A steel tube concrete special-shaped column frame system

Abstract

The application discloses a kind of steel pipe concrete special-shaped column frame system, belong to prefabricated building technical field.The application includes special-shaped column, steel beam and floor cover.Among them, the special-shaped column is T-O type special-shaped column, it includes steel pipe and the T type steel being set to the outside of the steel pipe;The lower cover plate of the floor cover is set on the lower flange of H type steel beam, and the web of the H type steel beam is provided with lap steel bars;At the same time, recess is formed in the connecting direction of the width of lower cover plate, by placing connecting component in recess, then cast-in-situ concrete will two lower cover plates be spliced in width direction.This structure mode, not only can reduce the thickness of overall floor cover, also can guarantee the connecting strength of lower cover plate in span direction and width direction.In addition, based on the foundation of T-O type special-shaped column, column interlayer vertical connection node, beam-column joint form is also provided, while guaranteeing the high assembly rate of node system, make it have better mechanical properties and integrity.

Description

Technical Field

[0001] This invention belongs to the field of prefabricated building technology, and more specifically, relates to a steel-concrete composite irregular column frame system. This application claims priority; the earlier application application number is 2023113971370, entitled "A Steel-Concrete Composite Irregular Column Frame System," with a priority date of October 25, 2023. Background Technology

[0002] Prefabricated construction is a direction for the transformation and upgrading of the construction industry and a promising emerging industry that the country is vigorously promoting. Currently, steel structure prefabricated buildings account for about 30% of all prefabricated buildings, most of which are public buildings, while residential products are almost negligible. With the goal of achieving 30% of new buildings being prefabricated by 2025, the development prospects of steel structure prefabricated housing are enormous. In steel structure building systems, floor slabs, as one of the components with the largest amount of concrete, can significantly reduce energy consumption and overall structural weight through lightweight and prefabricated design, thereby lowering costs.

[0003] Currently, precast concrete slabs or reinforced concrete composite slabs combining precast and cast-in-place concrete are commonly used, which can save on molds and improve construction efficiency. In particular, reinforced concrete composite slabs have good integrity, high rigidity, and smooth upper and lower surfaces, which facilitates the finishing layer. They are suitable for high-rise buildings and large-span buildings with high requirements for overall rigidity.

[0004] Traditional steel-concrete composite floor slabs use studs welded to steel beams to ensure the interoperability between the steel and concrete layers. When high seismic resistance requirements are needed, this results in a denser arrangement of studs, leading to a large workload and increased material costs. In addition, traditional prefabricated beam-slab composite floor slabs are relatively thick, typically consisting of the beam section height plus the thickness of the composite slab, which limits the floor height.

[0005] A search revealed Chinese Patent Application No. CN 211396201 U, which discloses a connection structure between an embedded steel beam and a precast composite floor slab. This application includes a steel beam and a composite floor slab; the steel beam has an I-shaped cross-section; the composite floor slab includes a precast slab and a cast-in-place composite layer; a steel truss is embedded in the precast slab; the lower chord reinforcement of the steel truss is embedded in the precast slab; the upper chord reinforcement of the steel truss is located above the precast slab, with both ends extending beyond the sides of the precast slab; connectors are provided on the left and right sides of the precast slab; the connectors include a horizontal plate and a vertical plate; the vertical plate is tightly attached to the corresponding side of the precast slab and welded to the lower chord reinforcement within the precast slab; the connectors on both sides of the precast slab are respectively mounted on the upper flanges of the steel beams on both sides and fixed with bolts. In this application, the connection is achieved by the connecting plates overlapping the steel beams, providing shear resistance without the need for welding studs, simplifying the connection structure and reducing workload. However, in this application, the precast slab base plate overlaps the upper flange of the steel beam via connectors, resulting in a relatively thick overall thickness. This significantly increases the floor height and affects the utilization rate of indoor space. Furthermore, in this application, the precast slab base plates are only connected by connectors, and the connection strength needs further improvement. Summary of the Invention

[0006] 1. The problem to be solved

[0007] To address at least some of the problems existing in the prior art, this invention proposes a steel-concrete composite irregular column frame system, which aims to solve the problems of the large overall thickness of existing composite floor slabs affecting the usable floor height, and the poor connection strength of precast base slabs in the span direction.

[0008] 2. Technical Solution

[0009] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0010] The present invention provides a steel-concrete composite irregular column frame system, comprising irregular 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 precast lower cover plate, a cast-in-place upper cover plate and a steel truss.

[0011] The lower cover plate has a slot in the span direction for overlapping the lower flange of the steel beam. The web of the steel beam has a through hole for the first lapped reinforcing bar to pass through. After the first lapped reinforcing bar passes through the corresponding through hole, its two ends overlap the lower cover plate on both sides of the steel beam.

[0012] Furthermore, the lower flange of the steel beam is wider than the upper flange, the upper flange is provided with studs, and lightweight fillers are provided between the steel trusses.

[0013] Furthermore, the lower cover plate has an upper groove in the width direction, and the upper grooves of the two lower cover plates are spliced ​​together to form 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.

[0014] Furthermore, the connecting component includes a bent bar and a steel reinforcement cage; wherein, the upper groove is an L-shaped groove, the bent bar is located in its respective L-shaped groove, and the bent bar is formed by bending the bottom steel reinforcement during prefabrication; the steel reinforcement cage is located in the groove after splicing.

[0015] Furthermore, the upper groove is a trapezoidal groove, and the connecting component includes at least three sets of second lapped reinforcing bars, wherein the first and second sets are prefabricated in their respective lower cover plates, and their free ends extend into their respective trapezoidal grooves; the third set is located in the groove after splicing, and its two ends are staggered and lapped with the free ends of the other two sets respectively.

[0016] Furthermore, anchor plates are provided at both ends of the second lapped reinforcing bar.

[0017] Furthermore, the bottom of two adjacent lower cover plates along the width direction is provided with interlocking grooves, the two lower cover plates overlap through the overlapping grooves, and a foam strip is provided at the overlap.

[0018] Furthermore, the irregularly shaped column includes a steel pipe and several T-shaped steel sections arranged along the periphery of the steel pipe;

[0019] The steel beam is bolted to the flange of the T-shaped steel via a connecting plate, and a reinforcing member is provided at the connection node between the two.

[0020] The reinforcing member includes a sleeve and stiffening ribs disposed 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 its end is connected to the flange of the T-shaped steel.

[0021] Furthermore, the irregularly shaped columns are connected in the vertical direction by vertical connection nodes, which include ring ribs, connecting steel bars, and connecting cover plates.

[0022] The connecting steel bars are distributed in a ring, with one end inside the steel pipe and the other end extending out of the steel pipe for connecting to another steel pipe.

[0023] The aforementioned ring ribs are set on the inner wall of the steel pipe. After the steel pipe concrete is poured, when it is subjected to tensile force, the ring ribs play an anchoring role for the connecting steel bars.

[0024] The connecting cover plate is used to connect T-shaped steel.

[0025] Furthermore, the end of the connecting steel bar is provided with an end plate, which includes a long end plate and a short end plate, wherein the end of the long end plate abuts against the inner wall of the steel pipe.

[0026] 3. Beneficial effects

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) A steel-concrete composite irregular column frame system of the present invention, wherein the lower cover plate is provided with a lower groove in the span direction, and the lower cover plate is lapped on the lower flange of the H-shaped steel beam through the lower groove, which can effectively reduce the overall floor thickness; in addition, the web of the H-shaped steel is provided with through holes, and the first lapped steel bar passes through the corresponding through hole, and its two ends are respectively lapped on the lower cover plate on both sides of the steel beam; through the setting of the first lapped steel bar, the normal service load of the floor slab can be effectively transferred, avoiding the formation of a single span slab and effectively reducing the mid-span deflection; it can also avoid cracking at the connection of the overlapping floor cover plates.

[0029] (2) A steel-concrete composite irregular column frame system of the present invention, wherein the lower cover plate is provided with an upper groove in the width direction, and the upper grooves of two lower cover plates are spliced ​​together to form 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 pre-set 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, which requires grouting joints and has dense reinforcement at the grouting joints, making the overlapping construction difficult, the connection method of the present invention is simpler and more convenient to construct.

[0030] (3) The present invention provides a steel-concrete composite irregular column frame system, wherein the irregular column includes steel pipes and T-shaped steel, and the steel beams are connected to the flanges of the T-shaped steel by means of connecting plates using bolts; thereby solving the problems of complex welding process, large internal stress, affecting the performance of nodes and low assembly efficiency when traditional steel nodes are prefabricated or welded on site; in addition, by setting up reinforcing components, the load transfer path is optimized, so that the force can be directly transferred from the stiffening ribs to the sleeve, and then the load is transferred to the core steel-concrete composite node part through the sleeve, which can effectively avoid the steel pipe on the outside of the concrete being directly subjected to normal load, thereby greatly improving the stiffness and strength of the node area and ensuring safety.

[0031] (4) The steel-concrete composite irregular column frame system of the present invention, for the connection of the inner core steel-concrete composite, uses ring ribs and connecting steel bars inside the steel pipe, which can be prefabricated in the factory; compared with traditional connection nodes, it completely avoids on-site welding operations and improves assembly efficiency; at the same time, after pouring and curing, when the steel-concrete composite is subjected to tensile force, the ring ribs anchor 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 irregular column, bolt holes are opened on both the web and flange of the T-shaped steel, and then high-strength bolts and splicing cover plates are used to connect them in a fully bolted connection manner; similarly, no on-site welding is required, which can improve assembly efficiency. In addition, the connection between the T-shaped steels not only ensures equal strength in the butt joint, but also helps the core steel-concrete composite to be positioned during construction. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of a steel-concrete composite irregular column frame system according to the present invention;

[0033] Figure 2 This is a schematic diagram of the internal structure of the composite floor slab in this invention;

[0034] Figure 3 for Figure 2 Sectional view at point 1-1;

[0035] Figure 4 for Figure 2 Sectional view at point 2-2;

[0036] Figure 5 for Figure 2 Sectional view at point 3-3;

[0037] Figure 6 This is a schematic diagram of the H-shaped steel beam inside the composite floor slab in this invention;

[0038] Figure 7 This is one embodiment of the connecting component in the present invention;

[0039] Figure 8 This is another embodiment of the connecting member in the present invention;

[0040] Figure 9 This is one assembly method for the foam pressure strip in this invention;

[0041] Figure 10 This is a partially enlarged schematic diagram of a steel-concrete composite irregular column frame system according to the present invention;

[0042] Figure 11 This is a schematic diagram of the reinforcing component in this invention;

[0043] Figure 12 This is an enlarged schematic diagram of the external corner of the beam-column joint in this invention;

[0044] Figure 13 This is an enlarged schematic diagram of the inside corner of the beam-column joint in this invention;

[0045] Figure 14 This is a schematic diagram of the ultimate stress state at the reinforcing member in this invention;

[0046] Figure 15 This is a schematic diagram of the stress state of the core steel pipe at the beam-column joint in this invention;

[0047] Figure 16 This is a schematic diagram of the cross-sectional shape of the steel-concrete composite irregular column in this invention;

[0048] Figure 17 This is a schematic diagram of the vertical connection node between columns in this invention;

[0049] Figure 18 for Figure 17 Sectional view along the middle AA direction;

[0050] Figure 19 for Figure 17 Sectional view along the BB direction;

[0051] Figure 20 This is a schematic diagram of the connection of the T-shaped steel on the outer side of the steel-concrete composite irregular column in this invention;

[0052] Figure 21 This is a diagram illustrating the force mechanism of the vertical connection node between columns in this invention.

[0053] Figure 22 This is a comparison diagram of seismic damage at the vertical connection node between columns in this invention and when there are no ring ribs.

[0054] Figure 23 This is the hysteresis curve of the vertical connection node between columns in this invention after being subjected to force;

[0055] Figure 24 This 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 This is a schematic diagram of the external flange of the steel pipe in this invention.

[0057] In the diagram: 1. Irregularly shaped column; 11. Steel pipe; 12. T-shaped steel; 13. Concrete;

[0058] 2. Steel beam; 21. Connecting plate; 22. Steel beam flange; 23. Through-reinforcement hole; 24. Stud;

[0059] 3. Reinforcing components; 31. Sleeves; 32. Stiffening ribs;

[0060] 4. Vertical connection node; 41. Ring rib; 42. Connecting reinforcement; 43. End plate; 431. Long end plate; 432. Short end plate; 44. Stirring reinforcement; 45. Connecting cover plate; 46. Fastener; 47. Positioning flange;

[0061] 5. Floor slab; 51. Lower cover plate; 511. Lower groove; 512. Upper groove;

[0062] 52. Top cover plate; 53. Steel truss; 54. First lapped reinforcement; 55. Lightweight infill material;

[0063] 56. Connecting components; 561. Bent bars; 562. Reinforcing steel cage; 563. Second lapped reinforcing bars; 564. Anchor plates; 57. Foam strips; 58. Top reinforcing bars of slab; 59. Bottom reinforcing bars of slab. Detailed Implementation

[0064] This invention discloses a steel-concrete composite irregular column frame system, mainly comprising key connection parts in building structures such as column members, vertical joints between columns, beam-column joints, beam-slab joints, and slab-slab connection joints. The column members used are T-shaped steel-concrete composite irregular columns, and the vertical joints between columns, beam-column joints, beam-slab joints, and slab-slab joints all employ prefabricated connection methods to ensure on-site construction efficiency.

[0065] The present invention will be further described below with reference to specific embodiments.

[0066] Example 1

[0067] like Figure 1 , Figure 4 As shown, this embodiment of a steel-concrete composite irregular column frame system includes irregular columns (1), steel beams (2), and floor slabs (5). The floor slab 5 is a composite floor slab, which includes a precast lower cover plate 51, a cast-in-place upper cover plate 52, and a steel truss 53; the steel beams (2) are H-shaped steel beams.

[0068] 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 slab 5. Both the top reinforcement bars 58 and the bottom reinforcement bars 59 include transverse reinforcement bars and longitudinal reinforcement bars.

[0069] This embodiment is one implementation method for beam-slab joints, referencing... Figure 3 , Figure 4 , Figure 6 As shown, the lower cover plate 51 is provided with a lower groove 511 in the span direction for lapping on the lower flange of the steel beam 2. The web of the steel beam 2 is provided with a through hole 23 for the first lapped reinforcing bar 54 to pass through, and after the first lapped reinforcing bar 54 passes through the corresponding through hole 23, its two ends are respectively lapped on the lower cover plates 51 on both sides of the steel beam 2.

[0070] In this specific embodiment, the H-shaped steel beam is a welded steel beam, and its lower flange is slightly wider than its upper flange to facilitate the placement of the lower cover plate 51.

[0071] In addition, to reduce the overall weight of the floor slab 5 and save on foundation costs, a lightweight infill 55 is installed between the steel truss 53 in this embodiment. This lightweight infill 55 needs to possess characteristics such as thermal insulation, sound insulation, and lightweight properties; therefore, polystyrene board, polyurethane foam, rock wool, etc., can be selected. Although polyurethane foam has the best performance and longest lifespan, polystyrene board is preferred considering both economic efficiency and material density.

[0072] In this embodiment, a steel-concrete composite irregular column frame system effectively reduces the overall thickness of the floor slab 5 by placing the lower cover plate 51 of the composite floor slab on the lower flange of the steel beam 2. Simultaneously, the floor slab 5 is connected to the steel beam 2 using PBL shear keys, which offer superior connection performance, ensuring connection strength.

[0073] Example 2

[0074] This embodiment of the steel-concrete composite irregular column frame system proposes an implementation method for slab-slab joints based on Embodiment 1.

[0075] Specifically, refer to Figure 5 As shown, the lower cover plate 51 has an upper groove 512 in the width direction, and the upper grooves 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.

[0076] This embodiment of a steel-concrete composite irregular column frame system abandons the traditional splicing construction method of prefabricated concrete floor slabs and adopts a connection method of pre-set connecting components 56 plus post-casting, which ensures the crack resistance and stress performance of the connection; at the same time, the connection method is simple and easy to construct.

[0077] In this embodiment, a steel-concrete composite irregular column frame system is described, with the beam-slab joints and slab-slab joints specifically constructed as follows:

[0078] 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 fabricated using the pre-tensioning method to reduce the deflection of the plate during construction. At the same time, to improve the stiffness of the bottom plate, the top steel bars in the steel truss can be made of large-size steel bars or replaced with steel pipes (which can be filled with high-grade mortar). Especially when the span of the plate is large, this method can effectively improve the stiffness of the bottom plate and control the deflection.

[0079] While prefabricating the lower cover plate 51, the H-shaped steel beam is also fabricated. A row of through holes 23 is provided on the underside of the web of the H-shaped steel beam for subsequent reinforcement insertion. Since the spacing of these through holes 23 determines the number and spacing of the reinforcing bars, it must be set according to the floor slab design requirements. Of course, to ensure the joint operation of the H-shaped steel beam and the post-cast concrete composite layer, studs 24 can be welded to the top of the steel beam. The dimensions and spacing of the studs 24 must comply with the relevant provisions of the "Code for Design of Composite Structures" JGJ138.

[0080] After the lower cover plate 51 and the H-beam are fabricated, the H-beam and the precast lower cover plate 51 are installed. For the connection of the precast lower cover plate 51 in the span direction, the plate must first be placed on the lower flange of the H-beam, and then the first lapped reinforcing bar 54 is inserted at the corresponding position of the through-hole 23 in the H-beam according to design requirements. This first lapped reinforcing bar 54 can effectively transfer the normal service load of the floor slab, avoid forming a single-span slab, and effectively reduce mid-span deflection; it can also prevent cracking of the composite floor slab bottom plate at the supports. To further enhance the strength of the lap joint, the size of this first lapped reinforcing bar 54 should be larger than the bottom reinforcing bar 59.

[0081] For the connection of the lower cover plate 51 of the composite floor slab in the width direction, an upper groove 512 must first be set at the connection point, followed by splicing to form a groove, and then placing the connecting component 56 in the groove. It is worth noting that the splicing and installation of the lower cover plate 51 must be carried out according to the design requirements of the construction stage, with formwork support set at the bottom to reduce the stress on the plate and avoid local crushing. After the formwork support is set, a lightweight infill body 55 is set between the steel trusses 53, followed by the laying of the top steel reinforcement 58 and the pouring of the cast-in-place composite layer (upper cover plate 52). The curing of the cast-in-place composite layer must meet the requirements of current specifications.

[0082] Example 3

[0083] This embodiment is one way of connecting member 56 and is used in conjunction with the L-shaped upper slot 512.

[0084] Specifically, refer to Figure 7 As shown, the connecting member 56 includes a bent bar 561 and a steel reinforcement cage 562; wherein, the bent bar 561 is located in its respective upper groove 512, and the bent bar 561 is generally inverted U-shaped, with both ends extending into the lower cover plate 51. The steel reinforcement cage 562 is located in the spliced ​​groove and covers the entire area of ​​the bent bar 561.

[0085] The steel reinforcement cage 562 includes longitudinal bars and stirrups; and the bent bars 561 are formed by bending the bottom steel bars 59 during prefabrication to resist torque at the connection.

[0086] In this embodiment of a steel-concrete composite irregular column frame system, when the composite floor slab is used as a two-way slab, significant bending moment or torsional loads may occur at the connection points. The arrangement of the stirrups and bent bars 561 in the steel reinforcement cage can effectively resist the load and ensure stiffness. Therefore, the size of the stirrups in the steel reinforcement cage should not be smaller than the size of the bottom reinforcement 59 of the composite floor slab in the width direction, and the spacing should not be greater than the spacing of the bottom reinforcement 59 of the composite floor slab.

[0087] Example 4

[0088] This embodiment is another embodiment of the connecting member 56.

[0089] refer to Figure 8 The connecting member 56 includes at least three sets of second lapped steel bars 563, and each set of second lapped steel bars 563 has multiple bars along the width direction of the floor slab.

[0090] The first and second groups are prefabricated in their respective lower cover plates 51, and their free ends extend into their respective upper slots 512 areas; the third group is located in the spliced ​​groove, and its two ends are respectively offset and overlapped with the free ends of the other two groups.

[0091] Since the stress of the bottom reinforcement 59 is mainly transferred by the second lap reinforcement 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 the excessively large groove, an anchor plate 564 needs to be set at the end of the second lap reinforcement 563.

[0092] According to preliminary tests, using anchor plate 564 lap splicing can reduce the total lap length by 85%. For common bottom reinforcement sizes of Φ8-Φ10, the lap length is only about 50mm. At this time, the length of the upper groove 512 can be taken as 100mm, which is only about 10% of the width of conventional composite plates, and has little impact on the plate itself.

[0093] Example 5

[0094] In addition, considering that in actual construction, the splicing joints of the composite floor slab bottom plate (that is, the splicing point in the width direction of the lower cover plate 51) are prone to grout leakage and the L-shaped groove is prone to stress concentration at the inside corner and damage.

[0095] To address the aforementioned issues, in this embodiment, the upper slot 512 is trapezoidal in shape, and this trapezoidal upper slot 512 is used in conjunction with the connecting member 56 in Embodiment 3. Additionally, a foam strip 57 is provided at the joint.

[0096] Specifically, refer to Figure 9As shown, the bottom of the two adjacent lower cover plates 51 are provided with interlocking grooves along the width direction. The two lower cover plates 51 are overlapped through the overlap grooves, and a foam strip 57 is provided at the overlap.

[0097] During on-site construction, foam strips 57 are placed at the joints, and the pressure between the composite slabs is used to compress the foam strips 57, thereby achieving a water-stopping effect. For slabs with a low thickness of post-cast concrete and where the local pressure on the foam strips 57 is relatively small during construction, foam strips can also be placed directly on the trapezoidal grooves (e.g., Figure 8 (As shown).

[0098] Example 6

[0099] This embodiment is one implementation method for beam-column joints.

[0100] Specifically, refer to Figure 16 As shown in this embodiment, the irregularly shaped column 1 is a TO steel tube concrete irregularly shaped column, hereinafter referred to as a TO irregularly shaped column. This TO irregularly shaped column includes a steel pipe 11 and several T-shaped steel sections 12 disposed on the outside of the steel pipe 11. The inner cavity of the steel pipe 11 is used for pouring concrete 13. The T-shaped steel sections 12 are welded to the outer wall of the steel pipe 11 through their webs, and this welding operation can be performed in a factory.

[0101] The specific distribution of the T-shaped steel 12 varies. This embodiment lists several common cross-sectional formations of the T-shaped column. Of course, other cross-sectional forms can also be used according to actual construction needs.

[0102] like Figure 16 As shown in (a), there are two T-shaped steel sections 12 arranged symmetrically, and the webs of the two T-shaped steel sections 12 form a straight line; as shown in (a). Figure 16 As shown in (b), there are also two T-shaped steel sections 12, but the webs of the two T-shaped steel sections 12 are perpendicular to form an L-shape; as Figure 16 As shown in (d), there are three T-beams 12, and the webs of the three T-beams 12 are arranged in a T-shape; as Figure 16 As shown in (c), there are four T-shaped steel sections 12, and the webs of the four T-shaped steel sections 12 are arranged in a cross shape.

[0103] like Figure 10 As shown, the end of the steel beam 2 is provided with a connecting plate 21, and the connecting plate 21 is provided with mounting holes; the wing plates of the T-shaped steel 12 are also provided with mounting holes at their relative positions, and the assembly operation between the steel beam 2 and the irregular column 1 can be completed by high-strength bolts. This solves the problems of complex welding process, large internal stress, and low assembly efficiency in traditional steel node prefabrication or on-site welding.

[0104] Because the out-of-plane bending resistance of the flange of the T-shaped steel 12 and the wall of the steel pipe 11 is poor, in this embodiment, a reinforcing member 3 is provided at the connection node between the steel beam 2 and the irregular column 1 to enhance the stiffness and strength of the node area.

[0105] refer to Figure 11 , Figure 12 , Figure 13 As shown, the reinforcing member 3 includes a sleeve 31 and a stiffening rib 32 disposed 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.

[0106] Of course, the specific distribution of the stiffening ribs 32 is consistent with the cross-sectional shape of the corresponding irregular column 1. That is to say, the commonly used cross-sectional shapes of the stiffening ribs 32 are also I-shaped, L-shaped, T-shaped, and cross-shaped.

[0107] In this embodiment, an L-shaped reinforcing member 3 and an L-shaped irregular column 1 are used as an example. The stiffening ribs 32 are arranged in pairs, located on both sides of the same web of the T-shaped steel 12; and each steel beam 2 is equipped with two pairs of stiffening ribs 32 at its end, with each pair of stiffening ribs 32 positioned at the same height as the corresponding steel beam flange 22.

[0108] This embodiment of a steel-concrete composite irregular column frame system optimizes the load transfer path and enhances the stiffness and strength of the joint area by setting stiffening ribs 32 at the same height as the steel beam flange 22 on the inner side of the irregular column 1. However, considering that the steel pipe is prone to tearing at the intersection of the stiffening ribs 32 and the steel pipe 11, it needs to be reinforced.

[0109] Specifically, for circular steel-concrete composite tubes, a sleeve 31 is installed at the intersection of the stiffening rib 32 and the steel pipe 11, and the sleeve is fitted over the steel pipe 11. This allows the force to be directly transmitted from the stiffening rib 32 to the sleeve 31, and then the load is transmitted to the core steel-concrete composite tube joint through the sleeve 31. This method avoids the steel pipe 11 being directly subjected to normal loads, thus improving its safety.

[0110] Of course, for rectangular or square steel-concrete composite tubes, the ends of the stiffening ribs 32 can be flush with the rectangular steel tube, and load-bearing connecting steel plates can be installed on the sides. These steel plates can directly transfer the load of the steel beam flange 22 to the side of the rectangular steel tube, instead of letting the tube side intersecting with the stiffening ribs 32 bear the normal load.

[0111] This embodiment presents a steel-concrete composite irregular column frame system. The proposed TO irregular column cross-section features a core steel-concrete composite section that primarily bears compressive stress, while T-shaped steel sections are 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-concrete composite section and the outer T-shaped steel sections) while maintaining sufficient bending resistance. The smaller cross-sectional width allows the column members to be concealed within the walls, increasing usable interior space and enhancing the flexibility of apartment layout and furniture placement.

[0112] From the perspective of the stress mechanism, the proposed column member has a reasonable cross section and a clear division of labor between the bending and compression parts. It makes full use of the advantages of easy expansion of steel sections and the high bearing capacity and stiffness of steel tube concrete sections, resulting in a smaller amount of steel and lower cost compared with traditional composite structural members.

[0113] Meanwhile, based on the TO irregular column design, the beam-column joint completely eliminates on-site welding connections, adopting a fully bolted connection to achieve a rigid beam-column connection. Furthermore, through the inclusion of reinforcing member 3, the sleeve 31 drives the overall stress on the steel-concrete composite structure, achieving efficient transmission of bending moment in the steel beam. This also avoids the need for reinforcing rings on the outside of the steel-concrete composite structure, reducing the cross-sectional width of each component at the beam-column joint and increasing usable space within the building.

[0114] Example 7

[0115] Based on the above embodiments, to avoid the reduction in mechanical properties of the beam-column joint area caused by excessive residual stress from factory welding, in this embodiment, the stiffening rib 32 and the sleeve 31 are directly manufactured as cast steel parts. Using integral cast steel parts has two main advantages: 1) Each part of the casting forms a self-contained whole, significantly reducing the impact of welding of small components on their internal stress; 2) When the casting and the prefabricated TO-shaped column are welded in the factory, the number and length of welds are smaller, significantly improving the performance of the joint area. Simultaneously, the welding deformation of the casting and the TO-shaped column caused by welding stress is smaller, making deformation correction and on-site installation easier.

[0116] 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 installed along the entire length to ensure the effective transmission of bending moment at the beam end.

[0117] Specifically, in this embodiment, the sleeve 31 has the same wall thickness as the steel pipe 11, the stiffening rib 32 has the same thickness as the steel beam flange 22, and 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 pipe 11. According to the 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 joint under bending moment, thus meeting the joint's seismic resistance requirements.

[0118] Finite element analysis was performed on the beam-column joint, such as... Figure 14 , Figure 15 As shown. Strengthening the node using the above method results in a lower stress level in the node area, preventing tearing failure when the sleeve 31 and the steel pipe 11 have similar wall thicknesses. Conversely, the Mises stress in the upper and lower parts of the steel pipe within the node region is relatively high, which can be mitigated by locally increasing the wall thickness during prefabrication or by using an inner ring plate.

[0119] Based on the finite element analysis results, stiffening rib 32 and sleeve 31 are key load-bearing components in the design. To ensure their safety during service, the thickness of stiffening rib 32 should not exceed the thickness of sleeve 31, i.e., t 加劲肋 ≦t 套管， This ensures that the sleeve 31 is not prone to localized tearing under the tensile force along the longitudinal direction of the stiffening rib 32.

[0120] The determination of the sleeve 31 wall thickness should consider the influence of four key factors: the wall thickness of the outer steel pipe of the core steel pipe concrete, the thickness of the stiffening ribs, the height of the joint area, and the strength of the core concrete. 套管 =α1α2α3t 钢管 In the formula, α1, α2, and α3 represent the influence coefficients considering the stiffening rib thickness, the nodal region height, and the core concrete strength, respectively. The stiffening rib thickness is a crucial parameter affecting the failure mode and failure load of the steel tube within the nodal region; its ratio t to the wall thickness of the outer steel tube of the core steel tube concrete is... 加劲肋 / t 钢管 As the basic independent variable in the formula for calculating the influence coefficient, α1 can be considered as A*(t) 加劲肋 / t 钢管 The coefficient A should be determined based on regression analysis of experimental data; when experimental data is lacking, it can be taken as 1. Similarly, the calculation methods for α2 and α3 are determined based on common node heights and concrete strengths, i.e., α2 = B * (h 节点域 / 300), α3=C*(fc / 30), the coefficients B and C should be determined based on regression analysis of experimental data, and can be taken as 1 when experimental data is lacking. In the formula, h 节点域 'fc' and 'fc' represent the node height and the 28-day axial compressive strength of the core concrete, respectively. The denominators 300 and 30 represent commonly used node heights and concrete strengths with dimensionless scaling of height and strength. It should be noted that in actual engineering projects, the main beam height is usually higher than 300mm (i.e., the node height is higher than 300mm), and this value varies with the span, generally ranging from 300 to 1000mm. To ensure the safe application of this node and its structural system, a conservative choice of 300mm is made.

[0121] Example 8

[0122] This embodiment of a steel-concrete composite irregular column frame system, based on the above embodiment, also provides a vertical connection node 4 between the T-shaped columns. This vertical connection node 4 mainly includes the connection of the inner core steel-concrete composite (steel pipe 11) and the connection of the outer T-shaped steel 12. Of course, this vertical connection node 4 needs to be staggered from the beam-column joint.

[0123] For the TO-shaped columns, internal hot-rolled ribbed steel bars are used for connection and concrete is poured. For the connection between the T-shaped steel 12 on the outside of the column, holes can be drilled in the T-shaped steel 12, and high-strength bolts and splicing cover plates can be used to connect them in a fully bolted connection method.

[0124] Specifically, refer to Figures 17-19 As shown, the steel pipe 11 is provided with annular ribs 41 and connecting reinforcing bars 42. The annular ribs 41 are located on the inner wall of the steel pipe 11, near the end of the steel pipe 11. Multiple connecting reinforcing bars 42 are distributed in a ring, with one end inside the steel pipe 11 and the other end extending outside the steel pipe 11 for connecting to another steel pipe 11. After the concrete 13 is poured, when the concrete in the steel pipe is subjected to tensile force, the annular ribs 41 anchor the connecting reinforcing bars 42.

[0125] The ring rib 41 is preferably a steel pipe rib, and it can be selected from various cross-sectional forms, such as T-shaped steel, channel steel, solid round / rectangular steel bars, etc.

[0126] In this embodiment, a steel-concrete composite irregular column frame system is provided, in which the inner core steel-concrete composite section is connected by internal connecting steel bars 42 and then by pouring concrete. The key to achieving a tensile strength equal connection lies in whether the steel pipe 11 provides sufficient anchorage for the internal connecting steel bars 42.

[0127] Based on the preliminary refined finite element analysis, the anchoring force is transferred by setting a ring rib 41 at the inner end of the steel pipe 11, which allows the shear force between the two to be effectively transferred, thereby enhancing the anchoring force on the connecting steel bar 42. The specific force mechanism can be found in [reference needed]. Figure 21 .

[0128] To further improve 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 / hot-bent straight seam welded steel pipes, sandblasting (shot blasting) can also be performed on the plate before the bending process to increase the friction coefficient and thus achieve the optimal anchoring effect.

[0129] To reduce the impact of the welding precision of the ring rib 41 at the factory on on-site construction, a certain amount of welding space needs to be left. It is recommended to place the ring rib 41 about 30mm from the end of the steel pipe 11.

[0130] Meanwhile, to minimize the volume and damage of the upper concrete of the ring rib (which is prone to tensile damage under seismic loads, while the lower concrete of the ring rib is mainly subjected to compressive stress, effectively utilizing the material properties of concrete), based on the inventors' previous theoretical and experimental research, the distance between the location of the ring rib 41 and the end of the steel pipe 11 needs to be less than 0.3l. R Among them, l R The anchorage length refers to the depth of the connecting steel bar 42 within a single steel pipe 11.

[0131] Furthermore, the distance between the connecting steel bar 42 and the ring rib 41 should not exceed the difference between the anchorage length of the steel bar and the depth of the ring rib 41. This is because the transmission of anchorage force mainly relies on the shear force between concrete units and the pressure between upper and lower units. The resultant force of these two forces has a maximum angle of 45 degrees. At this angle, the distance between the connecting steel bar 42 and the ring rib 41 is exactly equal to the difference between the anchorage length of the steel bar and the depth of the ring rib 41. When the distance between the connecting steel bar 42 and the ring rib 41 exceeds this value, the anchorage force cannot be effectively transmitted, and local shear failure will occur in the concrete inside the joint.

[0132] refer to Figure 20 As shown, 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 the connecting cover plate 45 and fasteners 46. After the upper and lower layers of T-shaped steel 12 are aligned and tightened, the upper and lower sections of the core steel pipe concrete are also aligned. The fasteners 46 are preferably high-strength bolts.

[0133] This embodiment of a steel-concrete composite irregular column frame system, for the connection of the inner core steel-concrete composite tube, uses ring ribs 41 and connecting steel bars 42 inside the steel tube, which can be prefabricated in the factory; compared with traditional connection nodes, it completely avoids on-site welding operations and improves assembly efficiency; at the same time, after the pouring and curing are completed, when the steel-concrete composite tube is subjected to tensile force, the ring ribs 41 play an anchoring role for the connecting steel bars 42, thereby ensuring the connection strength at the connection node.

[0134] The outer T-shaped steel sections 12 are connected by bolts, eliminating the need for on-site welding and improving assembly efficiency. Furthermore, the connection between the T-shaped steel sections 12 not only ensures equal strength at the joint but also assists in the positioning of the core steel-concrete composite structure during construction.

[0135] The inventors conducted a refined finite element modeling analysis of the vertical connection nodes in this embodiment to evaluate their mechanism of action and impact on this type of connection node. The model has approximately 150,000 solid elements, which can accurately reflect the mechanical properties of the nodes. The analysis results are as follows: Figure 22-24 As shown.

[0136] Depend on Figure 22 It can be seen that after adding steel pipe ribs to the end of steel pipe 11 for reinforcement, the concrete damage is significantly reduced; at the same time, the hysteresis curve is relatively full. Figure 23 This indicates that this type of node has a strong seismic energy dissipation capacity.

[0137] In addition, according to the model analysis results, when the diameter of the connecting steel bar exceeds 22mm, the hysteresis curve will show a significant "pinching" phenomenon. Figure 24 This significantly reduces the energy dissipation capacity of the joint, therefore it is recommended that the diameter of the reinforcing bars not exceed 22mm. The reason for this "pinching" phenomenon is that, under the premise of equal reinforcement ratio, excessively large reinforcing bar size will lead to a reduction in the number of reinforcing bars, significant reinforcing bar-concrete bond slip around a single reinforcing bar, and a significant increase in bond stress, making the concrete around the reinforcing bar more prone to damage, reducing the overall energy dissipation capacity of the joint, hence the "pinching" of the hysteresis curve.

[0138] Example 9

[0139] To facilitate the positioning of the connecting steel bar 42 and ensure its sufficient stability during concrete pouring, this embodiment further improves the specific structure of the vertical connecting node 4 based on embodiment 3.

[0140] refer to Figure 17 As shown, the end of the connecting steel bar 42 is provided with an end plate 43. During assembly, the end of the end plate 43 abuts against the inner wall of the steel pipe 11 to position the connecting steel bar 42 and ensure its verticality.

[0141] The inner side of the connecting steel bar 42 is also provided with a ring-shaped reinforcing bar 44, and multiple sets of the reinforcing bar 44 are arranged along the length of the connecting steel bar 42. That is, by setting the reinforcing bar 44, multiple connecting steel bars 42 are combined into a whole, which can be prefabricated in the factory, thereby further saving on-site construction time.

[0142] Since multiple connecting steel bars 42 are connected into a complete ring by the upright steel 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 against the inner wall of the steel pipe 11, the overall verticality of the connecting steel bars 42 can be guaranteed.

[0143] Specifically in this embodiment, refer to Figure 19 As shown, the end plate 43 includes a long end plate 431 and a short end plate 432, which are arranged alternately. By setting the long end plate 431 and the short end plate 432, not only can the anchorage force of the connecting steel bar 42 be improved, but the connecting steel bar 42 can also be positioned to ensure its verticality.

[0144] In addition, to prevent the connecting steel bar 42 from shifting downwards due to the impact of concrete during the pouring process, in this embodiment, a supporting bar (not shown in the figure) is provided on the outer side of the connecting steel bar 42. The connecting steel bar 42 is hung on the ring rib 41 through the supporting bar, thereby enabling the connecting steel bar 42 to be effectively supported.

[0145] A steel-concrete composite irregular column frame system, through the joint restraint of end plates 43, upright steel bars 44 and supporting bars on the connecting steel bars 42, not only ensures the verticality of the connecting steel bars 42, but also increases the stability of the connecting steel bars 42. It can effectively prevent the displacement of the connecting steel bars caused by the scouring of concrete during concrete pouring, thereby affecting the final connection effect.

[0146] Example 10

[0147] refer to Figure 25 As shown, in order to further facilitate the positioning of the core steel pipe concrete, a positioning flange 47 is provided on the outer side of the end of the steel pipe 11, and the positioning flanges 47 can also be connected by high-strength bolts.

[0148] Compared to the traditional method of directly using flanges for connection, the flanges in this embodiment have lower space requirements and only serve to position and bear construction loads during construction. After the concrete is poured and cured to the design strength, the combined effect of the internal reinforcing steel and the outer steel pipe mainly bears the tensile / bending moment, thereby reducing the mechanical performance requirements of the flange joint, reducing the space occupied by the joint, reducing the amount of steel used, and reducing the cost of the connection joint.

[0149] In addition, to further reduce the space occupied by the node, the flange can also be cut off after the curing is completed. Of course, the setting of the positioning flange 47 in this embodiment, and whether to carry out the subsequent cutting operation, can be selected according to the actual construction requirements.

[0150] In summary, the steel-concrete composite irregular column frame system of this invention, with its proposed TO composite column section form, achieves relative separation of column compression and bending at the composite section. The circular steel-concrete composite section in the composite section has high axial stiffness, bearing most of the pressure according to the stiffness distribution principle (fully leveraging the high axial compressive bearing capacity of the circular steel-concrete composite section, facilitating the use of high-strength steel pipes and high-strength concrete materials). The outer T-shaped steel (facilitating connection) significantly increases the height of the composite section. Bending moment = force * lever arm; the significantly increased lever arm correspondingly increases the bending bearing capacity and bending stiffness of the composite section, thus expected to have good bending bearing capacity and stiffness. Furthermore, based on this, vertical connection nodes between columns, beam-column nodes, beam-slab nodes, and slab-slab connection nodes are proposed to complement the above structural system. While ensuring a high assembly rate of the node system, it also possesses good mechanical properties and overall integrity. Ultimately, a novel frame system with superior seismic performance, low steel consumption, good overall integrity, high assembly rate, large usable space, and flexible structural layout is obtained, promoting high-quality development in the construction industry.

[0151] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A steel-concrete composite irregular column frame system, comprising irregular columns (1), steel beams (2), and floor slabs (5), wherein, The steel beam (2) is an H-shaped steel beam, and the floor slab (5) is a composite floor slab, which includes a precast lower cover plate (51), a cast-in-place upper cover plate (52), and a steel truss (53). The lower cover plate (51) is provided with a lower slot (511) in the span direction for lapping on the lower flange of the steel beam (2). The web of the steel beam (2) is provided with a through hole (23) for the first lapped steel bar (54) to pass through. After the first lapped steel bar (54) passes through the corresponding through hole (23), its two ends are respectively lapped on the lower cover plate (51) on both sides of the steel beam (2). The lower cover plate (51) has an upper groove (512) in the width direction, and the upper grooves (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. The upper groove (512) is a trapezoidal groove, and the connecting member (56) includes at least three sets of second lapped steel bars (563). The first and second sets are prefabricated in their respective lower cover plates (51), and their free ends extend into their respective trapezoidal grooves. The third set is located in the groove after splicing, and its two ends are staggered and lapped with the free ends of the other two sets, and the free ends of the first and second sets are left with a certain distance. Anchor plates (564) are provided at both ends of the second lapped steel bars (563). Along the width direction, the bottom of two adjacent lower cover plates (51) are provided with interlocking grooves, the two lower cover plates (51) overlap through the overlapping grooves, and foam strips (57) are provided at the overlap. The irregular column (1) is connected in the vertical direction by a vertical connecting node (4), which includes a ring rib (41), a connecting steel bar (42) and a connecting cover plate (45). Among them, there are multiple connecting steel bars (42) arranged in a ring, one end of which is located inside the steel pipe (11) and the other end extends out of the steel pipe (11) for connecting another steel pipe (11). The ring rib (41) is set on the inner wall of the steel pipe (11). After the steel pipe concrete is poured, when it is subjected to tensile force, the ring rib (41) will anchor the connecting steel bar (42). The connecting cover plate (45) is used to connect the T-shaped steel (12).

2. The steel-concrete composite irregular column frame system according to claim 1, characterized in that: The lower flange of the steel beam (2) is wider than the upper flange, and the upper flange is provided with studs (24). Lightweight fillers (55) are provided between the steel trusses (53).

3. The steel-concrete composite irregular column frame system according to claim 2, characterized in that: The irregular column (1) includes a steel pipe (11) and a number of T-shaped steels (12) arranged along the periphery of the steel pipe (11); The steel beam (2) is bolted to the flange 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) includes a sleeve (31) and a stiffening rib (32) provided on the sleeve (31); wherein the sleeve (31) is fixedly sleeved on the steel pipe (11), the side of the stiffening rib (32) is connected to the web of the T-shaped steel (12), and its end is connected to the flange of the T-shaped steel (12).

4. The steel-concrete composite irregular column frame system according to claim 3, characterized in that: The end of the connecting steel bar (42) is provided with an end plate (43), 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) abuts against the inner wall of the steel pipe (11).

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