Miniature pipe jacking construction device and method based on out-hole driving

Abstract

The invention discloses a miniature pipe-jacking construction device based on out-hole driving, which specifically comprises a drilling machine main machine, a pipe-jacking tunneling device and a drilling rod, the drilling machine main machine is provided with a power head for driving the drilling rod to rotate and jack, and the pipe-jacking tunneling device is provided with a cutterhead and a cutterhead main shaft; a driving shaft of the power head is connected with a cutterhead main shaft of the pipe-jacking tunneling device through a drill rod; a driving shaft of the power head is of a large-diameter double-wall structure and is composed of an inner driving shaft and an outer driving shaft, the inner driving shaft and the outer driving shaft are each of a hollow structure, the inner driving shaft is arranged at the inner axis of the outer driving shaft, and the outer driving shaft is arranged at the outer axis of the outer driving shaft. The inner space of the outer driving shaft is divided into two channels, namely an inner shaft hole and a driving shaft double-wall interlayer between the outer wall of the inner driving shaft and the inner wall of the outer driving shaft; the technical route of out-of-hole driving serves as the innovation direction, the defects existing in the traditional miniature pipe jacking technology and a pipe jacking machine are avoided and improved in principle, and the problems in the field of miniature pipe jacking at present are thoroughly solved.

Description

Technical Field

[0001] This invention relates to the field of trenchless pipeline construction technology, and in particular to a micro-pipe jacking construction device based on external borehole drive. Background Technology

[0002] Trenchless pipeline construction is an engineering technology that uses geotechnical drilling to lay, repair, or replace underground pipelines without damaging the surface. This technology uses methods such as directional drilling to excavate only a very small part of the surface (such as small excavation areas at the entrance and exit) to complete the laying, replacement, or repair of pipelines. Its core advantage is that it avoids the damage to traffic, environment, and surrounding buildings caused by traditional excavation construction, significantly reducing the interference with residents' lives. At the same time, it improves construction efficiency through processes such as reverse circulation cleaning and mud recycling.

[0003] Traditional pipe jacking technology involves using a pipe jacking machine to excavate in front of the pipeline and then using a hydraulic jacking device to push it from the rear. Soil can be removed by circulating water through the pipeline, called "slurry pipe jacking," or by using mechanical methods to directly remove the soil, called "soil pipe jacking." The pipe jacking machine is divided into two sections, front and rear. By using a correction cylinder, the axes of the front and rear sections can be forced to form an angle, thereby achieving correction and steering.

[0004] This traditional pipe jacking technology is very popular in the field of large-diameter pipe jacking where people can enter the interior. It has no obvious defects or pain points and can cover various geological conditions. Therefore, for large-diameter pipe jacking, traditional pipe jacking technology and traditional pipe jacking machines are the absolute mainstream technology and equipment.

[0005] Miniature pipe jacking refers to pipe jacking used for laying pipes with an inner diameter of 600mm or less, which means that people cannot enter the pipe. Miniature pipe jacking machines that use traditional pipe jacking technology are called traditional miniature pipe jacking machines.

[0006] In summary, existing devices still have the following technical problems: The internal structure of traditional pipe jacking machines is quite complex. This is not a problem for large-diameter pipe jacking machines, as personnel can enter and handle internal malfunctions. However, micro pipe jacking machines still use such internal structures. If a malfunction occurs inside the machine during construction, it is difficult to troubleshoot, leading to project failure. At the same time, due to the limited internal space and complex structure of micro pipe jacking machines, the diameter of the mud inlet and outlet pipes is restricted, making them prone to mud discharge blockage, which is a significant pain point. Therefore, it is necessary to propose a micro pipe jacking construction device based on external drive to provide a new technical solution to the technical problems mentioned in the above patent. Summary of the Invention

[0007] Therefore, it is necessary to provide a micro-pipe jacking construction device based on external borehole drive to address the aforementioned technical problems.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] The micro-pipe jacking construction device based on external drive specifically includes a drilling rig main unit, a pipe jacking machine, and drill rods. The drilling rig main unit is equipped with a power head that drives the drill rods to rotate and jack. The pipe jacking machine is equipped with a cutterhead and a cutterhead spindle. The drive shaft of the power head is connected to the cutterhead spindle of the pipe jacking machine through the drill rods. The drive shaft of the power head adopts a large-diameter double-wall structure, consisting of an inner drive shaft and an outer drive shaft. Both the inner and outer drive shafts are hollow structures. The inner drive shaft is located at the inner axis of the outer drive shaft, dividing the internal space of the outer drive shaft into two channels: an inner shaft hole and a double-wall sandwich between the outer and inner walls of the inner and outer drive shafts.

[0010] The outer drive shaft is fitted with an outer drive transmission gear, and the rear end of the inner drive shaft extends beyond the outer drive shaft and is equipped with an inner drive transmission gear; the drilling rig host can drive the outer drive transmission gear and the inner drive transmission gear respectively to drive the outer drive shaft and the inner drive shaft to rotate.

[0011] The front end side wall of the external drive shaft is provided with a grouting port, and the power head is provided with a sealing bushing at the position corresponding to the grouting port, and a grouting connector is provided on the sealing bushing.

[0012] The front end of the external drive shaft is provided with an external drive connector, and the front end of the internal drive shaft is provided with an internal drive connector.

[0013] The drill rod adopts a large-diameter double-wall structure, consisting of an outer drill rod and an inner drill rod. The inner drill rod is fixed in the center of the inner hole of the outer drill rod, dividing the internal space of the outer drill rod into two channels: the inner rod hole and the double-wall interlayer of the drill rod between the outer wall of the inner drill rod and the inner wall of the outer drill rod.

[0014] The rear end of the external drill pipe is provided with an external rod rear connector adapted to the external drive connector, and the front end is provided with an external rod front connector identical to the external drive connector; the rear end of the internal drill pipe is provided with an internal rod rear connector adapted to the internal drive connector, and the front end is provided with an internal rod front connector identical to the internal drive connector.

[0015] The cutter head spindle adopts a large-diameter double-wall structure, consisting of an outer shaft and a core tube. The front end of the outer shaft is connected to the cutter head and is responsible for driving the cutter head to rotate. The core tube is fixedly installed at the axis of the outer shaft, dividing the internal space of the outer shaft into two channels: the core tube hole and the double-wall sandwich layer between the outer wall of the core tube and the inner wall of the outer shaft. Several spray nozzles are opened on the front side wall of the outer shaft.

[0016] The rear end of the outer shaft is provided with an outer shaft connector that is adapted to the front connector of the outer rod, and the rear end of the core tube is provided with a core tube rear connector that is adapted to the front connector of the inner rod.

[0017] Preferably, the outer drive connector is a socket connector outer sleeve with several tongue and groove joints at the front end, and the outer rod rear connector is a plug connector outer sleeve with a locking block at the rear end that matches the tongue and groove joints; when the plug is inserted into place, the locking block and the tongue and groove joints of the outer drive connector engage with each other to achieve torque transmission and form an internal and external seal at the connection.

[0018] Preferably, the inner drive connector is an inner octagonal connector, and the inner rod rear connector is an outer octagonal connector that matches the inner octagonal connector.

[0019] Preferably, the outer sleeve of the socket joint is provided with a pair of rectangular locking rod holes, and the outer sleeve of the plug joint is provided with a bolt hole at the center of the rectangular locking rod hole corresponding to the position after insertion. When the insertion is in place, a locking rod stop is embedded in the rectangular locking rod hole, and the locking rod stop is fixed at the bolt hole by bolts.

[0020] Preferably, the number of tongue and groove joints and the number of interlocking blocks are each symmetrically arranged in two.

[0021] Furthermore, the tunnel boring machine is a slurry-type tunnel boring machine, consisting of a machine housing, a main shaft seat, a cutterhead, and a cutterhead spindle. The machine housing has a cylindrical structure with a socket for a pipe at its outer edge at the rear end. The main shaft seat is located in the rear half of the machine housing, and the front half of the machine housing is a slurry chamber. The cutterhead is located at the front end of the machine housing. The rear end of the cutterhead spindle is mounted on the main shaft seat, and its front end is connected to the cutterhead. The outer wall of the core tube has several internal mud discharge ports, and the outer shaft sidewall has external mud discharge ports at corresponding positions. The internal and external mud discharge ports are connected by a short pipe. The front end of the cutterhead has a split joint.

[0022] The usage of this invention with a slurry-type pipe jacking device is as follows:

[0023] Install and fix the drilling rig in the working well, connect the pilot drill bit, and after completing the pilot hole drilling, remove the theodolite behind the drilling rig and the optical target at the front end of the pilot drill rod. Install the mud discharge port connector at the rear end of the inner drive shaft of the power head drive shaft, connect the mud discharge pipeline, remove the pilot drill bit, connect the pipe jacking device, connect the split joint at the front end of the cutterhead to the tail end of the drill rod in the pilot hole, and use the drilling rig power head to push the pipe jacking device forward into the soil layer.

[0024] Insert the drill pipe into a pipe section of equal length and hoist them together into the working well, then place them on the pipe support.

[0025] Insert the outer shaft connector of the cutterhead spindle into the front connector of the outer rod of the drill pipe, and insert the rear connector of the core tube into the corresponding front connector of the inner rod. Lock the outer shaft connector and the front connector of the outer rod with the locking rod block to ensure a stable connection between the cutterhead spindle and the drill pipe. After the connection is completed, a ring-shaped grouting channel is formed from the grouting port of the drilling rig to the mud chamber of the jacking machine along the double-walled interlayer of the drive shaft inside the power head drive shaft of the drilling rig, the double-walled interlayer of the drill pipe inside the drill pipe, and the double-walled interlayer of the main shaft inside the cutterhead spindle of the jacking machine. At the same time, a closed mud discharge channel is formed from the mud chamber to the rear end of the inner drive shaft of the power head of the drilling rig along the core tube hole of the cutterhead spindle of the jacking machine, the inner rod hole of the drill pipe, and the inner shaft hole of the power head of the drilling rig.

[0026] Connect the rear end of the drill rod to the front end of the power head drive shaft of the drilling rig, and connect the front end to the rear end of the cutterhead spindle of the pipe jacking machine. Insert the outer sleeve of the socket connector at the rear end of the outer drill rod into the outer sleeve of the socket connector of the outer drive shaft, and insert the outer octagonal sleeve at the rear end of the inner drill rod into the inner octagonal sleeve of the inner drive shaft. Embed the locking rod block into the rectangular locking rod hole of the outer drive shaft, and fix the locking rod block in the bolt hole with bolts to ensure a stable connection between the drill rod and the drive shaft of the power head.

[0027] Then start the drilling rig to push the pipe section forward and insert the front end of the pipe section into the socket on the outer edge of the end of the tunneling machine housing.

[0028] While the external drive shaft rotates, it accompanies the power head's jacking operation, driving the outer shaft of the cutterhead main shaft to rotate via the outer drill rod. This drives the cutterhead to rotate and cut and break the strata ahead, forming excavated soil that enters the mud-water chamber. Simultaneously, the grouting pump of the mud inlet and outlet system injects water or mud from the grouting port of the drilling rig main unit. This water or mud enters the mud-water chamber and mixes with the excavated soil through the annular grouting channel formed by the double-walled interlayer of the main shaft inside the power head drive shaft of the drilling rig main unit, the double-walled interlayer of the drill rod inside the drill rod, and the double-walled interlayer of the main shaft inside the cutterhead main shaft of the pipe jacking machine. Meanwhile, the mud discharge pump of the mud inlet and outlet system draws outward from the rear end of the internal drive shaft, along the sealed inner mud discharge channel formed by the core tube hole of the cutterhead main shaft of the pipe jacking machine, the inner rod hole of the drill rod, and the inner shaft hole of the power head of the drilling rig main unit. This suction draws the excavated mud from the mud-water chamber. Combined with the pressure created in the mud-water chamber during the cutterhead's excavation process, the excavated mud is forced to exit from the mud-water chamber into the sealed inner mud discharge channel and be discharged backward.

[0029] After one pipe section is jacked up, the above steps are repeated to add more pipe sections and drill rods for jacking up. At the same time, the pilot drill rod that was jacked up is removed from the receiving well until the entire pipeline laying operation is finally completed.

[0030] Furthermore, the tunnel boring machine is a soil-type tunnel boring machine, consisting of a machine housing, a main shaft seat, a cutterhead, and a cutterhead spindle. The machine housing has a cylindrical structure. The main shaft seat is located in the rear half of the machine housing, and the front half of the machine housing is a soil chamber. The cutterhead is located at the front end of the machine housing. The rear end of the cutterhead spindle is located on the main shaft seat, and the front end is connected to the cutterhead. The core tube has helical blades outside its tube body. The outer shaft has a soil inlet on its outer wall in the soil chamber. The front end of the cutterhead has a hollow split joint, which communicates with the outer shaft. The front end of the core tube has a core tube front joint that is compatible with the rear joint of the inner rod.

[0031] The usage of this invention with a slurry-type pipe jacking device is as follows:

[0032] Install and fix the drilling rig main unit in the working well, connect the pilot drill bit, and after completing the pilot hole drilling, remove the theodolite behind the drilling rig main unit and the optical target at the front end of the pilot drill rod. In the working well, connect and insert the soil discharge auger rod one by one along the inner hole of the outer drill rod of the pilot drill rod to push out the inner drill rod of the pilot drill rod until the soil discharge auger rod reaches the receiving well. The diameter of the rod body of the soil discharge auger rod is the same as that of the core tube, and the rod body is equipped with helical blades of the same specification as the core tube.

[0033] Connect the tunnel boring machine (TBM), with the front end of the core tube connected to the rear end of the soil discharge auger, and the split joint at the front end of the cutterhead connected to the tail end of the pilot drill rod in the pilot hole. Use the main power head of the drilling rig to push the TBM forward into the soil layer.

[0034] Insert the drill pipe into a pipe section of equal length and hoist them together into the working well, then place them on the pipe support.

[0035] Insert the outer shaft connector of the cutter head spindle into the outer rod front connector of the drill pipe, insert the core tube rear connector into the corresponding inner rod front connector, and use the locking rod stop to lock the outer shaft connector and the outer rod front connector, thereby ensuring a stable connection between the cutter head spindle and the drill pipe.

[0036] Connect the rear end of the drill rod to the front end of the power head drive shaft of the drilling rig, and connect the front end to the rear end of the cutterhead spindle of the pipe jacking machine. Insert the outer sleeve of the socket connector at the rear end of the outer drill rod into the outer sleeve of the socket connector of the outer drive shaft, and insert the outer octagonal sleeve at the rear end of the inner drill rod into the inner octagonal sleeve of the inner drive shaft. Embed the locking rod block into the rectangular locking rod hole of the outer drive shaft, and fix the locking rod block in the bolt hole with bolts to ensure a stable connection between the drill rod and the drive shaft of the power head.

[0037] Then, the drilling rig main unit is started to insert and tighten the pipe section forward; the outer drive shaft rotates while the power head pushes forward, and the rotation is in the high torque low speed gear. The outer drill rod drives the outer shaft of the cutter head main shaft to rotate, driving the cutter head to rotate with high torque to cut and break the strata in front, forming slag that enters the soil chamber and then enters the cutter head main shaft through the soil inlet; at the same time, the inner drive shaft drives the inner drill rod to rotate in the low torque high speed gear, thereby driving the core tube and the soil discharge auger to rotate. Under the action of the auger blades, the slag is transported forward and discharged from the receiving well.

[0038] After one pipe section is jacked up, continue jacking up pipe sections and drill rods according to the above steps. At the same time, remove the jacked-up pilot drill rod and soil removal auger rod in the receiving well until the entire pipeline laying operation is finally completed.

[0039] Preferably, the back of the cutter head is provided with several stirring paddles, which extend into the mud-water chamber / soil chamber. During the rotation and jacking process of the cutter head, the stirring paddles rotate with the cutter head to stir the mud / slag entering the mud-water chamber / soil chamber, thereby making it easier to discharge from the mud discharge channel and preventing blockage.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] This invention provides a micro-jacking construction device based on external borehole drive. This novel jacking technology achieves a breakthrough in both precision and efficiency through a step-by-step construction mode of guiding before jacking. The invention's innovative "external borehole drive" approach fundamentally avoids and improves upon the shortcomings of traditional micro-jacking technologies and machines, such as high risk, difficult operation, easy pipe blockage, and high overall construction costs. It completely solves the problem of the lack of ideal technology and equipment available in the current micro-jacking field. By using an external drilling rig to provide driving force to the cutterhead of the jacking machine, it is not limited by the space inside the borehole, can provide greater power, and can significantly improve construction efficiency. It can also cover hard strata, rock strata, strata containing pebbles and gravel, mixed fill strata, and water-rich sandy strata, greatly improving geological adaptability and providing a better solution for urban underground space development.

[0042] The micro-jacking construction device based on external drive provided by this invention adopts a large-diameter double-wall structure for the power head drive shaft of the drilling rig host, in conjunction with drill rods and slurry-type pipe jacking devices that also adopt a large-diameter double-wall structure. The double-wall interlayer of the main shaft inside the power head drive shaft of the drilling rig host, the double-wall interlayer of the drill rod inside the drill rod, and the double-wall interlayer of the main shaft inside the cutterhead main shaft of the pipe jacking device serve as slurry inlet channels, while the core tube hole of the cutterhead main shaft of the pipe jacking device, the rod hole inside the drill rod, and the shaft hole inside the power head of the drilling rig host serve as mud discharge channels. There is no need to set up separate slurry inlet and mud discharge channels, which greatly simplifies the structure of the pipe jacking device.

[0043] The micro-jacking construction device based on external drive provided by this invention consists of an inner drive shaft and an outer drive shaft in the power head drive shaft of the drilling rig. The inner drive shaft and the outer drive shaft can work simultaneously at different gears. In conjunction with the drill rod with a large-diameter double-wall structure and the soil-type pipe jacking machine, it can provide a high-torque, low-speed driving force for the cutterhead of the pipe jacking machine, while providing a low-torque, high-speed driving force for the core tube and the soil discharge auger of the pipe jacking machine. Thus, the high-speed rotation of the core tube and the soil discharge auger can quickly discharge the excavated soil in the soil chamber forward, ensuring that the cutterhead has sufficient torque to cut and break the soil in front, while also ensuring the efficiency of excavated soil discharge and avoiding soil blockage.

[0044] This invention simplifies the structure of the tunnel boring machine head section, greatly reducing equipment costs. One set of jacking drilling rig main unit can be equipped with multiple tunnel boring machine heads of different specifications, thereby achieving tunnel jacking operations adapted to different pipe diameters at a very low cost. At the same time, the tunnel boring machine head of this invention does not require a drive device or a separate mud inlet / outlet system, so the head length can be made shorter, and tunnel jacking operations can be completed with a smaller working shaft, further reducing the overall construction cost. Attached Figure Description

[0045] To more clearly illustrate the solutions in this invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of the structure of the micro-pipe jacking construction device based on external hole drive provided by the present invention;

[0047] Figure 2 This is a schematic diagram of the drilling rig main unit in the micro pipe jacking construction device based on external hole drive provided by the present invention;

[0048] Figure 3 A schematic diagram of the power head of the micro-pipe jacking construction device based on external hole drive provided by the present invention;

[0049] Figure 4 A cross-sectional view of the power head of the micro-jacking construction device based on external hole drive provided by the present invention.

[0050] Figure 5 A schematic diagram of the drive shaft of the micro-jacking pipe construction device based on external hole drive provided by the present invention;

[0051] Figure 6 A cross-sectional view of the drive shaft of the micro-jacking pipe construction device based on external hole drive provided by the present invention.

[0052] Figure 7 A schematic diagram of the drill rod structure of the micro pipe jacking construction device based on external hole drive provided by the present invention;

[0053] Figure 8 A cross-sectional view of the drill rod of the micro-jacking construction device based on external hole drive provided by the present invention;

[0054] Figure 9 A schematic diagram of the structure of the slurry-type pipe jacking excavator, a micro-pipe jacking construction device based on external hole drive, provided by the present invention.

[0055] Figure 10 A schematic diagram of the structure of the soil-type pipe jacking excavator, a micro-pipe jacking construction device based on external hole drive, provided by the present invention.

[0056] Figure 11 This is a schematic diagram of the pilot hole drilling operation of the micro jacking construction device based on external hole drive provided by the present invention.

[0057] Figure 12 This is a schematic diagram of the tunneling and pipeline laying of the slurry micro-jacking construction method based on external borehole drive provided by the present invention.

[0058] Figure 13 This is a schematic diagram of the tunneling and pipeline laying of the soil-based micro-jacking construction method based on external borehole drive provided by the present invention.

[0059] The markings in the diagram are explained as follows:

[0060] 1. Drilling rig main unit; 2. Pipe jacking machine; 3. Drill rod; 4. Power head; 5. Cutterhead; 6. Cutterhead spindle; 7. Drive shaft; 8. Inner drive shaft; 9. Outer drive shaft; 10. Inner shaft hole; 11. Double-walled sandwich structure of drive shaft; 12. Outer drive transmission gear; 13. Inner drive transmission gear; 14. Grouting port; 15. Sealing bushing; 16. Grouting joint; 17. Outer drive joint; 18. Inner drive joint; 19. Outer drill rod; 20. Inner drill rod; 21. Inner rod hole; 22. Double-walled sandwich structure of drill rod; 23. Outer rod rear joint; 24. Outer rod front joint; 25. Inner rod rear joint; 26. 1. Inner rod front connector; 27. Outer shaft; 28. Core tube; 29. ​​Core tube hole; 30. Main shaft double-wall sandwich layer; 31. Grouting nozzle; 32. Outer shaft connector; 33. Core tube rear connector; 34. Tongue and groove joint; 35. Engaging block; 36. Rectangular locking rod hole; 37. Tunnel boring machine housing; 38. Main shaft seat; 39. Socket; 40. Mud chamber; 41. Inner mud discharge port; 42. Outer mud discharge port; 43. Divider joint; 44. Agitator; 45. Pilot drill bit; 46. Pipe section; 47. Soil chamber; 48. Soil inlet; 49. Core tube front connector; 50. Blade; 51. Soil discharge auger. Detailed Implementation

[0061] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0062] Example 1:

[0063] This embodiment provides a micro-pipe jacking construction device based on external borehole drive, the structure of which is as follows: Figure 1-9 As shown, the system includes a drilling rig main unit 1, a pipe jacking machine 2, and a drill rod 3. The drilling rig main unit 1 is equipped with a power head 4 that drives the drill rod 3 to rotate and jack. The pipe jacking machine 2 is equipped with a cutterhead 5 and a cutterhead spindle 6. The drive shaft 7 of the power head 4 is connected to the cutterhead spindle 6 of the pipe jacking machine 2 through the drill rod 3. The drive shaft 7 of the power head 4 adopts a large-diameter double-wall structure, consisting of an inner drive shaft 8 and an outer drive shaft 9. Both the inner drive shaft 8 and the outer drive shaft 9 are hollow structures. The inner drive shaft 8 is located at the inner axis of the outer drive shaft 9, dividing the internal space of the outer drive shaft 9 into two channels: an inner shaft hole 10 and a double-walled interlayer 11 between the outer wall of the inner drive shaft 8 and the inner wall of the outer drive shaft 9.

[0064] The outer drive shaft 9 is nested with an outer drive transmission gear 12, and the rear end of the inner drive shaft 8 extends beyond the outer drive shaft 9 and is provided with an inner drive transmission gear 13; the drilling rig host 1 can drive the outer drive shaft 9 and the inner drive shaft 8 to rotate respectively by driving the outer drive transmission gear 12 and the inner drive transmission gear 13 respectively.

[0065] The front end side wall of the external drive shaft 9 is provided with a grouting port 14, and the power head 4 is provided with a sealing bushing 15 at the position corresponding to the grouting port 14. A grouting connector 16 is provided on the sealing bushing 15.

[0066] The front end of the external drive shaft 9 is provided with an external drive connector 17, and the front end of the internal drive shaft is provided with an internal drive connector 18.

[0067] The drill rod 3 adopts a large-diameter double-wall structure consisting of an outer drill rod 19 and an inner drill rod 20. The inner drill rod 20 is fixed in the center of the inner hole of the outer drill rod 19, dividing the internal space of the outer drill rod 19 into two channels: an inner rod hole 21 and a drill rod double-wall interlayer 22 between the outer wall of the inner drill rod 20 and the inner wall of the outer drill rod 19.

[0068] The rear end of the external drill pipe 19 is provided with an external rod rear connector 23 adapted to the external drive connector 17, and the front end is provided with an external rod front connector 24 identical to the external drive connector 17; the rear end of the internal drill pipe 20 is provided with an internal rod rear connector 25 adapted to the internal drive connector 18, and the front end is provided with an internal rod front connector 26 identical to the internal drive connector 18.

[0069] The cutter head spindle 6 adopts a large-diameter double-wall structure, consisting of an outer shaft 27 and a core tube 28. The front end of the outer shaft 27 is connected to the cutter head 5 and is responsible for driving the cutter head 5 to rotate. The core tube 28 is fixedly installed at the axis of the outer shaft 27, dividing the internal space of the outer shaft 27 into two channels: a core tube hole 29 and a double-wall sandwich layer 30 between the outer wall of the core tube 28 and the inner wall of the outer shaft 27. Several spray nozzles 31 are opened on the front side wall of the outer shaft 27.

[0070] The outer shaft 27 has an outer shaft connector 32 at its rear end that is adapted to the outer rod front connector 24, and the core tube 28 has a core tube rear connector 33 at its rear end that is adapted to the inner rod front connector 26.

[0071] The external drive connector 17 is a socket connector outer sleeve with two tongue and groove joints 34 at the front end. The external rod rear connector 23 is a plug connector outer sleeve with a locking block 35 at the rear end that matches the tongue and groove joints 34. When the connector is inserted into place, the locking block 35 and the tongue and groove joints 34 of the external drive connector 17 engage with each other to achieve torque transmission and form an internal and external seal at the connection.

[0072] The inner drive connector 18 is an inner octagonal connector, and the inner rod rear connector 25 is an outer octagonal connector that matches the inner octagonal connector.

[0073] The outer sleeve of the socket joint is provided with a pair of rectangular locking rod holes 36. The outer sleeve of the plug joint is provided with a bolt hole at the center of the rectangular locking rod holes 36 after insertion. When the plug is inserted into place, a locking rod stop is embedded in the rectangular locking rod holes 36 and the locking rod stop is fixed at the bolt hole by bolts.

[0074] The tunnel boring machine 2 is a slurry-type tunnel boring machine, consisting of a machine housing 37, a spindle seat 38, a cutterhead 5, and a cutterhead spindle 6. The machine housing 37 has a cylindrical structure with a socket 39 for inserting a pipe on its outer edge at the rear end. The spindle seat 38 is located in the rear half of the machine housing 37, and the front half of the machine housing 37 is a slurry chamber 40. The cutterhead 5 is located at the front end of the machine housing 37. The rear end of the cutterhead spindle 6 is located on the spindle seat 38, and its front end is connected to the cutterhead 5. The outer wall of the core tube 28 has several inner mud discharge ports 41, and the side wall of the outer shaft 27 has corresponding outer mud discharge ports 42. The inner mud discharge ports 41 and the outer mud discharge ports 42 are connected by a short pipe. The front end of the cutterhead 5 has a split joint 43.

[0075] The back of the cutter head 5 is provided with several stirring paddles 44, which extend into the mud and water chamber 40. During the rotation and jacking process of the cutter head 5, the stirring paddles 44 rotate with the cutter head 5 to stir the mud entering the mud and water chamber 40, so that it is easier to be discharged from the mud discharge channel and blockage is prevented.

[0076] Example 2:

[0077] Based on Example 1, a slurry-type micro-jacking construction method based on external borehole drive is obtained, specifically, as follows: Figures 1-9 and Figure 11 , Figure 12 As shown, the drilling rig host 1 is installed and fixed in the working well, and the pilot drill bit 45 is connected. After the pilot hole drilling is completed, the theodolite and the light target at the front end of the pilot drill rod are removed from the back of the drilling rig host 1. The mud discharge port connector is installed at the rear end of the inner drive shaft 8 of the drive shaft 7 of the power head 4, and the mud discharge pipeline is connected. The pilot drill bit 45 is removed, and the pipe jacking device 2 is connected. The split joint 43 at the front end of the cutterhead 5 is connected to the tail end of the drill rod in the pilot hole. The power head 4 of the drilling rig host 1 pushes the pipe jacking device 2 forward into the soil layer.

[0078] Insert drill pipe 3 into pipe section 46 of the same length, hoist them together into the working well, and place them on the pipe bracket;

[0079] Insert the outer shaft connector 32 of the cutterhead spindle 6 into the outer rod front connector 24 of the drill rod 3, and insert the core tube rear connector 33 into the corresponding inner rod front connector 26. Lock the outer shaft connector 32 and the outer rod front connector 24 with the locking rod block to ensure a stable connection between the cutterhead spindle 6 and the drill rod 3. After the connection is completed, a ring-shaped grouting channel is formed along the double-walled interlayer 11 of the drive shaft 7 of the power head 4 of the drilling rig host 1, the double-walled interlayer 22 of the drill rod 3, and the double-walled interlayer 30 of the main shaft of the cutterhead spindle 6 of the pipe jacking device 2, from the grouting port 14 of the drilling rig host 1 to the mud and water chamber 40 of the pipe jacking device 2. At the same time, a closed mud discharge channel is formed along the core tube hole 29 of the cutterhead spindle 6 of the pipe jacking device 2, the inner rod hole 21 of the drill rod 3, and the inner shaft hole 10 of the power head 4 of the drilling rig host 1, from the mud and water chamber 40 to the rear end of the inner drive shaft 8 of the power head 4 of the drilling rig host 1.

[0080] Connect the rear end of drill rod 3 to the front end of drive shaft 7 of power head 4 of drilling rig 1, and connect the front end to the rear end of cutterhead spindle 6 of pipe jacking machine 2. Insert the outer sleeve of the socket connector at the rear end of outer drill rod 19 into the outer sleeve of socket connector of outer drive shaft 9, and insert the outer octagonal sleeve at the rear end of inner drill rod 20 into the inner octagonal sleeve of inner drive shaft 8. Embed the locking rod block into the rectangular locking rod hole 36 of outer drive shaft 9, and fix the locking rod block at the bolt hole with bolts to ensure a stable connection between drill rod 3 and drive shaft 7 of power head 4.

[0081] Then start the drilling rig 1 to push the pipe section 46 forward and insert the front end of the pipe section 46 into the socket 39 on the outer edge of the tail end of the tunneling machine housing 37.

[0082] The outer drive shaft 12 rotates while the power head 4 pushes forward, and drives the outer shaft 27 of the cutter head main shaft 6 to rotate through the outer drill rod 19, driving the cutter head 5 to rotate and cut and break the strata in front, forming slag that enters the mud and water chamber 40. Meanwhile, the grouting pump of the mud inlet and outlet system injects water or mud into the grouting port 14 of the drilling rig host 1. The mud enters the mud-water chamber 40 and mixes with the excavated soil through the annular grouting channel formed by the double-walled interlayer 11 of the drive shaft 7 of the power head 4 of the drilling rig host 1, the double-walled interlayer 22 of the drill rod 3, and the double-walled interlayer 30 of the main shaft 6 of the cutterhead of the pipe jacking device 2. The mud discharge pump of the mud inlet and outlet system draws outward from the rear end of the inner drive shaft 8 and through the inner closed mud discharge channel formed by the core tube hole 29 of the main shaft 6 of the cutterhead of the pipe jacking device 2, the rod hole 21 of the drill rod 3, and the shaft hole 10 of the power head 4 of the drilling rig host 1. This suctions the excavated mud in the mud-water chamber 40. In addition, the pressure formed in the mud-water chamber 40 during the excavation of the cutterhead 5 causes the excavated mud to enter the inner closed mud discharge channel from the mud-water chamber 40 and be discharged backward.

[0083] After one pipe section is jacked up, the above steps are repeated to add more pipe sections and drill rods for jacking up. At the same time, the pilot drill rod that was jacked up is removed from the receiving well until the entire pipeline laying operation is finally completed.

[0084] Example 3:

[0085] This embodiment provides a micro-pipe jacking construction device based on external borehole drive, the structure of which is as follows: Figure 1-8 and Figure 10 As shown, the system includes a drilling rig main unit 1, a pipe jacking machine 2, and a drill rod 3. The drilling rig main unit 1 is equipped with a power head 4 that drives the drill rod 3 to rotate and jack. The pipe jacking machine 2 is equipped with a cutterhead 5 and a cutterhead spindle 6. The drive shaft 7 of the power head 4 is connected to the cutterhead spindle 6 of the pipe jacking machine 2 through the drill rod 3. The drive shaft 7 of the power head 4 adopts a large-diameter double-wall structure, consisting of an inner drive shaft 8 and an outer drive shaft 9. Both the inner drive shaft 8 and the outer drive shaft 9 are hollow structures. The inner drive shaft 8 is located at the inner axis of the outer drive shaft 9, dividing the internal space of the outer drive shaft 9 into two channels: an inner shaft hole 10 and a double-walled interlayer 11 between the outer wall of the inner drive shaft 8 and the inner wall of the outer drive shaft 9.

[0086] The outer drive shaft 9 is nested with an outer drive transmission gear 12, and the rear end of the inner drive shaft 8 extends beyond the outer drive shaft 9 and is provided with an inner drive transmission gear 13; the drilling rig host 1 can drive the outer drive shaft 9 and the inner drive shaft 8 to rotate respectively by driving the outer drive transmission gear 12 and the inner drive transmission gear 13 respectively.

[0087] The front end side wall of the external drive shaft 9 is provided with a grouting port 14, and the power head 4 is provided with a sealing bushing 15 at the position corresponding to the grouting port 14. A grouting connector 16 is provided on the sealing bushing 15.

[0088] The front end of the external drive shaft 9 is provided with an external drive connector 17, and the front end of the internal drive shaft is provided with an internal drive connector 18.

[0089] The drill rod 3 adopts a large-diameter double-wall structure consisting of an outer drill rod 19 and an inner drill rod 20. The inner drill rod 20 is fixed in the center of the inner hole of the outer drill rod 19, dividing the internal space of the outer drill rod 19 into two channels: an inner rod hole 21 and a drill rod double-wall interlayer 22 between the outer wall of the inner drill rod 20 and the inner wall of the outer drill rod 19.

[0090] The rear end of the external drill pipe 19 is provided with an external rod rear connector 23 adapted to the external drive connector 17, and the front end is provided with an external rod front connector 24 identical to the external drive connector 17; the rear end of the internal drill pipe 20 is provided with an internal rod rear connector 25 adapted to the internal drive connector 18, and the front end is provided with an internal rod front connector 26 identical to the internal drive connector 18.

[0091] The cutter head spindle 6 adopts a large-diameter double-wall structure, consisting of an outer shaft 27 and a core tube 28. The front end of the outer shaft 27 is connected to the cutter head 5 and is responsible for driving the cutter head 5 to rotate. The core tube 28 is fixedly installed at the axis of the outer shaft 27, dividing the internal space of the outer shaft 27 into two channels: a core tube hole 29 and a double-wall sandwich layer 30 between the outer wall of the core tube 28 and the inner wall of the outer shaft 27. Several spray nozzles 31 are opened on the front side wall of the outer shaft 27.

[0092] The outer shaft 27 has an outer shaft connector 32 at its rear end that is adapted to the outer rod front connector 24, and the core tube 28 has a core tube rear connector 33 at its rear end that is adapted to the inner rod front connector 26.

[0093] The external drive connector 17 is a socket connector outer sleeve with two tongue and groove joints 34 at the front end. The external rod rear connector 23 is a plug connector outer sleeve with a locking block 35 at the rear end that matches the tongue and groove joints 34. When the connector is inserted into place, the locking block 35 and the tongue and groove joints 34 of the external drive connector 17 engage with each other to achieve torque transmission and form an internal and external seal at the connection.

[0094] The inner drive connector 18 is an inner octagonal connector, and the inner rod rear connector 25 is an outer octagonal connector that matches the inner octagonal connector.

[0095] The outer sleeve of the socket joint is provided with a pair of rectangular locking rod holes 36. The outer sleeve of the plug joint is provided with a bolt hole at the center of the rectangular locking rod holes 36 after insertion. When the plug is inserted into place, a locking rod stop is embedded in the rectangular locking rod holes 36 and the locking rod stop is fixed at the bolt hole by bolts.

[0096] The tunnel boring machine 2 is a soil-type tunnel boring machine, consisting of a machine housing 37, a main shaft seat 38, a cutterhead 5, and a cutterhead spindle 6. The machine housing 37 has a cylindrical structure. The main shaft seat 38 is located in the rear half of the machine housing 37, and the front half of the machine housing 37 is a soil chamber 47. The cutterhead 5 is located at the front end of the machine housing 37. The rear end of the cutterhead spindle 6 is located on the main shaft seat 38, and the front end is connected to the cutterhead 5. The core tube 28 has helical blades outside its tube body. The outer shaft 27 has a soil inlet 48 on the outer wall of its shaft section in the soil chamber 47. The front end of the cutterhead 5 has a hollow split joint 43, which is connected to the outer shaft 27. The front end of the core tube 28 has a core tube front joint 49 that is adapted to the inner rod rear joint 25.

[0097] The back of the cutter head 5 is provided with several blades 50, which extend into the soil chamber 47. During the rotation and jacking process of the cutter head 5, the blades 50 rotate with the cutter head 5 to crush the slag entering the soil chamber 47, making it easier to discharge and preventing blockage.

[0098] Example 4:

[0099] Based on Example 3, a soil-based micro-jacking construction method based on external borehole drive is obtained, specifically, as follows: Figures 1-8 and Figure 10 , Figure 11 , Figure 13 As shown, the drilling rig host 1 is installed and fixed in the working well, and the pilot drill bit 45 is connected. After the pilot hole drilling is completed, the theodolite behind the drilling rig host 1 and the optical target at the front end of the pilot drill rod are removed. In the working well, the soil discharge auger rods 51 are connected one by one along the inner hole of the outer drill rod of the pilot drill rod to push out the inner drill rod of the pilot drill rod until the soil discharge auger rod reaches the receiving well. The diameter of the rod body of the soil discharge auger rod 51 is the same as that of the core tube 28, and the rod body is provided with helical blades of the same specification as the core tube 28.

[0100] Connect the pipe jacking machine 2, the front end of the core tube 28 is connected to the rear end of the soil discharge auger 51, the split joint 43 at the front end of the cutterhead 5 is connected to the tail end of the pilot drill rod in the pilot hole, and the power head 4 of the drilling rig host 1 pushes the pipe jacking machine 2 forward into the soil layer.

[0101] Insert drill pipe 3 into pipe section 46 of the same length, hoist them together into the working well, and place them on the pipe bracket;

[0102] Insert the outer shaft connector 32 of the cutter head spindle 6 into the outer rod front connector 24 of the drill rod 3, insert the core tube rear connector 33 into the corresponding inner rod front connector 26, and lock the outer shaft connector 32 and the outer rod front connector 24 with the locking rod block to ensure a stable connection between the cutter head spindle 6 and the drill rod 3.

[0103] Connect the rear end of drill rod 3 to the front end of drive shaft 7 of power head 4 of drilling rig host 1, and connect the front end to the rear end of cutterhead spindle 6 of pipe jacking machine 2. Insert the outer sleeve of the socket connector at the rear end of outer drill rod 19 into the outer sleeve of socket connector of outer drive shaft 9, and insert the outer octagonal sleeve at the rear end of inner drill rod 20 into the inner octagonal sleeve of inner drive shaft 8. Embed the locking rod block into the rectangular locking rod hole 36 of outer drive shaft 9, and fix the locking rod block at the bolt hole with bolts to ensure a stable connection between drill rod 3 and drive shaft 7 of power head 4.

[0104] Then, the drilling rig main unit 1 is started to insert and tighten the pipe section 46 forward; the outer drive shaft 9 rotates while the power head 4 pushes forward, and the rotation adopts a high torque and low speed gear. Through the outer drill rod 19, the outer shaft 27 of the cutter head main shaft 6 is rotated, which drives the cutter head 5 to rotate with high torque to cut and break the strata in front, forming slag that enters the soil chamber 47 and then enters the interior of the cutter head main shaft 6 through the soil inlet 48; at the same time, the inner drive shaft 8 drives the inner drill rod 20 to rotate with a low torque and high speed gear, thereby driving the core tube 28 and the soil discharge auger 51 to rotate. Under the action of the auger blades, the slag is transported forward and discharged from the receiving well.

[0105] After one pipe section is jacked up, continue jacking up pipe sections and drill rods according to the above steps. At the same time, remove the jacked-up pilot drill rod and soil removal auger rod in the receiving well until the entire pipeline laying operation is finally completed.

Claims

1. A micro-pipe jacking construction device based on external borehole drive, comprising a drilling rig, a pipe jacking tool, and drill rods, characterized in that; The drilling rig host is equipped with a power head that drives the drill rod to rotate and advance. The pipe jacking machine is equipped with a cutterhead and a cutterhead spindle. The drive shaft of the power head is connected to the cutterhead spindle of the pipe jacking machine through the drill rod. The drive shaft of the power head adopts a large-diameter double-wall structure, consisting of an inner drive shaft and an outer drive shaft. Both the inner drive shaft and the outer drive shaft are hollow structures. The inner drive shaft is located at the inner axis of the outer drive shaft, dividing the internal space of the outer drive shaft into two channels: an inner shaft hole and a double-wall sandwich between the outer wall of the inner drive shaft and the inner wall of the outer drive shaft. An external drive gear is nested on the external drive shaft, and the rear end of the internal drive shaft extends beyond the external drive shaft and is provided with an internal drive gear; the drilling rig host can drive the external drive gear and the internal drive gear respectively to drive the external drive shaft and the internal drive shaft to rotate. The front end side wall of the external drive shaft is provided with a grouting port, and the power head is provided with a sealing bushing at the position corresponding to the grouting port. A grouting connector is provided on the sealing bushing. The front end of the outer drive shaft is provided with an outer drive connector, and the front end of the inner drive shaft is provided with an inner drive connector. The drill rod adopts a large-diameter double-wall structure consisting of an outer drill rod and an inner drill rod. The inner drill rod is fixed in the center of the inner hole of the outer drill rod, dividing the internal space of the outer drill rod into two channels: the inner rod hole and the double-wall interlayer of the drill rod between the outer wall of the inner drill rod and the inner wall of the outer drill rod. The rear end of the external drill pipe is provided with an external rod rear connector adapted to the external drive connector, and the front end is provided with an external rod front connector identical to the external drive connector; the rear end of the internal drill pipe is provided with an internal rod rear connector adapted to the internal drive connector, and the front end is provided with an internal rod front connector identical to the internal drive connector. The rear end of the outer shaft is provided with an outer shaft connector that is adapted to the front connector of the outer rod, and the rear end of the core tube is provided with a core tube rear connector that is adapted to the front connector of the inner rod.

2. The micro-pipe jacking construction device based on external borehole drive according to claim 1, characterized in that, The cutter head spindle adopts a large-diameter double-wall structure, consisting of an outer shaft and a core tube. The front end of the outer shaft is connected to the cutter head and is responsible for driving the cutter head to rotate. The core tube is fixedly installed at the axis of the outer shaft, dividing the internal space of the outer shaft into two channels: the core tube hole and the double-wall sandwich layer between the outer wall of the core tube and the inner wall of the outer shaft. Several spray nozzles are opened on the front side wall of the outer shaft.

3. The micro-pipe jacking construction device based on external borehole drive according to claim 1, characterized in that, The outer drive connector is a socket connector outer sleeve with several tongue and groove joints at the front end. The outer rod rear connector is a plug connector outer sleeve with a locking block at the rear end that matches the tongue and groove joints. When the plug is inserted into place, the locking block and the tongue and groove joints of the outer drive connector engage with each other to achieve torque transmission and form an internal and external seal at the connection. The inner drive connector is an inner octagonal connector, and the inner rod rear connector is an outer octagonal connector that matches the inner octagonal connector.

4. The micro-pipe jacking construction device based on external borehole drive according to claim 3, characterized in that, The outer sleeve of the socket joint is provided with a pair of rectangular locking rod holes. The outer sleeve of the plug joint is provided with a bolt hole at the center of the rectangular locking rod hole corresponding to the insertion position. When the insertion is in place, the locking rod stop is embedded in the rectangular locking rod hole and the locking rod stop is fixed at the bolt hole by bolts.

5. The micro-pipe jacking construction device based on external drive according to any one of claims 1-4, characterized in that, The tunnel boring machine is a slurry-type tunnel boring machine, consisting of a machine housing, a main shaft seat, a cutterhead, and a cutterhead spindle. The machine housing is a cylindrical structure with a socket for a pipe at its outer edge at the rear end. The main shaft seat is located in the rear half of the machine housing, and the front half of the machine housing is a slurry chamber. The cutterhead is located at the front end of the machine housing. The rear end of the cutterhead spindle is mounted on the main shaft seat, and its front end is connected to the cutterhead. The outer wall of the core tube has several internal mud discharge ports, and the outer shaft sidewall has external mud discharge ports at corresponding positions. The internal and external mud discharge ports are connected by a short pipe. The front end of the cutterhead has a split joint.

6. The micro-pipe jacking construction device based on external borehole drive according to claim 5, characterized in that, The back of the cutter head is provided with several stirring paddles, which extend into the mud and water chamber.

7. The micro-pipe jacking construction device based on external drive according to any one of claims 1-4, characterized in that, The tunnel boring machine (TBM) is a soil-type TBM, consisting of a TBM housing, a main shaft seat, a cutterhead, and a cutterhead spindle. The TBM housing has a cylindrical structure. The main shaft seat is located in the rear half of the TBM housing, and the front half of the TBM housing is a soil chamber. The cutterhead is located at the front end of the TBM housing. The rear end of the cutterhead spindle is mounted on the main shaft seat, and its front end is connected to the cutterhead. The core tube has helical blades outside its tube body. The outer shaft has a soil inlet on its outer wall within the soil chamber. The front end of the cutterhead has a hollow split joint that communicates with the outer shaft. The front end of the core tube has a core tube front joint that is compatible with the rear joint of the inner rod.

8. The micro-pipe jacking construction device based on external borehole drive according to claim 7, characterized in that, The back of the cutterhead is provided with several blades, which extend into the soil chamber.

9. A slurry-driven micro-jacking method based on external borehole drive, applicable to claim 5, characterized in that, Includes the following steps: S1. Install and fix the drilling rig in the working well, connect the pilot drill bit, and after completing the pilot hole drilling work, remove the theodolite behind the drilling rig and the optical target at the front end of the pilot drill rod. Install the mud discharge port connector at the rear end of the inner drive shaft of the power head drive shaft, connect the mud discharge pipeline, remove the pilot drill bit, connect the pipe jacking device, connect the split joint at the front end of the cutterhead to the tail end of the drill rod in the pilot hole, and use the power head of the drilling rig to push the pipe jacking device forward into the soil layer. S2. Place the drill pipe into a pipe section of the same length, hoist them together into the working well, and place them on the pipe support. S3. Insert the outer shaft connector of the cutterhead spindle into the outer rod front connector of the drill rod, and insert the core tube rear connector into the corresponding inner rod front connector. Lock the outer shaft connector and the outer rod front connector with the locking rod block to ensure a stable connection between the cutterhead spindle and the drill rod. After the connection is completed, a ring-shaped grouting channel is formed from the grouting port of the drilling rig to the mud chamber of the jacking machine along the double-walled interlayer of the drive shaft inside the power head drive shaft of the drilling rig, the double-walled interlayer of the drill rod inside the drill rod, and the double-walled interlayer of the main shaft inside the cutterhead spindle of the jacking machine. At the same time, a closed mud discharge channel is formed from the mud chamber to the rear end of the inner drive shaft of the power head of the drilling rig along the core tube hole of the cutterhead spindle of the jacking machine, the inner rod hole of the drill rod, and the inner shaft hole of the power head of the drilling rig. S4. Connect the rear end of the drill rod to the front end of the power head drive shaft of the drilling rig, and connect the front end to the rear end of the cutterhead spindle of the pipe jacking machine. Insert the outer sleeve of the socket connector at the rear end of the outer drill rod into the outer sleeve of the socket connector of the outer drive shaft, and insert the outer octagonal sleeve at the rear end of the inner drill rod into the inner octagonal sleeve of the inner drive shaft. Embed the locking rod block into the rectangular locking rod hole of the outer drive shaft, and fix the locking rod block in the bolt hole with bolts to ensure a stable connection between the drill rod and the drive shaft of the power head. S5. Then start the drilling rig main unit to push the pipe section forward and insert the front end of the pipe section into the socket on the outer edge of the end of the tunneling machine housing; S6. The external drive shaft rotates while the power head pushes forward, driving the outer shaft of the cutter head spindle to rotate through the external drill rod, which in turn drives the cutter head to rotate and cut and break the strata in front, forming slag that enters the mud and water chamber. Meanwhile, the grouting pump of the mud inlet and outlet system injects water or mud from the grouting port of the drilling rig main unit. The mud enters the mud-water chamber and mixes with the excavated soil through the annular grouting channel formed by the double-walled interlayer of the main shaft inside the power head drive shaft of the drilling rig main unit, the double-walled interlayer of the drill rod inside the drill pipe, and the double-walled interlayer of the main shaft inside the cutterhead main shaft of the pipe jacking machine. The mud discharge pump of the mud inlet and outlet system draws outward from the rear end of the inner drive shaft. It draws out the excavated mud in the mud-water chamber through the inner closed mud discharge channel formed by the core tube hole of the cutterhead main shaft of the pipe jacking machine, the inner rod hole of the drill pipe, and the inner shaft hole of the power head of the drilling rig main unit. In addition, the pressure formed in the mud-water chamber during the excavation of the cutterhead causes the excavated mud to enter the inner closed mud discharge channel from the mud-water chamber and be discharged backward. S7. After one pipe section is jacked up, add more pipe sections and drill rods according to the above steps and jack up again. At the same time, remove the jacked-up pilot drill rods from the receiving well until the entire pipeline laying operation is finally completed.

10. A soil-based micro-jacking method based on external borehole drive, applicable to claim 7, characterized in that, Includes the following steps: S1. Install and fix the drilling rig main unit in the working well, connect the pilot drill bit, and after completing the pilot hole drilling work, remove the theodolite behind the drilling rig main unit and the optical target at the front end of the pilot drill rod. In the working well, connect and push in the soil discharge auger rod one by one along the inner hole of the outer drill rod of the pilot drill rod to push out the inner drill rod of the pilot drill rod until the soil discharge auger rod reaches the receiving well; the rod body of the soil discharge auger rod has the same diameter as the tube body of the core tube, and the rod body is provided with helical blades of the same specification as the core tube; S2. Connect the pipe jacking machine. Connect the front end of the core tube to the rear end of the soil discharge auger. Connect the split joint at the front end of the cutterhead to the tail end of the pilot drill rod in the pilot hole. Use the power head of the drilling rig to push the pipe jacking machine forward into the soil layer. S3. Place the drill pipe into a pipe section of the same length, hoist them together into the working well, and place them on the pipe support. S4. Insert the outer shaft connector of the cutter head spindle into the outer rod front connector of the drill rod, insert the core tube rear connector into the corresponding inner rod front connector, and lock the outer shaft connector and the outer rod front connector with the locking rod block to ensure a stable connection between the cutter head spindle and the drill rod. S5. Connect the rear end of the drill rod to the front end of the power head drive shaft of the drilling rig, and connect the front end to the rear end of the cutterhead spindle of the pipe jacking machine. Insert the outer sleeve of the socket connector at the rear end of the outer drill rod into the outer sleeve of the socket connector of the outer drive shaft, and insert the outer octagonal sleeve at the rear end of the inner drill rod into the inner octagonal sleeve of the inner drive shaft. Embed the locking rod block into the rectangular locking rod hole of the outer drive shaft, and fix the locking rod block in the bolt hole with bolts to ensure a stable connection between the drill rod and the drive shaft of the power head. S6. Then start the drilling rig and insert the pipe section forward and tighten it. The outer drive shaft rotates while the power head pushes forward. The rotation uses a high torque, low speed gear. The outer drill rod drives the outer shaft of the cutterhead spindle to rotate, driving the cutterhead to rotate with high torque to cut and break the strata in front, forming slag that enters the soil chamber and then enters the cutterhead spindle through the soil inlet. At the same time, the inner drive shaft drives the inner drill rod to rotate with a low torque, which in turn drives the core tube and the soil discharge auger to rotate. Under the action of the auger blades, the slag is transported forward and discharged from the receiving well. S7. After one pipe section is jacked up, add more pipe sections and drill rods according to the above steps and jack up again. At the same time, remove the jacked-up pilot drill rod and soil removal auger rod in the receiving well until the entire pipeline laying operation is finally completed.

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