Construction method for large-span single-box multi-chamber steel box girder of single-tower cable-stayed bridge

Abstract

The invention relates to a construction method for a large-span single-box multi-chamber steel box girder of a single-tower cable-stayed bridge. The construction method comprises the following steps that an assembling platform is erected; assembling in a sliding manner; dynamically controlling the beam transporting barge; a liftable welding platform; and constructing a closure section. The problems of difficult foundation treatment, low assembly precision, unstable transportation, poor welding quality, high hoisting difficulty and the like in traditional construction are solved through systematic innovation, the construction efficiency and safety are remarkably improved, and the method is suitable for river-crossing, sea-crossing and other complex environments.

Description

Technical Field

[0001] This invention relates to a construction method for a long-span single-box multi-cell steel box girder of a single-tower cable-stayed bridge, applicable to steel box girder hoisting projects in confined spaces of complex navigable waterways. Background Technology

[0002] Bridge construction in complex terrains such as those spanning rivers, seas, or canyons typically employs cable-stayed bridge structures with large spans. During construction, the main towers are usually built first, followed by the main girder. Considering the bridge's span and the challenges of erection, the main girder usually utilizes a steel box girder structure.

[0003] Currently, the installation of precast segmental beams is usually carried out using bridge erection machines. One type of segmental beam installation device includes a main load-bearing frame and a tilting frame for supporting and fixing the segmental beams, enabling rotating and hoisting of the segmental beams. Another type is a tire-mounted guide beam bridge erection machine and segmental beam installation process. The tire-mounted guide beam bridge erection machine includes two sets of load-bearing sliding devices and at least two opening and closing trusses, achieving uniform transfer of hoisting loads. A motor-driven automatic walking segmental beam installation full-coverage bottom protection platform enhances the safety of segmental beam erection construction.

[0004] Analysis shows that the above-mentioned segmental beam installation construction mostly uses bridge erection machines. Further research is needed on the technical challenges in the segmental beam erection process, such as the precise installation and positioning of matching beams, the lifting of segmental beams and hoisting by gantry cranes, and the reduction of the difficulty of segmental beam closure.

[0005] A method for hoisting steel box girders in confined spaces within complex navigable waterways has been developed. This method includes the installation of a gantry crane foundation, the establishment of lateral connections between the gantry crane's pipe piles, segmentation of the main bridge, transportation of steel box girder components, trial hoisting of the steel box girder, hoisting of the steel box girder, and hoisting of the first and last steel box girder segments and the box girder chamber components. This method effectively solves the hoisting work of steel box girders within confined spaces. Through the erection of the gantry crane and the segmentation of the girder, the hoisting and lowering of the girder can be completed relatively well. However, this technology does not address the quality control of the main girder segment connections or the hoisting control of the transport barge.

[0006] One example is a method and apparatus for ocean transporting large-segment steel box girders. Barges are positioned at both ends of the steel box girder to support the large segments, facilitating their hoisting. The large segments are safely hoisted onto the barges within the harbor basin, and then transferred from the barges to a semi-submersible vessel in the corresponding waters, completing the loading process smoothly. After the large segments are transported to their designated locations, the semi-submersible vessel submerges, allowing the large segments to float on the water using two barges. By pulling the barges, the large segments can be moved to their installation positions, greatly facilitating bridge erection. This technology does not involve segmental hoisting and positioning of the steel box girder or barge water flow control.

[0007] One method for constructing a large-span S-shaped steel box girder with minimal support involves a precast steel box girder consisting of 14 small segments. These segments are assembled on-site into seven large segments and then hoisted and secured. The construction method specifically includes the prefabrication and assembly of the steel box girder, the construction of temporary supports in the water, the hoisting and positioning of the steel box girder segments, the connection of the steel box girder interfaces, the construction of the closure section, and the welding of the steel box girder circumferential joints. During construction, a prefabrication and assembly method is used, employing a floating crane. Temporary supports are installed at the circumferential joints of the large steel girder segments to facilitate navigation under the bridge during construction, minimizing the impact on navigation under the bridge and the surrounding environment. This technology does not address the issues of height-adjustable working platforms or the sliding assembly of steel box girder segments.

[0008] In summary, existing technologies in steel box girder transportation, hoisting, and construction supports do not address issues such as devices to improve the assembly accuracy and efficiency of steel box girders, enhance the stability of steel box girder transportation in waterways, or improve the connection quality of steel box girder segments. Therefore, relevant technological innovations are urgently needed. Summary of the Invention

[0009] The purpose of this invention is to provide a construction method for a large-span single-box multi-cell steel box girder for a single-tower cable-stayed bridge that can not only improve the assembly accuracy of steel box girders, but also reduce the difficulties in transportation and hoisting, and improve the connection quality of steel box girder segments.

[0010] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: The construction method for a long-span single-box multi-cell steel box girder of a single-tower cable-stayed bridge includes the following steps: S00, Assembly platform setup: An assembly platform is erected, which includes a first assembly plate and a second assembly plate for supporting the box girder segments. S10, Box Girder Segment Transport by Barge: The assembled box girder segments (36) are transported by a beam transport barge (30); the side of the cabin (32) of the beam transport barge (30) is equipped with a control airbag (31), and the buoyancy of the barge is controlled by inflating or deflating the control airbag (31), and the box girder segments (36) are fixed by fixing devices (39,42,43); S20, Box Girder Segment Transportation: The assembled box girder segments are transported by girder transport barges. The girder transport barges are equipped with position control airbags, and the buoyancy of the girder transport barges is controlled by controlling the inflation / depression of the position control airbags. S30, Box Girder Segment Lifting and Connection: A mobile crane is set up on the installed beam segment. The direction of the beam transport barge is adjusted by the balance actuator set on the beam transport barge. The box girder segment is lifted with the help of the control airbag and counterweight adjustment. The box girder segment is then lifted to the installation position by the mobile crane. S40, Welding between box girder segments: A liftable construction platform is installed on the outside of the crane connecting plate of the mobile crane. The liftable construction platform moves vertically along the lifting guide rail to allow workers to carry out welding operations. S50, hoisting of the box girder closure section: First and second support piers are set on the box girder segments on both sides of the box girder closure section. Top pressure is applied to the first and second support piers by the support pressure body to reserve closure space. Then the box girder closure section is hoisted and welded.

[0011] Furthermore, the specific steps for setting up the S00 assembly platform include: Expansion and expansion supports are installed in the foundation soil on the side of the embankment, and strip-shaped connecting plates are laid on the expansion and expansion supports. Insert the connecting anchor pipe into the expansion support pier, and inject sodium-based bentonite into the expansion support pier through the connecting anchor pipe. The first and second support columns are installed by passing through the strip connecting plate, and a closed cofferdam is set around the outer periphery of the first and second support columns; A first assembly plate is installed at the top of the first support column, and a second assembly plate is installed at the top of the second support column.

[0012] Further, step S10: The box girder segments are slid to the designated positions of the first and second assembly plates using a mobile trolley; Install height-adjustable bodies and height-adjustable angle steel at the joints; The temperature of the high-temperature heat transfer oil inside the temperature compensation bag is controlled to 150-200℃.

[0013] Furthermore, the temperature compensation bag is delivered to the joint along the cavity of the box girder segment via a movable support; support rollers are provided at the contact points between the movable support and the inner surface of the box girder segment.

[0014] Furthermore, in step S30: The crane guide rail is equipped with an inverted T-shaped crane slide groove, and the moving crane is slidably connected to the crane slide groove through the crane slider; The balancing actuators are electric propellers, located on both sides of the beam transport barge.

[0015] Furthermore, in step S20: The control airbag is installed on the side of the barge cabin of the beam transport barge; The box girder segments are also secured using rotating fixing frames, positioning bolts, upper fixing bodies, and lower fixing bodies.

[0016] Furthermore, the control airbag is connected to the inflation pump and the depressurization pump via inflation and depressurization pipes, respectively; the rotating mounting bracket is connected to the barge deck via a mounting bracket shaft.

[0017] Furthermore, in step S30: The mobile crane is set on the crane guide rail laid on the installed beam segment, and the mobile crane is slidably connected to the crane slide groove on the crane guide rail through the crane slider; The box girder segments are adjusted in mid-air by rotating the adjusting body and connecting the suspension rod.

[0018] Furthermore, in step S40: The lifting guide rail is equipped with a guide rail groove; The liftable construction platform is connected to the lifting connecting body via a rigid suspension rod, and the lifting connecting body slides in conjunction with the guide rail groove. The lifting connection body is driven by a cable winding machine to achieve vertical movement of the liftable construction platform.

[0019] Furthermore, in step S50: The counter-bracing pressure body is a hydraulic jack, which presses against the end plate of the crossbeam and the counter-bracing beam to apply pressure. The end plate of the crossbeam is slidably connected to the end plate groove set on the second support pier; The box girder closure section is suspended by rotating the support plate.

[0020] This invention has the following characteristics and beneficial effects. (1) Expansion support piers are set in the foundation soil, and sodium-based bentonite is injected into the expansion support piers through connecting anchor pipes, thereby achieving a rapid improvement in the bearing capacity of the foundation soil; at the same time, the first support column, the second support column and the closed cofferdam are connected into a whole by connecting tie rods, which enhances the stability of the assembly platform.

[0021] (2) The assembly platform includes a first assembly plate and a second assembly plate, and the second assembly plate can be lifted by an adjustable support, which effectively reduces the hoisting difficulty of pre-assembling the box girder segment platform.

[0022] (3) A height adjustment body and height adjustment angle steel were installed outside the joint between the wing plate section and the middle section of the box girder, and a temperature compensation bag was installed inside, which solved the problems of uneven joint of box girder segments and excessive stability gradient of steel plate at weld.

[0023] (4) A control airbag is installed on the side of the barge cabin, which can be combined with the rotating pressure plate to realize the dynamic control of the buoyancy of the barge; at the same time, the box girder segments can be combined and positioned by the upper fixed body below the rotating fixed frame and the lower fixed body above the barge deck, which enhances the transportation stability of the box girder segments.

[0024] (5) The two mobile cranes are connected into a whole by the crane connecting plate, and the longitudinal position of the mobile crane can be controlled by the crane control body. The angle of the box girder segment can be adjusted by rotating the control body and rotating the support plate, thus realizing the aerial adjustment of the box girder segment.

[0025] (6) When lifting the box girder segments, the stability of the transport barge and the box girder segments in the water is first controlled by the balance actuator. Then, the weight and volume of the transport barge are changed to make the transport barge float. Then, the box girder segments are lifted by adjusting the support body. Finally, the box girder segments are lifted by the rod end coiling machine, which effectively reduces the difficulty of the box girder segment lifting construction.

[0026] (7) The construction platform for welding between segment beams can move along the lifting guide rail under the action of the cable winding machine, realizing the rapid deployment of the construction platform and reducing the difficulty of construction operations.

[0027] (8) When hoisting the box girder closure section, the top pressure is first applied to the box girder segments on both sides of the box girder closure section by the support pressure body, and the box girder closure section can be hoisted onto the installed box girder segments by rotating the support plate, which reduces the difficulty of installing the box girder closure section. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating the construction process of a single-tower cable-stayed bridge with a large span single-box multi-cell steel box girder, according to an embodiment of the present invention. Figure 2 yes Figure 1 The structural diagram of the assembly platform; Figure 3 yes Figure 1 Internal structural diagram of the sliding assembly of box girder segments; Figure 4 yes Figure 1 Diagram of the transport structure of the box girder segment transport barge; Figure 5 yes Figure 1 A top view of the hoisting and connection of box girder segments; Figure 6 yes Figure 1 Construction structure diagram of box girder segments; Figure 7 yes Figure 6 Diagram showing the connection structure between the guide rail slide and the lifting connector; Figure 8 yes Figure 1 The installation structure diagram of the merging segment.

[0029] In the diagram: 1. Waterfront embankment; 2. Foundation soil; 3. Expansion support pier; 4. Strip connecting plate; 5. Connecting anchor pipe; 6. First support column; 7. Second support column; 8. Connecting tie rod; 9. Support column connecting hoop; 10. Closed cofferdam; 11. Connecting tenon plate; 12. Connecting wedge groove; 13. Diagonal bracing; 14. Connecting bottom beam; 15. Adjustable support body; 16. First assembled plate; 17. Second assembled plate; 18. Mechanical support pier; 19. Winding mechanism; 20. Limiting inclined plate; 21. Moving trolley; 22. Box girder wing plate segment; 23. Suspension end plate; 24. 25. Displacement cable; 26. Middle section of box girder; 27. Height adjustment body; 28. Height adjustment angle steel; 29. ​​Movable support frame; 30. Temperature compensation bag; 31. Beam transport barge; 32. Position control airbag; 33. Barge cabin; 34. Rotating pressure plate; 35. Water area; 36. Pressure plate adjusting bolt; 37. Box girder segment; 38. Barge deck; 39. Fixed height support body; 40. Rotating fixing frame; 41. Limiting clamp; 42. Positioning bolt shaft; 43. Upper fixing body; 44. Lower fixing body; 45. Pressure reducing pump; 46. Pressure reducing pipe; 47. Crane guide rail; 7. Mobile crane; 48. Crane connecting plate; 49. Crane slider; 50. Crane positioning body; 51. Balance actuator; 52. Counterweight adjusting pump; 53. Counterweight water pipe; 54. Counterweight box; 55. Height adjustment support body; 56. Rod end winding machine; 57. Rotation adjustment body; 58. Connecting rod; 59. Lifting guide rail; 60. Cable winding machine; 61. Platform positioning cable; 62. Lifting connecting body; 63. Rigid rod; 64. Construction platform; 65. First support pier; 66. Second support pier; 67. Counter-bracing pressure body; 68. Crossbeam end plate; 69. Support beam; 70. Rotating support plate; 71. Box girder closure section; 72. Pressurization pipe; 73. Pressurization pump; 74. Fixed frame pivot; 75. Pressure plate pivot; 76. Bolt end ball joint; 77. Fixed body end hinge; 78. Fixed pressure plate; 79. Crane slide rail; 80. Positioning support plate; 81. Installed beam section; 82. Connecting base plate; 83. Connecting vertical plate; 84. Guide rail connector; 85. Guide rail slide rail; 86. End plate slide rail; 87. Support plate pivot; 88. Support roller; 89. Bag support plate; 90. Support tie rod; 91. Lifting beam rope. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0031] Those skilled in the art should understand that, in the disclosure of this application, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this application.

[0032] The technical requirements for the manufacturing and construction of precast segmental beams, the technical requirements for the casting of cast-in-place bridge piers, and the technical requirements for the prestressing tensioning of segmental beams will not be elaborated in this embodiment. The focus is on describing the implementation method of the method involved in this invention.

[0033] Example 1 In this embodiment, Figure 2 yes Figure 1 Assembly platform structure diagram; Figure 3 yes Figure 1 Internal structural diagram of box girder segment sliding assembly; Figure 4 yes Figure 1 Diagram of the transport structure of the box girder segments by barge; Figure 5 yes Figure 1 Top view of box girder segment hoisting and connection; Figure 6 yes Figure 1 Box girder segment construction structure diagram; Figure 7 yes Figure 6 Connection structure diagram of guide rail slide and lifting connector; Figure 8 yes Figure 1 Installation structure diagram of the merging segment. See also Figures 2-8 The implementation method of the large-span single-box multi-cell steel box girder of the single-tower cable-stayed bridge shown is as follows: An expansion support pier 3 is installed in the foundation soil 2 on the side of the water-facing embankment 1. The water-facing embankment 1 is a masonry slope protection with a height of 10m. The foundation soil 2 is cohesive soil in a stiff plastic state. The expansion support pier 3 is cylindrical and formed by compacting and expanding crushed stone material. A connecting anchor pipe 5 is installed in the middle of the expansion support pier 3. The connecting anchor pipe 5 is a steel pipe with a diameter of 60mm. A hole with a diameter of 30mm is installed every 50cm along the height direction of the connecting anchor pipe 5.

[0034] A strip connecting plate 4 is laid on the upper surface of the expansion support pier 3. The strip connecting plate 4 is made of steel plate with a thickness of 3mm and a width of 0.8m. Holes are pre-set on the strip connecting plate 4 for connecting the anchor pipe 5, the first support column 6 and the second support column 7 to pass through.

[0035] Insert the connecting anchor pipe 5 into the extrusion support pier 3 through the reserved hole on the strip connecting plate 4, and then inject sodium-based bentonite into the extrusion support pier 3 through the connecting anchor pipe 5 to fill the extrusion support pier 3.

[0036] External hoisting equipment is used to hoist the first support column 6 and the second support column 7 into the reserved holes of the strip connecting plate 4, and to position the second support column 7 close to the side of the water-facing embankment 1. Support column connecting hoops 9, which are connected to the connecting rod 8, are respectively installed on the first support column 6 and the second support column 7. The first support column 6 and the second support column 7 are both made of steel pipe with a diameter of 300mm. The connecting rod 8 is made of steel pipe with a diameter of 100mm. The support column connecting hoop 9 is made of steel plate with a thickness of 10mm and includes two hoop plates of the same shape, which are fitted on the outside of the first support column 6 and the second support column 7 and fastened with bolts.

[0037] A closed cofferdam 10 is circumferentially installed around the outer periphery of the first support column 6 and the second support column 7, and the closed cofferdam 10 is connected to the connecting tie rod 8 via a connecting tenon plate 11. The closed cofferdam 10 is made of interlocking Larssen steel sheet piles and has a length of 8m. A connecting wedge groove 12 is provided on the side of the closed cofferdam 10 facing the first support column 6 and the second support column 7. The connecting wedge groove 12 is a right trapezoid with a height of 10cm. The connecting tenon plate 11 is made of 10mm thick rolled steel plate and has a width of 10cm.

[0038] An inclined bracing 13 is provided between the closed cofferdam 10 and the strip connecting plate 4. The inclined bracing 13 is made of steel pipe with a diameter of 100mm.

[0039] A connecting bottom beam 14 is installed at the top of the second support column 7, and an adjustable support body 15 and a second assembly plate 17 are sequentially installed on the connecting bottom beam 14; the connecting bottom beam 14 is made of H-beam with specifications of 300×150×6.5×9; the adjustable support body 15 is a hydraulic jack with a stroke of 50cm; the second assembly plate 17 is made of steel plate with a thickness of 10cm.

[0040] A first assembly plate 16 is installed at the top of the first support column 6. The first assembly plate 16 is made of steel plate with a thickness of 10cm.

[0041] Mechanical support blocks 18 are installed on the upper surface of the first assembly plate 16. The mechanical support blocks 18 are made of 10mm thick steel plate, 1m high, and have a right-angled trapezoidal cross-section. A winding machine 19 is installed on the mechanical support blocks 18. The winding machine 19 is an electric wire rope winch.

[0042] A limiting inclined plate 20 and a moving trolley 21 are provided on the upper surfaces of the first assembly plate 16 and the second assembly plate 17. The limiting inclined plate 20 is made of rolled steel plate, with a right-angled trapezoidal cross section and a height of 10cm. It is welded to the upper surfaces of the adjacent first assembly plate 16 and second assembly plate 17. The moving trolley 21 is a steel trolley with steel rollers at the bottom. Its top surface elevation is the same as that of the limiting inclined plate 20.

[0043] The box girder segment 36 includes the box girder flange segment 22 and the middle segment 25; during hoisting construction, according to the hoisting construction sequence, it is divided into the installed beam segment 81, the box girder segment 36, and the box girder closure segment 71. The box girder segment 36 is made of 10mm thick steel plate.

[0044] First, external hoisting equipment is used to hoist the box girder wing plate section 22 onto the mobile trolley 21 on the second assembly plate 17, and a suspension end plate 23 is set on the side away from the first assembly plate 16. The suspension end plate 23 is made of 10mm thick steel plate, with a cross section in the shape of "U". The top is equipped with a displacement cable 24 connected to the coiling machine 19. The displacement cable 24 is made of 30mm diameter steel wire rope.

[0045] The same hoisting and relocation method as the wing plate segment 22 of the box girder was used to hoist and relocate the middle section 25 of the box girder. A height adjustment body 26 and a height adjustment angle steel 27 were installed at the joint between the wing plate segment 22 and the middle section 25 of the box girder. The height adjustment body 26 and the height adjustment angle steel 27 were installed using a hydraulic jack. The height adjustment angle steel 27 was made of 20mm thick steel plate with an L-shaped cross section and was welded to the upper surface of the middle section 25 of the box girder. The temperature compensation bag 29 is conveyed along the cavity of the middle section 25 of the box girder to the joint between the wing section 22 and the middle section 25 of the box girder via a movable support frame 28. The temperature compensation bag 29 is made of polyester material with a melting point of 250~260℃. The movable support frame 28 is made of 3mm thick rolled steel plate, and support rollers 88 are installed at the junction with the inner surface of the box girder segment 36. The support rollers 88 are steel rollers with a diameter of 20cm. A bag support plate 89 is installed at the junction of the movable support frame 28 and the temperature compensation bag 29. The position of the movable support frame 28 is controlled by a support rod 90. The bag support plate 89 is made of 10mm thick rolled steel plate. The support rod 90 is a steel pipe with a diameter of 60mm.

[0046] When welding the joint between the wing plate section 22 and the middle section 25 of the box girder, the temperature of the high-temperature heat transfer oil in the temperature compensation bag 29 is controlled to 150~200℃ according to the temperature gradient at the welding point between the wing plate section 22 and the middle section 25 of the box girder, so as to increase the temperature of the steel plate at the joint between the wing plate section 22 and the middle section 25 of the box girder.

[0047] The beam-carrying barge 30 is a 30-ton steel plate rolled vessel, comprising a barge cabin 32, a barge deck 37, and a counterweight box 54. The counterweight box 54 is made of steel plate with a volume of 5m³. A positioning airbag 31 and a balancing actuator 51 are installed on the outside of the barge cabin 32. The positioning airbag 31 is made of 2mm thick rubber sheets stitched into a sealed cavity; the balancing actuator 51… A rotating fixing frame 39, a fixed height support 38, an adjustable height support 55, a lower fixing body 43, and a counterweight box 54 are installed on the barge deck 37. A control airbag 31 is installed on the side of the barge compartment 32 of the transport barge 30, with its side surface bonded to the side plate of the transport barge compartment 32 and its top surface bonded to the rotating pressure plate 33. The control airbag 31 is connected to the pressure pump 73 and the pressure pump 44 via the pressure pipe 72 and pressure pipe 45, respectively. The rotating pressure plate 33 is made of 10mm thick rolled steel plate, with its upper surface connected to the pressure plate adjusting bolt 35, its lower surface bonded to the control airbag 31, and its end connected to the barge compartment 32 via the pressure plate rotating shaft 75. The pressure plate adjusting bolt 35 is a hydraulic jack, with both ends connected to the barge deck 37 and the rotating pressure plate 33 via bolt end ball joints 76, respectively. Both the pressure plate rotating shaft 75 and the bolt end ball joints 76 are universal ball joints. Both the upper fixing body 42 and the lower fixing body 43 are hydraulic jacks. The fixing body end hinge 77 and the fixing pressure plate 78 are sequentially set at the top of the hydraulic jack telescopic rod, and the fixing pressure plate 78 is connected to the surface of the box girder segment 36.

[0048] Both the pressurization pipe 72 and the depressurization pipe 45 are made of 60mm diameter rubber hoses; the pressurization pump 73 and the depressurization pump 44 are respectively an air pump and an air extraction pump. The beam transport barge 30 is moored in the water area 34 outside the assembly platform. The water depth of the water area 34 is 10-15m, and the water flow velocity is 2m / s. First, the rotating pressure plate 33 is rotated to a horizontal position using the pressure plate adjusting bolt 35, and simultaneously the control airbag 31 is inflated to make the beam transport barge 30 float. Then, the assembled box girder segment 36 is hoisted onto the fixed-height support 38 on the barge deck 37. Subsequently, the rotating fixing frame 39 is rotated to a vertical position along the limiting clamp 40. The fixed-height support 38 is made of H-beams with specifications of 340×250×9×14 mm.

[0049] The positioning bolt shaft 41 passes sequentially through the limiting clamp plate 40 and the rotating fixing frame 39, and then the upper fixing body 42 and the lower fixing body 43 apply fixing pressure to the box girder segment 36. During the transportation of the box girder segment 36, the gas in the control airbag 31 is released through the pressure reducing pump 44 and the pressure reducing pipe 45. The rotating fixing frame 39 is made of 20mm thick steel plate rolled into an L shape with a width of 20cm. The rotating fixing frame 39 is connected to the barge deck 37 through the fixing frame rotating shaft 74, which is a 10mm diameter steel rotating shaft. The upper fixing body 42 is set on the lower surface of the rotating fixing frame 39, and the upper fixing body 42 is a hydraulic jack. Two limiting clamp plates 40 are set parallel to the rotation direction of the rotating fixing frame 39, and holes for the positioning bolt shaft 41 to pass through are set on the limiting clamp plates 40. The limiting clamp plates 40 are made of 10mm thick steel plate rolled into shape.

[0050] Two parallel crane guide rails 46 are laid on the upper surface of the installed beam segment 81. The crane guide rails 46 are made of 10mm thick rolled steel plate. Crane grooves 79 with an inverted "T" shaped cross section and a height of 5cm are set on the crane guide rails 46. The mobile crane 47 is connected to the crane guide rails 46 through the crane slider 49 on the lower surface of the crane connecting plate 48. The crane connecting plate 48 is made of 10mm thick rolled steel plate and connects the two parallel mobile cranes into a whole. The crane slider 49 is made of 20mm thick rolled steel plate, with a T-shaped cross section, and matches the crane groove 79.

[0051] Two crane control bodies 50, parallel to the crane guide rail 46, are installed on the inner side of the crane guide rail 46. The crane control bodies 50 are hydraulic jacks, and the control support plates 80 at both ends are firmly connected to the installed beam segment 81 and the crane connecting plate 48, respectively. The mobile crane 47 is a cantilever crane.

[0052] The box girder segment 36 is transported to the area below the mobile crane 47 via the girder transport barge 30. First, the balancing actuator 51 is activated according to the water flow direction to align the girder transport barge 30 with the installation direction of the box girder segment 36. Three balancing actuators 51 are installed on each side of the girder transport barge 30, using electric propellers. The propeller speed is adjusted to provide lateral thrust to the girder transport barge 30. The rotating pressure plate 33 is rotated to a horizontal position via the pressure plate adjusting bolt 35, and then the counterweight adjusting pump 52 is used to adjust the... The heavy water pipe 53 removes the water from the counterweight box 54 and simultaneously inflates the control airbag 31, causing the beam transport barge 30 to float. First, the box girder segment 36 is lifted by adjusting the support body 55, and then the box girder segment 36 is hoisted to the set height by the pole end winch 56 on the mobile crane 47. The pole end winch 56 is a wire rope winch, fixed to the bottom end of the connecting rod 58, and connected to the box girder segment 36 by the lifting beam rope 91. The lifting beam rope 91 is a 60mm diameter wire rope.

[0053] The orientation of the box girder segment 36 is adjusted by rotating the adjusting body 57 and the connecting rod 58. The adjusting body 57 includes a 60mm diameter screw and a nut, with the tightening directions of the screws on both sides of the nut reversed. The crane control body 50 is used to drag the crane connecting plate 48 and the mobile crane 47 to connect the box girder segment 36 with the installed beam segment 81. The connecting rod 58 is a 60cm diameter steel pipe, the top of which passes through the crane crossbeam of the mobile crane 47 and connects to the rotating support plate 70, which is made of 10mm thick rolled steel plate.

[0054] Two parallel lifting guide rails 59 are installed vertically on the outer side of the crane connecting plate 48, and a cable winding machine 60 is installed at the top of the lifting guide rails 59. The cable winding machine 60 is connected to the lifting connecting body 62 through the platform adjustment cable 61. The lifting guide rails 59 are made of 10mm thick steel plate. A guide rail groove 85 is provided on the lifting guide rails 59 for the guide rail connecting body 84 to slide. The cross section of the guide rail groove 85 is "T". The cable winding machine 60 is an electric wire rope winding machine. The platform adjustment cable 61 is a 30mm diameter wire rope. The lifting connecting body 62 is made of 10mm thick steel plate and includes a 60cm wide connecting base plate 82, a 50cm wide connecting vertical plate 83, and a T-shaped guide rail connecting body 84. The upper surface of the connecting base plate 82 is vertically welded to the connecting vertical plate 83, and the lower surface of the connecting base plate 82 is welded to the guide rail connecting body 84. A rigid suspension rod 63 is installed at the lower part of the lifting connection body 62 and connected to the construction platform 64; the workers are lifted and lowered with the construction platform 64 and carry out welding construction of the installed beam segment 81 and box girder segment 36 on the construction platform 64. First piers 65 and second piers 66 are respectively installed on the box girder segments 36 on both sides of the box girder closure section 71. Both first piers 65 and second piers 66 are made of 20mm thick steel plates and have an "L" shaped cross section. An inverted "T" shaped end plate groove 86 is provided on the second pier 66 to allow the crossbeam end plate 68 to move, and the crossbeam end plate 68 is connected to the end plate groove 86. The crossbeam end plate 68 is made of 20mm thick steel plates and has an inverted "T" shaped cross section. The box girder closure section 71 is constructed by first applying pressure to the crossbeam end plate 68 and the crossbeam support beam 69 via the counter-bracing pressure body 67. The counter-bracing support beam 69 is made of rolled steel with specifications of 588×300×12×20 mm. One end is welded to the first support pier 65, and the other end is welded to the crossbeam end plate 68. First, top pressure is applied to the box girder segments 36 on both sides of the box girder closure section 71. Then, the box girder closure section 71 is lifted, and then the box girder closure section 71 is suspended on the installed box girder segments 36 by rotating the support plate 70. The counter-bracing pressure body 67 is a hydraulic jack with a stroke of 30 cm. One end is connected to the vertical plate of the second support pier 66, and the other end is connected to the crossbeam end plate 68. The rotating support plate 70 is made of rolled steel plate with a thickness of 20 mm and is connected to the box girder closure section 71 through the support plate pivot.

[0055] Example 2 Based on Example 1, Figure 1 This is a construction flowchart of a single-tower cable-stayed bridge with a large span single-box multi-cell steel box girder, as per the present invention. Figure 1 As shown, the construction of a single-tower cable-stayed bridge with a large span single-box multi-cell steel box girder includes the following construction steps: 1) Assembly Platform Construction: An expansion support pier 3 is installed within the foundation soil 2 on the side of the waterfront embankment 1. A strip-shaped connecting plate 4 is laid on the upper surface of the expansion support pier 3. Holes are pre-drilled in the strip-shaped connecting plate 4 for connecting anchor pipes 5, first support columns 6, and second support columns 7 to pass through. First, the connecting anchor pipe 5 is inserted into the expansion support pier 3 through the pre-drilled holes in the strip-shaped connecting plate 4. Then, sodium-based bentonite is injected into the expansion support pier 3 through the connecting anchor pipe 5. External hoisting equipment is used to hoist the first support column 6 and the second support column 7 into the pre-drilled holes in the strip-shaped connecting plate 4, with the second support column 7 positioned close to the waterfront embankment 1. Support column connecting hoops 9, connected to connecting tie rods 8, are respectively installed on the first support column 6 and the second support column 7. Adjacent first support columns 6 and 7 are connected to each other. A connecting rod 8 is provided between the two support columns 7; a closed cofferdam 10 is provided circumferentially around the outer periphery of the first support column 6 and the second support column 7, and the closed cofferdam 10 is connected to the connecting rod 8 through a connecting tenon plate 11; an inclined bracing rib 13 is provided between the closed cofferdam 10 and the strip connecting plate 4; a connecting bottom beam 14 is provided at the top of the second support column 7, and an adjustable support body 15 and a second assembly plate 17 are sequentially provided on the connecting bottom beam 14; a first assembly plate 16 is provided at the top of the first support column 6, and a mechanical support block 18 is provided on the upper surface of the first assembly plate 16, and a winding and pulling machine 19 is provided on the mechanical support block 18; a limiting inclined plate 20 and a moving trolley 21 are provided on the upper surfaces of the first assembly plate 16 and the second assembly plate 17; 4) Box Girder Segment Sliding Assembly: First, external hoisting equipment is used to lift the box girder flange segment 22 onto the moving trolley 21 on the second assembly plate 17, and a suspension end plate 23 is set on the side away from the first assembly plate 16; then, the adjustable support 15 is used to lift the second assembly plate 17 to the elevation of the first assembly plate 16, and then the box girder flange segment 22 is moved to the set position on the first assembly plate 16 using the winding machine 19 and the displacement cable 24; the lifting and displacement method of the box girder flange segment 22 is repeated to carry out the lifting and displacement construction of the middle section 25 of the box girder; the box girder flange segment 22 and the box girder A height adjustment body 26 and a height adjustment angle steel 27 are installed at the joint of the intermediate section 25; the temperature compensation bag 29 is sent along the cavity of the intermediate section 25 of the box girder to the joint between the wing plate section 22 and the intermediate section 25 of the box girder by the movable support 28; when welding the joint between the wing plate section 22 and the intermediate section 25 of the box girder, the temperature of the high-temperature heat transfer oil in the temperature compensation bag 29 is controlled to 150~200℃ according to the temperature gradient of the welding part between the wing plate section 22 and the intermediate section 25 of the box girder, so as to increase the temperature of the steel plate at the joint between the wing plate section 22 and the intermediate section 25 of the box girder.

[0056] 5) Transportation of box girder segments 36 by the transport barge 30: A control airbag 31 is installed on the side of the barge compartment 32 of the transport barge 30, and the side of the control airbag 31 is bonded to the side plate of the transport barge compartment 32, and the top surface is bonded to the rotating pressure plate 33; the transport barge 30 is moored to the water area 34 outside the assembly platform, and the rotating pressure plate 33 is first rotated to a horizontal position using the pressure plate adjusting bolt 35, while simultaneously inflating the control airbag 31 to make the transport barge 30 float. The assembled box girder segment 36 is hoisted onto the fixed-height support 38 on the barge deck 37. Then, the rotating fixing frame 39 is rotated to a vertical position along the limiting clamp 40, and the positioning bolt shaft 41 passes through the limiting clamp 40 and the rotating fixing frame 39 in sequence. Then, the upper fixing body 42 and the lower fixing body 43 apply fixing pressure to the box girder segment 36. During the transportation of the box girder segment 36, the gas in the control airbag 31 is released through the pressure reducing pump 44 and the pressure reducing pipe 45.

[0057] 4) Box Girder Segment Lifting and Connection: Two parallel crane guide rails 46 are laid on the upper surface of the installed girder segment 81, and the mobile crane 47 is connected to the crane guide rails 46 via the crane slider 49 on the lower surface of the crane connecting plate 48; two crane control bodies 50 parallel to the crane guide rails 46 are set on the inner side of the crane guide rails 46; the box girder segment 36 is transported to the area below the mobile crane 47 by the girder transport barge 30, and the balancing actuator 51 is activated according to the water flow direction to make the girder transport barge 30 parallel to the installation direction of the box girder segment 36, and then the pressure plate 33 is rotated by the pressure plate adjusting bolt 35. After rotating to a horizontal position, the water in the counterweight box 54 is pumped out through the counterweight adjustment pump 52 and the counterweight water pipe 53, and the control airbag 31 is inflated simultaneously to make the beam transport barge 30 float. First, the box girder segment 36 is lifted by the height adjustment support 55, and then the box girder segment 36 is hoisted to the set height by the rod end coiling machine 56 on the mobile crane 47. Then, the direction of the box girder segment 36 is adjusted by rotating the adjustment body 57 and the connecting rod 58. Finally, the crane control body 50 is used to drag the crane connecting plate 48 and the mobile crane 47 to connect the box girder segment 36 with the installed beam segment 81. 5) Welding between box girder segments: Two parallel lifting guide rails 59 are set vertically on the outside of the crane connecting plate 48, and a cable winding machine 60 is set at the top of the lifting guide rails 59. The cable winding machine 60 is connected to the lifting connecting body 62 through the platform adjustment cable 61. A rigid hanging rod 63 is set at the lower part of the lifting connecting body 62 and connected to the construction platform 64. The workers are raised and lowered with the construction platform 64 and the welding construction of the installed beam segment 81 and box girder segment 36 is carried out on the construction platform 64. 6) Erection of the box girder closure section: First support 65 and second support 66 are set on the box girder segments 36 on both sides of the box girder closure section 71 respectively; first, the crossbeam end plate 68 and the support beam 69 are pressed by the support pressure body 67 to apply top pressure to the box girder segments 36 on both sides of the box girder closure section 71, and then the hoisting construction of the box girder closure section 71 is repeated. Then, the box girder closure section 71 is hoisted on the installed box girder segments 36 by rotating the support plate 70, and then the welding between the segments is repeated.

[0058] The parts not described in detail in this application are prior art, and therefore are not described in detail in this application.

[0059] It is understood that the term "a" should be understood as "at least one" or "one or more," that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0060] Although this document uses a significant amount of technical terminology, the possibility of using other terms is not excluded. These terms are used merely to facilitate the description and explanation of the nature of this application; interpreting them as any additional limitation would be contrary to the spirit of this application.

[0061] This application is not limited to the above-described preferred embodiments. Anyone can derive other products in various forms under the guidance of this application. However, regardless of any changes made to their shape or structure, any technical solution that is the same as or similar to that of this application falls within the protection scope of this application.

Claims

1. A construction method for a large-span single-box multi-chamber steel box girder of a single-tower cable-stayed bridge, characterized in that, The method comprises the following steps: S00, assembling platform erection: Erecting an assembling platform, which comprises a first assembling plate (16) and a second assembling plate (17) for carrying a box girder segment (36); S10, box girder segment barge transportation: Transporting the assembled box girder segment (36) by using a girder barge (30); the side of the barge cabin (32) of the girder barge (30) is provided with a position control air bag (31), the buoyancy of the barge is controlled by pressurizing or depressurizing the position control air bag (31), and the box girder segment (36) is fixed by using a fixing device (39, 42, 43); S20, box girder segment transportation: Transporting the assembled box girder segment (36) by using a girder barge (30); the girder barge (30) is provided with a position control air bag (31), and the buoyancy of the girder barge (30) is controlled by pressurizing or depressurizing the position control air bag (31); S30, box girder segment hoisting and connection: A mobile crane (47) is arranged on the installed girder segment (81), the direction of the girder barge (30) is adjusted by a balance actuator (51) arranged on the girder barge (30), the box girder segment (36) is lifted by using the position control air bag (31) and a counterweight, and the box girder segment (36) is hoisted to a position to be installed by the mobile crane (47); S40, box girder segment inter-welding: A liftable construction platform (64) is arranged outside a crane connecting plate (48) of the mobile crane (47), the liftable construction platform (64) moves vertically along a lifting guide rail (59) to provide a welding work position for workers; S50, box girder closure segment hoisting: First and second support piers (65, 66) are arranged on the box girder segments (36) on both sides of a box girder closure segment (71), a support pressurizing body (67) is used to apply a pressing force to the first and second support piers (65, 66) to reserve a closure space, and then the box girder closure segment (71) is hoisted and welded.

2. The construction method according to claim 1, characterized in that, The step S00 of assembling platform erection specifically comprises: An extruded support pier (3) is arranged in a foundation soil body (2) on the side of a water bank (1), and a strip-shaped connecting plate (4) is laid on the extruded support pier (3); A connecting anchor pipe (5) is inserted into the extruded support pier (3), and sodium-based bentonite is injected into the extruded support pier (3) through the connecting anchor pipe (5); First and second support columns (6, 7) are arranged through the strip-shaped connecting plate (4), and a closed cofferdam (10) is arranged on the outer periphery of the first and second support columns (6, 7); The first assembling plate (16) is arranged at the top end of the first support column (6), and the second assembling plate (17) is arranged at the top end of the second support column (7).

3. The construction method according to claim 1, characterized in that, Step S10: The box girder segment (36) is slid to the set position of the first and second assembling plates (16, 17) by using a mobile trolley (21); A height adjusting body (26) and a height adjusting angle steel (27) are arranged at the joint; The temperature of the high-temperature heat-conducting oil in the temperature compensation bag (29) is controlled to 150-200℃.

4. The construction method according to claim 3, characterized in that, The temperature compensation bag (29) is sent to the joint along the cavity of the box girder segment (36) by the moving support frame (28); the moving support frame (28) is provided with support frame rollers (88) at the position where the moving support frame (28) is in contact with the inner surface of the box girder segment (36).

5. The construction method according to claim 1, characterized in that, In step S20, The position control air bag (31) is arranged on the side of the barge cabin (32) of the girder transporting barge (30). The box girder segment (36) is also fixed by the rotating fixing frame (39), the positioning bolt shaft (41), the upper fixing body (42) and the lower fixing body (43).

6. The construction method according to claim 5, characterized in that, The position control air bag (31) is connected with the pressure charging pump (73) and the pressure reducing pump (44) through the pressure charging pipe (72) and the pressure reducing pipe (45) respectively; the rotating fixing frame (39) is connected with the barge deck (37) through the fixing frame rotating shaft (74).

7. The construction method according to claim 1, characterized in that, In step S30, The balance actuator (51) is an electric propeller arranged on both sides of the girder transporting barge (30).

8. The construction method according to claim 1, characterized in that, In step S30, The moving crane (47) is arranged on the crane guide rail (46) laid on the installed girder segment (81), and the moving crane (47) is connected with the crane sliding groove (79) on the crane guide rail (46) through the crane sliding block (49). The angle of the box girder segment (36) is adjusted in the air by rotating the position adjusting body (57) and the connecting boom (58).

9. The construction method according to claim 1, characterized in that, In step S40, The lifting guide rail (59) is provided with a guide rail sliding groove (85); The liftable construction platform (64) is connected with the lifting connecting body (62) through the rigid boom (63), and the lifting connecting body (62) is slidingly matched with the guide rail sliding groove (85); The lifting connecting body (62) is driven by the cable winding and pulling machine (60) to realize the vertical movement of the liftable construction platform (64).

10. The construction method according to claim 1, characterized in that, In step S50, The supporting and pressing body (67) is a hydraulic jack, and the supporting and pressing body (67) presses the cross beam end plate (68) and the supporting beam (69) to exert the pressing force; The cross beam end plate (68) is slidingly connected with the end plate sliding groove (86) arranged on the second supporting pier (66); The box girder closing segment (71) is hung by rotating the supporting plate (70).

Images