A test device and method suitable for the sealing performance of a shield tail brush of a shield tunneling machine

Abstract

The application belongs to the field of shield tail brush sealing performance test, and discloses a test device and method suitable for shield tail brush sealing performance of a shield tunneling machine, which comprises a pressure cover plate, a pressure adjusting bolt, a base, a shield segment and a shield segment driving device. In the test process, the pressure between the shield shell and the shield segment is adjusted by the pressure adjusting bolt, the simulated shield segment is pushed out by the driving device after the grease is injected, and the sealing performance of the shield tail brush is evaluated by monitoring the sealing pressure of the sealing cavity. The device and method can effectively solve the problem of no shield segment disengagement in the test, and have good verification and research prospects in analyzing the sealing performance of the shield tail brush under different pressures and different strata considering different shield traveling speeds.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of shield tail brush sealing performance testing, and particularly relates to a test device and method suitable for shield tail brush sealing performance of a shield tunneling machine. BACKGROUND

[0002] When shield tunneling method is used in water-rich strata, the shield tail brush, as a key sealing component of the shield tunneling machine, realizes the sealing of the underground water in the strata and the synchronous grouting slurry in the shield tail to the internal space of the shield tunneling machine by injecting specific grease between the shield tail brushes, so the sealing performance of the shield tail is crucial to guarantee the tunnel construction quality and construction safety. However, the existing shield tail brush sealing performance test device and method has obvious limitations. At present, the shield tail brush sealing chamber is usually in a static state during the test, and this test method cannot accurately simulate the relative movement between the segment and the shield tail brush in the actual engineering scene.

[0003] In the actual shield tunneling process, the installation and splicing of the segment is a dynamic process, and the segment and the shield tail brush will produce complex relative movement, including axial displacement, radial swing and circumferential rotation. This relative movement will significantly affect the sealing effect of the shield tail brush, which may lead to sealing failure, grouting leakage and other problems, thereby affecting the waterproof performance and structural stability of the tunnel.

[0004] The existing static sealing chamber test device and method cannot simulate the relative movement between the segment and the shield tail brush, so there is a large deviation between the test results and the actual engineering conditions, which cannot truly reflect the sealing performance of the shield tail brush under actual working conditions. This not only limits the accurate evaluation of the sealing performance of the shield tail brush, but also is not conducive to the optimization design and improvement of the shield tail brush, and cannot provide reliable sealing performance guarantee basis for shield tunneling construction. Therefore, developing a test device and method that can simulate the relative movement between the segment and the shield tail brush has important significance for improving the accuracy and practicality of the sealing performance test of the shield tail brush, thereby promoting the further development of shield tunneling construction technology. SUMMARY

[0005] The present application proposes a new test device and method suitable for the sealing performance of the shield tail brush of a shield tunneling machine to solve the problems in the existing test device and method. The device and method can simulate the relative sliding between the shield segment and the shield tail brush in actual engineering, thereby more accurately evaluating the sealing performance of the shield tail brush.

[0006] To solve the above technical problems, the technical solution adopted by the present application is: a test device suitable for the sealing performance of the shield tail brush of a shield tunneling machine, comprising:

[0007] a base, which is used to support the entire test device;

[0008] The pressure cover plate is installed on the base, and at least two groups of shield tail brushes are arranged below the pressure cover plate. Grease injection ports are arranged on the pressure cover plate between the shield tail brushes, and soil chamber pressure adjusting ports are arranged on the pressure cover plate between the shield tail brushes and the shield segment inlets.

[0009] The shield segment is located in the slot of the base below the shield tail brush, and one end of the shield segment is provided with a driving device. The driving device drives the shield segment to slide in the slot relative to the shield tail brush.

[0010] The pressure adjusting bolt is used to fix the pressure cover plate, so that the shield segment is in contact with the shield tail brush.

[0011] Further, the number of shield tail brushes is three groups, and first and second grease chambers are formed between adjacent shield tail brushes. The shield tail brush close to the shield segment inlet and the base form a soil chamber pressure cavity.

[0012] Further, flow sensors and pressure sensors are arranged at the grease injection ports and the soil chamber pressure adjusting ports.

[0013] Further, the driving device and the shield segment are provided with a force transmission steel plate. The driving device applies jacking force to the shield segment through the force transmission steel plate.

[0014] Further, the driving device is driven by a hydraulic system. The hydraulic driving system is used to control the jacking force, jacking speed of the shield segment and the movement position of the shield segment.

[0015] A test method suitable for the sealing performance of a shield tail brush of a shield tunneling machine, which is tested by using the above-mentioned test device suitable for the sealing performance of the shield tail brush of the shield tunneling machine. The specific steps are as follows:

[0016] Step S1, butter is applied to both sides and the bottom of the shield segment, and is pushed to the slot of the base, so that a part of the shield segment is inserted into the base at the head;

[0017] Step S2, connect the force transmission steel plate, the driving device and the shield segment, and increase the counterforce device at the rear of the driving device to pressurize to a pre-tightening state;

[0018] Step S3, install the pressure cover plate and the base, and arrange sealing rubber strips at the four edge joints to prevent grease overflow;

[0019] Step S4, tighten the pressure adjusting bolt and level it;

[0020] Step S5, add grease through the grease injection port, and determine the grease pressure through the pressure adjusting bolt and the pressure sensor in the grease cavity;

[0021] Step S6, water and sand are injected into the earth chamber pressure cavity through the earth chamber pressure adjusting port, and the water pressure and the pressure adjusting bolt are adjusted to simulate the shield earth chamber pressure in the high water content sandy soil stratum;

[0022] Step S7, when the grease pressure and the earth chamber pressure reach the test pressure stability, the shield segment is pushed by the driving device, and the grease chamber pressure and the earth chamber pressure cavity pressure are measured by the pressure sensor in the process.

[0023] Further, the evaluation method of the test process is as follows:

[0024] When the first grease chamber oil pressure is greater than the earth chamber pressure cavity pressure and the pressure maintaining capacity of the shield tail brush, the phenomenon of oil leakage from the first grease chamber to the earth chamber pressure cavity is prone to occur, that is, when the following formula Q > 0, the oil leaks on this side, Q ≤ 0, the oil does not leak on this side;

[0025] Q 1= P 油1 - P 土 - σ 盾

[0026] In the formula: Q 1 is the oil leakage coefficient of one side of the earth chamber pressure cavity, P 油1 P1 is the first grease chamber pressure, P 土 P2 is the earth chamber pressure cavity pressure, σ 盾 P3 is the pressure maintaining capacity of the shield tail brush;

[0027] When the second grease chamber oil pressure on the side of the shield tail is greater than the pressure maintaining capacity of the shield tail brush, the phenomenon of oil leakage from the shield tail is prone to occur;

[0028] Q 2= P 油2 - σ 盾

[0029] In the formula: Q 2 is the oil leakage coefficient of one side of the shield tail, P 油2 P4 is the second grease chamber pressure, σ 盾 P3 is the pressure maintaining capacity of the shield tail brush.

[0030] Compared with existing technologies, the advantages of this invention are as follows: This invention adjusts the pressure between the cover plate and the tunnel lining segments using pressure regulating bolts. After grease injection, a simulated tunnel lining segment is pushed by a driving device, and the sealing pressure of the sealing cavity is monitored to evaluate the sealing performance of the tail brush. This invention's device and method can effectively solve the problem of no segment detachment during experiments. It has good verification and research prospects in analyzing the tail brush sealing performance under different pressures and geological formations, considering different tunnel travel speeds. Attached Figure Description

[0031] The invention will now be further described with reference to the accompanying drawings.

[0032] Figure 1 This is a schematic diagram of the structure of the present invention.

[0033] Figure 2 This is a top view of the experimental apparatus of the present invention.

[0034] Figure 3 This is a front view of the experimental apparatus of the present invention.

[0035] Figure 4 This is a side view of the test apparatus of the present invention.

[0036] In the diagram, 1 is the pressure adjusting bolt, 2 is the pressure cover plate, 3 is the grease injection port, 4 is the shield tail brush, 5 is the base, 6 is the shield segment, 7 is the force transmission steel plate, 8 is the drive device, 9 is the earth chamber pressure chamber, 10 is the first grease chamber, 11 is the second grease chamber, and 12 is the earth chamber pressure adjusting port. Detailed Implementation

[0037] like Figure 1 As shown, a test device for the sealing performance of the tail brush of a tunnel boring machine includes: a base 5, a pressure cover plate 2, a tunnel segment 6, and a drive device 8. The base 5 is the foundation of the entire test device, used to support the other components of the test device. The base 5 has slots to facilitate the entry of the tunnel segment 6 into the slots, simulating the movement process of the tunnel segment 6.

[0038] A pressure cover plate 2 is installed on the base 5, and sealing strips are installed around the pressure cover plate 2 to prevent grease leakage. Three sets of tail brushes 4 are installed below the pressure cover plate 2. The shield tunnel segment 6 is located in the slot of the base 5 below the tail brushes 4. Under the action of the pressure adjusting bolt 1, the shield tunnel segment 6 is brought into contact with the tail brushes 4. In this way, the two tail brushes 4, the pressure cover plate 2 above, and the shield tunnel segment 6 form a sealed cavity. Since there are three sets of tail brushes 4, two adjacent tail brushes 4 form a first grease chamber 10 and a second grease chamber 11, respectively. Grease injection ports 3 are provided on the pressure cover plate 2 above the first grease chamber 10 and the second grease chamber 11.

[0039] The soil chamber pressure cavity 9 is formed between the shield tail brush 4, the pressure cover plate 2 and the base 5 close to one side of the shield segment 6, and the pressure cover plate 2 above the soil chamber pressure cavity 9 is provided with a soil chamber pressure adjusting opening 12. The grease is injected into the grease chamber, and the water and sand are injected into the soil chamber pressure cavity, so that the real shield tail brush 4 scene is simulated. In addition, the flow sensor and the pressure sensor are arranged at the grease injection opening 3 and the soil chamber pressure adjusting opening 12, so as to monitor the pressure and flow change in the grease chamber and the soil chamber pressure cavity in real time and accurately.

[0040] The movement process of the shield segment 6 is realized through the driving device 8. The driving device 8 is provided with the force transmission steel plate 7 between the driving device 8 and the shield segment 6. The driving device 8 applies the jacking force to the shield segment 6 through the force transmission steel plate 7, so as to simulate the different relative movement conditions between the shield segment 6 and the shield tail brush 4 in the actual engineering. In the actual test process, the lubricating oil is smeared around the shield segment 6, so as to provide lubrication for the movement of the shield segment 6.

[0041] The driving device 8 can be selected as the electric drive or the hydraulic drive, and the movement of the shield segment 6 can be realized. In the embodiment, the driving device 8 is driven by the hydraulic system. The hydraulic system is used to control the jacking force, the jacking speed and the movement position of the shield segment 6. The hydraulic system can provide a large jacking force. The jacking force and the jacking speed of the hydraulic system can be monitored by the flow, so as to better monitor.

[0042] In the above embodiment, the structure of the test device suitable for the sealing performance of the shield tail brush 4 of the shield tunneling machine is introduced in detail. On the basis of the above structure, a test method suitable for the sealing performance of the shield tail brush 4 of the shield tunneling machine is also provided. The specific steps of the test method are as follows:

[0043] Step S1, butter is smeared on both sides and the bottom of the shield segment 6, which is beneficial to the lubrication of the butter between the shield segment 6 and the base 5. The shield segment 6 is pushed to the slot of the base 5, so that a part of the shield segment 6 is inserted into the base 5, and the driving device 8 is prepared to push the shield segment 6 to move.

[0044] Step S2, the force transmission steel plate 7 and the driving device 8 are connected with the shield segment 6. The counterforce device is increased at the rear of the driving device 8 to be pre-tightened.

[0045] Step S3, the pressure cover plate 2 and the base 5 are installed, and the sealing rubber strip is arranged at the four edge joints to prevent the grease from overflowing. Other sealing forms can also be used, and the purpose is to prevent the grease in the grease chamber from overflowing.

[0046] Step S4, the pressure adjusting bolt 1 is tightened, and the leveling is performed.

[0047] Step S5, add oil through the oil injection port 3, and determine the oil pressure through the pressure adjusting bolt 1 and the oil cavity pressure sensor.

[0048] Step S6, inject water and sand into the soil chamber pressure cavity 9 through the soil chamber pressure adjusting port 12, and adjust the water pressure and the pressure adjusting bolt 1 to simulate the shield soil chamber pressure of the high water content sandy soil layer.

[0049] Step S7, when the oil pressure and the soil chamber pressure reach the test pressure and are stable, push the shield segment 6 through the driving device 8. During this process, measure the oil chamber pressure and the soil chamber pressure cavity pressure through the pressure sensor, and analyze the sealing performance of the shield tail brush 4 under different soil chamber pressures and shield running speed conditions according to the monitoring data. The jacking force and jacking speed of the shield segment 6 are adjusted by the driving device 8, so as to simulate different relative motion conditions between the shield segment 6 and the shield tail brush 4 in actual engineering.

[0050] After measuring the pressure value during the test process, the sealing performance of the shield tail brush 4 is determined through the following evaluation method.

[0051] When the oil pressure in the sealing chamber (the first oil chamber 10) on one side of the soil pressure chamber is greater than the soil chamber pressure and the pressure maintaining capacity of the shield tail brush 4, the oil is easy to leak from the oil chamber to the soil pressure chamber, that is, when the following formula is greater than 0, the oil leaks on this side, Q Q when the following formula is less than or equal to 0, the oil does not leak on this side;

[0052] Q 1= P 油1 - P 土 - σ 盾

[0053] In the formula: Q 1 is the oil leakage coefficient on one side of the soil chamber pressure cavity 9, P 油1 P1 is the pressure of the first oil chamber 10, P 土 P2 is the pressure of the soil chamber pressure cavity 9, σ 盾 P3 is the pressure maintaining capacity of the shield tail brush 4.

[0054] On the side of the shield tail, when the oil pressure in the second oil chamber 11 is greater than the pressure maintaining capacity of the shield tail brush 4, the oil is easy to leak from the shield tail;

[0055] Q 2= P 油2 - σ 盾

[0056] ​In the formula: Q 2 is the grease leakage coefficient of the tail side, P 油2 P2 is the second grease bin pressure, σ 盾 P4 is the pressure maintaining capacity of the tail brush 4.

[0057] Therefore, after the pressure is stabilized, if the pressure in the soil bin pressure chamber 9 increases, it indicates that the grease leaks to the soil pressure bin; if the pressure in the first grease chamber decreases, it indicates that the grease leaks to the tail, and there is a risk of overturning in the sandy soil layer.

[0058] The embodiments of the application are described in detail above with reference to the drawings, but the application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application.

Claims

1. A test device suitable for testing the sealing performance of a shield tail brush of a shield tunneling machine, characterized in that It comprises: a base (5) for supporting the entire test device; a pressure cover plate (2) mounted on the base (5), and at least two groups of tail brushes (4) are arranged below the pressure cover plate (2), and grease injection ports (3) are arranged on the pressure cover plate (2) between the tail brushes (4), and soil chamber pressure adjusting ports (12) are arranged on the pressure cover plate (2) between the tail brushes (4) and the entrances of the shield segments (6); shield segments (6) located in the slots of the base (5) below the tail brushes (4), and one end of the shield segments (6) is provided with a driving device (8) for driving the shield segments (6) to slide in the slots relative to the tail brushes (4); a pressure adjusting bolt (1) for fixing the pressure cover plate (2) so that the shield segments (6) are in contact with the tail brushes (4); flow sensors and pressure sensors are arranged at the grease injection ports (3) and the soil chamber pressure adjusting ports (12); a force transmission steel plate (7) is arranged between the driving device (8) and the shield segments (6), and the driving device (8) applies jacking force to the shield segments (6) through the force transmission steel plate (7); the driving device (8) is driven by a hydraulic system, and the hydraulic driving system is used to control the jacking force, jacking speed of the shield segments (6) and the movement position of the shield segments (6).

2. The test device for the sealing performance of the tail brush of a shield tunneling machine according to claim 1, characterized in that: The number of the tail brushes (4) is three, and first grease chambers (10) and second grease chambers (11) are formed between adjacent tail brushes (4), and a soil chamber pressure cavity (9) is formed between the tail brush (4) close to the entrance of the shield segment (6) and the base (5).

3. A test method suitable for testing the sealing performance of a shield tail brush of a shield tunneling machine, characterized in that: The test is carried out by using the test device for testing the sealing performance of the tail brush of the shield machine according to claim 1, and the specific steps are as follows: Step S1, butter is applied to both sides and the bottom of the shield segment (6), and the shield segment (6) is pushed to the slot of the base (5), so that a part of the shield segment (6) is inserted into the base (5) at the head; Step S2, the force transmission steel plate (7), the driving device (8) and the shield segment (6) are connected, and a counterforce device is added to the rear of the driving device (8) to pressurize to a pre-tightening state; Step S3, the pressure cover plate (2) and the base (5) are installed, and sealing rubber strips are arranged at the four edge joints to prevent grease from overflowing; Step S4, tighten the pressure adjusting bolt (1) and level it; Step S5, add grease through the grease injection port (3), and determine the grease pressure through the pressure sensor in the grease chamber and the pressure adjusting bolt (1); Step S6, water and sand are injected into the soil chamber pressure cavity (9) through the soil chamber pressure adjusting port (12), and the water pressure and the pressure adjusting bolt (1) are adjusted to simulate the shield soil chamber pressure in high water content sandy soil stratum; Step S7, when the grease pressure and the soil chamber pressure reach the test pressure and are stable, the shield segment (6) is pushed by the driving device (8), and the grease chamber pressure and the soil chamber pressure cavity (9) pressure are measured by the pressure sensor during the process.

4. The test method for the sealing performance of the tail brush of a shield tunneling machine according to claim 3, characterized in that: The evaluation method of the test process is as follows: When the grease pressure in the first grease chamber (10) is greater than the pressure in the soil pressure chamber (9) and the pressure maintaining capacity of the shield tail brush, the phenomenon of leakage of the grease from the grease chamber to the soil pressure chamber is likely to occur, i.e. when the following formula is greater than 0 Q the grease leaks on this side, Q when the following formula is less than or equal to 0, the grease does not leak on this side. Q 1= P 油1 - P 土 - σ 盾 In the formula: Q 1 is the oil leakage coefficient of the soil chamber pressure cavity (9) on one side, P 油1 P1 is the pressure of the first oil chamber (10), P 土 P2 is the pressure of the soil chamber pressure cavity (9), σ 盾 P3 is the pressure maintaining capacity of the shield tail brush. When the oil pressure in the second grease chamber (11) on the side of the shield tail is greater than the pressure maintaining capacity of the tail brush, the phenomenon of oil leakage from the shield tail is easy to occur; Q 2= P 油2 - σ 盾 In the formula: Q 2 is the grease leakage coefficient on the tail side of the shield, P 油2 P2 is the pressure in the second grease reservoir, σ 盾 P3 is the pressure maintaining ability of the tail brush.

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