Dual-mode shield machine with adjustable density, mud, water and earth pressure

Abstract

The present invention discloses a dual-mode shield machine with adjustable density, which has a mud-water working state, an earth pressure working state, and an adjustable density working state. When it is in the adjustable density working state, the mud-water bin is connected to the air cushion bin, the slurry inlet pipeline and the slurry replenishment pipeline are opened, the conveying device is separated from the outlet of the screw machine, and the outlet of the screw machine is connected to the mud box, the density measurement pipeline is opened and the mud density in the mud-water bin is measured, the measured value is compared with the standard range, and the input amount of the slurry inlet pipeline and the slurry replenishment pipeline and the output amount of the screw machine are adjusted according to the comparison result, so that the mud density in the mud-water bin is kept within the standard range. By adopting the above technical scheme, the present invention switches the mud-water and earth pressure modes for different strata geology, especially under the condition that the pressure control cannot form an effective mud film under the extremely special geology such as karst caves and soil caves, the density pressure gradient control is used to replace the traditional pressure control, so as to achieve efficient excavation under complex geology.

Description

Technical Field

[0001] The invention relates to a density-adjustable mud-water-earth pressure dual-mode shield machine, which is suitable for use in areas with complex geological formations containing special geological features such as karst caves and soil caves, and belongs to the field of shield construction. Background Art

[0002] Shield machines have become one of the core components of shield construction in today's underground tunnel construction. The mainstream ones are earth pressure balance shield machines and slurry balance shield machines. Currently, most construction projects use single-mode shield machines in earth pressure mode or slurry mode based on parameters such as stratum moisture content. This type of shield machine cannot switch modes.

[0003] The above two single-mode shield machines will encounter difficulties in excavating in areas with greatly changing geological conditions, and will encounter difficulties in excavating in geologically complex sections, which will greatly increase the construction period and cost, and may even cause dangers such as landslides, posing safety hazards to tunnel construction and safe construction.

[0004] In response to the above problems, single-mode shield machines have gradually moved towards the research and development of earth pressure and mud water dual-mode shield machines. At present, cases of shield machines combining earth pressure and mud water have gradually appeared in the industry. For example, the invention patent with application number 2019106754166 discloses a mud water and earth pressure dual-mode shield machine. However, this type of dual-mode shield machine cannot solve the problem that when encountering special geological conditions such as karst caves, the mud film in front of the cutter head is destroyed, the mud escapes, and the pressure cannot be controlled to maintain pressure. Summary of the invention

[0005] In order to solve the above problems, the object of the present invention is to provide a mud-water-earth pressure dual-mode shield machine with adjustable density.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is: a dual-mode shield machine with adjustable density of mud, water and earth pressure, including a shield body, an air cushion chamber arranged in front of the shield body, a mud and water chamber arranged in front of the air cushion chamber, a cutter head arranged in front of the mud and water chamber, a slurry inlet pipeline connected to the mud and water chamber at the output end, a slurry supply pipeline connected to the slurry inlet pipeline at the input end and connected to the air cushion chamber at the output end, a screw machine with an inlet connected to the bottom of the mud and water chamber, a mud box detachably connected to the outlet of the screw machine, a slurry discharge pipeline connected to the mud box at the input end, a conveying device detachably connected to the outlet of the screw machine and used to convey slag, the mud and water chamber and the air cushion chamber are blocked and connected to each other, the shield machine has a mud and water working state and an earth pressure working state,

[0007] The shield machine also includes a density measuring pipeline whose input and output ends are both connected to the mud and water bin and is used to measure the density of the mud in the mud and water bin, and a mud injection pipeline whose output end is connected to the mud and water bin and is used to inject high-density mud into the mud and water bin. The shield machine also has an adjustable density working state. When the shield machine is in the adjustable density working state, the mud and water bin is connected to the air cushion bin, the slurry inlet pipeline and the slurry replenishment pipeline are opened, the conveying device is separated from the outlet of the screw machine and the outlet of the screw machine is connected to the mud box, the density measuring pipeline is opened and measures the density of the mud in the mud and water bin, compares the measured value with the standard range, and adjusts the input amount of the mud injection pipeline and the slurry replenishment pipeline and the output amount of the screw machine according to the comparison result, so that the mud density in the mud and water bin is kept within the standard range.

[0008] Furthermore, when the shield machine is in a mud and water working state, the slurry inlet pipeline and the grouting pipeline are opened, the conveying device is separated from the outlet of the screw machine, and the outlet of the screw machine is connected to the mud box; when the shield machine is in an earth pressure working state, the mud and water bin and the air cushion bin are blocked, the slurry inlet pipeline and the grouting pipeline are closed, the mud box is separated from the outlet of the screw machine, and the outlet of the screw machine is connected to the conveying device; when the shield machine is in a mud and water working state and an earth pressure working state, the density measurement pipeline is closed.

[0009] Furthermore, the density of the high-density mud is greater than the density of the mud in the mud inlet pipeline.

[0010] Furthermore, the density measuring pipeline includes a pipeline, a density measuring circulation pump capable of circulating the mud in the mud and water tank through the pipeline, and a density meter for measuring the density of the mud in the pipeline.

[0011] Furthermore, the shield machine also includes a bypass pipeline capable of discharging the mud in the mud and water bin when the screw machine is not working, the input end of the bypass pipeline is connected to the mud and water bin and the output end is connected to the slurry discharge pipeline.

[0012] Furthermore, the shield machine also includes a flushing pipeline whose input end is connected to the slurry inlet pipeline and whose output end is connected to the central part of the cutter disc and the screw machine.

[0013] Furthermore, the shield machine also includes an anti-delay pipeline whose input end is connected to the lower part of the mud and water bin and the lower part of the air cushion bin and whose output end is connected to the mud box, and a dilution pipeline whose input end is connected to the slurry inlet pipeline and whose output end is connected to the mud box.

[0014] Furthermore, a crusher capable of crushing large pieces of solid matter is provided at the outlet of the screw machine.

[0015] Furthermore, a connecting pipe is connected between the mud and water bin and the air cushion bin, and a valve that can be opened and closed is provided on the connecting pipe.

[0016] Furthermore, the shield machine also includes an air pressure-maintaining pipeline whose output end is connected to the upper part of the air cushion chamber to transport gas into the air cushion chamber to maintain pressure balance in the air cushion chamber.

[0017] By adopting the above technical scheme, the dual-mode shield machine with adjustable density of mud, water and earth pressure is effectively combined on the basis of the original earth pressure balance system and the mud and water balance system, and the mud and water and earth pressure modes are switched according to different geological formations. Especially under the conditions of extremely special geological conditions such as karst caves and soil caves where effective mud film cannot be formed and pressure control is required, density control is carried out by comparing the measured value of the density measuring pipeline with the standard range provided by the ground, and density pressure gradient control is used instead of traditional pressure control to achieve efficient excavation under complex geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attached Figure 1 It is a schematic diagram of the principle of a slurry-water and earth pressure dual-mode shield machine with adjustable density in one embodiment of the present invention in a slurry-water working state and an adjustable density working state;

[0019] Attached Figure 2 For attachment Figure 1 The schematic diagram of the principle of the adjustable density mud-water earth pressure dual-mode shield machine in the earth pressure working state.

[0020] The numbers in the figure are:

[0021] 1. Shield; 2. Air cushion bin; 3. Mud and water bin; 4. Screw machine; 5. Conveying device; 6. Mud box; 7. Slurry discharge pipeline; 8. Slurry inlet pipeline; 9. Slurry replenishment pipeline; 91. Slurry replenishment circulation pump; 10. Density measurement pipeline; 101. Density measurement circulation pump; 11. Flushing pipeline; 111. Flushing circulation pump; 12. Anti-stagnation pipeline; 121. Anti-stagnation circulation pump; 13. Mud injection pipeline; 14. Air pressure maintenance pipeline; 15. Crusher; 16. Bypass pipeline; 17. Connecting pipe; 18. Dilution pipeline. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art.

[0023] Reference Figure 1 To Attachment Figure 2The adjustable density mud, water and earth pressure dual-mode shield machine in this embodiment includes a shield body 1, an air cushion chamber 2 arranged in front of the shield body 1, a mud and water chamber 3 arranged in front of the air cushion chamber 2, a cutter head arranged in front of the mud and water chamber 3 (not shown in the drawings), a slurry inlet pipeline 8 connected to the mud and water chamber 3 at the output end, a slurry supply pipeline 9 connected to the slurry inlet pipeline 8 at the input end and connected to the air cushion chamber 2 at the output end, a screw machine 4 connected to the bottom of the mud and water chamber 3 at the inlet, a mud box 6 detachably connected to the outlet of the screw machine 4, a slurry discharge pipeline 7 connected to the mud box 6 at the input end, and a conveying device 5 detachably connected to the outlet of the screw machine 4 and used for conveying slag.

[0024] The mud and water tank 3 and the air cushion tank 2 are connected in a blockable manner. Specifically, a connecting pipe 17 is connected between the mud and water tank 3 and the air cushion tank 2. A valve that can be opened and closed is provided on the connecting pipe 17. The connection and blocking between the mud and water tank 3 and the air cushion tank 2 are achieved by opening and closing the valve. More specifically, the connecting pipe is connected to the upper part of the mud and water tank 3 and the upper part of the air cushion tank 2.

[0025] The shield machine also includes a density measuring pipeline 10 whose input and output ends are both connected to the mud and water bin 3 and is used to measure the density of the mud in the mud and water bin 3. Specifically, the density measuring pipeline 10 includes a pipeline (not shown in the drawings), a density measuring circulation pump 101 that can circulate the mud in the mud and water bin 3 through the pipeline, and a densitometer (not shown in the drawings) that measures the density of the mud in the pipeline.

[0026] The shield machine also includes a mud injection pipeline 13 whose output end is connected to the mud and water bin 3. When the shield machine is in an adjustable density working state, the pre-mixed high-density mud is injected into the mud and water bin 3 through the mud injection pipeline 13. The density of the high-density mud is greater than the mud in the slurry inlet pipeline 8. When the shield machine is in the mud and water working state, bentonite is also injected into the front of the cutter head through the mud injection pipeline 13 to form an effective mud film.

[0027] The shield machine has a muddy working state, an earth pressure working state, and an adjustable density working state based on the muddy working state. When the shield machine is in the muddy working state, the slurry inlet pipeline 8 and the slurry replenishment pipeline 9 are opened, the conveying device 5 is disconnected from the outlet of the screw machine 4, and the outlet of the screw machine 4 is connected to the slurry box 6. When the shield machine is in the earth pressure working state, the mud water bin 3 and the air cushion bin 2 are blocked, the slurry inlet pipeline 8 and the slurry replenishment pipeline 9 are closed, the slurry box 6 is disconnected from the outlet of the screw machine, and the outlet of the screw machine 4 is connected to the conveying device 5.

[0028] The adjustable density working state is a working state of the shield machine based on the muddy and water working state, which is suitable for complex bottom layers such as those containing caves. When the shield machine is in the adjustable density working state, on the basis of the connection structure that maintains the muddy and water working state (that is, the muddy and water tank 3 is connected to the air cushion tank 2, the slurry inlet pipeline 8 and the slurry replenishment pipeline 9 are opened, the conveying device 5 is separated from the outlet of the screw machine 4, and the outlet of the screw machine 4 is connected to the mud box 6), the slurry inlet pipeline 8 is opened, the density measurement pipeline 10 is opened and the mud density in the muddy and water tank 3 is measured, and the measured value is compared with the standard range, and the input amount of the mud injection pipeline 13 and the slurry replenishment pipeline 9 and the output amount of the screw machine 4 are adjusted according to the comparison result, so that the mud density in the muddy and water tank 3 is kept within the standard range. When the shield machine is in the muddy and water working state and the earth pressure working state, since there is no need to monitor the density, the density measurement pipeline 10 is closed.

[0029] The above-mentioned grouting pipeline 9 includes a grouting circulation pump 91. When the grouting pipeline 9 is opened, the slurry in the grouting pipeline 8 is pumped into the air cushion bin 2 for grouting under the action of the grouting circulation pump 91. In the adjustable density working state, when the pressure in the mud and water bin 3 is lower than that in the air cushion bin 2, the slurry in the air cushion bin 2 will enter the mud and water bin 2, and the liquid level in the air cushion bin 2 will drop. Then, the grouting of the air cushion bin 2 is performed to keep the liquid level in the air cushion bin 2 stable. At the same time, the pressure of the tunnel face can be fine-tuned in combination with the air pressure maintenance system described below.

[0030] In a more preferred embodiment, the shield machine further comprises an air pressure maintaining pipeline 14 whose output end is connected to the upper part of the air cushion chamber 2 to transport gas into the air cushion chamber 2 so as to maintain pressure balance in the air cushion chamber 2 .

[0031] In a more preferred embodiment, the shield machine further comprises a flushing pipeline 11, the input end of which is connected to the slurry inlet pipeline 8 and the output end of which is connected to the center of the cutter disc and the screw machine. The flushing pipeline 11 comprises a flushing circulation pump 111, under the action of the flushing circulation pump 111, the slurry in the slurry inlet pipeline 8 is transported to the center of the cutter disc and the screw machine, so as to perform high-pressure flushing on the center of the cutter disc and the screw machine.

[0032] In a more preferred embodiment, the shield machine also includes an anti-delay drainage pipeline 12 whose input end is connected to the lower part of the mud and water bin 3 and the lower part of the air cushion bin 2 and whose output end is connected to the mud box 6. The anti-delay drainage pipeline 12 includes an anti-delay drainage circulation pump 121. In the mud and water working state and the adjustable density working state, under the action of the anti-delay drainage circulation pump 121, the sludge slurry accumulated in the air cushion bin 2 and the mud and water bin 3 is transported to the mud box 6, thereby solving the problem of high-density mud deposition at the bottom of the air cushion bin 2 and the mud and water bin 3. There will be a dilution pipeline 18 on the slurry inlet pipeline 8 connected to the mud box 6. The input end of the dilution pipeline 18 is connected to the slurry inlet pipeline 8 and the output end is connected to the mud box 6. The relatively diluted slurry inlet mud is transported to the mud box 6, and the mud box 6 is flushed and diluted, so that the high-density mud is fully flushed and diluted in the mud box 6 and then discharged from the slurry drainage pipeline 7. When the shield machine is switched to the earth pressure working state, the dilution pipeline 18 will be closed or removed together with the mud box 6 .

[0033] In a more preferred embodiment, a crusher 15 is provided at the outlet of the screw machine 4, which can crush large solid materials. The crusher 15 is used in muddy water working state, preferably, in the earth pressure working state, the crusher 15 is removed.

[0034] In a more preferred embodiment, the shield machine also includes a bypass pipe 16 whose input end is connected to the mud and water bin 3 and whose output end is connected to the slurry discharge pipe 7. The bypass pipe 16 can output the mud in the mud and water bin 3 when the screw machine 4 is not working. The bypass pipe 16 is mainly used for replacing mud in the mud and water bin 3 when the shield machine switches from the mud and water working state to the earth pressure working state.

[0035] Working principle:

[0036] When the shield machine switches from the earth pressure working state to the mud and water working state for excavation, first stop excavation, the cutter head rotates slowly, and bentonite is injected into the front of the cutter head through the mud injection pipeline 13 to form an effective mud film in front of the cutter head. Mud is added to the mud and water bin 3 through the slurry inlet pipeline 8. At the same time, under the action of the slurry circulation pump 91, the slurry pipeline 9 slurries the air cushion bin 2 to the half position. During this process, the screw machine 4 maintains the slag discharge state to discharge the slag at the bottom of the mud and water bin 3. When the pressure and slag discharge are When the state changes significantly in the screw machine 4, that is, the soil in the screw machine 4 obviously changes into mud, the gate at the entrance of the screw machine 4 is closed, the conveying device 5 is removed, the mud box 14, the crusher 15 and the slurry discharge pipeline 7 are installed, and after the installation is completed, the gate at the entrance of the screw machine 4 is opened, the slurry discharge pipeline 7 is started, the connecting pipe 17 is connected, and the air pressure maintaining pipeline 7 is opened. The mud mixed with sand and gravel output by the screw machine 4 is crushed by the crusher 15 and then diluted in the mud box 14, and then transported out of the tunnel through the slurry discharge pipeline 7.

[0037] When the shield machine is switched from the mud-water working state to the earth pressure working state for excavation, first stop the slurry feeding pipeline 8, stop the screw machine 4 from rotating, close the screw machine 4 gate, the air pressure system 14 and the connecting pipe 17, open the bypass valve group 16, and the shield machine still keeps slowly excavating. As the slag accumulates, the mud in the mud-water bin 3 passes through the bypass pipe 16 to the slurry discharge pipe 7 and is transported out of the tunnel. When the mud in the mud-water bin 3 is replaced (i.e., the mud is discharged and the mud-water bin 3 is filled with slag), remove the mud box 6, the crusher 15 and the slurry discharge pipe 7, replace it with the conveying device 5, rotate the screw machine 4 forward and reverse, discharge large particles, and gradually increase the gate opening until it is switched to the normal earth pressure working state for excavation.

[0038] When the shield machine is switched from the mud and water working state to the adjustable density working state for excavation, since the excavation stratum contains caves at this time, the mud in the mud and water tank 3 escapes and the pressure changes significantly. At this time, the mud and water tank 3 is filled with high-density mud through the mud injection pipeline 13, and the air cushion tank 2 is filled with mud through the grouting pipeline 9. The density measurement pipeline 10 is opened to detect the mud density in the mud and water tank 3, and the detection value is compared with the density standard range provided by the ground for reference. According to the comparison result, the slurry injection amount of the mud injection pipeline 13 and the slurry discharge amount of the screw machine 4 are adjusted (the slurry discharge amount is achieved by adjusting the speed of the screw machine 4) to stabilize the density of the mud and water tank 3 within the standard range, and the face pressure is controlled to remain stable through the density pressure gradient. The mud mixed with sand and gravel discharged from the mud and water tank 3 is crushed by the crusher 15 and then diluted in the mud box 6, and then transported out of the tunnel through the slurry discharge pipeline 7.

[0039] The density-adjustable mud-water-earth pressure dual-mode shield machine in this embodiment is effectively combined on the basis of the original earth pressure balance system and the mud-water balance system, and switches between mud-water and earth pressure modes according to different geological formations. Especially under conditions where extremely special geological conditions such as karst caves and soil caves cannot form an effective mud film and pressure control is required, density control is performed by comparing the measured value of the density measuring pipeline with the standard range provided by the ground, and density pressure gradient control replaces traditional pressure control, thereby achieving efficient excavation under complex geological conditions.

[0040] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A dual-mode shield machine with adjustable density, comprising a shield body (1), an air cushion chamber (2) arranged in front of the shield body (1), a mud and water chamber (3) arranged in front of the air cushion chamber (2), a cutter head arranged in front of the mud and water chamber (3), a slurry inlet pipeline (8) connected to the mud and water chamber (3) at its output end, a slurry supply pipeline (9) connected to the slurry inlet pipeline (8) at its input end and connected to the air cushion chamber (2) at its output end, a screw machine (4) connected to the bottom of the mud and water chamber (3) at its inlet, a mud box (6) detachably connected to the outlet of the screw machine (4), a slurry discharge pipeline (7) connected to the mud box (6) at its input end, and a conveying device (5) detachably connected to the outlet of the screw machine (4) and used for conveying slag, the mud and water chamber (3) and the air cushion chamber (2) being blockably connected to each other, the shield machine having a mud and water working state and an earth pressure working state, and characterized in that: The shield machine further comprises a density measuring pipeline (10) whose input end and output end are both connected to the mud and water bin (3) and used to measure the density of mud in the mud and water bin (3), and a mud injection pipeline (13) whose output end is connected to the mud and water bin (3) and used to inject high-density mud into the mud and water bin (3). The shield machine also has an adjustable density working state. When the shield machine is in the adjustable density working state, the mud and water bin (3) is connected to the air cushion bin (2), and the slurry inlet pipeline (8), the slurry replenishing pipeline (9), The mud adding and injection pipeline (13) is opened, the conveying device (5) is disconnected from the outlet of the screw machine (4) and the outlet of the screw machine (4) is connected to the mud box (6), the density measuring pipeline (10) is opened and measures the density of the mud in the mud and water bin (3), compares the measured value with the standard range, and adjusts the input amount of the mud adding and injection pipeline (13) and the grouting pipeline (9) and the output amount of the screw machine (4) according to the comparison result, so that the mud density in the mud and water bin (3) is maintained within the standard range.

2. The density-adjustable mud-water-earth-pressure dual-mode shield machine according to claim 1, characterized in that: When the shield machine is in the mud and water working state, the slurry inlet pipeline (8) and the slurry replenishing pipeline (9) are opened, the conveying device (5) is disconnected from the outlet of the screw machine (4), and the outlet of the screw machine (4) is connected to the slurry box (6); when the shield machine is in the earth pressure working state, the mud and water bin (3) and the air cushion bin (2) are blocked, the slurry inlet pipeline (8) and the slurry replenishing pipeline (9) are closed, the slurry box (6) is disconnected from the outlet of the screw machine, and the outlet of the screw machine (4) is connected to the conveying device (5); when the shield machine is in the mud and water working state and the earth pressure working state, the density measuring pipeline (10) is closed.

3. The density-adjustable mud-water-earth-pressure dual-mode shield machine according to claim 1, characterized in that: The density of the high-density mud is greater than the density of the mud in the mud inlet pipeline (8).

4. The density-adjustable mud-water-earth-pressure dual-mode shield machine according to claim 1, characterized in that: The density measurement pipeline (10) comprises a pipeline, a density measurement circulation pump (101) capable of circulating the mud in the mud-water bin (3) through the pipeline, and a densitometer for measuring the density of the mud in the pipeline.

5. The density-adjustable mud-water-earth-pressure dual-mode shield machine according to claim 1, characterized in that: It also includes a bypass pipeline (16) capable of discharging the mud in the mud and water bin (3) when the screw machine (4) is not working, wherein the input end of the bypass pipeline (16) is connected to the mud and water bin (3) and the output end is connected to the mud discharge pipeline (7).

6. The density-adjustable mud-water-earth-pressure dual-mode shield machine according to claim 1, characterized in that: It also comprises a flushing pipeline (11) whose input end is connected to the slurry inlet pipeline (8) and whose output end is connected to the central part of the cutter disc and the screw machine (4).

7. The density-adjustable mud-water-earth-pressure dual-mode shield machine according to claim 1, characterized in that: It also includes an anti-delay pipeline (12) whose input end is connected to the lower part of the mud and water tank (3) and the lower part of the air cushion tank (2) and whose output end is connected to the mud box (6), and a dilution pipeline (18) whose input end is connected to the slurry inlet pipeline (8) and whose output end is connected to the mud box (6).

8. The density-adjustable mud-water-earth-pressure dual-mode shield machine according to claim 1, characterized in that: A crusher (15) capable of crushing large pieces of solid matter is provided at the outlet of the screw conveyor (4).

9. The density-adjustable mud-water-earth-pressure dual-mode shield machine according to claim 1, characterized in that: A connecting pipe (17) is connected between the mud and water bin (3) and the air cushion bin (2), and a valve that can be opened and closed is provided on the connecting pipe (17).

10. The density-adjustable mud-water-earth-pressure dual-mode shield machine according to claim 1, characterized in that: It also comprises an air pressure-maintaining pipeline (14) whose output end is connected to the upper part of the air cushion chamber (2) so as to transport gas into the air cushion chamber (2) so as to maintain pressure balance in the air cushion chamber (2).

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