A model test device for slurry balance shield

Abstract

The application relates to the field of shield model testing and monitoring, and particularly discloses a slurry balance shield model testing device, which comprises a soil bin, a counterforce frame fixed to one side of the soil bin, a moving cabin capable of reciprocating sliding between the soil bin and the counterforce frame, and a multi-source sensor system. The moving cabin comprises a slurry cabin and an air cushion cabin which are independent of each other. A cutter head is arranged at the front end of the slurry cabin. A centrifugal pump is connected in series to a slurry inlet pipeline and a slurry discharge pipeline of the slurry cabin. The multi-source sensor system comprises a torque sensor connected to the cutter head, a pressure sensor connected to the slurry cabin, a pump body acceleration sensor connected to the centrifugal pump, and a condenser microphone arranged in the soil bin and facing a tunneling face. The device can simulate the coupling process of shield tunneling and slurry circulation under laboratory conditions in a high simulation mode, and can realize the synchronous and real-time collection of key multi-source physical parameters of cabin pressure, cutter head load, pumping vibration and tunneling face acoustic signals, thereby providing technical support for in-depth research on the evolution mechanism of complex working conditions such as slurry balance shield lagging.

Description

Technical Field

[0001] This invention relates to the field of shield tunneling model testing and monitoring, and in particular to a slurry balance shield tunneling model testing device. Background Technology

[0002] Slurry-balanced shield tunneling relies on the pressure in the slurry chamber to maintain the stability of the excavation face, and completes the transportation of excavated soil and the renewal of slurry through the circulation of slurry intake and discharge. Among them, the slurry discharge system plays a crucial role in timely discharging the slurry containing excavated soil from the excavation chamber and maintaining the stability of the flow and pressure within the chamber. However, in strata with cohesive soil, high fine particle content, or strong agglomeration, the excavated soil easily forms high-viscosity flocs or mud cakes with the slurry, leading to solid phase enrichment and significantly increased flow resistance in the slurry discharge channel. This results in phenomena such as delayed excavated soil discharge, insufficient discharge volume, and discontinuous slurry discharge, known as "stagnant discharge."

[0003] When sludge buildup occurs, the excavated soil cannot be discharged from the excavation chamber in a timely manner, leading to an increase in the concentration of sludge-containing slurry and a corresponding increase in pressure loss in the circulation loop. This manifests as increased load on the slurry pump, decreased pumping efficiency, and even abnormal pump vibration. Simultaneously, the accumulation of sludge in the chamber alters the pressure distribution and flow pattern within the slurry chamber, creating localized high-pressure zones, exacerbating pressure fluctuations, and increasing the cutterhead load. In severe cases, sludge buildup can evolve into a complex problem involving blockages in the slurry discharge pipeline, pumping system, and thickening of the mud cake in the excavation area. These issues not only affect tunneling efficiency and increase energy consumption but also weaken the ability to control surface pressure, increasing construction risks and the frequency of downtime for sludge removal.

[0004] Existing research and experimental platforms still have shortcomings: On the one hand, some indoor model devices cannot simultaneously reproduce the coupled process of "cutterhead cutting - propulsion tunneling - chamber pressure balancing - slurry supply and discharge circulation - muck transportation", especially lacking controllable induction and repeatable verification methods for slurry discharge lag and muck deposition accumulation; on the other hand, monitoring methods are mostly concentrated on single parameters or macroscopic phenomena, lacking synchronous observation of chamber pressure distribution, cutterhead load and pumping status, and even more so lacking real-time capture of tunnel face morphology and soil disturbance process, making it difficult to establish and verify the slurry discharge formation mechanism, development path and early warning criteria.

[0005] Therefore, it is necessary to propose a slurry balance shield tunnel model test device that can stably reproduce the stagnant drainage condition under laboratory conditions and support multi-source monitoring and intelligent judgment. Summary of the Invention

[0006] The purpose of this invention is to provide a slurry balance shield tunneling model test device, aiming to solve the problems in existing technologies where it is difficult to controllably reproduce the slurry balance shield tunneling process under laboratory conditions, and where there is insufficient synchronous monitoring of key parameters and observation of the tunnel face status during the slurry evolution process. This device enables continuous tunneling simulation of "cutterhead rotation cutting + axial propulsion" under slurry circulation, pressure stabilization, and slag removal transport conditions. It also allows for synchronous acquisition of data on chamber pressure, cutterhead load, pumping vibration, and changes in tunnel face morphology, thereby outputting slurry / blockage risk assessment results or early warning signals.

[0007] To achieve the above objectives, the present invention provides the following solution: a slurry balance shield tunneling model test device, comprising: a soil chamber filled with soil, wherein a reaction frame is fixedly mounted on one side of the soil chamber; a movable chamber that reciprocates between the soil chamber and the reaction frame, including an independent slurry chamber and an air cushion chamber; a cutterhead rotatably connected to the front end of the slurry chamber facing the soil chamber and driven by a motor; a slurry inlet pipe and a slurry outlet pipe connected to the slurry chamber, wherein a centrifugal pump is connected in series on both the slurry inlet pipe and the slurry outlet pipe; and a multi-source sensor system, including multiple pressure sensors, a torque sensor, a pump body acceleration sensor, and a capacitive microphone, wherein the torque sensor is connected to the cutterhead, the pressure sensor is connected to the slurry chamber, the pump body acceleration sensor is connected to the centrifugal pump, and the capacitive microphone is disposed in the soil chamber and faces the tunneling face or the soil disturbance area; The torque sensor is used to collect the cutterhead torque signal, the pressure sensor is used to collect the slurry chamber pressure signal, the pump body acceleration sensor is used to collect the centrifugal pump vibration signal, and the capacitive microphone is set in the soil chamber and faces the tunneling face or the soil disturbance area to collect the acoustic signals generated during the tunneling process.

[0008] Optionally, the multi-source sensor system further includes a triaxial accelerometer mounted on the cutterhead, which is used to collect vibration signals generated when the cutterhead cuts the soil.

[0009] Optionally, the torque sensor is located at the cutter head drive shaft and at the drive shaft between the motor output end and the cutter head.

[0010] Optionally, the pressure sensors are positioned at different heights in the mud-water chamber to form a pressure distribution and to calculate the pressure gradient or pressure difference.

[0011] Optionally, a guide rail is laid between the soil chamber and the reaction frame, the mobile cabin is slidably connected to the guide rail by pulleys, and a jack is connected between the mobile cabin and the reaction frame.

[0012] Optionally, a pressure sensor is also installed on the hydraulic circuit of the jack.

[0013] Optionally, one end of the slurry inlet pipe is connected to the slurry supply port of the mud-water chamber, and the other end is connected to an external slurry supply system. A second centrifugal pump is connected in series on the slurry inlet pipe. One end of the slurry discharge pipe is connected to the slurry discharge port of the mud-water chamber, and the other end is connected to a slag collection box. A first centrifugal pump is connected in series on the slurry discharge pipe.

[0014] Optionally, the pump body acceleration sensor is disposed at the pump body or bearing housing of the first centrifugal pump and the second centrifugal pump.

[0015] Optionally, the slag collection box includes a settling chamber and a filter section.

[0016] Optionally, the slurry balance shield tunneling model test device further includes a control center, which includes a test control system and a data processing system. The test control system centrally controls the start and stop of the motor and its speed, the propulsion speed and thrust of the jack, and the start and stop and frequency of the first centrifugal pump and the second centrifugal pump. The data processing system receives and processes real-time data from the multi-source sensor system.

[0017] Compared with the prior art, the present invention discloses at least the following beneficial effects: This invention constructs a test platform capable of fully simulating the multi-physics coupling effects of "cutterhead rotation cutting - axial propulsion - chamber pressure balance - mud circulation" during slurry balance shield tunneling in a laboratory environment by integrating a soil chamber and reaction frame, a movable slurry chamber and air cushion chamber, a cutterhead drive mechanism, independent slurry inlet and outlet circulation pipelines, and a multi-source sensor system. This device structure can directly achieve high-fidelity simulation of the tunneling process and precise independent control of slurry pressure and flow rate, thereby stably reproducing and actively inducing typical engineering problems such as slurry blockage under controlled conditions. Simultaneously, relying on multiple types of sensors deployed at key locations, it can synchronously and in real-time collect chamber pressure distribution, cutterhead load torque, pumping system vibration, and acoustic signals from the tunnel face. For the first time, it achieves comprehensive perception and correlation analysis of multi-dimensional physical parameters during the occurrence and development of slurry blockage at the model scale, providing a direct, rich, and reliable experimental data foundation for revealing the slurry blockage mechanism and establishing early warning criteria. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1This is a schematic diagram of the structure of the slurry balance shield tunneling model test device provided in an embodiment of the present invention; Attached reference numerals: 1. Soil chamber; 2. Soil; 3. Guide rail; 4. Pulley; 5. Slurry chamber; 6. Cutterhead; 7. Air cushion chamber; 8. Cutterhead main bearing; 9. Slurry discharge pipeline; 10. First centrifugal pump; 11. Slag collection box; 12. Reaction frame; 13. Slurry inlet pipeline; 14. Jack; 15. Water stop valve; 16. Motor; 17. Torque sensor; 18. Pressure sensor; 19. Pump body acceleration sensor; 20. Second centrifugal pump; 21. Triaxial acceleration sensor; 22. Capacitive microphone; 23. Control center. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Reference Figure 1 As shown, this embodiment provides a slurry balance shield tunneling model test device, including a soil chamber 1 filled with soil 2 for simulating excavation to form a tunneling face. A reaction frame 12 is fixedly installed on one side of the soil chamber 1, and multiple guide rails 3 are laid parallel between the soil chamber 1 and the reaction frame 12. A movable cabin is slidably connected to the guide rails 3 via pulleys 4 installed at its bottom, allowing the movable cabin to move smoothly in a first direction toward or away from the soil chamber 1.

[0023] In this embodiment, the mobile chamber includes an adjacent but independent mud-water chamber 5 and an air cushion chamber 7. The mud-water chamber 5 is in direct contact with the cutterhead 6 and is filled with a mud / slag mixture to balance the pressure at the excavation face. The air cushion chamber 7 is typically located behind the mud-water chamber 5 and uses an air cushion (compressed air) to regulate and stabilize the pressure in the mud-water chamber 5.

[0024] It should be understood that in practical applications, there is usually a gas-liquid interface or connecting structure between the mud and water chamber 5 and the air cushion chamber 7, so that the air cushion pressure can be transmitted to the mud and water chamber 5 to achieve the pressure regulation function. However, the two are not completely connected, that is, the mud and water will not directly enter the air cushion chamber 7.

[0025] At the front end of the mud chamber 5 facing the soil chamber 1, a cutterhead 6 is rotatably connected via a cutterhead main bearing 8. The cutterhead 6 is driven to rotate by a motor 16. One end of a jack 14 abuts against the reaction frame 12, and the other end is connected to the moving cabin, providing axial thrust to the moving cabin to simulate the tunnel boring machine's propulsion process. Thus, by driving the cutterhead 6 to rotate via the motor 16, and simultaneously pushing the moving cabin along the guide rail 3 towards the soil chamber 1 via the jack 14, the coupled motion simulation of "cutterhead rotation cutting" and "axial propulsion" is achieved.

[0026] Based on the above embodiments, this device further includes an independent mud circulation and slag discharge system. The mud-water chamber 5 is equipped with a mud supply port and a mud discharge port. One end of the mud inlet pipe 13 is connected to the mud supply port of the mud-water chamber 5, and the other end is connected to an external mud supply system, with a second centrifugal pump 20 connected in series on the pipe. One end of the mud discharge pipe 9 is connected to the mud discharge port of the mud-water chamber 5, and the other end is connected to the slag collection box 11, with a first centrifugal pump 10 connected in series on the pipe.

[0027] Water stop valves 15 are installed on both the slurry inlet pipe 13 and the slurry outlet pipe 9 to control the opening and closing of the pipes and regulate the flow rate. By controlling the second centrifugal pump 20 to supply slurry into the mud-water chamber 5, and controlling the first centrifugal pump 10 to extract the slurry containing slag from the mud-water chamber 5 and transport it to the slag collection box 11, a complete mud-water circulation loop is formed.

[0028] The slag collection box 11 can settle or filter the discharged slag to achieve solid-liquid separation. By adjusting the opening of each stop valve 15 and the operating conditions of the two centrifugal pumps, the pressure and slurry circulation state in the slurry chamber 5 can be precisely controlled, thereby simulating different tunneling conditions under laboratory conditions and actively inducing the phenomenon of poor slurry discharge, i.e., "stagnant discharge".

[0029] Based on the above embodiments, in order to comprehensively and synchronously monitor the key physical parameters in the process of stagnation occurrence and development, this device integrates a multi-source sensor system.

[0030] Multiple pressure sensors 18 are arranged at different heights on the inner wall of the mud tank 5. For example, pressure measuring points are set at the upper, lower and middle parts of the tank to monitor the pressure distribution of mud in the tank. By calculating the pressure difference or pressure gradient at different heights, the situation of slag accumulation in the tank can be reflected.

[0031] Specifically, the pressure sensor 18 is positioned at least as follows: a first pressure measuring point located at the top of the mud-water tank 5, a second pressure measuring point located in the middle of the mud-water tank 5, and a third pressure measuring point located at the bottom of the mud-water tank 5, in order to form a pressure distribution and to calculate the pressure gradient or pressure difference.

[0032] A torque sensor 17 is installed on the drive shaft of the cutterhead 6 to collect the torque experienced by the cutterhead 6 when cutting the soil 2 in real time; at the same time, a torque sensor 17 is also installed at the coupling between the output shaft of the motor 16 and the drive shaft of the cutterhead 6 to monitor the load changes of the drive system.

[0033] Pump body acceleration sensors 19 are installed on the pump bodies or bearing seats of the first centrifugal pump 10 and the second centrifugal pump 20 to collect vibration signals during pump operation. Changes in vibration intensity can reflect whether the pumping load is abnormal and whether the pipeline is prone to blockage.

[0034] To further optimize the scheme, in order to obtain the state information of the soil 2 near the tunnel face, a condenser microphone 22 is installed on the inner wall of the soil chamber 1. Its sound pickup direction is directly facing the tunnel face or the area of ​​soil 2 that is disturbed by cutting in front of the cutterhead 6, and is used to collect the acoustic signals generated during the tunneling process.

[0035] A triaxial accelerometer 21 is installed on the surface of the cutterhead 6 to collect vibration signals generated when the cutterhead 6 cuts the soil 2. The acoustic and vibration signals acquired by the condenser microphone 22 and the triaxial accelerometer 21 can be used to indirectly analyze the properties of the soil 2 (such as compaction and moisture content) and the interaction state between the cutterhead 6 and the soil 2, providing auxiliary information for comprehensively judging the cause of runoff.

[0036] Based on the above embodiments, the mobile cabin, mud-water circulation system, and multi-source sensor system are all connected to a control center 23.

[0037] In one specific embodiment, the control center 23 includes a test control system and a data processing system. The test control system is used to centrally control the start / stop and speed of the motor 16, the propulsion speed and thrust of the jack 14, the start / stop and frequency of the first centrifugal pump 10 and the second centrifugal pump 20, and the opening and closing of each stop valve 15. The data processing system receives and processes real-time data from the torque sensor 17, pressure sensor 18, pump body acceleration sensor 19, triaxial acceleration sensor 21, and capacitive microphone 22. The data processing system can visualize the pressure distribution inside the chamber and calculate the pressure gradient, analyze the time and frequency domain characteristics of the cutterhead 6 torque, monitor the acceleration amplitude of the pump body vibration, and fuse acoustic and vibration signals. Through comprehensive analysis of this multi-source information, the control center 23 can online identify the risk of mud cake formation on the cutterhead 6 and the risk of mud pipeline stagnation, and output early warning signals.

[0038] In another embodiment, the slag collection box 11 can be designed as a box with a detachable structure and a slag discharge port, which facilitates the cleaning of collected solid particles after the test to meet the needs of repeated tests. The sliding guide mechanism composed of the guide rail 3 and the pulley 4, and the stable support provided by the reaction frame 12 for the jack 14, ensure the smoothness and precision of the propulsion process.

[0039] The slurry balance shield tunneling model test device in this embodiment can simulate the complete coupled process of slurry balance shield tunneling and slurry circulation. Its working process is as follows: During operation, motor 16 drives the cutterhead to rotate and cut the soil 2, while jack 14 pushes the entire moving chamber along guide rail 3 towards the soil chamber 1, simulating the tunneling action of a tunnel boring machine. Second centrifugal pump 20 continuously supplies slurry into the slurry chamber 5 through slurry inlet pipe 13 to maintain the set chamber pressure, simulating a stable excavation face. First centrifugal pump 10 extracts the slurry containing slag generated during cutting through slurry discharge pipe 9, achieving slag separation via slag collection box 11. By adjusting the opening of stop valve 15 or changing the pump's operating conditions, conditions such as poor slurry discharge and decreased flow rate can be simulated. During this process, pressure sensor 18, torque sensor 17, and pump body acceleration sensor 19, located at key locations, simultaneously collect multi-source physical signals such as chamber pressure distribution, cutterhead 6 load, and pumping vibration. Meanwhile, capacitive microphone 22 and triaxial accelerometer 21 capture the acoustic and vibration responses of the excavation face. All data is collected at the control center 23 for processing and analysis, thereby enabling the observation and quantitative study of the entire process of "stagnation" phenomenon from its induction and development to risk warning.

[0040] Compared with the prior art, the experimental apparatus of this embodiment has the following beneficial effects: First, by guiding the guide rail 3-pulley 4 and coordinating the propulsion and loading of the jack 14 with the rotation of the cutterhead for cutting, the continuous tunneling process of "cutterhead rotation cutting + axial propulsion" can be realistically simulated.

[0041] Secondly, through the cooperation of independent inlet and outlet slurry pipelines 9 with centrifugal pumps and water stop valves 15, the pressure and slurry circulation status of the mud chamber 5 can be precisely controlled. This can simulate normal tunneling conditions and actively and controllably induce stagnation, providing repeatable experimental conditions for mechanism research.

[0042] Third, by integrating pressure sensor 18, torque sensor 17, acceleration sensor, and acoustic and vibration sensors, multi-dimensional, synchronous, and real-time monitoring of pressure gradient inside the chamber, load on cutterhead 6, status of pumping system, and disturbance of soil 2 at the tunnel face is achieved, which greatly improves the observability of the stagnation evolution process and the comprehensiveness of data acquisition.

[0043] In summary, the device in this embodiment provides a highly integrated, controllable, and data-rich experimental platform for in-depth research on the evolution mechanism of "stagnation" and blockage in slurry balance shield tunneling, comparative experiments on key parameters, and verification and optimization of early warning algorithms.

[0044] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "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, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0045] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A slurry balance shield tunneling model test device, characterized in that, include: A soil chamber (1) filled with soil (2), and a reaction frame (12) is fixed on one side of the soil chamber (1). The mobile cabin, which slides back and forth between the soil chamber (1) and the reaction frame (12), includes an independent mud chamber (5) and an air cushion chamber (7). The cutter head (6) is rotatably connected to the front end of the mud and water chamber (5) facing the soil chamber (1) and drives the connected motor (16). The slurry inlet pipe (13) and the slurry outlet pipe (9) are connected to the mud and water tank (5), and a centrifugal pump is connected in series on both the slurry inlet pipe (13) and the slurry outlet pipe (9). The multi-source sensor system includes multiple pressure sensors (18), torque sensors (17), pump body acceleration sensors (19), and a capacitive microphone (22). The torque sensors (17) are connected to the cutterhead (6), the pressure sensors (18) are connected to the mud chamber (5), the pump body acceleration sensors (19) are connected to the centrifugal pump, and the capacitive microphone (22) is located in the soil chamber (1) and faces the disturbed area of ​​the excavation face or soil (2).

2. The slurry balance shield tunneling model test device according to claim 1, characterized in that, The multi-source sensor system also includes a triaxial accelerometer (21) mounted on the cutterhead (6), which is used to collect vibration signals generated when the cutterhead (6) cuts the soil (2).

3. The slurry balance shield tunneling model test device according to claim 1, characterized in that, The torque sensor (17) is located at the transmission shaft of the cutter head (6) and at the transmission shaft between the output end of the motor (16) and the cutter head (6).

4. The slurry balance shield tunneling model test device according to claim 1, characterized in that, The pressure sensor (18) is positioned at different heights in the mud chamber (5) to form a pressure distribution and to calculate the pressure gradient or pressure difference.

5. The slurry balance shield tunneling model test device according to claim 1, characterized in that, A guide rail (3) is laid between the soil chamber (1) and the reaction frame (12). The mobile cabin is slidably connected to the guide rail (3) by pulleys (4). A jack (14) is connected between the mobile cabin and the reaction frame (12).

6. The slurry balance shield tunneling model test device according to claim 5, characterized in that, A pressure sensor (18) is also installed on the hydraulic oil circuit of the jack (14).

7. The slurry balance shield tunneling model test device according to claim 5, characterized in that, One end of the slurry inlet pipe (13) is connected to the slurry supply port of the mud and water tank (5), and the other end is connected to the external slurry supply system. A second centrifugal pump (20) is connected in series on the slurry inlet pipe (13). One end of the slurry discharge pipe (9) is connected to the slurry discharge port of the mud and water tank (5), and the other end is connected to the slag collection box (11). A first centrifugal pump (10) is connected in series on the slurry discharge pipe (9).

8. The slurry balance shield tunneling model test device according to claim 7, characterized in that, The pump body acceleration sensor (19) is installed on the pump body or bearing seat of the first centrifugal pump (10) and the second centrifugal pump (20).

9. The slurry balance shield tunneling model test device according to claim 7, characterized in that, The slag collection box (11) includes a settling chamber and a filter section.

10. The slurry balance shield tunneling model test device according to claim 7, characterized in that, It also includes a control center (23), which includes a test control system and a data processing system. The test control system centrally controls the start and stop and speed of the motor (16), the propulsion speed and thrust of the jack (14), and the start and stop and frequency of the first centrifugal pump (10) and the second centrifugal pump (20). The data processing system receives and processes real-time data from the multi-source sensor system.

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