A dual-mode shield machine tunnel internal pressure stabilization and mold changing construction system and method

Abstract

The present invention relates to the technical field of shield machines, and in particular to a dual-mode shield machine in-hole pressure stabilization and mold changing construction system and method. The construction system in the earth pressure mode includes a slag discharge system 1; the slag discharge system 1 includes a screw machine and a belt conveyor assembly under the rear gate. The construction system in the mud-water mode includes a mud circulation system 1, and the mud circulation system 1 includes a slurry inlet pipe and a slurry discharge pipe. The dual-mode conversion construction system includes a slag discharge system 2, a mud circulation system 2 and a pressure stabilization system; the slag discharge system 2 includes a screw machine; the mud circulation system 2 is connected to the mud circulation system 1 with a dilution system; the dilution system is used to dilute the slag entering the dilution box through the screw machine during the mode conversion process and send it into the slurry discharge pipe. It solves the problems commonly found in existing dual-mode shield machines, such as large pressure fluctuations during mold changing, long mold changing cycles, and high mold changing costs.

Description

Technical Field

[0001] The present invention relates to the technical field of shield machines, and in particular to a dual-mode shield machine in-tunnel pressure stabilizing and mold changing construction system and method. Background Art

[0002] At present, the earth pressure slurry dual-mode shield machine has good adaptability to complex geological environments, but it is inevitable to switch between modes during the construction process. Even when encountering long distances and complex strata, multiple mode switches need to be made according to actual conditions. According to existing mature experience, the mold change time is about 20 days. In addition, the time cost and economic cost of mode conversion are relatively high, and the mode conversion plan needs to be determined according to the geology. These comprehensive factors lead to the complexity, inconsistency and high construction difficulty of the mode conversion of the existing dual-mode shield. Therefore, a simple mold change construction method with low technical requirements is extremely needed. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention proposes a dual-mode shield machine in-tunnel pressure stabilization and mold changing construction system and method, which solves the problems commonly existing in existing dual-mode shield machines such as large pressure fluctuations during mold changing, long mold changing cycle, and high mold changing cost.

[0004] The present invention provides the following technical solutions:

[0005] A dual-mode shield machine tunnel pressure stabilization and mold changing construction system, the dual modes are earth pressure mode and slurry water mode, and the mold changing includes converting the earth pressure mode to slurry water mode and vice versa;

[0006] The construction system under the earth pressure mode includes a slag discharge system 1; the slag discharge system 1 includes a screw machine and a belt conveyor assembly under the rear gate. The screw machine is arranged at an angle on the inner side of the shield machine body to facilitate the transportation of slag; the belt conveyor assembly is used to transfer the material output by the screw machine to the slag truck, and then transport it out of the tunnel.

[0007] The construction system in the mud-water mode includes a mud circulation system 1, which includes a slurry inlet pipe and a slurry discharge pipe; the slurry inlet pipe is used to inject the slurry with lower specific gravity from the separation station into the excavation chamber; the slurry discharge pipe is used to discharge the mixed slurry of slag and slurry in the excavation chamber to the separation station on the ground for mud-water diversion;

[0008] The construction system of dual-mode conversion includes a second slag discharge system, a second mud circulation system and a pressure stabilizing system; the second slag discharge system includes a screw machine; the second mud circulation system is connected to a dilution system on the basis of the first mud circulation system; the dilution system includes a dilution box, which is arranged under the rear gate of the screw machine, and the two ends of the dilution box are a dilution box feed pipe connected to the slurry inlet pipe and a dilution box discharge pipe connected to the slurry discharge pipe; the dilution system is used to dilute the slag entering the dilution box through the screw machine during the mode conversion process and send it into the slurry discharge pipe.

[0009] As an optimal technical solution, the outlet end of the slurry inlet pipe is located at the top of the excavation bin, and the inlet end is connected to the ground separation station through a slurry inlet pump; the inlet end of the slurry discharge pipe is located at the bottom of the excavation bin, and the outlet end is connected to the ground separation station.

[0010] As an optimal technical solution, the slurry inlet pipe is provided with a slurry inlet ball valve 1, a slurry inlet ball valve 2, a slurry inlet pressure sensor, a slurry inlet flowmeter and a slurry inlet density meter; the slurry inlet flowmeter calculates the flow in the pipeline at all times, and the slurry inlet density meter is used to calculate the instantaneous density of the slurry in the pipeline; the slurry discharge pipe is provided with a slurry discharge ball valve 1, a slurry discharge pressure sensor, a slurry discharge flowmeter and a slurry discharge pump.

[0011] As an optimal technical solution, a flushing ball valve is provided on the dilution box feed pipe; a slag removal door is provided on the dilution box, and the inlet of the dilution box is directly opposite to the bottom of the rear gate of the screw machine.

[0012] As a preferred technical solution, it also includes a pressure stabilizing system, which is arranged on the slurry inlet pipe and is used to provide constant pressure to the slurry in the slurry inlet pipe.

[0013] As a preferred technical solution, the pressure stabilizing system includes a pressure stabilizer, a pressure stabilizing tank and a pressure stabilizing pipeline connected to the slurry inlet pipe; the pressure stabilizing tank is a tank body for storing slurry, and the pressure stabilizing tank is provided with a liquid level switch and a pressure stabilizer, and the liquid level switch is used to display the height of the slurry in the pressure stabilizing tank; the pressure stabilizer is used to provide constant pressure to the slurry in the pressure stabilizing tank.

[0014] As an optimal technical solution, the pressure-stabilizing pipeline includes an inlet pipeline connected to the pressure-stabilizing pump and an outlet pipeline connected to the slurry inlet pipe. The pressure-stabilizing tank is connected between the inlet pipeline and the outlet pipeline. A pressure-stabilizing flowmeter and a pressure-stabilizing gate valve 1 are provided on the inlet pipeline, and a pressure-stabilizing gate valve 2 is provided on the outlet pipeline.

[0015] As a preferred technical solution, the specific process of converting the earth pressure mode to the mud water mode is as follows:

[0016] (1) When conditions permit, select a stable stratum for mode conversion;

[0017] (2) Stop excavation before changing the mold, and conduct joint commissioning and testing of the ground separation station and mud circulation system to ensure normal operation;

[0018] (3) Remove the belt conveyor assembly and install the flushing ball valve, dilution box feed pipe, dilution box, dilution box discharge pipe, and slurry discharge ball valve II;

[0019] (4) When the entire mud circulation system is ensured to be able to operate, close the slurry inlet ball valve 1, open the slurry inlet ball valve 2, the flushing ball valve, and the slurry discharge ball valve 2, and adjust the slurry inlet pump and the slurry discharge pump, and observe the slurry inlet pressure sensor until it reaches the ideal value;

[0020] (5) After ensuring that the slurry inlet pipe is not blocked, open the pressure stabilizing gate valve 1, start the pressure stabilizing pump, and start injecting slurry into the pressure stabilizing tank. A liquid level switch is installed on the pressure stabilizing tank to detect the height of the slurry in the tank;

[0021] (6) Start the voltage stabilizer and design relevant parameters of the voltage stabilizer to meet the requirements of the excavation chamber, such as setting a certain pressure value so that the pressure provided by the voltage stabilizer system matches the pressure required by the excavation chamber;

[0022] (7) Open the second pressure-stabilizing gate valve and start delivering slurry into the excavation chamber;

[0023] (8) Open the screw conveyor gate, slowly rotate the cutter head and screw conveyor, and the slag enters the dilution box through the screw conveyor. The larger stones are stored in the dilution box, and the smaller slag and slag enter the slurry discharge pipe through the dilution box discharge pipe, thereby completing the slag carrying task;

[0024] (9) Continue in this way until the soil in the excavation bin is completely replaced. There are many ways to determine whether the soil replacement is complete. Here we only introduce one method: when the slurry density meter on the slurry inlet pipe and the slurry density meter on the slurry discharge pipe display the same value, it can be determined that the soil in the excavation bin is completely replaced. The other methods will not be introduced here one by one.

[0025] (10) Open the slurry inlet ball valve 1 and the slurry discharge ball valve 1, close the flushing ball valve and the slurry discharge ball valve 2, and stop flushing the dilution tank; turn off the pressure stabilizing pump, pressure stabilizing gate valve 1, pressure stabilizing gate valve 2 and the pressure stabilizing system in turn;

[0026] (11) Once the mud circulation system runs smoothly, close the rear gate of the screw machine. The conversion from soil pressure mode to mud-water mode is now complete.

[0027] As a preferred technical solution, the specific process of converting the mud-water mode to the earth pressure mode is as follows:

[0028] (1) First, continue to run the mud and water mode to empty the slag and rock in the excavation chamber;

[0029] (2) Debug the voltage stabilization system and set relevant parameters according to the actual situation on site;

[0030] (3) Open the flushing ball valve and the slurry discharge ball valve 2, and connect the dilution system to the mud circulation system 1;

[0031] (4) Close the slurry inlet ball valve 1 and the slurry discharge ball valve 1, and use the screw machine channel slag discharge mode to carry the slag;

[0032] (5) Ensure that the pressure stabilizing gate valve 1 is closed and open the pressure stabilizing gate valve 2, so that the pressure stabilizing system intervenes in the mud circulation system 2 and provides stable pressure for the system;

[0033] (6) Open the rear gate of the screw machine and run the screw machine;

[0034] (7) The shield machine continues to advance forward, and the mixture of slag and mud in the mud and water bin enters the dilution box through the screw machine, and after being mixed with the slurry, it enters the slurry discharge pipe, thereby replacing the slag in the dilution box. During this process, it should be noted that compared with the normal earth pressure excavation mode, the advancement speed should be greater than the slag discharge speed of the screw machine, so that the slag in the screw machine forms a soil plug effect, thereby ensuring that the shield machine achieves the full bin excavation requirement.

[0035] (8) As the machine continues to advance, the specific gravity of the original slurry in the mud and water bin gradually increases, and the slurry discharged by the screw machine gradually turns into slag, thereby achieving slurry replacement in the bin. After advancing a certain distance, the mud circulation system 2 is closed, the rear gate of the screw machine is closed, and the dilution system is dismantled;

[0036] (9) Install the belt conveyor assembly, open the rear gate of the screw machine, and start the screw machine to run the soil pressure mode. At this point, the mode conversion is completed.

[0037] The present invention also discloses a method for discharging slurry from the above-mentioned dual-mode shield machine tunnel internal pressure-stabilizing mold-changing construction system. The slurry inlet pipe continuously transports slurry to the mud and water bin. After the slurry is mixed in the mud and water bin, it enters the dilution box through the screw machine channel. A flushing pipeline is connected to the dilution box to further dilute the mixed slurry entering the dilution box. When the mixture reaches a specified specific gravity, it is transported to the ground for separation under the action of a mud pump, thereby completing the replacement of the slag.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The existing dual-mode shield has high requirements for the stratum during the mold changing process. The present invention has strong applicability to the stratum and provides a new construction system and method for the earth pressure mud water dual-mode shield, especially the slag discharge method, which can effectively alleviate the stagnation phenomenon during the mold changing process.

[0040] 2. The mode conversion operation is simple and convenient, the mold changing speed is fast, the use cost is low, and it has great promotion potential.

[0041] 3. Existing dual-mode shield machines have problems such as long preparation time before mold change, complex mold change process, high mold change risk, and high mold change cost. This patent can effectively alleviate the above problems. In theory, it can continuously and uninterruptedly maintain the stability of the excavation chamber pressure, quickly switch modes, and realize the free conversion between earth pressure mode and mud water mode.

[0042] 4. The seamless transition between soil pressure slag discharge and mud and water slag discharge is truly realized, which is of great benefit to the stability of the tunnel face. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort. Among them:

[0044] Figure 1 Schematic diagram of the construction system of the present invention working in earth pressure mode;

[0045] Figure 2 Schematic diagram of the construction system of the present invention working in muddy water mode;

[0046] Figure 3 Schematic diagram of the operation of the construction system of the present invention when the soil pressure mode switches to the mud-water mode;

[0047] Figure 4 It is a schematic diagram of the operation of the construction system of the present invention when switching from mud-water mode to earth pressure mode.

[0048] Figure: 1. Tunnel face; 2. Cutterhead; 3. Excavation chamber; 4. Air cushion chamber; 5. Slurry inlet pipe; 6. Slurry inlet ball valve 1; 7. Slurry inlet ball valve 2; 8. Screw conveyor; 9. Screw conveyor gate; 10. Slurry inlet density meter; 11. Slurry inlet pump; 12. Slurry discharge density meter; 13. Slurry discharge pump; 14. Belt conveyor assembly; 15. Slurry discharge ball valve 1; 16. Slurry discharge pipe; 17. Flush ball valve; 18. Slurry discharge flowmeter; 19. , slurry discharge pump station; 20. Dilution box discharge pipe; 21. Slurry discharge ball valve 2; 22. Dilution box; 23. Slag removal door; 24. Dilution box feed pipe; 25. Slurry discharge pressure sensor; 26. Slurry inlet pressure sensor; 27. Slurry inlet flowmeter; 28. Pressure regulating pump; 29. ​​Pressure regulating flowmeter; 30. Pressure regulating gate valve 1; 31. Pressure stabilizer; 32. Pressure regulating tank; 33. Pressure regulating gate valve 2; 34. Liquid level switch. DETAILED DESCRIPTION

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0050] like Figure 1-4 As shown, the present invention provides a dual-mode shield machine in-hole pressure stabilization and mold changing construction system, the dual modes are earth pressure mode and mud water mode, and the mold changing includes converting the earth pressure mode into mud water mode and converting the mud water mode into earth pressure mode.

[0051] like Figure 1 As shown, the construction system under the earth pressure mode includes a slag discharge system 1; the slag discharge system 1 includes a screw machine and a belt conveyor assembly 14 under the rear gate. The screw machine 8 is tiltedly arranged on the inner side of the shield machine body to facilitate the transportation of slag; the belt conveyor assembly is used to transfer the material output by the screw machine to the slag truck, and then transport it outside the tunnel.

[0052] Operating principle of earth pressure mode: The shield machine excavates in the tunnel in earth pressure mode. The cutterhead 2 cuts the soil in the excavation chamber 3 (the soil chamber in this mode). The cut soil is transported to the belt conveyor assembly 14 by the screw conveyor, and then the soil is transported to the outside of the tunnel by the soil truck, completing the entire excavation process.

[0053] like Figure 2 As shown, the construction system in the mud-water mode includes a mud circulation system 1, which includes a slurry inlet pipe 5 and a slurry discharge pipe 16; specifically, the outlet end of the slurry inlet pipe 5 is located at the top of the excavation chamber 3, and the inlet end is connected to the ground separation station through a slurry pump 11, which is used to inject the slurry with lower specific gravity in the separation station into the excavation chamber 3; the inlet end of the slurry discharge pipe 16 is located at the bottom of the excavation chamber, and the outlet end is connected to the ground separation station, which is used to discharge the mixed slurry of the debris and slurry in the excavation chamber to the ground separation station for mud and water diversion. The slurry inlet pipe 5 is provided with a slurry inlet ball valve 16, a slurry inlet ball valve 27, a slurry inlet pressure sensor 26, a slurry inlet flowmeter 27 and a slurry inlet density meter 10. The slurry inlet flowmeter 27 constantly calculates the flow in the pipeline, and the slurry inlet density meter 10 is used to calculate the instantaneous density of the slurry in the pipeline; the slurry discharge pipe 16 is provided with a slurry discharge ball valve 15, a slurry discharge pressure sensor 25, a slurry discharge flowmeter 18 and a slurry discharge pump 13.

[0054] The operating principle of the mud and water mode: the shield machine excavates in the tunnel in the mud and water mode, the cutter head 2 cuts the soil of the excavation chamber 3 (the mud and water chamber in this mode), and the slurry pump 11 injects slurry with a lower specific gravity into the mud and water chamber through the slurry inlet pipe 5. After mixing with the debris cut by the cutter head 2, the mixed slurry is discharged through the slurry discharge pipe 16. The discharged slurry is separated into mud and water by the separation station on the ground, and finally converted into slurry with a smaller specific gravity and recycled into the slurry inlet pipe 5. The circulation continuously dilutes the debris in the excavation chamber 3 to achieve the transportation of the debris in the excavation chamber 3.

[0055] like Figure 3-4As shown, the dual-mode conversion construction system includes a second slag discharge system, a second mud circulation system and a pressure stabilization system; the second slag discharge system includes a screw conveyor 8; the second mud circulation system is connected to a dilution system on the basis of the first mud circulation system; the dilution system includes a dilution box 22, which is located below the rear gate of the screw conveyor 8. The functions of the dilution box 22 are: It has the function of storing stone; It has the effect of diluting the slag; the two ends of the dilution box 22 are the dilution box feed pipe 24 connected to the slurry inlet pipe 5 and the dilution box discharge pipe 20 connected to the slurry discharge pipe; the dilution system is used to dilute the slag entering the dilution box 22 through the screw machine 8 during the mode conversion process and send it into the slurry discharge pipe 16.

[0056] The feed end of the dilution box feed pipe 24 is connected to the slurry feed pipe 5 between the slurry feed ball valve 1 6 and the slurry feed ball valve 2 7, and the discharge end of the dilution box discharge pipe 20 is connected to the slurry discharge pipe; a flushing ball valve 17 is provided on the dilution box feed pipe 24; a slag removal door 23 is provided on the dilution box, and the inlet of the dilution box 22 is directly opposite to the bottom of the rear gate of the screw machine 8.

[0057] The existing technology uses a direct-discharge mold changing method, that is, without the assistance of a pressure stabilizing system, the slag or slurry in the excavation chamber is completely emptied, and then the slurry is poured in or the slag pushing operation is performed. During the mode conversion process of the dual-mode shield machine, the core of the control is the stability of the face pressure. Once the face pressure becomes unstable during the conversion process, it will cause the ground to collapse or uplift, bringing great construction risks. Therefore, the present invention is also provided with a pressure stabilizing system, which is arranged on the slurry inlet pipe 5 and is used to provide a constant pressure to the slurry in the slurry inlet pipe 5 to ensure the stability of the slurry pressure in the excavation chamber 3. The pressure stabilizing system includes a pressure stabilizer 31, a pressure stabilizing tank 32, and a pressure stabilizing pipeline connected to the slurry inlet pipe 5. The pressure stabilizing tank 32 is a tank body for storing slurry. The pressure stabilizing tank 32 is provided with a liquid level switch 34 and a pressure stabilizer 31. The liquid level switch 34 is used to display the height of the slurry in the pressure stabilizing tank 32. The pressure stabilizer 31 is used to provide a constant pressure to the slurry in the pressure stabilizing tank 32. The technical principle of the pressure stabilizer is common knowledge and will not be described here. The pressure stabilizing pipeline includes an inlet pipeline connected to the pressure stabilizing pump 28 and an outlet pipeline connected to the slurry inlet pipe 5. The pressure stabilizing tank 32 is connected between the inlet pipeline and the outlet pipeline. A pressure stabilizing flowmeter 29 and a pressure stabilizing gate valve 1 30 are provided on the inlet pipeline, and a pressure stabilizing gate valve 2 33 is provided on the outlet pipeline. In the soil pressure to mud-water mode, the incoming slurry is delivered to the pressure-stabilizing tank 32 via the pressure-stabilizing pump 28. Under the action of the pressure stabilizer, the slurry in the pressure-stabilizing tank 32 is pressed into the excavation chamber 3. It should be noted that the pressure stabilizer 31 provides a constant pressure, which is then applied to the excavation chamber 3 through slurry transmission, indirectly ensuring a stable pressure within the excavation chamber 3. Therefore, the slurry continuously enters the excavation chamber 3 to mix with the slag soil, and is then discharged through the screw conveyor channel. During this process, it should be noted that the excavation chamber 3 is always filled with medium, providing support for the tunnel face 1.

[0058] In the mud-water-to-earth pressure mode, first stop injecting slurry into the pressure-surge tank 32 and empty the slurry in the tank. In addition, the tank still needs to be filled with compressed air to provide a constant gas pressure in the pressure-surge tank 32 during the subsequent process. The shield machine continues to excavate, and the screw machine 8 channel continues to transport slurry and slag. As the excavation continues, because no slurry is injected into the excavation chamber 3, the proportion of the mixed slurry in the excavation chamber 3 gradually increases. The medium transported by the screw machine 8 channel gradually changes from slurry to slag, and the slurry replacement is completed. It should be clarified again that in this process, the excavation chamber 3 is filled with a mixture of slurry and slag, which plays a certain supporting role on the tunnel face 1; the compressed air only provides a pressure stabilizing effect in the excavation chamber 3 to offset the pressure fluctuations that may occur in the excavation chamber during the slag discharge process of the screw machine 8.

[0059] In the working method of the dual-mode shield machine tunnel internal pressure stabilization and mold changing construction system, the specific process of converting the earth pressure mode to the slurry mode is as follows:

[0060] (12) When conditions permit, select a stable stratum for mode conversion;

[0061] (13) Stop excavation before changing the mold, and conduct joint commissioning and testing of the ground separation station and mud circulation system to ensure normal operation;

[0062] (14) Remove the belt conveyor assembly and install the flushing ball valve 17, dilution box feed pipe 24, dilution box 22, dilution box discharge pipe 20, and slurry discharge ball valve 21;

[0063] (15) When the entire mud circulation system is ensured to be able to operate, close the slurry inlet ball valve 1 6, open the slurry inlet ball valve 2 7, the flushing ball valve 17, and the slurry discharge ball valve 2 21, and adjust the slurry inlet pump 11 and the slurry discharge pump 13, and observe the slurry inlet pressure sensor 26 until it reaches the ideal value;

[0064] (16) After ensuring that the slurry inlet pipe 5 is not blocked, open the pressure-stabilizing gate valve 30, start the pressure-stabilizing pump 28, and start injecting slurry into the pressure-stabilizing tank 32. A liquid level switch 34 is installed on the pressure-stabilizing tank 32 to detect the height of the slurry in the tank;

[0065] (17) Starting the pressure stabilizer and designing relevant parameters of the pressure stabilizer to meet the requirements of the excavation chamber 3, such as setting a certain pressure value so that the pressure provided by the pressure stabilization system 31 matches the pressure required by the excavation chamber 3;

[0066] (18) Open the second pressure-stabilizing gate valve 33 to start delivering slurry into the excavation chamber 3;

[0067] (19) Open the screw machine gate 9, slowly rotate the cutter head 2 and the screw conveyor, and the slag enters the dilution box 22 through the screw machine 8. The larger stones are stored in the dilution box 22, and the smaller slag stones and slag enter the slurry discharge pipe 16 through the dilution box discharge pipe 20, thereby completing the slag carrying task;

[0068] (20) This process is continued until the slag in the excavation chamber 3 is completely replaced. There are many methods for determining that the slag replacement is complete. Here, only one method is introduced: when the values ​​displayed by the slurry inlet density meter 10 on the slurry inlet pipe 5 and the slurry discharge density meter 12 on the slurry discharge pipe 16 are the same, it can be determined that the slag in the excavation chamber 3 is completely replaced. The other methods are not introduced here one by one.

[0069] (21) Open the slurry inlet ball valve 16 and the slurry discharge ball valve 15, close the flushing ball valve and the slurry discharge ball valve 21, and stop flushing the dilution tank 22; turn off the pressure stabilizing pump 28, the pressure stabilizing gate valve 1 30, the pressure stabilizing gate valve 2 33 and the pressure stabilizing system 31 in sequence;

[0070] (22) Once the mud circulation system is running smoothly, close the rear gate of screw machine 8. The conversion from soil pressure mode to mud-water mode is now complete.

[0071] The above conversion uses 8 channels of screw machine for slurry discharge, or you can directly use the direct discharge mode of mud and water mode. The mode here is determined according to the actual situation on site.

[0072] The specific process of converting the mud-water mode to the earth pressure mode in the present invention is as follows:

[0073] (10) First, continue to operate the mud and water mode to empty the slag and rock in the excavation chamber 3;

[0074] (11) Debug the voltage stabilization system and set relevant parameters according to the actual situation on site;

[0075] (12) Open the flushing ball valve 17 and the slurry discharge ball valve 21 to connect the dilution system to the mud circulation system 1;

[0076] (13) Close the slurry inlet ball valve 6 and the slurry discharge ball valve 15, and use the screw machine 8-channel slag discharge mode to carry the slag;

[0077] (14) Ensure that the pressure stabilizing gate valve 1 30 is closed, and open the pressure stabilizing gate valve 2 33, so that the pressure stabilizing system intervenes in the mud circulation system 2 and provides stable pressure for the system;

[0078] (15) Open the rear gate of the screw machine 8 and operate the screw machine 8;

[0079] (16) The shield machine continues to advance forward, and the mixture of slag and mud in the mud and water bin enters the dilution box 22 through the screw machine 8, and enters the slurry discharge pipe after being mixed with the slurry, thereby replacing the slag in the dilution box 22. During this process, it should be noted that compared with the normal earth pressure excavation mode, the advancement speed should be greater than the slag discharge speed of the screw machine 8, so that the slag in the screw machine 8 forms a soil plug effect, thereby ensuring that the shield machine achieves the full bin excavation requirement.

[0080] (17) As the vehicle continues to advance, the specific gravity of the original slurry in the mud and water bin gradually increases, and the slurry discharged by the screw machine 8 gradually converts into slag, thereby achieving slurry replacement in the bin. After advancing a certain distance, the mud circulation system 2 is closed, the rear gate 9 of the screw machine is closed, and the dilution system is dismantled;

[0081] (18) Install the belt conveyor assembly 14, open the rear gate of the screw machine 8, and start the screw machine 8 to start running the earth pressure mode. At this point, the mode conversion is completed.

[0082] In the mud-water mode of this patent, as mentioned above, there are two options for the slurry discharge mode of the shield machine: the first is to transport through the straight discharge pipe in the main section of the shield machine, and the straight discharge pipe is directly inserted into the mud-water bin, so the mixed slurry can be directly extracted from the mud-water bin and transported to the ground by the pump, and the upper slurry slurry continuously transports slurry with a smaller specific gravity to the mud-water bin, thereby circulating to achieve the replacement of the slag in the mud-water bin. The other slurry discharge mode is that the slurry inlet pipe 5 continuously transports the slurry to the mud-water bin, and after the slurry is mixed in the mud-water bin, it enters the dilution box 22 through the screw machine 8 channel. A flushing pipeline is connected to the dilution box 22 to further dilute the mixed slurry entering the dilution box 22. When the mixture reaches the specified specific gravity, it is transported to the ground for separation under the action of the mud pump, thereby completing the replacement of the slag.

[0083] In the earth pressure mode, the slag in the main section of the shield machine is only transported by the screw conveyor 8, and the slag in the trailer section is mainly transported by the belt conveyor.

[0084] Although the present invention has been described above with reference to embodiments, various modifications may be made thereto and equivalent components may be substituted without departing from the scope of the present invention. In particular, as long as there are no structural conflicts, the various features of the embodiments disclosed herein may be combined with each other in any manner, and the omission of an exhaustive description of such combinations in this specification is solely for the sake of space and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A dual-mode shield machine tunnel pressure stabilization and mold change construction system, wherein the dual modes are earth pressure mode and slurry water mode, and mold change includes converting the earth pressure mode to slurry water mode and vice versa; characterized by: The construction system in earth pressure mode includes a first slag discharge system; the first slag discharge system includes a screw conveyor and a belt conveyor assembly below the rear gate. The screw conveyor is tilted inside the shield machine body to facilitate the transportation of slag or mud-slag mixture; the belt conveyor assembly is used to transfer the material output by the screw conveyor to the slag truck, and then transport it outside the tunnel; The construction system in the mud-water mode includes a mud circulation system 1, which includes a slurry inlet pipe and a slurry discharge pipe; the slurry inlet pipe is used to inject the slurry with lower specific gravity from the separation station into the excavation chamber; the slurry discharge pipe is used to discharge the mixed slurry of slag and slurry in the excavation chamber to the separation station on the ground for mud-water diversion; The dual-mode conversion construction system includes a second slag discharge system, a second mud circulation system, and a pressure stabilization system; the second slag discharge system includes a screw conveyor; the second mud circulation system is connected to a dilution system on the basis of the first mud circulation system; the dilution system includes a dilution box, which is located below the rear gate of the screw conveyor, with two ends of the dilution box connected to the slurry inlet pipe and the dilution box outlet pipe connected to the slurry discharge pipe; the dilution system is used to dilute the slag entering the dilution box through the screw conveyor during the mode conversion process and send it to the slurry discharge pipe; It also includes a pressure stabilizing system, which is arranged on the slurry inlet pipe and is used to provide constant pressure to the slurry in the slurry inlet pipe; the pressure stabilizing system includes a pressure stabilizer, a pressure stabilizing tank and a pressure stabilizing pipeline connected to the slurry inlet pipe; the pressure stabilizing tank is a tank body for storing slurry, and the pressure stabilizing tank is provided with a liquid level switch and a pressure stabilizer, and the liquid level switch is used to display the height of the slurry in the pressure stabilizing tank; the pressure stabilizer is used to provide constant pressure to the slurry in the pressure stabilizing tank; the pressure stabilizing pipeline includes an inlet pipeline connected to the pressure stabilizing pump and an outlet pipeline connected to the slurry inlet pipe, the pressure stabilizing tank is connected between the inlet pipeline and the outlet pipeline, a pressure stabilizing flowmeter and a pressure stabilizing gate valve 1 are provided on the inlet pipeline, and a pressure stabilizing gate valve 2 is provided on the outlet pipeline.

2. The dual-mode shield machine in-tunnel pressure stabilization and mold changing construction system according to claim 1, characterized in that: The outlet end of the slurry inlet pipe is located at the top of the excavation bin, and the inlet end is connected to the ground separation station through a slurry inlet pump; the inlet end of the slurry discharge pipe is located at the bottom of the excavation bin, and the outlet end is connected to the ground separation station.

3. The dual-mode shield machine in-hole pressure stabilization and mold changing construction system according to claim 2, characterized in that: The slurry inlet pipe is provided with a slurry inlet ball valve 1, a slurry inlet ball valve 2, a slurry inlet pressure sensor, a slurry inlet flowmeter and a slurry inlet density meter; the slurry inlet flowmeter calculates the flow in the pipeline at all times, and the slurry inlet density meter is used to calculate the instantaneous density of the slurry in the pipeline; the slurry discharge pipe is provided with a slurry discharge ball valve 1, a slurry discharge pressure sensor, a slurry discharge flowmeter and a slurry discharge pump.

4. The dual-mode shield machine in-tunnel pressure stabilization and mold changing construction system according to claim 3, characterized in that: A flushing ball valve is provided on the dilution box feed pipe; a slag removal door is provided on the dilution box, and the inlet of the dilution box is directly opposite to the bottom of the rear gate of the screw machine.

5. The working method of the dual-mode shield machine in-hole pressure stabilization and mold changing construction system according to claim 1 is characterized in that: The specific process of converting the earth pressure mode to mud water mode is as follows: (1) When conditions permit, select a stable stratum for mode conversion; (2) Stop excavation before changing the mold, and conduct joint commissioning and testing of the ground separation station and mud circulation system to ensure normal operation; (3) Remove the belt conveyor assembly and install the flushing ball valve, dilution box feed pipe, dilution box, dilution box discharge pipe, and slurry discharge ball valve II; (4) When the entire mud circulation system is ensured to be able to operate, close the slurry inlet ball valve 1, open the slurry inlet ball valve 2, the flushing ball valve, and the slurry discharge ball valve 2, and adjust the slurry inlet pump and the slurry discharge pump, and observe the slurry inlet pressure sensor until it reaches the ideal value; (5) After ensuring that the slurry inlet pipe is not blocked, open the pressure stabilizing gate valve 1, start the pressure stabilizing pump, and start injecting slurry into the pressure stabilizing tank. A liquid level switch is installed on the pressure stabilizing tank to detect the height of the slurry in the tank; (6) Start the pressure stabilizer and set the pressure value so that the pressure provided by the pressure stabilization system matches the pressure required by the excavation chamber; (7) Open the second pressure-stabilizing gate valve and start delivering slurry into the excavation chamber; (8) Open the screw conveyor gate, slowly rotate the cutter head and screw conveyor, and the slag enters the dilution box through the screw conveyor. The larger stones are stored in the dilution box, and the smaller slag and slag enter the slurry discharge pipe through the dilution box discharge pipe, thereby completing the slag carrying task; (9) When the slurry density meter on the slurry inlet pipe and the slurry density meter on the slurry discharge pipe display the same value, it is determined that the slag in the excavation bin has been replaced; (10) Open the slurry inlet ball valve 1 and the slurry discharge ball valve 1, close the flushing ball valve and the slurry discharge ball valve 2, and stop flushing the dilution tank; turn off the pressure stabilizing pump, pressure stabilizing gate valve 1, pressure stabilizing gate valve 2 and the pressure stabilizing system in sequence; (11) Once the mud circulation system runs smoothly, close the rear gate of the screw machine. The conversion from soil pressure mode to mud-water mode is now complete.

6. The working method of the dual-mode shield machine in-hole pressure stabilization and mold changing construction system according to claim 1, characterized in that: The specific process of converting mud water mode to earth pressure mode is as follows: (1) First, continue to run the mud and water mode to empty the slag and rock in the excavation chamber; (2) Debug the voltage stabilization system and set relevant parameters according to the actual situation on site; (3) Open the flushing ball valve and the slurry discharge ball valve 2, and connect the dilution system to the mud circulation system 1; (4) Close the slurry inlet ball valve 1 and the slurry discharge ball valve 1, and use the screw machine channel slag discharge mode to carry the slag; (5) Ensure that the pressure stabilizing gate valve 1 is closed and open the pressure stabilizing gate valve 2, so that the pressure stabilizing system intervenes in the mud circulation system 2 and provides stable pressure for the system; (6) Open the rear gate of the screw machine and run the screw machine; (7) The shield machine continues to advance forward, and the mixture of slag and mud in the mud and water bin enters the dilution box through the screw machine, and after being mixed with the slurry, it enters the slurry discharge pipe, thereby replacing the slag in the dilution box. During this process, it should be noted that compared with the normal earth pressure excavation mode, the advancement speed should be greater than the slag discharge speed of the screw machine, so that the slag in the screw machine forms a soil plug effect, thereby ensuring that the shield machine achieves the full bin excavation requirement. (8) As the machine continues to advance, the specific gravity of the original slurry in the mud and water bin gradually increases, and the slurry discharged by the screw machine gradually turns into slag, thereby achieving slurry replacement in the bin. After advancing a certain distance, the mud circulation system 2 is closed, the rear gate of the screw machine is closed, and the dilution system is dismantled; (9) Install the belt conveyor assembly, open the rear gate of the screw machine, and start the screw machine to run the soil pressure mode. At this point, the mode conversion is completed.

7. A method for slurry discharge using the dual-mode shield machine tunnel pressure stabilization and mold changing construction system according to claim 1, characterized in that: The slurry inlet pipe continuously transports slurry to the mud and water bin. After the slurry is mixed in the mud and water bin, it enters the dilution box through the screw machine channel. The flushing pipeline is connected to the dilution box to further dilute the mixed slurry entering the dilution box. When the mixture reaches the specified specific gravity, it is transported to the ground for separation under the action of the mud pump, thereby completing the replacement of the slag.

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