A sealing air bag tool for shield tunneling and a method of use

Abstract

The application discloses a sealing air bag tool for shield tunneling in and out of a hole, which comprises a hole portal foundation bearing assembly and an outer air and inner grease double-layer sealing assembly. The hole portal foundation bearing assembly comprises a hole portal embedded steel ring, an externally connected extended steel ring and a foundation sealing element. The hole portal embedded steel ring is embedded in concrete, and the externally connected extended steel ring is rigidly connected to one end of the hole portal embedded steel ring and provided with a recess and a mounting hole on the other end. The outer air and inner grease double-layer sealing assembly comprises an outer cavity air bag, an inner cavity grease bag and a gas and grease control unit. The inner cavity grease bag is arranged in the outer cavity air bag. The gas and grease control unit comprises a gas and grease mixing injection head and a gas pressure monitoring element. The gas and grease mixing injection head is connected to the gas cavity of the outer cavity air bag and the grease cavity of the inner cavity grease bag respectively, and the gas pressure monitoring element is arranged in the outer cavity air bag to monitor the pressure change in the outer cavity air bag in real time. The application realizes dynamic sealing and fitting of a shield tunneling machine when the shield tunneling machine starts and receives in and out of a hole, quickly adapts to space change caused by gradient change and blocks a stratum leakage channel.

Description

Technical Field

[0001] This invention relates to the field of sealing for tunnel boring machines (TBMs) entering and exiting tunnels. More specifically, this invention relates to a sealing airbag fixture for TBMs entering and exiting tunnels and its method of use. Background Technology

[0002] As shield tunneling projects, including urban tunnels, water intake tunnels, and deep pipeline networks, develop towards greater depth, size, length, geological undulations, and more complex surface conditions, the initial entry and exit phase of the tunnel boring machine (TBM) has become the most risky and prone to failure due to ground loss during TBM construction, attracting special attention from project managers. The sealing of the TBM's entry and exit portals is affected by variations in the diameter of the TBM's excavation diameter, the gradient of the front shield, the gradient of the front shield, the gradient of the middle shield, and the gradient of the tail shield, as well as the diameter variations of the tunnel segment. Other factors include the failure of the sliding elastic seal of the portal due to excessive eccentric pressure and load during TBM entry and exit, and the ease with which the lower curtain rubber flap pressure plate can be folded or damaged without repair space or means. Consequently, the portal sealing lacks reliable, elastic, dynamic, and redundant safety measures.

[0003] In previous high-risk operations of tunnel boring machine (TBM) launching and receiving, engineering design and construction management personnel have used strong reinforcement measures for unfavorable geological ends, such as vertical freezing reinforcement, U-shaped or mouth-shaped plain concrete walls with dewatering wells, and sleeve auxiliary processes, to avoid the leakage, soil and water loss and excessive ground settlement caused by insufficient sliding seal of the tunnel portal. Summary of the Invention

[0004] To achieve these objectives and other advantages according to the invention, a preferred embodiment of the invention provides a sealing airbag fixture for tunnel boring machine (TBM) entry and exit, comprising a tunnel portal foundation support assembly and an external air / internal grease double-layer sealing assembly, wherein... The portal foundation bearing assembly includes a portal embedded steel ring, an external extension steel ring, and a foundation sealing element. The portal embedded steel ring is embedded in concrete. One end of the external extension steel ring is rigidly connected to the portal embedded steel ring, and the other end has a pre-set groove and installation hole on its inner side. The foundation sealing element includes a sealing wire brush and a curtain rubber plate, which are arranged sequentially along the inner side of the external extension steel ring and fixed to the inner wall of the external extension steel ring by bolts to form a primary sealing layer. The dual-layer sealing assembly includes an outer air bladder, an inner grease bladder, and an air-grease control unit. The inner grease bladder is disposed inside the outer air bladder. The air-grease control unit includes an air-grease mixing injection head and a pressure monitoring element. The air-grease mixing injection head is connected to the air cavity of the outer air bladder and the grease cavity of the inner grease bladder, respectively. The pressure monitoring element is built into the outer air bladder to monitor the pressure changes inside the outer air bladder in real time.

[0005] Preferably, it also includes an emergency towing sealing assembly, which includes a lower 120° emergency towing airbag chamber, a quick-installable airbag assembly, and a towing and inflation unit; the lower 120° emergency towing airbag chamber is a cavity pre-set between the curtain rubber plate and the sealing wire brush, and is only distributed in the lower 120° range of the tunnel entrance; the lower 120° emergency towing airbag chamber is provided with openable and closable covers on both sides, and the towing and inflation unit is pre-inserted into its cavity; the quick-installable airbag assembly is located in the lower 120° emergency towing airbag chamber, one end of the towing and inflation unit is connected to the quick-installable airbag assembly, and the other end extends to the outside of the tunnel entrance.

[0006] Preferably, the outer cavity airbag is mechanically fixed by being embedded in the preset groove of the external extension steel ring through the protruding rubber platform at the bottom, and the outer cavity airbag is located outside the action range of the sealing wire brush, forming a layered sealing structure with the basic sealing element; When the outer cavity airbag or the basic seal fails to seal, the airbag assembly can be quickly installed to the area of ​​the seal failure of the outer cavity airbag by dragging and inflating the unit. After inflation, it fits against the outside of the outer cavity airbag to form an emergency seal compensation.

[0007] Preferably, grease is injected into the inner grease bladder through a gas-grease mixing injection head. When the outer grease bladder is damaged and cannot maintain pressure, the grease injected into the inner grease bladder expands to form a flexible seal, and the outer grease bladder acts as its protective sleeve, contacting external rigid bodies and debris.

[0008] Preferably, the gas-grease mixing injection head includes a grease injection inner tube and an inflation tube. The grease injection inner tube is located inside the inflation tube, and the length of the grease injection inner tube is greater than the length of the inflation tube. When inflating, the inner screw plug of the grease injection inner tube is closed, and the inflation tube is connected through the inflation tube and spring clip. When injecting grease, the inflation tube is removed and a sealing cap is installed. After unscrewing the plug of the grease injection inner tube, it is connected to the grease injection pipeline, which can realize the interchange of gas and grease media.

[0009] Preferably, the lower 120° emergency towing airbag chamber is located outside the reverse bending influence zone of the curtain rubber plate. The airbag assembly can be quickly installed and locked by inserting and unplugging the nylon rope of the towing and inflation unit through the locking holes on both sides. The airbag assembly is composed of multiple airbag components spliced ​​together, with adjacent airbag components connected in series. The number of airbag components can be adjusted to adapt to different leakage ranges.

[0010] Preferably, the outer cavity airbag is an inflatable sealing body with a raised rubber platform at the bottom. The outer cavity airbag is divided into several blocks according to the diameter of the opening, and adjacent blocks are connected by an irregularly shaped structure.

[0011] Another preferred embodiment of the present invention provides a method for using a sealing airbag fixture for tunnel boring machine entry and exit, characterized by comprising the following steps: S1. After the shield machine cutterhead passes through the working shaft structure portal sealing device, pressurized gas is injected into the outer cavity airbag through the gas-grease mixing injection head, causing the outer cavity airbag to expand and squeeze and wrap the shield body, forming the third sealing system of the portal. S2. As the tunnel boring machine moves forward, the gradient change of the shield body causes the space of the sealing cavity to change. The curtain rubber plate is tightened by the springback of the folding pressure plate, the sealing wire brush springs up and fits tightly, and the outer cavity airbag monitors the internal pressure in real time through the air pressure monitoring element and inflates and deflates the outer cavity airbag in real time to maintain the tight fit between the outer cavity airbag and the shield body / segment. S3. Repeat S1 and S2 until the tunnel segment passes through the tunnel portal sealing device, which serves as the outer template for the tunnel portal grouting, assisting in compensating for the gap between the tunnel portal and the tunnel segment with grouting and sealing, thus completing the permanent seal.

[0012] Preferably, during use, when foreign objects, sharp objects, or the outer peripheral cutter of the tunnel boring machine cutterhead puncture the outer side of the airbag in the tunnel portal sealing area, causing the air pressure to be unable to be dynamically maintained, or when the outer peripheral airbag is damaged during the slurry shield construction process and the air pressure cannot be dynamically maintained, the sealing airbag is expanded by injecting grease into the built-in grease bladder, which wraps tightly around and binds the outer periphery of the gradient change of the cutterhead-shield-segment, thereby achieving tunnel portal sealing.

[0013] Preferably, during use, when the folding plate of the curtain rubber sheet bends in the opposite direction, or when the sealing device is damaged or pulled off due to posture bias, resulting in leakage, the quick-installable airbag assembly, which is pre-placed in the lower 120° emergency towing airbag cavity, is towed to the leakage or failure area through the towing and inflation unit; gas is then injected into the quick-installable airbag assembly through the hollow tube of the towing and inflation unit, causing it to expand and tightly adhere to the outer periphery of the shield, forming an emergency seal and blocking the leakage channel.

[0014] The present invention has at least the following beneficial effects: (1) The airbag fixture of the present invention realizes dynamic sealing and fitting of the shield machine starting and receiving in and out of the tunnel, quickly adapts to the spatial changes caused by gradient changes, and blocks the seepage channels of the stratum. (2) The airbag fixture of the present invention has a double-layer insurance of external airbag inflation and internal grease bag grease sealing. When the external airbag ruptures and loses pressure and dynamic compensation fails, the internal grease bag is activated. The external airbag serves as a protection system for the internal grease bag, ensuring functional safety and reliability. (3) In the airbag tooling of the present invention, the external airbag and the internal grease bag are only medium changes, and the internal grease filling has the characteristics of stability, soft deformation and good tightness. In emergency situations, the grease can be discharged after the double airbag is filled, or the use of the double grease bag can be changed. (4) In the airbag fixture of the present invention, the emergency dragging airbag in the lower 120° range solves the high-frequency failure problem between the external curtain rubber plate and the folding plate and the steel wire sealing brush. It quickly drags the airbag assembly to the place where the sealing device loses its elasticity and cannot be folded and sealed, and inflates and wraps it to eliminate the leakage channel. It solves the disadvantages of poor operability, no working space and slow and long time consumption of the emergency blockage solution for the lower leakage channel, and quickly realizes the closure of the leakage channel.

[0015] (5) In the airbag tooling of the present invention, the pressure monitoring element provides real-time feedback on the pressure change inside the airbag wall, providing a basis for the activation of internal grease injection, inflation or grease compensation, etc. (6) In the airbag tooling of the present invention, the airbag combination, the towed emergency airbag, etc. can all achieve zero pollution, high turnover, reuse and functional expansion. It is an environmentally friendly, cost-effective and functionally expandable high-efficiency tooling.

[0016] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0017] Figure 1 This is a side view of the sealing airbag fixture used for shield tunneling in and out of the tunnel in this invention.

[0018] Figure 2 This is a schematic diagram of the structure of the double-layer sealing assembly with external air and internal grease in this invention.

[0019] Figure 3 This is a schematic diagram of the structure of the gas-grease mixing injection head in this invention.

[0020] Figure 4 This is a schematic diagram of the lower 120° emergency towing airbag cavity in this invention.

[0021] Figure 5 This is a side view of the gradient changes between the shield machine cutterhead, shield body, and tunnel segments as the tunnel boring machine (TBM) enters and exits the tunnel. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0023] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious modifications will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0024] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0025] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0026] like Figure 1-5 As shown, a preferred embodiment of the present invention provides a sealing airbag fixture for tunnel boring machine (TBM) entry and exit, including a tunnel portal foundation support assembly and an external air-oil double-layer sealing assembly 3. The tunnel portal foundation support assembly is connected to the external air-oil double-layer sealing assembly, wherein... The portal foundation bearing assembly includes a portal embedded steel ring 1, an external extension steel ring 2, and a foundation sealing element. The portal embedded steel ring is embedded in concrete. One end of the external extension steel ring 2 is rigidly connected to the portal embedded steel ring 1, and the other end has a pre-set groove and installation hole on its inner side. The foundation sealing element includes a sealing wire brush 7 and a curtain rubber plate 8, which are arranged sequentially along the inner side of the external extension steel ring 2 and fixed to the inner wall of the external extension steel ring 2 by bolts to form a primary sealing layer. The dual-layer sealing assembly 3 includes an outer air bladder 4, an inner grease bladder 5, and an air-grease control unit. The inner grease bladder 5 is disposed inside the outer air bladder 4. The air-grease control unit includes an air-grease mixing injection head 12 and a pressure monitoring element 14. The air-grease mixing injection head 12 is connected to the air cavity of the outer air bladder 4 and the grease cavity of the inner grease bladder 5, respectively. The pressure monitoring element 14 is built into the outer air bladder 4 to monitor the pressure changes inside the outer air bladder in real time.

[0027] In the above technical solution, the pre-embedded steel ring 1 of the tunnel portal is pre-cast into the concrete structure at the tunnel portal, serving as the reference fixing component for the entire tooling. One end of the external extension steel ring 2 is rigidly connected to the pre-embedded steel ring 1 of the tunnel portal by welding or flange bolts, while the other end has a groove and mounting hole machined on its inner side. The groove is used to fix the outer cavity airbag 4, and the mounting hole is used to fix the base sealing component. The curtain rubber plate 8 and the sealing wire brush 7 in the base sealing component are arranged sequentially from the outside to the inside along the inner side of the external extension steel ring 2, and are fixed to the inner wall of the pre-embedded steel ring 1 of the tunnel portal by bolts passing through the mounting hole. The curtain rubber plate 8 is made of wear-resistant rubber material, and the edge is provided with a folding pressure plate, which can rebound through its own elasticity. The sealing wire brush 7 is composed of spring steel plate and dense steel wire, with the top of the steel wire slightly inclined outward, and is kept in contact with the outer periphery of the shield by the elasticity of the spring steel plate.

[0028] The outer cavity airbag 4 is made of high-strength wear-resistant rubber, with a raised rubber platform integrally formed at the bottom. The inner cavity grease bladder 5 is nested inside the outer cavity airbag 4. Both are made of the same material, and the surface of the inner cavity grease bladder 5 has a herringbone pattern to increase friction with the outer cavity airbag 4. The gas-grease mixing injection head 12 is installed at the ends of the outer cavity airbag 4 and the inner cavity grease bladder 5. It has two independent channels inside, which connect the air cavity of the outer cavity airbag 4 and the grease cavity of the inner cavity grease bladder 5 respectively. The air pressure monitoring element 14 is embedded in the inner wall of the outer cavity airbag 4 and is connected to an external monitoring device through a wire, which can transmit the pressure data inside the cavity in real time. During assembly, the outer cavity airbag 4 is inserted into the preset groove of the external extension steel ring 2 through the raised rubber platform at the bottom, realizing mechanical fixation with the portal foundation bearing component and forming a layered sealing structure.

[0029] The portal foundation support assembly provides a stable installation base for the entire tooling. The sealing wire brush 7 and the curtain rubber plate 8 form a primary seal, which can initially prevent water and soil leakage inside and outside the portal. The external air and internal grease double-layer sealing assembly further conforms to the outer periphery of the shield through the inflation and expansion of the external cavity airbag 4, enhancing the sealing effect; the air pressure monitoring element 14 monitors the external cavity pressure in real time, providing a basis for subsequent seal adjustments.

[0030] Another technical solution also includes an emergency towing sealing assembly, which includes a lower 120° emergency towing airbag chamber 6, a quick-installable airbag assembly 11, and a towing and inflation unit. The lower 120° emergency towing airbag chamber 6 is a cavity pre-set between the curtain rubber plate 8 and the sealing wire brush 7, and is only distributed in the lower 120° range of the tunnel entrance. The lower 120° emergency towing airbag chamber 6 is provided with openable and closable covers on both sides, and the towing and inflation unit is pre-inserted into its cavity. One end of the towing and inflation unit 9 is connected to the quick-installable airbag assembly 11, and the other end extends to the outside of the tunnel entrance.

[0031] In the above technical solution, when installing the curtain rubber plate 8 and the sealing wire brush 7, an annular cavity is reserved in the lower 120° range of the opening between them. Openable and closable metal covers are installed on both sides of the cavity. The covers are connected by hinges, normally closed to protect the internal structure, and opened for easy access to the airbag assembly in an emergency. The towing and inflation unit 9 is made of high-strength nylon and has a hollow channel inside. One end is pre-inserted into the lower 120° emergency towing airbag cavity 6, and the other end extends to the operating platform outside the opening. A quick connector is provided at the end for connecting to inflation equipment. Each airbag component of the quick-installable airbag assembly 11 is elongated, and adjacent airbag components can be detached and connected in series. The number of airbag components can be increased or decreased according to the leakage range. During assembly, the quick-installable airbag assembly 11 is folded and placed into the lower 120° emergency towing airbag cavity 6, with one end connected and fixed to the inner end of the towing and inflation unit 9 through a locking hole. When needed, the operator pulls the outer end of the towing and inflation unit 9 outside the tunnel entrance to pull the quick-installation airbag assembly 11 out of the cavity to the leakage area, and then inflates the airbag assembly with pressurized gas.

[0032] The addition of the emergency towable sealing assembly solves the problem of sealing operations being difficult due to limited space at the bottom of the tunnel entrance during shield tunneling. When the basic seal or the external air-inner grease double-layer sealing assembly fails, the quick-installable airbag assembly 11 can be rapidly deployed to the leakage point via the towable and inflation unit 9. After inflation, it forms a temporary seal, effectively preventing water and soil seepage. Its modular design allows for flexible adjustment of the sealing range, is easy to operate, and responds quickly, adding an emergency guarantee for shield tunneling construction and further reducing the risk of seal failure.

[0033] In another technical solution, the outer cavity airbag 4 is mechanically fixed by embedding the protruding rubber platform at the bottom into the preset groove of the external extension steel ring 2, and the outer cavity airbag 4 is located outside the action range of the sealing wire brush, forming a layered sealing structure with the basic sealing component. When the outer cavity airbag or the basic seal fails to seal, the airbag assembly can be quickly installed to the area of ​​the seal failure of the outer cavity airbag by dragging and inflating the inflation unit 9. After inflation, it fits against the outside of the outer cavity airbag to form an emergency seal compensation.

[0034] In the above technical solution, during installation, the protruding rubber platform of the outer cavity airbag 4 is aligned with the groove, and pressure is applied to embed it. The elastic deformation of the rubber makes the two fit tightly together, achieving mechanical fixation and preventing gas leakage from the connection. When the tunnel boring machine moves forward, the curtain rubber plate 8 first rebounds and fits tightly against the outer circumference of the shield through the folding pressure plate, and the sealing wire brush 7 then further fits tightly through the elasticity of the spring steel plate. Finally, the outer cavity airbag 4 is squeezed and fitted by the inflation pressure. The three-layer structure plays its role in sequence. When the outer cavity airbag 4 cannot maintain pressure due to damage or when the basic seals leak, the emergency towing sealing assembly is activated: the operator opens the cover plate of the lower 120° emergency towing airbag cavity 6, pulls the towing and inflation unit 9 to drag the quick-install airbag assembly 11 to the failure area 10, ensuring that the airbag assembly completely covers the leakage point; after connecting the inflation equipment, gas is slowly inflated, causing the airbag assembly to gradually expand until it fits tightly against the outer side of the outer cavity airbag 4 and the outer circumference of the shield, forming a circumferential seal.

[0035] In another technical solution, grease is injected into the inner grease bladder through the gas-grease mixing injection head 12. When the outer grease bladder is damaged and cannot maintain pressure, the grease injected into the inner grease bladder expands to form a flexible seal, and the outer grease bladder acts as its protective sleeve and comes into contact with the external rigid body and debris.

[0036] In the above technical solution, the grease channel of the gas-grease mixing injection head 12 is connected to an external high-pressure grease pump. The sealing grease stored in the grease pump is in paste form, with good adhesion and compression resistance. When the air pressure monitoring element 14 detects a continuous drop in pressure in the outer cavity airbag 4 and confirms that the outer cavity airbag 4 is damaged beyond repair, the grease injection procedure is initiated: first, the inflation channel of the outer cavity airbag 4 is closed to prevent gas leakage from affecting the grease injection effect; then, the grease pump is turned on, and the sealing grease enters the inner cavity grease bladder 5 through the grease injection inner tube 15, causing it to gradually expand. The herringbone pattern on the surface of the inner cavity grease bladder 5 is about 1mm deep, which can increase the friction with the inner wall of the outer cavity airbag 4 and prevent relative sliding between the two during grease expansion. At this time, although the damaged outer cavity airbag 4 cannot be inflated, it can still block external debris such as gravel and steel bars through its outer steel wire nylon protective sleeve, preventing puncture of the inner cavity grease bladder 5; at the same time, the rubber material of the outer cavity airbag 4 can evenly transmit the expansion force of the inner cavity grease bladder 5 to the outer periphery of the shield, making the grease bladder fit tightly. The amount of grease injected needs to be determined based on the gap between the outer periphery of the shield and the outer cavity airbag 4. Usually, the grease bag is expanded to fit the outer periphery of the shield and the pressure is stable.

[0037] The activation of the inner grease bladder 5 provides a reliable backup sealing solution in the event of external airbag failure. The properties of the sealing grease allow it to adapt to gradient changes around the shield's perimeter, tightly filling gaps and effectively preventing water and soil leakage. The protective function of the outer airbag 4 prevents direct damage to the inner grease bladder 5 from foreign objects, extending its service life. This dual-insurance design of external air and internal grease significantly improves the fault tolerance of the sealing system, ensuring that sealing function is maintained even if a single seal fails, thus guaranteeing the continuity of shield tunneling construction.

[0038] In another technical solution, the gas-grease mixing injection head includes a grease injection inner tube 15 and an inflation tube 16. The grease injection inner tube is the inner tube of the gas-grease mixing injection head, and its diameter is smaller than that of the inflation tube 16, while its length is greater than that of the inflation tube 16. The inflation tube 16 is the outer tube of the gas-grease mixing injection head, with a grease injection tube embedded inside. It is opened or closed by a stopcock. When inflating, the inner screw-type stopcock of the grease injection inner tube 15 is closed, and the inflation tube is connected through the inflation tube 16 and a spring clip. When injecting grease, the inflation tube is removed and a sealing cap is installed. After unscrewing the stopcock of the grease injection inner tube, it is connected to the grease injection pipeline, which can realize the interchange of gas and grease media.

[0039] In the above technical solution, during assembly, the grease injection inner tube 15 is coaxially inserted into the inflation tube 16, and the gap between the two is sealed by a sealing ring to prevent the media from mixing. The inflation tube 16 connects to the air chamber of the outer cavity airbag 4, and the grease injection inner tube 15 connects to the grease chamber of the inner cavity grease bladder 5. During inflation, the inner screw plug of the grease injection inner tube 15 is rotated to close, the plug of the inflation tube 16 is opened, and the quick connector of the inflation tube is connected to the end of the inflation tube 16 via a spring clip. Pressurized gas enters the outer cavity airbag 4 evenly through the small hole of the inflation tube 16. During grease injection, the inflation tube is removed, an O-ring seal is installed at the end of the inflation tube 16, the inner screw plug of the grease injection inner tube 15 is rotated to open, and the grease injection tube is connected to its end. The sealed grease enters the inner cavity grease bladder 5 through the inner tube. If the media needs to be interchanged, for example, grease is injected into the outer cavity airbag 4 and the inner cavity grease bladder 5 is inflated, the operation can be reversed.

[0040] In another technical solution, the lower 120° emergency towing airbag chamber is located outside the reverse bending influence zone of the curtain rubber plate. The quick-installable airbag assembly 11 can be quickly inserted and locked by the nylon rope of the towing and inflation unit 9 through the locking holes on both sides. The quick-installable airbag assembly 11 is composed of multiple airbag components spliced ​​together, and adjacent airbag components are connected in series. The number of airbag components can be adjusted to adapt to different leakage ranges.

[0041] In the above technical solution, the position of the lower 120° emergency towing airbag chamber 6 must be determined to avoid the area affected by the reverse bending of the curtain rubber plate 8, ensuring that the curtain rubber plate 8 will not squeeze or damage the airbag assembly inside the chamber when it bends in the reverse direction. The quick-installable airbag assembly 11 is composed of multiple airbag components spliced ​​and connected in series. When the leakage range is small, 1-2 airbag components are used; when the range is large, 3-5 airbag components can be connected in series, and the number can be adjusted to adapt to different sizes of leakage areas.

[0042] In another technical solution, the outer cavity airbag 4 is an inflatable sealing body with a raised rubber platform at its bottom. The outer cavity airbag 4 is divided into several blocks according to the diameter of the opening, and adjacent blocks are connected by an irregular concave-convex structure.

[0043] In the above technical solution, the number of sections of the outer cavity airbag 4 is determined according to the diameter of the tunnel entrance: 4 sections for tunnel entrance diameters of 6-8 meters; 6 sections for diameters of 8-10 meters; and 8 sections for diameters above 10 meters. This segmented design of the outer cavity airbag 4 allows it to adapt to tunnel entrances of different diameters, improving the versatility of the tooling. The curvature of each airbag matches the curvature of the tunnel entrance. The edges of each airbag are machined into an irregular concave-convex structure, with one edge protruding outwards to form a flange, and the other edge concave inwards to form a groove. The groove size matches the flange, ensuring that the flange can be fully embedded in the groove when two adjacent airbags are joined. The airbag is made of nitrile rubber, which has good wear resistance and elasticity. The raised rubber platform at the bottom is integrally vulcanized with the airbag to ensure connection strength. During installation, first insert the raised rubber platform of the first airbag into the groove of the outer extension steel ring 2. Then align the groove of the second airbag with the flange of the first airbag and gently press to fit them together. Repeat this process to assemble all the airbag blocks, forming a complete ring-shaped airbag. After inflation, the flanges and grooves of adjacent airbag blocks fit tightly together under gas pressure. The flanges are compressed and deformed, filling the gaps in the grooves and preventing gas leakage from the joints. Additionally, the corners of each airbag are designed to be rounded to prevent damage to right-angled corners due to stress concentration during inflation.

[0044] Another technical solution provides a method for using a sealing airbag fixture for tunnel boring machine entry and exit, including the following steps: S1. After the shield machine cutterhead passes through the working shaft structure portal sealing device, pressurized gas is injected into the outer cavity airbag 4 through the gas-grease mixing injection head 12, causing the outer cavity airbag 4 to expand and squeeze and wrap the shield body, forming the third sealing system of the portal. S2. As the tunnel boring machine moves forward, the gradient change of the shield body causes the space of the sealing cavity to change. The curtain rubber plate 8 is tightened by the springback of the folding pressure plate, and the sealing wire brush 7 springs up to fit tightly. The outer cavity airbag 4 monitors the internal pressure in real time through the air pressure monitoring element 14 and inflates and deflates the outer cavity airbag 4 in real time to maintain the tight fit between the outer cavity airbag 4 and the shield body / segment. S3. Repeat S1 and S2 until the tunnel segment passes through the tunnel portal sealing device, which serves as the outer template for the tunnel portal grouting, assisting in compensating for the gap between the tunnel portal and the tunnel segment with grouting and sealing, thus completing the permanent seal.

[0045] In step S1, after the tunnel boring machine cutterhead has completely passed through the curtain rubber plate 8 and the sealing wire brush 7, the operator, on the operating platform outside the tunnel entrance, injects compressed air into the outer cavity airbag 4 through the inflation tube 16 of the gas-grease mixing injection head 12. The initial air pressure is set to 0.2 MPa, and the reading of the air pressure monitoring element 14 is observed. After the pressure stabilizes, it is slowly increased to 0.3-0.5 MPa (adjusted according to geological conditions), causing the outer cavity airbag 4 to expand and tightly wrap around the shield body, forming the third seal. At this time, the hinge plate of the curtain rubber plate 8 rebounds under its own elasticity and adheres tightly to the outer periphery of the shield body; the spring steel plate of the sealing wire brush 7 springs upward under force, causing the wires to adhere tightly to the shield body, and the three work together to form the initial seal.

[0046] In step S2, as the tunnel boring machine moves forward, the gradient 20 between the cutterhead and the front shield, the gradient 21 between the front shield, the middle shield, and the tail shield, and the gradient 22 between the tail shield and the tunnel segment pass through the sealing area in sequence, causing the spatial dimensions of the sealing cavity to change continuously. The air pressure monitoring element 14 transmits the internal pressure data of the outer cavity airbag 4 to the control console in real time. When the pressure is lower than the set value, the pressurized gas injection system automatically starts to replenish the gas; when the pressure is higher than the set value, the exhaust valve automatically opens to release some gas, ensuring that the outer cavity airbag 4 is always in close contact with the shield / tunnel segment.

[0047] In step S3, operations S1 and S2 are repeated until the last ring of tunnel segments completely passes through the portal sealing device. At this time, the outer cavity airbag 4 remains inflated, with its outer side fitting against the portal extension steel ring and its inner side fitting against the outer circumference of the tunnel segment, forming a closed annular space that serves as a grouting template. Cement grout is injected into this space through a pre-set grouting pipe. After the grout solidifies, it fills the gap between the portal and the tunnel segment, completing a permanent seal. Subsequently, air is released from the outer cavity airbag 4, separating it from the tunnel segment.

[0048] This method utilizes the dynamic inflation and deflation of the external airbag 4 to achieve adaptive sealing in response to changes in the gradient around the tunnel boring machine (TBM), ensuring continuous sealing during the TBM's entry and exit from the tunnel. The initial seal provides a fundamental guarantee for construction, dynamic pressure adjustment adapts to spatial changes at different stages, and the grouting template after the tunnel segments pass through achieves a permanent seal. The entire process is simple to operate, highly automated, and effectively prevents water and soil exchange between the inside and outside of the tunnel portal, ensuring the safety and stability of the TBM construction.

[0049] In another technical solution, during use, when foreign objects, sharp objects, or the outer peripheral cutter of the tunnel boring machine cutterhead puncture the outer side of the airbag in the tunnel portal sealing area, causing the air pressure to be unable to be dynamically maintained, or when the outer peripheral airbag is damaged during the slurry shield construction process and the air pressure cannot be dynamically maintained, grease is injected into the built-in grease bladder to expand the sealing airbag, wrap it tightly around the outer periphery of the gradient change of the cutterhead-shield-segment, and achieve tunnel portal sealing.

[0050] In the above technical solution, when foreign objects (such as uncleaned gravel) are present in the tunnel portal sealing area or when the outer cutterhead of the tunnel boring machine scratches the outer cavity airbag 4, the air pressure monitoring element 14 will detect a continuous drop in pressure. At this time, the grease injection procedure of the inner cavity grease bladder 5 will be initiated. First, the inflation channel of the outer cavity airbag 4 is closed to stop inflation; then, the grease injection pump is connected to the grease injection inner tube 15 of the gas-grease mixing injection head 12, and the grease injection pump is turned on to inject sealing grease into the inner cavity grease bladder 5. During the grease injection process, the grease injection volume and pressure changes are observed. When the grease bladder expands to fit against the outer circumference of the tunnel boring machine and the pressure stabilizes, the grease injection is stopped. At this time, although the damaged outer cavity airbag 4 cannot be inflated, it can still wrap around the inner cavity grease bladder 5, preventing it from directly contacting external foreign objects. The inner cavity grease bladder 5 tightly fills the gaps through the plasticity of the grease, achieving a seal. If, during the construction of a mud-water shield chamber, the outer air bladder 4 ruptures, causing the internal pressure to become unsustainable, compressed air can be first injected into the inner grease bladder 5 to rapidly expand and seal the leakage channels. Once the internal pressure has temporarily stabilized, grease can be injected using a grease pump while simultaneously releasing the gas slowly to replace the grease. Ultimately, this maintains stable pressure in the inner grease bladder 5, achieving a long-term seal. During grease injection, it is crucial to avoid injecting grease too quickly, which could cause a sudden pressure surge; a uniform injection rate should be maintained.

[0051] In another technical solution, during use, when the folding plate of the curtain rubber sheet 8 is bent in the opposite direction, or when the sealing device is damaged or pulled off due to posture bias, resulting in leakage, the quick-installable airbag assembly 11, which is pre-placed in the lower 120° emergency drag-type airbag cavity 6, is dragged to the leakage or failure area through the dragging and inflation unit 9; gas is injected into the quick-installable airbag assembly 11 through the hollow tube of the dragging and inflation unit 9, causing it to expand and tightly adhere to the outer periphery of the shield, forming an emergency seal and blocking the leakage channel.

[0052] In the above technical solution, when the folding plate of the curtain rubber sheet 8 bends in the opposite direction, the sealing device is damaged or pulled off due to posture bias, and obvious leakage occurs, the emergency drag-and-seal procedure is immediately initiated. First, the operator opens the covers on both sides of the lower 120° emergency drag-and-seal airbag chamber 6, exposing the quick-installable airbag assembly 11 and the dragging and inflation unit 9 inside the chamber. The required number of airbag components is determined based on the size of the leakage area. Then, the outer end of the dragging and inflation unit 9 is pulled to drag the assembled airbag assembly from inside the chamber to the leakage area, ensuring that the center of the airbag assembly is aligned with the leakage point, and that both ends extend at least 100mm beyond the leakage range. Subsequently, the quick connector at the outer end of the dragging and inflation unit 9 is connected to the inflation device, and the inflation device is turned on, inflating the airbag assembly with compressed air through the hollow tube inside the rope. During inflation, the expansion of the airbag assembly is observed, allowing it to gradually conform to the outer circumference of the shield until it completely covers the leakage area without obvious leakage. The inflation device is then turned off, completing the emergency seal.

[0053] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A sealing airbag fixture for shield tunneling entry and exit, characterized in that, This includes the portal foundation load-bearing components and the external air-inner grease double-layer sealing components, among which, The portal foundation bearing assembly includes a portal embedded steel ring, an external extension steel ring, and a foundation sealing element. The portal embedded steel ring is embedded in concrete. One end of the external extension steel ring is rigidly connected to the portal embedded steel ring, and the other end has a pre-set groove and installation hole on its inner side. The foundation sealing element includes a sealing wire brush and a curtain rubber plate, which are arranged sequentially along the inner side of the external extension steel ring and fixed to the inner wall of the external extension steel ring by bolts to form a primary sealing layer. The dual-layer sealing assembly includes an outer air bladder, an inner grease bladder, and an air-grease control unit. The inner grease bladder is disposed inside the outer air bladder. The air-grease control unit includes an air-grease mixing injection head and an air pressure monitoring element. The air-grease mixing injection head is connected to the air cavity of the outer air bladder and the grease cavity of the inner grease bladder, respectively. The air pressure monitoring element is built into the outer air bladder to monitor the pressure changes inside the outer air bladder in real time. It also includes an emergency towing sealing assembly, which includes a lower 120° emergency towing airbag chamber, a quick-installable airbag assembly, and a towing and inflation unit. The lower 120° emergency towing airbag chamber is a cavity pre-set between the curtain rubber plate and the sealing wire brush, and is only distributed in the lower 120° range of the tunnel entrance. The lower 120° emergency towing airbag chamber has openable and closable covers on both sides, and the towing and inflation unit is pre-inserted into the cavity. The quick-installable airbag assembly is located in the lower 120° emergency towing airbag chamber. One end of the towing and inflation unit is connected to the quick-installable airbag assembly, and the other end extends to the outside of the tunnel entrance.

2. The sealing airbag fixture for shield tunnel entry and exit according to claim 1, characterized in that, The outer cavity airbag is mechanically fixed by being embedded in the preset groove of the external extension steel ring through the protruding rubber platform at the bottom. The outer cavity airbag is located outside the action range of the sealing wire brush, forming a layered sealing structure with the basic sealing component. When the outer cavity airbag or the basic seal fails to seal, the airbag assembly can be quickly installed to the area of ​​the seal failure of the outer cavity airbag by dragging and inflating the unit. After inflation, it fits against the outside of the outer cavity airbag to form an emergency seal compensation.

3. The sealing airbag fixture for shield tunnel entry and exit according to claim 1, characterized in that, Grease is injected into the inner grease bladder through the gas-grease mixing injection head. When the outer grease bladder is damaged and cannot maintain pressure, the grease injected into the inner grease bladder expands to form a flexible seal, and the outer grease bladder acts as its protective sleeve, contacting external rigid bodies and debris.

4. The sealing airbag fixture for shield tunnel entry and exit according to claim 1, characterized in that, The gas-grease mixing injection head includes a grease injection inner tube and an inflation tube. The grease injection inner tube is located inside the inflation tube, and its length is greater than that of the inflation tube. When inflating, the inner screw plug of the grease injection inner tube is closed, and the inflation tube is connected through the inflation tube and spring clip. When injecting grease, the inflation tube is removed and a sealing cap is installed. After unscrewing the plug of the grease injection inner tube, it is connected to the grease injection pipeline, which can realize the interchange of gas and grease media.

5. The sealing airbag fixture for shield tunnel entry and exit according to claim 1, characterized in that, The lower 120° emergency towing airbag chamber is located outside the reverse bending influence zone of the curtain rubber plate. The airbag assembly can be quickly installed and locked by inserting and unplugging the nylon rope of the towing and inflation unit through the locking holes on both sides. The quick-installable airbag assembly is composed of multiple airbag components spliced ​​together, with adjacent airbag components connected in series. The number of airbag components can be adjusted to adapt to different leakage ranges.

6. The sealing airbag fixture for shield tunnel entry and exit according to claim 1, characterized in that, The outer cavity airbag is an inflatable sealed body with a raised rubber platform at the bottom. The outer cavity airbag is divided into several blocks according to the diameter of the opening, and adjacent blocks are connected by an irregular concave-convex structure.

7. The method of using the sealing airbag fixture for shield tunnel entry and exit as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. After the shield machine cutterhead passes through the working shaft structure portal sealing device, pressurized gas is injected into the outer cavity airbag through the gas-grease mixing injection head, causing the outer cavity airbag to expand and squeeze and wrap the shield body, forming the third sealing system of the portal. S2. As the tunnel boring machine moves forward, the gradient change of the shield body causes the space of the sealing cavity to change. The curtain rubber plate is tightened by the springback of the folding pressure plate, the sealing wire brush springs up and fits tightly, and the outer cavity airbag monitors the internal pressure in real time through the air pressure monitoring element and inflates and deflates the outer cavity airbag in real time to maintain the tight fit between the outer cavity airbag and the shield body / segment. S3. Repeat S1 and S2 until the tunnel segment passes through the tunnel portal sealing device, which serves as the outer template for the tunnel portal grouting, assisting in compensating for the gap between the tunnel portal and the tunnel segment with grouting and sealing, thus completing the permanent seal.

8. The method of use according to claim 7, characterized in that, During use, when foreign objects, sharp objects, or the outer periphery of the shield machine cutterhead puncture the airbag in the tunnel portal sealing area, causing the air pressure to be unable to be dynamically maintained, or when the outer periphery airbag is damaged during the slurry shield construction process and the air pressure cannot be dynamically maintained, grease is injected into the built-in grease bladder to expand the sealing airbag, wrap it tightly around the outer periphery of the gradient change of the cutterhead-shield-segment, and achieve tunnel portal sealing.

9. The method of use according to claim 7, characterized in that, During use, when the folding plate of the curtain rubber sheet bends in the opposite direction, or when the sealing device is damaged or pulled off due to posture bias, causing leakage, the quick-installable airbag assembly, which is pre-placed in the lower 120° emergency towing airbag chamber, is towed to the leakage or failure area through the towing and inflation unit; gas is then injected into the quick-installable airbag assembly through the hollow tube of the towing and inflation unit, causing it to expand and tightly adhere to the outer periphery of the shield, forming an emergency seal and blocking the leakage channel.

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