Shield disintegration section waterproof structure for tunnel and construction method

Abstract

The invention discloses a shield disintegration section waterproof structure for a tunnel and a construction method. The shield disintegration section waterproof structure comprises a shield abandoned shell, a steel pipe piece and a supporting part, and the shield abandoned shell is fixedly connected with a rock-soil body of an external tunnel; the steel pipe piece is arranged in the shield abandoned shell in a sleeved mode, and the supporting part is arranged on one side of the shield disintegration section and used for reinforcing and protecting the shield disintegration section. The steel pipe piece is adopted as the last ring segment lining constructed before shield disassembly, the shield shell and the steel pipe piece are welded and connected into a whole through the connecting steel ring after the shield reaches the disassembly position, the waterproof structure is simple, the waterproof capacity is high, the structural integrity is good, the shield tail can be rapidly sealed, and the construction cost is reduced. A large amount of grouting plugging, component connection and other work can be effectively omitted, the operation process is greatly simplified, and the construction cost is greatly reduced while the long-term waterproof capacity is effectively guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of shield disintegration section waterproofing, in particular to a shield disintegration section waterproofing structure for a tunnel and an installation method thereof. Background Art

[0002] With the rapid growth of tunnel construction, the number of shield machines being disassembled and reassembled within a dark tunnel has also increased. During disassembly, the shield shell is typically left inside the tunnel as the primary lining. A secondary lining is then cast within the shell and connected to the assembled segment structure to form a complete structure.

[0003] On the one hand, since the secondary lining structure in the shield shell is behind the temporary pipe piece, the connection gap between the secondary lining and the temporary pipe piece is prone to cause structural leakage and the sealing is affected to a certain extent. On the other hand, the connection is made of two materials, steel and concrete, and the end conversion method is relatively complicated, which makes it difficult to ensure the waterproof quality of the end. In particular, the risk of leakage is higher after the tunnel has been in operation for a long time. Therefore, the problem of leakage at the connection point of the tunnel construction method conversion is gradually exposed. What's worse, it has affected the operation of the subway or high-speed rail in the tunnel, and the economic losses caused are immeasurable.

[0004] For example, the patent with publication number CN116044442B discloses a shield underground docking section structure and its construction method. The patent specifically discloses "a shield underground docking section structure and its construction method, including a prefabricated structure part and a cast-in-place reinforced concrete structure part, the prefabricated structure part includes assembled pipe segments, anti-loosening components, a shield shell and a steel component connecting the prefabricated part and the cast-in-place part, the anti-loosening component includes a pre-embedded steel plate for the pipe segment, a connecting longitudinal beam, a lifting hole connector, a grouting anchor pipe, an anchor body and an anti-loosening steel piece, and the anti-loosening steel piece is circumferentially spaced. The technical means of "arranged at the concave angle formed by the embedded steel plate of the pipe segment and the shield shell, the steel assembly connecting the prefabricated part and the cast-in-place part extends into the cast-in-place reinforced concrete structure and is welded to the steel components in the cast-in-place reinforced concrete structure" realizes the technical effect of "the present invention has a total of three anti-loosening and limiting measures to achieve a firm connection between the prefabricated structure and the cast-in-place reinforced concrete structure and installation accuracy during the installation process, and the construction is convenient and fast without damaging the assembled pipe segment, while at the same time being connected to the assembled pipe segment into a whole"

[0005] However, in actual application, the technical solution of this patent uses three anti-loosening and limiting measures to stabilize the connection between the prefabricated pipe segments and the cast-in-place structure. Therefore, the structure of this patent is complex and there are many process conversions. Moreover, the waterproofing of the connection of this patent mainly relies on grouting of the surrounding strata, and the grouting body will lose its water-stopping effect after a long time. There is a high risk of water leakage after long-term operation of the tunnel.

[0006] In addition, the water-swelling rubber strips and grouting seals installed in the device will age over a long period of time, and there is no connection between the shield shell and the pipe segments, which are only sealed by grouting, resulting in a high risk of water leakage after long-term operation. In addition, there are many connection structures and complex processes, making implementation difficult. Summary of the Invention

[0007] The purpose of the present invention is to provide a waterproof structure and construction method for the shield disintegration section for a tunnel. The waterproof structure is simple, the waterproof ability is strong, the structural integrity is good, and the shield tail can be quickly sealed. It can effectively save a lot of grouting and component connection work, greatly simplify the operation process, and greatly reduce the project cost while effectively ensuring long-term waterproof ability, and can solve the problems raised in the above-mentioned background technology.

[0008] To achieve the above-mentioned object, the present invention provides the following technical solution: a shield disintegration section waterproof structure for a tunnel, installed in the shield disintegration section, characterized in that it comprises:

[0009] A shield shell, which is fixedly connected to the rock and soil of the external tunnel; a steel pipe segment, which is sleeved inside the shield shell; a support part, which is arranged on one side of the shield disintegration section and provides reinforcement and protection therefor, and the support part includes a connecting steel ring, a cast second lining and second lining steel bars; the connecting steel ring is fixedly installed inside the shield shell, one side of which is fixedly connected to the steel pipe segment, and the other side is fixedly connected to the second lining steel bars through the cast second lining; and a grouting layer, which is arranged in the gap between the shield shell and the steel pipe segment, and a reserved grouting pipe connected to the gap is opened inside the connecting steel ring, and water-blocking material is input into the gap through the reserved grouting pipe.

[0010] A method for constructing a waterproof structure for a shield disintegration section of a tunnel, comprising the following construction steps:

[0011] Step S1: After the shield machine is stopped, pre-grouting of the shield disassembly section and the shield machine is performed to prevent groundwater from seeping into the shield machine; wherein:

[0012] Before the shield machine advances to the disintegration section, the excavation speed and other parameters must be gradually reduced. 3-5m before the disintegration section, the excavation speed must not exceed 5mm / min. The error between the shield machine posture and the designed axis must not exceed 5mm / m to ensure that the shield machine stops accurately at the predetermined disintegration position. The misalignment within the ring after the steel pipe segments are assembled must not exceed 10mm, and the misalignment between rings must not exceed 15mm. The prefabricated steel pipe segments must have an anti-corrosion and waterproof layer to ensure the self-waterproofing ability of the steel pipe segment lining. The grouting material must have the ability to solidify quickly, with an initial setting time of no more than 1 minute, and be able to promptly prevent groundwater from entering the shield stop range.

[0013] Step S2: After the shield machine's jacking tank is withdrawn, the shield disassembly section and the support portion are welded to prevent the steel pipe segments from loosening; wherein:

[0014] The shield machine's jacking cylinder must be withdrawn in sections, with no less than 4 sections. After the cylinder of each section is withdrawn, the connecting steel ring of the corresponding area is welded to the shield shell and steel pipe segments. Only after the connection is stable can the jacking cylinder of the next section be withdrawn and the structure connected to prevent the entire ring of steel pipe segments from loosening;

[0015] The prefabricated blocks of the connecting steel rings should match the cylinder withdrawal zones and must have an anti-corrosion and waterproof layer. The welds of the welded connections must meet the requirements of the specifications, the joints must be strong, and match the steel strength of the shield shell, connecting steel rings, and steel pipe segments. Weld flaw detection must be carried out to prevent weld defects from affecting the waterproofing ability.

[0016] Step S3: Grouting is performed in the gap to enhance the waterproof capability of the shield dismantling section;

[0017] Step S4: After the shield machine is dismantled, a waterproof leveling layer is provided inside the shield shell to enhance the corrosion and waterproof capabilities of the shield dismantling section; wherein:

[0018] Spray anti-corrosion and waterproof coating, and the coating thickness must be no less than 4mm to ensure the shield shell's self-waterproofing ability as the primary lining;

[0019] The length of a single application should not exceed 3m to prevent deformation, cracking and other problems that may affect the waterproofing effect;

[0020] Step S5: After the stabilizing wing plates are removed and the secondary lining steel bars are welded to the connecting steel rings, the secondary lining is poured to achieve the actual connection between the shield disassembly section and the waterproof structure; wherein:

[0021] The removal of the stabilizing wing plate must be carried out in zones, with no less than 4 zones. After the stabilizing wing plate of each zone is removed, the connecting steel ring body of the corresponding zone is welded to the secondary lining steel bar. Only after the connection is stable can the stabilizing wing plate of the next zone be removed and welded to prevent the connecting steel ring body from being excessively deformed under the action of lateral force.

[0022] The inner diameter error between the cast secondary lining, connecting steel ring and steel pipe segments should not exceed 15mm to ensure the smoothness of the tunnel interior.

[0023] As a further solution of the present invention: a waterproof structure of a shield disintegration section for a tunnel, further comprising a stabilizing wing plate, which is obliquely placed inside the cast second lining and assists in connecting steel rings to support and fix the shield shell.

[0024] As a further solution of the present invention: a waterproof structure of a shield disintegration section for a tunnel also includes a waterproof leveling layer, which is fixedly installed on the inner wall of the shield abandoned shell and is used for pouring the second lining.

[0025] As a further solution of the present invention: a waterproof structure of a shield disintegration section for a tunnel, wherein the shield shell, steel pipe segments, connecting steel rings and secondary lining steel bars are all made of steel metal, and the shield shell, steel pipe segments and secondary lining steel bars are all well welded to the connecting steel rings.

[0026] As a further solution of the present invention: a shield disintegration section waterproof structure for a tunnel, wherein the waterproof leveling layer is made by coating with a polymer modified asphalt waterproof coating.

[0027] As a further solution of the present invention: a shield disintegration section waterproof structure for a tunnel, wherein the water blocking material is a polyurethane grouting material that is injected.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. In this application, the last ring of segment lining constructed before the shield disintegrates is made of steel segments, and after the shield reaches the disintegration position, the shield shell and the steel segments are welded together as a whole using connecting steel rings. This not only effectively stops water but also prevents the segments from loosening. Then, water-blocking materials are injected into the grouting pipes reserved on the connecting steel rings to construct a waterproof and anti-corrosion layer inside the shield shell, and the annular steel plate is connected to the second lining steel bars inside the shield shell. Finally, the second lining is cast, which can quickly seal the shield tail and form good waterproof integrity.

[0030] 2. This application has a simple structure and is easy to implement. It mainly uses connecting steel rings to connect steel segments and shield shells and cast the secondary lining. This eliminates a lot of conventional techniques such as ground reinforcement, segment anti-loosening, waterproof rubber, and rebar connection after the shield is dismantled, greatly simplifying the structure and construction process.

[0031] 3. This application has a strong long-term waterproof effect. The steel pipe segments, connecting steel rings, and shield abandoned shells are all connected by welding machines, and the sealing ability of the joints is strong; the steel pipe segments and connecting steel rings are prefabricated structures, and anti-corrosion and waterproofing treatments are done in advance. The anti-corrosion and waterproofing layer is applied inside the shield after disassembly, which ensures the long-term self-waterproofing ability of the metal structure; the connecting steel rings have reserved grouting pipes for injecting water-blocking materials, which effectively isolates groundwater from invading the connection range between the shield and the steel pipe segments. Effectively ensure the long-term waterproofing ability of the disassembly. Conventional technology uses rubber sealing and grouting filling in the concrete of the pipe segments and the secondary lining. The contact surface materials are different, the micro cracks and channels at the joints are difficult to control, the rubber aging problem is difficult to solve, and the risk of water leakage after long-term use is high.

[0032] 4. The tunnel integrity of this application is excellent. Conventional technology uses concrete segments at the dismantling point, with no direct connection between the abandoned shell and the segments. The segments are connected to the cast-in-place secondary lining using embedded rebar. This technology uses welded steel segments, connecting steel rings, shield abandoned shell, and cast secondary lining main reinforcement, effectively connecting all structures and synergizing the load, ensuring the integrity of the tunnel at the dismantling point.

[0033] 5. This application causes minimal damage to existing structures. Structural connections are primarily made by welding, and grouting lines are reserved on the connecting steel rings, eliminating the need for extensive drilling and cutting, resulting in minimal damage to existing structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the overall structure of an embodiment of the present invention;

[0035] Figure 2 This is an assembly diagram of the shield casing, steel segments, and connecting steel rings in an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the structure of the connecting steel ring in an embodiment of the present invention;

[0037] In the figure: 1. Shield abandoned shell; 2. Steel pipe segments; 3. Connecting steel rings; 4. Casting of secondary lining; 5. Reserved grouting pipes; 6. Secondary lining reinforcement; 7. Waterproof leveling layer; 8. Water blocking material; 9. Stabilizing wing plates. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings.

[0039] In the embodiment of the present invention, the waterproof structure and construction method of the connection between the shield shell section and the pipe segment after the shield of the prior art disintegrates the blind hole are the waterproof weak points at the tunnel construction method conversion point. Specifically, when the shield is disintegrated, the shield shell is generally left in the hole as the primary lining, and the secondary lining is cast in the shield shell and connected to the assembled pipe segment structure to form a whole. Its main waterproofing methods include stratum reinforcement and laying water-stop rubber between the cast-in-place secondary lining and the concrete pipe segment. However, both methods have some limitations. The current stratum reinforcement measures will gradually become ineffective after a long time, and the aging problem of water-stop rubber is also more prominent. As a result, the problem of water leakage at the construction method conversion point of domestic tunnels is gradually exposed. In addition, high-speed rail and subway operating tunnels will install contact networks on the top of the tunnel to power locomotives. Water leakage threatens the safety of power supply. Therefore, the cost of repairing water leakage after it has occurred is high, and it may even lead to suspension of operation, and the economic losses caused are immeasurable.

[0040] Other embodiments of the present invention:

[0041] A waterproof structure for a shield dismantling section for a tunnel includes a shield dismantling section installed in a formed tunnel, the shield dismantling section including a shield shell 1, steel pipe segments 2, a support portion, and a grouting layer. The shield shell 1 is the shield shell remaining in the tunnel after the shield is dismantled, connected to the rock and soil outside the tunnel, and serves as a primary lining support to ensure the safety of the dismantling operation of the shield machine's internal system; the steel pipe segments 2 are prefabricated structures used for tunnel lining assembly during shield construction. Currently, reinforced concrete segments are often used in many cases, and the structural connection and waterproofing methods of the dismantling section are complex, and the integrity and waterproofing of the tunnel are weak, which has certain defects. The steel pipe segments 2 are embedded in the interior of the shield shell 1 and are fixedly connected to the rock and soil of the external tunnel in a sleeve manner. Specifically, the shield shell 1 is used as a structure that needs to support the rock and soil after the shield machine withdraws after working in the rock and soil. At the same time, the steel pipe segments 2 are used in conjunction with the shield shell 1 for effective internal support.

[0042] The support portion is arranged on one side of the shield disintegration section and provides reinforcement and protection thereof. The support portion includes a connecting steel ring 3, a cast secondary lining 4 and secondary lining steel bars 6, wherein the connecting steel ring 3 serves as the core support and implementation structure in the embodiment of the present application. The connecting steel ring 3 is fixedly installed inside the shield abandoned shell 1, one side of which is fixedly connected to the steel pipe segment 2, and the other side is fixedly connected to the secondary lining steel bar 6 by casting the secondary lining 4. The support portion supports the shield structure segment after the shield disintegration section is completed, mainly to prevent the problem of rock and soil collapse after the shield machine is withdrawn, and the structure also facilitates the subsequent waterproof grouting operation of the shield disintegration section, and the shield abandoned shell 1, steel pipe segment 2, connecting steel ring 3 and secondary lining steel bar 6 are all made of steel metal, and the shield abandoned shell 1, steel pipe segment 2 and secondary lining steel bar 6 have good welding firmness with the connecting steel ring 3;

[0043] The grouting part is arranged in the gap between the shield shell and the steel pipe segment, and the grouting layer is arranged in the gap between the shield shell and the steel pipe segment. A reserved grouting pipe connected to the gap is opened inside the connecting steel ring, and water-blocking material is injected into the gap through the reserved grouting pipe. That is, by injecting waterproof material into the grouting part, the overall waterproof protection operation of the shield disintegration section can be achieved.

[0044] Other embodiments of the present invention: Figure 1In summary, the waterproof structure at the shield disassembly connection proposed by the present invention is to maintain the structural stability of the rock cave before the shield disassembly and to carry out the subsequent waterproofing operation of the rock cave. Specifically, the last ring of segment lining applied before the shield disassembly adopts steel segments 2. That is, after the shield machine completes the drilling task, the normal operation of the existing technology is to excavate a vertical shaft and disassemble the shield machine. After the cutter head and hydraulic components of the shield machine are removed, the disassembled parts are lifted out with a crane. However, in general, when the shield machine is excavating, cement segments are laid immediately behind it, so that if the shield machine withdraws, the rock cave interior will lose its support and waterproofing effect. Therefore, this application is to leave a circular shield shell 1 after the shield machine is disassembled, and weld the shield shell 1, steel pipe segments 2 and connecting steel rings 3 to prevent water seepage at the tunnel interface. (The technical problem addressed by this application is not water seepage in all tunnel channels. The customer only wants to solve the water seepage at the last ring after the tunnel excavation is completed. Because the water seepage problem at the interface is relatively serious, and in most cases, the tunnel is actually in the center of the mountain or land, so the water seepage is not very serious. Since the interface is close to the outside world, the geology at the interface is often loose, which will cause serious water seepage problems).

[0045] Therefore, after the shield reaches the dismantling position, the shield shell 1 and the steel pipe segment 2 are welded together using the connecting steel ring 3, which not only effectively stops water but also prevents the steel pipe segment 2 from loosening. Then, the reserved grouting pipe 5 on the steel pipe segment 2 is injected with water blocking material, and the internal anti-corrosion layer of the shield shell 1 is applied. The connecting steel ring 3 is connected to the secondary lining steel bar 6 in the shield shell 1, and finally the construction of the secondary lining 4 is completed. This waterproof structure is simple, has strong waterproofing ability, good structural integrity, and can quickly seal the shield tail. It can effectively save a lot of grouting and component connection work, greatly simplifying the operation process, effectively ensuring long-term waterproofing ability while greatly reducing the project cost.

[0046] Other embodiments of the present invention: Since the steel pipe segments 2 of the prior art are used as prefabricated structures for tunnel lining assembly during shield construction. Currently, reinforced concrete segments are often used, and the structural connection and waterproofing of the disintegration section are complicated, and the integrity and waterproofing of the tunnel are weak, which has certain defects. Therefore, this patent uses steel pipe segments for lining at the shield disintegration section. Considering that the lining of the shield disintegration section, the connecting steel ring, and the shield abandoned shell are all made of metal materials, they are connected by welding, which improves the structural integrity and the sealing ability of the connection position, and simplifies the connection difficulty.

[0047] Other embodiments of the present invention: Figure 1 、 Figure 2 and Figure 3 Since the connecting steel ring 3 is the core structure of the embodiment of the present application, it has three main functions, including

[0048] 1. Connect the shield shell 1, cast secondary lining 4 and steel pipe segments 2, especially tighten the steel pipe segments 2 and fill the gaps between them. Because the shield shell 1, steel pipe segments 2 and the secondary lining steel bars 6 in the cast secondary lining 4 are welded to the connecting steel ring 3, the integrity of the tunnel structure and the sealing ability of the connection position can be improved. Compared with conventional technologies, this embodiment greatly simplifies the connection difficulty and comprehensively improves the coordinated force-bearing capacity of various structures in the disintegration section and the waterproof ability of the disintegration section through welding of the same material.

[0049] 2. When the shield machine advances to the disintegration point, the connecting steel ring 3 can be immediately welded to the steel pipe segment 2 and the shield shell 1, so that the pipe segment lining can be fixed as a whole, preventing the problem of loosening of the overall structure of the pipe segment lining in the shield disintegration section. Since the loosening tendency of the pipe segment lining will generate lateral force on the connecting steel ring 3, a stabilizing wing plate 9 is arranged on the connecting steel ring 3 to improve the stability of the structural connection. Compared with conventional technology, the connecting steel ring 3 also has the anti-loosening function of the steel pipe segment 2, thereby eliminating a lot of pipe segment anti-loosening structure and component installation work, and also saving costs.

[0050] 3. By reserving a grouting pipe 5 to inject water-blocking material into the gap between the shield shell 1 and the steel pipe segment 2, the structure of the shield shell 1 and the steel pipe segment 2 can be effectively sealed and groundwater can be prevented from invading the connection position, further improving the waterproof ability of the broken hook disintegration section. Compared with conventional technology, a large amount of structural opening and post-disintegration stratum reinforcement work is saved.

[0051] Other embodiments of the present invention: Figure 1 After the shield is dismantled, the shield shell 1 is used as the primary lining to ensure construction safety during the shield dismantling period. After the shield is dismantled, a reinforced concrete lining is poured into the shield shell 1 to form a cast secondary lining 4. The cast secondary lining 4 has the same inner diameter as the segment lining, and the secondary lining steel bars 6 and the connecting steel ring 3 in the cast secondary lining 4 are welded together, which can ensure the coordinated force bearing capacity of the cast secondary lining 4 and other structures and improve the integrity of the tunnel structure in the dismantling section.

[0052] Other embodiments of the present invention: Figure 1In this embodiment, the reserved grouting pipe 5 is used to fill the gap between the shield shell 1 and the steel pipe segment 2 with water-blocking material, and the reserved grouting pipe 5 is arranged on one side of the connecting steel ring 3, so that the reserved grouting pipe 5 is convenient to operate when injecting waterproof material into the gap between the shield shell 1 and the steel pipe segment 2. Therefore, this embodiment solves the shortcomings of structural openings in conventional technology by reserving, reducing structural damage. At the same time, the water-blocking material 8 is injected using polyurethane grouting material (features: excellent elasticity and impermeability, can be used in humid environments. Application: used for basement waterproofing, crack repair and grouting plugging). The water-blocking material 8 is the actual material for filling the gap between the shield shell 1 and the steel pipe segment 2. It is injected through the reserved grouting pipe of the connecting steel ring. It must have rapid solidification and long-term waterproof capabilities to block groundwater from entering the disintegration section, further enhancing the waterproof capability of the disintegration section.

[0053] Other embodiments of the present invention: Figure 1 The waterproof structure includes a waterproof leveling layer 7, which is fixedly installed on the inner wall of the shield shell 1 and is used for pouring the second lining 4. The waterproof leveling layer 7 is made of polymer modified asphalt waterproof coating (features: it has both the flexibility of asphalt and the durability of polymer, and can withstand certain deformation. Application: suitable for roofs, basements and other humid environments). Its laying inside the shield shell 1 is a conventional practice between the first and second linings. By laying the waterproof leveling layer 7, the quality of pouring the second lining 4 can be guaranteed while increasing the waterproof ability of the shield shell 1.

[0054] Other embodiments of the present invention: Figure 1 The shield casing 1 is further provided with stabilizing fins 9, which are placed obliquely inside the cast secondary lining 4 and assist the connecting steel ring 3 in supporting and securing the shield casing 1. Because loosening of the segmental lining can generate lateral forces on the connecting steel ring 3, the stabilizing fins 9 are provided on the connecting steel ring 3 to enhance the stability of the structural connection. Furthermore, the stabilizing fins 9 are bolted to the connecting steel ring 3, making them easy to remove before welding the cast secondary lining 4 to the connecting steel ring 3.

[0055] Other embodiments of the present invention: A method for constructing a shield disintegration section waterproof structure for a tunnel, characterized by comprising:

[0056] Step S1: After the shield machine is stopped, pre-grouting of the shield disassembly section and the shield machine is performed to prevent groundwater from seeping into the shield machine. Specifically, the shield machine is excavated to the disassembly section, and after the machine is stopped, the steel segments 2 of the disassembly section are assembled, and shield body grouting, shield tail synchronous grouting, and secondary grouting of the steel segments 2 are performed to preliminarily prevent groundwater from entering the shield machine range.

[0057] Step S11: Before the shield machine advances to the disintegration section, the excavation speed and other parameters must be gradually reduced. 3-5m before the disintegration section, the excavation speed must not exceed 5mm / min. The error between the shield machine posture and the design axis must not exceed 5mm / m. The posture of the steel segment 2 must not exceed the relevant specifications to ensure that the shield machine stops accurately at the predetermined disintegration position.

[0058] Step S12: After the steel segments 2 are assembled, the misalignment within the ring cannot exceed 10 mm, and the misalignment between rings cannot exceed 15 mm. The prefabricated steel segments 2 must have an anti-corrosion and waterproof layer to ensure the self-waterproofing ability of the lining of the steel segments 2;

[0059] Step S13: Shield body grouting, synchronous shield tail grouting, and secondary segment grouting are common measures in shield construction. The grouting material must have rapid solidification ability, with an initial setting time of no more than 1 minute, and be able to promptly prevent groundwater from entering the shield shutdown range.

[0060] Step S2: After the shield machine's jacking oil tank is retracted, the shield disassembly section and the support part are welded to achieve the anti-loosening effect of the steel pipe segment 2. Specifically, the shield machine's jacking oil cylinder is retracted, and the shield shell 1, the steel pipe segment 2 and the connecting steel ring 3 are welded together to perform the preliminary connection of the disassembly section structure while preventing the steel pipe segment 2 from loosening;

[0061] Step S21: The shield machine's jacking cylinder must be withdrawn in sections, with no less than 4 sections. After the cylinder of each section is withdrawn, the connecting steel ring 3 in the corresponding area is welded to the shield shell 1 and the steel pipe segment 2. Only after the connection is stable can the jacking cylinder of the next section be withdrawn and the structure connected to prevent the entire ring of the steel pipe segment 2 from loosening.

[0062] Step S22: The prefabricated blocks connecting the steel ring 3 should match the cylinder withdrawal partition and must have an anti-corrosion and waterproof layer to improve the self-waterproofing ability of the preliminary connection;

[0063] Step S23: The welds of the welded connections must meet the requirements of the specifications. The joints must be strong and match the strength of the steel used in the shield shell 1, steel segments 2, and connecting steel rings 3. Weld flaw detection must also be performed to prevent weld defects from affecting the waterproofing capability.

[0064] Step S3: Grouting is performed in the gap to enhance the waterproof capability of the shield dismantling section. Specifically, the water blocking material must have long-term water-stopping capability and must not contain materials such as water glass;

[0065] Step S4: After the shield machine is disassembled, a waterproof leveling layer 7 is provided inside the shield shell 1 to enhance the anti-corrosion and waterproof capabilities of the shield disassembly section. Specifically, after the internal disassembly of the shield machine is completed, an anti-corrosion and waterproof coating is sprayed inside the shield shell, and a waterproof leveling layer 7 is applied to enhance the self-waterproof capability of the shield shell.

[0066] Step S41: The anti-corrosion and waterproof coating must be sprayed to a thickness of not less than 4 mm to ensure the self-waterproofing capability of the shield shell as the primary lining;

[0067] Step S42: The length of the waterproof layer applied at a time should not exceed 3m to prevent deformation, cracking and other problems that may affect the waterproof effect;

[0068] Step S5: After the stabilizing wing plates 9 are removed and the secondary lining steel bars 6 are welded to the connecting steel ring 3, the secondary lining 4 is cast to achieve the actual connection between the shield dismantling section and the waterproof structure. Specifically, the stabilizing wing plates 9 in the connecting steel ring 3 are removed and the cast secondary lining 4 is welded to the secondary lining steel bars 6. Then, the secondary lining 4 is cast and the structural connection is completed, thereby improving the integrity of the tunnel and the overall waterproof capability of the dismantling section.

[0069] Step S51: The stabilizing flanges 9 must be removed in zones, with no less than four zones. After the stabilizing flanges 9 in each zone are removed, the connecting steel rings 3 and the secondary lining steel bars 6 in the corresponding zone are welded together. Only after the connection is stable can the stabilizing flanges 9 in the next zone be removed and welded together to prevent the steel pipe segments 2 from being excessively deformed under the action of lateral forces.

[0070] Step S52: The inner diameter error between the steel segments 2, the connecting steel rings 3 and the cast secondary lining 4 should not exceed 15 mm to ensure that the interior of the tunnel is smooth.

[0071] The working principle of the present invention is: the last ring of segment lining applied before the shield disintegrates adopts steel segments 2, and after the shield reaches the disintegration position, a connecting steel ring 3 is used to connect the shield shell 1 and the steel segments 2 into a whole, which can not only effectively stop water but also prevent the steel segments 2 from loosening. Then, the reserved grouting pipe 5 on the connecting steel ring 3 is injected with water-blocking material 8 to apply a waterproof and anti-corrosion layer inside the shield shell, and the connecting steel ring 3 is connected to the second lining steel bar 6 in the shield shell, and finally the second lining 4 is cast, which can quickly seal the shield tail and form good waterproof integrity.

[0072] The above is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A shield disintegration section waterproof structure for a tunnel, installed in the shield disintegration section, characterized in that: include: A shield casing (1), wherein the shield casing (1) is fixedly connected to the rock and soil of the external tunnel; The steel pipe segment (2) is sleeved inside the shield casing (1). A support portion, the support portion being arranged on one side of the shield disintegration section and providing reinforcement and protection therefor, the support portion comprising a connecting steel ring (3), a cast secondary lining (4) and secondary lining steel bars (6), the connecting steel ring (3) being fixedly mounted inside the shield abandoned shell (1), one side of the connecting steel ring being fixedly connected to the steel pipe segment (2), and the other side being fixedly connected to the secondary lining steel bars (6) by casting the secondary lining (4); and A grouting layer is provided in the gap between the shield casing (1) and the steel pipe segment (2); a reserved grouting pipe (5) communicating with the gap is provided inside the connecting steel ring (3); and a water blocking material (8) is injected into the gap through the reserved grouting pipe (5).

2. The shield disintegration section waterproof structure for a tunnel according to claim 1, characterized in that: It also includes a stabilizing wing plate (9), which is placed inside the cast secondary lining (4) and assists in connecting the steel ring (3) to support and fix the shield abandoned shell (1).

3. The shield disintegration section waterproof structure for a tunnel according to claim 2, characterized in that: It also includes a waterproof leveling layer (7), which is fixedly installed on the inner wall of the shield abandoned shell (1) and is used for pouring the second lining (4).

4. The shield disintegration section waterproof structure for a tunnel according to claim 3, characterized in that: The shield casing (1), steel pipe segments (2), connecting steel rings (3) and secondary lining steel bars (6) are all made of steel metal, and the shield casing (1), steel pipe segments (2) and secondary lining steel bars (6) are all well welded to the connecting steel rings (3).

5. The shield disintegration section waterproof structure for a tunnel according to claim 4, characterized in that: The waterproof leveling layer (7) is made by coating with a polymer modified asphalt waterproof coating.

6. The shield disintegration section waterproof structure for a tunnel according to claim 5, characterized in that: The water blocking material (8) is a polyurethane grouting material that is injected.

7. The method for constructing a shield disintegration section waterproof structure for a tunnel according to claim 6, characterized in that: The construction steps include: Step S1: After the shield machine is stopped, pre-grouting of the shield disassembly section and the shield machine is performed to prevent groundwater from seeping into the shield machine; wherein: Before the shield machine advances to the disintegration section, the excavation speed and other parameters must be gradually reduced. 3-5m before the disintegration section, the excavation speed must not exceed 5mm / min. The error between the shield machine posture and the designed axis must not exceed 5mm / m to ensure that the shield machine stops accurately at the predetermined disintegration position. After the steel pipe segments (2) are assembled, the misalignment within the ring shall not exceed 10 mm, and the misalignment between the rings shall not exceed 15 mm. The prefabricated steel pipe segments (2) shall have an anti-corrosion and waterproof layer to ensure the self-waterproofing ability of the steel pipe segment lining; The grouting material must have the ability to solidify quickly, with an initial setting time of no more than 1 minute, and be able to promptly prevent groundwater from entering the shield shutdown area; Step S2: After the shield machine's jacking oil tank is withdrawn, the shield disassembly section and the support portion are welded to achieve an anti-loosening effect on the steel pipe segment (2); wherein: The shield machine's top cylinder must be withdrawn in sections, with no less than 4 sections. After the cylinder of each section is withdrawn, the connecting steel ring (3) of the corresponding area is welded to the shield machine's discarded shell (1) and the steel pipe segment (2). Only after the connection is stable can the top cylinder of the next section be withdrawn and the structure connected to prevent the entire ring of the steel pipe segment (2) from loosening. The prefabricated blocks of the connecting steel ring (3) should match the oil cylinder withdrawal partition and must have an anti-corrosion and waterproof layer; the welds of the welded connections must meet the requirements of the specifications, the joints must be firm, and match the strength of the steel materials of the shield shell, connecting steel ring, and steel pipe segments, and weld flaw detection must be carried out to prevent weld defects from affecting the waterproofing ability; Step S3: Grouting is performed in the gap to enhance the waterproof capability of the shield dismantling section; Step S4: After the shield machine is disassembled, a waterproof leveling layer (7) is provided inside the shield shell (1) to enhance the anti-corrosion and waterproof capabilities of the shield disassembly section; wherein: Spray anti-corrosion and waterproof coating, and the coating thickness must be no less than 4mm to ensure the shield shell's self-waterproofing ability as the primary lining; The length of a single application should not exceed 3m to prevent deformation, cracking and other problems that may affect the waterproofing effect; Step S5: After the stabilizing wing plate (9) is removed and the secondary lining steel bar (6) and the connecting steel ring (3) are welded, the secondary lining (4) is cast to achieve the actual connection between the shield disintegration section and the waterproof structure; wherein: The removal of the stabilizing wing plate (9) must be carried out in zones, with no less than 4 zones. After the removal of the stabilizing wing plate (9) in each zone, the main body of the connecting steel ring (3) in the corresponding zone is welded to the secondary lining steel bar (6). Only after the connection is stable can the stabilizing wing plate (9) in the next zone be removed and welded to prevent the main body of the connecting steel ring (3) from being excessively deformed under the action of the lateral force. The inner diameter error between the cast secondary lining (4), the connecting steel ring (3) and the steel pipe segment (2) should not exceed 15 mm to ensure that the interior of the tunnel is smooth.

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