A steel-concrete composite hollow T-beam bridge structure and its manufacturing method

Abstract

The present invention proposes a steel-concrete composite hollow T-beam bridge structure and a manufacturing method thereof, comprising a prefabricated steel-concrete composite T-beam unit, wherein the prefabricated steel-concrete composite T-beam unit is provided with multiple pieces, the middle section of the bottom of the prefabricated steel-concrete composite T-beam unit is an arched structure, and a steel tie rod is provided at the arched structure to form a hollow shape. The beam ends of adjacent prefabricated steel-concrete composite T-beam units are connected by cast-in-place wet joints, the ends of adjacent prefabricated steel-concrete composite T-beam units are connected by a diaphragm, the middle sections are connected by a mid-span diaphragm, and the prefabricated steel-concrete composite T-beam unit is provided with a cast-in-place concrete bridge deck. T-shaped steel is embedded in the bottom of the concrete beam, and a composite joint tenon is formed by cutting the steel teeth of the cross section and reinforcing steel bars, which has high fatigue resistance. Compared with traditional large prestressed concrete structures, it can achieve a slender structure type, reduce the height of the concrete part of the beam in the mid-span, save concrete, reduce the hoisting weight, and increase the bearing capacity of the mid-span section by adding steel tie rods.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and in particular to a steel-concrete composite hollow T-beam bridge structure and a manufacturing method thereof. Background Art

[0002] T-beam bridges are the most common type of bridge built on Chinese highways. Early T-beams were mostly reinforced concrete, with spans ranging from 7 to 20 meters. Reinforced concrete T-beams not only required a large amount of reinforcement but were also prone to cracking. With the development of prestressing technology, prestressed concrete T-beams were gradually adopted, with spans of 20 to 50 meters being common. Prestressed concrete construction requires specialized equipment, and the grouting is not dense, which can lead to uncontrolled quality. Prestressed concrete T-beams are prone to lateral bending during the tensioning of the prestressing steel strands, and the inverted arching caused by the prestressing is difficult to control. Therefore, prestressing construction requires additional construction measures to ensure beam stability. Furthermore, cracks in the bottom plate and webs are prone to developing after long-term use, affecting the beam's durability.

[0003] Steel-plate composite beams, which fully utilize the material properties of both steel and concrete, have seen rapid development in recent years. However, they also have some drawbacks, primarily the use of welded shear studs to connect the steel and concrete, which is labor-intensive and difficult to ensure quality. The upper flange steel plate and concrete deck are subjected to combined compression, resulting in some wasted steel. Summary of the Invention

[0004] To address the challenges of T-beam bridges and traditional steel plate composite beam bridges, a steel-concrete composite hollow T-beam bridge was proposed. Rolled H-section steel is cut into two T-sections, which are then embedded in the bottom of the concrete beam. The serrated shape of the cut section and the reinforcement within the concrete beam form a composite joint. Compared to traditional large prestressed concrete structures, this eliminates the need for prestressing, making the structure lighter and thinner, and facilitating construction. Compared to welded sections, using half the rolled steel section offers economic and operational advantages, eliminating the need for shear studs at the steel-concrete connection and the process of welding the shear studs to the steel plate. The concrete section at mid-span is lowered in height, and the hollowing design reduces concrete usage and hoisting weight. The steel tie bars fully utilize the tensile properties of steel, improving the structure's load-bearing capacity. The larger shear forces at the fulcrums are borne by the concrete section, with the steel serving as external reinforcement. This structure offers strong load-bearing capacity, minimal deflection, and optimal material utilization, resulting in excellent load-bearing performance.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A steel-concrete composite hollow T-beam bridge structure includes prefabricated steel-concrete composite T-beam units, wherein the prefabricated steel-concrete composite T-beam units are provided with multiple pieces, the middle section of the bottom of the prefabricated steel-concrete composite T-beam unit is an arch structure, a steel tie rod is provided at the arch structure, two sections of the steel tie rod are connected at both ends of the arch structure to form a hollow shape, the beam ends of adjacent prefabricated steel-concrete composite T-beam units are connected by cast-in-situ wet joints, the ends of adjacent prefabricated steel-concrete composite T-beam units are connected by a diaphragm, the middle sections are connected by a mid-span diaphragm, and the prefabricated steel-concrete composite T-beam units are cast-in-situ concrete bridge decks.

[0007] Further technology of the present invention:

[0008] Preferably, each prefabricated steel-concrete composite T-beam unit is a T-shaped structure consisting of a precast concrete top plate and a precast concrete web concrete portion from top to bottom.

[0009] Preferably, the bottom of the precast concrete web is provided with several pieces of T-shaped steel with steel teeth, wherein the middle section of one piece of T-shaped steel is an arched structure, and several T-shaped steels are welded to form a steel skeleton, which is embedded in the concrete part to form a composite connecting tenon.

[0010] Preferably, the composite connecting tenon is composed of steel teeth, precast concrete webs, and reinforcing steel bars;

[0011] The reinforcing steel bars include web restraining steel bars, transverse shear steel bars, and longitudinal full-length steel bars at the bottom of the beam. The transverse shear steel bars are placed in the concrete bridge deck, the longitudinal full-length steel bars at the bottom of the beam are placed in the precast concrete web, and the web restraining steel bars are placed in the precast concrete web. The lower ends are connected to the longitudinal full-length steel bars at the bottom of the beam, and the tops pass through the precast concrete top plate and extend into the concrete bridge deck to be connected to the transverse shear steel bars.

[0012] The production method is carried out as follows:

[0013] Step (1): cutting the H-shaped steel into two pieces of T-shaped steel with steel teeth through a cutting process;

[0014] Step (2): The T-shaped steel is divided according to the designed length, one of the divided T-shaped steels is pre-arched according to the designed line shape to form an arch structure, the edges and surfaces of the steel teeth are polished and then subjected to anti-corrosion treatment, and finally the divided T-shaped steels are welded according to the designed line shape to form a steel skeleton;

[0015] Step (3): Place the steel frame on a fixed pedestal, tie the web restraint steel bars, transverse shear steel bars, and longitudinal steel bars at the bottom of the beam to form reinforcement bars;

[0016] Step (4): Check the steel bar binding inside the composite joint to ensure that the number, spacing and diameter of the steel bars inside the composite joint meet the design requirements;

[0017] Step (5): making a formwork, accurately positioning the formwork, and pouring concrete to form a prefabricated steel-concrete composite T-beam unit;

[0018] Step (6): welding the steel tie rods and the steel frame;

[0019] Step (7): hoisting the monolithic prefabricated steel-concrete composite T-beam unit and casting the cast-in-place wet joints, mid-span diaphragms and end diaphragms;

[0020] Step (8): Use ordinary concrete to integrally cast the upper cast-in-situ concrete bridge deck to form a steel-concrete composite hollow T-beam bridge structure.

[0021] The beneficial effects of the present invention are:

[0022] The innovative use of composite tenon structure replaces traditional shear nails, channel steel and other shear connectors. Since there is no welding work in the production of rolled beams, there is no risk of residual welding stress and deformation caused by welding, avoiding the maintenance and repair of welds in the later stage. U-shaped restraining steel bars are configured at the composite tenon to effectively prevent prying failures from occurring under the composite tenon, thereby ensuring the ductility and load-bearing performance of the main beam. Traditional concrete structures require the configuration of a large number of steel bars, and this cross-section can increase the force arm of the steel, which is equivalent to external steel bars, which cannot be achieved by traditional internal steel bars. Therefore, it has sufficient load-bearing capacity, good technical and economic advantages, and is a structural form that is easy to promote.

[0023] The steel-concrete composite hollow T-beam bridge structure adopts pre-arched T-shaped steel and steel tie rod construction, which does not require prestressed steel strands, making the concrete web section thinner and lighter, saving concrete while improving the bearing capacity. It can be manufactured using traditional T-section formwork, eliminating the need to produce special formwork and reducing production costs. The prefabricated steel-concrete composite T-beam units are prefabricated in a standardized manner in the factory and transported to the site. They are light in installation weight and can be quickly installed with the help of ordinary lifting equipment. The use of rolled steel instead of welding not only saves steel but also improves durability, facilitates maintenance, and saves costs throughout the entire life cycle.

[0024] The steel-concrete composite hollow T-beam bridge structure conforms to the characteristics of industrialized construction, has standardized design, factory production, mechanized assembly, and has the advantages of energy saving and environmental protection. It is the future development direction and trend of the construction industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the following is a brief introduction to the present invention in conjunction with the accompanying drawings required for the description, and further details are provided. It should be understood that the specific embodiments described herein are only for the purpose of explaining the present invention and are not intended to limit the present invention.

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of a prefabricated steel-concrete composite T-beam unit of the present invention;

[0028] Figure 3 This is a schematic diagram of rolling H-beam according to the present invention;

[0029] Figure 4 This is a schematic diagram of the steel skeleton of the present invention;

[0030] Figure 5 This is a schematic cross-sectional view of the end support of the present invention;

[0031] Figure 6 This is a cross-sectional schematic diagram of the present invention;

[0032] Figure 7 This is a schematic diagram of the cross-section reinforcement of the present invention;

[0033] Figure 8 This is a schematic diagram of the composite connecting tenon of the present invention;

[0034] The serial numbers in the above figure are: 1-steel-concrete composite T-beam unit, 2-steel tie rod, 3-cast-in-situ wet joint, 4-concrete bridge deck, 5-rolled H-shaped steel, 6-T-shaped steel, 7-steel skeleton, 8-steel teeth, 9-composite joint tenon, 10-precast concrete web, 11-precast concrete top plate, 12-web restraining steel bar, 13-transverse shear steel bar, 14-longitudinal full-length steel bar at the bottom of the beam, 15-wet joint connecting steel bar, 16-mid-span transverse diaphragm, 17-end transverse diaphragm. DETAILED DESCRIPTION

[0035] In order to make the technical means, creative features, purpose and efficacy of the present invention easier to understand, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain this description and are not intended to limit the present invention.

[0036] like Figure 1-5As shown. A steel-concrete composite hollow T-beam bridge structure includes prefabricated steel-concrete composite T-beam units, each of which is provided with multiple pieces. The middle section of the bottom of the prefabricated steel-concrete composite T-beam unit is an arched structure, and a steel tie rod 2 is provided at the arched structure to form a hollow structure. The steel tie rod can be made of T-shaped steel, variable thickness steel plate, or high-strength steel plate. Two sections of the steel tie rod 2 are connected at both ends of the arched structure to form a hollow shape. The ends of adjacent prefabricated steel-concrete composite T-beam units are connected by cast-in-place wet joints 3. The ends of adjacent prefabricated steel-concrete composite T-beam units are connected by end transverse diaphragms 17. The middle sections are connected by mid-span transverse diaphragms 16. A cast-in-place concrete bridge deck 4 is placed on the prefabricated steel-concrete composite T-beam unit. The concrete bridge deck 4 and the wet joints 3 connect the multiple prefabricated steel-concrete composite T-beam units into a whole.

[0037] Each prefabricated steel-concrete composite T-beam unit is a T-shaped structure consisting of the concrete portion of a prefabricated concrete top plate 11 and a prefabricated concrete web plate 10 from top to bottom.

[0038] The bottom of the precast concrete web 10 is provided with several pieces of T-shaped steel with steel teeth. The rolled H-shaped steel is cut through a cutting process to form two pieces of T-shaped steel with steel teeth 8. The T-shaped steel is divided according to the designed length. One of the divided T-shaped steel pieces is designed into an arch structure according to the designed linear shape. The edges and surface are polished and then treated with anti-corrosion. Finally, the divided T-shaped steel pieces are welded according to the designed linear shape to form a steel skeleton 7. The steel skeleton 7 is embedded in the concrete part to form a composite joint 9.

[0039] The composite connecting tenon 9 is composed of a steel tooth 8, a precast concrete web 10, and a reinforcing steel bar; the steel tooth 8 is the top end of a T-shaped steel and is inserted into the precast concrete web 10;

[0040] The reinforcing steel bars include web restraint steel bars 12, transverse shear steel bars 13, and longitudinal full-length steel bars 14 at the bottom of the beam. The transverse shear steel bars 13 are placed in the concrete bridge deck 4, and the longitudinal full-length steel bars 14 at the bottom of the beam are placed in the precast concrete web 10. The web restraint steel bars 12 are placed in the precast concrete web 10, with the lower end connected to the longitudinal full-length steel bars 14 at the bottom of the beam, and the top passing through the precast concrete top plate 11 and extending into the concrete bridge deck 4, and connected to the transverse shear steel bars 13.

[0041] The present invention embeds T-shaped steel sections into the bottom of the concrete beam, and forms a composite joint 9 by cutting steel teeth 8 and reinforcing steel bars, resulting in high fatigue resistance. Compared to traditional large prestressed concrete structures, this design achieves a slender structure with high load-bearing capacity and high rigidity. The high load-bearing capacity and sufficient rigidity minimize beam deflection and provide excellent load-bearing performance. The concrete section at mid-span is lowered in height, saving concrete and reducing lifting weight. The addition of steel tie rods 2 improves the load-bearing capacity of the mid-span section.

[0042] A steel-concrete composite hollow T-beam bridge structure, the manufacturing method of which is carried out according to the following steps:

[0043] Step (1): cutting the H-shaped steel 5 to form two pieces of T-shaped steel 6 having a convoluted line shape through a cutting process;

[0044] Step (2): split the T-shaped steel 6 according to the designed length, pre-arch one of the split T-shaped steel 5 according to the designed line shape, grind the edge and surface of the steel teeth 8 and then perform anti-corrosion treatment, and finally weld the split T-shaped steel 5 according to the designed line shape to form a steel skeleton 7;

[0045] Step (3): placing the steel frame 7 on a fixed pedestal, tying the web restraining steel bars 12, the transverse shear steel bars 13, and the longitudinal full-length steel bars 14 at the bottom of the beam to form reinforcement bars;

[0046] Step (4): Check the steel bar binding condition in the composite joint tenon 9 to ensure that the number, spacing and diameter of the steel bars in the composite joint tenon 9 meet the design requirements.

[0047] Step (5): making a formwork, accurately positioning the formwork, and pouring concrete to form a prefabricated steel-concrete composite T-beam unit 1;

[0048] Step (6): welding the steel tie rod 2 and the steel frame 7;

[0049] Step (7): hoisting the single-piece prefabricated steel-concrete composite T-beam unit 1, casting the cast-in-situ wet joint 3, the mid-span diaphragm 16 and the end diaphragm 17;

[0050] Step (8): Use ordinary concrete to integrally cast the upper cast-in-situ concrete bridge deck 4 to form a steel-concrete composite hollow T-beam bridge structure.

[0051] It should be noted that before pouring the cast-in-place wet joints, wet joint connecting steel bars 15 are provided in the precast concrete top plate 11. The wet joint connecting steel bars 15 of each precast steel-concrete composite T-beam unit are tied. After the tying is completed, the cast-in-place wet joints 3, mid-span cross diaphragms 16 and end cross diaphragms 17 are poured.

[0052] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A steel-concrete composite hollow T-beam bridge structure, characterized by: It comprises a prefabricated steel-concrete composite T-beam unit, wherein the prefabricated steel-concrete composite T-beam unit is provided with multiple pieces, the middle section of the bottom of the prefabricated steel-concrete composite T-beam unit is an arch structure, a steel tie rod is provided at the arch structure, two sections of the steel tie rod are connected at both ends of the arch structure to form a hollow shape, the beam ends of adjacent prefabricated steel-concrete composite T-beam units are connected by cast-in-situ wet joints, the ends of adjacent prefabricated steel-concrete composite T-beam units are connected by diaphragms, the middle sections are connected by mid-span diaphragms, and the prefabricated steel-concrete composite T-beam units are cast-in-situ concrete bridge decks; Each precast steel-concrete composite T-beam unit is a T-shaped structure consisting of a precast concrete top plate and a precast concrete web from top to bottom; The bottom of the precast concrete web is provided with several pieces of T-shaped steel with steel teeth, wherein the middle section of one piece of T-shaped steel is an arched structure, and the several T-shaped steels are welded to form a steel skeleton, which is embedded in the concrete part to form a composite joint tenon; The composite connecting tenon is composed of steel teeth, precast concrete webs, and reinforcing steel bars; The reinforcing steel bars include web restraining steel bars, transverse shear steel bars, and longitudinal continuous steel bars at the bottom of the beam. The transverse shear steel bars are placed in the concrete bridge deck, the longitudinal continuous steel bars at the bottom of the beam are placed in the precast concrete web, and the web restraining steel bars are placed in the precast concrete web. The lower ends of the bars are connected to the longitudinal continuous steel bars at the bottom of the beam, and the top ends pass through the precast concrete top plate and extend into the concrete bridge deck to connect to the transverse shear steel bars. The production method is carried out as follows: Step (1): cutting the H-shaped steel into two pieces of T-shaped steel with steel teeth through a cutting process; Step (2): The T-shaped steel is divided according to the designed length, one of the divided T-shaped steels is pre-arched according to the designed line shape to form an arch structure, the edges and surfaces of the steel teeth are polished and then subjected to anti-corrosion treatment, and finally the divided T-shaped steels are welded according to the designed line shape to form a steel skeleton; Step (3): Place the steel frame on a fixed pedestal, tie the web restraint steel bars, transverse shear steel bars, and longitudinal steel bars at the bottom of the beam to form reinforcement bars; Step (4): Check the steel bar binding inside the composite joint to ensure that the number, spacing and diameter of the steel bars inside the composite joint meet the design requirements; Step (5): making a formwork, accurately positioning the formwork, and pouring concrete to form a prefabricated steel-concrete composite T-beam unit; Step (6): welding the steel tie rods and the steel frame; Step (7): hoisting the monolithic prefabricated steel-concrete composite T-beam unit and casting the cast-in-place wet joints, mid-span diaphragms and end diaphragms; Step (8): Use ordinary concrete to integrally cast the upper cast-in-situ concrete bridge deck to form a steel-concrete composite hollow T-beam bridge structure.

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