A prestressed structure of an upper turntable of a rotating bridge

Abstract

The embodiment of the present application provides a prestressed structure of an upper turntable of a rotating bridge, comprising an upper turntable, at least one row of longitudinal post-tensioned prestressed tendons and at least one row of transverse post-tensioned prestressed tendons; the at least one row of longitudinal post-tensioned prestressed tendons is anchored on the top of the upper turntable, and all of the longitudinal post-tensioned prestressed tendons in each row are spaced apart along the transverse direction of the upper turntable and extend along the longitudinal direction of the upper turntable; the at least one row of transverse post-tensioned prestressed tendons is anchored in the upper turntable, and all of the transverse post-tensioned prestressed tendons in each row are spaced apart along the longitudinal direction of the upper turntable and present a curve shape with a high middle and low ends along the transverse direction of the upper turntable. The prestressed structure of the upper turntable of the embodiment of the present application is relatively economical while meeting the structural force requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and in particular to a prestressed structure of an upper turntable of a rotary bridge. Background Art

[0002] A rotating bridge is a bridge constructed off-axis and then rotated into place. It is particularly well-suited for applications where support is unavailable, such as crossing railways, highways, rivers, and canyons. The upper turntable is a key structure in the design and construction of rotating bridges. Throughout the rotation process, it facilitates the transition from the central "point" support load of large or extra-large bridges to the longitudinal load of wide piers or cable-stayed bridge towers.

[0003] However, the upper turntable is subjected to concentrated and complex forces, resulting in a small structure, high stress, and a three-dimensional stress state. Current designs for upper turntable structures typically employ multiple rows of longitudinal, transverse, and vertical prestressed tendons within the turntable to create a three-dimensional prestressed structure. However, this design employs excessive prestressed tendons, resulting in insufficient economic efficiency and significantly weakening the mechanical properties of the structural cross-section. Summary of the Invention

[0004] In view of this, the main purpose of the embodiments of the present application is to provide a prestressed structure for the upper turntable of a rotating bridge that is relatively economical while ensuring that the all-directional forces meet the design requirements.

[0005] To achieve the above objectives, the technical solution of the embodiment of the present application is implemented as follows:

[0006] The embodiment of the present application provides a prestressed structure of an upper turntable of a rotating bridge, comprising:

[0007] Upper turntable;

[0008] At least one row of longitudinal post-tensioned prestressed tendons, wherein the at least one row of longitudinal post-tensioned prestressed tendons is anchored at the top of the upper turntable, and all the longitudinal post-tensioned prestressed tendons in each row of the longitudinal post-tensioned prestressed tendons are spaced apart in a transverse direction of the upper turntable and extend in a longitudinal direction of the upper turntable;

[0009] At least one row of transverse post-tensioned tendons is anchored in the upper turntable, and all the transverse post-tensioned tendons in each row are spaced apart along the longitudinal direction of the upper turntable and are in a curved shape with a high middle and low ends along the transverse direction of the upper turntable.

[0010] In one embodiment, a row of the transverse post-tensioned prestressed tendons are anchored in the upper turntable, and each of the transverse post-tensioned prestressed tendons is arranged along the edge of the upper turntable in the transverse direction of the bridge.

[0011] In one embodiment, a row of the transverse post-tensioned prestressed tendons is anchored to at least one row of the longitudinal post-tensioned prestressed tendons on each of two opposite vertical sides.

[0012] In one embodiment, multiple rows of the longitudinal post-tensioned prestressed tendons and multiple rows of the transverse post-tensioned prestressed tendons are anchored in the upper turntable, and the multiple rows of the longitudinal post-tensioned prestressed tendons and the multiple rows of the transverse post-tensioned prestressed tendons are alternately arranged.

[0013] In one embodiment, the transverse post-tensioned prestressed tendons are curved steel strands.

[0014] In one embodiment, the longitudinal post-tensioned prestressed tendons are straight steel bars.

[0015] In one embodiment, all the longitudinal post-tensioned prestressed tendons in each row are in a curved shape along the longitudinal direction of the upper turntable with a high middle and low ends.

[0016] In one embodiment, the upper turntable prestressed structure also includes a plurality of longitudinal embedded sleeves and a plurality of transverse embedded sleeves arranged in the upper turntable, each of the longitudinal embedded sleeves is respectively passed through one of the longitudinal post-tensioned prestressed tendons, and each of the transverse embedded sleeves is respectively passed through one of the transverse post-tensioned prestressed tendons.

[0017] In one embodiment, the longitudinal post-tensioned prestressed tendons are straight steel bars, and the longitudinal embedded sleeves are iron sleeves.

[0018] In one embodiment, the transverse embedded sleeve is a metal corrugated circular tube or a plastic corrugated tube.

[0019] The embodiment of the present application provides a prestressed structure for an upper turntable of a rotating bridge, wherein the prestressed structure of the upper turntable is composed of at least one row of longitudinal post-tensioned prestressed tendons and at least one row of transverse post-tensioned prestressed tendons, wherein the transverse post-tensioned prestressed tendons are arranged at intervals along the longitudinal direction of the upper turntable and are curved with a high middle and low ends along the transverse direction of the upper turntable. In the structural force analysis, the vertical component of the transverse post-tensioned prestressed tendons provides the prestress required for the vertical direction of the structure, and the transverse component provides the prestress required for the transverse direction of the structure. Therefore, the stress characteristics of the structure in the transverse, vertical and longitudinal directions can be well matched without the need to set vertical prestressed tendons. While ensuring that the stress in each direction meets the design requirements, the economy is relatively high. In addition, since the number of prestressed tendons is reduced, the prestressed structure of the upper turntable of the embodiment of the present application can also reduce the difficulty of on-site construction and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1This is a schematic diagram of the coordination relationship between the upper turntable prestressed structure, the rotation hinge, and the tower column of a rotating bridge according to one embodiment of the present application;

[0021] Figure 2 for Figure 1 Side view of;

[0022] Figure 3 for Figure 1 The front view of the upper turntable prestressed structure shown in;

[0023] Figure 4 for Figure 3 The layout diagram of prestressed tendons in the aa direction;

[0024] Figure 5 for Figure 3 Layout diagram of prestressed tendons in bb direction.

[0025] Description of Reference Numerals

[0026] Upper turntable prestressed structure 10; longitudinal post-tensioned prestressed tendons 11; transverse post-tensioned prestressed tendons 12; upper turntable 13; swivel hinge 20; tower column 30. DETAILED DESCRIPTION

[0027] It should be noted that, unless there is a conflict, the embodiments and technical features in the embodiments of this application can be combined with each other, and the detailed description in the specific implementation method should be understood as an explanation of the purpose of this application and should not be regarded as an improper restriction on this application.

[0028] In this application, the "transverse" and "vertical" directions or positional relationships are based on the attached Figure 1 As shown, the “along the bridge” orientation or position relationship is based on the attached Figure 2 It should be understood that these directional terms are only used to facilitate the description of this application and simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting this application.

[0029] The present application embodiment provides a prestressed structure 10 of the upper turntable of a rotating bridge. Figures 1 to 5The upper turntable prestressed structure 10 includes an upper turntable 13, at least one row of longitudinal post-tensioned prestressed tendons 11 and at least one row of transverse post-tensioned prestressed tendons 12. At least one row of longitudinal post-tensioned prestressed tendons 11 is anchored at the top of the upper turntable 13, that is, the tension zone of the upper turntable 13. All longitudinal post-tensioned prestressed tendons 11 in each row of longitudinal post-tensioned prestressed tendons 11 are spaced apart along the transverse direction of the upper turntable 13 and extend along the longitudinal direction of the upper turntable 13; at least one row of transverse post-tensioned prestressed tendons 12 is anchored in the upper turntable 13, and all transverse post-tensioned prestressed tendons 12 in each row of transverse post-tensioned prestressed tendons 12 are spaced apart along the longitudinal direction of the upper turntable 13 and are curved with a high middle and low ends along the transverse direction of the upper turntable 13.

[0030] The upper turntable prestressed structure 10 of the embodiment of the present application is a prestressed component formed by a post-tensioning method.

[0031] The transverse post-tensioned prestressed tendons 12 are curved along the transverse direction of the upper turntable 13, with the middle being higher and the two ends being lower. This means that under the premise of satisfying the conditions of being higher in the middle and lower at both ends, at least part of the transverse post-tensioned prestressed tendons 12 is curved. For example, the transverse post-tensioned prestressed tendons 12 can be curved by combining curved segments and straight segments, or the transverse post-tensioned prestressed tendons 12 can be curved without straight segments.

[0032] Specifically, the upper turntable prestressed structure 10 of the embodiment of the present application is composed of at least one row of longitudinal post-tensioned prestressed tendons 11 and at least one row of transverse post-tensioned prestressed tendons 12. All the transverse post-tensioned prestressed tendons 12 in each row of transverse post-tensioned prestressed tendons 12 are curved along the transverse direction of the upper turntable 13, with the middle being high and the two ends being low. In other words, the transverse post-tensioned prestressed tendons 12 of the present application are curved prestressed tendons. In terms of structural mechanical properties, since the prestressed vertical component of the transverse post-tensioned prestressed tendons 12 provides the prestressed required for the vertical direction of the structure, the prestressed transverse component of the transverse post-tensioned prestressed tendons 12 provides the prestressed required for the transverse direction of the structure, and the prestressed longitudinal component provided by the longitudinal post-tensioned prestressed tendons 11, the upper turntable prestressed structure 10 of the present application does not need to be provided with vertical prestressed tendons to well meet the three-dimensional force requirements of the structure, thereby reducing the number of prestressed tendons arranged and improving economy.

[0033] Furthermore, in related art, to address the overly concentrated and complex forces on the upper turntable, prestressed tendons are arranged by placing multiple rows of longitudinal, transverse, and vertical prestressed tendons within the upper turntable. Because the upper turntable's structural height is too small, vertical prestressed tendons are generally made of thick vertical prestressed steel bars or rods. However, if the vertical prestressed tendons are slightly relaxed or not anchored sufficiently or promptly after tensioning, the actual tensioning force will fall short of the design requirements and fail to meet design expectations. To avoid this, on-site construction sometimes employs a method of appropriately increasing the tensioning force, but this approach often results in over-tensioning. Furthermore, because the multiple rows of longitudinal, transverse, and vertical prestressed tendons within the upper turntable are not arranged in accordance with the structural stress characteristics, particularly because the thick vertical prestressed steel bars or rods are arranged too densely, the prestressed tendon arrangement is extremely uneconomical, significantly weakening the stress-bearing performance of the concrete sections in key locations. All of these issues are detrimental to the structural stress safety, resulting in an unreasonable design and difficulty ensuring design and construction safety.

[0034] The upper turntable prestressed structure 10 of the embodiment of the present application adopts a combined structure of at least one row of longitudinal post-tensioned prestressed tendons 11 and at least one row of transverse post-tensioned prestressed tendons 12, and the transverse post-tensioned prestressed tendons 12 are curved along the transverse direction of the upper turntable 13, with the middle being high and the two ends being low. Compared with the three-way prestressed structure in the related art, the upper turntable prestressed structure 10 of the embodiment of the present application eliminates the vertical prestressed tendons, greatly reduces the number of prestressed tendons arranged, and simplifies the arrangement of the prestressed tendons. Thus, it can avoid the actual tensioning force of the vertical prestressed tendons failing to meet the design requirements or exceeding the design tensioning force. The upper turntable prestressed structure 10 of the embodiment of the present application is closer to the structural stress, can ensure the integrity of the cross section, is easy to construct, has low difficulty in on-site construction control, is conducive to improving on-site construction quality, has a good overall effect, and is very technically and economically reasonable. It has good social and economic benefits and a prospect for promotion and application. In one embodiment, a plurality of longitudinal embedded sleeves and a plurality of transverse embedded sleeves can also be provided in the upper turntable prestressed structure 10, and a longitudinal post-tensioned prestressed tendon 11 is respectively passed through each longitudinal embedded sleeve, and a transverse post-tensioned prestressed tendon 12 is respectively passed through each transverse embedded sleeve. The longitudinal post-tensioned prestressed tendon 11 can be anchored on the top of the upper turntable 13 by an anchor, and the transverse post-tensioned prestressed tendon 12 can also be anchored in the upper turntable 13 by an anchor.

[0035] In one embodiment, please refer to Figure 3 The transverse post-tensioned prestressed tendons 12 are arranged along the transverse edges of the upper turntable 13. By arranging the transverse post-tensioned prestressed tendons 12 along the transverse edges of the upper turntable 13, the tensile stress concentrated on the upper edge of the upper turntable 13 is offset, thereby improving the crack resistance, rigidity, and impermeability of the upper turntable 13 and fully utilizing the material's performance.

[0036] In one embodiment, please refer to Figure 3 A row of transverse post-tensioned tendons 12 is anchored with at least one row of longitudinal post-tensioned tendons 11 on each of the two opposite sides in the vertical direction. That is to say, a row of transverse post-tensioned tendons 12 can be anchored with one or more rows of longitudinal post-tensioned tendons 11 on the two opposite sides in the vertical direction, which can give full play to the role of prestressed steel bars and ensure the quality of the project.

[0037] In some embodiments, under the premise of meeting the stress requirements, only one row of longitudinal post-tensioned prestressed tendons 11 can be arranged on one side of the transverse post-tensioned prestressed tendons 12 along the vertical direction. This can greatly reduce the number of prestressed tendons arranged, simplify the prestressed tendon arrangement, reduce the difficulty of on-site construction and control, and is conducive to improving the quality of on-site construction. The technical and economic rationality is obvious.

[0038] In one embodiment, multiple rows of longitudinal post-tensioned prestressed tendons 11 and multiple rows of transverse post-tensioned prestressed tendons 12 are anchored in the upper turntable 13, and the multiple rows of longitudinal post-tensioned prestressed tendons 11 and multiple rows of transverse post-tensioned prestressed tendons 12 are arranged alternately. That is to say, the embodiment of the present application can arrange multiple rows of longitudinal post-tensioned prestressed tendons 11 and multiple rows of transverse post-tensioned prestressed tendons 12, and the longitudinal post-tensioned prestressed tendons 11 and transverse post-tensioned prestressed tendons 12 are arranged alternately, which is equivalent to arranging a row of transverse post-tensioned prestressed tendons 12 between every two adjacent rows of longitudinal post-tensioned prestressed tendons 11, or arranging a row of longitudinal post-tensioned prestressed tendons 11 between every two adjacent transverse post-tensioned prestressed tendons 12, which can make the prestressed tendon arrangement more in line with the stress and design requirements, and avoid a large weakening of the structural cross-section.

[0039] In one embodiment, the transverse post-tensioned prestressed tendons 12 may be curved steel strands.

[0040] In a specific embodiment, the specification of the curved steel strand can be 19-φ15.2mm, the basic spacing of each transverse post-tensioned prestressed tendon 12 is 60cm, the tensioning control force under the anchor is 3325.0KN, and the arrangement range along the bridge direction is about 10m.

[0041] It should be noted that the specifications, spacing, number, coverage and prestressing force of the transverse post-tensioned prestressed tendons 12 can be adjusted according to the specific conditions and actual needs of the project.

[0042] In one embodiment, the longitudinal post-tensioned prestressed tendons 11 are straight steel bars.

[0043] In a specific embodiment, the specification of the linear steel bars can be φ32mm, the basic spacing between each longitudinal post-tensioned prestressed tendon 11 is 60cm, the tensioning control force of each bundle is 635.8kN, and the arrangement range along the bridge direction is about 4m.

[0044] It should be noted that the specifications, spacing, quantity, coverage and prestressing size of the longitudinal post-tensioned prestressed tendons 11 can be adjusted according to the specific conditions and actual needs of the project, so as to better meet the requirements of the project design.

[0045] In one embodiment, all longitudinal post-tensioned prestressed tendons 11 in each row are arranged in a curved pattern, with a high center and low ends, along the longitudinal direction of the upper turntable 10. In other words, each row of longitudinal post-tensioned prestressed tendons 11 can be arranged in a curved pattern, with a high center and low ends, based on the size of the upper turntable 13 and the transition from the central "point" support force of the swivel hinge 20 to the longitudinal force of the tower column 30 during rotation.

[0046] In one embodiment, the longitudinal post-tensioned prestressed tendons 11 are straight steel bars, and the embedded sleeves are iron sleeves.

[0047] In a specific embodiment, the inner diameter of the iron casing may be φ45 mm.

[0048] In one embodiment, the transverse embedded sleeve is a metal corrugated circular tube or a plastic corrugated tube.

[0049] In a specific embodiment, the inner diameter of the metal corrugated tube or the plastic corrugated tube may be φ100 mm.

[0050] It should be noted that the specifications and types of the transverse embedded sleeves and the longitudinal embedded sleeves can be adjusted according to the types and specifications of the prestressed tendons to be anchored.

[0051] The above is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A prestressed structure of an upper turntable of a rotating bridge, characterized in that: include: Upper turntable; At least one row of longitudinal post-tensioned prestressed tendons, wherein the at least one row of longitudinal post-tensioned prestressed tendons is anchored at the top of the upper turntable, and all the longitudinal post-tensioned prestressed tendons in each row of the longitudinal post-tensioned prestressed tendons are spaced apart in a transverse direction of the upper turntable and extend in a longitudinal direction of the upper turntable; At least one row of transverse post-tensioned prestressed tendons, wherein the at least one row of transverse post-tensioned prestressed tendons is anchored in the upper turntable, wherein all the transverse post-tensioned prestressed tendons in each row are spaced apart along the longitudinal direction of the upper turntable and form a curved shape with a high center and low ends along the transverse direction of the upper turntable; A row of transverse post-tensioned prestressed tendons is anchored in the upper turntable, and each of the transverse post-tensioned prestressed tendons is arranged along the edge of the upper turntable in the transverse direction of the bridge.

2. The upper turntable prestressed structure according to claim 1, characterized in that: At least one row of longitudinal post-tensioned prestressed tendons is anchored on each of two opposite vertical sides of a row of transverse post-tensioned prestressed tendons.

3. The upper turntable prestressed structure according to claim 1, characterized in that: Multiple rows of the longitudinal post-tensioned prestressed tendons and multiple rows of the transverse post-tensioned prestressed tendons are anchored in the upper turntable, and the multiple rows of the longitudinal post-tensioned prestressed tendons and the multiple rows of the transverse post-tensioned prestressed tendons are alternately arranged.

4. The upper turntable prestressed structure according to any one of claims 1 to 3, characterized in that: The transverse post-tensioned prestressed tendons are curved steel strands.

5. The upper turntable prestressed structure according to any one of claims 1 to 3, characterized in that: The longitudinal post-tensioned prestressed reinforcement is a straight steel bar.

6. The upper turntable prestressed structure according to any one of claims 1 to 3, characterized in that: All the longitudinal post-tensioned prestressed tendons in each row are in a curved shape along the longitudinal direction of the upper turntable with a high middle and low ends.

7. The upper turntable prestressed structure according to any one of claims 1 to 3, characterized in that: The upper turntable prestressed structure also includes a plurality of longitudinal embedded sleeves and a plurality of transverse embedded sleeves arranged in the upper turntable, each of the longitudinal embedded sleeves is respectively passed through with one longitudinal post-tensioned prestressed tendon, and each of the transverse embedded sleeves is respectively passed through with one transverse post-tensioned prestressed tendon.

8. The upper turntable prestressed structure according to claim 7, characterized in that: The longitudinal post-tensioned prestressed reinforcement is a straight steel bar, and the longitudinal embedded sleeve is an iron sleeve.

9. The upper turntable prestressed structure according to claim 7, characterized in that: The transverse embedded sleeve is a metal corrugated circular tube or a plastic corrugated tube.

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