Porous steel beam bidirectional composite floor and construction method

Abstract

The application discloses a kind of porous steel beam bidirectional combination floor and construction method, belong to the technical field of fabricated steel reinforced concrete composite floor.The floor includes steel frame and combination panel, steel frame is formed by the assembly of bidirectional orthogonal arrangement porous beam section and connecting node component, at least one hole connecting plate is provided in porous beam section, at least two adjacent openings are formed, the calculation length of open web is shortened to reduce local bending effect, connecting node component is structured using steel pipe plus bidirectional through connecting plate, realize upper and lower rib axial force cross node continuous transmission, cooperate with web connecting plate to transfer shear force, can effectively reduce the local bending moment of hole edge of large grid floor, improve the reliability of node force transmission, tensile and shear performance, enhance the flexibility of structure grid size division, and realize factory prefabrication and on-site rapid assembly, adapt to the use demand of large-span fabricated building.

Description

Technical Field

[0001] This invention relates to the field of building structure and prefabricated steel-concrete composite floor slab technology, specifically to a multi-hole steel beam bidirectional composite floor slab and its construction method. Background Technology

[0002] Two-way open-web floor slabs typically consist of upper and lower ribs arranged in two orthogonal directions, along with vertical members connecting the ribs. They feature high structural height utilization, clear two-way force transmission, and ease of equipment and pipeline passage, making them suitable for large-span public buildings, industrial buildings, parking garages, stations, and other buildings requiring large column-free spaces. Traditional steel open-web sandwich slabs usually have a large open-web unit between adjacent main nodes, with the open area bearing the two-way shear force transmission. In existing steel open-web floor slabs, beam segments often employ single-span or partially solid-web designs to meet basic load-bearing and pipeline passage requirements.

[0003] As the main mesh size increases, the computational width of a single hollow element also increases, significantly enhancing the local bending effect of the upper and lower chords caused by shear force transmission. Simply increasing the mesh size can easily lead to stress concentration at the hole edges, local deformation of the chords, and increased shear deformation of the hollow elements, thus limiting the development of structures towards larger spans. If this is addressed by increasing beam height, thickening plates, or reducing the size of the openings, it will increase the structural self-weight and steel consumption, and reduce the flexibility of equipment traversing space and building layout. On the other hand, ordinary hollow steel pipe nodes easily cause the axial force of the chords to concentrate on the sidewall of the steel pipe, resulting in out-of-plane deformation of the pipe wall, stress concentration in the weld, and insufficient rotational stiffness of the node. The compressive, shear, and pull-out properties of the node are easily controlled by local structural features.

[0004] Furthermore, traditional integral welded steel grid floor slabs typically feature large component dimensions, leading to challenges such as difficulty in standardizing factory fabrication units, limited transport width, significant lifting weight, and substantial on-site welding workload. For different grid spans, redesigning beam segments and node interfaces is also detrimental to modular component production and prefabricated construction. Therefore, there is an urgent need to propose a novel floor slab system that reduces local bending effects while maintaining the main grid layout, clearly defining the force transmission path at the nodes, and improving the efficiency of prefabricated construction. Summary of the Invention

[0005] This invention aims to solve the problems in the prior art, such as the sharp increase in local bending moment of single-hole hollow floor slabs with increasing grid size, unclear bidirectional force transmission path of ordinary steel pipe nodes, and insufficient prefabrication of integral welded floor slabs. It provides a multi-hole steel beam bidirectional composite floor slab and its construction method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A perforated steel beam bidirectional composite floor slab includes a steel frame and a composite panel. The steel frame is assembled from multiple perforated beam segments and multiple connecting node components disposed at the connection of the perforated beam segments.

[0008] The multi-hole beam segment includes an upper rib T-shaped steel, a lower rib T-shaped steel, two end connecting plates, and at least one hole connecting plate. The two end connecting plates are respectively disposed at both ends of the multi-hole beam segment, and the hole connecting plate is disposed at intervals between the two end connecting plates. The upper and lower ends of the end connecting plates and the hole connecting plates are respectively connected to the upper rib T-shaped steel and the lower rib T-shaped steel, so that at least two adjacent openings are formed inside the beam segment along the beam length.

[0009] The connecting node assembly includes a steel pipe, an upper connecting plate, a lower connecting plate, and a web connecting plate. The upper connecting plate and the lower connecting plate are respectively disposed on the upper and lower parts of the steel pipe, and are at the same height as the upper rib T-shaped steel and the lower rib T-shaped steel, and are fixedly connected to the upper rib T-shaped steel and the lower rib T-shaped steel. The web connecting plate is fixed to the side wall of the steel pipe. The end connecting plate is connected to the corresponding web connecting plate. The lower end of the connecting node assembly is not connected to the column. The combined panel is installed on the upper part of the multi-hole beam segment.

[0010] Furthermore, each of the aforementioned multi-hole beam segments is provided with m connecting plates, where m ≥ 1. The local bending moment in the opening area of ​​the multi-hole beam segment satisfies the formula M = α·β·q·(L / (m+1))². In the formula, α is the end constraint coefficient, β is the web constraint enhancement coefficient, q is the equivalent line load, and L is the total length of the open space between nodes.

[0011] Furthermore, the hole connecting plate is a continuous steel plate or a combined web plate with local stiffening plates, and the connection method between the hole connecting plate, the end connecting plate and the upper rib T-shaped steel and the lower rib T-shaped steel is one of welding, bolting or bolt-welding combination connection.

[0012] Furthermore, the connecting plate with holes is provided with stiffening ribs on both sides, and the corners of the openings are provided with arc transition sections or bevel transition sections, with the stiffening ribs and the arc transition sections corresponding one-to-one.

[0013] Furthermore, both the upper connecting plate and the lower connecting plate are formed by two orthogonal plates interlocking and welding to form a cross-shaped whole, or by welding a continuous plate in one direction to two separate plates in another direction to form a cross-shaped whole. The portions of the upper connecting plate and the lower connecting plate extending out of the steel pipe are respectively connected to the corresponding upper rib T-shaped steel or the lower rib T-shaped steel by butt welding, connecting plate bolt connection, or bolt welding combination connection.

[0014] Furthermore, the connecting node assembly also includes bidirectional tie bars, the two ends of which are respectively anchored to the lower rib T-shaped steel on both sides of the steel pipe.

[0015] Furthermore, the steel pipe is filled with concrete or grouting material, and the upper connecting plate is provided with a pouring through hole.

[0016] Furthermore, the steel pipe is also provided with an inner partition, which is arranged horizontally.

[0017] Furthermore, the composite panel includes a precast slab and a cast-in-place surface layer cast above the precast slab. The precast slab rests on the upper rib T-shaped steel. The top of the upper rib T-shaped steel is provided with a plurality of shear-resistant connectors. The shear-resistant connectors are studs welded to the top of the upper rib T-shaped steel and embedded in the cast-in-place surface layer. The cast-in-place surface layer is provided with at least one of two-way surface layer reinforcement, slab joint connection reinforcement, and additional reinforcement near the node.

[0018] On the other hand, a construction method for a multi-hole steel beam bidirectional composite floor slab is also provided, including the following steps:

[0019] S1, the factory manufactures a multi-hole beam segment and a connecting node assembly, with at least two openings provided in the multi-hole beam segment, and the upper connecting plate, lower connecting plate and web connecting plate are welded to the steel pipe to form the connecting node assembly;

[0020] S2, hoist the connecting node assembly and the multi-hole beam segment, weld or bolt the upper rib T-shaped steel of the multi-hole beam segment to the corresponding upper connecting plate, weld or bolt the end connecting plate of the multi-hole beam segment to the corresponding web connecting plate, and weld or bolt the lower rib T-shaped steel of the multi-hole beam segment to the corresponding lower connecting plate to form a steel frame;

[0021] S3, the multi-hole beam segments located on both sides of the connecting node assembly are anchored and pre-tightened by bidirectional tie rods;

[0022] S4, concrete is poured inside the steel pipe, and the upper composite panel is constructed after the concrete reaches the required standard.

[0023] S5. Install precast slabs on the steel frame, tie reinforcing bars, and then pour concrete for the surface layer to complete the composite floor slab construction.

[0024] Compared with the prior art, the present invention has the following significant advantages:

[0025] 1. By dividing a single hollow section into multiple smaller segments through a hole-connecting plate, the local bending moment amplitude at the hole edge is significantly reduced, the local stability of the plate is improved, and it is suitable for the stress requirements and grid division flexibility of large-span grid floor slabs.

[0026] 2. By adopting a joint structure using steel pipes or steel pipes with internally welded stirrups and filled with concrete, the axial force of the upper and lower ribs can be continuously transferred across the joint, the shear force and axial force transmission mechanism can be clarified, and the tensile and shear resistance of the joint can be improved.

[0027] 3. Both beam segments and nodes use standardized components, and on-site assembly is mainly done by welding or bolting, which results in high construction efficiency. The grid size and load level can be flexibly adjusted to adapt to different engineering scenarios. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the multi-hole steel beam bidirectional composite floor slab according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the connection node component structure according to an embodiment of the present invention. Figure 1 ;

[0030] Figure 3 This is a schematic diagram of the connection node component structure according to an embodiment of the present invention. Figure 2 ;

[0031] Figure 4 This is a schematic diagram of the multi-connection node component structure according to an embodiment of the present invention. Figure 3 ;

[0032] Figure 5 This is a schematic diagram of the multi-hole beam segment structure of the multi-hole steel beam bidirectional composite floor slab according to an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of a rectangular porous beam segment structure according to an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of a circular porous beam segment structure according to an embodiment of the present invention;

[0035] Figure 8 This is a schematic diagram of a hexagonal porous beam segment structure according to an embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram of the combined panel structure according to an embodiment of the present invention;

[0037] Figure 10 This is a schematic diagram of the structure of the connection node component according to an embodiment of the present invention.

[0038] The components include: 1. Composite panel; 11. Precast slab; 12. Cast-in-place surface layer; 2. Multi-hole beam segment; 21. Upper rib T-shaped steel; 22. Lower rib T-shaped steel; 23. Hole connection plate; 231. Stiffening rib; 24. Opening; 25. End connection plate; 3. Connection node assembly; 31. Steel pipe; 32. Upper connection plate; 33. Lower connection plate; 34. Web connection plate; 35. Bidirectional tie rod; 36. Cast-in-place through hole; 37. Concrete infill; 4. Shear connector. Detailed Implementation

[0039] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0040] The following is combined with Figures 1 to 10 The following describes embodiments of the present invention.

[0041] According to an embodiment of the present invention, a multi-hole steel beam bidirectional composite floor slab is provided, comprising a steel frame and a composite panel 1. The steel frame is assembled from multiple bidirectional orthogonally arranged multi-hole beam segments 2 and multiple connecting node components 3 connected to the multi-hole beam segments 2. The multi-hole beam segment 2 includes an upper rib T-shaped steel 21, a lower rib T-shaped steel 22, two end connecting plates 25, and at least one hole connecting plate 23. The two end connecting plates 25 are respectively disposed at both ends of the multi-hole beam segment 2, and the hole connecting plate 23 is spaced between the two end connecting plates 25. The upper and lower ends of the end connecting plates 25 and the hole connecting plate 23 are respectively connected to the upper rib T-shaped steel 21 and the lower rib T-shaped steel 22, so that at least two adjacent openings 24 are formed inside the beam segment along the beam length. The connecting node assembly 3 includes a steel pipe 31, an upper connecting plate 32, a lower connecting plate 33, and a web connecting plate 34. The upper connecting plate 32 and the lower connecting plate 33 are respectively located at the upper and lower parts of the steel pipe 31, and are at the same height as the upper rib T-shaped steel 21 and the lower rib T-shaped steel 22 in terms of force transmission. They are also fixedly connected to the upper rib T-shaped steel 21 and the lower rib T-shaped steel 22. The web connecting plate 34 is fixedly connected to the side wall of the steel pipe 31. The end connecting plate 25 is connected to the corresponding web connecting plate 34. The lower end of the connecting node assembly 3 is not connected to the column. The combined panel 1 is installed on the upper part of the multi-hole beam segment 2.

[0042] Specifically, the steel frame serves as the load-bearing skeleton of the two-way composite floor slab, transferring the vertical load of the floor slab to the supporting structure below. The two-way orthogonal arrangement enables the floor slab to have two-way force transmission performance, and it can be adapted to various grid layouts such as squares and rectangles to meet the layout requirements of different building plans.

[0043] The composite panel 1 is installed on the upper part of the perforated beam segment 2. On the one hand, it works together with the steel frame to resist bending, improve the overall rigidity and normal use performance of the floor, and reduce floor deflection and vibration. On the other hand, it provides a flat floor base for building use, meeting the needs of building functions and pipeline laying.

[0044] The perforated beam segment 2 is the basic load-bearing unit of the steel frame. It is set between two adjacent connecting node components 3. The hollow opening structure reduces the self-weight of the structure, reduces the total load of the structure and the stress on the lower support, and provides a passage for mechanical and electrical equipment pipelines without having to reduce the floor height, thus improving the utilization rate of building space.

[0045] The upper rib T-shaped steel 21 is the upper chord member of the multi-hole beam segment 2. After being combined with the upper composite panel 1, it jointly bears the pressure of the floor compression zone. The T-shaped steel section can provide sufficient compressive bearing capacity and flange width to ensure effective connection with the composite panel 1, while facilitating the welding arrangement of the shear connector 4.

[0046] The lower rib T-shaped steel 22 is the lower chord member of the multi-hole beam segment 2, mainly bearing the tensile force in the tension zone of the floor slab. It works with the upper rib T-shaped steel 21 to form a hollow truss force system, giving full play to the tensile properties of steel and improving the material utilization efficiency of the structure.

[0047] The hole connecting plate 23 is set between two adjacent end connecting plates 25, dividing the single-section hollow beam into multiple adjacent openings 24. On the one hand, it transmits the vertical shear force inside the beam section, increases the vertical force transmission path between the upper rib T-shaped steel 21 and the lower rib T-shaped steel 22, and reduces the hollow shear deformation. On the other hand, it shortens the calculated length of the hollow section, significantly reduces the local bending moment in the opening 24 area, and shortens the free deformation length of the compression chord, thereby improving the local stability and buckling resistance of the plate.

[0048] The end connecting plate 25 is set at both ends of the porous beam segment 2 to provide a connection interface between the porous beam segment 2 and the connecting node assembly 3, ensuring the effective transmission of shear force at the end of the beam segment, while restricting the relative rotation of the beam ends, and improving the rotational stiffness and overall stress performance of the node area.

[0049] The opening 24 is formed by the upper rib T-shaped steel 21, the lower rib T-shaped steel 22, the adjacent end connecting plate 25, and the hole connecting plate 23. It can be used for the zoned passage of equipment pipelines, realizing the layered and zoned arrangement of pipelines, avoiding pipeline interference, and reducing the self-weight of the multi-hole beam segment 2, thereby reducing the total structural load and material consumption. The hole shape of the opening 24 can be one or more combinations of rectangular holes, rounded rectangular holes, circular holes, square holes, hexagonal holes, or other polygonal holes. Multiple openings 24 within the same multi-hole beam segment 2 can use the same hole shape or different combinations of hole shapes, flexibly selected according to pipeline passage requirements and local stress requirements.

[0050] The lower end of the connecting node component 3 is not connected to the column, but together with the multi-hole beam segment 2, it forms a bending-resistant member. No column connection is required on the lower side. The steel pipe 31 serves as the vertical main component of the connecting node component 3, providing an installation base for the internal force-transmitting components and the external connecting plate. It also constrains the internal filling material, forming a combined force-bearing system, improving the overall stability and load-bearing capacity of the node, and facilitating the orthogonal connection of the bidirectional multi-hole beam segment 2. The connecting node component 3 can be divided into cross-shaped internal nodes, T-shaped edge nodes, and L-shaped corner nodes according to the floor plan position. All types of nodes use compatible steel pipe 31 sections, force-transmitting component elevations, and bolt hole groups, achieving standardized prefabrication and universal assembly.

[0051] The upper connecting plate 32 is set on the upper part of the steel pipe 31, corresponding to the force transmission height of the upper rib T-shaped steel 21. It penetrates the side wall of the steel pipe 31 in both directions, so that the axial force of the upper rib in both directions can be continuously transmitted across the node, avoiding the axial force concentration acting on the side wall of the steel pipe 31 and causing local out-of-plane deformation, reducing the stress concentration of the weld, and improving the force transmission reliability of the node.

[0052] The lower connecting plate 33 is located at the lower part of the steel pipe 31 and corresponds to the force transmission height of the lower rib T-shaped steel 22. It penetrates the side wall of the steel pipe 31 in both directions, so that the axial force of the lower rib in both directions can be continuously transmitted across the node. It works with the upper connecting plate 32 to form a complete chord axial force transmission path, effectively reducing the out-of-plane stress on the side wall of the steel pipe 31 and improving the tensile performance of the node.

[0053] The web plate connecting plate 34 is fixedly connected to the side wall of the steel pipe 31 and is correspondingly connected to the end connecting plate 25 of the multi-hole beam segment 2. It mainly bears the shear force transmission at the end of the beam segment. At the same time, together with the upper connecting plate 32 and the lower connecting plate 33, it restricts the rotation of the beam end, improves the overall stiffness of the node, and forms a clear force mechanism for the separate transmission of axial force and shear force.

[0054] In some embodiments, each porous beam segment 2 is provided with m hole connecting plates 23, where m ≥ 1. The local bending moment in the opening area 24 of the porous beam segment 2 satisfies the formula M = α·β·q·(L / (m+1))². In the formula, M is the local bending moment of the beam segment corresponding to a single hollow segment, α is the end constraint coefficient, β is the web constraint enhancement coefficient, q is the equivalent uniformly distributed line load of the floor slab, and L is the total length of the hollow segment between two adjacent connecting node components 3.

[0055] Under vertical shear force, the open section between the adjacent end connecting plate 25 and the perforated connecting plate 23 can be equivalent to a beam member constrained at both ends, bearing the equivalent uniformly distributed load transmitted by the floor slab. Its mid-span local bending moment is proportional to the square of the calculated span. Based on the traditional single-span open beam, the perforated connecting plate 23 is introduced to divide the single open section into m+1 small segments, making the calculated span of a single segment 1 / (m+1) of the original length. At the same time, considering the reinforcing effect of the stiffness of the perforated connecting plate 23 on the end constraint, a β coefficient is introduced to correct the calculation results, resulting in a local bending moment calculation formula suitable for this structural system.

[0056] M is the local bending moment of the beam segment corresponding to a single hollow segment. It is the core design index for controlling the stress at the hole edge and the deformation of the plate. It can be used to guide the design of the number of hole connection plates 23 and the size of the opening 24, and ensure that the local stress of the multi-hole beam segment 2 meets the bearing capacity requirements.

[0057] α is the end constraint coefficient, which reflects the degree of rotational constraint at both ends of the hollow segment. Its value is related to the node stiffness and the beam line stiffness ratio. The stronger the constraint, the smaller the value of α and the lower the local bending moment. It can usually be selected between 1 / 8 and 1 / 12 according to the degree of node rigidity.

[0058] β is the web constraint enhancement coefficient, which reflects the strengthening effect of the stiffness of the hole connection plate 23 on the end constraint of the hollow segment. This parameter is a specific correction coefficient for multi-hole hollow beams. Conventional single-hole hollow beams do not have this parameter. The greater the thickness of the hole connection plate 23 and the stronger the stiffening structure, the smaller the value of β and the more significant the local bending moment control effect. The value range is usually from 0.75 to 0.95.

[0059] q is the equivalent uniformly distributed line load of the floor slab, which is obtained by converting the vertical surface load of the floor slab. It reflects the load intensity borne by the open section and includes the basic combination value of dead load and live load.

[0060] L is the total length of the hollow section between two adjacent connecting node components 3, which is the span size of the main grid. It determines the overall stress scale of the hollow section and can be flexibly adjusted according to the building column grid size.

[0061] In specific engineering design, for a floor grid with a standard span of 3 meters, the total length L of the open section between adjacent connecting node components 3 is taken as 3000mm, and the equivalent uniformly distributed line load q of the floor is taken as 20kN / m. The end constraint coefficient α is taken as 1 / 12 based on the rigidity of the node connection, and the web constraint enhancement coefficient β is taken as 0.85 based on the stiffness of the hole connection plate 23. When one hole connection plate 23 is set, m=1, and the calculated length of a single segment is 1500mm. Substituting into the formula, the local bending moment M=1 / 12×0.85×20×(1.5)²≈3.19kN·m can be obtained. If the traditional single-hole scheme is adopted, m=0, and the local bending moment is about 15kN·m. This scheme can reduce the local bending moment to about one-quarter of the traditional scheme, showing a significant advantage in stress distribution. When two hole connection plates 23 are set, m=2, and the local bending moment can be further reduced. The number of hole connection plates 23 can be flexibly selected according to the load level and the opening requirements.

[0062] In some embodiments, the hole connecting plate 23 is a continuous steel plate or a combined web plate with a local stiffening plate, and the connection method between the hole connecting plate 23, the end connecting plate 25 and the upper rib T-shaped steel 21 and the lower rib T-shaped steel 22 is one of welding, bolting, or a combination of bolting and welding.

[0063] Specifically, the continuous steel plate form of the hole connection plate 23 is simple in construction, easy to process, and saves materials, making it suitable for standard beam segments with low shear force. The combined web with locally stiffened plates can adopt forms such as vertical web with side stiffeners or vertical web with central stiffeners to improve the out-of-plane stability and shear bearing capacity of the hole connection plate 23, preventing shear buckling of the web, and is suitable for transition zones and supporting beam segments with high loads. Welded connections can use fillet welds, full penetration groove welds, etc., offering good integrity, uniform force transmission, and high stiffness, suitable for factory-prefabricated multi-hole beam segments 2, ensuring component processing accuracy and quality. Bolted connections can use friction-type high-strength bolts, facilitating on-site disassembly and adjustment, adapting to the construction requirements of fully assembled structures, and reducing on-site welding workload. Bolted-welded combined connections balance assembly efficiency and force transmission reliability. Initial positioning and tightening of bolts, followed by position correction and reinforcement with fillet welds, is a commonly used connection method in prefabricated steel structures.

[0064] Furthermore, stiffening ribs 231 are provided on both sides of the hole connecting plate 23, and the corner of the hole 24 is provided with an arc transition section, with the positions of the stiffening ribs 231 and the arc transition section corresponding one-to-one.

[0065] Specifically, stiffening ribs 231 are arranged around the hole-connecting plate 23, which can effectively improve the local stability and out-of-plane stiffness of the hole-connecting plate 23, restrain the lateral deformation of the hole-connecting plate 23, prevent buckling instability of the hole-connecting plate 23 under shear force, and improve the safety reserve of the multi-hole beam segment 2. The arc transition section is arranged at the corner of the hole 24, which can alleviate the stress concentration phenomenon at the hole corner, prevent fatigue cracks from appearing at the hole corner under repeated loads, and improve the durability and fatigue life of the multi-hole beam segment 2. The stiffening ribs 231 and the arc transition section are positioned one-to-one, so that the stiffening ribs directly correspond to the hole corner area where the stress concentration is most significant, maximizing the local bearing capacity of the hole edge, while making the stiffness transition of the beam segment more uniform and avoiding secondary stress caused by abrupt stiffness changes.

[0066] In some embodiments, the upper connecting plate 32 and the lower connecting plate 33 are both formed by two orthogonal plates being slotted and interlocked or cross-welded together.

[0067] Specifically, the two orthogonal plates correspond to the force transmission requirements of beam segments in two orthogonal directions. The slotted interlocking welded structure allows the plates in both directions to be at the same elevation, resulting in more direct force transmission, better overall joint integrity, and smoother force flow. This is suitable for internal cross-shaped joints with large loads. Cross-welding can be achieved by welding a continuous through-plate in one direction and a separate through-plate in the other, simplifying processing, eliminating the need for slotting, and reducing manufacturing costs. This is suitable for edge and corner joints. Both welding methods ensure effective bidirectional axial force transmission, achieving the design goal of continuous axial force transmission across joints in chord members.

[0068] In some embodiments, the connecting node assembly 3 further includes a bidirectional tie rod 35, the two ends of which are respectively anchored to the lower rib T-shaped steel 22 on both sides of the steel pipe 31.

[0069] The bidirectional tie rod 35 is mainly used to bear the tensile force of the lower rib, and is especially suitable for areas with large bending moments and nodes with high tensile strength requirements. The bidirectional tie rod 35 can be made of high-strength threaded steel bars, precision-rolled threaded steel bars, high-strength bolts, or prestressed tie rods, selected flexibly according to the magnitude of the tensile force and construction conditions. The bidirectional tie rod 35 penetrates the steel pipe 31 and is anchored to the multi-hole beam segments 2 on both sides, forming a continuous tensile force transmission path, further reducing the tensile load on the sidewalls of the steel pipe 31 and improving the overall tensile performance of the node. The bidirectional tie rod 35 can be pre-stressed or preloaded, so that the node is in a pre-compressed state before the load is applied, effectively reducing tensile cracking deformation of the node and improving the stiffness and fatigue performance of the node.

[0070] In some embodiments, the steel pipe 31 is filled with concrete or grouting material to form a concrete filler 37, and the upper connecting plate 32 is provided with a pouring through hole 36.

[0071] Specifically, the steel pipe 31 can be made of square steel pipe, rectangular steel pipe, round steel pipe, rhomboid steel pipe, or box-shaped steel pipe welded from steel plates, and can be flexibly selected according to the building shape, stress requirements, and processing conditions. The filling material inside the steel pipe 31 can be one of ordinary concrete, self-compacting concrete, lightweight aggregate concrete, ceramsite concrete, or lightweight high-strength grouting material. After filling, it can form a combined stress system with the steel pipe 31, which can significantly improve the local stability of the steel pipe 31 and the compressive and shear resistance of the joints, while improving the fire resistance and durability of the joints and slowing down the temperature rise rate of the steel pipe 31 under fire. Shear connectors can also be provided on the inner wall of the steel pipe 31. The shear connectors can be at least one of shear connectors, short steel bars, perforated steel plates, angle steel ribs, or rib plates, which can enhance the interfacial bonding between the steel pipe 31 and the internal concrete filling body 37, prevent relative slippage between the two, and improve the combined stress performance. The pouring through-hole 36 provided in the upper connecting plate 32 ensures the flow of concrete during pouring, avoids pouring blind spots below the connecting plate, and ensures that the filling material is dense and uniform. The grouting material is suitable for filling small-section steel pipes 31, with better fluidity and higher density. The filling material can be flexibly selected according to the cross-sectional size of the steel pipe 31 and design requirements.

[0072] Furthermore, the steel pipe 31 is also equipped with an internal partition, which is arranged horizontally inside the steel pipe 31.

[0073] The inner diaphragm can be horizontal, annular, cross-shaped, or perforated, adaptable to different cross-sections of the steel pipe 31 and their stress requirements. The inner diaphragm further strengthens the force transmission path within the steel pipe 31, distributing the axial force of the chord members more evenly to the steel pipe 31 and the internal concrete infill 37. After welding the inner diaphragm to the upper connecting plate 32 and the lower connecting plate 33, a rigid force transmission frame is formed, improving the overall stiffness and deformation resistance of the joint, while simultaneously constraining the deformation of the internal concrete infill 37, fully leveraging the combined effect of steel-concrete composite structures.

[0074] In some embodiments, the composite panel 1 includes a precast slab 11 and a cast-in-place surface layer 12 cast above the precast slab 11. The precast slab 11 rests on an upper rib T-shaped steel 21. The top of the upper rib T-shaped steel 21 is provided with a plurality of shear connectors 4. The shear connectors 4 are studs welded to the top of the upper rib T-shaped steel 21 and embedded in the cast-in-place surface layer 12. The cast-in-place surface layer 12 is provided with at least one of two-way surface layer reinforcement, slab joint connection reinforcement and additional reinforcement near the node.

[0075] The precast slab 11 can be one of the following: precast reinforced concrete composite base slab, steel truss floor deck slab, or profiled steel sheet. It can serve as the bottom formwork for the cast-in-place surface layer 12, eliminating the need for additional formwork and supports, significantly improving on-site construction efficiency. Furthermore, the factory precast quality of the slab 11 is more stable, and its flatness is easier to guarantee. After casting, the cast-in-place surface layer 12 forms an integral whole with the precast slab 11, jointly bearing the floor load, while also encasing the shear connector 4 to form a combined effect. The shear connector 4 is a shear connector welded to the top of the upper rib T-shaped steel 21 and embedded in the cast-in-place surface layer 12. It ensures effective bonding between the steel frame and the concrete panel, enabling their coordinated work, preventing slippage at the contact surface, and fully utilizing the structural advantages of the composite structure. The cast-in-place surface layer 12 can be internally reinforced with bidirectional surface reinforcement, slab joint connection reinforcement, and additional reinforcement near nodes, improving the overall performance and local crack resistance of the panel.

[0076] On the other hand, this embodiment also provides a construction method for a two-way composite floor slab with porous steel beams, the specific steps of which are as follows:

[0077] The first step involves fabricating the multi-hole beam segment 2 and the connecting node assembly 3 in the factory. At least two openings 24 are set within the multi-hole beam segment 2. The upper connecting plate 32, lower connecting plate 33, and web connecting plate 34 are welded to the steel pipe 31 to form the connecting node assembly 3. Specifically, the upper rib T-shaped steel 21, lower rib T-shaped steel 22, end connecting plate 25, and hole connecting plate 23 are cut to the design dimensions in the factory. These are then welded together to form the multi-hole beam segment 2 with multiple openings 24. Simultaneously, the steel pipe 31 is processed, and the upper connecting plate 32, lower connecting plate 33, and web connecting plate 34 are welded at corresponding elevations to complete the prefabrication of the connecting node assembly 3. Bolt holes at the beam ends are also machined to ensure assembly accuracy. After prefabrication, trial assembly and quality inspection are conducted. The components are numbered and treated with anti-corrosion measures to ensure that the component dimensions and interface accuracy meet the requirements.

[0078] The second step involves hoisting and connecting the node assembly 3 to the multi-hole beam segment 2. The upper rib T-shaped steel 21 of the multi-hole beam segment 2 is welded or bolted to the corresponding upper connecting plate 32. The end connecting plate 25 of the multi-hole beam segment 2 is welded or bolted to the corresponding web connecting plate 34. The lower rib T-shaped steel 22 of the multi-hole beam segment 2 is welded or bolted to the corresponding lower connecting plate 33, forming a steel frame. Specifically, temporary supports are first set up on the construction site. The node assembly 3 is hoisted in the order from the corner to the edge and then to the interior. After correcting the axial position, installation elevation, and verticality, the multi-hole beam segments 2 in both directions are hoisted sequentially. The initial connection between the multi-hole beam segments 2 and the nodes is completed using high-strength bolts. After correcting the flatness and grid size of the overall frame, the final bolt tightening and supplementary welds are performed.

[0079] The third step is to anchor and pre-tighten the multi-hole beam segments 2 located on both sides of the connecting node assembly 3 using bidirectional tie rods 35. Specifically, for nodes with bidirectional tie rods 35, the bidirectional tie rods 35 are passed through the steel pipe 31, and both ends are connected to the lower rib T-shaped steel 22 of the corresponding multi-hole beam segment 2. They are pre-tightened or tensioned according to design requirements to establish an initial pre-tension force in the bidirectional tie rods 35, ensuring the continuity of tension transmission and reducing tensile deformation of the node.

[0080] The fourth step is to pour concrete inside the steel pipe 31. After the concrete reaches the required standard, the upper composite panel 1 will be constructed. Specifically, when using the on-site post-grouting process, self-compacting concrete is poured into the grouting hole at the top of the steel pipe 31. The air is vented through the venting hole to ensure that the concrete is densely filled to form the concrete filling body 37. After the concrete reaches the design strength, the temporary support is removed and the upper construction can proceed.

[0081] The fifth step involves installing precast slabs 11 on the steel frame, tying the reinforcing bars, and then pouring the surface concrete to complete the composite floor slab construction. Specifically, the precast slabs 11 are hoisted and placed on the upper rib T-shaped steel 21. The width of the slab joints and the elevation of the slab surface are adjusted. The slab joints, edges, and reserved openings are sealed and formwork is erected. The surface reinforcement, slab joint connection reinforcement, and additional node reinforcement are tied. After checking that the position of the shear connector 4 is correct, the cast-in-place surface concrete 12 is poured as a whole. After curing to the design strength, the overall construction and quality acceptance are completed.

[0082] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A multi-hole steel beam bidirectional composite floor slab, characterized in that, It includes a steel frame and a composite panel. The steel frame is assembled from multiple perforated beam segments and multiple connecting node components connected to the perforated beam segments. The multi-hole beam segment includes an upper rib T-shaped steel, a lower rib T-shaped steel, two end connecting plates, and at least one hole connecting plate. The two end connecting plates are respectively disposed at both ends of the multi-hole beam segment, and the hole connecting plate is disposed between the two end connecting plates. The upper and lower ends of the end connecting plates and the hole connecting plates are respectively connected to the upper rib T-shaped steel and the lower rib T-shaped steel, so that at least two adjacent openings are formed inside the beam segment along the beam length. The connecting node assembly includes a steel pipe, an upper connecting plate, a lower connecting plate, and a web connecting plate. The upper connecting plate and the lower connecting plate are respectively disposed on the upper and lower parts of the steel pipe, and are at the same height as the upper rib T-shaped steel and the lower rib T-shaped steel, and are fixedly connected to the upper rib T-shaped steel and the lower rib T-shaped steel. The web connecting plate is fixed to the side wall of the steel pipe. The end connecting plate is connected to the corresponding web connecting plate. The lower end of the connecting node assembly is not connected to the column. The combined panel is installed on the upper part of the multi-hole beam segment.

2. The multi-hole steel beam bidirectional composite floor slab according to claim 1, characterized in that, Each of the multi-hole beam segments is provided with m hole connecting plates, where m ≥ 1. The local bending moment of the opening area of ​​the multi-hole beam segment satisfies the formula M = α·β·q·(L / (m+1))²; where α is the end constraint coefficient, β is the web constraint enhancement coefficient, q is the equivalent line load, and L is the total length of the open space between nodes.

3. The multi-hole steel beam bidirectional composite floor slab according to claim 1, characterized in that, The hole connecting plate is a continuous steel plate or a combined web plate with local stiffening plates. The connection method between the hole connecting plate, the end connecting plate and the upper rib T-shaped steel and the lower rib T-shaped steel is one of welding, bolting or bolt-welding combination connection.

4. The multi-hole steel beam bidirectional composite floor slab according to claim 3, characterized in that, The connecting plate with holes is provided with stiffening ribs on both sides, and the corner of the opening is provided with a rounded transition section or an oblique transition section. The positions of the stiffening ribs and the rounded transition sections correspond one-to-one.

5. The multi-hole steel beam bidirectional composite floor slab according to claim 1, characterized in that, Both the upper connecting plate and the lower connecting plate are formed by two orthogonal plates interlocking and welding to form a cross-shaped whole, or by welding a continuous plate in one direction to two separate plates in another direction to form a cross-shaped whole. The portions of the upper connecting plate and the lower connecting plate that extend out of the steel pipe are respectively connected to the corresponding upper rib T-shaped steel or the lower rib T-shaped steel by butt welding, connecting plate bolt connection, or bolt welding combination connection.

6. The multi-hole steel beam bidirectional composite floor slab according to claim 1, characterized in that, The connection node assembly also includes bidirectional tie bars, the two ends of which are respectively anchored to the lower rib T-shaped steel on both sides of the steel pipe.

7. The multi-hole steel beam bidirectional composite floor slab according to claim 1, characterized in that, The steel pipe is filled with concrete or grout, and the upper connecting plate is provided with a pouring through hole.

8. The multi-hole steel beam bidirectional composite floor slab according to claim 7, characterized in that, The steel pipe is also equipped with an internal partition.

9. The multi-hole steel beam bidirectional composite floor slab according to claim 1, characterized in that, The composite panel includes a precast slab and a cast-in-place surface layer cast on top of the precast slab. The precast slab rests on the upper rib T-shaped steel. The top of the upper rib T-shaped steel is provided with multiple shear connectors. The shear connectors are studs welded to the top of the upper rib T-shaped steel and embedded in the cast-in-place surface layer. The cast-in-place surface layer is provided with at least one of two-way surface reinforcement, slab joint connection reinforcement, and additional reinforcement near the joint.

10. A construction method for the multi-hole steel beam bidirectional composite floor slab as described in claim 1, characterized in that, Includes the following steps: S1, the factory manufactures a multi-hole beam segment and a connecting node assembly, with at least two openings provided in the multi-hole beam segment, and the upper connecting plate, lower connecting plate and web connecting plate are welded to the steel pipe to form the connecting node assembly; S2, hoist the connecting node assembly and the multi-hole beam segment, weld or bolt the upper rib T-shaped steel of the multi-hole beam segment to the corresponding upper connecting plate, weld or bolt the end connecting plate of the multi-hole beam segment to the corresponding web connecting plate, and weld or bolt the lower rib T-shaped steel of the multi-hole beam segment to the corresponding lower connecting plate to form a steel frame; S3, the multi-hole beam segments located on both sides of the connecting node assembly are anchored and pre-tightened by bidirectional tie rods; S4, concrete is poured inside the steel pipe, and the upper composite panel is constructed after the concrete reaches the required standard. S5. Install precast slabs on the steel frame, tie reinforcing bars, and then pour concrete for the surface layer to complete the composite floor slab construction.

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