 1 to 9, characterized in that, Includes the following steps: The upper column (10), lower column (20) and column adapter (30) are prefabricated respectively; Fill the space between the inner steel pipe (1) and the outer steel pipe (2) of the lower column (20) with concrete. After the concrete has solidified, turn the lower column (20) over. Connect the second end plate (305) of the adapter at the bottom of the column adapter (30) to the end plate (4) of the lower column (20); Connect the first end plate (304) of the inter-column adapter (30) to the end plate (4) of the upper column (10); Fill the through hole on the side of the outer steel pipe (303) of the adapter with grout; fill the space between the inner steel pipe (1) and the outer steel pipe (2) of the upper column (10) with concrete.

Images