Large-diameter steel pipe arch suitable for meshy suspender half-through arch bridge and construction method of large-diameter steel pipe arch

Abstract

The invention discloses a large-diameter steel pipe arch suitable for a net-shaped suspender half-through arch bridge and a construction method of the large-diameter steel pipe arch, and relates to the technical field of bridge structures. The large-diameter steel pipe arch comprises a large-diameter circular steel pipe arch rib, a butterfly-shaped cross brace and sling anchor points, the large-diameter circular steel pipe arch rib comprises a circular steel pipe, longitudinal stiffening ribs, an annular transverse partition plate and an edging. The longitudinal stiffening ribs are plate ribs and are uniformly arranged in an umbrella shape along the inner wall of the circular steel pipe; the annular diaphragm plate is perpendicular to the inner wall of the circular steel pipe; the plurality of butterfly-shaped cross braces are arranged between the two large-diameter circular steel pipe arch ribs and are symmetrically distributed along the center line of the bridge; and the sling anchor point is arranged at the bottom of the large-diameter circular steel pipe arch rib. The large-diameter steel pipe arch can be matched with the structural stress of the net-shaped suspender half-through arch bridge, the transparent and light landscape attributes of the net-shaped suspender half-through arch bridge can be improved, and meanwhile the arch rib structural form of the large-span arch bridge is enriched.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge structures, and in particular relates to a large-diameter steel pipe arch suitable for a mesh hanger half-through arch bridge and a construction method thereof. Background Art

[0002] Modern bridges can be divided into four basic systems according to their structural stress characteristics: beam bridges, arch bridges, rigid frame bridges and suspension bridges. Arch bridges are widely used due to their economical cost and beautiful appearance. Traditional mid-span arch bridges usually use a parallel vertical hanger system. The main arch ribs are the main load-bearing components, bearing almost all the loads on the bridge. The main arch structure of this type of arch bridge generally uses steel box arches, steel tube concrete arches and truss arches.

[0003] In the 1920s, Danish engineer Nielsen proposed the Nielsen arch bridge. In 1955, Per Tveit made innovations based on this and proposed a mesh-type tie-bar arch bridge. With the advancement of science and technology, mesh-type tie-bar arch bridges have gradually been recognized by bridge engineers for their advantages such as "good force-bearing performance, high structural rigidity, material saving, lightness and beauty", and have gradually become the new favorite of arch bridge design. The mesh-type arch bridge originated from the Nielsen arch bridge. It adopts an oblique hanger arrangement, and the oblique hangers cross other oblique hangers at least twice, so as to ensure the coordinated force of each structure, significantly reduce the bending moment of the arch ribs and main beams, and make the bending moment distribution more uniform. This design innovation can greatly reduce the deadweight of the structure, and the axial force of the main arch is also reduced, making the main arch ribs more slender, the structure more transparent and light, and effectively saving materials.

[0004] In the current cases of mesh arch bridges, the main arch ribs are mostly steel box structures, single small-diameter steel tube structures or steel tube concrete composite structures, and reinforced concrete arch ribs are relatively rare. The system stress of mesh arch bridges is quite different from that of traditional parallel vertical hanger arch bridges. In view of the stress characteristics and landscape attributes of mesh tie arch bridges, it is necessary to find a more economical, reasonable and convenient main arch structure for them.

[0005] Steel tube concrete arch bridge is a common structural form for long-span arch bridges across rivers and canyons. The stability of the steel tube wall is enhanced by filling concrete inside, and the steel tube's hooping effect on the core concrete can improve the concrete's compressive strength. However, for mesh arch bridges, due to the dense and staggered anchor points, the anchor point reinforcement design can only be set on the outside of the arch rib, which results in poor force transmission effect, and the irregular anchor point structure affects the landscape effect of the arch rib. In addition, the surface temperature of the steel tube in the steel tube concrete arch rib is very high under sunlight, while the internal concrete temperature is low, which easily produces a temperature difference, resulting in the steel tube and the concrete inside the tube being emptied. When using trussed steel tube concrete arch ribs, the structure of the welded joints between the tubes is complex, which is easy to cause welding defects, and the later maintenance workload of the trussed steel tube concrete arch ribs is large and difficult.

[0006] Steel box arch rib is a common main arch rib structure of mesh arch bridges, and its cross-sectional forms generally include single box single chamber, single box multi-chamber and multi-box single chamber. The single box single chamber section is simple in structure and easy to construct; the single box multi-chamber and multi-box single chamber sections have greater bending and torsional rigidity, and are suitable for steel box arch bridges with large spans or wide bridge decks. Steel box arch ribs can be made of high-strength steel, which has the characteristics of light weight and high strength. The steel box structural components can be prefabricated in the factory and assembled on site, and the construction speed is fast. However, since the steel box arch rib adopts a box-shaped blunt section, the blunt body characteristics of the steel box structure damage the landscape attributes of the slender and light posture of the mesh arch bridge. At the same time, compared with the circular section, the box section has poor wind resistance and stability.

[0007] A single small-diameter circular steel tube arch rib is also a common main arch rib structure for mesh arch bridges. It is usually rolled and welded from steel plates into a closed circular steel tube structure. The inner diameter of a small-diameter circular steel tube arch rib is generally less than 1.5m. Due to its small inner diameter, it is limited by the operating space and cannot be equipped with stiffening ribs and diaphragms. In order to solve the problem of main arch rib compression and stability, the diameter-to-thickness ratio must be met. Therefore, the arch rib wall thickness is relatively thick, the engineering economy is poor, and the bearing capacity of the structure is limited. It is usually suitable for urban pedestrian bridges, but cannot be used in large-span mesh arch bridges across rivers and canyons.

[0008] The mesh hanger mid-span arch bridge is a large-span mid-span arch bridge. The steel box structure, single small-diameter steel pipe structure, steel tube concrete composite structure and other structures currently used in the main arch ribs of the mesh hanger arch bridge are not suitable for the mesh hanger mid-span arch bridge.

[0009] In view of this, the present invention provides a large-diameter steel pipe arch and a construction method thereof, which can not only match the structural stress of a mid-span arch bridge with a mesh hanger, but also further enhance the transparent and light landscape attributes of the mid-span arch bridge with a mesh hanger. By adopting a factory-prefabricated assembly and on-site hoisting process, the construction progress is accelerated, the construction period is saved, and the advantages of efficient force transmission, economical cost, safety and durability, landscape coordination, and convenient construction are achieved. Summary of the invention

[0010] The object of the present invention is to provide a large-diameter steel pipe arch suitable for a mesh hanger half-span arch bridge and a construction method thereof, so as to solve the defects or shortcomings of the main arch structure of the existing large-span half-span arch bridge mentioned in the above background technology, and at the same time, it can match the structural stress of the mesh tie-bar arch bridge and improve the landscape attributes of the mesh tie-bar arch bridge.

[0011] To achieve the above object, the present invention adopts the following technical solutions:

[0012] On the one hand, the present invention provides a large-diameter steel pipe arch suitable for a mesh hanger mid-through arch bridge, comprising a large-diameter circular steel pipe arch rib, a butterfly-shaped cross brace and a sling anchor point;

[0013] The large-diameter circular steel pipe arch ribs are provided with two, and are in the shape of an inwardly inclined basket; the large-diameter circular steel pipe arch ribs include circular steel pipes, longitudinal stiffening ribs, annular diaphragms and edging; the longitudinal stiffening ribs are plate ribs, and are evenly arranged in an umbrella shape along the inner wall of the circular steel pipe; the annular diaphragms are arranged perpendicular to the inner wall of the circular steel pipe, and the edging is connected to the inner edge of the annular diaphragms;

[0014] The butterfly-shaped cross braces are arranged in plurality between two large-diameter circular steel tube arch ribs, symmetrically distributed along the center line of the bridge, and are used to connect the two large-diameter circular steel tube arch ribs;

[0015] The sling anchor point is installed at the bottom of the large-diameter circular steel pipe arch rib and is used to connect the mesh suspender system.

[0016] Preferably, an annular pressure plate for transmitting force to the arch hinge structure is connected to the end of the arch foot segment of the large-diameter circular steel tube arch rib, and an annular plate is provided inside the circular steel tube of the arch foot segment, and the annular plate is connected to the longitudinal stiffening rib on the side away from the inner wall of the circular steel tube. A CA-UHPC transition section is formed by pouring CA-UHPC into a chamber surrounded by the longitudinal stiffening rib, the circular steel tube, the annular pressure plate and the annular plate, and shear nails are evenly arranged along the inner wall of the chamber.

[0017] Preferably, the annular diaphragm includes a structural diaphragm and a force transmission diaphragm, the structural diaphragm is arranged between adjacent sling anchor points; the force transmission diaphragm is arranged at the sling anchor points.

[0018] Furthermore, the outer ring of the annular transverse diaphragm is connected to the inner wall of the circular steel pipe, and the inner ring diameter of the annular transverse diaphragm is smaller than the inner ring diameter of the annular cross section of the longitudinal stiffening ribs uniformly arranged in an umbrella shape.

[0019] Preferably, the butterfly-shaped cross brace includes a cross brace node, a cross brace support rod and a cross brace joint. There are four cross brace support rods, one end of all the cross brace support rods intersects and merges at the cross brace node, and the other end is connected to the large-diameter circular steel pipe arch rib through the cross brace joint.

[0020] Preferably, the cross brace nodes, cross brace struts and cross brace joints each include a top plate, a bottom plate, a web plate, a diaphragm and a rim;

[0021] The top plate, the bottom plate and the web plates on both sides form a box-shaped structure, the transverse partition is arranged transversely inside the box-shaped cross-section structure, a circular hole is opened in the center of the transverse partition, and the edging is connected to the edge of the circular hole;

[0022] The top plates of the cross brace nodes, cross brace struts and cross brace joints are aligned and connected in sequence, the bottom plates of the cross brace nodes, cross brace struts and cross brace joints are aligned and connected in sequence, and the web plates of the cross brace nodes, cross brace struts and cross brace joints are aligned and connected in sequence.

[0023] Furthermore, the cross bracing node includes a cross bracing node top plate, a cross bracing node bottom plate, a cross bracing node inner web plate, a cross bracing node outer web plate, and a cross bracing node arc-shaped decorative plate; the two sides below the cross bracing node top plate are connected to one side of the cross bracing node outer web plate, and the middle position is connected to one side of the cross bracing node inner web plate, and the cross bracing node bottom plate on the other side of the cross bracing node inner web plate and the cross bracing node outer web plate;

[0024] Furthermore, the cross brace support rod adopts a box-shaped cross-section design, and the cross brace support rod comprises a cross brace support rod top plate, a cross brace support rod bottom plate, a cross brace support rod web plate, a cross brace support rod stiffening rib, a cross brace support rod diaphragm and a cross brace support rod edging; the cross brace support rod top plate, the cross brace support rod bottom plate and the cross brace support rod web plates on both sides form a box-shaped cross-section structure, the cross brace support rod stiffening rib is connected to the inner wall of the box-shaped cross-section structure, the cross brace support rod diaphragm is transversely connected to the inner side of the box-shaped cross-section structure, a circular hole is opened in the center of the cross brace support rod diaphragm, and the cross brace support rod edging is connected to the outer side of the edge of the circular hole;

[0025] The top plate of the cross brace support rod is aligned and connected with the top plate of the cross brace node, the bottom plate of the cross brace support rod is aligned and connected with the bottom plate of the cross brace node, the web plate of the cross brace support rod located on the outside is aligned and connected with the outer web plate of the cross brace node in a circular arc shape, the web plate of the cross brace support rod located on the inside is aligned and connected with the inner web plate of the cross brace node in a circular arc shape, and the ends of the inner web plates of the two cross brace nodes away from the web plates of the cross brace support rod gradually approach and are arranged in a dovetail plate shape; the arc-shaped decorative plate of the cross brace node is arranged on the outside of the tail end of the dovetail plate shape of the inner web plates of the two cross brace nodes, and is connected between the inner web plates of the two cross brace nodes.

[0026] Furthermore, the cross brace joint comprises a cross brace joint top plate, a cross brace joint bottom plate, a cross brace joint web plate, a cross brace joint diaphragm plate, a cross brace joint edging, a cross brace joint arc-shaped decorative plate and a cross brace joint connecting plate; the cross brace joint top plate, the cross brace joint bottom plate and the cross brace joint web plates on both sides form a box-shaped structure, the cross brace joint diaphragm plate is laterally connected to the inner side of the box-shaped cross-section structure, a circular hole is opened in the center of the cross brace joint diaphragm plate, and the cross brace joint edging is connected to the edge of the circular hole;

[0027] The top plate and the bottom plate of the cross brace joint are both aligned with the longitudinal stiffening ribs; the web of the cross brace joint is bent in an arc form to be aligned with the annular cross partition; the outer side of the web of the cross brace joint is connected to one side of the arc-shaped decorative plate of the cross brace joint, and the other side of the arc-shaped decorative plate of the cross brace joint is connected to the cross brace joint connecting plate, and the cross brace joint connecting plate is connected to the longitudinal stiffening ribs.

[0028] Preferably, the sling anchor point comprises an ear plate, a post plate, an outer stiffening plate, an inner stiffening plate and an extension plate;

[0029] The ear plate is provided with a pasting plate at the pin shaft hole, and the ear plate is inserted into the circular steel pipe as a whole plate and is located between the longitudinal stiffening ribs; the longitudinal bridge of the ear plate is connected to the extension plate at both ends, the transverse bridge of the ear plate is provided with external stiffening plates on the outside of the circular steel pipe on both sides, and the transverse bridge of the ear plate is provided with internal stiffening plates on both sides inside the circular steel pipe.

[0030] On the other hand, the present invention provides a construction method for a large-diameter steel pipe arch suitable for a mesh hanger mid-through arch bridge, comprising the following steps:

[0031] S1. Determine the division position of the small segments of the overall large-diameter steel tube arch, and determine the division position of the hoisting segments of the overall large-diameter circular steel tube arch rib;

[0032] S2. Welding and preparing each small segment of the large diameter circular steel tube arch rib;

[0033] S3. Weld the corresponding sling anchor points and cross brace joints on the small segments of the large-diameter circular steel tube arch ribs to complete the processing and manufacturing of each small segment;

[0034] S4, welding several small segments along the arch axis curve line shape to form a hoisting segment of a circular steel tube arch rib for hoisting at the construction site;

[0035] S5. After all the hoisting segments of the circular steel tube arch ribs are manufactured, the arch ribs are pre-assembled and tested in the factory. After the tests are completed, the hoisting segments are transported to the construction site;

[0036] S6. After the construction of the arch seat and the arch hinge structure is completed, the large-diameter circular steel pipe arch ribs are installed using the inclined cable hanging system. After each lifting segment is completed, the cross bracing nodes and cross bracing rods are installed using the cable lifting system.

[0037] Preferably, S2 specifically includes:

[0038] The hot-rolled steel plate is rolled into a circular steel pipe, and longitudinal stiffening ribs are welded on the inner wall of the circular steel pipe; the circular steel pipe welded with the longitudinal stiffening ribs is placed vertically, and the annular diaphragm and the edging are cut into three pieces, which are respectively pushed vertically into the designated position by a crane and welded; each segment of the large-diameter circular steel pipe arch rib is prepared in sequence.

[0039] Preferably, the circular steel tube plate thickness is designed to be segmented thickening along the arch axis to meet the stress state of different parts of the main arch. The inner diameter of the circular steel tube of all arch rib segments remains unchanged, and the arch ring wall thickness is thickened by increasing the outer diameter.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) The large-diameter steel pipe arch in the present invention is composed of large-diameter circular steel pipe arch ribs, butterfly-shaped cross braces and cable anchor points. The large-diameter circular steel pipe arch ribs adopt an inward-inclined basket form in space and are the main load-bearing components of the mesh hanger mid-span arch bridge. The cross braces of the mesh hanger mid-span arch bridge are structurally found by the bidirectional progressive structural optimization method (BESO) to obtain butterfly-shaped cross braces. The four support rods of the butterfly cross brace are integrated and symmetrically arranged along the center line and mid-span of the bridge, connecting the two inward-inclined large-diameter circular steel pipe arch ribs. The butterfly cross brace not only increases the lateral stability of the mesh hanger mid-span arch bridge, but also ensures the landscape effect of the mesh hanger mid-span arch bridge with a light body. The cable anchor point is the main force transmission component, which transmits the cable force to the large-diameter circular steel pipe arch ribs through the cable anchor point. The large-diameter steel tube arch in the present invention can not only match the structural stress of the mesh hanger mid-span arch bridge, but also further enhance the transparent and light landscape attributes of the mesh hanger mid-span arch bridge, while enriching the arch rib structure of the large-span arch bridge; the large-diameter steel tube arch adopts an all-steel structure design, and is prefabricated and assembled in the factory and hoisted on site, which speeds up the construction progress and saves construction period. It has the characteristics of efficient force transmission, economical cost, safety and durability, landscape coordination, and convenient construction.

[0042] (2) The large-diameter circular steel tube arch ribs in the present invention are based on the characteristics of the circular cross-section with isotropic bending stiffness and good compression and torsion resistance, which can evenly transfer loads and improve the stability of the structure. Circular steel tubes are generally made of high-strength steel with high yield strength and tensile strength, and can withstand large internal forces. At the same time, the steel has good toughness and can absorb and dissipate energy under dynamic loads such as earthquakes, thereby improving the seismic performance of the structure. The main arch of the mesh hanger mid-span arch bridge is mainly under compression, and the values ​​of the in-plane and out-of-plane bending moments are comparable. Therefore, the circular cross-section can evenly distribute the arch rib pressure on the circular arch rib cross-section, effectively avoiding the stress concentration phenomenon. That is, under the same stress condition of the mesh hanger mid-span arch bridge, the use of circular steel tube arch ribs is the most economical and reasonable solution. At the same time, the circular steel tube arch ribs have excellent wind resistance, small later maintenance workload, simple shape, and good landscape effect. In order to ensure that the circular steel tube arch can achieve a large span on the mesh hanger half-through arch bridge, the present invention improves and upgrades the single small-diameter circular tube structure, and introduces the "design → factory manufacturing → on-site assembly" model to speed up the progress of engineering construction.

[0043] (3) In order to solve the problem of compression and buckling stability of large-diameter circular steel tube arch ribs, the present invention provides umbrella-shaped longitudinal stiffening ribs in the circular steel tube, and vertically arranges annular diaphragms and edging along the axis of the main arch rib; the annular diaphragms are divided into structural diaphragms and force-transmitting diaphragms according to their functions; the structural diaphragms are distributed between adjacent cable anchor points, and are mainly used to prevent the circular steel tube from being compressed and unstable and damaged; the force-transmitting diaphragms are distributed at the cable anchor points, and are mainly used to transfer the cable force to the circular steel tube arch rib through the cable anchor point structure and the force-transmitting diaphragms.

[0044] (4) In order to adapt to the stress state of different parts of the main arch rib, the present invention adopts a segmented thickening design for the large-diameter circular steel pipe along the arch axis. The inner diameter of the circular steel pipe of all arch rib segments remains unchanged, and the arch ring wall thickness is thickened by increasing the outer diameter. This is convenient for processing and manufacturing and can adapt to the stress requirements of different parts.

[0045] (5) The present invention provides an annular pressure plate at the end of the arch foot segment for transmitting force to the arch hinge structure, and provides a coarse aggregate ultra-high performance concrete CA-UHPC local transition section in the chamber surrounded by the annular pressure plate, the circular steel pipe, the longitudinal stiffening rib and the annular plate. Through this structure, the internal force of the arch rib is transmitted to the arch seat.

[0046] (6) The present invention provides a pin-ear type anchor connection structure for connecting the mesh hanger and the large-diameter circular steel tube arch rib at the bottom of the large-diameter circular steel tube arch rib. The ear plate serves as the main force transmission plate. It is inserted into the large-diameter circular steel tube as a whole plate and is distributed between the longitudinal stiffening ribs of the circular arch rib. Stiffening plates and force transmission extension plates are provided inside and outside the circular steel tube to ensure the force transmission, lateral stiffness and stability of the structure.

[0047] (7) The main arch of the mesh-suspended mid-span arch bridge is the main load-bearing structure, which is mainly under pressure. Therefore, the overall instability or local instability of the main arch rib is a key technical problem. The large-diameter circular steel tube arch rib of the present invention is provided with umbrella-shaped longitudinal stiffening ribs inside, and annular cross partitions and edgings are arranged vertically along the axis of the main arch rib to solve the problem of local instability; the main arch rib transmits the cross-mesh cable force to the main arch structure by setting cable anchor points, thereby ensuring the overall stability of the main arch surface; butterfly-shaped cross braces are used to connect the two main arch ribs, and an inward-inclined basket arch design is adopted to ensure the lateral stability of the main arch surface, thereby ensuring the safety of the structure during use.

[0048] (8) The large-diameter steel pipe arch in the present invention adopts the "design → factory manufacturing → on-site assembly" model. The large-diameter circular steel pipe is rolled into small segments in the factory using hot-rolled steel plates through a tube rolling process. The length of the small segment is generally within 4 meters. In the factory, many small segments are welded to each other along the curved line shape of the arch axis by "bending instead of bending" to form arch rib hoisting segments for assembly on the construction site; the construction site adopts a cable tower inclined buckle hanging system to carry out the erection of the large-diameter circular steel pipe arch rib segments, and a cable hoisting system is used to install the cross bracing nodes and cross bracing support rods. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a three-dimensional axial perspective view of a large-diameter steel pipe arch in the present invention;

[0050] Figure 2 It is the elevation layout diagram of the large diameter steel tube arch in the present invention;

[0051] Figure 3 It is a plan layout diagram of the large diameter steel pipe arch in the present invention;

[0052] Figure 4 is a cross-sectional view of a large diameter steel pipe arch in the present invention;

[0053] Figure 5 It is a three-dimensional axial perspective view of a large-diameter circular steel pipe arch rib in the present invention;

[0054] Figure 6 is a cross-sectional view of a large-diameter circular steel pipe arch rib in the present invention;

[0055] Figure 7 It is a elevational layout diagram of the arch foot segment of the large-diameter steel pipe arch in the present invention;

[0056] Figure 8 It is a three-dimensional axial perspective view of the arch foot segment of the large-diameter steel pipe arch in the present invention;

[0057] Fig. 9 It is a cross-sectional view of the arch foot segment of the large-diameter steel pipe arch in the present invention;

[0058] Fig.10 It is a plan view of the butterfly-shaped cross brace in the present invention;

[0059] Fig.11 is a cross-sectional view of the cross brace support rod in the present invention;

[0060] Fig.12 A three-dimensional axial perspective view of a cross bracing node in the present invention;

[0061] Fig.13 It is a plan view of the cross brace joint in the present invention;

[0062] Fig.14 is a cross-sectional view of a cross brace joint in the present invention;

[0063] Fig.15 A three-dimensional axial perspective view of a cross brace joint in the present invention;

[0064] Fig.16 It is a elevational layout diagram of the sling anchor points in the present invention;

[0065] Fig.17 It is a plan layout diagram of the sling anchor points in the present invention;

[0066] Fig.18 A three-dimensional axial perspective view of a sling anchor point in the present invention;

[0067] Fig.19 It is a schematic diagram of the processing, manufacturing and assembly steps of the large-diameter circular steel pipe arch rib in the present invention;

[0068] Fig. 20 It is a schematic diagram of the construction steps of the butterfly-shaped cross brace in the present invention;

[0069] Fig.21 It is a layout diagram of the large-diameter steel pipe arch rib "using folds instead of curves" to form an arch arc line in the present invention;

[0070] Fig. 22 It is the overall construction plan layout diagram of the large-diameter steel pipe arch in the present invention.

[0071] Markings in the figure:

[0072] 1. Large diameter circular steel pipe arch rib; 11. Circular steel pipe; 12. Longitudinal stiffening rib; 13. Annular diaphragm; 14. Edge; 15. Ring plate; 16. CA-UHPC transition section; 17. Shear studs; 18. Force transfer plate; 19. Annular pressure plate;

[0073] 2. Butterfly-shaped cross brace; 21. Cross brace node; 211. Cross brace node top plate; 212. Cross brace node bottom plate; 213. Cross brace node inner web plate; 214. Cross brace node outer web plate; 215. Cross brace node arc-shaped decorative plate; 22. Cross brace support rod; 221. Cross brace support rod top plate; 222. Cross brace support rod bottom plate; 223. Cross brace support rod web plate; 224. Cross brace support rod stiffening rib; 225. Cross brace support rod diaphragm; 226. Cross brace support rod edging; 23. Cross brace joint; 231. Cross brace joint top plate; 232. Cross brace joint bottom plate; 233. Cross brace joint web plate; 234. Cross brace joint diaphragm; 235. Cross brace joint edging; 236. Cross brace joint arc-shaped decorative plate; 237. Cross brace joint connecting plate;

[0074] 3. Cable anchor point; 31. Ear plate; 32. Plate; 33. External stiffening plate; 34. Internal stiffening plate; 35. Extension plate;

[0075] 4. Arch seat; 5. Arch hinge structure; 6. Inclined stay and buckle system; 7. Cable lifting system. DETAILED DESCRIPTION

[0076] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0077] Embodiment 1:

[0078] The large diameter steel pipe arch in the present invention is composed of three parts: a large diameter circular steel pipe arch rib 1, a butterfly cross brace 2 and a cable anchor point 3. The large diameter circular steel pipe arch rib 1 is the main force transmission component of the mesh hanger mid-through arch bridge. The butterfly cross brace 2 is used to connect two large diameter circular steel pipe arch ribs 1 to ensure that the entire arch rib system is synergistically stressed. The cable anchor point 3 is arranged at the bottom of the large diameter circular steel pipe arch rib 1 and is used to connect the mesh hanger system and transmit the force flow in the system from the mesh hanger to the large diameter circular steel pipe arch rib 1.

[0079] In this embodiment, the specific structure of the large diameter circular steel tube arch rib 1 is as follows:

[0080] The typical segment of the large diameter circular steel tube arch rib 1 is composed of a circular steel tube 11, longitudinal stiffening ribs 12, annular diaphragms 13 and edging 14. In order to adapt to the stress state of different parts of the main arch rib, the circular steel tube 11 can be designed with variable thickness. For the convenience of processing and manufacturing, the inner diameter remains unchanged, and the plate thickness is thickened by increasing the outer diameter. The longitudinal stiffening ribs 12 are plate ribs and are evenly arranged in an umbrella shape along the center of the circular steel tube 11. The annular diaphragm 13 and the edging 14 are arranged perpendicular to the center axis of the circular steel tube 11.

[0081] The large diameter circular steel tube arch rib 1 is provided with an annular pressure plate 19 for transmitting force to the arch hinge structure 5 at the end of the arch foot segment, and a CA-UHPC transition section 16 of a certain range is provided at the arch foot. CA-UHPC is distributed in a chamber surrounded by the longitudinal stiffening ribs 12, the circular steel tube 11, the annular pressure plate 19 and the ring plate 15, and shear studs 17 are evenly arranged along the inner wall of the chamber. A force transmission plate 18 is connected between the longitudinal stiffening ribs 12.

[0082] In this embodiment, the specific structure of the butterfly-shaped cross brace 2 is as follows:

[0083] The butterfly-shaped cross brace 2 consists of three parts: a cross brace node 21, a cross brace support rod 22 and a cross brace joint 23, and is symmetrically arranged along the center line of the bridge and the mid-span.

[0084] Specifically, the cross brace support rod 22 has a box-shaped cross section, and is composed of a cross brace support rod top plate 221 , a cross brace support rod bottom plate 222 , a cross brace support rod web plate 223 , a cross brace support rod stiffening rib 224 , a cross brace support rod cross partition 225 and a cross brace support rod edging 226 .

[0085] The four cross bracing rods 22 intersect and merge into one at the cross bracing node 21, the cross bracing rod top plate 221 is aligned and connected with the cross bracing node top plate 211, the cross bracing rod bottom plate 222 is aligned and connected with the cross bracing node bottom plate 212, the cross bracing rod webs 223 are connected in an arc shape on the outside through the cross bracing node outer web 214, the cross bracing node inner web 213 is disconnected in advance at the intersection and set into a dovetail plate shape, and a cross bracing node arc-shaped decorative plate 215 is set on the outside of the two dovetail plates.

[0086] Specifically, the cross brace joint 23 is a force transmission structure for connecting the cross brace support rod 22 with the circular steel pipe 11. The cross brace joint top plate 231 and the cross brace joint bottom plate 232 are aligned with the longitudinal stiffening rib 12 to ensure smooth force transmission; the cross brace joint web plate 233 is bent in an arc form and aligned with the annular cross diaphragm 13 to ensure smooth force transmission; to prevent the cross brace joint 23 structure from buckling and instability, an appropriate number of cross brace joint cross diaphragms 234 and cross brace joint edging are arranged inside it; to ensure the landscape effect, a cross brace joint arc decorative plate 236 is arranged on the outside. The cross brace joint 23 and the large-diameter circular steel pipe arch rib 1 are processed and manufactured synchronously in the factory.

[0087] In this embodiment, the specific structure of the sling anchor point 3 is as follows:

[0088] A sling anchor point 3 for connecting the mesh hanger and the large diameter circular steel tube arch rib 1 is set at the bottom of the large diameter circular steel tube arch rib 1. The sling anchor point 3 adopts a pin-ear connection and is composed of an ear plate 31, a plate 32, an outer stiffening plate 33, an inner stiffening plate 34 and an extension plate 35. The ear plate 31 is the main force transmission plate. It is inserted into the circular steel tube 11 as a whole plate and distributed between the longitudinal stiffening ribs 12. In order to ensure smooth force transmission in the local transverse bridge direction of the sling anchor point 3 and structural safety, an inner stiffening plate 34 is set in the circular steel tube 11, an outer stiffening plate 33 is set outside the circular steel tube 11, and an annular diaphragm 13 and a rim 14 for force transmission are set at the corresponding position of the sling anchor point 3. In order to ensure smooth force transmission in the longitudinal bridge direction and structural safety, an extension plate 35 is set at the corresponding position along the outer side of the annular diaphragm 13.

[0089] In the present invention, the circular steel pipe 11 is formed by rolling hot-rolled steel plates through a tube rolling process, and the small segments formed by the tube rolling process "replace bends with bends" to form an arch arc line; the construction site uses a cable buckle tower inclined buckle hanging system 6 to erect the large-diameter circular steel pipe arch rib 1 segment, and uses a cable hoisting system 7 to install the cross bracing node 21 and the cross bracing support rod 22; the specific detailed construction steps are as follows:

[0090] S1. Determine the location of the small segments based on the design drawings of the large-diameter steel pipe arch and the coiling capacity of the factory coiling equipment, and determine the location of the arch rib hoisting segments based on the capacity of the construction site hoisting equipment;

[0091] S2. The hot-rolled steel plate is rolled into a round steel tube 11 by using a tube rolling device, and a rounding correction process is performed to ensure the roundness accuracy of the round steel tube 11.

[0092] S3. Welding longitudinal stiffening ribs 12 in the circular steel pipe 11.

[0093] S4. Place the circular steel pipe 11 with welded longitudinal stiffening ribs 12 after step S3 vertically by crane, cut the annular diaphragm 13 and the edging 14 into three pieces, push them vertically into designated positions by crane respectively and perform welding operations.

[0094] S5, welding the sling anchor point 3 and the cross brace joint 23, and now the processing and manufacturing of the large-diameter circular steel pipe arch rib 1 small section is completed.

[0095] S6. Weld the numerous small segments along the arch axis curve to form a circular steel tube arch rib 1 hoisting segment for hoisting at the construction site; robot welding technology should be used for welding between small segments.

[0096] S7. After all the hoisting segments of circular steel tube arch rib 1 are manufactured, the arch rib pre-assembly and inspection will be carried out in the factory. After the inspection is completed, the hoisting segments will be transported to the construction site.

[0097] S8. After the construction of the arch seat 4 and the installation of the arch hinge structure 5 are completed, the large-diameter circular steel pipe arch rib 1 is installed using the inclined buckle hanging system 6. After each lifting segment is completed, the cable lifting system 7 should be used to install the cross bracing nodes 21 and the cross bracing support rods 22 in priority.

[0098] Embodiment 2:

[0099] This embodiment is a large-span reticular hanger mid-through arch bridge with a calculated span of 470m, a rise of 80m, a rise-span ratio of 1 / 5.875, an inclination angle of 9°, a quadratic parabola as the arch axis, and a double-hinged arch system.

[0100] The large-diameter steel pipe arch is composed of three parts: a large-diameter circular steel pipe arch rib 1, a butterfly-shaped cross brace 2 and a sling anchor point 3.

[0101] In this embodiment, the large-diameter circular steel pipe arch rib 1 is made of Q420D steel, and a typical segment is composed of a circular steel pipe 11 , a longitudinal stiffening rib 12 , an annular transverse diaphragm 13 and a rim 14 .

[0102] Specifically, the inner diameter of the circular steel pipe 11 is 3.4m, and is divided into three types: 36mm, 40mm, and 44mm according to the stress-bearing wall thickness of the main arch rib structure. To ensure the convenience of processing and manufacturing the annular diaphragm 13 in the circular steel pipe 11, the thickness change adopts the principle of "inner diameter remains unchanged and thickening outwards".

[0103] Specifically, the longitudinal stiffening plate 12 adopts plate ribs and is evenly arranged in an umbrella shape along the center of the circular arch rib. A total of 16 longitudinal stiffening ribs 12 are arranged. The angle formed between adjacent longitudinal stiffening ribs 12 and the center of the circular steel pipe is 22.5°. The longitudinal stiffening ribs 12 are divided into two types of 36×360mm and 40×400mm along the arch axis. The cross partition 13 and the edging 14 are arranged perpendicular to the axis of the circular arch rib.

[0104] In this embodiment, the large-diameter circular steel tube arch rib 1 is provided with an annular pressure plate 19 for transmitting force to the arch hinge structure 5 at the end of the arch foot segment, with an inner and outer diameters of 2.58m and 3.78m respectively, and a plate thickness of 60mm; in order to ensure that the load of the thin-walled arch rib is transmitted to the pressure surface of the annular arch hinge structure, a 3m long CA-UHPC transition section 16 is provided at the arch foot, and an annular plate is welded between two adjacent longitudinal stiffening ribs 12 to form a chamber with the longitudinal stiffening ribs 12, the circular steel tube 11 and the annular pressure plate 19, and shear nails 17 are evenly arranged on the inner wall of the chamber to achieve uniform force transmission, and CA-UHPC is cast in the chamber and steam cured.

[0105] In this embodiment, the butterfly-shaped cross brace 2 is made of Q420D steel and consists of three parts: a cross brace node 21, a cross brace support rod 22 and a cross brace joint 23. A total of 16 butterfly-shaped cross braces 2 are arranged on the entire bridge (6 butterfly-shaped cross braces 2 below the bridge deck and 10 butterfly-shaped cross braces 2 above the bridge deck), and are arranged symmetrically along the center line of the bridge and the mid-span.

[0106] Specifically, the cross brace support rod 22 adopts a rectangular box-shaped cross section, and is composed of a cross brace support rod top plate 221, a cross brace support rod bottom plate 222, a cross brace support rod web 223, a cross brace support rod stiffening rib 224, a cross brace support rod cross partition 225 and a cross brace support rod edging 226; the cross brace support rod top plate 221, the cross brace support rod bottom plate 222 and the cross brace support rod web 223 are set to three plate thicknesses of 16mm, 20mm and 24mm according to the force.

[0107] Specifically, the four cross bracing rods 22 intersect and merge into one at the cross bracing node 21; the cross bracing rod top plate 221 is aligned and connected with the cross bracing node top plate 211, the cross bracing rod bottom plate 222 is aligned and connected with the cross bracing node bottom plate 212, the cross bracing rod webs 223 are connected in an arc shape on the outside through the cross bracing node outer web 214, the cross bracing node inner web 213 is disconnected in advance at the intersection and set into a dovetail plate shape, and a cross bracing node arc-shaped decorative plate 215 is set on the outside of the two dovetail plates.

[0108] Specifically, the cross brace joint 23 is connected to the large-diameter circular steel pipe arch rib 1 and is simultaneously processed and manufactured in the factory; to ensure smooth force transmission, the cross brace joint top plate 231 and the cross brace joint bottom plate 232 are aligned with the longitudinal stiffening rib 12, and the cross brace joint web 233 is bent in an arc form and aligned with the annular cross diaphragm 13; to prevent the cross brace joint 23 from structural compression and instability, an appropriate amount of cross brace joint cross diaphragms 234 and cross brace joint edging are arranged inside it; to ensure the landscape effect, a cross brace joint arc-shaped decorative panel 236 is arranged on the outside.

[0109] In this embodiment, a sling anchor point 3 for connecting the mesh hanger and the large diameter circular steel tube arch rib 1 is set at the bottom of the large diameter circular steel tube arch rib 1. The sling anchor point 3 adopts a pin-ear type connection, and is composed of an ear plate 31, a plate 32, an outer stiffening plate 33, an inner stiffening plate 34 and an extension plate 35. There are Z-direction performance requirements at the sling anchor point 3, and Q420qE-Z35 steel is used.

[0110] Specifically, the ear plate 31 serves as the main force-transmitting plate of the sling anchor point 3. A whole plate is inserted into the circular steel tube 11 and distributed between the longitudinal stiffening ribs 12. Two inner stiffening plates 34 are arranged inside the circular steel tube 11, and two outer stiffening plates 33 are arranged outside the circular steel tube to ensure the lateral rigidity and stability of the sling anchor point 3. An annular diaphragm 13 and a rim 14 are arranged inside the circular steel tube 11 at the sling anchor point 3. To ensure that the stress at the anchor point is further diffused in the longitudinal direction, an extension plate 35 is arranged at the corresponding position of the ear plate along the outer side of the annular diaphragm.

[0111] In this embodiment, the specific detailed construction steps of the large diameter steel pipe arch are as follows:

[0112] S1. The location of the small segments is determined based on the design drawings of the large-diameter steel tube arch and the rolling capacity of the factory's tube rolling equipment. In this embodiment, the length of the small segment is controlled within 4m, and the segmentation position of the small segment should avoid the positions of the annular diaphragm 13, the cross brace joint 23 and the cable anchor point 3. The whole bridge is divided into 160 small segments in total. According to the capacity of the lifting equipment on the construction site and the transportation conditions, the large-diameter circular steel tube arch rib 1 segment is divided to control the maximum segment lifting weight to 200t, and the segment length is controlled to be 30m, with a total of 19 lifting segments.

[0113] S2. The hot-rolled steel plate is rolled into a round steel tube 11 by using a tube rolling device. A rounding correction process is performed to ensure the roundness of the round steel tube 11. The out-of-roundness of the round steel tube port (the difference between the horizontal inner diameter and the vertical inner diameter of the round steel tube) should be controlled within 2 mm.

[0114] S3. Welding longitudinal stiffening ribs 12 in the circular steel pipe 11.

[0115] S4. Place the circular steel pipe 11 with the welded longitudinal stiffening ribs 12 after step S3 vertically by a crane, cut the annular diaphragm 13 and the edging 14 into three pieces, and push them vertically into designated positions by a crane for welding.

[0116] S5. On the basis of step S4, continue welding the sling anchor point 3 or the cross brace joint 23. At this point, the processing and manufacturing of the large-diameter steel pipe arch rib small segment is completed.

[0117] S6. Weld the numerous small segments along the curved line of the arch axis to form circular arch rib hoisting segments for hoisting at the construction site. Robot welding technology should be used for welding between small segments. When welding between small segments, the misalignment of the segment end annular seam should be controlled within 1mm.

[0118] S7. After all the arch rib hoisting segments are manufactured, the arch rib pre-assembly and inspection will be carried out in the factory. The pre-assembly adopts the "3+1" segment pre-assembly method. The allowable deviation of the total pre-assembly length should be controlled within 10mm, and the deviation of the arch rib assembly axis from the designed arch axis should be controlled within 5mm. After the inspection, the hoisting segments will be transported to the construction site.

[0119] S8. The arch seat 4 adopts open excavation to expand the foundation, and the arch hinge structure 5 adopts an ultra-large tonnage arch hinge structure with an axial bearing capacity of 160MN and the same service life as the main structure of the bridge; during construction, the arch seat 4 is constructed first, and then the cable-stayed buckle tower system 6 and the cable lifting system 7 are constructed. In this embodiment, the cable-stayed buckle tower is directly based on the arch seat to save engineering cost; after the arch hinge structure 5 is installed, the cable-stayed buckle tower system 6 is used to install the large-diameter steel pipe arch rib 1. After each lifting segment is completed, the corresponding butterfly cross brace 2 should be installed first to connect the two arch rib segments and the butterfly cross brace 2 as a whole to ensure safety and stability during construction, and this process is repeated until the large-diameter steel pipe arch is closed.

[0120] This embodiment compares the structural performance and engineering cost of a large-diameter steel tube arch of a lattice hanger half-through arch bridge and a conventional half-through truss steel tube concrete arch.

[0121] a) Structural performance comparison is as follows:

[0122] Table 1 Comparison of structural performance of large diameter steel tube arch and trussed steel tube concrete arch

[0123]

[0124] From the analysis of Table 1, it can be seen that the mesh hanger mid-through arch bridge using large-diameter steel tube arch ribs not only has good engineering economy, but also has better mechanical parameter indicators. Under the basic combination, the ratio of the main arch rib axial force value is only 151198 / 251768=60.1%; under the action of automobile load, the deflection ratio of the main span is 94.5 / 195=48.5%; the structural dynamic characteristics ratio is 0.315 / 0.174=181%, that is, the mesh hanger mid-through arch bridge with large-diameter steel tube arch ribs has a slender and light structure, but the structural stiffness of the system is greater, and its stiffness is basically twice that of the mid-through truss steel tube concrete arch; in terms of buckling stability, the first-order instability coefficient ratio is 8.82 / 4.46=197.8%, that is, the anti-buckling stability is better.

[0125] b) The project cost comparison is as follows:

[0126] The total steel consumption of the large-diameter steel pipe arch of the lattice hanger mid-through arch bridge is 6810t, and the external coating area is 10820m 2 The total steel consumption of the main arch rib of the half-through steel tube concrete arch bridge with the same span (calculated span 470m, rise 104.44m, rise-span ratio 1 / 4.5, catenary arch axis, truss section main arch rib) is 6150t, and the filling of C60 concrete is 6378m 3 , external coating area 51200m 2 .

[0127] According to the engineering cost calculation: the construction cost of large diameter steel tube arch is 1.6×6810=108.96 million yuan (comprehensive unit price of steel structure is 16,000 yuan / t), the construction cost of trussed steel tube concrete arch is 1.6×6150+0.1×6378=104.78 million yuan (comprehensive unit price of steel structure is 16,000 yuan / t, comprehensive unit price of filling concrete is 1,000 yuan / m 3 ), it can be seen that the construction cost of large-diameter steel tube arch is basically the same as that of truss steel tube concrete arch; however, large-diameter steel tube arch adopts prefabricated assembly technology, which saves the process of pouring and filling concrete for truss steel tube concrete arch, which can greatly shorten the construction period and reduce the cost of construction measures. In addition, the coating area of ​​large-diameter steel tube arch is 10820m 2 The coating area of ​​the trussed steel tube concrete arch is 51200m 2 Much smaller, (51200-10820)×0.01×4=16.15 million yuan (coating cost 100 yuan / m 2 , repainted 4 times during the whole life cycle), the large-diameter steel pipe arch can greatly save the maintenance work and costs during the operation period. Therefore, the large-diameter steel pipe arch not only has better mechanical parameter indicators, but also has better engineering economy. It has the characteristics of "efficient force transmission, economical cost, safety and durability, landscape coordination, and convenient construction".

[0128] The above description is only used to help understand the method of the present invention and its core essence, but the protection scope of the present invention is not limited thereto. For those skilled in the art in the art, equivalent replacement or change according to the technical solution and inventive concept of the present invention within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A large diameter steel pipe arch suitable for a mesh hanger half-through arch bridge, characterized in that: It comprises a large-diameter circular steel pipe arch rib (1), a butterfly-shaped cross brace (2) and a sling anchor point (3); The large-diameter circular steel tube arch ribs (1) are provided with two, and are in the shape of an inwardly inclined basket; the large-diameter circular steel tube arch ribs (1) include a circular steel tube (11), longitudinal stiffening ribs (12), an annular diaphragm (13) and a rim (14); the longitudinal stiffening ribs (12) are plate ribs, and are evenly arranged in an umbrella shape along the inner wall of the circular steel tube (11); the annular diaphragm (13) is arranged perpendicular to the inner wall of the circular steel tube (11), and the rim (14) is connected to the inner edge of the annular diaphragm (13); The butterfly-shaped cross braces (2) are arranged in plurality between two large-diameter circular steel tube arch ribs (1), symmetrically distributed along the center line of the bridge, and are used to connect the two large-diameter circular steel tube arch ribs (1); The sling anchor point (3) is installed at the bottom of the large-diameter circular steel pipe arch rib (1) and is used to connect the mesh sling system.

2. The large diameter steel pipe arch according to claim 1, characterized in that: The end of the arch foot segment of the large-diameter circular steel tube arch rib (1) is connected to an annular pressure plate (19) for transmitting the force of the arch hinge structure (5); and an annular plate (15) is provided inside the circular steel tube (11) of the arch foot segment, and the annular plate (15) is connected to the longitudinal stiffening rib (12) at a side away from the inner wall of the circular steel tube (11). CA-UHPC is poured into a chamber surrounded by the longitudinal stiffening rib (12), the circular steel tube (11), the annular pressure plate (19) and the annular plate (15) to form a CA-UHPC transition section (16), and shear nails (17) are evenly arranged on the inner wall of the chamber.

3. The large diameter steel pipe arch according to claim 2, characterized in that: The annular diaphragm (13) comprises a structural diaphragm and a force transmission diaphragm, wherein the structural diaphragm is arranged between adjacent sling anchor points (3), and the force transmission diaphragm is arranged at the sling anchor point (3).

4. The large diameter steel pipe arch according to claim 3, characterized in that: The butterfly-shaped cross brace (2) is composed of a cross brace node (21), a cross brace support rod (22) and a cross brace joint (23). There are four cross brace support rods (22). One end of all the cross brace support rods (22) intersects and merges at the cross brace node (21), and the other end is connected to the large-diameter circular steel pipe arch rib (1) through the cross brace joint (23).

5. The large diameter steel pipe arch according to claim 4, characterized in that: The cross brace nodes (21), cross brace struts (22) and cross brace joints (23) all include a top plate, a bottom plate, a web plate, a cross diaphragm and a rim; The top plate, the bottom plate and the web plates on both sides form a box-shaped structure, the transverse partition is transversely arranged inside the box-shaped structure, a circular hole is arranged at the center of the transverse partition, and the edges of the circular hole are connected with the edging; the top plate, the bottom plate and the web plates of the transverse bracing node (21), the transverse bracing support rod (22) and the transverse bracing joint (23) correspond to each other and are connected in sequence.

6. The large diameter steel pipe arch according to claim 5, characterized in that: The cross brace joint (23) comprises a cross brace joint top plate (231), a cross brace joint bottom plate (232), a cross brace joint web plate (233), a cross brace joint arc-shaped decorative plate (236) and a cross brace joint connecting plate (237); the cross brace joint top plate (231), the cross brace joint bottom plate (232) and the cross brace joint web plates (233) on both sides form a box-shaped structure; The cross brace joint top plate (231) and the cross brace joint bottom plate (232) are both aligned with the longitudinal stiffening rib (12), and the cross brace joint web plate (233) is aligned with the annular cross partition (13) by bending in an arc form; the outer side of the cross brace joint web plate (233) is connected to one side of the cross brace joint arc decorative plate (236), and the other side of the cross brace joint arc decorative plate (236) is connected to the cross brace joint connecting plate (237), and the cross brace joint connecting plate (237) is connected to the longitudinal stiffening rib (12).

7. The large diameter steel pipe arch according to claim 6, characterized in that: The sling anchor point (3) comprises an ear plate (31), a mounting plate (32), an outer stiffening plate (33), an inner stiffening plate (34) and an extension plate (35); The ear plate (31) is provided with a pasting plate (32) at the pin shaft hole. The ear plate (31) is inserted into the circular steel pipe (11) as a whole plate and is located between the longitudinal stiffening ribs (12). The longitudinal bridge of the ear plate (31) is connected to the extension plate (35) at both ends. The transverse bridge of the ear plate (31) is provided with an outer stiffening plate (33) on both sides outside the circular steel pipe (11). The transverse bridge of the ear plate (31) is provided with an inner stiffening plate (34) on both sides inside the circular steel pipe (11).

8. The construction method of a large diameter steel pipe arch according to any one of claims 4 to 7, characterized in that: The following steps are involved: S1, determining the division positions of the small segments of the overall large-diameter steel tube arch, and determining the division positions of the hoisting segments of the overall large-diameter circular steel tube arch rib (1); S2, welding and preparing each small segment of the large-diameter circular steel tube arch rib (1); S3, correspondingly welding the sling anchor points (3) and the cross brace joints (23) on the small sections of the large-diameter circular steel tube arch rib (1), and completing the processing and manufacturing of each small section; S4, welding a plurality of small segments along the arch axis curve line shape to form a hoisting segment of a circular steel tube arch rib (1) for hoisting at the construction site; S5. After all the hoisting segments of the circular steel tube arch ribs (1) are manufactured, the arch ribs are pre-assembled and tested in the factory. After the tests are completed, the hoisting segments are transported to the construction site; S6. After the construction of the arch seat (4) and the installation of the arch hinge structure (5) are completed, the large-diameter circular steel pipe arch rib (1) is installed using the inclined hanging system (6). After each lifting segment is completed, the cross bracing node (21) and the cross bracing support rod (22) are installed using the cable lifting system (7).

9. The construction method of a large-diameter steel pipe arch according to claim 8, characterized in that: The S2 specifically comprises: The hot-rolled steel plate is rolled into a circular steel pipe (11), and a longitudinal stiffening rib (12) is welded to the inner wall of the circular steel pipe (11); the circular steel pipe (11) welded with the longitudinal stiffening rib (12) is placed vertically, and the annular cross partition (12) and the edging (14) are cut into three pieces, which are respectively pushed vertically into designated positions by a crane and welded; and each small segment of the large-diameter circular steel pipe arch rib (1) is prepared in sequence.

10. The construction method of a large diameter steel pipe arch according to claim 9, characterized in that: The thickness of the circular steel pipe (11) is designed to be thickened in sections along the arch axis to meet the stress conditions of different parts of the main arch. The inner diameters of the circular steel pipes (11) of all arch rib segments remain unchanged, and the arch rib wall thickness is thickened by increasing the outer diameter.

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