Sea area mud flat section large-diameter steel pipe grooving and laying construction method

Abstract

The invention relates to the technical field of pipe network construction, and discloses a sea area mud flat section large-diameter steel pipe grooving and laying construction method which comprises the following steps that S1, double-row PLC construction method pile construction and groove excavation are conducted; according to the large-diameter steel pipe grooving and laying construction method for the sea area mud flat section, a groove side slope is not prone to collapse through double-row PLC construction method pile supporting, the tops of the PLC construction method piles are higher than the high tide level of 10 years by 1 m, construction is prevented from being affected by tides, an assembly type bridge deck slab is reused as an operation platform, the tide switching preparation time is shortened by 70%, a high-pressure water gun and a buoyancy tank type slurry pump are cooperatively excavated, and the construction efficiency is improved. The double-row PLC construction method piles intercept the sludge on the two sides, the sludge backflow rate is reduced, the dumbbell-shaped riding wheels control the water entry angle of the pipeline, the pipeline in-place accuracy is improved, the floating sending and water injection sinking technology is adopted, the stranding deformation risk of the pipeline in the low tide period is avoided, the movable discharging opening technology enables backfilling and bridge deck slab circulation to move forwards, and the equipment transition time is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of pipe network construction, in particular to a method for grooving and laying large-diameter steel pipes in a sea area mudflat section. Background Art

[0002] With the rapid development of coastal cities, various cross-sea water supply and drainage pipelines and oil and gas pipelines have also entered a period of rapid construction. However, in my country, the distribution of silt coast is relatively large. The nearshore silt beaches are relatively flat. The soil is mainly composed of silt layers, which are all in a plastic state. The soil is uneven, with a high water content and poor bearing capacity. Moreover, due to the influence of the rising and falling tides, the mudflats are submerged at high tide and exposed at low tide. The pipeline project construction content involves laying DN1800 steel pipes with a wall thickness of 20mm and a trench width of 5m on the sea beach. After the trench is laid, it is backfilled with crushed stone soil.

[0003] There are many problems with traditional construction methods:

[0004] Conventional dredgers cannot operate during the open-bank period, while land-based excavators tend to sink in fluidized silt, making it difficult to stabilize the excavated slopes. The soil in the trenches flows back with the tide, leading to repeated dredging. During pipeline installation, floating cranes are restricted by tide levels and cannot operate around the clock. During low tide, pipelines are easily deformed when stranded. The silt foundation cannot support heavy lifting equipment, making it difficult to accurately position the pipelines. During trench backfilling, transport machinery cannot approach the trench within the narrow working area, and reliance on manual labor is inefficient.

[0005] In summary, there is an urgent need for a construction method for grooving and laying large-diameter steel pipes in the mudflat section of the sea area to achieve coordinated and efficient operations of trench support, pipeline delivery and backfilling. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the present invention provides a method for grooving and laying large-diameter steel pipes in a sea area mudflat section, which solves the problems mentioned in the above background.

[0007] The present invention provides the following technical solution: a method for grooving and laying large-diameter steel pipes in a sea area mudflat section, comprising the following steps:

[0008] Step S1: Construction of double-row PLC construction method piles and trench excavation: double-row PLC construction method piles are driven to form a trench enclosure structure, and the prefabricated bridge deck is laid on the pile tops before excavating the trench;

[0009] Step S2: The pipeline is installed in place, a pipeline delivery platform is set up on the top of the double-row PLC construction method piles, the pipeline is welded in sections, and the pipeline is pulled and delivered to the trench;

[0010] Step S3: After the trench is backfilled and the pipeline is sunk into place, the pipeline delivery platform is removed, the prefabricated bridge deck is re-laid on the pile top, and crushed stone soil is transported to backfill the trench;

[0011] Step S4: removing the double-row PLC construction piles one by one from the sea area toward the seawall.

[0012] Preferably, in step S1: a pile driver is used to drive double rows of PLC construction piles from the foot of the seabed toward the sea area, with the spacing between the two rows being equal to the bottom width of the trench, the bottom width of the trench being 5m, and the tops of the double rows of PLC construction piles being 1m higher than the 10-year high tide level;

[0013] The double-row PLC piles are constructed by alternating 820mm diameter steel pipe piles and Larsen steel sheet piles. Prefabricated bridge decks are laid on top of the steel pipe piles and Larsen steel sheet piles, serving as a driving platform for the pile foundation and a channel for transporting materials.

[0014] High-pressure water guns are used to cut the soil to form mud, which is then transported to the mud barge through the mud pump on the first pontoon for transportation.

[0015] Preferably, the mud pump is suspended on the first buoyancy box by a hand hoist, and the mud pump suction port is lower than the bottom surface of the first buoyancy box;

[0016] The high-pressure water gun and the mud pump work together. The high-pressure water gun is connected to the clean water pipe, the clean water pipe is connected to the clean water pump, and the clean water pump is installed on the second pontoon. The second clean water pump transports clean water to the high-pressure water gun through the clean water pipe. The high-pressure water gun cuts and dilutes the soil into mud, and then uses the mud pump to transport the mud to the mud barge through the mud discharge pipe. After the overflow in the loading bin, it is transported to the mud dumping site.

[0017] Preferably, step S2 includes:

[0018] Step S21: Sending platform construction, setting up double-jointed I-beam crossbeams on the top of the PLC steel pipe piles, and setting dumbbell-shaped supporting wheels in the middle of the crossbeams;

[0019] The spacing between the double-jointed I-beam crossbeam and the supporting rollers is 5m. When installing the supporting rollers, the elevation should be accurately controlled so that the line connecting the centers of the supporting rollers forms an angle of entry into the water;

[0020] The fixed pulley is connected by welding a lifting lug on the double-jointed I-beam crossbeam. The steel plate slideway of the movable pulley is set on the double-jointed I-beam crossbeam of the first three spans. The movable pulley is connected to the fixed pulley through the main steel wire rope. One end of the main steel wire rope is connected to the main winch. The other end of the main steel wire rope passes through the fixed pulley and the movable pulley and is anchored in the anchor ring of the fixed pulley. The main winch is arranged at the foot of the seawall slope and is connected to the fixed pulley and the movable pulley through the main steel wire rope.

[0021] Step S22: Pipeline in-place construction. Each section of the pipeline is 12m long. The pipeline is transported by land to the embankment road near the sending platform. A crane is used to lift the pipeline onto the sending platform for welding and assembly. After the first section of the pipeline is lifted onto the platform, the end is closed with a blind plate. Then the auxiliary winch is started, the auxiliary wire rope is tightened, and the movable pulley is dragged to the pipe mouth of the pipeline through the steel plate slide. Then the hook of the movable pulley is manually hooked to the pipe mouth of the pipeline. At this time, the main winch is started, the main wire rope is tightened to move the pipeline back one pipe position, and then the second section of the pipeline is lifted. After welding with the first section of the pipeline is completed, the above operations are repeated to complete the delivery of the pipeline.

[0022] Preferably, in step S21, grooves are cut at the tops of the steel pipe piles and the Larsen steel sheet piles, and the double-jointed I-beams are inserted into the grooves and firmly welded to the double-jointed I-beams with reinforcing steel plates.

[0023] Preferably, in step S21, steel grating walkways are provided at both ends of the beam, and two rows of steel pipe columns are provided at a distance of 1.2 m from the center of the supporting wheel to facilitate the lifting of the steel pipes into place, and diagonal braces are provided on the surface of the steel pipe columns.

[0024] Preferably, in step S22, the end of the first section of the pipeline is closed and floats on the water surface by its own buoyancy, and the other end of the pipeline is still on the sending platform for welding and assembly. After all the pipelines in the mudflat section are welded, the pipeline is sent into the groove and floats on the water surface, and then the pipeline is returned to the reserved opening position of the embankment section, water is injected and sunk, and the pipeline is docked with the reserved pipe opening.

[0025] Preferably, in step S3, a single bridge deck is removed at a preset position of the bridge deck at the pile top to form a unloading gap, the transport vehicle reverses to the gap to dump gravel and soil, the excavator levels and moves the bridge deck forward to form a new gap, and the unloading position is moved in a cycle until backfilling is completed.

[0026] Preferably, in step S4, the pile driver stands on the assembled bridge deck, pulls out the steel pipe piles and Larsen steel sheet piles by vibration, and places them on a transport vehicle at the rear for transportation.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention uses double-row PLC pile support to prevent the trench slope from collapsing. The top of the PLC pile is 1 meter higher than the 10-year high tide level to avoid construction being affected by tides. The prefabricated bridge deck is reused as an operating platform, reducing the tidal switching preparation time by 70%. High-pressure water guns and pontoon-type mud pumps work together to quickly remove silt. Double-row PLC piles intercept silt on both sides and reduce the silt return rate. Dumbbell-shaped rollers control the pipeline entry angle and improve the pipeline positioning accuracy. Floating delivery and water injection sinking technology avoid the risk of pipeline stranding and deformation during low tide. Mobile discharge port technology enables backfilling. The bridge deck cyclic forward movement mechanism reduces equipment transfer time. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Flowchart of the present invention;

[0030] Figure 2 This is a schematic diagram of the double-row PLC construction method pile erection structure of the present invention;

[0031] Figure 3 This is a schematic cross-sectional view of the trench excavation according to the present invention;

[0032] Figure 4 This is a top view schematic diagram of the trench excavation of the present invention;

[0033] Figure 5 This is a cross-sectional schematic diagram of the pipeline sending platform of the present invention;

[0034] Figure 6 This is a schematic top view of the pipeline sending platform of the present invention;

[0035] Figure 7 This is a schematic diagram of trench backfilling according to the present invention.

[0036] In the figure: 1. Road on top of embankment; 2. Wave-breaking wall; 3. Double-row PLC construction piles; 4. Bridge deck; 5. Pipeline; 6. Pile driver; 7. Steel pipe piles; 8. Larsen steel sheet piles; 9. First pontoon; 10. Mud pump; 11. Hand hoist; 12. Mud discharge pipe; 13. High-pressure water gun; 14. Clean water pipe; 15. Clean water pump; 16. Double-piece I-beam; 17. Support wheel; 18. Fixed pulley; 19. Movable pulley; 20. Steel plate slideway; 21. Main steel wire rope; 22. Steel grating sidewalk; 23. Diagonal brace; 24. Main winch; 25. Auxiliary winch; 26. Second pontoon; 27. Column. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0038] See also Figure 1-7 A method for laying large-diameter steel pipes by slotting in a sea area mudflat section comprises the following steps:

[0039] Step S1: Construction of double-row PLC piles 3 and trench excavation: Double-row PLC piles 3 are driven to form a trench enclosure structure, and prefabricated bridge decks 4 are laid on top of the piles before trench excavation.

[0040] Step S2: The pipeline 5 is installed in place, a pipeline 5 sending platform is set up on the top of the double-row PLC construction method pile 3, the pipeline 5 is welded in sections, and the pipeline 5 is pulled and sent to the trench;

[0041] Step S3: After the trench is backfilled and the pipeline 5 is sunk into place, the pipeline 5 delivery platform is removed, the assembled bridge deck 4 is re-laid on the pile top, and crushed stone soil is transported to backfill the trench;

[0042] Step S4: removing the double-row PLC construction piles 3 , removing the double-row PLC construction piles 3 one by one from the sea area toward the seawall.

[0043] In step S1: a pile driver 6 is used to drive double rows of PLC piles 3 from the foot of the seabed toward the sea area, with the spacing between the two rows equal to the bottom width of the trench, which is 5 meters. The tops of the double rows of PLC piles 3 are 1 meter higher than the 10-year high tide level.

[0044] The double-row PLC piles 3 are constructed by alternating 820mm diameter steel pipe piles 7 and Larsen steel sheet piles 8. The assembled bridge deck 4 is laid on top of the steel pipe piles 7 and Larsen steel sheet piles, serving as a piling platform for the pile foundation and a transportation channel for materials.

[0045] The soil is cut by a high-pressure water gun 13 to form mud, which is then transported to a mud barge for transportation via a mud pump 10 on the first pontoon 9 .

[0046] The mud pump 10 is suspended on the first buoyancy box 9 by a hand hoist 11, and the water suction port of the mud pump 10 is lower than the bottom surface of the first buoyancy box 9;

[0047] The high-pressure water gun 13 works in conjunction with the mud pump 10. The high-pressure water gun 13 is connected to the clean water pipe 14, and the clean water pipe 14 is connected to the clean water pump 15. The clean water pump 15 is installed on the second pontoon 26. The second clean water pump 15 transports clean water to the high-pressure water gun 13 through the clean water pipe 14. After the high-pressure water gun 13 cuts and dilutes the soil into mud, the mud pump 10 is used to transport the mud to the mud barge through the mud discharge pipe 12. After the overflow in the loading bin, it is transported to the mud dumping site.

[0048] Step S2 includes:

[0049] Step S21: Sending the platform for construction, setting up a double-jointed I-steel beam 16 on the top of the PLC steel pipe pile 7, and setting a dumbbell-shaped supporting wheel 17 in the middle of the beam;

[0050] The spacing between the double-jointed I-beam beam 16 and the supporting rollers 17 is 5m. When installing the supporting rollers 17, the elevation should be precisely controlled so that the line connecting the centers of the supporting rollers 17 forms an angle of entry into the water.

[0051] A lifting lug is welded on the double-jointed I-steel crossbeam 16 to connect the fixed pulley 18. A steel plate slideway 20 for a movable pulley 19 is provided on the first three spans of the double-jointed I-steel crossbeam 16. The movable pulley 19 is connected to the fixed pulley 18 through a main steel wire rope 21. One end of the main steel wire rope 21 is connected to a main winch 24. The other end of the main steel wire rope 21 passes through the fixed pulley 18 and the movable pulley 19 and is anchored in the anchor ring of the fixed pulley 18. The main winch 24 is arranged at the foot of the seawall and is connected to the fixed pulley 18 and the movable pulley 19 through the main steel wire rope 21.

[0052] Step S22: Pipeline 5 is put into place for construction. Each section of pipeline 5 is 12m long. Pipeline 5 is transported by land to the embankment road 1 near the sending platform. A crane is used to lift the pipeline 5 onto the sending platform for welding and assembly. After the first section of pipeline 5 is lifted onto the platform, the end is closed with a blind plate, and then the auxiliary winch 25 is started, the auxiliary wire rope is tightened, and the movable pulley 19 is dragged through the steel plate slideway 20 to the pipe mouth of pipeline 5. Then, the hook of the movable pulley 19 is manually hooked onto the pipe mouth of pipeline 5. At this time, the main winch 24 is started, the main wire rope 21 is tightened to move the pipeline 5 back one pipe position, and then the second section of pipeline 5 is lifted. After welding with the first section of pipeline 5 is completed, the above operations are repeated to complete the sending of pipeline 5.

[0053] In step S21, grooves are cut on the tops of the steel pipe piles 7 and the Larsen steel sheet piles 8, and the double-jointed I-beam crossbeam 16 is inserted into the grooves and firmly welded to the double-jointed I-beam crossbeam 16 with a reinforcing steel plate.

[0054] In step S21 , steel grating walkways 22 are set at both ends of the beam, and two rows of steel pipe columns 27 are set 1.2 m away from the center of the supporting wheel 17 to facilitate the lifting of steel pipes into place, and diagonal braces 23 are set on the surface of the steel pipe columns 27.

[0055] In step S22, the end of the first section of the pipeline 5 is closed and floats on the water surface by its own buoyancy. The other end of the pipeline 5 is still on the sending platform and is welded and assembled until all the pipelines 5 in the mudflat section are welded. The pipeline 5 is sent into the groove and floats on the water surface. The pipeline 5 is then pulled back to the reserved opening position of the embankment section, water is added to sink it, and the docking with the reserved pipe opening is completed.

[0056] In step S3, a single bridge deck 4 is removed at a preset position of the bridge deck 4 at the pile top to form a unloading gap, the transport vehicle reverses to the gap to dump gravel and soil, the excavator levels and moves the bridge deck 4 forward to form a new gap, and the unloading position is moved cyclically until backfilling is completed.

[0057] In step S4 , the pile driver 6 stands on the prefabricated bridge deck 4 , pulls out the steel pipe piles 7 and Larsen steel sheet piles by vibration, and places them on a transport vehicle at the rear for transport.

[0058] During construction, double rows of PLC piles 33 are first constructed and trenches are excavated. A pile driver 6 is used to start from the foot of the seabed and erect double rows of PLC piles 3 towards the sea. PLC stands for Pipe-Larssen. Combination, PLC construction method pile is a combined support pile, its core structure is connected by steel pipe pile 7 and Larsen steel sheet pile 8 through welding lock, steel pipe pile 7 undertakes earth retaining function, Larsen steel sheet pile 8 is responsible for water stopping, double rows of PLC construction method pile 3 form a continuous wall structure, the spacing between the two rows is the same as the designed trench bottom width, the diameter of the steel pipe pile 7 of the PLC construction method pile is 820mm, the steel pipe wall thickness is 14mm, the Larsen steel sheet pile 8 is type IV Larsen steel sheet pile 8, multiple steel pipe piles 7 and multiple Larsen steel sheet piles 8 are alternately set up, in order to avoid the influence of tide on trench excavation, the pile tops of steel pipe pile 7 and Larsen steel sheet pile 8 are about 1m higher than the 10-year high tide level, and can meet the height required for trench excavation, steel pipe pile 7 and Larsen The assembled bridge deck 4 is laid on the top of the steel sheet pile 8, which serves as a piling platform for the pile foundation and a transportation channel for materials. High-pressure water flushing is used in conjunction with a mud pump 10 to excavate the trench. The high-power mud pump 10 is suspended on the first pontoon 9 by a hand hoist 11. The water suction port of the mud pump 10 is slightly lower than the bottom surface of the first pontoon 9. The high-pressure water gun 13 works in coordination with the mud pump 10. The high-pressure water gun 13 is connected to a clean water pipe 14, and the clean water pipe 14 is connected to a clean water pump 15. The clean water pump 15 is installed on the second pontoon 26. The second clean water pump 15 delivers clean water to the high-pressure water gun 13 through the clean water pipe 14. The high-pressure water gun 13 cuts and dilutes the soil into mud, and then the mud pump 10 is used to transport the mud to the mud barge. After the overflow is loaded into the bunker, it is transported to the mud dumping site.

[0059] The sending platform is constructed. After the excavation of the trench about 60m near the seawall is completed, the bridge deck 4 of this section is removed from the seawall toward the sea area. In the process of removing the bridge deck 4, the sending platform of the pipeline 5 is gradually constructed. The sending platform of the pipeline 5 is to set up a double I-beam 16 on the top of the PLC steel pipe pile 7, and a dumbbell-shaped supporting wheel 17 is set in the middle of the beam. In order to ensure the stability of the sending platform, a groove is cut on the top of the steel pipe pile 7, and the double I-beam 16 is embedded in the groove and firmly welded to the I-beam with a reinforcing steel plate. The double I-beam 16 and the supporting wheel 17 are arranged at a spacing of 5m. When installing the supporting wheel 17, the elevation should be accurately controlled so that the line connecting the centers of each supporting wheel 17 forms an entry angle into the water. Steel grating sidewalks 22 are set at both ends of the double I-beam 16 to facilitate the entry and exit of personnel. Two rows of steel pipe columns 27 are set 1.2m away from the center of the supporting wheel 17 to facilitate the lifting of the steel pipe into place.

[0060] A lifting lug is welded on the middle double I-beam 16, and a fixed pulley 18 is connected to the lifting lug through a lifting ring. A 50 cm wide steel plate is welded on the first three spans of the double I-beam 16 to serve as a steel plate slideway 20 to guide the movable pulley 19. The movable pulley 19 is connected to the fixed pulley 18 through a main steel wire rope 21. One end of the main steel wire rope 21 is connected to the main winch 24, and the other end passes through the pulley block and is anchored in the anchor ring of the fixed pulley 18.

[0061] The main winch 24 is arranged at the foot of the seawall and is connected to the fixed pulley 18 and the movable pulley 19 via the main steel wire rope 21. The line connecting the main winch 24 and the fixed pulley 18 forms an angle with the centerline of the launching platform. The auxiliary winch 25 is arranged at the end of the slideway of the movable pulley 19, near the foot of the seawall, and is connected to the movable pulley 19 via the auxiliary steel wire rope.

[0062] The pipeline 5 is put in place. Each section of the pipeline 5 is 12 meters long and is transported by land to the embankment road 1 near the sending platform. Then, it is lifted and lowered to the sending platform by a crane for welding and assembly. After the first section of the pipeline 5 is lifted and lowered onto the platform, the end of the pipeline 5 is closed with a blind plate. Then, the auxiliary winch 25 is started, the auxiliary wire rope is tightened, and the movable pulley 19 is dragged to the pipe mouth through the slideway. Then, the operator hooks the movable pulley 19 to the pipe mouth of the pipeline 5. At this time, the main winch 24 is started, the main wire rope 21 is tightened, and the pipe section is moved back one pipe position. Then, the second section of the pipeline 5 is lifted and welded to the first section of the pipeline 5. The above operation is repeated to complete the delivery of the pipeline 5.

[0063] After the first section of pipe enters the water, it floats on the water surface by its own buoyancy. The other end of the pipe section remains on the sending platform for welding and assembly. After all the pipes 5 in the mudflat section are welded, they are sent into the trench and float on the water surface. Then, the pipe 5 is pulled back to the reserved opening of the embankment section, water is added to sink it, and it is docked with the reserved pipe opening.

[0064] After the trench is backfilled and the pipe 5 is sunk into place, the pipe 5 sending platform is removed and a prefabricated bridge deck 4 is re-laid on the pile top as a transportation channel for gravel and soil. A small transport vehicle reverses into the bridge deck 4 and the excavator removes a bridge deck 4 at the predetermined unloading position behind it to form a unloading gap. The transport vehicle unloads the gravel and soil into the trench through the gap and then returns along the original route. The excavator levels the backfill through the unloading gap and moves the bridge deck 4 in front back to form a new unloading gap, waiting for the arrival of the next transport vehicle. This cycle repeats until the trench is backfilled.

[0065] Finally, the double-row PLC method piles 3 are pulled out. The order of pulling out the method piles is from one end of the sea area to the seawall. The pile driver 6 stands on the assembled bridge deck 4, pulls out the steel pipe piles 7 and Larsen steel plates through vibration, and then places them on the transport vehicle at the rear for transportation.

[0066] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for laying large diameter steel pipes by slotting in a sea area mudflat section, characterized in that: The following steps are involved: Step S1: Construction of double-row PLC construction method piles (3) and trench excavation: double-row PLC construction method piles (3) are driven to form a trench enclosure structure, and assembled bridge decks (4) are laid on the pile tops before excavating the trench; Step S2: The pipeline (5) is installed in place, a pipeline (5) sending platform is set up on the top of the double-row PLC construction method pile (3), the pipeline (5) is welded in sections, and the pipeline (5) is pulled and sent to the groove; Step S3: After the trench is backfilled and the pipeline (5) is sunk into place, the pipeline (5) delivery platform is removed, the assembled bridge deck (4) is re-laid on the pile top, and crushed stone soil is transported to backfill the trench; Step S4: removing the double-row PLC construction piles (3), removing the double-row PLC construction piles (3) one by one from the sea area toward the seawall.

2. The method for grooving and laying large-diameter steel pipes in a sea area mudflat section according to claim 1 is characterized in that: In step S1: a pile driver (6) is used to drive double rows of PLC construction piles (3) from the foot of the seabed slope toward the sea area, with the spacing between the two rows being equal to the bottom width of the trench, the bottom width of the trench being 5m, and the tops of the double rows of PLC construction piles (3) being 1m higher than the 10-year high tide level; The double-row PLC construction method piles (3) are composed of 820mm diameter steel pipe piles (7) and Larsen steel sheet piles (8) arranged alternately. The assembled bridge deck (4) is laid on the top of the steel pipe piles (7) and the Larsen steel sheet, serving as a pile driving platform for the pile foundation and a transportation channel for materials. A high-pressure water gun (13) is used to cut the soil to form mud, which is then transported to a mud barge for transportation via a mud pump (10) on the first buoyancy box (9).

3. The method for grooving and laying large-diameter steel pipes in a sea area mudflat section according to claim 2 is characterized in that: The mud pump (10) is suspended on the first buoyancy box (9) through a hand hoist (11), and the water suction port of the mud pump (10) is lower than the bottom surface of the first buoyancy box (9); The high-pressure water gun (13) and the mud pump (10) work together. The high-pressure water gun (13) is connected to the clean water pipe (14), and the clean water pipe (14) is connected to the clean water pump (15). The clean water pump (15) is installed on the second buoyancy box (26). The second clean water pump (15) transports clean water to the high-pressure water gun (13) through the clean water pipe (14). After the high-pressure water gun (13) cuts and dilutes the soil into mud, the mud pump (10) is used to transport the mud to the mud barge through the mud discharge pipe (12). After the overflow is loaded into the bunker, it is transported to the mud dumping site.

4. The method for grooving and laying large-diameter steel pipes in a sea area mudflat section according to claim 3 is characterized in that: Step S2 includes: Step S21: Sending platform construction, setting up a double-jointed I-beam crossbeam (16) on the top of the PLC steel pipe pile (7), and setting a dumbbell-shaped supporting wheel (17) in the middle of the crossbeam; The spacing between the double-jointed I-beam beam (16) and the supporting roller (17) is 5m. When the supporting roller (17) is installed, the elevation should be accurately controlled so that the line connecting the centers of the supporting rollers (17) forms an angle of entry into the water; A fixed pulley (18) is connected to the double-jointed I-beam cross beam (16) by welding a lifting lug, and a steel plate slideway (20) of a movable pulley (19) is provided on the first three spans of the double-jointed I-beam cross beam (16). The movable pulley (19) is connected to the fixed pulley (18) by a main steel wire rope (21). One end of the main steel wire rope (21) is connected to a main hoist (24). The other end of the main steel wire rope (21) passes through the fixed pulley (18) and the movable pulley (19) and is anchored in the anchor ring of the fixed pulley (18). The main hoist (24) is arranged at the foot of the seawall slope and is connected to the fixed pulley (18) and the movable pulley (19) by the main steel wire rope (21); Step S22: The pipeline (5) is constructed in place. Each section of the pipeline (5) is 12m long. The pipeline (5) is transported by land to the embankment road (1) near the sending platform. A crane is used to lift the pipeline (5) onto the sending platform for welding and assembly. After the first section of the pipeline (5) is lifted onto the platform, the end is closed with a blind plate. Then, the auxiliary winch (25) is started, the auxiliary wire rope is tightened, and the movable pulley (19) is dragged through the steel plate slideway (20) to the pipe mouth of the pipeline (5). Then, the hook of the movable pulley (19) is manually hooked to the pipe mouth of the pipeline (5). At this time, the main winch (24) is started, the main wire rope (21) is tightened, and the pipeline (5) is moved back one pipe position. Then, the second section of the pipeline (5) is lifted and welded to the first section of the pipeline (5). The above operation is repeated to complete the sending of the pipeline (5).

5. The method for grooving and laying large-diameter steel pipes in a sea area mudflat section according to claim 1 is characterized in that: In step S21, grooves are cut at the tops of the steel pipe piles (7) and the Larsen steel sheet piles (8), and the double-jointed I-beam crossbeam (16) is embedded in the grooves and firmly welded to the double-jointed I-beam crossbeam (16) with a reinforcing steel plate.

6. The method for grooving and laying large-diameter steel pipes in a sea area mudflat section according to claim 1 is characterized in that: In step S21, steel grating walkways (22) are set at both ends of the beam, and two rows of steel pipe columns (27) are set at a position 1.2m away from the center of the supporting wheel (17) to facilitate the lifting of steel pipes, and diagonal braces (23) are set on the surface of the steel pipe columns (27).

7. The method for grooving and laying large-diameter steel pipes in a sea area mudflat section according to claim 1 is characterized in that: In step S22, the end of the first section of the pipeline (5) is closed and floats on the water surface by its own buoyancy, and the other end of the pipeline (5) is still on the sending platform and is welded and assembled until all the pipelines (5) in the mudflat section are welded. The pipeline (5) is sent into the groove and floats on the water surface, and then the pipeline (5) is returned to the reserved opening position of the embankment section, water is injected and the pipeline is sunk to complete the docking with the reserved pipe opening.

8. The method for grooving and laying large-diameter steel pipes in a sea area mudflat section according to claim 1 is characterized in that: In step S3, a single bridge deck (4) is removed at a preset position of the bridge deck (4) at the top of the pile to form a discharge gap, a transport vehicle moves backward to the gap to dump gravel and soil, an excavator moves the bridge deck (4) forward after leveling to form a new gap, and the discharge position is moved cyclically until backfilling is completed.

9. The method for grooving and laying large-diameter steel pipes in a sea area mudflat section according to claim 1 is characterized in that: In step S4, the pile driver (6) stands on the assembled bridge deck (4), pulls out the steel pipe piles (7) and the Larsen steel sheet piles (8) by vibration, and places them on a transport vehicle at the rear for transportation.

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