Device for preventing mud backflow of shield tunnel synchronous grouting pipe and grouting method thereof

Abstract

The present application relates to shield tunnel synchronous grouting technical field, especially to prevent the device of shield tunnel synchronous grouting duct slurry backflow, it includes grouting duct, drive part, blocking door body and connecting duct, grouting duct is docked with connecting duct and communicates, and grouting duct and connecting duct are equipped with blocking door body between, blocking door body is rotatably connected with the end of grouting duct, drive part drives blocking door body to rotate to be used for opening or covering grouting duct, at least two pressure sensors are provided on connecting duct;The present application also provides the grouting method of preventing slurry backflow of the device, the device is through setting grouting duct, drive part, blocking door body and connecting duct, blocking door body is rotatably connected with the end of grouting duct, drive part drives blocking door body to rotate to be used for opening or covering grouting duct, grouting, blocking door body is opened by grouting pressure to facilitate grouting, after grouting is completed, drive part drives blocking door body to block grouting duct mouth, to prevent slurry backflow.

Description

Technical Field

[0001] This invention relates to the field of synchronous grouting technology for shield tunnels, and in particular to a device and grouting method for preventing backflow of grout in synchronous grouting conduits in shield tunnels. Background Technology

[0002] With rapid economic development, subways are being built in more and more cities, including an increasing number of ultra-large diameter tunnel projects. Among the many tunnel construction methods, the shield tunneling method has been widely used due to its advantages such as high efficiency, safety and strong adaptability, especially in urban tunnel construction in soft soil geology.

[0003] During tunnel boring machine (TBM) excavation, factors such as the cutterhead cutting through the soil and rock, the TBM's own vibration, and the voids between the tunnel lining segments and the soil and rock all cause surface deformation. Among the corresponding treatment measures, the most crucial is to inject grout into the gap between the lining ring behind the shield tail and the strata, thereby effectively filling it. This process is called backfill grouting. Simultaneous grouting is a relatively advanced backfill grouting method that has developed in recent years, relying on geotechnical engineering grouting theory and practice, and has achieved significant progress.

[0004] Synchronous grouting in shield tunnels refers to the process during shield tunneling where, after the tunnel segments are assembled, a suitable amount of well-mixed, high-performance grout with a certain early strength is injected into the gap between the tunnel segments and the soil through a synchronous grouting system. After the material hardens, it can form a working system with the tunnel segments and the soil and play a role.

[0005] After tunnel excavation, the original soil equilibrium is disrupted, generating significant soil pressure. When grouting stops, the compressed mud mixture enters the guide pipe, solidifies, and blocks it. The next time it's used, the blockage needs to be cleaned, requiring a large amount of water for flushing. This wastewater flows into the tunnel, hindering further excavation. Sometimes, the guide pipe needs to be disassembled to remove the blockage. Patent application number 202122884419.6 discloses a small guide pipe for tunnel pre-support, which uses a manually rotated grout-stopping disc to open and close the grouting hole. However, this method has a small grouting volume and low grouting efficiency. Summary of the Invention

[0006] This invention provides a device to prevent backflow of grout in the synchronous grouting conduit of a shield tunnel, aiming to solve the problem of grout backflow clogging the conduit.

[0007] To achieve the above objectives, the present invention proposes a device for preventing backflow of grout in a synchronous grouting conduit in a shield tunnel, comprising: a grouting conduit, a drive unit, a blocking gate, and a connecting conduit. The grouting conduit is connected to and connected to the connecting conduit, and a blocking gate is provided between the grouting conduit and the connecting conduit. The blocking gate is rotatably connected to the end of the grouting conduit. The drive unit drives the blocking gate to rotate to open or close the grouting conduit. At least two pressure sensors are provided on the connecting conduit.

[0008] As an optional implementation, in the device for preventing backflow of grouting duct in shield tunnel provided by the present invention, the blocking door includes a central door and side doors respectively disposed on both sides of the central door. The central door and the side doors on both sides are connected by hinges, and a return spring is installed between the central door and the side doors on both sides.

[0009] As an optional implementation, in the device for preventing backflow of grouting duct mud in shield tunnels provided by the present invention, the top end of the central body is provided with a horizontally arranged bushing, and a shaft is provided on the grouting duct at a position corresponding to the bushing. The central body rotates around the shaft through the bushing.

[0010] As an optional implementation, in the device for preventing backflow of grouting duct in shield tunnel provided by the present invention, the blocking gate has a circular structure, and the outer diameter of the blocking gate is larger than the inner diameter of the grouting duct.

[0011] As an optional implementation, in the device for preventing backflow of grouting duct mud in shield tunnels provided by the present invention, the grouting duct is provided with an installation groove along the circumferential direction, and the drive unit is provided in the installation groove.

[0012] As an optional implementation, in the device for preventing backflow of grouting duct mud in shield tunnels provided by the present invention, the driving part is an electromagnet, the electromagnet includes an annular conductive part and a coil wound on the annular conductive part, and part of the coil is used to connect to an external power supply.

[0013] As an optional implementation, in the device for preventing backflow of grouting duct in shield tunnel provided by the present invention, an arc-shaped contraction hole is provided at one end of the grouting duct away from the blocking gate.

[0014] As an optional implementation, in the device for preventing backflow of grouting duct in shield tunnel provided by the present invention, a first pressure sensor is provided at one end of the connecting duct near the grouting duct, and a second pressure sensor is provided at the other end.

[0015] As an optional implementation, in the device for preventing backflow of grouting duct mud in shield tunnels provided by the present invention, the first pressure sensor and the second pressure sensor are located on the same axis.

[0016] Furthermore, the present invention also provides a grouting method for preventing mud backflow in the synchronous grouting duct of a shield tunnel as described above, comprising the following steps:

[0017] S1: When synchronous grouting of the shield tunnel begins, the grout flows from the grouting pipe and breaks through the blocking gate with impact force. The grout flows through the pressure sensor and grouting proceeds normally.

[0018] S2: When grouting ends, the grouting pressure disappears, and the external mud mixture will rush into the connecting pipe. The mud mixture flows through the pressure sensor, and the drive unit drives the blocking gate to rotate and block the grouting pipe to prevent mud backflow.

[0019] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows: In the device for preventing backflow of grout in the synchronous grouting conduit of the shield tunnel provided by the present invention, by setting up a grouting conduit, a driving part, a blocking gate body and a connecting conduit, the conduit can be automatically blocked when grout backflows, without manual operation, with a high degree of automation, saving manpower and material resources; the blocking gate body of the present invention is rotatably connected to the end of the grouting conduit, and the driving part drives the blocking gate body to rotate to open or close the grouting conduit. During grouting, the blocking gate body is pushed open by the grouting pressure to facilitate grouting. After grouting is completed, the driving part drives the blocking gate body to block the grouting conduit opening to prevent grout backflow. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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 the structures shown in these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the device for preventing backflow of grouting duct in shield tunnels provided by the present invention;

[0022] Figure 2 for Figure 1 Schematic diagram of the grouting conduit structure;

[0023] Figure 3 This is a schematic diagram of the installation structure of the drive unit;

[0024] Figure 4 This is a structural diagram of the blocking door;

[0025] Figure 5 This is a schematic diagram of the installation structure of the grouting conduit and the blocking gate.

[0026] [Explanation of Labels in the Attached Image]

[0027] 1: Grouting conduit; 11: Installation slot;

[0028] 2: Driving section; 21: Annular conductive section; 22: Coil;

[0029] 3: Blocking door body; 31: Middle door body; 32: Side door body; 33: Hinge; 34: Bushing; 35: Shaft; 36: Return spring;

[0030] 4: Connect the conduit;

[0031] 51: First pressure sensor; 52: Second pressure sensor;

[0032] 6: Arc-shaped shrinkage hole; Detailed Implementation

[0033] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] It should be noted that all directional indications in the embodiments of the present invention are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0035] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] This invention provides a device for preventing the backflow of grouting duct 1 in a shield tunnel, such as... Figures 1-5As shown, it includes: a grouting conduit 1, a driving unit 2, a blocking gate 3, and a connecting conduit 4. The grouting conduit 1 is connected to and connected to the connecting conduit 4, and a blocking gate 3 is provided between the grouting conduit 1 and the connecting conduit 4. The blocking gate 3 is rotatably connected to the end of the grouting conduit 1. The driving unit 2 drives the blocking gate 3 to rotate to open or close the grouting conduit 1. At least two pressure sensors are provided on the connecting conduit 4.

[0038] The device for preventing backflow of grout in a shield tunnel synchronous grouting conduit 1 provided by the present invention automatically seals the conduit when grout backflow occurs by setting up a grouting conduit 1, a driving unit 2, a blocking gate 3, and a connecting conduit 4. It requires no manual operation, has a high degree of automation, and saves manpower and resources. The blocking gate 3 is rotatably connected to the end of the grouting conduit 1. The driving unit 2 drives the blocking gate 3 to rotate to open or close the grouting conduit 1. During grouting, the blocking gate 3 is opened by the grouting pressure to facilitate grouting. After grouting is completed, the driving unit 2 drives the blocking gate 3 to block the opening of the grouting conduit 1 to prevent grout backflow.

[0039] In the device for preventing backflow of grout in a shield tunnel synchronous grouting conduit 1 provided by the present invention, the blocking door 3 includes a central door 31 and side door 32 respectively disposed on both sides of the central door 31. The central door 31 and the side door 32 are connected by hinges 33. The top of the central door 31 is provided with a horizontally arranged bushing 34. The grouting conduit 1 is provided with a shaft 35 at a position corresponding to the bushing 34. The shaft 35 is horizontally arranged and disposed at the end of the grouting conduit 1. The central door 31 can rotate around the shaft 35 through the bushing 34 for installation. The side door 32 is connected to the central door 31 by door hinges 33 and can be flipped. When the grouting fluid rushes open the door, the side door 32 can be flipped, making the blocking door 3 fit more closely to the inner wall of the conduit, achieving maximum flow output, which is beneficial to the transport of grout.

[0040] like Figure 4 and Figure 5 As shown, in the device for preventing backflow of grout in the synchronous grouting conduit 1 of the shield tunnel provided by the present invention, the blocking gate 3 has a circular structure and can be made of iron sheet structure. It can be magnetically attracted, and the outer diameter of the blocking gate 3 is larger than the inner diameter of the grouting conduit 1 to open and block the grouting conduit 1. In addition, a return spring 36 is installed between the central gate 31 and the side gates 32 on both sides. One end of the return spring 36 is fixed to the central gate 31 and the other end is fixed to the side gate 32. When the blocking gate 3 is opened by the grout and the side gates 32 are flipped, the return spring 36 is deformed by external force, so that the blocking gate 3 fits more closely to the inner wall of the conduit. After grouting is completed, the action of the return spring 36 helps to close the blocking gate 3.

[0041] In addition, in the device for preventing backflow of grouting duct 1 in shield tunnel provided by the present invention, the grouting duct 1 is provided with an installation groove 11 along the circumferential direction, and the driving part 2 is provided in the installation groove 11; the driving part 2 is an electromagnet, the electromagnet includes an annular conductive part 21 and a coil 22 wound on the annular conductive part 21, which is used to attract and block the door 3 when energized, and part of the coil 22 is used to connect to an external power source, wherein the annular conductive part 21 is made of silicon steel.

[0042] Furthermore, in the device for preventing backflow of grout in the synchronous grouting conduit 1 of the shield tunnel provided by the present invention, an arc-shaped contraction hole is provided at one end of the grouting conduit 1 away from the blocking gate 3; by setting the arc-shaped contraction hole, the cross section of the grouting conduit 1 gradually contracts to increase the fluid pressure, which can open the blocking gate 3 by impact force, and at the same time, it is beneficial for the pressure sensor to determine the direction of fluid flow.

[0043] Additionally, a first pressure sensor 51 is provided at one end of the connecting conduit 4 near the grouting conduit 1, and a second pressure sensor 52 is provided at the other end. The first pressure sensor 51 and the second pressure sensor 52 are located on the same axis. When the grout begins to flow normally during grouting, the electromagnet is not energized, and the pressure sensed by the first sensor is greater than the pressure sensed by the second sensor. The grout is then forced open by the grouting force to open the blocking gate 3 for grouting. When the grout flows back after grouting is completed, the second pressure sensor 52 senses a pressure greater than the pressure sensed by the first pressure sensor 51. The electromagnet is then energized and becomes magnetic, attracting the blocking gate 3 to rotate downwards to seal the conduit and prevent backflow.

[0044] The grouting method of the device for preventing backflow of grout duct mud in shield tunnels provided by the present invention includes the following steps:

[0045] S1: When synchronous grouting of the shield tunnel begins, the grout flows from the grouting pipe 1 and breaks through the blocking gate 3 by impact force. The grout flows through the pressure sensor and grouting proceeds normally.

[0046] S2: When grouting ends, the grouting pressure disappears, and the external mud mixture will rush into the connecting pipe. The mud mixture flows through the pressure sensor, and the drive unit 2 drives the blocking gate 3 to rotate and block the grouting pipe 1 to prevent mud backflow.

[0047] Specifically, the working process of the grouting method of the device for preventing backflow of grout in the synchronous grouting conduit of the shield tunnel is as follows: When the synchronous grouting of the shield tunnel begins, the electromagnet is not energized, the pressure sensor is turned on, and the grout pressure at the arc-shaped contraction hole of the grouting conduit 1 further increases. The grout relies on the impact force to break through the blocking gate 3. The side gates 32 on both sides of the blocking gate 3 flip around the hinge 33 and stick tightly to the upper wall of the conduit. The reset spring 36 deforms and generates a force that restores the side gates 32 to their original position. The grout flows through the pressure sensor, and the pressure sensed by the first pressure sensor 51 is greater than the pressure sensed by the second pressure sensor 52. When this stage of grouting ends, the grouting pressure disappears. Due to the shield tunneling disrupting the original soil balance, earth pressure is generated. Under the action of earth pressure, the external mud mixture will flow into the duct. The mud mixture flows through the pressure sensor. The second pressure sensor 52 senses a pressure greater than the first pressure sensor 51 senses a pressure. The electromagnet coil 22 is energized, and the electromagnet generates magnetism, attracting the blocking gate 3 to block the duct. The blocking gate 3 rotates around the shaft 35. The force generated by the reset spring 36 makes the side gates 32 on both sides return to their original positions. The blocking gate 3 completely blocks the grouting duct 1. The mud mixture is blocked outside the blocking gate 3 and can no longer flow into the depth of the duct, so the inside of the duct will not be blocked by the mud mixture.

[0048] After the next segment is assembled, the above process is repeated, and synchronous grouting begins again. When the electromagnet coil 22 is de-energized and its magnetism disappears, the pressure of the grout increases at the arc-shaped contraction hole of the grouting conduit 1. The impact force opens the blocking gate 3, and the grout fills the gap between the segment and the soil. The grout flows through the pressure sensor, and the pressure sensed by the first pressure sensor 51 is greater than that sensed by the second pressure sensor 52. After the grouting of this segment is completed, the grouting pressure disappears, and the external mud mixture rushes into the conduit under the action of soil pressure. The mud mixture flows through the pressure sensor, and the pressure sensed by the second pressure sensor 52 is greater than that sensed by the first pressure sensor 51. The electromagnet coil 22 is energized, and the electromagnet generates magnetism, attracting the blocking gate 3 to block the conduit. The blocking gate 3 rotates around the shaft 35, and the force generated by the return spring 36 causes the side gates 32 on both sides to return to their original positions. The blocking gate 3 completely blocks the grouting conduit 1, and the mud mixture is blocked outside the blocking gate 3, unable to rush into the depth of the conduit, thus preventing the conduit from being blocked by the mud mixture.

[0049] After the segments are assembled, repeat this process until all segments are assembled and the gaps between the segments and the soil are filled by grouting.

[0050] It should be understood that the above description of specific embodiments of the present invention is only for illustrating the technical approach and features of the present invention, and is intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. However, the present invention is not limited to the specific embodiments described above. All changes or modifications made within the scope of the claims of the present invention should be covered within the protection scope of the present invention.

Claims

1. A device for preventing backflow of grouting duct mud in a shield tunnel, characterized in that, The device includes a grouting conduit (1), a drive unit (2), a blocking gate (3), and a connecting conduit (4). The grouting conduit (1) is connected to and communicates with the connecting conduit (4). A blocking gate (3) is provided between the grouting conduit (1) and the connecting conduit (4). The blocking gate (3) is rotatably connected to the end of the grouting conduit (1). The drive unit (2) drives the blocking gate (3) to rotate to open or close the grouting conduit (1). At least two pressure sensors are provided on the connecting conduit (4). The blocking door (3) includes a central door (31) and side door (32) respectively located on both sides of the central door (31). The central door (31) and the side door (32) are connected by hinges (33). A return spring (36) is installed between the central door (31) and the side door (32) respectively. The side door (32) flips relative to the central door (31), so that the blocking door (3) can fit against the inner wall of the conduit during grouting to reduce flow resistance. Under the action of the return spring (36), it returns to the initial position at the end of grouting to block the mud mixture in the grouting conduit (1) outside the blocking door (3). An arc-shaped shrinkage hole is provided at one end of the grouting conduit (1) away from the blocking door (3). A first pressure sensor (51) is provided at one end of the connecting conduit (4) near the grouting conduit (1), and a second pressure sensor (52) is provided at the other end. The driving unit (2) is used to drive the blocking gate (3) to rotate according to the pressure difference value of the first pressure sensor (51) and the second pressure sensor (52) to open or close the grouting conduit (1). Specifically, when the pressure value detected by the first pressure sensor (51) is greater than the pressure value of the second pressure sensor (52), the driving unit (2) is de-energized to open the blocking gate (3) under the impact of grouting; when the pressure value detected by the second pressure sensor (52) is greater than the pressure value of the first pressure sensor (51), the driving unit (2) is energized to attract the blocking gate (3) to close.

2. The device for preventing backflow of grouting duct mud in shield tunnels according to claim 1, characterized in that, The top of the central body (31) is provided with a horizontally arranged bushing (34), and the grouting conduit (1) is provided with a shaft (35) at a position corresponding to the bushing (34). The central body (31) rotates around the shaft (35) through the bushing (34).

3. The device for preventing backflow of grouting duct mud in shield tunnels according to claim 2, characterized in that, The blocking gate (3) has a circular structure, and the outer diameter of the blocking gate (3) is larger than the inner diameter of the grouting conduit (1).

4. The device for preventing backflow of grouting duct mud in shield tunnels according to any one of claims 1-3, characterized in that, The grouting conduit (1) is provided with an installation groove (11) along the circumferential direction, and the drive unit (2) is provided in the installation groove (11).

5. The device for preventing backflow of grouting duct mud in shield tunnels according to claim 4, characterized in that, The driving part (2) is an electromagnet, which includes an annular conductive part (21) and a coil (22) wound on the annular conductive part (21). Part of the coil (22) is used to connect to an external power source.

6. The device for preventing backflow of grouting duct mud in shield tunnels according to any one of claims 1-3, characterized in that, The first pressure sensor (51) and the second pressure sensor (52) are located on the same axis.

7. A grouting method for preventing mud backflow using a device for preventing mud backflow in a synchronous grouting duct of a shield tunnel as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: When the synchronous grouting of the shield tunnel begins, the grout flows from the grouting pipe (1) and breaks through the blocking gate (3) by impact force. The grout flows through the pressure sensor and the grouting proceeds normally. S2: When the grouting ends, the grouting pressure disappears, and the external mud mixture will rush into the connecting pipe. The mud mixture flows through the pressure sensor, and the drive unit (2) drives the blocking gate (3) to rotate and seal the grouting pipe (1) to prevent the mud from flowing back.

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