Concrete-filled steel tubular special-shaped column frame system

Abstract

The present invention relates to the technical field of fabricated buildings, and disclosed is a concrete-filled steel tubular special-shaped column frame system. The present invention comprises special-shaped columns, steel beams, and floor systems. The special-shaped columns are T-O special-shaped columns and each comprise a steel tube and a plurality of T-section steels arranged on the outer side of the steel tube; a lower slab of each floor system is provided on a bottom flange of a corresponding H-shaped steel beam, and lap-joint steel bars pass through a web of the H-shaped steel beam; and additionally, recesses are formed in the width connecting direction of the lower slabs, connecting components are placed in the recesses, and then two lower slabs are connected in the width direction by means of cast-in-place concrete. Such a structural mode reduces the whole thickness of floor systems, and can also guarantee the connecting strength of the lower slabs in the span direction and the width direction. In addition, on the basis of the T-O special-shaped columns, the present invention further provides an inter-column vertical connection joint and beam-column joint form, thereby guaranteeing the high assembly rate of a joint system, and also achieving good mechanical properties and integrity of the joint system.

Description

A steel tube concrete special-shaped column frame system Technical Field

[0001] The present invention belongs to the technical field of prefabricated buildings, and more specifically, relates to a steel tube concrete special-shaped column frame system. Background Art

[0002] Prefabricated construction is a key area of ​​transformation and upgrading in the construction industry, and is a rising, promising industry that the government is actively promoting. Currently, prefabricated steel structures account for approximately 30% of prefabricated buildings, the majority of which are public buildings, with residential buildings representing a negligible proportion. With the goal of achieving a 30% share of prefabricated buildings in new construction by 2025, the development prospects for prefabricated steel residential buildings are enormous. In steel construction systems, floor slabs, as one of the largest concrete-intensive components in a building, are lightweight and prefabricated, significantly reducing energy consumption and overall structural weight, thereby lowering costs.

[0003] Currently, reinforced concrete composite slabs, or a combination of precast concrete slabs and cast-in-place concrete, are commonly used to save on molds and improve construction efficiency. Reinforced concrete composite slabs, in particular, offer excellent integrity and high rigidity, with smooth upper and lower surfaces, making them easy to finish. They are suitable for high-rise buildings and large-span buildings that require high overall rigidity.

[0004] Traditional steel-concrete composite floors utilize studs welded to steel beams to ensure interoperability between the steel and concrete. However, when seismic requirements are high, this results in dense stud placement, increasing workload and material costs. Furthermore, traditional prefabricated beam-slab composite floors are relatively thick (typically the sum of the beam cross-section height and the combined slab thickness), limiting floor heights.

[0005] After searching, the application with Chinese patent publication number CN 211396201 U discloses a connection structure between an embedded steel beam and a prefabricated composite floor. This application includes a steel beam and a composite floor; the cross-section of the steel beam is I-shaped; the composite floor includes a prefabricated slab and a cast-in-place composite layer; a steel truss is embedded in the prefabricated slab; the lower chord of the steel truss is embedded in the prefabricated slab; the upper chord of the steel truss is located above the prefabricated slab, and the two ends of the upper chord extend beyond the two sides of the prefabricated slab; the left and right sides of the prefabricated slab are provided with connecting pieces; the connecting pieces include a horizontal plate and a vertical plate; the vertical plate is tightly attached to the side of the corresponding side of the prefabricated slab and is welded to the lower chord of the prefabricated slab; the connecting pieces on both sides of the prefabricated slab are respectively placed on the upper flanges of the steel beams on both sides and fixed by bolts. In this application, the connecting plate is overlapped on the steel beam to connect to the steel beam, providing shear resistance without the need for welding bolts, simplifying the connection structure and reducing the workload. However, in this application, the precast floor panels are connected to the upper flanges of the steel beams via connectors, resulting in a relatively thick overall structure. This also significantly increases floor heights and affects indoor space utilization. Furthermore, in this application, the precast floor panels are connected only by connectors, and the strength of the connection needs to be further improved.

[0006] Summary of the Invention

[0007] 1. Problems to be solved

[0008] In response to at least some of the problems existing in the above-mentioned prior art, the present invention proposes a steel tube concrete special-shaped column frame system, the purpose of which is to solve the problem that the overall thickness of the existing composite floor slabs is large, affecting the use of floor height; and the problem that the connection strength of the prefabricated base plate in the span direction is poor.

[0009] 2. Technical solution

[0010] In order to solve the above problems, the technical solutions adopted by the present invention are as follows:

[0011] The present invention provides a steel tube concrete special-shaped column frame system, comprising special-shaped columns, steel beams and floor slabs, wherein the steel beams are H-shaped steel beams, and the floor slabs are composite floor slabs comprising a prefabricated lower cover plate, a cast-in-place upper cover plate and steel trusses;

[0012] The lower cover plate is provided with a lower notch in the span direction for overlapping the lower flange of the steel beam, and the web of the steel beam is provided with a reinforcement hole for the first lap steel bar to pass through, and after the first lap steel bar passes through the corresponding reinforcement hole, its two ends are respectively overlapped on the lower cover plates on both sides of the steel beam.

[0013] Furthermore, the lower flange of the steel beam is wider than the upper flange, bolts are provided on the upper flange, and lightweight filling bodies are provided between the steel bar trusses.

[0014] Furthermore, the lower cover plate is provided with an upper notch in the width direction, and the upper notches of the two lower cover plates are spliced ​​into a groove; a connecting member is provided in the groove, and the connecting member splices the two lower cover plates in the width direction through cast-in-place concrete.

[0015] Furthermore, the connecting member includes bent bars and a steel frame; wherein, the upper notch is an L-shaped groove, the bent bars are located in their respective L-shaped grooves, and the bent bars are formed by bending the bottom steel bars of the plate during prefabrication; the steel frame is located in the groove after splicing.

[0016] Furthermore, the upper notch is a trapezoidal notch, and the connecting member includes at least three groups of second overlapping steel bars, wherein the first group and the second group are respectively prefabricated in their respective lower cover plates, and their free ends extend into their respective trapezoidal notches; the third group is located in the groove after splicing, and its two ends are respectively staggered and overlapped with the free ends of the other two groups.

[0017] Furthermore, anchor plates are provided at both ends of the second overlapping steel bars.

[0018] Furthermore, overlapping grooves that cooperate with each other are opened at the bottoms of two adjacent lower cover plates in the width direction, and the two lower cover plates are overlapped through the overlapping grooves, and foam strips are provided at the overlapping positions.

[0019] Furthermore, the special-shaped column includes a steel pipe and a plurality of T-shaped steels arranged along the peripheral wall of the steel pipe;

[0020] The steel beam is connected to the flange of the T-shaped steel by means of a connecting plate, and a reinforcing member is provided at the connection node between the two;

[0021] The reinforcing member includes a sleeve and a stiffening rib arranged on the sleeve; wherein the sleeve is fixedly sleeved on the steel pipe, the side of the stiffening rib is connected to the web of the T-shaped steel, and the end thereof is connected to the wing plate of the T-shaped steel.

[0022] Furthermore, the special-shaped columns are connected in the vertical direction through vertical connection nodes, and the vertical connection nodes include ring ribs, connecting steel bars and connecting cover plates;

[0023] There are multiple connecting steel bars distributed in a ring, one end of which is located inside the steel pipe and the other end extends outside the steel pipe for connecting to another steel pipe;

[0024] The ring ribs are arranged on the inner wall of the steel pipe. After the pouring is completed, when the steel pipe concrete is subjected to tension, the ring ribs play an anchoring role for the connecting steel bars.

[0025] The connecting cover plate is used to connect T-shaped steel.

[0026] Furthermore, the ends of the connecting steel bars are provided with end plates, and the end plates include long end plates and short end plates, wherein the ends of the long end plates are in conflict with the inner wall of the steel pipe. 3. Beneficial effects

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The present invention provides a steel tube concrete special-shaped column frame system, wherein the lower cover plate is provided with a lower notch in the span direction, and the lower cover plate is overlapped on the lower flange of the H-shaped steel beam through the lower notch, which can effectively reduce the overall floor thickness; in addition, the web of the H-shaped steel is provided with reinforcement holes, and after the first lap steel bar passes through the corresponding reinforcement hole, its two ends are overlapped on the lower cover plates on both sides of the steel beam respectively; through the provision of the first lap steel bar, the normal use load of the floor plate can be effectively transmitted, thus avoiding the formation of a single-span plate and effectively reducing the mid-span deflection; and cracking at the connection of the lower cover plate of the composite floor can also be avoided.

[0029] (2) The present invention provides a steel tube concrete special-shaped column frame system, wherein the lower cover plate is provided with an upper notch in the width direction, and the upper notches of the two lower cover plates are spliced ​​into a groove; a connecting member is provided in the groove, and the connecting member splices the two lower cover plates in the width direction by cast-in-place concrete. The present invention adopts a connection method with a preset connecting member, which not only ensures the crack resistance and stress performance of the connection; in addition, compared with the traditional prefabricated composite floor slab connection construction requiring seams, dense beard bars at the seams, and difficult overlap construction, the connection method of the present invention is simpler and more convenient to construct.

[0030] (3) The present invention provides a steel tube concrete special-shaped column frame system, wherein the special-shaped column comprises a steel tube and a T-shaped steel, and the steel beam is connected to the wing plate of the T-shaped steel by a full bolt form through a connecting plate; thereby solving the problem that when traditional steel nodes are prefabricated or welded on site, the welding process is complicated, the internal stress is large, the node performance is affected, and the assembly efficiency is low; in addition, by setting the reinforcing member, the load transfer path is optimized, so that the force can be directly transferred from the stiffening rib to the sleeve, and then the load is transferred to the core steel tube concrete node part through the sleeve, which can effectively avoid the steel tube outside the concrete being directly subjected to the normal load, thereby greatly improving the stiffness and strength of the node domain and ensuring safety.

[0031] (4) The present invention provides a steel tube concrete special-shaped column frame system. For the connection of the inner core steel tube concrete, annular ribs and connecting steel bars are provided in the steel tube, and the system can be prefabricated in the factory. Compared with the traditional connection nodes, the on-site welding operation is completely avoided, and the assembly efficiency is improved. At the same time, after the pouring and curing are completed, when the steel tube concrete is subjected to tension, the annular ribs play an anchoring role for the connecting steel bars, thereby ensuring the connection strength at the connection node. For the connection between the T-shaped steels on the outside of the special-shaped columns, bolt holes are provided on the web and wing plates of the T-shaped steels, and then high-strength bolts and splicing cover plates are used to connect them in a full bolt connection mode. Similarly, no on-site welding is required, which can improve the assembly efficiency. In addition, the connection between the T-shaped steels not only ensures the strength of the butt joint, but also helps the core steel tube concrete to be positioned during construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG1 is a schematic diagram of the overall structure of a steel tube concrete special-shaped column frame system of the present invention;

[0033] FIG2 is a schematic diagram of the internal structure of the composite floor in the present invention;

[0034] FIG3 is a cross-sectional view of point 1-1 in FIG2;

[0035] FIG4 is a cross-sectional view of FIG2 at 2-2;

[0036] FIG5 is a cross-sectional view of FIG2 at 3-3;

[0037] FIG6 is a schematic diagram of the structure of the H-shaped steel beam in the composite floor of the present invention;

[0038] FIG7 is an embodiment of a connecting member in the present invention;

[0039] FIG8 is another embodiment of the connecting member of the present invention;

[0040] FIG9 is a diagram illustrating an assembly method of the foam strips of the present invention;

[0041] FIG10 is a partially enlarged schematic diagram of a steel tube concrete special-shaped column frame system of the present invention;

[0042] FIG11 is a schematic structural diagram of a reinforcement member in the present invention;

[0043] FIG12 is an enlarged schematic diagram of the positive angle of the beam-column node of the present invention;

[0044] FIG13 is an enlarged schematic diagram of the inner corner of the beam-column node of the present invention;

[0045] FIG14 is a schematic diagram of the ultimate stress state of the reinforcement member in the present invention;

[0046] FIG15 is a schematic diagram of the stress state of the core steel pipe at the beam-column node of the present invention;

[0047] FIG16 is a schematic diagram of the cross-section of a special-shaped concrete-filled steel tube column according to the present invention;

[0048] FIG17 is a schematic structural diagram of a vertical connection node between columns according to the present invention;

[0049] FIG18 is a cross-sectional view taken along line AA in FIG17 ;

[0050] FIG19 is a cross-sectional view taken along line BB in FIG17 ;

[0051] FIG20 is a schematic diagram of the connection of the T-shaped steel on the outside of the special-shaped concrete-filled steel tube column in the present invention;

[0052] FIG21 is a diagram showing the stress mechanism of the vertical connection node between columns of the present invention;

[0053] FIG22 is a comparison diagram of earthquake damage between the vertical connection nodes between the columns of the present invention and those without the ring rib;

[0054] FIG23 is a hysteresis curve of the vertical connection node between columns after being subjected to stress in the present invention;

[0055] FIG24 is a schematic diagram of the “pinching” of the hysteresis curve of the vertical connection node between columns after being subjected to force according to the present invention;

[0056] Figure 25 is a schematic diagram of the structure of the flange formed outside the steel pipe in the present invention.

[0057] Figure: 1. Special-shaped column; 11. Steel pipe; 12. T-steel; 13. Concrete; 2. Steel beam; 21. Connecting plate; 22. Steel beam flange; 23. Through-hole for reinforcement; 24. Stud; 3. Reinforcement member; 31. Casing; 32. Stiffener; 4. Vertical connection node; 41. Ring rib; 42. Connecting reinforcement; 43. End plate; 431. Long end plate; 432. Short end plate; 44. Frame reinforcement; 45. Connecting cover plate; 46. Fastener; 47. Positioning flange; 5. Floor; 51. Lower cover plate; 511. Lower notch; 512. Upper notch; 52. Upper cover plate; 53. Rebar truss; 54. First lap reinforcement; 55. Lightweight infill; 56. Connecting member; 561. Bending reinforcement; 562. Steel skeleton; 563. Second lap reinforcement; 564. Anchor plate; 57. Foam strip; 58. Top reinforcement of slab; 59. Bottom reinforcement of slab. DETAILED DESCRIPTION

[0058] The present invention provides a steel tube concrete-filled special-shaped column frame system, which primarily includes column components, vertical joints between columns, beam-column joints, beam-slab joints, and slab-slab joints, among other key connection points in building structures. The columns employed are T-steel and steel tube concrete-filled composite special-shaped columns, and the vertical joints between columns, beam-column joints, beam-slab joints, and slab-slab joints all utilize prefabricated connections to ensure efficient on-site construction.

[0059] The present invention will be further described below with reference to specific embodiments.

[0060] Example 1

[0061] As shown in Figures 1 and 4, a steel tube concrete special-shaped column frame system of this embodiment includes special-shaped columns (1), steel beams (2) and floor slabs (5). The floor slabs 5 are composite floor slabs including a prefabricated lower cover plate 51, a cast-in-place upper cover plate 52 and steel trusses 53; and the steel beams (2) are H-shaped steel beams.

[0062] The lower cover plate 51 is provided with bottom reinforcement bars 59, and the upper cover plate 52 is provided with top reinforcement bars 58 to increase the overall strength of the floor 5. The top reinforcement bars 58 and bottom reinforcement bars 59 both include transverse bars and longitudinal bars.

[0063] In this embodiment, as an implementation of a beam-slab joint, as shown in Figures 3, 4, and 6, the lower cover plate 51 is provided with a lower notch 511 in the span direction for overlapping the lower flange of the steel beam 2. The web of the steel beam 2 is provided with reinforcement holes 23 for passing first lap reinforcement bars 54. After passing through the corresponding reinforcement holes 23, the first lap reinforcement bars 54 are respectively overlapped on the lower cover plates 51 on both sides of the steel beam 2.

[0064] Specifically in this embodiment, the H-shaped steel beam is a welded steel beam, and the width of the lower flange is slightly wider than the upper flange, so as to facilitate the placement of the lower cover plate 51.

[0065] Furthermore, to reduce the weight of the entire floor slab 5 and save on foundation costs, in this embodiment, lightweight fillers 55 are installed between the steel trusses 53. This lightweight filler 55 needs to provide thermal insulation, sound insulation, and lightweight properties. Therefore, polystyrene boards, polyurethane foam, rock wool, and other materials can be used. Although polyurethane foam offers the best performance and longest lifespan, polystyrene boards are preferred based on both economic efficiency and bulk density.

[0066] This embodiment of a steel tube concrete-filled special-shaped column frame system effectively reduces the thickness of the overall floor slab 5 by placing the lower cover plate 51 of the composite floor slab on the lower flange of the steel beam 2. Furthermore, the floor slab 5 is connected to the steel beam 2 in the span direction using PBL shear keys, which have excellent connection performance, to ensure connection strength.

[0067] Example 2

[0068] This embodiment of a steel tube concrete special-shaped column frame system proposes an implementation method of a plate-plate node based on Example 1.

[0069] Specifically, as shown in FIG5 , the lower cover plate 51 is provided with an upper notch 512 in the width direction, and the upper notches 512 of the two lower cover plates 51 are spliced ​​together to form a groove. A connecting member 56 is provided in the groove, and the connecting member 56 splices the two lower cover plates 51 in the width direction by cast-in-place concrete.

[0070] The steel tube concrete special-shaped column frame system of this embodiment abandons the traditional splicing construction method of prefabricated concrete floor slabs and adopts a connection method of pre-set connection members 56 plus post-casting to ensure the crack resistance and stress performance of the connection; at the same time, the connection method is simple and easy to construct.

[0071] In this embodiment, a steel tube concrete special-shaped column frame system has the following specific methods for the beam-slab joints and the slab-slab joints:

[0072] First, the lower cover plate 51 is prefabricated in the factory. Prestressed steel bars can be installed in the lower cover plate 51, and the plate is pre-tensioned to reduce plate deflection during construction. To increase the rigidity of the base plate, the top steel bars in the steel trusses can be replaced with large-sized steel bars or steel pipes (which can be filled with high-grade mortar). This approach can effectively increase base plate rigidity and control deflection, especially when the span is large.

[0073] While prefabricating the lower cover plate 51, the H-shaped steel beam is also fabricated. A row of rebar holes 23 are provided on the underside of the H-shaped steel beam web to facilitate subsequent rebar insertion. Since the spacing of these holes 23 determines the number and spacing of the reinforcing bars inserted, they must be positioned according to the floor slab design requirements. Of course, to ensure interoperability between the H-shaped steel beam and the post-cast concrete overlay, studs 24 can be welded to the top of the beam. The size and spacing of these studs 24 must comply with the relevant provisions of the "Code for Design of Composite Structures" (JGJ138).

[0074] After the lower cover plate 51 and the H-shaped steel beam are manufactured, the H-shaped steel beam and the prefabricated lower cover plate 51 are installed. To connect the prefabricated lower cover plate 51 in the span direction, the plate must first be placed on the lower flange of the H-shaped steel beam. Then, according to the design requirements, the first lap steel bar 54 is inserted into the corresponding position of the H-shaped steel beam through-hole 23. This first lap steel bar 54 can effectively transfer the normal service load of the floor slab, avoid the formation of a single-span slab, and effectively reduce the mid-span deflection; it can also prevent the bottom plate of the composite floor slab from cracking at the support. To further enhance the strength of the lap joint, the size of the first lap steel bar 54 should be larger than the bottom steel bar 59 of the slab.

[0075] The lower cover plate 51 of the composite floor must be connected in the width direction by first setting an upper notch 512 at the joint, then splicing to form a groove, and placing the connecting member 56 in the groove. It is worth noting that the splicing and installation of the lower cover plate 51 requires the installation of formwork support at the bottom according to the design requirements of the construction phase to reduce stress on the plate and avoid localized damage. After the formwork support is set up, lightweight filler 55 is installed between the steel trusses 53, and then the top steel bars 58 are laid and the cast-in-place concrete composite layer (upper cover plate 52) is poured. The maintenance of the cast-in-place composite layer must meet the requirements of current regulations.

[0076] Example 3

[0077] This embodiment is an embodiment of the connecting member 56 and is used in conjunction with the L-shaped upper notch 512 .

[0078] Specifically, as shown in FIG7 , the connecting member 56 includes a bent rib 561 and a steel frame 562. The bent rib 561 is located within its respective upper notch 512. The bent rib 561 is generally inverted U-shaped, with both ends extending into the lower cover plate 51. The steel frame 562 is located within the groove after splicing and covers the entire area of ​​the bent rib 561.

[0079] The steel frame 562 includes longitudinal reinforcement and stirrups; and the bent reinforcement 561 is formed by bending the bottom reinforcement 59 during prefabrication to resist the torque at the connection.

[0080] In this embodiment of a steel tubular concrete-filled special-shaped column frame system, when the composite floor is used as a two-way slab, significant bending moments or torsional loads may occur at the joints. However, the arrangement of the stirrups and bending bars 561 in the steel skeleton effectively resists these loads and ensures rigidity. Therefore, the stirrups in the steel skeleton should not be smaller than the width of the composite floor slab bottom reinforcement 59, and the spacing between the stirrups should not be larger than the spacing between the composite floor slab bottom reinforcement 59.

[0081] Example 4

[0082] This embodiment is another embodiment of the connecting member 56 .

[0083] 8 , the connecting member 56 includes at least three groups of second lap steel bars 563 , and each group of second lap steel bars 563 is provided with a plurality of bars along the width direction of the floor slab.

[0084] The first and second groups are prefabricated in their respective lower cover plates 51, and their free ends extend into their respective upper notches 512. The third group is located in the groove after splicing, and its two ends are staggered and overlapped with the free ends of the other two groups.

[0085] Since the stress of the bottom plate steel bar 59 is mainly transmitted by the second lap steel bar 563, in order to reduce the lap length, meet the on-site installation size requirements and avoid the reduction of the bottom plate strength / rigidity caused by excessively large notches, an anchor plate 564 needs to be set at the end of the second lap steel bar 563.

[0086] According to preliminary tests, the overlapped anchor plates 564 can reduce the total overlap length by 85%. For common slab bottom rebar sizes of Φ8-Φ10, the overlap length is only about 50 mm. In this case, the length of the upper notch 512 can be set to 100 mm, which is only about 10% of the width of a conventional composite slab, with minimal impact on the slab itself.

[0087] Example 5

[0088] In addition, it is considered that in actual construction, the joints of the composite floor slab (that is, the joints in the width direction of the lower cover plate 51) are prone to leakage and the L-shaped notches are prone to stress concentration at the inner corners and damage.

[0089] To solve the above problem, in this embodiment, the upper notch 512 is trapezoidal in shape as a whole, and the trapezoidal upper notch 512 is used in conjunction with the connecting member 56 in embodiment 3. In addition, a foam strip 57 is provided at the joint.

[0090] Specifically, as shown in FIG9 , the bottoms of the two adjacent lower cover plates 51 are provided with overlapping grooves that fit together along the width direction. The two lower cover plates 51 are overlapped through the overlapping grooves, and a foam strip 57 is provided at the overlapping portion.

[0091] During on-site construction, foam strips 57 are placed at the joints, and the pressure between the laminated panels is used to compress the foam strips 57, thereby achieving a water-stopping effect. For panels with low post-cast concrete thickness and low local pressure on the foam strips 57 during construction, foam strips can also be placed directly on the trapezoidal notches (as shown in Figure 8).

[0092] Example 6

[0093] This embodiment is an implementation method of a beam-column joint.

[0094] Specifically, referring to Figure 16 , in this embodiment, the special-shaped column 1 is a TO steel tube concrete special-shaped column, hereinafter referred to as a TO special-shaped column. The TO special-shaped column comprises a steel tube 11 and a plurality of T-shaped steel sections 12 disposed outside the steel tube 11. The inner cavity of the steel tube 11 is used for pouring concrete 13. The T-shaped steel sections 12 are welded to the outer wall of the steel tube 11 via their webs, and this welding operation can be performed in a factory.

[0095] The specific distribution of the T-shaped steel 12 is varied, and this embodiment lists several conventional cross-sectional forms of TO special-shaped columns. Of course, other cross-sectional forms can also be used according to actual construction requirements.

[0096] As shown in (a) of Figure 16 , there are two T-shaped steels 12 symmetrically arranged, and the webs of the two T-shaped steels 12 form a straight line; as shown in (b) of Figure 16 , there are also two T-shaped steels 12, but the webs of the two T-shaped steels 12 are perpendicular to form an L-shape; as shown in (d) of Figure 16 , there are three T-shaped steels 12, and the webs of the three T-shaped steels 12 are arranged in a T-shape; as shown in (c) of Figure 16 , there are four T-shaped steels 12, and the webs of the four T-shaped steels 12 are arranged in a cross shape.

[0097] As shown in Figure 10, the ends of the steel beams 2 are provided with connecting plates 21 with mounting holes. Mounting holes are also provided on the opposite sides of the flanges of the T-shaped steel 12. High-strength bolts are used to assemble the steel beams 2 and the special-shaped columns 1. This solves the problem of traditional steel joint prefabrication or on-site welding, which involves complex welding processes, high internal stresses, poor joint performance, and low assembly efficiency.

[0098] Since the out-of-plane bending resistance of the flange of the T-shaped steel 12 and the wall of the steel pipe 11 is relatively poor, in this embodiment, a reinforcing member 3 is provided at the connection node between the steel beam 2 and the special-shaped column 1 to enhance the rigidity and strength of the node area.

[0099] 11, 12 and 13, the reinforcement member 3 includes a sleeve 31 and a stiffening rib 32 provided on the sleeve 31. The sleeve 31 is fixedly sleeved on the steel pipe 11, and the end of the stiffening rib 32 is connected to the inner side of the flange of the T-shaped steel 12.

[0100] Of course, the specific distribution of the stiffening ribs 32 is consistent with the cross-sectional form of the corresponding special-shaped column 1. In other words, the commonly used cross-sectional forms of the stiffening ribs 32 are also straight, L-shaped, T-shaped and cross-shaped.

[0101] In this embodiment, an L-shaped reinforcement member 3 is used in conjunction with an L-shaped special-shaped column 1. The stiffening ribs 32 are arranged in pairs, located on either side of the same web of the T-shaped steel 12. Each end of the steel beam 2 is equipped with two pairs of stiffening ribs 32, each pair of stiffening ribs 32 being positioned at the same height as the corresponding steel beam flange 22.

[0102] In this embodiment, a steel tube concrete-filled special-shaped column frame system optimizes the load transfer path and enhances the stiffness and strength of the joint region by providing stiffening ribs 32 on the inside of the special-shaped column 1 at the same height as the steel beam flange 22. However, given the vulnerability of the steel tube 11 to tearing at the intersection of stiffening ribs 32 and the steel tube, reinforcement is required.

[0103] Specifically, for circular concrete-filled steel tubes, a sleeve 31 is installed at the intersection of the stiffening rib 32 and the steel tube 11, and is wrapped around the steel tube 11. This allows force to be directly transferred from the stiffening rib 32 to the sleeve 31, which then transfers the load to the core concrete-filled steel tube node. This approach prevents the steel tube 11 from being directly subjected to normal loads, improving its safety.

[0104] Of course, for rectangular or square steel tube concrete-filled structures, the ends of the stiffening ribs 32 can be flush with the rectangular steel tube, and a load-transmitting connecting steel plate can be provided on the side. This steel plate can directly transfer the load of the steel beam flange 22 to the side of the rectangular steel tube, rather than allowing the tube side intersecting with the stiffening ribs 32 to bear the normal load.

[0105] This embodiment presents a steel tube concrete-filled frame system with a special-shaped column. The proposed TO special-shaped column cross-section utilizes a core steel tube concrete structure that primarily bears pressure, while T-shaped steel is used to expand the column's cross-sectional dimensions. This allows for a smaller cross-sectional width for each component (i.e., the core steel tube concrete structure and the outer T-shaped steel structure) while maintaining sufficient bending resistance. This smaller cross-sectional width allows the column components to be embedded within the wall, increasing usable interior space and enhancing flexibility in apartment layout and furniture placement.

[0106] From the perspective of the force mechanism, the cross-section of the proposed column component is reasonable, and the division of labor between the bending / compression parts is clear. It greatly utilizes the advantages of easy expansion of steel sections and high bearing capacity and stiffness of steel tube concrete sections, making it use less steel and have lower cost than traditional composite structural components.

[0107] The proposed beam-column joint, based on the TO-shaped column, eliminates on-site welding and instead utilizes a fully bolted connection, achieving a rigid beam-column connection. Furthermore, through the provision of reinforcement member 3, the sleeve 31 drives the overall load of the concrete-filled steel tube, effectively transferring the bending moment of the steel beam. Furthermore, the connection method of installing a reinforcement ring on the outside of the concrete-filled steel tube is avoided, reducing the cross-sectional width of each component at the beam-column joint and increasing the usable space within the building.

[0108] Example 7

[0109] On the basis of the above embodiment, in order to avoid the reduction of mechanical properties of the beam-column node domain caused by excessive residual stress of factory welding. In this embodiment, the stiffening rib 32 and the sleeve 31 are directly made into steel castings. The use of integral steel castings has the following two main advantages: 1) Each part of the casting forms a whole, which can significantly reduce the impact of welding of small parts on its internal stress; 2) When the casting and the prefabricated TO special-shaped column are welded in the factory, the number and length of the welds are small, which significantly improves the node domain performance. At the same time, the welding deformation of the casting and the TO special-shaped column caused by welding stress is small, and the deformation correction and on-site installation are less difficult.

[0110] In addition, the height of the sleeve 31 at the node should be higher than the top surface of the steel beam flange to avoid welding in the node area. At the same time, the sleeve 31 should be set throughout the length to ensure effective transmission of the bending moment at the beam end.

[0111] Specifically in this embodiment, the sleeve 31 has the same wall thickness as the steel tube 11, and the stiffener 32 has the same thickness as the steel beam flange 22. The steel strength grade is Q345. Furthermore, the end of the sleeve 31 extends beyond the end of the steel beam flange 22 by 0.35D, where D is the outer diameter of the steel tube 11. According to finite element analysis results, when the end of the sleeve 31 extends beyond the end of the steel beam flange 22 by more than 0.35D, the column will yield before the node under the action of bending moment, thus meeting the node's seismic resistance requirements.

[0112] Finite element analysis of this beam-column joint is shown in Figures 14 and 15. Strengthening the joint using this method reduces stress levels in the joint region. When the wall thickness of the casing 31 is comparable to that of the steel pipe 11, the pipe will not tear. In contrast, the Mises stress in the steel pipes above and below the joint region is higher. This can be mitigated by locally increasing the wall thickness during prefabrication or using an inner ring plate.

[0113] According to the finite element calculation results, the stiffening ribs 32 and the sleeve 31 are key load-bearing components in the design. To ensure their safety during service, the thickness of the stiffening ribs 32 is not greater than the thickness of the sleeve 31, that is, t 加劲肋 ≦t 套管， This ensures that the sleeve 31 is not prone to local tearing under the action of tension along the longitudinal direction of the stiffening rib 32.

[0114] Among them, the determination of the wall thickness of the casing 31 should take into account the influence of four key factors: the outer wall thickness of the core steel tube concrete, the thickness of the stiffening ribs, the height of the node domain, and the strength of the core concrete, that is, t 套管 =α1α2α3t 钢管 , where α1, α2 and α3 represent the influence coefficients of stiffener thickness, node height and core concrete strength respectively. Stiffener thickness is an important parameter affecting the failure mode and failure load of steel tube in the node domain. The ratio of stiffener thickness to the outer wall thickness of core steel tube concrete is t 加劲肋 / t 钢管 It is the basic independent variable of the calculation formula of the influence coefficient, and it can be considered that α1=A*(t 加劲肋 / t 钢管 ), the coefficient A should be determined based on the regression analysis of test data. When there is a lack of test data, it can be taken as 1. Similarly, the calculation method of α2 and α3 is determined based on the common node domain height and concrete strength, that is, α2=B*(h 节点域 / 300), α3=C*(fc / 30), coefficients B and C should be determined based on regression analysis of test data, and can be taken as 1 when there is a lack of test data. 节点域 and fc are the joint height and the 28-day axial compressive strength of the core concrete, respectively. The denominators 300 and 30 represent the commonly used joint height and concrete strength for dimensionless purposes. It should be noted that in actual projects, main beam heights are typically greater than 300mm (i.e., the joint height is greater than 300mm). This value varies with span, generally ranging from 300 to 1000mm. To ensure the safe application of this joint and the structural system it encompasses, a value of 300mm is considered safe.

[0115] Example 8

[0116] The present embodiment of a steel tube concrete-filled special-shaped column frame system, based on the above embodiment, further provides a vertical connection node 4 between the TO special-shaped columns. The vertical connection node 4 mainly includes the connection of the inner core steel tube concrete (steel tube 11) and the connection of the outer T-shaped steel 12. Of course, the vertical connection node 4 needs to be staggered with the beam-column node.

[0117] The TO special-shaped columns are connected by internal hot-rolled ribbed steel bars and poured concrete. The T-shaped steel 12 on the outside of the special-shaped columns can be connected by drilling holes in the T-shaped steel 12 and using high-strength bolts and spliced ​​cover plates to form a fully bolted connection.

[0118] Specifically, as shown in Figures 17-19 , the steel tube 11 is provided with annular ribs 41 and connecting bars 42. The annular ribs 41 are located on the inner wall of the steel tube 11, near the end of the tube. Multiple connecting bars 42 are arranged in a circular pattern, with one end located within the steel tube 11 and the other end extending outside the tube 11 for connection to another steel tube 11. After concrete 13 is poured, the annular ribs 41 anchor the connecting bars 42 when the concrete in the steel tube is subjected to tension.

[0119] The annular rib 41 is preferably a steel tube rib, and can be in various cross-sectional forms, such as T-shaped steel, channel steel, solid circular / rectangular steel bar, etc.

[0120] In this embodiment of a steel tube concrete-filled special-shaped column frame system, the inner core steel tube concrete portion is connected by internal connecting steel bars 42 and poured concrete. The key to achieving a strong connection such as tensile strength lies in whether the steel tube 11 has a sufficient anchoring effect on the internal connecting steel bars 42.

[0121] According to the previous refined finite element analysis, the anchoring force is transmitted by setting a ring rib 41 at the inner end of the steel pipe 11, so that the shear force between the two can be effectively transmitted, thereby enhancing the anchoring force of the connecting steel bar 42. The specific force mechanism can be seen in Figure 21.

[0122] To further enhance the anchoring effect, the steel pipe 11 is preferably made of a material with a surface friction coefficient of not less than 0.5, such as a threaded steel pipe. For cold-bent or hot-bent straight-seam welded steel pipes, sandblasting (shot blasting) can also be performed on the sheet before the bending process to increase the friction coefficient and achieve optimal anchoring.

[0123] In order to reduce the impact of the welding accuracy of the ring rib 41 in the factory on the on-site construction, a certain amount of welding space needs to be reserved. It is recommended to arrange the ring rib 41 about 30 mm away from the end of the steel pipe 11.

[0124] At the same time, in order to minimize the volume and damage of the concrete above the ring rib (which is prone to tensile damage under earthquake loads, while the concrete below the ring rib is mainly under pressure, which can effectively exert the performance of concrete materials), according to the previous theoretical and experimental research of the inventors, the distance between the position of the ring rib 41 and the end of the steel pipe 11 should be less than 0.3l R Among them, l R The anchoring length is the steel bar anchoring length, which refers to the depth of the connecting steel bar 42 located in the single steel pipe 11.

[0125] Furthermore, the spacing between the connecting reinforcement 42 and the ring rib 41 should not be greater than the difference between the reinforcement anchorage length and the depth of the ring rib 41. This is because the anchoring force is primarily transmitted through the shear force between concrete units and the pressure between the upper and lower units. The combined force of these two forces is directed at a maximum of 45 degrees. In this case, the spacing between the connecting reinforcement 42 and the ring rib 41 is exactly equal to the difference between the reinforcement anchorage length and the depth of the ring rib 41. If the spacing between the connecting reinforcement 42 and the ring rib 41 exceeds this value, the anchoring force cannot be effectively transmitted, and localized shear failure of the concrete within the joint will occur.

[0126] As shown in Figure 20 , the web and flanges of the T-shaped steel 12 are provided with assembly holes. After the upper and lower layers of T-shaped steel 12 are aligned, they are connected using a connecting cover plate 45 and fasteners 46. After the upper and lower layers of T-shaped steel 12 are aligned and fastened, the upper and lower cross-sections of the core steel tube concrete-filled structure are also aligned. The fasteners 46 are preferably high-strength bolts.

[0127] In the present embodiment, a steel tube concrete-filled special-shaped column frame system is provided with ring ribs 41 and connecting steel bars 42 in the steel tube for the connection of the inner core steel tube concrete, and these ring ribs 41 and connecting steel bars 42 can be prefabricated in a factory. Compared with traditional connection nodes, on-site welding operations are completely avoided, thereby improving assembly efficiency. At the same time, after pouring and curing are completed, when the steel tube concrete is subjected to tension, the ring ribs 41 anchor the connecting steel bars 42, thereby ensuring the connection strength at the connection node.

[0128] The outer T-shaped steel bars 12 are connected by full bolts, which also eliminates the need for on-site welding and improves assembly efficiency. In addition, the connection between the T-shaped steel bars 12 not only ensures the strength of the butt joint, but also helps to position the core steel tube concrete during construction.

[0129] The inventors conducted a detailed finite element modeling analysis of the vertical connection node of this embodiment to assess its mechanism and impact on this type of connection node. The model, with a total of approximately 150,000 solid elements, accurately reflects the mechanical properties of the node. The analysis results are shown in Figures 22-24.

[0130] As can be seen from Figure 22, after the steel tube rib reinforcement connection is set at the end of the steel tube 11, the concrete damage is significantly reduced; at the same time, the hysteresis curve is relatively full (Figure 23), indicating that this type of node has a strong seismic energy absorption capacity.

[0131] Furthermore, according to model analysis, when the diameter of connecting rebar 42 exceeds 22 mm, a significant "pinching" phenomenon (Figure 24) appears in the hysteresis curve, significantly reducing the energy dissipation capacity of the joint. Therefore, it is recommended that the rebar diameter not exceed 22 mm. This "pinching" phenomenon occurs because, assuming the reinforcement ratio remains constant, excessively large rebar size results in a reduced number of rebars. This leads to significant rebar-concrete bond slip around individual rebars, significantly increasing bond stress and making the concrete around the rebar more susceptible to damage. This reduces the overall energy dissipation capacity of the joint, resulting in a "pinching" phenomenon in the hysteresis curve.

[0132] Example 9

[0133] In order to facilitate the positioning of the connecting steel bar 42 and ensure that the connecting steel bar 42 has sufficient stability during concrete pouring, this embodiment further improves the specific structure of the vertical connecting node 4 based on the embodiment 3.

[0134] As shown in FIG. 17 , the end of the connecting steel bar 42 is provided with an end plate 43 . During assembly, the end of the end plate 43 is pressed against the inner wall of the steel pipe 11 to achieve positioning of the connecting steel bar 42 and ensure its verticality.

[0135] Annular stand bars 44 are further provided inside the connecting steel bars 42, and multiple groups of the stand bars 44 are provided along the length of the connecting steel bars 42. That is, by providing the stand bars 44, multiple connecting steel bars 42 are combined into a whole, which can be prefabricated in a factory, thereby further saving on-site construction time.

[0136] Because multiple connecting steel bars 42 are connected into a complete ring by the supporting bars 44, it is not necessary to position each connecting steel bar 42 individually; instead, it is sufficient to position the entire connecting steel bar ring as a whole. In other words, as long as the ends of some end plates 43 can abut the inner wall of the steel pipe 11, the verticality of the entire connecting steel bar 42 can be guaranteed.

[0137] Specifically in this embodiment, as shown in FIG19 , the end plates 43 include long end plates 431 and short end plates 432, which are arranged alternately. The arrangement of the long end plates 431 and short end plates 432 not only improves the anchoring force of the connecting steel bars 42 but also allows for positioning of the connecting steel bars 42 to ensure their verticality.

[0138] In addition, in order to prevent the connection steel bars 42 from moving downward due to the impact of concrete during the pouring process, in this embodiment, support bars (not shown) are provided on the outside of the connection steel bars 42, and the connection steel bars 42 are hung on the ring ribs 41 through the support bars, so that the connection steel bars 42 can be effectively supported.

[0139] A steel tube concrete special-shaped column frame system, which uses end plates 43, frame steel bars 44 and support bars to limit the connecting steel bars 42, not only ensuring the verticality of the connecting steel bars 42, but also increasing the stability of the connecting steel bars 42, and effectively preventing the displacement of the connecting steel bars due to concrete scouring during concrete pouring, thereby affecting the final connection effect.

[0140] Example 10

[0141] Referring to FIG. 25 , in order to further facilitate the positioning of the core steel tube concrete, a positioning flange 47 is provided on the outer side of the end of the steel tube 11 , and the positioning flanges 47 can also be connected with high-strength bolts.

[0142] Compared to traditional direct flange connections, the flanges in this embodiment require less space and only serve to locate and bear construction loads during construction. After the concrete is poured and cured to reach the design strength, the tension and bending moments are primarily borne by the combined effect of the internal rebar and external steel pipe. This reduces the mechanical performance requirements of the flange joint, reduces the space occupied by the joint, reduces steel consumption, and reduces the cost of the connection.

[0143] In addition, in order to further reduce the space occupied by the node, the flange can also be removed after the maintenance is completed. Of course, the setting of the positioning flange 47 in this embodiment, and whether to carry out the removal operation in the later stage, can be selected according to actual construction requirements.

[0144] In summary, the present invention provides a steel tube concrete special-shaped column frame system, and the proposed TO composite column section form can achieve the relative separation of column compression and bending on the composite section. The circular steel tube concrete part in the composite section has a large axial stiffness and bears most of the pressure according to the stiffness distribution principle (it can give full play to the advantage of the high axial compression bearing capacity of circular steel tube concrete, and is convenient for using high-strength steel tubes and high-strength concrete materials); the peripheral T-shaped steel (for easy connection) greatly increases the height of the composite section, bending moment = force * lever arm, and the lever arm is greatly increased. The bending bearing capacity and bending stiffness of the composite section are greatly increased accordingly, so it is expected to have better bending bearing capacity and stiffness. At the same time, on this basis, vertical connection nodes between columns, beam-column nodes, beam-slab nodes, and plate-slab connection node forms that are compatible with the above-mentioned structural system are proposed, which ensure a high assembly rate of the node system while giving it better mechanical properties and integrity. Finally, a new frame system with superior seismic performance, small steel consumption, good integrity, high assembly rate, large usable space, and flexible structural layout is obtained, which promotes high-quality development of the construction industry.

[0145] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs a structure and embodiment similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A steel tube concrete special-shaped column frame system, comprising a special-shaped column (1), a steel beam (2) and a floor slab (5), wherein: The steel beam (2) is an H-shaped steel beam, and the floor (5) is a composite floor, which includes a prefabricated lower cover plate (51), a cast-in-place upper cover plate (52) and a steel truss (53), characterized in that: the lower cover plate (51) is provided with a lower notch (511) in the span direction for overlapping the lower flange of the steel beam (2), and the web of the steel beam (2) is provided with a reinforcement hole (23) for the first overlapping reinforcement (54) to pass through, and after the first overlapping reinforcement (54) passes through the corresponding reinforcement hole (23), its two ends are respectively overlapped on the lower cover plate (51) on both sides of the steel beam (2).

2. The steel tube concrete special-shaped column frame system according to claim 1, characterized in that: The lower flange width of the steel beam (2) is wider than the upper flange width, the upper flange is provided with bolts (24), and a lightweight filling body (55) is provided between the steel bar trusses (53).

3. A steel tube concrete special-shaped column frame system according to claim 1 or 2, characterized in that: The lower cover plate (51) is provided with an upper notch (512) in the width direction, and the upper notches (512) of the two lower cover plates (51) are spliced ​​into a groove; a connecting member (56) is provided in the groove, and the connecting member (56) splices the two lower cover plates (51) in the width direction by cast-in-place concrete.

4. The steel tube concrete special-shaped column frame system according to claim 3, characterized in that: The connecting member (56) comprises a bending rib (561) and a steel frame (562); wherein the upper notch (512) is an L-shaped groove, the bending rib (561) is located in the respective L-shaped groove, and the bending rib (561) is formed by bending the bottom steel bar (59) during prefabrication; the steel frame (562) is located in the groove after splicing.

5. The steel tube concrete special-shaped column frame system according to claim 3, characterized in that: The upper notch (512) is a trapezoidal notch, and the connecting member (56) includes at least three groups of second overlapping steel bars (563), wherein the first group and the second group are respectively prefabricated in their respective lower cover plates (51), and their free ends extend into their respective trapezoidal notches; the third group is located in the groove after splicing, and its two ends are respectively overlapped with the free ends of the other two groups in an offset manner.

6. The steel tube concrete special-shaped column frame system according to claim 5, characterized in that: Both ends of the second overlapping steel bars (563) are provided with anchor plates (564).

7. The steel tube concrete special-shaped column frame system according to claim 6, characterized in that: Mutually matching overlapping grooves are provided at the bottoms of two adjacent lower cover plates (51) in the width direction. The two lower cover plates (51) are overlapped via the overlapping grooves, and a foam pressure strip (57) is provided at the overlapping position.

8. The steel tube concrete special-shaped column frame system according to claim 3, characterized in that: The special-shaped column (1) comprises a steel pipe (11) and a plurality of T-shaped steels (12) arranged along the peripheral wall of the steel pipe (11); The steel beam (2) is connected to the flange bolts of the T-shaped steel (12) via a connecting plate (21), and a reinforcing member (3) is provided at the connection node between the two; The reinforcing member (3) comprises a sleeve (31) and a stiffening rib (32) arranged on the sleeve (31); wherein the sleeve (31) is fixedly sleeved on the steel pipe (11), the side surface of the stiffening rib (32) is connected to the web of the T-shaped steel (12), and the end portion thereof is connected to the wing plate of the T-shaped steel (12).

9. The steel tube concrete special-shaped column frame system according to claim 3, characterized in that: The special-shaped columns (1) are connected in the vertical direction via a vertical connection node (4), and the vertical connection node (4) comprises a ring rib (41), a connection steel bar (42) and a connection cover plate (45); There are a plurality of connecting steel bars (42) distributed in a ring shape, one end of which is located inside the steel pipe (11) and the other end of which extends outside the steel pipe (11) for connecting to another steel pipe (11); The annular rib (41) is arranged on the inner wall of the steel tube (11). After the pouring is completed, when the steel tube concrete is subjected to tensile force, the annular rib (41) plays an anchoring role for the connecting steel bars (42); The connecting cover plate (45) is used to connect the T-shaped steel (12).

10. The steel tube concrete special-shaped column frame system according to claim 9, characterized in that: An end plate (43) is provided at the end of the connecting steel bar (42), and the end plate (43) includes a long end plate (431) and a short end plate (432), wherein the end of the long end plate (431) is in contact with the inner wall of the steel pipe (11).

Images