Sealing device for shield interval tunnel portal

Abstract

The utility model relates to the technical field of shield construction, and particularly discloses a sealing device for a shield interval tunnel portal, which comprises a water stop tank body and a back covering steel plate, the back covering steel plate is arranged on the negative ring duct piece, the water stop tank body is L-shaped, and the two ends of the water stop tank body abut against the back covering steel plate and the steel ring respectively; the water stop tank body is fully welded on the back covering steel plate and the steel ring; the positive ring duct piece, the negative ring duct piece, the water stop tank body, the back covering steel plate, the steel ring and the enclosure structure jointly form a filler area; a valve body used for filling filler is arranged on the water stop tank body, and the hardened filler can be tightly combined with the positive ring pipe piece, the negative ring pipe piece, the water stop tank body, the back covering steel plate, the steel ring, the enclosure structure, the cord fabric rubber plate and the folding pressing plate. Therefore, the problems that in the prior art, a sealing device formed by combining a cord fabric rubber plate and a folding pressing plate loses efficacy under the working condition that underground water is rich or the stratum stability is poor, the sealing capacity is not matched with the geological load, and the risks of water gushing, sand gushing and ground collapse exist are solved.

Description

Technical Field

[0001] This utility model relates to the field of shield tunneling technology, specifically to a sealing device for the tunnel entrance of a shield tunnel section. Background Technology

[0002] In the field of tunnel boring machine (TBM) construction, the sealing device for the launching and receiving tunnel portals generally adopts a combination of curtain rubber sheets and hinged pressure plates to stop water in the portals.

[0003] Because the rubber sheeting relies primarily on elastic deformation to adhere to the tunnel boring machine (TBM) shell, forming a water-stop barrier through the compression of the hinged pressure plate, this structure is effective in static or low-water-pressure environments. However, under dynamic water pressure (such as abundant groundwater) or lateral soil pressure (such as unstable strata), the elastic deformation capacity of the rubber sheeting may not be able to completely fill the gap between the TBM and the tunnel entrance. Furthermore, the hinged pressure plate, being a rigid structure, has poor adaptability to TBM attitude deviations. If the TBM deviates during entry and exit from the tunnel, uneven compression between the pressure plate and the rubber sheeting may occur, leading to localized seal failure.

[0004] When groundwater is abundant, high water pressure directly affects the inner side of the rubber sheet of the tunnel boring machine (TBM). If the water pressure exceeds the impermeability threshold of the rubber sheet (usually 0.2~0.3MPa), water will seep along the contact surface between the rubber sheet and the TBM shell, even breaking through the sealing structure and causing water inrush. The water pressure will also push the curtain fabric outwards from the tunnel entrance, causing the fixing force of the hinge plate to be insufficient to maintain the sealing pressure, forming a "water hammer effect" and exacerbating the seal failure. In addition, when the groundwater flow rate is fast and the water pressure is high, the water flow will continuously scour the soil around the tunnel entrance, especially sand or silt layers, easily carrying out soil particles and forming a "piping" channel. Once the rubber sheet of the tunnel boring machine has a small damage or gap, the water flow will quickly expand the channel, causing sand inrush. If the tunnel entrance is located in a confined aquifer, and the pressure is not reduced in advance or is insufficiently released, the confined water will break through the soil and sealing device, causing sudden water and sand inrush, and even causing ground subsidence. For soft soil strata (such as silty soil), sandy layers, or fractured rock strata, due to their poor self-stability, collapse is highly likely to occur after the tunnel portal is breached during shield launching / receiving, as the soil loses its support. Ground collapse leads to a redistribution of stress in the surrounding soil, generating lateral earth pressure that squeezes the rubber sheeting, increasing the gap between it and the shield machine and accelerating seal failure. At this point, the rubber sheeting cannot prevent significant soil loss, leading to groundwater inflow.

[0005] Therefore, the sealing device using the combination of rubber sheet and hinged pressure plate in the existing technology fails under conditions of abundant groundwater or poor geological stability. Its sealing capacity is mismatched with the geological load, posing a risk of water and sand inrush and ground collapse. Therefore, it is necessary to optimize and improve the structure of the sealing device to enhance its applicability, especially in geological environments with abundant groundwater or poor geological stability. Utility Model Content

[0006] The purpose of this utility model is to provide a sealing device for the tunnel portal of a shield tunnel, which can solve the problems of the sealing device using the combination of curtain rubber sheet and folding pressure plate in the background art failing under conditions of abundant groundwater or poor stratum stability, the sealing capacity not matching the geological load, and the risk of water and sand inrush and ground collapse.

[0007] This utility model is achieved through the following technical solution:

[0008] A sealing device for the tunnel portal of a shield tunnel includes a curtain rubber sheet and a hinged pressure plate. The inner wall of the shield tunnel is provided with a positive ring segment and a negative ring segment. The negative ring segment abuts against the positive ring segment and is located on the side of the structural wall near the tunnel portal. A steel ring is attached to the structural wall. The curtain rubber sheet and the hinged pressure plate are connected to the steel ring.

[0009] The sealing device also includes a water-stop box and a backing steel plate; the backing steel plate is disposed on the negative ring segment, the water-stop box is L-shaped, and its two ends abut against the backing steel plate and the steel ring respectively; the water-stop box is fully welded to the backing steel plate and the steel ring; the positive ring segment, negative ring segment, water-stop box, backing steel plate, steel ring and enclosure structure together form a filling area;

[0010] The water-stop box is equipped with a valve body for injecting filler material, so that filler material can be injected into the filler area through the valve body, so that the hardened filler material can be tightly bonded to the positive ring segment, negative ring segment, water-stop box, backing steel plate, steel ring, enclosure structure, curtain rubber plate and folding pressure plate.

[0011] Alternatively, both the hinge plate and the fabric rubber sheet are connected to the steel ring via studs.

[0012] Alternatively, when fully welded, all weld heights must be greater than or equal to 8 mm.

[0013] Alternatively, the waterstop box body includes multiple steel plates that are sequentially overlapped, and adjacent steel plates are fully welded together to form a closed ring structure.

[0014] Optionally, the side of the steel plate that abuts against the steel ring is the short side, with a length of 8-12cm; the side that abuts against the backing steel plate is the long side, with a length of 40-50cm; and the length of the steel plate along the circumferential direction is 70-90cm.

[0015] Alternatively, anchor bars are welded to the inner arc surface of the backing steel plate, the anchor bars are embedded in the negative ring segment, the backing steel plate is closely attached to the negative ring segment, and the outer arc surface of the backing steel plate is flush with the outer arc surface of the negative ring segment.

[0016] Optionally, multiple anchor bars are provided and spaced apart on the backing steel plate, wherein the spacing between adjacent anchor bars is 10-15cm along the width direction of the backing steel plate, the spacing between adjacent anchor bars is 15-20cm along the length direction of the backing steel plate, and the length of the anchor bars is 15-20cm; the width of the backing steel plate is 40-60cm and the thickness is 1cm.

[0017] Alternatively, a sponge may be attached to the rubber sheet, with the sponge located on the soil-facing side of the rubber sheet.

[0018] Alternatively, the sponge may be bonded to the fabric rubber sheet using a chloroprene-phenolic adhesive.

[0019] Alternatively, the edge of the fabric rubber sheet is provided with mounting holes arranged along its circumferential direction, and the steel ring is provided with screw holes that correspond one-to-one with the mounting holes, wherein the diameter of the mounting holes is 3-5 mm larger than the diameter of the screw holes.

[0020] Alternatively, the length of the fabric rubber sheet may be greater than the length of the hinge plate.

[0021] The advantages of this utility model compared to the prior art are as follows:

[0022] Through the above technical solution, the L-shaped structure based on the waterstop box connects the backing steel plate, steel ring, and tunnel segments into a whole. After the filler hardens, it forms a rigid support that can withstand water pressure of over 1 MPa (traditional methods can only withstand 0.2~0.3 MPa). The filler covers all possible leakage paths (such as tunnel segment joints, steel ring and structural wall joints), eliminating the "sealing blind spots" in traditional methods. The combination of flexible rubber sheet and rigid filler ensures that even if the rubber sheet is partially damaged, the filler can still block water flow, reducing the risk of collapse. This sealing device, through a combination of "structural rigidity, sealing composite, and construction standardization," upgrades the traditional "flexible passive sealing" to "rigid-flexible combined active sealing." The rigid sealing system formed by the waterstop box and filler can effectively resist high water and soil pressure, solve the problem of water and sand inrush during the shield tunneling launch / receiving stages, and provide safety assurance for tunnel construction under complex geological conditions. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the exemplary embodiments of this utility model, the drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this utility model and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0024] Figure 1 A schematic diagram of the longitudinal section of the sealing device for the tunnel portal of a shield tunnel provided by this utility model applied to the launching portal;

[0025] Figure 2 A longitudinal cross-sectional schematic diagram of the sealing device for the tunnel portal of a shield tunnel provided by this utility model applied to the receiving portal;

[0026] Figure 3 A schematic diagram of the structure of the curtain rubber plate in the sealing device for the tunnel entrance of a shield tunnel provided by this utility model;

[0027] Figure 4 A schematic diagram of the hinge plate in the sealing device for the tunnel portal of a shield tunnel provided by this utility model;

[0028] Figure 5 A cross-sectional view of the hinge plate in the sealing device for the tunnel portal of a shield tunnel provided by this utility model;

[0029] Figure 6 A schematic diagram of the structure of the sealing device for the tunnel entrance of a shield tunnel provided by this utility model, in which a high-density sponge is pasted onto a fabric rubber sheet;

[0030] Figure 7 A schematic diagram of the structure of the backing steel plate embedded in the negative ring segment in the sealing device for the tunnel portal of the shield tunnel provided by this utility model;

[0031] Figure 8 A schematic diagram of the water-stopping tank body of the sealing device for the tunnel portal of a shield tunnel provided by this utility model;

[0032] Figure 9 This is a cross-sectional structural diagram of the water-stopping tank body in the sealing device for the tunnel portal of a shield tunnel provided by this utility model.

[0033] The attached diagram shows the markings and corresponding component names: 1-Cloth rubber sheet, 11-Mounting hole, 2-Folding pressure plate, 31-Positive ring segment, 32-Negative ring segment, 41-Structural wall, 42-Enclosure structure, 5-Steel ring, 6-Waterstop box, 61-Steel plate, 601-Short side, 602-Long side, 7-Backing steel plate, 71-Backing steel plate, 72-Anchor bar, 8-Filling material, 9-Sponge, 10-Valve body, 101-Stud. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that while the description of these embodiments is intended to aid in understanding the present invention, it does not constitute a limitation thereof. The specific structural and functional details disclosed herein are only for describing exemplary embodiments of the present invention. However, the present invention may be embodied in many alternative forms and should not be construed as being limited to the embodiments described herein.

[0035] According to a first aspect of this disclosure, a sealing device for a tunnel portal in a shield tunnel section is provided. Figures 1 to 9 Specific embodiments thereof are shown. The following will detail this disclosure with a practical application example of a sealing device used for tunnel portals in shield tunnel sections.

[0036] See Figures 1 to 9 As shown, the sealing device for the tunnel portal of the shield tunnel includes a curtain rubber plate 1 and a hinged pressure plate 2. The inner wall of the shield tunnel is provided with a positive ring segment 31 and a negative ring segment 32. The negative ring segment 32 presses against the positive ring segment 31, and the negative ring segment 32 is located on one side of the structural wall 41 near the tunnel portal. A steel ring 5 is attached to the structural wall 41, and the curtain rubber plate 1 and the hinged pressure plate 2 are connected to the steel ring 5. The sealing device also includes a water-stop box 6 and a backing steel plate 71; the backing steel plate 71 is disposed on the negative ring segment 32, the water-stop box 6 is L-shaped, and its two ends abut against the backing steel plate 71 and the steel ring 5 respectively; the water-stop box 6 is fully welded to the backing steel plate 71 and the steel ring 5; the positive ring segment 31, the negative ring segment 32, the water-stop box 6, the backing steel plate 71, the steel ring 5 and the enclosure structure 42 together form a filling area; the water-stop box 6 is provided with a valve body 10 for injecting filler material 8, so that filler material 8 can be injected into the filling area through the valve body 10, so that the hardened filler material 8 can be tightly bonded to the positive ring segment 31, the negative ring segment 32, the water-stop box 6, the backing steel plate 71, the steel ring 5, the enclosure structure 42, the curtain rubber plate 1 and the hinge pressure plate 2.

[0037] In this disclosure, the elastic deformation of the rubber sheet is used to tightly adhere to the outer shell of the tunnel boring machine. The hinge plate 2 is fixed to the steel ring 5 by bolts, forming the first flexible water-stop barrier to block a small amount of seepage and fine particles. The steel ring 5 is pre-embedded in the structural wall 41 (such as a continuous wall or retaining structure 42) as a supporting base for the entire sealing device, providing a rigid connection fulcrum. The two ends of the water-stop box 6 are fully welded to the backing steel plate 71 and the steel ring 5, respectively, forming a closed "L-shaped rigid frame". The gaps between the positive ring segment 31, the negative ring segment 32, the water-stop box 6, the backing steel plate 71, the steel ring 5, and the retaining structure 42 are filled with filler material 8 (such as cement grout, polyurethane, etc.) through the valve body 10 on the water-stop box 6, which hardens to form a rigid seal.

[0038] The folding pressure plate 2 presses against the rubber sheet 1, making it adhere tightly to the shield machine shell, using the elastic pressure of the rubber to block water flow; the negative ring segment 32 presses against the positive ring segment 31, and through the rigid support of the backing steel plate 71 and the water-stop box 6, the pressure between the segments is transferred to the steel ring 5, reducing joint displacement. After the filler 8 is injected, it fills all gaps, and after hardening, it is tightly bonded to the surfaces of the segments, steel ring 5, and water-stop box 6, forming a "rigid water-stop ring" that blocks the path of groundwater seepage. The fluidity of the filler 8 can fill the tiny gaps that are difficult for mechanical seals to cover (such as segment assembly errors, the joint between the steel ring 5 and the structural wall 41). Thus, through the rubber sheet 1 (flexible barrier), the hardened filler 8 (rigid barrier), and the full welded connection between the water-stop box 6 and the steel ring 5 (rigid structural barrier), a triple mechanism works together to resist high water pressure and groundwater pressure, preventing water and sand inrush.

[0039] During the construction of the retaining structure 42 (such as a diaphragm wall), steel rings 5 ​​are pre-embedded at the designed locations to ensure that the steel rings 5 ​​are firmly welded to the reinforcing bars of the structural wall 41, and the accuracy of the pre-embedded positions is controlled within ±5mm. Before the shield tunneling machine launches / receives, the negative ring segment 32 and the positive ring segment 31 are assembled. The side of the negative ring segment 32 closest to the portal structural wall 41 is connected to the positive ring segment 31 with bolts to form an integral pressure-bearing structure. A backing steel plate 61 is laid on the outside of the negative ring segment 32. The steel plate 61 covers the outer edge of the negative ring segment 32 and is welded and fixed to the segment, so that the steel plate 61 is tightly fitted to the surface of the segment. The two ends of the L-shaped waterstop box 6 are welded to the backing steel plate 71 and the steel ring 5 respectively. The welding adopts a continuous full welding process, and a penetration test is performed after welding to check the sealing performance. A curtain rubber plate 1 is installed on the inside of the steel ring 5. The edge of the rubber plate is fixed to the steel ring 5 by a folding pressure plate 2 and bolts to ensure that the rubber plate is taut and wrinkle-free.

[0040] The grouting pump is connected to the valve body 10 on the water-stop box 6. Filler material 8 (such as cement-water glass double-liquid grout or polyurethane) is injected according to the designed ratio until grout overflows from all vent holes. After the filler material 8 has cured, the sealing performance of the valve body 10 is checked. If necessary, additional grout is added to ensure the filling area is completely compacted. During the tunnel boring machine's advance, the deformation and leakage of the tunnel portal sealing device can be monitored. If a small amount of seepage is detected, sealing material can be added through the reserved grouting holes, thereby effectively supporting and protecting the retaining structure.

[0041] Through the above technical solution, the L-shaped structure of the waterstop box 6 connects the backing steel plate 71, steel ring 5, and tunnel segments into a whole. After the filler 8 hardens, it forms a rigid support that can withstand water pressure of over 1 MPa (traditional methods can only withstand 0.2~0.3 MPa). The filler 8 covers all possible leakage paths (such as tunnel segment joints and the joint between steel ring 5 and structural wall 41), eliminating the "sealing blind spots" in traditional methods. The combination of flexible rubber sheet and rigid filler ensures that even if the rubber sheet is partially damaged, the filler 8 can still block water flow and reduce the risk of collapse. This sealing device, through a combination of "structural rigidity, sealing composite, and construction standardization," upgrades the traditional "flexible passive sealing" to "rigid-flexible combined active sealing." The rigid sealing system formed by the waterstop box 6 and filler 8 can effectively resist high water and soil pressure, solve the problem of water and sand inrush during the shield tunneling launch / receiving stage, and provide safety assurance for tunnel construction under complex geological conditions.

[0042] It should be noted that the directional terms used, such as "inner" and "outer," refer to "inner" and "outer" relative to the outline of the component, and are directed towards the device (which can be combined with...). Figure 1 (For clarification) The direction inside is "inside," and vice versa. Furthermore, it should be noted that terms such as "first" and "second" are used to distinguish one element from another and do not indicate sequence or importance. Moreover, in the following descriptions with accompanying drawings, the same reference numerals in different drawings represent the same element.

[0043] In this disclosure, the valve body 10 is a ball valve. However, those skilled in the art can choose any suitable valve based on the technical concept of this disclosure, and this disclosure does not impose any limitations on this.

[0044] Specifically, both the hinge plate 2 and the fabric rubber sheet 1 are connected to the steel ring 5 via studs 101. The stud 101 connection is a detachable rigid connection. By fixing the flexible fabric rubber sheet 1 and the rigid hinge plate 2 to the steel ring 5, the axial pressure generated during tightening can cause the rubber sheet to undergo elastic deformation, tightly adhering to the shield machine shell to form a sealing surface. This is especially suitable for working conditions that require dynamic adjustment of the sealing pressure.

[0045] The steel ring 5 has a pre-drilled threaded hole that matches the stud 101. Therefore, during on-site construction, it is only necessary to put the hinge plate 2 and the fabric rubber plate 1 into the stud 101 and tighten the nut, thereby shortening the construction time.

[0046] In this disclosure, all weld heights are greater than or equal to 8 mm during full welding. When the weld height is ≥8 mm, the water and soil pressure is transmitted to the waterstop box 6, then acts on the weld, and is transmitted to the segment structure (positive ring segment 31 and negative ring segment 32) through the backing steel plate 71 / steel ring 5. The weld height of not less than 8 mm increases the shear force value borne by the weld per unit area.

[0047] The waterstop box 6 is L-shaped and mainly bears the pressure of the ground water and soil as well as the pressure of the grout generated during grouting. The weld joint is prone to compound stress concentration. The larger weld joint height increases the connection cross section between the waterstop box 6 and the steel ring 5 / backing steel plate 71, resulting in a more uniform stress distribution.

[0048] In one embodiment provided in this disclosure, the water-stop box 6 includes a plurality of steel plates 61 that are sequentially overlapped, and adjacent steel plates 61 are fully welded together to form a closed ring structure.

[0049] This split design of the waterstop box 6 solves the transportation problem of the large-sized components of the integrated transmission waterstop box 6, and also facilitates lifting by hoisting equipment. Furthermore, it allows for dynamic adjustment during assembly to better adapt to the irregular contours of the tunnel portal, ensuring the rapid installation and reliable operation of the shield tunnel portal sealing device.

[0050] During the installation process, the bottom steel plate 61 is first installed as a reference, and the elevation deviation is adjusted by measuring control points. When overlapping the plates one by one upwards, the overlapping edge of the adjacent steel plates 61 is used as a positioning reference to effectively control the overall cumulative error.

[0051] Further, see Figure 9 As shown, the side of the steel plate that abuts against the steel ring is the short side, with a length of 8-12 cm; the side that abuts against the backing steel plate is the long side, with a length of 40-50 cm. Further, the length of the steel plate along the circumferential direction is 70-90 cm, for example... Figure 8 As shown, the inner arc edge of the steel plate is 759.22 mm, and the outer arc edge of the steel plate is 877.03 mm.

[0052] In one embodiment provided in this disclosure, an anchor bar 72 is welded to the inner arc surface of the backing steel plate 71. The anchor bar 72 is embedded in the negative ring tube segment 32. The backing steel plate 71 is closely attached to the negative ring tube segment, and the outer arc surface of the backing steel plate is flush with the outer arc surface of the negative ring tube segment, thereby forming a more stable sealing and pressure-resistant structure.

[0053] In one embodiment provided in this disclosure, a sponge 9 is attached to the rubber sheet 1, with the sponge 9 located on the soil-facing side of the rubber sheet 1. The sponge 9 has high elasticity and compressibility, and can tightly conform to the irregular curved surface of the tunnel boring machine (TBM) shell during tunnel entry and exit. When a small gap appears between the TBM and the rubber sheet 1, the sponge 9 will deform under the action of water and soil pressure, actively filling the gap and effectively preventing sand and soil particles from entering the tunnel through these gaps. Compared with the simple rubber sheet 1, the addition of the sponge 9 upgrades the sealing structure from "passive sealing" to "active adaptation," thereby effectively controlling the leakage of sand and soil particles during the TBM entry and exit stages.

[0054] In this disclosure, the sponge 9 has a porous mesh structure inside, which gives it excellent filtration performance. As groundwater carries sand and soil particles into the tunnel, the sponge 9 layer can act like a filter to intercept larger particles; at the same time, the porous structure of the sponge 9 also hinders the passage of smaller particles, thus achieving dual interception of sand and soil particles and reducing the risk of sand inrush.

[0055] In this disclosure, the sponge 9 is bonded to the rubber sheet 1 using a chloroprene-phenolic adhesive. The chloroprene-phenolic adhesive is a two-component, high-performance adhesive that provides strong adhesion between the rubber and the sponge 9, thus ensuring the bond strength between the two. Furthermore, given the humid underground environment and the presence of acidic or alkaline media, the chloroprene rubber component of the chloroprene-phenolic adhesive exhibits excellent water resistance and corrosion resistance, while the phenolic resin enhances its heat resistance and anti-aging properties.

[0056] Furthermore, the sponge 9 is configured as a high-density sponge 9. High-density sponge 9 (density ≥ 40 kg / m³) 3 The pore structure is more compact, and the pore size is smaller than that of conventional sponges, which can effectively intercept sand particles with a diameter of 0.1 mm or larger.

[0057] Furthermore, the edge of the fabric rubber sheet 1 is provided with mounting holes 11 arranged circumferentially. The steel ring 5 is provided with screw holes corresponding to the mounting holes 11. The diameter of the mounting holes 11 is 3-5 mm larger than the diameter of the screw holes, thus providing a certain radial adjustment margin, allowing the bolts to quickly pass through the mounting holes 11 and align with the screw holes, avoiding installation jamming caused by difficulty in precise hole alignment. Traditional equal-diameter hole connections require the bolts to fit tightly with the hole wall, while the large-diameter design allows the bolts to form a "loose fit" within the hole. When multiple sets of bolts are tightened simultaneously, the circumferential position of the fabric rubber sheet 1 can be finely adjusted through the gap within the holes to ensure that the sealing surface is evenly attached to the steel ring 5, avoiding tearing of the rubber sheet due to local stress concentration.

[0058] Furthermore, the mounting hole 11 extends in the circumferential direction (the arc edge of the fan shape), and the arc of adjacent mounting holes 11 is 5°.

[0059] In one embodiment provided in this disclosure, the length of the fabric rubber sheet 1 is greater than the length of the hinge pressure plate 2, and the difference in length between the two is 5-10 cm. When the tunnel boring machine (TBM) enters or exits the tunnel, lateral displacement may occur (such as uneven geological conditions causing the machine to tilt). If the fabric rubber sheet 1 and the hinge pressure plate 2 are the same length, the fabric on the outside of the pressure plate will lose support and flip outwards during displacement, forming a leakage channel. The design of the fabric rubber sheet 1 extending beyond the pressure plate to be longer than the hinge pressure plate 2 ensures that the extended portion always covers the outer shell of the TBM during displacement, maintaining the continuity of the sealing surface.

[0060] Finally, it should be noted that this utility model is not limited to the above-described optional embodiments, and anyone can derive other various forms of products under the guidance of this utility model. The above specific embodiments should not be construed as limiting the scope of protection of this utility model, which should be determined by the claims, and the description can be used to interpret the claims.

Claims

1. A sealing device for a tunnel portal in a shield tunnel section, the sealing device comprising a rubber sheet and a hinged pressure plate, wherein the inner wall of the shield tunnel section is provided with a positive ring segment and a negative ring segment, the negative ring segment abutting against the positive ring segment, and the negative ring segment is located on one side of the structural wall near the portal, a steel ring is affixed to the structural wall, and the rubber sheet and the hinged pressure plate are connected to the steel ring, characterized in that, The sealing device also includes a water-stop box and a backing steel plate; The backing steel plate is disposed on the negative ring segment, and the waterstop box is formed in an L shape, with its two ends respectively abutting against the backing steel plate and the steel ring; the waterstop box is fully welded to the backing steel plate and the steel ring; the positive ring segment, negative ring segment, waterstop box, backing steel plate, steel ring and enclosure structure together form the filling area; The water-stop box is equipped with a valve body for injecting filler material, so that filler material can be injected into the filler area through the valve body, so that the hardened filler material can be tightly bonded to the positive ring segment, negative ring segment, water-stop box, backing steel plate, steel ring, enclosure structure, curtain rubber plate and folding pressure plate.

2. The sealing device for the tunnel portal of a shield tunnel according to claim 1, characterized in that, When fully welded, the height of all welds must be greater than or equal to 8mm.

3. The sealing device for the tunnel portal of a shield tunnel section according to claim 1, characterized in that, The water-stop box body comprises multiple steel plates that are sequentially overlapped, and adjacent steel plates are fully welded together to form a closed ring structure.

4. The sealing device for the tunnel portal of a shield tunnel section according to claim 3, characterized in that, The side of the steel plate that abuts against the steel ring is the short side, with a length of 8-12cm; the side that abuts against the backing steel plate is the long side, with a length of 40-50cm; and the length of the steel plate along the circumference is 70-90cm.

5. The sealing device for the tunnel portal of a shield tunnel section according to claim 1, characterized in that, Anchor bars are welded to the inner arc surface of the backing steel plate, and the anchor bars are embedded in the negative ring segment. The backing steel plate is closely attached to the negative ring segment, and the outer arc surface of the backing steel plate is flush with the outer arc surface of the negative ring segment.

6. The sealing device for the tunnel portal of a shield tunnel section according to claim 1, characterized in that, A sponge is attached to the rubber curtain sheet, and the sponge is located on the soil-facing side of the rubber curtain sheet.

7. The sealing device for the tunnel portal of a shield tunnel section according to claim 6, characterized in that, The sponge is bonded to the fabric rubber sheet using chloroprene-phenolic adhesive.

8. The sealing device for the tunnel portal of a shield tunnel section according to claim 1, characterized in that, The edge of the fabric rubber sheet is provided with mounting holes arranged along its circumferential direction, and the steel ring is provided with screw holes that correspond one-to-one with the mounting holes, wherein the diameter of the mounting hole is 3-5 mm larger than the diameter of the screw hole.

9. The sealing device for the tunnel portal of a shield tunnel according to claim 1, characterized in that, The length of the fabric rubber sheet is greater than the length of the hinge plate, and the difference between the two lengths is 5~10cm.

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