Extra-large diameter pipe jacking pipe withdrawing device for crossing a lake and its construction method

Abstract

The present invention provides an oversized-diameter pipe jacking pipe withdrawing device and a construction method thereof. The ring beam is arranged at the pipe jacking hole and is coaxial with the pipe section. At least one jack for reverse jacking is provided on both sides of the ring beam. A reaction frame is also provided on one side of the ring beam. The telescopic ends of the jacks for reverse jacking on both sides are connected to the reaction frame. A plurality of threaded tie rods are provided on the reaction frame. One end of the threaded tie rod is connected to the head of the pipe jacking machine, and the other end is connected to the reaction frame. During pipe withdrawal, the stability of the formation can be maintained, preventing formation collapse and excessive surface settlement. It can solve many problems of oversized-diameter pipe jacking withdrawal, and at the same time improve the tunneling efficiency of pipe jacking re-jacking.

Description

Technical Field

[0001] The present invention relates to the field of civil engineering, and particularly relates to an oversized-diameter pipe jacking pipe withdrawing device for crossing a lake and a construction method thereof. Background Art

[0002] As a trenchless tunnel construction technology, pipe jacking technology can cross roads, rivers, ground and underground buildings, etc., and has been greatly developed in China. However, in actual projects, when the pipe jacking encounters an obstacle that cannot be removed during the jacking process or a failure of the jacking system, the pipe withdrawing construction becomes a difficult problem. At present, the more common method is to use a combined steel frame pulling back plus steel strands, but this method is restricted by the site, and the force at the welding point is uneven and easy to break, which is suitable for pipes with a relatively small diameter and not suitable for withdrawing pipes with an oversized diameter.

[0003] CN107504262A discloses a pipe withdrawing construction method for a cross-river pipe jacking in soft soil strata. The method includes the following steps: first, the original equipment and devices in the pipe to be withdrawn are removed and cleaned, then pipe withdrawing equipment and devices such as a steel sealing door, a reaction jacking hydraulic cylinder, a reaction pulling steel beam, a steel strand group, etc. are installed and their safety measures are checked, and after debugging, the pipe withdrawing construction is carried out. This scheme is prone to the pipe section or the pipe jacking machine being pushed out of the hole under the action of the soil pressure in front of the machine head during construction, and the construction is complex. Summary of the Invention

[0004] The main purpose of the present invention is to provide an oversized-diameter pipe jacking pipe withdrawing device for crossing a lake and a construction method thereof, which can solve many problems of withdrawing an oversized-diameter pipe jacking, and at the same time can also improve the tunneling efficiency of the pipe jacking for re-jacking.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: an oversized-diameter pipe jacking pipe withdrawing device for crossing a lake, including a ring beam, the ring beam is arranged at the pipe jacking hole and is coaxial with the pipe section, at least one reaction jacking jack is arranged on both sides of the ring beam, a reaction frame is also arranged on one side of the ring beam, the telescopic ends of the reaction jacking jacks on both sides are connected to the reaction frame, and a plurality of threaded tie rods are arranged on the reaction frame, one end of the threaded tie rod is connected to the head of the pipe jacking machine, and the other end is connected to the reaction frame.

[0006] In a preferred embodiment, the threaded tie rod is composed of butt-jointed threaded steels, and two threaded steels are connected through a threaded sleeve.

[0007] In a preferred embodiment, the end of the threaded tie rod passes through the reaction frame, and a limit nut is arranged at the end of the threaded tie rod, and the limit nut abuts against the end face of the reaction frame.

[0008] In a preferred embodiment, installation frames are also arranged on both sides of the ring beam, and the reaction jacking jacks are arranged on the installation frames.

[0009] In a preferred embodiment, the lower end of the installation frame is arranged on the ground, the upper end is connected to the side surface of the ring beam, and the installation frame abuts against the side surface of the caisson.

[0010] In the preferred embodiment, a delivery pump is further provided. The delivery pump is connected to the sludge discharge pipe inside the pipe jacking machine through a grouting pipe, and the end of the sludge discharge pipe is connected to the end of the machine head.

[0011] In the preferred embodiment, a retarding support is further provided. The retarding support is arranged between the pipe section and the main jack cylinder, and the retarding support is arranged on the slide rail.

[0012] In the preferred embodiment, a reverse force tripod for preventing retreat is further provided on the slide rail. The reverse force tripod for preventing retreat includes an end top and a bottom plate. The end top and the bottom plate form a right-angle structure, and a plurality of strengthening columns are arranged between the end top and the bottom plate.

[0013] The method includes:

[0014] S1. After completing the installation preparation of the pipe retreating overall device and before the pipe retreating construction, construct a reverse jacking back wall in the caisson, install a ring beam on the wall, install the ring beam coaxially with the pipe section, and install the reverse jacking jacks, reaction frames and threaded tie rods;

[0015] A plurality of threaded steel bars are assembled into threaded tie rods inside the pipeline. The end of the threaded tie rod is connected to the bracket inside the machine head, and the other end passes through the reaction frame, and a thread is installed on the threaded tie rod and abuts against the reaction frame;

[0016] During jacking, after jacking one pipe section, disassemble one threaded steel bar and continue to jack and retreat;

[0017] S2. It is difficult to directly retreat the pipe as a whole. It is planned to first use small jacks to jack the pipeline section by section to loosen the pipeline, reduce the friction resistance coefficient, and then retreat the pipe as a whole;

[0018] By burying small jacks in the deviation correction oil cylinder bin, provide the reverse jacking force for loosening the pipe;

[0019] S3. During pipe retreating, synchronously grout outside the pipe section through the grouting holes on the pipe section to reduce friction, and the pipe section reduces the friction resistance;

[0020] Apply lubricating oil on the waterproof rubber ring at the caisson hole to prevent the pipe section from retreating and damaging the rubber structure, which affects the sealing effect during the next jacking;

[0021] Control the reverse jacking jacks according to the reverse pulling force determined by the trial pull, jack the reaction frame, and pull back the pipe section and the pipe jacking machine as a whole;

[0022] S4. The formula of the backfill material is yellow clay: fly ash: cement: water: bentonite = 42:20:15:32:3. During preparation, first stir yellow clay, fly ash, water and bentonite, and then move them to the delivery pump by an excavator and then add cement to ensure that the backfill has certain strength, fluidity and appropriate setting time;

[0023] A concrete delivery pump is used as the pumping equipment. The equipment is arranged next to the ground operation room of the caisson. In order to reduce the installation and removal of pipe sections, the mud discharge pipe of the pipe jacking machine is directly used as the pump pipe. A grouting hole is opened above the cutter head surface and connected to the grouting pipe.

[0024] Connect the grouting pipe to the delivery pump firmly. After checking that everything is correct, start pumping the backfill material. While pulling the pipe section back, withdraw the pipe and inject the backfill material. The grouting pressure is controlled at 0.1-0.3MPa.

[0025] S5. As the pipeline retreats, the friction resistance of the outer wall of the pipe segment gradually decreases as the length of the pipeline in the soil decreases. In order to prevent the pipe segment or the pipe jacking machine from being pushed out of the hole under the soil pressure in front of the machine head, anti-retraction measures must be taken during the pipe retreat process;

[0026] Before withdrawing the pipe, the anti-retraction bracket is in close contact with the end face of the pipe joint, the main top jack cylinder is in the jacking state, and a 3cm gap is reserved between the top head of the jack and the anti-retraction bracket;

[0027] When withdrawing the pipe, the main top cylinder is retracted synchronously with the outward pulling of the pipe section. By observing the gap between the main top cylinder and the anti-retraction bracket, it can be preliminarily judged whether the pipe section is sliding outward and whether the anti-pushing force is set reasonably. When an abnormal situation occurs and the pipe section obviously accelerates outward movement, the main top cylinder is stopped from retracting, and the anti-retraction bracket is used to hold the pipe to limit its movement and prevent it from rushing out.

[0028] S6. After the backfill material in front of the pipe jacking machine has initially solidified, start lifting the pipe. First, use a gantry crane to lift the pipe section through a special lifting beam. After the pipe is lifted out of the caisson, move it to the designated pipe section storage area. Before lowering the pipe, use the auxiliary hook to turn it over so that the pipe is flat on the ground, and then transport the pipe step by step.

[0029] S7. During the pipeline retreat process, the surrounding soil will be disturbed, causing displacement of the soil and resulting in ground subsidence. Therefore, the monitoring of the surrounding ground soil should be continuously strengthened;

[0030] S8. During the pipe withdrawal process, in order to prevent the cave opening from collapsing when the machine head is finally pulled out, when the machine head has not been completely withdrawn into the working well, the machine head is still left 1-2m in the cave opening, the pipe withdrawal is suspended, and anti-withdrawal measures are taken to seal the cave opening;

[0031] A circle of water-stop curtain piles is constructed at 0.75-1.3m outside the well wall. To facilitate the construction of steel sheet piles, the Larsen steel sheet piles are located between the caisson wall and the water-stop curtain piles, and Larsen SP-IV steel plates are used;

[0032] The construction width of Larsen steel sheet pile is 6-8m, and the two sides are enclosed and closed with the well wall. To ensure a good sealing effect, the bottom of the steel sheet pile should be inserted more than 1m below the bottom of the pipe.

[0033] The present invention provides a pipe withdrawal device for super-large diameter pipe jacking across a lake and its construction method, including pipe loosening, overall withdrawal, preparation of backfill material, pumping, anti-withdrawal protection, and portal plugging. During pipe withdrawal, the stability of the formation can be maintained, preventing formation collapse and excessive surface settlement, solving many problems of super-large diameter pipe jacking withdrawal, and improving the tunneling efficiency of pipe jacking re-jacking at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below in conjunction with the drawings and embodiments:

[0035] Figure 1 is a schematic diagram of the pipe section layout of the present invention;

[0036] Figure 2 is a schematic diagram of the overall pipe withdrawal of the present invention;

[0037] Figure 3 is a schematic diagram of the backfill mixed backfill material of the present invention;

[0038] Figure 4 is a schematic diagram of the anti-withdrawal pipe section of the present invention;

[0039] Figure 5 is a schematic diagram of the portal plugging of the present invention;

[0040] Figure 6 is a schematic diagram of the reaction frame steps of the present invention.

[0041] In the figure: open caisson 1; small jack 2; pipe section 3; deviation correction oil cylinder chamber 4; machine head 5; delivery pump 6; grouting pipe 7; sludge discharge pipe 8; mixed backfill material 9; water-stop curtain pile 10; ring beam 11; slide rail 12; reaction frame 13; anti-jacking jack 14; installation rack 15; threaded tie rod 16; main jacking oil cylinder 17; pipe section to be hoisted 18; anti-withdrawal reaction tripod 19; anti-withdrawal support 20; Larssen steel sheet pile 21. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] Embodiment 1

[0043] As Figures 1 to 6 shown, a pipe withdrawal device for super-large diameter pipe jacking across a lake includes a ring beam 11. The ring beam 11 is arranged at the pipe jacking portal and is coaxial with the pipe section 3. At least one anti-jacking jack 14 is provided on both sides of the ring beam 11. A reaction frame 13 is also provided on one side of the ring beam 11. The telescopic ends of the anti-jacking jacks 14 on both sides are connected to the reaction frame 13. A plurality of threaded tie rods 16 are provided on the reaction frame 13. One end of the threaded tie rod 16 is connected to the machine head 5 of the pipe jacking machine, and the other end is connected to the reaction frame 13. The ring beam 11 is a circular barrel structure, which facilitates the sliding of the pipe section 3 inside the ring beam 11. When the pipe section 3 is withdrawn, it can ensure that the pipe section 3 does not directly fall to the ground, but slides onto the slide rail 12 through the ring beam 11, protecting the pipe section 3.

[0044] In the preferred embodiment, the threaded tie rod 16 is formed by connecting a plurality of threaded steel bars, and two threaded steel bars are connected by threaded sleeves. During the process of withdrawing the pipe, as the pipe becomes shorter and shorter, the threaded tie rod 16 will also adapt to the shorter and shorter pipe by disassembling the threaded sleeves.

[0045] In the preferred embodiment, the end of the threaded rod 16 passes through the reaction frame 13, and a limiting nut is provided at the end of the threaded rod 16, and the limiting nut abuts against the end surface of the reaction frame 13. The limiting nut plays a limiting role.

[0046] In the preferred embodiment, mounting frames 15 are further provided on both sides of the ring beam 11, and the counter-jack 14 is arranged on the mounting frames 15. The mounting frames 15 are used for processing the counter-jack 14.

[0047] In the preferred embodiment, the lower end of the mounting frame 15 is arranged on the ground, and the upper end is connected to the side of the ring beam 11, and the mounting frame 15 is against the side of the caisson 1. The position of the anti-top jack 14 is reinforced.

[0048] In the preferred embodiment, a delivery pump 6 is further provided, which is connected to a mud discharge pipe 8 inside the pipe jacking machine through a grouting pipe 7, and the end of the mud discharge pipe 8 is connected to the end of the machine head 5. The concrete delivery pump 6 is used as a pumping device, and the device is arranged next to the ground operation room of the caisson 1. In order to reduce the installation and disassembly of the pipe section 3, the mud discharge pipe 8 of the pipe jacking machine is directly used as a pump pipe, and a grouting hole is opened above the cutter head surface and connected to the grouting pipe 7.

[0049] In the preferred embodiment, a back-stop bracket 20 is also provided, which is arranged between the pipe section 3 and the main top oil cylinder 17, and the back-stop bracket 20 is arranged on the slide rail 12. The slide rail 12 is also provided with a back-stop reaction force tripod 19, which includes an end top and a bottom plate, and the end top and the bottom plate are in a right-angle structure, and a plurality of reinforcing columns are arranged between the end top and the bottom plate. Before the pipe is withdrawn, the back-stop bracket is in close contact with the end face of the pipe section, the main top jack oil cylinder is in a jacking state, and a gap of 3 cm is reserved between the jack top head and the back-stop bracket 20. The back-stop bracket 20 plays a role in limiting the retreat of the pipe section.

[0050] When retracting the pipe, the main top cylinder 17 is retracted synchronously with the outward pulling of the pipe section 3. By observing the gap between the main top cylinder 17 and the anti-retraction bracket 20, it can be preliminarily judged whether the pipe section 3 is sliding outward and whether the anti-pushing force is set reasonably. When an abnormal situation occurs and the pipe section obviously accelerates outward movement, the main top cylinder 17 is stopped from retracting, and the anti-retraction bracket 20 is used to support the pipe to limit its movement and prevent it from rushing out.

[0051] Example 2

[0052] Further illustrate with reference to Example 1, Figures 1-6For the structure shown, after the installation preparation of the overall pipe withdrawal device is completed and before the pipe withdrawal construction, a reaction back wall is constructed in the caisson, and a ring beam 11 is installed on the wall. The ring beam 11 is installed coaxially with the pipe section 3, and the reaction jack 14, reaction frame 13, and threaded tie rod 16 are installed.

[0053] Multiple threaded steel bars are assembled into the threaded tie rod 16 inside the pipeline. One end of the threaded tie rod 16 is connected to the bracket inside the machine head 5, and the other end passes through the reaction frame 13, and a thread is installed on the threaded tie rod 16 to abut against the reaction frame 13.

[0054] During jacking, after jacking one pipe section 3, one section of threaded steel bar is disassembled, and continuous jacking and withdrawal are carried out.

[0055] The difficulty of directly withdrawing the whole pipe is relatively large. It is planned to first use a small jack 2 to jack the pipeline section by section to loosen the pipeline and reduce the friction resistance coefficient, and then withdraw the whole pipe.

[0056] By burying a small jack 2 in the deviation correction oil cylinder chamber 4, the reaction force for loosening the pipe is provided.

[0057] During pipe withdrawal, synchronous grouting is carried out outside the pipe section 3 through the grouting holes on the pipe section 3 to reduce friction, and the friction resistance of the pipe section 3 is reduced.

[0058] Lubricating oil is applied to the waterproof rubber ring at the opening of the caisson 1 to prevent the pipe section 3 from damaging the rubber structure during backward movement and affecting the sealing effect during the next jacking.

[0059] According to the reaction force determined by the trial pull, the reaction jack 14 is controlled, and the reaction frame 13 is jacked to pull back the pipe section 3 and the pipe jacking machine as a whole.

[0060] The formula of the backfill material is yellow clay: fly ash: cement: water: bentonite = 42:20:15:32:3. During preparation, first stir yellow clay, fly ash, water and bentonite, and then move them to the transfer pump 6 by an excavator and then add cement to ensure that the backfill has certain strength, fluidity and appropriate setting time.

[0061] A concrete transfer pump 6 is used as the pumping equipment. The equipment is arranged beside the ground operation room of the caisson 1. To reduce the installation and disassembly of the pipe section 3, the mud discharge pipe 8 of the pipe jacking machine is directly used as the pump pipe, and a grouting hole is opened above the cutter head surface and connected to the grouting pipe 7.

[0062] Connect the grouting pipe 7 firmly to the transfer pump 6. After checking and confirming, carry out the pumping construction of the backfill material. While pulling back the pipe section 3, grout the backfill material while withdrawing the pipe, and control the grouting pressure at 0.1 - 0.3 MPa.

[0063] As the pipeline retreats, the frictional resistance on the outer wall of the pipe section 3 gradually decreases as the length of the pipeline in the soil decreases. To prevent the pipe section 3 or the pipe jacking machine from being pushed out of the opening under the action of the soil pressure in front of the machine head 5, anti-withdrawal measures must be taken during the pipe withdrawal process.

[0064] Before pipe withdrawal, the pipe-blocking support is in close contact with the end face of the pipe section, the main jack cylinder is in the jacking state, and there is a 3-cm gap reserved between the end of the jack and the pipe-blocking support 20.

[0065] During pipe withdrawal, the main jack cylinder 17 retracts synchronously with the outward pull of the pipe section 3. By observing the gap between the main jack cylinder 17 and the pipe-blocking support 20, it can be preliminarily judged whether the pipe section 3 slides outward and whether the reverse jacking force is set reasonably. When abnormal conditions occur and the pipe section moves outward significantly faster, stop the retraction of the main jack cylinder 17, and use the pipe-blocking support 20 to resist the pipeline and restrict the movement of the pipeline to prevent it from rushing out.

[0066] After the backfill in front of the pipe jacking machine starts to set, start hoisting the pipe. First, use the gantry crane to hoist the pipe section through a special lifting beam. After lifting the pipeline out of the caisson, move it to the designated pipe section storage area. Before lowering the pipeline, use the auxiliary hook to turn it over so that the pipeline lies flat on the ground and gradually transport the pipe.

[0067] During the backward movement of the pipeline, the surrounding soil of the pipeline itself will be disturbed, causing the soil to displace, which will lead to ground settlement. Therefore, continuously strengthen the monitoring of the surrounding ground soil.

[0068] During pipe withdrawal, to prevent the collapse of the hole opening during the last process of pulling out the machine head, when the machine head has not been completely withdrawn into the working well, 1 - 2 m of the machine head still remains in the hole opening at the end, suspend pipe withdrawal, take pipe-blocking measures, and seal the hole opening.

[0069] Construct a ring of water-stop curtain piles 10 at a distance of 0.75 - 1.3 m outside the well wall. For the convenience of the construction of sheet piles, the position of the Larssen sheet pile 21 is set between the caisson wall and the water-stop curtain pile 10, and Larssen SP-IV type steel sheets are used.

[0070] The construction width of the Larssen sheet pile 21 is 6 - 8 m, and the two sides are enclosed and sealed with the well wall. To ensure a good sealing effect, the bottom of the sheet pile should be inserted more than 1 m below the bottom of the pipe.

[0071] The above embodiments are only the preferred technical solutions of the present invention and should not be regarded as limitations on the present invention. The protection scope of the present invention should be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, the equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. Construction method of a pipe withdrawing device for a super-large diameter pipe jacking across a lake, characterized in that: The method includes: S1. After the installation preparation of the overall pipe withdrawal device is completed and before the pipe withdrawal construction, an anti-pushing back wall is constructed in the caisson, and a ring beam (11) is installed on the wall. The ring beam (11) is coaxially installed with the pipe section (3), and the anti-pushing jack (14), reaction frame (13), and threaded tie rod (16) are installed; Multiple threaded steels are assembled into a threaded tie rod (16) inside the pipeline. One end of the threaded tie rod (16) is connected to the bracket inside the machine head (5), and the other end passes through the reaction frame (13), and a limit nut is installed on the threaded tie rod (16). The limit nut abuts against the reaction frame (13); During pushing, after pushing one pipe section (3), one section of threaded steel is disassembled, and continuous pushing and withdrawing are carried out; S2. It is difficult to directly withdraw the pipe as a whole. It is planned to first use a small jack (2) to push the pipeline section by section to loosen the pipeline and reduce the friction resistance coefficient, and then withdraw the pipe as a whole; By burying a small jack (2) in the deviation correction oil cylinder chamber (4), the anti-pushing force for loosening the pipe is provided; S3. During pipe withdrawal, synchronous grouting is carried out outside the pipe section (3) through the grouting holes on the pipe section (3) to reduce friction, and the friction resistance of the pipe section (3) is reduced; Lubricating oil is applied to the waterproof rubber ring at the opening of the caisson (1) to prevent the pipe section (3) from damaging the rubber structure during backward movement and affecting the sealing effect during the next jacking; According to the anti-pulling force determined by the trial pull, the anti-pushing jack (14) is controlled, and the reaction frame (13) is pushed to pull back the pipe section (3) and the pipe jacking machine as a whole; S4. The formula of the backfill material is yellow clay: fly ash: cement: water: bentonite = 42:20:15:32:

3. During preparation, first stir yellow clay, fly ash, water, and bentonite, and then move them to the conveyor pump (6) by an excavator and then add cement to ensure that the backfill has certain strength, fluidity, and appropriate setting time; A concrete conveyor pump (6) is used as the pumping equipment. The equipment is arranged beside the ground operation room of the caisson (1). To reduce the installation and disassembly of the pipe section (3), the mud discharge pipe (8) of the pipe jacking machine is directly used as the pump pipe, and a grouting hole is opened above the cutter head surface and connected to the grouting pipe (7); The grouting pipe (7) is firmly connected to the conveyor pump (6). After checking and being correct, the backfill pumping construction is carried out. While the pipe section (3) is being pulled back, the pipe is withdrawn and the backfill is injected at the same time, and the grouting pressure is controlled at 0.1 - 0.3 MPa; S5. As the pipeline retreats, the frictional resistance on the outer wall of the pipe section (3) gradually decreases as the length of the pipeline in the soil decreases. To prevent the pipe section (3) or the pipe jacking machine from being pushed out of the opening under the action of the soil pressure in front of the machine head (5), anti-withdrawal measures must be taken during the pipe withdrawal process; Before pipe withdrawal, the anti-withdrawal bracket is in close contact with the end face of the pipe section, the main jacking jack cylinder is in the jacking state, and a 3 cm gap is reserved between the end of the main jacking jack and the anti-withdrawal bracket (20); When withdrawing the pipe, the main jack cylinder (17) retracts synchronously with the outward pulling of the pipe section (3). By observing the gap between the main jack cylinder (17) and the anti-withdrawal support (20), it is possible to preliminarily judge whether the pipe section (3) slips outward and whether the setting of the reaction force is reasonable. When abnormal conditions occur and the pipe section significantly accelerates outward, stop the retraction of the main jack cylinder (17), resist the pipe through the anti-withdrawal support (20), limit the movement of the pipe, and prevent it from rushing out. S6. After the backfill in front of the pipe jacking machine has initially set, start hoisting the pipe. First, use a gantry crane to hoist the pipe section through a special lifting beam. After lifting the pipe out of the caisson, move it to the designated pipe storage area. Before lowering the pipe, use the auxiliary hook to turn it over so that the pipe lies flat on the ground and gradually transport the pipe. S7. During the backward movement of the pipe, it will disturb the surrounding soil mass of itself, causing the soil mass to displace, which will lead to ground settlement. Therefore, continuously strengthen the monitoring of the surrounding ground soil mass. S8. During the pipe withdrawal process, to prevent the collapse of the hole opening during the pulling out of the last machine head, when the machine head has not been fully withdrawn into the working well, leave 1 - 2 m of the machine head still in the hole opening at the end, pause the pipe withdrawal, take anti-withdrawal measures, and seal the hole opening. Construct a circle of water-stop curtain piles (10) at a distance of 0.75 - 1.3 m outside the well wall. For the convenience of steel sheet pile construction, the position of the Larssen steel sheet pile (21) is set between the caisson wall and the water-stop curtain pile (10), and Larssen SP-IV type steel sheets are used. The construction width of the Larssen steel sheet pile (21) is 6 - 8 m, and it is enclosed and sealed on both sides with the well wall. To ensure a good sealing effect, the bottom of the steel sheet pile is inserted more than 1 m below the pipe bottom.

2. The pipe jacking pipe withdrawing device for the construction method of the super-large diameter lake-crossing pipe jacking pipe withdrawing device according to claim 1, characterized in that: It includes a ring beam (11). The ring beam (11) is set at the pipe jacking hole and is coaxial with the pipe section (3). At least one reaction jack (14) is provided on both sides of the ring beam (11). A reaction frame (13) is also provided on one side of the ring beam (11). The telescopic ends of the reaction jacks (14) on both sides are connected to the reaction frame (13). A plurality of threaded tie rods (16) are provided on the reaction frame (13). One end of the threaded tie rod (16) is connected to the pipe jacking machine head (5), and the other end is connected to the reaction frame (13). The threaded tie rod (16) is composed of the butt joint of multiple threaded steels, and the two threaded steels are connected through a threaded sleeve. The end of the threaded tie rod (16) passes through the reaction frame (13), and a limit nut is provided at the end of the threaded tie rod (16), and the limit nut abuts against the end face of the reaction frame (13). Installation frames (15) are also provided on both sides of the ring beam (11), and the reaction jacks (14) are set on the installation frames (15). An anti-withdrawal support (20) is also provided. The anti-withdrawal support (20) is arranged between the pipe section (3) and the main jack cylinder (17), and the anti-withdrawal support (20) is set on the slide rail (12). A stop reaction force tripod (19) is also provided on the slide rail (12). The stop reaction force tripod (19) includes an end top and a bottom plate. The end top and the bottom plate are in a right-angle structure, and a plurality of strengthening columns are provided between the end top and the bottom plate.

3. The pipe jacking pipe withdrawing device of the construction method of the ultra-large diameter pipe jacking pipe withdrawing device according to claim 2, wherein the lower end of the installation frame (15) is arranged on the ground, the upper end is connected to the side surface of the ring beam (11), and the installation frame (15) abuts against the side surface of the caisson (1).

4. The pipe jacking pipe withdrawing device for the construction method of the super-large diameter pipe jacking through lake according to claim 2, characterized in that: A delivery pump (6) is further provided, and the delivery pump (6) is communicated with the sludge discharge pipe (8) inside the pipe jacking machine through a grouting pipe (7), and the end of the sludge discharge pipe (8) is communicated with the end of the machine head (5).

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