A non-symmetrical steel arch cable anchorage joint of a long-span arch bridge

Abstract

The utility model discloses a kind of sling anchorage of large-span arch bridge asymmetric steel arch, it is related to bridge engineering technical field, the sling anchorage is anchored in the steel arch middle section spliced by multiple box-type steel sections, sling anchorage and its adjacent upper and lower box-type steel section socket positioning connection, and this socket positioning receiving point is located at the concave arc surface side of steel arch;Sling anchorage includes anchorage box, lug and multiple rib plate, wherein anchorage box is fixedly supported lug by multiple rib plate inside, the lug one end is fixedly connected with the concave arc surface inner wall of anchorage box, the middle section of lug is fixedly connected with the inner wall of anchorage box, and the other end of lug penetrates the convex arc surface of anchorage box and hangs sling.The sling anchorage is through optimization steel arch cross section design, reinforcing anchorage node rigidity and adapting sling arrangement form, realize the efficient load transfer of asymmetric arch bridge and long-term stable operation, satisfy the safety demand of municipal large-span river-crossing bridge engineering.

Description

Technical Field

[0001] This utility model relates to the field of bridge engineering technology, specifically to a cable anchorage joint for an asymmetric steel arch of a long-span arch bridge. Background Technology

[0002] In municipal long-span bridge projects, arch bridges are widely used due to their advantages such as strong span capacity and beautiful structural design, especially in complex scenarios such as crossing rivers and railways. With the increase in bridge span and the upgrading of functional requirements, traditional symmetrical cross-section steel arches have problems such as uneven stress and low material utilization. Moreover, the cable anchoring system often fails due to insufficient structural stiffness and unclear load transfer path, which seriously affects the operational safety of the bridge.

[0003] In existing technologies, steel arches mostly adopt a uniform cross-section design, which is difficult to adapt to the stress requirements of asymmetric arch bridges. When the arch height is large, the box girder lacks an effective supporting structure, making it prone to local buckling deformation. At the same time, cable anchorages mostly use simple welding or bolt connections, resulting in insufficient stiffness and shear resistance at the anchorage nodes. Furthermore, the cable arrangement is not optimized in conjunction with the load differences at the hole positions, leading to stress concentration in some areas. In addition, corrosive environments such as seawater and rainwater will accelerate the corrosion of anchorage nodes and shorten the service life of the bridge.

[0004] To address the aforementioned issues, there is an urgent need to design a steel arch and cable anchorage system that is rationally stressed, highly stable, and suitable for asymmetric arch bridges. By optimizing the steel arch cross-sectional structure, strengthening the stiffness of the anchorage nodes, and adapting the cable arrangement, the shortcomings of traditional systems can be resolved, thus meeting the safe operation requirements of long-span arch bridges. Utility Model Content

[0005] This utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, one objective of this utility model is to propose a cable anchorage joint for asymmetrical steel arches of long-span arch bridges, addressing the issues of poor restraint of traditional steel arches, insufficient stability of cable anchorage, and low structural adaptability. By optimizing the steel arch cross-section design, strengthening the stiffness of the anchorage node, and adapting the cable arrangement, efficient load transfer and long-term stable operation of asymmetrical arch bridges can be achieved, meeting the safety requirements of municipal long-span river-crossing bridge projects.

[0006] To address the aforementioned problems, this utility model provides a cable anchoring section for an asymmetric steel arch of a long-span arch bridge. This cable anchoring section is anchored to the middle section of a steel arch composed of multiple box-shaped steel sections. The cable anchoring section is connected to its adjacent upper and lower box-shaped steel sections via socket positioning, with the socket positioning receiving point located on the concave arc side of the steel arch. The cable anchoring section includes an anchoring section box, ear plates, and multiple stiffening plates. The ear plates are fixedly supported within the anchoring section box by the multiple stiffening plates. One end of the ear plate is fixedly connected to the inner wall of the concave arc surface of the anchoring section box, the middle section of the ear plate is fixedly connected to the inner wall of the anchoring section box, and the other end of the ear plate penetrates the convex arc surface of the anchoring section box and carries the cable.

[0007] Preferably, the splice anchoring section and its adjacent upper and lower box-type steel sections are connected by a socket-type positioning structure including: a blind hole support, a through hole support, and a pin arranged perpendicular to the horizontal plane. The blind hole support is fixed to the lower part of the splice anchoring section and its adjacent upper box-type steel section near the concave arc surface of the steel arch, and the through hole support is fixed to the upper part of the splice anchoring section and its adjacent lower box-type steel section near the concave arc surface of the steel arch. The pin penetrates the through hole support vertically from bottom to top and is welded and fixed inside the blind hole support. The pin resists the tension between the multiple box-type steel sections when the sling is tensioned on the convex arc surface of the steel arch.

[0008] Preferably, the stiffening plate includes a transverse stiffening plate, a longitudinal rib, and a hole reinforcing ring; the transverse stiffening plate is fixedly covered on both sides of the end of the ear plate that penetrates the convex arc surface of the anchoring section box, and the hole reinforcing ring is fixedly covered on the transverse stiffening plate, and the transverse stiffening plate and ear plate surrounding the hole reinforcing ring have through holes for hanging slings; the longitudinal rib forms a 90° angle with the ear plate, one end of the longitudinal rib is welded to the inner wall of the anchoring section box, and the other end of the longitudinal rib is welded and fixed to the ear plate and the transverse stiffening plate.

[0009] Preferably, the anchorage box is a box-shaped cross-section structure with a transverse width of 6m, and its cross-section height gradually decreases from 4 to 9m along the arch, and the thickness of the outer wall plate of the anchorage box is 20 to 30mm.

[0010] Preferably, multiple longitudinal ribs are arranged in parallel with a spacing of 500mm between them, and the thickness of the longitudinal ribs is 12~16mm.

[0011] Preferably, the slings are made of high-strength galvanized steel wire bundles with a nominal diameter of 15~20mm and a breaking strength of not less than 1860MPa.

[0012] The advantages of this utility model for a cable anchorage joint of an asymmetric steel arch for a long-span arch bridge compared with the prior art are as follows: 1. Rational structural stress and strong stability: The asymmetric box-section steel arch adopts a gradually varying height design (4~9m), combined with the gradient distribution of the outer wall panel thickness (20~30mm), effectively adapting to the load requirements of different parts of the arch bridge, reducing the structural self-weight, and improving material utilization. The addition of horizontal diaphragms inside the box section, longitudinal stiffening ribs (500mm spacing) on ​​the inner side of the wall panels, and internal transverse diaphragms (6~9m spacing) significantly enhance the buckling resistance and overall stiffness of the steel arch.

[0013] 2. High reliability of cable anchorage: The parallel double-plane cable arrangement (5m spacing in the transverse direction and 6m spacing in the longitudinal direction) works in conjunction with the steel anchor box assembly. The anchorage nodes are designed in an integrated manner through ear plates, transverse stiffeners, and longitudinal ribs to ensure uniform load transfer, strong shear resistance, and avoid stress concentration.

[0014] 3. Excellent adaptability and durability: The system optimizes the number of suspenders for the different span loads of asymmetrical arch bridges (80 suspenders in total: 24 on the left span, 38 on the main span, and 18 on the right span), and sets up suspender-free zones (maximum length 16m) to avoid structural interference. The suspenders use high-strength galvanized steel wire bundles (breaking strength ≥1860MPa), and the inner wall of the cable guide is coated with an epoxy resin anti-corrosion coating (thickness 0.8~1.2mm) to improve corrosion resistance and extend the service life of the bridge.

[0015] 4. Convenient construction: The steel arch and anchoring components adopt standardized welding and forging processes, such as the integrated structure of anchor plate and bearing plate, which reduces on-site processing difficulty and improves construction efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the cable anchoring and clamping during the construction of a steel arch bridge according to this utility model; Figure 2 This is a partially enlarged view of the sling anchorage section in this utility model; Figure 3 for Figure 2 Sectional view of section AA; In the figure: 1-sling; 2-steel arch; 3-sling anchor joint; 4-box steel section; 5-blind hole support; 6-through hole support; 7-pin; 8-ear plate; 9-longitudinal rib; 10-hole reinforcing ring; 11-transverse stiffener. Detailed Implementation

[0018] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0019] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0020] The present invention will now be described in further detail with reference to the accompanying drawings.

[0021] This utility model discloses a cable anchoring section for an asymmetric steel arch of a long-span arch bridge. The cable anchoring section 3 is anchored to the middle section of a steel arch 2 composed of multiple box-shaped steel sections 4. The cable anchoring section is connected to its adjacent upper and lower box-shaped steel sections by socket positioning. The socket positioning receiving point is located on the concave arc side of the steel arch. The cable anchoring section includes an anchoring section box, ear plates 8, and multiple stiffening plates. The ear plates are fixedly supported by multiple stiffening plates inside the anchoring section box. One end of the ear plate is fixedly connected to the inner wall of the concave arc surface of the anchoring section box, the middle section of the ear plate is fixedly connected to the inner wall of the anchoring section box, and the other end of the ear plate penetrates the convex arc surface of the anchoring section box and hangs the cable.

[0022] Preferably, the splice anchoring section and its adjacent upper and lower box-type steel sections are connected by a socket-type positioning structure including: a blind hole support 5, a through hole support 6 and a pin 7 arranged perpendicular to the horizontal plane. The blind hole support is fixed to the lower part of the splice anchoring section and its adjacent upper box-type steel section near the concave arc surface of the steel arch, and the through hole support is fixed to the upper part of the splice anchoring section and its adjacent lower box-type steel section near the concave arc surface of the steel arch. The pin penetrates the through hole support vertically from bottom to top and is welded and fixed inside the blind hole support. The pin resists the tension between the multiple box-type steel sections when the splice 1 tensions the convex arc surface of the steel arch.

[0023] Preferably, the stiffening plate includes a transverse stiffening plate 9, a longitudinal rib 11, and a hole reinforcing ring 10; the transverse stiffening plate is fixedly covered on both sides of the ear plate penetrating the convex arc surface of the anchoring section box, and the hole reinforcing ring is fixedly covered on the transverse stiffening plate, and the transverse stiffening plate and ear plate surrounding the hole reinforcing ring have through holes for hanging slings; the longitudinal rib forms a 90° angle with the ear plate, one end of the longitudinal rib is welded to the inner wall of the anchoring section box, and the other end of the longitudinal rib is welded and fixed to the ear plate and the transverse stiffening plate.

[0024] Preferably, the anchorage box is a box-shaped cross-section structure with a transverse width of 6m, and its cross-section height gradually decreases from 4 to 9m along the arch, and the thickness of the outer wall plate of the anchorage box is 20 to 30mm.

[0025] Preferably, multiple longitudinal ribs are arranged in parallel with a spacing of 500mm between them, and the thickness of the longitudinal ribs is 12~16mm.

[0026] Preferably, the slings are made of high-strength galvanized steel wire bundles with a nominal diameter of 15~20mm and a breaking strength of not less than 1860MPa.

[0027] To more clearly illustrate the specific implementation of this utility model, an embodiment is provided below: 1. Implementation of Asymmetric Box-Section Steel Arches The steel arch is made of Q355ND low-alloy high-strength steel. The transverse width is fixed at 6m, and the cross-sectional height gradually varies from 4 to 9m along the arch: the load at the arch crown is smaller, so the cross-sectional height is 4-6m; the load at the arch foot is larger, so the cross-sectional height is 7-9m. The thickness of the outer wall panels is adjusted according to location: 30mm at the arch foot and 20mm at the arch crown. When the box girder height is greater than 6m, horizontal partitions are added, welded to the wall panels, with the same thickness as the outer wall panels (20-30mm). Longitudinal stiffening ribs are welded to the inner side of the wall panels. These stiffening ribs are strip steel plates, with a height of 1 / 5 to 1 / 3 of the wall panel height (e.g., when the wall panel height is 8m, the stiffening rib height is 1.6-2.7m), a thickness of 12-16mm, and a spacing of 500mm. The interior of the steel arch is arranged with transverse diaphragms at intervals of 6 to 9 meters. The transverse diaphragms are 16 mm thick rectangular steel plates with circular weight-reducing holes (80 to 120 mm in diameter). The total area of ​​the weight-reducing holes does not exceed 30% of the area of ​​the transverse diaphragms.

[0028] 2. Implementation of the parallel double-plane cable anchoring mechanism The suspender cable assemblies are made of high-strength galvanized steel wire bundles with a nominal diameter of 15-20mm and a breaking strength of not less than 1860MPa, and are covered with a PE sheath (5-8mm thick). The suspenders are arranged in parallel double-plane configurations: 5m spacing in the transverse direction and 6m spacing in the longitudinal direction, totaling 80 cables for the entire bridge (12 pairs (24 cables) on the left span, 19 pairs (38 cables) on the main span, and 9 pairs (18 cables) on the right span). The maximum length of the cable-free zone near the piers is 16m. The steel anchor box assemblies are welded between the steel arch webs.

[0029] 3. Detailed Components and Quality Control During implementation, strict quality control must be exercised over the details of the components: the welding of longitudinal stiffening ribs to the wall panels must be continuous, and the edges of the weight-reducing holes in the transverse diaphragms must be ground smooth to avoid stress concentration. After the steel anchor box is assembled, non-destructive testing is performed to ensure the quality of the welds.

[0030] The working principle of this utility model is as follows: The working principle of this invention is based on the load transfer path and structural synergy: the bridge deck load is transferred to the steel arch through the cable assembly, and the anchorage between the cables and the steel arch is achieved through the steel anchor box assembly. The steel anchor box is built between the two webs of the steel arch, with the anchor plate bearing the cable tension, the pressure plate distributing the load to the webs of the steel arch, the shear plate resisting shear force, and the stiffening plate enhancing the joint stiffness. Simultaneously, the gradually changing cross-section of the steel arch and its internal supporting structures (such as horizontal diaphragms, longitudinal stiffeners, and transverse diaphragms) effectively disperse the load, prevent local deformation, and ensure the balance and stability of the entire system under asymmetric loads. The cable-free zone further optimizes the force flow path and avoids stress concentration in the pier area.

[0031] Finally, any aspects of this utility model not fully described herein utilize existing mature products and technologies.

[0032] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A cable anchorage section for an asymmetric steel arch of a long-span arch bridge, wherein the cable anchorage section is anchored to the middle section of a steel arch composed of multiple box-shaped steel sections, characterized in that: The sling anchor section is connected to its adjacent upper and lower box-shaped steel sections by socket positioning, and the socket positioning receiving point is located on the concave arc side of the steel arch; the sling anchor section includes an anchor section box, ear plates and multiple stiffening plates, wherein the ear plates are fixedly supported by multiple stiffening plates inside the anchor section box, one end of the ear plate is fixedly connected to the inner wall of the concave arc surface of the anchor section box, the middle section of the ear plate is fixedly connected to the inner wall of the anchor section box, and the other end of the ear plate penetrates the convex arc surface of the anchor section box and hangs the sling.

2. The cable anchorage joint for an asymmetric steel arch of a long-span arch bridge according to claim 1, characterized in that: The cable anchoring section and its adjacent upper and lower box-type steel sections are connected by a socket-type positioning structure including: a blind hole support, a through hole support, and a pin arranged perpendicular to the horizontal plane. The blind hole support is fixed to the lower part of the cable anchoring section and its adjacent upper box-type steel section near the concave arc surface of the steel arch, and the through hole support is fixed to the upper part of the cable anchoring section and its adjacent lower box-type steel section near the concave arc surface of the steel arch. The pin penetrates the through hole support vertically from bottom to top and is welded and fixed inside the blind hole support. The pin resists the tension between multiple box-type steel sections when the cable tensions the convex arc surface of the steel arch.

3. The cable anchorage joint for an asymmetric steel arch of a long-span arch bridge according to claim 1, characterized in that: The stiffening plate includes a transverse stiffening plate, a longitudinal rib, and a hole reinforcing ring; the transverse stiffening plate is fixedly covered on both sides of the end of the ear plate that penetrates the convex arc surface of the anchoring section box, and the hole reinforcing ring is fixedly covered on the transverse stiffening plate, and the transverse stiffening plate and ear plate surrounding the hole reinforcing ring have through holes for hanging slings; the longitudinal rib forms a 90° angle with the ear plate, one end of the longitudinal rib is welded to the inner wall of the anchoring section box, and the other end of the longitudinal rib is welded and fixed to the ear plate and the transverse stiffening plate.

4. The cable anchorage joint for an asymmetric steel arch of a long-span arch bridge according to claim 3, characterized in that: The anchorage section box is a box-shaped cross-section structure with a transverse width of 6m. Its cross-section height gradually decreases from 4 to 9m along the arch, and the thickness of the outer wall plate of the anchorage section box is 20 to 30mm.

5. The cable anchorage joint for an asymmetric steel arch of a long-span arch bridge according to claim 3, characterized in that: The longitudinal ribs are arranged in parallel with a spacing of 500 mm between them, and the thickness of the longitudinal ribs is 12~16 mm.

6. The cable anchorage joint for an asymmetric steel arch of a long-span arch bridge according to claim 3, characterized in that: The slings are made of high-strength galvanized steel wire bundles with a nominal diameter of 15-20 mm and a breaking strength of not less than 1860 MPa.

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