Shield tunneling model test portal and main shaft sealing system and verification method

Abstract

The application provides a shield tunneling model test tunnel mouth and main shaft sealing system and a verification method, effectively solves the problem that the influence of underground water on the test cannot be considered in the simulation test link of the prior art; the technical solution is that the application comprises a tunnel mouth sealing system and a main shaft sealing system; the tunnel mouth sealing system is composed of a first anti-fouling ring, a first sliding bearing, a first main seal, a first auxiliary sealing ring, a dustproof ring and a first static sealing ring, wherein the tunnel mouth sealing system is arranged on a tunnel mouth connecting piece and connected with a pressure container; the main shaft sealing system is composed of a second anti-fouling ring, a second sliding bearing, a second main seal, a second auxiliary sealing ring and a second static sealing ring; the application can accurately reproduce the tunneling process such as shield cutter disc rotation and shield advancement under high water pressure, and can provide more reference value test data for the optimization of shield construction parameters such as cutter disc rotating speed, thrust control and sealing structure design improvement of deep buried cross-sea and cross-river tunnels.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction equipment testing technology, and in particular to a TBM tunneling model test portal and main shaft sealing system and verification method. Background Technology

[0002] With the rapid development of underground engineering, tunnel boring machine (TBM) technology is being used more and more widely in tunnel construction. During the tunneling process, the TBM disturbs the surrounding strata, especially under complex geological conditions. This disturbance can lead to a series of problems such as surface subsidence and groundwater leakage. Therefore, studying the patterns of strata disturbance during TBM tunneling is of great significance for optimizing construction techniques, reducing construction risks, and protecting the surrounding environment.

[0003] Currently, numerous scholars have conducted shield tunneling model tests to study the ground disturbance patterns during shield tunneling. However, these tests are constrained by the dynamic high-pressure sealing challenges of small-sized shield tunneling model experimental devices, necessitating simplifications that cannot simulate the dynamic tunneling process under high water pressure. The baffle-retraction type shield excavation face instability model test, which simulates excavation face instability through baffle retraction, differs significantly from actual shield tunneling face instability during the forward movement (Centrifugal Model Test Study on Excavation Face Instability of Shield Tunnels in Dense Sandy Soil). The tunnel shrinkage model test, represented by Franza et al. (2019), controls the tunnel diameter reduction using a drainage method to simulate ground losses during tunnel excavation, simplifying shield tunnel construction to a two-dimensional condition. However, this approach cannot simulate the shield tunneling process or consider high water pressure environments (Greenfield tunnelling insands: the effects of soil density and relative depth). The shield tunneling model test represented by Berthoz et al. (2018) carried out shield tunneling model tests by manufacturing a small scale model test device, which can realize the dynamic tunneling of the shield. However, due to the high pressure sealing problem, it still cannot take into account the influence of groundwater on the test.

[0004] To address the aforementioned technical problems, this application provides a shield tunneling model test portal and main shaft sealing system and verification method. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a shield tunneling model test portal and main shaft sealing system and verification method, which effectively solves the problem that the prior art is constrained by the high pressure sealing problem in the simulation test stage and cannot take into account the influence of groundwater on the test.

[0006] The technical solution includes an opening sealing system and a main shaft sealing system. The opening sealing system consists of a first anti-fouling ring, a first sliding bearing, a first main seal, a first auxiliary sealing ring, a dustproof ring, and a first static sealing ring. The opening sealing system is installed on the opening connector and connected to the pressure vessel.

[0007] The main shaft sealing system consists of a second anti-fouling ring, a second sliding bearing, a second main seal, a second auxiliary sealing ring, and a second static sealing ring, and is installed on the main shaft connector.

[0008] Furthermore, the first and second anti-fouling rings can also serve a sealing function.

[0009] Furthermore, two of the first sliding bearings are provided, distributed on both sides of the first main seal, to ensure that the shield tunneling model can be pushed into the pressure vessel.

[0010] Furthermore, the first and second main seals are GY1 shaft sealing rings.

[0011] Furthermore, the first auxiliary sealing ring, the static sealing ring, the second auxiliary sealing ring, and the second static sealing ring are O-rings.

[0012] Furthermore, the opening sealing system is installed on the opening connector and connected to the pressure vessel via hexagon socket screws.

[0013] Furthermore, the spindle sealing system is mounted on the spindle connector and fixed by external hexagonal screws.

[0014] Furthermore, the shield tunneling model also includes rolling bearings, axle stops, pressurization holes, pressure gauges, water injection ports, drainage ports, support frames, jacking plates, jacks, handles, pressure vessels, main shafts, fixing bolts, tunnel opening connectors, and main shaft connectors.

[0015] Furthermore, the rolling bearing ensures that the spindle rotates normally under high pressure.

[0016] Furthermore, the shaft stop ensures a stable connection between the rolling bearing and the main shaft connector.

[0017] Furthermore, the pressure port is a pre-reserved hole that can be connected to an air compressor to pressurize the pressure vessel.

[0018] Furthermore, the pressure gauge is a shock-resistant pressure gauge with a range of 0~10MPa.

[0019] Furthermore, the jacking plate ensures that the thrust applied by the jacks is evenly applied to the model shield 29.

[0020] Furthermore, the jack is a manual or automatic bidirectional hydraulic jack, and the jacking speed can be controlled by a handle or automatically.

[0021] Furthermore, the pressure vessel can withstand a maximum pressure of 4.0 MPa.

[0022] Furthermore, the main shaft, used to simulate the shield tunneling machine's main shaft, has a hole drilled at its rear to facilitate control of its rotation.

[0023] Furthermore, the support frame ensures the overall stability of the device.

[0024] The beneficial effects of this invention are as follows:

[0025] Existing shield tunneling model testing devices, constrained by the technical challenge of dynamic sealing at the main shaft and tunnel entrance, mostly use dry sand for testing and cannot simulate the shield tunneling process under a high water pressure environment of 2MPa. This device innovatively proposes a dynamic sealing solution for shield tunneling, successfully overcoming the aforementioned technical bottleneck. It can accurately reproduce the entire shield tunneling process of deep-buried cross-sea and cross-river tunnels under high water pressure in the laboratory, providing crucial experimental support for related engineering technology research.

[0026] Existing devices, due to sealing challenges, can only be tested under low or normal pressure environments. The test data deviates significantly from the actual engineering conditions of deeply buried tunnels, such as sea-crossing tunnels, making it difficult to provide accurate support for engineering design. This new device can accurately reproduce the tunneling process, including cutterhead rotation and shield advance, under high water pressure. The test scenario is more closely aligned with actual engineering conditions, providing more valuable test data for optimizing shield construction parameters in deeply buried sea-crossing and river-crossing tunnels, such as cutterhead speed, thrust control, and improvements to sealing structure design.

[0027] By constructing a shield tunneling model test tunnel entrance and main shaft sealing system, the experimental requirements of the shield mechanism in complex external environments can be met, thereby improving the reliability of the verification and processing of the shield mechanism's working status.

[0028] The construction of a sealing system makes it possible to simulate the high water pressure environment during shield tunneling, fully taking into account the impact of groundwater on the test, and also providing the possibility for early experimental verification of the shield mechanism.

[0029] Secondly, this application provides a verification method applied to the aforementioned shield tunneling model test portal and main shaft sealing system, comprising the following steps:

[0030] Step 1: Assemble the device and close the pressure port and drain valve;

[0031] Step 2: Pour water into the pressure vessel, close the water inlet, and check the airtightness of the device;

[0032] Step 3: Control the jack to advance at a constant speed and the main shaft to rotate at a constant speed until the pressure gauge reading reaches the target reading and then stop the operation;

[0033] Step 4: Hold the load for the preset time, during which the spindle is rotated at unit intervals, and the pressure gauge reading is observed to see if it changes.

[0034] Step 5: Observe the pressure gauge reading and check for water stains at the opening and main shaft;

[0035] Step Six: Disassemble the device and complete the sealing verification.

[0036] Specifically, if there are water droplets or traces of water flow at the opening and main shaft, then it is determined that there is water at the opening and main shaft.

[0037] It is understandable that if the number of times the adjustment method is processed within the preset time interval does not meet the requirements for the adjustment result per unit time, then it is determined that the verification method adjustment process needs to be performed. Attached Figure Description

[0038] Figure 1 This is a structural diagram of the sealing system for the tunnel entrance and main shaft of a shield tunneling model test;

[0039] Figure 2 This is a structural diagram of the opening sealing system;

[0040] Figure 3 This is a structural diagram of the spindle sealing system;

[0041] Figure 4 This is a flowchart of the verification method for a high-pressure sealing system;

[0042] Figure 5 This is a physical image of the experimental results of this application;

[0043] Reference numerals: 1. First anti-fouling ring; 2. First sliding bearing; 3. First main seal; 4. First auxiliary sealing ring; 5. Dustproof ring and first static sealing ring; 6. Second anti-fouling ring; 7. Second sliding bearing; 8. Second main seal; 9. Second auxiliary sealing ring and second static sealing ring; 10. Rolling bearing; 12. Shaft stop; 13. Internal hexagon screw; 14. External hexagon screw; 15. Pressure hole; 16. Pressure gauge; 17. Water inlet; 18. Drain outlet; 19. Support frame; 20. Push plate; 21. Jack; 22. Handle; 23. Pressure vessel; 24. Main shaft; 25. Fixing bolt; 26. Opening connector; 27. Main shaft 25 connector. Detailed Implementation

[0044] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0045] like Figure 1 As shown, the present invention includes an opening sealing system and a main shaft 25 sealing system, such as Figure 2 The diagram shown is a structural diagram of the opening sealing system. The opening sealing system consists of a first anti-fouling ring 1, a first sliding bearing 2, a first main seal 3, a first auxiliary sealing ring 4, a dustproof ring 5, and a first static sealing ring 6. The opening sealing system is installed on the opening connector 27 and connected to the pressure vessel 24.

[0046] The main shaft 25 sealing system consists of a second anti-fouling ring 7, a second sliding bearing 8, a second main seal 9, a second auxiliary sealing ring 10, and a second static sealing ring 11. The main shaft 25 sealing system is installed on the main shaft 25 connector.

[0047] Furthermore, the first anti-fouling ring 1 and the second anti-fouling ring 7 can also serve as a sealing function.

[0048] Furthermore, two first sliding bearings 2 are provided, distributed on both sides of the first main seal 3, to ensure that the shield tunneling model can be pushed into the pressure vessel 24.

[0049] Furthermore, the first main seal 3 and the second main seal 9 are sealing rings for the GY1 shaft.

[0050] Furthermore, the first auxiliary sealing ring 4, the static sealing ring, the second auxiliary sealing ring 10, and the second static sealing ring 11 are O-rings.

[0051] Furthermore, the opening sealing system is installed on the opening connector 27 and connected to the pressure vessel 24 via an internal hexagon screw 14.

[0052] Furthermore, the spindle 25 sealing system is mounted on the spindle 25 connector and fixed by external hexagonal screws 15.

[0053] Furthermore, such as Figure 3 The diagram shown is a structural diagram of the sealing system of the main shaft 25. The shield tunneling model also includes a rolling bearing 12, a shaft stop 13, a pressure hole 16, a pressure gauge 17, a water injection port 18, a drainage port 19, a support frame 20, a jacking plate 21, a jack 22, a handle 23, a pressure vessel 24, a main shaft 25, fixing bolts 26, a tunnel opening connector 27, and a main shaft 25 connector.

[0054] Furthermore, the rolling bearing 12 ensures that the spindle 25 rotates normally under high pressure.

[0055] Furthermore, the axle stop 13 can ensure a stable connection between the rolling bearing 12 and the main shaft 25 connector.

[0056] Furthermore, the pressure port 16 is a reserved hole that can be connected to an air compressor to pressurize the pressure vessel 24.

[0057] Furthermore, the pressure gauge 17 is a shock-resistant pressure gauge 17 with a range of 0~10MPa.

[0058] Furthermore, the jacking plate 21 ensures that the thrust applied by the jack 22 is evenly applied to the model shield 29.

[0059] Furthermore, the jack 22 is a manual or automatic bidirectional hydraulic jack 22, and the jacking speed can be controlled by the handle 23 or automatically.

[0060] Furthermore, the pressure vessel 24 can withstand a maximum pressure of 4.0 MPa.

[0061] Furthermore, the main shaft 25 is used to simulate the shield tunneling main shaft 25 of the model. A hole is drilled at the rear of the main shaft 25 to facilitate control of the rotation of the main shaft 25.

[0062] Furthermore, the support frame 20 ensures the overall stability of the device.

[0063] Secondly, such as Figure 4 As shown, this application provides a verification method applied to the sealing system of the tunnel entrance and main shaft 25 of the above-mentioned shield tunneling model test, including the following steps:

[0064] Step 1: Assemble the device and close the valves at the pressurization port 16 and the drain port 19;

[0065] Step 2: Inject water into pressure vessel 24, close water inlet 18, and check the airtightness of the device;

[0066] Step 3: Control the jack 22 to advance at a constant speed and the main shaft 25 to rotate at a constant speed until the pressure gauge 17 reaches the target reading and then stop the operation;

[0067] Step 4: Hold the load for the preset time, during which the main shaft 25 is rotated every unit time interval, and the reading of pressure gauge 17 is observed to see if it changes.

[0068] Step 5: Observe the reading of pressure gauge 17 and check for water stains at the opening and main shaft 25;

[0069] Step Six: Disassemble the device and complete the sealing verification.

[0070] In one possible specific embodiment:

[0071] Step 1: Assemble the device and close the valves at the pressurization port 16 and the drain port 19;

[0072] Step 2: Inject water into pressure vessel 24, close water inlet 18, and check the airtightness of the device;

[0073] Step 3: Manually control the jack 22 to push forward at a constant speed and the main shaft 25 to rotate at a constant speed until the pressure gauge 17 reads 2.0 MPa and then stop the operation;

[0074] Step 4: Hold the load for 24 hours, rotating the main shaft 25 every 30 minutes during this period and observing whether the reading of pressure gauge 17 changes;

[0075] Step 5: Observe the reading of pressure gauge 17 and check for wetness at the opening and main shaft 25;

[0076] Step Six: Disassemble the device and complete the sealing verification.

[0077] like Figure 5 The image shown is a physical representation of the experimental results of this application.

[0078] Specifically, if there are water droplets or traces of water flow at the opening and the main shaft 25, it is determined that there are water traces at the opening and the main shaft 25.

[0079] Furthermore, before rotating the main shaft 25 in step four, the unit time needs to be adjusted based on the detection data from the pressure gauge 17. Specifically, this includes:

[0080] Based on the reading of the pressure gauge 17, the change data of the pressure gauge 17 reading during the monitoring process after different spindle 25 rotation processes is determined. Based on the change data, when it is determined that there is a suspected abnormality in the sealing state, the adjustment result per unit time in the current adjustment process is determined based on the change data.

[0081] Based on the adjustment data of the verification method in different adjustment processes, determine whether the verification method needs to be adjusted when the pressure gauge 17 changes in future adjustment processes.

[0082] Furthermore, the change data of the pressure gauge 17 reading refers to the change data of the pressure gauge 17 reading during the monitoring period after the spindle 25 is rotated, that is, the change data of the pressure gauge 17 reading within a unit time after the spindle 25 is rotated, which is specifically determined based on the deviation from the target degree.

[0083] Furthermore, it was determined that there were suspected abnormalities in the sealing condition, specifically including:

[0084] The monitoring period in which the change occurred is determined by the change data of the pressure gauge 17 during the monitoring period after the main shaft 25 is rotated.

[0085] Based on the changes in the monitoring period and the corresponding changes in the readings of pressure gauge 17, it is determined whether there is any suspected abnormality in the sealing status.

[0086] It is understandable that when there is a monitoring period in which the reading of pressure gauge 17 is outside the preset range, the change in the sealing state is relatively drastic. Therefore, it can be directly determined that the sealing state is abnormal, and the verification result can be directly output, that is, the sealing state is abnormal.

[0087] Additionally, it should be noted that when there is no monitoring period in which the reading of pressure gauge 17 changes outside the preset range, the monitoring period in which the reading of pressure gauge 17 changes is determined. If the constituent data of the monitoring period in which the reading of pressure gauge 17 changes before the current adjustment process does not meet the requirements, that is, if the number of monitoring periods in which the reading of pressure gauge 17 changes before the current adjustment process is large, then it is determined that the sealing state has a suspected abnormality.

[0088] In one possible embodiment, when the absolute value of the difference between the reading of pressure gauge 17 and the target reading during the monitoring period and the ratio of the target reading to the target reading are greater than a preset threshold, that is, the change rate is greater than 2%, it is determined that the change data of the reading during the monitoring period is not within the preset range, wherein the monitoring period in which the reading of pressure gauge 17 changes is the monitoring period in which the reading of pressure gauge 17 is not within the target reading.

[0089] In one possible specific embodiment, if the ratio of the number of monitoring periods in which the pressure gauge 17 reading changed before the current adjustment process to the number of monitoring periods before the current adjustment process is greater than a preset ratio threshold, or if the ratio of the number of monitoring periods in which the pressure gauge 17 reading changed before the current adjustment process to the number of monitoring periods before the current adjustment process is greater than 0.3, then it is determined that the sealing state has a suspected abnormality.

[0090] It is understandable that when there is no suspected abnormality in the sealing state, there is no need to perform unit time adjustment processing during the current adjustment process.

[0091] Furthermore, the method for determining the adjustment result per unit time in the current adjustment process is as follows:

[0092] Based on the change data, the monitoring period in which the reading of pressure gauge 17 changed before the current adjustment process is determined;

[0093] By using the monitoring period in which the pressure gauge 17 reading changed prior to the current adjustment process, and the adjustment data of the verification method, the adjustment result per unit time in the current adjustment process is determined.

[0094] Understandably, by utilizing the monitoring period during which the pressure gauge 17 readings changed prior to the current adjustment process, and the adjustment data from the verification method, the adjustment result per unit time during the current adjustment process is determined, specifically including:

[0095] Based on the adjustment data of the verification method, determine the number of adjustments to the verification method before the current adjustment process in the current test, and use this number as the number of adjustments to the verification method;

[0096] The ratio of the number of monitoring periods in which the pressure gauge 17 readings changed before the current adjustment process to the number of monitoring periods before the current adjustment process is taken as the reading change period ratio.

[0097] Based on the number of adjustments and the proportion of time periods with varying readings obtained using the verification method, the adjustment result per unit time period in the current adjustment process is determined.

[0098] In one possible embodiment, the baseline adjustment duration is determined by multiplying the proportion of the reading change period by a preset duration, the adjustment ratio factor is determined by multiplying the preset weight coefficient by the number of adjustments made by the verification method, the product of the adjustment ratio factor and the baseline adjustment duration is used as a compensation term for the adjustment duration, and the adjustment result per unit time in the current adjustment process is determined based on the sum of the compensation term and the baseline adjustment duration.

[0099] It should be noted that once the adjustment result per unit time in the current adjustment process is determined, the spindle 25 should be rotated at least a preset number of times. Specifically, after one rotation, the duration corresponding to the adjustment result per unit time should be maintained. Then, it should be rotated once more, and the duration corresponding to the adjustment result per unit time should be maintained again, until the preset number of times is reached.

[0100] In one possible specific embodiment, the preset duration is 10 minutes, the preset weighting coefficient is 0.1, and the preset number of times is 3.

[0101] It should be noted that after adjusting the unit duration, that is, after adjusting the verification method, if the reading changes are found to be outside the preset range after the spindle 25 rotates, the verification result will be output directly, indicating that there is an abnormality in the sealing state.

[0102] Furthermore, determine whether adjustments to the verification method are needed when pressure gauge 17 changes, specifically including:

[0103] By using the adjustment processing data of the verification method in different adjustment processes, the adjustment result per unit time in different adjustment processes is determined;

[0104] Based on the adjustment processing data of the verification method, determine the number of adjustment processes for the verification method;

[0105] By analyzing the changes in the reading of the pressure gauge 17, the adjustment results per unit time during different adjustment processes, and the number of times the adjustment method is processed, it is determined whether an adjustment process for the verification method is required.

[0106] It is understandable that when the reading of the pressure gauge 17 is within the preset range, the degree of variation of the reading of the pressure gauge 17 is relatively high, so it is determined that the verification method needs to be adjusted.

[0107] In one possible embodiment, when the absolute value of the difference between the pressure gauge 17 reading and the target reading during the monitoring period and the ratio of the target reading to the target reading are greater than 1%, the fluctuation data of the reading during the monitoring period is determined to be within a preset range.

[0108] It should also be noted that when the reading of the pressure gauge 17 is not within the preset range, the number of adjustment processing times is obtained. When the number of adjustment processing times is greater than the preset adjustment number threshold, since the number of adjustment processing times is already very high, it can be directly determined that no adjustment processing of the verification method is required.

[0109] Furthermore, when the number of times the adjustment method is processed is not greater than the preset adjustment number threshold, it is also necessary to determine the adjustment result per unit time in different adjustment processes. If the number of times the adjustment method is processed within the preset time interval meets the requirements for the adjustment result per unit time, then it can be directly determined that no adjustment processing of the verification method is required.

[0110] In one possible embodiment, when the adjustment method is processed more than 8 times, it can be directly determined that no adjustment processing of the verification method is required. If the adjustment result per unit time is more than 7 minutes and the adjustment method is processed more than 3 times, it is determined that no adjustment processing of the verification method is required.

Claims

1. A sealing system for the tunnel entrance and main shaft of a shield tunneling model test, characterized in that, Specifically, it includes: Includes a hole sealing system and a main shaft (25) sealing system. The hole sealing system is composed of a first anti-fouling ring (1), a first sliding bearing (2), a first main seal (3), a first auxiliary sealing ring (4), a dustproof ring (5), and a first static sealing ring (6). The hole sealing system is installed on the hole connector (27) and connected to the pressure vessel (24). The main shaft (25) sealing system consists of a second anti-fouling ring (7), a second sliding bearing (8), a second main seal (9), a second auxiliary sealing ring (10), and a second static sealing ring (11). The main shaft (25) sealing system is installed on the main shaft (25) connector. Two first sliding bearings (2) are provided, distributed on both sides of the first main seal (3) to ensure that the shield tunneling model can be pushed into the pressure vessel (24); The opening sealing system is installed on the opening connector (27) and connected to the pressure vessel (24) by an internal hexagon screw (14); The shield tunneling model also includes rolling bearings (12), shaft stops (13), pressurization holes (16), pressure gauges (17), water injection ports (18), drainage ports (19), support frames (20), jacking plates (21), jacks (22), handles (23), pressure vessels (24), main shafts (25), fixing bolts (26), tunnel opening connectors (27), and main shaft (25) connectors; The pressure port (16) is a reserved hole that can be connected to an air compressor to pressurize the pressure vessel (24).

2. The shield tunneling model test portal and main shaft sealing system according to claim 1, characterized in that, The first anti-fouling ring (1) and the second anti-fouling ring (7) can also serve as a sealing function.

3. The shield tunneling model test portal and main shaft sealing system according to claim 1, characterized in that, The first auxiliary sealing ring (4), the first static sealing ring (6), the second auxiliary sealing ring (10) and the second static sealing ring (11) are O-rings.

4. The shield tunneling model test portal and main shaft sealing system according to claim 1, characterized in that, The axle stop (13) ensures a stable connection between the rolling bearing (12) and the main shaft (25) connector.

5. The shield tunneling model test portal and main shaft sealing system according to claim 1, characterized in that, The jack (22) is a manual or automatic bidirectional hydraulic jack (22), and the jacking speed can be controlled by the handle (23) or automatically.

6. A verification method based on the shield tunneling model test portal and main shaft sealing system, applied to the shield tunneling model test portal and main shaft sealing system as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Assemble the device and close the valves of the pressurization port (16) and the drain port (19); Step 2: Inject water into the pressure vessel (24), close the water inlet (18), and check the airtightness of the device; Step 3: Control the jack (22) to advance at a constant speed and the main shaft (25) to rotate at a constant speed until the pressure gauge (17) pointer reads the target reading and then stop the operation; Step 4: Hold the load for the preset time, during which the main shaft (25) is rotated every unit time, and the pressure gauge (17) reading is observed to see if it changes. Step 5: Observe the pressure gauge (17) reading and check for water stains at the opening and main shaft (25); Step Six: Disassemble the device and complete the sealing verification.

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