Precast steel structure and UHPC precast slab combined bridge deck structure

Abstract

The utility model discloses a prefabricated steel structure and UHPC (Ultra High Performance Concrete) prefabricated slab combined bridge deck structure which is characterized by comprising a steel box girder and UHPC prefabricated slabs, the steel box girder comprises prefabricated steel structure sections which are sequentially spliced in the length direction of the bridge deck, and each prefabricated steel structure section comprises first U-shaped beams and second U-shaped beams which are alternately arranged in the width direction of the bridge deck at intervals and connected. The edge parts of the first U-shaped beams and the second U-shaped beams are connected to form corrugated beams which are sequentially and alternately bent up and down; a plurality of shear nails are arranged on the upper surface of the first U-shaped beam at intervals in the length direction; post-pouring holes matched with the shear nails in position are formed in the UHPC prefabricated slab; and a post-pouring layer used for connecting the first U-shaped beam, the shear nails and the UHPC prefabricated slab is poured in the post-pouring hole. The utility model has the benefits that the UHPC prefabricated slab is adopted to replace cast-in-place concrete, so that early cracking of the UHPC layer and shear deformation of shear nails are prevented, and the quality of a bridge floor structure is improved.

Description

Technical Field

[0001] This utility model relates to the field of bridge structure technology, specifically to a bridge deck structure combining a precast steel structure and a UHPC precast slab. Background Technology

[0002] Currently, long-span bridges widely adopt bridge deck structures composed of orthotropic steel deck panels and asphalt pavement. However, numerous engineering examples show that this bridge deck structure has significant defects. Its insufficient stiffness leads to frequent fatigue cracking of the steel deck panels and damage to the asphalt pavement layer during operation, seriously threatening the safe operation of the bridge and shortening its service life.

[0003] Steel bridge decks, as a cohesive structural form consisting of mutually perpendicular top plates, longitudinal ribs, and transverse diaphragms connected by welds, possess advantages such as light weight, high load-bearing capacity, wide applicability, fast construction speed, and aesthetic appeal. However, fatigue cracking during service is becoming increasingly serious. Research on the distribution of fatigue cracks in steel bridge decks reveals that most fatigue cracks are concentrated at the connection between the steel bridge deck and the longitudinal ribs. The main reasons are as follows: 1. Currently, most longitudinal ribs in steel bridge decks are closed ribs, allowing only partial penetration welding from the outside when connecting to the top plate. The unfused portion on the inside forms the initial crack, which continues to propagate towards the top plate and longitudinal ribs during subsequent service. 2. Under wheel loads, the connection between the top plate and longitudinal ribs experiences significant out-of-plane deformation due to its proximity to the load, causing the connecting weld to bear substantial local stress, thus making it more prone to fatigue cracking. Even with the adoption of a steel-UHPC composite bridge deck structure, which reduces the stress level in this area, it remains relatively high compared to other fatigue cracking sites, making fatigue cracking difficult to avoid over long-term service.

[0004] Ultra-High Performance Concrete (UHPC) can effectively improve bridge deck stiffness when used as bridge deck pavement, thereby reducing bridge deck deformation under wheel loads and mitigating fatigue cracking of steel bridge decks and damage to asphalt pavement. In the current implementation plan, UHPC is cast on-site onto the steel bridge deck to be shear studded, ensuring a tight bond between the UHPC pavement and the steel bridge deck. However, this on-site casting implementation plan has obvious drawbacks: 1. Due to the limitations of on-site construction conditions, the quality of UHPC casting and curing is difficult to guarantee, and defects such as inadequate compaction and early cracking are prone to occur. In addition, the surface flatness of UHPC is poor, resulting in poor overall bridge deck structure quality; 2. Since the spatial position of the tied steel mesh is difficult to fix precisely, the protective layer thickness of the UHPC layer is usually relatively thick for the sake of conservatism, and a thicker protective layer has a higher risk of cracking; 3. The on-site casting operation has high requirements for temperature and weather, and the on-site casting plan takes into account the curing time of concrete, resulting in a long construction period; 4. For long and large-span steel bridges, since no bridge deck joints are set, the tensile stress of the UHPC layer caused by UHPC shrinkage and temperature effects is high, which has a greater risk of cracking when combined with wheel loads.

[0005] Therefore, it is necessary to improve existing technologies. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a bridge deck structure that combines a precast steel structure with UHPC precast panels, thereby improving the quality of the bridge deck structure.

[0007] The technical solution adopted in this utility model is: a bridge deck structure combining a precast steel structure and a UHPC precast slab, including a steel box girder and a UHPC precast slab (1).

[0008] The steel box girder includes prefabricated steel structure segments (2) spliced ​​sequentially along the length of the bridge deck. Each prefabricated steel structure segment (2) includes a first U-shaped beam (3) and a second U-shaped beam (8) that are alternately arranged and connected along the width of the bridge deck. The first U-shaped beam (3) is arched upwards, and the second U-shaped beam (8) is concave downwards. The edges of each first U-shaped beam (3) and each second U-shaped beam (8) are connected to form a wave-shaped beam that is alternately bent up and down. The length direction of the first U-shaped beam (3) and the second U-shaped beam (8) is consistent with the length direction of the bridge deck.

[0009] Multiple shear studs (6) are spaced apart along the length direction on the upper surface of the first U-shaped beam (3).

[0010] The UHPC precast slab (1) is placed on the first U-shaped beam (3) of the precast steel structure section (2), and the UHPC precast slab (1) is provided with a post-casting hole (5) that matches the position of the shear stud (6); the post-casting hole (5) is filled with a post-cast layer for connecting the first U-shaped beam (3), the shear stud (6) and the UHPC precast slab (1).

[0011] According to the above scheme, the prefabricated steel structure section (2) is also provided with a transverse diaphragm (4); the transverse diaphragm (4) is arranged horizontally at the lower part of the first U-shaped beam (3) and the second U-shaped beam (8), and the transverse diaphragm (4) is welded to the first U-shaped beam (3) and the second U-shaped beam (8) respectively.

[0012] According to the above scheme, the diaphragm (4) is perpendicular to the first U-shaped beam (3) and the second U-shaped beam (8).

[0013] According to the above scheme, holes (9) are made in the transverse diaphragm (4) at the bottom of the second U-shaped beam (8).

[0014] According to the above scheme, connecting plates (7) are respectively set on both sides of the precast steel structure section (2), and shear studs (6) are set on the connecting plates (7); the UHPC precast slab (1) is located on the connecting plates (7), and the shear studs (6) correspond to the post-casting holes (5) on the UHPC precast slab (1). The post-casting layer connecting the shear studs (6) and the UHPC precast slab (1) is poured in the post-casting holes (5).

[0015] According to the above scheme, the UHPC prefabricated plate (1) is provided with a wear layer.

[0016] According to the above scheme, the post-cast hole (5) is a stepped hole with a larger top and a smaller bottom.

[0017] According to the above scheme, the lower diameter of the post-cast hole (5) is 2-4 mm larger than the lower diameter of the shear nail (6), and the upper diameter of the post-cast hole (5) is 8-10 mm larger than the head diameter of the shear nail (6).

[0018] According to the above scheme, the lower end of the diaphragm (4) extends beyond the lower surface of the second U-shaped beam (8); the length direction of the diaphragm (4) is consistent with the width direction of the bridge deck.

[0019] According to the above scheme, the diaphragm (4) has a groove that is adapted to the first U-shaped beam (3) and the second U-shaped beam (8). The first U-shaped beam (3) and the second U-shaped beam (8) are located in the groove, and the lower surface and outer side of the first U-shaped beam (3) and the outer side of the second U-shaped beam (8) are welded to the diaphragm (4).

[0020] The beneficial effects of this utility model are as follows:

[0021] 1. This utility model uses UHPC precast slabs to replace on-site cast concrete, avoiding the tensile stress on the UHPC layer and shear studs caused by concrete shrinkage and creep when using on-site casting. This effectively prevents early cracking of the UHPC layer and shear deformation of the shear studs, and improves the load-bearing capacity of the UHPC layer and shear studs during service. Compared with the prior art, this improves the quality of the bridge deck structure.

[0022] 2. The steel box girder of this utility model includes prefabricated steel structure segments arranged along the longitudinal direction of the bridge. Each prefabricated steel structure segment includes a first U-shaped beam and a second U-shaped beam. Compared with the existing conventional structure, the welds of the top plate and longitudinal ribs are eliminated, which greatly reduces the amount of welding work and significantly reduces fatigue cracking of the bridge deck structure. At the same time, the steel box girder and UHPC prefabricated slab are connected by shear studs to ensure the bending stiffness of the bridge deck structure.

[0023] 3. The UHPC precast panels used in this utility model are prefabricated in a standardized manner in the factory and then transported to the site for construction. The production of UHPC precast panels is not limited by the external environment and site. Compared with on-site casting, the quality of UHPC is easier to guarantee, with higher processing precision, superior mechanical properties, higher prefabrication and construction efficiency, and controllable quality, which has huge market application prospects. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of Embodiment 1.

[0025] Figure 2 This is a schematic diagram of the steel box girder in Example 1.

[0026] Figure 3 This is a schematic diagram showing the connection between the precast steel structure section and the UHPC precast slab in Example 1.

[0027] Figure 4 This is a schematic diagram of the arrangement of shear studs and post-cast holes in Example 2.

[0028] The components are: 1. UHPC precast slab; 2. Precast steel structure section; 3. First U-shaped beam; 4. diaphragm; 5. Post-cast hole; 6. Shear stud; 7. Connecting plate; 8. Second U-shaped beam; 9. Hole. Detailed Implementation

[0029] To better understand this utility model, it will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] like Figures 1-3 The bridge deck structure shown is a combination of a precast steel structure and a UHPC precast slab, including a steel box girder and a UHPC precast slab 1;

[0032] The steel box girder includes prefabricated steel structure segments 2 spliced ​​sequentially along the length of the bridge deck. Each prefabricated steel structure segment 2 includes a first U-shaped beam 3 and a second U-shaped beam 8 that are alternately arranged and connected along the width of the bridge deck. The first U-shaped beam 3 arches upward, and the second U-shaped beam 8 is concave downward. The edges of each first U-shaped beam 3 and each second U-shaped beam 8 are connected to form a corrugated beam that bends alternately upward and downward. The length direction of the first U-shaped beam 3 and the second U-shaped beam 8 is consistent with the length direction of the bridge deck.

[0033] Multiple shear studs 6 are spaced apart along the length of the upper surface of the first U-shaped beam 3;

[0034] The UHPC precast slab 1 is placed on the first U-shaped beam 3 of the precast steel structure section 2, and the UHPC precast slab 1 is provided with post-casting holes 5 that match the positions of the shear studs 6; the post-casting holes 5 are filled with a post-cast layer for connecting the first U-shaped beam 3, the shear studs 6 and the UHPC precast slab 1.

[0035] In this utility model, such as Figure 2 As shown, the precast steel structure segment 2 is a continuous, vertically bent corrugated beam formed by alternating and connected first U-shaped beams 3 and second U-shaped beams 8. Shear studs 6 are evenly spaced along the length of the first U-shaped beams 3, and can be arranged in a single or double row; the lower ends of the shear studs 6 are welded to the upper surface of the first U-shaped beams 3. The ends of the first U-shaped beams 3 of two adjacent precast steel structure segments 2 are aligned and welded, and the ends of the second U-shaped beams 8 of two adjacent precast steel structure segments 2 are aligned and welded.

[0036] Preferably, the prefabricated steel structure section 2 is further provided with a transverse diaphragm 4, which is transversely arranged at the lower part of the first U-shaped beam 3 and the second U-shaped beam 8, and the transverse diaphragm 4 is welded to the first U-shaped beam 3 and the second U-shaped beam 8 respectively.

[0037] In this utility model, the diaphragm 4 has a groove adapted to the first U-shaped beam 3 and the second U-shaped beam 8. The first U-shaped beam 3 and the second U-shaped beam 8 are located in the groove, and the lower surface and outer side of the first U-shaped beam 3 and the outer side of the second U-shaped beam 8 are welded to the diaphragm 4.

[0038] In this preferred embodiment, the diaphragm 4 is perpendicular to the first U-shaped beam 3 and the second U-shaped beam 8, and the lower end of the diaphragm 4 extends beyond the lower surface of the second U-shaped beam 8.

[0039] In this invention, the length direction of the diaphragm 4 is consistent with the width direction of the bridge deck.

[0040] Preferably, an arc-shaped hole 9 is provided on the transverse diaphragm 4 at the bottom of the second U-shaped beam 8.

[0041] Under vehicle load, significant stress concentration occurs at the connection between the transverse diaphragm 4 and the second U-shaped beam 8. The arc-shaped hole 9 in this invention effectively reduces stress concentration at the connection, disperses stress, and lowers stress peaks, thereby improving the fatigue performance of the structure and extending its service life. Furthermore, under vehicle load, the precast steel structure segment undergoes vertical deflection; the arc-shaped hole 9 provides space for this deformation, preventing stress increase due to restricted deformation.

[0042] In this utility model, connecting plates 7 are respectively provided on both sides of the precast steel structure section 2, and shear studs 6 are provided on the connecting plates 7; the UHPC precast slab 1 is located on the connecting plates 7, and the shear studs 6 correspond to the post-casting holes 5 on the UHPC precast slab 1. The post-casting holes 5 are filled with a post-cast layer that connects the shear studs 6 and the UHPC precast slab 1.

[0043] Preferably, the UHPC precast panel 1 is provided with a wear layer.

[0044] Example 2

[0045] The difference between this embodiment and Embodiment 1 is that: Figure 4 As shown, the post-casting hole 5 is a stepped hole with a larger upper part and a smaller lower part. The lower diameter of the post-casting hole 5 is 2-4 mm larger than the lower diameter of the shear nail 6, and the upper diameter of the post-casting hole 5 is 8-10 mm larger than the head diameter of the shear nail 6.

[0046] In this invention, each shear stud 6 is provided with a corresponding post-casting hole 5. The post-casting hole 5 is designed in a stepped manner, which allows the upper diameter of the concrete column of the post-cast layer to be larger than that of the lower part. Compared with the traditional concrete column with the same upper and lower diameters, it can provide more mechanical interlocking force when fixing the UHPC precast slab 1, so that the UHPC precast slab 1 and the precast steel structure section 2 can be better connected.

[0047] The construction method of this utility model is as follows:

[0048] (1) UHPC precast slab 1 is precast in the factory, prestressed steel mesh is embedded in UHPC precast slab 1, and post-casting holes 5 are reserved;

[0049] (2) The corrugated beam consisting of the first U-shaped beam 3, the second U-shaped beam 8 and the transverse diaphragm 4 is manufactured in the factory and assembled into a prefabricated steel structure section 2;

[0050] (3) Weld shear nails 6 at intervals on the contact surface between the first U-shaped beam 3 and the UHPC precast slab 1. After welding, perform surface sandblasting and anti-corrosion coating on the precast steel structure section 2.

[0051] (4) Each precast steel structure section 2 is transported to the construction site, then hoisted and spliced ​​in sections to form a complete steel box girder;

[0052] (5) Lay the prefabricated UHPC precast slab 1 on the steel box beam composed of prefabricated steel structure section 2, so that the shear studs 6 are inserted into the corresponding post-cast holes 5;

[0053] (6) Concrete is poured in the post-pouring hole 5 to form a post-pouring layer, which connects the UHPC precast slab 1 and the steel box girder.

[0054] (7) After the concrete of the post-cast layer poured on site has cured, apply epoxy resin adhesive to the UHPC precast slab 1, and finally lay the wear layer on the UHPC precast slab 1.

[0055] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0056] Finally, it should be noted that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A bridge deck structure combining prefabricated steel structures and UHPC prefabricated slabs, characterized in that, Including steel box girders and UHPC precast slabs (1); The steel box girder includes prefabricated steel structure segments (2) spliced ​​sequentially along the length of the bridge deck. Each prefabricated steel structure segment (2) includes a first U-shaped beam (3) and a second U-shaped beam (8) that are alternately arranged and connected along the width of the bridge deck. The first U-shaped beam (3) is arched upwards, and the second U-shaped beam (8) is concave downwards. The edges of each first U-shaped beam (3) and each second U-shaped beam (8) are connected to form a wave-shaped beam that is alternately bent up and down. The length direction of the first U-shaped beam (3) and the second U-shaped beam (8) is consistent with the length direction of the bridge deck. Multiple shear studs (6) are spaced apart along the length direction on the upper surface of the first U-shaped beam (3). The UHPC precast slab (1) is placed on the first U-shaped beam (3) of the precast steel structure section (2), and the UHPC precast slab (1) is provided with a post-casting hole (5) that matches the position of the shear stud (6); the post-casting hole (5) is filled with a post-cast layer for connecting the first U-shaped beam (3), the shear stud (6) and the UHPC precast slab (1).

2. The bridge deck structure of claim 1, wherein, The prefabricated steel structure section (2) is also provided with a diaphragm (4); the diaphragm (4) is arranged horizontally at the lower part of the first U-shaped beam (3) and the second U-shaped beam (8), and the diaphragm (4) is welded to the first U-shaped beam (3) and the second U-shaped beam (8) respectively.

3. The bridge deck structure of claim 2, wherein, The diaphragm (4) is perpendicular to the first U-beam (3) and the second U-beam (8).

4. The bridge deck structure of claim 3, wherein, Holes (9) are provided on the transverse diaphragm (4) at the bottom of the second U-shaped beam (8).

5. The bridge deck structure of claim 1, wherein, Connecting plates (7) are provided on both sides of the precast steel structure section (2), and shear studs (6) are provided on the connecting plates (7); the UHPC precast slab (1) is located on the connecting plates (7), and the shear studs (6) correspond to the post-casting holes (5) on the UHPC precast slab (1). The post-casting layer connecting the shear studs (6) and the UHPC precast slab (1) is poured into the post-casting holes (5).

6. The bridge deck structure of claim 1, wherein, The UHPC precast panel (1) is provided with a wear layer.

7. The bridge deck structure of claim 1, wherein, The post-cast hole (5) is a stepped hole with a larger top and a smaller bottom.

8. The bridge deck structure of claim 7, wherein, The lower diameter of the post-cast hole (5) is 2-4 mm larger than the lower diameter of the shear nail (6), and the upper diameter of the post-cast hole (5) is 8-10 mm larger than the head diameter of the shear nail (6).

9. The bridge deck structure of claim 3, wherein, The lower end of the diaphragm (4) extends beyond the lower surface of the second U-shaped beam (8); the length direction of the diaphragm (4) is consistent with the width direction of the bridge deck.

10. The bridge deck structure of claim 2, wherein, The diaphragm (4) has grooves that fit the first U-shaped beam (3) and the second U-shaped beam (8). The first U-shaped beam (3) and the second U-shaped beam (8) are located in the grooves, and the lower surface and outer side of the first U-shaped beam (3) and the outer side of the second U-shaped beam (8) are welded to the diaphragm (4).

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