Cable-stayed bridge combined pylon

Abstract

The present application relates to the field of bridge structure engineering, and particularly relates to a cable-stayed bridge combined pylon, which comprises at least one anchoring segment, the anchoring segment comprises: a pressure shell, which is internally provided with core concrete, the pressure shell and the core concrete are provided with first cable-stayed cable holes; outer combined box bodies, which are respectively arranged on opposite sides of the pressure shell, the outer combined box body comprises an outer wall plate, an inner wall plate and a concrete core layer, a closed cavity is formed between the outer wall plate and the inner wall plate, the concrete core layer is filled in the closed cavity, and the outer combined box body structure is provided with second cable-stayed cable holes corresponding to the positions of the first cable-stayed cable holes on the corresponding side. The present application has high overall rigidity, simplifies the internal structure, is beneficial to reducing the amount of steel, facilitates inspection and maintenance, greatly reduces the amount of concrete compared with a concrete bridge tower, is beneficial to realizing carbon emission reduction, has good stress effect and economic benefits, and is suitable for scenes with higher rigidity requirements.

Description

Technical Field

[0001] This invention relates to the field of bridge structural engineering, and in particular to a composite pylon for a cable-stayed bridge. Background Technology

[0002] Cable-stayed bridges, as an important type of long-span bridge structure, consist of load-bearing main towers, tension-bearing stay cables, and bending-resistant main girders. With the rapid development of transportation infrastructure construction, the spans of cable-stayed bridges are constantly increasing, and the height of the bridge towers is also getting taller. As the core load-bearing component of a cable-stayed bridge, the rational design of its structural form has a decisive impact on the safety, economy, and durability of the bridge.

[0003] Currently, cable-stayed bridge towers mainly employ either concrete or steel structures, but both have inherent drawbacks. Concrete towers offer advantages such as relatively low cost, high rigidity, and good compressive strength, but their heavy weight, large cross-sectional dimensions, and relatively low tensile strength make them prone to tensile cracking under the immense horizontal force of the stay cables. Furthermore, the shrinkage and creep of concrete, as well as effects from solar radiation and hydration heat, all contribute to tensile stress in the tower walls, leading to surface cracking. Several completed long-span cable-stayed bridges have already been found to have cracks of varying degrees in their concrete towers, which not only affect the structural aesthetics but also accelerate the corrosion of internal steel reinforcement, reducing the structure's overall lifespan durability. While steel bridge towers offer advantages such as light weight, good seismic performance, and fast construction speed, their unit price is much higher than that of concrete. Furthermore, large-span cable-stayed bridge towers are tall and require a huge amount of steel. Moreover, the steel structure towers have thinner walls, making them prone to local buckling and overall instability under immense pressure. To prevent buckling, numerous stiffening ribs and diaphragms are required, resulting in a complex structure and a large amount of welding work. The numerous welds generate significant residual welding stress, which can easily lead to fatigue cracks at the weld joints under alternating loads such as vehicle live loads and wind loads, affecting structural safety.

[0004] To combine the advantages of concrete bridge towers and steel bridge towers, existing technologies have proposed composite concrete-steel bridge tower solutions. For example, Chinese invention patent CN110184916A discloses a cable-stayed bridge main tower, such as... Figure 1 , Figure 2As shown, the structure employs a pressure-bearing shell enclosing a core concrete 101, with intersecting stay cables 100. The core concrete 101 bears the compressive force, while the outer pure steel box 102 bears the tensile force. Horizontal diaphragms 103 and vertical stiffening ribs 104 are installed inside the steel box to prevent instability of the steel plate surface. This design leverages the compressive strength of concrete and the tensile strength of steel to a certain extent. To reduce the risk of out-of-plane deflection of the steel wall panels (i.e., the steel sidewalls of the steel box) under pressure, the constraint of the steel box wall panels mainly relies on their own stiffness and the support of the diaphragms and stiffening ribs. To improve the buckling resistance of the wall panels, it is often necessary to increase the wall panel thickness or increase the density of stiffening ribs, leading to increased steel consumption and weakening the economic advantages of the composite structure. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of existing concrete-steel composite bridge towers, which use a "core concrete + outer pure steel box" structure and have steel wall panels that are prone to out-of-plane deflection, and to provide a composite cable-stayed bridge tower.

[0006] This invention provides a composite pylon for a cable-stayed bridge, comprising at least one anchoring segment, the anchoring segment comprising:

[0007] A pressure-bearing shell with a core concrete core, wherein the pressure-bearing shell and the core concrete core are connected by a first inclined cable hole; The outer combined box is respectively located on opposite sides of the pressure-bearing shell. The outer combined box includes an outer wall panel, an inner wall panel, and a concrete core layer. The outer wall panel and the inner wall panel are both semi-enclosed. Both ends of the outer wall panel and the inner wall panel are connected to the pressure-bearing shell. A closed cavity is formed between the outer wall panel and the inner wall panel. The concrete core layer fills the closed cavity. Each side of the outer combined box is provided with a second inclined cable hole corresponding to the position of the first inclined cable hole on the corresponding side.

[0008] In the above solution, the pressure-bearing shell is arranged to enclose the core concrete and is disposed in the middle of the outer combined boxes on both sides, and the overall structure is in a "Japanese character" shaped plane layout. The pressure-bearing shell in the middle and the core concrete can be used for cross-anchoring of stay cables, so that the core concrete is in a compression state, which fully utilizes the advantage of high compressive strength of concrete. Meanwhile, in order to resist buckling instability of the tower column wall plates, the outer combined box adopts a sandwich structure, the concrete core layer restrains the buckling of the outer wall plate and the inner wall plate, and the ends of the outer combined box are integrally connected to both sides of the pressure-bearing shell, which improves the overall stiffness of the structure. The concrete core layer in the present solution also participates in bearing pressure, which can appropriately reduce the size of the core concrete (i.e., the core concrete inside the pressure-bearing shell). Compared with the prior art in which a pure steel structure is adopted at the peripheral steel box, and a large number of transverse partitions and stiffeners are arranged inside the steel box to reduce buckling deformation, the present solution simplifies the internal structure, which is beneficial to reducing steel consumption, facilitates inspection and maintenance, greatly reduces concrete consumption compared with concrete bridge towers, is conducive to achieving carbon emission reduction, has good stress effect and economic benefit, and is suitable for scenes with higher requirements on stiffness.

[0009] Preferably, a plurality of connecting pieces are arranged in the closed cavity and / or the pressure-bearing shell. The arrangement of the connecting pieces can resist the flow pressure of concrete during the concrete pouring stage, and can provide a constraining effect on the internal concrete during the service stage, forming a hoop effect, thereby effectively overcoming the brittleness of high-strength concrete and improving the overall bearing capacity of the component.

[0010] Preferably, the connecting piece is at least one of vertical stiffeners, horizontal stiffeners, horizontal angle steels, vertical angle steels, shear studs and counter-pulled steel bars. Further preferably, the vertical stiffener / the horizontal stiffener may be provided with openings, which is beneficial to improving the fluidity of concrete.

[0011] Preferably, a plurality of prestressed cables are arranged in the inner cavity of the pressure-bearing shell, and all the prestressed cables are arranged along the transverse direction of the cable tower, which can be well applied to the situation where the stay cables are in a spatial cable plane but the transverse inclination angle of the stay cables is large, and the stay cables will generate a large outward transverse component force on the middle wall plate to cause the concrete to be tensioned. By arranging the prestressed cables in the transverse direction of the cable tower, that is, in the direction substantially perpendicular to the plane of the stay cables, transverse horizontal prestress can be formed on the middle wall plate formed by the pressure-bearing shell and the core concrete, so that the middle wall plate is still in a three-dimensional compression state (transverse + longitudinal + vertical), adapts to large horizontal component force, and improves the crack resistance of the cable tower.

[0012] Preferably, at least one vibration damping device is arranged in at least one of the first stay cable hole and the second stay cable hole, and the vibration damping device is used for clamping the stay cable and reducing the vibration of the stay cable. Arranging the vibration damping device in the stay cable hole can form an elastic constraint on the stay cable and reduce the free length of the stay cable. Compared with the conventional method of simply arranging a damper at the beam end, the invention effectively improves the fatigue problem of the cable end stay cable anchor and improves the fatigue life of the stay cable.

[0013] In existing technologies, the cables of long-span cable-stayed bridges often experience vortex-induced vibration, buffeting, and wind-induced vibration under vehicle dynamic loads and wind loads, which reduces the fatigue life of the cables. The commonly used method is to install beam-end dampers on the bridge deck to reduce cable vibration. However, the bridge tower location does not meet the conditions for installing dampers. Therefore, although it can improve the fatigue problem of the cable beam-end anchorages, it has a smaller effect on improving the fatigue of the tower-end anchorages.

[0014] Preferably, the thickness of the outer wall panel is greater than or equal to 14 mm.

[0015] Preferably, the thickness of the inner wall panel is 6-10 mm.

[0016] Preferably, the total thickness of the outer combined box is 80cm-100cm, which provides constraint without significantly increasing its weight.

[0017] Preferably, the total thickness of the pressure-bearing shell and the core concrete is 200-300cm.

[0018] Preferably, two adjacent first cable holes are arranged in a figure-eight shape.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a composite cable-stayed bridge tower, which uses a core concrete core encased in a pressure-bearing shell for cross-anchoring and pressure bearing of the cable stays, and sets outer composite box bodies on opposite sides of the pressure-bearing shell to prevent buckling instability of the tower column sidewalls. It makes full use of the steel box concrete conduit effect, resulting in high overall tower stiffness, good stress-bearing effect and economic benefits, and is suitable for scenarios with high stiffness requirements. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cross-sectional structure of a steel-concrete composite cable tower in the prior art; Figure 2 This is a sectional elevation model of a steel-concrete composite cable tower in the existing technology; Figure 3 This is a schematic diagram of the cross-sectional structure of a composite pylon for a cable-stayed bridge in one of the embodiments. Figure 1 ; Figure 4 for Figure 3 Elevation structural diagram; Figure 5 This is a schematic diagram of the cross-sectional structure of a composite pylon for a cable-stayed bridge in one of the embodiments. Figure 2 .

[0021] In the diagram, the markings are: 100 - cable stay; 101 - core concrete; 102 - steel box girder; 103 - diaphragm; 104 - stiffening rib. 1-Pressure shell; 11-Core concrete; 12-First cable hole; 13-Prestressed cable; 2-Outer composite box; 21-Outer wall panel; 22-Inner wall panel; 23-Concrete core layer; 24-Second stay cable hole; 3-Vibration damping device. Detailed Implementation

[0022] 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.

[0023] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," and "outer," etc., used in the description of specific embodiments of the present invention to indicate orientation or positional relationships, are 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 usually 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, and for 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.

[0024] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are arranged as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in "horizontal," "vertical," "suspended," "parallel," or "coaxial" directions, 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%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0025] 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.

[0026] 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 two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0027] 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 connection methods commonly used 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.

[0028] Example This embodiment provides a combined cable-stayed bridge tower, comprising at least one anchored section and at least one non-anchored section, connected together. The anchored section is used to anchor the stay cables and includes multiple sequentially connected anchored segments; the non-anchored section includes multiple sequentially connected non-anchored segments and does not have stay cables. The overall shape and structure of the tower are similar to those of a conventional concrete bridge tower, except that the upper tower column cable anchoring section adopts a single-box double-cell single-limb tower column structure.

[0029] Specifically, in this embodiment, the upper tower column of the cable-stayed area is a hollow thin-walled structure formed by seven thin-walled steel shells installed in segments, such as... Figure 3 , Figure 4 As shown, each anchoring segment includes a pressure-bearing shell 1 and an outer combined box 2 located on opposite sides of the pressure-bearing shell 1. The cross-section of the pressure-bearing shell 1 is a closed structure, forming a cavity. In this embodiment, a rectangular structure is preferably adopted. Several sets of first inclined cable holes 12 are provided through the opposite side walls of the pressure-bearing shell 1. The outer combined box 2 includes an outer wall panel 21 and an inner wall panel 22. The outer wall panel 21 and the inner wall panel 22 are semi-enclosed on both sides of the pressure-bearing shell 1. Both ends of the outer wall panel 21 and the inner wall panel 22 are integrally connected to the pressure-bearing shell 1. A closed cavity is also formed between the outer wall panel 21 and the inner wall panel 22. The concrete core layer 23 is filled in the closed cavity. Several second inclined cable holes 24 are provided on the outer wall panel 21, the inner wall panel 22 and the concrete core layer 23 on the same side. The second inclined cable holes 24 correspond to the positions of the first inclined cable holes 12 on the corresponding side, allowing the inclined cables to pass through in sequence.

[0030] Further, in this embodiment, a plurality of connecting members are provided in the outer combined box body 2, such as vertical stiffeners, horizontal stiffeners, horizontal angle steels, vertical angle steels, welding studs, opposite-pulled steel bars, etc. The connecting members are arranged on the inner side walls of the outer wall plate 21 and the inner wall plate 22, and transverse supports or inclined supports are also used to transversely connect the outer wall plate 21 and the inner wall plate 22, so that a steel framework is formed in the closed cavity and embedded in the concrete core layer 23. It can resist the flowing pressure of concrete during the concrete pouring stage, and provide a restraining effect on the internal concrete during the service stage to form a hoop effect, thereby effectively overcoming the brittleness of high-strength concrete and improving the overall bearing capacity of the component.

[0031] The pressure-bearing shell 1, the outer wall plate 21, the inner wall plate 22, the connecting members and other components are preferably made of steel structure. The standard thickness of the outer steel wall plate is preferably not less than 14 mm, the standard thickness of the inner steel wall plate is preferably 6 mm to 10 mm, and the total thickness of the outer combined box body 2 is set to 80 cm to 100 cm, which provides restraint without significantly increasing the self-weight; circular holes are provided on both the vertical stiffeners and horizontal stiffeners in the steel box for vertical steel bars and horizontal steel bars to pass through in sequence, so as to form reinforced concrete tenons (PBL shear connectors), which are supplemented with welding stud structures, thereby realizing the cooperative work of steel structure and concrete; the stiffeners can be locally widened to adapt to angle steel connection, the vertical angle steels and horizontal angle steels connect the thin-walled structures inside and outside the steel box into a whole and control the structural deformation during concrete pouring. Similarly, a plurality of connecting members are also provided inside the pressure-bearing shell 1.

[0032] During construction, after the current anchoring segment is hoisted and installed in place, steel conduits are respectively installed in the pressure-bearing shell 1 and the outer combined box body 2, and then high-performance self-compacting micro-expansion concrete is poured into the steel shell to form a steel-concrete composite structure section of single box with double chambers. At this time, the core concrete 11 in the pressure-bearing shell 1 and the concrete core layer 23 in the closed cavity of the outer combined box body 2 respectively form the first stay cable hole 12 and the second stay cable hole 24, and the cross-section of the cable tower presents a "日"-shaped cross-section. The pressure-bearing shell 1 and its core concrete 11 integrally form a middle wall structure of a one-way double-chamber structure, and serve as the inner core cross cable anchoring structure of the upper tower column. According to the stress requirements of stay cables with different spans and different specifications, the thickness of the middle wall can be about 2m to 3m, and the thickness of other wall plates can be 0.8m to 1m by taking into account the overall stress requirements of the structural section and the construction operation space.

[0033] In operation, the stay cables on both sides of the tower are symmetrically and crosswise anchored to the central wall panel. This ensures that the core concrete 11 of the central wall panel is always under compression in the longitudinal direction of the bridge, transforming the traditional single-box, single-cell concrete tower wall panel from being under tension to being under compression, fully utilizing the high compressive strength of concrete. Simultaneously, the central wall panel obviously bears its own weight and the vertical component of the cable forces in the vertical direction. Furthermore, due to the constraint of the steel shell structure in the horizontal direction, the concrete inside the tower is under triaxial compression, similar to that of steel-tube concrete. Thus, the tower concrete benefits from the constraint of the steel shell structure, which improves its plasticity and toughness, while the thin-walled steel shell benefits from the constraint of the concrete, which improves its local buckling stability. The two complement each other, resulting in a significant improvement in the overall structural load-bearing capacity and ductility of the tower.

[0034] Furthermore, considering that in the existing technology, the cables of long-span cable-stayed bridges often experience vortex-induced vibration, buffeting, and wind-induced vibration under vehicle dynamic loads and wind loads, which reduces the fatigue life of the cables, the commonly used method is to install beam-end dampers on the bridge deck to reduce cable vibration. However, the bridge tower location does not meet the conditions for installing dampers. Therefore, although beam-end dampers can improve the fatigue problem of cable-stayed beam-end anchorages, they have a smaller effect on improving the fatigue of tower-end anchorages. Therefore, in this embodiment, it is preferable to further install at least one vibration damping device 3 at at least one location in the first and second cable-stayed cable holes. The vibration damping device 3 is used to clamp the cable, fill the gap of the cable in the cable hole, and reduce cable vibration. For example, vibration damping devices 3 can be installed at both ends of each second cable-stayed cable hole and at the end of each first cable-stayed cable hole away from the cable anchor head, forming multi-point elastic constraints and reducing the free length of the cable. Compared to the conventional method of simply installing dampers at the beam ends, installing vibration reduction devices 3 inside the stay cable holes effectively improves the fatigue problem of the tower end stay cable anchors and helps to improve the fatigue life of stay cables.

[0035] like Figure 3 , Figure 4 This applies to situations where the stay cables are parallel cable surfaces, or when a spatial cable surface is used but the lateral inclination angle of the cable is small (the angle between the cable and the longitudinal axis). When the stay cables are parallel cable surfaces, or spatial cable surfaces with a small lateral inclination angle are used, the first stay cable holes 12 on the middle wall plate are parallel or nearly parallel to each other, and the second stay cable holes 24 on both sides of the middle wall plate are also parallel or nearly parallel to each other.

[0036] If the stay cable is a spatial cable surface but the lateral inclination angle of the cable is large (the angle between the cable and the longitudinal axis), such as Figure 5As shown, the two adjacent first cable holes 12 are arranged in a figure-eight shape, and the second cable holes 24 on the outer combined box 2 are also arranged in a figure-eight shape accordingly. At this time, the cable will generate a large outward lateral component force on the middle wall plate in the lateral direction, causing the concrete to be under tension. At this time, by applying the lateral prestressed cable 13 to the middle wall plate, a horizontal prestress is formed, which can keep it in a triaxial compression state.

[0037] Furthermore, in this embodiment, the non-anchored section below the cable anchorage zone can gradually transition into a two-limb tower or a four-limb tower, and the tower shape can be an inverted Y-shape, a diamond shape, or a spatial diamond shape with four limbs.

[0038] Because the bending moment distribution of cable-stayed bridge towers follows a triangular pattern that gradually increases from the top to the bottom, the bending moment on the upper tower columns in the cable-stayed zone is relatively small, and the main stress is compression. This embodiment fully utilizes this stress characteristic by setting a middle wall plate near the neutral axis of the cross-section as an anchoring member for the cable stays. Below the cable anchoring zone, the tower column cross-section becomes the conventional form. The middle wall plate mainly bears the huge concentrated force and axial force of the complex cable anchoring zone, while the tower bending moment is mainly borne by the outer wall plate. The division of labor between the two is clear, avoiding the complex stress state of traditional tower wall plates simultaneously bearing the concentrated force of cable anchoring, as well as the axial force, bending moment, and shear force of the tower.

[0039] Taking into account the characteristics of steel-concrete composite structures, the bridge towers are manufactured in the factory in segments or units, and then assembled on-site as whole segments (when transported as units). The construction process involves hoisting and pouring concrete. The specific construction flow is as follows: ① Steel shell manufacturing and pre-assembly in the factory; ② Steel shell transportation, either segmental or unit-based, depending on actual transportation conditions; ③ On-site assembly at the bridge site (when transported as unit-based) as whole segments for hoisting; ④ Matching and positioning of steel shell segments; ⑤ Connection of reinforcing bars inside the steel shell and welding between segments; ⑥ Pouring and vibration of concrete inside the steel shell; ⑦ Concrete curing; ⑧ Roughening and cleaning of the concrete inside the steel shell; ⑨ Hoisting of the next standard segment.

[0040] The beneficial effects of this plan are: (1) From a stress perspective, the steel-concrete-core-confined concrete box-type composite cable tower proposed in this scheme fully utilizes the advantages of high strength, good plasticity and toughness of steel and high compressive strength of concrete. The steel shell and concrete provide strong mutual constraints—the concrete can provide constraints on the thin-walled steel shell to prevent buckling instability; while the steel shell is designed with a large number of longitudinal and transverse stiffening ribs, which are connected to each other by steel sections. During the concrete pouring stage, they can resist the flow pressure of concrete, and during the service stage, they can provide constraints on the internal concrete, forming a hoop effect, thereby effectively overcoming the brittleness of high-strength concrete and improving the overall load-bearing capacity of the component.

[0041] (2) Concrete bridge towers used in high-intensity earthquake zones have the disadvantages of large cross-sectional dimensions, poor structural ductility, and easy occurrence of brittle shear failure and joint plastic failure. In contrast, the composite structure cable tower has the advantages of high bearing capacity, good plasticity and toughness, thus having better ductility and toughness in earthquake resistance, stronger ability to absorb earthquake energy, and stronger earthquake resistance toughness.

[0042] (3) The cross-cable anchoring structure transforms the traditional concrete tower wall panels from being under tension to being under compression. The core concrete 11 of the middle wall panel is under triaxial compression under the constraint of the horizontal and vertical components of the cables and the pressure shell, resulting in a very reasonable stress distribution. When the stay cables are spatial cable surfaces, transverse prestress can be applied, resulting in even better triaxial compression performance and greatly improving the tower's crack resistance. This effectively avoids the construction drawbacks and stress defects of circumferential prestressing, as well as the disadvantages of difficult construction, poor economy, and inconvenient maintenance of steel anchor beams and steel anchor boxes.

[0043] (4) Compared with the steel box-core concrete composite cable tower disclosed in the patent document with publication number CN 110184916 A, the cable tower structure proposed in this scheme has a higher cost performance. Under the same cost, the composite cable tower of this scheme has a compressive stiffness that is about 1.8 times higher and a bending stiffness that is about 3 times higher than the existing steel box-core concrete composite cable tower, which greatly improves the overall stiffness of the cable-stayed bridge.

[0044] (5) Since the cable tower section in this scheme adopts a single-box double-cell section, up to three vibration damping devices can be installed between the stay cables and the tower wall panels (e.g., Figure 3 or Figure 5 This provides multi-point elastic constraint to the cables, reducing their free length. Compared to simply installing dampers at the beam ends, this effectively improves the fatigue problem of the tower-end cable anchors and significantly increases the fatigue life of the stay cables by more than 50%.

[0045] (6) Steel-concrete composite-core-confined concrete box-type composite cable tower is a green and environmentally friendly type of bridge tower—transforming a large amount of high-energy-consuming on-site work into low-carbon factory production, effectively reducing the intensity and difficulty of on-site work, realizing the industrialization and assembly manufacturing of cable tower construction, and making on-site construction faster and more convenient; the steel shell can serve as a formwork for concrete construction, eliminating the need for additional formwork; it has a good appearance quality, isolates the concrete structure from the outside world, and has better durability; compared with concrete bridge towers, it greatly reduces the amount of concrete used, effectively achieving carbon emission reduction.

[0046] (7) The proposed pylon structure can be applied to single-tower or double-tower cable-stayed bridges without auxiliary piers with weak stiffness, as well as multi-tower cable-stayed bridges. Changing the transverse double-limb tower column to the longitudinal double-limb tower column can effectively improve the overall stiffness of the bridge and reduce the internal force and deflection of the main beam.

[0047] (8) The high-strength, high-toughness, and high-crack-resistant composite structure cable tower and cable anchoring method in this scheme have the advantages of low carbon and environmental protection, excellent stress, simplified design, convenient construction and operation and maintenance. Compared with traditional bridge towers, it can reduce the cost by more than 20%, achieving the dual goals of cost reduction and performance upgrade, and has significant technical and economic benefits.

[0048] 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 composite pylon for a cable-stayed bridge, comprising at least one anchoring segment, characterized in that, The anchoring segment includes: The pressure-bearing shell (1) is provided with a core concrete (11), and the pressure-bearing shell (1) and the core concrete (11) are provided with a first cable hole (12). The outer combined box (2) is respectively located on opposite sides of the pressure-bearing shell (1); the outer combined box (2) includes an outer wall panel (21), an inner wall panel (22) and a concrete core layer (23). The outer wall panel (21) and the inner wall panel (22) are both semi-enclosed. Both ends of the outer wall panel (21) and the inner wall panel (22) are connected to the pressure-bearing shell (1). A closed cavity is formed between the outer wall panel (21) and the inner wall panel (22). The concrete core layer (23) is filled in the closed cavity. Each side of the outer combined box (2) is provided with a second inclined cable hole (24) corresponding to the position of the first inclined cable hole (12) on the corresponding side.

2. The composite pylon for a cable-stayed bridge according to claim 1, characterized in that, The enclosed cavity and / or the pressure-bearing shell (1) are provided with a number of connecting parts.

3. A composite pylon for a cable-stayed bridge according to claim 2, characterized in that, The connecting component is at least one of the following: vertical stiffening rib, horizontal stiffening rib, horizontal angle steel, vertical angle steel, weld stud, and tie bar.

4. A composite pylon for a cable-stayed bridge according to claim 1, characterized in that, The pressure-bearing shell (1) is provided with a number of prestressed cables (13) inside the cavity, and the prestressed cables (13) are all arranged along the transverse direction of the tower.

5. A composite pylon for a cable-stayed bridge according to claim 1, characterized in that, At least one of the first cable hole (12) and the second cable hole (24) is provided with at least one vibration damping device (3), which is used to clamp the cable.

6. A composite pylon for a cable-stayed bridge according to claim 1, characterized in that, The thickness of the outer wall panel (21) is greater than or equal to 14 mm.

7. A composite pylon for a cable-stayed bridge according to claim 1, characterized in that, The thickness of the inner wall panel (22) is 6-10 mm.

8. A composite pylon for a cable-stayed bridge according to claim 1, characterized in that, The total thickness of the outer combined box (2) is 80cm-100cm.

9. A composite pylon for a cable-stayed bridge according to any one of claims 1-8, characterized in that, The total thickness of the pressure-bearing shell (1) and the core concrete (11) is 200-300cm.

10. A composite pylon for a cable-stayed bridge according to any one of claims 1-8, characterized in that, The two adjacent first cable holes (12) are arranged in a figure-eight shape.

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