Walking type pushing construction method for crossing high-speed large-span steel box girder

Abstract

The invention discloses a walking type pushing construction method for a high-speed large-span steel box girder, and relates to the technical field of steel box girder construction. Comprising the following steps: 1) bracket assembling and mounting; (2) the pushing sections are hoisted in a fragmented mode; 3) measuring and adjusting the steel box girder; (4) splicing of the pushing sections is completed; 5) welding the steel box girder; (6) mounting a steel guide beam; (7) pushing equipment is installed and debugged; (8) steel box girder incremental launching construction is conducted; (9) pushing in place and falling the beam; (10) mounting a hoisting section of the steel box girder; according to the steel box girder pushing support structure system, highway passing is not affected, and the steel box girder pushing support structure system is economical, firm and stable.

Description

Technical Field

[0001] The invention relates to the technical field of steel box girder construction, in particular to a construction method for walking-type jacking of a high-speed large-span steel box girder. Background Art

[0002] During the construction of a large-span steel box girder bridge across a highway, it is easy to cause obstacles to the traffic on the highway under the bridge, especially the curved shape, which is difficult to install. In addition, the highway needs to be closed for a long time for safety during construction, and the traffic is interrupted. The installation of a large-span steel box girder also brings great safety hazards to the road traffic under the bridge. Therefore, the construction site needs to adopt a method that does not affect the traffic on the highway and can quickly and efficiently complete the installation of the steel box girder across the highway.

[0003] To this end, we provide a construction method of walking jacking across high-speed and large-span steel box girders to solve the above problems. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a construction method for walking-type jacking of a high-speed large-span steel box girder, comprising the following steps:

[0005] 1) Bracket assembly and installation;

[0006] 2) Lifting of the top-pushing section in sections;

[0007] 3) Measurement and adjustment of steel box beams;

[0008] 4) The assembly of the push section is completed;

[0009] 5) Steel box girder welding;

[0010] 6) Installation of steel guide beam;

[0011] 7) Installation and commissioning of jacking equipment;

[0012] 8) Steel box girder jacking construction;

[0013] 9) Push the beam into place and drop it;

[0014] 10) Installation of steel box girder hoisting section;

[0015] In step S2, the lifting of the pushing section in sections includes the following:

[0016] S21, Steel Box Girder Segmentation

[0017] The steel box girder is planned to be processed in sections and pieces in the factory and installed by large machinery on site. Based on the requirements of the design drawings and the structural characteristics of the steel box girder, combined with the restrictions of road transportation and the principle of convenient on-site installation, the section-by-section principles for hoisting the steel box girder are as follows:

[0018] A. The top plate, bottom plate and web of the steel box girder are made into a tongue-and-groove shape, and the staggered seam is not less than 250mm;

[0019] B. The staggered seams between the stiffening ribs and the top plate, bottom plate and web of the steel box girder shall not be less than 200mm;

[0020] The steel box girders across the high-speed bridge are divided into multiple groups and arranged obliquely; cantilevers are set on both sides, and multiple box chambers are welded in the middle of each group of steel box girders, and at least 7 are installed;

[0021] There are multiple groups of steel box girders, which are distributed in an arc shape with an arc of 60°, and at least 15 groups are provided;

[0022] S22. After the steel box girder is transported to the site in sections and pieces, an assembly cradle is arranged at the assembly site, and then a 350t crawler crane is used to assemble the steel box girder. When the steel box girder is assembled on site, the truck crane travels on the left side of the bridge.

[0023] In a further technical solution, step S1, assembling and installing the bracket, includes:

[0024] S11. Support foundation construction:

[0025] b) Dig out the soft ground at the bottom of the foundation and backfill it with gravel;

[0026] b) A foundation bearing capacity test must be conducted before foundation construction, and the foundation bearing capacity must meet the calculation requirements;

[0027] c) The foundation measurement and layout position must be accurate, and the position of the foundation embedded parts must be accurate;

[0028] d) Strengthen the vibration of foundation concrete, cover and water the concrete to ensure the strength of foundation concrete;

[0029] S12. Set up assembly brackets at the 2.5 span position of the starting jacking, set up jacking brackets at the steel box girder spans on both sides of the expressway, and set up a row of jacking brackets at the green belt position of the expressway;

[0030] S13. Installation of assembly brackets. When assembling steel box girders on site, circular tube lattice columns are used as temporary support structures. Temporary supports are arranged on both sides of the butt joints of steel box girders. Temporary supports are connected by welding. Circular tube lattice columns are arranged at the segmented butt joints. Circular tube lattice columns are set at the segmented butt joints of steel box girders. There are sections A to R. Six groups of circular tube lattice columns are set at the butt joints of sections K to R. The spacing between circular tube lattice columns is 5m, and the size of circular tube lattice columns is 2m*2m.

[0031] S14. Multiple groups of jacking brackets are set up, each group uses 4 Ф610*10mm steel pipes as columns, 3m vertically × 2.5m horizontally arranged, the foundation uses an expanded foundation of 4m×6m×1m, the connection system specification is 14a I-beam, the top of the column is a four-piece 40a I-beam horizontal distribution beam, the length is 4m; above the horizontal distribution beam is a four-piece 588*300 I-beam longitudinal jacking platform, the length of the platform is 4m; the walking jacking equipment is placed on it;

[0032] Along the bridge, handover conversion columns and transverse distribution beams are arranged before and after the jacking equipment. The conversion columns are made of Ф273*7mm, and the transverse distribution beams are made of double-jointed 40a I-beams with a length of 4m.

[0033] S15. The support components are hoisted by crawler cranes. During hoisting, the support uprights are installed first, and then the column supports are installed. The column supports and columns are fixed by welding. After the installation is completed, the temporary support needs to be checked. After it is correct, the column base and the embedded foundation parts are fixed by high-strength bolts.

[0034] In a further technical solution, step S3, steel guide beam production and installation:

[0035] S31, Steel guide beam production: adopt variable cross-section I-shaped, the connection with the steel box beam gradually decreases towards the end;

[0036] The steel guide beam is composed of 4 sets of longitudinal beams, with a length of 35m. Its structural dimensions are consistent with those of the steel box beam. The root of the steel guide beam is welded to the bottom plate and the second web of the main beam. The 4 sets of longitudinal beams are connected by transverse distribution beams to form a whole.

[0037] The upper flange plate is 16mm thick, the lower flange plate is 20mm thick, the web plate is 20mm thick, the connection system is φ630*9mm, φ325*7mm, the cross diaphragm is 14mm thick, and the connecting transverse distribution beam is a steel tube truss structure;

[0038] S32. Installation of steel guide beams: The steel guide beams are pre-assembled into a whole on the ground and installed by crane; the transverse connections of the steel guide beams are installed later, and the temporary supports are removed after the whole is formed; the connection roots between the steel guide beams and the steel box beams are welded, the welds are full penetration welds, the weld grade is level 2, and the welding quality of each contact point needs to be strengthened.

[0039] In a further technical solution, S4, steel box girder measurement and adjustment:

[0040] After the steel box girder is assembled and installed, a total station is set up on the steel box girder to measure the designed three-dimensional coordinates of the four locating corner points of the steel box girder and compare them with the actual coordinate positions; if there is any deviation, a three-way fine-tuning jack is used to make real-time adjustments so that the locating point accuracy meets the requirements; the elevation of the steel box girder is re-measured with a level, and if there is any error, it is adjusted in real time.

[0041] In a further technical solution, S5, steel box girder welding:

[0042] S51, performing preliminary preprocessing;

[0043] S52, clamping and welding the panels; welding starts from the bottom plate of the box, and welds in the order of the bottom plate, top plate, side plate, partition plate 17, and bottom plate;

[0044] S53, processing the weld; for the fillet weld, a butt weld welding method is used, and for the straight weld, a butt weld welding method is used;

[0045] S54, performing welding processing on the entity parts.

[0046] In a further technical solution, S6, installation and commissioning of jacking equipment

[0047] The steel box girder jacking adopts a walking type continuous jacking method, and the walking type jacking equipment is installed on the jacking bracket; the walking type jacking equipment includes a walking type jacking machine, and a group of transverse distribution beams are arranged above the two groups of transverse jacks to support the steel box girder. The bottom of the transverse distribution beam is fixed with the jack, and the layout is inclined and increased;

[0048] Place a crawler jacking machine on the temporary pier jacking platform. The jacking direction must be correct and parallel to the direction of the bridge. Place the pump station reasonably in the middle of the temporary pier and choose a reasonable location on site to place the control center. During the equipment lifting process, there must be a dedicated person to observe and direct the lifting equipment, and the installation of each equipment must comply with the installation requirements.

[0049] In a further technical solution, S7, steel box girder top-pushing construction:

[0050] S71, Steel Box Girder Pushing Process

[0051] The jacking method uses a walking jacking device to push the installed steel box girder to the designed position after the steel box girder is assembled on the supporting structure on one side of the main bridge.

[0052] The workflow is as follows:

[0053] a) Preparation of walking type jacking equipment;

[0054] b) Start the hydraulic pump station to enable the lifting cylinder in the walking type jacking equipment to lift the steel box girder synchronously;

[0055] c) The lifting cylinder is stopped, and the pushing cylinder is pushed forward one stroke synchronously, that is, the steel box girder moves forward one stroke;

[0056] d) The oil cylinder stops, the lifting cylinder retracts, and the pushed component falls on the temporary support;

[0057] e) Retract the push cylinder and repeat steps 1 to 4 after it is in place until the pushed component is pushed to the installation position;

[0058] S72, Steel Box Girder Pushing Steps

[0059] f) First, install the assembly bracket; then, install the jacking bracket; finally, install the first jacking section K / L / M / N / P / R of the segmental steel box girder on the assembly bracket, and install the guide beam at the end;

[0060] g) First, the first jacking stroke; then the front end of the right guide beam reaches the position of the jacking bracket D5 and is about to step onto D5;

[0061] h) The left guide beam crosses D5, and the right guide beam is suspended;

[0062] i) Steel box girder tail assembly segment F / G / H / J;

[0063] j) First, the overall jacking stroke of the steel box girder; then the front end of the left guide beam reaches the position of the jacking bracket D6, and is about to step onto D6 and support on the right side;

[0064] k) The overall jacking stroke of the steel box girder is firstly made; the front end of the steel box girder then reaches the jacking bracket D7 and the guide beam is removed;

[0065] l) The steel box girder is pushed to the bridge position;

[0066] m) Segmental hoisting of assembled steel box girders;

[0067] S73, Monitoring measures for top-pushing construction of steel box beams

[0068] Geometric linear monitoring: high-precision leveling instruments are used, with accidental errors of ≤1mm / km. Level II leveling leveling measurement standards are used as the control network for elevation control, and level III leveling leveling elevation accuracy control joint measurement is used for box girder casting;

[0069] In a further technical solution, S8, beam drop process:

[0070] S81, beam dropping idea: after pushing into place, use 8 400-ton jacks with a stroke of 200 mm to lift the steel box beam and add pads, then remove the walking jacks and brackets, and drop the beam on the permanent pier cap beam; when the remaining 500 mm is dropped, replace it with a jack with a stroke of 50 mm to continue dropping the beam;

[0071] After pushing to the designed plane position, start linear adjustment and beam drop construction. The steps are as follows:

[0072] a) Use 8 400-ton 200-stroke jacks and support blocks to drop the beam on the cap beam, with each block 100 mm high;

[0073] b) Use the jack to lift the steel box girder and the steel pads at the support to make them empty; after removing one layer of steel pads at the support, use the jack to lower the steel box girder as a whole by 100mm, so that the steel box girder can be supported on the steel pads again;

[0074] c) The oil of the jack is returned to the bottom of the beam, so that the plunger of the jack is separated from the bottom of the beam; after removing a layer of steel pads under the jack, the plunger is extended and tightened against the bottom of the beam again;

[0075] Repeat the above steps a to c, and extract the steel pads at the support and under the jack layer by layer; until the steel box girder is completely dropped onto the support;

[0076] S82, steel box girder adjustment

[0077] After the steel box girder is hoisted to the predetermined position, if there is an error between the position and the designed position, the hoisting position of the steel box girder needs to be adjusted in detail and accurately. The adjustment is carried out in the order of plane position first and then elevation;

[0078] Here are the steps:

[0079] 1) Precise adjustment of plane position

[0080] a) Adjustment of the forward and backward position of the bridge

[0081] Adjustment of the rear point position: weld two stress points on the web plates on both sides of the box chamber of the installed steel box girder and the steel box girder to be adjusted, then install a 10t three-way flat set between the two stress points, and adjust the fastening screw buckle on the three-way flat set to complete the adjustment of the rear point position of the steel box girder;

[0082] Adjustment of the front point position: weld two stress points on the bottom plate of the inner surface of the steel box girder and the H-shaped steel at the position to be adjusted, and install a 10t horizontal three-way set between the stress points to complete the adjustment of the front point position;

[0083] b) Adjustment of the left and right position of the transverse bridge;

[0084] In a further technical solution, S9, the assembly section steel box girder installation

[0085] A 350t crawler crane is used to lift the steel box girders in sections and pieces onto the assembly bracket for assembly, welding, painting, and then adjusting the dropped beams.

[0086] Compared with the prior art, the circulating heat exchange device and heat exchange method of the heat exchange station of the thermal power plant have the following beneficial effects:

[0087] The walking-type jacking construction method of the large-span steel box girder across the highway solves the problem that the construction of the steel box girder across the highway affects the normal traffic of the highway and poses a great safety hazard. It also solves the problem of the installation accuracy of the steel box girder, effectively ensures the passage of the highway under the bridge, and can quickly and efficiently complete the installation of the large-span curved section steel box girder. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 It is a construction flow chart of the construction method of the present invention;

[0089] Figure 2 It is a schematic diagram of the steel box girder segmentation and fragmentation of the construction method of the present invention;

[0090] Figure 3 is a schematic diagram of step 1 of the construction method of the present invention;

[0091] Figure 4 It is a schematic diagram of steps two and three of the construction method of the present invention;

[0092] Figure 5 is a schematic diagram of steps four and five of the construction method of the present invention;

[0093] Figure 6 is a schematic diagram of step six of the construction method of the present invention;

[0094] Figure 7 is a schematic diagram of step seven of the construction method of the present invention;

[0095] Figure 8 is a schematic diagram of step eight of the construction method of the present invention;

[0096] Fig. 9 It is a schematic diagram of the longitudinal staggered joint of the steel box girder of the present invention;

[0097] Fig.10 This is a schematic diagram of the longitudinal staggered joints of the stiffening ribs of the present invention;

[0098] Fig.11 It is a schematic diagram of a transverse division of a set of steel box girders of the present invention;

[0099] Fig.12 This is a schematic diagram of a group of transverse sections of a steel box girder of the present invention.

[0100] Fig.13 It is a schematic diagram of the automobile crane hoisting a steel box girder of the present invention;

[0101] Fig.14 is a layout diagram of the push support of the present invention;

[0102] Fig.15 It is a schematic diagram of the bottom foundation of the jacking support column of the present invention;

[0103] Fig.16 is a schematic front view of a steel guide beam of the present invention;

[0104] Fig.17 is a schematic side view of a steel guide beam of the present invention;

[0105] Fig.18 yes Fig.17 AA cross-section diagram.

[0106] In the figure:

[0107] 1. Steel box girder; 2. Steel guide beam; 3. Truck crane; 4. Gravel backfill; 5. Assembly bracket; 6. Push bracket; 11. Cantilever arm; 12. Box chamber; 13. Box bottom plate; 14. Top plate; 15. Side plate; 16. Web plate 1; 21. Longitudinal beam; 22. Upper flange plate; 23. Lower flange plate; 24. Web plate 2; 61. Column; 62. Horizontal distribution beam; 63. Longitudinal push platform; 64. Walking push equipment. DETAILED DESCRIPTION

[0108] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0109] See also Figure 1-18 The present invention provides a technical solution: a method for step-by-step jacking construction of a high-speed large-span steel box girder, the specific operation is as follows:

[0110] The construction process is:

[0111] 1) Bracket assembly and installation;

[0112] 2) Lifting of the top-pushing section in sections;

[0113] 3) Measurement and adjustment of steel box girder 1;

[0114] 4) The assembly of the push section is completed;

[0115] 5) Welding of steel box girder 1;

[0116] 6) Installation of steel guide beam 2;

[0117] 7) Installation and commissioning of jacking equipment;

[0118] 8) Pushing construction of steel box girder 1;

[0119] 9) Push the beam into place and drop it;

[0120] 10) Installation of hoisting section 1 of steel box girder;

[0121] S1. Bracket assembly and installation

[0122] S11. Construction of support foundation: a) Dig out the soft foundation at the bottom of the foundation and perform gravel backfill 4 treatment; b) Before foundation construction, a foundation bearing capacity test is required, and the foundation bearing capacity must meet the calculation requirements; c) The foundation measurement and layout position must be accurate, and the position of the foundation embedded parts must be accurate; d) Strengthen the vibration of the foundation concrete, do a good job of covering and watering the concrete for maintenance, and ensure the strength of the foundation concrete.

[0123] S12. An assembly bracket 5 is set at the 2.5 span position of the starting jacking, a jacking bracket is set at the 1 span position of the steel box girder on both sides of the expressway, and a row of jacking brackets is set at the green belt position of the expressway.

[0124] S13, assembly bracket 5 is installed. When the steel box girder 1 is assembled on site, the circular tube lattice column is used as the temporary support structure. The temporary support is arranged on both sides of the butt ring of the steel box girder 1. The temporary support rods are connected by welding. The main limbs are butt-jointed with full penetration welds, and the tie bars and the main limbs are connected with full-penetration fillet welds. The weld leg size is not less than the specification requirements. The temporary support of the lattice column of the steel box girder 1 is arranged at the segmented butt joint. Lattice columns are set at the segmented butt joints of the steel box girder 1. Six groups of lattice columns are set at the K~R butt joints. The lattice columns are 5m apart and the lattice columns are 2m*2m.

[0125] S14, such as Fig.14 As shown, each group of the jacking bracket 6 uses 4 610*10mm steel pipes as columns 61, 3m longitudinally × 2.5m transversely arranged, the foundation uses an expanded foundation of 4m×6m×1m, the connection system specification is 14a I-beam, the top of the column 61 is a four-piece 40a I-beam transverse distribution beam 62, the length of which is 4m, and above the transverse distribution beam 62 is a four-piece 588*300 I-beam longitudinal jacking platform 63, the platform length is 4m, and the walking jacking equipment 64 is placed on it. In the direction of the bridge, the hand-over conversion column and the transverse distribution beam 62 are arranged before and after the jacking equipment. The conversion column uses 273*7mm, and the transverse distribution beam 62 uses double-piece 40a I-beams, the length of which is 4m.

[0126] S15. The support components are hoisted by crawler cranes. During hoisting, the support poles are installed first, and then the inter-column supports are installed. The inter-column supports are fixed to the columns 61 by welding. After the installation is completed, the temporary support needs to be checked. After it is correct, the column foot and the embedded foundation parts are fixed by high-strength bolts.

[0127] S2. Lifting of the top push section in sections

[0128] S21, steel box girder 1 segment division

[0129] The steel box girder 1 is planned to be processed in sections and pieces in the factory and installed by large machinery on site. According to the requirements of the design drawings and the structural characteristics of the steel box girder 1, combined with the restrictions of road transportation and the principle of convenient on-site installation, the section-by-section principles for hoisting the steel box girder 1 are as follows:

[0130] like Fig. 9 and 10 As shown, A. the top plate 14, the bottom plate 13 and the web plate 16 of the steel box girder 1 are made into a tongue-and-groove shape, and the staggered seam is not less than 250mm;

[0131] B. The staggered joints between the stiffening ribs of the steel box girder 1 and the top plate 14, the bottom plate 13, and the web plate 16 shall not be less than 200mm;

[0132] S22, after the steel box girder 1 is transported to the site in sections and pieces, an assembly cradle is arranged at the assembly site, and then the steel box girder 1 is installed by a truck crane 3, which is a 350t crawler crane. When the steel box girder 1 is assembled on site, the truck crane 3 moves on the left side of the bridge;

[0133] S3. Fabrication and installation of steel guide beam 2

[0134] S31, Steel Guide Beam 2 Fabrication: A guide beam is required at the front end of the steel box beam 1. To reduce the deadweight of the guide beam and meet the requirements of the top-pushing construction of the steel box beam 1, a variable-section I-shaped guide beam is designed, which gradually decreases from the root to the connection with the steel box beam 1 to the end. Since the main line bridge port is an oblique structure, such as Figure 16-18 As shown, the steel guide beam 2 is composed of 4 sets of longitudinal beams 21, and the length of the longitudinal beam 21 is 35m. Its structural dimensions are consistent with the box beam. The root of the guide beam is welded to the bottom plate of the main beam and the second web plate 24. The four sets of longitudinal beams 21 are connected to form a whole through a transverse distribution beam 62. The upper flange plate 22 of the longitudinal beam 21 is 16mm thick, the lower flange plate 23 is 20mm thick, the thickness of the second web plate 24 is 20mm, the connection system is φ630*9, φ325*7, the cross partition is 14mm thick, and the connecting transverse distribution beam 62 is a steel tube truss structure.

[0135] S32, installation of steel guide beam 2: Steel guide beam 2 is pre-assembled into a whole on the ground and installed by crane; steel diagonal braces and wind cables are set to prevent overturning. Finally, the transverse connection of steel guide beam 2 is installed, and the temporary support is removed after forming a whole. The connection root between steel guide beam 2 and steel box beam 1 is welded, and the weld is a penetration weld with a weld grade of level 2. Considering the importance of the connection between steel guide beam 2 and steel box beam 1, the welding quality at this location must be strictly guaranteed and strengthened. The connection section of steel guide beam 2 is welded and strengthened.

[0136] S4, Steel Box Girder 1 Measurement and Adjustment

[0137] After the steel box girder 1 is assembled and installed, a total station is set up on the steel box girder 1 to measure the designed three-dimensional coordinates of the four positioning corner points of the steel box girder 1 and compare them with the actual coordinate positions. If there is a deviation, a three-way fine-tuning jack is used to make real-time adjustments to ensure that the positioning point accuracy meets the requirements. The elevation of the steel box girder 1 is re-measured using a level, and if there is an error, it is adjusted in real time.

[0138] S5, Steel Box Girder 1 Welding

[0139] S51, perform preliminary treatment, such as grinding, cleaning the surface dirt, and removing burrs on the board with a file.

[0140] S52, clamping and welding the panels. Generally, welding starts from the bottom plate 13 of the box, and is performed in the order of the bottom plate 13, the top plate 14, the side plate 15, the partition plate 17, and the bottom plate.

[0141] S53. Process the weld. Different parts require different weld processing options. For fillet welds, the welding method of butt welds is used, and for straight welds, the welding method of butt welds is used.

[0142] S54, perform welding processing on the entity parts, such as welding of the box body and the end plate, and welding processing of the cascade hinge parts.

[0143] S6. Installation and commissioning of jacking equipment

[0144] The steel box girder 1 is pushed by a walking continuous pushing method. A walking pushing device 64 for the steel box girder 1 is installed on the distribution beam of the pushing bracket 6. A group of transverse distribution beams 62 are arranged above the two transverse groups of walking pushes to support the steel box girder 1. The bottom of the transverse distribution beam 62 is fixed to the jack.

[0145] The jacking pump station is placed on the platform between the two jacking machines. The oil port is facing the opposite direction of the bridge. The overall dimensions of the jacking pump station are: 2075mm*1170mm*723mm long*wide*high, and the weight is about 1.5t / unit.

[0146] Power distribution requirements: A secondary power box is set up on the platform, within 10m of the pump station. The power demand of a single hydraulic pump station is AC380V±10%, three-phase five-wire system, the actual current is greater than 30A, and the grounding resistance is less than 4 ohms. Because there is a frequency converter in the system, the leakage protection item needs to set the leakage current to be large enough, or cancel the leakage protection at one end of the frequency converter.

[0147] Place the crawler jacking machine on the temporary pier jacking platform. The jacking direction must be correct and must be parallel to the direction of the bridge. Place the pump station reasonably in the middle of the temporary pier and choose a reasonable location on site to place the control center. During the equipment lifting process, there must be a dedicated person to observe and direct the lifting equipment. Connect the equipment according to the "Installation Diagram of the Walking Jacking Machine": install them in the order of control center to sub-control box, sub-control box to sub-control box, sub-control box to distribution box, and pump station to walking jacking machine. The high-voltage cable from sub-control box to distribution box, and the transmission data cable from control center to sub-control box and sub-control box to sub-control box must be correctly connected. The pump station to the crawler oil pipeline is correctly connected, and the signal cable from the pump station to the walking jacking machine is correctly connected. The vertical displacement sensor is correctly connected, and the pull wire is correctly installed. After the installation is completed, check the integrity and correctness of the entire set of equipment again, tighten the bolts, and re-tighten the joints of each device.

[0148] S7, Steel Box Girder 1 Pushing Construction

[0149] S71, Steel Box Girder 1 Pushing Process

[0150] The jacking method uses a walking jacking device to push the installed steel box girder 1 as a whole to the designed position after the steel box girder 1 is assembled as a whole on the supporting structure on one side of the main bridge. The steel guide beam 2 plays the role of load-bearing and guiding during the jacking construction process.

[0151] Working principle of the jacking system: equipment preparation → jacking cylinder lifts up the bridge supported by the jacking cylinder → forward → jacking cylinder drops down the bridge is supported by temporary support → push the equipment back to the initial state, thus completing a jacking work of one stroke, and the box girder is transported forward in a walking manner in this way. The working process is shown in the figure below:

[0152] a) Preparation of walking type pushing equipment 64

[0153] b) Start the hydraulic pump station to enable the lifting cylinder in the walking jacking device 64 to synchronously lift the steel box girder 1.

[0154] c) The lifting cylinder is stopped, and the pushing cylinder is pushed forward one stroke synchronously, that is, the steel box girder 1 moves forward one stroke.

[0155] d) The oil cylinder stops, the lifting cylinder retracts, and the pushed component falls on the temporary support.

[0156] e) Retract the push cylinder and repeat steps 1 to 4 when it is in place until the pushed component is pushed to the installation position.

[0157] This steel box adopts a multi-point jacking method. When multi-point jacking is used, a sliding device and a jacking device are set on each support frame to disperse the concentrated jacking force to each support frame.

[0158] Compared with centralized single-point jacking, multi-point jacking can avoid the need for large-scale jacking equipment, effectively control the displacement of the beam during jacking, and reduce the horizontal thrust on the bridge pier to a very small level. However, multi-point jacking requires more equipment and devices, and the synchronization requirements during operation are very high.

[0159] S72, Steel Box Girder 1 Pushing Steps

[0160] f) First, the assembly bracket 5 is installed; then, the jacking bracket 6 is installed; then, the interval K / L / M / N / P / R of the first jacking segment steel box girder 1 is installed on the assembly bracket 5, and the steel guide beam 2 is installed at the end;

[0161] g) First, the first jacking stroke; then the front end of the right steel guide beam 2 reaches the position of the jacking bracket 6D5, and is about to step onto D5;

[0162] h) The left steel guide beam 2 spans D5, and the right steel guide beam 2 is suspended in the air;

[0163] i) Steel box girder 1 tail assembly segment F / G / H / J;

[0164] j) First, the steel box girder 1 has an overall jacking stroke; then the front end of the left steel guide beam 2 reaches the position of the jacking bracket 6D6, and is about to step onto D6, and the right side supports;

[0165] k) First, the steel box girder 1 has an overall jacking stroke; then the front end of the steel box girder 1 reaches the jacking support 6D7, and the steel guide beam 2 is removed;

[0166] l) The steel box girder 1 is pushed to the bridge position;

[0167] m) Hoisting of one section of assembled steel box girder;

[0168] S73, Steel Box Girder 1 Pushing Construction Monitoring Measures

[0169] Geometric Linearity Monitoring:

[0170] The principle of bridge construction control is the comprehensive consideration of deformation and stress, among which deformation control is the main one, strictly controlling the deflection of each control section and the axis transverse bridge deviation, and controlling the stress development through theoretical calculation. The linear control of the main beam is completed by construction control calculation and the deflection and elevation control of each section of the box beam. The deflection and elevation control of the box beam is achieved by observing the elevation of the top and bottom of the beam, and then combining the theoretical control calculation results to achieve the control purpose. This requires the establishment of a corresponding construction control measurement network, through the monitoring of the elevation of each beam section during the construction process, monitoring the changes in the position of the box beam axis during the construction process, to ensure that the error control of the main beam is within the range allowed by the design requirements and specifications. Combined with the actual situation of this project, a monitoring point is arranged every 10m at the axis position of the top plate 14 of the steel box beam.

[0171] In order to ensure the construction accuracy of the box girder axis elevation, the deviation value that occurs during construction is timely and accurately controlled and adjusted through on-site actual measurement. A high-precision level is selected, and the accidental error is ≤1mm / km. The elevation control is based on the II-level elevation control measurement standard as the control network, and the box girder casting is based on the III-level elevation accuracy control joint measurement.

[0172] S74, Steel Box Girder 1 Pushing Synchronous Guarantee Measures

[0173] Although the friction force cannot be guaranteed to be consistent during the jacking process, the synchronization of the jacks can ensure the consistency of displacement and reduce the occurrence of adverse structural deflection.

[0174] When the lifting jack piston extends to lift the box beam, the push jack piston extends to push the beam forward. This process requires displacement synchronization control, pressure balance control, and lateral adjustment control. In addition to controlling the unified action of the push jacks on all piers, the main console must also ensure the synchronization of each stroke of all push jacks. The control strategy is: among the horizontal push jacks on the same pier, the 1# top is the active point, and the cylinder is extended at a certain speed. The other horizontal tops are the follower points and compared with the 1# top. The displacement difference between each top and the 1# top is controlled within the set value. If any top extends the cylinder faster, the flow of the corresponding proportional valve is reduced, otherwise, the flow of the corresponding proportional valve is increased. The synchronous control method of horizontal jacking jacks on different piers is: take the 1# top on the N1 pier as the active point, and compare it with the 1# top of the N2 pier to the LN temporary pier. If any jacking cylinder is faster, the flow of the corresponding proportional valve will be reduced, otherwise, the flow of the corresponding proportional valve will be increased, so as to achieve the synchronization of all horizontal jacking. The synchronization accuracy of this process can be controlled within 5mm between each pier, and within 1mm on both sides of the same pier. There is no need for synchronous control of the jacking jack cylinder retraction.

[0175] Since each jack is equipped with a pressure transmitter for monitoring load changes, the maximum pressure of each jack and the maximum pressure difference of several jacks on the same pier can be set through the field controller or the panel on the main console. The computer accurately coordinates the load distribution of the entire system by monitoring the load changes of each jack. If the load of a jack reaches the set maximum pressure or the maximum pressure difference of several jacks on the same pier is greater than the set value, the system will automatically shut down and alarm.

[0176] This is a synchronous control with pressure control as the main control and displacement control as the auxiliary control.

[0177] S75, vertical lifting control

[0178] When the piston of the vertical lifting jack extends, the box beam is lifted. In this process, the main console not only controls the unified action of the cluster lifting jacks, but also detects the lifting height through the displacement sensor installed between the box beam and the cushion beam to ensure the synchronization of the lifting jacks on both sides. The control strategy is to use one side as the reference, and control the displacement difference between the two sides within the set range. If the lifting height of the following side is larger, the flow of the proportional valve on that side is reduced, otherwise, the flow of the proportional valve on that side is increased. The synchronization accuracy of this process can be controlled within 4mm.

[0179] When the vertical lifting jack retracts, the jacking wedge and beam drop and fall onto the jacking device bracket again. In this process, in addition to controlling the unified action of the cluster lifting jacks, the main console also detects the lifting height through the displacement sensor installed between the box beam and the cushion beam to ensure the synchronization of the lifting jacks on both sides. The control strategy is to use one side as the reference, and the displacement difference on both sides is controlled within the set range. If the lifting height of the following side is larger, the flow of the proportional valve on that side is increased, otherwise, the flow of the proportional valve on that side is reduced. Synchronization of each stroke of the jack. The synchronization accuracy of this process can be controlled within 4mm.

[0180] Since one pressure sensor is installed on each of the four vertical lifting jacks at each stress point to monitor the load at each stress point, the maximum pressure at each stress point and the maximum pressure difference between stress points on the same pier can be set through the on-site controller or the panel on the main console. The computer accurately coordinates the load distribution of the entire system by monitoring the load changes at each stress point. If the load at a stress point reaches the set maximum pressure or the maximum pressure difference between stress points on the same pier is greater than the set value, the system will automatically shut down and sound an alarm.

[0181] S76, Balance Control

[0182] Since a tilt sensor is installed on the cushion beam of each pier to detect the tilt angle of the box beam in the X-axis and Y-axis directions, the balance of the box beam can be controlled by setting the maximum tilt angle of each tilt sensor in the X-axis and Y-axis directions. If the tilt angle of any tilt sensor in the X-axis and Y-axis directions exceeds the set value, the system will stop and alarm.

[0183] The detection and control of balance runs through the entire pushing process.

[0184] S77, control of cumulative error

[0185] During the translation of the box girder, the main console calculates the total displacement of the horizontal jacking jack at each force point, and deducts the minimum displacement from the maximum displacement to obtain the cumulative error. If the cumulative error exceeds the requirement, the "automatic" mode is stopped and the "manual" mode is entered, and the action of the oil cylinder on one side is adjusted separately to correct the error. If the total station monitors that the cumulative error exceeds the requirement, the "automatic" mode is also stopped and the "manual" mode is entered, and the action of the oil cylinder on one side is adjusted separately to correct the error.

[0186] S78. Corrective measures

[0187] During the jacking process, it is necessary to monitor the axis deviation of the steel box girder 1 and adjust the walking jack for real-time lateral deviation correction. The adjustment steps are as follows: jacking a stroke → check the web plate 16 deviation → confirm the lateral adjustment distance → use the beam drop pad to support → use the walking jack to adjust horizontally → the front and rear ends of the steel box girder 1 rotate in the opposite direction around the central axis → construction cycle.

[0188] S8, beam drop process

[0189] S81. Beam dropping idea: Since the height of the beam is high after the box beam is pushed into place, the beam dropping process is as follows: after the box beam is pushed into place, 8 400-ton jacks with a stroke of 200 mm are used to lift the steel box beam 1 and add pads, then the walking jacks and brackets are removed, and the beam is dropped on the permanent pier cap beam. When the beam is dropped to 500 mm, it is replaced with a jack with a stroke of 50 mm to continue dropping the beam.

[0190] After pushing to the designed plane position, start linear adjustment and beam drop construction. The steps are as follows:

[0191] a. Use 8 400-ton 200-stroke jacks and support blocks to lower the beam onto the cap beam. The height of each block is 100 mm.

[0192] b. Use the jack to lift the steel box girder 1 and the steel pads at the supports; after removing one layer of steel pads at the supports, use the jack to lower the steel box girder 1 as a whole by 100mm, so that the steel box girder 1 can be supported on the steel pads again.

[0193] c. Return the oil to the jack, so that the jack plunger is separated from the bottom of the beam; after removing one layer of the steel pad under the jack, extend the plunger and tighten it against the bottom of the beam again.

[0194] Repeat steps a to c, and extract the steel pads at the supports and under the jacks layer by layer; until the steel box girder 1 is completely lowered onto the supports.

[0195] S82, steel box girder 1 adjustment

[0196] After the steel box girder 1 is hoisted to the predetermined position, if there is an error between the position and the designed position, the hoisting position of the steel box girder 1 needs to be adjusted in detail and accurately. The adjustment is carried out in the order of plane position first and then elevation. The specific method is as follows:

[0197] 1. Precise adjustment of plane position

[0198] a. Adjustment of front and rear positions along the bridge direction

[0199] Adjustment of the rear point position: weld two stress points on the web plates 24 on both sides of the box chamber 12 of the installed steel box girder 1 and the steel box girder 1 to be adjusted, then install a 10t flat three-piece set between the two stress points, and complete the adjustment of the rear point position of the steel box girder 1 by adjusting the fastening screw buckles on the flat three-piece set.

[0200] Adjustment of the front point position: Two stress points are welded on the inner surface bottom plate of the box chamber 12 of the steel box girder 1 at the position to be adjusted and the H-shaped steel, and a 10t horizontal three-set is also installed between the stress points to complete the adjustment of the front point position.

[0201] b. Adjustment of the left and right position of the bridge

[0202] S9, Installation of assembled steel box girder 1

[0203] A 350t crawler crane is used to lift the segmented steel box girder 1 onto the assembly bracket 5 for assembly, welding, painting, and then adjusting the dropped beam.

[0204] In summary, the method of walking-type jacking construction of the large-span steel box girder 1 across the highway solves the problem that the construction of the steel box girder 1 across the highway affects the normal traffic of the highway and poses a greater safety hazard, solves the problem of installation accuracy of the steel box girder 1, effectively ensures the passage of the highway under the bridge, and can quickly and efficiently complete the installation of the large-span curved section steel box girder 1.

Claims

1. A construction method for walking-type jacking across a high-speed large-span steel box girder, characterized in that: The following steps are involved: 1) Bracket assembly and installation; 2) Lifting of the top-pushing section in sections; 3) Measurement and adjustment of steel box girder (1); 4) The assembly of the push section is completed; 5) Steel box girder (1) welding; 6) Installation of steel guide beam (2) 7) Installation and commissioning of jacking equipment; 8) Steel box girder (1) jacking construction; 9) Push the beam into place and drop it; 10) Installation of hoisting section of steel box girder (1); The step S2 of lifting the top push section in sections includes the following: S21, Steel Box Girder (1) Segment Division The steel box girder (1) is to be processed in sections and pieces in the factory and installed by large machinery on site. Based on the requirements of the design drawings and the structural characteristics of the steel box girder (1), combined with the restrictions of road transportation and the principle of convenient on-site installation, the principle of segmented hoisting of the steel box girder (1) is as follows: A. The top plate (14), bottom plate (13) and web plate (24) of the steel box girder (1) are made into a tongue-and-groove shape, and the staggered seam is not less than 250 mm; B. The staggered joints between the stiffening ribs of the steel box girder (1) and the top plate (14), the bottom plate (13) and the web plate (24) shall not be less than 200 mm; The steel box beam (1) across the high-speed bridge is divided into multiple groups and arranged in an inclined manner; cantilevers (11) are arranged on both sides, and multiple box chambers (12) are welded in the middle of each group of steel box beams (1), and at least 7 of them are installed; A plurality of steel box girders (1) are provided, and the plurality of steel box girders (1) are distributed in an arc shape with an arc of 60°, and at least 15 groups are provided; S22. After the steel box girder (1) is transported to the site in sections and pieces, an assembly cradle is arranged at the assembly site, and then a 350t crawler crane is used to assemble the steel box girder (1). When the steel box girder (1) is assembled on site, a truck crane (3) travels on the left side of the bridge.

2. The construction method of walking-type jacking for high-speed and large-span steel box girders according to claim 1 is characterized in that: Step S1, assembling and installing the bracket, includes: S11. Support foundation construction: a) Dig out the soft ground at the bottom of the foundation and backfill it with gravel (4); b) A foundation bearing capacity test must be conducted before foundation construction, and the foundation bearing capacity must meet the calculation requirements; c) The foundation measurement and layout position must be accurate, and the position of the foundation embedded parts must be accurate; d) Strengthen the vibration of foundation concrete, cover and water the concrete to ensure the strength of foundation concrete; S12, setting an assembly support (5) at the 2.5 span position of the starting jacking, setting a jacking support at the span position of the steel box girder (1) on both sides of the expressway, and setting a row of jacking supports at the position of the green belt of the expressway; S13, installation of the assembly bracket (5), when the steel box girder (1) is assembled on site, the circular tube lattice column (51) is used as a temporary support structure, and the temporary support is arranged on both sides of the butt joint of the steel box girder (1); the temporary supports are connected by welding; the circular tube lattice column (51) is arranged at the segmented butt joint position, and the segmented butt joint of the steel box girder (1) is provided with a circular tube lattice column (51), and there are intervals A to R, wherein the butt joint of the intervals K to R is provided with 6 groups of circular tube lattice columns (51), the intervals between the circular tube lattice columns (51) are all 5m, and the size of the circular tube lattice column (51) is 2m*2m; S14, multiple groups of jacking brackets (6) are arranged, each group uses 4 610*10mm steel pipes as columns (61), 3m vertically × 2.5m horizontally arranged, the foundation uses an expanded foundation of 4m×6m×1m, the connection system specification is 14a I-beam, the top of the column (61) is a four-piece 40a I-beam transverse distribution beam (62), the length of which is 4m; above the transverse distribution beam (62) is a four-piece 588*300 I-beam longitudinal jacking platform (63), the length of the platform is 4m; the walking jacking equipment (64) is placed on it; A hand-changing conversion column and a transverse distribution beam (62) are arranged in front and behind the jacking equipment along the bridge direction. The conversion column is made of Ф273*7mm, and the transverse distribution beam (62) is made of double-jointed 40a I-beams with a length of 4m; S15. The support member is hoisted by a crawler crane. During hoisting, the support upright pole is installed first, and then the inter-column support is installed. The inter-column support and the column (61) are fixed by welding. After the installation is completed, the temporary support needs to be checked. After it is correct, the column foot and the foundation embedded part are fixed by high-strength bolts.

3. The construction method of walking-type jacking for high-speed and large-span steel box girders according to claim 1 is characterized in that: Step S3: Fabrication and installation of steel guide beam (2): S31, steel guide beam (2) is manufactured by adopting a variable cross-section I-shaped beam, and the cross-section of the steel guide beam (2) gradually decreases toward the end at the connection with the steel box beam (1); The steel guide beam (2) is composed of four groups of longitudinal beams (21), and the length of the longitudinal beam (21) is 35m. Its structural dimensions are consistent with those of the steel box beam (1). The root of the steel guide beam (2) is welded to the main beam bottom plate and the second web plate (24). The four groups of longitudinal beams (21) are connected to form a whole through a transverse distribution beam (62). The upper flange plate (22) is 16 mm thick, the lower flange plate (23) is 20 mm thick, the web plate (24) is 20 mm thick, the connection system is φ630*9 mm, φ325*7 mm, the diaphragm (17) is 14 mm thick, and the connecting transverse distribution beam (62) is a steel tube truss structure; S32, installation of steel guide beam (2): the steel guide beam (2) is pre-assembled into a whole on the ground and installed in place by a crane; the transverse connection of the steel guide beam (2) is then installed, and the temporary support is removed after the whole is formed; the connection root between the steel guide beam (2) and the steel box beam (1) is welded, the weld is a full penetration weld, the weld grade is level 2, and the welding quality of each contact point needs to be strengthened.

4. The construction method of walking-type jacking for a high-speed and large-span steel box girder according to claim 3 is characterized in that: S4. Measurement and adjustment of steel box girder (1): After the steel box girder (1) is assembled and installed, a total station is set up on the steel box girder (1) to measure the designed three-dimensional coordinates of the four positioning corner points of the steel box girder (1) and compare them with the actual coordinate positions; if there is a deviation, a three-way fine-tuning jack is used to make real-time adjustments so that the positioning point accuracy meets the requirements; the elevation of the steel box girder (1) is re-measured using a level, and if there is an error, it is adjusted in real time.

5. The construction method of walking-type jacking for high-speed and large-span steel box girders according to claim 4 is characterized in that: S5. Steel box girder (1) welding: S51, performing preliminary preprocessing; S52, clamping and welding the panels; welding starts from the bottom plate (13), and welding is performed in the order of the bottom plate (13), the top plate (14), the side plate (15), the partition plate (17), and the bottom plate; S53, processing the weld; for the fillet weld, a butt weld welding method is used, and for the straight weld, a butt weld welding method is used; S54, performing welding processing on the entity parts.

6. The construction method of walking-type jacking for a high-speed and large-span steel box girder according to claim 5 is characterized in that: S6. Installation and commissioning of jacking equipment The steel box girder (1) is pushed by a walking continuous pushing method, and a walking pushing device (64) is installed on a pushing bracket (6); the walking pushing device (64) comprises a walking pushing machine, and a group of transverse distribution beams (62) are arranged above two groups of transverse walking beams to support the steel box girder (1), and the bottom of the transverse distribution beam (62) is fixed to a jack, and the layout is inclined and increased; Place a crawler jacking machine on the temporary pier jacking platform. The jacking direction must be correct and parallel to the direction of the bridge. Place the pump station reasonably in the middle of the temporary pier and choose a reasonable location on site to place the control center. During the equipment lifting process, there must be a dedicated person to observe and direct the lifting equipment, and the installation of each equipment must comply with the installation requirements.

7. The construction method of walking-type jacking for high-speed and large-span steel box girders according to claim 6 is characterized in that: S7. Steel box girder (1) jacking construction: S71, Steel Box Girder (1) Pushing Process The jacking method uses a walking-type jacking device (64) to push the installed steel box girder (1) to the designed position as a whole after the steel box girder (1) is assembled on the supporting structure on one side of the main bridge. The workflow is as follows: a) Preparation of walking type pushing equipment (64); b) starting the hydraulic pump station so that the lifting cylinder in the walking type jacking device (64) can synchronously lift the steel box girder (1); c) the lifting cylinder is stopped, and the pushing cylinder is pushed forward synchronously for one stroke, that is, the steel box girder (1) moves forward for one stroke; d) The oil cylinder stops, the lifting cylinder retracts, and the pushed component falls on the temporary support; e) Retract the push cylinder and repeat steps 1 to 4 after it is in place until the pushed component is pushed to the installation position; S72, Steel Box Girder (1) Pushing Steps f) first installing the assembly bracket (5); then installing the jacking bracket (6); then installing the first jacking section K / L / M / N / P / R of the segmental steel box girder (1) on the assembly bracket (5), and installing the steel guide beam 2 at the end; g) First, the first jacking stroke; then, the front end of the right steel guide beam 2 reaches the D5 position of the jacking bracket (6) and is about to step onto D5; h) The left steel guide beam 2 spans D5, and the right steel guide beam 2 is suspended in the air; i) Steel box girder (1) tail assembly segment F / G / H / J; j) First, the steel box girder (1) has an overall jacking stroke; then the front end of the left steel guide beam 2 reaches the D6 position of the jacking support (6) and is about to step onto D6 and support the right side; k) The first steel box girder (1) performs overall jacking travel; the second steel box girder (1) reaches the support D7 of the jacking bracket (6), and the steel guide beam 2 is removed; l) The steel box girder (1) is pushed up to the bridge position; m) Segmental hoisting of assembled steel box girders (1); S73, Steel Box Girder (1) Monitoring Measures for Pushing Construction Geometric linear monitoring: high-precision leveling instruments are used, with accidental errors of ≤1mm / km. The elevation control is based on the II-level elevation control measurement standard as the control network, and the box girder casting is based on the III-level elevation accuracy control joint measurement.

8. The construction method of walking-type jacking for high-speed and large-span steel box girders according to claim 7 is characterized in that: S8, beam dropping process: S81, beam lowering idea: after the jacking is in place, eight 400-ton jacks with a stroke of 200 mm are used to lift the steel box beam (1) and add shims, then the walking jacks and brackets are removed, and the beam is lowered on the permanent pier cap beam; when the beam is lowered to 500 mm, it is replaced with a jack with a stroke of 50 mm to continue lowering the beam; After pushing to the designed plane position, start linear adjustment and beam drop construction. The steps are as follows: a) Use 8 400-ton 200-stroke jacks and support blocks to drop the beam on the cap beam, with each block 100 mm high; b) Using a jack to lift the steel box girder (1) and the steel pads at the supports to separate; after removing one layer of the steel pads at the supports, using a jack to lower the steel box girder (1) as a whole by 100 mm, so that the steel box girder (1) is supported on the steel pads again; c) The oil of the jack is returned to the bottom of the beam, so that the plunger of the jack is separated from the bottom of the beam; after removing a layer of steel pads under the jack, the plunger is extended and tightened against the bottom of the beam again; Repeat the above steps a to c, and extract the steel pads at the support and under the jack layer by layer; until the steel box girder (1) is completely lowered onto the support; S82, Steel Box Girder (1) Adjustment After the steel box girder (1) is hoisted to the predetermined position, if there is an error between the position and the designed position, the hoisting position of the steel box girder (1) needs to be adjusted in detail and accurately, and the adjustment is performed in the order of first the plane position and then the elevation; Here are the steps: 1) Precise adjustment of plane position a) Adjustment of the forward and backward position of the bridge Adjustment of the rear point position: two stress points are welded on the web plates (16) on both sides of the box chamber (12) of the installed steel box girder (1) and the steel box girder (1) to be adjusted, and then a 10t flat three-piece set is installed between the two stress points. The rear point position of the steel box girder (1) is adjusted by adjusting the fastening screw buckles on the flat three-piece set; Adjustment of the front point position: two stress points are welded on the inner surface bottom plate and H-shaped steel of the box chamber (12) of the steel box girder (1) at the position to be adjusted, and a 10t horizontal three-piece set is also installed between the stress points to complete the adjustment of the front point position; b) Adjustment of the left and right position of the transverse bridge.

9. The construction method of walking-type jacking for a high-speed and large-span steel box girder according to claim 8 is characterized in that: S9. Installation of assembled steel box beam (1) A 350t crawler crane is used to lift the segmented steel box beam (1) onto an assembly bracket (5) for assembly, welding, and painting, and then the beam is adjusted.

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