Anchoring structure of cable-stayed bridge steel-concrete combined cable bent tower and construction method

Abstract

The invention belongs to the technical field of bridge engineering, and discloses a cable-stayed bridge steel-concrete combined cable bent tower anchoring structure and a construction method.The cable-stayed bridge steel-concrete combined cable bent tower anchoring structure comprises a combined cable bent tower and an anchor pipe body structure, the anchor pipe body structure comprises a steel anchor pipe, an anchor bearing plate is welded to the top end of the steel anchor pipe, and triangular stiffening plates, vertical stiffening plates and transverse stiffening plates are fixed to the periphery of the steel anchor pipe; the triangular stiffening plate is fixed with the inner steel shell; the ends, away from the steel anchor pipe, of the transverse stiffening plates perpendicularly fix triangular side plates, the long sides of the side plates are fixedly connected with the inner steel shell, and the side plates are fixedly connected with the anchor bearing plate. A bottom plate is welded to the side, away from the steel anchor pipe, of the vertical stiffening plate, the bottom plate is fixedly connected with the side plate, outer transverse stiffening plates are fixed to the side, facing the inner steel shell, of the steel anchor pipe and the two sides of the triangular stiffening plate, and the outer transverse stiffening plates are fixed to the side plate; and built-in stiffening plates are fixed among the transverse stiffening plates, the vertical stiffening plates or the triangular stiffening plates, the bottom plate or the outer transverse stiffening plate and the side plates. The device has the technical effect of being convenient to regulate and control when facing different anchoring angles.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering technology, specifically relating to an anchorage structure and construction method for a steel-concrete composite cable tower of a cable-stayed bridge. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] A cable-stayed bridge is a type of bridge where the main girder is directly anchored to the bridge towers using numerous cables. The cable towers of a cable-stayed bridge are primarily compression-bending structures, and the anchorage zone of the cables within the tower is called the tower anchorage zone. In modern cable-stayed bridge engineering, the most commonly used tower anchorage methods include circumferential prestressed anchorage, steel anchor beam anchorage, and steel anchor box anchorage. However, all three have drawbacks: circumferential prestressed anchorage requires a large amount of prestressed steel reinforcement, making high-altitude construction difficult and requiring high precision control, and it cannot be inspected or replaced after construction; steel anchor beam anchorage places stringent requirements on the internal space of the tower, making hoisting difficult and unsuitable for spatial tower structures; steel anchor box anchorage uses a large amount of steel, is costly, and has stringent requirements for hoisting capacity and installation precision, limiting its applicability in scenarios with special durability requirements, such as marine environments.

[0004] To address the aforementioned technical problems, the prior art discloses a cable-stayed bridge steel-concrete composite bridge tower anchorage structure, including a cable guide tube, which is fixedly connected to the inner surface of the bridge tower's inner wall. An anchor is fixedly connected to the bridge tower's inner wall through a force transmission component. The force transmission component includes a steel anchor pipe, one end of which is fixedly connected to the bridge tower's inner wall, and the other end of which is fixedly connected to an anchor plate. Several pipe ribs are fixedly provided along the circumference of the steel anchor pipe, and the pipe ribs are fixedly connected to the anchor plate and the bridge tower's inner wall.

[0005] The above solution has the following drawbacks: In the above scheme, the cable force is transmitted to the steel anchor pipe and the inner wall of the bridge tower through the local contact of the ribs and side plates. The force transmission path lacks three-dimensional coordination. Under the action of a large cable force of thousands of tons, stress concentration is likely to form at the connection between the ribs and the steel anchor pipe and the inner wall of the bridge tower. Long-term stress may lead to cracking of the welded joints, which cannot meet the stringent requirements of uniform force transmission for long-span cable-stayed bridges. Moreover, the size and arrangement of the ribs and side plates do not take into account the changes in stress characteristics caused by the change of anchorage angle. When the anchorage angle between the cable and the tower wall increases (bearing greater horizontal compressive stress) or decreases (bearing greater vertical shear stress), the conventional approach can only be to add reinforcement by increasing the number of ribs and thickening the side plates. This will not only greatly increase the amount of steel used and squeeze the space inside the tower, but also cause stress distribution imbalance due to the inherent defects of the force transmission system, which is still difficult to match the force requirements under different angles. In addition, the steel shell in the above scheme improves the connection strength with the concrete by reinforcing ribs. However, the reinforcing ribs are local protrusion structures and lack a comprehensive mechanical interlocking and force transmission mechanism. Under the repeated action of thousands of tons of cable force and during long-term service, interface peeling and relative slippage are likely to occur between the steel shell and the concrete, resulting in low overall stress performance of the combined tower wall. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide an anchoring structure and construction method for a steel-concrete composite cable-stayed bridge tower, which can solve the technical problems of lack of three-dimensional coordination of force transmission path and low overall stress performance of composite tower wall in the prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In the first aspect, an anchoring structure for a steel-concrete composite pylon of a cable-stayed bridge is provided, comprising a composite pylon and a symmetrically arranged anchor pipe main structure, wherein the composite pylon comprises an inner steel shell and an outer steel shell; The main structure of the anchor pipe includes a steel anchor pipe that runs through the inner steel shell and the outer steel shell. An anchor plate is welded to the top of the steel anchor pipe. Triangular stiffening plates, vertical stiffening plates and horizontal stiffening plates are fixed around the steel anchor pipe. The long side of the triangular stiffening plate is fixedly connected to the inner steel shell. The vertical stiffening plate and the triangular stiffening plate are in the same plane. The horizontal stiffening plate is perpendicular to the triangular stiffening plate. A triangular side plate is vertically fixed to the end of the transverse stiffening plate away from the steel anchor pipe. The long side of the side plate is fixedly connected to the inner steel shell, and the side plate is also fixedly connected to the anchor plate. A bottom plate is welded to the side of the vertical stiffening plate away from the steel anchor pipe. The bottom plate is fixedly connected to the side plate. On the side of the steel anchor pipe facing the inner steel shell, outer transverse stiffening plates are fixed on both sides of the triangular stiffening plate. The outer transverse stiffening plates are fixed to the side plates. An internal stiffening plate is fixed between the transverse stiffening plate, the vertical stiffening plate or the triangular stiffening plate, the bottom plate or the outer transverse stiffening plate and the side plate.

[0008] Preferably, within the combined cable tower, multiple horizontal perforated plates are fixed vertically on the inner and outer steel shells, and multiple vertical perforated plates perpendicular to the horizontal perforated plates are fixed circumferentially on the inner and outer steel shells, with the width of the vertical perforated plates being smaller than the width of the horizontal perforated plates.

[0009] Preferably, horizontal reinforcing bars are arranged inside the holes of the vertical perforated plate, and vertical reinforcing bars are arranged inside the holes of the horizontal perforated plate.

[0010] Preferably, an angle steel connector is provided between the transverse perforated plates on the inner steel shell and the outer steel shell at intervals of a set number of layers; the end of the angle steel connector is connected to the connecting plate of the transverse perforated plate of the inner steel shell or the outer steel shell, and multiple connecting plates are evenly fixed in the circumferential direction of the transverse perforated plate.

[0011] Preferably, the outer steel shell and the inner steel shell are each connected to a first angle steel connector on their corresponding sides, and the first angle steel connector is perpendicular to the inner steel shell and the outer steel shell.

[0012] Preferably, a first angle steel connector is also connected at the right angle point between the outer steel shell and the inner steel shell, and a second angle steel connector is fixedly connected to the first angle steel connector at the right angle point, and the second angle steel connector is fixedly connected to the transverse perforated plate of the outer steel shell.

[0013] Preferably, on the side of the combined cable tower with multiple first angle steel connectors, a third angle steel connector is also connected. One end of the third angle steel connector is connected to the middle connecting plate of the inner steel shell on the current side, and the other end is connected to the connecting plates on both sides of the middle connecting plate of the outer steel shell on the current side.

[0014] Preferably, the upper and lower adjacent angle steel connectors are connected by diagonal braces, and the upper and lower diagonal braces are in a cross state, with the two ends of the diagonal braces connected to the vertical perforated plates corresponding to the middle connecting plate.

[0015] Preferably, within the combined cable tower, the inner steel shell and the outer steel shell are fixed with several studs at equal intervals, and the length of the studs is greater than the width of the vertical perforated plate and less than the width of the horizontal perforated plate.

[0016] Secondly, a construction method for the anchorage structure of the aforementioned steel-concrete composite pylon of a cable-stayed bridge is provided, the specific steps of which include: Prefabricate the components of the composite cable tower and assemble them on site; pass steel anchor pipes through the inner and outer steel shells and fix the steel anchor pipes to the inner and outer steel shells; Then, based on the anchoring angle between the steel anchor pipe and the composite cable tower, the side length and angle of the side plate and the triangular stiffening plate are calculated, and the side plate and the triangular stiffening plate are fabricated together with the horizontal stiffening plate, the vertical stiffening plate, the outer horizontal stiffening plate, the bottom plate, and the internal stiffening plate. Anchor plates are welded and fixed onto the steel anchor pipe. Then, horizontal stiffening plates, triangular stiffening plates, and vertical stiffening plates are welded onto the steel anchor pipe. Next, the outer horizontal stiffening plate, bottom plate, and inner stiffening plate are welded in sequence, and finally, the side plates are welded.

[0017] Compared with the prior art, the advantages and positive effects of this invention are: The anchor pipe main structure of this invention, through the arrangement of anchor plates, triangular stiffening plates, vertical stiffening plates, outer transverse stiffening plates, transverse stiffening plates, and internal stiffening plates, enables the anchor pipe main structure to directly and safely transfer the horizontal compressive stress generated by the cable force to the composite cable tower. The long sides of the left side plate, right side plate, and triangular stiffening plate of the anchor pipe main structure are welded and fixed to the inner steel shell, and the weld can safely transfer the vertical shear stress generated by the cable force to the composite cable tower. This invention, through the multi-directional coordinated arrangement of stiffening plate components, can effectively bear horizontal compressive stress and vertical shear stress, effectively solving the problems of lack of three-dimensional coordination in the cable force transmission path, stress concentration, and weld joint cracking in the prior art. When facing different anchoring angles, this invention can adjust the stress borne per unit weld length by adjusting the dimensions of the triangular side plates and triangular stiffening ribs, providing a convenient controllable technical effect. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 This is an overall schematic diagram of the anchorage structure of a steel-concrete composite cable tower for a cable-stayed bridge according to Embodiment 1 or Embodiment 2 of the present invention; Figure 2 This is an overall schematic diagram of the anchor pipe main structure of Embodiment 1 or Embodiment 2 of the present invention; Figure 3 This is an axial cross-sectional view of the anchor pipe main structure of Embodiment 1 or Embodiment 2 of the present invention; Figure 4 This is an exploded view of the anchor pipe main structure of Embodiment 1 or Embodiment 2 of the present invention; Figure 5 This is a cross-sectional view of the anchor pipe main structure and the combined cable tower anchoring angle of Embodiment 1 or Embodiment 2 of the present invention at 25°. Figure 6 This is a cross-sectional view of the anchor pipe main structure and the combined cable tower anchoring angle of Embodiment 1 or Embodiment 2 of the present invention at 40°. Figure 7 This is a top view of the combined cable tower of Embodiment 1 or Embodiment 2 of the present invention; Figure 8 This is in Embodiment 1 or Embodiment 2 of the present invention. Figure 7 AA section diagram; Figure 9 This is in Embodiment 1 or Embodiment 2 of the present invention. Figure 7 BB cross-section diagram; Figure 10 This is a calculation principle diagram of the triangular ribbed plate and triangular side plate in Embodiment 1 or Embodiment 2 of the present invention; Cross-sectional view; In the picture: 1. Inner steel shell; 2. Outer steel shell; 3. Horizontal perforated plate; 4. Vertical perforated plate; 5. Stud; 6. Angle steel connector; 7. Steel anchor pipe; 8. Anchor plate; 9. Left side plate; 10. Triangular stiffening plate; 11. Right side plate; 12. Outer horizontal stiffening plate; 13. Vertical stiffening plate; 14. Base plate; 15. Horizontal stiffening plate; 16. Internal stiffening plate; 17. Diagonal brace. Detailed Implementation

[0020] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] The present invention will now be described in detail with reference to the accompanying drawings.

[0022] Example 1 This embodiment discloses an anchoring structure for a steel-concrete composite cable-stayed bridge tower, such as... Figure 1 As shown, the structure includes a combined cable tower and an anchor pipe main structure symmetrically arranged relative to the center of the combined cable tower. The combined cable tower includes an inner steel shell 1 and an outer steel shell 2, as well as concrete between them. The anchor pipe main structure includes a steel anchor pipe 7, which is the core component of the anchor pipe main structure. The inside of the steel anchor pipe is used to pass through the stay cables. The steel anchor pipe 7 passes through the inner steel shell 1 and the outer steel shell 2 and is welded and fixed to them to ensure that the cable force can be transmitted from the steel anchor pipe to the inner steel shell 1 and the outer steel shell 2.

[0023] like Figure 1 As shown, inside the inner steel shell 1, an anchor plate 8 is welded to the top of the steel anchor pipe 7. The function of the anchor plate 8 is to provide a flat bearing surface for the anchorage of the stay cable and to evenly distribute the cable force to the steel anchor pipe 7 and the stiffening plate of the steel anchor pipe 7. Figure 2 , Figure 3 , Figure 4As shown, the stiffening plates specifically include a triangular stiffening plate 10, a vertical stiffening plate 13, and a transverse stiffening plate 15, which are circumferentially fixedly connected to the steel anchor pipe 7. The long side of the triangular stiffening plate 10 is fixedly connected to the inner steel shell 1. The vertical stiffening plate 13 is in the same plane as the triangular stiffening plate 10, and the two transverse stiffening plates 15 are perpendicular to the triangular stiffening plate 10 and the vertical stiffening plate 13. The triangular stiffening plate 10, the vertical stiffening plate 13, and the transverse stiffening plates 15 can enhance the local stiffness of the steel anchor pipe 7, prevent local deformation of the steel anchor pipe 7 under cable force, and assist in transferring the cable force to other force-transmitting plates of the anchor pipe's main structure.

[0024] like Figures 1 to 4 As shown, the end of the transverse stiffening plate 15 furthest from the steel anchor pipe 7 is vertically fixed to a triangular side plate. There are two transverse stiffening plates 15, therefore there are two triangular side plates, namely the left side plate 9 and the right side plate 11. The long sides of both the left side plate 9 and the right side plate 11 are fixedly connected to the inner steel shell 1, and the right-angled side of both the left side plate 9 and the right side plate 11 is fixedly connected to the anchor plate 8. The connection between the left side plate 9 and the right side plate 11, the anchor plate 8, and the transverse stiffening plate 15 forms a stable force transmission frame, which transmits the vertical component of the cable force to the steel shell of the tower.

[0025] like Figures 1 to 4 As shown, a base plate 14 is welded to the side of the vertical stiffening plate 13 away from the steel anchor pipe 7. The base plate 14 is also fixedly connected to the other right-angled side of the left side plate 9 and the right side plate 11. The function of the base plate 14 is to improve the bottom support of the anchor pipe main structure, forming a closed or semi-closed box-shaped structure, thereby enhancing the integrity and compressive strength of the anchor pipe main structure. Figures 2 to 4 As shown, on the side of the steel anchor pipe 7 facing the inner steel shell 1, outer transverse stiffening plates 12 are welded and fixed to both sides of the triangular stiffening plate 10. The outer transverse stiffening plates 12 are parallel to the transverse stiffening plates 15 and are welded and fixed to the left side plate 9 or the right side plate 11. In this embodiment, the function of the outer transverse stiffening plates is to strengthen the rigidity of the connection area between the anchor pipe main structure and the tower steel shell, and to optimize the transmission path of horizontal compressive stress.

[0026] like Figures 2 to 4 As shown, an internal stiffening plate 16 is welded and fixed between the transverse stiffening plate 15, the vertical stiffening plate 13, the bottom plate 14, and the left side plate 9 or the right side plate 11. The internal stiffening plate 16 is also welded and fixed between the transverse stiffening plate 15, the triangular stiffening plate 10, the outer transverse stiffening plate 12, and the left side plate 9 or the right side plate 11. The function of the internal stiffening plate 16 is to further enhance the internal stiffness and compressive strength of the anchor pipe main structure, ensuring that the structure does not buckle or experience local instability when subjected to large cable forces.

[0027] In this embodiment, when the anchorage angle between the steel anchor pipe 7 and the composite cable tower increases, the vertical shear stress borne by the anchorage zone of the cable tower decreases, while the horizontal compressive stress increases. Conversely, the situation is reversed when the anchorage angle decreases. The anchor pipe main structure, through the arrangement of anchor plates, triangular stiffening plates, vertical stiffening plates, outer transverse stiffening plates, transverse stiffening plates, and internal stiffening plates, enables the anchor pipe main structure to directly and safely transfer the horizontal compressive stress generated by the cable force to the composite cable tower. The long sides of the left side plate, right side plate, and triangular stiffening plate of the anchor pipe main structure are welded and fixed to the inner steel shell 1, and the weld can safely transfer the vertical shear stress generated by the cable force to the composite cable tower.

[0028] It should be noted that cable-stayed bridges have multiple stay cables, each with a different anchorage angle. When dealing with stay cables at different anchorage angles, the resulting stress varies. Traditional structural designs typically reinforce this by adding steel anchor tubes with circumferential ribs. However, this method is cumbersome to adjust during actual construction due to the large number of stay cables. In this embodiment, however, the stress per unit weld length can be adjusted simply by modifying the dimensions of the triangular side plates and triangular stiffening ribs, offering a convenient and efficient adjustment mechanism.

[0029] Specifically, such as Figure 5 , Figure 6 , Figure 10 As shown, when the anchorage angle of the anchorage zone decreases, that is, when the vertical shear stress borne by the anchorage zone increases, and when the long side of the triangular side plate and the triangular stiffening rib is insufficient to safely and effectively transmit these increased stresses, the long side dimension of the triangular side plate and the triangular stiffening rib can be increased, that is, the overall dimension of the triangular side plate and the triangular stiffening rib can be increased, so that the weld length between the triangular side plate or the triangular stiffening rib and the inner steel shell 1 becomes longer, and the vertical shear stress generated by the cable force is distributed to a larger welding area, thereby reducing the stress borne per unit weld length.

[0030] It is also understood that the anchor pipe main structure of this embodiment, through the arrangement of multi-directional coordinating stiffening plate components, can effectively bear horizontal compressive stress and vertical shear stress, effectively solving the problems of lack of three-dimensional coordination of cable force transmission path, stress concentration and cracking of welded joints in the prior art.

[0031] In addition, in this embodiment, when the anchorage angle of the anchorage zone increases, the anchorage zone needs to withstand greater horizontal compressive stress. Since the short column has high axial compressive stability, the built-in stiffening plate usually does not need detailed design. However, for safety reasons, the built-in stiffening plate 16 should be designed according to the relevant requirements of the "Steel Structure Design Standard" (GB 50017-2017). The built-in stiffening plate can be added to enhance the compressive performance of the anchor pipe main structure.

[0032] like Figure 1 , Figure 5 , Figure 6 As shown, along the vertical direction of the composite cable tower, between the inner steel shell 1 and the outer steel shell 2, multiple horizontal perforated plates 3 are fixedly connected (e.g., welded) to both the inner steel shell 1 and the outer steel shell 2. Along the circumference of the composite cable tower, multiple vertical perforated plates 4 perpendicular to the horizontal perforated plates 3 are fixedly connected (e.g., welded) to both the inner steel shell 1 and the outer steel shell 2, thereby forming a denser shear force transmission network and enhancing the shear force transmission capacity between the inner steel shell 1, the outer steel shell 2 and the internal concrete of the cable tower.

[0033] like Figure 5 , Figure 6 As shown, the width of the vertical perforated plate 4 is smaller than the width of the transverse perforated plate 3. It should be noted that in the anchorage zone of a cable-stayed bridge pylon, the cable force exerts a significant shear force on the interface between the inner steel shell and the concrete in the transverse component. Therefore, the transverse (circumferential) shear force transfer requirement is typically large. A wider transverse perforated plate can provide a larger shear bonding area and stiffness to effectively resist these major transverse shear forces. While the vertical perforated plate also provides shear bonding, its main function may be more focused on assisting in confining the concrete, transferring local stress, and improving the overall structural stability. Therefore, a relatively smaller width can be used to optimize material usage and construction efficiency while meeting structural stress requirements.

[0034] It is understandable that the interface between the perforated plate and the concrete alone is insufficient to fully resist complex shear and tensile stresses, especially in the concrete region inside the perforated plate, where the connection strength and crack resistance with the steel shell are limited, thus affecting the overall collaborative performance and load-bearing capacity of the steel-concrete composite structure. Therefore, in this embodiment, transverse reinforcing bars are arranged inside the holes of the vertical perforated plate 4, and vertical reinforcing bars are arranged inside the holes of the transverse perforated plate 3.

[0035] It should be noted that transverse reinforcement enhances the vertical shear force transfer capacity between the concrete and the inner and outer steel shells, and resists transverse tensile stress caused by axial forces or localized stress concentrations in the tower. Vertical reinforcement enhances the transverse shear force transfer capacity between the concrete and the inner and outer steel shells, and resists vertical tensile stress caused by transverse forces or localized bending in the tower. This effectively improves the transverse shear strength and crack resistance of the concrete, ensuring the coordinated work of the steel shell and concrete in the transverse direction.

[0036] like Figure 1 , Figure 5 , Figure 6 , Figure 7As shown, along the vertical direction of the composite cable tower, between the transverse perforated plates 3 on the inner steel shell 1 and the outer steel shell 2, a layer of angle steel connectors 6 is installed at intervals of a set number of layers; the ends of the angle steel connectors 6 are connected to the connecting plates of the transverse perforated plates 3 on the inner steel shell 1 or the outer steel shell 2, and multiple connecting plates are evenly fixed on the circumference of the transverse perforated plates 3.

[0037] It should be noted that an angle steel connector 6 is installed at every set interval of a predetermined number of layers. The predetermined number of layers can be precisely calculated and determined based on the height of the tower, its stress characteristics, and design specifications, in order to achieve optimal material utilization while ensuring structural safety. In this embodiment, the predetermined number of layers is two, which balances the continuity of the connection and construction costs, ensures sufficient connection strength in critical stress areas, and avoids unnecessary material waste.

[0038] Understandably, the connecting plate provides a reliable connection interface, evenly transferring the force borne by the angle steel connector to the transverse perforated plates on the inner and outer steel shells. The angle steel connector 6 has an L-shaped cross-section, possessing excellent bending and shear resistance, effectively transmitting tensile, compressive, and shear forces. This structural configuration allows the inner and outer steel shells to form a more tightly integrated whole, effectively and collaboratively resisting vertical loads, thus avoiding localized stress concentration and differential deformation that might occur due to insufficient connection between the steel shells.

[0039] Because the cross-section of the composite cable tower is irregular, the arrangement of the angle steel connectors 6 between the inner steel shell 1 and the outer steel shell 2 also differs. For example... Figure 1 , Figure 7 As shown, the outer steel shell 2 has the same shape as the inner steel shell 1. The size of the outer steel shell 2 is a predetermined multiple of the size of the inner steel shell 1, and this multiple is greater than 1. First angle steel connectors are connected to the corresponding sides of the outer steel shell 2 and the inner steel shell 1, and the first angle steel connectors are perpendicular to the inner steel shell 1 and the outer steel shell 2. Figure 7 As shown, at the right angle point between the outer steel shell 2 and the inner steel shell 1, a first angle steel connector is also connected, and a second angle steel connector is fixedly connected to the first angle steel connector at the right angle point. The second angle steel connector is fixedly connected to the transverse perforated plate 3 of the outer steel shell 2, which can enhance the torsional and shear resistance of the right angle area of ​​the composite cable tower, disperse the stress in the right angle area of ​​the composite cable tower, and prevent local buckling or cracking.

[0040] like Figure 7As shown, on the side of the combined cable tower with multiple first angle steel connectors, third angle steel connectors are also connected to provide additional support. One end of the third angle steel connector is connected to the middle connecting plate of the inner steel shell on the current side, and the other end is connected to the connecting plates on both sides of the middle connecting plate of the outer steel shell on the current side. This asymmetrical or staggered connection method can distribute the connection stress more evenly, avoid stress concentration, and further improve the overall stiffness and stability of the long side area, promoting the coordinated stress distribution between the inner and outer steel shells and the concrete.

[0041] like Figure 8 As shown, along the vertical direction of the composite cable tower, adjacent layers of angle steel connectors are connected by diagonal braces 17, with the upper and lower diagonal braces 17 intersecting each other. The main function of the diagonal braces is to resist shear forces and improve the out-of-plane stability of the structure. The intersecting arrangement of the diagonal braces effectively forms a truss unit, significantly enhancing the shear stiffness and torsional resistance of the composite cable tower. Through this intersecting bracing, the structure can more effectively resist shear forces from different directions and prevent local instability, thereby improving the overall stability and load-bearing capacity of the entire composite cable tower.

[0042] It is important to note that, such as Figure 7 , Figure 9 As shown, the two ends of the diagonal brace 17 are connected to the vertical perforated plates corresponding to the intermediate connecting plate. However, diagonal braces are not connected to the vertical perforated plates at other locations.

[0043] like Figure 1 As shown, several studs 5 are fixedly connected at equal intervals on the inner wall between the inner steel shell 1 and the outer steel shell 2, and the length of the studs 5 is greater than the width of the vertical perforated plate and less than the width of the horizontal perforated plate.

[0044] Understandably, the studs are used to effectively transfer the shear force borne by the inner steel shell 1 or outer steel shell 2 to the concrete, while limiting the relative displacement between the inner steel shell 1 or outer steel shell 2 and the concrete. This ensures that the two can work together as a whole to reduce the risk of interface debonding and localized failure between the steel and concrete. The studs are arranged at equal intervals, which helps to achieve a balanced distribution of shear force on the steel-concrete interface, avoid localized stress concentration, and thus improve the overall shear resistance of the interface. In addition, the length of the studs 5 is designed to be greater than the width of the vertical perforated plate and less than the width of the horizontal perforated plate. This means that the studs can penetrate deeply into the concrete area formed by the vertical perforated plate, ensuring that the studs have sufficient anchorage depth and an effective shear force transfer path in the concrete.

[0045] Example 2 This embodiment discloses a construction method for the anchorage structure of a cable-stayed bridge steel-concrete composite pylon, applying the anchorage structure for a cable-stayed bridge steel-concrete composite pylon disclosed in Embodiment 1. Specific steps include: Step 1: Prefabricate the inner steel shell 1, outer steel shell 2, horizontal perforated plate 3, vertical perforated plate 4, studs 5, angle steel connectors 6, and diagonal braces of the composite cable tower in the prefabrication plant, and assemble them into a composite cable tower after transporting them to the site; pass the steel anchor pipe 7 through the reserved channels in the inner steel shell 1 and outer steel shell 2, and weld the steel anchor pipe 7 to the inner steel shell 1 and outer steel shell 2 for fixation; Step 2: Based on the anchoring angle between the steel anchor pipe 7 and the combined cable tower, calculate the side length and angle of each left side plate, right side plate and triangular stiffening plate, and fabricate the left side plate, right side plate and triangular stiffening plate together with the horizontal stiffening plate, vertical stiffening plate, outer horizontal stiffening plate, bottom plate and internal stiffening plate. Step 3: Weld the anchor plate onto the steel anchor pipe 7, then weld the horizontal stiffening plate, triangular stiffening plate, and vertical stiffening plate onto the steel anchor pipe 7, and then weld the outer horizontal stiffening plate, bottom plate, and inner stiffening plate in sequence. Finally, weld the left side plate and right side plate. Step 4: Pour concrete to complete the construction of the anchorage structure of the steel-concrete composite cable tower.

[0046] In this embodiment, the calculation of the side lengths and angles of the left side plate, right side plate, and triangular stiffening plate in step 2 is as follows: like Figure 10 As shown, the internal spacing of the combined cable tower is reserved. L 1. For subsequent maintenance and inspection, the net distance of the anchor pipe main structure within the combined cable tower. L 3. Design according to requirements, for example L 1 to L 3. The ratio k is satisfied (the value of k depends on the design, for example, k=2). Therefore, the value of k is known, so we can deduce... .

[0047] The anchor angle θ is determined based on the actual bridge construction and is a known value. It can be determined using geometric relationships. Therefore, obtain L b Specific numerical values. Utilizing geometric relationships. Therefore, it is possible to obtain L c .

[0048] By measuring the anchor angle θ at different height positions of the stay cable, L b and L c The geometric dimensions of the right side plate 11 can be obtained from the value.

[0049] In this embodiment, the stay cables are installed after step 4 is completed.

[0050] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An anchoring structure for a steel-concrete composite pylon of a cable-stayed bridge, comprising the composite pylon and symmetrically arranged anchor pipe main structures, wherein the composite pylon comprises an inner steel shell and an outer steel shell; characterized in that, The main structure of the anchor pipe includes a steel anchor pipe that penetrates the inner steel shell and the outer steel shell. An anchor plate is welded to the top of the steel anchor pipe. A triangular stiffening plate, a vertical stiffening plate and a horizontal stiffening plate are fixed around the steel anchor pipe. The long side of the triangular stiffening plate is fixedly connected to the inner steel shell. The vertical stiffening plate and the triangular stiffening plate are in the same plane. The horizontal stiffening plate is perpendicular to the triangular stiffening plate. A triangular side plate is vertically fixed to the end of the transverse stiffening plate away from the steel anchor pipe. The long side of the side plate is fixedly connected to the inner steel shell, and the side plate is also fixedly connected to the anchor plate. A bottom plate is welded to the side of the vertical stiffening plate away from the steel anchor pipe. The bottom plate is fixedly connected to the side plate. On the side of the steel anchor pipe facing the inner steel shell, outer transverse stiffening plates are fixed on both sides of the triangular stiffening plate. The outer transverse stiffening plates are fixed to the side plates. An internal stiffening plate is fixed between the transverse stiffening plate, the vertical stiffening plate or the triangular stiffening plate, the bottom plate or the outer transverse stiffening plate and the side plate.

2. The anchoring structure of a steel-concrete composite cable-stayed bridge tower as described in claim 1, characterized in that, Inside the combined cable tower, multiple horizontal perforated plates are fixed vertically on the inner and outer steel shells, and multiple vertical perforated plates perpendicular to the horizontal perforated plates are fixed circumferentially on the inner and outer steel shells, with the width of the vertical perforated plates being smaller than the width of the horizontal perforated plates.

3. The anchoring structure of a steel-concrete composite cable-stayed bridge tower as described in claim 2, characterized in that, The vertical perforated plate has horizontal reinforcing bars arranged inside the holes, and the horizontal perforated plate has vertical reinforcing bars arranged inside the holes.

4. The anchoring structure of a steel-concrete composite cable-stayed bridge tower as described in claim 2, characterized in that, Between the transverse perforated plates on the inner and outer steel shells, an angle steel connector is provided at intervals of a set number of layers; the end of the angle steel connector is connected to the connecting plate of the transverse perforated plate of the inner or outer steel shell, and multiple connecting plates are evenly fixed in the circumferential direction of the transverse perforated plate.

5. The anchoring structure of a steel-concrete composite cable-stayed bridge tower as described in claim 4, characterized in that, The outer steel shell and the inner steel shell are each connected to a first angle steel connector on their corresponding sides, and the first angle steel connector is perpendicular to the inner steel shell and the outer steel shell.

6. The anchoring structure of a steel-concrete composite cable-stayed bridge tower as described in claim 4, characterized in that, At the right angle point between the outer steel shell and the inner steel shell, a first angle steel connector is also connected, and a second angle steel connector is fixedly connected to the first angle steel connector at the right angle point. The second angle steel connector is fixedly connected to the transverse perforated plate of the outer steel shell.

7. The anchoring structure of a steel-concrete composite cable-stayed bridge tower as described in claim 5, characterized in that, On the side of the combined cable tower with multiple first angle steel connectors, a third angle steel connector is also connected. One end of the third angle steel connector is connected to the middle connecting plate of the inner steel shell on the current side, and the other end is connected to the connecting plates on both sides of the middle connecting plate of the outer steel shell on the current side.

8. The anchoring structure of a steel-concrete composite cable-stayed bridge tower as described in claim 4, characterized in that, The angle steel connectors of the upper and lower adjacent layers are connected by diagonal braces, and the upper diagonal brace and the lower diagonal brace are in a cross state. The two ends of the diagonal brace are connected to the vertical opening plate corresponding to the middle connecting plate.

9. The anchoring structure of a steel-concrete composite cable-stayed bridge tower as described in claim 1, characterized in that, Inside the combined cable tower, the inner and outer steel shells are fixed with a number of studs at equal intervals, and the length of the studs is greater than the width of the vertical perforated plate but less than the width of the horizontal perforated plate.

10. A construction method for the anchorage structure of a steel-concrete composite cable-stayed bridge tower as described in any one of claims 1-9, characterized in that, The specific steps include: Prefabricate the components of the composite cable tower and assemble them on site; pass steel anchor pipes through the inner and outer steel shells and fix the steel anchor pipes to the inner and outer steel shells; Then, based on the anchoring angle between the steel anchor pipe and the composite cable tower, the side length and angle of the side plate and the triangular stiffening plate are calculated, and the side plate and the triangular stiffening plate are fabricated together with the horizontal stiffening plate, the vertical stiffening plate, the outer horizontal stiffening plate, the bottom plate, and the internal stiffening plate. Anchor plates are welded and fixed onto the steel anchor pipe. Then, horizontal stiffening plates, triangular stiffening plates, and vertical stiffening plates are welded onto the steel anchor pipe. Next, the outer horizontal stiffening plate, bottom plate, and inner stiffening plate are welded in sequence, and finally, the side plates are welded.

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