Space special-shaped steel box girder jig frame and assembling process applying jig frame

Abstract

The invention discloses a space special-shaped steel box girder jig frame and an assembling technology applying the jig frame, and particularly relates to the technical field of steel box girder construction.The space special-shaped steel box girder jig frame is characterized in that middle arch feet are installed at the bottoms of two sets of goose towers, main arch ribs are installed on the two sides of the two sets of middle arch feet, and the overall structure of each main arch rib is in a herringbone shape; auxiliary arch ribs are arranged on the inner sides of the herringbone structures of the main arch ribs respectively, each auxiliary arch rib is specifically composed of an inclined rod and a curved rod, side arch feet are installed at the herringbone tail ends of the main arch ribs respectively, arch rib supports are sequentially arranged below the main arch ribs along radian stress points, and steel box girders are arranged below the arch rib supports 5. The projection on the plane is a cubic parabola, so that the bridge body shows a unique visual effect at different visual angles, an engineering structure and artistic aesthetics are perfectly combined to become an urban landmark building, and the landscape value and cultural connotation of a region are improved.

Description

Technical Field

[0001] The present application relates to the technical field, and more specifically, to a spatial special-shaped steel box girder cradle and an assembly process using the cradle. Background Art

[0002] When the main span of a large municipal bridge crosses a river navigable channel, a large floating crane + steel pipe pier method is usually used to erect steel box girder segments one by one. Several large temporary piers are set between two adjacent concrete piers to form multiple navigation holes. The "inverted hole method" is used to set up temporary small piers between adjacent temporary piers. Small temporary piers are only installed on one navigation hole at a time. The pre-fabricated steel box girder segments are hoisted to the temporary piers by a large floating crane, and the head and tail ends of the steel box girder segments are respectively abutted on the adjacent temporary piers to complete the erection of the steel box girder segments above the navigation hole. After that, the small temporary piers on the navigation hole are removed to restore normal navigation of the navigation hole. The piers are used inverted to the next navigation hole, and the same steps are used to complete the erection of steel box girder segments at subsequent navigation holes. The existing publication number: CN112523111A, discloses; Steel box girder hoisting and splicing process, the key points of its technical solution include the following steps: Step 1, preparatory work before installation; Step 2, selection of hoisting equipment; Step 3, on-site assembly of steel box girder; Step 4, hoisting and hoisting process; Step 5, adjustment of the position of steel box girder; Step 6, on-site welding of steel box girder segments; Step 7, unloading of temporary supports. It has the effect of reducing the deviation of steel box girder from the predetermined position and improving the quality of the project. In the process of realizing this application, the inventor found that the existing technology has the following problems: Among them, a large floating crane + steel pipe pier method is used to erect steel box girder segments one by one, and several large temporary piers are set between two adjacent concrete piers to form multiple navigation holes. The "inverted hole method" is used to set up temporary small piers between adjacent temporary piers. The traditional construction method requires repeated insertion and removal of the steel pipe piles of the temporary piers when erecting the steel box girder segments above the navigation holes. The construction period is long, the cost investment is large, and the construction progress is seriously affected.

[0003] Therefore, in order to solve the above problems, a spatial special-shaped steel box girder cradle and an assembly process using the cradle are proposed. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present application provides a spatial special-shaped steel box girder cradle and an assembly process using the cradle to solve the problems raised in the above-mentioned background technology.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions: a spatial special-shaped steel box girder frame, including goose towers, two groups of goose towers are installed with middle arch feet at the bottom, and main arch ribs are installed on both sides of the two groups of middle arch feet. The overall structure of the main arch ribs is in a herringbone shape, and auxiliary arch ribs are respectively arranged on the inner side of the herringbone structure of the main arch ribs. The auxiliary arch ribs are specifically composed of oblique rods and curved rods. Side arch feet are respectively installed at the herringbone ends of the main arch ribs. Arch rib supports are arranged in sequence along the arc stress points below the main arch ribs. A steel box girder is arranged below the arch rib support 5, and the steel box girder is arranged in sequence below the steel box girder. The lower part of the ZP1 pier, the lower part of the ZP2 pier, the lower part of the ZP3 pier, the lower part of the ZP4 pier and the lower part of the ZP5 pier are provided. A second steel box beam frame is provided in the gap between the lower part of the ZP1 pier, the lower part of the ZP2 pier and the lower part of the ZP3 pier. Two groups of navigation hole steel beams are provided between the lower part of the ZP3 pier and the lower part of the ZP4 pier. A first steel box beam frame is provided between the lower part of the ZP4 pier and the lower part of the ZP5 pier, and the top ends of the navigation hole steel beam, the first steel box beam frame and the second steel box beam frame are fixedly connected to the steel box beam, and navigation hole 1, navigation hole 2 and navigation hole 3 are arranged in sequence between the two groups of navigation hole steel beams.

[0006] Preferably, the assembling process of the spatial special-shaped steel box girder frame comprises the following steps: S1. Define the overall construction plan, determine the steel beam segmentation method and technical parameters, complete riverbed dredging, make cargo supply planning and transportation plan design, select suitable transport vessels and make sailing preparations, and select and arrange rigging equipment; S2. Steel box girder installation: Assemble the temporary building structure, install the steel box girder in sequence, and implement positioning and adjustment measures, including positioning and adjustment of the first steel box girder frame, the second steel box girder frame and the navigation channel steel beam; S3. Installation of main arch ribs, secondary arch ribs, and goose towers: Install the main and secondary arch ribs and goose towers in sequence, and implement the positioning and adjustment plan; S4, closure construction: Carry out the closure construction technology of the goose tower and the main and secondary arch ribs respectively, and complete the closure of key parts; S5. Support treatment: dismantle the navigation channel steel beam, the first steel box beam frame, the second steel box beam frame and the arch rib support, and deal with the support settlement problem; S6. Pole and Transportation Management: Re-inspect incoming poles and handle defects, ensuring safety in all aspects of steel box girder transportation, including on-site ship positioning and implementation of transportation safety measures; S7. Welding operation: Implement on-site welding of steel box girders, including welding process operation at the installation site, as well as weld inspection and non-destructive testing; S8. Painting acceptance: Carry out on-site painting process for steel box girders, conduct anti-corrosion painting construction, control and inspection, and complete construction acceptance.

[0007] Preferably, in step S1, an expert discussion is organized to formulate an overall construction plan based on the actual project and geological conditions, and to clarify the construction sequence, resource allocation and schedule. According to the steel beam structure, the steel box beam, main and secondary arch ribs and goose tower are divided into sections, the size, weight and connection method of each section are determined, the technical parameters are calculated and clarified, and the riverbed is comprehensively dredged by combining mechanical dredging with manual cleaning to ensure that the dredging depth and range meet the design requirements. The cleaned silt is transported to the designated dumping site in accordance with regulations, and then the cargo supply batch, time and quality standards are determined with the supplier. Multiple sets of steel beam transportation plans are designed and compared, and suitable transport ships are selected based on the size, weight and transportation route of the steel beams, and sufficient lifting equipment is equipped. A detailed investigation of the meteorological and hydrological conditions at the construction site is conducted, a navigation plan is formulated, and ship communication and navigation equipment debugging and material supply work are carried out. According to the weight, installation height and lifting environment of each part of the steel box beam, mechanical calculation and simulation analysis are performed to accurately select the lifting rigging, determine the wire rope specifications, shackle model and pulley block configuration, and conduct strict quality inspection and load testing.

[0008] Preferably, in step S2, the water support of the steel box beam is inserted and the structure construction of the lower part of the ZP1 pier to the lower part of the ZP5 pier is carried out, and the riverbed on the upstream side of the lower part of the ZP4 pier to the lower part of the ZP5 pier is dredged; the lower part of the ZP1 pier to the lower part of the ZP5 pier is installed; the steel box beam, the main and secondary arch ribs and the goose tower are processed in the steel structure processing plant at the same time; the pier top steel beam of the lower part of the ZP3 pier is hoisted by a 660t floating crane, and the permanent support is installed as the reference installation section; the ZP The steel box girder in the area between the lower part of Pier 1 and the lower part of Pier ZP3, and all the steel beams on the small mileage side of Navigation Slot 1; Use a 660t floating crane to install the steel beam at Navigation Slot 1, and use Navigation Slots 2 and 3 as temporary passages for ships on the Dongjiang waterway; Install the steel beam at Navigation Slot 2, and use Navigation Slots 1 and 3 as temporary passages for ships on the Dongjiang waterway; Install the steel beam at Navigation Slot 3, and use Navigation Slots 1 and 2 as temporary passages for ships on the Dongjiang waterway; Use a 660t floating crane to install the steel box girder in the area between the lower part of Pier ZP4 and the lower part of Pier ZP5.

[0009] Preferably, in step S3, the single row of column pads and pads on the right side of the navigation channel 3 are removed so that they do not participate in the later stress; the arch rib bracket is installed by using a 660t floating crane; the lower structure of the goose tower and the arch ribs at the middle arch foot are installed by using a 660t floating crane; the goose tower tension structure is installed, and the line shape of the joint mouth is adjusted; the goose tower joint section is installed; the 660t floating crane is used to install it section by section from the arch feet on both sides to the joint mouth; the joint section is installed; the arch rib axis, elevation and verticality of the goose tower are measured using a total station and a GPS measuring instrument, and the temporary support height and the cable guy rope tension are adjusted in time during the construction stage to control the installation error within the design allowable range; after the adjustment is completed, the segmented interfaces of the main and secondary arch ribs and the goose tower are welded or bolted, and the welding process parameters are strictly controlled during welding; the bolt connections are pre-tightened as required by the specifications and quality inspections are carried out.

[0010] Preferably, in step S4, a period of stable temperature is selected for joint closure, the joint section is temporarily fixed at one end, and after the other end is adjusted into place, bolt connection is performed; during the joint closure process, structural deformation and stress changes are monitored in real time, and before installing the joint section, the ends of the arch ribs on both sides are polished to ensure that the interface is flat; after the joint closure, the arch rib line shape is monitored, and the bracket force is adjusted according to the monitored changes.

[0011] Preferably, in step S5, the support is inspected and the ancillary facilities are dismantled; and the dismantling sequence and safety measures are formulated, and technical instructions are given to the operating personnel. The construction method of supporting first and then dismantling, or dismantling last, is carried out in sequence according to the construction sequence. The support is gradually dismantled by coordination between machinery and manpower, and a dedicated person is assigned to monitor and confirm the construction process. The dismantled materials are taken away by a floating crane, and are sorted and stacked by a dedicated person, and cleared out of the site in a timely manner. Before the support is erected, the foundation is compacted and a cushion layer is laid. During the construction process, the settlement of the support is monitored regularly. If abnormal settlement is found, the cause is analyzed in a timely manner, and the height of the support is adjusted in a timely manner.

[0012] Preferably, in step S6, the steel beam members are processed and manufactured in the factory and undergo a trial assembly. After passing the inspection, they are transported to the construction site. After arrival at the site, the technical data and the actual objects are checked against the design documents, registered and signed by the supervisor. If any distortion or cracks are found, they must be repaired by the manufacturer. Minor local deformation can be adjusted by hammering with a backing plate or cold working with a jack with the supervisor's approval. Severely damaged parts must be returned to the factory for processing. Burrs and welding spatter on the assembly area must be cleaned and removed and polished smooth. Paint damage caused by transportation and loading and unloading must be repainted according to the original factory standards. If rust spots or large-scale peeling problems occur, they must be reported to the supervisor and the manufacturer for processing.

[0013] Preferably, in step S7, after welding is completed, a dedicated person cleans the welding area to remove oil and rust; selects appropriate welding materials and process parameters according to the material of the steel beam, the thickness of the plate and the welding position; conducts skill training and assessment for welders, and they are certified to work, and weld in strict accordance with the sequence and method determined by the welding process assessment, adopts multi-layer and multi-pass welding, and controls the temperature between layers; strengthens quality inspections during the welding process, and corrects welding defects in a timely manner. The appearance inspection of the weld should be smooth, free of pores and slag inclusions; adopts ultrasonic testing and radiographic testing non-destructive testing methods, and inspects the welds according to the proportion required by the design, and repairs and re-inspects unqualified welds in a timely manner.

[0014] Preferably, in step S8, the steel beam surface is sandblasted for rust removal to meet the specified cleanliness and roughness standards; the coating system is sprayed in layers according to the design requirements, including primer, intermediate paint and topcoat, and the thickness and interval time of each layer of coating are controlled; during the coating process, the ambient temperature and humidity are kept appropriate, and construction is avoided on rainy or windy days. The coating thickness, adhesion and appearance quality are regularly tested, and construction records are kept; coating defects are repaired in a timely manner to ensure the anti-corrosion effect. After the coating is completed, the relevant units are organized to conduct acceptance, and the construction materials are submitted. The problems raised in the acceptance are rectified and improved, and the equipment is put into use after passing the inspection.

[0015] The technical effects and advantages of this application are: 1. Compared with the existing technology, the structural design of the spatial special-shaped steel box girder cradle and the assembly process using the cradle is very innovative. The main arch ribs use four symmetrical spatial oblique span arch ribs, and the auxiliary arch ribs are spatial curved arch ribs. The main and auxiliary arches both use octagonal cross-sections. This geometric design enables the structure to evenly distribute the load when subjected to stress. The main arch section has a variable height and a constant width. The key stress-bearing parts such as the side arch feet of the middle support and the side arch feet of the side support are heightened. At about 1 / 4 of the arch span, the main arch is octagonal. The cross-section height is 3.5m, the side arch foot is raised to 5m at the middle support, and to 6m at the side support. The gradual design can better adapt to the stress changes in different parts, ensuring that the structure maintains good mechanical properties when subjected to vehicle loads and wind loads. At the same time, the angle between the diagonal rod and the road centerline is 53°, and the spacing between the diagonal rods varies from 5.7 to 9.0m. By welding decorative curved plates on the outside of the diagonal rods to create a feather shape, it not only achieves structural function but also adds artistic beauty. In addition, the axis of the secondary arch is a spatial curve. The projection on the facade coincides with the axis of the main arch, and the projection on the plane is a cubic parabola, which makes the bridge body show a unique visual effect from different perspectives. It perfectly combines engineering structure with artistic aesthetics, becoming a city landmark building and enhancing the landscape value and cultural connotation of the region.

[0016] 2. Compared with the existing technology, the space special-shaped steel box girder cradle and the assembly process of the cradle adopt scientific and reasonable construction planning to ensure the efficient and safe progress of the project. During the construction plan formulation stage, experts are organized to discuss and formulate an overall construction plan based on the actual project and geological conditions, clarify the construction sequence, resource allocation and schedule, divide each component into sections according to the steel beam structure, determine detailed technical parameters, and provide precise guidance for construction. During the installation of the steel box girder, the "large segment, multiple blocks" method is adopted. The hoisting method uses a 660t deck detachable floating crane to carry out the operation. At the same time, the steel box girder at the navigation hole is manufactured and installed in large longitudinal sections and multiple transverse blocks. The navigation needs of the river and the structural characteristics of the steel box girder are fully considered to ensure both the construction progress and the normal navigation of the river. At the same time, in terms of construction safety management, strict safety measures are taken in each link. When dismantling the support, the principle of "support first and then dismantle, and then dismantle the last support first" is followed, and the coordination of machinery and manual work is adopted. Special personnel supervise and formulate detailed dismantling sequence and safety measures. During the transportation of steel beams, the incoming rods are re-inspected and defects are handled to ensure safety in all links of transportation, including on-site ship positioning and the implementation of transportation safety measures. In addition, the structural deformation, stress, and support settlement are monitored in real time during the construction process. For example, the structural deformation and stress changes are monitored in real time during the joint closure process, the foundation is compacted and a cushion layer is laid before the support is erected, and the support settlement is monitored regularly during the construction process. When problems are found, timely adjustments are made, which effectively ensures the safety and stability of the construction process, avoids the occurrence of safety accidents, and guarantees the quality of the project, ensuring that the project can be completed on time and with high quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall front view structure of this application; Figure 2 This is a schematic diagram of the structure of the Goose Pagoda from above; Figure 3 This is a schematic diagram of the top view of the lower part of the ZP1 pier of this application; Figure 4 This is a schematic diagram of the front structure of the lower part of the ZP2 pier of this application; Figure 5 This is a schematic diagram of the top structure of the second steel box girder frame of the present application; Figure 6 This is a side structural diagram of the steel box girder of this application; Figure 7 This is a left-side structural schematic diagram of the arch rib support of this application; Figure 8 This is a right side structural schematic diagram of the arch rib support of this application.

[0018] The accompanying drawings are marked as follows: 1. Goose tower; 2. Middle arch foot; 3. Main arch rib; 4. Side arch foot; 5. Arch rib support; 6. Steel box girder; 7. Lower part of ZP1 pier; 8. Lower part of ZP2 pier; 9. Lower part of ZP3 pier; 10. Lower part of ZP4 pier; 11. Lower part of ZP5 pier; 12. Navigation hole steel beam; 13. First steel box girder frame; 14. Second steel box girder frame. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0020] Example 1 As attached Figures 1 to 8 The spatial special-shaped steel box girder frame shown in the figure includes a goose tower 1. The bottoms of the two groups of goose towers 1 are both installed with middle arch feet 2. Both sides of the two groups of middle arch feet 2 are installed with main arch ribs 3. The overall structure of the main arch rib 3 is in a herringbone shape. The inner sides of the herringbone structure of the main arch rib 3 are respectively provided with auxiliary arch ribs. The auxiliary arch ribs are specifically composed of oblique rods and curved rods. Side arch feet 4 are respectively installed at the herringbone ends of the main arch ribs 3. Arch rib supports 5 are arranged in sequence along the arc stress points below the main arch ribs 3. A steel box girder 6 is arranged below the arch rib support 5. Below the steel box girder 6, the lower part of the ZP1 pier 7, the lower part of the ZP2 pier 8, and the lower part of the ZP3 pier are arranged in sequence. A second steel box girder frame 14 is arranged in the gap between the ZP1 pier lower part 7, the ZP2 pier lower part 8 and the ZP3 pier lower part 9, two groups of navigation hole steel beams 12 are arranged between the ZP3 pier lower part 9 and the ZP4 pier lower part 10, and a first steel box girder frame 13 is arranged between the ZP4 pier lower part 10 and the ZP5 pier lower part 11, and the top ends of the navigation hole steel beam 12, the first steel box girder frame 13 and the second steel box girder frame 14 are fixedly connected to the steel box girder 6, and the navigation hole 1, the navigation hole 2 and the navigation hole 3 are arranged in sequence between the two groups of navigation hole steel beams 12.

[0021] The bridge structure of this application adopts a 50m+180m+180m+50m=460m, four-span continuous oblique span special-shaped tie arch bridge, in which an arch-beam consolidation and pier-beam separation system is used. The middle goose tower 1 adopts a construction method of consolidating the goose tower 1 and the steel box beam 6. The standard section width of the bridge deck is 45m. The side arch foot 4 bridge deck pedestrians go around the outside of the arch foot, and the bridge deck is widened to 49.5m; the center beam of the main beam of the steel box beam 6 is 3.5m high, and the arch span standard section adopts a separated double small side box + I-beam structure, which is connected horizontally with a box-type crossbeam and the top plate is hollowed out; the beam span standard section adopts a semi-enclosed double small side box structure, which is connected with an inverted T-beam; the arch beam consolidation area and the beam span side support of the middle arch foot 2 and the side arch foot 4 adopt a fully enclosed whole box structure, and the steel beam box 6 consists of three parts: the arch span steel beam standard section, the arch beam node and the beam span steel beam standard section. The steel beam box 6 has a total of 51 sections; The arch span main girder steel structure adopts a longitudinal two-track split design, consisting of a small side box and an I-beam. The total length of the standard arch span main girder section is 144m, with a standard segment length of 9m. The top plate width of the single-track split structure is 20.25m. The small side box adopts a trapezoidal cross-section, with two webs aligned with the four side arch feet. The top plate width is 4.4m, the bottom plate width is 5m, and the small side box cantilever length is 5.85m. The center web is a plumb straight web, while the side webs are diagonally arranged, tilted 11° inward into the box, the angle coordinated with the cables. The I-beam is aligned with the center support arch foot web, and the bottom plate width is 0.6m. The clear distance between the small side box and the I-beam is 10.25m.

[0022] Box beams are installed every 9 meters, with a width of 3 meters, matching the position of the slings. The top plate has a hollowed-out opening. Solid-web diaphragms and outer cantilevers are installed every 3.0 meters. The cable-free section of the arch span is 56 meters long, and the standard sections of the arch span steel beams are classified into three types: A1, A2, and A3.

[0023] The standard thickness of the arch span main beam top plate is 16mm, which is locally thickened to 30mm near the middle support and 30mm near the secondary side support. Under the motor vehicle lane, 8mm thick U-ribs with an opening of 300m are used, and the U-rib spacing is 600m. Under the sidewalk and non-motor vehicle lane, 16mm thick plate ribs are used, and the plate rib spacing is 350mm. The standard thickness of the main beam bottom plate is 16mm, which is locally thickened to 30mm near the middle support and side support. The bottom plate adopts; The bridge arch rib system of the present application consists of five parts: the main arch rib 3, the secondary arch ribs, the oblique rods between the main and secondary arch ribs, the curved rods between the secondary arches, and the flexible cables between the curved rods, as well as the decoration between the main arch rib 3 and the goose tower 1 and the decorative components at the tail of the side arch; The main arch ribs 3 are four symmetrical spatial oblique arch ribs, and the auxiliary arch ribs are spatial curved arch ribs. The main and auxiliary arches both adopt octagonal cross-sections, and the oblique rods and curved rods both adopt quadrilateral cross-sections. Flexible cables are tensioned between the curved rods to provide in-plane stiffness of the curved rods.

[0024] Four main arches span symmetrically across the main beam, converging at the center support and separately at the side supports. The main arch tilts symmetrically outward. Two secondary arches merge into one at the center support before merging into the main arch. The two secondary arches merge into the main arch at the side supports. The main and secondary arches are connected by diagonal rods, and the two secondary arches are connected by curved rods and horizontal cables.

[0025] The main arch has a diagonal span of 176 meters and a height of 39.404 meters above the bridge deck. The main arch axis has a span-rise ratio of 1 / 4.5. The main arch axis is a cubic curve in plane, with the main arch ribs symmetrically canting 5.49 degrees toward the pedestrian side. The secondary arch axis is a spatial curve, projected onto the facade coinciding with the main arch axis and forming a cubic parabola in plane.

[0026] Both the main and secondary arch ribs feature octagonal cross-sections. The main arch's cross-section varies in height, with a constant width. The height is 3.5m at approximately one-quarter of the span, rising to 5m at the midpoint and 6m at the side points, with a linear height change between them. The main arch's width is 2.8m. The secondary arch features a variable height cross-section with a constant width. The height varies from 2m at approximately one-quarter of the span to 2.5m at the fulcrum, with a linear height change between them. The secondary arch's width is 12m. The main arch's soffit and roof and floor panels are 36-40mm thick, while the secondary arch's roof and floor panels are 16mm thick.

[0027] Thirteen diagonal bars are installed between each pair of primary and secondary arch ribs, for a total of 52 diagonal bars (4 x 13 = 52) across the entire bridge. The diagonal bars form a 53° angle with the road centerline, and the spacing between them varies from 5.7 to 9.0 meters. The diagonal bars have a box-shaped cross-section, with their webs aligned with the bulkheads within the primary and secondary arches, and their top and bottom plates aligned with the longitudinal stiffeners within the primary and secondary arches. The cross-section measures 0.8 x 1.0 meters. Decorative curved plates are welded to the outside of the diagonal bars to create the feather-like shapes on either side. The diagonal plates are 16 to 24 mm thick.

[0028] Two curved rods are arranged between the two secondary arches. They have a rectangular cross-section of 0.85m x 1.0m, and the curved lengths of the arches are 9.1m and 13.8m respectively. The thickness of the curved rods is 24mm.

[0029] Goose Pagoda 1 features a flat curved tower column with an octagonal cross-section. The main bridge is equipped with 17 pairs of cables, forming a spatial radial arrangement. The Goose Pagoda is a spatially curved tower column, 58.866m high above the bridge deck, and 36.324m wide in the middle curved section. The cross-section of the Goose Pagoda is an octagonal cross-section, with a width × height of 1.566 × 1.63m at the goosebump, a width × height of 4.061 × 4.692m at the maximum offset of the gooseneck along the bridge, and a width × height of 3.219 × 3.306m at the base of Goose Pagoda 1. The base of Goose Pagoda 1 is bonded to the main beam, forming an integrally rigid node.

[0030] Example 2 Based on Example 1, the solution in Example 1 is further detailed in combination with the following specific working methods. Figures 1 to 8 As shown, see the following description for details: S1. Define the overall construction plan, determine the steel beam segmentation method and technical parameters, complete riverbed dredging, make cargo supply planning and transportation plan design, select suitable transport vessels and make sailing preparations, and select and arrange rigging equipment; S2, steel box girder installation: assemble the temporary building structure, install the steel box girder 6 in sequence according to the steps, and implement positioning and adjustment measures, including positioning and adjustment of the first steel box girder frame 13, the second steel box girder frame 14 and the navigation channel steel beam 12; S3, installation of main arch rib 3, secondary arch rib, and goose tower 1: Install the main and secondary arch ribs and goose tower 1 in sequence, and implement the positioning and adjustment plan; S4, closure construction: Carry out the closure construction technology of Goose Pagoda 1 and the main and secondary arch ribs respectively, and complete the closure of key parts; S5, support treatment: dismantle the navigation channel steel beam 12, the first steel box beam frame 13 and the second steel box beam frame 14 and the arch rib support 5, and deal with the support settlement problem; S6, Pole and Transportation Management: Re-inspect incoming poles and deal with defects, and ensure safety in all aspects of steel box girder 6 transportation, including on-site ship positioning and implementation of transportation safety measures; S7, Welding Operation: Implement on-site welding of steel box girder 6, including welding process operation at the installation site, as well as weld inspection and non-destructive testing; S8. Painting acceptance: Carry out on-site painting process of steel box girder 6, conduct anti-corrosion painting construction, control and inspection, and complete construction acceptance.

[0031] As a preferred embodiment, in step S1, an expert discussion is organized to formulate an overall construction plan based on the actual project and geological conditions, clarifying the construction sequence, resource allocation, and schedule. Based on the steel beam structure, the steel box beam 6, main and secondary arch ribs, and goose tower 1 are divided into sections. The size, weight, and connection method of each section are determined, and the technical parameters are calculated and clarified. A combination of mechanical dredging and manual cleaning is used to comprehensively dredge the riverbed, ensuring that the dredging depth and range meet the design requirements. The cleaned silt is transported to the designated dumping site in accordance with regulations. The cargo supply batch, time, and quality standards are then determined with the supplier. Multiple steel beam transportation plans are designed and compared. Based on the size, weight, and transportation route of the steel beams, suitable transport vessels are selected and equipped with sufficient lifting equipment. A detailed investigation of the meteorological and hydrological conditions at the construction site is conducted, a navigation plan is formulated, and ship communication and navigation equipment commissioning and material replenishment are carried out. Based on the weight, installation height, and lifting environment of the six parts of the steel box beam, mechanical calculations and simulation analysis are used to accurately select lifting rigging, determine the wire rope specifications, shackle models, and pulley block configurations, and conduct strict quality inspections and load tests.

[0032] As a preferred embodiment, in step S2, the water support of the steel box girder 6 is inserted and driven, the structure of the ZP1 pier lower part 7 to the ZP5 pier lower part 11 is constructed, and the upstream riverbed of the ZP4 pier lower part 10 to the ZP5 pier lower part 11 is dredged; the ZP1 pier lower part 7 to the ZP5 pier lower part 11 are installed; the steel box girder 6, the main and secondary arch ribs and the goose tower 1 are processed simultaneously in the steel structure processing plant; the pier top steel beam of the ZP3 pier lower part 9 is hoisted by a 660t floating crane, and a permanent support is installed as a reference installation section; the 660t floating crane is used to install the pier top steel beam of the ZP3 pier lower part 9 .... A t floating crane was used to install the steel box girder 6 in the area between the lower part 7 of ZP1 pier and the lower part 9 of ZP3 pier, as well as all the steel beams on the short-mileage side of navigation channel 1; a 660t floating crane was used to install the steel beam of navigation channel 1, and navigation channels 2 and 3 were used as temporary passages for ships on the Dongjiang waterway; the steel beam at navigation channel 2 was installed, and navigation channels 1 and 3 were used as temporary passages for ships on the Dongjiang waterway; the steel beam at navigation channel 3 was installed, and navigation channels 1 and 2 were used as temporary passages for ships on the Dongjiang waterway; a 660t floating crane was used to install the steel box girder 6 in the area between the lower part 10 of ZP4 pier and the lower part 11 of ZP5 pier.

[0033] As a preferred embodiment, in step S3, the single row of column pads and pads on the right side of the navigation channel 3 are removed so that they do not participate in the later stress; the arch rib bracket 5 is installed using a 660t floating crane; the lower structure of the goose tower 1 and the arch ribs at the middle arch foot 2 are installed using a 660t floating crane; the tensioning structure of the goose tower 1 is installed, and the line shape of the joint mouth is adjusted; the joint section of the goose tower 1 is installed; the 660t floating crane is used to install it section by section from the arch feet on both sides to the joint mouth; the joint section is installed; the total station and GPS measuring instruments are used to measure the arch rib axis, elevation and verticality of the goose tower 1, and the temporary support height and cable guy rope tension are adjusted at any time during the construction phase to control the installation error within the design allowable range; after the adjustment is completed, the segmented interfaces of the main and secondary arch ribs and the goose tower 1 are welded or bolted, and the welding process parameters are strictly controlled during welding; the bolt connections are pre-tightened according to the specifications and quality inspections are carried out.

[0034] As a preferred embodiment, in step S4, a period of stable temperature is selected for joint closure, the joint section is first temporarily fixed at one end, and after the other end is adjusted into place, bolt connection is performed; during the joint closure process, structural deformation and stress changes are monitored in real time, and before installing the joint section, the ends of the arch ribs on both sides are polished to ensure that the interface is flat; after the joint is closed, the arch rib line shape is monitored, and the bracket force is adjusted according to the monitored changes.

[0035] As a preferred embodiment, in step S5, the support is inspected and the ancillary facilities are dismantled; and the dismantling sequence and safety measures are formulated, and technical instructions are given to the operating personnel. Following the principle of "support first and then dismantle, support last and then dismantle" the support is gradually dismantled by mechanical and manual coordination, and a dedicated person is assigned to monitor and confirm the construction process; the dismantled materials are taken away by floating cranes, and are sorted and stacked by dedicated personnel and cleared out of the site in a timely manner; before the support is erected, the foundation is compacted and a cushion layer is laid; during the construction process, the support settlement is monitored regularly, and if abnormal settlement is found, the cause is analyzed in a timely manner, and the support height is adjusted in a timely manner.

[0036] As a preferred embodiment, in step S6, the steel beam members are processed and manufactured in the factory, undergoing trial assembly, and then transported to the construction site after passing inspection. Upon arrival, the technical data and physical objects are checked against the design documents, registered, and approved by the supervisor. Any defects such as skew and cracks found are to be repaired by the manufacturer. Minor local deformations may be adjusted with hammering using pads or cold working using a jack, subject to supervisor approval. Severely damaged parts must be returned to the factory for processing. Burrs and weld spatter on the areas to be assembled must be cleaned, scraped, and polished smooth. Paint damage caused by transportation and loading and unloading must be repainted according to the original factory standards. Any rust or large-scale peeling must be promptly reported to the supervisor and the manufacturer for resolution.

[0037] As a preferred embodiment, in step S7, after welding is completed, a dedicated person cleans the welding area to remove oil and rust; selects appropriate welding materials and process parameters based on the steel beam material, plate thickness and welding position; conducts skill training and assessment for welders, and requires them to hold a certificate before taking up their posts. Welding is carried out strictly in the order and method determined by the welding process assessment, and multi-layer and multi-pass welding is used to control the interlayer temperature; quality inspections are strengthened during the welding process, and welding defects are corrected in a timely manner. The appearance inspection of the weld should ensure that the surface is flat, free of pores and slag inclusions; ultrasonic testing and radiographic testing non-destructive testing methods are used to inspect the welds according to the proportions required by the design, and unqualified welds are repaired and re-tested in a timely manner.

[0038] As a preferred embodiment, in step S8, the steel beam surface is sandblasted for rust removal to meet the specified cleanliness and roughness standards; the coating system is sprayed in layers according to the design requirements, including primer, intermediate paint and topcoat, and the thickness and interval time of each layer of coating are controlled; during the coating process, the ambient temperature and humidity are maintained at a suitable level, and construction is avoided on rainy or windy days; the coating thickness, adhesion and appearance quality are regularly tested, and construction records are kept; coating defects are repaired in a timely manner to ensure the anti-corrosion effect; after the coating is completed, the relevant units are organized to conduct acceptance, and the construction materials are submitted. The problems raised during the acceptance are rectified and improved, and the project is put into use after passing the inspection.

[0039] The working process of this application is as follows: three navigation holes are arranged at the lower part of ZP3 pier 9 and the lower part of ZP4 pier 10 to ensure navigation. The arrangement of the navigation holes fully considers the influence of the Dongjiang River gate, and the steel box girder 6 at the navigation hole is manufactured and installed in longitudinal large sections and transverse multiple blocks. After the in-plant manufacturing is completed, it is pre-assembled to simulate the on-site conditions and then transported to the bridge site by water. The "large sections, multiple blocks" are lifted using a 660t deck detachable floating crane. 2.2 Temporary pier arrangement. The temporary piers are arranged according to the width of three 45-meter navigation holes. Three groups of temporary piers are arranged in the water longitudinally. The piers are arranged in the transverse direction of the bridge according to three groups of lattice columns. A group of lattice columns is set at the bottom of each box chamber. The lattice column columns are made of 820x10mm steel pipes. A three-level distribution beam is set on the upper part of the steel pipe piles to transmit force. The modeling analysis of the whole bridge construction stage by Midas can meet the force requirements of the main beam and the subsequent upper arch rib installation; Longitudinal segmentation: During factory manufacturing, the 145.25-meter steel box girder 6 above the navigation channel is re-divided into segments of 48 meters, 51 meters, and 46.25 meters in the longitudinal direction. Horizontal division: It is divided into 5 blocks horizontally according to the box chamber. Block 1, block 3 and block 5 are box chambers. Their on-site installation adopts 48-meter, 51-meter and 46.25-meter whole-segment lifting.

[0040] Blocks 2 and 4 are the combination of the crossbeam and the bridge deck system. Considering the deformation caused by their own rigidity during installation, they are installed in 9 to 15 meter lengths during hoisting. Since the three box chambers of the upper steel box girder 6 of the navigation channel are subjected to different forces after installation, different downward disturbances and rotation angles will be generated. Therefore, during in-factory manufacturing, they must be manufactured according to the different pre-camber schemes for different blocks that have been calculated in advance. Blocks one, three, and five must be manufactured in accordance with the "long line method" to ensure their linear shape. After manufacturing is completed, the overall pre-assembly in the factory is carried out. Before pre-assembly in the factory, a tire frame is set up at a site with a certain foundation bearing capacity. The lower part of the box chamber block needs to be set up with a tire frame support point according to the manufacturing section to ensure that there is no internal stress when each box chamber block segment is assembled. After the tire frame is erected and the measurement is correct, the steel box girder 6 at the navigation channel can be pre-assembled. The specific process is as follows: Simulate the on-site installation sequence, hoist blocks 1, 3, and 5 as small segments onto the cradle for assembly. After blocks 1, 3, and 5 are assembled into a large segment, unload the middle cradle of the large segment and subject it to stress, simulating the stress conditions during on-site installation. Lift block 2 and adjust the matching accuracy between it and the chamber block. After the adjustment is completed, temporarily fix it. Lift block 4 and adjust the matching accuracy between it and the chamber block. After the adjustment is completed, temporarily fix it. After the overall assembly is completed, the overall linear shape is measured and evaluated and compared with the theoretical calculated value. After meeting the requirements, temporary matching parts are installed, and the mold removal, painting and shipment are carried out according to the on-site lifting section; Due to the limitation of the river gate, a 660t floating crane with a detachable deck is selected for lifting. The lifting capacity of all sections can be met through lifting and setting out. The transport ship transports the steel beam to the bridge position and stops perpendicular to the bridge position. After the front end of the transport ship is anchored in an "eight-shaped" shape, the floating crane sails to the position behind it. The front end of the floating crane is connected to the steel pipe pile through the anchor chain, and the rear end is anchored in an "eight-shaped" shape: the rear end of the transport ship is connected to the floating crane. After the transport ship and the floating crane are anchored in place, a pre-lifting trial is carried out. After the trial lifting is completed, the anchor chain on one side of the floating crane is released, and the transport ship reels in the anchor and sails away from the bridge position. After the floating crane reeled in the anchor, it sails forward to the designated beam drop position and performs the rear "eight-shaped" anchoring again. After anchoring in place, the steel beam is hoisted to the designed position to complete the steel beam installation; Install the steel box girder 6, including the steel box girder 6 in the pier area from the lower part 9 of ZP3 to the lower part 10 of ZP4, and all the steel beams on the small mileage side of the navigation channel 1; A 660t floating crane was used to install the steel beams for Navigation Slot 1. The installation sequence was: side block, middle block, deck system, side block, deck system. The deck system was installed from the fulcrum to the mid-span. Navigation Slots 2 and 3 served as temporary passages for ships on the Dongjiang waterway. A 660t floating crane was used to hoist Blocks 1 and 3, each 48m long, onto the piers. Three-dimensional jacks were used for fine-tuning, and anti-overturning support measures were installed. A 66-ton floating crane was used to hoist Block 2, which had three lengths: 9m, 12m, and 15m. After the Block 2 segments were hoisted into place, they were positioned and temporarily fixed using matching parts. After the crossbeams were fixed, the hooks were released, and then the subsequent Block 2 segments were hoisted in sequence. A 66t floating crane was used to hoist block 5, which was 48m long, and anti-overturning support measures were installed. Block 4 was then hoisted in sequence. After all four blocks 1 to 5 were hoisted into place, all welds were welded. After the weld inspection was completed, the girth weld between the navigation channel 1 and the small mileage erected beam was welded; Install the steel beam at navigation hole 2. Navigation holes 1 and 3 are used as temporary passages for ships on the Dongjiang waterway. The specific installation steps are the same as those for navigation hole 1. Install the steel beam at navigation hole 3. Navigation holes 1 and 2 are used as temporary passages for ships on the Dongjiang waterway. The specific installation steps are the same as those for navigation hole 1. After the installation of the navigation hole steel box girder 6 is completed, continue to install the remaining steel box girder 6 of the side span; During the installation of the second navigation channel steel beam 12, navigation channel pier 3 was subjected to eccentric loading. To prevent the pier from overturning due to the eccentric loading, an anti-overturning support point was added to navigation channel pier 3, located 5mm below the left support point. During the installation of the second navigation channel steel beam, the deformation of the pier and the distance between the anti-overturning support point and the steel box girder 6 were monitored. If the load was not automatically transferred to the anti-overturning support point during the pier deformation, a pad was added to the anti-overturning support point to transfer the load to the anti-overturning support point. The box chamber was hoisted onto the temporary pier in sections. Once adjusted into position, it was temporarily secured to the erected beam section and welded to ensure lateral anti-overturning resistance. 2.9.2 Crash Cushion Installation: Triangular crash piers were installed 5 meters outboard of the temporary piers on both sides of the navigation channel, upstream and downstream. These triangular crash piers consisted of three medium 450*8 steel pipe piles and a medium 428*6 connecting system. The connecting system was arranged in layers every 2 meters, for a total of four layers. Two 1mx1m warning signs are added to the outside of the steel pipe piles. One warning sign prompts "Construction ahead, please pay attention to safety!", and the other warning sign prompts "Net height 10 meters, net width 45 meters". The above is the working principle of the spatial special-shaped steel box girder cradle and the assembly process using the cradle.

Claims

1. A spatial special-shaped steel box girder frame, including a goose tower (1), characterized in that: The bottoms of the two groups of goose towers (1) are both equipped with middle arch feet (2), and both sides of the two groups of middle arch feet (2) are both equipped with main arch ribs (3), the overall structure of the main arch ribs (3) is in a herringbone shape, and the inner sides of the herringbone structure of the main arch ribs (3) are respectively provided with auxiliary arch ribs, and the auxiliary arch ribs are specifically composed of inclined rods and curved rods. The herringbone ends of the main arch ribs (3) are respectively equipped with side arch feet (4), and temporary arch rib supports (5) are arranged in sequence along the arc stress points below the main arch ribs (3). A steel box beam (6) is arranged below the arch rib support (5), and the lower part of the ZP1 pier (7), the lower part of the ZP2 pier (8), the lower part of the ZP3 pier (9), and the lower part of the ZP4 pier (10) are arranged in sequence below the steel box beam (6). A second steel box girder frame (14) is provided at the gap between the lower part (10) of the ZP4 pier and the lower part (11) of the ZP5 pier, the lower part (7) of the ZP1 pier, the lower part (8) of the ZP2 pier and the lower part (9) of the ZP3 pier, two groups of navigation hole steel beams (12) are provided between the lower part (9) of the ZP3 pier and the lower part (10) of the ZP4 pier, a first steel box girder frame (13) is provided between the lower part (10) of the ZP4 pier and the lower part (11) of the ZP5 pier, the top ends of the navigation hole steel beam (12), the first steel box girder frame (13) and the second steel box girder frame (14) are all fixedly connected to the steel box girder (6), and navigation hole 1, navigation hole 2 and navigation hole 3 are arranged in sequence between the two groups of navigation hole steel beams (12).

2. An assembly process for a spatial special-shaped steel box girder cradle, applied to the spatial special-shaped steel box girder cradle according to claim 1, characterized in that: The assembly process comprises the following steps: S1. Define the overall construction plan, determine the steel beam segmentation method and technical parameters, complete riverbed dredging, make cargo supply planning and transportation plan design, select suitable transport vessels and make sailing preparations, and select and arrange rigging equipment; S2, steel box girder installation: assemble the temporary building structure, install the steel box girder (6) in sequence according to the steps, and implement positioning and adjustment measures, including positioning and adjustment of the first steel box girder frame (13), the second steel box girder frame (14) and the navigation hole steel beam (12); S3. Installation of main arch ribs (3), auxiliary arch ribs, and goose tower (1): Install the main and auxiliary arch ribs and goose tower (1) in sequence, and implement the positioning and adjustment plan; S4, closure construction: perform the closure construction process of the goose tower (1) and the main and secondary arch ribs respectively, and complete the closure of the key parts; S5, support treatment: dismantle the navigation hole steel beam (12), the first steel box beam frame (13), the second steel box beam frame (14) and the arch rib support (5), and deal with the support settlement problem; S6. Management of rods and transportation: Re-inspect and deal with defects of the rods entering the site, and ensure the safety of all links in the transportation of steel box girders (6), including on-site ship positioning and implementation of transportation safety measures; S7, Welding operation: Implement on-site welding of steel box girders (6), including welding process operation at the installation site, as well as weld inspection and non-destructive testing; S8. Painting acceptance: Carry out on-site painting process of steel box girder (6), conduct anti-corrosion painting construction, control and inspection, and complete construction acceptance.

3. The process for assembling a space-shaped steel box girder frame according to claim 2, characterized in that: In step S1, organize experts to discuss and formulate an overall construction plan based on the actual project and geological conditions, clarify the construction sequence, resource allocation and schedule; divide the steel box girder (6), main and secondary arch ribs and goose tower (1) into sections according to the steel beam structure, determine the size, weight and connection method of each section, confirm the technical parameters, and use a combination of mechanical dredging and manual cleaning to dredge the riverbed. The cleaned silt is transported to the designated dumping site, and then determine the cargo supply batch, time and quality standards with the supplier; design multiple sets of transportation plans based on the size, weight and transportation route of the steel beam, determine the transportation ship after comparison and selection, and equip the lifting equipment; investigate the meteorological and hydrological conditions at the construction site, formulate a navigation plan, do a good job in ship communication, navigation equipment debugging and material supply work, and select the appropriate lifting rigging according to the weight, installation height and lifting environment of each part of the steel box girder (6) through mechanical calculation and simulation analysis, and determine the wire rope specifications, shackle model and pulley group configuration.

4. The process for assembling a space-shaped steel box girder frame according to claim 2, characterized in that: In step S2, the water support of the steel box girder (6) is inserted and the structure construction of the lower part of the ZP1 pier (7) to the lower part of the ZP5 pier (11) is carried out. In the construction order, the lower part of the pier is installed to have navigation hole 1, navigation hole 2 and navigation hole 3 in sequence, and the riverbed of the lower part of the ZP4 pier (10) to the lower part of the ZP5 pier (11) is dredged; the lower part of the ZP1 pier (7) to the lower part of the ZP5 pier (11) is installed; the steel box girder (6), the main arch rib, the secondary arch rib and the goose tower (1) are processed respectively in the steel structure processing plant; ZP3 is hoisted by using a 660t floating crane The pier top steel beam at the lower part of the pier (9) is installed with a permanent support as the reference installation section; the steel beam of navigation hole 1 is installed using a 660t floating crane; during the installation, navigation holes 2 and 3 remain open for temporary passage of ships; the steel beam at navigation hole 2 is installed, and navigation holes 1 and 3 are used as temporary passages for ships; the steel beam at navigation hole 3 is installed, and navigation holes 1 and 2 are used as temporary passages for ships; the steel box beam (6) in the area between the lower part of ZP4 pier (10) and the lower part of ZP5 pier (11) is hoisted into place using a 660t floating crane.

5. The process for assembling a space-shaped steel box girder cradle according to claim 2 is characterized in that: In step S3, the single-row column pads and pads on the right side of the navigation hole 3 are removed so that they do not participate in the later stress; a 660t floating crane is used to install a temporary arch rib support (5); a 660t floating crane is used to install the lower structure of the goose tower (1) and the arch ribs at the middle arch foot (2); the goose tower (1) tension structure is installed, and the line shape of the joint mouth is adjusted; the joint section of the goose tower (1) is installed; a 660t floating crane is used to install the arch ribs from both sides to the joint mouth, and finally the joint section is installed; a total station and a GPS measuring instrument are used to measure the arch rib axis, elevation and verticality of the goose tower (1), and the temporary support height and cable tension are adjusted at any time during the construction stage; after the adjustment is completed, the segment interfaces of the main and secondary arch ribs and the goose tower (1) are welded or bolted.

6. The process for assembling a space-shaped steel box girder cradle according to claim 2, characterized in that: In step S4, a period of stable temperature is selected for joint closure. The joint section is first temporarily fixed at one end, and after the other end is adjusted into place, bolt connection is performed. During the joint closure process, structural deformation and stress changes are monitored in real time. Before installing the joint section, the ends of the arch ribs on both sides are polished to confirm that the interface is flat. After the joint is closed, the arch rib line shape is monitored, and the support force is adjusted according to the monitored changes.

7. The process for assembling a space-shaped steel box girder cradle according to claim 2, characterized in that: In step S5, the support is inspected and the ancillary facilities are dismantled; a dismantling sequence and safety measures are formulated, and technical instructions are given to the operators. The construction method of supporting first and then dismantling, or dismantling last, is carried out in sequence. Mechanical and manual coordination is used to gradually dismantle the support, and a dedicated person is arranged to monitor and confirm the construction process. The dismantled materials are taken away by a floating crane, sorted and stacked by a dedicated person, and cleared out of the site in a timely manner. Before the support is erected, the foundation is compacted and a cushion layer is laid. During the construction process, the settlement of the support is monitored, and if abnormal settlement is found, the support height is adjusted.

8. The process for assembling a space-shaped steel box girder cradle according to claim 2, characterized in that: In step S6, the steel beams are manufactured and assembled in the factory for trial assembly. After passing inspection, they are transported to the construction site. Upon arrival, the technical data and physical components are checked against the design documents, registered, and approved by the supervisor. Any unacceptable defects are repaired by the manufacturer. Minor local deformations can be corrected with hammering or cold jacking with a backing plate, subject to supervisor approval. Severely damaged components are returned to the factory for processing. Burrs and weld spatter on the assembly area must be cleaned and polished. Paint damage caused by transportation and handling must be repainted according to the original factory standard. Any rust or large-scale peeling should be reported to the supervisor and the manufacturer for resolution.

9. The process for assembling a space-shaped steel box girder cradle according to claim 2, characterized in that: In step S7, after welding is completed, a dedicated person cleans the welding area to remove oil and rust; according to the material of the steel beam, the thickness of the plate and the welding position, appropriate welding materials and process parameters are selected, and multi-layer and multi-pass welding is adopted to control the temperature between layers. The appearance inspection of the weld should be smooth, without pores and slag inclusion defects; ultrasonic testing or radiographic testing is used as a non-destructive testing method to inspect the weld according to the proportion required by the design.

10. The process for assembling a space-shaped steel box girder cradle according to claim 2, characterized in that: In step S8, the steel beam surface is sandblasted to remove rust and meet the specified cleanliness and roughness standards; the coating system is sprayed in layers according to the design requirements, including primer, intermediate paint and topcoat, and the thickness and interval time of each layer of coating are controlled; during the coating process, the ambient temperature and humidity are maintained at a suitable level, and construction is avoided on rainy or windy days. The coating thickness, adhesion and appearance quality are regularly tested, and construction records are kept; coating defects are repaired in a timely manner to ensure the anti-corrosion effect. After the coating is completed, the corresponding unit is organized to conduct acceptance, and the construction materials are submitted. The problems raised in the acceptance are rectified and improved, and the project is put into use after passing the inspection.

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