A shield prefabricated segment

Abstract

The present invention discloses a shield prefabricated segment, comprising a plurality of interlaced and mutually fitted first and second segments, wherein the head end of the first segment is provided with two convex edges spaced apart along its width direction, a lug is provided downwardly extending from the middle of one end of the two convex edges, and a tensioning column is provided on the inner side surface of the lug extending horizontally along the width direction of the first segment, and the tail end of the second segment is provided with a bearing groove along its length direction, and a tensioning hole is provided in the groove body of the bearing groove along its length direction. During the assembly process, when the first segment is pushed onto the second segment from the side, the tensioning column on the first segment is inserted into the tensioning hole on the second segment, so that the ends of the first and second segments are tightly attached together under the tension of the tensioning hole and the tensioning column, so that the first segment will not fall off after being placed on the second segment, and the ring is assembled in this manner. The process does not require the segments on both sides to be bolted in advance, thereby effectively improving the efficiency of the ring assembly.

Description

Technical Field

[0001] The invention relates to a prefabricated shield segment and belongs to the technical field of shield machines. Background Art

[0002] The basic working principle of a shield machine is that a cylindrical steel component advances forward along the axis of the tunnel while excavating the soil. The shell of the cylindrical component is the shield, which plays a temporary support role for the excavated tunnel section that has not yet been lined, and bears the pressure of the surrounding soil. Excavation, soil discharge, lining and other operations are carried out under the cover of the shield. Among them, the lining operation is mostly carried out using shield segments. However, in the process of assembling the existing shield segments into rings, bolts are mostly used for locking. The assembly is not convenient. In order to prevent the top shield segment from falling after placement, the segments assembled on both sides need to be pre-locked during the assembly process. After the pre-locking is completed, the top segment can be assembled. This operation results in low assembly efficiency. Summary of the Invention

[0003] The present invention aims to provide a shield prefabricated segment, which can improve the segment assembly efficiency and prevent water leakage after being assembled into a ring.

[0004] The technical solution of the present invention is: a shield prefabricated pipe segment, including multiple No. 1 pipe segments and No. 2 pipe segments that are staggered and fitted together, the head end of the No. 1 pipe segment is provided with two convex edges spaced apart along its width direction, a lug is provided downwardly extending from the middle of one side end of the two convex edges, a tensioning column is provided on the inner side surface of the lug extending horizontally along the width direction of the No. 1 pipe segment, the tail end of the No. 2 pipe segment is provided with a bearing groove along its length direction, and a tensioning hole is provided in the groove body of the bearing groove along its length direction.

[0005] In the aforementioned shield prefabricated pipe segment, an extrusion seal is provided between the convex edge and the bearing groove. The extrusion seal includes two No. 1 sealing grooves arranged at the two side ends of the tensioning hole, and a No. 2 sealing groove is provided on each of the corresponding end faces of the two convex edges. The No. 2 sealing groove is arranged opposite to the No. 1 sealing groove, and a rubber sleeve is clamped inside the No. 2 sealing groove.

[0006] The lockhole that is formed on the two ends of the support frame is formed on the upper portion of the support frame, and the lockhole engages with the upper portion of the support frame by the spring or the like.

[0007] In the aforementioned shield prefabricated pipe segment, the elastic component includes a No. 1 cavity arranged at the relatively proximal ends of the two core columns, each No. 1 cavity is provided with a limiting cap, a No. 1 spring body is embedded in the cavity between the limiting cap and the bottom of the No. 1 cavity, and a connecting column is embedded between the two limiting caps.

[0008] In the aforementioned shield prefabricated segments, a top plate is fitted at each end of the cavity structure inside the rubber sleeve, each core column moves through a top plate, and the two top plates are fixedly connected together by a support rod.

[0009] In the aforementioned shield prefabricated pipe segment, a self-locking part is provided inside the tensioning column, and the self-locking part includes a pushing prism movably installed inside the tensioning column along the length direction of the tensioning column, and the head end of the pushing prism extends to the outside of the tensioning column. A plurality of No. 2 cavities are arranged inside the tensioning column along its length direction, and an oblique notch is provided on the upper end face of the pushing prism corresponding to each No. 2 cavity, and a limiting square sleeve is provided in the oblique notch. The bottom end of the limiting square sleeve is a semicircular structure, and an ejection spring is embedded in the limiting square sleeve. The other end of the ejection spring rests on the bottom of the locking prism, and the locking prism extends from the top of the limiting square sleeve and extends into a guide hole that penetrates the upper end of each No. 2 cavity. A plurality of locking holes are evenly spaced on the top wall of the tensioning hole.

[0010] In the aforementioned shield prefabricated pipe segment, an L-shaped frame is fixedly installed inside the upper end of the No. 2 cavity, and a limiting square sleeve fits through the upper end surface of the L-shaped frame. An extension plate extends from the side of the limiting square sleeve, and a No. 3 spring body is embedded between the upper end of the extension plate and the inner upper end of the No. 2 cavity.

[0011] In the aforementioned shield prefabricated pipe segment, a top plate is fixedly installed at the end of the pushing prism located inside the tensioning column. The top plate fits the inner side of the tensioning column, and a No. 2 spring body is embedded between the side of the top plate and the inner side of the tensioning column.

[0012] In the aforementioned shield prefabricated segment, the inlet of the tensioning hole 5 is a bell-mouth structure; the end of the tensioning column is a conical structure.

[0013] Beneficial effects of the present invention: Compared with the prior art, the present invention has the following advantages:

[0014] 1. During the assembly process, when the No. 1 pipe segment is pushed onto the No. 2 pipe segment from the side, the tensioning column on the No. 1 pipe segment will be inserted into the tensioning hole on the No. 2 pipe segment. Under the tension of the tensioning hole and the tensioning column, the ends of the No. 1 pipe segment and the No. 2 pipe segment are pressed together, so that the No. 1 pipe segment will not fall off after being placed on the No. 2 pipe segment. The process is similar to assembling into a ring. There is no need to pre-tighten the bolts on the pipe segments on both sides, thereby effectively improving the efficiency of assembling into a ring.

[0015] 2. When the tensioning column is inserted into the tensioning hole, the pushing prism on the tensioning column will first press against the end of the tensioning hole. At this time, when the tensioning column continues to be inserted, the pushing prism remains stationary, the No. 2 spring body contracts and deforms, and at the same time, the limiting square sleeve slowly moves up along the oblique side of the oblique notch on the pushing prism, thereby driving the locking prism to move up slowly. When the locking prism is slowly moving up, the end of the locking prism will first press against the inner wall of the tensioning hole, and the limiting square sleeve will continue to move up. At this time, the contraction and deformation of the ejection spring absorbs the upward force of the limiting square sleeve. When the tensioning column is fully inserted into the tensioning hole and the guide hole on the tensioning column is aligned with the locking hole on the inner wall of the tensioning hole, the ejection spring will restore its deformation to release the absorbed upward force, so that the locking prism moves upward to be inserted into the locking hole, so as to lock the tensioning column in the tensioning hole, that is, the No. 1 pipe segment and the No. 2 pipe segment are locked together. The process does not require subsequent manual tightening with bolts, thereby effectively improving the convenience of assembly. At the same time, it saves the time spent on frequently tightening the bolts, thereby further promoting the efficiency of assembling into rings.

[0016] 3. When the No. 1 pipe segment is pushed onto the No. 2 pipe segment from the side, the rubber sleeve on the convex edge will enter the No. 1 sealing groove to seal the joint. When the No. 1 pipe segment is completely pushed onto the No. 2 pipe segment, the end of the core column will first fit into the end of the bearing groove. At this time, when the No. 1 pipe segment continues to be pushed to be completely placed on the No. 2 pipe segment, the end of the bearing groove and the inner wall of the convex edge will squeeze the two ends of the two core columns. At this time, the two core columns gather inward, and in the process of gathering, the inclined push frame will be driven to move to push the tightening plate, so that the tightening plate expands outward in a straight line under the guidance of the guide column and the guide sleeve, so as to press the rubber sleeve into the No. 1 sealing groove and the No. 2 sealing groove, so that the rubber sleeve and the No. 2 sealing groove and the No. 1 sealing groove can fit tightly to promote the sealing strength of the rubber sleeve, thereby ensuring that there will be no leakage after assembly into a ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 Exploded view of the first and second pipe segments of the present invention;

[0019] Figure 3 A bottom view of the tensioning post of the present invention;

[0020] Figure 4 This is a cross-sectional view of the tensioning column after assembly of the present invention;

[0021] Figure 5 This is a cross-sectional view of the limiting square sleeve of the present invention;

[0022] Figure 6 An internal view of the rubber sleeve of the present invention;

[0023] Figure 7 It is a schematic diagram of the top plate of the present invention;

[0024] Figure 8 This is a cross-sectional view of the connecting column of the present invention.

[0025] In the figure: 1. Segment No. 1; 2. Segment No. 2; 3. Sealing groove No. 1; 4. Load-bearing groove; 5. Tensioning hole; 6. Lug; 7. Flange; 8. Tensioning column; 9. Pushing prism; 10. Sealing groove No. 2; 11. Rubber sleeve; 12. Core column; 13. Top plate; 14. Connecting column; 15. Pushing frame; 16. Slot frame No. 1; 17. Slot frame No. 2; 18. Tightening plate; 19. Guide column; 20. Guide sleeve; 21. Cavity No. 1; 22. Limiting cap; 23. Spring body No. 1; 24. Cavity No. 2; 25. Extension plate; 26. Oblique notch; 27. Top plate; 28. Spring body No. 2; 29. ​​Limiting square sleeve; 30. Locking prism; 31. Guide hole; 32. Locking hole; 33. L-shaped frame; 34. Spring body No. 3; 35. Ejector spring; 36. Support rod. Implementation Method

[0026] The present invention will be further described below with reference to the accompanying drawings and examples, but they are not intended to limit the present invention.

[0027] Example 1: A shield prefabricated segment, such as Figure 1-8As shown, it includes multiple pieces of No. 1 pipe segments 1 and No. 2 pipe segments 2 that are staggered and fitted together. The head end of the No. 1 pipe segment 1 is provided with two flanges 7 spaced apart along its width direction, and a lug 6 is provided downwardly extending from the middle of one side end of the two flanges 7. The inner side surface of the lug 6 is provided with a tensioning column 8 extending horizontally along the width direction of the No. 1 pipe segment 1. The tensioning column 8 and the two flanges 7 are provided parallel to each other. The tail end of the No. 2 pipe segment 2 is provided with a bearing groove 4 along its length direction, and a tensioning hole 5 is provided in the groove body of the bearing groove 4 along its length direction. The convex edge 7 and the bearing groove 4 are both concave in shape. The cooperation between the bearing groove 4 and the convex edge 7 can increase the unevenness of the assembly surface of the No. 1 pipe segment 1 and the No. 2 pipe segment 2, thereby improving the sealing of the assembly surface of the No. 1 pipe segment 1 and the No. 2 pipe segment 2. During use, the lug 6 and the convex edge 7 are both tightly attached to the bearing groove 4, and the tensioning column 8 is tightly attached to the inside of the tensioning hole 5. The cooperation between the tensioning column 8 and the tensioning hole 5 plays a role in tightening the No. 1 pipe segment 1 and the No. 2 pipe segment 2 together.

[0028] An extrusion seal is provided between the flange 7 and the bearing groove 4. The extrusion seal comprises two No. 1 sealing grooves 3 located on either side of the tensioning hole 5. A No. 2 sealing groove 10 is provided on the corresponding end faces of the two flanges 7. The No. 2 sealing grooves 10 are arranged opposite the No. 1 sealing grooves 3. A rubber sleeve 11 is clamped within the No. 1 sealing grooves 3. The cooperation between the rubber sleeve 11, the No. 2 sealing grooves 10, and the No. 1 sealing grooves 3 improves the sealing performance between the flange 7 and the bearing groove 4.

[0029] The interior of the rubber sleeve 11 is a cavity structure, in which two core columns 12 are arranged in sequence and at intervals. The ends of the two core columns 12 that are away from each other are movably extended from the end of the rubber sleeve 11, and the proximal ends of the two core columns 12 are connected by an elastic component. A tightening plate 18 is movably provided on each side of the cavity outside the two core columns 12, and the four tightening plates 18 are respectively attached to the four sides of the interior of the rubber sleeve 11. Each core column 12 is provided with multiple sets of top-tension plate pushing devices, each set of top-tension plate pushing devices includes four annular arrays of No. 1 slot frames 16 arranged on the body of the core column 12. The No. 1 slot frame 16 is rotatably connected to the push frame 15, which serves to connect the push frame 15. The push frame 15 extends upward obliquely and is rotatably connected to the No. 2 slot frame 17 at the bottom of the top-tension plate 18. The No. 2 slot frame 17 serves to connect the push frame 15. The push frames 15 on the two core columns 12 are arranged at a relative angle. Each core column 12 is also connected to the four top-tension plates 18 via multiple sets of connecting devices. Each set of connecting devices includes four guide sleeves 20 arranged in an annular array on the body of the core column 12. A guide column 19 is slidably sleeved in each guide sleeve 20. The other end of each guide column 19 is fixedly connected to the bottom of a top-tension plate 18. The guide sleeves 20 and guide columns 19 ensure that the top-tension plate 18 moves linearly.

[0030] The elastic assembly includes a first cavity 21 disposed at the proximal ends of two stems 12. Each of the first cavities 21 is provided with a limiting cap 22. A first spring body 23 is embedded in the cavity between the limiting cap 22 and the bottom of the first cavity 21. A connecting post 14 is embedded between the two limiting caps 22. The cooperation between the limiting cap 22 and the connecting post 14 acts to pull the stem 12, thereby limiting the distance pushed out by the first spring body 23.

[0031] A top plate 13 is fitted onto each end of the cavity structure within the rubber sleeve 11. Each core column 12 is movable through a top plate 13. The two top plates 13 are fixedly connected at their corners via a support rod 36. The support rod 36 secures the two top plates 13. The top plates 13 press the ends of the rubber sleeve 11 against the ends of the bearing groove 4 and the inner wall of the flange 7.

[0032] When in use, the No. 1 segment 1 is pushed and placed on the No. 2 segment 2 from the side, and so on, to assemble into a ring. When pushing and placing, the tensioning column 8 on the No. 1 segment 1 will be inserted into the tensioning hole 5 on the No. 2 segment 2. At the same time, during the pushing and placing process, the rubber sleeve 11 on the flange 7 will enter the No. 1 sealing groove 3 to seal the joint. When the No. 1 segment 1 is completely pushed and placed on the No. 2 segment 2, the end of the core column 12 will first fit at the end of the bearing groove 4. At this time, when the No. 1 segment 1 continues to be pushed to be completely placed on the No. 2 segment 2, the end of the bearing groove 4 and the inner wall of the flange 7 will contact the two core columns 12. The two ends are squeezed, and the two core columns 12 will overcome the elastic force of the elastic component and gather inward. In the process of gathering, the inclined push frame 15 will be driven to move to push the tightening plate 18 upward, so that the tightening plate 18 expands outward in a straight line under the guidance of the guide column 19 and the guide sleeve 20, thereby causing the rubber sleeve 11 to expand outward and be pressed tightly against the No. 1 sealing groove 3 and the No. 2 sealing groove 10, so that the rubber sleeve 11 and the No. 2 sealing groove 10 and the No. 1 sealing groove 3 can fit tightly to improve the sealing strength of the rubber sleeve 11.

[0033] Example 2: A shield prefabricated segment, such as Figure 1-8As shown, it includes multiple pieces of No. 1 pipe segments 1 and No. 2 pipe segments 2 that are staggered and fitted together. The head end of the No. 1 pipe segment 1 is provided with two flanges 7 spaced apart along its width direction, and a lug 6 is provided downwardly extending from the middle of one side end of the two flanges 7. The inner side surface of the lug 6 is provided with a tensioning column 8 extending horizontally along the width direction of the No. 1 pipe segment 1. The tensioning column 8 and the two flanges 7 are provided parallel to each other. The tail end of the No. 2 pipe segment 2 is provided with a bearing groove 4 along its length direction, and a tensioning hole 5 is provided in the groove body of the bearing groove 4 along its length direction. The convex edge 7 and the bearing groove 4 are both concave in shape. The cooperation between the bearing groove 4 and the convex edge 7 can increase the unevenness of the assembly surface of the No. 1 pipe segment 1 and the No. 2 pipe segment 2, thereby improving the sealing of the assembly surface of the No. 1 pipe segment 1 and the No. 2 pipe segment 2. During use, the lug 6 and the convex edge 7 are both tightly attached to the bearing groove 4, and the tensioning column 8 is tightly attached to the inside of the tensioning hole 5. The cooperation between the tensioning column 8 and the tensioning hole 5 plays a role in tightening the No. 1 pipe segment 1 and the No. 2 pipe segment 2 together.

[0034] The interior of the tensioning column 8 is provided with a self-locking part, and the self-locking part includes a pushing edge frame 9 movably installed inside the tensioning column 8 along the length direction thereof, and the head end of the pushing edge frame 9 extends into the outside of the tensioning column 8. The interior of the tensioning column 8 is provided with a plurality of No. 2 cavities 24 arranged along its length direction. The upper end face of the pushing edge frame 9 corresponding to each No. 2 cavity 24 is provided with an oblique notch 26, and a limiting square sleeve 29 is movably provided in the oblique notch 26. The oblique notch 26 on the pushing edge frame 9 plays a role in limiting the square sleeve 29. The limiting square sleeve 29 is pushed to drive the limiting square sleeve 29 to move upward. The bottom end of the limiting square sleeve 29 is a semicircular structure, which can be pushed by the oblique notch 26. An ejection spring 35 is embedded in the limiting square sleeve 29. The other end of the ejection spring 35 is against the bottom of the locking prism 30. The locking prism 30 is movably extended from the top of the limiting square sleeve 29 and extends into the guide hole 31 that is provided through the upper end of the interior of each No. 2 cavity 24. A plurality of locking holes 32 are evenly spaced on the inner top wall of the tightening hole 5.

[0035] As the tensioning column 8 is fully inserted into the tensioning hole 5, the locking prism 30 will fit into the inside of the locking hole 32. The cooperation between the locking hole 32 and the locking prism 30 plays a locking role. An ejection spring 35 is embedded between the lower end of the locking prism 30 and the inner bottom surface of the limiting square sleeve 29. The ejection spring 35 pushes the locking prism 30 and at the same time offsets the force of the limiting square sleeve 29 to continue to move upward when the locking prism 30 is blocked by the inner wall of the tensioning hole 5 and cannot move upward.

[0036] An L-shaped frame 33 is fixedly mounted within the upper end of the second cavity 24. The restricting sleeve 29 fits snugly through the upper end of the L-shaped frame 33. A protruding plate 25 extends from the side of the restricting sleeve 29. A third spring 34 is embedded between the upper end of the protruding plate 25 and the upper end of the second cavity 24. The L-shaped frame 33 serves to support and guide the restricting sleeve 29, while the third spring 34 pushes the restricting sleeve 29, ensuring that the restricting sleeve 29 is always in contact with the pushing rib 9.

[0037] A top plate 27 is fixedly mounted on the end of the push rib 9 located inside the tensioning post 8. The top plate 27 fits against the inner side of the tensioning post 8, and a second spring body 28 is embedded between the side of the top plate 27 and the inner side of the tensioning post 8. The top plate 27 ensures that the limiting square sleeve 29 and the push rib 9 are in constant contact, and the second spring body 28 serves to push the push rib 9 out from the end of the tensioning post 8.

[0038] The inlet of the tightening hole 5 is a bell-mouth structure; the end of the tightening column 8 is a conical structure, which facilitates the insertion of the tightening column 8 into the tightening hole 5.

[0039] During use, segment 1 is pushed sideways onto segment 2, and so on, forming a ring. During this process, the tensioning posts 8 on segment 1 are inserted into the tensioning holes 5 on segment 2. The tensioning holes 5 and the tensioning posts 8 force the ends of segment 1 and segment 2 together, preventing segment 1 from falling off once it is placed on segment 2. In the process of inserting the tensioning column 8 into the tensioning hole 5, the pushing prism 9 on the tensioning column 8 will first press against the end of the tensioning hole 5. At this time, when the tensioning column 8 continues to be inserted, the pushing prism 9 remains stationary, and the second spring body 28 contracts and deforms, while restricting the square sleeve 29 to slowly move upward along the oblique edge of the oblique notch 26 on the pushing prism 9, thereby driving the locking prism 30 to slowly move upward. When the locking prism 30 is slowly moving upward, the end of the locking prism 30 will first press against the inner wall of the tensioning hole 5, and be affected by the oblique notch 26. Continuing to squeeze the limiting square sleeve 29 will cause it to continue to move upward. At this time, the ejection spring 35 will shrink and deform to absorb the upward force of the limiting square sleeve 29. When the tensioning column 8 is fully inserted into the tensioning hole 5 and the guide hole 31 on the tensioning column 8 is aligned with the locking hole 32 on the inner wall of the tensioning hole 5, the ejection spring 35 will restore its deformation to release the absorbed upward force, so that the locking prism 30 moves upward and is inserted into the locking hole 32, locking the tensioning column 8 in the tensioning hole 5, that is, locking the No. 1 pipe segment 1 and the No. 2 pipe segment 2 together well.

Claims

1. A shield prefabricated segment, characterized by: The invention comprises a plurality of interlaced and mutually fitted first tube segments (1) and second tube segments (2), the head end of the first tube segment (1) is provided with two convex edges (7) spaced apart along its width direction, a lug (6) is provided extending downwardly from the middle of one end of the two convex edges (7), a tensioning column (8) is provided on the inner side surface of the lug (6) extending horizontally along the width direction of the first tube segment (1), the tail end of the second tube segment (2) is provided with a bearing groove (4) along its length direction, and a tensioning hole (5) is provided in the groove body of the bearing groove (4) along its length direction; An extrusion seal is provided between the convex edge (7) and the bearing groove (4), and the extrusion seal includes two No. 1 sealing grooves (3) provided at both sides of the tensioning hole (5), and a No. 2 sealing groove (10) is provided on the corresponding end faces of the two convex edges (7), and the No. 2 sealing groove (10) is arranged opposite to the No. 1 sealing groove (3), and a rubber sleeve (11) is clamped inside the No. 2 sealing groove (10); The interior of the rubber sleeve (11) is a cavity structure, in which two core columns (12) are sequentially and spaced apart. The ends of the two core columns (12) are movably extended from the end of the rubber sleeve (11). The proximal ends of the two core columns (12) are connected via an elastic component. A top tightening plate (18) is movably provided on each side of the cavity outside the two core columns (12). Each core column (12) is provided with a plurality of top tightening plate pushing devices. Each group of top tightening plate pushing devices includes four annular arrays of No. 1 slot frames (16) arranged on the column body of the core column (12). The No. 1 slot frame ( 16) is rotatably connected to a push frame (15), which extends obliquely upward and is rotatably connected to the second slot frame (17) at the bottom of the top tightening plate (18). The push frames (15) on the two core columns (12) are relatively inclined. Each core column (12) is also connected to the four top tightening plates (18) through multiple groups of connecting devices. Each group of connecting devices includes four annular arrays of guide sleeves (20) arranged on the column body of the core column (12). A guide column (19) is slidably sleeved in each guide sleeve (20), and the other end of each guide column (19) is fixedly connected to the bottom of a top tightening plate (18).

2. The shield prefabricated segment according to claim 1, characterized in that: The elastic component includes a No. 1 cavity (21) arranged at the relatively proximal ends of two core columns (12), a limiting cap (22) is arranged in each No. 1 cavity (21), a No. 1 spring body (23) is embedded in the cavity between the limiting cap (22) and the bottom of the No. 1 cavity (21), and a connecting column (14) is embedded between the two limiting caps (22).

3. The shield prefabricated segment according to claim 1, characterized in that: A top plate (13) is fitted at each end of the cavity structure inside the rubber sleeve (11), and each core column (12) moves through each top plate (13). The two top plates (13) are fixedly connected together via a support rod (36).

4. The shield prefabricated segment according to claim 1, characterized in that: The tensioning column (8) is provided with a self-locking part inside, and the self-locking part includes a pushing edge frame (9) movably installed inside the tensioning column (8) along the length direction, and the head end of the pushing edge frame (9) extends to the outside of the tensioning column (8). The tensioning column (8) is provided with a plurality of No. 2 cavities (24) arranged along the length direction, and the upper end surface of the pushing edge frame (9) corresponding to each No. 2 cavity (24) is provided with an oblique notch (26), and a limiting square is provided in the oblique notch (26). The bottom end of the limiting square sleeve (29) is a semicircular structure, and an ejection spring (35) is embedded in the limiting square sleeve (29). The other end of the ejection spring (35) abuts against the bottom of the locking prism (30). The locking prism (30) extends from the top end of the limiting square sleeve (29) and extends into the guide hole (31) provided through the upper end of each No. 2 cavity (24). A plurality of locking holes (32) are evenly spaced on the top wall of the tensioning hole (5).

5. The shield prefabricated segment according to claim 4, characterized in that: An L-shaped frame (33) is fixedly installed inside the upper end of the second cavity (24), and the limiting square sleeve (29) fits through the upper end surface of the L-shaped frame (33). A protruding plate (25) extends from the side of the limiting square sleeve (29), and a third spring body (34) is embedded between the upper end of the protruding plate (25) and the inner upper end of the second cavity (24).

6. The shield prefabricated segment according to claim 4, characterized in that: A top plate (27) is fixedly mounted on the end of the pushing rib (9) located inside the tensioning column (8). The top plate (27) fits against the inner side of the tensioning column (8). A second spring body (28) is embedded between the side surface of the top plate (27) and the inner side surface of the tensioning column (8).

7. The shield prefabricated segment according to claim 1, characterized in that: The inlet of the tensioning hole (5) is a bell-mouth structure; the end of the tensioning column (8) is a conical structure.

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