A three-mode tunneling machine mode fast switching method

Abstract

The application discloses a kind of three mode heading machine mode quick conversion method, including slurry mode conversion into earth pressure mode operating procedure;Slurry type TBM conversion into earth pressure mode operating procedure;Slurry conversion into slurry type TBM operating procedure;Earth pressure mode conversion into slurry type TBM operating procedure;Slurry type TBM conversion into slurry operating procedure;Earth pressure mode conversion into slurry operating procedure.The method of the application can solve the problem that single / dual mode shield machine / heading machine is difficult to adapt in the stratum where existing clay, mud, water-rich and hard rock and other various geological conditions appear alternately, and can realize corresponding heading mode conversion according to different geological conditions, to realize the quick conversion of slurry, earth pressure, TBM three heading modes.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction technology, specifically to a method for rapid mode switching of a three-mode tunneling machine. Background Technology

[0002] Currently, tunnel boring machines (TBMs) are a commonly used construction machine for subway construction. Based on their operating modes, they can be divided into slurry shield tunnels, earth pressure balance (EPB) shield tunnels, and full-face hard rock tunnel boring machines (TBMs). Based on the number of operating modes, they can be divided into dual-mode and triple-mode TBMs. Dual-mode TBMs include slurry-Earth pressure balance (EPB) dual-mode TBMs, slurry-TBM dual-mode TBMs, and EPB-TBM dual-mode TBMs. Generally speaking, the more types of TBMs available, the more complex the geological environments they can adapt to. Especially in situations where various geological conditions such as clay, soil, water-rich soil, and hard rock strata alternate, conventional dual-mode TBMs / tunnel boring machines are slow, have poor engineering adaptability, and struggle to meet the geological conditions. During mode conversion, conventional dual-mode TBMs / tunnel boring machines consume significant manpower and resources, and the conversion time is excessively long. Furthermore, the cumbersome conversion procedures often make mode conversion difficult to implement, causing numerous problems for construction.

[0003] Invention patent CN104895576A, "TBM-EPB Dual-Mode Shield Tunneling Machine Mode Conversion Method," discloses a TBM-EPB dual-mode shield tunneling machine mode conversion method in hard rock and soft soil strata. It belongs to the field of shield tunneling technology and can realize the switching between TBM and EPB modes at the interface between hard and soft soil to adapt to the requirements of different strata. This tunneling mode is simpler than the mode conversion of the center belt conveyor type TBM-EPB dual-mode shield tunneling machine, which not only saves a lot of manpower and material resources, but also greatly shortens the construction period.

[0004] Invention patent CN111219194A, "Dual-mode Shield Tunneling Machine of Slurry and Earth Pressure Pressure and its Tunneling Mode Conversion Method," discloses a dual-mode shield tunneling machine of slurry and earth pressure pressure in soft soil, clay and other strata, and its tunneling mode conversion method. It belongs to the field of shield tunneling technology and can realize the switching between slurry and earth pressure pressure modes at the boundary between strata with high and low settlement requirements, so as to adapt to the requirements of different strata. This tunneling mode is simpler than the mode conversion of TBM-EPB dual-mode shield tunneling machine. It is converted through the internal slurry system and does not require additional manpower and material resources, which is both time-saving and economical.

[0005] To adapt to the alternating geological conditions of clay, soil, water-rich soil, and hard rock strata, multi-mode tunnel boring machines (TBMs) are required. Each time a new geological condition is encountered, the corresponding tunneling mode must be switched. Initially, three types were commonly used: slurry-earth pressure dual-mode TBMs, slurry-TBM dual-mode TBMs, and earth pressure dual-TBM dual-mode TBMs. Except for the slurry-earth pressure dual-mode TBM, switching between these three types of TBMs / tunneling machines requires dismantling the equipment, which is time-consuming and labor-intensive. Furthermore, existing dual-mode TBMs / tunneling machines are difficult to adapt to the alternating geological conditions of clay, soil, water-rich soil, and hard rock strata. When the tunneling mode cannot correspond to the tunneling strata, it can easily lead to shield attitude deviation and tunneling difficulties, thus affecting the normal tunneling operation.

[0006] In the past, when switching modes, especially in strata with high settlement requirements, failure to switch modes quickly could lead to surface subsidence. If the switching time was too long, it could also delay the construction period. In addition, the traditional earth pressure-TBM and slurry-TBM mode switching environments were poor, with a lot of dust and residual slag causing pollution to the tunnel segments and tunnels. Transporting slag also required additional manpower and resources for processing.

[0007] While the slurry-earth pressure dual-mode shield tunneling conversion method does not result in a poor conversion environment, this method cannot adapt to full-face hard rock formations. Although dual-mode tunneling machines such as earth pressure-TBM and slurry-TBM can adapt to full-face hard rock formations, they each have their own geological limitations. Furthermore, the mode conversion process is cumbersome, difficult to operate, and requires significant space, leading to excessively high equipment costs and difficult maintenance.

[0008] In summary, during the tunnel boring machine excavation process, when the geological strata require rapid switching between three excavation modes, the initially widely used dual-mode tunnel boring machine was time-consuming and labor-intensive to switch modes and had insufficient adaptability to the geological strata. The slurry-earth pressure dual-mode shield tunneling machine adopted later had problems such as limitations in engineering adaptability. Summary of the Invention

[0009] To address the aforementioned issues, this invention provides a rapid mode switching method for a three-mode tunneling machine, which can achieve corresponding tunneling mode switching according to different geological conditions, enabling rapid switching between slurry, earth pressure, and TBM tunneling modes.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A method for rapid mode conversion of a three-mode tunneling machine includes the following procedures: conversion from slurry mode to earth pressure test (EPT) operation; conversion from slurry TBM to EPT operation; conversion from slurry mode to slurry TBM operation; conversion from EPT operation to slurry TBM operation; conversion from slurry TBM operation to slurry operation; and conversion from EPT operation to slurry mode.

[0012] Furthermore, the aforementioned mud-water to earth pressure balance mode conversion operation procedure is used to convert the mud-water balance mode to the earth pressure balance mode, including the following steps:

[0013] 1.1 Preparatory Work

[0014] Select a stable conversion stratum as the switching point for mode conversion. When the switching point is about to be reached, reduce the speed of the cutterhead and run the shield tunneling system in slurry mode. After reaching the switching point, the shield tunneling system stops advancing and runs the slurry chamber circulation system in slurry mode to discharge the remaining slag in the slurry chamber through the slurry pipeline.

[0015] 1.2 Inspect components and piping

[0016] The shield tunneling system closes ball valves V67, V68, F11, F32, and F37, opens ball valve F38, opens the propulsion bypass shielding state, and enters the circulating conventional bypass mode. The pressure of the slurry in the mud and water pipeline is used to determine whether there is a leakage problem in the closed ball valves.

[0017] 1.3 Slag and Soil Accumulation

[0018] After confirming that there is no leakage in the ball valve, continue to operate the circulating conventional bypass mode in the slurry mode, start the cutterhead, advance the shield forward, and at the same time open the upper ball valve F11 to open the upper slurry inlet pipeline for slurry discharge, so as to realize the accumulation of slag in the soil chamber.

[0019] 1.4 Slag Replacement with Grease Filling

[0020] The tunneling distance of the shield is used to determine whether the excavated soil in the soil chamber has reached the upper grout inlet, i.e., the height of ball valve F11. During this process, it is necessary to constantly control the tunneling speed of the shield system to match the grout discharge speed of the upper grout inlet to stabilize the water and soil pressure in the soil chamber. If it has reached the upper grout chamber, the upper soil chamber detection pipe is opened to observe the excavated soil height. The monitoring port of the main grout inlet pipe is opened to detect whether there is grout leakage from the discharged excavated soil. Combined with the recorded changes in the cutterhead torque value, it is determined whether the excavated soil replacement in the soil chamber is complete. If there is grout leakage or excessive cutterhead torque, experts need to be consulted to determine whether replacement can begin. After the excavated soil replacement is completed, the tunneling of the shield system is stopped, the upper grout inlet F11 is closed, and the conventional bypass mode of the circulating flow is stopped. After the slurry mode is stopped, shield tail grease is injected into the pipeline through the grout discharge port, grout inlet, and branch port of the soil chamber connecting pipe to fill the pipeline and prevent pipeline blockage during the transition. At the same time, the excess pressure needs to be discharged by opening the upper detection pipe to stabilize the soil pressure in the soil chamber.

[0021] 1.5 Controlling the gushing flow

[0022] Open the front and rear gates of the screw conveyor and extend the screw conveyor to the designated position. During the extension process, avoid interference between the screw conveyor and other components. After the screw conveyor is fully extended, slowly start the cutterhead and the tunnel boring machine (TBM) advances slowly. At the same time, slightly open the lower gate at the screw conveyor outlet and adjust the opening range of the lower gate according to the mud and water gushing situation. During this process, it is necessary to stabilize the water and soil pressure in the soil chamber by controlling the opening range of the lower gate at the outlet and the tunneling speed of the TBM.

[0023] 1.6 Improved soil replacement completed

[0024] After the mud and water gushing phenomenon ends, continue to advance the shield tunneling system. By activating the foam system and bentonite system, inject bentonite and foam into the soil chamber. At the same time, observe whether the discharge of excavated soil is stable through the auger discharge port. During this process, the properties of the excavated soil need to be adjusted by adjusting the ratio between bentonite and foam. After the excavated soil discharge is stable, slowly increase the tunneling speed of the shield tunneling system and run the earth pressure mode for tunneling. At this time, the mode conversion is completed.

[0025] Furthermore, the aforementioned process for converting a slurry TBM to earth pressure balance mode is used to convert a slurry TBM to earth pressure balance mode, and includes the following steps:

[0026] 2.1 Large stones are discharged via a screw conveyor.

[0027] Select a stable conversion stratum as the switching point for mode conversion. When the switching point is about to be reached, slow down the cutterhead speed and continue to run the slurry TBM. Observe whether there are large-diameter rocks in the discharged slag. If so, use a screw conveyor to discharge the large-diameter rocks.

[0028] The shield tunneling system closes the lower ball valves F17, F18, F66, and F32 of the slurry TBM, opens the propulsion bypass shield, and enters the normal bypass mode. After confirming that there is no leakage in the ball valves, the cutterhead is slowly started, and the shield tunneling system advances slowly. The shield tunneling slurry pipeline operates in the normal bypass mode to ensure the normal operation of the slurry pipeline. Then, the upper ball valve F11 and the upper slurry inlet pipeline are opened to discharge slurry. During this process, it is necessary to constantly control the tunneling speed of the shield to match the slurry discharge speed of the upper slurry inlet to stabilize the water and soil pressure in the soil chamber.

[0029] 2.3 Slag Replacement

[0030] The tunneling distance of the shield is used to determine whether the height of the excavated soil in the soil chamber has reached the upper grout inlet. If it is expected to have reached the upper soil chamber detection pipe, the height of the excavated soil is observed, and the tunneling of the shield system is stopped. To prevent the mud and water from gushing for too long during the conversion, the monitoring port of the main grout inlet pipe is opened to detect whether there is grout leakage from the discharged excavated soil. Combined with the recorded changes in the cutterhead torque value, a comprehensive judgment is made on whether the excavated soil conversion in the soil chamber is complete. If there is grout leakage or excessive cutterhead torque, experts need to be consulted to determine whether the conversion can begin.

[0031] 2.4 Controlling the screw compressor's jetting

[0032] After the slag and soil replacement is completed, close the upper grouting port F11, stop the operation of the conventional bypass mode, and after the slurry mode stops, inject the shield tail grease into the pipeline through the grout discharge port, grout inlet port, and branch port of the soil chamber connecting pipe to fill the pipeline and prevent pipeline blockage during the transition. At the same time, it is also necessary to open the upper detection pipeline to release excess pressure and stabilize the soil pressure in the soil chamber. Open the front and rear gates of the screw conveyor and extend the screw conveyor to the specified position. During the extension process, avoid interference between the screw conveyor and other components. After the screw conveyor is fully extended, slowly start the cutterhead and the shield system advances slowly. At the same time, slightly open the lower gate at the outlet of the screw conveyor and adjust the opening range of the lower gate according to the slurry gushing situation. During this process, it is necessary to stabilize the water and soil pressure in the soil chamber by controlling the opening range of the lower gate at the outlet and the tunneling speed of the shield.

[0033] 2.5 Stable slag discharge

[0034] After the mud and water gushing phenomenon ends, continue to advance the shield tunneling system. By activating the foam system and bentonite system, inject bentonite and foam into the soil chamber to improve the slag inside the chamber. Observe whether the slag discharge is stable through the auger discharge port. During this process, the properties of the slag need to be adjusted by using an appropriate ratio between bentonite and foam. After the slag discharge is stable, slowly increase the tunneling speed of the shield tunneling system.

[0035] 2.6 Switching to Earth Pressure Mode for Tunneling

[0036] The earth pressure mode tunneling is now running, and the mode conversion is complete.

[0037] Furthermore, the aforementioned mud-water to mud-water TBM conversion operation procedure is used to convert the mud-water balance mode to a mud-water TBM, and includes the following steps:

[0038] 3.1 Reduce the tunnel boring machine speed

[0039] Select a stable conversion stratum as the switching point for mode conversion. When the switching point is about to be reached, reduce the cutterhead speed and the shield tunneling system runs in slurry mode.

[0040] 3.2 Cleaning the air cushion chamber

[0041] After reaching the switching point, the tunnel boring machine stops advancing and operates in the slurry mode to wash the slurry chamber, discharging the remaining slag and soil in the slurry chamber through the slurry pipeline.

[0042] 3.3 Inspect components and piping

[0043] When the tunnel boring machine is operating in slurry mode, the propulsion bypass shield is opened, and the relevant components to be inspected (such as ball valves: F23, F24) are closed. The pressure of the slurry in the slurry pipeline is used to determine whether there is a leakage problem in the closed ball valve.

[0044] 3.4 Controlling the volume of excavated soil

[0045] After confirming there are no leaks in the ball valves, continue operating the propulsion bypass shield in slurry mode, slowly start the cutterhead, and the tunnel boring machine (TBM) system advances slowly forward. Open the upper air pressure connection pipe and connect the hose to the slurry level detection pipe in the middle of the shield body. Operate the TBM slurry pipeline in the circulating conventional bypass mode to ensure normal operation of the slurry pipeline. Then open the lower slurry discharge ball valves F50, F66, and F38 to open the lower slurry discharge pipeline for slag discharge. Release excess pressure by opening the upper detection pipeline. Pengrun soil can be injected appropriately to improve the slag and soil conditions. When the soil level in the detection soil chamber reaches one-third, stop the TBM system tunneling.

[0046] 3.5 Stable slag discharge

[0047] Open the grout inlet ball valves F51, F30, F17, and F18 to allow grout to enter through the lower grout inlet pipe, while keeping the other grout inlet ball valves closed. Observe whether the excavated soil discharge is stable. Once the excavated soil discharge is stable, slowly increase the tunneling speed of the shield system.

[0048] 3.6 Switching to slurry-type TBM tunneling

[0049] The slurry TBM tunneling operation is now complete, and the mode switch is finished.

[0050] Furthermore, the earth pressure balance mode to slurry TBM conversion operation procedure is used to convert the earth pressure balance mode to a slurry TBM, including the following steps:

[0051] 4.1 Simultaneous improvement of slag soil and simultaneous discharge of slag by screw conveyor

[0052] Select a stable conversion stratum as the switching point for mode conversion. When approaching the switching point, slow down the cutterhead speed. After reaching the switching point, stop the tunnel boring machine (TBM) and slowly rotate the cutterhead in place. The screw conveyor slowly discharges the slag to reduce the slag volume in the soil chamber. When slurry spraying occurs at the lower gate of the screw conveyor, immediately stop and reduce the slag discharge speed. During this process, a certain amount of compressed air needs to be injected into the soil chamber through the connecting pipe at the top to maintain the stability of the pressure inside the soil chamber, or an appropriate amount of bentonite can be injected to improve the mud film at the working face, maintain the pressure inside the soil chamber, and ensure that the working face does not collapse.

[0053] 4.2 Controlling the volume of excavated soil

[0054] After the volume of slag in the soil bin is reduced to about one-third of the bin's height, the rear gate of the screw conveyor is closed, and the screw conveyor is returned to the designated position. The bentonite system is then activated to improve the slag and enhance its properties, creating a soil plug effect in the space of the front cylinder of the screw conveyor. During this process, compressed air needs to be introduced into the soil bin through the upper connecting pipe in the air cushion bin to maintain stable pressure inside the bin. At the same time, the bentonite system needs to be activated to control the volume and properties of the slag in the soil bin.

[0055] 4.3 Improved Slag Soil

[0056] The system operates in conventional bypass mode. The mud and water pipelines used are checked in advance for blockage. The shield cutterhead is kept rotating. Grout is injected into the soil chamber by opening the grout ball valves F51, F30, F17, and F18. The remaining grout ball valves are closed. When the grout pipeline outputs grout, the grouting speed is adjusted to keep the liquid level not exceeding one-third of the soil chamber.

[0057] 4.4 Unblocking pipes

[0058] Run the backwashing pipeline to clean and discharge the slag in the internal pipes, and enter the reverse circulation mode to unclog the mud and water pipeline in front of the shield. After confirming that all pipelines are unobstructed, open the upper air pressure connection pipe and connect the hose to the mud and water chamber liquid level detection pipe in the middle of the shield. Use the liquid level sensor to observe the mud height in the mud chamber. Stop grouting when the mud level in the mud chamber is about to reach one-third of the height.

[0059] 4.5 Stable slag discharge

[0060] After confirming that the upper connecting pipe, the slurry inlet and outlet pipes, etc. are all unobstructed, the system operates in slurry TBM tunneling mode, the shield advances slowly, and the advancing speed is gradually increased according to the muck discharge situation.

[0061] 4.6 Switching to slurry TBM tunneling

[0062] Switch to slurry-water TBM tunneling.

[0063] Furthermore, the aforementioned process for converting a slurry-type TBM into a slurry-water operation mode includes the following steps:

[0064] 5.1 Smooth slag discharge

[0065] Select a stable conversion stratum as the switching point for mode conversion. When the switching point is about to be reached, slow down the cutterhead speed and continue to run the slurry TBM. Observe whether there are large-diameter rocks in the discharged slag. If so, use a screw conveyor to discharge the large-diameter rocks.

[0066] 5.2 Inspect components and piping

[0067] The shield tunneling system closes the lower grout ball valve of the slurry TBM, opens the propulsion bypass shield, and checks for leaks in the ball valve. During this process, it is necessary to check the slurry pipelines used in advance for blockages, and stabilize the pressure by operating the internal bypass mode and controlling the grouting speed.

[0068] 5.3 Improved Slag Soil

[0069] Rotate the cutterhead in place and inject grout into the soil chamber by opening the upper grout ball valves F30 and F11. At the same time, open the upper connecting pipe of the soil chamber connected to the air cushion chamber to absorb or input air into the soil chamber to help balance the pressure of the soil chamber and maintain the pressure stability. When the grout is introduced into the main grouting pipeline, pay attention to adjusting the grouting speed to maintain the pressure stability in the soil chamber. On the control panel, disconnect the mud-water circulation system from the liquid level.

[0070] 5.4 Unblocking pipes

[0071] Before starting the conventional bypass mode for mud and water, first run the internal reverse circulation system to clear the mud and water pipeline in front of the central shield, and then run the internal reverse circulation system to clear the slurry discharge pipeline and slurry discharge port.

[0072] 5.5 Grouting of the Air Cushion Chamber

[0073] After confirming that all pipelines are unobstructed, grouting is carried out on the air cushion chamber. The level sensor is used to observe the mud height in the chamber. When the mud is about to reach the upper connecting pipe opening, grouting is stopped. The SAMSON pressure holding system is run and the air cushion chamber pressure is set. The connecting gate valves V67 / V68 inside the air cushion chamber are opened.

[0074] 5.6 Switching to mud-water mode for tunneling

[0075] After confirming that the upper connecting pipe, the inlet and outlet slurry pipes, etc. are all unobstructed, the system operates in the air cushion direct discharge tunneling mode, the shield advances slowly, and the advance speed is gradually increased to the normal tunneling state according to the muck discharge situation, and the slurry mode switch is completed.

[0076] Furthermore, the earth pressure balance mode to slurry balance operation procedure is used to convert the earth pressure balance mode to the slurry balance mode, including the following steps:

[0077] 6.1 Simultaneous improvement of slag soil and simultaneous discharge of slag by screw conveyor

[0078] Select a stable conversion stratum as the switching point for mode conversion. When approaching the switching point, slow down the cutterhead speed. After reaching the switching point, stop the tunnel boring machine (TBM) and slowly rotate the cutterhead in place. The screw conveyor slowly discharges the slag to reduce the slag volume in the soil chamber. When slurry spraying occurs at the lower gate of the screw conveyor, immediately stop and reduce the slag discharge speed. During this process, a certain amount of compressed air needs to be injected into the soil chamber through the connecting pipe at the top to maintain the stability of the pressure inside the soil chamber, or an appropriate amount of bentonite can be injected to improve the mud film at the working face, maintain the pressure inside the soil chamber, and ensure that the working face does not collapse.

[0079] 6.2 Controlling the volume of excavated soil

[0080] After the volume of slag in the soil bin is reduced to about one-third of the bin's height, the rear gate of the screw conveyor is closed, and the screw conveyor is returned to the designated position. The bentonite system is then activated to improve the slag and enhance its properties, creating a soil plug effect in the space of the front cylinder of the screw conveyor. During this process, compressed air needs to be introduced into the soil bin through the upper connecting pipe in the air cushion bin to maintain stable pressure inside the bin. At the same time, the bentonite system needs to be activated to control the volume and properties of the slag in the soil bin.

[0081] 6.3 Improved Slag Soil

[0082] Prepare to activate the conventional slurry bypass mode. Keep the tunnel boring machine cutterhead rotating and inject slurry into the soil chamber by opening the upper slurry ball valves F30 and F11. At the same time, open the upper connecting pipe of the soil chamber connected to the air cushion chamber to absorb the air coming from the soil chamber, helping to balance the soil chamber pressure and maintain pressure stability. When the main slurry pipeline outputs slurry, pay attention to adjusting the slurry injection speed to maintain the stability of the pressure in the soil chamber. In the operation panel, disconnect the connection between the slurry circulation system and the liquid level. During this process, it is necessary to check whether the slurry pipelines used are blocked in advance, and stabilize the pressure by running the machine bypass mode and controlling the grouting speed.

[0083] 6.4 Unblocking pipes

[0084] Start the conventional bypass mode for mud and water, first run the reverse circulation system inside the machine to clear the mud and water pipeline in front of the central shield, and then run the reverse circulation system inside the chamber to clear the slurry discharge pipeline and slurry discharge port.

[0085] 6.5 Grouting of the air cushion chamber

[0086] After confirming that all pipelines are unobstructed, the air cushion chamber is grouted, and the slurry level in the chamber is observed using a liquid level sensor; the SAMSON pressure holding system is run and the air cushion chamber pressure is set, and the connecting gate valves V67 / V68 inside the air cushion chamber are opened;

[0087] 6.6 Switching to mud-water mode for tunneling

[0088] After confirming that the upper connecting pipe, the inlet and outlet slurry pipes, etc. are all unobstructed, the system operates in the air cushion direct discharge tunneling mode, the shield advances slowly, and the advance speed is gradually increased to the normal tunneling state according to the muck discharge situation, and the slurry mode switch is completed.

[0089] The method of this invention can solve the problem that single / dual mode shield tunneling machines / tunnel boring machines are difficult to adapt to in strata with alternating geological conditions such as clay, soil, water-rich soil and hard rock. It can realize the corresponding tunneling mode conversion according to different geological conditions and achieve rapid conversion between slurry, earth pressure, and TBM tunneling modes. Attached Figure Description

[0090] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0091] Figure 1 is a flowchart of the mud-water to earth-press process.

[0092] Figure 2 is a flowchart of the slurry-type TBM earth pressure conversion mode.

[0093] Figure 3 This is a flowchart of a mud-to-water TBM process.

[0094] Figure 4 is a flowchart of the earth pressure to slurry TBM process.

[0095] Figure 5 is a flow chart of the slurry-water TBM to slurry-water conversion process.

[0096] Figure 6 This is a flowchart illustrating the transition from earth pressure monitoring mode to slurry mode.

[0097] Figure 7 is a schematic diagram of the earth pressure balance model.

[0098] Figure 8 This is a schematic diagram of the mud-water balance mode.

[0099] Figure 9 This is a schematic diagram of a mud-water type TBM. Detailed Implementation

[0100] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0101] Example 1

[0102] 1. Procedure for converting from mud-water mode to earth pressure mode

[0103] like Figure 1 As shown, the conversion from slurry balance mode to earth pressure balance mode mainly involves six steps: preparation, inspection of components and pipelines, spoil stockpiling, spoil replacement, control of gushing, and switching to earth pressure mode. The following is an analysis of the specific operation process for converting from slurry mode to earth pressure mode.

[0104] 1.1 Preparatory Work

[0105] Select a stable transition stratum as the mode switching point. As the switching point approaches, reduce the cutterhead speed, and the tunnel boring machine (TBM) system operates in slurry mode. Figure 1 (See step 1). After reaching the switching point, the tunnel boring machine (TBM) stops advancing and operates the slurry chamber circulation system in slurry mode. This allows as much of the excavated material remaining in the slurry chamber as possible to be discharged through the slurry pipelines within the system.

[0106] 1.2 Inspect components and piping

[0107] When the tunnel boring machine (TBM) is operating in slurry mode, close the relevant components to be inspected (such as ball valves: F23, F24) and open the propulsion bypass shielding mode (also known as the circulating conventional bypass mode). Figure 1 As shown in step 2), the pressure of the slurry in the mud and water pipeline is used to determine whether there is a leakage problem in the closed ball valve.

[0108] 1.3 Slag and Soil Accumulation

[0109] After confirming there is no leakage in the ball valve, continue operating in the slurry mode with the propulsion bypass shielded state (also known as the circulating conventional bypass mode). Slowly start the cutterhead, and the tunnel boring machine (TBM) will advance slowly. At the same time, open the upper ball valve F11 and open the upper slurry inlet pipe for slurry discharge (the screw conveyor remains unchanged). Figure 1 As shown in step 3), during the shield tunneling process, the height of the excavated soil in the soil chamber reaches the upper grout inlet (i.e., the height of ball valve F11). During this process, it is necessary to constantly stabilize the water and soil pressure within the soil chamber. This is achieved by matching the shield tunneling speed with the grout discharge speed from the upper grout inlet.

[0110] 1.4 Slag Replacement with Grease Filling

[0111] The tunneling distance of the shield is used to determine whether the excavated soil in the soil chamber has reached the predetermined height. If it is expected to have reached the predetermined height, the upper soil chamber detection pipe is opened to observe the soil height. To prevent excessive slurry jetting during the conversion, the monitoring port of the main grouting pipeline is opened to detect whether slurry is flowing out of the discharged excavated soil and to record changes in the cutterhead torque value to comprehensively determine whether the soil conversion in the soil chamber is complete. If there is slurry outflow or excessive cutterhead torque, experts need to be consulted to determine whether the conversion can begin. After the soil replacement is completed, the shield tunneling system is stopped, the upper grouting port F11 is closed, and the conventional bypass mode of the circulating flow is stopped. After the slurry mode is stopped, shield tail grease is injected into the pipeline through the slurry discharge port, slurry inlet port, and branch port of the soil chamber connecting pipe to fill the pipeline and prevent pipeline blockage during the conversion. At the same time, the soil pressure in the soil chamber must be stabilized. This is done by opening the upper detection pipeline to release excess pressure. Figure 1 (As shown in step 4)

[0112] 1.5 Controlling the gushing flow

[0113] Open the front and rear gates of the screw conveyor, extending it to the designated position. During extension, avoid interference between the screw conveyor and other components. After fully extending the screw conveyor, slowly start the cutterhead, and the tunnel boring machine (TBM) advances at a slow speed. Because the replaced excavated soil has a certain degree of fluidity, the lower gate at the screw conveyor outlet needs to be opened slightly. Adjust the opening of the lower gate according to the slurry flow, while maintaining stable water and soil pressure in the soil chamber. This is achieved by controlling the opening of the lower gate at the outlet and the tunneling speed of the TBM. Figure 1 (As shown in step 5)

[0114] 1.6 Improved soil replacement completed

[0115] After the mud and water gushing phenomenon subsides, the tunnel boring machine (TBM) continues to advance. The foam and bentonite systems are activated, injecting bentonite and foam into the soil chamber to improve the soil composition and reduce its fluidity. After soil improvement, the stability of soil discharge is observed through the screw conveyor's outlet. Once the discharge is stable, the TBM's tunneling speed is slowly increased, and earth pressure monitoring (EPM) mode is activated. At this point, the mode transition is complete. Throughout this process, the soil properties must be maintained. This is achieved by adjusting the appropriate ratio of bentonite to foam to control the soil properties. Figure 1 (As shown in step 6)

[0116] 2. Procedure for converting a slurry TBM to an earth pressure monitoring system

[0117] like Figure 2As shown, the conversion of a slurry TBM to earth pressure balance mode mainly involves six steps: screw conveyor slag discharge, slag stockpiling, slag replacement, controlled gushing, stable slag discharge, and switching to earth pressure balance mode. The specific conversion process is analyzed below.

[0118] 2.1 Large stones are discharged via a screw conveyor.

[0119] Select a stable transition stratum as the switching point for mode conversion. As the switching point approaches, reduce the cutterhead speed while the tunnel boring machine (TBM) continues operation, observing the discharged excavated soil for large-diameter rocks. If any are found, use a screw conveyor to remove them. Figure 2 (As shown in step 1)

[0120] 2.2 Slag and Soil Accumulation

[0121] The shield tunneling system closes the lower ball valves (F17, F18, F66, F32) of the slurry TBM, opens the propulsion bypass shield, and checks for leaks in the ball valves. The cutterhead is slowly started, and the shield system advances slowly. The shield slurry pipeline operates in normal bypass mode to ensure its normal operation, while the upper ball valve F11 is opened (…). Figure 2 As shown in step 2, the upper grout inlet pipe is opened for grout discharge, and the soil accumulation height in the soil chamber reaches the upper grout inlet during the shield tunneling process. During this process, it is necessary to constantly stabilize the water and soil pressure within the soil chamber. This is achieved by matching the shield tunneling speed with the grout discharge speed from the upper grout inlet.

[0122] 2.3 Slag Replacement

[0123] The tunneling distance of the shield machine is used to determine whether the excavated soil in the soil chamber has reached the predetermined height. If it is expected to have reached the predetermined height, the upper soil chamber detection pipe is opened to observe the soil height and the shield machine's tunneling is stopped. To prevent excessive slurry jetting during the conversion process, the monitoring port of the main slurry inlet pipe is opened to detect whether slurry is flowing out of the discharged excavated soil and to record changes in the cutterhead torque value, thus comprehensively judging whether the soil conversion in the soil chamber is complete. If there is slurry outflow or excessive cutterhead torque, experts need to be consulted to determine whether the conversion can begin. Figure 2 (As shown in step 3)

[0124] 2.4 Controlling the screw compressor's jetting

[0125] After the soil replacement is completed, close the upper grouting port F11 and stop the conventional bypass mode. After the slurry mode stops, inject shield tail grease into the pipeline through the grout discharge port, grout inlet, and branch port of the soil chamber connecting pipe to fill the pipeline and prevent pipeline blockage during the transition. At the same time, it is also necessary to stabilize the soil pressure in the soil chamber. This is done by opening the upper detection pipeline to release excess pressure. Open the front and rear gates of the screw conveyor and extend the screw conveyor to the specified position. During the extension process, avoid interference between the screw conveyor and other components. After the screw conveyor is fully extended, slowly start the cutterhead, and the shield system advances slowly. Because the replaced soil has a certain degree of fluidity, it is necessary to slightly open the lower gate at the screw conveyor outlet. Adjust the opening range of the lower gate according to the slurry flow. During this process, it is still necessary to stabilize the water and soil pressure in the soil chamber. This is done by controlling the opening range of the lower gate at the outlet and the tunneling speed of the shield. Figure 2 (As shown in step 4)

[0126] 2.5 Stable slag discharge

[0127] After the mud and water gushing phenomenon subsides, the tunnel boring machine (TBM) continues to advance. The foam and bentonite systems are activated, injecting bentonite and foam into the soil chamber to improve the soil's properties and reduce its fluidity. After soil improvement, the stability of soil discharge is observed through the screw conveyor's outlet. Once the discharge is stable, the TBM's tunneling speed is slowly increased, while maintaining the soil's properties throughout the process. This is achieved by adjusting the soil's properties using an appropriate ratio of bentonite to foam. Figure 2 (As shown in step 5)

[0128] 2.6 Switching to Earth Pressure Mode for Tunneling

[0129] The earth pressure mode tunneling is now running, and the mode conversion is complete.

[0130] 3. Operation process for converting muddy water into muddy water TBM

[0131] The conversion from slurry balance mode to slurry-type TBM mainly involves five steps: reducing the tunneling speed, cleaning the air cushion chamber, inspecting components and pipelines, controlling the muck volume, and ensuring smooth muck discharge. The following is an analysis of the specific operational process of the slurry-to-slurry-type TBM conversion. Figure 3 This is a flowchart of the slurry-to-water conversion process of a slurry-water TBM.

[0132] 3.1 Reduce the tunnel boring machine speed

[0133] A stable transition stratum is selected as the switching point for mode conversion. As the switching point approaches, the cutterhead speed is reduced, and the tunnel boring machine (TBM) system operates in slurry mode. Figure 3 (As shown in step 1)

[0134] 3.2 Cleaning the air cushion chamber

[0135] After reaching the switching point, the tunnel boring machine system stops advancing and operates in the slurry mode to wash the slurry chamber. This allows most of the excavated soil remaining in the slurry chamber to be discharged through the slurry pipelines within the system.

[0136] 3.3 Inspect components and piping

[0137] The tunnel boring machine (TBM) system closes ball valves V67, V68, F11, F32, and F37, opens ball valve F38, and activates the propulsion bypass shielding mode (i.e., the previously mentioned recirculation bypass mode). The pressure of the slurry in the slurry pipeline is used to determine if there is a leak in the closed ball valves. Figure 3 (As shown in step 3)

[0138] 3.4 Controlling the volume of excavated soil

[0139] After confirming there are no leaks in the ball valves, continue operating in the slurry mode with the propulsion bypass shielded state, slowly start the cutterhead, and the tunnel boring machine (TBM) system advances slowly forward. Open the upper air pressure connection pipe and connect the hose to the slurry level detection pipe in the middle of the shield body. Operate the TBM slurry pipeline in the circulating conventional bypass mode to ensure normal operation of the slurry pipeline. Then open the lower slurry discharge ball valves F50, F66, and F38 to open the lower slurry discharge pipeline for slag discharge. Excess pressure is discharged by opening the upper detection pipeline. Appropriate injection of bentonite can be used to improve the slag and soil condition. When the soil level in the detection chamber reaches one-third, stop the TBM system's tunneling. Figure 3 (As shown in step 4)

[0140] 3.5 Stable slag discharge

[0141] Open grout inlet ball valves F51, F30, F17, and F18 to allow grout to enter through the lower grout inlet pipe; keep the remaining grout inlet ball valves closed. Observe whether the excavated soil discharge is stable. Once the excavated soil discharge is stable, slowly increase the tunneling speed of the shield system. Figure 3 (As shown in step 5)

[0142] 3.6 Switching to slurry-type TBM tunneling

[0143] The slurry TBM tunneling operation is now complete, and the mode switch is finished.

[0144] 4. Procedure for converting Earth Pressure Monitoring System (EPP) mode to Slurry TBM operation

[0145] like Figure 4 As shown, the conversion from Earth Pressure Balance (EPB) mode to a slurry TBM mainly involves five steps: simultaneous soil improvement and screw conveyor discharge, control of soil volume, soil improvement, pipeline unblocking, and stable discharge. The following analysis details the specific operational process of converting from EPB mode to a slurry TBM.

[0146] 4.1 Simultaneous improvement of slag soil and simultaneous discharge of slag by screw conveyor

[0147] Select a stable transition stratum as the switching point for mode conversion. As you approach the switching point, slow down the cutterhead speed. After reaching the switching point, stop the tunnel boring machine (TBM) and slowly rotate the cutterhead in place, allowing the screw conveyor to slowly discharge muck and reduce the muck volume in the soil chamber. Once grouting occurs at the lower gate of the screw conveyor, immediately stop and reduce the muck discharge speed. Throughout this process, it is crucial to maintain stable pressure within the soil chamber. This can be achieved by injecting a certain amount of compressed air into the soil chamber through the top connecting pipe, or by injecting an appropriate amount of bentonite to improve the mud film at the tunnel face, maintain pressure within the soil chamber, and prevent tunnel face collapse. Figure 4 (As shown in step 1)

[0148] 4.2 Controlling the volume of excavated soil

[0149] After reducing the volume of excavated soil in the soil chamber to approximately one-third of its height, close the rear gate of the screw conveyor and return it to the designated position. Activate the bentonite system to improve the excavated soil's properties. This creates a soil plug effect within the front cylinder space of the screw conveyor. During this process, it is crucial to maintain stable pressure within the soil chamber, as well as control the volume and properties of the excavated soil. This can be achieved by introducing compressed air into the soil chamber through the upper connecting pipe within the air cushion chamber, or by activating the bentonite system to improve the soil properties. Figure 4 (As shown in step 2)

[0150] 4.3 Improved Slag Soil

[0151] The system operates in standard bypass mode, with pre-emptive checks of the slurry pipelines for blockages. The tunnel boring machine cutterhead continues to rotate, and slurry is injected into the soil chamber by opening slurry inlet ball valves F51, F30, F17, and F18; the remaining slurry inlet ball valves remain closed. When slurry is output from the inlet pipeline, the slurry inlet speed should be adjusted to maintain the slurry level not exceeding one-third of the soil chamber's height. Figure 4 (As shown in step 3)

[0152] 4.4 Unblocking pipes

[0153] Run the backflushing pipeline to clean and discharge the slag and debris from the internal pipes. Perform internal reverse circulation mode (…). Figure 4 (As shown in step 4) Clear the mud and water pipes at the front of the shield. After confirming that all pipes are unobstructed, open the upper air pressure connection pipe and connect the hose to the mud and water chamber level detection pipe in the middle of the shield. Use the level sensor to observe the mud height in the chamber. Stop grouting when the mud level is about to reach one-third of the chamber level.

[0154] 4.5 Stable slag discharge

[0155] After confirming that the upper connecting pipes and the slurry inlet and outlet pipes are all unobstructed, the system operates in slurry-type TBM tunneling mode, with the tunnel boring machine advancing slowly and the speed gradually increased based on the muck discharge situation. Figure 4 (As shown in step 5)

[0156] 4.6 Switching to slurry TBM tunneling

[0157] Switch to slurry-water TBM tunneling.

[0158] 5. Conversion process of TBM from mud-water type to mud-water type

[0159] like Figure 5 As shown, the conversion of a slurry-type TBM to slurry balance mode mainly involves six steps: stable slag discharge, inspection of components and pipelines, improvement of slag, dredging of pipelines, grouting of the air cushion chamber, and switching to slurry mode. The following is an analysis of the specific operation process of converting a slurry-type TBM to slurry mode.

[0160] 5.1 Smooth slag discharge

[0161] Select a stable transition stratum as the switching point for mode conversion. As the switching point approaches, reduce the cutterhead speed while the tunnel boring machine (TBM) continues operation, observing the discharged excavated soil for large-diameter rocks. If any are found, use a screw conveyor to remove them. Figure 5 (As shown in step 1)

[0162] 5.2 Inspect components and piping

[0163] The shield tunneling system closes the lower grout inlet ball valve of the slurry TBM, opens the propulsion bypass shield, and checks for leaks in the ball valve. During this process, it is necessary to pre-check the slurry pipelines for blockages and determine how to stabilize the pressure. This is achieved by operating the internal bypass mode and controlling the grouting speed, etc. Figure 5 (As shown in step 2)

[0164] 5.3 Improved Slag Soil

[0165] Rotate the cutterhead in place and inject grout into the soil chamber by opening the upper grout inlet ball valves F30 and F11. Simultaneously, open the upper connecting pipe of the soil chamber, which is connected to the air cushion chamber, to absorb or introduce air into the soil chamber, helping to balance the pressure and maintain stability during grouting. When injecting grout into the main grout inlet pipe, pay attention to adjusting the grout injection speed to maintain stable pressure within the soil chamber. On the control panel, disconnect the mud-water circulation system from the liquid level. Figure 5 (As shown in step 3)

[0166] 5.4 Unblocking pipes

[0167] Before activating the conventional bypass mode for mud and water, first run the internal reverse circulation system. Figure 5(As shown in step 4), unclog the mud and water pipes at the front of the central shield, and then run the reverse circulation system inside the chamber (as shown in the previous diagram) (all of these can be done in the control room) to unclog the slurry discharge pipes and slurry discharge outlets.

[0168] 5.5 Grouting of the Air Cushion Chamber

[0169] After confirming that all pipelines are unobstructed, grouting is initiated into the air cushion chamber. A level sensor is used to monitor the grout level within the chamber; grouting is stopped when the grout is about to reach the upper connecting pipe inlet. The SAMSON pressure holding system is then activated and the air cushion chamber pressure is set. The connecting gate valves V67 / V68 within the air cushion chamber are then opened. Figure 5 (As shown in step 5)

[0170] 5.6 Switching to mud-water mode for tunneling

[0171] After confirming that the upper connecting pipe and the slurry inlet and outlet pipes are all unobstructed, the system operates in air cushion direct discharge tunneling mode, with the tunnel boring machine advancing slowly. The advance speed is gradually increased to normal tunneling conditions based on the muck discharge situation, and the slurry mode switch is complete. Figure 5 (As shown in step 6)

[0172] 6. Procedure for switching from earth pressure monitoring mode to slurry mode

[0173] The conversion from earth pressure balance (EPP) mode to slurry balance (SPP) mode mainly involves six steps: screw conveyor slag removal, controlling slag height, improving slag, clearing pipelines, grouting the air cushion chamber, and switching to SPP mode. The specific operational process of converting from EPP to SPP mode is analyzed below. Figure 6 This is a flowchart for the conversion from earth pressure monitoring mode to slurry mode.

[0174] 6.1 Simultaneous improvement of slag soil and simultaneous discharge of slag by screw conveyor

[0175] Select a stable transition stratum as the switching point for mode conversion. As you approach the switching point, slow down the cutterhead speed. After reaching the switching point, stop the tunnel boring machine (TBM) and slowly rotate the cutterhead in place, allowing the screw conveyor to slowly discharge muck and reduce the muck volume in the soil chamber. Once grouting occurs at the lower gate of the screw conveyor, immediately stop and reduce the muck discharge speed. Throughout this process, it is crucial to maintain stable pressure within the soil chamber. This can be achieved by injecting a certain amount of compressed air into the soil chamber through the top connecting pipe, or by injecting an appropriate amount of bentonite to improve the mud film at the tunnel face, maintain pressure within the soil chamber, and prevent tunnel face collapse. Figure 6 (As shown in step 1)

[0176] 6.2 Controlling the volume of excavated soil

[0177] After reducing the volume of excavated soil in the soil chamber to approximately one-third of its height, close the rear gate of the screw conveyor and return it to the designated position. Activate the bentonite system to improve the excavated soil's properties. This creates a soil plug effect within the front cylinder space of the screw conveyor. During this process, it is crucial to maintain stable pressure within the soil chamber, as well as control the volume and properties of the excavated soil. This can be achieved by introducing compressed air into the soil chamber through the upper connecting pipe within the air cushion chamber, or by activating the bentonite system to improve the soil properties. Figure 6 (As shown in step 2)

[0178] 6.3 Improved Slag Soil

[0179] Prepare to activate the conventional slurry bypass mode. Keep the tunnel boring machine cutterhead rotating and inject slurry into the soil chamber by opening the upper slurry ball valves F30 and F11. Simultaneously, open the upper connecting pipe of the soil chamber connected to the air cushion chamber to absorb air from within, helping to balance the pressure and maintain stability. When slurry is output from the main slurry pipeline, carefully adjust the slurry injection rate to maintain stable pressure within the soil chamber. Disconnect the slurry circulation system from the liquid level via the control panel. During this process, it is necessary to pre-check the slurry pipelines for blockages and determine how to stabilize the pressure. This is done by operating the internal bypass mode and controlling the grouting rate. Figure 6 (As shown in step 3)

[0180] 6.4 Unblocking pipes

[0181] Activate the conventional slurry bypass mode, first run the internal reverse circulation system to clear the slurry pipeline in front of the central shield, and then run the internal reverse circulation system (all of which can be done in the control room) to clear the slurry discharge pipeline and discharge port. (Same as Section 5.4)

[0182] 6.5 Grouting of the air cushion chamber

[0183] After confirming that all pipelines are unobstructed, grouting is performed on the air cushion chamber, and the grout level is monitored using a level sensor. The SAMSON pressure holding system is activated and the air cushion chamber pressure is set. The connecting gate valves V67 / V68 inside the air cushion chamber are then opened. Figure 6 (As shown in step 5)

[0184] 6.6 Switching to mud-water mode for tunneling

[0185] After confirming that the upper connecting pipe and the slurry inlet and outlet pipes are all unobstructed, the system operates in air cushion direct discharge tunneling mode, with the tunnel boring machine advancing slowly. The advance speed is gradually increased to normal tunneling conditions based on the muck discharge situation, and the slurry mode switch is complete. Figure 6 (As shown in step 6)

[0186] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for fast mode switching of a three-mode roadheader mode, characterized in that: include: The procedure for converting mud-water balance mode to earth pressure balance mode is used to convert mud-water balance mode to earth pressure balance mode. The procedure for converting a slurry TBM to earth pressure balance mode is used to convert a slurry TBM to earth pressure balance mode. The process for converting mud-water mode to mud-water TBM operation is used to convert mud-water balance mode to mud-water TBM. The process for converting earth pressure balance mode to slurry TBM is used to convert earth pressure balance mode to slurry TBM. The procedure for converting a mud-water TBM to mud-water mode is used to convert a mud-water TBM to mud-water balance mode. The procedure for converting earth pressure balance mode to slurry balance mode is used to convert earth pressure balance mode to slurry balance mode. The process of converting the slurry mode to the earth pressure mode includes the following steps: 1.1 Preparatory Work Select a stable conversion stratum as the switching point for mode conversion. When the switching point is about to be reached, reduce the speed of the cutterhead and run the shield tunneling system in slurry mode. After reaching the switching point, the shield tunneling system stops advancing and runs the slurry chamber circulation system in slurry mode to discharge the remaining slag in the slurry chamber through the slurry pipeline. 1.2 Inspect components and piping The shield tunneling system closes ball valves V67, V68, F11, F32, and F37, opens ball valve F38, advances into bypass shielded state, enters circulating conventional bypass mode, and uses the slurry pressure in the mud-water pipeline to determine whether there is a leakage problem in the closed ball valves; 1.3 Slag and Soil Accumulation After confirming that there is no leakage in the ball valve, continue to operate the circulating conventional bypass mode in the slurry mode, start the cutterhead, advance the shield forward, and at the same time open the upper ball valve F11 to open the upper slurry inlet pipeline for slurry discharge, so as to realize the accumulation of slag in the soil chamber. 1.4 Slag Replacement with Grease Filling The tunneling distance of the shield is used to determine whether the excavated soil in the soil chamber has reached the upper grout inlet, i.e., the height of ball valve F11. During this process, it is necessary to constantly control the tunneling speed of the shield system to match the grout discharge speed of the upper grout inlet to stabilize the water and soil pressure in the soil chamber. If it has reached the upper grout inlet, the monitoring port of the main grout inlet pipeline is opened to detect whether grout flows out of the discharged excavated soil. Combined with the recorded changes in the cutterhead torque value, it is determined whether the excavated soil replacement in the soil chamber is complete. After the excavated soil replacement is completed, the tunneling of the shield system is stopped, the upper ball valve F11 is closed, and the slurry system is stopped. Then, the shield tail grease is injected into the pipeline through the grout discharge port, grout inlet, and branch port of the soil chamber connecting pipe to fill the pipeline and prevent pipeline blockage during the transition. At the same time, the excess pressure needs to be discharged by opening the upper detection pipeline to stabilize the soil pressure in the soil chamber. 1.5 Controlling the gushing flow Open the front and rear gates of the screw conveyor and extend the screw conveyor to the designated position. During the extension process, avoid interference between the screw conveyor and other components. After the screw conveyor is fully extended, slowly start the cutterhead and the tunnel boring machine (TBM) advances slowly. At the same time, open the lower gate at the outlet of the screw conveyor and adjust the opening range of the lower gate according to the mud and water gushing situation. During this process, it is necessary to stabilize the water and soil pressure in the soil chamber by controlling the opening range of the lower gate at the outlet and the tunneling speed of the TBM. 1.6 Improved soil replacement completed After the mud and water gushing phenomenon ends, continue to advance the shield tunneling system. By activating the foam system and bentonite system, inject bentonite and foam into the soil chamber. At the same time, observe whether the discharge of the excavated soil is stable through the slag discharge port of the screw conveyor. During this process, the properties of the excavated soil need to be adjusted by adjusting the ratio between bentonite and foam. After the excavated soil discharge is stable, slowly increase the tunneling speed of the shield tunneling system and run the earth pressure mode for tunneling. At this time, the mode conversion is completed. The process for converting a slurry TBM to earth pressure monitoring mode includes the following steps: 2.1 Large stones are discharged via a screw conveyor. Select a stable conversion stratum as the switching point for mode conversion. When the switching point is about to be reached, slow down the cutterhead speed and continue to run the slurry TBM. Observe whether there are large-diameter rocks in the discharged slag. If so, use a screw conveyor to discharge the large-diameter rocks. 2.2 Slag and Soil Accumulation The shield tunneling system closes the lower ball valves F17, F18, F66, and F32 of the slurry TBM, opens the propulsion bypass shield, and enters the normal bypass mode. After confirming that there is no leakage in the ball valves, the cutterhead is slowly started, and the shield tunneling system advances slowly. The shield tunneling slurry pipeline operates in the normal bypass mode to ensure the normal operation of the slurry pipeline. Then, the upper ball valve F11 and the upper slurry inlet pipeline are opened to discharge slurry. During this process, it is necessary to constantly control the tunneling speed of the shield to match the slurry discharge speed of the upper slurry inlet to stabilize the water and soil pressure in the soil chamber. 2.3 Slag Replacement The tunneling distance of the shield is used to determine whether the height of the excavated soil in the soil chamber has reached the upper grout inlet. If it is expected to have reached the upper soil chamber detection pipe, the height of the excavated soil is observed, the excavated soil replacement begins, and the tunneling of the shield system is stopped. The monitoring port of the main grout inlet pipe is opened to detect whether there is grout leakage from the discharged excavated soil. Combined with the recorded changes in the cutterhead torque value, a comprehensive judgment is made on whether the excavated soil conversion in the soil chamber is complete. 2.4 Controlling the screw compressor's jetting After the slag and soil replacement is completed, close the upper ball valve F11 to stop the operation of the conventional bypass mode. After the slurry mode is stopped, inject the shield tail grease into the pipeline through the slurry discharge port, slurry inlet port, and branch port of the soil chamber connecting pipe to fill the pipeline and prevent pipeline blockage during the transition. At the same time, it is also necessary to open the upper detection pipeline to release excess pressure and stabilize the soil pressure in the soil chamber. Open the front and rear gates of the screw conveyor and extend the screw conveyor to the specified position. During the extension process, avoid interference between the screw conveyor and other components. After the screw conveyor is fully extended, slowly start the cutterhead and the shield system advances slowly. At the same time, open the lower gate at the outlet of the screw conveyor and adjust the opening range of the lower gate according to the slurry gushing situation. During this process, it is necessary to stabilize the water and soil pressure in the soil chamber by controlling the opening range of the lower gate at the outlet and the tunneling speed of the shield. 2.5 Stable slag discharge After the mud and water gushing phenomenon ends, continue to advance the shield tunneling system. By activating the foam system and bentonite system, inject bentonite and foam into the soil chamber to improve the soil inside the chamber. Observe whether the soil discharge is stable through the auger discharge port. During this process, the properties of the soil need to be adjusted by using an appropriate ratio between bentonite and foam. After the soil discharge is stable, slowly increase the tunneling speed of the shield tunneling system. 2.6 Switching to Earth Pressure Mode for Tunneling The earth pressure monitoring mode tunneling is now running, and the mode conversion is complete. The aforementioned process for converting a slurry-water mode to a slurry-water TBM is used to convert a slurry-water balance mode to a slurry-water TBM, and includes the following steps: 3.1 Reduce the tunnel boring machine speed Select a stable conversion stratum as the switching point for mode conversion. When the switching point is about to be reached, reduce the cutterhead speed and the shield tunneling system runs in slurry mode. 3.2 Cleaning the air cushion chamber After reaching the switching point, the tunnel boring machine stops advancing and operates in the slurry mode to wash the slurry chamber, discharging the remaining slag and soil in the slurry chamber through the slurry pipeline. 3.3 Inspect components and piping When the tunnel boring machine is operating in slurry mode, the propulsion bypass shield is opened, the relevant components to be inspected are closed, and the slurry pressure in the slurry pipeline is used to determine whether there is a leakage problem in the closed ball valve. 3.4 Controlling the volume of excavated soil After confirming that there is no leakage in the ball valve, continue to operate in the propulsion bypass shielding state in slurry mode, slowly start the cutterhead, and the shield system advances slowly forward; Open the upper air pressure connection pipe and connect the hose to the slurry level detection pipe in the middle of the shield body. The shield slurry pipeline operates in the normal circulation bypass mode to ensure the normal operation of the slurry pipeline. Then open the lower slurry discharge ball valves F50, F66, and F38 to open the lower slurry discharge pipeline for slag discharge. Release excess pressure by opening the upper detection pipeline and inject appropriate amounts of bentonite to improve the slag and soil. When the detection soil level reaches one-third, stop the shield system tunneling. 3.5 Stable slag discharge Open the grout ball valves F51, F30, F17, and F18 to allow grout to enter through the lower grout pipe, while keeping the other grout ball valves closed. Observe whether the excavated soil discharge is stable. Once the excavated soil discharge is stable, slowly increase the tunneling speed of the shield system. 3.6 Switching to slurry-type TBM tunneling The slurry TBM tunneling operation is now complete; The process of converting the earth pressure monitoring mode to a slurry TBM includes the following steps: 4.1 Simultaneous improvement of slag soil and simultaneous discharge of slag by screw conveyor Select a stable conversion stratum as the switching point for mode conversion. When approaching the switching point, slow down the cutterhead speed. After reaching the switching point, stop the tunnel boring machine (TBM) and slowly rotate the cutterhead in place. The screw conveyor slowly discharges the slag to reduce the slag volume in the soil chamber. When slurry spraying occurs at the lower gate of the screw conveyor, immediately stop and reduce the slag discharge speed. During this process, compressed air needs to be injected into the soil chamber through the connecting pipe at the top to maintain the stability of the pressure in the soil chamber, or an appropriate amount of bentonite can be injected to improve the mud film at the working face, maintain the pressure in the soil chamber, and ensure that the working face does not collapse. 4.2 Controlling the volume of excavated soil After the volume of slag in the soil bin is reduced to one-third of the bin's height, the rear gate of the screw conveyor is closed, and the screw conveyor is returned to the designated position. The bentonite system is then activated to improve the slag and enhance its properties, creating a soil plug effect in the space of the front cylinder of the screw conveyor. During this process, compressed air needs to be introduced into the soil bin through the upper connecting pipe in the air cushion bin to maintain stable pressure inside the bin. At the same time, the bentonite system needs to be activated to control the volume and properties of the slag in the soil bin. 4.3 Improved Slag Soil The system operates in conventional bypass mode. The mud and water pipelines used are checked in advance for blockage. The shield cutterhead is kept rotating. Grout is injected into the soil chamber by opening the grout ball valves F51, F30, F17, and F18. The remaining grout ball valves are closed. When the grout pipeline outputs grout, the grouting speed is adjusted to keep the liquid level not exceeding one-third of the soil chamber. 4.4 Unblocking pipes Run the backwashing pipeline to clean and discharge the slag in the internal pipes, and enter the reverse circulation mode to unclog the mud and water pipeline in front of the shield. After confirming that all pipelines are unobstructed, open the upper air pressure connection pipe and connect the hose to the mud and water chamber liquid level detection pipe in the middle of the shield. Use the liquid level sensor to observe the mud height in the mud chamber. Stop grouting when the mud level in the mud chamber is about to reach one-third of the height. 4.5 Stable slag discharge After confirming that the upper connecting pipe and the inlet and outlet slurry pipes are unobstructed, the system operates in slurry TBM tunneling mode, with the shield advancing slowly and the speed gradually increased according to the muck discharge situation. 4.6 Switching to slurry TBM tunneling Switch to slurry-type TBM tunneling; The process for converting a mud-water TBM to mud-water mode includes the following steps: 5.1 Smooth slag discharge Select a stable conversion stratum as the switching point for mode conversion. When the switching point is about to be reached, slow down the cutterhead speed and continue to run the slurry TBM. Observe whether there are large-diameter rocks in the discharged slag. If so, use a screw conveyor to discharge the large-diameter rocks. 5.2 Inspect components and piping The shield tunneling system closes the lower grout ball valve of the slurry TBM, opens the propulsion bypass shield, and checks for leaks in the ball valve. During this process, it is necessary to check the slurry pipelines used in advance for blockages, and stabilize the pressure by operating the internal bypass mode and controlling the grouting speed. 5.3 Improved Slag Soil Rotate the cutterhead in place and inject grout into the soil chamber by opening the upper grout ball valves F30 and F11. At the same time, open the upper connecting pipe of the soil chamber connected to the air cushion chamber to absorb or input air into the soil chamber to help balance the pressure of the soil chamber and maintain the pressure stability. When the grout is introduced into the main grouting pipeline, pay attention to adjusting the grouting speed to maintain the pressure stability in the soil chamber. On the control panel, disconnect the mud-water circulation system from the liquid level. 5.4 Unblocking pipes Before starting the conventional bypass mode for mud and water, first run the internal reverse circulation system to clear the mud and water pipeline in front of the central shield, and then run the internal reverse circulation system to clear the slurry discharge pipeline and slurry discharge port. 5.5 Grouting of the Air Cushion Chamber After confirming that all pipelines are unobstructed, grouting is carried out on the air cushion chamber. The level sensor is used to observe the mud height in the chamber. When the mud is about to reach the upper connecting pipe opening, grouting is stopped. The SAMSON pressure holding system is run and the air cushion chamber pressure is set. The connecting gate valves V67 / V68 inside the air cushion chamber are opened. 5.6 Switching to mud-water mode for tunneling After confirming that the upper connecting pipe and the inlet and outlet slurry pipes are unobstructed, the system operates in the air cushion direct discharge tunneling mode, and the shield advances slowly. The advance speed is gradually increased to the normal tunneling state according to the muck discharge situation. The slurry mode switch is completed. in: The front of the tunneling machine is equipped with a cutterhead, a slurry chamber and an air cushion chamber in sequence. V67 and V68 are installed in the upper part of the air cushion chamber, and V67 and V68 are connected to the slurry chamber and the air cushion chamber through the upper connecting pipe in the air cushion chamber. The slurry inlet pipe and the slurry outlet pipe are respectively connected to the upper and lower parts of the mud-water tank; F51, F30 and F11 are installed sequentially along the slurry inlet direction on the main pipe of the slurry inlet pipeline; F17 and F18 are installed at the front end of the lower slurry inlet pipe of the slurry inlet pipeline, and the lower slurry inlet pipe is located between F30 and F11. F17 and F18 are installed in parallel in the middle and lower part of the mud and water tank. F32, F66, F38 and F50 are installed on the main pipe of the slurry discharge pipeline along the slurry discharge direction. F32 and F66 are installed in parallel at the front end of the main pipe of the slurry discharge pipeline to connect to the lower part of the mud-water tank. F24 and F23 are connected on the upper slurry discharge pipe of the slurry discharge pipeline. The upper slurry discharge pipe is located in front of F38 and behind F32 and F66. A connecting pipe is installed between the slurry inlet pipe and the slurry outlet pipe; the upper end of the connecting pipe is located between F11 and F30 so that the upper end of the connecting pipe is connected to F11 and F30, and the lower end is located between F38 and F50; F37 is installed on the connecting pipe.

2. A method of fast mode switching for a three-mode tunneling machine mode as claimed in claim 1, characterized in that: The process of converting the earth pressure monitoring mode to the slurry mode includes the following steps: 6.1 Simultaneous improvement of slag soil and simultaneous discharge of slag using a screw conveyor Select a stable conversion stratum as the switching point for mode conversion. When approaching the switching point, slow down the cutterhead speed. After reaching the switching point, stop the tunnel boring machine (TBM) and slowly rotate the cutterhead in place. The screw conveyor slowly discharges the slag to reduce the slag volume in the soil chamber. When slurry spraying occurs at the lower gate of the screw conveyor, immediately stop and reduce the slag discharge speed. During this process, a certain amount of compressed air needs to be injected into the soil chamber through the connecting pipe at the top to maintain the stability of the pressure inside the soil chamber, or an appropriate amount of bentonite can be injected to improve the mud film at the working face, maintain the pressure inside the soil chamber, and ensure that the working face does not collapse. 6.2 Controlling the volume of excavated soil After the volume of slag in the soil bin is reduced to one-third of the bin's height, the rear gate of the screw conveyor is closed, and the screw conveyor is returned to the designated position. The bentonite system is then activated to improve the slag and enhance its properties, creating a soil plug effect in the space of the front cylinder of the screw conveyor. During this process, compressed air needs to be introduced into the soil bin through the upper connecting pipe in the air cushion bin to maintain stable pressure within the bin. At the same time, the bentonite system needs to be activated to control the volume and properties of the slag in the soil bin. 6.3 Improved Slag Soil Prepare to activate the conventional slurry bypass mode. Keep the tunnel boring machine cutterhead rotating and inject slurry into the soil chamber by opening the upper slurry ball valves F30 and F11. Simultaneously, open the upper connecting pipe of the soil chamber connected to the air cushion chamber to absorb air from the soil chamber, helping to balance the soil chamber pressure and maintain pressure stability. When the main slurry inlet pipe outputs slurry, pay attention to adjusting the slurry inlet speed to maintain stable pressure within the soil chamber. On the control panel, disconnect the slurry circulation system from the liquid level. During this process, it is necessary to check the slurry pipelines for blockages in advance and stabilize the pressure by operating the machine bypass mode and controlling the grouting speed. 6.4 Unblocking pipes Start the conventional bypass mode for mud and water, first run the reverse circulation system inside the machine to clear the mud and water pipeline in front of the central shield, and then run the reverse circulation system inside the chamber to clear the slurry discharge pipeline and slurry discharge port. 6.5 Grouting of the air cushion chamber After confirming that all pipelines are unobstructed, the air cushion chamber is grouted, and the slurry level in the chamber is observed using a liquid level sensor; the SAMSON pressure holding system is run and the air cushion chamber pressure is set, and the connecting gate valves V67 / V68 inside the air cushion chamber are opened; 6.6 Switching to mud-water mode for tunneling After confirming that the upper connecting pipe and the inlet and outlet slurry pipes are unobstructed, the system operates in the air cushion direct discharge tunneling mode, and the shield advances slowly. The advance speed is gradually increased to the normal tunneling state according to the muck discharge situation, and the slurry mode switch is completed.

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