A novel bridge deck system combining dense crossbeams and plate girder

Abstract

This invention relates to the field of bridge technology and discloses a novel bridge deck system combining closely spaced crossbeams and trusses. It includes two parallel chords connected to truss nodes to form a continuous structure along the bridge direction. Multiple crossbeams are spaced apart between the chords. Each crossbeam includes an upper flange, a lower flange, and stiffening ribs on its web. A web is installed between the upper and lower flanges, and the web and stiffening ribs are interconnected. A bridge deck panel is arranged above the crossbeams, and longitudinal stiffening ribs and transverse connecting plates are arranged below the deck panel. This invention eliminates crossbeams in the truss node area, simplifying the connection structure, reducing fatigue details, and lowering the risk of fatigue cracking in the node area. The crossbeams in the bridge deck system have consistent cross-sections and dimensions, resulting in minimal stiffness differences and a more uniform load distribution. The fish-belly arrangement of the crossbeams further enhances the local stiffness of the bridge deck system.

Description

Technical Field

[0001] This invention belongs to the field of wooden pallet processing technology, specifically, it relates to a novel bridge deck system combining dense crossbeams and trusses. Background Technology

[0002] Truss structures are widely used in the main girders of various bridge types, such as steel truss bridges and steel truss stiffened girders. A truss main girder generally consists of a main truss, a connecting system, and a deck system. The deck system and connecting system act as force transmission structures, transferring the deck load to the main truss. To fully utilize the role of the deck system and improve its material utilization rate, the deck system can be connected to the main truss to form a plate-truss combined deck system. In this case, the deck system, in addition to acting as a force transmission structure, also shares the external load with the main truss.

[0003] The arrangement of longitudinal and transverse beams in the bridge deck system is the key to the design of plate girder combined bridge deck systems. Existing plate girder combined bridge deck systems can be broadly divided into two categories according to the different arrangements of longitudinal and transverse beams: ① longitudinal and transverse beam plate girder combined bridge deck system, ② dense transverse beam plate girder combined bridge deck system.

[0004] Bridge deck crossbeams (node ​​crossbeams) are installed at truss nodes, and multiple longitudinal beams are arranged between the node crossbeams to form a combined longitudinal and transverse beam-truss bridge deck system. At this time, the bridge deck and longitudinal beams transfer the bridge deck load along the longitudinal direction to the node crossbeams, and then through the node crossbeams along the transverse direction to the truss nodes. The force transmission path is clear, and the crossbeams dominate the transmission of the bridge deck load, which leads to the complex stress on the crossbeams and truss nodes. Larger structural dimensions and complex connection structures are required to ensure the transmission of the bridge deck load.

[0005] By setting multiple crossbeams (inter-segment crossbeams) between the node crossbeams and reducing the number of longitudinal beams, a closely spaced crossbeam-plate truss bridge deck system is formed. This increases the load transfer paths on the bridge deck. The load is transferred not only to the truss nodes through the node crossbeams but also to the chords through the inter-segment crossbeams before finally reaching the truss nodes. The more inter-segment crossbeams there are, the more evenly the load is transferred on the bridge deck. However, the truss nodes bear not only the load directly transferred by the node crossbeams but also the load transferred by the chords. This makes it difficult to clearly define the force transfer mechanism of the truss nodes, reducing the reliability of the nodes under stress.

[0006] From the existing design of plate girder combined bridge deck systems, the load transfer path of the bridge deck system is complex and the load distribution is uneven, which leads to the following problems:

[0007] 1. Truss nodes are subjected to complex stresses. In addition to in-plane loads in the truss structure, they are also subjected to out-of-plane loads transmitted by the node beams and chords. The combination of multiple loads reduces the bearing capacity and fatigue performance of the nodes, while also reducing the stiffness and stability of the bridge deck system.

[0008] 2. The presence of the node beams necessitates the addition of more stiffening ribs and diaphragms at the truss node locations, which not only increases the manufacturing difficulty but also increases fatigue details at the nodes, further reducing the fatigue performance of the nodes.

[0009] 3. The numerous cross-sectional types and dimensions of components such as longitudinal beams, transverse beams, and cross bracing reduce the efficiency of bridge deck system fabrication in the factory and make it difficult to achieve standardized manufacturing.

[0010] 4. When a truss-type transverse bracing system is used in a double-deck bridge structure, it will reduce the clearance of the lower deck, affecting the traffic safety of the lower deck.

[0011] In view of this, the present invention is proposed. Summary of the Invention

[0012] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0013] A novel bridge deck system combining a dense crossbeam and a truss includes two parallel chords connected to truss nodes to form a continuous structure along the bridge direction; multiple crossbeams are spaced apart between the chords, and each crossbeam includes an upper flange, a lower flange, and stiffening ribs on the web of the crossbeam.

[0014] A crossbeam web is installed between the upper flange and the lower flange of the crossbeam, and the crossbeam web and the crossbeam web stiffening ribs are connected to each other; a bridge deck is arranged above the crossbeam, and longitudinal stiffening ribs and transverse connecting plates are arranged below the bridge deck.

[0015] In a preferred embodiment of the present invention, the chord members are arranged flush with the truss nodes, no crossbeams are provided at the truss nodes, and the crossbeams are arranged at equal intervals along the bridge direction.

[0016] In a preferred embodiment of the present invention, the upper flange before the crossbeam is connected to the bridge deck serves as a component of the crossbeam cross section, forming an I-shaped cross section to resist the self-weight of the crossbeam.

[0017] In a preferred embodiment of the present invention, after the crossbeam is connected to the bridge deck, the upper flange serves as a horizontal stiffening rib for the crossbeam of the bridge deck system, thereby enhancing the stability of the crossbeam web.

[0018] In a preferred embodiment of the present invention, the stiffening ribs of the crossbeam web are installed at intervals on the crossbeam web, and the height of the two sides of the crossbeam is lower than the height of the central crossbeam.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. The absence of crossbeams in the truss node area simplifies the connection structure of the truss node area, reduces fatigue details in the node area, and lowers the risk of fatigue cracking in the node area.

[0021] 2. The load transmission path of the bridge deck is clear: bridge deck → crossbeam → chord → truss node. The node does not directly bear the out-of-plane load transmitted from the crossbeam, and the node can be designed locally according to the in-plane force.

[0022] 3. The crossbeams of the bridge deck system have the same cross-section and dimensions, and are all connected to the chord members. The stiffness difference between the crossbeams is small, and the load is distributed more evenly on the bridge deck system. The crossbeams are arranged in a fish-belly pattern, which is beneficial to improving the local stiffness of the bridge deck system.

[0023] 4. The longitudinal stiffening ribs of the upper flange and web of the bridge deck beam can ensure the stability of the beam during the fabrication of the beam. The upper flange can be used as a connecting plate to the bridge deck to realize the prefabrication of the bridge deck system. The upper flange can also be used as a transverse stiffening rib of the bridge deck beam to further improve the local stiffness and stability of the bridge deck system.

[0024] 5. The cross-sections of the constituent components are simple, and the dimensions of each beam remain unchanged, reducing the types of plates required for factory production, improving production efficiency and reducing production costs, and enabling standardized production of plate girder combined bridge deck systems.

[0025] In summary, the present invention has a simple structure, reasonable design, convenient manufacturing and low cost, and excellent mechanical properties. It can effectively solve the problems of complex node stress and difficulty in standardized manufacturing in existing plate girder bridge deck systems.

[0026] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0027] In the attached diagram:

[0028] Figure 1 This is a general layout diagram of a double-layer steel truss stiffening beam according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0030] Figure 3 This is a cross-sectional schematic diagram of Embodiment 1 of the present invention.

[0031] Figure 4 This is a top view schematic diagram of Embodiment 1 of the present invention.

[0032] In the diagram: 1. Chord member; 2. Truss node; 3. Bridge deck; 4. Longitudinal stiffener of bridge deck; 5. Transverse joint of bridge deck system; 6. Upper flange of crossbeam; 7. Lower flange of crossbeam; 8. Web of crossbeam; 9. Stiffener of web of crossbeam. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention. Example

[0034] like Figures 1 to 3 As shown, a novel bridge deck system combining a dense crossbeam and a truss includes two parallel chords 1, which are connected to a truss node 2 to form a continuous structure along the bridge direction; multiple crossbeams are spaced apart between the chords 1, and each crossbeam includes an upper flange 6, a lower flange 7, and stiffening ribs 9 on the web of the crossbeam.

[0035] A crossbeam web 8 is installed between the upper flange 6 and the lower flange 7 of the crossbeam, and the crossbeam web 8 and the crossbeam web stiffening ribs 9 are interconnected. A bridge deck 3 is arranged above the crossbeam, and longitudinal stiffening ribs 4 and transverse connecting plates 5 are arranged below the bridge deck 3. The chord members 1 are arranged flush with the truss node 2. No crossbeams are installed at the truss node 2. The crossbeams are arranged at equal intervals along the bridge direction, and the bottom of the truss node 2 is provided with an arc groove to facilitate quick connection of the node during later assembly, improving assembly efficiency. The web of the crossbeam (i.e., the planar part of the beam) is prone to local buckling when subjected to external loads. Stiffening ribs can effectively increase the stability of the web and prevent such buckling. Web buckling may lead to crossbeam instability, affecting the structural safety. When the steel beam is subjected to shear force, the web is the main load-bearing part. By adding stiffening ribs, the shear bearing capacity of the web can be increased, avoiding cracks and deformation caused by excessive shear force. Example

[0036] The difference between the above embodiments and this embodiment is that: Figures 1 to 3 As shown, a novel bridge deck system combining a crossbeam and a plate girder is described. Before the crossbeam is connected to the bridge deck 3, the upper flange 6 serves as a component of the crossbeam cross section, forming an I-shaped cross section to resist the self-weight of the crossbeam. After the crossbeam is connected to the bridge deck 3, the upper flange 6 serves as a horizontal stiffening rib of the bridge deck system crossbeam to enhance the stability of the crossbeam web. The crossbeam web stiffening ribs 9 are installed at intervals on the crossbeam web 8, and the height of the two sides of the crossbeam is lower than the height of the central crossbeam.

[0037] The same type of plates for the crossbeams use the same plate thickness. Automated welding is used to connect the upper flange 6, lower flange 7, and web stiffeners 9 of the crossbeams to the web 8 of the crossbeams to form the crossbeam components. The longitudinal stiffeners 4 and transverse connecting plates 5 are welded to the bridge deck 3 to form an orthotropic bridge deck. The transverse connecting plates 5 of the bridge deck system are connected to the upper flange 6 of the crossbeams, so that the orthotropic bridge deck and the crossbeam components form the bridge deck system. Finally, the bridge deck system is welded to the chord 1 to form an embodiment of the present invention.

[0038] The bridge deck layout of this invention is reasonable and compact, the stress on each component is clearly defined, the force transmission path is simple, it adapts to the requirements of multi-lane traffic, and can be used for large-span and super-large-span double-deck suspension bridges. Those skilled in the art will readily understand that the above are merely preferred embodiments of this invention and are not intended to limit the invention. Any modifications, combinations, substitutions, improvements, etc., made under the spirit and principles of this invention are included within the protection scope of this invention.

Claims

1. A new type of dense beam slab truss combined bridge deck system, characterized in that, It comprises two chord bars (1) arranged in parallel, the chord bars (1) are connected with truss nodes (2) to form a continuous structure along the bridge direction; multiple cross beams are arranged between the chord bars (1), the cross beams comprise upper flange plates (6), lower flange plates (7) and cross beam web stiffening ribs (9); The truss nodes (2) are provided with arc grooves at the bottom; The cross beam webs (8) are arranged between the upper flange plates (6) and the lower flange plates (7), and the cross beam webs (8) and the cross beam web stiffening ribs (9) are connected with each other; Bridge deck plates (3) are arranged above the cross beams, longitudinal stiffening ribs (4) and transverse connecting plates (5) are arranged below the bridge deck plates (3); The chord bars (1) are arranged in parallel with the truss nodes (2), no cross beam is arranged at the truss nodes (2), and the cross beams are arranged at equal intervals along the bridge direction; Before the cross beams are connected with the bridge deck plates (3), the upper flange plates (6) of the cross beams serve as cross section components of the cross beams to form I-shaped cross sections and resist the dead weight of the cross beams; After the cross beams are connected with the bridge deck plates (3), the upper flange plates (6) of the cross beams serve as horizontal stiffening ribs of the bridge deck system cross beams to enhance the stability of the cross beam webs; The cross beam web stiffening ribs (9) are arranged at intervals on the cross beam webs (8), and the heights of the cross beams on the two sides are lower than the height of the central cross beam.

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