Steel plate floor support plate and implementation method

Abstract

The invention discloses a steel plate floor support plate and an implementation method, and aims at solving the problems that a traditional floor support plate is insufficient in rigidity and strength, large in steel consumption, complex in construction, low in material utilization rate and the like. The floor support plate comprises a wide upper flange (the minimum width is larger than or equal to 30 mm), a wave-shaped reinforcing steel bar web member, a lower chord reinforcing steel bar and a profiling thin-bottom steel plate, the wide upper flange is of a combined type or thin steel plate type or trapezoidal steel pipe structure, and a side plate forming an inclination angle with a vertical shaft enhances the out-of-plane stability; the inclination angles of the steel bar web members are consistent with those of longitudinal ribs (trapezoidal ribs, closed inverted triangular ribs and the like) of the upper flange side plates and the profiled thin-bottom steel plates, so that line-surface contact welding is realized; the profiled thin-bottom steel plate is provided with longitudinal ribs and transverse ribs, so that the overall rigidity is improved; the lower chord steel bar adopts a double-layer design to strengthen node stress. According to the implementation method, industrial production is achieved through cold roll forming, automatic resistance welding and other processes. A traditional triangular truss is optimized into a trapezoid and four-side box type space structure, the bending rigidity is remarkably improved (the inertia distance between the upper flange and the profiling thin bottom steel plate is increased by 40% or above), the steel consumption is reduced by about 30%, the connection reliability is enhanced, meanwhile, the concrete consumption is reduced, the construction process is simplified, and the structure is suitable for various building scenes such as large span and heavy load.

Description

Technical Field

[0001] The present invention relates specifically to the field of engineering technology, and in particular to a steel floor deck and an implementation method, which can be widely used in floor slabs of various projects. Background Art

[0002] In modern engineering, floor decking, as a crucial component of floor structures, directly impacts building safety, construction efficiency, and economic viability. While widely used in construction, traditional floor decking, such as composite decking made of corrugated steel sheets, has numerous limitations. Their limited stiffness and bearing capacity make them inadequate for complex construction conditions such as large spans and heavy loads.

[0003] With the acceleration of urbanization and innovations in construction technology, the construction industry is trending toward larger spans, super-high-rise buildings, green and environmentally friendly, and industrialized construction. The continued emergence of large-span public buildings, high-rise commercial complexes, and industrial plants places higher demands on the mechanical properties, ease of construction, and environmental performance of floor decking. The increasing adoption of green building concepts is driving the development of sustainable and low-energy building materials, making traditional floor decking insufficient to meet the demands of the industry. Against this backdrop, the development of new, high-performance floor decking has become a pressing need in the construction industry.

[0004] Traditional steel floor decks include corrugated steel floor decks and reinforced steel truss floor decks. Their rigidity and strength are difficult to meet the requirements of existing buildings, resulting in a large number of secondary beams or the need for supports, and a large amount of steel. The specific problems are as follows:

[0005] Corrugated steel floor decking is made of steel plates at least 0.8mm thick, cold-pressed and bent into a continuous series of bends. This bending provides the steel plates with the rigidity and strength to withstand vertical loads. This results in high steel usage and thickness. If the steel plates are to be used as load-bearing structures, they must be treated with fireproofing, rust prevention, and anti-corrosion treatments, resulting in high costs. If not used as load-bearing structures, the thicker steel plates would be wasted as floor slabs.

[0006] Steel truss floor decking is mostly made by welding steel trusses with cold-pressed steel plates. Cold-pressed steel plates are mostly about 0.5mm thick. The steel plates only serve as the bottom formwork for concrete pouring and do not bear any force. The steel truss is formed by a single steel bar in the upper chord, two steel bars in the lower chord, and a web member. The web member is connected to the ribs on the bottom plate by folding outward at the trough. Such floor decking has the following problems: 1. The floor decking has low stiffness and strength, and the support-free span provided by the same amount of steel is small. The protective layer thickness of the upper chord steel bar is 15mm, and the diameter of the upper and lower steel bars is generally 10mm~12mm. The distance between the centroid of the upper chord steel bar and the concrete surface is 20mm. The protective layer thickness of the lower chord steel bar is also 15mm, and the distance between the centroid of the lower chord steel bar and the bottom surface is 20mm. For floor slabs of around 120mm, the sacrificed centroid distance is large, resulting in lower stiffness and strength of the truss floor decking; 2. The steel trusses of the steel truss floor decking are denser, with a spacing of generally 200mm, and the spacing of the lower chord steel bars is 100, resulting in a large amount of steel used and a large waste of steel. Since the steel bottom plate is thinner and weaker, the web spacing of the truss cannot be large, otherwise the bottom plate strength between the truss webs will be destroyed. The traditional steel truss webs are 80mm apart at the bottom plate, with a spacing of 200mm and a maximum distance of 120mm between the webs. If the spacing of the trusses is increased, the distance between the webs increases, and the steel plates between the webs are prone to deformation and damage, resulting in safety and the risk of uneven bottom of the plate in the later stage. 3. The upper chord of the truss of two longitudinally adjacent floor decking plates is disconnected and cannot be used as negative bending reinforcement, and re-reinforcement is required.

[0007] The patent (CN 214614890 U) uses steel tubes for the upper chord. The web reinforcement is connected to the tubes using four-point welding. The web troughs are bent outward and then welded to the metal base plate to form the floor deck. The preferred method for connecting the webs to the upper chord is point welding, which makes the connection between the upper chord and the truss a weak point. Under high loads, the truss cannot guarantee the load-bearing safety of the truss. Secondly, the webs are bent outward before connecting to the base plate, which limits the base plate's participation in the load. When the base plate is loaded, the truss webs will experience significant shear deformation due to the bending, reducing the base plate's participation in the truss performance. Finally, the centroid of the upper chord is far away from the lower chord. Because the upper chord is made of steel tubes, with the same steel usage, the centroid of the upper chord is far away from the concrete surface and closer to the metal base plate. This results in limited improvement in the stiffness of the floor deck and limited increase in the span of the component.

[0008] The patent (CN 119825071 A) uses flat tubes, and while the spacing between the web members is slightly increased compared to traditional reinforced steel trusses, the increased steel content due to the use of steel tubes or various steel sections limits the increase in web member spacing. This is detrimental to providing lateral bending strength for trusses such as composite slabs, floor decks, and thin base beams. Steel plates between the trusses of floor decks in the same truss combination are prone to deformation, posing a safety risk. Thin-base composite slabs in the same truss combination are prone to cracking in the concrete base between the trusses. The upper flange is constructed of steel bars, steel tubes, or steel sections. Given the same cross-sectional steel content, the centroid of the upper flange section is too close to the centroid of the truss bottom chord, significantly reducing the truss's moment of inertia and, consequently, the flexural strength and stiffness of the truss. Consequently, the span of precast slabs and floor decks in the same truss combination is reduced. The distance from the top surface of the poured concrete slab significantly reduces the upper flange's utilization within the concrete slab, hindering the full utilization of the material's strength. In the literature, the trough of the web member is connected to the steel plate, and a raised rib is cold-bent on the cold-bent part of the steel plate. The shape of the rib is relatively complex, and the trough of the web member is welded to the top surface of the raised rib, which is still a point-to-surface contact connection. The connection strength and reliability are very weak, and the bent part of the steel bar exists as a stress-bearing area, which is not conducive to fully utilizing the role of the steel plate when the truss is subjected to stress. Summary of the Invention

[0009] (1) Purpose of the invention

[0010] The purpose of the present invention is to overcome the defects of the existing floor decking in the prior art, such as poor coordination between the steel plate and the truss, the inability of the steel plate to participate in the overall force, insufficient structural rigidity, excessive steel consumption, and high construction cost, and to provide a steel plate floor deck and its implementation method that can achieve coordinated work of various components, greatly improve the overall performance, save steel consumption and is convenient to construct. Summary of the Invention

[0011] In order to achieve the above technical objectives, the present invention provides the following technical solutions:

[0012] A steel plate floor deck comprises a relatively wide upper flange (1), a steel web (2), a lower chord steel bar (3) and a corrugated thin bottom steel plate (4), the specific structure of each component being as follows:

[0013] 1. Wider upper flange (1)

[0014] Its minimum width is not less than 30mm, and it can adopt the following three structural forms, which are thin-walled upper flanges:

[0015] a. Combined structure: It consists of a top plate (5) and two side plates (6) in an eight-shaped shape, which are formed by bending steel plates with a thickness of 0.8~3mm in one piece; the width of the side plates (6) is 10~20mm, and forms a preset inclination angle with the vertical axis; the opening edge of the eight-shaped side plates (6) can be bent inward or outward according to the force requirements to enhance the connection strength with other components. In this structure, the top plate is set on the upper side and away from the bottom plate. This design allows the centroid of the upper flange to reach the maximum distance from the bottom plate under limited conditions. In this way, the truss can form the maximum strength and rigidity under limited space and the same material usage. The eight-shaped inclined structure can strengthen the out-of-plane stability strength of the upper flange on the one hand, and facilitate connection with the web on the other hand, so that a reliable line-surface contact connection is formed between the web and the two side plates, and low-cost resistance welding can be used for connection operation. At the same time, the opening edge is set to be bent inward or outward. This curved structure further strengthens the upper flange's rigidity and enhances its out-of-plane stability, thus preventing the upper chord between the web crests from buckling. This is because when a truss is subjected to stress, the upper flange is typically in compression. If the upper flange's moment of inertia is too small or its slenderness ratio is too large, localized buckling and failure are very likely to occur. The curved design at the opening edge precisely avoids this problem.

[0016] b. Steel plate structure: A thin steel plate with a thickness of not less than 1 mm is used; longitudinal concave-convex ribs can be provided at the transverse edge or transverse middle position of the thin steel plate to improve its own rigidity; the longitudinal concave-convex ribs are disconnected at the position corresponding to the wave crest of the steel web (2) to avoid interference with the steel web (2), avoid reducing the transverse local rigidity of the flange, and affect the strength of the truss. For the thin steel plate as the upper flange, its out-of-plane moment of inertia itself is relatively small. When the truss is subjected to stress, the thin steel plate is in a compressed state, and the slenderness ratio of the steel plate between the wave crests is very large, which makes it very easy to cause instability and failure. To solve this problem, concave-convex ribs are added to the steel plate between the wave crests. Through this design, the moment of inertia of the steel plate is increased, the slenderness ratio of the steel plate is reduced, and the strength of the truss is thereby improved. It should be noted that due to the inclination angle between the web and the vertical axis, the web will exert a certain pressure on the flange steel plate when subjected to stress. If the ribs are installed throughout the entire length of the steel plate, the transverse compressive capacity of the steel plate will be weakened, which will in turn affect the strength of the truss. Therefore, the ribs are disconnected at the crests and installed only between the crests. This allows the ribs to enhance the performance of the steel plate while avoiding any adverse effect on the transverse compressive capacity of the steel plate, thus ensuring the overall strength of the truss.

[0017] c. Trapezoidal steel tube structure: The top and bottom surfaces of the steel tube are parallel, the width of the top surface is smaller than the width of the bottom surface, and the left and right side plates (6) form a preset inclination angle with the vertical axis, which has good compressive resistance. The steel tube used in the structure has excellent characteristics. It has a good moment of inertia. When subjected to stress, the slenderness is small and the stability is high, which can effectively improve the strength of the truss. At the same time, the inclined setting of the left and right side plates is conducive to providing sufficient contact surface for the connection with the web, thereby significantly increasing the connection reliability of the flange and the web, further ensuring the overall stability and stress performance of the truss structure.

[0018] The wider upper flange (1) also has the following features:

[0019] a. The distance between the upper surface of the top plate (5) and the upper surface after concrete pouring is 10~20mm, ensuring that the upper flange can effectively participate in the concrete composite force. The closer the upper flange top plate is to the top surface of the concrete, the greater the distance between the upper flange and the bottom plate, and the higher the moment of inertia of the truss formed by the flange and the bottom plate, which can significantly improve the bending stiffness of the structure and increase the brace-free span of the component. At the same time, this closer distance can enable the upper flange to better withstand the tensile force exerted on the concrete surface and prevent cracking on the top of the concrete. However, this distance must be controlled within a reasonable range: if the distance is less than 10mm, the protective layer of the concrete will be too thin, which is easy to cause cracking; when the distance is greater than 20mm, it will have a negative impact on the moment of inertia and the effective section height, resulting in the performance of the upper flange not being fully utilized.

[0020] b. Single or multiple connection holes (8) can be provided at both ends of the top plate (5), with the end holes being 30-50 mm from both ends of the top plate, so as to facilitate connection with adjacent components. At the longitudinal disconnection of the floor slab, in order to make the upper flanges of the two end floor slabs overlap each other, steel rods or screws are strung through the holes. After the concrete is poured, the force transmission connection of the upper flanges can be achieved, giving full play to the mechanical properties of the upper flanges and saving more steel. The connection method can be to overlap the upper flange top plates of the longitudinally adjacent floor slabs, or to add a connecting thin plate, which is connected to the upper flanges of the two truss floor slabs respectively, and holes are also reserved on the connecting plate, which are aligned with the holes of the upper flange top plates, and then steel rods or screws are strung through the holes. The longitudinal connection point is usually the support of the plate. After the concrete is poured, the floor slab will form a negative bending moment at the support. Connecting the upper flanges of the adjacent plates through connectors can greatly reduce the use of connecting steel bars and give full play to the strength of the upper flange steel in the use state. Furthermore, to prevent thermal cracking, concrete floor slabs require continuous reinforcement along the slab surface. If the upper flanges of adjacent slabs are connected longitudinally, the upper flange steel can be used to relieve thermal stress after concrete pouring, maximizing its effectiveness. During construction, the upper flange is in compression, increasing the strength and rigidity of the truss and reducing support requirements. In service, it withstands the tensile forces of the floor slab, fully utilizing the material's properties.

[0021] c. At least one end of the wider upper flange (1) extends beyond the edge of the corrugated thin bottom steel plate (4), with the excess length being 100 to 500 mm. At the longitudinal break of the floor deck, in order to allow the upper flanges of the floor decks at both ends to overlap and connect, the upper flange of the floor deck at one end must span the beam at the break. The beam is generally 200 to 300 mm wide. If the length is too short, the flange top plate cannot be overlapped. If the length is too long, it will waste materials and be more difficult to manufacture.

[0022] d. The ends of the wider upper flange (1) can be bent downward and welded to the thin corrugated bottom steel plate (4), and the side plates (6) at the bend are notched. The ends of the floor decking are often the places where the shear force is the greatest at the beams or shear walls. Due to the influence of the structural dimensions, the end truss webs of some floor decking cannot be placed on the beams or shear walls, which can easily cause shear failure. The present invention uses a thin-walled upper flange, which has the characteristic of being easy to bend. By simply bending the upper flange downward and welding it to the bottom plate, the shear force transmission of the truss can be achieved compared to the traditional method of welding a section of steel at the end. This design not only saves materials, but also simplifies the processing process, while reducing the amount of welding and being more energy-efficient.

[0023] e. The surface of the top plate (5) of the wider upper flange (1) may be provided with at least one of notches, concave-convex indentations, transverse ribs or longitudinal ribs. The upper flange is formed by bending thin steel plates, and these structures can enhance the local yield bearing capacity of the thin steel plates. After the concrete is poured, the upper flange is very close to the top of the concrete, which can withstand the tensile force of the concrete surface and prevent the top of the concrete from cracking. The notches or concave-convex indentations can also enhance the bonding strength between the upper flange and the concrete, giving full play to the mechanical properties of the thin steel of the upper flange.

[0024] 2. Steel web members (2)

[0025] A steel bar is continuously bent into a wave shape and symmetrically arranged in two rows on the left and right; the steel bar web (2) forms a preset inclination angle with the vertical axis, and as a preferred solution, a straight section is provided at the trough or peak position to facilitate welding and fixing;

[0026] a. When the wider upper flange (1) is a modular structure, the crest of the steel web (2) is welded and fixed to the inner or outer side of the figure eight side plate (6);

[0027] b. When the wider upper flange (1) is a trapezoidal steel tube structure, the crest of the steel web (2) is welded and fixed to the outer side of the steel tube side plate (6);

[0028] c. When the wider upper flange (1) is a steel plate structure, the crest top surface of the steel web (2) is welded and fixed to the bottom surface of the thin steel plate.

[0029] 3. Bottom chord reinforcement (3)

[0030] Arranged in parallel just below the wider upper flange (1), and welded and fixed to the trough of the steel web (2), specifically, it can be connected to the inner side, outer side or bottom surface of the trough;

[0031] The lower chord reinforcement (3) can be divided into an upper lower chord reinforcement (3-1) and a lower lower chord reinforcement (3-2); the diameter of the upper lower chord reinforcement (3-1) is not greater than 14 mm and is welded to the inner or outer side of the reinforcement web (2); the diameter of the lower lower chord reinforcement (3-2) is not greater than 6 mm and is welded to the bottom surface of the reinforcement web (2) and the corrugated thin bottom steel plate (4) to form a double load-bearing node. Increasing the lower lower chord reinforcement is beneficial to improving the strength and rigidity of the truss. The lower lower chord reinforcement is welded to the bottom surface of the web trough to maximize the distance between the lower chord and the upper flange, thereby increasing the moment of inertia of the truss. At the same time, the lower lower chord is welded to the bottom plate to form a line-surface contact, which more effectively increases the connection reliability of the truss and the bottom plate.

[0032] 4. Profiled thin bottom steel plate (4)

[0033] A thin steel plate is formed by cold bending, and a plurality of longitudinal ribs (7) are pressed on the surface of the plate. The longitudinal ribs (7) extend in a direction parallel to the wider upper flange (1) and are welded to the steel web (2).

[0034] The longitudinal ribs (7) can adopt the following three structures:

[0035] a. Trapezoidal ribs ("J" ribs): Rib edges are symmetrical and form a preset angle with the vertical axis. Rib height is at least 50mm, with a greater longitudinal rib height. Rib edges can contain multiple stiffening ribs, which protrude from the surface of the thin, corrugated base steel plate and are welded to the reinforced web to enhance shear resistance. The stiffening ribs increase local stiffness along the oblique edges of the longitudinal ribs. The protruding surface of the stiffening ribs is welded to the web. Due to the thin base plate thickness, weld penetration is facilitated when welding the web to the base plate. The presence of stiffening ribs prevents fully exposed welds, which could later rust and affect the aesthetics of the base plate. The inclination of the two oblique edges of the trapezoidal ribs matches the inclination of the web, creating a curved shape with a smaller top edge and a larger bottom edge. This not only increases the strength of the thin base steel plate but also ensures full contact between the web and the angled weld. Unlike conventional point connections of the web plate, this line-surface connection provides a larger contact surface and a more reliable connection, fully utilizing the strength of the steel base plate, thereby increasing the strength and stiffness of the truss deck. The trapezoidal ribs are relatively high, increasing the rigidity of the base plate. The combination of the ribs and the trusses provides both the rigidity of the upper flange and base plate combined with the rigidity of the ribs, significantly increasing the rigidity of the floor deck and increasing the unsupported span of the deck. Furthermore, because the trapezoidal ribs protrude by at least 50mm, a multi-ribbed slab can be formed after concrete pouring, reducing the amount of concrete and steel required.

[0036] b. Closed inverted triangular ribs: Rib height is no more than 15mm, providing excellent overall stability. The closed triangle shape of the longitudinal ribs ensures a smooth baseplate. The welds formed by welding the ribs to the webs are within the closed shape, ensuring a smooth and aesthetically pleasing baseplate while concealing the welds and eliminating any rust spots. Triangular ribs can be welded to the webs from either the top or the side. When welding to the sides, the weld contact surface is larger, further ensuring the connection strength between the web and baseplate. The height of the triangular longitudinal ribs should not be too high, sufficient to ensure connection to the webs. If the height exceeds 15mm, the protective layer thickness of the lower chord reinforcement will not meet the regulatory requirements.

[0037] c. Stacked ribs: formed by multiple layers of bending, the structural parameters can be adjusted according to load requirements.

[0038] d. Transverse ribs can be pressed between the rib edges of adjacent longitudinal ribs (7). The extension direction of the transverse ribs is perpendicular to the longitudinal ribs (7) to improve the out-of-plane stiffness of the corrugated thin bottom steel plate (4). When the bottom plate is thin, the oblique edges of the longitudinal ribs can increase the out-of-plane stiffness of the bottom plate. When the distance between the oblique edges is large, the out-of-plane stiffness of the bottom plate is weak. Adding transverse ribs between the oblique edges can improve the stiffness of the bottom plate between the ribs. When the top of the longitudinal rib is large, adding transverse ribs can also increase the out-of-plane local stiffness of the longitudinal rib top plate.

[0039] Key structure matching relationship

[0040] a. One or two longitudinal trapezoidal ribs may be provided between the left and right rows of steel web members (2). The height of the trapezoidal ribs shall not exceed 20 mm to enhance the stability of the local structure.

[0041] b. The connection method of the steel web (2) and the longitudinal rib (7) is: welding with the rib edge of the trapezoidal rib and the closed inverted triangle rib; welding with the top of the closed inverted triangle rib and the stacked rib through the trough bottom.

[0042] c. The rib edges of the trapezoidal ribs, the rib edges of the closed inverted triangular ribs, the steel web members (2), and the side panels (6) of the wider upper flange (1) are aligned with the vertical axis to ensure sufficient connection and contact between the components and a uniform force transmission direction, thereby avoiding stress concentration. The longitudinal ribs of the upper flange side panels and the cold-formed bottom panels formed by cold-formed upper flanges and cold-formed steel plates are aligned with the side angles. The upper flange and bottom panel are connected together by web members to form a truss floor deck. Compared with traditional truss floor decks, the inertia distance between the upper flange and the thin corrugated bottom steel plate is increased by more than 40%, significantly improving the bending stiffness.

[0043] The present invention also discloses a method for implementing the above steel floor deck, comprising the following steps:

[0044] Step 1: Raw material pretreatment: Thin steel strip and rebar are straightened using straightening equipment. A three-roll straightener is used to straighten cold-rolled thin steel strip with a thickness of 0.8-3mm. The straightening speed is controlled at 2-5m / min, ensuring a flatness error of ≤1mm / m after straightening. Meanwhile, a rebar straightener can be used to straighten rebar with a diameter of 6-12mm. During the straightening process, the rebar surface must be free of visible damage and the straightness error must be ≤2mm / m. By precisely controlling the straightening parameters, raw materials with qualified dimensional accuracy are provided for subsequent processing.

[0045] Step 2: Synchronous forming processing, cold-bending the thin steel strip to prepare the prototype of the wider upper flange (1), and continuously bending the steel bars to form the wavy steel web (2). The straightened thin steel strip is fed into the cold-bending machine. According to the design requirements of the upper flange, the roller shape and spacing of the cold-bending machine are adjusted to form the thin steel strip into an upper flange structure including a vertical web and two symmetrical legs, wherein the angle between the legs and the web is controlled to be 90°-135°, and the leg extension length is 10-20mm. At the same time, the straightened steel bars are fed into the synchronous bending device, which is linked to the cold-bending machine to ensure that the bending rhythm of the steel bars is synchronized with the cold-bending roller speed. The bending angle of the steel bars is set by the program so that the inclination angle of the diagonal rod of the steel web with the horizontal plane is equal to the bending angle of the legs, thereby forming a continuously bent steel web structure.

[0046] Step 3: Positioning and fixing: Position the wider upper flange (1) and the steel web (2) according to the designed position and fix them with a temporary fixing device. A pneumatic clamp is set up on the continuous production line. When the cold-formed upper flange and the bent steel web are transported to the designated position, the pneumatic clamp positions and clamps them at the node with a positioning accuracy of ±0.5mm. The clamping force of the clamp needs to be adjusted according to the material properties of the upper flange and the steel web to ensure that they do not move during the welding process and to ensure the assembly accuracy of the truss structure.

[0047] Step 4: Truss welding: Using the resistance automatic welding process, the wave crest of the steel web (2) is welded to the wider upper flange (1) to form a wider upper flange truss. A multi-electrode resistance welding machine is used to automatically weld the positioned upper flange and the wave crest node of the steel web. During the welding process, the welding pressure is controlled to 200-400N, the electrode travel speed is 1-3m / min, and the welding temperature is controlled to 70%-85% of the melting point of the steel. A double-pulse welding process is used, with the first pulse current of 800-1200A and a duration of 0.1-0.3s; the second pulse current of 300-500A and a duration of 0.5-1s. By precisely controlling the welding parameters, a solid weld connection is ensured between the web and the upper flange, thereby ensuring the structural strength and stability of the truss.

[0048] Step 5: Forming the base plate: Cold-bending the thin steel plate to form longitudinal ribs (7) and transverse stiffening ribs to produce a profiled thin base steel plate (4). Control the bending radius according to the base plate design requirements to avoid cracks or excessive deformation of the thin steel plate. The flatness error of the longitudinal ribs and transverse stiffening ribs after cold bending should be ≤1.5mm / m to ensure the overall flatness of the base plate.

[0049] Step 6: Assemble the entire structure. Align and secure the steel webs (2) of the wider upper flange trusses with the longitudinal ribs (7) of the profiled thin bottom steel plate (4). Use welding to complete the connection and form a complete steel plate floor deck. Assemble the prepared bottom plate longitudinal ribs and transverse stiffening ribs into a bottom plate frame structure. Then place the thin-walled upper flange trusses on the bottom plate frame so that the trough nodes of the truss webs are accurately aligned with the longitudinal rib sides of the bottom plate. Use positioning fixtures to fix the trusses and the bottom plate to ensure that the relative positions between the two meet the design requirements. Afterwards, use gas shielded welding or resistance welding to weld the webs to the longitudinal rib sides of the bottom plate. During welding, control the welding current and welding speed to avoid deformation of the bottom plate due to excessive welding heat, and ensure the strength and reliability of the connection between the trusses and the bottom plate.

[0050] (3) Core innovations

[0051] To address the problems of insufficient rigidity, large steel consumption, and poor connection reliability of traditional floor decking, the innovation of this invention focuses on structural optimization and coordinated force design, as follows:

[0052] 1. Innovation in upper flange structure

[0053] a. Adopt thin-wall wide design (minimum width ≥30mm) and maximize the distance between the upper flange centroid and the bottom plate through modular, steel plate or trapezoidal steel tube structure, thereby increasing the truss inertia moment by more than 20% with the same material usage.

[0054] b. The distance between the top plate and the top surface of the concrete is controlled at 10~20mm, which not only ensures the thickness of the protective layer, but also allows the upper flange to directly participate in the tensile stress of the concrete, solving the problem of low utilization rate of the traditional upper flange.

[0055] c. The opening edge bending and figure-eight side panel design enhance out-of-plane stability and simultaneously achieve line-surface contact welding between the web and the side panels (instead of traditional point connection), improving connection reliability.

[0056] 2. Web and connection optimization

[0057] a. The steel web is continuously bent into a wave shape, which is consistent with the inclination angle of the upper flange side plate and the bottom plate longitudinal ribs, forming full contact welding to avoid stress concentration.

[0058] b. The lower chord reinforcement adopts a double-layer design (upper layer diameter ≤14mm, lower layer ≤6mm), and is double-welded to the web trough and bottom plate to strengthen the node stress.

[0059] c. The longitudinal connection is connected through upper flange overlap + steel rod / screw connection, replacing the traditional additional reinforcement to achieve negative bending moment transmission and serve as temperature stress release steel.

[0060] 3. Innovation of bottom plate and rib structure

[0061] a. The corrugated thin bottom steel plate is provided with trapezoidal ribs with a height of ≥50mm. The stiffening ribs on the rib edges are welded to the web members, which not only enhances the shear resistance but also prevents the welds from being exposed and corroded.

[0062] b. The inclination angle of the trapezoidal rib is consistent with that of the web, forming a "small at the top and large at the bottom" shape, realizing a line-surface connection of the web, which increases the contact surface by more than 50% compared with traditional point connections.

[0063] 4. Structural combination innovation

[0064] a. By combining a wider upper flange with a metal base plate, the traditional triangular truss is changed to a trapezoidal truss, which has better structural performance.

[0065] b. The original triangular space structure was changed to a four-sided box-type space structure, which significantly improved the stability, load-bearing capacity and anti-deformation ability of the overall structure, further optimizing the structural performance.

[0066] 5. Process and adaptability innovation

[0067] a. The thin-walled upper flange can be directly bent and welded to the base plate, replacing the traditional end-welded steel, reducing welding volume by more than 30% and lowering processing costs.

[0068] b. The web member spacing is expanded to 160mm (traditional steel trusses are only 80~110mm). The number of trusses can be reduced by 30% for the same width of floor deck, which greatly saves steel.

[0069] (IV) Gain Effect

[0070] Compared with the prior art, the present invention has the following significant beneficial effects:

[0071] a. The flexural strength and rigidity of the floor deck are significantly improved: The longitudinal ribs of the upper flange and the cold-formed steel plate are formed by cold-bending the upper flange side panels and the cold-formed bottom panel, with the side angles aligned. The upper flange and bottom panel are connected by web members to form a trussed floor deck. Compared to traditional trussed floor decks, the inertial distance between the upper flange and the thin corrugated bottom steel plate is increased by over 20%, significantly improving flexural rigidity.

[0072] b. Increased connection strength and reliability between the web members and the upper and lower flanges: In the prior art, the web members are spot-welded to the upper and lower flanges. The upper flange is made of steel bars or steel pipes, the lower flange is made of steel plates, and the web members are made of steel bars. The present invention bends both the upper and lower flanges into inclined surfaces, allowing the web member reinforcement to be welded to the inclined surfaces of the upper and lower flanges. High-efficiency resistance welding can be used, replacing spot welding with line-surface welding. This results in higher weld strength and a more reliable connection, ensuring that the base plate participates in the load-bearing process.

[0073] c. Reduced truss usage and steel consumption for decks of the same width: This invention unfolds steel into thin-walled steel plates, which are then bent into upper flanges with splayed side panels. While maintaining the same steel usage, the unfolded steel is wider, and the web member troughs are further apart. Combined with the thin steel base plate, the upper flange enhances the truss's out-of-plane stiffness and strength. Conventional steel and truss web trough distances are approximately 80mm, while those of steel pipe webs are 110mm. However, unfolding the steel plates with the same flange steel increases this trough distance to 160mm, reducing the number of trusses by approximately 30% for decks of the same width.

[0074] d. Saving the amount of steel used in floor slabs: The steel bars of concrete cast floor slabs are divided into bottom steel bars and top steel bars. The bottom steel bars bear the mid-span bending moment, and the top steel bars bear the negative bending moment of the floor slab. In the prior art, due to the narrow width of the trusses and the dense laying, the number of lower chord steel bars and web members is increased, and the amount of steel used is increased. At the same time, the upper chord steel bars are disconnected at the adjacent longitudinal parts of the floor slabs and cannot be fully utilized. Additional steel bars must be laid at the disconnected parts, which increases the amount of steel bars used. The present invention utilizes the wide and thin characteristics of the upper top plate to form holes in the top plate, allowing the upper flanges of the longitudinally adjacent floor slabs to be mechanically connected through the holes, giving full play to the strength of the upper flange steel plates and reducing the amount of steel bars used.

[0075] e. After the floor slab is poured, the upper flange steel utilization rate is increased: After the upper flange is unfolded, the distance between the centroid and the top of the poured floor slab is reduced, which further enhances the upper flange's strength. Furthermore, the increased contact surface between the upper flange and the concrete improves the bond between the concrete and the upper flange, fully utilizing the upper flange's strength. This is especially true when the assembled floor slab or deck is used in a span beam, maximizing the upper flange steel utilization and reducing steel consumption.

[0076] f. The production of floor decking is simpler, energy-saving and lower in cost: the thin-walled upper flange side panels and the longitudinal rib sides of the bottom plate are in full contact with the web members, and can be connected by resistance welding, which saves welding materials. Compared with the welding process of the upper flange of steel pipes, which requires gas shielded welding, it is simpler, more material-saving and efficient.

[0077] g. Excellent synergistic load-bearing performance: By setting the rib edges of the trapezoidal ribs, the steel web members (2), and the side plates (6) of the wider upper flange (1) to the same inclination angle, the angle matching of each component is achieved, so that the corrugated thin bottom steel plate (4) can participate in the overall load-bearing as the lower chord of the truss, changing the current situation in which the steel plate in the traditional floor deck only plays a dependent role, and greatly improving the material utilization rate and the overall load-bearing capacity.

[0078] h. Strong structural stability: Line-surface contact welding is used instead of traditional point connection, which significantly increases the contact area between the steel web (2) and the longitudinal ribs (7) and the wider upper flange (1), greatly improving the connection strength and force transmission efficiency. At the same time, the double-layer setting of the lower chord steel bars (3) and the arrangement of the stiffening ribs further enhance the deformation resistance of the structure.

[0079] i. Convenient and efficient construction: Through standardized cold-bending forming and resistance automatic welding processes, the industrialized production of floor decking is realized, reducing manual operation errors; the precise matching design of each component simplifies the on-site installation process and improves construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 A schematic diagram of the thin-walled upper flange structure of a steel floor deck (figure eight);

[0081] Figure 2 This is a schematic diagram of the thin-walled upper flange structure of a steel floor deck (the side inside the figure eight);

[0082] Figure 3 This is a schematic diagram of the thin-walled upper flange structure of a steel floor deck (outside the figure eight shape);

[0083] Figure 4 Schematic diagram of the thin-walled upper flange structure of a steel floor deck (steel plate);

[0084] Figure 5 This is a schematic diagram of the thin-walled upper flange structure of a steel floor deck (with concave and convex ribs in the middle of the steel plate);

[0085] Figure 6 A schematic diagram of the thin-walled upper flange structure of a steel floor deck (with concave and convex ribs on the edge of the steel plate);

[0086] Figure 7 A schematic diagram of the thin-walled upper flange structure of a steel floor deck (with bent ribs on the edge of the steel plate);

[0087] Figure 8 A schematic diagram of the thin-walled upper flange structure of a steel floor deck (trapezoidal tube);

[0088] Figure 9 This is a schematic diagram of the steel web structure of a steel floor deck;

[0089] Figure 10 This is a schematic diagram of the steel web structure of a steel floor deck (horizontal bending of the trough);

[0090] Figure 11 A schematic diagram of the steel web structure of a steel floor deck (horizontally bent at the crest);

[0091] Figure 12A schematic diagram of the steel web structure of a steel floor deck (horizontally bent at the trough and crest);

[0092] Figure 13 A schematic diagram of a truss structure of a steel floor deck (figure eight upper chord, single lower chord);

[0093] Figure 14 A schematic diagram of a truss structure of a steel plate floor deck (steel plate top chord, double bottom chord);

[0094] Figure 15 A schematic diagram of a truss structure of a steel floor deck (with an upper chord with an outer folded edge and double lower chords);

[0095] Figure 16 Schematic diagram of a corrugated thin bottom steel plate structure of a steel floor deck Figure 1 ;

[0096] Figure 17 Schematic diagram of a corrugated thin bottom steel plate structure of a steel floor deck Figure 2 ;

[0097] Figure 18 Schematic diagram of a corrugated thin bottom steel plate structure of a steel floor deck Figure 3 ;

[0098] Figure 19 Schematic diagram of a corrugated thin bottom steel plate structure of a steel floor deck Figure 4 ;

[0099] Figure 20 This is a structural diagram of a steel floor deck;

[0100] Figure 21 This is a structural diagram of a steel floor deck;

[0101] Figure 22 This is a structural diagram of a steel floor deck;

[0102] Figure 23 This is a structural diagram of a steel floor deck;

[0103] Figure 24 This is a structural diagram of a steel floor deck;

[0104] Figure 25 This is a structural diagram of a steel floor deck;

[0105] Figure 26 This is a structural diagram of a steel floor deck;

[0106] Figure 27 This is a structural diagram of the longitudinal connection of a steel floor deck at a beam;

[0107] Figure 28This is a schematic diagram of the front elevation structure of a steel floor deck connected longitudinally at the beam;

[0108] Figure 29 This is a schematic diagram of the AA cross-section structure of a steel floor deck connected longitudinally at the beam;

[0109] Figure 30 Schematic diagram of the inclination angles of the upper flange side plates, steel web members and longitudinal rib sides of a steel floor deck.

[0110] In the figure: 1. Thin-walled upper flange; 2. Steel web; 3. Lower chord steel bars; 3-1. Upper lower chord steel bars; 3-2. Lower lower chord steel bars; 4. Corrugated thin bottom steel plate; 5. Top plate; 6. Side plates; 7. Longitudinal ribs; 8. Connection holes. DETAILED DESCRIPTION

[0111] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0112] Example 1

[0113] Referring to Figures 1-30 , the present invention provides a technical solution: the steel floor deck comprises a wide upper flange, a steel web, a lower chord steel bar, and a corrugated thin bottom steel plate. The specific structure is as follows:

[0114] (1) Wider upper flange: It consists of a top plate and two side plates in an eight-shaped shape. It is formed by bending steel plates with a thickness of 0.8~3mm in one piece, and the side plates are 10~20mm wide. The edges of the two side plates in the eight-shaped shape are folded inward or outward. This design allows the upper flange to be expanded as much as possible by bending thin steel plates, so that the centroid of the upper flange moves upward, thereby increasing the moment of inertia and lateral stability of the truss. Among them, the width of the side plates covers the bending area of ​​the web, and the middle connection is a straight rod, which can ensure the maximum stiffness of the axial force of the truss web; the thickness of the upper flange meets the expansion width requirement and ensures sufficient thickness for connection with the web (for example, a 1.1mm thick upper flange, a 50mm wide top plate, a 10mm wide side plate, and a cross-sectional area of ​​77mm², which is equivalent to the cross-sectional area of ​​a 10mm diameter steel bar).

[0115] (2) Steel web: The steel web is continuously bent into a wave shape, with the same inclination angle as the side panels along the vertical axis. The wave crest is welded to the side panels. This design achieves line-surface contact welding between the web and the side panels, avoiding stress concentration and improving connection reliability.

[0116] (3) Bottom chord reinforcement: It is placed parallel to the corrugated thin bottom steel plate and welded to the trough of the steel web. The bottom chord reinforcement also functions as concrete reinforcement, which can increase the stiffness of the floor deck.

[0117] (4) Corrugated thin bottom steel plate: It is formed by bending thin steel plate, and multiple longitudinal ribs parallel to the upper flange of the thin wall are pressed on the surface. The inclined rib edges of the longitudinal ribs are consistent with the inclination angle of the vertical axis and the inclination angle of the side plate and the steel web, and are welded to the web.

[0118] The advantages of this embodiment are:

[0119] The centroid distance between the top flange and the concrete slab surface is better (for example, the centroid of a 1.1mm thick top flange is 15mm from the concrete slab surface, which is closer to the slab surface than the 20mm distance of a 10mm diameter steel bar). For a 100mm thick slab, the bearing capacity can be increased by about 10%.

[0120] The bottom spacing of the web members is widened from the traditional 80mm to 150mm, and the number of trusses in a 600mm wide floor deck can be optimized from 3 to 2, reducing the amount of steel used.

[0121] In the prior art, the minimum spacing between the bottom chord reinforcement bars of the three trusses is 100mm, far exceeding the 180mm spacing actually required for the floor slab, resulting in a waste of steel. By reducing the number of trusses in this embodiment, the redundancy of the bottom chord reinforcement bars and web members can be avoided. At the same time, the longitudinal ribs of the corrugated thin bottom steel plate are fully connected to the web members, allowing the bottom plate to participate in the load-bearing process, thereby improving the overall stiffness and strength of the floor deck and increasing the support-free span.

[0122] Furthermore, the longitudinal ribs are trapezoidal ribs, and the rib edges are welded to the troughs of the web members (as shown in Figures 7, 8, 9, 11, 12, and 14):

[0123] When the trapezoidal rib is small (as shown in Figures 7 and 14), the web member spacing is much larger than the rib width, and the two web members of the truss are welded to the outer rib edges of the two ribs respectively;

[0124] When the width of the upper side of the trapezoidal rib is consistent with the distance between the troughs of the web members (as shown in Figures 8 and 11), the web members are welded to both sides of the ribs, which can not only give full play to the bottom plate strength and increase the support-free span, but also reduce the length of the web member reinforcement;

[0125] When the height of the trapezoidal rib is large (as shown in Figures 9 and 12), the base plate itself bends to form a certain rigidity, and the two troughs of the truss are welded to the top of the rib edge.

[0126] Compared with traditional large-wave bent floor decks (no trusses, large thickness, and high steel consumption), this embodiment combines a corrugated thin bottom steel plate with a thin-walled upper flange truss, thereby saving steel while improving mechanical properties, increasing the span, and reducing the amount of cast-in-place concrete and the weight of the floor slab.

[0127] In addition, multiple stiffening ribs (horizontally or longitudinally) can be pressed on both sides of the trapezoidal rib. The stiffening ribs protrude from the bottom plate surface and are welded to the web (see Figures 9 and 12):

[0128] Longitudinal stiffeners are used for small-height trapezoidal ribs to avoid exposed welding points that affect the appearance of the base plate;

[0129] Transverse stiffeners are used for high-height trapezoidal ribs to enhance the lateral strength and local stability of the rib edges, while avoiding corrosion problems caused by exposed welds.

[0130] The corrugated thin bottom steel plate presses the transverse ribs (extending direction perpendicular to the longitudinal ribs, such as Figure 7-15 ), which can improve the out-of-plane stiffness of the intercostal bottom plate, especially suitable for scenarios with large hypotenuse distances, while also enhancing the local stiffness of the longitudinal rib top plate.

[0131] The distance between the top surface of the upper flange and the finished concrete pouring surface should be controlled between 10 and 20 mm. A distance too close (less than 10 mm) can result in a thin concrete cover and susceptibility to cracking. A distance too far (greater than 20 mm) can affect the moment of inertia and effective cross-sectional height, reducing the performance of the upper flange. This distance significantly improves the stiffness of the floor deck and the bearing capacity and crack resistance of the upper flange after concrete pouring.

[0132] Example 2

[0133] The invention is basically the same as Example 1, except that the wider upper flange (1) is made of 2mm thick steel plate with a width of 50mm, and there is an upward convex longitudinal rib in the transverse center of the steel plate. The steel web has a straight section at the wave crest, and the longitudinal rib is disconnected at the corresponding position of the wave crest. The lower chord steel bar (3) can be divided into an upper lower chord steel bar (3-1) and a lower lower chord steel bar (3-2); the upper lower chord steel bar (3-1) has a diameter of not more than 14mm and is welded to the inner or outer side of the steel web (2); the lower lower chord steel bar (3-2) has a diameter of not more than 6mm and is welded to the bottom surface of the steel web (2) and the corrugated thin bottom steel plate (4) to form a double load-bearing node.

[0134] Example 3

[0135] The method is basically the same as Example 1, except that the wider upper flange (1) is made of a trapezoidal steel tube with a thickness of 1 mm and a width of 50 mm at the top. The steel plate has an upward convex longitudinal rib at the transverse center. The steel web has a straight section at the crest, and the longitudinal rib is disconnected at the corresponding position of the crest.

[0136] Example 4

[0137] It is basically the same as Example 1, except that: a single or multiple connection holes are left at both ends of the wider upper flange top plate, the holes are 30-50 mm away from both ends of the top plate, and the thin-walled upper flange extends 100-500 mm beyond both ends of the corrugated thin bottom steel plate (as shown in Figures 11-14 and 16-18).

[0138] The length of a floor deck typically spans one to three beams. When spanning beams, the upper flange can bear negative bending moments, making the deck continuous. This increases the span distance between beams and allows the upper flange to bear negative bending moments on the upper portion of the floor. However, when the deck is disconnected at a beam, conventional technology requires additional reinforcement at the top of the beam, failing to utilize the strength of the upper flange. This embodiment addresses this issue through the following design:

[0139] The upper flange adopts a steel plate expansion design, with holes opened at the end of the top plate. The upper flange top plates of the longitudinally adjacent floor decking plates overlap each other, and steel rods or screws are inserted after the holes overlap. After the concrete is poured, the upper flange force transmission connection is realized, giving full play to its mechanical properties and saving steel.

[0140] The connection method can be to directly overlap the upper flange top plate, or to add a new connecting plate (the connecting plate has holes aligned with the upper flange, and steel rods or screws are strung in).

[0141] The extra-long part of the upper flange (100~500mm) needs to span the beam (usually the beam width is 200~300mm) to ensure effective overlap of the upper flanges of the floor decking at both ends.

[0142] Example 5

[0143] It is basically the same as Example 1, except that: both ends of the wider upper flange are bent downward and welded to the corrugated thin bottom steel plate, and the side plates at the bend are notched (see Figure 15).

[0144] Shear forces are greatest at the ends of floor decks where they rest on beams or shear walls. Due to structural size limitations, some end truss webs cannot rest on supports, making them susceptible to shear failure. Traditionally, this problem has been addressed by welding vertical webs, a complex process. This embodiment utilizes the flexible nature of the thin-walled upper flange, directly bending it downward and welding it to the base plate to achieve shear force transfer. This approach offers the advantages of material savings, simplified processing, reduced welding effort, and energy savings.

[0145] Notches are opened at the bends of the side panels to release bending stress, avoid irregular deformation of the upper flange, and ensure bending accuracy.

[0146] Example 6

[0147] The embodiment is basically the same as the embodiment 1, except that the top plate surface of the thin-walled upper flange is provided with at least one of notches, concave-convex indentations, transverse ribs or longitudinal ribs.

[0148] The upper flange is constructed from bent thin steel plate. This surface structure enhances the plate's local yield strength. After concrete is poured, the upper flange's proximity to the concrete surface allows it to withstand surface tension and prevent cracking. Furthermore, the notches and indentations enhance the bond between the upper flange and the concrete, fully utilizing the mechanical properties of thin-walled steel.

[0149] Example 7

[0150] It is basically the same as Example 1, except that the longitudinal rib is a closed triangular rib with a height of no more than 15 mm, and is welded to the trough of the web member (see Figures 10 and 13).

[0151] The closed triangular rib design ensures a flat baseplate, with welds hidden within the closed opening, enhancing the baseplate's aesthetics while preventing rust. The ribs can be welded to the web either through the top of the rib or through the side of the rib (side welding provides a larger contact surface and higher connection strength). The triangular rib height is controlled within 15mm, meeting the bottom chord reinforcement cover thickness requirement (exceeding 15mm is non-compliant).

[0152] A method for implementing a steel floor deck, characterized in that it comprises the following steps:

[0153] Step 1: Straightening thin steel strips and steel bars

[0154] A three-roll straightening machine is used to straighten cold-rolled thin steel strip with a thickness of 0.8-3mm. The straightening speed is controlled at 2-5m / min, ensuring a flatness error of ≤1mm / m after straightening. Similarly, a rebar straightener can be used to straighten rebar with a diameter of 6-12mm. During the straightening process, the rebar surface must be free of visible damage and the straightness error must be ≤2mm / m. By precisely controlling the straightening parameters, raw materials with qualified dimensional accuracy are provided for subsequent processing.

[0155] Step 2: Cold-bend the steel strip and bend the steel bars at the same time

[0156] The straightened thin steel strip is fed into a roll-forming machine. Based on the design requirements of the upper flange, the roll-forming machine's roller shape and spacing are adjusted to form the thin steel strip into an upper flange structure consisting of a vertical web and bilaterally symmetrical legs. The angle between the legs and the web is controlled between 90° and 135°, and the legs extend 10-20mm. Simultaneously, the straightened rebar is fed into a synchronous bending device, which is linked to the roll-forming machine to ensure that the bending rhythm of the rebar is synchronized with the speed of the roll-forming rollers. The bending angle of the rebar is programmed so that the angle of inclination of the web member's diagonal rod with the horizontal plane is equal to the bending angle of the legs, thus forming a continuously bent rebar web structure.

[0157] Step 3: Fix the upper flange and web reinforcement

[0158] A pneumatic clamp is installed on the continuous production line. When the cold-formed upper flange and bent steel web are delivered to the designated position, the pneumatic clamp positions and clamps them at the joint with an accuracy of ±0.5mm. The clamping force is adjusted according to the material properties of the upper flange and steel web to ensure that they do not move during the welding process, thus ensuring the assembly accuracy of the truss structure.

[0159] Step 4: Use resistance automatic welding to weld the web and upper flange to form a thin-walled upper flange truss

[0160] A multi-electrode resistance welding machine is used to automatically weld the crest joints of the positioned upper flange and the steel web. During welding, the welding pressure is controlled at 200-400N, the electrode travel speed is 1-3m / min, and the welding temperature is maintained at 70%-85% of the steel's melting point. A double-pulse welding process is employed, with the first pulse current at 800-1200A and a duration of 0.1-0.3s; the second pulse current at 300-500A and a duration of 0.5-1s. Precise control of welding parameters ensures a secure weld connection between the web and upper flange, guaranteeing the structural strength and stability of the truss.

[0161] Step 5: Cold-formed longitudinal and transverse stiffeners of the base plate

[0162] According to the baseplate design requirements, the thin steel plates used to make the baseplate are cold-bent to form longitudinal ribs and transverse stiffeners. The cross-sectional shape and dimensions of the longitudinal and transverse stiffeners must conform to the design specifications. The bending radius must be controlled during the cold-bending process to avoid cracking or excessive deformation of the thin steel plates. The flatness error of the longitudinal and transverse stiffeners after cold bending should be ≤1.5mm / m to ensure the overall flatness of the baseplate.

[0163] Step 6: Fix and weld the web of the thin-walled upper flange truss to the longitudinal rib side of the bottom plate

[0164] The fabricated longitudinal and transverse stiffeners of the baseplate are assembled into a baseplate frame structure. The thin-walled upper flange trusses are then placed on the baseplate frame, ensuring that the trough nodes of the truss webs are precisely aligned with the sides of the longitudinal ribs of the baseplate. Positioning fixtures are used to secure the trusses and baseplate to ensure their relative position meets design requirements. The webs are then welded to the sides of the longitudinal ribs of the baseplate using either gas shielded welding or resistance welding. The welding current and speed must be controlled to avoid deformation of the baseplate due to excessive heat. This ensures the strength and reliability of the connection between the trusses and baseplate, ultimately forming a complete truss structure.

[0165] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A steel floor deck, characterized in that: include: A wider upper flange (1), the minimum width of which is not less than 30 mm; The steel web (2) is formed by continuously bending steel bars into a wave shape, and is composed of two rows on the left and right, forming an inclination angle with the vertical axis; The lower chord steel bar (3) is arranged parallel to the lower side of the wider upper flange (1) and is welded and fixed to the inner side, outer side or bottom surface of the trough of the steel bar web (2); The profiled thin bottom steel plate (4) is formed by bending a thin steel plate, and a plurality of longitudinal ribs (7) parallel to the wider upper flange (1) are pressed on the surface, and the longitudinal ribs (7) are welded to the steel web (2).

2. The steel floor deck according to claim 1, characterized in that: The longitudinal rib (7) is any of the following structures a. Trapezoidal ribs, with rib sides symmetrical on both sides and forming an inclination angle with the vertical axis; b. The height of the closed inverted triangular rib shall not exceed 15mm; c. Stacked ribs.

3. The steel floor deck according to claim 2, characterized in that: The trapezoidal rib height is not less than 50 mm.

4. The steel floor deck according to claim 3, characterized in that: A plurality of stiffening ribs are pressed on both sides of the trapezoidal rib.

5. The steel floor deck according to claim 1, characterized in that: There is one or two longitudinal trapezoidal ribs between the left and right steel bar webs (2), and the height of the trapezoidal ribs is no more than 20 mm.

6. A steel floor deck according to claims 1 and 2, characterized in that: The steel web (2) is welded to the rib edges of the trapezoidal rib and the rib edges of the closed inverted triangle rib.

7. A steel floor deck according to claims 1 and 2, characterized in that: The trough bottom of the steel web (2) is welded to the closed inverted triangle rib and the stacked rib top.

8. The steel floor deck according to claim 1, characterized in that: The profiled thin bottom steel plate (4) has transverse ribs pressed between the rib edges of adjacent longitudinal ribs (7), and the extending direction of the transverse ribs is perpendicular to the longitudinal ribs (7).

9. The steel floor deck according to claim 1, characterized in that: The wider upper flange (1) is any of the following structures a. It consists of a top plate (5) and two side plates (6) in an eight-shaped shape, which are formed by bending a steel plate with a thickness of 0.8 to 3 mm, and the width of the side plates (6) is 10 to 20 mm, and the side plates (6) form an inclination angle with the vertical axis; b. Thin steel plate, with a thickness of not less than 1mm; c. A trapezoidal steel tube, wherein the top and bottom surfaces are parallel, the width of the top surface is smaller than the width of the bottom surface, and the left and right side plates (6) and the side plates (6) form an inclination angle with the vertical axis.

10. The steel floor deck according to claim 9, characterized in that: The opening edges of the two side plates (6) of the figure eight are bent inward or outward.

11. The steel floor deck according to claim 9, characterized in that: The thin steel plate is provided with longitudinal concave-convex ribs at the transverse edge or the transverse middle.

12. The steel floor deck according to claim 11, characterized in that: The longitudinal concave-convex ribs are disconnected at positions corresponding to the wave crests of the steel bar web (2).

13. The steel floor deck according to claims 1, 2 and 9, characterized in that: The rib sides of the trapezoidal ribs, the triangular rib sides, the steel web members (2) and the side plates (6) of the wider upper flanges have the same inclination angle with the vertical axis.

14. The steel floor deck according to claim 1, characterized in that: The steel web (2) has a straight section bent at the trough or crest.

15. The steel floor deck according to claims 1 and 9, characterized in that: The crest of the steel web (2) is welded to the inner side or outer side of the two side plates (6) of the wider flange (1).

16. The steel floor deck according to claims 1 and 9, characterized in that: The crest of the steel web (2) is welded to the outer side of the side plate (6) of the trapezoidal steel tube.

17. The steel floor deck according to claims 1 and 9, characterized in that: The top surface of the wave crest of the steel web (2) is welded to the bottom surface of the thin steel plate.

18. The steel floor deck according to claim 1, characterized in that: The lower chord steel bars (3) are divided into upper lower chord steel bars (3-1) and lower lower chord steel bars (3-2).

19. The steel floor deck according to claims 1 and 18, characterized in that: The upper layer lower chord steel bars (3-1) are welded to the inner side or outer side of the steel bar web, and the lower layer lower chord steel bars (3-2) are welded to the bottom surface of the steel bar web and the corrugated thin bottom steel plate (4).

20. The steel floor deck according to claim 18, characterized in that: The diameter of the upper layer lower chord steel bar (3-1) is not greater than 14 mm; the diameter of the lower layer lower chord steel bar (3-2) is not greater than 6 mm.

21. The steel floor deck according to claim 1, characterized in that: The upper surface of the wider upper flange (1) is 10 to 20 mm away from the upper surface of the concrete pouring.

22. The steel floor deck according to claim 1, characterized in that: Single or multiple connection holes (8) are left at both ends of the wider upper flange (1).

23. The steel floor deck according to claim 1, characterized in that: At least one end of the wider upper flange (1) extends beyond the end edge of the profiled thin bottom steel plate (4).

24. The steel floor deck according to claim 1, characterized in that: The two ends of the wider upper flange (1) are bent downward and welded to the profiled thin bottom steel plate (4), and the side plates (6) at the bent positions are notched.

25. The steel floor deck according to claim 1, characterized in that: The surface of the wider upper flange (1) is provided with at least one of notches, concave-convex indentations, transverse ribs or longitudinal ribs.

26. A method for implementing a steel floor deck, characterized in that The following steps are involved: Step 1: Straighten thin steel strips and steel bars; Step 2: Cold-bend the steel strip and bend the steel bars at the same time; Step 3: Fix the upper flange and web reinforcement; Step 4: Use resistance automatic welding to weld the web and upper flange to form a wider upper flange truss; Step 5: Cold-bend the longitudinal ribs and transverse stiffeners of the bottom plate; Step 6: Fix and weld the web of the wider upper flange truss to the longitudinal rib side of the bottom plate.

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