Steel and concrete composite beam

Abstract

The utility model provides a steel and concrete composite beam which comprises a bridge deck slab and a composite rib plate located on the bottom face of the bridge deck slab, the composite rib plate comprises a concrete rib plate and a steel beam, and the concrete rib plate is located between the bridge deck slab and the steel beam; the steel beam comprises a steel bottom plate and a steel web plate arranged on the steel bottom plate, steel tenons and mortises are alternately arranged on the upper edge of the steel web plate in the longitudinal bridge direction, and the steel tenons and the mortises are embedded in concrete at the lower end of the concrete rib plate; the steel webs and the concrete rib plates are connected together through the steel tenons, the mortises, the lower opening stirrups, the upper opening stirrups and the transverse short steel bars, and compared with an existing stud shear key connection mode, the connection mode has higher initial rigidity, shear strength and ductility; meanwhile, welding is not needed, welding defects and residual stress are avoided, the corners of the steel tenons and the mortises adopt arc chamfers, stress concentration is effectively avoided, and the anti-fatigue performance is excellent.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge engineering, in particular to a composite beam of steel and concrete. Background Art

[0002] As an improvement to traditional technologies, steel-UHPC composite beams have been gradually promoted and applied in recent years. However, conventional steel-UHPC composite beams also suffer from drawbacks such as insufficient material performance, high steel consumption, and high welding workload. To fully utilize the superior properties of steel and UHPC materials and further improve the economic and applicability of steel-UHPC composite beams, several new composite beam structures have been proposed. Patent application publication number CN112342889A proposes an assembled lightweight composite beam bridge with a steel-UHPC composite web. The concept is to use UHPC to bear the high compressive stresses of the upper flange and the low tensile stresses of the composite web, while using steel to bear the high tensile stresses of the lower portion. However, in patent application publication number CN112342889A, the T-shaped UHPC main beam is connected to the inverted T-shaped steel beam via lateral shear studs. These lateral shear studs need to be welded to the T-shaped steel beam, which is prone to welding defects and residual stresses. Furthermore, the initial stiffness, shear strength, and ductility are poor.

[0003] In summary, there is an urgent need for a composite beam of steel and concrete to solve the problems existing in the prior art. Utility Model Content

[0004] The utility model aims to provide a composite beam of steel and concrete, aiming to solve the problem that welding shear studs on T-shaped steel beams to connect the T-shaped UHPC main beam and the inverted T-shaped steel beam in existing steel-UHPC composite beams easily leads to welding defects and residual stress. The specific technical solution is as follows:

[0005] A composite beam of steel and concrete, comprising a bridge deck and a composite rib located on the bottom surface of the bridge deck, wherein the composite rib comprises a concrete rib and a steel beam, wherein the concrete rib is located between the bridge deck and the steel beam;

[0006] The steel beam includes a steel bottom plate and a steel web disposed on the steel bottom plate, wherein the upper edge of the steel web is alternately provided with steel tenons and mortises along the longitudinal direction of the bridge, and the steel tenons and mortises are embedded in the concrete at the lower end of the concrete rib; the concrete rib includes a rib concrete layer and a rib steel reinforcement skeleton located inside the rib concrete layer;

[0007] The rib steel bar skeleton includes the bottom layer of longitudinal steel bars, the second bottom layer of longitudinal steel bars, longitudinal distribution steel bars, transverse short steel bars and a vertical stirrup group; the vertical stirrup group includes lower open stirrups and upper open stirrups alternately arranged along the longitudinal bridge direction, the lower open stirrups are arranged in a one-to-one correspondence with the steel tenons, the upper open stirrups are arranged in a one-to-one correspondence with the mortise, the steel tenons are inserted into the openings at the lower ends of the lower open stirrups, the lower ends of the upper open stirrups are placed in the mortise, and transverse short steel bars are provided on both sides of the lower ends of the upper open stirrups; the bottom layer of longitudinal steel bars is used to connect the lower ends of the lower open stirrups along the longitudinal direction, and the second bottom layer of longitudinal steel bars is used to connect the lower ends of the upper open stirrups along the longitudinal direction; a plurality of longitudinal distribution steel bars are arranged inside the vertical stirrup group along the vertical direction, and a single longitudinal distribution steel bar passes through the alternately arranged upper open stirrups and lower open stirrups along the longitudinal direction.

[0008] Preferably, the number of the bottom layer of longitudinal steel bars and the second bottom layer of longitudinal steel bars are both two, and both are symmetrically arranged on both sides of the steel web.

[0009] Preferably, the distance between the transverse short steel bar and the lower end of the upper open stirrup in the longitudinal bridge direction is greater than 0.

[0010] Preferably, the depth of the mortise is h D , the lower end of the upper opening stirrup is located at 1 / 2h D The position of the lower end of the lower opening stirrup is lower than the position of the lower end of the upper opening stirrup.

[0011] Preferably, the concrete ribs are thickened at the locations where the steel tenons and mortises are embedded; and the corners of the steel tenons and mortises are chamfered with arcs.

[0012] Preferably, the distance C between the bottom edge of the mortise and the lower edge of the concrete rib is D Greater than 20mm.

[0013] Preferably, the number of composite ribs in the composite beam is at least two, and a transverse partition is provided between two adjacent concrete ribs.

[0014] Preferably, the bridge deck comprises a bridge deck concrete layer and a bridge deck steel reinforcement skeleton located inside the bridge deck concrete layer, and the rib steel reinforcement skeleton is connected to the bridge deck steel reinforcement skeleton.

[0015] Preferably, the bridge deck steel bar skeleton includes an upper transverse steel bar group, a lower transverse steel bar group and a bridge deck longitudinal main bar; a plurality of bridge deck longitudinal main bars are arranged at intervals along the transverse direction of the bridge, the upper transverse steel bar group is located on the upper side of the bridge deck longitudinal main bars, the upper transverse steel bar group includes a plurality of bridge deck transverse main bars arranged at intervals along the longitudinal direction of the bridge, and the bridge deck longitudinal main bars are overlapped with the bridge deck transverse main bars in the upper transverse steel bar group; the lower transverse steel bar group is located on the lower side of the bridge deck longitudinal main bars, the lower transverse steel bar group includes a plurality of bridge deck transverse main bars arranged at intervals along the longitudinal direction of the bridge, and the bridge deck transverse main bars in the lower transverse steel bar group are not overlapped with the bridge deck longitudinal main bars; the upper end of the lower open stirrup is overlapped with the bridge deck longitudinal main bars.

[0016] Preferably, the bridge deck concrete layer and the rib concrete layer are cast together using UHPC concrete.

[0017] The application of the technical solution of the utility model has the following beneficial effects:

[0018] (1) In the composite beam of the utility model, the steel beam is placed in the highest tensile stress area, the UHPC concrete material is placed in the highest compressive stress area of the bridge deck and the low tensile stress area of the rib plate. The steel beam is far away from the neutral axis of the composite beam cross section and is in the high tensile stress area. The upper flange steel plate with less stress is eliminated, which fully utilizes the tensile properties of steel and the ultra-high tensile and compressive properties of UHPC, and greatly reduces the amount of steel used.

[0019] (2) The ultimate tensile strain of UHPC in the composite beam of the utility model is similar to the yield strain of the steel beam (≈2‰). The steel beam and the concrete ribs are continuously combined to maintain coordinated force, and the structure has strong crack resistance and integrity. The composite ribs formed by the steel beam and the concrete ribs cooperate in shear resistance and have high shear strength, which can greatly simplify the arrangement of the lower open stirrups and the upper open stirrups.

[0020] (3) The connection between the steel beam and the concrete rib is achieved through steel tenons, mortise holes, lower open stirrups, upper open stirrups and transverse short steel bars. Compared with the existing bolt shear key connection method, the connection method between the steel beam and the concrete rib in the utility model has higher initial stiffness, shear strength and ductility; at the same time, the connection method between the steel beam and the concrete rib in the utility model does not require welding, avoiding welding defects and residual stress, and the corners of the steel tenons and mortise holes are chamfered with arcs, which effectively avoids stress concentration and has excellent fatigue resistance.

[0021] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 It is a structural diagram of a composite beam;

[0024] Figure 2 yes Figure 1 Schematic diagram of the arrangement of the upper and lower open stirrups;

[0025] Figure 3 yes Figure 1 A partial cross-sectional view of the connection structure between the steel web and the concrete ribs;

[0026] Figure 4 (a) is Figure 1 Schematic diagram of the cross section of the composite beam;

[0027] (b) Yes Figure 1 Strain distribution diagram in the cross section of the composite beam;

[0028] (c) Yes Figure 1 Stress distribution diagram in the cross section of the composite beam;

[0029] Among them, 100, composite beam; 110, bridge deck, 111, transverse main reinforcement of bridge deck, 112, longitudinal main reinforcement of bridge deck; 120, composite rib, 121, concrete rib, 122, transverse short reinforcement, 123, steel bottom plate, 124, steel web, 125, lower open stirrups, 126, steel tenon, 127, mortise, 128, upper open stirrups, 129, longitudinal distribution reinforcement, 1210, the bottom layer of longitudinal reinforcement, 1211, the second bottom layer of longitudinal reinforcement. DETAILED DESCRIPTION

[0030] To facilitate understanding of the present invention, the following provides a more comprehensive description of the present invention and presents preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to facilitate a more thorough and comprehensive understanding of the disclosure of the present invention.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0032] Example 1:

[0033] See also Figure 1 This embodiment provides a composite beam of steel and concrete. The composite beam 100 includes a bridge deck 110 and a composite rib 120 located on the bottom surface of the bridge deck 110. The composite rib 120 includes a concrete rib 121 and a steel beam (not shown). The concrete rib 121 is located between the bridge deck 110 and the steel beam. That is, the concrete rib 121 and the bridge deck 110 are cast together with concrete to form a T-shaped structure. The upper edge of the steel beam is connected to the lower end of the concrete rib 121.

[0034] like Figure 1 and Figure 3 As shown, the steel beam includes a steel bottom plate 123 and a steel web 124 arranged on the steel bottom plate 123, which form a T-shaped structure. The upper edge of the steel web 124 (i.e., the side close to the concrete rib 121) is alternately provided with steel tenons 126 and mortises 127 along the longitudinal direction of the bridge. Figure 3 As shown, Figure 3 The gray area in the figure is the mortise 127, and the distance between two adjacent tenons 126 is e x The height of the steel tenon (ie the depth of the mortise) is h D The steel tenon 126 and the mortise 127 are embedded in the concrete at the lower end of the concrete rib 121. The distance between the lower edge of the concrete rib 121 and the bottom edge of the mortise 127 is C D Preferably, the spacing e of the steel tenons is x Generally 150~500mm, height h D With spacing e x The ratio of the cutting shape is between 0.27 and 0.4, and the thickness of the steel tenon is h D The ratio range is 0.08 to 0.5; the distance C between the bottom edge of the mortise 127 and the lower edge of the concrete rib 121 D Should be greater than 20mm. Under the same cutting shape, the spacing of steel dowels does not affect the horizontal shear bearing capacity of the composite beam and is inversely proportional to the ductility.

[0035] Preferably, the bridge deck 110 includes a bridge deck concrete layer and a bridge deck steel frame located inside the bridge deck concrete layer, the concrete rib 121 includes a rib concrete layer and a rib steel frame located inside the rib concrete layer, the rib steel frame is connected to the bridge deck steel frame, and the bridge deck concrete layer and the rib concrete layer are cast together.

[0036] like Figure 1As shown, the bridge deck reinforcement skeleton includes an upper transverse reinforcement group, a lower transverse reinforcement group and a bridge deck longitudinal main reinforcement 112; a plurality of bridge deck longitudinal main reinforcements 112 are arranged at intervals along the transverse direction of the bridge, the upper transverse reinforcement group is located on the upper side of the bridge deck longitudinal main reinforcement 112, the upper transverse reinforcement group includes a plurality of bridge deck transverse main reinforcements 111 arranged at intervals along the longitudinal direction of the bridge, the bridge deck longitudinal main reinforcement 112 is overlapped with the bridge deck transverse main reinforcement 111 in the upper transverse reinforcement group, and the bridge deck longitudinal main reinforcement 111 is connected to the bridge deck longitudinal main reinforcement 111 through the bridge deck longitudinal main reinforcement 111. 2 and the bridge deck transverse main reinforcement 111 in the upper transverse reinforcement group provide bending and crack resistance in the longitudinal and transverse directions respectively; the lower transverse reinforcement group is located on the lower side of the bridge deck longitudinal main reinforcement 112, and the lower transverse reinforcement group includes a plurality of bridge deck transverse main reinforcements 111 arranged at intervals along the longitudinal direction of the bridge. The bridge deck transverse main reinforcements 111 in the lower transverse reinforcement group and the bridge deck longitudinal main reinforcements 112 are not overlapped, and the bridge deck transverse main reinforcements in the lower transverse reinforcement group provide bending and crack resistance in the transverse positive moment of the bridge. The arrangement of the bridge deck reinforcement skeleton in this embodiment can avoid the problem of concrete pouring quality caused by too dense steel bars in the thin plate. Due to the small thickness of the bridge deck, the arrangement of the bridge deck transverse main reinforcements 111 and the bridge deck longitudinal main reinforcements 112 generally adopts the method of dense distribution of fine bars. The diameter of the steel bars generally does not exceed 16 mm, and the spacing is generally between 80 and 120 mm.

[0037] Furthermore, the ribbed steel frame includes the bottom longitudinal steel bar 1210, the second bottom longitudinal steel bar 1211, the longitudinal distribution steel bar 129, the transverse short steel bar 122 and the vertical stirrup group (not shown in the figure); the vertical stirrup group includes the lower open stirrups 125 and the upper open stirrups 128 arranged alternately along the longitudinal bridge direction, as shown in FIG. Figure 1 and Figure 2 As shown, the lower open stirrup 125 and the steel tenon 126 are arranged in a one-to-one correspondence, the upper open stirrup 128 and the mortise 127 are arranged in a one-to-one correspondence, the steel tenon 126 is inserted into the opening at the lower end of the lower open stirrup 125, the lower end of the upper open stirrup 128 is placed in the mortise 127, and transverse short steel bars 122 are provided on both sides of the lower end of the upper open stirrup 128, and the transverse short steel bars 122 are spaced from the lower end of the upper open stirrup 128 (that is, the two are not overlapped, and the distance between the two in the longitudinal bridge upward direction is greater than 0), as shown. Figure 3As shown; the position of the lower end of the lower open stirrup 125 is lower than the position of the lower end of the upper open stirrup 128, the bottom layer of longitudinal steel bars 1210 is used to connect the lower ends of each lower open stirrup 125 along the longitudinal direction, and the second bottom layer of longitudinal steel bars 1211 is used to connect the lower ends of each upper open stirrup 128 along the longitudinal direction. Specifically, in this embodiment, the number of the bottom layer of longitudinal steel bars 1210 and the second bottom layer of longitudinal steel bars 1211 are both two, and are symmetrically arranged on both sides of the steel web 124; a plurality of longitudinal distribution steel bars 129 are arranged inside the vertical stirrup group along the vertical direction, specifically, a single longitudinal distribution steel bar 129 passes through the alternating upper open stirrups 128 and lower open stirrups 125 along the longitudinal direction.

[0038] Specifically, the vertical sections of the upper open stirrups 128 and the lower open stirrups 125 can improve the shear resistance of the oblique section of the concrete rib, and the horizontal section of the lower end of the upper open stirrups 128 and the transverse short steel bars 122 can improve the anti-pushing ability of the steel tenons in the concrete rib, and the diameters of both need to be above 10 mm; the bottom layer of longitudinal steel bars 1210 and the second bottom layer of longitudinal steel bars 1211 are beneficial supplements to the anti-bending cracking ability of the concrete rib 121 under the action of positive bending moment, and the diameter should be above 12 mm, and the distance between the two in the height direction should be greater than 0.15 times the spacing of the steel tenons 126.

[0039] Preferably, the bridge deck concrete layer and the rib concrete layer are both cast using UHPC concrete, and the UHPC concrete is ultra-high performance concrete with ultra-high durability and ultra-high mechanical properties.

[0040] Preferably, the lower end of the upper opening stirrup 128 in this embodiment is located at 1 / 2h D The upper end of the lower open stirrup 125 is connected to the bridge deck steel frame, specifically, overlapped with the bridge deck longitudinal main reinforcement 112.

[0041] Preferably, the lower end of the concrete rib 121 is thickened at the buried steel tenon 126 and mortise 127 to ensure that the horizontal distance from the steel tenon to the edge of the concrete rib 121 is not less than 5 times the height of the steel tenon, thereby improving the fault tolerance of the centering error between the steel web 124 and the concrete rib 121, and at the same time providing bending space for the upper open stirrups and the lower open stirrups and reserving sufficient protective layer thickness for the stirrups, thereby improving the bonding ability of the steel web and the concrete rib 121.

[0042] Furthermore, in this embodiment, the number of composite ribs 120 in the composite beam 100 is at least two. When the span of the composite beam is large, a diaphragm (the diaphragm is cast using UHPC concrete, not shown) can be provided between two adjacent concrete ribs 121. The diaphragm can increase the structural stability of the composite beam. The composite beam 100 includes at least two composite ribs 120, so that the composite beam 100 has a self-stabilizing system (i.e., the composite beam 100 can be placed stably through multiple composite ribs 120), which facilitates the transportation and lifting of the composite beam 100. Of course, in some embodiments, the composite beam 100 may not be required to have a self-stabilizing system. In this case, it is also feasible for a single composite beam 100 to include only one composite rib 120.

[0043] Preferably, the thickness of the concrete ribs 121 is generally 12 to 20 cm. For larger bridge spans, the ribs can be thickened at the pier supports. The concrete ribs 121 are cast in the factory, and the overall beam height can be adjusted as needed to accommodate changes in bridge span. Furthermore, a pre-throw height can be added to the continuous structural system based on calculation results and design requirements to offset beam deformation under dead loads and some live loads.

[0044] Preferably, the bridge deck can be a flat plate or a plate with transverse ribs for carrying vehicles. The thickness of a flat plate is generally 10 to 14 cm, and is used when the transverse spacing between adjacent concrete ribs 121 is not large; the thickness of a plate with transverse ribs is generally 8 to 12 cm, and the transverse ribs generally adopt an inverted T-shaped cross-section. The transverse rib height ranges from about 10 to 16 cm, and the transverse rib spacing is 50 to 70 cm. The spacing between two concrete ribs 121 in the transverse direction of the bridge is generally 1.2 to 2.4 m, and is usually determined based on the transverse bending resistance of the bridge deck under the action of wheels and the angle for convenient transportation and lifting.

[0045] Preferably, the T-shaped steel beam can be cut from an H-shaped steel or welded from two steel plates. The thickness of the steel bottom plate is preferably 24 to 50 mm and the width is 200 to 600 mm. The thickness of the steel web is preferably 14 to 20 mm, and the ratio of its height to the height of the composite beam is generally 0.2 to 0.8 times, which requires taking into account the crack resistance of the lower edge of the concrete rib, the internal force arm of the cross section, and the production specifications of the H-shaped steel; the smaller the ratio of its height to the height of the composite beam, the smaller the internal force arm of the cross section, the lower the efficiency of the steel beam, and the greater the crack resistance risk faced by the lower end of the concrete rib.

[0046] like Figure 4As shown in (a)-(c), the composite beam in this embodiment utilizes UHPC to bear the high compressive stress of the upper flange and the low tensile stress of the composite web, while the steel beam bears the high tensile stress of the lower portion, fully utilizing the material properties. The steel beam bears high tensile stress away from the neutral axis of the cross section, which can significantly improve the structure's positive moment bearing capacity. Because the steel beam is arranged externally, unlike an internal arrangement, its structure is not restricted by the concrete ribs, which can significantly increase the internal moment resistance of the internal force arm and allow for flexible allocation of steel material usage.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A composite beam of steel and concrete, characterized in that: The invention comprises a bridge deck (110) and a composite rib (120) located on the bottom surface of the bridge deck (110), wherein the composite rib (120) comprises a concrete rib (121) and a steel beam, and the concrete rib (121) is located between the bridge deck (110) and the steel beam; The steel beam comprises a steel bottom plate (123) and a steel web (124) arranged on the steel bottom plate (123); the upper edge of the steel web (124) is alternately provided with steel tenons (126) and mortises (127) along the longitudinal bridge direction; the steel tenons (126) and mortises (127) are embedded in the concrete at the lower end of the concrete rib (121); the concrete rib (121) comprises a rib concrete layer and a rib steel reinforcement skeleton located inside the rib concrete layer; The ribbed steel reinforcement skeleton includes the bottom layer of longitudinal steel bars (1210), the second bottom layer of longitudinal steel bars (1211), longitudinal distribution steel bars (129), transverse short steel bars (122) and a vertical stirrup group; the vertical stirrup group includes lower opening stirrups (125) and upper opening stirrups (128) arranged alternately along the longitudinal bridge direction, the lower opening stirrups (125) and the steel tenons (126) are arranged in a one-to-one correspondence, the upper opening stirrups (128) and the mortise (127) are arranged in a one-to-one correspondence, the steel tenon (126) is inserted into the opening at the lower end of the lower opening stirrup (125), and the upper opening stirrups ( The lower end of the upper open stirrup (128) is placed in the mortise (127), and transverse short steel bars (122) are provided on both sides of the lower end of the upper open stirrup (128); the bottom layer of longitudinal steel bars (1210) is used to connect the lower ends of the lower open stirrups (125) in the longitudinal direction, and the second bottom layer of longitudinal steel bars (1211) is used to connect the lower ends of the upper open stirrups (128) in the longitudinal direction; a plurality of longitudinal distribution steel bars (129) are arranged in the vertical direction inside the vertical stirrup group, and a single longitudinal distribution steel bar (129) passes through the alternately arranged upper open stirrups (128) and lower open stirrups (125) in the longitudinal direction.

2. The composite beam of steel and concrete according to claim 1, characterized in that: The number of the bottom layer of longitudinal steel bars (1210) and the second bottom layer of longitudinal steel bars (1211) is two, and both are symmetrically arranged on both sides of the steel web (124).

3. The composite beam of steel and concrete according to claim 1, characterized in that: The distance between the transverse short steel bar (122) and the lower end of the upper open stirrup (128) in the longitudinal bridge direction is greater than 0.

4. The composite beam of steel and concrete according to claim 1, characterized in that: The depth of the mortise is h D The lower end of the upper opening stirrup (128) is located at 1 / 2h D The lower end of the lower opening stirrup (125) is located lower than the lower end of the upper opening stirrup (128).

5. The composite beam of steel and concrete according to claim 1, characterized in that: The concrete rib (121) is thickened at the locations where the steel tenons (126) and mortises (127) are embedded; and the corners of the steel tenons and mortises are chamfered with circular arcs.

6. The composite beam of steel and concrete according to claim 1, characterized in that: The distance C between the bottom edge of the mortise (127) and the lower edge of the concrete rib (121) is D Greater than 20mm.

7. The composite beam of steel and concrete according to claim 1, characterized in that: The number of composite ribs (120) in the composite beam (100) is at least two, and a transverse partition is provided between two adjacent concrete ribs (121).

8. The composite beam of steel and concrete according to any one of claims 1 to 7, characterized in that: The bridge deck (110) comprises a bridge deck concrete layer and a bridge deck steel frame located inside the bridge deck concrete layer, and the rib steel frame is connected to the bridge deck steel frame.

9. The composite beam of steel and concrete according to claim 8, characterized in that: The bridge deck reinforcement skeleton includes an upper transverse reinforcement group, a lower transverse reinforcement group and a bridge deck longitudinal main reinforcement (112); a plurality of bridge deck longitudinal main reinforcements (112) are arranged at intervals along the transverse bridge direction, the upper transverse reinforcement group is located on the upper side of the bridge deck longitudinal main reinforcement (112), the upper transverse reinforcement group includes a plurality of bridge deck transverse main reinforcements (111) arranged at intervals along the longitudinal bridge direction, and the bridge deck longitudinal main reinforcements (112) are overlapped with the bridge deck transverse main reinforcements (111) in the upper transverse reinforcement group; the lower transverse reinforcement group is located on the lower side of the bridge deck longitudinal main reinforcement (112), the lower transverse reinforcement group includes a plurality of bridge deck transverse main reinforcements (111) arranged at intervals along the longitudinal bridge direction, and the bridge deck transverse main reinforcements (111) in the lower transverse reinforcement group are not overlapped with the bridge deck longitudinal main reinforcement (112); the upper end of the lower open stirrup (125) is overlapped with the bridge deck longitudinal main reinforcement (112).

10. The composite beam of steel and concrete according to claim 9, characterized in that: The bridge deck concrete layer and the rib concrete layer are cast together using UHPC concrete.

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