Method for replacing the tail brush of a shield tunnel using threaded quick-connect fittings

Abstract

This invention provides a method for replacing the tail brush of a shield tunnel using a threaded quick-connect fitting, comprising the following steps: Step S1: Customizing a single-segment threaded screw, the single-segment threaded screw including a first nut and a first threaded segment and a smoothing platform stage fixedly connected to both ends of the first nut; Step S2: After the shield machine advances to the selected position for replacing the tail brush, the segment is assembled using the single-segment threaded screw; Step S3: The shield machine advances one ring of segments, and the ring of segments pressing on the tail brush is removed without damage using a segment assembly machine; Step S4: Replacing the tail brush; Step S5: Reassembling the segment using a double-segment threaded screw. This invention, through the dual innovation of "special screw structure + staged connection process," overcomes the technical bottleneck of "irreversible installation" of threaded connectors, achieving high efficiency, economy, and safety in tail brush replacement while ensuring structural performance.

Description

Technical Field

[0001] This invention relates to the field of shield tunnel construction technology, and in particular to a method for replacing the tail brush of a shield tunnel using threaded quick-connect fittings. Background Technology

[0002] In shield tunneling construction, threaded quick-connect fittings are widely used due to their advantages such as reliable connection and convenient construction. These fittings mainly consist of a pre-embedded nut and a threaded rod, with tensile strength achieved through thread engagement. However, existing threaded quick-connect fittings have significant drawbacks:

[0003] Irreversible: If the segments need to be removed after installation, the bolts must be pulled out forcefully, which will damage the threads, making them unusable and affecting the structural load-bearing capacity;

[0004] Maintenance limitations: Replacing the tail brush requires removing the segment, but the existing connection method means that removal will inevitably damage the component, increasing maintenance costs and time, which restricts the promotion and application of this connector.

[0005] Currently, there is no non-destructive dismantling technology for threaded quick connectors in shield tunnel construction, and there is an urgent need for a method that can both ensure connection performance and enable repeated dismantling of tunnel segments. Summary of the Invention

[0006] In view of the above, the present invention provides a method for replacing the tail brush of a shield tunnel using threaded quick connectors, so as to solve the problem that the tunnel segments cannot be removed without damage when replacing the shield brush during shield tunnel construction using conventional threaded connectors.

[0007] The technical solution adopted in this invention is as follows:

[0008] This invention provides a method for replacing the tail brush of a shield tunnel using a threaded quick-connect fitting, characterized by the following steps:

[0009] Step S1: Customize a single-segment threaded screw, wherein the single-segment threaded screw includes a first nut and a first threaded segment and a smoothing stage fixedly connected to both ends of the first nut;

[0010] Step S2: After the tunnel boring machine has advanced to the selected position for replacing the tail brush, the segment assembly is completed using the single-section threaded screw.

[0011] Step S3: The tunnel boring machine advances one ring of segments, and the ring of segments pressing on the tail brush is removed without damage using the segment assembly machine;

[0012] Step S4: Replace the shield tail brush;

[0013] Step S5: Reassemble the tube segments using a double-segment threaded screw.

[0014] Furthermore, the dual-segment threaded screw includes a second nut and a second threaded segment and a third threaded segment fixedly connected to both ends of the second nut.

[0015] Furthermore, after replacing the tail brush, apply a layer of tail grease to the tail brush and reassemble the segments using the double-segment threaded screw to achieve a non-destructive segment connection for replacing the tail brush.

[0016] Further, step S2 includes:

[0017] S2.1: When the shield tunneling reaches the selected shield tail brush replacement position, screw the first threaded section of the single-section threaded screw into the first pre-embedded nut embedded in the end face of the segment to be assembled;

[0018] S2.2: The segment assembly machine grabs the segment to be assembled, aligns the smooth platform stage of the single-segment threaded screw with the pre-embedded sleeve embedded in the end face of the assembled segment, and then the shield machine jack presses the smooth platform stage on the segment to be assembled into the pre-embedded sleeve of the assembled segment. The first nut is embedded in the countersunk hole of the two segments that are tightly installed. The entire ring segment assembly is completed in this sequence.

[0019] Furthermore, the pre-embedded sleeve is provided with stepped holes that are adapted to the smooth platform stage.

[0020] Furthermore, step S3, which involves using a segment assembly machine to remove the ring-shaped segments pressing against the shield tail brush without damage, includes:

[0021] The segment assembly machine is used to grab the capping block of the lining segment to be removed, and the capping block segment is removed by moving it longitudinally along the centerline of the tunnel.

[0022] The remaining segments should be removed sequentially in the order of "first the capping block, then the tunnel segments" to avoid stress concentration.

[0023] Further, step S4 includes:

[0024] S4.1: Use a wrench to remove the old shield tail brush fixing bolts, and at the same time check whether the shield tail brush seat is damaged, and clean the rust and debris on the surface of the brush seat;

[0025] S4.2: Inspect the wear condition of the shield tail, and grind or repair it if necessary. At the same time, clean the soil and sand inside and around the shield tail to ensure it is clean and free of debris.

[0026] S4.3: Align the new tail brush with the tail brush holder, ensuring the position is correct. Secure the new tail brush to the tail brush holder with bolts and tighten the bolts with a wrench. Check that the new tail brush is securely installed and ensure there is no misalignment.

[0027] Further, step S5 includes:

[0028] S5.1: Apply the replaced shield tail brush to the shield tail grease to ensure a good seal;

[0029] S5.2: Remove the single-section threaded screw and replace it with the double-section threaded screw to complete the assembly of the entire ring segment.

[0030] Further, S5.2 includes: screwing the second threaded section of the double-segment threaded screw into the second pre-embedded nut embedded in the end face of the segment to be installed, then the shield machine jack is placed on the jack face, and the third threaded section on the segment to be assembled is pressed into the third pre-embedded nut of the assembled segment. The whole ring segment assembly is completed in this sequence to restore the segment connection strength and realize the replacement of the shield tail brush without damage to the segment connection.

[0031] Furthermore, the second nut is embedded in the countersunk hole of the two pipe segments that are tightly installed.

[0032] This invention provides a method for replacing the tail brush of a shield tunnel segment connection based on a single-segment / double-segment threaded screw combination. Through structural innovation and process optimization, it significantly improves the reliability and economy of shield tunnel construction and maintenance. The specific beneficial effects are as follows:

[0033] 1. A breakthrough solution to the problem of damaged parts during the removal of threaded connectors, achieving non-destructive disassembly of tunnel segments.

[0034] Single-sided threadless structure design: By using the smooth platform stage (threadless) of the single-segment threaded screw and the clearance fit (non-threaded engagement) of the pre-embedded sleeve, the segments can be separated by longitudinal translation only when they are removed. This avoids damage such as screw deformation and nut stripping caused by traditional threaded forced pull-out, ensuring the integrity of basic components such as the pre-embedded sleeve and the first pre-embedded nut, and laying the foundation for the reuse of segments.

[0035] Stress-controlled demolition process: The process adopts the order of "first sealing the top block, then the segments" and the longitudinal translation demolition path to avoid radial stress impact during traditional demolition, further reduce the risk of segment joint damage and improve structural safety.

[0036] 2. Innovative screw assembly system ensures reliable connection performance throughout the entire process.

[0037] Staged screw adapter:

[0038] Assembly stage: The first threaded section 12 of the single-section threaded screw forms a reliable threaded connection with the first pre-embedded nut to ensure the initial bearing capacity during segment assembly; the smooth table stage achieves rapid positioning through mechanical embedding (non-threaded force), taking into account both connection strength and subsequent disassembly.

[0039] Reassembly stage: The second and third threaded sections of the double-segment threaded screw form a full thread engagement with the second and third pre-embedded nuts, respectively, restoring the complete tensile strength performance of traditional threaded connectors and ensuring structural safety during tunnel operation.

[0040] Nut-embedded design: The first nut and the second nut are embedded in the countersunk hole of the tube segment to form a planar contact force transmission, avoiding stress concentration caused by the traditional screw protruding from the surface of the tube segment, and improving the overall integrity of the joint.

[0041] 3. Significantly improves the efficiency of shield tail brush replacement and reduces maintenance costs.

[0042] Rapid assembly and disassembly process: The press-fit assembly and threadless disassembly process in the smooth platform stage reduces the assembly and disassembly time of a single ring segment by about 50%, significantly reducing the downtime for tunnel boring machine maintenance and lowering the risk of construction delays.

[0043] Material loss reduction: Avoiding the one-time scrapping of screws and nuts due to thread damage in traditional processes, single-ring segment maintenance can save about 30%-50% of the material cost of connectors, which is especially suitable for long tunnels with multiple maintenance scenarios.

[0044] 4. Expand the application scenarios of threaded fasteners and promote innovation in construction technology.

[0045] Assembly and inspection versatility: The non-destructive disassembly and assembly characteristics of the single-section threaded screw can be directly applied to the three-ring horizontal assembly and inspection of lining segments, avoiding thread wear caused by repeated disassembly and assembly in traditional inspection, reducing trial assembly losses, and improving the economy of precast segment quality inspection.

[0046] Technical system completeness: It fills the technical gap in the field of "repeated disassembly and maintenance" of threaded quick connectors, forms a complete process technical solution of "assembly-maintenance-reassembly", enhances the applicability of such connectors in complex geological conditions and high maintenance demand scenarios, and helps the localization and standardization of the domestic shield tunneling equipment technology system.

[0047] 5. Multiple process safeguards enhance tunnel sealing and long-term performance.

[0048] Quality control of shield tail brush replacement: The removal of old brushes and the installation of new brushes are precisely controlled by torque wrenches. Combined with shield tail wear detection, impurity cleaning and full grease injection processes, the reliability of the sealing system is ensured and the risk of tunnel water leakage is reduced.

[0049] Improved construction safety: Standardized dismantling sequence and mechanical assistance (segment assembly machine) reduce manual intervention and avoid safety hazards such as segment breakage and bolt splashing that may be caused by traditional force dismantling, which meets the safety and environmental protection requirements of modern tunnel construction.

[0050] This invention breaks through the technical bottleneck of "irreversible installation" of threaded connectors through the dual innovation of "special screw structure + phased connection process". It achieves high efficiency, economy and safety of shield tail brush replacement while ensuring structural performance. It has both engineering practical value and promotes the upgrading of industry technology, and has significant social and economic benefits and market promotion prospects. Attached Figure Description

[0051] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but should not be construed as limiting the invention. In the drawings:

[0052] Figure 1 : A cross-sectional view of the single-segment threaded screw of the present invention;

[0053] Figure 2 : A cross-sectional view of the double-segment threaded screw of the present invention;

[0054] Figure 3 This invention employs a method for replacing the tail brush of a shield tunnel using threaded quick-connect fittings. The diagram shows the segment installation structure.

[0055] Reference numerals: 1. Single-segment threaded screw, 11. First nut, 12. First threaded segment, 13. Smooth table stage, 2. Tube segment, 3. First embedded nut, 4. Embedded sleeve, 5. Double-segment threaded screw, 51. Second nut, 52. Second threaded segment, 53. Third threaded segment, 6. Second embedded nut, 7. Detailed Implementation

[0056] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0057] like Figures 1 to 3 As shown, the present invention provides a method for replacing the tail brush of a shield tunnel using a threaded quick-connect fitting, comprising the following steps:

[0058] Step S1: Customize a single-segment threaded screw 1: The single-segment threaded screw 1 includes a first nut 11 and a first threaded segment 12 fixedly connected to both ends of the first nut 11 and a smooth platform stage 13 (without threads);

[0059] Step S2: Assemble segment 2 using single-section threaded screw 1: After the tunnel boring machine has advanced to the selected position for replacing the tail brush, segment 2 is assembled using single-section threaded screw 1.

[0060] S2.1: When the shield tunneling reaches the selected shield tail brush replacement position, screw the first threaded section 12 of the single-section threaded screw 1 into the first pre-embedded nut 3 embedded in the end face of the segment 2 to be assembled;

[0061] S2.2: The segment assembly machine grabs the segment 2 to be assembled, aligns the smooth platform stage 13 of the single-section threaded screw 1 with the embedded sleeve 4 embedded in the end face of the assembled segment 2, and then the shield machine jack is placed on the jacking surface to press the smooth platform stage 13 on the segment 2 to be assembled into the embedded sleeve 4 of the assembled segment 2. The first nut 11 is embedded in the countersunk hole of the two segments 2 that are tightly installed. The entire ring segment assembly is completed in this order. The embedded sleeve 4 is provided with a stepped hole that matches the smooth platform stage 13.

[0062] Step S3: The tunnel boring machine advances one ring of tunnel segments, and the ring of tunnel segments pressing against the tail brush is removed without damage using a segment assembly machine.

[0063] S3.1: Distance of one ring of tunnel segments advanced by the tunnel boring machine;

[0064] S3.2: Use a segment assembly machine to grab the capping block of the lining segment to be removed, and move it longitudinally along the centerline of the tunnel to remove the capping block segment;

[0065] S3.3: Remove the remaining segments 2 in sequence according to the order of "first the capping block, then the segments" to avoid stress concentration.

[0066] Step S4: Replace the shield tail brush;

[0067] S4.1: Use a wrench to remove the old shield tail brush fixing bolts, and at the same time check whether the shield tail brush seat is damaged, and clean the rust and debris on the surface of the brush seat;

[0068] S4.2: Inspect the wear condition of the shield tail, and grind or repair it if necessary. At the same time, clean the soil and sand inside and around the shield tail to ensure it is clean and free of debris.

[0069] S4.3: Align the new tail brush with the tail brush holder, ensuring the position is correct. Secure the new tail brush to the tail brush holder with bolts and tighten the bolts with a wrench. Check that the new tail brush is securely installed and ensure there is no misalignment.

[0070] Step S5: Reassemble the tube segment 2 using a double-segment threaded screw 5: The double-segment threaded screw 5 includes a second nut 51 and a second threaded section 52 and a third threaded section 53 fixedly connected to both ends of the second nut 51; Apply shield tail grease to the replaced shield tail brush, and reassemble the tube segment using the double-segment threaded screw 5 to achieve non-destructive tube segment connection and replacement of the shield tail brush.

[0071] S5.1: Apply the replaced shield tail brush to the shield tail grease to ensure a good seal.

[0072] S5.2: Remove the single-section threaded screw 1 and replace it with a double-section threaded screw 5. Screw the second threaded section 52 of the double-section threaded screw 5 into the second pre-embedded nut 6 embedded in the end face of the segment 2 to be installed. Then, the shield machine jack is placed on the jack face, and the third threaded section 53 on the segment 2 to be assembled is pressed into the third pre-embedded nut 7 of the assembled segment 2. The second nut 51 is embedded in the countersunk hole of the two segments 2 that are tightly installed. The entire ring segment assembly is completed in this order to restore the segment connection strength and achieve non-destructive segment connection replacement of the tail brush.

[0073] This invention provides a method for replacing the tail brush of a shield tunnel segment connection based on a single-segment / double-segment threaded screw combination. Through structural innovation and process optimization, it significantly improves the reliability and economy of shield tunnel construction and maintenance. The specific beneficial effects are as follows:

[0074] 1. A breakthrough solution to the problem of damaged parts during the removal of threaded connectors, achieving non-destructive disassembly of tunnel segments.

[0075] Single-sided threadless structure design: Through the smooth platform stage 13 (threadless) of the single-segment threaded screw 1 and the clearance fit (non-threaded engagement) of the pre-embedded sleeve 4, the segments can be separated by longitudinal translation only when they are removed. This avoids damage such as screw deformation and nut stripping caused by traditional threaded forced pull-out, and ensures the integrity of basic components such as the pre-embedded sleeve 4 and the first pre-embedded nut 3, laying the foundation for the reuse of segments.

[0076] Stress-controlled demolition process: The process adopts the order of "first sealing the top block, then the segments" and the longitudinal translation demolition path to avoid radial stress impact during traditional demolition, further reduce the risk of segment joint damage and improve structural safety.

[0077] 2. Innovative screw assembly system ensures reliable connection performance throughout the entire process.

[0078] Staged screw adapter:

[0079] Assembly stage: The first threaded section 12 of the single-section threaded screw 1 forms a reliable threaded connection with the first pre-embedded nut 3 to ensure the initial bearing capacity during segment assembly; the smooth table stage 13 achieves rapid positioning through mechanical embedding (non-threaded force), taking into account both connection strength and subsequent disassembly.

[0080] Reassembly stage: The second threaded section 52 and the third threaded section 53 of the double-segment threaded screw 5 form a full thread engagement with the second pre-embedded nut 6 and the third pre-embedded nut 7 respectively, restoring the complete tensile strength performance of the traditional threaded connector and ensuring the structural safety of the tunnel during operation.

[0081] Nut-embedded design: The first nut 11 and the second nut 51 are embedded in the countersunk hole of the tube segment to form a planar contact force transmission, avoiding stress concentration caused by the traditional screw protruding from the surface of the tube segment, and improving the overall integrity of the joint.

[0082] 3. Significantly improves the efficiency of shield tail brush replacement and reduces maintenance costs.

[0083] Rapid assembly and disassembly process: The press-fit assembly and threadless disassembly process in stage 13 of the smooth platform reduces the assembly and disassembly time of a single ring segment by about 50%, significantly reduces the downtime for tunnel boring machine maintenance, and reduces the risk of construction delays.

[0084] Material loss reduction: Avoiding the one-time scrapping of screws and nuts due to thread damage in traditional processes, single-ring segment maintenance can save about 30%-50% of the material cost of connectors, which is especially suitable for long tunnels with multiple maintenance scenarios.

[0085] 4. Expand the application scenarios of threaded fasteners and promote innovation in construction technology.

[0086] Assembly and inspection versatility: The non-destructive disassembly and assembly characteristics of the single-section threaded screw 1 can be directly applied to the three-ring horizontal assembly and inspection of lining segments, avoiding thread wear caused by repeated disassembly and assembly in traditional inspection, reducing trial assembly losses, and improving the economy of precast segment quality inspection.

[0087] Technical system completeness: It fills the technical gap in the field of "repeated disassembly and maintenance" of threaded quick connectors, forms a complete process technical solution of "assembly-maintenance-reassembly", enhances the applicability of such connectors in complex geological conditions and high maintenance demand scenarios, and helps the localization and standardization of the domestic shield tunneling equipment technology system.

[0088] 5. Multiple process safeguards enhance tunnel sealing and long-term performance.

[0089] Quality control of shield tail brush replacement: The removal of old brushes and the installation of new brushes are precisely controlled by torque wrenches. Combined with shield tail wear detection, impurity cleaning and full grease injection processes, the reliability of the sealing system is ensured and the risk of tunnel water leakage is reduced.

[0090] Improved construction safety: Standardized dismantling sequence and mechanical assistance (segment assembly machine) reduce manual intervention and avoid safety hazards such as segment breakage and bolt splashing that may be caused by traditional force dismantling, which meets the safety and environmental protection requirements of modern tunnel construction.

[0091] This invention breaks through the technical bottleneck of "irreversible installation" of threaded connectors through the dual innovation of "special screw structure + phased connection process". It achieves high efficiency, economy and safety of shield tail brush replacement while ensuring structural performance. It has both engineering practical value and promotes the upgrading of industry technology, and has significant social and economic benefits and market promotion prospects.

[0092] Any combination of various embodiments of the present invention, provided it does not violate the inventive concept of the present invention, shall be regarded as the content disclosed by the present invention; within the scope of the technical concept of the present invention, any simple modifications to the technical solution and any combination of different embodiments that do not violate the inventive concept of the present invention shall be within the protection scope of the present invention.

Claims

1. A method for replacing the tail brush of a shield tunnel using a threaded quick-connect fitting, characterized in that, Includes the following steps: Step S1: Customize a single-segment threaded screw (1), the single-segment threaded screw (1) includes a first nut (11) and a first threaded segment (12) fixedly connected to both ends of the first nut (11) and a smooth table stage (13); Step S2: After the tunnel boring machine has advanced to the selected position for replacing the tail brush, the single-section threaded screw (1) is used to complete the assembly of the segments (2); Step S3: The tunnel boring machine advances one ring of segments, and the ring of segments pressing on the tail brush is removed without damage using the segment assembly machine; Step S4: Replace the shield tail brush; Step S5: Use a double-segment threaded screw (5) to reassemble the tube segment (2); The double-segment threaded screw (5) includes a second nut (51) and a second threaded segment (52) and a third threaded segment (53) fixedly connected to both ends of the second nut (51); Step S2 includes: S2.1: When the shield tunneling reaches the selected shield tail brush replacement position, screw the first threaded section (12) of the single-section threaded screw (1) into the first pre-embedded nut (3) embedded in the end face of the segment to be assembled (2); S2.2: The segment assembly machine grabs the segment to be assembled (2), aligns the smooth platform stage (13) of the single-segment threaded screw (1) with the embedded sleeve (4) embedded in the end face of the assembled segment (2), and then the shield machine jack is placed on the jacking surface to press the smooth platform stage (13) on the segment to be assembled (2) into the embedded sleeve (4) of the assembled segment (2). The first nut (11) is embedded in the countersunk hole of the two segments (2) that are tightly installed. The whole ring segment assembly is completed in this order.

2. The method for replacing the tail brush of a shield tunnel using a threaded quick-connect fitting as described in claim 1, characterized in that, After replacing the shield tail brush, apply shield tail grease and then reassemble the tube segment (2) using the double-segment threaded screw (5) to achieve a non-destructive tube segment connection and shield tail brush replacement.

3. The method for replacing the tail brush of a shield tunnel using threaded quick-connect fittings as described in claim 1, characterized in that, The pre-embedded sleeve (4) is provided with a stepped hole that is compatible with the smooth stage (13).

4. The method for replacing the tail brush of a shield tunnel using threaded quick-connect fittings as described in claim 1, characterized in that, Step S3, which involves using a segment assembly machine to remove the ring-shaped segments pressing against the tail brush without damage, includes: The segment assembly machine is used to grab the capping block of the lining segment to be removed, and the capping block segment is removed by moving it longitudinally along the centerline of the tunnel. Remove the remaining segments in sequence according to the order of "first the capping block, then the segment" (2) to avoid stress concentration.

5. The method for replacing the tail brush of a shield tunnel using a threaded quick-connect fitting as described in claim 1, characterized in that, Step S4 includes: S4.1: Use a wrench to remove the old shield tail brush fixing bolts, and at the same time check whether the shield tail brush seat is damaged, and clean the rust and debris on the surface of the brush seat; S4.2: Inspect the wear of the shield tail, grind or repair it, and clean the soil and sand inside and around the shield tail to ensure it is clean and free of debris; S4.3: Align the new tail brush with the tail brush holder, ensuring the position is correct. Secure the new tail brush to the tail brush holder with bolts and tighten the bolts with a wrench. Check that the new tail brush is securely installed and ensure there is no misalignment.

6. The method for replacing the tail brush of a shield tunnel using a threaded quick-connect fitting as described in claim 1, characterized in that, Step S5 includes: S5.1: Apply the replaced shield tail brush to the shield tail grease to ensure a good seal; S5.2: Remove the single-section threaded screw (1) and replace it with the double-section threaded screw (5) to complete the assembly of the entire ring segment.

7. The method for replacing the tail brush of a shield tunnel using a threaded quick-connect fitting as described in claim 6, characterized in that, S5.2 includes: screwing the second threaded section (52) of the double-segment threaded screw (5) into the second pre-embedded nut (6) embedded in the end face of the segment to be installed (2), and then the shield machine jack is placed on the jack face to press the third threaded section (53) on the segment to be assembled (2) into the third pre-embedded nut (7) of the assembled segment (2), and so on to complete the assembly of the whole ring segment, restore the connection strength of the segment, and realize the replacement of the shield tail brush without damage to the segment connection.

8. The method for replacing the tail brush of a shield tunnel using a threaded quick-connect fitting as described in claim 7, characterized in that, The second nut (51) is embedded in the countersunk hole of the two pipe segments (2) that are tightly installed.

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