Tunnel portal composite sealing device and sealing structure

Abstract

The application discloses a tunnel portal composite sealing device and a sealing structure. The sealing device comprises a stop grouting panel and a pressure bearing panel, a main grouting pipe and a reinforcing grouting pipe. The stop grouting panel and the pressure bearing panel are annular structures. The stop grouting panel is provided with a first pipe perforation, and the pressure bearing panel is provided with a second pipe perforation. The top of the pressure bearing panel is provided with a pouring opening, and the pressure bearing panel is provided with a reinforcing pipe perforation. The sealing structure comprises a portal and the sealing device. The pressure bearing panel is arranged outside the portal relative to the stop grouting panel, and filling concrete is arranged between the two. The main grouting pipe extends to the inner side of the stop grouting panel, and the reinforcing grouting pipe extends to the outer periphery of the filling concrete. Pressure reinforcing concrete is arranged between the filling concrete and the portal wall. The application has the beneficial effects that the composite pressure bearing body formed by the steel ring and the concrete has a clear stress path and excellent integrity, can effectively resist high grouting pressure and stratum water and soil pressure, and avoids the problems of insufficient strength and stability of the traditional brick masonry structure.

Description

Technical Field

[0001] This application belongs to the field of tunnel and underground engineering technology, specifically relating to a composite sealing device and sealing structure for tunnel portals, used in conjunction with the launching and receiving portals of tunnel boring machines (TBMs). Background Technology

[0002] Tunnel portal sealing is a crucial step in tunnel construction, especially when using tunnel boring machines (TBMs). The sealing process directly impacts construction progress and watertightness. Existing portal sealing technologies mainly rely on brick masonry, concrete grouting, or steel structure sealing, but these traditional methods generally have some significant technical problems.

[0003] Traditional brick masonry sealing structures typically involve brick wall construction, mortar finishing, and subsequent grouting sealing, and are widely used for portal sealing in shield tunnels. However, this structure has the following drawbacks: Poor shear and compressive strength: The brick masonry structure has poor rigidity and insufficient tensile and shear strength, making it prone to cracking or deformation under high-pressure grouting and water pressure, leading to sealing failure; Difficulty in controlling leakage: Multiple micro-permeability channels exist between the brick masonry and the mortar finishing, which easily lead to water leakage, especially under high water pressure, resulting in repeated repairs in the later stages of construction; Long construction cycle: The construction process of brick masonry is relatively complicated, usually requiring a long time for construction, curing, and finishing, which affects the overall progress of tunnel construction, especially in TBM construction where rapid advancement is required, where the traditional method has low construction efficiency.

[0004] In addition, some sealing structures using steel rings and concrete may also have the following limitations due to improper design or construction: the force transmission path is unclear, which may lead to local stress concentration; similar to traditional brick masonry, the construction gaps formed between it and the gravel layer are also difficult to seal effectively; and the construction process is still relatively complicated, failing to give full play to the advantages of prefabrication and assembly.

[0005] Existing grouting sealing technologies typically rely on pressure injection through grouting pipes to fill construction gaps. However, this grouting technology still has the following shortcomings: uneven grouting: due to issues with the arrangement of grouting pipes and control of grouting pressure, grout often fails to penetrate evenly into all cracks, resulting in some areas not being effectively sealed and creating potential leakage risks; structural damage due to excessive pressure: during high-pressure grouting, if the pressure is not effectively controlled, it may damage the surrounding structure, leading to grouting failure or structural damage; in water-rich sand layers or high water pressure environments, conventional grouting methods often cannot fully control the flow of water and grout, resulting in unsatisfactory grouting effects or even grout leakage.

[0006] In summary, existing tunnel portal sealing technologies generally suffer from insufficient compressive strength, long construction periods, and uneven grouting effects. Especially under complex conditions such as high water pressure and water-rich strata, traditional technologies struggle to meet stringent sealing requirements. To address these issues, a new tunnel portal sealing technology is urgently needed that can improve construction efficiency, reduce leakage, and meet the demands of construction under complex geological conditions while ensuring structural strength. Utility Model Content

[0007] The purpose of this application is to address the shortcomings of traditional brick masonry sealing structures in existing technologies, which suffer from insufficient rigidity, poor shear resistance, and susceptibility to damage under high water pressure or grouting pressure, leading to sealing failure. Furthermore, the presence of multiple interfaces increases the risk of leakage, complicates construction procedures, and extends the construction period. Additionally, the reinforcement effect in concealed areas such as construction joints between the gravel layer and the structure is poor. This application provides a composite sealing device and structure for tunnel portals. By employing a novel combination of steel rings and wooden boards, along with innovative grouting and sealing technologies, it effectively improves the sealing effect of tunnel portals and solves various problems inherent in traditional technologies.

[0008] The objective of this application is achieved through the following technical solution: A composite sealing device for tunnel portals includes a grout-stopping panel and a pressure-bearing panel, as well as a main grouting pipe and a reinforcing grouting pipe. Both the grout-stopping panel and the pressure-bearing panel are annular structures. The grout-stopping panel has several first pipe perforations for the main grouting pipe to pass through, and the pressure-bearing panel has several second pipe perforations for the main grouting pipe to pass through. The top of the pressure-bearing panel is reserved with an injection port, and the pressure-bearing panel has several reinforcing pipe perforations for the reinforcing grouting pipe to pass through.

[0009] Furthermore, the grout-stopping panel is made of wood, and the pressure-bearing panel is made of steel.

[0010] Furthermore, the pressure-bearing panel is assembled from several fan-shaped steel rings. Bolt holes are pre-drilled at the ends of the steel rings. Adjacent steel rings are fixed together by bolts inserted into the bolt holes. The outer side of the joint between adjacent steel rings is reinforced by welding.

[0011] Furthermore, it also includes several brackets, the base plate of which has pre-drilled holes for chemical anchor bolts, the inner end of the bracket is the support end of the grouting panel, and the outer end of the bracket is the support end of the pressure-bearing panel.

[0012] A composite sealing structure for a tunnel portal includes a tunnel entrance and the aforementioned composite sealing device for a tunnel portal. A grout-stopping panel and a pressure-bearing panel are both installed at the tunnel entrance and are sealed and fitted against the tunnel wall. The pressure-bearing panel is arranged relative to the grout-stopping panel on the outside of the tunnel, and there is filling concrete between the two. The main grouting pipe passes through the grout-stopping panel and the pressure-bearing panel and extends to the inside of the grout-stopping panel. The reinforcing grouting pipe passes through the pressure-bearing panel and extends to the outer periphery of the filling concrete. Pressure reinforcing concrete is provided between the filling concrete and the tunnel wall.

[0013] Furthermore, the main grouting pipe is screwed into the first pipe perforation, and a sealing gasket is provided between the first pipe perforation and the main grouting pipe. The main grouting pipe is screwed into the second pipe perforation, and a sealing gasket is provided between the second pipe perforation and the main grouting pipe.

[0014] Furthermore, a first sealing strip and a secondary sealing water-resistant sealant are provided between the outer periphery of the grout-stopping panel and the tunnel wall, and a sealing groove is provided on the outer periphery of the pressure-bearing panel, with a second sealing strip fitted to the tunnel wall inside the sealing groove.

[0015] Furthermore, the inner extension length of the main grouting pipe is arranged in an alternating pattern of near and far extensions.

[0016] Furthermore, it also includes several brackets. The base plate of the bracket is fixed to the tunnel wall by chemical anchors. The inner end of the bracket provides positioning support for the grout-stopping panel, and the outer end of the bracket provides fixed support for the pressure-bearing panel. The connecting seat plate of the bracket is fixed to the connecting seat plate of the pressure-bearing panel by bolts. The connecting seat plate has an elongated hole for slight position adjustment.

[0017] Furthermore, the pressure-bearing panel is provided with an ear plate, and the reinforcing grouting pipe is embedded in the ear plate at a 45° angle and welded and fixed. Compressed foam is inserted into the outer end of the reinforcing grouting pipe, and the outer end of the reinforcing grouting pipe is sealed with a threaded end cap. A gap of 20~50mm is reserved between the inner end of the reinforcing grouting pipe and the outer surface of the cavity.

[0018] The beneficial effects of this application are: (1) The composite pressure-bearing body composed of steel ring and concrete has a clear force path and excellent integrity, which can effectively resist high grouting pressure and soil and water pressure in the stratum, thus avoiding the problem of insufficient strength and stability of traditional brick masonry structure.

[0019] (2) The multiple sealing system formed by combining the initial sealing of the expandable sealing strip, the double sealing around the wooden board, the precision sealing of the through-board grouting joint, and the secondary reinforcement grouting of the inclined pipe greatly improves the sealing reliability and reduces the risk of leakage.

[0020] (3) The core components of the device can be prefabricated in the factory, and the on-site assembly construction is highly automated. This eliminates a large amount of wet work such as bricklaying and plastering, significantly shortens the construction cycle, and meets the requirements of TBM rapid construction.

[0021] (4) The pioneering sequential grouting process ensures the uniformity and integrity of grouting, effectively solving the problem of insufficient grouting in concealed areas by traditional processes.

[0022] (5) The device also has good maintainability and adaptability, and is particularly suitable for complex geological conditions such as high water pressure and water-rich sand layers, and has broad engineering application prospects.

[0023] The aforementioned main solution and its various further alternatives can be freely combined to form multiple solutions, all of which are solutions that can be adopted and claimed in this application; furthermore, the (non-conflicting alternatives) can also be freely combined with each other and with other alternatives. Those skilled in the art, after understanding this solution, will realize from the prior art and common general knowledge that there are many combinations, all of which are technical solutions to be protected in this application, and will not be exhaustively listed here. Attached Figure Description

[0024] Figure 1 This is a structural cross-sectional view of this application.

[0025] Figure 2 This is a schematic diagram of the inner structure of the grout-stopping panel of this application.

[0026] Figure 3 This is a schematic diagram of the outer structure of the grout-stopping panel of this application.

[0027] Figure 4 This is a schematic diagram of the outer structure of the pressure-bearing panel in this application.

[0028] Figure 5 This is a schematic diagram of the inner structure of the pressure-bearing panel in this application.

[0029] Figure 6 This is a structural schematic diagram of the grouting pipe used in this application.

[0030] In the diagram: 1-Grouting stop panel, 2-Pressure bearing panel, 3-First pipe perforation, 4-First sealing strip, 5-Second pipe perforation, 6-Sealing groove, 7-Second sealing strip, 8-Main grouting pipe, 9-Injection port, 10-Bracket, 11-Chemical anchor, 12-Reinforcing grouting pipe, 13-Ear plate, 14-Compressed foam, 15-Threaded end cap, 16-Steel ring, 17-Bolt hole, 18-Assembly bolt, 19-Filling concrete, 20-Process opening. Detailed Implementation

[0031] The present application will be further described below with reference to specific embodiments and accompanying drawings.

[0032] Example 1 refer to Figures 1-6As shown, a composite sealing device for a tunnel portal includes a grout-stopping panel 1 and a pressure-bearing panel 2, a main grouting pipe 8, a bracket 10, and a reinforcing grouting pipe 12.

[0033] Both the grout-stopping panel 1 and the pressure-bearing panel 2 are ring-shaped structures. The grout-stopping panel 1 is arranged on the inner side of the opening and is used for permanent grout-stopping enclosure. The pressure-bearing panel 2 is arranged on the outer side of the opening and is used for structural pressure enclosure, facilitating the overall structural forming. The bracket 10 is arranged between the two panels to assist in the positioning and installation of the two panels.

[0034] The grout-stopping panel 1 has several first pipe perforations 3 for the main grouting pipe 8 to pass through, and the pressure-bearing panel 2 has several second pipe perforations 5 for the main grouting pipe 8 to pass through. The first pipe perforations 3 and the second pipe perforations 5 together realize the installation of the main grouting pipe 8, and the main grouting pipe 8 extends inward for the initial grouting operation. The top of the pressure-bearing panel 2 is reserved with a grouting port 9. The cavity between the two panels is filled through the grouting port 9 to combine the two panels to form an integral sealing structure.

[0035] The pressure-bearing panel 2 is provided with several reinforcing pipe perforations for the reinforcing grouting pipes 12 to pass through. The reinforcing pipe perforations are used to realize the installation of the reinforcing grouting pipes 12. The inner end of the reinforcing grouting pipe 12 is the outer peripheral reinforcing end (i.e., it needs to extend to the outer periphery), and the outer end is the panel penetration end. Pressure grouting can be performed from the outer side of the pressure-bearing panel 2 inward to reinforce and fill the outer peripheral area.

[0036] The grout-stopping panel 1 is made of wood, and the pressure-bearing panel 2 is made of steel plate. The pressure-bearing panel 2 is assembled from several fan-shaped steel ring pieces 16. Preferably, the pressure-bearing panel 2 is composed of six 60° fan-shaped steel ring pieces 16. The steel ring pieces 16 are prefabricated in the factory and pre-assembled off-site, with roundness and hole positions checked. Bolt holes 17 are pre-drilled at the ends of the steel ring pieces 16. During assembly, the holes are aligned, and adjacent steel ring pieces 16 are fixed together by bolts 18 inserted into the bolt holes 17. The outer side of the joint between adjacent steel ring pieces 16 is reinforced by welding. Specifically, continuous fillet welds are applied to the outer side of the joint to form a closed annular pressure-bearing component. When the steel rings are prefabricated in the factory, a concrete pouring port is opened at the crown.

[0037] The bracket 10 is an H-beam. The base plate of the bracket 10 has pre-drilled holes for chemical anchor bolts 11. The base plate of the bracket 10 is fixed to the tunnel wall using the chemical anchor bolts 11. Based on the bracket 10, auxiliary installation of the panels on both sides can be performed. The inner end of the bracket 10 serves as the support end for the grout-stopping panel 1, and the outer end of the bracket 10 serves as the support end for the pressure-bearing panel 2.

[0038] Example 2 refer to Figures 1-6As shown, a composite sealing structure for a tunnel portal includes a tunnel entrance and a composite sealing device for a tunnel portal as described in Example 1. Both the grout-stopping panel 1 and the pressure-bearing panel 2 are installed at the tunnel entrance and are sealed and fitted to the tunnel wall.

[0039] The bracket 10 is an H-beam. The base plate of the bracket 10 is fixed to the tunnel wall by chemical anchor bolts 11. The anchor bolt construction adopts the process of "drilling-cleaning-injecting glue-implanting-curing-tightening". The burial depth and diameter are checked according to the design load.

[0040] The inner end of the bracket 10 provides positioning support for the grout-stopping panel 1. The grout-stopping panel 1 is made of wooden board. Measurements are taken based on the tunnel entrance opening, and a wooden board ring is installed on the soil-facing side as the front grout-stopping surface. The outer diameter of the wooden board matches the tunnel entrance opening. The wooden board is positioned and fixed using a steel bracket, chemical anchors, and temporary supports. A first sealing strip 4 and a secondary water-resistant sealant are installed between the outer periphery of the grout-stopping panel 1 and the tunnel wall to ensure the formation of the first grout-stopping seal.

[0041] The pressure-bearing panel 2 is made of steel plate. The outer end of the bracket 10 provides fixed support for the pressure-bearing panel 2. The connecting seat plate of the bracket 10 is fixed to the connecting seat plate of the pressure-bearing panel 2 by bolts. An elongated hole with a slight adjustment is opened on the connecting seat plate. Through the bracket 10, the steel ring is finally reliably fixed to the tunnel entrance and maintains a 300mm clearance from the wooden ring. The outer periphery of the pressure-bearing panel 2 is provided with a sealing groove 6. The sealing groove 6 is provided with a second sealing strip 7 that fits against the tunnel wall. Specifically, an expansion sealing strip is installed. During installation, a 10~20% pre-compression deformation is used to make it tightly fit against the concrete interface of the tunnel entrance, forming an initial periphery seal.

[0042] The pressure-bearing panel 2 is arranged relative to the grout-stopping panel 1 outside the hole, and a filling concrete 19 is provided between the two. Specifically, the top of the pressure-bearing panel 2 is reserved with a grouting port 9. Concrete is poured into the cavity between the grout-stopping panel 1 and the pressure-bearing panel 2 through the grouting port 9, so that the concrete fills the cavity. Then the concrete is cured. The filling concrete 19, together with the grout-stopping panel 1 and the pressure-bearing panel 2, forms an integral structure.

[0043] The main grouting pipe 8 passes through the grout-stopping panel 1 and the pressure-bearing panel 2 and extends to the inner side of the grout-stopping panel 1. During the tunnel boring machine's excavation process, the main grouting pipe 8 is used to perform the first grouting into the space between the shield tail and the tunnel wall. The reinforcing grouting pipe 12 passes through the pressure-bearing panel 2 and extends to the outer periphery of the filling concrete 19. Pressure reinforcing concrete is provided between the filling concrete 19 and the tunnel wall, that is, secondary pressure grouting is performed on the outer periphery through the reinforcing grouting pipe 12 to pressure reinforce the gravel layer and construction joint.

[0044] The main grouting pipe 8 (specifically, the connector at this location) is screwed into the first pipe perforation 3. A sealing gasket is provided between the first pipe perforation 3 and the main grouting pipe 8. The main grouting pipe 8 (specifically, the connector at this location) is screwed into the second pipe perforation 5. A sealing gasket is also provided between the second pipe perforation 5 and the main grouting pipe 8. The main grouting pipe 8 is fixedly installed by screwing, and the sealing gasket ensures that no grout or liquid leakage occurs in the first pipe perforation 3.

[0045] A check valve is installed inside the main grouting pipe 8 to ensure unidirectional grout flow and prevent backflow of grout. The inner extension length of the main grouting pipe 8 is arranged alternately at near and far distances, with alternating extension lengths of 0.3m and 1.0m, forming a complementary coverage range for near-field and far-field grouting.

[0046] The pressure-bearing panel 2 is provided with ear plate 13. The reinforcing grouting pipe 12 is embedded in the ear plate 13 at a 45° angle and welded and fixed. The construction personnel use the prefabricated process opening 20 of the steel ring to position and install the inclined reinforcing grouting pipe with a diameter of DN25-DN32 at a design angle of about 45°.

[0047] Compressed foam 14 is inserted into the outer end of the reinforcing grouting pipe 12, and a threaded end cap 15 is used to seal the outer end of the reinforcing grouting pipe 12 to prevent concrete from entering the steel pipe and ensure smooth use of the steel pipe during subsequent grouting. A gap of 20-50mm is reserved between the inner end of the reinforcing grouting pipe 12 and the outer surface of the cavity. During concrete pouring, ensure that the inclined steel pipe is completely wrapped to avoid obstruction during later construction. After all inclined pipes are installed, close the process opening 20, leaving only the crown grouting port open.

[0048] The core of this application is to provide a steel ring-concrete-wood composite sealing technology. A steel ring is used as the main load-bearing component, reliably connected to the portal concrete structure via an anchoring system. A wooden board is placed on the side of the steel ring facing the soil as a permanent grout-stopping panel. Concrete is poured between the steel ring and the wooden board to form an integral pressure-bearing structure. Through-board grouting joints are pre-embedded in the wooden board to form the initial grouting system. Reinforcing grouting pipes are pre-embedded obliquely in the concrete layer, with an openable and closable sealing structure at the outer end and a non-penetrating layer reserved near the outer surface of the structure at the inner end for subsequent secondary pressure grouting. An expandable sealing strip is provided on the outer edge of the steel ring, which expands and tightens to seal the contact interface after installation.

[0049] During construction, the steel rings and wooden boards are first installed and fixed, and the perimeter of the cavity between them and the steel rings is sealed. Then, concrete is poured and cured to form a composite structure. After the tunneling machine advances and completes the assembly of several rings of segments, gravel is blown in. Then, the first grouting is carried out through the through-slab grouting system. Finally, the non-penetrating layer reserved by the inclined reinforcing grouting pipe is drilled through, and secondary pressure reinforcing grouting is carried out through the pipe to achieve a comprehensive and effective seal.

[0050] The foregoing basic examples and their further alternative examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed in this application. In the scheme of this application, each alternative example can be arbitrarily combined with any other basic example and alternative example.

[0051] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A composite sealing device for tunnel portals, comprising a grout-stopping panel (1) and a pressure-bearing panel (2), characterized in that: It also includes a main grouting pipe (8) and a reinforcing grouting pipe (12). The grout-stopping panel (1) and the pressure-bearing panel (2) are both ring structures. The grout-stopping panel (1) is provided with several first pipe perforations (3) for the main grouting pipe (8) to pass through. The pressure-bearing panel (2) is provided with several second pipe perforations (5) for the main grouting pipe (8) to pass through. The top of the pressure-bearing panel (2) is reserved with an injection port (9). The pressure-bearing panel (2) is provided with several reinforcing pipe perforations for the reinforcing grouting pipe (12) to pass through.

2. The tunnel portal composite sealing device according to claim 1, characterized in that: The grout-stopping panel (1) is made of wood, and the pressure-bearing panel (2) is made of steel plate.

3. The tunnel portal composite sealing device according to claim 2, characterized in that: The pressure-bearing panel (2) is assembled from several fan-shaped steel ring pieces (16). The ends of the steel ring pieces (16) are reserved with bolt holes (17). Adjacent steel ring pieces (16) are fixed by assembly bolts (18) passing through the bolt holes (17). The outer side of the joint between adjacent steel ring pieces (16) is welded for reinforcement.

4. The tunnel portal composite sealing device according to claim 1, characterized in that: It also includes several brackets (10), with pre-drilled holes for chemical anchor bolts (11) on the base plate of the brackets (10), the inner end of the brackets (10) being the support end of the grouting panel (1), and the outer end of the brackets (10) being the support end of the pressure-bearing panel (2).

5. A composite sealing structure for a tunnel portal, comprising a portal opening, characterized in that: It also includes the tunnel portal composite sealing device according to any one of claims 1 to 4, wherein the grout-stopping panel (1) and the pressure-bearing panel (2) are both installed at the tunnel entrance and sealed to the tunnel wall, the pressure-bearing panel (2) is arranged relative to the grout-stopping panel (1) on the outside of the tunnel and there is filling concrete (19) between the two, the main grouting pipe (8) passes through the grout-stopping panel (1) and the pressure-bearing panel (2) and extends to the inside of the grout-stopping panel (1), the reinforcing grouting pipe (12) passes through the pressure-bearing panel (2) and extends to the outer periphery of the filling concrete (19), and there is pressure reinforcing concrete between the filling concrete (19) and the tunnel wall.

6. The composite sealing structure for tunnel portals according to claim 5, characterized in that: The main grouting pipe (8) is screwed into the first pipe perforation (3), and a sealing gasket is provided between the first pipe perforation (3) and the main grouting pipe (8). The main grouting pipe (8) is screwed into the second pipe perforation (5), and a sealing gasket is provided between the second pipe perforation (5) and the main grouting pipe (8).

7. The composite sealing structure for tunnel portals according to claim 5, characterized in that: The outer periphery of the grout-stopping panel (1) is provided with a first sealing strip (4) and a secondary sealing water-resistant sealant between the outer periphery and the tunnel wall. The outer periphery of the pressure-bearing panel (2) is provided with a sealing groove (6), and a second sealing strip (7) is provided in the sealing groove (6) to fit against the tunnel wall.

8. The composite sealing structure for tunnel portals according to claim 5, characterized in that: The inner extension length of the main grouting pipe (8) is arranged in an alternating pattern of near and far.

9. The composite sealing structure for tunnel portals according to claim 5, characterized in that: It also includes several brackets (10), the base plate of the bracket (10) is fixed to the tunnel wall by chemical anchors (11), the inner end of the bracket (10) provides positioning support for the grout-stopping panel (1), the outer end of the bracket (10) provides fixed support for the pressure-bearing panel (2), the connecting seat plate of the bracket (10) is fixed to the connecting seat plate of the pressure-bearing panel (2) by bolts, and an elongated hole for position adjustment is opened on the connecting seat plate.

10. The composite sealing structure for tunnel portals according to claim 5, characterized in that: The pressure-bearing panel (2) is provided with an ear plate (13). The reinforcing grouting pipe (12) is inlaid on the ear plate (13) at a 45° angle and welded and fixed. The outer end of the reinforcing grouting pipe (12) is filled with compressed foam (14), and the outer end of the reinforcing grouting pipe (12) is sealed with a threaded end cap (15). A gap of 20~50mm is reserved between the inner end of the reinforcing grouting pipe (12) and the outer surface of the cavity.

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