Steel-concrete composite bridge deck panel with inverted U-shaped shear connector and construction method

Abstract

The application belongs to the technical field of bridge structure, and particularly relates to a steel-concrete combined bridge deck panel adopting inverted U-shaped shear connectors and a construction method. The application forms a bridge deck concrete layer by pouring on a bottom steel plate, and sets inverted U-shaped perforated steel plate units on the bottom steel plate and sets a steel bar mesh on the inverted U-shaped perforated steel plate units, so that the shear bearing capacity of the steel-concrete combined bridge deck panel is further improved. In addition, the application also provides a construction method of the combined bridge deck panel, which can relatively simply and efficiently complete the whole construction process of the combined bridge deck panel by fixing the bottom steel plate first, then welding the inverted U-shaped perforated steel plate units, then welding the steel bar mesh, and finally pouring to form the bridge deck concrete layer.

Description

Technical Field

[0001] This invention belongs to the field of bridge structure technology, and in particular relates to a steel-concrete composite bridge deck using inverted U-shaped shear connectors and its construction method. Background Technology

[0002] As an important component of the bridge structure, the bridge deck directly bears the wheel pressure and impact of vehicles above it. Its working condition directly affects the performance of the bridge. Therefore, the correct selection of the bridge deck structure is of great significance in bridge design.

[0003] Steel-concrete composite bridge decks are a new type of bridge deck composed of a steel base plate and an upper layer of concrete, assembled into a whole through various shear connectors such as studs or perforated plate connectors (PBLs) to share the load. Under load, it can fully utilize the combined advantages of the high tensile strength of steel and the high compressive strength of concrete.

[0004] Currently, in steel-concrete composite bridge deck construction, elastic connectors such as densely packed shear studs or rigid connectors such as perforated steel plates (PBL) are typically used in combination with studs. In some cases, longitudinal steel bars are inserted into the holes of the perforated steel plate connectors (PBL) to connect with densely packed studs in other areas, thereby improving the overall shear bearing capacity of the steel-concrete composite bridge deck.

[0005] In this type of combined shear connector, the perforated steel plate itself has a large anti-slip stiffness and high shear strength, and can enhance the connection of the bottom steel plate of the bridge deck and the lateral stiffness of the bridge deck. It is a new type of steel-concrete composite bridge deck, which is an innovation and development of the traditional reinforced concrete composite slab. It is more suitable for use as a bridge deck for bridges that bear large loads, complex loads and fatigue loads.

[0006] However, using densely packed shear studs on the bridge deck significantly increases the construction work area and workload, and the welding quality of the studs is affected by various factors such as the welding skills of the technicians and the welding equipment. Even with shear connectors that combine perforated plate connectors (PBLs) with studs, a relatively large number of studs are still required to meet the shear design requirements.

[0007] The new shear-resistant composite connector using perforated steel plate connectors (PBL) + studs + longitudinal reinforcement requires the longitudinal reinforcement to pass through the perforated steel plate hole. The shear section of the reinforcement inside the hole is very small, and the shear performance improvement of the reinforcement + concrete dowel combination formed by it and the concrete section inside the hole is very small compared with the steel plate perforated full concrete section dowel.

[0008] Secondly, rigid perforated plate connectors (PBLs) have high rigidity but a small contact area with the bridge deck concrete, making them prone to cracking at the steel-concrete interface under load. Finally, even with the novel combined shear connector (PBL + studs + longitudinal reinforcement), it still requires the studs to work together to resist shear to meet shear design requirements. This results in a complex bridge deck structure, a large construction area, increased steel consumption and deck weight, low economic efficiency, and limits its application in larger span bridge decks. Furthermore, it does not align with the development direction of bridge deck systems towards durability, lightweight design, and ease of construction.

[0009] Therefore, it is necessary to design a structural form and construction method for steel-concrete composite bridge decks that are structurally reasonable, lightweight, durable, easy to construct, and economically practical. This method should effectively solve the problems of complex construction and construction, large working area, numerous defects, and low durability of current steel-concrete composite bridge decks.

[0010] Chinese utility model patent with patent publication number CN214328517U and publication date of October 1, 2021 discloses a U-shaped connection structure for steel fiber reinforced concrete composite bridge deck with milled steel ingot. The bridge deck surface is provided with inverted U-shaped reinforcing ribs, and several through holes are opened on both sides of the reinforcing ribs. The original rivets are replaced with inverted U-shaped reinforcing ribs with through holes, which increases the contact area between the steel plate, concrete and reinforcing ribs. The through holes allow concrete to flow in, so that the reinforcing ribs can be completely embedded in the concrete.

[0011] However, the U-shaped reinforcing bar + reinforcing bar structure in this utility model patent is the above-mentioned combination of steel bar + concrete dowels. Compared with the steel plate perforated full concrete section dowels, its shear resistance is only slightly improved. On the contrary, it significantly increases the bridge weight and the complexity of construction. Summary of the Invention

[0012] This invention provides a steel-concrete composite bridge deck using inverted U-shaped shear connectors. By casting a bridge deck concrete layer on a bottom steel plate, setting inverted U-shaped perforated steel plate units on the bottom steel plate, and setting a steel mesh on the inverted U-shaped perforated steel plate units, the shear bearing capacity of the steel-concrete composite bridge deck is further improved.

[0013] In addition, the present invention also provides a construction method for the composite bridge deck, which can complete the entire construction process of the composite bridge deck relatively simply and efficiently by first fixing the bottom steel plate, then welding the inverted U-shaped perforated steel plate unit, then welding the steel mesh, and finally pouring the concrete layer of the bridge deck.

[0014] The technical solution adopted by the present invention to solve the above problems is: a steel-concrete composite bridge deck with inverted U-shaped shear connectors, the structure including a bottom steel plate and a bridge deck concrete layer, wherein an inverted U-shaped perforated steel plate unit is provided on the upper surface of the bottom steel plate, and a steel mesh is provided at the upper end of the inverted U-shaped perforated steel plate unit.

[0015] A further preferred technical solution is that the length direction of the inverted U-shaped perforated steel plate unit is the transverse direction of the bridge deck, and both long sides of the inverted U-shaped perforated steel plate unit are set on the upper surface of the bottom steel plate.

[0016] A further preferred technical solution is that the inverted U-shaped perforated steel plate unit includes two inverted U-shaped steel plates with their long sides bent downwards, which are arranged on the central axis of the long side of the inverted U-shaped steel plates and used to form the top opening of the concrete shear stud, and two rows of side openings respectively arranged on both sides of the top opening and used to form the concrete shear stud.

[0017] A further preferred technical solution is that the top opening and the side opening are both elliptical in shape, and the long axis of the ellipse is along the long side of the inverted U-shaped steel plate.

[0018] A further preferred technical solution is that: the short axis length of the side opening is greater than 1 / 2 of the height of the inverted U-shaped opening steel plate unit; and the short axis length of the top opening is greater than 1 / 2 of the width of the inverted U-shaped opening steel plate unit.

[0019] A further preferred technical solution is that the inverted U-shaped steel plate is also provided with a connecting frame unit for installing the reinforcing mesh.

[0020] A further preferred technical solution is that the connecting frame unit includes a vertical rectangular plate, an arc-shaped groove on the bottom edge of the vertical rectangular plate for inserting into the inverted U-shaped steel plate, and a semi-split pipe on the upper surface of the vertical rectangular plate for installing the reinforcing bars below the steel mesh.

[0021] A further preferred technical solution is that the connecting frame unit further includes a through hole disposed between the arc-shaped groove and the vertical side of the vertical rectangular plate, and a plug-in post disposed on the two through holes and passing through the two side openings.

[0022] A further preferred technical solution is that the connecting frame unit further includes two fastening nuts respectively disposed at both ends of the plug-in post and used to clamp the vertical side of the vertical rectangular plate.

[0023] The construction method for steel-concrete composite bridge decks using inverted U-shaped shear connectors includes the following steps:

[0024] S1. Fix the bottom steel plate on the main steel beam of the bridge;

[0025] S2. Weld both long sides of the inverted U-shaped perforated steel plate unit to the upper surface of the bottom steel plate;

[0026] S3. Weld the reinforcing mesh to the upper end of the inverted U-shaped perforated steel plate unit;

[0027] S4. Pour bridge deck concrete onto the bottom steel plate and compact it both inside and outside the inverted U-shaped perforated steel plate unit. Then cover and cure it until it reaches the design strength, and finally form a complete bridge deck.

[0028] The present invention has the following advantages.

[0029] First, the bridge deck concrete layer forms a large number of concrete shear studs with large cross sections on the inverted U-shaped perforated steel plate unit, which significantly enhances the shear resistance of the bridge deck.

[0030] Secondly, the inverted U-shaped perforated steel plate unit plus the steel mesh together form the internal steel reinforcement "skeleton" of the bridge deck concrete layer, further improving the structural integrity of the bridge deck.

[0031] Third, there is a connecting frame unit between the inverted U-shaped perforated steel plate unit and the steel mesh, which ensures that the steel mesh has sufficient welding area and that it is firmly welded to the inverted U-shaped perforated steel plate unit.

[0032] Fourth, the connecting frame unit can further adjust the relative height of the steel mesh to the bottom steel plate.

[0033] Fifth, the connecting frame unit can also reinforce the inverted U-shaped perforated steel plate unit.

[0034] Sixth, the construction method of the entire composite bridge deck is relatively simple and convenient, proceeding from bottom to top, first the steel structure and then the concrete structure, with reasonable and orderly construction operations. Attached Figure Description

[0035] Figure 1 This is a schematic cross-sectional view of the present invention along the longitudinal direction of the bridge.

[0036] Figure 2 This is a schematic diagram of the structural shape of the inverted U-shaped perforated steel plate unit in this invention when it is not bent.

[0037] Figure 3 This is a schematic diagram of the position and structure of the connecting frame unit in this invention.

[0038] Figure 4 This is a schematic diagram illustrating the use of the half-sectioned tube in this invention.

[0039] Figure 5This is a schematic diagram of the position structure of the insertion post in this invention.

[0040] Figure 6 This is a schematic diagram of the position and structure of the fastening nut in this invention.

[0041] In the attached diagram, the meanings of each number are as follows: longitudinal bridge direction A, bottom steel plate a, bridge deck concrete layer b, inverted U-shaped perforated steel plate unit 1, steel mesh 2, inverted U-shaped steel plate 101, top opening 102, side opening 103, connecting frame unit 3, vertical rectangular plate 301, arc groove 302, half-sectioned pipe 303, through hole 304, plug-in column 305, fastening nut 306. Detailed Implementation

[0042] The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

[0043] As attached Figure 1-6 As shown, the steel-concrete composite bridge deck adopts inverted U-shaped shear connectors. The structure includes a bottom steel plate a and a bridge deck concrete layer b. The upper surface of the bottom steel plate a is provided with an inverted U-shaped perforated steel plate unit 1, and the upper end of the inverted U-shaped perforated steel plate unit 1 is provided with a steel mesh 2.

[0044] In this embodiment, the direction of the arrangement of several inverted U-shaped perforated steel plate units 1 is the longitudinal direction of the bridge deck, i.e. the driving direction. The inverted U-shaped perforated steel plate unit 1 itself is a large shear-resistant connector.

[0045] The length direction of the inverted U-shaped perforated steel plate unit 1 is the transverse direction of the bridge deck, and both long sides of the inverted U-shaped perforated steel plate unit 1 are set on the upper surface of the bottom steel plate a.

[0046] In this embodiment, the inverted U-shaped perforated steel plate unit 1 is welded to the upper surface of the bottom steel plate a. Furthermore, ordinary shear studs may also be provided on the upper surface of the bottom steel plate a.

[0047] The inverted U-shaped perforated steel plate unit 1 includes two inverted U-shaped steel plates 101 with their long sides bent downwards, which are arranged on the central axis of the long side of the inverted U-shaped steel plates 101 and used to form a top opening 102 for concrete shear studs, and two rows of side openings 103 respectively arranged on both sides of the top opening 102 and used to form concrete shear studs.

[0048] In this embodiment, the inverted U-shaped steel plate 101 is formed by bending a rectangular straight steel plate, and after bending, it is fixed in an inverted U-shape. Furthermore, the top opening 102 and the side opening 103 are also created during the bending of the rectangular straight steel plate.

[0049] The top opening 102 and the side opening 103 are both elliptical in shape, with the major axis of the ellipse pointing in the direction of the long side of the inverted U-shaped steel plate 101.

[0050] In this embodiment, the top opening 102 and the side opening 103 cannot be polygonal, such as rectangular or triangular, because the stress will be too concentrated at the corners of polygons, and the inverted U-shaped steel plate 101 is prone to cracking at the corners of the openings. In addition, circular holes are preferred, which can alleviate the above-mentioned stress concentration problem. However, for the elongated inverted U-shaped steel plate 101, if the circular hole is too small, the resulting concrete shear studs will not be large enough, and the shear resistance will be average. If the circular hole is too large, an area with too small a width will easily form at the inverted U-shaped steel plate 101, and this area is also prone to breakage.

[0051] Therefore, the optimal shape is an ellipse, specifically an ellipse with its major axis laterally, which can alleviate the problem of excessively thin steel plate sides caused by circular holes.

[0052] The minor axis length of the side opening 103 is greater than 1 / 2 of the height of the inverted U-shaped opening steel plate unit 1; the minor axis length of the top opening 102 is greater than 1 / 2 of the width of the inverted U-shaped opening steel plate unit 1.

[0053] In this embodiment, the minor axis lengths of the side opening 103 and the top opening 102 are both planar dimensions of the steel plate before bending. Both types of elliptical holes are made as large as possible in order to maximize the size of the concrete shear studs formed at the side opening 103 and the top opening 102 without significantly reducing the structural strength of the inverted U-shaped steel plate 101, thereby improving the shear resistance performance of the entire composite bridge deck.

[0054] The inverted U-shaped steel plate 101 is also provided with a connecting frame unit 3 for installing the steel mesh 2.

[0055] In this embodiment, without the connecting frame unit 3, the use of the steel mesh 2 would have at least two shortcomings: First, only a small area at the top of the inverted U-shaped steel plate 101 can be used to weld the steel mesh 2, so the weld between the two is not strong enough; Second, once the height of the inverted U-shaped steel plate 101 is determined, the steel mesh 2 cannot be properly adjusted in height.

[0056] Therefore, the solution to the above two problems is precisely the purpose of setting up the connecting frame unit 3.

[0057] The connecting frame unit 3 includes a vertical rectangular plate 301, an arc groove 302 disposed on the bottom edge of the vertical rectangular plate 301 and used to insert into the inverted U-shaped steel plate 101, and a semi-sectioned tube 303 disposed on the upper surface of the vertical rectangular plate 301 and used to install the reinforcing bars below the reinforcing mesh 2.

[0058] In this embodiment, the use of the connecting frame unit 3 requires that the steel mesh 2 be perpendicular to the length direction of the inverted U-shaped steel plate 101.

[0059] Therefore, the arc-shaped groove 302 is welded to the upper surface of the inverted U-shaped steel plate 101, and the half-section tube 303 is welded to the lower reinforcing bars of the steel mesh 2, ensuring that both welds have sufficiently large welding surfaces. Of course, the vertical rectangular plate 301 and the half-section tube 303 are either integrally formed or already firmly welded together from the beginning.

[0060] Finally, the inverted U-shaped steel plate 101 does not need to be connected to each of the lower reinforcing bars of the reinforcing mesh 2 through the connecting frame unit 3. It is sufficient to ensure that the fixing strength of the reinforcing mesh 2 meets the design requirements.

[0061] The connecting frame unit 3 also includes a through hole 304 disposed between the arc groove 302 and the vertical side of the vertical rectangular plate 301, and a plug post 305 disposed on the two through holes 304 and passing through the two side openings 103.

[0062] In this embodiment, the plug-in post 305 passes through the first through hole 304, the first side opening 103, the second side opening 103, and the second through hole 304 in sequence, ensuring that the vertical rectangular plate 301 and the inverted U-shaped steel plate 101, in addition to the above-mentioned welding position, also have the locking and fixing effect of the plug-in post 305, ultimately ensuring that the connecting frame unit 3 can be firmly installed on the inverted U-shaped steel plate 101.

[0063] Of course, it should be noted that the plug post 305 should not be too thick, and the size of the concrete shear stud formed at the side opening 103 should not be significantly reduced.

[0064] The connecting frame unit 3 also includes two fastening nuts 306 respectively disposed at both ends of the plug-in post 305 and used to clamp the vertical side of the vertical rectangular plate 301.

[0065] In this embodiment, threaded sections are provided at both ends of the plug post 305, which, when used with the fastening nut 306, can further secure the plug post 305.

[0066] The construction method for steel-concrete composite bridge decks using inverted U-shaped shear connectors includes the following steps:

[0067] S1. Fix the bottom steel plate a on the main steel beam of the bridge;

[0068] S2. Weld both long sides of the inverted U-shaped perforated steel plate unit 1 to the upper surface of the bottom steel plate a;

[0069] S3. Weld the reinforcing mesh 2 to the upper end of the inverted U-shaped perforated steel plate unit 1;

[0070] S4. Pour bridge deck concrete onto the bottom steel plate a, and tamp it tightly inside and outside the inverted U-shaped perforated steel plate unit 1. Then cover and cure it until the design strength is reached, and finally form a complete bridge deck.

[0071] In S2 of this embodiment, ordinary studs can be welded onto the upper surface of the bottom steel plate a, and these ordinary studs can also be located inside the inverted U-shaped perforated steel plate unit 1.

[0072] Ultimately, the steel-concrete composite bridge deck exhibits outstanding shear resistance.

[0073] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various modifications can be made without departing from the spirit of the present invention. These are non-inventive modifications and are protected by patent law as long as they fall within the scope of the claims of the present invention.

Claims

1. A steel-concrete composite bridge deck using inverted U-shaped shear connectors, characterized in that: The structure includes a bottom steel plate (a) and a bridge deck concrete layer (b). The bottom steel plate (a) has an inverted U-shaped perforated steel plate unit (1) on its upper surface, and a steel mesh (2) is provided at the upper end of the inverted U-shaped perforated steel plate unit (1). The inverted U-shaped perforated steel plate unit (1) includes two inverted U-shaped steel plates (101) with their long sides bent downwards, which are arranged on the long side of the inverted U-shaped steel plate (101) towards the central axis and are used to form a top opening (102) for concrete shear studs, and two rows of side openings (103) respectively arranged on both sides of the top opening (102) for forming concrete shear studs. Both the top opening (102) and the side opening (103) are elliptical in shape, with the major axis of the ellipse pointing in the direction of the long side of the inverted U-shaped steel plate (101). The minor axis length of the side opening (103) is greater than 1 / 2 of the height of the inverted U-shaped opening steel plate unit (1); the minor axis length of the top opening (102) is greater than 1 / 2 of the width of the inverted U-shaped opening steel plate unit (1). The inverted U-shaped steel plate (101) is also provided with a connecting frame unit (3) for installing the steel mesh (2). The connecting frame unit (3) includes a vertical rectangular plate (301), an arc groove (302) on the bottom edge of the vertical rectangular plate (301) for inserting into the inverted U-shaped steel plate (101), and a half-section pipe (303) on the upper surface of the vertical rectangular plate (301) for installing the reinforcing bars below the steel mesh (2).

2. The steel-concrete composite bridge deck with inverted U-shaped shear connectors as described in claim 1, characterized in that: The length direction of the inverted U-shaped perforated steel plate unit (1) is the transverse direction of the bridge deck, and both long sides of the inverted U-shaped perforated steel plate unit (1) are set on the upper surface of the bottom steel plate (a).

3. The steel-concrete composite bridge deck with inverted U-shaped shear connectors as described in claim 1, characterized in that: The connecting frame unit (3) also includes a through hole (304) disposed between the arc groove (302) and the vertical side of the vertical rectangular plate (301), and a plug-in post (305) disposed on the two through holes (304) and passing through the two side openings (103).

4. The steel-concrete composite bridge deck with inverted U-shaped shear connectors as described in claim 3, characterized in that: The connecting frame unit (3) also includes two fastening nuts (306) respectively disposed at both ends of the plug-in post (305) and used to clamp the vertical side of the vertical rectangular plate (301).

5. The construction method for steel-concrete composite bridge deck using inverted U-shaped shear connectors as described in claim 1, characterized in that... The steps are as follows: S1. Fix the bottom steel plate (a) on the main steel beam of the bridge. S2. Weld both long sides of the inverted U-shaped perforated steel plate unit (1) to the upper surface of the bottom steel plate (a); S3. Weld the steel mesh (2) to the upper end of the inverted U-shaped perforated steel plate unit (1); S4. Pour bridge deck concrete on the bottom steel plate (a) and compact it inside and outside the inverted U-shaped perforated steel plate unit (1). Then cover and cure it until the design strength is reached, and finally form a complete bridge deck.

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