A structure for providing counterforce for secondary launching of a variable-diameter shield tunneling machine after in-hole expansion

Abstract

The application discloses a structure for providing counterforce for secondary launching of a variable-diameter shield machine after in-hole diameter expansion, comprising a small-shield tail ring cavity steel pipe piece, a diameter-expanding temporary support end wall steel pipe piece, a large-shield head ring cavity steel pipe piece and a counterforce conversion steel rib plate structure; the small-shield tail ring cavity steel pipe piece is arranged at the tail end of a small-shield conventional concrete pipe piece, the diameter-expanding temporary support end wall steel pipe piece is arranged at the outer periphery of the small-shield tail ring cavity steel pipe piece, the large-shield head ring cavity steel pipe piece is fixedly arranged at one side of the diameter-expanding temporary support end wall steel pipe piece, the counterforce conversion steel rib plate structure is fixedly arranged at the inner peripheral surface of the large-shield head ring cavity steel pipe piece, and the counterforce conversion steel rib plate structure is fixedly connected with the diameter-expanding temporary support end wall steel pipe piece and the small-shield tail ring cavity steel pipe piece. Through the above arrangement, the application can set a structure system of an existing small-shield tunnel pipe piece and a stable bedrock attached thereto, so that the structure system has a clear stress transmission path, high bearing capacity and safety and reliability.

Description

Technical Field

[0001] This invention belongs to the technical field of providing initial reaction force structures, specifically relating to a structure that provides reaction force for secondary initial launch of a variable diameter shield machine after its diameter is expanded inside the tunnel. Background Technology

[0002] In shield tunneling, when the tunnel diameter needs to be changed or the tunnel needs to traverse complex geological formations, a "secondary launch with in-situ diameter expansion" technique is employed. This involves first using a small-diameter shield tunneling machine (small shield) to excavate a pilot tunnel. Then, a variable-diameter shield tunneling machine is used to expand the diameter in situ, transforming and assembling it into a large-diameter shield tunneling machine (large shield). After assembly, a secondary launch is initiated to continue tunneling. The core technical challenge in this process is how to provide reliable and stable reaction force support for the large shield tunneling machine launched in the second phase.

[0003] Based on existing technology, the mainstream technical solutions for solving the problem of secondary initial reaction force inside the tunnel can be summarized into the following categories:

[0004] (1) Reinforced concrete reaction ring / backward reaction structure technology

[0005] This technology involves pre-embedded connectors and then pouring reinforced concrete into the secondary lining of an existing small shield tunnel or an enlarged tunnel chamber to form a ring-shaped reaction wall or structure. This structure is typically composed of a lower reaction structure (mostly reinforced concrete) and an upper reaction structure (steel reaction ring or fan-shaped ring plate). It is connected to the existing tunnel structure through a bendable first connector (such as reinforcing bars) and a first inclined rib support (such as a steel plate with anchors) pre-embedded in the lining, thus transferring the initial thrust to the surrounding rock.

[0006] This technology typically suffers from the following problems: it fails to fully utilize the existing small-diameter tunnel segments and the stable bedrock they are attached to—the most direct and reliable natural reaction force support. The reaction force transmission path is usually long and indirect. The secondary thrust of the shield needs to pass through multiple stages, including the reaction frame, intermediate support structures, and existing lining, before it can finally be transmitted to a reliable stratum. This lengthy path inevitably leads to a complex and cumbersome structural system.

[0007] (2) Pre-embedded steel component reaction structure technology in mined tunnels

[0008] This technology involves pre-embedding supporting steel columns, guide steel rings, reaction brackets, and I-beams during the concrete lining construction phase of a mined tunnel, forming an integrated spatial steel frame reaction system. The working principle is as follows: the supporting steel columns are arranged uniformly in a ring and anchored to the inner wall of the concrete lining, with guide steel rings fixed on them. The reaction brackets abut against the guide steel rings through limiting grooves, transferring the tunnel boring machine's thrust through the guide steel rings to the supporting steel columns and the pre-embedded I-beams and supporting steel plates, ultimately borne by the entire tunnel lining structure.

[0009] This technology typically has the following problems: the support system (such as grid arch frame + shotcrete) of the tunnel structure formed after the diameter expansion by manual excavation is a completely different structural system from the precast segments of the original small shield tunnel, and there is a lack of effective and predictable mechanical connection between the two. Summary of the Invention

[0010] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a structure that provides reaction force for the secondary launch of a variable diameter shield tunneling machine after the tunnel is expanded inside the tunnel. The structure system can be set up in the existing small shield tunnel segments and the stable bedrock on which they are attached, so that the force transmission path of the structure system is clear, the bearing capacity is high, and it is safe and reliable.

[0011] The objective of this invention is achieved through the following technical solution:

[0012] A structure providing reaction force for secondary launch of a variable-diameter shield tunneling machine after diameter expansion inside the tunnel includes a small shield tunneling machine's final ring cavity steel pipe segment, a diameter expansion temporary support end wall steel pipe segment, a large shield tunneling machine's first ring cavity steel pipe segment, and a reaction force conversion steel rib structure. The small shield tunneling machine's final ring cavity steel pipe segment is located at the end of the small shield tunneling machine's conventional concrete pipe segment. The diameter expansion temporary support end wall steel pipe segment is located on the outer periphery of the small shield tunneling machine's final ring cavity steel pipe segment. The large shield tunneling machine's first ring cavity steel pipe segment is fixedly located on one side of the diameter expansion temporary support end wall steel pipe segment. The reaction force conversion steel rib structure is fixedly located on the inner periphery of the large shield tunneling machine's first ring cavity steel pipe segment. The reaction force conversion steel rib structure is fixedly connected to the diameter expansion temporary support end wall steel pipe segment and the small shield tunneling machine's final ring cavity steel pipe segment.

[0013] Furthermore, the cross-section of the reaction force conversion steel rib structure is triangular, so that the large shield tunnel's first ring cavity steel pipe segment and the expanded diameter temporary support end wall steel pipe segment are arranged vertically, and provide stable structural stress.

[0014] Furthermore, the reaction force conversion steel rib structure includes several reaction force conversion steel rib units distributed along the circumferential direction. The reaction force conversion steel rib units are arc-shaped, and adjacent reaction force conversion steel rib units are fixedly connected. Each reaction force conversion steel rib unit includes a reaction force conversion arc-shaped plate. The reaction force conversion arc-shaped plate is fixedly connected to the steel pipe segment of the expanded diameter temporary support end wall and the steel pipe segment of the small shield end ring cavity. Several longitudinally and transversely distributed reaction force conversion longitudinal ribs and reaction force conversion circumferential ribs are fixedly connected to the side of the reaction force conversion arc-shaped plate.

[0015] Furthermore, a plurality of longitudinal reaction force conversion ribs are equally spaced along the arc direction of the arc-shaped reaction force conversion plate. The longitudinal reaction force conversion ribs are triangular in shape. One right-angle side of the longitudinal reaction force conversion rib is fixedly connected to the arc-shaped reaction force conversion plate, and the other right-angle side of the longitudinal reaction force conversion rib is fixedly connected to the hollow steel tube segment of the first ring of the large shield tunnel. A plurality of circumferential reaction force conversion ribs are equally spaced along the width direction of the arc-shaped reaction force conversion plate. Both ends of the circumferential reaction force conversion ribs extend to the ends along the arc direction of the arc-shaped reaction force conversion plate, and the side of the circumferential reaction force conversion ribs extends to the hypotenuse of the longitudinal reaction force conversion ribs.

[0016] Furthermore, the large shield tunnel's first ring cavity steel tube segment includes several large shield tunnel segment standard blocks. The large shield tunnel segment standard blocks are arc-shaped, and large shield tunnel segment adjacent blocks are provided at both ends of each large shield tunnel segment standard block. The large shield tunnel segment adjacent blocks of adjacent large shield tunnel segment standard blocks are interlocked and connected by bolts. The overall shape of several interconnected large shield tunnel segment standard blocks is circular with an opening at the top, and a large shield tunnel segment capping block is fixedly installed at the opening.

[0017] Furthermore, the large shield tunnel standard block includes an outer peripheral segment, an inner peripheral segment, several longitudinal ribs, and several circumferential ribs. Both the inner and outer peripheral segments are arc-shaped. The inner peripheral segment is fixedly connected to the reaction force conversion steel rib structure, and the outer peripheral segment is located on the outer periphery of the inner peripheral segment. The longitudinal and circumferential ribs are distributed longitudinally and transversely and fixedly between the outer and inner peripheral segments. The longitudinal ribs are evenly spaced along the arc direction of the inner peripheral segment, and the reversing ribs are evenly spaced along the width direction of the inner peripheral segment.

[0018] Furthermore, the small shield tunnel's end ring cavity steel tube segment is located inside the small shield tail steel shell before the diameter expansion.

[0019] Furthermore, the small shield tunnel's end ring cavity steel pipe segments, the expanded diameter temporary support end wall steel pipe segments, and the large shield tunnel's first ring cavity steel pipe segments all have cavities. After the small shield tunnel's end ring cavity steel pipe segments, the expanded diameter temporary support end wall steel pipe segments, and the large shield tunnel's first ring cavity steel pipe segments are all assembled, the cavities of the small shield tunnel's end ring cavity steel pipe segments, the expanded diameter temporary support end wall steel pipe segments, and the large shield tunnel's first ring cavity steel pipe segments are all sealed and filled with cement concrete.

[0020] Furthermore, temporary steel support reinforcements are provided on the inner side of the hollow steel tube segment of the first ring of the large shield tunnel.

[0021] The present invention has the following beneficial effects:

[0022] 1. The overall structural system of this invention has a clear force transmission path, high bearing capacity, and is safe and reliable. The shield tunneling reaction force is transmitted through the hollow steel segments of the large shield tunnel's first ring to the steel segments of the expanded-diameter temporary support end wall, which then transmits it to the surrounding rock on the outside. The reaction force conversion steel rib structure further strengthens the connection between the large shield tunnel steel segments and the end wall steel segments, preventing structural instability and failure.

[0023] 2. The steel pipe segments of the expanded diameter temporary support end wall are connected to the steel pipe segments of the small shield end ring cavity through the conversion arc plate of the reaction force conversion steel rib plate structure. After the shield advance is completed, the structure can support the soil and water pressure of the outer surrounding rock, and realize the full-process lining support covering temporary and permanent working conditions.

[0024] 3. The small shield tunneling machine's final ring cavity steel pipe segments, the expanded diameter temporary support end wall steel pipe segments, and the large shield tunneling machine's first ring cavity steel pipe segments of this invention can all be prefabricated, tested, and trial-assembled in the factory, effectively controlling component manufacturing errors. On-site assembly is performed using a shield tunneling robotic arm, resulting in high construction efficiency, high precision, and fully guaranteed structural quality.

[0025] 4. In the small shield tunnel end ring cavity steel pipe segment, the expanded diameter temporary support end wall steel pipe segment, and the large shield tunnel first ring cavity steel pipe segment of the present invention, adjacent pipe segments are connected by bolt locking and / or welding fixing. At the same time, cement concrete material can be used to fill the cavity between the ribs, which has good integrity and waterproof guarantee.

[0026] 5. The thickness of the small shield tunnel end ring cavity steel pipe segment, the expanded diameter temporary support end wall steel pipe segment, and the large shield tunnel first ring cavity steel pipe segment of the present invention can be adjusted according to the stress and surrounding rock conditions. When the stress is large and the surrounding rock strata are poor, a temporary steel support reinforcement structure can be added. Therefore, this structure can be applied to different rock and soil strata and has strong stratum adaptability. Attached Figure Description

[0027] Figure 1 This is a longitudinal cross-sectional view of the secondary initial reaction force conversion system after the shield tunneling diameter expansion is completed according to the present invention.

[0028] Figure 2 for Figure 1 A partial schematic diagram.

[0029] Figure 3 The images show the elevation view and sectional view along the AA direction of the reaction force conversion steel rib structure of the present invention.

[0030] Figure 4 This is a longitudinal sectional view of the reaction force conversion steel rib unit of the present invention.

[0031] Figure 5 for Figure 4 Cross-sectional view along the BB direction.

[0032] Figure 6for Figure 4 A cross-sectional view along the CC direction.

[0033] Figure 7 This is a plan view of the reaction force conversion arc plate of the reaction force conversion steel rib plate unit.

[0034] Figure 8 The present invention includes an elevation view and a sectional view along the DD direction of the hollow steel tube segment of the first ring of the large shield tunnel.

[0035] Figure 9 This is a longitudinal cross-sectional view of the standard block for the large shield tunneling machine according to the present invention.

[0036] Figure 10 for Figure 9 A cross-sectional view along the EE direction.

[0037] Figure 11 for Figure 9 A cross-sectional view along the FF direction.

[0038] In the diagram: 1. Hollow steel segment of the first ring of the large shield tunnel; 2. Reaction force conversion steel rib structure; 3. Hollow steel segment of the last ring of the small shield tunnel; 4. Steel segment of the end wall of the expanded diameter temporary support; 5. Conventional concrete segment of the large shield tunnel; 6. Conventional concrete segment of the small shield tunnel; 7. Cutterhead of the large shield tunnel after expansion; 8. Main drive structure of the large shield tunnel; 9. Steel shell of the tail of the small shield tunnel before expansion; 10. Steel shell assembly of the large shield tunnel; 11. Top block of the large shield tunnel segment; 12. Adjacent block of the large shield tunnel segment; 13. Standard block of the large shield tunnel segment; 14. Longitudinal rib of the standard block; 15. Circumferential rib of the standard block; 16. Outer circumferential segment of the standard block; 17. Inner circumferential segment of the standard block; 18. Longitudinal rib of the reaction force conversion; 19. Circumferential rib of the reaction force conversion; 20. Arc plate of the reaction force conversion. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Terms such as “upper,” “inner,” “middle,” “left,” “right,” and “one” used in this specification are merely for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0040] A structure that provides reaction force for the secondary launch of a variable-diameter tunnel boring machine after its diameter is expanded inside the tunnel, such as... Figure 1 and Figure 2 As shown, it includes the small shield tunnel end ring cavity steel pipe segment 3, the expanded diameter temporary support end wall steel pipe segment 4, the large shield tunnel first ring cavity steel pipe segment 1, and the reaction force conversion steel rib plate structure 2.

[0041] The small shield tunneling machine's final ring hollow steel segment 3 is installed at the end of the small shield tunneling machine's conventional concrete segment 6 using expansion bolts or concrete pouring. Both the small shield tunneling machine's final ring hollow steel segment 3 and the small shield tunneling machine's conventional concrete segment 6 at the end are located inside the small shield tunneling machine's tail steel shell 9 before diameter expansion. The diameter expansion temporary support end wall steel segment 4 is installed on the outer periphery of the small shield tunneling machine's final ring hollow steel segment 3 using expansion bolts or concrete pouring. The small shield tunneling machine's tail steel shell 9 before diameter expansion is located between the diameter expansion temporary support end wall steel segment 4 and the small shield tunneling machine's final ring hollow steel segment 3, with gaps between each pair. The first ring hollow steel segment 1 of the large shield tunnel is bolted and fixed to the side of the expanded diameter temporary support end wall steel segment 4. The reaction force conversion steel rib structure 2 is bolted or welded to the inner circumference of the first ring hollow steel segment 1 of the large shield tunnel. The reaction force conversion steel rib structure 2 is connected to the expanded diameter temporary support end wall steel segment 4 and the last ring hollow steel segment 3 of the small shield tunnel by bolting or welding. The conventional concrete segment 5 of the large shield tunnel is set on one side of the first ring hollow steel segment 1 of the large shield tunnel.

[0042] On one side of the overall structural system after the diameter is expanded, there is a large shield cutterhead 7, a large shield main drive structure 8, and a large shield steel shell assembly 10 after the diameter is expanded. The large shield steel shell assembly 10 after the diameter is expanded is opposite to the conventional concrete tunnel segment 5 of the large shield. The large shield cutterhead 7 is connected to the large shield main drive structure 8. The large shield main drive structure 8 drives the large shield cutterhead 7 to work and move forward under the reaction force of the tunnel segment, thereby realizing the function of the expanded diameter shield.

[0043] This demonstrates that the structural system of the present invention, which provides reaction force for the secondary launch of a variable-diameter shield tunneling machine after its diameter expansion within the tunnel, has a clear force transmission path, high bearing capacity, and is safe and reliable. The shield jacking reaction force is transmitted through the large shield's first ring cavity steel pipe segment 1 to the expanded diameter temporary support end wall steel pipe segment 4, which then transmits it to the surrounding rock on the outside. The reaction force conversion steel rib structure 2 further strengthens the connection between the large shield steel pipe segment and the end wall steel pipe segment, preventing structural instability and failure.

[0044] In this embodiment, as Figures 3 to 7 As shown, the cross-section of the reaction force conversion steel rib structure 2 is approximately triangular, ensuring that the large shield tunnel's first ring cavity steel segment 1 and the expanded diameter temporary support end wall steel segment 4 are vertically aligned and providing stable structural stress. The reaction force conversion steel rib structure 2 comprises several reaction force conversion steel rib units distributed along the annular direction. These units are arc-shaped, and adjacent units are fixedly connected. Dividing the reaction force conversion steel rib structure 2 into multiple reaction force conversion steel rib units facilitates modular production using small-scale machinery, replacing bulky machinery production, thus enabling efficient mass production and assembly.

[0045] The reaction force conversion steel rib unit includes a reaction force conversion arc-shaped plate 20, which is connected to the steel pipe segment 4 of the expanded diameter temporary support end wall and the steel pipe segment 3 of the small shield tunnel's final ring cavity by bolting or concrete pouring. Several longitudinal and circumferential reaction force conversion ribs 18 and 19 are fixedly connected to the sides of the reaction force conversion arc-shaped plate 20 to ensure good structural stability and stress distribution of the overall structure of the reaction force conversion steel rib unit. The longitudinal reaction force conversion ribs 18 are evenly spaced along the arc direction of the reaction force conversion arc-shaped plate 20, and are approximately triangular in shape. One right-angled side of the longitudinal reaction force conversion rib 18 is fixedly connected to the reaction force conversion arc-shaped plate 20, and the other right-angled side is welded and fixed to the steel pipe segment 1 of the large shield tunnel's first ring cavity. Several reaction force conversion circumferential ribs 19 are evenly distributed along the width direction of the reaction force conversion arc plate 20. The two ends of the reaction force conversion circumferential ribs 19 extend to the end along the arc direction of the reaction force conversion arc plate 20, and the side of the reaction force conversion circumferential ribs 19 extends to the hypotenuse of the reaction force conversion longitudinal ribs 18.

[0046] In this embodiment, as Figures 8 to 11 As shown, the large shield tunnel's first ring hollow steel segment 1 includes several large shield tunnel segment standard blocks 13. Each large shield tunnel segment standard block 13 is arc-shaped, and each end of the standard block 13 has a large shield tunnel segment adjacent block 12. The adjacent large shield tunnel segment adjacent blocks 12 of adjacent large shield tunnel segment standard blocks 13 are interlocked and connected by bolts. The overall shape of the several interconnected large shield tunnel segment standard blocks 13 is circular with an opening at the top, and a large shield tunnel segment capping block 11 is fixedly installed at the opening. During installation, a robotic arm assembles the large shield tunnel segment standard blocks 13 one by one from bottom to top, so that the adjacent large shield tunnel segment adjacent blocks 12 of adjacent large shield tunnel segment standard blocks 13 are interlocked and connected by bolts, thereby forming an opening at the top of the several interconnected large shield tunnel segment standard blocks 13, facilitating the installation of the large shield tunnel segment capping block 11 at the opening position by the robotic arm.

[0047] The standard block of the large shield tunnel includes an outer circumferential segment 16, an inner circumferential segment 17, several longitudinal ribs 14, and several circumferential ribs 15. Both the inner circumferential segment 17 and the outer circumferential segment 16 are arc-shaped. The inner circumferential segment 17 is welded and fixed to the reaction force conversion steel rib structure 2. The outer circumferential segment 16 is located on the outer periphery of the inner circumferential segment 17. The longitudinal ribs 14 and circumferential ribs 15 are distributed longitudinally and transversely, and are welded and fixed between the outer circumferential segment 16 and the inner circumferential segment 17. The longitudinal ribs 14 are evenly spaced along the arc direction of the inner circumferential segment 17, and the reversing ribs are evenly spaced along the width direction of the inner circumferential segment 17. It can be seen that the interior of the large shield tunnel standard block is mainly composed of several longitudinally and transversely distributed standard block longitudinal ribs 14 and standard block circumferential ribs 15, which gives the overall structure of the large shield tunnel standard block better structural stress and can improve the overall bearing capacity of the tunnel segments, while also helping to save on the use of raw materials.

[0048] In this embodiment, the small shield tunnel's end ring cavity steel segment 3, the expanded diameter temporary support end wall steel segment 4, and the large shield tunnel's first ring cavity steel segment 1 all have cavities. After the small shield tunnel's end ring cavity steel segment 3, the expanded diameter temporary support end wall steel segment 4, and the large shield tunnel's first ring cavity steel segment 1 are all assembled, the cavities of the small shield tunnel's end ring cavity steel segment 3, the expanded diameter temporary support end wall steel segment 4, and the large shield tunnel's first ring cavity steel segment 1 are all sealed and filled with cement concrete. This can further improve the overall load-bearing capacity of the segments, while better covering the steel structure and reducing the risk of corrosion to the steel structure.

[0049] In this embodiment, a temporary steel support reinforcement is provided on the inner side of the first ring hollow steel segment 1 of the large shield tunnel, such as a temporary steel support to strengthen and reinforce the segment structure system. Therefore, when the reaction force conversion structure at the beginning of the shield expansion and contraction is subjected to the shield jacking reaction force, the overall structure can withstand a greater thrust.

[0050] In summary, the structure of the present invention, which provides reaction force for the secondary launch of a variable-diameter shield machine after its diameter expansion inside the tunnel, has the following advantages compared to the prior art:

[0051] 1. The overall structural system of this invention has a clear force transmission path, high bearing capacity, and is safe and reliable. The shield tunneling reaction force is transmitted through the large shield tunneling head cavity steel segment 1 to the expanded diameter temporary support end wall steel segment 4, which in turn transmits it to the surrounding rock on the outside. The reaction force conversion steel rib structure 2 further strengthens the connection between the large shield tunneling steel segment and the end wall steel segment, preventing structural instability and failure.

[0052] 2. The steel pipe segments 4 of the expanded diameter temporary support end wall are connected to the steel pipe segments 3 of the small shield end ring cavity through the conversion arc plate of the reaction force conversion steel rib plate structure 2. After the shield is advanced, the structure can support the soil and water pressure of the surrounding rock on the outside, and realize the full-process lining support covering temporary and permanent working conditions.

[0053] 3. The small shield tunneling machine's final ring cavity steel segment 3, the expanded diameter temporary support end wall steel segment 4, and the large shield tunneling machine's first ring cavity steel segment 1 can all be prefabricated, tested, and trial-assembled in the factory, effectively controlling component manufacturing errors. On-site assembly is performed using a shield tunneling robotic arm, resulting in high construction efficiency, high precision, and fully guaranteed structural quality.

[0054] 4. In the small shield tunnel end ring cavity steel pipe segment 3, the expanded diameter temporary support end wall steel pipe segment 4, and the large shield tunnel first ring cavity steel pipe segment 1 of the present invention, adjacent pipe segments are connected by bolt locking and / or welding fixing. At the same time, cement concrete material can be used to fill the cavity between the ribs, which has good integrity and waterproof guarantee.

[0055] 5. The thickness of the small shield tunnel end ring cavity steel pipe segment 3, the expanded diameter temporary support end wall steel pipe segment 4, and the large shield tunnel first ring cavity steel pipe segment 1 can be adjusted according to the stress and surrounding rock conditions. When the stress is large and the surrounding rock strata are poor, temporary steel support reinforcement structures can be added. Therefore, this structure can be applied to different rock and soil strata and has strong stratum adaptability.

[0056] The embodiments of the present invention are not limited thereto. Based on the above description of the present invention, and using common technical knowledge and conventional means in the field, the present invention can be modified, replaced or combined in various other forms without departing from the basic technical idea of ​​the present invention, and all such modifications, replacements or combinations fall within the scope of protection of the present invention.

Claims

1. A structure for providing reaction force for the secondary launch of a variable-diameter shield tunneling machine after its diameter is expanded inside the tunnel, characterized in that, The system includes a small shield tunneling machine's end ring hollow steel pipe segment, an expanded diameter temporary support end wall steel pipe segment, a large shield tunneling machine's first ring hollow steel pipe segment, and a reaction force conversion steel rib structure. The small shield tunneling machine's end ring hollow steel pipe segment is located at the end of the conventional concrete pipe segment of the small shield tunneling machine. The expanded diameter temporary support end wall steel pipe segment is located on the outer periphery of the small shield tunneling machine's end ring hollow steel pipe segment. The large shield tunneling machine's first ring hollow steel pipe segment is fixedly located on one side of the expanded diameter temporary support end wall steel pipe segment. The reaction force conversion steel rib structure is fixedly located on the inner periphery of the large shield tunneling machine's first ring hollow steel pipe segment. The reaction force conversion steel rib structure is fixedly connected to both the expanded diameter temporary support end wall steel pipe segment and the small shield tunneling machine's end ring hollow steel pipe segment. The cross-section of the reaction force conversion steel rib structure is triangular to ensure that the large shield tunnel's first ring cavity steel pipe segment and the expanded diameter temporary support end wall steel pipe segment are vertically arranged and to provide stable structural stress. The reaction force conversion steel rib structure includes several reaction force conversion steel rib units distributed along the circumferential direction. The reaction force conversion steel rib units are arc-shaped, and adjacent reaction force conversion steel rib units are fixedly connected. Each reaction force conversion steel rib unit includes a reaction force conversion arc-shaped plate, which is fixedly connected to the expanded diameter temporary support end wall steel pipe segment and the small shield tunnel's last ring cavity steel pipe segment, respectively. Several longitudinally and transversely distributed reaction force conversion longitudinal ribs and reaction force conversion circumferential ribs are fixedly connected to the sides of the reaction force conversion arc-shaped plate. The large shield tunnel's first ring hollow steel segment comprises several large shield tunnel segment standard blocks. Each large shield tunnel segment standard block is arc-shaped, with adjacent large shield tunnel segment connecting blocks at both ends. Adjacent large shield tunnel segment connecting blocks are interlocked and connected by bolts. The overall structure of these interconnected large shield tunnel segment standard blocks is circular with an opening at the top, where a large shield tunnel segment capping block is fixedly installed. Each large shield tunnel segment standard block includes an outer peripheral segment, an inner peripheral segment, several longitudinal ribs, and several standard... The standard block has circumferential ribs; both the inner and outer circumferential segments of the standard block are arc-shaped. The inner circumferential segment of the standard block is fixedly connected to the reaction force conversion steel rib structure, and the outer circumferential segment of the standard block is located on the outer periphery of the inner circumferential segment of the standard block. A plurality of longitudinal and circumferential ribs of the standard block are distributed longitudinally and transversely, and are fixedly arranged between the outer and inner circumferential segments of the standard block. The longitudinal ribs of the standard block are evenly spaced along the arc direction of the inner circumferential segment of the standard block, and the circumferential ribs of the standard block are evenly spaced along the width direction of the inner circumferential segment of the standard block.

2. The structure described in claim 1 for providing reaction force for the secondary launch of a variable-diameter shield machine after internal diameter expansion, characterized in that, A plurality of longitudinal reaction force conversion ribs are equally spaced along the arc direction of the reaction force conversion arc plate. The longitudinal reaction force conversion ribs are in the shape of a triangle. One right-angle side of the longitudinal reaction force conversion rib is fixedly connected to the arc plate of the reaction force conversion, and the other right-angle side of the longitudinal reaction force conversion rib is fixedly connected to the steel tube segment of the first ring cavity of the large shield tunnel. A plurality of circumferential reaction force conversion ribs are equally spaced along the width direction of the arc plate of the reaction force conversion. Both ends of the circumferential reaction force conversion ribs extend to the ends along the arc direction of the arc plate of the reaction force conversion, and the side of the circumferential reaction force conversion ribs extends to the hypotenuse of the longitudinal reaction force conversion ribs.

3. The structure described in claim 1 for providing reaction force for the secondary launch of a variable-diameter shield machine after internal diameter expansion, characterized in that, The small shield tunnel's end ring cavity steel tube segment is located inside the small shield tail steel shell before the diameter expansion.

4. The structure described in claim 1 for providing reaction force for the secondary launch of a variable-diameter shield machine after internal diameter expansion, characterized in that, The small shield tunnel's end ring cavity steel pipe segments, the expanded diameter temporary support end wall steel pipe segments, and the large shield tunnel's first ring cavity steel pipe segments all have cavities. After the small shield tunnel's end ring cavity steel pipe segments, the expanded diameter temporary support end wall steel pipe segments, and the large shield tunnel's first ring cavity steel pipe segments are all assembled, the cavities of the small shield tunnel's end ring cavity steel pipe segments, the expanded diameter temporary support end wall steel pipe segments, and the large shield tunnel's first ring cavity steel pipe segments are all sealed and filled with cement concrete.

5. The structure as described in claim 1 for providing reaction force for the secondary launch of a variable-diameter shield machine after internal diameter expansion, characterized in that, Temporary steel support reinforcements are installed on the inner side of the hollow steel tube segment of the first ring of the large shield tunnel.

Images