Pier beam consolidation structure suitable for concrete filled steel tube lattice pier

Abstract

The invention relates to the technical field of pier beam consolidation of continuous steel structure bridges, in particular to a pier beam consolidation structure suitable for a concrete filled steel tube lattice pier. The top sections of the lattice pier steel pipes are connected to form a high-stability space truss system through the profile steel framework, the transverse partition plate transverse prestressed steel beams and the longitudinal anchoring prestressed steel beams, and meanwhile the transverse partition plate transverse prestressed steel beams are arranged corresponding to the 0 # transverse partition plate of the main beam in position; web transverse prestressed steel beams are transversely arranged on the basis of the profile steel frameworks on the two sides of the transverse bridge direction, so that the web transverse prestressed steel beams are transversely connected with the main beam 0 # block web and the profile steel frameworks, and the main beam 0 # block is arranged in the center area of a plurality of steel pipes of the lattice pier, so that a multidirectional force transmission path is achieved; and concrete cracking is restrained through normal pressure stress generated by prestress, meanwhile, the load of the main beam can be directly transmitted to the core stress area of the four-limb latticed column through the web plates and the transverse partition plates, concentrated stress can be reduced, and the rigidity, bearing capacity and durability of a bridge are improved.

Description

Technical Field

[0001] This invention relates to the field of pier-beam consolidation technology for continuous steel structure bridges, and particularly to a pier-beam consolidation structure suitable for steel-concrete composite lattice piers. Background Technology

[0002] Continuous rigid frame bridges, as a common type of long-span bridge structure, require a rigid connection between the piers and the main girder to ensure effective load transfer. In traditional designs, such as... Figure 1 , Figure 2 As shown, both the pier column 11 and the main beam are usually made of reinforced concrete. The pier-beam connection is achieved by extending the web reinforcement 10 of the pier column into the main beam body and pouring concrete to form an integral anchorage, thereby transferring the beam load to the pier column 11.

[0003] However, with the diversification of bridge structural forms, steel-concrete composite truss piers, due to their advantages such as light weight, high load-bearing capacity, and superior seismic performance, have been gradually applied to continuous rigid frame bridges. For example... Figure 3 As shown, the steel-concrete composite lattice pier mainly consists of four steel-concrete composite columns as the main load-bearing components. These four columns are connected by bracing to form a lattice-type load-bearing system. Its load-bearing mechanism differs significantly from that of traditional reinforced concrete piers. Traditional reinforced concrete pier-beam consolidation methods are difficult to directly apply to this new type of pier structure: traditional pier-beam consolidation relies on the anchoring effect of the web reinforcement 10 of the pier columns, while the core load-bearing component of the steel-concrete composite lattice pier is the four-limb lattice columns. If only the inter-column concrete rib reinforcement of the steel-concrete composite lattice pier is extended into the main beam, although a connection can be achieved to some extent, there will be abrupt changes in stiffness and discontinuous force transmission paths in the pier-beam anchorage joint area, easily leading to stress concentration, which may cause concrete cracking or localized damage, affecting the structural durability and safety. Figure 3 As shown, if the steel-concrete composite column 13 in the steel-concrete composite pier is directly inserted into the bottom of the beam, and a bearing end plate 14 is set at the top in the insertion section 15, and welded stud connectors are set around the steel pipe, the load on the main beam can be transferred to the main pier through compression and shear. This connection method transmits force directly, but the steel-concrete composite column 13 needs to be inserted into the No. 0 block 1 of the main beam for a certain length. The steel reinforcement in the No. 0 block 1 of the main beam is relatively dense, which is not conducive to the compaction of concrete. In addition, the bottom plate reinforcement of the No. 0 block will also be cut off by the column, resulting in slightly poor overall structural integrity.

[0004] Therefore, it is necessary to propose a new structure for the consolidation of steel-concrete composite piers and main beams to optimize the load transfer mechanism, avoid stress concentration, and ensure the safety and reliability of the bridge structure. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing pier-beam consolidation methods that rely on the anchoring effect of the reinforcement in the web of the pier column, where the main beam load is concentrated in the web of the pier column. In contrast, the load of a steel-concrete composite lattice pier needs to be transferred through the four limb lattice columns. When steel-concrete composite lattice piers are applied to continuous steel bridges, the existing pier-beam consolidation structures cannot meet this stress requirement. Therefore, this invention provides a pier-beam consolidation structure suitable for steel-concrete composite lattice piers.

[0006] This invention provides a pier-beam reinforcement structure suitable for steel-concrete composite lattice piers, comprising a main beam block 0 and a lattice pier. The lattice pier includes at least four steel pipes interconnected by tie rods. The main beam block 0 is located in the central area of ​​the top section of the lattice pier. The top section of the lattice pier is provided with a steel frame and prestressed steel strands. The steel frame connects two adjacent steel pipes. Each steel pipe is located on the outer side of the web of the main beam block 0, and the two sets of steel pipes along the longitudinal direction are respectively connected to the main beam block 0. The positions of the two transverse diaphragms in front and behind block 0 correspond to each other; the prestressed steel strands are arranged at intervals along the height direction, and the prestressed steel strands include longitudinal anchoring prestressed steel strands, transverse diaphragm transverse prestressed steel strands and web transverse prestressed steel strands. The longitudinal anchoring prestressed steel strands pass through two adjacent steel pipes along the longitudinal direction of the bridge, the transverse diaphragm transverse prestressed steel strands pass through two adjacent steel pipes along the transverse direction of the bridge, and the web transverse prestressed steel strands are transversely arranged at the web positions on both sides of block 0 of the main beam and connected to the steel frame on the corresponding side of the transverse direction of the bridge.

[0007] Preferably, a shear-resistant member is provided on the outer wall of the top section of the steel pipe, and the shear-resistant member is positioned towards the side where the No. 0 block of the main beam is located, which helps to reduce the thickness of the outer concrete and at the same time enhances the bonding force with the concrete poured for the No. 0 block.

[0008] Preferably, the inner wall of the top section of the steel pipe is provided with shear-resistant members, which are arranged at intervals along the circumferential direction.

[0009] Preferably, the shear-resistant component is a stud or a stiffening rib.

[0010] Preferably, the stiffening rib is a PBL shear key.

[0011] Preferably, the transverse prestressed steel strands of the diaphragm are provided on both sides of the steel frame along the longitudinal bridge, both forward and backward.

[0012] Preferably, the longitudinal anchoring prestressed steel strand is located inside the steel frame on the corresponding side of the transverse bridge, i.e., on the side facing block 0.

[0013] Preferably, the prestressed steel strands further include vertical prestressed steel strands, which are arranged vertically and correspond to the web position of the No. 0 block of the main beam.

[0014] Preferably, a plurality of PBL shear keys are provided on the inner side of the steel frame on both sides of the transverse bridge, and the PBL shear keys are arranged vertically.

[0015] Preferably, the lattice pier further includes concrete rib reinforcement bars, which are arranged on both sides of the transverse bridge direction. The concrete rib reinforcement bars include vertical reinforcement bars, which extend upward into the flange plate of the No. 0 block of the main beam.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The pier-beam truss structure provided by this invention connects the top section of the lattice pier steel pipes through a steel frame, transverse prestressed steel strands in the diaphragms, and longitudinal anchored prestressed steel strands to form a highly stable spatial truss system. Simultaneously, the transverse prestressed steel strands in the diaphragms are positioned corresponding to the transverse diaphragm position of the main beam block 0. Based on the transverse steel frame on both sides of the bridge, transverse prestressed steel strands in the web are transversely connected to the web of the main beam block 0 and the steel frame. The main beam block 0 is positioned in the central area of ​​several steel pipes in the lattice pier. This not only achieves multi-directional force transmission paths but also utilizes the normal compressive stress generated by prestressing to suppress concrete cracking. Furthermore, the main beam load can be directly transferred to the core stress area of ​​the four-limb lattice columns through the web and diaphragms, effectively reducing concentrated stress and improving the overall stiffness, load-bearing capacity, and durability of the bridge. Attached Figure Description

[0017] Figure 1 This is an elevation view of the traditional pier-beam connection structure along the transverse direction of the bridge. Figure 2 A schematic diagram of the longitudinal reinforcement anchorage structure of a traditional pier-beam connection. Figure 3 This is a structural diagram of an existing pier-beam insertion structure; Figure 4 This is a standard cross-sectional view of a four-limbed steel-tube concrete lattice pier. Figure 5 This is a cross-sectional view of the steel-concrete composite truss pier being fixed to the main beam in the top section. Figure 6 This is a half-section elevation view of the steel-concrete lattice pier and the main beam along the longitudinal direction of the bridge. Figure 7 Plan layout of anchorage prestressed steel strands for pier-beam structural reinforcement; Figure 8 for Figure 7 Sectional view along line AA in the middle; Figure 9 for Figure 7 BB-direction sectional view in the middle; Figure 10A schematic diagram of the elevation of the pier-beam structure along both sides of the transverse bridge direction (the left half is viewed from the outside, and the right half is viewed from the inside). Figure 11 This is a diagram showing the layout of the reinforced concrete reinforcement for segment 0 of the main beam.

[0018] Markings in the diagram: 1-Main beam block 0; 101-Web plate; 102-Diaphragm; 103-Flange plate; 2-Steel pipe; 3-Steel frame; 4-Longitudinal anchorage prestressed steel strands; 5-Diaphragm transverse prestressed steel strands; 6-Web transverse prestressed steel strands; 7-PBL shear key; 8-Vertical reinforcement; 9-Transverse reinforcement; 10-Pier column web reinforcement; 11-Pier column; 12-Inter-column concrete rib; 13-Steel pipe concrete column; 14-Bearing end plate; 15-Insertion section. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0020] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0021] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0022] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0023] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0024] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0025] Example like Figures 4-11 As shown, a pier-beam fixed structure suitable for steel-concrete composite lattice piers includes a main beam block 01 and a lattice pier. The two ends of the lattice pier are fixedly connected to the main beam and the abutment of the bridge, respectively. The main beam block 01 is used to be set in the central area of ​​the top section of the lattice pier.

[0026] The lattice pier comprises at least four steel pipes 2, which are arranged in a rectangular pattern along the longitudinal and transverse directions of the bridge. Several connecting members are spaced along the height between adjacent steel pipes 2 in the transverse direction and between two steel pipes 2 in the longitudinal direction, connecting the steel pipes 2 into a whole. In this embodiment, each steel pipe 2 is respectively positioned on the outer side of the web plates 101 on both sides of the main beam block 0. The two adjacent transverse diaphragms 102 of the main beam block 0 are correspondingly positioned with the steel pipes 2 on both sides. Subsequently, the top section of the lattice pier is integrally cast with the main beam block 0 using concrete, and structural reinforcement is tied to the web plates 101 on both sides of the lattice pier in the transverse direction, encasing the steel pipes 2 in concrete.

[0027] In this embodiment, the lattice pier is preferably configured as a four-limb lattice column, with four steel pipes 2 serving as the main load-bearing components of the lattice pier. For example... Figures 7-10As shown, the top section of the lattice pier is equipped with a steel frame 3 and prestressed steel strands. The steel frame 3 connects two adjacent steel pipes 2. The specific structure of the steel frame 3 on both sides of the transverse bridge direction and both sides of the longitudinal bridge direction can be the same or different. Each steel pipe 2 is located on the outer side of the web 101 on both sides of the main beam No. 0 block 1, and the front and rear sets of steel pipes 2 along the longitudinal bridge direction correspond to the positions of the front and rear transverse diaphragms 102 of the main beam No. 0 block 1, respectively. The prestressed steel strands are arranged at intervals along the height direction. The prestressed steel strands include longitudinal anchoring prestressed steel strands 4 and transverse diaphragm prestressed steel strands 5. The transverse prestressed steel strands 6 and the longitudinal anchoring prestressed steel strands 4 pass through two adjacent steel pipes 2 along the longitudinal direction of the bridge, and are preferably arranged on the inner side of the steel frame 3 on both sides of the transverse direction of the bridge. The transverse prestressed steel strands 5 of the transverse diaphragm pass through two adjacent steel pipes 2 along the transverse direction of the bridge. The transverse prestressed steel strands 5 of the transverse diaphragm are preferably arranged symmetrically on both sides of the steel frame 3 in the longitudinal direction of the bridge. The transverse prestressed steel strands 6 of the web are transversely set at the web 101 position on both sides of the main beam 0 block 1 and connected to the steel frame 3 on the corresponding side of the transverse direction of the bridge, so as to realize the composite anchoring connection between the four-limb lattice column and the main beam body. This scheme arranges a steel frame 3 between the four limb steel pipes 2, forming a highly stable spatial truss system in the top section where the lattice pier is fixed to the main beam, thus constituting the lattice skeleton of the steel tube concrete lattice pier. Then, by arranging a series of prestressed steel strands in the four limb steel pipes 2 of the lattice skeleton, the fixed structure forms a rigid force transmission path, directly transferring the main beam load to the core stress area of ​​the four limb lattice column through the web 101 and the transverse diaphragm 102. The force transmission path is clear and efficient, which helps to reduce stress concentration and fully utilize the high load-bearing capacity of the steel tube concrete lattice column.

[0028] Furthermore, in this embodiment, as Figure 7 As shown, shear members are provided on the outer wall of the top section of steel pipe 2. These shear members are arranged radially and at intervals towards the side where block 0 of the main beam is located, which helps to reduce the thickness of the outer concrete and enhances the connection with the concrete poured for block 0. The shear members can be studs or stiffeners, preferably stiffeners, and PBL shear keys 7 are preferred to improve the connection with the poured concrete and provide compressive and shear strength. Shear members are also provided on the inner wall of the top section of steel pipe 2, arranged at intervals along the circumference to strengthen the connection between steel pipe 2 and the concrete inside, reducing the risk of concrete voids.

[0029] In optional implementations, such as Figure 7 , Figure 10 As shown, several PBL shear keys 7 are also provided on the inner side of the steel frame 3 on both sides of the transverse bridge. The PBL shear keys 7 are arranged vertically. Figure 11As shown, the lattice pier also includes reinforced concrete ribs, which are arranged on both sides of the transverse bridge direction. The reinforced concrete ribs include vertical bars 8, longitudinal bars, and transverse bars 9. The vertical bars 8 extend upwards into the flange plate 103 of the main beam block 0 1. The longitudinal bars are connected along the longitudinal bridge direction and to the steel pipes 2. The transverse bars 9 are transversely connected to the vertical bars 8 and the structural reinforcement of the corresponding side web plates 101 of the main beam block 0 1. After the top section of the lattice pier and the main beam block 0 1 are integrally cast with concrete, the concrete encases the outer wall of the steel pipes 2 and the steel frame 3 between the two steel pipes 2 in the longitudinal bridge direction, forming the inter-column concrete ribs 12.

[0030] Furthermore, the prestressed steel strands also include vertical prestressed steel strands, which are arranged vertically and correspond to the position of the web 101 of the main beam block 0.

[0031] The core of the pier-beam rigid structure construction in this embodiment lies in the synergistic design of the "spatial truss system" and "prestressed composite anchorage," ensuring that the load of the continuous rigid frame main beam is directly and effectively transferred to the four-limb lattice columns, thus solving the technical bottleneck of stress concentration at the pier-beam anchorage node of the steel-concrete composite lattice pier. Specifically, the welded connection between the steel frame 3 and the PBL shear key 7 forms a multi-directional force transmission path, which can effectively disperse the shear force at the node; at the same time, the prestressed steel strands penetrate the steel pipe 2 and are anchored to the web 101 or diaphragm 102 of the main beam, using the normal compressive stress generated by the prestress to suppress concrete cracking, which can significantly improve the durability and load-bearing efficiency of the node. Finite element analysis and full-scale tests have verified that this structure can homogenize the stress distribution in the node area and reduce the peak stress by about 35%.

[0032] This structure is specifically designed for steel-concrete composite lattice piers. It has high strength in the pier-beam consolidation zone, which solves the connection problem with traditional reinforced concrete main beams and broadens the application range of steel-concrete composite lattice piers in continuous rigid frame bridges. At the same time, the stiffening frame of the lattice pier can be prefabricated in the factory, which helps to ensure quality and improve construction efficiency.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pier-beam structural design suitable for steel-concrete composite lattice piers, characterized in that, The structure includes a main beam block 0 (1) and a lattice pier. The lattice pier includes at least four steel pipes (2) connected to each other by tie rods. The main beam block 0 (1) is located in the central area of ​​the top section of the lattice pier. The top section of the lattice pier is provided with a steel frame (3) and prestressed steel strands. The steel frame (3) connects two adjacent steel pipes (2). Each steel pipe (2) is located on the outer side of the web (101) on both sides of the main beam block 0 (1). The front and rear sets of steel pipes (2) along the longitudinal direction of the bridge are respectively connected to the front and rear transverse diaphragms (102) of the main beam block 0 (1). The positions correspond; the prestressed steel strands are arranged at intervals along the height direction. The prestressed steel strands include longitudinal anchoring prestressed steel strands (4), transverse diaphragm transverse prestressed steel strands (5) and web transverse prestressed steel strands (6). The longitudinal anchoring prestressed steel strands (4) pass through two adjacent steel pipes (2) along the longitudinal direction of the bridge. The transverse diaphragm transverse prestressed steel strands (5) pass through two adjacent steel pipes (2) along the transverse direction of the bridge. The web transverse prestressed steel strands (6) are transversely arranged at the web (101) positions on both sides of the main beam No. 0 block (1) and connected to the steel frame (3) on the corresponding side of the transverse direction of the bridge.

2. The pier-beam solid structure for steel-concrete lattice piers according to claim 1, characterized in that, Shear-resistant members are provided on the outer wall of the top section of the steel pipe (2), and the shear-resistant members are positioned facing the side where the main beam block 0 (1) is located.

3. The pier-beam structural system for steel-concrete composite lattice piers according to claim 2, characterized in that, The inner sidewall of the top section of the steel pipe (2) is provided with shear-resistant members, which are arranged at intervals along the circumferential direction.

4. The pier-beam solid structure for steel-concrete composite lattice piers according to claim 2, characterized in that, The shear-resistant component is a stud or a stiffening rib.

5. The pier-beam solid structure for steel-concrete composite lattice piers according to claim 4, characterized in that, The stiffening ribs are PBL shear keys (7).

6. The pier-beam solid structure for steel-concrete composite lattice piers according to claim 1, characterized in that, The transverse prestressed steel strands (5) of the steel frame (3) along the longitudinal bridge are provided on both sides of the front and rear sides.

7. The pier-beam solid structure for steel-concrete lattice piers according to claim 1, characterized in that, The longitudinal anchoring prestressed steel strand (4) is located inside the steel frame (3) on the corresponding side of the transverse bridge.

8. The pier-beam solid structure for steel-concrete composite lattice piers according to claim 1, characterized in that, The prestressed steel strands also include vertical prestressed steel strands, which are arranged vertically and correspond to the position of the web (101) of the main beam block 0 (1).

9. The pier-beam rigid structure for steel-concrete composite lattice piers according to any one of claims 1-8, characterized in that, Several PBL shear keys (7) are provided on the inner side of the steel frame (3) on both sides of the transverse bridge, and the PBL shear keys (7) are arranged vertically.

10. The pier-beam structural system for steel-concrete composite lattice piers according to any one of claims 1-8, characterized in that, The lattice pier also includes concrete rib reinforcement bars, which are arranged on both sides of the transverse bridge direction. The concrete rib reinforcement bars include vertical reinforcement bars (8), which extend upward into the flange plate (103) of the main beam block 0 (1).

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