Push-to-install method for large sections of anchored steel beams spanning the sea

Abstract

The present invention provides a method for jacking and installing a large segment of an anchored steel beam across the sea. Temporary piers are arranged between permanent piers, and jacking equipment is arranged on the tops of each permanent pier and temporary pier; a first segment and a front guide beam are hoisted to the tops of the jacking equipment on the tops of the first permanent pier and the first temporary pier by a floating crane, the first segment and the front guide beam are jacked using the jacking equipment to a position where the end of the first segment is located at the top of the first permanent pier, the rear guide beam is fixedly installed by a guide beam joint device to obtain a segment steel box beam; the jacking equipment is used to continue jacking the entire segment steel box beam to the tops of the jacking equipment on the tops of the second permanent pier and the second temporary pier; by adopting a combination of floating crane and jacking, and a solution for quickly assembling and disassembling the rear guide beam, the number of temporary piers to be arranged can be greatly reduced, the construction amount of temporary support can be greatly reduced, the construction cost can be reduced, and the construction efficiency can be improved. The guide beam joint device of the present invention can greatly improve the assembly and disassembly efficiency of the guide beam.

Description

Technical Field

[0001] The present invention relates to the field of offshore bridge construction, in particular to a method for jacking and installing a large segment of an anchored steel beam spanning the sea. Background Art

[0002] For steel box girder bridges in coastal and sea-crossing projects, the large-segment lifting method is currently the primary method for installing prefabricated steel box girders for sea-crossing bridges. This method involves using a large floating crane to lift the steel box girder in sections to the bridge site and then precisely adjust its position. This method leverages the advantages of factory-based steel box girder manufacturing and rapid offshore construction. Due to the use of large-segment construction, the bridge alignment is essentially set during the manufacturing phase, leaving very limited room for adjustment at the bridge site. Failure to properly control the alignment can lead to difficulties in connecting the steel box girders on-site. While the large-segment lifting method is technically mature and highly efficient, it presents significant challenges in installing the steel box girders due to the influence of structures such as the anchors themselves and cofferdams. Furthermore, large floating cranes are expensive to install and market resources are scarce. Dismantling and subsequent restoration work is labor-intensive, costly, and carries significant safety risks, significantly impacting subsequent construction. CN114000437A records a continuous jacking and deviation correction system for steel box girders, which uses a jacking device, a traction device and a lateral deviation correction device to continuously jack the steel box girder in a step-by-step manner. However, this solution is mainly suitable for bridge piers with small spans. For bridge piers with larger spans, for example, a single segment is not sufficient to cover a single span construction site, it is difficult to use a jacking device for construction. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for jacking installation of large sections of anchored steel beams across the sea, which can reduce the occupancy of floating cranes, and can use jacking equipment to assist in installation, reduce temporary support measures, reduce the number of hoisting and docking times, improve construction efficiency, and facilitate the linear control of the bridge.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: a method for jacking and installing a large segment of an anchored steel beam across the sea, comprising the following steps:

[0005] S1. Set up temporary piers between permanent piers and install jacking equipment on the top of each permanent pier and temporary pier;

[0006] S2. Prefabricate the first section of the steel box girder, securely connect the first section to the leading beam, and transport it to the site;

[0007] S3. Use a floating crane to hoist the first segment and the leading guide beam to the top of the pier top pushing equipment of the first permanent pier and the first temporary pier, where the first permanent pier is located away from the closure;

[0008] S4. Use a pushing device to push the first segment and the front guide beam to the end of the first segment at the top of the first permanent pier, and fix and install the rear guide beam using a guide beam joint device to obtain a segmental steel box beam;

[0009] S5. Use the jacking equipment to continue jacking the entire segmental steel box girder to the top of the jacking equipment on the top of the second permanent pier and the second temporary pier;

[0010] S6. Remove the rear guide beam, use a floating crane to lift the second segment to the tail end of the segmental steel box girder, and securely connect the second segment to the tail end of the segmental steel box girder.

[0011] S7. Use the jacking equipment to push the segmental steel box girder forward until the tail end of the segmental steel box girder reaches the top of the jacking equipment on the top of the first permanent pier, and then install the rear guide beam again;

[0012] S8, repeat steps S6 and S7 to install the third segment;

[0013] S9. Use the jacking equipment to push the segmental steel box girder to the over-top position and remove the leading beam section by section;

[0014] S10, splicing the remaining segments into a large fourth segment spanning the first and second permanent piers, removing the jacking equipment and cushion piers on the first and second permanent piers, and hoisting the fourth segment to the tops of the first and second permanent piers using a floating crane;

[0015] S11. Use the pushing equipment to push the segmental steel box girder back;

[0016] S12, beam drop, dismantle the jacking equipment, and drop the segmental steel box beam to the top of the permanent pier;

[0017] S13, accurately butting the segmental steel box girder with the fourth segment and welding them into an integral steel box girder;

[0018] The above steps complete the jacking installation of the large section of the upper-span anchor steel beam in the sea.

[0019] In a preferred solution, the jacking device is a three-way jacking device, which is provided with hydraulic cylinders in three directions: jacking, front and back, and left and right.

[0020] In a preferred solution, the structure of the front guide beam and the rear guide beam is that the side truss steel beams are located on both sides, and the side truss steel beams are connected by a connecting beam;

[0021] The thickness of the side truss steel beam gradually decreases near the free end.

[0022] In a preferred solution, the guide beam joint device includes a first connecting portion and a second connecting portion, which are connected to the guide beam and the steel box beam respectively;

[0023] A connecting end plate is provided at the position where the first connecting portion and the second connecting portion are connected to each other. The connecting end plate is arranged vertically and has a plurality of connecting screw holes. The back of the connecting end plate is connected to the connecting plate and the connecting rib plate. The connecting plate and the connecting rib plate are perpendicular to each other.

[0024] A conical guide head and a conical guide hole are respectively provided on the first connecting portion and the second connecting portion, and a plurality of guide hole ribs are provided on both sides of the conical guide hole;

[0025] A corresponding tensioning device is provided on the first connecting portion and the second connecting portion. The tensioning device is provided with a tensioning plate. The tensioning plate is connected to the connecting end plate through a tensioning side plate. The tensioning plate is used to install a tensioning hydraulic cylinder to tension the threaded steel bar.

[0026] Positioning pin holes are also provided on the first connecting portion and the second connecting portion for connection via positioning pins.

[0027] In the preferred solution, the over-top position means that the pushing equipment pushes beyond the preset installation position of the segment steel box girder, leaving enough space for the installation of the fourth segment.

[0028] In a preferred solution, in step 11, the method further includes correcting the position of the segmental steel box girder laterally by using a jacking device.

[0029] In a preferred embodiment, the length of the fourth segment is between the lengths of the first segment 1 and 2.

[0030] In a preferred solution, in step S11, a laser rangefinder and a target are respectively set on the segment steel box girder and the fourth segment, and the number of the targets is two;

[0031] The laser rangefinder is located at the centerline of the fourth segment, and the targets are symmetrically arranged on both sides of the centerline of the segment steel box girder. The targets use highly reflective targets with specific patterns. The laser rangefinder detects the relative distance between the laser rangefinder reference point and the two targets, and feeds back the distance to the jacking equipment according to the following simultaneous formula to control the jacking parameters;

[0032] L n1 = L i1 - L0;

[0033] L n2 = L i2 - L0;

[0034] │L n1 -L n2 │<L a ;

[0035] <L b , L b >0; where L n1 is the first control distance, Ln2 is the second control distance, L i1 is the distance between the laser rangefinder and the first target, L i2 is the distance between the laser rangefinder and the second target, L0 is the preset correction distance, which is the distance between the laser rangefinder and the two targets when the segment steel box girder and the fourth segment are at the design position, L a L is the allowable error value of the distance difference between the laser rangefinder and the two targets, b The error value allowed between the laser rangefinder and the two targets is greater than 0.

[0036] In a preferred solution, when dropping the beam, a pad pier and a beam-dropping jack are set on the top of each permanent pier. The pad pier is a multi-layer structure. After the beam-dropping jack lifts the segmental steel box beam, the pad pier is raised above the top elevation of the jacking equipment. Then the beam-dropping jack is lowered to drop the segmental steel box beam on the top of the pad pier, and then the jacking equipment is removed.

[0037] After demolition, the beam-dropping jack lifts the segmental steel box girder, removes one layer of piers, and then the beam-dropping jack descends to drop the segmental steel box girder on top of the piers, using a layered beam-dropping method until it reaches the preset position.

[0038] In the preferred solution, in step S13, connecting auxiliary bases are respectively provided on the segment steel box girder and the fourth segment, and a through-core hydraulic cylinder is provided on the connecting auxiliary base, which is connected to the threaded steel bar through the through-core hydraulic cylinder, and the threaded steel bar is tensioned by the through-core hydraulic cylinder to assist the precise docking of the segment steel box girder and the fourth segment.

[0039] The present invention provides a method for jacking and installing large sections of anchored steel beams across the sea. By combining floating cranes with jacking and rapid assembly and disassembly of the rear guide beam, this method significantly reduces the number of temporary piers and the amount of temporary support required, lowering construction costs and improving efficiency. The guide beam joint device of the present invention significantly improves the efficiency of guide beam assembly and disassembly. Furthermore, the present invention significantly reduces the number of lifting and docking operations. The present invention offers high efficiency, simpler alignment control, and easier assurance of the quality of the completed bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will be further described below with reference to the accompanying drawings and examples:

[0041] Figure 1 It is a schematic front view of the overall structure of the present invention.

[0042] Figure 2 This is a schematic diagram of the installation of the first section of the present invention.

[0043] Figure 3 This is a schematic diagram of the hoisting of the third section of the present invention.

[0044] Figure 4 This is a schematic diagram of the hoisting of the fourth section of the present invention.

[0045] Figure 5 It is a schematic diagram of the connection between the fourth segment and the segmental steel box girder of the present invention.

[0046] Figure 6 It is a structural schematic diagram of the guide beam and the guide beam joint device of the present invention.

[0047] Figure 7 It is a schematic top view of the structure of the guide beam and the guide beam joint device of the present invention.

[0048] Figure 8 It is a top view schematic diagram of the guide beam joint device of the present invention.

[0049] Figure 9 It is a front view of the connecting end plate of the guide beam joint device of the present invention.

[0050] Figure 10 It is a side view schematic diagram of the present invention when the segments are connected.

[0051] Figure 11 It is a top view schematic diagram of the segments of the present invention when they are connected.

[0052] In the figure: steel box girder 1, segmental steel box girder 100, first segment 101, second segment 102, third segment 103, fourth segment 104, front guide beam 2, rear guide beam 3, jacking device 4, cushion pier 5, permanent pier 6, first permanent pier 61, second permanent pier 62, third permanent pier 63, fourth permanent pier 64, fifth permanent pier 65, temporary pier 7, first temporary pier 71, second temporary pier 72, third temporary pier 73, fourth temporary pier 74, floating crane 8, guide beam joint device 9, tapered guide head 91, tapered guide Guide hole 92, guide hole rib plate 93, tensioning plate 94, tensioning side plate 95, connecting end plate 96, connecting plate 97, connecting rib plate 98, positioning pin 99, positioning pin hole 90, connecting screw hole 900, first connecting part 901, second connecting part 902, joint mouth 10, connecting positioning auxiliary device 11, laser rangefinder 111, target 112, first target 1121, second target 1122, connecting auxiliary base 113, connecting auxiliary through-core hydraulic cylinder 114, side truss steel beam 200, connecting beam 201. DETAILED DESCRIPTION

[0053] A method for jack-pushing and installing a large segment of an anchored steel beam spanning the sea, comprising the following steps:

[0054] like Figures 1 to 5 In step S1, temporary piers 7 are set between permanent piers 6, and jacking equipment 4 is set on the top of each permanent pier 6 and temporary pier 7; Figure 2As shown in FIG, a first temporary pier 71, a second temporary pier 72, a third temporary pier 73, and a fourth temporary pier 74 are respectively arranged between the first permanent pier 61, the second permanent pier 62, the third permanent pier 63, the fourth permanent pier 64, and the fifth permanent pier 65 to shorten the span between the supporting structures. In a preferred embodiment, the first temporary pier 71 is located closer to the second permanent pier 62, the second temporary pier 72 is located closer to the second permanent pier 62, the third temporary pier 73 is located closer to the third permanent pier 63, and the fourth temporary pier 74 is located closer to the fifth permanent pier 65. This structure facilitates subsequent jacking operations and can reduce the number of temporary piers 7. In a preferred embodiment, the jacking device 4 is a three-way jacking device, equipped with hydraulic cylinders in the jacking, front-back, and left-right directions. The hydraulic cylinders in the jacking and front-back directions are used to achieve step-by-step jacking, and the hydraulic cylinders in the left-right direction are used to achieve deviation correction.

[0055] S2. Prefabricate the first segment 101 of the steel box girder 1. Fix the first segment 101 to the leading beam 2 and transport it to the site. The length of the first segment 101 is less than the span between the two permanent piers 6.

[0056] S3. Use the floating crane 8 to hoist the first segment 101 and the leading beam 2 to the top of the pier top pushing device 4 of the first permanent pier 61 and the first temporary pier 71. The first permanent pier 61 is located away from the closure 10.

[0057] S4. Use the pushing device 4 to push the first segment 101 and the front guide beam 2 to the end of the first segment 101 at the top of the first permanent pier 61, and fix the rear guide beam 3 through the guide beam joint device 9 to obtain the segment steel box beam 100; using the guide beam joint device 9 to install the rear guide beam 3 can greatly improve the assembly and disassembly efficiency and accuracy of the rear guide beam 3.

[0058] The preferred solution is Figures 6-9 In the structure of the front guide beam 2 and the rear guide beam 3, the side truss steel beams 200 are located on both sides, and the side truss steel beams 200 are connected by a connecting beam 201;

[0059] The thickness of the side truss steel beam 200 decreases gradually near the free end. This structure can reduce the weight of the guide beam while ensuring the rigidity of the guide beam, thereby reducing the sag of the guide beam in the cantilever state and allowing the guide beam to span as large a span as possible.

[0060] The preferred solution is Figure 8 In the figure, the guide beam joint device 9 includes a first connecting part 901 and a second connecting part 902, which are connected to the guide beams 2, 3 and the steel box beam 1 respectively; the first connecting part 901 and the second connecting part 902 are welded to the ends of each segment that need to be connected during prefabrication.

[0061] A connecting end plate 96 is provided at the location where the first connecting portion 901 and the second connecting portion 902 are connected to each other. The connecting end plate 96 is arranged vertically and has a plurality of connecting screw holes 900. The back of the connecting end plate 96 is connected to a connecting plate 97 and a connecting rib 98. The connecting plate 97 and the connecting rib 98 are perpendicular to each other.

[0062] The first and second connecting portions 901, 902 are provided with a tapered guide head 91 and a tapered guide hole 92, respectively. A plurality of guide hole ribs 93 are provided on either side of the tapered guide hole 92. The tapered guide head 91 is preferably provided on the first connecting portion 901, which is fixedly connected to the rear guide beam 3. It should be noted that the guide beam joint device 9 can also be used at the connection between the front guide beam 2 and the first segment 101.

[0063] Corresponding tensioning devices are provided on the first connection part 901 and the second connection part 902. The tensioning device is provided with a tensioning plate 94. The tensioning plate 94 is connected to the connecting end plate 96 through a tensioning side plate 95. The tensioning plate 94 is used to install a tensioning hydraulic cylinder to perform tensioning by tensioning threaded steel bars; the tensioning of the tensioning device is used to assist in adjusting the position between the first connection part 901 and the second connection part 902 to achieve precise positioning.

[0064] Positioning pin holes 90 are further provided on the first connecting portion 901 and the second connecting portion 902 for connection via positioning pins 99. With this structure, the position accuracy between the first connecting portion 901 and the second connecting portion 902 is improved.

[0065] During use, the first and second connecting portions 901, 902 of the guide beam joint device 9 are respectively connected to the ends of the segments, for example, the first segment 101 and the ends of the rear guide beam 3. The floating crane 8 hoists the rear guide beam 3 until it is roughly aligned with the segment ends. A tensioning hydraulic cylinder is installed at the tensioning plate 94. The tensioning threaded steel bar passes through the tensioning plate 94 and is connected to the tensioning hydraulic cylinder. The tensioning threaded steel bar is tensioned, bringing the first and second connecting portions 901, 902 closer together. The tapered guide head 91 enters the corresponding tapered guide hole 92. The guide hole rib 93 increases the deformation resistance of the tapered guide hole 92, ensuring precise alignment of the first and second connecting portions 901, 902. The locating pin 99 is then inserted into the locating pin hole 90. Bolts are then installed in the connecting screw holes 900, completing the quick installation of the guide beam.

[0066] S5. Use the jacking device 4 to continue jacking the entire segmental steel box girder 100 to the top of the pier top of the second permanent pier 62 and the second temporary pier 72;

[0067] S6. Remove the rear guide beam 3, use the floating crane 8 to hoist the second segment 102 to the tail end of the segment steel box beam 100, and fix the second segment 102 to the tail end of the segment steel box beam 100;

[0068] S7. Use the pushing device 4 to push the segmental steel box girder forward until the tail end of the segmental steel box girder reaches the top of the pushing device 4 on the top of the first permanent pier 61, and then install the rear guide beam 3 again;

[0069] S8, repeat steps S6 and S7 to install the third segment 103;

[0070] According to different bridge lengths, the third segment 103 may also be multiple segments.

[0071] S9. Use the jacking device 4 to jack the segmental steel box girder 100 to the over-top position, and remove the leading guide beam 2 section by section;

[0072] The preferred over-top position means that the pushing device 4 pushes beyond the preset installation position of the segment steel box girder 100, leaving enough space for the installation of the fourth segment 104. Figure 4 As shown in .

[0073] S10: Assemble the remaining segments into a large fourth segment 104 spanning the first and second permanent piers 61, 62. Remove the jacking equipment 4 and cushion piers 5 on the first and second permanent piers 61, 62, and use the floating crane 8 to hoist the fourth segment 104 to the top of the first and second permanent piers 61, 62. In a preferred embodiment, the length of the fourth segment 104 is between the length of the first segment 101 and the length of the second segment 101. That is, the length of the fourth segment 104 is the remainder of the total length of the steel box girder 1 divided by the length of the single segment plus the length of the single segment.

[0074] S11. Use the pushing device 4 to push the segmental steel box girder 100 back. In a preferred solution, the pushing device 4 is used to perform transverse deviation correction on the position of the segmental steel box girder 100.

[0075] The preferred solution is Figure 10 、 11 In the embodiment, a laser rangefinder 111 and a target 112 are respectively provided on the segment steel box girder 100 and the fourth segment 104, and there are two targets 112;

[0076] The laser rangefinder 111 is located at the centerline of the fourth segment 104. The targets 112 are symmetrically arranged on both sides of the centerline of the segmental steel box girder 100. The targets 112 are highly reflective targets with specific patterns. The laser rangefinder 111 detects the relative distance between the laser rangefinder reference point and the two targets 112, and feeds back the information to the jacking device 4 according to the following simultaneous formula to control the jacking parameters.

[0077] L n1 = L i1 - L0;

[0078] L n2= L i2 - L0;

[0079] │L n1 -L n2 │<L a ;

[0080] L n1 , L n2 <L b , L b >0; where L n1 is the first control distance, L n2 is the second control distance, L i1 is the distance between the laser rangefinder 111 and the first target 1121, L i2 is the distance between the laser rangefinder 111 and the second target 1122, L n and L n2 is a set of matrix data, i.e., reflective points arranged in an array on the first target 1121 and the second target 1122, such as reflective points arranged in a cross shape or at least a vertical line, and the corresponding other parameters are the corresponding matrix data. L0 is the preset correction distance, which is the distance between the laser rangefinder 111 and the two targets 112 when the segment steel box girder 100 and the fourth segment 104 are at the design position. L a is the allowable error value of the distance difference between the laser rangefinder 111 and the two targets 112, L b is the allowable error between the laser rangefinder 111 and the two targets 112, which is greater than 0. Based on the data obtained by the laser rangefinder 111, the correction parameters of each jacking device 4 are calculated to control the action of the hydraulic cylinder and achieve correction. In this example, a T-shaped line method is used for control, that is, the entire segmental steel box girder 100 is simplified into a T-shaped line, where the horizontal line is the centerline of the segmental steel box girder 100, and the end of the centerline is provided with a line segment perpendicular to the centerline as a vertical line. The centerline is used to control the relative position and deflection angle between the segmental steel box girder 100 and the fourth segment 104. The position refers to the distance between the current position of the centerline and the designed position, and the deflection angle refers to the horizontal projection angle between the current centerline and the designed centerline. The deflection angle is calculated from the distance between the two targets 112 and the distance between the laser rangefinder 111 and the two targets 112. The vertical line is used to calculate the elevation and pitch angle of the entire segmental steel box girder 100. The pitch angle is obtained from the matrix data of the surface of the target 112 .

[0081] S12, lowering the beam, removing the jacking device 4, and lowering the segmental steel box beam 100 to the top of the permanent pier 6;

[0082] In a preferred solution, when dropping the beam, a cushion pier 5 and a beam-dropping jack are set on the top of each permanent pier. The cushion pier 5 is a multi-layer structure. After the beam-dropping jack lifts the segmental steel box beam 100, the cushion pier 5 is raised above the top elevation of the jacking device 4. Then the beam-dropping jack is lowered to drop the segmental steel box beam 100 on the top of the cushion pier 5, and then the jacking device 4 is removed.

[0083] After demolition, the beam-dropping jacks lift the segmental steel box girder 100, remove one layer of piers 5, and then lower the beam-dropping jacks to drop the segmental steel box girder 100 onto the top of the piers 5. Layered beam dropping is done by removing the next layer of piers 5 each time the segmental steel box girder 100 is lifted. After checking the posture, alignment, and position of the segmental steel box girder 100, the segmental steel box girder 100 is lifted again, and the next layer of piers 5 is removed until it is completely dropped onto the permanent piers 6.

[0084] S13, accurately butting the segment steel box girder 100 and the fourth segment 104 together, and welding them into an integral steel box girder 1;

[0085] In the preferred solution, a connecting auxiliary base 113 is respectively provided on the segment steel box girder 100 and the fourth segment 104, and a through-core hydraulic cylinder 114 is provided on the connecting auxiliary base 113, which is connected to the threaded steel bar through the through-core hydraulic cylinder 114, so that the threaded steel bar is tensioned by the through-core hydraulic cylinder 114 to assist the precise docking of the segment steel box girder 100 and the fourth segment 104.

[0086] The above steps complete the jacking installation of the large section of the upper-span anchor steel beam in the sea.

[0087] In the preferred solution, a crossbeam is provided on the top of the jacking device 4, and the width of the crossbeam is greater than the width of the jacking device 4. A frame structure is provided around the jacking device 4. When jacking up, the segmental steel box girder 100 falls on the crossbeam, and when lowering, the segmental steel box girder 100 falls on the frame structure. By combining the jacking device 4 with the frame structure and the crossbeam, the offset of the curved beam can be matched during the jacking process, that is, it is suitable for the segmental steel box girder 100 with a curved segment, so that during the jacking construction of the curved segment, the curved beam is always supported by the frame structure of the jacking device, and can automatically adapt to the change of the web position during the jacking process of the curved beam, and realize the function of automatic correction after the jacking of the designed mileage is completed. The overall structure is simplified, the control difficulty is reduced, and the construction efficiency can be improved.

[0088] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The embodiments and features in the embodiments of this application may be arbitrarily combined with each other unless they conflict. The scope of protection of the present invention shall be the technical solutions described in the claims, including equivalent alternatives to the technical features of the technical solutions described in the claims. Equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for installing a large segment of an anchored steel beam across the sea, characterized by: The following steps are involved: S1. Setting temporary piers (7) between permanent piers (6), and setting jacking equipment (4) on the top of each permanent pier (6) and temporary pier (7); S2, prefabricating the first section (101) of the steel box beam (1), fixing the first section (101) to the front guide beam (2), and transporting them to the site; S3, using a floating crane (8) to hoist the first segment (101) and the front guide beam (2) to the top of the pier top pushing device (4) of the first permanent pier (61) and the first temporary pier (71), wherein the first permanent pier (61) is located at a position away from the closure (10); S4, using a pushing device (4) to push the first segment (101) and the front guide beam (2) to the end of the first segment (101) to the top of the first permanent pier (61), and fixing the rear guide beam (3) with the guide beam joint device (9) to obtain a segmental steel box beam (100); S5, using the jacking device (4) to continue jacking the entire segmental steel box girder (100) to the top of the pier top jacking device (4) of the second permanent pier (62) and the second temporary pier (72); S6. Remove the rear guide beam (3), use the floating crane (8) to hoist the second segment (102) to the tail of the segment steel box beam (100), and fix the second segment (102) to the tail of the segment steel box beam (100); S7, using the jacking device (4) to push the segmental steel box girder forward until the tail end of the segmental steel box girder reaches the top of the pier top jacking device (4) of the first permanent pier (61), and then installing the rear guide beam (3) again; S8, repeat steps S6 and S7 to install the third segment (103); S9, using the jacking device (4) to jack the segmental steel box girder (100) to the over-top position, and removing the leading guide beam (2) section by section; S10, splicing the remaining segments into a large fourth segment (104) spanning the first permanent pier (61) and the second permanent pier (62), removing the jacking equipment (4) and the cushion pier (5) on the first permanent pier (61) and the second permanent pier (62), and using a floating crane (8) to hoist the fourth segment (104) to the top of the first permanent pier (61) and the second permanent pier (62); S11, using the jacking device (4) to push the segmental steel box girder (100) back; S12, drop the beam, remove the jacking equipment (4), and drop the segmental steel box beam (100) onto the top of the permanent pier (6); S13, accurately butting the segmental steel box girder (100) and the fourth segment (104), and welding them into an integral steel box girder (1); The above steps complete the jacking installation of the large section of the upper-span anchor steel beam in the sea.

2. The method for installing a large segment of an anchored steel beam spanning the sea according to claim 1 is characterized by: The pushing device (4) is a three-way pushing device, which is provided with hydraulic cylinders in three directions: lifting, front and back, and left and right.

3. The method for installing a large segment of an anchored steel beam spanning the sea according to claim 1 is characterized by: The structure of the front guide beam (2) and the rear guide beam (3) is that the side truss steel beams (200) are located on both sides, and the side truss steel beams (200) are connected by a connecting beam (201); The thickness of the side truss steel beam (200) gradually decreases near the free end.

4. The method for installing a large segment of an anchored steel beam spanning the sea according to claim 1 is characterized by: The guide beam joint device (9) comprises a first connecting portion (901) and a second connecting portion (902), which are respectively connected to the guide beams (2, 3) and the steel box beam (1); A connecting end plate (96) is provided at a position where the first connecting portion (901) and the second connecting portion (902) are connected to each other. The connecting end plate (96) is arranged vertically and has a plurality of connecting screw holes (900) provided on the connecting end plate (96). The back of the connecting end plate (96) is connected to a connecting plate (97) and a connecting rib plate (98). The connecting plate (97) and the connecting rib plate (98) are perpendicular to each other. A conical guide head (91) and a conical guide hole (92) are respectively provided on the first connecting portion (901) and the second connecting portion (902), and a plurality of guide hole ribs (93) are provided on both sides of the conical guide hole (92); Corresponding tensioning devices are provided on the first connecting portion (901) and the second connecting portion (902), and the tensioning devices are provided with tensioning plates (94). The tensioning plates (94) are connected to the connecting end plates (96) via tensioning side plates (95). The tensioning plates (94) are used to install tensioning hydraulic cylinders to perform tensioning via tensioning threaded steel bars. Positioning pin holes (90) are also provided on the first connecting portion (901) and the second connecting portion (902) for connection via positioning pins (99).

5. The method for installing a large segment of an anchored steel beam spanning the sea according to claim 1 is characterized by: The over-top position refers to the position where the pushing device (4) pushes beyond the preset installation position of the segment steel box girder (100), leaving enough space for the installation of the fourth segment (104).

6. The method for installing a large segment of an anchored steel beam across the sea according to claim 1 is characterized by: Step 11 also includes performing lateral deviation correction on the position of the segmental steel box girder (100) by using a jacking device (4).

7. The method for installing a large segment of an anchored steel beam spanning the sea according to claim 1 is characterized by: The length of the fourth segment (104) is between the lengths of the first segment (101) of sections 1 and 2.

8. The method for installing a large segment of an anchored steel beam spanning the sea according to claim 1 is characterized by: In step S11, a laser rangefinder (111) and a target (112) are respectively provided on the segment steel box girder (100) and the fourth segment (104), wherein two targets (112) are provided; The laser rangefinder (111) is located at the centerline of the fourth segment (104), and the targets (112) are symmetrically arranged on both sides of the centerline of the segment steel box girder (100). The targets (112) use highly reflective targets with specific patterns. The laser rangefinder (111) detects the relative distance between the laser rangefinder reference point and the two targets (112), and feeds back the distance to the jacking device (4) according to the following simultaneous formula to control the jacking parameters; L n1 = L i1 - L0; L n2 = L i2 - L0; │L n1 - L n2 │<L a ; (L n1 , L n2 )<L b , L b >0; where L n1 is the first control distance, L n2 is the second control distance, L i1 is the distance between the laser rangefinder (111) and the first target (1121), L i2 is the distance between the laser rangefinder (111) and the second target (1122), L0 is the preset correction distance, which is the distance between the laser rangefinder (111) and the two targets (112) when the segment steel box girder (100) and the fourth segment (104) are located at the design position, L a is the allowable error value of the distance difference between the laser rangefinder (111) and the two targets (112), L b is the allowable error value between the laser rangefinder (111) and the two targets (112), and the error value is greater than 0.

9. The method for jack-pushing and installing a large section of an anchored steel beam spanning the sea according to claim 1 is characterized by: When the beam is dropped, a cushion pier (5) and a beam-dropping jack are set on the top of each permanent pier, wherein the cushion pier (5) is a multi-layer structure. After the beam-dropping jack lifts the segmental steel box beam (100), the cushion pier (5) is raised above the top elevation of the jacking device (4). Then, the beam-dropping jack is lowered to drop the segmental steel box beam (100) on the top of the cushion pier (5), and then the jacking device (4) is removed. After demolition, the beam-dropping jack lifts the segmental steel box girder (100), removes one layer of cushion piers (5), and lowers the beam-dropping jack to drop the segmental steel box girder (100) on top of the cushion piers (5), using a layered beam-dropping method until it reaches a preset position.

10. The method for installing a large segment of an anchored steel beam spanning the sea according to claim 1, wherein: In step S13, a connection auxiliary base (113) is respectively provided on the segment steel box girder (100) and the fourth segment (104), and a through-core hydraulic cylinder (114) is provided on the connection auxiliary base (113). The through-core hydraulic cylinder (114) is connected to the threaded steel bar, and the threaded steel bar is tensioned by the through-core hydraulic cylinder (114) to assist in the precise docking of the segment steel box girder (100) and the fourth segment (104).

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