A method for treating sludge and pipeline lagging of a slurry chamber of a slurry shield

Abstract

The present application relates to the field of subway construction technology, and discloses a gas cushion balanced slurry shield slurry tank sediment and pipeline lagging discharge treatment method, which comprises the following steps: investigating and analyzing the determined lagging discharge pipeline, which is the pipeline between the first preset ball valve on the main slurry discharge pipeline and the slurry tank slurry discharge pipeline; setting a slurry circulation system and performing first cleaning on the lagging discharge pipeline; when the first preset ball valve does not meet the preset cleaning condition, the first preset ball valve is closed, and second cleaning is performed on the first preset ball valve based on the preset cleaning scheme; third cleaning is performed on the lagging discharge pipeline based on a layered reverse flushing mode until the preset cleaning requirement is met, and it is determined whether the lagging discharge pipeline cleaning is completed; long-time shutdown special measures of the slurry shield and special measures for excavation face stability during long-time shutdown of the slurry shield are determined, the present application can clean the lagging discharge soil of the main slurry discharge pipeline, solve the lagging discharge problem of the main slurry discharge pipeline, restore the normal tunneling of the shield machine, and ensure the construction safety.

Description

Technical Field

[0001] This invention relates to the field of subway construction technology, and more specifically, to a method for treating sediment and pipeline retention in the slurry chamber of an air-cushion balanced slurry shield tunnel. Background Technology

[0002] A slurry shield tunneling machine (SPB) is a type of closed-loop tunnel boring machine. It consists of a baffle at the front of a mechanical shield, a cutterhead, slurry delivery and discharge pipes, and hydraulic cylinders for propulsion. Slurry treatment equipment is also installed on the ground. Slurry shield tunneling machines are particularly suitable for subway tunnels passing under rivers, lakes, and ultra-large cross-section tunnels.

[0003] Current slurry shield tunneling machines use slurry pipelines to remove the soil in front of the excavation face, which is then separated by a slurry treatment system. Generally, as long as the sludge is not larger than the minimum diameter of the slurry pipeline, it can be discharged smoothly. However, if there are large gravels or pebbles in the underlying strata, prolonged downtime, or lack of slurry circulation within the tunnel chamber, these gravels and pebbles can easily accumulate, causing sediment buildup in the slurry chamber, cutterhead jamming, and slurry discharge stagnation, preventing the slurry shield tunneling machine from advancing normally. If these cannot be removed, the tunnel chamber must be opened for cleaning, which carries significant safety risks. Summary of the Invention

[0004] This invention provides a method for treating sediment and pipeline blockage in a slurry tank of an air-cushion balanced slurry shield tunnel, which solves the technical problem in the prior art where pipeline dredging and cleaning of obstructions in front of the cutterhead are impossible when sediment in the slurry tank causes cutterhead jamming and main slurry discharge pipeline blockage.

[0005] To achieve the above objectives, the present invention provides a method for treating sediment and pipeline retention in a slurry chamber of an air-cushion balanced slurry shield tunnel, comprising:

[0006] Based on the preset sludge discharge analysis method, the corresponding sludge discharge pipeline is determined, and the sludge discharge pipeline is investigated and analyzed. The sludge discharge pipeline is the pipeline between the first preset ball valve on the main slurry discharge pipeline and the slurry discharge pipeline of the mud and water silo. The investigation and analysis includes building investigation and geological supplementary exploration.

[0007] Based on the investigation and analysis results, a mud circulation system is set up, and the stagnant drainage pipeline is cleaned for the first time according to the mud circulation system;

[0008] The first cleaning is monitored in real time. When the first preset ball valve does not meet the preset cleaning conditions, the first preset ball valve is closed, and the first preset ball valve is cleaned a second time based on the preset cleaning plan.

[0009] The stagnant drainage pipeline is cleaned a third time based on the layered backflushing mode until the preset cleaning requirements are met, and the cleaning of the stagnant drainage pipeline is determined to be completed.

[0010] After the drainage pipeline is cleaned, special measures for long-term shutdown of the slurry shield tunneling machine and special measures for stabilizing the excavation face during long-term shutdown of the slurry shield tunneling machine are determined.

[0011] Furthermore, when setting up the mud circulation system based on the investigation and analysis results, it includes:

[0012] Obtain the current tunneling speed and set the slurry flow rate of the slurry pump in the mud circulation system according to the tunneling speed;

[0013] The discharge flow rate of the slurry pump in the mud circulation system is set according to the tunneling speed;

[0014] The slurry inlet power and slurry outlet power of the slurry inlet pump and the slurry outlet pump are respectively set based on the slurry inlet flow rate and the slurry outlet flow rate;

[0015] The mud circulation system is configured based on the mud inlet flow rate, the mud outlet flow rate, the mud inlet power, and the mud outlet power.

[0016] Furthermore, when setting the slurry flow rate of the slurry pump in the mud circulation system according to the tunneling speed, the following steps are included:

[0017] A first preset tunneling speed and a second preset tunneling speed are preset.

[0018] The slurry flow rate of the slurry pump in the mud circulation system is set according to the tunneling speed, the first preset tunneling speed, and the second preset tunneling speed.

[0019] When the tunneling speed is less than the first preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to P1.

[0020] When the tunneling speed is greater than or equal to the first preset tunneling speed and the tunneling speed is less than the second preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to P1.

[0021] When the tunneling speed is greater than or equal to the second preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to P3.

[0022] Furthermore, when setting the discharge flow rate of the slurry pump in the mud circulation system according to the tunneling speed, the following steps are included:

[0023] The discharge flow rate of the slurry pump in the mud circulation system is set according to the tunneling speed, the first preset tunneling speed, and the second preset tunneling speed;

[0024] When the tunneling speed is less than the first preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to W1.

[0025] When the tunneling speed is greater than or equal to the first preset tunneling speed and the tunneling speed is less than the second preset tunneling speed, the slurry inlet flow rate of the slurry pump in the mud circulation system is set to W2.

[0026] When the tunneling speed is greater than or equal to the second preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to W3.

[0027] Furthermore, real-time monitoring of the first cleaning includes:

[0028] The flushing pressure of the area where the first preset ball valve is located is obtained, and the relationship between the flushing pressure and the preset flushing pressure is used to determine whether the area where the first preset ball valve is located meets the preset cleaning conditions.

[0029] When the flushing pressure is greater than the preset flushing pressure, it is determined that the first preset ball valve does not meet the preset cleaning conditions.

[0030] When the flushing pressure is less than or equal to the preset flushing pressure, it is determined that the first preset ball valve meets the preset cleaning conditions.

[0031] Furthermore, when performing a second cleaning on the first preset ball valve based on a preset cleaning plan, the process includes:

[0032] Close the first preset ball valve and open the pipeline behind the first preset ball valve;

[0033] Open the observation ball valve between the first preset ball valve and the manual knife switch;

[0034] High-pressure mud at a preset pressure is injected into the observation ball valve for backflushing, and it is determined whether the second cleaning is successful. If not, the stagnant pipeline is cleaned a third time based on the layered backflushing mode.

[0035] Furthermore, when the stagnant drainage pipeline is cleaned a third time based on a stratified backflushing mode until the preset cleaning requirements are met, the cleaning of the stagnant drainage pipeline is considered complete, including:

[0036] The first preset ball valve area is cleaned layer by layer.

[0037] During the layer-by-layer cleaning process, the status of the cutter head is collected in real time. When the status of the cutter head meets the preset state, the rotation speed range of the cutter head is set to 0.3-0.5 rpm.

[0038] Furthermore, when performing a third cleaning of the stagnant drainage pipeline based on a stratified backflushing mode until the preset cleaning requirements are met, and when it is determined that the cleaning of the stagnant drainage pipeline is complete, the process further includes:

[0039] A dredging tool is installed at the first preset ball valve, and a fourth cleaning is performed on the pipeline in front of the first preset ball valve based on the dredging tool.

[0040] Determine whether the fourth cleaning was successful. If not, increase the rotation speed of the cutter head.

[0041] The fifth cleaning of the stagnant drainage pipeline is performed based on the adjusted cutter head with increased rotation speed and the preset cleaning scheme until the stagnant drainage pipeline meets the preset cleaning requirements, and the cleaning of the stagnant drainage pipeline is determined to be complete.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] This invention discloses a method for treating sludge and pipeline stagnation in a slurry shield tunneling machine with an air cushion balance. The method includes: investigating and analyzing a determined stagnation pipeline, which is the pipeline between a first preset ball valve on the main slurry discharge pipeline and the slurry discharge pipeline of the slurry shield; setting up a slurry circulation system and performing a first cleaning of the stagnation pipeline; closing the first preset ball valve when it does not meet preset cleaning conditions, and performing a second cleaning based on a preset cleaning scheme; performing a third cleaning of the stagnation pipeline based on a layered backflushing mode until the preset cleaning requirements are met, and determining that the cleaning of the stagnation pipeline is complete; and determining special measures for long-term shutdown of the slurry shield tunneling machine and special measures for stabilizing the excavation face during long-term shutdown. This invention can clear sludge and soil stagnation in the main slurry discharge pipeline, solve the stagnation problem, allow the tunnel boring machine to resume normal tunneling, ensure construction safety, and eliminates the need for renting large machinery, ground reinforcement, or pressurized operation, resulting in low construction costs and significant economic benefits. Attached Figure Description

[0044] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0045] Figure 1 A schematic flowchart of a method for treating sediment and pipeline sludge in a slurry tank of an air-cushion balanced slurry shield tunneling machine is shown in an embodiment of the present invention.

[0046] Figure 2 A diagram showing the conversion of the mud circulation mode in a slurry shield tunneling project according to an embodiment of the present invention is provided.

[0047] Figure 3 A schematic diagram of the slurry circulation shutdown and pressure maintenance mode of the slurry shield tunneling machine in an embodiment of the present invention is shown;

[0048] Figure 4 A schematic diagram of the slurry circulation bypass mode of the slurry shield tunneling in an embodiment of the present invention is shown;

[0049] Figure 5 A schematic diagram of the mud circulation and washing mode of the slurry shield tunneling machine in an embodiment of the present invention is shown;

[0050] Figure 6 A schematic diagram of the slurry circulation backwashing mode of the slurry shield tunneling machine in an embodiment of the present invention is shown;

[0051] Figure 7 A schematic diagram of the slurry circulation tunneling mode of the slurry shield tunneling in an embodiment of the present invention is shown;

[0052] Figure 8 A schematic diagram illustrating an example of a maintenance pressure-holding mode in an embodiment of the present invention is shown;

[0053] Figure 9 This diagram illustrates an example of a pipeline extension and slurry collection mode in an embodiment of the present invention. Detailed Implementation

[0054] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0055] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0056] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0057] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0058] The following is a description of preferred embodiments of the present invention in conjunction with the accompanying drawings.

[0059] like Figure 1-4 As shown, an embodiment of the present invention discloses a method for treating sediment and pipeline retention in a slurry chamber of an air-cushion balanced slurry shield tunnel, comprising:

[0060] S110: Based on the preset sludge discharge analysis method, determine the corresponding sludge discharge pipeline and conduct an investigation and analysis on the sludge discharge pipeline, wherein the sludge discharge pipeline is the pipeline between the first preset ball valve on the main slurry discharge pipeline and the slurry discharge pipeline of the mud and water silo, and the investigation and analysis includes building investigation and geological supplementary exploration;

[0061] This embodiment is applicable to situations where slurry shield tunneling is carried out in geological conditions such as water-rich gravel and pebbles, and when sediment in the slurry chamber causes the cutterhead to jam and the main slurry discharge pipeline to stagnate, requiring pipeline dredging and clearing of obstructions in front of the cutterhead.

[0062] In this embodiment, the first preset ball valve is an F32 ball valve.

[0063] In this embodiment, mechanical drawings and slurry discharge pipeline operation were checked to identify the stagnant pipeline. The stagnant discharge analysis revealed that the slurry discharge pipeline from the F32 ball valve in the main slurry discharge pipeline to the slurry tank was blocked, and the sediment thickness in the slurry tank was about 2m, resulting in excessive cutter head torque and cutter head jamming.

[0064] In this embodiment, an investigation was conducted on buildings and structures within a range of twice the tunnel diameter along the section. The investigation included checking for tilting, cracks in load-bearing components, and damage to the walls.

[0065] In this embodiment, control boreholes comprise no less than 1 / 3 of the total number of boreholes, and the number of exploration boreholes for taking soil and rock samples and conducting in-situ tests comprises no less than 2 / 3 of the total number of boreholes (including detailed exploration boreholes). During drilling, the sampling depth and characteristics of water, soil, sand, and rock samples are recorded in detail, and a supplementary exploration report is issued.

[0066] The beneficial effects of the above technical solution are: by determining the corresponding drainage pipeline and conducting investigation and analysis on the drainage pipeline, the present invention can lay the foundation for subsequent cleaning, achieve good control of surface subsidence and building deformation, and have high safety and stability when crossing buildings and rivers.

[0067] S120: Based on the investigation and analysis results, a mud circulation system is set up, and the stagnant discharge pipeline is cleaned for the first time according to the mud circulation system;

[0068] In some embodiments of this application, when setting up a mud circulation system based on investigation and analysis results, the following are included:

[0069] Obtain the current tunneling speed and set the slurry flow rate of the slurry pump in the mud circulation system according to the tunneling speed;

[0070] The discharge flow rate of the slurry pump in the mud circulation system is set according to the tunneling speed;

[0071] The slurry inlet power and slurry outlet power of the slurry inlet pump and the slurry outlet pump are respectively set based on the slurry inlet flow rate and the slurry outlet flow rate;

[0072] The mud circulation system is configured based on the mud inlet flow rate, the mud outlet flow rate, the mud inlet power, and the mud outlet power.

[0073] In this embodiment, the slurry inlet flow rate, the slurry outlet flow rate, and the tunneling speed of the slurry shield are matched.

[0074] In this embodiment, the slurry inlet flow rate can be set to 850 m³ / h, and the slurry outlet flow rate can be set to 950 m³ / h. Both the slurry inlet flow rate and the slurry outlet flow rate are not less than 630 m³ / h.

[0075] In this embodiment, a heavy-duty slurry pump is used, with full consideration given to its wear resistance and other properties. The feed pump and all relay mud pumps can be controlled independently, both locally and in the main control room.

[0076] In this embodiment, the slurry steel pipe is made of Q345B material, and the main inlet / outlet slurry pipe has a wall thickness of 12mm. The number of bends in the pipeline layout is minimized, and 90° sharp turns are avoided. All bends are designed with internal welded wear-resistant mesh and external thickened steel plate for wear resistance.

[0077] In this embodiment, the tunnel boring machine is in a shutdown state for an extended period, which may result in the loss of slurry in the slurry chamber. In this case, the shutdown pressure-maintaining mode is used to control the slurry level in the air cushion chamber, and slurry should be replenished as necessary.

[0078] In this embodiment, the bypass mode is an intermediate mode of the mud circulation system. Before tunneling, the tunnel boring machine operator controls the pressure of the slurry inlet and outlet pipes by adjusting the speed of the slurry inlet pump and the slurry outlet pump until the optimal flow rate of mud circulation is reached. At the same time, the slurry outlet pump / slurry inlet pump in the tunnel is synchronously adjusted to the required speed and flow rate.

[0079] The beneficial effects of the above technical solution are: the present invention accurately sets the slurry flow rate and slurry power of the slurry pump, and sets the slurry discharge flow rate and slurry discharge power of the discharge pump, thereby providing reliable data support for the safe and smooth completion of slurry chamber sediment, cutterhead jamming, and main slurry discharge pipeline stagnation treatment of slurry shield machine in tunnel.

[0080] In some embodiments of this application, setting the slurry flow rate of the slurry pump in the mud circulation system according to the tunneling speed includes:

[0081] A first preset tunneling speed and a second preset tunneling speed are preset.

[0082] The slurry flow rate of the slurry pump in the mud circulation system is set according to the tunneling speed, the first preset tunneling speed, and the second preset tunneling speed.

[0083] When the tunneling speed is less than the first preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to P1.

[0084] When the tunneling speed is greater than or equal to the first preset tunneling speed and the tunneling speed is less than the second preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to P1.

[0085] When the tunneling speed is greater than or equal to the second preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to P3.

[0086] The beneficial effects of the above technical solution are: the present invention sets the slurry flow rate of the slurry pump in the slurry circulation system according to the tunneling speed, the first preset tunneling speed and the second preset tunneling speed. The present invention can achieve precise setting of the slurry flow rate and realize dynamic setting.

[0087] In some embodiments of this application, setting the discharge flow rate of the slurry pump in the mud circulation system according to the tunneling speed includes:

[0088] The discharge flow rate of the slurry pump in the mud circulation system is set according to the tunneling speed, the first preset tunneling speed, and the second preset tunneling speed;

[0089] When the tunneling speed is less than the first preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to W1.

[0090] When the tunneling speed is greater than or equal to the first preset tunneling speed and the tunneling speed is less than the second preset tunneling speed, the slurry inlet flow rate of the slurry pump in the mud circulation system is set to W2.

[0091] When the tunneling speed is greater than or equal to the second preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to W3.

[0092] The beneficial effects of the above technical solution are: the present invention sets the discharge flow rate of the slurry pump in the mud circulation system according to the tunneling speed, the first preset tunneling speed and the second preset tunneling speed. The present invention can realize the intelligent setting of the discharge flow rate and avoid large errors.

[0093] S130: The first cleaning is monitored in real time. When the first preset ball valve does not meet the preset cleaning conditions, the first preset ball valve is closed, and the first preset ball valve is cleaned a second time based on the preset cleaning plan.

[0094] like Figure 5 As shown, in some embodiments of this application, real-time monitoring of the first cleaning includes:

[0095] The flushing pressure of the area where the first preset ball valve is located is obtained, and the relationship between the flushing pressure and the preset flushing pressure is used to determine whether the area where the first preset ball valve is located meets the preset cleaning conditions.

[0096] When the flushing pressure is greater than the preset flushing pressure, it is determined that the first preset ball valve does not meet the preset cleaning conditions.

[0097] When the flushing pressure is less than or equal to the preset flushing pressure, it is determined that the first preset ball valve meets the preset cleaning conditions.

[0098] In this embodiment, the inlet pipe connecting the air cushion chamber and the mud-water chamber was found to be blocked during the chamber washing mode. This indicated that the chamber was quite deep. Flushing the chamber using the F1 slurry inlet revealed the sound of stones hitting the pipe. After backflushing with F1 until the impact sound ceased, the chamber washing mode was restarted to force backflushing. This allowed slurry to enter the pipe, clearing the blockage.

[0099] In this embodiment, if the flushing pressure is found to be greater than the preset flushing pressure when flushing the sediment near the F32 discharge port, it is determined that the first preset ball valve does not meet the preset cleaning conditions.

[0100] In this embodiment, the washing mode needs to be switched via a bypass mode. By switching the inlet / outlet slurry flow direction, the bottom of the air cushion chamber is flushed to remove the slag deposited at the bottom of the air cushion chamber, ensuring the normal operation of the air cushion chamber.

[0101] The beneficial effects of the above technical solution are: the present invention achieves targeted cleaning based on the washing mode, ensuring cleaning efficiency.

[0102] In some embodiments of this application, when performing a second cleaning on the first preset ball valve based on a preset cleaning scheme, the process includes:

[0103] Close the first preset ball valve and open the pipeline behind the first preset ball valve;

[0104] Open the observation ball valve between the first preset ball valve and the manual knife switch;

[0105] High-pressure mud at a preset pressure is injected into the observation ball valve for backflushing, and it is determined whether the second cleaning is successful. If not, the stagnant pipeline is cleaned a third time based on the layered backflushing mode.

[0106] In this embodiment, after closing the hydraulic ball valve F32 of the main slurry discharge pipe to ensure safety, the pipeline behind F32 is manually opened for manual cleaning, and the slag in the quarry box is cleaned at the same time.

[0107] In this embodiment, the 2-inch observation ball valve between the main grout discharge pipe F32 hydraulic ball valve and the manual knife gate is opened. By changing the synchronous grouting pipe to the 2-inch ball valve, high-pressure mud of about 16 bar (preset pressure) is injected for backflushing to try to flush out the blocked pebbles and determine whether the test can clear the blockage.

[0108] S140: Perform a third cleaning on the stagnant drainage pipeline based on the layered backflushing mode until the preset cleaning requirements are met, and determine that the cleaning of the stagnant drainage pipeline is complete.

[0109] like Figure 6 As shown, in some embodiments of this application, when the stagnant drainage pipeline is cleaned for the third time based on a layered backflushing mode until the preset cleaning requirements are met, the cleaning of the stagnant drainage pipeline is determined to be complete, including:

[0110] The first preset ball valve area is cleaned layer by layer.

[0111] During the layer-by-layer cleaning process, the status of the cutter head is collected in real time. When the status of the cutter head meets the preset state, the rotation speed range of the cutter head is set to 0.3-0.5 rpm.

[0112] In this embodiment, backwashing is performed to flush the sediment near the F32 discharge port. "Layered backwashing" is used to clean the sediment in the chamber layer by layer. During the backwashing process, the mud separation station separates approximately 4 m³ of sludge from the mud-water chamber, reducing resistance within the chamber. By increasing the pressure in the air cushion chamber and mud-water chamber, releasing the pressure of the propulsion cylinder, simultaneously retracting the articulated cylinder, frequently reversing the cutterhead, and initiating the detachment torque, the cutterhead gradually detaches. The cutterhead speed decreases from 0.2 rpm, and the torque gradually decreases from 5.5 MN.m to 1.0 MN.m. To prevent the cutterhead from jamming again, it is kept rotating continuously at 0.3–0.5 rpm during the process of resolving the stagnation issue. Simultaneously, the cutterhead rotation stirs the sediment in the chamber. It was observed that the cutterhead torque exhibits a regular increase and decrease during rotation. Analysis indicates that the residual sediment in the chamber is approximately 2–2.5 m high.

[0113] In this embodiment, the backwash mode needs to be switched through the bypass mode. By switching the flow direction of the inlet / outlet slurry, the stagnant area at the bottom of the air cushion chamber and the blocked pipeline in front of the P2.1 pump are flushed. This mode can achieve continuous flushing until the blocked area is cleared.

[0114] The beneficial effects of the above technical solution are: the construction efficiency of the present invention is high. Compared with the traditional normal pressure opening and pressurized opening construction process, this method does not require ground reinforcement or pressurized operation, which greatly shortens the time required for cleaning sludge in the mud and water chamber, cutting head jamming, and pipeline stagnation.

[0115] In some embodiments of this application, when the stagnant drainage pipeline is cleaned a third time based on a layered backflushing mode until the preset cleaning requirements are met, and it is determined that the cleaning of the stagnant drainage pipeline is complete, the method further includes:

[0116] A dredging tool is installed at the first preset ball valve, and a fourth cleaning is performed on the pipeline in front of the first preset ball valve based on the dredging tool.

[0117] Determine whether the fourth cleaning was successful. If not, increase the rotation speed of the cutter head.

[0118] The fifth cleaning of the stagnant drainage pipeline is performed based on the adjusted cutter head with increased rotation speed and the preset cleaning scheme until the stagnant drainage pipeline meets the preset cleaning requirements, and the cleaning of the stagnant drainage pipeline is determined to be complete.

[0119] In this embodiment, a dredging tool is installed behind F32: a welded skylight opening is used, which is then sealed with a bolted blind flange. A 4-inch ball valve is installed on the blind flange. The plan is to clean the pipeline mechanically and manually by opening the hydraulic ball valve of F32 using the 4-inch ball valve. A series of measures, including manual cleaning, 800-bar high-pressure water jet flushing, high-pressure mud flushing, and reverse circulation flushing, are used to clean the pipeline in front of F32.

[0120] In this embodiment, if the pipeline in front of F32 is not completely cleared, it is determined that the fourth cleaning was unsuccessful. Through a series of measures such as increasing the speed of the cutter head for stirring, manual cleaning, high-pressure water flushing, and repeated forward and reverse circulation flushing, the 4-inch ball valve of the tooling starts to flow a small amount of slurry. After quickly closing the ball valve, forward pumping and discharge of slurry begins, and the pumping pressure is increased. A knocking sound is heard in the discharge pipe, indicating that the pipeline is clear. Subsequently, the flow rate is further increased to wash the chamber. After about 20 to 25 minutes, the knocking sound in the discharge pipe gradually decreases, and the pipeline and chamber are completely cleared.

[0121] The beneficial effects of the above technical solution are: the present invention, in conjunction with auxiliary tooling, effectively solves problems such as sludge in the slurry chamber, cutterhead jamming, and sludge discharge stagnation in the main slurry discharge pipeline during shield tunneling by using manual labor and the addition of dredging equipment. Moreover, the construction is highly safe, with low risk, does not require opening the chamber, has good control over surface settlement, and the construction safety is controllable.

[0122] S150: After the drainage pipeline is cleaned, determine the special measures for long-term shutdown of the slurry shield tunnel and the special measures for stabilizing the excavation face when the slurry shield tunnel is shut down for a long time.

[0123] In this embodiment, specific measures for long-term shutdown of slurry shield tunneling machines are determined:

[0124] 1. After each ring is completed, the washing time should be appropriately increased according to the actual situation, from the original 3-4 minutes washing time after each ring is completed to 5-6 minutes washing time (the time should be appropriately extended as the advancing distance increases). At the same time, in order to ensure the stability of the working face, the circulating washing discharge rate should be controlled at 400-600 m³ / h.

[0125] 2. If the tunnel boring machine is stopped for too long, perform a circulating flushing of the chamber for 4 minutes every hour, while rotating the cutterhead to prevent sludge accumulation and cutterhead jamming.

[0126] 3. If the tunnel boring machine is stopped for more than 2 or 3 hours, advance the machine by about 10 to 20 cm to prevent the tail of the shield from seizing up.

[0127] 4. When signs of stagnation are found in the pipeline or the inlet pressure of the P2.1 pump is too low, the backflushing mode should be activated in time to flush the main slurry discharge pipeline and the slurry inlet of the main slurry discharge pipeline.

[0128] 5. When the shield tail reaches the corresponding cutterhead position for shutdown, increase the synchronous grouting volume (9 cubic meters or more) to fill the formation loss during shutdown and sludge washing.

[0129] 6. Strengthen the management of secondary grouting within 10 rings before and after the shutdown location, and continuously monitor ground settlement in the vicinity of this location.

[0130] In this embodiment, specific measures are determined to stabilize the excavation face when the slurry shield tunneling machine is shut down for an extended period of time:

[0131] 1. Instability of the excavation face

[0132] 1) Correctly calculate and select a reasonable chamber pressure, which is about 1.2 times the static water and soil pressure; the excavation face is stabilized by establishing a mud film with high-quality mud, and the mud-water pressure can be finely adjusted.

[0133] 2) During the cleaning process of sludge in the slurry tank, cutterhead jamming, and stagnant discharge in the main slurry pipeline, fresh slurry should be replenished promptly. Before replenishment, the physical properties of the slurry should be tested, including the density of solid particles, slurry density, plastic viscosity, and particle size distribution. The slurry can penetrate to a certain depth into sandy soil layers to form a mud film, which helps improve the soil's self-supporting capacity, thus enabling the slurry in the slurry tank to effectively support the entire excavation face. For cohesive soils with low permeability, undisturbed soil can be used to prepare the slurry, and the slurry pressure should always maintain a dynamic balance with the soil layers at the excavation face.

[0134] 3) Control the advancing speed, the amount of sludge discharged, and the amount of fresh mud replenishment.

[0135] 4) Conduct timely construction monitoring and provide guidance for construction.

[0136] 2. Shield tail seal failure under high water pressure

[0137] 1) The tunnel boring machine is equipped with four rows of sealing brushes, and an emergency water-stopping device and a row of sealing brushes are added. The last two rows of wire brushes can be replaced after the emergency water-stopping device is activated.

[0138] 2) Strengthen construction process management; for example, if grout leakage occurs at the shield tail, then:

[0139] ① If the leakage at the shield tail is severe, polyurethane is injected into the grouting hole of the nearest segment to the adjacent shield tail to achieve a better water-blocking effect.

[0140] ② While ensuring the stability of the excavation face, appropriately reduce the water pressure at the cut;

[0141] ③ At the tail of the shield inside the tunnel boring machine, use 10 cm thick sponge strips (all the sponge strips are coated with grease) to fill the entire gap between the tunnel segments and the shield shell.

[0142] 3. Grouting for settlement and deformation of buildings and structures

[0143] 1) Grouting hole arrangement: Grouting holes are arranged around the foundation of the building, with a spacing of 1 to 3 meters between grouting pipes, and the hole depth is determined according to the depth of the foundation of the building.

[0144] 2) Grouting grout: Cement-water glass double-liquid grout is used, and the grouting pressure is generally controlled between 0.2 and 1 MPa. In actual construction, the grouting pressure is controlled by inspecting and monitoring ground settlement and building settlement. The grouting pressure near the building foundation is ≤0.2 MPa to prevent the building from heaving.

[0145] like Figure 7 In some embodiments of this application, a tunneling mode is also disclosed. This mode requires switching via a bypass mode, and the required flow rate and pressure are achieved by adjusting the speed of the feed / discharge pumps. This flow rate and pressure are adapted to the advancing speed and geological conditions. In tunneling mode, the feed slurry enters the air cushion chamber and the slurry chamber, flushing the cutterhead, the slurry chamber, and the bottom of the air cushion chamber. Pressure is transmitted through the mud gate. The feed slurry mixes with the excavated soil to form a discharge slurry of appropriate concentration, which is then transported to the surface separation equipment via the discharge pump and pipeline. A diversion rock-fall box is installed at the inlet end of pump P2.1 to screen large-diameter stones, effectively preventing blockage of the mud pump and subsequent pipelines.

[0146] like Figure 8 In some embodiments of this application, a maintenance pressure-maintaining mode is also disclosed. When the operator is maintaining components in the air cushion chamber at atmospheric pressure, the connecting pipeline gate valve is closed, and the air cushion chamber and the mud-water chamber are no longer connected. At this time, the main slurry inlet pipe is used to replenish slurry to ensure the stability of the pressure in the mud-water chamber.

[0147] like Figure 9 In some embodiments of this application, a pipeline extension and slurry collection mode is also disclosed. The pipeline extension mode needs to be switched during machine shutdown. During tunneling, the pipeline needs to be extended periodically using an extension device to lengthen the inlet / outlet slurry pipes, while simultaneously treating the slurry within the slurry pipes. The designed slurry collection system can discharge the slurry from the main inlet and outlet slurry pipes to an air cushion chamber or a temporary slurry storage tank, effectively recycling the slurry and achieving zero leakage and zero pollution.

[0148] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0149] Although the invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, features in the embodiments disclosed herein can be combined with each other in any manner, provided there is no structural conflict. The omission of all such combinations in this specification is merely for brevity and resource conservation. Therefore, the invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0150] It will be understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for treating sediment and pipeline retention in the slurry chamber of an air-cushion balanced slurry shield tunnel, characterized in that, include: Based on the preset sludge discharge analysis method, the corresponding sludge discharge pipeline is determined, and the sludge discharge pipeline is investigated and analyzed. The sludge discharge pipeline is the pipeline between the first preset ball valve on the main slurry discharge pipeline and the slurry discharge pipeline of the mud and water silo. The investigation and analysis includes building investigation and geological supplementary exploration. Based on the investigation and analysis results, a mud circulation system is set up, and the stagnant drainage pipeline is cleaned for the first time according to the mud circulation system; The first cleaning is monitored in real time. When the first preset ball valve does not meet the preset cleaning conditions, the first preset ball valve is closed, and the first preset ball valve is cleaned a second time based on the preset cleaning plan. The stagnant drainage pipeline is cleaned a third time based on the layered backflushing mode until the preset cleaning requirements are met, and the cleaning of the stagnant drainage pipeline is determined to be completed. After the drainage pipeline is cleaned, special measures for long-term shutdown of slurry shield tunneling machine and special measures for stabilizing the excavation face during long-term shutdown of slurry shield tunneling machine are determined. When designing a mud circulation system based on the results of the investigation and analysis, the following should be included: Obtain the current tunneling speed and set the slurry flow rate of the slurry pump in the mud circulation system according to the tunneling speed; The discharge flow rate of the slurry pump in the mud circulation system is set according to the tunneling speed; The slurry inlet power and slurry outlet power of the slurry inlet pump and the slurry outlet pump are respectively set based on the slurry inlet flow rate and the slurry outlet flow rate; The mud circulation system is configured based on the mud inlet flow rate, the mud outlet flow rate, the mud inlet power, and the mud outlet power. Setting the slurry flow rate of the slurry pump in the mud circulation system according to the tunneling speed includes: A first preset tunneling speed and a second preset tunneling speed are preset. The slurry flow rate of the slurry pump in the mud circulation system is set according to the tunneling speed, the first preset tunneling speed, and the second preset tunneling speed. When the tunneling speed is less than the first preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to P1. When the tunneling speed is greater than or equal to the first preset tunneling speed and the tunneling speed is less than the second preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to P1. When the tunneling speed is greater than or equal to the second preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to P3. When setting the discharge flow rate of the slurry pump in the mud circulation system according to the tunneling speed, the following is included: The discharge flow rate of the slurry pump in the mud circulation system is set according to the tunneling speed, the first preset tunneling speed, and the second preset tunneling speed; When the tunneling speed is less than the first preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to W1. When the tunneling speed is greater than or equal to the first preset tunneling speed and the tunneling speed is less than the second preset tunneling speed, the slurry inlet flow rate of the slurry pump in the mud circulation system is set to W2. When the tunneling speed is greater than or equal to the second preset tunneling speed, the slurry flow rate of the slurry pump in the mud circulation system is set to W3.

2. The method for treating sediment and pipeline retention in the slurry chamber of an air-cushion balanced slurry shield tunnel as described in claim 1, characterized in that, Real-time monitoring of the first cleaning process includes: The flushing pressure of the area where the first preset ball valve is located is obtained, and the relationship between the flushing pressure and the preset flushing pressure is used to determine whether the area where the first preset ball valve is located meets the preset cleaning conditions. When the flushing pressure is greater than the preset flushing pressure, it is determined that the first preset ball valve does not meet the preset cleaning conditions. When the flushing pressure is less than or equal to the preset flushing pressure, it is determined that the first preset ball valve meets the preset cleaning conditions.

3. The method for treating sediment and pipeline retention in the slurry chamber of an air-cushion balanced slurry shield tunneling machine according to claim 1, characterized in that, When performing a second cleaning on the first preset ball valve based on a preset cleaning plan, the following steps are included: Close the first preset ball valve and open the pipeline behind the first preset ball valve; Open the observation ball valve between the first preset ball valve and the manual knife switch; High-pressure mud at a preset pressure is injected into the observation ball valve for backflushing, and it is determined whether the second cleaning is successful. If not, the stagnant pipeline is cleaned a third time based on the layered backflushing mode.

4. The method for treating sediment and pipeline retention in the slurry chamber of an air-cushion balanced slurry shield tunneling machine according to claim 1, characterized in that, When the stagnant drainage pipeline is cleaned for the third time based on a stratified backflushing mode until the preset cleaning requirements are met, the cleaning of the stagnant drainage pipeline is considered complete, including: The first preset ball valve area is cleaned layer by layer. During the layer-by-layer cleaning process, the status of the cutter head is collected in real time. When the status of the cutter head meets the preset state, the rotation speed range of the cutter head is set to 0.3-0.5 rpm.

5. The method for treating sediment and pipeline retention in the slurry chamber of an air-cushion balanced slurry shield tunnel as described in claim 4, characterized in that, When performing a third cleaning of the stagnant drainage pipeline based on a stratified backflushing mode until the preset cleaning requirements are met, and when it is determined that the cleaning of the stagnant drainage pipeline is complete, the process further includes: A dredging tool is installed at the first preset ball valve, and a fourth cleaning is performed on the pipeline in front of the first preset ball valve based on the dredging tool. Determine whether the fourth cleaning was successful. If not, increase the rotation speed of the cutter head. The fifth cleaning of the stagnant drainage pipeline is performed based on the adjusted cutter head with increased rotation speed and the preset cleaning scheme until the stagnant drainage pipeline meets the preset cleaning requirements, and the cleaning of the stagnant drainage pipeline is determined to be complete.

Images