A steel-concrete composite bridge deck reinforced with steel bar-steel plate composite trusses

Abstract

The present invention relates to the technical field of bridge engineering, and specifically to a steel-concrete composite bridge deck reinforced by a steel-rebar-steel plate composite truss. It comprises a steel base plate, upper chord steel bars, diagonal web bars, transverse steel bars, transverse support diagonal bars, support annular steel bars, shear nails and a concrete slab; the steel base plate is welded to a lattice beam composed of a transverse beam and a longitudinal beam, and a broken line armpit is provided near the lattice beam; the upper chord steel bars and diagonal web bars are arranged along the span direction of the bridge deck, and are welded to the steel base plate to form a steel-rebar-steel plate composite truss. The present invention utilizes standardized, modularized and industrialized steel bar products to simplify the construction process, reduce the difficulty of construction, and give full play to the respective advantages of steel and concrete materials. Due to the reinforcing effect of the steel-rebar-steel plate composite truss, the bearing capacity of the bridge deck is effectively improved, the thickness of the bridge deck is reduced, and the structural weight is close to that of an orthotropic steel bridge deck, which is suitable for use in bridge decks of large span bridges.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and in particular to a steel-concrete composite bridge deck reinforced by a steel bar-steel plate composite truss. Background Art

[0002] In modern bridge design, there are generally three types of bridge deck structures: concrete bridge deck, steel bridge deck or steel-concrete composite bridge deck.

[0003] Concrete bridge decks are relatively thick, have a large structural deadweight, and are difficult to install. Therefore, their application in large-span bridge structures is restricted. In order to reduce the deadweight of the structure, steel bridge decks become the preferred bridge deck form when the span reaches a certain level. However, many examples at home and abroad show that with the increase in operating time, steel bridge decks are prone to two diseases: pavement damage and fatigue cracking of the steel bridge deck. Steel-concrete composite bridge decks combine the advantages of both, with the advantages of light deadweight, high bearing capacity, and good durability. However, existing steel-concrete composite bridge decks generally use perforated plates for reinforcement and as connectors. The continuous welds between the perforated plates and the steel bottom plate can easily cause the steel bottom plate to deform. The through-steel bars need to pass through the holes in the perforated plates, which makes construction complicated and has poor applicability to construction-restricted sections on both sides of the bridge. In addition, the internal steel bar arrangement of the bridge deck is complex. At the same time, research shows that the concrete bridge deck and the steel base plate at the armpit of the steel-concrete composite bridge deck reinforced with perforated plates are bonded together only by friction. Under the action of fatigue load, they are very easy to separate and crack. The cracking occurs inside the structure and cannot be observed and inspected, which greatly increases the risk factor of the structure during operation. On the other hand, the perforated plate acts as a shear key, and the cross-sectional strength is greatly weakened. Under the action of fatigue load, the top of the perforated plate is easily torn.

[0004] Therefore, in order to reduce the deadweight of the bridge deck system, give full play to the respective advantages of steel and concrete materials, strengthen the bonding between the concrete slab and the steel base plate, optimize the arrangement of steel bars in the concrete slab, give full play to the performance of the steel bars in the concrete, and facilitate construction, a steel-concrete composite bridge deck reinforced with a steel bar-steel plate composite truss is a solution. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a steel-concrete composite bridge deck reinforced with a steel bar-steel plate composite truss. The concrete plate of the bridge deck is tightly combined with the steel base plate, and the overall stress performance is good, the dead weight is light, the bearing capacity is high, the economy is good, and the durability is good. The steel bars adopt standardized modular products, and the construction is fast and convenient, which is suitable for the bridge deck system of large span bridges.

[0006] The technical solution adopted in the present invention is as follows:

[0007] A steel-concrete composite bridge deck reinforced with a steel bar-steel plate composite truss comprises a steel bottom plate, upper chord steel bars, web member diagonal bars, transverse steel bars, transverse support diagonal bars, support hoop steel bars, shear nails and a concrete slab.

[0008] The thickness of the steel bottom plate is about 8-10 mm. The steel bottom plate is welded to a lattice beam composed of a transverse beam and a longitudinal beam, and a broken line and a haunch are provided near the lattice beam.

[0009] The upper chord reinforcement and web member diagonal reinforcement are arranged along the "longitudinal direction".

[0010] The diagonal reinforcement of the web member is in a continuous broken line shape in the "longitudinal direction", and the oblique side of the broken line is equivalent to the web member of the steel bar-steel plate composite truss, and the angle between the oblique side of the broken line and the horizontal plane is about 40-50 degrees; every two diagonal reinforcements of the web member are inclined "transversely" by about 10-20 degrees, and the tops are tilted together and welded to an upper chord steel bar at the top to form an integral standard part. The integral standard part can be mass-produced in the factory and then welded to the steel base plate, which is convenient and quick to construct.

[0011] The transverse spacing of the integral standard components on the steel base plate is 150mm-200mm. The diagonal web reinforcement of the integral standard components is expanded outward at the bottom into an arc with a radius of 30-50mm. This arc is welded to the lower chord steel base plate, forming a steel-steel composite truss. The steel base plate serves as the lower chord of the steel-steel composite truss. At the haunch, the diagonal web reinforcement extends along the hypotenuse of the steel base plate to the top surface of the lattice beam and is welded to it.

[0012] The transverse steel bars are perpendicular to the upper chord steel bars and are evenly arranged on the upper layer or lower layer of the upper chord steel bars.

[0013] The transverse support diagonal reinforcement is perpendicular to the upper chord reinforcement and is evenly arranged at the axil. The transverse support diagonal reinforcement is welded to the lattice beam and the steel bottom plate, and overlapped with the transverse reinforcement at the top.

[0014] The support annular steel bars are evenly arranged at the axils.

[0015] A small number of shear nails are arranged on the steel bottom plate and the lattice beam.

[0016] The concrete slab is cast in place, with a standard concrete thickness of 12-15 cm, and a thickness of 24-30 cm near the armpits of the lattice beams. Conventional strength concrete is used, and a certain amount of steel fiber or mixed fiber may be incorporated into the concrete to achieve low shrinkage, high crack resistance, and high toughness.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] Compared with concrete bridge decks, the thickness of the bridge deck is reduced, the deadweight of the bridge deck structure is reduced, the spanning capacity of the bridge structure is improved, and the bending resistance of the bridge deck structure is increased.

[0019] Compared with steel bridge decks, it reduces the amount of steel used in steel structures, solves the fatigue problems of steel bridge decks and pavement damage problems, and improves the structural economy and durability.

[0020] Compared with the existing steel-concrete composite bridge deck reinforced with perforated plates, a steel-concrete composite bridge deck reinforced with a steel bar-steel plate composite truss has an integral standard component composed of upper chord steel bars and web diagonal bars that can be standardized, modularized, and industrially produced, and the transverse steel bars do not need to be passed through the holes of the perforated plates, which greatly simplifies the construction process and difficulty, improves construction efficiency and construction accuracy, and saves construction costs; since the interaction force between the steel bottom plate and the concrete is mainly transmitted through the bond force between the upper chord steel bars, web diagonal bars and concrete, the bond between the steel bottom plate and the concrete is tighter and more integrated; the problem of the concrete bridge deck and the steel bottom plate at the armpit of the steel-concrete composite bridge deck reinforced with perforated plates being easily separated and cracked under fatigue loads is avoided; and the problem of the top of the perforated plate being easily broken under fatigue loads due to the large weakening of the cross-section is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic cross-sectional view along the longitudinal direction of a specific embodiment of the present invention;

[0022] Figure 2 It is a cross-sectional schematic diagram of a specific embodiment of the present invention along the horizontal direction;

[0023] Figure 3 It is a schematic diagram of the plan layout of a specific embodiment of the present invention.

[0024] Markers in the figure:

[0025] 1. Steel base plate; 2. Shear studs (φ22×200mm); 21. Shear studs (φ10×100mm); 3. Top chord reinforcement; 4. Web member diagonal reinforcement; 5. Transverse reinforcement; 51. Transverse support diagonal reinforcement; 52. Support ring reinforcement; 6. Concrete slab; 7. Broken line haunch;

[0026] L is the span of the bridge deck; α is the angle between the web member diagonal reinforcement and the bridge deck in the "longitudinal" direction; β is the "transverse" inclination angle of the web member diagonal reinforcement; r is the outward expansion radius of the bottom of the web member diagonal reinforcement. DETAILED DESCRIPTION

[0027] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0028] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, certain parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, the omission of certain well-known structures and their descriptions in the accompanying drawings is understandable.

[0029] like Figure 1-3 As shown, a steel-concrete composite bridge deck reinforced with a steel bar-steel plate composite truss includes a steel base plate 1, upper chord steel bars 3, web member diagonal bars 4, transverse steel bars 5, transverse support diagonal bars 51, support annular steel bars 52, shear studs 2 and a concrete slab 6.

[0030] See also Figure 1 、 Figure 2 The steel base plate 1 is welded to the lattice beams, which are composed of transverse and longitudinal beams. A fold line haunch 7 is provided near the lattice beams. The thickness of the steel base plate 1 is 8-10mm. The longitudinal spacing of the lattice beams (i.e., the bridge deck span L) is 3-4m, and the transverse spacing of the lattice beams is 5-12m. The increased structural height at the fold line haunch 7 can accommodate the greater shear forces and negative bending moments at the lattice beams, improving load-bearing performance.

[0031] A small number of shear studs are installed on the steel base plate 1 and lattice beams. Shear studs 21 are installed on the steel base plate 1, measuring 10 x 100 mm and spaced 300-400 mm apart. Shear studs 2 are installed on the lattice beams, measuring 22 x 200 mm and spaced 140-250 mm apart. Shear studs 21 are welded to the steel base plate 1 at the fold line haunches (7) to strengthen the connection between the concrete slab 6 and the steel base plate 1 at these locations, preventing concrete separation and cracking at these locations. Shear studs 2 and 21 are staggered.

[0032] See also Figure 1 、 Figure 2 The concrete slab 6 is 12-15 cm thick, and the thickness of the concrete slab 6 at the fold line and arm 7 is 24-30 cm. This relatively thin concrete slab 6 effectively reduces the weight of the bridge deck, and the structural deadweight is relatively close to that of an orthotropic steel bridge deck, making it suitable for bridge decks of long-span bridges. The steel bottom plate 1 not only serves as the primary load-bearing member to withstand the tensile stress at the bottom of the bridge deck, but also serves as the steel formwork during construction, eliminating the need for formwork work, facilitating construction, and reducing construction time.

[0033] The concrete slab 6 is constructed of high-performance hybrid fiber concrete, grade C50, containing 0.7-0.9 kg / m³ of polyacrylonitrile fiber and 40-50 kg / m³ of steel fiber. Hybrid fiber concrete effectively improves the concrete's material properties, achieving low shrinkage, high crack resistance, and high toughness.

[0034] See also Figure 1 、 Figure 2 、 Figure 3 The upper chord reinforcement 3 and web diagonal reinforcement 4 are arranged longitudinally. The web diagonal reinforcement 4 forms a continuous broken line in the longitudinal direction, with the hypotenuse corresponding to the web of the steel-steel composite truss. The web diagonal reinforcement forms an angle a of 40-50° with the bridge deck in the longitudinal direction, and the truss inter-node spacing is approximately 200 mm.

[0035] Every two web member diagonal bars 4 are tilted transversely, bringing the tops together at an angle of 70-80°. The diagonal bars are welded to an upper chord steel bar 3 to form a single, integrated standard component. The diagonal bars 4 expand outward at the bottom into an arc shape, with a bottom expansion radius r of 30-50mm. They are welded to the steel base plate 1, effectively increasing the contact length between the diagonal bars 4 and the steel base plate 1. The diagonal bars 4 extend along the oblique edge of the steel base plate 1 at the fold line arm 7 to the top surface of the lattice beam and are welded thereto. This effectively prevents the concrete slab 6 of the steel base plate 1 from splitting due to the local pressure of the shear studs 21 at the fold line arm 7, while also participating in bearing the shear force on the lattice beam. The "transverse" spacing of the above-mentioned integrated standard components on the steel base plate 1 is 150mm-200mm. The diameter of the upper chord steel bar 3 is determined according to the force requirements and is 16-22mm. The diameter of the diagonal bars 4 is 8-10mm. The steel-steel composite truss, formed by welding standard components consisting of upper chord reinforcement 3 and web diagonal reinforcement 4 to the steel base plate 1, not only provides reinforcement during concrete pouring, preventing deformation of the steel base plate 1, but also acts as a shear key to transmit the interaction forces between the concrete and the steel base plate 1. Furthermore, the standard components consisting of upper chord reinforcement 3 and web diagonal reinforcement 4 are prefabricated in the factory and welded to the steel base plate 1 on-site, achieving standardized, modular, and industrialized production. This simplifies the construction process and complexity, improves construction efficiency and precision, and reduces construction costs. The steel-steel composite truss exhibits clear load characteristics and excellent structural bending and shear resistance, capable of meeting the load requirements under repeated vehicle loads.

[0036] The concrete slab 6 is provided with a transverse reinforcement 5 in the "transverse direction", which is located below the upper chord reinforcement 3 and tied to it. A transverse support diagonal reinforcement 51 is provided at the fold line armpit 7. The transverse support diagonal reinforcement 51 is welded to the lattice beam and the steel bottom plate 1, and overlapped with the transverse reinforcement 5 at the top, which can effectively prevent the concrete at the fold line armpit 7 of the lattice beam and the steel bottom plate 1 from splitting due to the local pressure of the shear nails 21, and at the same time participate in bearing the shear force on the lattice beam. Support annular reinforcement 52 is provided on the lattice beam in both the longitudinal and transverse directions to enhance the overall performance of the concrete slab at the fold line armpit 7, ensure the accurate positioning of the reinforcement, and prevent local cracks from occurring in the middle of the concrete slab 6. The diameter of the above-mentioned reinforcement is 12-16mm.

[0037] In summary, a steel-concrete composite bridge deck reinforced with a steel-steel plate composite truss utilizes standardized, modular, and industrialized steel reinforcement products to simplify the construction process, reduce construction difficulty, and fully leverage the respective strengths of steel and concrete. The reinforcement provided by the steel-steel plate composite truss effectively increases the load-bearing capacity of the bridge deck, reduces its thickness, and achieves a structural weight comparable to that of an orthotropic steel bridge deck, making it suitable for use on long-span bridge decks.

[0038] Compared to existing bridge decks, this new bridge deck has the following advantages: Compared to concrete bridge decks, it reduces the thickness of the deck, reduces the weight of the deck structure, improves the spanning capacity of the bridge structure, and increases the bending resistance of the deck structure. Compared to steel bridge decks, it reduces the amount of steel used in the structure, solves the fatigue problems of steel bridge decks and pavement damage, and improves the economic efficiency and durability of the structure.

[0039] Compared with the existing steel-concrete composite bridge deck reinforced by perforated plates, a steel-concrete composite bridge deck reinforced by a steel bar-steel plate composite truss has an integral standard component composed of upper chord steel bars and web diagonal bars that can be standardized, modularized, and industrially produced, and the transverse steel bars do not need to be passed through the holes of the perforated plates, which greatly simplifies the construction process and difficulty, improves construction efficiency and construction accuracy, and saves construction costs; since the interaction force between the steel bottom plate and the concrete is mainly transmitted through the bond force between the upper chord steel bars, web diagonal bars and concrete, the bond between the steel bottom plate and the concrete is tighter and more integrated; the problem of the concrete bridge deck and the steel bottom plate at the armpit of the steel-concrete composite bridge deck reinforced by the perforated plates being easily separated and cracked under fatigue loads is avoided; and the problem of the top of the perforated plate being easily broken under fatigue loads due to the large weakening of the cross section is avoided.

Claims

1. A steel-concrete composite bridge deck reinforced with steel bar-steel plate composite trusses, characterized in that: It includes a steel base plate (1), upper chord steel bars (3), web member diagonal bars (4), transverse steel bars (5), transverse support diagonal bars (51), support annular steel bars (52), shear studs (2) and a concrete slab (6); The steel bottom plate (1) is welded to a lattice beam composed of a transverse beam and a longitudinal beam, and a broken line haunch (7) is provided near the lattice beam; the upper chord steel bars (3) and the web member diagonal bars (4) are arranged along the span direction of the bridge deck and are welded to the steel bottom plate (1) to form a steel bar-steel plate composite truss; The transverse reinforcement (5) is arranged perpendicular to the span direction of the bridge deck; a plurality of shear nails (2) are arranged on the steel bottom plate (1) and the lattice beam; concrete is poured on the steel bottom plate (1) and the lattice beam, and the concrete and the steel bottom plate (1) are connected through the shear nails (2) and the reinforcement-steel plate composite truss to form a steel-concrete composite bridge deck that is subjected to common stress; The web member diagonal reinforcement (4) in the steel bar-steel plate composite truss is in a continuous broken line shape in the longitudinal direction, the oblique side of the broken line is equivalent to the web member of the steel bar-steel plate composite truss, and the oblique side of the broken line forms an angle with the horizontal plane; every two web member diagonal reinforcements (4) are inclined at a certain angle in the transverse direction, and the tops of the two web member diagonal reinforcements (4) are inclined together and welded to an upper chord steel bar (3) at the top; The web member diagonal reinforcement (4) is expanded outward at the bottom and welded to the steel bottom plate (1), and the steel bottom plate (1) is equivalent to the lower chord of the steel bar-steel plate composite truss; The transverse support oblique reinforcement (51) is perpendicular to the upper chord reinforcement (3) and is evenly arranged at the haunch. The transverse support oblique reinforcement (51) is welded to the lattice beam and the steel bottom plate (1) and overlapped with the transverse reinforcement (5) at the top. The support ring steel bars (52) are evenly arranged at the axils.

2. The steel-concrete composite bridge deck reinforced with steel bar-steel plate composite trusses according to claim 1, characterized in that: The "longitudinal" spacing of the lattice beam crossbeams is 3-4m, and the "transverse" spacing of the lattice beam longitudinal beams is 5-12m.

3. The steel-concrete composite bridge deck reinforced with steel bar-steel plate composite trusses according to claim 1, characterized in that: The steel base plate (1) also serves as a steel formwork during the construction process.

4. The steel-concrete composite bridge deck reinforced with steel bar-steel plate composite trusses according to claim 1, characterized in that: The web member diagonal reinforcement (4) extends along the oblique edge of the steel bottom plate (1) at the haunch to the top surface of the lattice beam and is welded thereto.

5. The steel-concrete composite bridge deck reinforced with steel bar-steel plate composite trusses according to claim 1, characterized in that: The transverse steel bars (5) are perpendicular to the upper chord steel bars (3) and are evenly arranged on the upper layer or lower layer of the upper chord steel bars (3).

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