Method for extricating slurry shield machine in cement-based grouting body

Abstract

This invention discloses a method for escaping a slurry-water tunnel boring machine (TBM) trapped in a cement-based grouting body, belonging to the field of TBM technology. The method includes: preparing new bentonite grout to replace the thin grout in the TBM's slurry chamber; initially increasing the pressure of the slurry chamber; hydraulically injecting bentonite drag-reducing grout to the outer sides of the middle and tail shells of the TBM; further increasing the pressure of the slurry chamber and sequentially advancing the TBM's propulsion cylinders in sections until the TBM advances a predetermined distance; then retracting the propulsion cylinders a predetermined distance, while extending the articulated cylinder between the middle and tail shells of the TBM another predetermined distance; connecting the tail shell to the tail section; repeatedly extending and retracting the articulated cylinder; rotating the cutterhead until the torque reaches a stable value; reducing the pressure of the slurry chamber and increasing the hydraulic pressure of the propulsion cylinders, allowing the TBM to resume forward tunneling. This invention solves the problem that existing TBM escaping methods cannot effectively address situations where the cutterhead and shield shell are both encased in cement-based grouting body, causing the TBM to become trapped.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction technology, specifically to a method for freeing a slurry TBM from a cement-based grouting body. Background Technology

[0002] Tunnel boring machines (TBMs) getting stuck in complex strata with soft upper layers and hard lower layers is a common technical challenge. Broadly speaking, TBM getting stuck refers to a situation where the equipment's capacity is nearing its limit but it cannot advance normally, its tunneling efficiency decreases, or it comes to a complete standstill. Narrowly defined, TBM getting stuck refers to a situation where the TBM is directly jammed, preventing normal tunneling, mainly manifested as the cutterhead failing to start or the TBM's thrust exceeding limits. However, in TBM construction in complex strata with soft upper layers and hard lower layers, additional measures such as filling and ground cement reinforcement are often required to assist in the excavation operation, leading to different TBM getting stuck situations. On the one hand, the pressure of cement grouting is greater than the water and soil pressure; disturbance will release and redistribute the stress in the surrounding rock, and the cement grout may erode the area around the TBM, forming a certain gripping force. On the other hand, the loss of the upper soil layer creates a back-soil effect; prolonged shutdown causes the surrounding rock to converge and compress the shield tail around the TBM. During the excavation and slurry replacement process, unstable wedge-shaped rock blocks in the lower part of the surrounding rock may further collapse, and their jamming effect exacerbates the cutterhead getting stuck situation. Therefore, the probability of a tunnel boring machine getting trapped and the difficulty of escaping are greatly increased in cement-based grouting bodies.

[0003] Existing methods for escaping trapped tunnel boring machines (TBMs) generally include the ultimate torque escaping method, the enlargement and clearing method, the auxiliary excavation and local decompression blasting method, and the use of reverse jacks. However, in cases where the cutterhead and shield shell are encased in cement-based grout after pressure-assisted excavation and clearing at the riverbed, leading to the TBM becoming trapped, the TBM is essentially held in place. The torque required for the shield shell to roll exceeds the ultimate torque of the cutterhead, meaning the shield will not roll. Furthermore, the ultimate torque load will be entirely borne by the bolt group connecting the main drive and the cutterhead flange, and stress concentration may damage the main drive connecting bolts. In fractured strata with a soft upper layer and a hard lower layer, the operating space for enlargement and clearing is limited, and the presence of hard rock blocks at the bottom significantly increases the opening time. Prolonged exposure to high-pressure environments increases the risk of instability at the excavation face. Local blasting is mostly used for stable full-section hard rock but is not suitable for strata with a soft upper layer and a hard lower layer. Considering the poor stability of the excavation face and the low bearing capacity of the soil, the effectiveness of using reverse jacks is limited, and the operating space is narrow.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, a method for escaping a slurry shield tunneling machine in a cement-based grouting body is provided. This method addresses the problem that existing shield escaping methods cannot effectively solve the situation where the cutterhead and shield shell are both encased in cement-based grouting body, causing the shield machine to become trapped.

[0006] To achieve the above objectives, a method for escaping a slurry shield tunneling machine trapped in a cement-based grouting body is provided, comprising the following steps: Includes the following steps: A new bentonite slurry is prepared to replace the thin slurry in the slurry chamber of the tunnel boring machine. The viscosity and specific gravity of the new bentonite slurry are greater than those of the thin slurry. The pressure of the slurry chamber is initially increased so that the pressure value of the slurry chamber is greater than the pressure value of the ground water pressure at the excavation face. The bentonite drag-reducing grout is hydraulically injected into the outer side of the middle shield shell and the tail shield shell of the tunnel boring machine; The shield machine's cutterhead and propulsion cylinders were rotated at low speeds in sequence to generate eccentric force in an attempt to break free from the obstacle. After the attempt to escape failed, the pressure of the mud chamber was increased again and the propulsion cylinder of the tunnel boring machine was retracted by a preset distance, so that the propulsion cylinder was separated from the assembled tunnel segment. The hinge cylinder between the middle shield shell and the tail shield shell of the tunnel boring machine extends the preset distance, so that the propulsion cylinder abuts against the tunnel segment to free the tail shield shell from obstruction; After the shield tail shell is freed, the shield tail shell is connected to the rear 10 ring segments of the shield tail through a connecting member to form a whole; The articulated hydraulic cylinder repeatedly extends and retracts, causing the cutterhead, front shield, and middle shield of the tunnel boring machine to retract as a whole; The cutter head rotated, and the cutter head successfully escaped the obstacle; Disassemble the connecting parts and reduce the pressure of the slurry chamber so that the pressure value of the slurry chamber is the same as the pressure value of the ground water pressure at the excavation face; The rotation of the cutterhead increases the hydraulic pressure of the propulsion cylinder, causing the tunnel boring machine to resume its forward excavation.

[0007] Furthermore, the initial pressure value of the slurry chamber is increased to 1.2 times the pressure value of the ground water pressure at the excavation face.

[0008] Furthermore, the pressure value of the slurry chamber is increased to 1.3 times the pressure value of the ground water pressure at the excavation face.

[0009] Furthermore, the preset distance is 20mm.

[0010] Furthermore, before initially increasing the pressure of the slurry chamber, replenish and inject the articulation sealing grease of the tunnel boring machine.

[0011] Furthermore, monitoring points are set at the tail of the tunnel boring machine to observe the cutterhead mileage, shield attitude, and displacement of the tail and segments during the extrication process.

[0012] Furthermore, the step of attempting to extricate the tunnel boring machine from its predicament by rotating the cutterhead at a low speed includes: Start the cutter head at a low speed and rotate it left and right once each; The propulsion cylinders of the tunnel boring machine are divided into four sections: upper, lower, left, and right. The cutterhead is rotated after the propulsion cylinders of the upper and lower sections are retracted. After the propulsion cylinders of the left and right partitions are retracted, the cutter head is rotated.

[0013] Furthermore, the shield machine's propulsion cylinder generates eccentric force to attempt to escape from a stuck situation, including: Retract all the propulsion cylinders, and then extend the propulsion cylinders corresponding to each segment of the tube other than the top block of the tube segment in a clockwise or counterclockwise direction to push the tube segment. Rotate the cutter head.

[0014] Furthermore, the propulsion cylinder extends and pushes the tube segment in multiple rounds in a clockwise or counterclockwise direction, and the propulsion oil pressure is increased step by step in each round.

[0015] The beneficial effects of this invention are that the method for escaping a slurry shield tunneling machine in a cement-based grouting body is a method for escaping a slurry shield tunneling machine in a cement-based grouting body. It utilizes the existing equipment system of the shield tunneling machine to solve the problem of the shield tunneling machine being trapped when both the cutterhead and the shield shell are wrapped by the cement-based grouting body under complex working conditions. It can be easily and quickly and safely escaped through convenient operation inside the tunnel. It has the characteristics of programmed operation, safety and convenience, and cost saving. Attached Figure Description

[0016] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic flowchart of the method for escaping a slurry shield tunneling machine in a cement-based grouting body according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of a slurry shield tunneling machine trapped in a working condition according to an embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram illustrating the preparation work for the slurry shield tunneling machine to escape from its obstacle, according to an embodiment of the present invention.

[0019] Figure 4 This is a schematic diagram showing the installation location of the observation device according to an embodiment of the present invention.

[0020] Figure 5for Figure 4 A magnified view of point B in the diagram.

[0021] Figure 6 This is a top view of the observation device according to an embodiment of the present invention.

[0022] Figure 7 This is a side view of the observation device according to an embodiment of the present invention.

[0023] Figure 8 This is a schematic diagram illustrating the eccentric force-assisted escape mechanism of the propulsion cylinder in an embodiment of the present invention.

[0024] Figure 9 This is a schematic diagram showing the positional correspondence between the tube segments and the propulsion cylinder in an embodiment of the present invention.

[0025] Figure 10 This is a schematic diagram showing the comparison of the articulated hydraulic cylinder before and after its initial extension, according to an embodiment of the present invention.

[0026] Figure 11 This is a schematic diagram of the longitudinal section of the pipe segment after the connecting member is installed, according to an embodiment of the present invention.

[0027] Figure 12 This is a schematic diagram of the cross-section of the pipe segment after the connector is installed, according to an embodiment of the present invention.

[0028] Figure 13 This is a schematic diagram illustrating the freeing of the cutter head and housing after the hinged retraction in an embodiment of the present invention.

[0029] Figure label: 1. Cutterhead, 2. Front shield shell, 3. Middle shield shell, 4. Cement-based grouting body, 5. Segment, 6. Bottom reserved hole, 7. Mud chamber, 8. Top ball valve, 9. Hinged sealing grease port, 10. Grease pump, 11. Pressure gauge, 12. Middle shield radial hole, 13. Observation device, 14. Marking scale, 15. Ink line, 16. Propulsion cylinder, 17. Air cushion chamber, 18. Hinged cylinder, 19. Connecting part, 20. Channel steel end, 21. Detailed Implementation

[0030] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] Reference Figures 1 to 13As shown, the present invention provides a method for freeing a slurry shield tunneling machine from a cement-based grouting body, comprising the following steps: S1. Prepare new bentonite slurry to replace the thin slurry in the slurry chamber of the tunnel boring machine. The viscosity and specific gravity of the new bentonite slurry are greater than those of the thin slurry.

[0033] See Figure 2 As shown, the cutterhead 1, front shield shell 2, middle shield shell 3, and tail shield shell 4 of the tunnel boring machine are all trapped by cement-based grouting body 5, and the tail shield contains the formed tunnel segments 6.

[0034] Before attempting to free a slurry shield tunneling machine from its entrapment, the following preparatory work should be carried out.

[0035] S11 uses fresh bentonite slurry to replace the slurry in the mud-water tank.

[0036] New bentonite slurry is mixed on the ground to increase its viscosity and specific gravity, and then transported to the tunnel and injected into the slurry chamber for replacement.

[0037] Specifically, new bentonite slurry is mixed on the ground to increase its viscosity and specific gravity. It is then transported to the tunnel and injected into the slurry chamber 8 through the pre-reserved hole 7 at the bottom of the slurry chamber. The slurry is then discharged from the bottom of the shield tail through the ball valve 9 at the top of the slurry chamber and pumped out of the tunnel for slurry replacement.

[0038] Add polymer materials to fresh bentonite slurry at a ratio of 1m 3 Mix 15 kg of HS-1, 5 kg of HS-3, and 40 kg of bentonite with water. After replacement, the slurry discharged from the top should have a viscosity of 60s.

[0039] Replace the bentonite with fresh slurry to fill the pores in the strata at the excavation face and prevent slurry leakage.

[0040] S12 utilizes the radial holes of the central shield to inject bentonite drag-reducing grout.

[0041] Around the middle shield shell 3 and the tail shield shell 4, bentonite drag-reducing grout is injected through the radial holes 13 of the middle shield, which can play a role in lubricating and reducing friction of the shell.

[0042] The mass ratio of drag-reducing grout is: composite bentonite: water = 1:1, and the grouting pressure does not exceed 0.4 MPa.

[0043] S13 increases the pressure in the mud and water chamber.

[0044] Increase the pressure setting of mud and water chamber 8 to 1.2 times the ground water pressure at the excavation face, and allow it to infiltrate for more than 3 hours.

[0045] Increase the pressure setting of the slurry chamber 8 to 1.2 times the ground water pressure at the excavation face, and allow it to infiltrate for 3 hours to achieve a stable pressure holding effect. Increasing the pressure of the slurry chamber can increase the slurry penetration distance and achieve a stable pressure holding effect.

[0046] S14 replenishes sealing grease.

[0047] Replenishing the articulated sealing grease of the tunnel boring machine can protect the seal.

[0048] Specifically, a grease pump 11 is connected to the hinge seal grease injection port 10 located in the central shield, and an external pressure gauge 12 is connected to facilitate inspection and verification of the hinge seal grease pressure. The pressure is required to be no less than 0.45 MPa, and grease should be added in time if the pressure is too low. Then, bentonite drag-reducing grout is injected through the radial holes of the central shield. The mass ratio of the drag-reducing grout is: composite bentonite: water = 1:1, and the grouting pressure does not exceed 0.4 MPa.

[0049] S15 sets up monitoring points at the tail of the shield.

[0050] After tightening the tail of the shield, nearly 10 rings of segment connection bolts were installed. Monitoring points were set up at the tail of the shield machine to observe the displacement of the tail and segments during the escape process.

[0051] Specifically, after measuring the gap between the tail shield shell 4 and the segment 6, eight observation devices 14 are welded at equal intervals around the inner side of the tail shield shell 4. The observation devices are used to indicate the relative displacement of the tail shield shell and the segment in the axial direction as well as their relative displacement in the circumferential and radial directions.

[0052] Specifically, the observation device includes a base plate, radial plates, and axial plates. The base plate is laid on the inner side of the tail shield shell. The radial plates are erected vertically on the base plate. The radial plates are arranged along the radial direction of the tail shield shell. The axial plates are connected to the radial plates. The axial plates abut against the outer wall of the tube segments. The axial plates are arranged along the axial direction of the tail shield shell. The axial plates are marked with graduation 15, with a total graduation length of 100mm, each graduation being 2mm. There are 25 graduations on both the inner and outer sides of the tube segment coverage area, allowing observation of the relative displacement of the tail shield shell 4 and the tube segments 6 along the propulsion direction.

[0053] Two ink lines 16 are marked radially on the side of the segment at the corresponding position of the observation device to indicate the initial position. The relative rotation angle between the tail shield shell and the segment can be observed. At the same time, the gap change value at each point of the tail shield shell and the segment can be obtained by observing the radial deformation of the device.

[0054] In addition, the cutterhead mileage and shield attitude data can be monitored in real time from the shield control room. Through these methods, it is possible to accurately determine whether the shield is moving forward, backward, rotating, bumping, or tilting.

[0055] S2. Attempt to break free by sequentially rotating the cutterhead and propulsion cylinders of the tunnel boring machine at low speeds to generate eccentric force.

[0056] In this embodiment, the cutterhead was first rotated at a low speed to attempt to escape the obstacle. Specifically, the cutterhead 1 was started at a low speed, and under the escape torque, it was attempted to rotate left and right once each. Then, the upper and lower partition propulsion cylinders were retracted by 20mm, and the cutterhead was started again twice. Finally, the propulsion cylinders were retracted completely by 20mm, and the cutterhead was started again twice. The cutterhead 1 stopped abruptly due to high torque and did not rotate. Through the observation device and measurement system, the roll angle of the front shield 2 and the middle shield 3 fluctuated slightly by 0.02 degrees before recovering. The special observation device 14 at the shield tail did not detect any changes in the shield tail shell 4 or the segment 6. The escape attempt under the ultimate torque condition failed, and the process proceeded to the next step.

[0057] Specifically, the step in S4 involving attempting to extricate the tunnel boring machine (TBM) cutterhead by rotating it at low speed includes the following steps: S21. Start the cutter head at low speed and rotate it left and right once each; S22. Divide the propulsion cylinders of the tunnel boring machine into four sections: upper, lower, left, and right. After retracting the propulsion cylinders of the upper and lower sections, rotate the cutterhead. S23. After retracting the propulsion cylinders of the left and right sections, rotate the cutter head.

[0058] In this embodiment, the tunnel boring machine has a total of 16 sets of propulsion cylinders, divided into four sections: upper, lower, left, and right, containing 3, 4, 5, and 4 sets of propulsion cylinders respectively. First, the cutterhead is started at low speed, and under the escape torque, it is attempted to rotate left and right once each. Then, the propulsion cylinders of the upper and lower sections are retracted by 20mm, and the cutterhead is started again twice. Finally, all propulsion cylinders are retracted by 20mm, and the cutterhead is started again twice. The cutterhead 1 trips and stops due to high torque, without rotating. Through the observation device and measurement system, the rolling angles of the front shield 2 and the middle shield 3 fluctuate slightly by 0.02 degrees before recovering. Through the observation device 14 and measurement system, no changes are observed in the tail shield 4, pipe 6, or cutterhead 1 during the process, indicating that the escape attempt under the ultimate torque condition has failed, and the eccentric force attempt to escape is initiated.

[0059] The shield tunneling machine's propulsion cylinders in S2 generate eccentric forces in an attempt to break free from their entrapment, including the following steps: S24. Retract all the propulsion cylinders, and then extend the corresponding propulsion cylinders of each segment other than the top block of the segment to push the segment out in a clockwise or counterclockwise direction. S25. Rotate the cutter head.

[0060] The propulsion cylinder extends the push tube segments in multiple rounds in a clockwise or counterclockwise direction, and the propulsion oil pressure is increased step by step in each round.

[0061] The process utilizes a combination of eccentric thrust to shear and compress the surrounding reinforcement material. When local shear failure occurs, the reinforcement material cracks and falls off, facilitating the shield's escape. All propulsion cylinders 17 are retracted by 50mm. Then, the three sets of propulsion cylinders corresponding to each segment (excluding the capping block) are extended in turn to support the segments. Before the cylinders extend, the pressure setting of the slurry chamber 8 is lowered and increased to match the ground water pressure at the excavation face to increase the effective eccentric force. Multiple rounds of operation are performed, with the propulsion cylinders retracting in groups, first clockwise and then counterclockwise, for each round.

[0062] Repeat this process three times for each cycle, then gradually increase the hydraulic pressure in stages, with each increase not exceeding 3 MPa. The maximum assembly hydraulic pressure should be set to 70% of the maximum propulsion hydraulic pressure, or stop operation when the cutter head moves forward 5 mm.

[0063] In this embodiment, all propulsion cylinders retract 50mm. In assembly mode, the three sets of propulsion cylinders corresponding to each segment other than the capping block (F) are extended and pushed onto the segments in turn, in the order of L2, B2, B3, B1, and L1. Before the propulsion cylinders extend, the pressure setting of the slurry chamber is reduced and increased to the ground water pressure at the excavation face to reduce the slurry reaction force and increase the effective eccentric force. The propulsion cylinders are extended and retracted in groups in a single round, first clockwise and then counterclockwise, for multiple rounds. Each round is repeated 3 times, and then the oil pressure is increased in stages, with each stage increasing by 2.5~3.0MPa. When the oil pressure reached 10 MPa, during the second cycle, when the top of the three sets of propulsion cylinders was at position B3, the cutterhead 1 mileage began to change by 1 mm, and the shield began to move forward. The oil pressure was further increased to 17 MPa, and during the second cycle, when the cutterhead mileage changed by a cumulative 5 mm and the shield moved forward by 5 mm, operation was stopped. At the same time, the shield tail observation device 14 was observed to have moved forward by a cumulative 5 mm, with no change in the tunnel segments, and no rotation or radial displacement of the observation device 14 was observed. During this period, the pressure in the mud-water chamber 8 fluctuated slightly, increasing by a cumulative 0.02 bar, and the liquid level in the air cushion chamber 18 rose significantly by 60 mm.

[0064] After the cutterhead moved forward 5mm and stopped, an attempt was made to start the cutterhead, turning it left and right twice each. Upon observation, the special observation device at the tail of the shield showed no rotation, the shield roll angle did not change, and the segments and tail shell did not rotate or move relative to each other. The cutterhead still could not be started, and the attempt to escape using the eccentric force of the propulsion cylinder failed.

[0065] S3. After the attempt to escape failed, the pressure of the mud chamber was increased again and the propulsion cylinder 10 of the tunnel boring machine was retracted by a preset distance, so that the propulsion cylinder 10 was separated from the assembled tunnel segment.

[0066] Increasing the pressure in the slurry chamber again can provide a backward reaction force after the propulsion cylinder retracts, which is beneficial for the tunnel boring machine to retreat.

[0067] Specifically, the pressure of the slurry chamber is further increased to 1.3 times the pressure of the ground water at the excavation face. Increasing the slurry chamber pressure provides a backward reaction force after the propulsion cylinder retracts, facilitating the tunnel boring machine's retreat.

[0068] As a preferred implementation method, the preset distance is 20mm.

[0069] Specifically, when retracting the propulsion cylinders, all propulsion cylinders are retracted symmetrically one by one from top to bottom, so that all propulsion cylinders are 20mm away from the tube segment.

[0070] S4. The hinge cylinder between the middle shield shell 3 and the tail shield shell 4 of the tunnel boring machine extends a preset distance, so that the propulsion cylinder 17 abuts against the segment 6 to free the tail shield shell 4.

[0071] Engage the active articulation, utilizing the thrust of the articulation cylinder 19 as it extends to push the rear of the shield and the tail of the shield backward until the propulsion cylinder fully contacts the tunnel segment. Specifically, the articulation cylinder is engaged and extends evenly by 20mm, with each extension controlled at 4mm / time, until the propulsion cylinder fully contacts the tunnel segment.

[0072] While maintaining the pressure in the front mud chamber, the thrust of the articulated hydraulic cylinder when it extends pushes the rear of the middle shield and the tail of the shield to move backward.

[0073] The observation device at the tail of the shield observed that the entire tail shell retreated 20mm, with no relative rotation between the segments and the tail shell, and no change in the moving segments, thus achieving the unblocking of the tail shell. During this period, the mileage of the cutterhead 1, the pressure of the mud-water chamber 8, and the liquid level of the air cushion chamber 18 all remained unchanged. After the active articulation was activated, a designated person observed the articulation grease pressure gauge 12, which slowly decreased from 0.50MPa to 0.45MPa. The grease pump 11 was immediately activated to replenish grease until the grease pressure reached 0.50MPa.

[0074] S5. After the shield tail shell 4 is freed, the shield tail shell 4 is connected to the rear 10 ring segments of the shield tail 4 through the connecting member 20 to form a whole.

[0075] In this embodiment, the connecting member 20 is a channel steel. The channel steel 21 is installed in the gap of the propulsion cylinder 17 to connect the 10 ring segments 6 behind the shield tail into a whole. The end of the channel steel 21 is welded to the shield tail 4, which can effectively constrain the relative displacement of the segments and the shield tail shell.

[0076] S6. The articulated hydraulic cylinder repeatedly extends and retracts, causing the cutterhead 1, front shield 2, and middle shield 3 of the tunnel boring machine to retract as a whole.

[0077] Specifically, the pressure in the slurry chamber 8 was increased to 1.35 times the ground water pressure at the excavation face. First, the propulsion cylinder was retracted 10mm, then the articulated cylinder was retracted 10mm. The cutterhead mileage was observed to change by 10mm. The cutterhead then retreated 10mm until the propulsion cylinder was fully against the tunnel segment. There was no change in the observation device 14 at the shield tail or the tunnel segment 6. The articulated cylinder stroke was then repeated 10-20mm, three times, achieving a 10mm back-and-forth movement of the cutterhead, middle shield, and front shield while the shield tail shell remained stationary. This ensured the complete release of the front and middle shield shells. Simultaneously, the slurry chamber pressure was observed to fluctuate slightly, decreasing cumulatively by 0.09ar, while the air cushion chamber level dropped significantly, accumulating a 150mm decrease. During this period, a designated person monitored the articulated grease pressure gauge 12, replenishing it as needed to maintain the grease pressure at 0.50MPa.

[0078] The articulated cylinder retracts within its extended stroke range to maintain the pressure in the front mud chamber. It extends and retracts within a 10-20mm stroke range of the articulated cylinder extension range, achieving a 10mm movement of the cutterhead and front shield while the shield tail remains stationary. This allows the cutterhead, front shield, and middle shield to retract as a whole, detaching from the surrounding cement-based slurry and freeing the front and middle shield shells. The articulated cylinder continues to extend and retract three more times to ensure that the shells are completely freed from all sides.

[0079] S7. Disassemble the connecting parts and reduce the pressure of the slurry chamber so that the pressure value of the slurry chamber is the same as the pressure value of the ground water pressure at the excavation face.

[0080] The articulated cylinder stops at the 10mm extension position, locks the active articulation, and starts the cutter head 1. First, it rotates to the right at a speed of 0.3 rpm. On the second start, the torque reaches a peak of 2640 kN·m. Continue to rotate for 3 revolutions until the torque stabilizes at around 550 kN·m. Then, the cutter head rotates to the left at a speed of 0.3 rpm, reaching a peak of 1280 kN·m. Continue to rotate for 2 revolutions until the torque stabilizes at around 500 kN·m, which is close to the propulsion torque, thus achieving complete freeing of the cutter head.

[0081] After the cutterhead is freed, the observation device at the shield tail is removed, and the connecting parts between the shield tail and the tunnel segments are cut off. The pressure in the slurry chamber at the face is reduced to the original set ground water pressure at the excavation face.

[0082] S8. The cutterhead rotates, increasing the hydraulic pressure of the propulsion cylinder, allowing the tunnel boring machine to resume its forward excavation.

[0083] Specifically, the cutterhead is rotated, and the hydraulic pressure of the propulsion cylinder is gradually increased, allowing the tunnel boring machine (TBM) to resume tunneling forward. After the total thrust reaches a certain peak, the stroke of the propulsion cylinder and the propulsion distance change significantly. The machine continues to propel the TBM for another 1-2 meters until the total thrust drops to a stable level, thus achieving normal TBM tunneling.

[0084] In this embodiment, the cutterhead rotation speed was set to 0.5 rpm and the propulsion speed to 1 mm / min. The hydraulic pressure of the propulsion cylinder was gradually increased, and the tunnel boring machine resumed forward excavation. The thrust limit of the tunnel boring machine was 41600 kN. After the thrust reached 35000 kN, the stroke of the propulsion cylinder and the mileage of the cutterhead changed significantly, and propulsion was successfully resumed. The slurry circulation was normal. After excavating for another 0.5 m, the cutterhead rotation speed was set to 1.0 rpm and the propulsion speed to 3 mm / min. After excavating for another 1.5 m, the total thrust dropped to a stable stage and was maintained at 25000 kN, achieving normal tunnel boring.

[0085] The present invention relates to a method for escaping a slurry shield tunneling machine trapped in a cement-based grouting body. This method utilizes the existing equipment system of the shield tunneling machine to solve the problem of the shield tunneling machine being trapped when both the cutterhead and the shield shell are wrapped in cement-based grouting body under complex working conditions. It can be easily and quickly and safely achieved through convenient operation inside the tunnel, and has the characteristics of programmed operation, safety and convenience, and cost saving.

[0086] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for escaping a slurry shield tunneling machine trapped in a cement-based grouting body, characterized in that, Includes the following steps: A new bentonite slurry is prepared to replace the thin slurry in the slurry chamber of the tunnel boring machine. The viscosity and specific gravity of the new bentonite slurry are greater than those of the thin slurry. The pressure of the slurry chamber is initially increased so that the pressure value of the slurry chamber is greater than the pressure value of the ground water pressure at the excavation face. The bentonite drag-reducing grout is hydraulically injected into the outer side of the middle shield shell and the tail shield shell of the tunnel boring machine; The tunnel boring machine was then subjected to eccentric forces through a combination of low-speed rotation of the cutterhead and the propulsion cylinders. After the attempt to escape failed, the pressure of the mud chamber was increased again and the propulsion cylinder of the tunnel boring machine was retracted by a preset distance, so that the propulsion cylinder was separated from the assembled tunnel segment. The hinge cylinder between the middle shield shell and the tail shield shell of the tunnel boring machine extends the preset distance, so that the propulsion cylinder abuts against the tunnel segment to free the tail shield shell from obstruction; After the shield tail shell is freed, the shield tail shell is connected to the rear 10 ring segments of the shield tail through a connecting member to form a whole; The articulated hydraulic cylinder repeatedly extends and retracts, causing the cutterhead, front shield, and middle shield of the tunnel boring machine to retract as a whole; The cutter head rotated, and the cutter head successfully escaped the obstacle; Disassemble the connecting parts and reduce the pressure of the slurry chamber so that the pressure value of the slurry chamber is the same as the pressure value of the ground water pressure at the excavation face; The rotation of the cutterhead increases the hydraulic pressure of the propulsion cylinder, causing the tunnel boring machine to resume its forward excavation. The shield machine's propulsion cylinders generate eccentric force to attempt to escape the obstacle, including: retracting all propulsion cylinders, and then extending the propulsion cylinders corresponding to each segment other than the top block of the segment in a clockwise or counterclockwise direction to push the segment. Rotate the cutter head; The propulsion cylinder extends and pushes the tube segment in multiple rounds in a clockwise or counterclockwise direction, and the propulsion oil pressure is increased step by step in each round.

2. The method for escaping a slurry shield tunneling machine in a cement-based grouting body according to claim 1, characterized in that, The initial pressure value of the slurry chamber is increased to 1.2 times the pressure value of the ground water pressure at the excavation face.

3. The method for escaping a slurry shield tunneling machine in a cement-based grouting body according to claim 2, characterized in that, The pressure value of the slurry chamber is increased again to 1.3 times the pressure value of the ground water pressure at the excavation face.

4. The method for escaping a slurry shield tunneling machine in a cement-based grouting body according to claim 1, characterized in that, The preset distance is 20mm.

5. The method for escaping a slurry shield tunneling machine in a cement-based grouting body according to claim 1, characterized in that, Before initially increasing the pressure of the slurry chamber, replenish and inject the articulation sealing grease of the tunnel boring machine.

6. The method for escaping a slurry shield tunneling machine in a cement-based grouting body according to claim 1, characterized in that, Monitoring points were set at the tail of the tunnel boring machine to observe the displacement of the tail and segments during the extrication process.

7. The method for escaping a slurry shield tunneling machine in a cement-based grouting body according to claim 1, characterized in that, The steps for attempting to extricate the tunnel boring machine from its predicament by rotating the cutterhead at a low speed include: Start the cutter head at a low speed and rotate it left and right once each; The propulsion cylinders of the tunnel boring machine are divided into four sections: upper, lower, left, and right. The cutterhead is rotated after the propulsion cylinders of the upper and lower sections are retracted. After retracting the propulsion cylinders of the left and right sections, the cutter head is rotated.

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