Construction method for open large-diameter pipe jacking underground linear butt joint

Abstract

The present application relates to a kind of open large-caliber pipe jacking underground linear butt joint construction method, comprising the following steps: S100: the assembly of tool pipe;S200: hole advance reinforcement construction: using advance drilling machinery, in the front of anti-top pipe jacking machine, in the front of top pipe jacking machine, after drilling into land layer, grouting is reinforced in the end of drilling;S300: pipe jacking machine excavation;S400: underground butt joint construction: measure the actual gap of two tool pipe time, and according to actual gap between two tool pipes Set linear butt joint to be closed, realize butt joint;S500: the cast-in of inner lining waterproof layer.The present application provides a kind of open large-caliber pipe jacking underground linear butt joint construction method, the way of hole advance reinforcement construction is used in this construction method, the influence of hole excavation on surrounding stratum is minimized;Meanwhile, the contact between hole excavation work surface and surrounding groundwater is cut off, and the safety of construction is improved.

Description

Technical Field

[0001] This invention relates to a construction method for an open-type large-diameter underground pipe jacking joint in a straight line, belonging to the field of pipeline engineering technology. Background Technology

[0002] Pipe jacking is a trenchless underground tunnel construction technology that developed after shield tunneling. Because this construction method does not require excavation of the surface layer and can cross railways, highways, rivers, surface buildings, underground structures, and various underground pipelines, it has become the main means of trenchless construction of urban underground pipe sections and has been widely used in water supply and drainage, sewage treatment, communication, and power pipe sections.

[0003] Existing pipe jacking construction projects generally employ a launching shaft and a receiving shaft method. This involves constructing launching and receiving shafts at specific locations along the pipe jacking axis at both ends of the target construction section, serving as the starting and ending points for each section. Then, using a pipe jacking machine as a guide, prefabricated pipe sections are jacked into the soil segment by segment according to the design axis until the first pipe section following the jacking machine enters the pre-drilled hole in the receiving shaft. The jacking machine head is then removed, completing the entire underground construction project. For longer pipe jacking distances, one or more intermediate relay stations can be set up along the pipeline for relay jacking, and lubricating slurry can be injected around the outer perimeter of the pipeline.

[0004] Specifically, the Chinese invention patent "Large-Diameter Pipe Jacking Connection Technology" (patent publication number CN101463924A) describes a method for connecting large-diameter pipe jacking machines. This method involves modifying the soil in the connection area to create a large-diameter pipe jacking tool and using pneumatic sealing in the connection area. This invention not only meets the requirements for large-diameter pipe jacking construction in restricted areas such as major traffic arteries, regional hubs, or areas with unavoidable underground pipelines, but also shortens the construction period for long-distance pipe jacking. During the large-diameter pipe jacking connection process, there is almost no impact on road traffic, surrounding pipelines, or people's lives, resulting in significant social benefits. This invention can make many impossibilities in underground pipeline construction a reality, with low project cost and risk, and broad market prospects. The underground connection uses an earth pressure balance pipe jacking head. Before connection, foundation treatment is used to reinforce the soil at the connection point, and then the cutterhead is disassembled and sealed to form a through channel.

[0005] For example, Chinese utility model patent CN212318966U, entitled "Hand-dug Pipe Jacking Joint Connection Structure," discloses a hand-dug pipe jacking joint connection structure. It includes a precast structure and a cast-in-place structure. The precast structure is located on the first pipe section of the jacking system, and the cast-in-place structure is located at the midpoint of the joint between the two pipe sections. The cast-in-place structure includes an Ω-shaped steel plate, a water-stop structure, and structural concrete. The Ω-shaped steel plate is tightly attached to the inner side of the precast structure, and the water-stop structure is tightly attached to the soil-facing side of the precast structure. This utility model has the advantages of strong integrity and preventing water leakage due to misalignment during pipe jacking. It is suitable for hand-dug pipe jacking, where the first pipe section is directly used underground, avoiding the disassembly of the underground jacking machine and the recovery of a large number of parts, as well as the cutting by the cutterhead.

[0006] However, in the invention patent CN101463924A, the underground pipe jacking docking scheme either uses slurry balance or earth pressure balance pipe jacking machinery. After achieving spatial docking at the jacking position, it is necessary to dismantle the panels, cutter heads, bearings, motors, planetary reducers and other components of the two machine heads, resulting in low construction efficiency and low recycling value.

[0007] While utility model patent CN212318966U describes a method of hand-dug pipe jacking for underground connection using U-shaped steel plates welded together before reinforced concrete is poured inside the pipe, this method, while meeting the requirements for connection construction, suffers from low efficiency. Furthermore, it lacks detailed specifications for the connection process and is unsuitable for connecting tool pipes of a certain length. Moreover, without internal reinforcement measures, hand-dug pipe jacking is prone to significant surface deformation, potentially leading to tunnel collapse and jeopardizing construction safety. Summary of the Invention

[0008] To overcome the above problems, this invention provides a construction method for an open-type large-diameter underground pipe jacking joint. This construction method adopts an in-tunnel pre-reinforcement construction method, which minimizes the impact of in-tunnel excavation on the surrounding strata; at the same time, it isolates the in-tunnel excavation face from the surrounding groundwater, thereby improving the safety of construction.

[0009] The technical solution of the present invention is as follows:

[0010] A construction method for an open-type large-diameter underground pipe jacking joint includes the following steps:

[0011] S100: Assembly of tool pipes: According to the docking requirements of the jacking pipes, process and assemble tool pipes, and fix the tool pipes to the front end of the front end of the reverse jacking pipe section and the front end of the forward jacking pipe section respectively.

[0012] S200: Pre-reinforcement construction inside the tunnel: According to the pipe jacking construction line, using advanced drilling machinery, after drilling into the soil layer in front of the reverse pipe jacking machine and the forward pipe jacking machine, grouting is injected at the end of the borehole for reinforcement.

[0013] S300: Pipe jacking machine excavation: According to the pipe jacking construction line, the reverse jacking machine and the forward jacking machine are advanced to the predetermined position;

[0014] S400: Underground docking construction: Measure the actual misalignment H between the front tool pipe of the reverse jacking machine and the front tool pipe of the forward jacking machine, and according to the actual misalignment H, set a straight docking joint between the front tool pipe of the reverse jacking machine and the front tool pipe of the forward jacking machine to seal it, so as to realize the docking of the two tool pipes;

[0015] S500: Cast-in-place waterproof lining: After the straight butt joint is completed, a cast-in-place section is set up between the front tool pipe of the reverse jacking machine and the reverse jacking pipe section, and between the front tool pipe of the forward jacking machine and the forward jacking pipe section for sealing.

[0016] Furthermore, the tool tube includes a tool tube outer shell, a tool tube inner shell, and a reinforcing steel plate; the tool tube outer shell and the tool tube inner shell are coaxially arranged; a plurality of reinforcing steel plates are evenly spaced between the inner wall of the tool tube outer shell and the outer wall of the tool tube inner shell; both ends of the reinforcing steel plates are fixed to the inner wall of the tool tube outer shell and the outer wall of the tool tube inner shell, respectively.

[0017] Furthermore, step S200: the pre-reinforcement construction inside the tunnel includes:

[0018] S210: Pre-drilling inside the tunnel: On the reverse side, using pre-drilling machinery, drill into the soil layer from near to far at a certain angle in front of the reverse jacking machine, and open multiple grouting holes at uniform annular intervals along the axial direction of the reverse jacking face; On the forward side, using pre-drilling machinery, drill into the soil layer from near to far at a certain angle in front of the forward jacking machine, and open multiple grouting holes at uniform annular intervals along the axial direction of the forward jacking face.

[0019] S220: End grouting reinforcement: Grouting reinforcement is carried out from far to near within a certain range at the end of the grouting borehole to form a grouting reinforcement section.

[0020] Further, in step S220: during end grouting reinforcement, the two grouting reinforcement sections located on the reverse top side overlap axially on the reverse top working face to form a reinforcement zone; on the reverse top side, the front ends of two adjacent grouting reinforcement sections on the same annulus overlap radially on both sides of the reverse top working face to form a reinforcement zone; the two grouting reinforcement sections located on the forward top side overlap axially on the forward top working face to form a reinforcement zone; on the forward top side, the front ends of two adjacent grouting reinforcement sections on the same annulus overlap radially on both sides of the forward top working face to form a reinforcement zone.

[0021] Furthermore, step S300: the pipe jacking machine excavation includes:

[0022] S310: Excavation of the tunnel face: Excavation of the reverse tunnel face in front of the reverse jacking machine and the forward tunnel face in front of the forward jacking machine;

[0023] S320: Transporting excavated soil: transporting the excavated soil from the tunnel face out of the tunnel entrance;

[0024] Repeat steps S310 and S320 until the reverse jacking machine and the forward jacking machine advance to the predetermined position, and the outer ends of the front tool tubes of the reverse jacking machine and the forward jacking machine are aligned to form a straight butt joint.

[0025] Further, step S400: Underground docking construction includes:

[0026] S410: Measure the actual misalignment H: Measure the actual misalignment H between the front tool pipe of the reverse jacking machine and the front tool pipe of the forward jacking machine;

[0027] S420: Machining the rigid inner liner ring: Machining the rigid inner liner ring used to close the straight butt joint according to the actual misalignment H; the rigid inner liner ring includes a circumferential sealing steel plate, a misalignment vertical sealing plate, and reinforcing ribs;

[0028] S430: Fixing the rigid inner liner ring: Fix the rigid inner liner ring between the front tool tube of the reverse jacking machine and the front tool tube of the forward jacking machine. The specific steps are as follows:

[0029] S431: Fixing the staggered vertical sealing plates: Fix the outer periphery of the two staggered vertical sealing plates to the staggered side of the inner periphery of the front tool tube of the reverse jacking machine and the staggered side of the inner periphery of the front tool tube of the forward jacking machine, respectively.

[0030] S432: Fixing of the circumferential sealing steel plate: One end of the circumferential sealing steel plate is overlapped and fixed to the inner circumference of the front tool tube of the reverse jacking machine, and the end is fixed to the end face of the staggered vertical sealing plate located on one side of the forward jacking machine; the other end of the circumferential sealing steel plate is overlapped and fixed to the inner circumference of the front tool tube of the forward jacking machine, and the end is fixed to the end face of the staggered vertical sealing plate located on one side of the reverse jacking machine;

[0031] S433: Fixing the reinforcing ribs: On the side of the staggered vertical sealing plate in the front tool tube of the reverse jacking machine away from the forward jacking machine, fix multiple reinforcing ribs between the staggered vertical sealing plate and the circumferential sealing steel plate; On the side of the staggered vertical sealing plate in the front tool tube of the forward jacking machine away from the reverse jacking machine, fix multiple reinforcing ribs between the staggered vertical sealing plate and the circumferential sealing steel plate to achieve the docking of the two tool tubes.

[0032] Furthermore, step S500: the in-situ casting of the inner waterproof lining includes:

[0033] S510: Casting of the in-situ section within the pipe: On the jacking side, a supporting steel pipe is installed between the front tool pipe of the jacking machine and the jacking pipe section, and the inner circumferences of both ends of the supporting steel pipe are attached to the outer circumferences of the front tool pipe of the jacking machine and the outer circumferences of the jacking pipe section; then a reinforcing cage is placed between the front tool pipe of the jacking machine and the jacking pipe section, and concrete is poured for casting; On the reverse jacking side, another supporting steel pipe is installed between the front tool pipe of the reverse jacking machine and the reverse jacking pipe section, and the inner circumferences of both ends of the supporting steel pipe are attached to the outer circumferences of the front tool pipe of the reverse jacking machine and the outer circumferences of the reverse jacking pipe section; then another reinforcing cage is placed between the front tool pipe of the reverse jacking machine and the reverse jacking pipe section, and concrete is poured for casting;

[0034] S520: Pouring of the external waterproof layer: Cement grout is injected around the outer periphery of the straight butt joint to seal it.

[0035] Further, in step S210: In the advance drilling inside the tunnel, on the reverse-top side, the angle α between the grouting borehole and the axis of the reverse-top working face is 15°~45°; on the reverse-top side, the angle β between the axes of two adjacent grouting boreholes on the same ring and the axis of the reverse-top working face is 10°~20°; on the lateral-top side, the angle between the grouting borehole and the axis of the lateral-top working face is 15°~45°; on the lateral-top side, the angle between the axes of two adjacent grouting boreholes on the same ring and the axis of the lateral-top working face is 10°~20°.

[0036] Furthermore, in step S220: during the end grouting reinforcement, the overlap length L1 of the two grouting reinforcement sections is not less than 1000mm.

[0037] Furthermore, in step S300: during the tunneling process, the length L2 of the front tool pipe of the reverse tunneling machine penetrating the soil layer is not less than 500mm; the length of the front tool pipe of the forward tunneling machine penetrating the soil layer is not less than 500mm.

[0038] The present invention has the following beneficial effects:

[0039] 1. This construction method adopts a reinforcement scheme of advanced circumferential grouting inside the tunnel, which can realize the tunnel operation mode of "reinforcement first, excavation later", minimizing the deformation of the surrounding strata caused by pipe jacking excavation; at the same time, it isolates the excavation face inside the tunnel from the surrounding groundwater, improving the safety of construction.

[0040] 2. When the pipe jacking machine is excavating, it uses small machinery for excavation and mechanical transportation inside the tunnel, which significantly improves the construction efficiency and greatly enhances the construction efficiency compared with the existing manual tunneling construction.

[0041] 3. When connecting pipes in a straight line underground, rigid welding is used to maximize the safety of the pipe structure and avoid the risk of water leakage at the pipe joint.

[0042] 4. Using this construction method can also avoid the scrapping of the two docking heads, achieving green and environmentally friendly construction. Attached Figure Description

[0043] Figure 1 This is a flowchart of the process of the present invention.

[0044] Figure 2 This is a schematic diagram illustrating the principle of the pre-reinforcement method for tunnels according to the present invention.

[0045] Figure 3 for Figure 2 A magnified view of a portion at point A.

[0046] Figure 4 This is a diagram showing the layout of boreholes for advanced reinforcement inside the tunnel.

[0047] Figure 5 This is a diagram showing the grouting reinforcement layout for pre-reinforcement inside the tunnel.

[0048] Figure 6 This is a cross-sectional view of the tool tube.

[0049] Figure 7 This is the main view of the tool tube.

[0050] Figure 8 This is a schematic diagram of the straight-line docking structure of the present invention.

[0051] Figure 9 This is a schematic diagram of the structure of the cast-in-place waterproof layer of the present invention.

[0052] Figure 10 for Figure 9 A magnified view of a portion of point B.

[0053] The reference numerals in the figure are as follows:

[0054] 1. Reverse jacking pipe machine; 11. Reverse jacking pipe section; 12. Tool pipe outer shell; 13. Tool pipe inner shell; 14. Reinforcing steel plate; 2. Forward jacking pipe machine; 21. Forward jacking pipe section; 3. Soil layer; 31. Reverse jacking face; 41. Grouting borehole; 42. Grouting reinforcement section; 5. Straight butt joint; 51. Circumferential sealing steel plate; 52. Staggered vertical sealing plate; 53. Reinforcing rib plate; 6. Cast-in-place section inside the pipe; 61. Supporting steel pipe; 62. Reinforcing cage; 63. Concrete; 64. Cement grout. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0056] See Figure 1-10 A construction method for an open-type large-diameter underground pipe jacking joint includes the following steps:

[0057] S100: Assembly of tool pipes: According to the docking requirements of the jacking pipes, process and assemble tool pipes, and fix the tool pipes to the front end of the front end of the reverse jacking pipe section and the front end of the forward jacking pipe section respectively.

[0058] S200: Pre-reinforcement construction inside the tunnel: According to the pipe jacking construction line, using advanced drilling machinery, in front of the reverse pipe jacking machine 1 and in front of the forward pipe jacking machine 2, after drilling into the soil layer 3, grouting is injected at the end of the borehole for reinforcement.

[0059] S300: Pipe jacking machine excavation: According to the pipe jacking construction line, the reverse jacking machine 1 and the forward jacking machine 2 are jacked to the predetermined position;

[0060] S400: Underground docking construction: Measure the actual misalignment H between the front tool pipe of the reverse jacking machine 1 and the front tool pipe of the forward jacking machine 2, and according to the actual misalignment H, set a straight docking joint 5 between the front tool pipe of the reverse jacking machine 1 and the front tool pipe of the forward jacking machine 2 to seal it, so as to realize the docking of the two tool pipes.

[0061] S500: Cast-in-place waterproof lining: After the straight butt joint 5 is completed, a cast-in-place section 6 is set up between the front tool pipe of the reverse jacking machine 1 and the reverse jacking pipe section 11, and between the front tool pipe of the forward jacking machine 2 and the forward jacking pipe section 21 for sealing.

[0062] In particular, Figure 2 A1 in the diagram represents the range of obstacles predicted during the pipe jacking construction process.

[0063] Furthermore, the tool pipe includes a tool pipe outer shell 12, a tool pipe inner shell 13, and reinforcing steel plates 14; the tool pipe outer shell 12 and the tool pipe inner shell 13 are coaxially arranged; a plurality of reinforcing steel plates 14 are evenly spaced between the inner wall of the tool pipe outer shell 12 and the outer wall of the tool pipe inner shell 13; both ends of the reinforcing steel plates 14 are respectively fixed to the inner wall of the tool pipe outer shell 12 and the outer wall of the tool pipe inner shell 13. The tool pipe adopts a steel structure and is designed according to the permanent load-bearing performance requirements, meeting the stress requirements of directional switching, and also meeting the durability requirements of large-diameter jacking pipes.

[0064] Specifically, as a simplified example, the tool tube in this invention is an open tool tube with a DN3200mm diameter and a wall thickness of 300mm, and the reinforcing steel plate 14 has a thickness of 20mm and a quantity of 24 pieces.

[0065] Furthermore, step S200: the pre-reinforcement construction inside the tunnel includes:

[0066] S210: Pre-drilling inside the tunnel: On the reverse side, using pre-drilling machinery, drilling is performed in front of the reverse jacking machine 1, drilling into the soil layer 3 from near to far at a certain angle, and opening multiple grouting holes 41 at uniform annular intervals along the axial direction of the reverse jacking face 31; On the forward side, using pre-drilling machinery, drilling is performed in front of the forward jacking machine 2, drilling into the soil layer 3 from near to far at a certain angle, and opening multiple grouting holes 41 at uniform annular intervals along the axial direction of the forward jacking face.

[0067] S220: End grouting reinforcement: Grouting reinforcement is carried out from far to near within a certain range at the end of the grouting borehole 41 to form a grouting reinforcement section 42.

[0068] Further, in step S220: during end grouting reinforcement, the two grouting reinforcement sections 42 located on the reverse top side overlap axially on the reverse top face 31 to form a reinforcement zone; on the reverse top side, the front ends of two adjacent grouting reinforcement sections 42 on the same ring overlap radially on both sides of the reverse top face 31 to form a reinforcement zone; the two grouting reinforcement sections 42 located on the forward top side overlap axially on the forward top face to form a reinforcement zone; on the forward top side, the front ends of two adjacent grouting reinforcement sections 42 on the same ring overlap radially on both sides of the forward top face to form a reinforcement zone.

[0069] Further, in step S210: During the advance drilling inside the tunnel, on the reverse-top side, the angle α between the grouting borehole 41 and the axis of the reverse-top working face 31 is 15°~45°; on the reverse-top side, the angle β between the axes of two adjacent grouting boreholes 41 on the same annulus and the axis of the reverse-top working face 31 is 10°~20°; on the lateral-top side, the angle between the grouting borehole 41 and the axis of the lateral-top working face is 15°~45°; on the lateral-top side, the angle between the axes of two adjacent grouting boreholes 41 on the same annulus and the axis of the lateral-top working face is 10°~20°.

[0070] Preferably, the included angle β is 15°.

[0071] Furthermore, in step S220: during the end grouting reinforcement, the overlap length L1 of the two grouting reinforcement sections 42 is not less than 1000mm, so as to form a stable and continuous reinforcement space.

[0072] Step S200: During the pre-reinforcement construction inside the tunnel, pre-drilling machinery is used to drill into the soil layer 3 at a certain angle in front of the open-type pipe jacking equipment (i.e., reverse pipe jacking machine 1 and forward pipe jacking machine 2) to form a grouting borehole 41. Then, grout is injected within a certain range at the end of the grouting borehole 41 to form a grouting reinforcement section 42. In the circumferential direction (see...) Figure 4 With the center of the working face as the axis, grouting boreholes 41 are arranged circumferentially at a specific angle (e.g., 15°), and drilling is carried out from the outside to the inside (see...). Figure 2 During grouting, only boreholes are drilled but not grouted within a 1000mm radius of the outer edge of the open-type pipe jacking equipment; each grouting reinforcement section 42 is longitudinally (see...). Figure 2 The reinforcement zone shall be formed with an overlap length of not less than 1000mm. In addition, the advance length of each grouting reinforcement shall not be less than 1500mm, and the construction distance shall be "from far to near", that is, the front end shall be constructed first, and then the process shall be gradually moved back towards the machine head.

[0073] In particular, the two rows of annular grouting holes 41 are arranged in a plum blossom shape.

[0074] Figure 5 In the diagram, A2 represents the schematic diagram of the annular reinforcement overlap of the first grouting section (i.e., the direction away from the machine head), and A3 represents the schematic diagram of the annular reinforcement overlap of the last grouting section (i.e., the direction close to the machine head).

[0075] Furthermore, step S300: the pipe jacking machine excavation includes:

[0076] S310: Excavation of the tunnel face: Excavation of the reverse tunnel face 31 in front of the reverse tunnel jacking machine 1 and the forward tunnel face in front of the forward tunnel jacking machine 2;

[0077] S320: Transporting excavated soil: transporting the excavated soil from the tunnel face out of the tunnel entrance;

[0078] Repeat steps S310 and S320 until the reverse jacking machine 1 and the forward jacking machine 2 are advanced to the predetermined position, and the outer ends of the front tool tubes of the reverse jacking machine 1 and the front tool tubes of the forward jacking machine 2 are aligned to form a straight butt joint 5.

[0079] When a pipe jacking machine is excavating, the pipe jacking construction process is as follows: surveying and setting out → guide rail installation → removal of the tunnel portal → pipe jacking equipment entering the tunnel → axis and elevation difference control → normal jacking. During pipe jacking construction, the branch pipe is jacked up together with the pipe jacking equipment.

[0080] When the reverse jacking machine 1 and the forward jacking machine 2 reach the docking position, the outer ends of the front tool pipes of the reverse jacking machine 1 and the front tool pipes of the forward jacking machine 2 are approximately on the same vertical plane, which can play a role in retaining soil and preventing large-scale collapse and leakage during docking.

[0081] The tool pipe used in this invention is an open-type tool pipe with a DN3200mm diameter and a wall thickness of 300mm. This allows small construction machinery to enter the large-diameter jacking pipe, thus enabling mechanical excavation of the soil at the tunnel face. Simultaneously, due to the grouting reinforcement of the tunnel's perimeter through pre-reinforcement construction, the adverse effects of excavation at the tunnel face are significantly limited, effectively reducing ground deformation beyond the reinforced body. The excavated soil is transported to the shaft via electric vehicles and then transferred to the surface for disposal by crane.

[0082] In particular, if water is found inside the tunnel during the excavation process, the open drainage method is used to remove the water from the tunnel.

[0083] Furthermore, in step S300: during pipe jacking, the length L2 of the front tool pipe of the reverse jacking machine 1 penetrating into the soil layer 3 is not less than 500mm; the length of the front tool pipe of the forward jacking machine 2 penetrating into the soil layer 3 is not less than 500mm. During pipe jacking, the construction control requirement of "penetration first, excavation later" must be strictly followed to ensure that the length of the pipe jacking tool pipe penetrating the soil is always not less than 500mm, in order to reduce construction risks and reasonably control the deformation of the surrounding strata.

[0084] Specifically, before the tunneling is completed and the two tool pipes are connected, the head panels and various internal instruments and equipment of the reverse jacking machine 1 and the forward jacking machine 2 must be removed, leaving the front tool pipe of the reverse jacking machine 1 and the front tool pipe of the forward jacking machine 2.

[0085] Further, step S400: Underground docking construction includes:

[0086] S410: Measure the actual misalignment H: Measure the actual misalignment H between the front tool pipe of the reverse jacking machine 1 and the front tool pipe of the forward jacking machine 2;

[0087] S420: Machining the rigid inner liner ring: Machining the rigid inner liner ring used to close the straight butt joint 5 according to the actual misalignment H; the rigid inner liner ring includes a circumferential sealing steel plate 51, a misalignment vertical sealing plate 52, and a reinforcing rib 53.

[0088] S430: Fixing the rigid inner liner ring: Fix the rigid inner liner ring between the front tool tube of the reverse jacking machine 1 and the front tool tube of the forward jacking machine 2. The specific steps are as follows:

[0089] S431: Fixing the staggered vertical sealing plate 52: Fix the outer periphery of the two staggered vertical sealing plates 52 to the staggered side of the inner periphery of the front tool tube of the reverse jacking machine 1 and the staggered side of the inner periphery of the front tool tube of the forward jacking machine 2, respectively.

[0090] S432: Fixing of the circumferential sealing steel plate 51: One end of the circumferential sealing steel plate 51 is overlapped and fixed to the inner circumference of the front tool tube of the reverse jacking machine 1, and the end is fixed to the end face of the staggered vertical sealing plate 52 located on one side of the forward jacking machine 2; the other end of the circumferential sealing steel plate 51 is overlapped and fixed to the inner circumference of the front tool tube of the forward jacking machine 2, and the end is fixed to the end face of the staggered vertical sealing plate 52 located on one side of the reverse jacking machine 1;

[0091] S433: Fixing of reinforcing ribs 53: On the side of the staggered vertical sealing plate 52 in the front tool tube of the reverse jacking machine 1 away from the forward jacking machine 2, multiple reinforcing ribs 53 are fixed between the staggered vertical sealing plate 52 and the circumferential sealing steel plate 51; On the side of the staggered vertical sealing plate 52 in the front tool tube of the forward jacking machine 2 away from the reverse jacking machine 1, multiple reinforcing ribs 53 are fixed between the staggered vertical sealing plate 52 and the circumferential sealing steel plate 51 to achieve docking of the two tool tubes.

[0092] In addition, after the rigid inner liner ring plates are processed, before welding and fixing, slag removal, surface cleaning, and rust removal to Sa2.5 are required before welding and fixing. After welding, the weld surface also needs to be treated with anti-corrosion paint.

[0093] Specifically, the joint reinforcement includes two parts: 1. The two tool pipes are welded together using a rigid inner lining ring; 2. Cast-in-place reinforced concrete inner lining rings are used between the front tool pipe of the jacking machine 2 and the jacking pipe section 21, and between the front tool pipe of the jacking machine 1 and the jacking pipe section 11.

[0094] Furthermore, step S500: the in-situ casting of the inner waterproof lining includes:

[0095] S510: Casting of the in-situ section 6: On the jacking side, a supporting steel pipe 61 is installed between the front tool pipe of the jacking machine 2 and the jacking pipe section 21, and the inner circumferences of both ends of the supporting steel pipe 61 are attached to the outer circumferences of the front tool pipe of the jacking machine 2 and the outer circumferences of the jacking pipe section 21; then a reinforcing cage 62 is placed between the front tool pipe of the jacking machine 2 and the jacking pipe section 21, and concrete 63 is poured for casting; on the reverse jacking side, another supporting steel pipe 61 is installed between the front tool pipe of the reverse jacking machine 1 and the reverse jacking pipe section 11, and the inner circumferences of both ends of the supporting steel pipe 61 are attached to the outer circumferences of the front tool pipe of the reverse jacking machine 1 and the outer circumferences of the reverse jacking pipe section 11; then another reinforcing cage 62 is placed between the front tool pipe of the reverse jacking machine 1 and the reverse jacking pipe section 11, and concrete 63 is poured for casting;

[0096] S520: Pouring of the external waterproof layer: Cement grout 64 is injected around the outer periphery of the straight butt joint 5 to seal it.

[0097] Specifically, before pouring concrete 63, the condition of the existing anti-corrosion coating on both tool pipes must be checked. If the anti-corrosion coating has been damaged before pouring, on-site application of anti-corrosion paint is required before pouring concrete 63.

[0098] Specifically, the strength of the cast-in-place concrete layer must reach C30, and the thickness must reach 250mm.

[0099] Specifically, the supporting steel pipe 61 used to seal the joint between the sealing tool pipe and the jacking pipe can be sealed by welding an 8mm×100mm steel plate made of Q345 material to meet waterproofing requirements. Anti-corrosion treatment should also be carried out after on-site welding is completed.

[0100] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A construction method for an open-type large-diameter underground pipe jacking joint in a straight line, characterized in that: Includes the following steps: S100: Assembly of tool pipes: According to the docking requirements of the jacking pipes, process and assemble the tool pipes, and fix the tool pipes to the front end of the front end of the reverse jacking pipe section and the front end of the front end of the forward jacking pipe section respectively. S200: In-tunnel reinforcement construction: According to the pipe jacking construction line, use advanced drilling machinery to drill into the soil layer (3) in front of the reverse jacking machine (1) and the forward jacking machine (2), and then grout at the end of the borehole for reinforcement. S300: Pipe jacking machine excavation: According to the pipe jacking construction line, the reverse jacking machine (1) and the forward jacking machine (2) are jacked to the predetermined position; S400: Underground docking construction: Measure the actual misalignment H between the front tool pipe of the reverse jacking machine (1) and the front tool pipe of the forward jacking machine (2), and according to the actual misalignment H, set a straight docking joint (5) between the front tool pipe of the reverse jacking machine (1) and the front tool pipe of the forward jacking machine (2) to seal it, so as to realize the docking of the two tool pipes; S500: Cast-in-place waterproof lining: After the straight butt joint (5) is completed, a cast-in-place section (6) is set up between the front tool pipe of the reverse jacking machine (1) and the reverse jacking pipe section (11), and between the front tool pipe of the forward jacking machine (2) and the forward jacking pipe section (21) for sealing. The tool tube includes a tool tube outer shell (12), a tool tube inner shell (13), and a reinforcing steel plate (14); the tool tube outer shell (12) and the tool tube inner shell (13) are coaxially arranged; a plurality of reinforcing steel plates (14) are evenly spaced between the inner wall of the tool tube outer shell (12) and the outer wall of the tool tube inner shell (13); the two ends of the reinforcing steel plate (14) are respectively fixed to the inner wall of the tool tube outer shell (12) and the outer wall of the tool tube inner shell (13); Step S400: Underground docking construction includes: S410: Measure the actual misalignment H: Measure the actual misalignment H between the front tool pipe of the reverse jacking machine (1) and the front tool pipe of the forward jacking machine (2); S420: Machining the rigid inner liner ring: Machining the rigid inner liner ring used to close the straight butt joint (5) according to the actual misalignment H; the rigid inner liner ring includes a circumferential sealing steel plate (51), a misalignment vertical sealing plate (52), and a reinforcing rib (53). S430: Fixing the rigid inner liner ring: Fix the rigid inner liner ring between the front tool tube of the reverse jacking machine (1) and the front tool tube of the forward jacking machine (2). The specific steps are as follows: S431: Fixing the staggered vertical sealing plate (52): Fix the outer periphery of the two staggered vertical sealing plates (52) to the staggered side of the inner periphery of the front tool tube of the reverse jacking machine (1) and the staggered side of the inner periphery of the front tool tube of the forward jacking machine (2), respectively. S432: Fixing of the circumferential sealing steel plate (51): One end of the circumferential sealing steel plate (51) is overlapped and fixed to the inner circumference of the front tool tube of the reverse jacking machine (1), and the end is fixed to the end face of the staggered vertical sealing plate (52) located on one side of the forward jacking machine (2); the other end of the circumferential sealing steel plate (51) is overlapped and fixed to the inner circumference of the front tool tube of the forward jacking machine (2), and the end is fixed to the end face of the staggered vertical sealing plate (52) located on one side of the reverse jacking machine (1); S433: Fixing of reinforcing ribs (53): On the side of the staggered vertical sealing plate (52) in the front tool tube of the reverse jacking machine (1) away from the forward jacking machine (2), fix multiple reinforcing ribs (53) between the staggered vertical sealing plate (52) and the circumferential sealing steel plate (51); On the side of the staggered vertical sealing plate (52) in the front tool tube of the forward jacking machine (2) away from the reverse jacking machine (1), fix multiple reinforcing ribs (53) between the staggered vertical sealing plate (52) and the circumferential sealing steel plate (51) to achieve docking of the two tool tubes.

2. The construction method for open-type large-diameter underground pipe jacking with a straight connection as described in claim 1, characterized in that: Step S200: Pre-reinforcement construction inside the tunnel includes: S210: Pre-drilling inside the tunnel: On the reverse side, using pre-drilling machinery, drill into the soil layer (3) from near to far at a certain angle in front of the reverse jacking machine (1), and open multiple grouting holes (41) at uniform annular intervals along the axial direction of the reverse jacking face (31); On the forward side, using pre-drilling machinery, drill into the soil layer (3) from near to far at a certain angle in front of the forward jacking machine (2), and open multiple grouting holes (41) at uniform annular intervals along the axial direction of the forward jacking face. S220: End grouting reinforcement: Grouting reinforcement is carried out from far to near within a certain range at the end of the grouting borehole (41) to form a grouting reinforcement section (42).

3. The construction method for open-type large-diameter underground pipe jacking with a straight connection as described in claim 2, characterized in that: Step S220: During the end grouting reinforcement, the two grouting reinforcement sections (42) located on the reverse top side overlap axially on the reverse top face (31) to form a reinforcement zone; On the top side, the front ends of two adjacent grouting reinforcement sections (42) on the same ring overlap on both radial sides of the top face (31) to form a reinforcement zone; on the top side, the front and rear grouting reinforcement sections (42) overlap axially on the top face to form a reinforcement zone; on the top side, the front ends of two adjacent grouting reinforcement sections (42) on the same ring overlap on both radial sides of the top face to form a reinforcement zone.

4. The construction method for open-type large-diameter underground pipe jacking with a straight connection as described in claim 1, characterized in that: Step S300: Pipe jacking includes: S310: Excavation of the face soil: Excavation of the anti-jacking face (31) in front of the anti-jacking pipe jacking machine (1) and the forward jacking face in front of the forward jacking pipe jacking machine (2); S320: Transporting excavated soil: transporting the excavated soil from the tunnel face out of the tunnel entrance; Repeat S310 and S320 until the reverse jacking machine (1) and the forward jacking machine (2) are pushed to the predetermined position, and the outer ends of the front tool tube of the reverse jacking machine (1) and the outer ends of the front tool tube of the forward jacking machine (2) are aligned to form a straight butt joint (5).

5. The construction method for open-type large-diameter underground pipe jacking with a straight connection as described in claim 1, characterized in that: Step S500: Casting of the inner waterproof lining includes: S510: Casting of the in-situ section (6) of the pipe: On the top side, a supporting steel pipe (61) is set between the front tool pipe of the top jacking machine (2) and the top jacking pipe section (21), and the inner circumference of both ends of the supporting steel pipe (61) is attached to the outer circumference of the front tool pipe of the top jacking machine (2) and the outer circumference of the top jacking pipe section (21) and fixed; then a reinforcing cage (62) is placed between the front tool pipe of the top jacking machine (2) and the top jacking pipe section (21), and then concrete (6) is injected. 3) Pour concrete; On the reverse jacking side, set another supporting steel pipe (61) between the front tool pipe of the reverse jacking machine (1) and the reverse jacking pipe section (11), and fix the inner circumference of both ends of the supporting steel pipe (61) to the outer circumference of the front tool pipe of the reverse jacking machine (1) and the outer circumference of the reverse jacking pipe section (11); Then place another steel cage (62) between the front tool pipe of the reverse jacking machine (1) and the reverse jacking pipe section (11), and then inject concrete (63) for pouring; S520: Pouring of the outer waterproof layer: Inject cement grout (64) around the outer periphery of the straight butt joint (5) to seal it.

6. The construction method for open-type large-diameter underground pipe jacking with a straight connection as described in claim 2, characterized in that: Step S210: In the advanced drilling inside the tunnel, on the reverse top side, the angle α between the grouting borehole (41) and the axis of the reverse top working face (31) is 15°~45°; on the reverse top side, the angle β between the axes of two adjacent grouting boreholes (41) on the same ring and the axis of the reverse top working face (31) is 10°~20°; on the top side, the angle between the grouting borehole (41) and the axis of the top working face is 15°~45°; on the top side, the angle between the axes of two adjacent grouting boreholes (41) on the same ring and the axis of the top working face is 10°~20°.

7. The construction method for open-type large-diameter underground pipe jacking with a straight connection as described in claim 3, characterized in that: Step S220: During the end grouting reinforcement, the overlap length L1 of the two grouting reinforcement sections (42) is not less than 1000mm.

8. The construction method for open-type large-diameter underground pipe jacking with a straight connection as described in claim 4, characterized in that: Step S300: During the tunneling of the pipe jacking machine, the length L2 of the front tool pipe of the reverse jacking machine (1) penetrating into the soil layer (3) is not less than 500mm; the length of the front tool pipe of the forward jacking machine (2) penetrating into the soil layer (3) is not less than 500mm.

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