Prefabricated steel-UHPC composite bridge deck panel steel box girder structure and construction method

Abstract

The application relates to an assembled prefabricated steel-UHPC combined bridge deck plate steel box girder structure, which comprises a steel box girder bottom plate, a steel box girder web plate, a steel box girder transverse plate and a steel-UHPC combined bridge deck plate. The steel-UHPC combined bridge deck plate comprises a plurality of bridge deck plate units welded together. The bridge deck plate unit comprises a cover plate and a rectangular frame body welded to the upper side of the cover plate. A UHPC plate is cast in the middle of the rectangular frame body. Wet joints are left between the rectangular frame bodies of two adjacent bridge deck plate units. The structure is reasonable in stress and high in strength, reduces the tensile stress of the bridge deck plate or the bridge deck pavement, improves the durability of the structure, can fully exert the performance advantages of the two materials, avoids the surface cracking problem caused by the early shrinkage of the UHPC layer due to the cast-in-place construction, can effectively avoid the diseases of the steel bridge deck system, adopts full prefabricated components, improves the construction speed, is more convenient for construction, and guarantees the quality and durability of the steel-UHPC combined bridge deck plate.

Description

Technical Field

[0001] This invention relates to the field of civil engineering technology, and in particular to a prefabricated steel-UHPC composite bridge deck steel box girder structure and its construction method. Background Technology

[0002] In recent years, there has been a significant increase in the construction of long-span steel box girder bridges. Steel bridge deck structures are characterized by their light weight, high load-bearing capacity, and wide applicability. However, due to their complex stress distribution, significant stress concentration at plate intersections, and susceptibility to fatigue under repeated wheel loads, these structures are prone to fatigue problems. To address this, we have employed various methods to reduce fatigue issues in steel bridge decks, such as optimizing structural design, controlling local stresses, controlling vehicle overloading, and minimizing welding defects.

[0003] Steel-UHPC composite bridge decks are a novel bridge structure that combines the tensile strength of steel with the high compressive strength and durability of UHPC, forming a lightweight composite structure. This design has been applied in numerous projects, such as the Qinglongzhou Bridge and the Dongting Lake Bridge on the Hangrui Expressway, both of which utilize cast-in-place construction, demonstrating excellent technical performance and economic benefits. While cast-in-place construction of steel-UHPC composite bridge decks offers advantages such as high strength, good durability, and fire resistance, it also presents some drawbacks. Due to the significant self-shrinkage of UHPC, improper control during cast-in-place construction can lead to cracking, severely impacting the structure's durability and load-bearing capacity. Furthermore, the elastic modulus of UHPC is much lower than that of steel, requiring strict control during construction to prevent affecting the overall stability and durability of the structure. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a prefabricated steel-UHPC composite bridge deck steel box girder structure and construction method that is reasonably stressed, has high strength, and is easy to construct, so as to ensure the quality and durability of the steel-UHPC composite bridge deck.

[0005] The present invention is implemented using the following scheme: a prefabricated steel-UHPC composite bridge deck steel box girder structure, including a steel box girder bottom plate, a steel box girder web plate, a steel box girder transverse diaphragm plate, and a steel-UHPC composite bridge deck. The steel-UHPC composite bridge deck includes several bridge deck units welded together. Each bridge deck unit includes a cover plate and a rectangular frame welded and fixed to the upper side of the cover plate. A UHPC plate is cast in the middle of the rectangular frame. The steel-UHPC composite bridge deck has a wet joint between the rectangular frames of two adjacent bridge deck units.

[0006] Furthermore, the rectangular frame is formed by welding four perforated ribs together, and a steel mesh embedded in the UHPC plate is arranged inside the rectangular frame. The steel bars of the steel mesh pass through the through holes on the perforated ribs and extend into the wet joint.

[0007] Furthermore, the ends of the reinforcing bars in the steel mesh are provided with external threads and are anchored to the perforated ribs by nuts.

[0008] Furthermore, the wet joint is provided with a connecting device for connecting the reinforcing bars between two adjacent rectangular frames.

[0009] Furthermore, the connecting device includes a connecting channel steel, an Fe-SMA connecting bar, and a nut. The Fe-SMA connecting bar is located in the middle of the connecting channel steel and has external threads at both ends. The two side plates of the connecting channel steel have connecting holes. The reinforcing bars of the steel mesh are anchored to the side plates of the connecting channel steel by the nuts. The two ends of the Fe-SMA connecting bar are connected to the ends of the reinforcing bars of the steel mesh by the same nut. The nut is located in the middle of the end face of the reinforcing bar and the Fe-SMA connecting bar.

[0010] Furthermore, a joint UHPC board is cast into the wet joint.

[0011] Furthermore, a welding stud is arranged in the middle of the rectangular frame, and the welding stud is welded to the cover plate and embedded in the UHPC board.

[0012] Furthermore, U-shaped ribs are welded at intervals to the bottom of the cover plate.

[0013] A construction method for a prefabricated steel-UHPC composite bridge deck steel box girder structure includes the following steps: (1) fabricating the bottom plate, web, and transverse diaphragm of the steel box girder, installing the bottom plate, web, and transverse diaphragm, and then welding them to form the main body of the steel box girder in a trough shape; (2) fabricating the cover plate, welding U-shaped ribs at a certain interval at the bottom of the cover plate; (3) fabricating the perforated ribs, welding the perforated ribs at a certain distance from the edge around the cover plate to form a rectangular frame, and arranging the welding studs welded to the cover plate in the middle of the rectangular frame; (4) arranging the steel mesh in the middle of the rectangular frame, making threads at both ends of the steel mesh, passing the two ends of the steel bars through the through holes of the perforated ribs, and anchoring the two ends of the steel bars to the perforated ribs with nuts, then pouring ultra-high performance concrete into the rectangular frame to form a UHPC plate and curing it to form a bridge deck unit; (5) fabricating the prefabricated steel box girder bottom plate, web, and transverse diaphragm of the steel box girder, installing the bottom plate, web, and transverse diaphragm of the steel box girder, and then welding them to form a bridge deck unit; (6) fabricating the prefabricated steel box girder bottom plate, web, and transverse diaphragm of the steel box girder, installing the bottom plate, web, and transverse diaphragm of the steel box girder, and then welding them to form a rectangular frame; (7) arranging the prefabricated steel box girder bottom plate, installing the bottom plate, web, and transverse diaphragm of the steel box girder, and then welding the two ends of the steel bars through the through holes of the perforated ribs, and then arranging the two ends of the steel bars to form a UH Good bridge deck unit is installed and fixed at the corresponding position of the steel box girder channel body, and the steel box girder channel body and bridge deck unit are welded together; (6) the ends of the steel bars on both sides of the wet joint pass through the connecting holes of the connecting channel steel and are anchored to the side plate of the connecting channel steel; (7) nuts are screwed on the ends of the steel bars on both sides respectively, and the Fe-SMA connecting bar is pre-stretched and unloaded. After the unloaded Fe-SMA connecting bar is threaded at both ends, it is abutted against the ends of the steel bars on both sides of the wet joint. The nuts are screwed back so that the nuts are in the middle position of the abutting end face of the steel bar and the Fe-SMA connecting bar; the Fe-SMA connecting bar and the power supply are connected by copper clamps and current wires, and phase change is induced by resistance heating; (8) after the Fe-SMA connecting bar cools down, ultra-high performance concrete is poured in the wet joint between the two adjacent bridge deck units to form a joint UHPC plate, and then cured and shaped.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The prefabricated steel-UHPC composite bridge deck steel box girder structure of the present invention has reasonable stress distribution and high strength, reduces the tensile stress of the bridge deck or bridge pavement, improves the durability of the structure, can give full play to the performance advantages of the two materials, avoids the problem of excessive early shrinkage and surface cracking of the material caused by the cast-in-place construction of the UHPC layer, not only effectively avoids the occurrence of defects in the steel bridge deck system, but also improves the construction speed and makes construction more convenient by using fully prefabricated components, ensuring the quality and durability of the steel-UHPC composite bridge deck.

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through specific embodiments and related drawings. Attached Figure Description

[0016] Figure 1 This is a front sectional view of the steel-UHPC composite bridge deck according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a partial structure of the bridge deck unit according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the welding structure between the rectangular frame and the cover plate in an embodiment of the present invention; Figure 4 This is a top view of the steel-UHPC composite bridge deck according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the connection device for the wet joint in an embodiment of the present invention; The following are the labels in the diagram: 1-Bridge deck unit, 101-Cover plate, 102-U-shaped rib, 2-Through hole, 3-Rectangular frame, 4-Weld stud, 5-Reinforcing bar, 501-Fe-SMA connecting bar, 502-External threaded part, 6-Wet joint, 601-Connecting channel steel, 7-Nut, 701-Washer, 8-UHPC plate. Detailed Implementation

[0017] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0018] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0019] like Figures 1-5 As shown, a prefabricated steel-UHPC composite bridge deck steel box girder structure includes a steel box girder bottom plate (not shown), a steel box girder web plate (not shown), a steel box girder diaphragm plate (not shown), and a steel-UHPC composite bridge deck. The steel-UHPC composite bridge deck includes several bridge deck units 1 welded together. Each bridge deck unit 1 includes a cover plate 101 and a rectangular frame 3 welded and fixed to the upper side of the cover plate. A UHPC plate 8 is cast in the middle of the rectangular frame 3. The steel-UHPC composite bridge deck has a wet joint 6 between the rectangular frames of two adjacent bridge deck units. The rectangular frame 3 serves as a perimeter template for the UHPC plate. The bridge adopts a prefabricated steel-UHPC composite bridge deck steel box girder structure. This structure has reasonable stress distribution and high strength, reduces tensile stress on the bridge deck or pavement, improves the durability of the structure, and can give full play to the performance advantages of the two materials. It avoids the problem of excessive early shrinkage and surface cracking of the UHPC layer caused by cast-in-place construction. It can not only effectively avoid the occurrence of defects in the steel bridge deck system, but also improve the construction speed and make construction more convenient by using fully prefabricated components, thus ensuring the quality and durability of the steel-UHPC composite bridge deck.

[0020] In this embodiment, the rectangular frame 3 is formed by welding four perforated ribs together. A steel mesh embedded in the UHPC plate is arranged inside the rectangular frame, and the steel bars 5 of the steel mesh extend into the wet joint 6 through the through holes 2 on the perforated ribs. When the bridge deck unit is located at the edge of the bridge deck, perforated ribs are welded on three sides of the bridge deck unit, and a non-perforated rib is welded on the other side.

[0021] In this embodiment, the ends of the reinforcing bars 5 of the steel mesh are provided with external threads 502 and are anchored to the perforated rib plate by nuts. The through-hole size of the perforated rib plate is 5mm to 20mm larger than the diameter of the reinforcing bar to facilitate the passage of the reinforcing bar, and a washer is provided between the nut and the perforated rib plate.

[0022] In this embodiment, the rectangular frame is 10cm to 25cm away from the edge of the cover plate, and the cover plate has a bevel on its side. The cover plates of two adjacent bridge deck units are welded together through the bevel.

[0023] In this embodiment, the wet joint 6 is provided with a connecting device for connecting the reinforcing bars between two adjacent rectangular frames.

[0024] In this embodiment, the connecting device includes a connecting channel steel 601, an Fe-SMA connecting rib 501, and a nut. The Fe-SMA connecting rib is located in the middle of the connecting channel steel and has external threads at both ends. The Fe-SMA connecting rib is made of Fe-SMA steel. Connecting holes are provided on the side plates of the connecting channel steel. The reinforcing bars of the steel mesh are anchored to the side plates of the connecting channel steel via the nut. A washer is provided between the nut and the side plates of the connecting channel steel. Both ends of the Fe-SMA connecting rib are connected to the ends of the reinforcing bars of the steel mesh via the same nut 7. The nut 7 is located in the middle of the abutting end face between the reinforcing bar and the Fe-SMA connecting rib. The nut 7 here is a wide nut, generally with a width of 25mm or more, to ensure a reliable connection.

[0025] In this embodiment, a joint UHPC board is cast into the wet joint 6.

[0026] In this embodiment, a welding stud 4 is arranged in the middle of the rectangular frame 3. The welding stud 4 is welded to the cover plate and embedded in the UHPC board.

[0027] In this embodiment, U-shaped ribs 102 are welded at intervals to the bottom of the cover plate, and the center line of the wet joint is located between the two U-shaped ribs.

[0028] A construction method for a prefabricated steel-UHPC composite bridge deck steel box girder structure includes the following steps: (1) drawing processing drawings and compiling manufacturing process documents according to the design drawings, performing straightening, cutting, drilling, grinding, beveling and bending of steel plates, and fabricating the bottom plate, web plate and transverse diaphragm of the steel box girder, wherein an opening is made at the top of the transverse diaphragm to allow U-shaped ribs to pass through, and installing the bottom plate, web plate and transverse diaphragm of the steel box girder, and then welding and fixing them to form a complete structure. (2) Make a cover plate, weld U-shaped ribs at a certain interval at the bottom of the cover plate, and make a bevel at the edge of the cover plate; (3) Make a perforated rib, weld perforated ribs at a certain distance from the edge of the cover plate to form a rectangular frame, and arrange welding studs welded to the cover plate in the middle of the rectangular frame; (4) Arrange a steel mesh in the middle of the rectangular frame, make threads at both ends of the steel bars of the steel mesh, pass through the through holes of the perforated rib, and anchor the steel bars to the perforated rib with nuts at both ends of the steel bars, and then arrange the steel mesh in the middle of the rectangular frame. (5) The prefabricated bridge panel unit is installed and fixed in the corresponding position of the steel box girder trough body, and the steel box girder trough body and bridge panel unit are welded together; (6) The ends of the steel bars on both sides of the wet joint pass through the connecting holes of the connecting channel steel and are anchored to the side plate of the connecting channel steel; (7) Nuts are screwed on the ends of the steel bars on both sides respectively, and the Fe-SMA connecting bar is pre-stretched and unloaded. After the unloaded Fe-SMA connecting bar is threaded at both ends, it is abutted against the ends of the steel bars on both sides of the wet joint. The nuts are screwed back so that the nuts are in the middle position of the abutting end face of the steel bar and the Fe-SMA connecting bar; the Fe-SMA connecting bar and the power supply are connected by copper clamps and current wires, and phase change is induced by resistance heating; (8) After the Fe-SMA connecting bar cools down, ultra-high performance concrete is poured in the wet joint between the two adjacent bridge panel units to form a joint UHPC plate, and then cured.

[0029] Unless otherwise stated, if any of the technical solutions disclosed in this invention specify a numerical range, then the disclosed numerical range is a preferred numerical range. Anyone skilled in the art should understand that the preferred numerical range is merely one among many feasible numerical values ​​that has a more obvious or representative technical effect. Because there are many numerical values, it is impossible to list them all. Therefore, this invention discloses only some numerical values ​​to illustrate the technical solutions of this invention. Furthermore, the numerical values ​​listed above should not constitute a limitation on the scope of protection of this invention.

[0030] If this invention discloses or relates to mutually fixedly connected components or structural parts, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0031] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0032] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A prefabricated steel-UHPC composite bridge deck steel box girder structure, comprising a steel box girder bottom plate, a steel box girder web plate, steel box girder transverse diaphragms, and a steel-UHPC composite bridge deck, characterized in that: The steel-UHPC composite bridge deck comprises several bridge deck units welded together. Each bridge deck unit includes a cover plate and a rectangular frame welded and fixed to the upper side of the cover plate. A UHPC slab is cast in the middle of the rectangular frame. A wet joint is left between the rectangular frames of adjacent bridge deck units. The rectangular frame is formed by welding four perforated ribs together. A steel mesh embedded in the UHPC slab is arranged inside the rectangular frame. The reinforcing bars of the steel mesh pass through through holes in the perforated ribs and extend into the wet joint. The ends of the reinforcing bars in the steel mesh are provided with external threads. The joint is anchored to the perforated rib plate via nuts. A connecting device is provided within the wet joint to connect the reinforcing bars between two adjacent rectangular frames. The connecting device includes a connecting channel steel, Fe-SMA connecting bars, and nuts. The Fe-SMA connecting bars are located in the middle of the connecting channel steel and have external threads at both ends. Connecting holes are provided on the side plates of the connecting channel steel. The reinforcing bars of the steel mesh are anchored to the side plates of the connecting channel steel via nuts. Both ends of the Fe-SMA connecting bars are connected to the ends of the reinforcing bars of the steel mesh via the same nut, which is positioned in the middle of the abutting end faces of the reinforcing bars and the Fe-SMA connecting bars.

2. The prefabricated steel-UHPC composite bridge deck steel box girder structure according to claim 1, characterized in that: The wet joint is filled with a joint UHPC board.

3. The prefabricated steel-UHPC composite bridge deck steel box girder structure according to claim 1, characterized in that: A welding stud is arranged in the middle of the rectangular frame. The welding stud is welded to the cover plate and embedded in the UHPC board.

4. The prefabricated steel-UHPC composite bridge deck steel box girder structure according to claim 1, characterized in that: The bottom of the cover plate is welded with U-shaped ribs at intervals.

5. A construction method for a prefabricated steel-UHPC composite bridge deck steel box girder structure, characterized in that: Includes the following steps: (1) Fabricate the bottom plate, web, and transverse diaphragm of the steel box girder. Install the bottom plate, web, and transverse diaphragm of the steel box girder and then weld them to form the main body of the steel box girder in a trough shape. (2) Fabricate the cover plate and weld U-shaped ribs at a certain interval at the bottom of the cover plate. (3) Fabricate the perforated ribs and weld the perforated ribs at a certain distance from the edge around the cover plate to form a rectangular frame. Arrange the welding studs welded to the cover plate in the middle of the rectangular frame. (4) Arrange the steel mesh in the middle of the rectangular frame. Thread the ends of the steel bars of the steel mesh. Pass the ends of the steel bars through the through holes of the perforated ribs and anchor the ends of the steel bars to the perforated ribs with nuts. Then pour ultra-high performance concrete into the rectangular frame to form a UHPC plate and cure it to form a bridge deck unit. (5) Install the prefabricated bridge deck unit onto the main body of the steel box girder in a trough shape. The position should be fixed, and the steel box girder trough body and bridge deck unit should be welded together; (6) the ends of the steel bars on both sides of the wet joint should pass through the connecting holes of the connecting channel steel and be anchored to the side plate of the connecting channel steel; (7) nuts should be screwed on the ends of the steel bars on both sides respectively, and the Fe-SMA connecting bar should be pre-stretched and unloaded. After the unloaded Fe-SMA connecting bar is threaded at both ends, it should be abutted against the ends of the steel bars on both sides of the wet joint. The nuts should be screwed back so that the nuts are in the middle of the abutting end face of the steel bar and the Fe-SMA connecting bar; the Fe-SMA connecting bar and the power supply should be connected by copper clamps and current wires, and phase change should be induced by resistance heating; (8) after the Fe-SMA connecting bar has cooled, ultra-high performance concrete should be poured in the wet joint between the two adjacent bridge deck units to form a joint UHPC plate, and then cured and shaped.

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