Construction method for manufacturing and forming large-span basket steel box arch bridge

Abstract

The invention provides a large-span basket steel box arch bridge manufacturing and forming construction method, and belongs to the technical field of steel box arch bridge manufacturing and forming construction.The method comprises the following steps that construction preparation is conducted, specifically, technical preparation, tool preparation, equipment preparation, material preparation and personnel preparation are conducted, and a basket steel box arch is manufactured in a field; comprising the steps of pretreatment, blanking correction, unit piece manufacturing, stage continuous matching manufacturing, identification and stage decomposition, coating, sand blasting room entering, surface cleaning, sand blasting rust removal, surface cleaning, seventh coating, intermediate paint coating, surface coating, identification, transportation, plate unit land-road transportation to a total splicing factory, segment waterway transportation to a bridge site, hoisting, line type adjustment, positioning welding and inspection. And welding and bolting the ring opening, inspecting, then coating, and completing for inspection.

Description

Technical Field

[0001] The invention relates to the technical field of steel box arch bridge manufacturing and forming construction, and in particular to a large-span basket steel box arch bridge manufacturing and forming construction method. Background Art

[0002] The Lantian Yangtze River Fifth Bridge of the Lantian Cross-River Channel in Luzhou City is located in Jiangyang District, Luzhou City, Sichuan Province. The construction site on the north bank is located on Danxia Road, spanning the Yangtze River Binjiang Road; the construction site on the south bank is located on the west side of Yujingwan Community, spanning Lantian Binjiang Road, Jingheyuan of the Gas Mine Community and National Highway G246.

[0003] The Lantian Cross-River Channel (Lantian Yangtze River Fifth Bridge) and connecting line project in Luzhou City is a cross-Yangtze River project for the main urban road from Danxia Road in the Central Peninsula to Future Avenue in Lantian District. The starting pile number of the project is K0+534.391, the end pile number is K1+890.391, the main line is 1356m long, including the main bridge across the river and the approach bridges on both sides. The main bridge across the river ranges from K0+713.391 to K1+325.391, the main bridge is 612m long, with six lanes in both directions, reserved tracks, and sidewalks on both sides. The standard section width is 43.5m, including the total width of the wind nozzle and the cable area, 48.5m, and the main bridge across the river is a steel box arch bridge with a clear span of 570m. The north bank approach bridge covers an area of ​​K0+534.391 to K0+713.391, with a length of 179m. It is divided from a single-lane three-lane bridge in the main bridge direction to a double-lane bridge and a single-lane bridge in the approach bridge section. The road project under the north bank approach bridge is the Danxia Road auxiliary road, sidewalk and Binjiang Road intersection widening and reconstruction project, of which the auxiliary road is divided into two sections, and one section is a double lane. The south bank approach bridge covers an area of ​​K1+325.391 to K1+890.391, with a length of 565m and a standard width of 43.5m.

[0004] Due to the large span and high requirements for the basket steel box, a corresponding structure needs to be designed to meet the relevant requirements. Therefore, it is necessary to design a manufacturing and forming construction method for a large-span basket steel box arch bridge. Summary of the invention

[0005] The purpose of the present invention is to provide a manufacturing and forming construction method for a large-span basket-handled steel box arch bridge, so as to solve the technical problems mentioned in the background technology that the large-span construction of the project bridge is difficult and the existing basket-handled steel box arch cannot meet the project requirements.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for manufacturing and forming a large-span basket-handled steel box arch bridge, the method comprising the following steps:

[0008] Step 1: Construction preparation, including technical preparation, tooling preparation, equipment preparation, material preparation and personnel preparation;

[0009] Step 2: Carry out on-site basket steel box arch production, including pretreatment, material correction, unit component manufacturing, stage continuous matching manufacturing, marking and stage decomposition;

[0010] Step 3: painting, entering the sandblasting room, surface cleaning, sandblasting and rust removal, surface cleaning, seventh painting, intermediate paint painting, surface painting, marking;

[0011] Step 4: Transportation: the plate units are transported by land to the assembly plant, and the segments are transported by water to the bridge site;

[0012] Step 5: First hoist, adjust the line type, position welding, inspect, ring welding and bolting, inspect, then paint, and report for completion.

[0013] Furthermore, the specific process of pretreatment and blanking correction in step 2 is as follows:

[0014] Pretreatment: Before cutting and unloading the steel plate, the steel plate is flattened and shot blasted to remove rust through the pretreatment production line. The flatness deviation is within the range of 1mm / m. After the surface treatment reaches Sa2.5 level, 20-25μm of alcohol-soluble inorganic zinc silicate workshop primer is sprayed. The pretreatment releases the residual stress of the steel plate during the rolling process and ensures that the flatness of the steel plate meets the requirements. At the same time, the workshop primer spraying ensures that the steel plate will not be rusted during the factory construction;

[0015] Cutting correction:

[0016] (1) Laying out, making samples and numbering materials:

[0017] 1) Laying out, making samples and numbering materials should be carried out according to the construction drawings and process documents. Check the brand, specification and quality of the steel materials before operation, and reserve margins as required;

[0018] 2) When the steel material is not straight, rusted, or has paint and dirt that affects the quality of the material, it should be corrected and cleaned before setting out or marking;

[0019] (2) Cutting:

[0020] 1) The cutting accuracy requirements shall be implemented in accordance with the requirements of the process drawings;

[0021] 2) Before cutting, straighten and level the steel plate, remove impurities such as rust, paint, and dust within 30 to 50 mm on both sides of the surface cut, and leave a fixed gap under the steel plate to facilitate the flow of slag generated by cutting;

[0022] 3) To reduce deformation of parts, the fulcrum must be placed directly below the parts;

[0023] 4) To ensure the quality of parts processing, test cutting should be carried out first if necessary;

[0024] 5) When cutting parts, the rolling direction of the steel plate should be consistent with the main force direction of the parts;

[0025] 6) All parts should be cut by precision cutting. For rectangular plates, both sides along the length should be cut at the same time. For parts with complex shapes, the geometric dimensions are determined by computer lofting, and the parts are cut by CNC cutting machine. Compensation is added to eliminate the influence of thermal deformation.

[0026] 7) After cutting the parts, the cutting edges need to be polished and cleaned, and the defects caused by the cutting pits need to be polished and repaired;

[0027] 8) When cutting the material, the length of the closing section should be reserved for cutting, and the cutting should be done after measuring before closing;

[0028] 9) Mark the number, specification and material on the end of the blank steel plate, and mark the specification, furnace batch number, material and steel plate number on the remaining material;

[0029] (3) Parts correction:

[0030] 1) Cold correction is used before the parts are corrected, and there are no dents or damage on the surface of the steel after correction;

[0031] 2) The ambient temperature during cold straightening of parts should not be lower than -12°C;

[0032] 3) The temperature of hot straightening is controlled at 600-800℃. Overburning is strictly prohibited, and the same part should not be heated repeatedly for several times. Before the temperature drops to room temperature, it is not allowed to be hammered or quenched with water;

[0033] (4) Parts processing:

[0034] 1) The burrs and slag on the edges of the parts should be ground to make the cross section smooth and even. For parts that require edge processing, processing allowance should be reserved when cutting;

[0035] 2) To ensure the manufacturing accuracy of parts, some parts are machined;

[0036] 3) The surface roughness of the machined surface shall not exceed Ra25μm, and the machining depth of the part edge shall not be less than 3mm. However, when the hardness of the part edge does not exceed 350HV10, the machining depth may not be limited.

[0037] Furthermore, the unit component manufacturing in step 2 includes unit component division, unit component manufacturing process, beam segment manufacturing process and main arch continuous matching production.

[0038] Further, the unit element division includes arch rib unit division, cross brace unit division and inter-rib cross beam unit division, the arch rib unit is divided into arch foot section unit and common arch rib section unit, the arch foot section plate unit is divided into arch foot section top plate unit, arch foot section bottom plate unit, arch foot section web plate unit, arch foot section diaphragm unit and arch foot section end cover plate unit, the common arch rib section unit is divided into common arch rib section top plate unit, common arch rib section bottom plate unit, common arch rib section web plate unit and common arch rib section diaphragm unit;

[0039] The cross bracing unit includes a cross bracing top plate unit, a cross bracing bottom plate unit, a cross bracing web plate unit, a cross bracing partition plate unit and a cross bracing decorative plate;

[0040] The intercostal beam unit includes the intercostal beam top plate unit, the intercostal beam bottom plate unit, the intercostal beam web plate unit, the intercostal beam diaphragm unit, the intercostal beam permanent support bearing plate and the intercostal beam temporary support corbel.

[0041] Furthermore, the manufacturing process of the common arch rib segment is as follows:

[0042] The production process of common arch rib section top plate unit and common arch rib section bottom plate unit is as follows:

[0043] 1. Cutting: the top plate unit and bottom plate unit of the ordinary arch rib section are cut by flame cutting, and the plate ribs are cut by CNC plasma cutting;

[0044] 2. Bevel processing: the bevel is flame cut;

[0045] 3. Plate rib hole making: the plate rib is placed on the drilling platform and drilled by a CNC drilling machine. The hole groups on the side plate ribs of each segment arch are made first, and the hole groups on the side of the arch foot are drilled after the excess is cut;

[0046] 4. Mark out the vertical and horizontal baselines and the assembly lines of the plate ribs and partitions;

[0047] 5. Assemble the plate ribs according to the line and use CO2 gas shielded welding to perform positioning welding;

[0048] 6. Welding of the common arch rib section top plate unit and the common arch rib section bottom plate unit is carried out by placing them on the arc-shaped frame and using CO2 gas shielded automatic welding. The welding is carried out strictly in accordance with the "Welding Process Regulations";

[0049] 7. Correction: Correct welding deformation;

[0050] 8. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code;

[0051] The production process of common arch rib section web element is as follows:

[0052] 1. Cutting: the web unit of the ordinary arch rib section is cut by plasma cutting, and the plate rib is cut by a multi-head straight strip cutting machine;

[0053] 2. Bevel processing: the bevel is flame cut;

[0054] 3. Plate rib hole making: the plate rib is placed on the drilling platform and drilled by a CNC drilling machine. The hole groups on the side plate ribs of each segment arch are made first, and the hole groups on the side of the arch foot are drilled after the excess is cut;

[0055] 4. Marking: Position on the platform, draw the vertical and horizontal baselines and the assembly lines of the plate ribs and partitions;

[0056] 5. Assemble the plate ribs according to the line and use CO2 gas shielded welding to perform positioning welding;

[0057] 6. Welding: The unit components are placed on a special welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0058] 7. Correction: Correct welding deformation;

[0059] 8. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code;

[0060] The ordinary arch rib section partition unit includes the ordinary arch rib section ordinary partition unit and the ordinary arch rib section hanging point partition unit. The production process of the ordinary arch rib section ordinary partition unit is as follows:

[0061] 1. Cutting: the partition is cut by plasma cutting, and the manhole retaining ring and stiffening rib are cut by multi-head CNC cutting machine;

[0062] 2. Bevel processing: the bevel is flame cut;

[0063] 3. Position the partition panels on a special assembly platform, assemble the partition parts into a whole, and weld them using CO2 gas shielded welding. During welding, strictly follow the "Welding Process Regulations";

[0064] 4. Marking: Position the partition on the assembly platform and mark the bending line of the manhole guard and the assembly line of the stiffening rib;

[0065] 5. Bending: The manhole guard ring is bent according to the bending line using a bending machine;

[0066] 6. Assemble and strengthen according to the line, and use CO2 gas shielded welding to perform positioning welding;

[0067] 7. For welding, the unit components are placed on a special clapboard welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0068] 8. Correction: Correct welding deformation;

[0069] 9. Identification, marking, identification unit number and direction identification code;

[0070] The production process of the common arch rib section hanging point partition unit is as follows:

[0071] 1. Cutting: the partition is cut by plasma cutting, and the manhole retaining ring and stiffening rib are cut by multi-head CNC cutting machine;

[0072] 2. Bevel processing: the bevel is flame cut;

[0073] 3. Position the partition panels on a special assembly platform, assemble the partition parts into a whole, and weld them using CO2 gas shielded welding. During welding, strictly follow the "Welding Process Regulations";

[0074] 4. Marking: Position the partition on the assembly platform and mark the bending line of the manhole guard and the assembly line of the stiffening rib;

[0075] 5. Bending: The manhole guard ring is bent according to the bending line using a bending machine;

[0076] 6. Assemble the stiffening and anchor plates, assemble the stiffening and anchor plates according to the line, and use CO2 gas shielded welding to perform positioning welding;

[0077] 7. For welding, the unit components are placed on a special clapboard welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0078] 8. Correction: Correct welding deformation;

[0079] 9. Identification and marking, identification unit number and direction identification code.

[0080] 6. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 4 is characterized in that the preparation process of the arch foot segment unit is as follows:

[0081] The preparation process of the arch foot section top plate unit, the arch foot section bottom plate unit and the arch foot section web plate unit is as follows:

[0082] 1. Cutting: the top, bottom and web plates are cut by flame cutting, and the stiffening ribs are cut by CNC cutting;

[0083] 2. Bevel processing: the bevel is flame cut;

[0084] 3. Marking: Position on a special platform, draw the vertical and horizontal baselines and the stiffening ribs and partition assembly lines;

[0085] 4. Assemble the stiffening ribs according to the line and use CO2 gas shielded welding to perform positioning welding;

[0086] 5. Welding: The unit is placed on a special welding frame and welded with CO2 gas shielded welding. The welding is carried out in sequence: symmetrical welding of single-sided knife-shaped stiffening ribs → turning over the plate unit → welding of annular stiffening and panel welds → symmetrical welding of knife-shaped stiffening, annular stiffening and panel welds, strictly in accordance with the "Welding Procedure Regulations";

[0087] 6. Correction: Correct welding deformation;

[0088] 7. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code;

[0089] The production process of the end cap plate unit of the arch foot section is as follows:

[0090] 1. Cutting: the end sealing plate is cut by flame cutting, and the stiffening rib is cut by CNC cutting;

[0091] 2. Bevel processing: the bevel is flame cut;

[0092] 3. Assemble the end sealing plate parts into a whole on a special assembly platform, and use CO2 gas protection for welding. The welding should be carried out strictly in accordance with the "Welding Process Regulations";

[0093] 4. Marking: Position the end cover plate on the assembly platform and mark the stiffening rib assembly line;

[0094] 5. Assembly: assemble the stiffening ribs according to the line and use CO2 gas shielded welding to perform positioning welding;

[0095] 6. Welding: Place the unit components on a special clapboard welding frame and use CO2 gas shielded welding for welding. Perform symmetrical welding of the horizontal and vertical reinforcements in sequence. After turning over, symmetrically weld the horizontal and vertical reinforcements on the other side. Welding should be carried out strictly in accordance with the "Welding Procedure Regulations";

[0096] 7. Correction: Correct welding deformation;

[0097] 8. Identification and marking, identification unit number and direction identification code.

[0098] 7. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 4 is characterized in that:

[0099] The preparation process of the cross brace element and the intercostal beam element is as follows:

[0100] The preparation process of the cross brace top plate element, cross brace bottom plate element, cross brace web plate element, intercostal beam top plate element, intercostal beam bottom plate element and intercostal beam web plate element is as follows:

[0101] 1. Cutting: the top, bottom and web plates are cut by flame cutting, and the plate ribs are cut by multi-head CNC plasma cutting;

[0102] 2. Bevel processing: the bevel is flame cut;

[0103] 3. Marking: Position on the platform, draw the vertical and horizontal baselines and the assembly lines of the plate ribs and transverse partitions;

[0104] 4. Assemble the plate ribs, assemble the plate ribs according to the line, and use CO2 gas shielded welding to perform positioning welding;

[0105] 5. For welding, the unit components are placed on a special welding frame and welded using CO2 gas shielded automatic welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0106] 6. Correction: Correct welding deformation;

[0107] 7. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code;

[0108] The preparation process of the cross brace diaphragm unit and the intercostal cross beam diaphragm unit is as follows:

[0109] 1. Cutting: the partition is cut by plasma cutting, and the manhole retaining ring and stiffening rib are cut by multi-head CNC cutting machine;

[0110] 2. Bevel processing: the bevel is flame cut;

[0111] 3. The partition is positioned on a special assembly platform, and the partition parts are assembled into a whole. CO2 gas shielded welding is used for welding. The welding is carried out strictly in accordance with the "Welding Process Regulations";

[0112] 4. Marking: Position the partition on the special assembly platform, mark the bending line of the manhole guard ring and the assembly line of the stiffening rib;

[0113] 5. Bending: The retaining ring is bent along the bending line using a bending machine;

[0114] 6. Assemble the stiffening ribs according to the line and use CO2 gas shielded welding for positioning welding;

[0115] 7. For welding, the unit components are placed on a special clapboard welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0116] 8. Correction: Correct welding deformation;

[0117] 9. Identification and marking, identification unit number and direction identification code.

[0118] Furthermore, in order to ensure the manufacturing accuracy and continuity of the steel box arch segments, the segments need to be continuously matched and manufactured on the general assembly tire. The specific manufacturing process is as follows:

[0119] (1) Assembly process of common arch rib segments

[0120] 1. Put the web plate units on the tire. After welding the web plate units two by two into a whole, place them on the overall tire frame. Use the total station to adjust the position so that the horizontal distance between the longitudinal reference line and the longitudinal reference line of the middle measuring landmark tower is accurate, and the transverse reference line is accurately aligned with the transverse reference line of the tire frame, and then fix it;

[0121] 2. Assemble the remaining web units from the middle to both sides, and perform preliminary positioning based on the longitudinal and transverse reference lines on the tire frame. Use a total station to control the spacing and horizontal distance between the longitudinal reference line and the longitudinal reference line of the measuring tower. At the same time, make its transverse reference line collinear with the transverse reference line of the web unit that was first installed, and use CO2 gas shielded welding to perform positioning welding;

[0122] 3. Welding: The butt weld between the webs is welded by CO2 gas shielded welding + submerged arc welding. The welding is carried out strictly in accordance with the "Welding Procedure Regulations";

[0123] 4. Correction: Correct welding deformation;

[0124] 5. Install the partition unit on the tire, position and install the partition unit according to the positioning line on the web, use CO2 gas shielded welding to perform positioning welding, and add temporary inclined support;

[0125] 6. Assemble the inclined web unit. The inclined web is initially positioned according to the longitudinal and transverse reference lines on the tire frame. The total station is used to control the distance and level between its longitudinal reference line and the longitudinal reference line at the measuring landmark tower, so that its transverse reference line is collinear with the transverse reference line of the flat web unit. Positioning welding is performed using CO2 gas shielded welding;

[0126] 7. Welding: CO2 gas shielded welding is used, and the welding is carried out in sequence: butt weld between web units → fillet weld between partition and flat web → fillet weld between partition and inclined web. The welding is carried out strictly in accordance with the "Welding Procedure Regulations";

[0127] 8. Correction: Correct welding deformation;

[0128] 9. Assemble the top and bottom plate units on both sides

[0129] The top and bottom plate units on both sides are welded together to form a whole, and then the overall tire is assembled. The total station is used to control the spacing and horizontal distance between the longitudinal reference line and the longitudinal reference line of the tire frame, and the transverse reference line is aligned with the transverse reference line of the inclined web unit for positioning, and CO2 gas shielded welding is used for positioning welding;

[0130] 10. Assemble the upper inclined web unit

[0131] The upper inclined web is preliminarily positioned according to the longitudinal and transverse reference lines on the tire frame, and the total station is used to control the distance and horizontal distance between its longitudinal reference line and the longitudinal reference line at the measuring tower, so that its transverse reference line is collinear with the transverse reference line of the top and bottom plate units, and CO2 gas shielded welding is used for positioning welding;

[0132] 11. Welding: CO2 gas shielded welding is used in sequence: butt welds between top and bottom plates and upper and lower inclined webs → fillet welds between partitions and top and bottom plates → fillet welds between partitions and inclined webs. Welding shall be carried out in strict accordance with the Welding Procedure Regulations.

[0133] 12. Correction: Correct welding deformation;

[0134] 13. Assemble the upper web unit and the upper flat web unit, and use CO2 gas shielded welding for positioning welding;

[0135] 14. Welding: CO2 gas shielded welding + submerged arc automatic welding is used for web butt welding, and CO2 gas shielded welding is used for bulkhead and web welding. The welding sequence is: butt weld between webs → fillet weld between bulkhead and web. Welding shall be carried out in strict accordance with the Welding Procedure Specification.

[0136] 15. Correction: Correct welding deformation;

[0137] 16. After all beam sections are welded and corrected, the distance between the two ends of the sections and the spacing between anchor rods are accurately measured. The sections are cut according to the measured data, and the anchor pipes are positioned and assembled.

[0138] 17. Plate rib holes are matched and standard templates are used to match and drill the plate ribs to ensure that the final bolt hole rate is 100% and that the two segments can be bolted normally;

[0139] 18. Installation of accessory structures, welding of matching parts, hanging points, ladders and other accessory structures;

[0140] 19. Mark and split, mark the beam segment number and direction identification code, and place each segment in the order of "first up, first down", leaving the last segment for the next round of pre-assembly.

[0141] Furthermore, the assembly process of the arch foot segment is as follows:

[0142] 1. Put the web plate units on the tire. After welding the web plate units two by two into a whole, place them on the overall tire frame. Use the total station to adjust the position so that the horizontal distance between the longitudinal reference line and the longitudinal reference line of the middle measuring landmark tower is accurate, and the transverse reference line is accurately aligned with the transverse reference line of the tire frame, and then fix it;

[0143] 2. Assemble the remaining web units from the middle to both sides, and perform preliminary positioning based on the longitudinal and transverse reference lines on the tire frame. Use a total station to control the spacing and horizontal distance between the longitudinal reference line and the longitudinal reference line of the measuring tower. At the same time, make its transverse reference line collinear with the transverse reference line of the web unit that was first installed, and use CO2 gas shielded welding to perform positioning welding;

[0144] 3. Welding: The butt weld between the webs is welded by CO2 gas shielded welding + submerged arc welding. The welding is carried out strictly in accordance with the "Welding Procedure Regulations";

[0145] 4. Correction: Correct welding deformation;

[0146] 5. Install the partition plate unit and the end sealing plate unit, and position and install them according to the positioning line on the web, use CO2 gas shielded welding to perform positioning welding, and add temporary inclined supports;

[0147] 6. Assemble the inclined web unit. The inclined web is initially positioned according to the longitudinal and transverse reference lines on the tire frame. The total station is used to control the distance and level between its longitudinal reference line and the longitudinal reference line at the measuring landmark tower, so that its transverse reference line is collinear with the transverse reference line of the flat web unit. Positioning welding is performed using CO2 gas shielded welding;

[0148] 7. Welding: CO2 gas shielded welding is used, and the welding is carried out in sequence: butt weld between web units → fillet weld between partition and flat web → fillet weld between partition and inclined web. The welding is carried out strictly in accordance with the "Welding Procedure Regulations";

[0149] 8. Correction: Correct welding deformation;

[0150] 9. Assemble and weld the inner ring plate corresponding to the web plate, and assemble and weld the inner ring plate corresponding to the lower web plate after the web plate butt weld is completed and tested to be qualified;

[0151] 10. Assemble the top and bottom plate units on both sides. After the top and bottom plate units on both sides are welded together into a whole, assemble the tire. Use a total station to control the distance and horizontal distance between the longitudinal reference line and the longitudinal reference line of the tire frame. Position the transverse reference line and the transverse reference line of the inclined web unit in the same line. Use CO2 gas shielded welding for positioning welding.

[0152] 11. Assemble the upper inclined web unit. The upper inclined web is preliminarily positioned according to the longitudinal and transverse reference lines on the tire frame. The total station is used to control the distance and horizontal distance between its longitudinal reference line and the longitudinal reference line at the measuring tower, so that its transverse reference line is collinear with the transverse reference line of the top and bottom plate units. Position welding is performed using CO2 gas shielded welding;

[0153] 12. Welding: Use CO2 gas shielded welding to weld the top and bottom plates and the upper and lower inclined webs in sequence, the fillet welds between the partition and the top and bottom plates, and the fillet welds between the partition and the inclined web. Welding should be carried out in strict accordance with the Welding Procedure Regulations.

[0154] 13. Correction: Correct welding deformation;

[0155] 14. Assemble the inner ring plate. After the top and bottom plates and the web plate butt welds are completed and tested to be qualified, assemble and weld the corresponding inner ring plate;

[0156] 15. Assemble the upper web unit and the upper flat web unit, and use CO2 gas shielded welding for positioning welding;

[0157] 16. Welding: CO2 gas shielded welding + submerged arc automatic welding is used for web butt welding, and CO2 gas shielded welding is used for bulkhead and web welding. The welding sequence is: butt weld between webs → fillet weld between bulkhead and upper web. Welding shall be carried out in strict accordance with the Welding Procedure Regulations.

[0158] 17. Correction: Correct welding deformation;

[0159] 18. Assemble the remaining inner ring plates. After the web plate butt weld is completed and tested to be qualified, assemble and weld the upper inner ring plate and the inner ring plate at the G1G2 interface;

[0160] 19. Labeling: marking the beam section number and direction identification code.

[0161] Furthermore, the assembly process of the cross brace and intercostal beam segments is as follows:

[0162] 1. Put the bottom plate unit on the tire frame and use the total station to adjust it into position so that its longitudinal reference line is level with the longitudinal reference line of the middle measuring landmark tower and the spacing is accurate, and the transverse reference line is precisely aligned with the transverse reference line of the tire frame, and then fix it;

[0163] 2. Assemble the partition unit, assemble the transverse partition unit according to the line, use CO2 gas shielded welding to implement positioning welding, and add temporary support;

[0164] 3. Assemble and weld the web unit. Assemble the web unit according to the line, and use CO2 gas shielded welding to perform positioning welding; weld the fillet weld between the web and the bottom plate, and the fillet weld between the partition and the bottom and web. Use CO2 gas shielded welding to weld. Strictly follow the "Welding Procedure Regulations" during welding, and correct after welding;

[0165] 4. Assemble and weld the top plate unit. When assembling the top plate unit, use CO2 gas shielded welding to perform positioning welding; weld the fillet weld between the web and the top plate, and the fillet weld between the partition and the top plate. Use CO2 gas shielded welding to perform welding. During welding, strictly follow the "Welding Procedure Regulations" and make corrections after welding.

[0166] 5. Assemble the decorative panels. Assemble the decorative panels according to the lines. Use CO2 gas shielded welding to perform positioning welding. Use CO2 gas shielded welding to weld the welds between the decorative panels and the cross brace body. Strictly follow the "Welding Procedure Regulations" when welding.

[0167] 6. Correction: Correct welding deformation;

[0168] 7. Mark and identify the beam section number and direction identification code.

[0169] The present invention has the following beneficial effects due to the adoption of the above technical solution:

[0170] The present invention completes the corresponding bridge construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0172] Figure 1 This is a flow chart of the steel box arch construction process of the present invention;

[0173] Figure 2 This is a schematic diagram of the structure of the arch foot section plate unit division of the present invention;

[0174] Figure 3 It is a schematic diagram of the structure division of the common arch rib segment plate unit of the present invention;

[0175] Figure 4 It is a schematic diagram of the structure division of the cross bracing unit of the present invention;

[0176] Figure 5 This is a schematic diagram of the structure of the intercostal beam-slab unit division of the present invention;

[0177] Figure 6 This is a flow chart for manufacturing the top and bottom units of the common arch rib unit of the present invention;

[0178] Figure 7 This is a process flow chart of manufacturing a common rib unit web unit of the present invention;

[0179] Figure 8 It is a flow chart of manufacturing common rib unit partition unit of the present invention;

[0180] Fig. 9 It is a flow chart for manufacturing the top, bottom and web plate units of the arch foot section plate unit of the present invention;

[0181] Fig.10 It is a manufacturing flow chart of the end sealing plate unit of the arch foot section plate unit of the present invention;

[0182] Fig.11 It is a flow chart of manufacturing top, bottom and web plate units of the cross brace and intercostal beam units of the present invention;

[0183] Fig.12It is a flow chart of manufacturing the cross brace and intercostal beam unit partition unit of the present invention;

[0184] Fig.13 It is a flow chart of assembling a common arch rib segment of the present invention;

[0185] Fig.14 It is a flow chart of assembling the arch foot segment of the present invention;

[0186] Fig.15 It is a flow chart of the assembly of the cross brace and intercostal cross beam segments of the present invention;

[0187] Fig.16 It is a schematic diagram of the division of rounds of matching production of steel box arch segments according to the present invention.

[0188] Numbers in the figure: 1-arch foot section top plate unit, 2-arch foot section bottom plate unit, 3-arch foot section web plate unit, 4-arch foot section partition unit, 5-arch foot section end sealing plate unit, 6-ordinary arch rib section top plate unit, 7-ordinary arch rib section bottom plate unit, 8-ordinary arch rib section web plate unit, 9-ordinary arch rib section partition unit, 10-cross brace top plate unit, 11-cross brace bottom plate unit, 12-cross brace web plate unit, 13-cross brace partition unit, 14-cross brace decorative plate, 15-intercostal beam top plate unit, 16-intercostal beam bottom plate unit, 17-intercostal beam web plate unit, 18-intercostal beam partition unit, 19-intercostal beam permanent support bearing plate, 20-intercostal beam temporary support corbel; DETAILED DESCRIPTION

[0189] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are only for the purpose of enabling the reader to have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be implemented even without these specific details.

[0190] like Figure 1-16 As shown, a method for manufacturing and forming a large-span basket-handled steel box arch bridge comprises the following steps:

[0191] Step 1: Construction preparation, including technical preparation, tooling preparation, equipment preparation, material preparation and personnel preparation.

[0192] Step 2: Carry out on-site basket steel box arch production, including pretreatment, cutting correction, unit component manufacturing, stage continuous matching manufacturing, marking and stage decomposition.

[0193] Step 3: painting, entering the sandblasting room, surface cleaning, sandblasting to remove rust, surface cleaning, seventh painting, intermediate paint painting, surface painting, marking.

[0194] Step 4: Transportation: the plate units are transported by land to the assembly plant, and the segments are transported by water to the bridge site.

[0195] Step 5: First hoist, adjust the line type, position welding, inspect, ring welding and bolting, inspect, then paint, and report for completion.

[0196] The process flow of steel box arch manufacturing, transportation and bridge connection in this project is as follows: plate unit production → plate unit transportation → segment continuous matching production → auxiliary facilities installation → matching parts installation → beam segment disassembly → sandblasting and painting → steel beam transportation → coordinated lifting into place → bridge connection → final painting”.

[0197] In the embodiment of the present invention, the specific process of pretreatment and blanking correction in step 2 is:

[0198] Pretreatment: Before cutting and unloading the steel plate, the steel plate is flattened and shot blasted to remove rust through the pretreatment production line. The flatness deviation is within the range of 1mm / m. After the surface treatment reaches Sa2.5 level, 20-25μm of alcohol-soluble inorganic zinc silicate workshop primer is sprayed. The pretreatment releases the residual stress of the steel plate during the rolling process and ensures that the flatness of the steel plate meets the requirements. At the same time, the workshop primer spraying ensures that the steel plate will not be rusted during the factory construction;

[0199] Cutting correction:

[0200] (1) Laying out, making samples and numbering materials:

[0201] 1) Laying out, making samples and numbering materials should be carried out according to the construction drawings and process documents. Check the brand, specification and quality of the steel materials before operation, and reserve margins as required;

[0202] 2) When the steel material is uneven, rusted, or has paint stains that affect the quality of the material, it should be corrected and cleaned before laying out or marking.

[0203] (2) Cutting:

[0204] 1) The cutting accuracy requirements shall be implemented in accordance with the requirements of the process drawings;

[0205] 2) Before cutting, straighten and level the steel plate, remove impurities such as rust, paint, and dust within 30 to 50 mm on both sides of the surface cut, and leave a fixed gap under the steel plate to facilitate the flow of slag generated by cutting;

[0206] 3) To reduce deformation of parts, the fulcrum must be placed directly below the parts;

[0207] 4) To ensure the quality of parts processing, test cutting should be carried out first if necessary;

[0208] 5) When cutting parts, the rolling direction of the steel plate should be consistent with the main force direction of the parts;

[0209] 6) All parts should be cut by precision cutting. For rectangular plates, both sides along the length should be cut at the same time. For parts with complex shapes, the geometric dimensions are determined by computer lofting, and the parts are cut by CNC cutting machine. Compensation is added to eliminate the influence of thermal deformation.

[0210] 7) After cutting the parts, the cutting edges need to be polished and cleaned, and the defects caused by the cutting pits need to be polished and repaired;

[0211] 8) When cutting the material, the length of the closing section should be reserved for cutting, and the cutting should be done after measuring before closing;

[0212] 9) Mark the number, specification and material on the end of the cut steel plate, and mark the specification, furnace batch number, material and steel plate number on the remaining material.

[0213] (3) Parts correction:

[0214] 1) Cold correction is used before the parts are corrected, and there are no dents or damage on the surface of the steel after correction;

[0215] 2) The ambient temperature during cold straightening of parts should not be lower than -12°C;

[0216] 3) The temperature of hot straightening is controlled at 600-800℃. Overburning is strictly prohibited, and repeated heating of the same part is not allowed. Before the temperature drops to room temperature, it is not allowed to be hammered or quenched with water.

[0217] (4) Parts processing:

[0218] 1) The burrs and slag on the edges of the parts should be ground to make the cross section smooth and even. For parts that require edge processing, processing allowance should be reserved when cutting;

[0219] 2) To ensure the manufacturing accuracy of parts, some parts are machined;

[0220] 3) The surface roughness of the machined surface shall not exceed Ra25μm, and the machining depth of the part edge shall not be less than 3mm. However, when the hardness of the part edge does not exceed 350HV10, the machining depth may not be limited.

[0221] In the embodiment of the present invention, the unit component manufacturing in step 2 includes unit component division, unit component manufacturing process, beam segment manufacturing process and main arch continuous matching production.

[0222] In the embodiment of the present invention, the unit element division includes arch rib unit division, cross brace unit division and inter-rib cross beam unit division. The arch rib unit is divided into arch foot segment unit and common arch rib segment unit. Figure 2-3As shown, the arch foot section plate unit is divided into an arch foot section top plate unit, an arch foot section bottom plate unit, an arch foot section web plate unit, an arch foot section diaphragm unit and an arch foot section end cover plate unit, and the common arch rib section unit is divided into a common arch rib section top plate unit, a common arch rib section bottom plate unit, a common arch rib section web plate unit and a common arch rib section diaphragm unit;

[0223] like Figure 3 As shown, the cross brace unit includes a cross brace top plate unit, a cross brace bottom plate unit, a cross brace web plate unit, a cross brace partition plate unit and a cross brace decorative plate;

[0224] like Figure 4 As shown, the intercostal beam unit includes an intercostal beam top plate unit, an intercostal beam bottom plate unit, an intercostal beam web plate unit, an intercostal beam diaphragm unit, an intercostal beam permanent support bearing plate and an intercostal beam temporary support corbel.

[0225] The plate unit manufacturing is carried out in the order of "steel plate leveling and pretreatment → precision cutting → assembly of plate ribs → plate unit anti-deformation welding → correction". The key processes are as follows:

[0226] (1) CNC precision cutting;

[0227] (2) Precision control of the arc-shaped tire frame of the top and bottom plate units.

[0228] (3) Precise assembly of web, bottom plate and plate stiffeners;

[0229] (4) Anti-deformation welding of web and bottom plate units.

[0230] In the embodiment of the present invention, the manufacturing process of the common arch rib segment is as follows:

[0231] The production process of the common arch rib section top plate unit and the common arch rib section bottom plate unit is as follows: Figure 5 As shown:

[0232] 1. Cutting: the top plate unit and bottom plate unit of the ordinary arch rib section are cut by flame cutting, and the plate ribs are cut by CNC plasma cutting;

[0233] 2. Bevel processing: the bevel is flame cut;

[0234] 3. Plate rib hole making: the plate rib is placed on the drilling platform and drilled by a CNC drilling machine. The hole groups on the side plate ribs of each segment arch are made first, and the hole groups on the side of the arch foot are drilled after the excess is cut;

[0235] 4. Mark out the vertical and horizontal baselines and the assembly lines of the plate ribs and partitions;

[0236] 5. Assemble the plate ribs according to the line and use CO2 gas shielded welding to perform positioning welding;

[0237] 6. Welding of the common arch rib section top plate unit and the common arch rib section bottom plate unit is carried out by placing them on the arc-shaped frame and using CO2 gas shielded automatic welding. The welding is carried out strictly in accordance with the "Welding Process Regulations";

[0238] 7. Correction: Correct welding deformation;

[0239] 8. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code;

[0240] The production process of the web element of the ordinary arch rib segment is as follows: Figure 6 As shown:

[0241] 1. Cutting: the web unit of the ordinary arch rib section is cut by plasma cutting, and the plate rib is cut by a multi-head straight strip cutting machine;

[0242] 2. Bevel processing: the bevel is flame cut;

[0243] 3. Plate rib hole making: the plate rib is placed on the drilling platform and drilled by a CNC drilling machine. The hole groups on the side plate ribs of each segment arch are made first, and the hole groups on the side of the arch foot are drilled after the excess is cut;

[0244] 4. Marking: Position on the platform, draw the vertical and horizontal baselines and the assembly lines of the plate ribs and partitions;

[0245] 5. Assemble the plate ribs according to the line and use CO2 gas shielded welding to perform positioning welding;

[0246] 6. Welding: The unit components are placed on a special welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0247] 7. Correction: Correct welding deformation;

[0248] 8. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code;

[0249] The ordinary arch rib section partition unit includes the ordinary arch rib section ordinary partition unit and the ordinary arch rib section hanging point partition unit. The production process of the ordinary arch rib section ordinary partition unit is as follows: Figure 7 As shown:

[0250] 1. Cutting: the partition is cut by plasma cutting, and the manhole retaining ring and stiffening rib are cut by multi-head CNC cutting machine;

[0251] 2. Bevel processing: the bevel is flame cut;

[0252] 3. Position the partition panels on a special assembly platform, assemble the partition parts into a whole, and weld them using CO2 gas shielded welding. During welding, strictly follow the "Welding Process Regulations";

[0253] 4. Marking: Position the partition on the assembly platform and mark the bending line of the manhole guard and the assembly line of the stiffening rib;

[0254] 5. Bending: The manhole guard ring is bent according to the bending line using a bending machine;

[0255] 6. Assemble and strengthen according to the line, and use CO2 gas shielded welding to perform positioning welding;

[0256] 7. For welding, the unit components are placed on a special clapboard welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0257] 8. Correction: Correct welding deformation;

[0258] 9. Identification, marking, identification unit number and direction identification code;

[0259] The production process of the common arch rib section suspension point partition unit is as follows: Figure 8 As shown:

[0260] 1. Cutting: the partition is cut by plasma cutting, and the manhole retaining ring and stiffening rib are cut by multi-head CNC cutting machine;

[0261] 2. Bevel processing: the bevel is flame cut;

[0262] 3. Position the partition panels on a special assembly platform, assemble the partition parts into a whole, and weld them using CO2 gas shielded welding. During welding, strictly follow the "Welding Process Regulations";

[0263] 4. Marking: Position the partition on the assembly platform and mark the bending line of the manhole guard and the assembly line of the stiffening rib;

[0264] 5. Bending: The manhole guard ring is bent according to the bending line using a bending machine;

[0265] 6. Assemble the stiffening and anchor plates, assemble the stiffening and anchor plates according to the line, and use CO2 gas shielded welding to perform positioning welding;

[0266] 7. For welding, the unit components are placed on a special clapboard welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0267] 8. Correction: Correct welding deformation;

[0268] 9. Identification and marking, identification unit number and direction identification code.

[0269] In the embodiment of the present invention, the preparation process of the arch foot segment unit is as follows:

[0270] The preparation process of the arch foot section top plate unit, the arch foot section bottom plate unit and the arch foot section web plate unit is as follows: Fig. 9 As shown:

[0271] 1. Cutting: the top, bottom and web plates are cut by flame cutting, and the stiffening ribs are cut by CNC cutting;

[0272] 2. Bevel processing: the bevel is flame cut;

[0273] 3. Marking: Position on a special platform, draw the vertical and horizontal baselines and the stiffening ribs and partition assembly lines;

[0274] 4. Assemble the stiffening ribs according to the line and use CO2 gas shielded welding to perform positioning welding;

[0275] 5. Welding: The unit is placed on a special welding frame and welded with CO2 gas shielded welding. The welding is carried out in sequence: symmetrical welding of single-sided knife-shaped stiffening ribs → turning over the plate unit → welding of annular stiffening and panel welds → symmetrical welding of knife-shaped stiffening, annular stiffening and panel welds, strictly in accordance with the "Welding Procedure Regulations";

[0276] 6. Correction: Correct welding deformation;

[0277] 7. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code;

[0278] The production process of the end cap plate unit of the arch foot section is as follows: Fig.10 As shown:

[0279] 1. Cutting: the end sealing plate is cut by flame cutting, and the stiffening rib is cut by CNC cutting;

[0280] 2. Bevel processing: the bevel is flame cut;

[0281] 3. Assemble the end sealing plate parts into a whole on a special assembly platform, and use CO2 gas protection for welding. The welding should be carried out strictly in accordance with the "Welding Process Regulations";

[0282] 4. Marking: Position the end cover plate on the assembly platform and mark the stiffening rib assembly line;

[0283] 5. Assembly: assemble the stiffening ribs according to the line and use CO2 gas shielded welding to perform positioning welding;

[0284] 6. Welding: Place the unit components on a special clapboard welding frame and use CO2 gas shielded welding for welding. Perform symmetrical welding of the horizontal and vertical reinforcements in sequence. After turning over, symmetrically weld the horizontal and vertical reinforcements on the other side. Welding should be carried out strictly in accordance with the "Welding Procedure Regulations";

[0285] 7. Correction: Correct welding deformation;

[0286] 8. Identification and marking, identification unit number and direction identification code.

[0287] In the embodiment of the present invention, the preparation process of the cross brace unit and the intercostal cross beam unit is as follows:

[0288] The preparation process of the cross brace top plate element, cross brace bottom plate element, cross brace web plate element, intercostal beam top plate element, intercostal beam bottom plate element and intercostal beam web plate element is as follows: Fig.11 As shown:

[0289] 1. Cutting: the top, bottom and web plates are cut by flame cutting, and the plate ribs are cut by multi-head CNC plasma cutting;

[0290] 2. Bevel processing: the bevel is flame cut;

[0291] 3. Marking: Position on the platform, draw the vertical and horizontal baselines and the assembly lines of the plate ribs and transverse partitions;

[0292] 4. Assemble the plate ribs, assemble the plate ribs according to the line, and use CO2 gas shielded welding to perform positioning welding;

[0293] 5. For welding, the unit components are placed on a special welding frame and welded using CO2 gas shielded automatic welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0294] 6. Correction: Correct welding deformation;

[0295] 7. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code;

[0296] The preparation process of the cross brace diaphragm unit and the intercostal cross beam diaphragm unit is as follows: Fig.12 As shown:

[0297] 1. Cutting: the partition is cut by plasma cutting, and the manhole retaining ring and stiffening rib are cut by multi-head CNC cutting machine;

[0298] 2. Bevel processing: the bevel is flame cut;

[0299] 3. The partition is positioned on a special assembly platform, and the partition parts are assembled into a whole. CO2 gas shielded welding is used for welding. The welding is carried out strictly in accordance with the "Welding Process Regulations";

[0300] 4. Marking: Position the partition on the special assembly platform, mark the bending line of the manhole guard ring and the assembly line of the stiffening rib;

[0301] 5. Bending: The retaining ring is bent along the bending line using a bending machine;

[0302] 6. Assemble the stiffening ribs according to the line and use CO2 gas shielded welding for positioning welding;

[0303] 7. For welding, the unit components are placed on a special clapboard welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations";

[0304] 8. Correction: Correct welding deformation;

[0305] 9. Identification and marking, identification unit number and direction identification code.

[0306] In the embodiment of the present invention, in order to ensure the manufacturing accuracy and continuity of the steel box arch segments, the segments need to be manufactured by continuous matching on the total assembly tire. The specific manufacturing process is as follows:

[0307] (1) Assembly process of common arch rib segments, such as Fig.13 As shown,

[0308] 1. Put the web plate units on the tire. After welding the web plate units two by two into a whole, place them on the overall tire frame. Use the total station to adjust the position so that the horizontal distance between the longitudinal reference line and the longitudinal reference line of the middle measuring landmark tower is accurate, and the transverse reference line is accurately aligned with the transverse reference line of the tire frame, and then fix it;

[0309] 2. Assemble the remaining web units from the middle to both sides, and perform preliminary positioning based on the longitudinal and transverse reference lines on the tire frame. Use a total station to control the spacing and horizontal distance between the longitudinal reference line and the longitudinal reference line of the measuring tower. At the same time, make its transverse reference line collinear with the transverse reference line of the web unit that was first installed, and use CO2 gas shielded welding to perform positioning welding;

[0310] 3. Welding: The butt weld between the webs is welded by CO2 gas shielded welding + submerged arc welding. The welding is carried out strictly in accordance with the "Welding Procedure Regulations";

[0311] 4. Correction: Correct welding deformation;

[0312] 5. Install the partition unit on the tire, position and install the partition unit according to the positioning line on the web, use CO2 gas shielded welding to perform positioning welding, and add temporary inclined support;

[0313] 6. Assemble the inclined web unit. The inclined web is initially positioned according to the longitudinal and transverse reference lines on the tire frame. The total station is used to control the distance and level between its longitudinal reference line and the longitudinal reference line at the measuring landmark tower, so that its transverse reference line is collinear with the transverse reference line of the flat web unit. Positioning welding is performed using CO2 gas shielded welding;

[0314] 7. Welding: CO2 gas shielded welding is used, and the welding is carried out in sequence: butt weld between web units → fillet weld between partition and flat web → fillet weld between partition and inclined web. The welding is carried out strictly in accordance with the "Welding Procedure Regulations";

[0315] 8. Correction: Correct welding deformation;

[0316] 9. Assemble the top and bottom plate units on both sides

[0317] The top and bottom plate units on both sides are welded together to form a whole, and then the overall tire is assembled. The total station is used to control the spacing and horizontal distance between the longitudinal reference line and the longitudinal reference line of the tire frame, and the transverse reference line is aligned with the transverse reference line of the inclined web unit for positioning, and CO2 gas shielded welding is used for positioning welding;

[0318] 10. Assemble the upper inclined web unit

[0319] The upper inclined web is preliminarily positioned according to the longitudinal and transverse reference lines on the tire frame, and the total station is used to control the distance and horizontal distance between its longitudinal reference line and the longitudinal reference line at the measuring tower, so that its transverse reference line is collinear with the transverse reference line of the top and bottom plate units, and CO2 gas shielded welding is used for positioning welding;

[0320] 11. Welding: CO2 gas shielded welding is used in sequence: butt welds between top and bottom plates and upper and lower inclined webs → fillet welds between partitions and top and bottom plates → fillet welds between partitions and inclined webs. Welding shall be carried out in strict accordance with the Welding Procedure Regulations.

[0321] 12. Correction: Correct welding deformation;

[0322] 13. Assemble the upper web unit and the upper flat web unit, and use CO2 gas shielded welding for positioning welding;

[0323] 14. Welding: CO2 gas shielded welding + submerged arc automatic welding is used for web butt welding, and CO2 gas shielded welding is used for bulkhead and web welding. The welding sequence is: butt weld between webs → fillet weld between bulkhead and web. Welding shall be carried out in strict accordance with the Welding Procedure Specification.

[0324] 15. Correction: Correct welding deformation;

[0325] 16. After all beam sections are welded and corrected, the distance between the two ends of the sections and the spacing between anchor rods are accurately measured. The sections are cut according to the measured data, and the anchor pipes are positioned and assembled.

[0326] 17. Plate rib holes are matched and standard templates are used to match and drill the plate ribs to ensure that the final bolt hole rate is 100% and that the two segments can be bolted normally;

[0327] 18. Installation of accessory structures, welding of matching parts, hanging points, ladders and other accessory structures;

[0328] 19. Mark and split, mark the beam segment number and direction identification code, and place each segment in the order of "first up, first down", leaving the last segment for the next round of pre-assembly.

[0329] In the embodiment of the present invention, Fig.14 As shown, the assembly process of the arch foot segment is as follows:

[0330] 1. Put the web plate units on the tire. After welding the web plate units two by two into a whole, place them on the overall tire frame. Use the total station to adjust the position so that the horizontal distance between the longitudinal reference line and the longitudinal reference line of the middle measuring landmark tower is accurate, and the transverse reference line is accurately aligned with the transverse reference line of the tire frame, and then fix it;

[0331] 2. Assemble the remaining web units from the middle to both sides, and perform preliminary positioning based on the longitudinal and transverse reference lines on the tire frame. Use a total station to control the spacing and horizontal distance between the longitudinal reference line and the longitudinal reference line of the measuring tower. At the same time, make its transverse reference line collinear with the transverse reference line of the web unit that was first installed, and use CO2 gas shielded welding to perform positioning welding;

[0332] 3. Welding: The butt weld between the webs is welded by CO2 gas shielded welding + submerged arc welding. The welding is carried out strictly in accordance with the "Welding Procedure Regulations";

[0333] 4. Correction: Correct welding deformation;

[0334] 5. Install the partition plate unit and the end sealing plate unit, and position and install them according to the positioning line on the web, use CO2 gas shielded welding to perform positioning welding, and add temporary inclined supports;

[0335] 6. Assemble the inclined web unit. The inclined web is initially positioned according to the longitudinal and transverse reference lines on the tire frame. The total station is used to control the distance and level between its longitudinal reference line and the longitudinal reference line at the measuring landmark tower, so that its transverse reference line is collinear with the transverse reference line of the flat web unit. Positioning welding is performed using CO2 gas shielded welding;

[0336] 7. Welding: CO2 gas shielded welding is used, and the welding is carried out in sequence: butt weld between web units → fillet weld between partition and flat web → fillet weld between partition and inclined web. The welding is carried out strictly in accordance with the "Welding Procedure Regulations";

[0337] 8. Correction: Correct welding deformation;

[0338] 9. Assemble and weld the inner ring plate corresponding to the web plate, and assemble and weld the inner ring plate corresponding to the lower web plate after the web plate butt weld is completed and tested to be qualified;

[0339] 10. Assemble the top and bottom plate units on both sides. After the top and bottom plate units on both sides are welded together into a whole, assemble the tire. Use a total station to control the distance and horizontal distance between the longitudinal reference line and the longitudinal reference line of the tire frame. Position the transverse reference line and the transverse reference line of the inclined web unit in the same line. Use CO2 gas shielded welding for positioning welding.

[0340] 11. Assemble the upper inclined web unit. The upper inclined web is preliminarily positioned according to the longitudinal and transverse reference lines on the tire frame. The total station is used to control the distance and horizontal distance between its longitudinal reference line and the longitudinal reference line at the measuring tower, so that its transverse reference line is collinear with the transverse reference line of the top and bottom plate units. Position welding is performed using CO2 gas shielded welding;

[0341] 12. Welding: Use CO2 gas shielded welding to weld the top and bottom plates and the upper and lower inclined webs in sequence, the fillet welds between the partition and the top and bottom plates, and the fillet welds between the partition and the inclined web. Welding should be carried out in strict accordance with the Welding Procedure Regulations.

[0342] 13. Correction: Correct welding deformation;

[0343] 14. Assemble the inner ring plate. After the top and bottom plates and the web plate butt welds are completed and tested to be qualified, assemble and weld the corresponding inner ring plate;

[0344] 15. Assemble the upper web unit and the upper flat web unit, and use CO2 gas shielded welding for positioning welding;

[0345] 16. Welding: CO2 gas shielded welding + submerged arc automatic welding is used for web butt welding, and CO2 gas shielded welding is used for bulkhead and web welding. The welding sequence is: butt weld between webs → fillet weld between bulkhead and upper web. Welding shall be carried out in strict accordance with the Welding Procedure Regulations.

[0346] 17. Correction: Correct welding deformation;

[0347] 18. Assemble the remaining inner ring plates. After the web plate butt weld is completed and tested to be qualified, assemble and weld the upper inner ring plate and the inner ring plate at the G1G2 interface;

[0348] 19. Labeling: marking the beam section number and direction identification code.

[0349] In the embodiment of the present invention, Fig.15 As shown in the figure, the assembly process of the cross brace and intercostal beam segments is as follows:

[0350] 1. Put the base plate unit on the tire and place it on the tire frame. Use the total station to adjust it into position so that its longitudinal reference line is horizontal with the longitudinal reference line of the middle measuring mark tower and the spacing is accurate, and the transverse reference line is accurately aligned with the transverse reference line of the tire frame, and then fix it.

[0351] 2. Assemble the partition unit, assemble the transverse partition unit according to the line, use CO2 gas shielded welding to perform positioning welding, and add temporary support.

[0352] 3. Assemble and weld the web units. Assemble the web units according to the line and use CO2 gas shielded welding for positioning welding. Weld the fillet welds between the web and the bottom plate, and the fillet welds between the partition and the bottom and the web. Use CO2 gas shielded welding. Strictly follow the "Welding Procedure Regulations" during welding and correct after welding.

[0353] 4. Assemble and weld the top plate unit. Assemble the top plate unit and use CO2 gas shielded welding to perform positioning welding. Weld the fillet weld between the web and the top plate, and the fillet weld between the partition and the top plate. Use CO2 gas shielded welding to perform welding. Strictly follow the "Welding Procedure Regulations" during welding and correct after welding.

[0354] 5. Assemble the decorative panels. Assemble the decorative panels along the lines. Use CO2 gas shielded welding to perform positioning welding. Use CO2 gas shielded welding to weld the welds between the decorative panels and the cross brace body. Strictly follow the "Welding Procedure Regulations" during welding.

[0355] 6. Correction: Correct welding deformation;

[0356] 7. Mark and identify the beam section number and direction identification code.

[0357] Main arch continuous matching production:

[0358] After the unit manufacturing is completed, multiple beams are continuously matched on the general assembly frame, that is, the beam segment welding and beam segment matching are completed on the frame at one time. The assembly adopts the "horizontal assembly method", with the frame as the outer frame and the transverse partition as the inner frame. Each plate unit is in place according to the longitudinal and transverse baselines, supplemented by reinforcement facilities to ensure accuracy and safety.

[0359] To ensure the smooth erection of the steel box arch, the beam sections are matched at the assembly site. If it is found that the beam section size is incorrect or the pre-arch degree does not match, the size correction and adjustment of the matching parts can be carried out at the assembly site, thereby avoiding adjustments at high altitudes, reducing the difficulty of high-altitude operations and speeding up the lifting speed.

[0360] This bridge adopts a continuous matching production plan, sets up two sets of general assembly frames, and assembles eight beam segments at a time according to the "7+1" continuous matching manufacturing method. A gap of 100mm is left between the segments to facilitate subsequent matching and cutting construction. After the beam segment matching inspection is passed, the matching parts (i.e. temporary connecting parts) between the beam segments are installed, and the first seven beam segments are produced, leaving the last beam segment to participate in the next round of matching production.

[0361] Continuous matching is a simulated installation carried out on site. All measurement work starts 2 hours after sunset and ends before sunrise. It is used to check the line type of the bridge, the matching accuracy at the interface of the beam segment, the length and width of the assembled beam segment, the vertical and horizontal distance of the sling, etc. The length of the beam is reserved during the general assembly. After the dimensions of each part are inspected and qualified, the temporary connectors are installed. When installing on the bridge, the temporary connectors are used to locate and connect the components so that each component is accurately in place. The general assembly line type is strictly executed according to the monitoring instructions, and the monitoring company is communicated in advance.

[0362] (1) Continuous matching production process

[0363] According to the structural characteristics, the beam segment assembly and welding is carried out in the order of "web plate unit positioning according to the line → assembly of partition plate unit → welding → trimming → top and bottom plate unit → welding → trimming → assembly and welding of auxiliary facilities". Repeat the above steps and continue to assemble the beam until the last beam segment is assembled.

[0364] (2) Continuous matching production rounds

[0365] The matching production of steel box arch is divided into three rounds, which are carried out symmetrically from both sides of the arch rib to the closing section of the arch rib center. The specific rounds are shown in the table below:

[0366] Table 1 Division of steel box arch matching production rounds

[0367]

[0368] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for manufacturing and forming a large-span basket-handled steel box arch bridge, characterized in that: The method comprises the following steps: Step 1: Construction preparation, including technical preparation, tooling preparation, equipment preparation, material preparation and personnel preparation; Step 2: Carry out on-site basket steel box arch production, including pretreatment, material cutting correction, unit component manufacturing, stage continuous matching manufacturing, marking and stage decomposition; Step 3: painting, entering the sandblasting room, surface cleaning, sandblasting and rust removal, surface cleaning, seventh painting, intermediate paint painting, surface painting, marking; Step 4: Transportation: the plate units are transported by land to the assembly plant, and the segments are transported by water to the bridge site; Step 5: First hoist, adjust the line type, position welding, inspect, ring welding and bolting, inspect, then paint, and report for completion.

2. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 1 is characterized in that: The specific process of pretreatment and blanking correction in step 2 is: Pretreatment: Before cutting and unloading the steel plate, the steel plate is flattened and shot blasted to remove rust through the pretreatment production line. The flatness deviation is within the range of 1mm / m. After the surface treatment reaches Sa2.5 level, 20-25μm of alcohol-soluble inorganic zinc silicate workshop primer is sprayed. The pretreatment releases the residual stress of the steel plate during the rolling process and ensures that the flatness of the steel plate meets the requirements. At the same time, the workshop primer spraying ensures that the steel plate will not be rusted during the factory construction; Cutting correction: (1) Laying out, making samples and numbering materials: 1) Laying out, making samples and numbering materials should be carried out according to the construction drawings and process documents. Check the brand, specification and quality of the steel materials before operation, and reserve margins as required; 2) When the steel material is not straight, rusted, or has paint and dirt that affects the quality of the material, it should be corrected and cleaned before setting out or marking; (2) Cutting: 1) The cutting accuracy requirements shall be implemented in accordance with the requirements of the process drawings; 2) Before cutting, straighten and level the steel plate, remove impurities such as rust, paint, and dust within 30 to 50 mm on both sides of the surface cut, and leave a fixed gap under the steel plate to facilitate the flow of slag generated by cutting; 3) To reduce deformation of parts, the fulcrum must be placed directly below the parts; 4) To ensure the quality of parts processing, test cutting should be carried out first if necessary; 5) When cutting parts, the rolling direction of the steel plate should be consistent with the main force direction of the parts; 6) All parts should be cut by precision cutting. For rectangular plates, both sides along the length should be cut at the same time. For parts with complex shapes, the geometric dimensions are determined by computer lofting, and the parts are cut by CNC cutting machine. Compensation is added to eliminate the influence of thermal deformation. 7) After cutting the parts, the cutting edges need to be polished and cleaned, and the defects caused by the cutting pits need to be polished and repaired; 8) When cutting the material, the length of the closing section should be reserved for cutting, and the cutting should be done after measuring before closing; 9) Mark the number, specification and material on the end of the blank steel plate, and mark the specification, furnace batch number, material and steel plate number on the remaining material; (3) Parts correction: 1) Cold correction is used before the parts are corrected, and there are no dents or damage on the surface of the steel after correction; 2) The ambient temperature during cold straightening of parts should not be lower than -12°C; 3) The temperature of hot straightening is controlled at 600-800℃. Overburning is strictly prohibited, and the same part should not be heated repeatedly for several times. Before the temperature drops to room temperature, it is not allowed to be hammered or quenched with water; (4) Parts processing: 1) The burrs and slag on the edges of the parts should be ground to make the cross section smooth and even. For parts that require edge processing, processing allowance should be reserved when cutting; 2) To ensure the manufacturing accuracy of parts, some parts are machined; 3) The surface roughness of the machined surface shall not exceed Ra25μm, and the machining depth of the part edge shall not be less than 3mm. However, when the hardness of the part edge does not exceed 350HV10, the machining depth may not be limited.

3. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 1 is characterized in that: The unit component manufacturing in step 2 includes unit component division, unit component manufacturing process, beam segment manufacturing process and main arch continuous matching production.

4. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 3 is characterized in that: Unit division includes arch rib unit division, cross brace unit division and inter-rib cross beam unit division. Arch rib unit is divided into arch foot section unit and common arch rib section unit. Arch foot section plate unit is divided into arch foot section top plate unit, arch foot section bottom plate unit, arch foot section web plate unit, arch foot section diaphragm unit and arch foot section end cover plate unit. Common arch rib section unit is divided into common arch rib section top plate unit, common arch rib section bottom plate unit, common arch rib section web plate unit and common arch rib section diaphragm unit. The cross bracing unit includes a cross bracing top plate unit, a cross bracing bottom plate unit, a cross bracing web plate unit, a cross bracing partition plate unit and a cross bracing decorative plate; The intercostal beam unit includes the intercostal beam top plate unit, the intercostal beam bottom plate unit, the intercostal beam web plate unit, the intercostal beam diaphragm unit, the intercostal beam permanent support bearing plate and the intercostal beam temporary support corbel.

5. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 4 is characterized in that: The manufacturing process of ordinary arch rib segment is as follows: The production process of common arch rib section top plate unit and common arch rib section bottom plate unit is as follows:

1. Cutting: the top plate unit and bottom plate unit of the ordinary arch rib section are cut by flame cutting, and the plate ribs are cut by CNC plasma cutting; 2. Bevel processing: the bevel is flame cut; 3. Plate rib hole making: the plate rib is placed on the drilling platform and drilled by a CNC drilling machine. The hole groups on the side plate ribs of each segment arch are made first, and the hole groups on the side of the arch foot are drilled after the excess is cut; 4. Mark out the vertical and horizontal baselines and the assembly lines of the plate ribs and partitions; 5. Assemble the plate ribs according to the line and use CO2 gas shielded welding to perform positioning welding; 6. Welding of the common arch rib section top plate unit and the common arch rib section bottom plate unit is carried out by placing them on the arc-shaped frame and using CO2 gas shielded automatic welding. The welding is carried out strictly in accordance with the "Welding Process Regulations"; 7. Correction: Correct welding deformation; 8. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code; The production process of ordinary arch rib section web unit is as follows:

1. Cutting: the web unit of the ordinary arch rib section is cut by plasma cutting, and the plate rib is cut by a multi-head straight strip cutting machine; 2. Bevel processing: the bevel is flame cut; 3. Plate rib hole making: the plate rib is placed on the drilling platform and drilled by a CNC drilling machine. The hole groups on the side plate ribs of each segment arch are made first, and the hole groups on the side of the arch foot are drilled after the excess is cut; 4. Marking: Position on the platform, draw the vertical and horizontal baselines and the assembly lines of the plate ribs and partitions; 5. Assemble the plate ribs according to the line and use CO2 gas shielded welding to perform positioning welding; 6. Welding: The unit components are placed on a special welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations"; 7. Correction: Correct welding deformation; 8. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code; The ordinary arch rib section partition unit includes the ordinary arch rib section ordinary partition unit and the ordinary arch rib section hanging point partition unit. The production process of the ordinary arch rib section ordinary partition unit is as follows:

1. Cutting: the partition is cut by plasma cutting, and the manhole retaining ring and stiffening rib are cut by multi-head CNC cutting machine; 2. Bevel processing: the bevel is flame cut; 3. Position the partition panels on a special assembly platform, assemble the partition parts into a whole, and weld them using CO2 gas shielded welding. During welding, strictly follow the "Welding Process Regulations"; 4. Marking: Position the partition on the assembly platform and mark the bending line of the manhole guard and the assembly line of the stiffening rib; 5. Bending: The manhole guard ring is bent according to the bending line using a bending machine; 6. Assemble and strengthen according to the line, and use CO2 gas shielded welding to perform positioning welding; 7. For welding, the unit components are placed on a special clapboard welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations"; 8. Correction: Correct welding deformation; 9. Identification, marking, identification unit number and direction identification code; The production process of the common arch rib section hanging point partition unit is as follows:

1. Cutting: the partition is cut by plasma cutting, and the manhole retaining ring and stiffening rib are cut by multi-head CNC cutting machine; 2. Bevel processing: the bevel is flame cut; 3. Position the partition panels on a special assembly platform, assemble the partition parts into a whole, and weld them using CO2 gas shielded welding. During welding, strictly follow the "Welding Process Regulations"; 4. Marking: Position the partition on the assembly platform and mark the bending line of the manhole guard and the assembly line of the stiffening rib; 5. Bending: The manhole guard ring is bent according to the bending line using a bending machine; 6. Assemble the stiffening and anchor plates, assemble the stiffening and anchor plates according to the line, and use CO2 gas shielded welding to perform positioning welding; 7. For welding, the unit components are placed on a special clapboard welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations"; 8. Correction: Correct welding deformation; 9. Identification and marking, identification unit number and direction identification code.

6. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 4 is characterized in that: The preparation process of the arch foot segment unit is as follows: The preparation process of the arch foot section top plate unit, the arch foot section bottom plate unit and the arch foot section web plate unit is as follows:

1. Cutting: the top, bottom and web plates are cut by flame cutting, and the stiffening ribs are cut by CNC cutting; 2. Bevel processing: the bevel is flame cut; 3. Marking: Position on a special platform, draw the vertical and horizontal baselines and the stiffening ribs and partition assembly lines; 4. Assemble the stiffening ribs according to the line and use CO2 gas shielded welding to perform positioning welding; 5. Welding: The unit is placed on a special welding frame and welded with CO2 gas shielded welding. The welding is carried out in sequence: symmetrical welding of single-sided knife-shaped stiffening ribs → turning over the plate unit → welding of annular stiffening and panel welds → symmetrical welding of knife-shaped stiffening, annular stiffening and panel welds, strictly in accordance with the "Welding Procedure Regulations"; 6. Correction: Correct welding deformation; 7. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code; The production process of the end cap plate unit of the arch foot section is as follows:

1. Cutting: the end sealing plate is cut by flame cutting, and the stiffening rib is cut by CNC cutting; 2. Bevel processing: the bevel is flame cut; 3. Assemble the end sealing plate parts into a whole on a special assembly platform, and use CO2 gas protection for welding. The welding should be carried out strictly in accordance with the "Welding Process Regulations"; 4. Marking: Position the end cover plate on the assembly platform and mark the stiffening rib assembly line; 5. Assembly: assemble the stiffening ribs according to the line and use CO2 gas shielded welding to perform positioning welding; 6. Welding: Place the unit components on a special clapboard welding frame and use CO2 gas shielded welding for welding. Perform symmetrical welding of the horizontal and vertical reinforcements in sequence. After turning over, symmetrically weld the horizontal and vertical reinforcements on the other side. Welding should be carried out strictly in accordance with the "Welding Procedure Regulations"; 7. Correction: Correct welding deformation; 8. Identification and marking, identification unit number and direction identification code.

7. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 4 is characterized in that: The preparation process of the cross brace element and the intercostal beam element is as follows: The preparation process of the cross brace top plate element, cross brace bottom plate element, cross brace web plate element, intercostal beam top plate element, intercostal beam bottom plate element and intercostal beam web plate element is as follows:

1. Cutting: the top, bottom and web plates are cut by flame cutting, and the plate ribs are cut by multi-head CNC plasma cutting; 2. Bevel processing: the bevel is flame cut; 3. Marking: Position on the platform, draw the vertical and horizontal baselines and the assembly lines of the plate ribs and transverse partitions; 4. Assemble the plate ribs, assemble the plate ribs according to the line, and use CO2 gas shielded welding to perform positioning welding; 5. For welding, the unit components are placed on a special welding frame and welded using CO2 gas shielded automatic welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations"; 6. Correction: Correct welding deformation; 7. Marking and marking: punch holes for the positioning reference line, mark the plate unit number and direction identification code; The preparation process of the cross brace diaphragm unit and the intercostal cross beam diaphragm unit is as follows:

1. Cutting: the partition is cut by plasma cutting, and the manhole retaining ring and stiffening rib are cut by multi-head CNC cutting machine; 2. Bevel processing: the bevel is flame cut; 3. The partition is positioned on a special assembly platform, and the partition parts are assembled into a whole. CO2 gas shielded welding is used for welding. The welding is carried out strictly in accordance with the "Welding Process Regulations"; 4. Marking: Position the partition on the special assembly platform, mark the bending line of the manhole guard ring and the assembly line of the stiffening rib; 5. Bending: The retaining ring is bent according to the bending line using a bending machine; 6. Assemble the stiffening ribs according to the line and use CO2 gas shielded welding for positioning welding; 7. For welding, the unit components are placed on a special clapboard welding frame and welded using CO2 gas shielded welding. The welding process is strictly carried out in accordance with the "Welding Process Regulations"; 8. Correction: Correct welding deformation; 9. Identification and marking, identification unit number and direction identification code.

8. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 7 is characterized in that: In order to ensure the accuracy and continuity of the steel box arch segment production, the segments need to be continuously matched and produced on the general assembly tire. The specific production process is as follows: (1) Assembly process of common arch rib segments 1. Put the web plate units on the tire. After welding the web plate units two by two into a whole, place them on the overall tire frame. Use the total station to adjust the position so that the horizontal distance between the longitudinal reference line and the longitudinal reference line of the middle measuring landmark tower is accurate, and the transverse reference line is accurately aligned with the transverse reference line of the tire frame, and then fix it; 2. Assemble the remaining web units from the middle to both sides, and perform preliminary positioning based on the longitudinal and transverse reference lines on the tire frame. Use a total station to control the spacing and horizontal distance between the longitudinal reference line and the longitudinal reference line of the measuring tower. At the same time, make its transverse reference line collinear with the transverse reference line of the web unit that was first installed, and use CO2 gas shielded welding to perform positioning welding; 3. Welding: The butt weld between the webs is welded by CO2 gas shielded welding + submerged arc welding. The welding is carried out strictly in accordance with the "Welding Procedure Regulations"; 4. Correction: Correct welding deformation; 5. Install the partition unit on the tire, position and install the partition unit according to the positioning line on the web, use CO2 gas shielded welding to perform positioning welding, and add temporary inclined support; 6. Assemble the inclined web unit. The inclined web is initially positioned according to the longitudinal and transverse reference lines on the tire frame. The total station is used to control the distance and level between its longitudinal reference line and the longitudinal reference line at the measuring landmark tower, so that its transverse reference line is collinear with the transverse reference line of the flat web unit. Positioning welding is performed using CO2 gas shielded welding; 7. Welding: CO2 gas shielded welding is used, and the welding is carried out in sequence: butt weld between web units → fillet weld between partition and flat web → fillet weld between partition and inclined web. The welding is carried out strictly in accordance with the "Welding Procedure Regulations"; 8. Correction: Correct welding deformation; 9. Assemble the top and bottom plate units on both sides The top and bottom plate units on both sides are welded together to form a whole, and then the overall tire is assembled. The total station is used to control the spacing and horizontal distance between the longitudinal reference line and the longitudinal reference line of the tire frame, and the transverse reference line is aligned with the transverse reference line of the inclined web unit for positioning, and CO2 gas shielded welding is used for positioning welding; 10. Assemble the upper inclined web unit The upper inclined web is preliminarily positioned according to the longitudinal and transverse reference lines on the tire frame, and the total station is used to control the distance and horizontal distance between its longitudinal reference line and the longitudinal reference line at the measuring tower, so that its transverse reference line is collinear with the transverse reference line of the top and bottom plate units, and CO2 gas shielded welding is used for positioning welding; 11. Welding: CO2 gas shielded welding is used in sequence: butt welds between top and bottom plates and upper and lower inclined webs → fillet welds between partitions and top and bottom plates → fillet welds between partitions and inclined webs. Welding shall be carried out in strict accordance with the Welding Procedure Regulations.

12. Correction: Correct welding deformation; 13. Assemble the upper web unit and the upper flat web unit, and use CO2 gas shielded welding for positioning welding; 14. Welding: CO2 gas shielded welding + submerged arc automatic welding is used for web butt welding, and CO2 gas shielded welding is used for bulkhead and web welding. The welding sequence is: butt weld between webs → fillet weld between bulkhead and web. Welding shall be carried out in strict accordance with the Welding Procedure Specification.

15. Correction: Correct welding deformation; 16. After all beam sections are welded and corrected, the distance between the two ends of the sections and the spacing between anchor rods are accurately measured. The sections are cut according to the measured data, and the anchor pipes are positioned and assembled.

17. Plate rib holes are matched and standard templates are used to match and drill the plate ribs to ensure that the final bolt hole rate is 100% and that the two segments can be bolted normally; 18. Installation of accessory structures, welding of matching parts, hanging points, ladders and other accessory structures; 19. Mark and split, mark the beam segment number and direction identification code, and place each segment in the order of "first up, first down", leaving the last segment for the next round of pre-assembly.

9. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 7 is characterized in that: The assembly process of the arch foot segment is as follows:

1. Put the web plate units on the tire. After welding the web plate units two by two into a whole, place them on the overall tire frame. Use the total station to adjust the position so that the horizontal distance between the longitudinal reference line and the longitudinal reference line of the middle measuring landmark tower is accurate, and the transverse reference line is accurately aligned with the transverse reference line of the tire frame, and then fix it; 2. Assemble the remaining web units from the middle to both sides, and perform preliminary positioning based on the longitudinal and transverse reference lines on the tire frame. Use a total station to control the spacing and horizontal distance between the longitudinal reference line and the longitudinal reference line of the measuring tower. At the same time, make its transverse reference line collinear with the transverse reference line of the web unit that was first installed, and use CO2 gas shielded welding to perform positioning welding; 3. Welding: The butt weld between the webs is welded by CO2 gas shielded welding + submerged arc welding. The welding is carried out strictly in accordance with the "Welding Procedure Regulations"; 4. Correction: Correct welding deformation; 5. Install the partition plate unit and the end sealing plate unit, and position and install them according to the positioning line on the web, use CO2 gas shielded welding to perform positioning welding, and add temporary inclined supports; 6. Assemble the inclined web unit. The inclined web is initially positioned according to the longitudinal and transverse reference lines on the tire frame. The total station is used to control the distance and level between its longitudinal reference line and the longitudinal reference line at the measuring landmark tower, so that its transverse reference line is collinear with the transverse reference line of the flat web unit. Positioning welding is performed using CO2 gas shielded welding; 7. Welding: CO2 gas shielded welding is used, and the welding is carried out in sequence: butt weld between web units → fillet weld between partition and flat web → fillet weld between partition and inclined web. The welding is carried out strictly in accordance with the "Welding Procedure Regulations"; 8. Correction: Correct welding deformation; 9. Assemble and weld the inner ring plate corresponding to the web plate, and assemble and weld the inner ring plate corresponding to the lower web plate after the web plate butt weld is completed and tested to be qualified; 10. Assemble the top and bottom plate units on both sides. After the top and bottom plate units on both sides are welded together into a whole, assemble the tire. Use a total station to control the distance and horizontal distance between the longitudinal reference line and the longitudinal reference line of the tire frame. Position the transverse reference line and the transverse reference line of the inclined web unit in the same line. Use CO2 gas shielded welding for positioning welding.

11. Assemble the upper inclined web unit. The upper inclined web is preliminarily positioned according to the longitudinal and transverse reference lines on the tire frame. The total station is used to control the distance and horizontal distance between its longitudinal reference line and the longitudinal reference line at the measuring tower, so that its transverse reference line is collinear with the transverse reference line of the top and bottom plate units. Position welding is performed using CO2 gas shielded welding; 12. Welding: Use CO2 gas shielded welding to weld the top and bottom plates and the upper and lower inclined webs in sequence, the fillet welds between the partition and the top and bottom plates, and the fillet welds between the partition and the inclined web. Welding should be carried out in strict accordance with the Welding Procedure Regulations.

13. Correction: Correct welding deformation; 14. Assemble the inner ring plate. After the top and bottom plates and the web plate butt welds are completed and tested to be qualified, assemble and weld the corresponding inner ring plate; 15. Assemble the upper web unit and the upper flat web unit, and use CO2 gas shielded welding for positioning welding; 16. Welding: CO2 gas shielded welding + submerged arc automatic welding is used for web butt welding, and CO2 gas shielded welding is used for bulkhead and web welding. The welding sequence is: butt weld between webs → fillet weld between bulkhead and upper web. Welding shall be carried out in strict accordance with the Welding Procedure Regulations.

17. Correction: Correct welding deformation; 18. Assemble the remaining inner ring plates. After the web plate butt weld is completed and tested to be qualified, assemble and weld the upper inner ring plate and the inner ring plate at the G1G2 interface; 19. Labeling: marking the beam section number and direction identification code.

10. The method for manufacturing and forming a large-span basket-handled steel box arch bridge according to claim 7 is characterized in that: The assembly process of the cross brace and intercostal beam segments is as follows:

1. Put the bottom plate unit on the tire frame and use the total station to adjust it into position so that its longitudinal reference line is level with the longitudinal reference line of the middle measuring landmark tower and the spacing is accurate, and the transverse reference line is precisely aligned with the transverse reference line of the tire frame, and then fix it; 2. Assemble the partition unit, assemble the transverse partition unit according to the line, use CO2 gas shielded welding to implement positioning welding, and add temporary support; 3. Assemble and weld the web unit. Assemble the web unit according to the line, and use CO2 gas shielded welding to perform positioning welding; weld the fillet weld between the web and the bottom plate, and the fillet weld between the partition and the bottom and web. Use CO2 gas shielded welding to weld. Strictly follow the "Welding Procedure Regulations" during welding, and correct after welding; 4. Assemble and weld the top plate unit. When assembling the top plate unit, use CO2 gas shielded welding to perform positioning welding; weld the fillet weld between the web and the top plate, and the fillet weld between the partition and the top plate. Use CO2 gas shielded welding to perform welding. During welding, strictly follow the "Welding Procedure Regulations" and make corrections after welding.

5. Assemble the decorative panels. Assemble the decorative panels according to the lines. Use CO2 gas shielded welding to perform positioning welding. Use CO2 gas shielded welding to weld the welds between the decorative panels and the cross brace body. Strictly follow the "Welding Procedure Regulations" when welding.

6. Correction: Correct welding deformation; 7. Mark and identify the beam section number and direction identification code.

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