Main tower structure of multi-tower suspension bridge and construction method thereof

Abstract

The application provides a new type of structure of a main tower in a multi-tower suspension bridge and a construction method thereof, which comprises a main tower, a plurality of oblique suspension cables, a first stiffening beam and a plurality of main cable saddles; the plurality of main cable saddles are vertically fixed on the top of the main tower in parallel and at intervals along the transverse direction of the main tower; the plurality of oblique suspension cables are respectively arranged on the two sides of the main tower in an inclined manner, the upper end of each oblique suspension cable is anchored in the lower bearing plate of the top of the main tower, and the lower end is connected to the corresponding first stiffening beam; and the first stiffening beam is arranged on the two sides of the main tower. The structure and the method utilize the components of the structure to improve the longitudinal bending stiffness of the main tower, do not affect the overall appearance of the whole bridge, are convenient for construction and do not increase the process.

Description

Technical Field

[0001] This application relates to the field of bridge engineering, and in particular to a main tower structure and construction method for a multi-tower suspension bridge. Background Technology

[0002] Compared to traditional twin-tower suspension bridges, multi-tower suspension bridges can effectively reduce tower height and construction costs, but they require higher longitudinal stiffness from the central main tower. Under eccentric loading conditions, a significant difference in force on either side of the central main tower can lead to displacement of the tower and relative slippage with the main cable. Current technologies still have certain limitations in addressing this "central tower effect," necessitating new construction methods and superior structural designs to resolve it.

[0003] To overcome the "mid-tower effect," existing technologies mainly improve the longitudinal bending stiffness of the main tower by using structural reinforcement. This further increases the project cost and makes the structure more complex, increasing the difficulty of manufacturing and hoisting. Summary of the Invention

[0004] One of the purposes of this application is to provide a main tower structure and its construction method for a multi-tower suspension bridge, so as to solve the problem of the high difficulty in manufacturing the main tower in the prior art.

[0005] The technical solution of this application is: A main tower structure for a multi-tower suspension bridge includes a central main tower, multiple inclined suspension cables, a first stiffening girder, and multiple main cable saddles. The multiple main cable saddles are vertically fixed to the top of the central main tower in parallel and at intervals along its transverse direction. The multiple inclined suspension cables are respectively inclinedly arranged on both sides of the central main tower, with the upper end of each cable anchored to the lower support plate at the top of the central main tower and the lower end connected to the corresponding first stiffening girder. The first stiffening girder is respectively arranged on both sides of the central main tower.

[0006] As one technical solution of this application, the main tower is a steel-concrete composite portal frame structure, including two upper tower columns, two lower tower columns, an upper crossbeam, and a second stiffening beam; the upper tower columns and the upper crossbeam are both steel structures, and the lower tower columns and the second stiffening beam are both reinforced concrete structures. The two lower tower columns are arranged vertically in parallel intervals, and the two upper tower columns are arranged vertically in parallel intervals. The upper tower columns are coaxially arranged on the top of the corresponding lower tower columns, and the upper crossbeam is arranged between the tops of the two upper tower columns. The second stiffening beam is arranged between the center of the main tower at the top of the two lower tower columns and is cast integrally with the main tower. The first stiffening beam is combined with the second stiffening beam through a steel-concrete composite section to form an integral structure.

[0007] As one technical solution of this application, the lower support plate is located on the top of the main tower and is equipped with anchors, and the upper end of the inclined suspension cable is connected to the lower support plate through the corresponding anchors.

[0008] As one technical solution of this application, the inclined suspension cable includes eight cables arranged in a longitudinal direction at an angle on opposite sides of the central main tower, and the inclined suspension cable includes parallel wire bundles of inclined suspension cables made of galvanized aluminum alloy high-strength steel wire.

[0009] As one technical solution of this application, ear plates are provided on both sides of the first stiffening beam along the transverse direction, and the ear plates are installed on the first stiffening beam by a plurality of high-strength bolts; the lower end of the inclined suspension cable is connected to the ear plate by a pin.

[0010] As one technical solution of this application, the first stiffening beam is a steel-concrete composite beam, and is constructed by steel beams together with concrete bridge deck through shear studs.

[0011] As one technical solution of this application, the second stiffening beam is a concrete beam, and it is integrated with the central main tower as an integral structure by cast-in-place method.

[0012] A construction method for the main tower structure of a multi-tower suspension bridge includes the following steps: S1, Construction of the main tower: The main tower is a steel-concrete composite portal frame structure and includes a steel upper tower column, a reinforced concrete lower tower column, a steel upper crossbeam, and a reinforced concrete second stiffening beam. The lower tower column and the second stiffening beam are constructed using the climbing formwork method, and the upper tower column and the upper crossbeam are constructed using a combination of factory segmented manufacturing and on-site bolting and welding. S2, When construction reaches the top of the upper tower column, the lower support plate is hoisted to the designated position by a crane, and then steel bars are laid on the top of the middle main tower; S3. After the lower support plate is completed, the upper end of the inclined suspension cable is anchored in the anchor on the lower support plate, and then concrete is poured together with the steel bars on the top of the middle main tower. S4. After the concrete poured on the main tower reaches 100% strength, hoist the main cable saddle and push it into place. S5. After the construction of the main tower is completed and the main cable is erected, the first stiffening beams on both sides of the main tower are hoisted and the first stiffening beams on both sides of the main tower are combined with the concrete section of the second stiffening beam at the location of the main tower through the steel-concrete joint section to form an integral structure. S6, after the first stiffening beam is constructed, the lower end of the inclined suspension cable is connected to the ear plate on the first stiffening beam through a pin shaft, and the middle main tower is connected to the first stiffening beam to form an integral structure.

[0013] The beneficial effects of this application are: In this application, the main tower structure and construction method for a multi-tower suspension bridge utilizes the structure's own components to enhance the longitudinal bending stiffness of the main tower. This does not affect the overall appearance of the bridge, is convenient to construct, and does not add any steps. Specifically, the first stiffening girder is fixed to the main tower, and then the main tower and the first stiffening girder are diagonally connected to form a whole using inclined suspension cables. This enhances the longitudinal bending stiffness of the main tower, effectively alleviating the problem of significantly reduced stiffness in the main tower of a multi-tower suspension bridge, and improving the overall stability, safety, and driving comfort of the bridge. Furthermore, by setting the inclined suspension cables on both sides of the main tower at an angle, it does not affect the transmission of the load from the first stiffening girder and can also provide opposing horizontal forces to assist in balancing the main tower when unbalanced horizontal forces occur on both sides. Moreover, compared to other methods of enhancing the main tower stiffness, this application's reasonable utilization of the structure's own components to enhance the longitudinal bending stiffness of the main tower has minimal impact on the overall appearance of the bridge, is convenient to construct, does not add any steps, and reduces construction costs. At the same time, it anchors the inclined suspension cable to the lower bearing plate of the main cable saddle to form a whole, which solves the problem of inclined suspension cable anchorage and strengthens the lower bearing plate of the main cable saddle, which is beneficial to the connection between the main cable saddle and the middle main tower. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a side view of the main tower structure in a multi-tower suspension bridge provided in an embodiment of this application; Figure 2 This is a front view of the main tower structure in a multi-tower suspension bridge provided in an embodiment of this application; Figure 3 This is a schematic diagram of the inclined cable-stayed tower end provided in an embodiment of this application; Figure 4 This is a schematic diagram of the end of the inclined cable beam provided in an embodiment of this application.

[0016] Icons: 1-Middle main tower; 2-Inclined suspension cable; 3-Anchorage; 4-First stiffening beam; 5-Ear plate; 6-Pin shaft; 7-Main cable saddle; 8-Lower bearing plate; 9-Main cable; 10-Upper tower column; 11-Lower tower column; 12-Upper crossbeam; 13-Second stiffening beam. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0019] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0020] In the description of this application, it should be noted that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only used to facilitate the description of this application and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] Furthermore, in this application, unless otherwise expressly specified and limited, "above or below" the first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Moreover, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] Example: Please refer to Figure 1 (Refer to) Figures 2 to 4 This application provides a main tower structure for a multi-tower suspension bridge. By fixing the first stiffening beam 4 to the middle main tower 1, and then connecting the middle main tower 1 and the first stiffening beam 4 obliquely with the inclined suspension cable 2 to form an integral structure, the longitudinal bending stiffness of the middle main tower 1 is improved, which effectively alleviates the problem of significant reduction in the stiffness of the main tower 1 in a multi-tower suspension bridge and improves the stability, safety and driving comfort of the entire bridge. It mainly includes a central main tower 1, multiple inclined suspension cables 2, a first stiffening beam 4, and multiple main cable saddles 7. The first stiffening beam 4 is a steel-concrete composite beam, and the second stiffening beam 13 is a concrete beam. The first stiffening beams 4 on both sides of the central main tower 1 are connected to the concrete sections of the second stiffening beams 13 at the location of the central main tower 1 through steel-concrete composite sections to form an integral structure. Multiple main cable saddles 7 are vertically fixed to the top of the central main tower 1 in parallel and at intervals along the transverse direction of the central main tower 1. In addition, multiple inclined suspension cables 2 are respectively inclinedly arranged on both sides of the central main tower 1, and the upper end of each inclined suspension cable 2 is anchored in the lower bearing plate 8 at the top of the main cable saddle 7, and the lower end is connected to the end of the corresponding first stiffening beam 4. They connect the central main tower 1 and the first stiffening beams 4 on both sides into an integral structure by inclined tension, thereby combining the first stiffening beams 4 and the central main tower 1 into an integral structure, thus improving the longitudinal bending stiffness of the central main tower 1.

[0025] It should be noted that, in this embodiment, the main tower 1 is a portal frame structure combining steel and concrete, and includes an upper tower column 10, a lower tower column 11, an upper crossbeam 12, and a second stiffening beam 13; the upper tower column 10 and the upper crossbeam 12 are both steel structures, while the lower tower column 11 and the second stiffening beam 13 are both reinforced concrete structures. The two lower tower columns 11 are arranged vertically in parallel intervals, and the two upper tower columns 10 are arranged vertically in parallel intervals. The upper tower columns 10 are coaxially arranged on the top of the corresponding lower tower columns 11, and the upper crossbeam 12 is arranged between the tops of the two upper tower columns 10. The second stiffening beam 13 is arranged between the center of the main tower at the top of the two lower tower columns 11 and is cast integrally with the main tower 1. The first stiffening beam 4 is combined with the second stiffening beam 13 through a steel-concrete joint section to form an integral structure.

[0026] Meanwhile, the lower part of the main cable saddle 7 has a vertically arranged lower support plate 8, which is located at the top of the middle main tower 1. Anchors 3 are installed on the lower support plate 8. The upper end of the inclined suspension cable 2 is connected to the lower support plate 8 through corresponding anchors 3. The inclined suspension cable 2 consists of eight cables arranged longitudinally on opposite sides of the middle main tower 1 in a diagonal manner, and is made of parallel wire bundles of high-strength galvanized aluminum alloy steel wire. In addition, ear plates 5 are provided on both sides of the first stiffening beam 4 in the transverse direction. The ear plates 5 are installed on the first stiffening beam 4 by multiple high-strength bolts. Furthermore, the lower end of the inclined suspension cable 2 is connected to the ear plate 5 through a pin 6.

[0027] Furthermore, the first stiffening girder 4 is a steel-concrete composite girder, constructed by connecting steel beams to the concrete bridge deck via shear studs. The first stiffening girders 4 located on both sides of the central main tower 1 are also constructed by connecting steel beams to the concrete bridge deck via shear studs. The main cable saddle 7 is a fully-constructed structure, cast from cast steel. The steel-concrete composite girder 4 located on both sides of the central main tower 1 uses Q345qD steel for its steel structure. The concrete bridge deck is a reinforced concrete structure, using C55 precast concrete slabs connected via cast-in-place wet joints. The first stiffening girders 4 on both sides of the central main tower 1 are integrated with the concrete section of the second stiffening girder 13 located at the central main tower 1 through a steel-concrete composite section, forming a unified structure. The main cable saddle 7 is fixed to the top of the central main tower 1, manufactured as a whole in the factory, and installed by hoisting to the top of the tower. The lower support plate 8 of the main cable saddle 7 is made of steel and is prefabricated and welded together with the anchor 3 in the factory. It is then transported to the construction site, hoisted to the top of the central main tower 1 for installation and precise positioning. The angle and position of the anchor 3 should be precisely determined beforehand during factory prefabrication. The inclined cable 2 transmits the load of the first stiffening beam 4 to the lower support plate 8 through the anchor 3. The horizontal component of the force generated by the inclined cable 2 is borne by the lower support plate 8, while the vertical component is directly transmitted to the central main tower 1 through the lower support plate 8. This solves the problem of anchoring the upper end of the inclined cable 2 and strengthens the connection between the main cable saddle 7 and the central main tower 1 by anchoring the inclined cable 2 in the lower support plate 8.

[0028] The beam ends of the inclined suspension cables 2 are connected to the first stiffening beam 4 by pin-connected pin shafts. The main tower 1 and the first stiffening beam 4 are connected into an integral structure by inclined tension, which improves the longitudinal bending stiffness of the main tower 1 and effectively alleviates the problem of significant reduction in the stiffness of the main tower 1 in multi-tower suspension bridges. At the same time, the structural components are rationally utilized. Because the inclination angle of the inclined suspension cables 2 on both sides of the main tower 1 is very small, the inclined suspension cables 2 on both sides can not only perform the original function of transferring the load of the first stiffening beam 4, but also improve the bending stiffness of the main tower 1. At the same time, it has little impact on the overall appearance of the bridge and is convenient for construction.

[0029] When unbalanced horizontal forces are generated on both sides of the main tower 1, the inclined suspension cables 2 on both sides provide opposite horizontal forces to assist the main tower 1 in balancing, preventing the main tower 1 from swaying left and right and slipping relative to the main cable 9, thus improving the stability of the entire bridge to a certain extent.

[0030] Furthermore, this embodiment also provides a construction method for the main tower structure of a multi-tower suspension bridge, which mainly includes the following steps: S1, Main Tower 1 under construction: The main tower 1 is a steel-concrete composite portal frame structure, including a steel upper tower column 10, a reinforced concrete lower tower column 11, a steel upper crossbeam 12, and a reinforced concrete second stiffening beam 13. The lower tower column 11 and the second stiffening beam 13 are constructed using the climbing formwork method, while the upper tower column 10 and the upper crossbeam 12 are constructed using a combination of factory segment manufacturing and on-site bolting and welding. S2, When construction reaches the top of the upper tower column 10, the lower support plate 8 is hoisted to the designated position by a crane, and then steel bars are laid on the top of the middle main tower 1. S3, after the lower bearing plate 8 is completed, the upper end of the inclined suspension cable 2 is anchored in the anchor 3 on the lower bearing plate 8, and then concrete is poured together with the steel bars on the top of the middle main tower 1. S4. After the concrete poured on the main tower 1 reaches 100% strength, hoist the main cable saddle 7 and push it into place. S5. After the construction of the central main tower 1 is completed and the main cable 9 is erected, the first stiffening beams 4 on both sides of the central main tower 1 are hoisted and the first stiffening beams 4 on both sides of the central main tower 1 are combined with the concrete section of the second stiffening beam 13 at the location of the central main tower 1 through the steel-concrete composite beam to form an integral structure. S6. After the first stiffening beam 4 is hoisted, the lower end of the inclined sling 2 is connected to the ear plate 5 on the first stiffening beam 4 through the pin 6, so that the main tower 1 and the first stiffening beam 4 are connected as an integral structure.

[0031] In summary, the main tower structure and construction method of the multi-tower suspension bridge in this application utilizes the structure's own components to enhance the longitudinal bending stiffness of the main tower 1, without affecting the overall appearance of the bridge, facilitating construction, and without adding procedures. By fixing the first stiffening beam 4 to the main tower 1, and then connecting the main tower 1 and the first stiffening beam 4 obliquely with inclined suspension cables 2 to form a whole, the longitudinal bending stiffness of the main tower 1 is enhanced, effectively alleviating the problem of significantly reduced stiffness of the main tower 1 in multi-tower suspension bridges, and improving the stability, safety, and driving comfort of the entire bridge. Furthermore, by setting the inclined suspension cables 2 on both sides of the main tower 1 obliquely, it does not affect the transmission of the load of the first stiffening beam 4, and can also provide opposite horizontal forces to assist the main tower 1 in balancing when unbalanced horizontal components are generated on both sides of the main tower 1. Moreover, compared with other schemes to enhance the stiffness of the main tower, this application rationally utilizes the structure's own components to enhance the longitudinal bending stiffness of the main tower 1, has minimal impact on the overall appearance of the bridge, facilitates construction, does not add procedures, and reduces construction costs. At the same time, it anchors the inclined cable 2 to the lower support plate 8 of the main cable saddle 7 to form a whole, which solves the anchoring problem of the inclined cable 2 and strengthens the lower support plate 8 of the main cable saddle 7, which is beneficial to the connection between the main cable saddle 7 and the middle main tower 1.

[0032] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A main tower structure in a multi-tower suspension bridge, characterized in that, The structure includes a central main tower, multiple inclined suspension cables, a first stiffening beam, and multiple main cable saddles. The multiple main cable saddles are vertically fixed to the top of the central main tower in parallel intervals along its transverse direction. Multiple inclined suspension cables are respectively inclinedly arranged on both sides of the central main tower, with the upper end of each cable anchored to the lower support plate at the top of the central main tower and the lower end connected to the corresponding first stiffening beam. The first stiffening beams are respectively arranged on both sides of the central main tower. The lower support plate is located at the top of the central main tower and is equipped with anchorages; the upper ends of the inclined suspension cables are connected to the lower support plate through the corresponding anchorages. The inclined suspension cables consist of eight cables arranged diagonally along the longitudinal direction on opposite sides of the central main tower, and each cable comprises parallel wire bundles of high-strength galvanized aluminum alloy steel wire.

2. The main tower structure of a multi-tower suspension bridge according to claim 1, characterized in that, The main tower is a steel-concrete composite portal frame structure, comprising two upper tower columns, two lower tower columns, an upper crossbeam, and a second stiffening beam. The upper tower columns and upper crossbeams are steel structures, while the lower tower columns and the second stiffening beam are reinforced concrete structures. The two lower tower columns are vertically arranged in parallel intervals, and the two upper tower columns are also vertically arranged in parallel intervals. Each upper tower column is coaxially positioned on top of its corresponding lower tower column, and the upper crossbeam is positioned between the tops of the two upper tower columns. The second stiffening beam is positioned between the center of the main tower at the tops of the two lower tower columns and is cast integrally with the main tower. The first stiffening beam is integrated with the concrete section of the second stiffening beam via a steel-concrete composite section, forming a unified structure.

3. The main tower structure of a multi-tower suspension bridge according to claim 1, characterized in that, Both sides of the first stiffening beam are provided with ear plates along the transverse direction, and the ear plates are installed on the first stiffening beam by a plurality of high-strength bolts; the lower end of the inclined suspension cable is connected to the ear plate by a pin.

4. The main tower structure of a multi-tower suspension bridge according to claim 1, characterized in that, The first stiffening girder is a steel-concrete composite beam, and is constructed by steel beams together with concrete bridge deck through shear studs.

5. The main tower structure of a multi-tower suspension bridge according to claim 2, characterized in that, The second stiffening beam is a concrete beam and is integrated with the central main tower as an integral structure by cast-in-place construction.

6. A construction method for the main tower structure of a multi-tower suspension bridge, characterized in that, Includes the following steps: S1, Construction of the main tower: The main tower is a steel-concrete composite portal frame structure and includes a steel upper tower column, a reinforced concrete lower tower column, a steel upper crossbeam, and a reinforced concrete second stiffening beam. The lower tower column and the second stiffening beam are constructed using the climbing formwork method, and the upper tower column and the upper crossbeam are constructed using a combination of factory segmented manufacturing and on-site bolting and welding. S2, When construction reaches the top of the upper tower column, the lower support plate is hoisted to the designated position by a crane, and then steel bars are laid on the top of the middle main tower; S3. After the lower support plate is completed, the upper end of the inclined suspension cable is anchored in the anchor on the lower support plate, and then concrete is poured together with the steel bars on the top of the middle main tower. S4. After the concrete poured on the main tower reaches 100% strength, hoist the main cable saddle and push it into place. S5. After the construction of the main tower is completed and the main cable is erected, the first stiffening beams on both sides of the main tower are hoisted and the first stiffening beams on both sides of the main tower are combined with the concrete section of the second stiffening beam at the location of the main tower through the steel-concrete composite section to form an integral structure. S6, after the first stiffening beam is constructed, the lower end of the inclined suspension cable is connected to the ear plate on the first stiffening beam through a pin shaft, and the middle main tower is connected to the first stiffening beam to form an integral structure.

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