Shield segment based on secondary service life concept and machining method thereof

Abstract

The invention discloses a shield segment based on the secondary service life concept and a machining method of the shield segment. The shield segment is mainly composed of a concrete shell, a steel honeycomb beam and a truss type floor support plate, and the service life of the shield segment is two times that of a traditional segment. According to the first-time service life, loads are mainly borne through a concrete shell and steel honeycomb beam combined structure, and according to the second-time service life, a secondary concrete pouring space of 20 cm (duct piece deformation 15 cm + protective layer thickness 5 cm) and a truss type floor support plate are reserved at the beginning of design, later-stage secondary lining pouring is facilitated, laying of a secondary pouring formwork can be avoided, and the construction cost is reduced. A structure composed of the outer-layer concrete shell, the steel honeycomb beams and the inner-layer truss type floor support plate concrete shell jointly bears loads, the truss type floor support plate serves as a force bearing component and also serves as a construction formwork, the cost is saved, the construction period is shortened, and the development concepts of environmental protection, energy conservation and emission reduction are met.

Description

Technical Field

[0001] This utility model invention patent is about a shield tunnel segment based on the concept of secondary service life and its processing method. Background Art

[0002] In recent years, major cities in China have set off a climax of rail transit construction, and the mileage of shield tunnels has been increasing. Shield segments play a vital role in tunnel engineering. They are key elements that support tunnel structures, resist stratum and water pressure, and can also cope with some specific loads. During the operation of shield tunnels, shield segments gradually deteriorate over time, and cracks and deformations appear on the surface; in addition, changes in the use environment, such as ground loading, unloading, and excavation, may also cause various quality problems in tunnel segments, which seriously threaten the safety of tunnels. In response to the above problems, local reinforcement is currently the main method used, but this local reinforcement method can only temporarily alleviate structural degradation, but cannot fundamentally extend the service life of the segments. For this reason, this article invents a shield segment based on the concept of secondary service life, which is fundamentally reinforced and extended, which is extremely important for ensuring the safe operation of tunnels and saving tunnel construction costs. Summary of the invention

[0003] The present invention aims to address the deficiencies of the prior art and to propose a shield segment and a processing method thereof based on the concept of secondary service life.

[0004] The objectives of the present invention are achieved through the following technical solutions: 1. A shield segment based on the concept of secondary service life, which is 20 cm larger than the inner diameter of the existing segment (segment deformation 15 cm + protective layer thickness 5 cm), and reserves space for the cast-in-place concrete lining when the segment deforms too much in the later stage. It mainly includes concrete shell, connecting blocks, longitudinal beams, cross beams, connecting seams, bent bolt holes, steel mesh, longitudinal steel bars, transverse steel bars, stirrups, reserved bars, reserved steel plates, right-angle connecting plates, straight bolts, bent bolts, threads, nuts, truss-type floor decking, T-shaped steel plates, U-shaped supports, welding screws, grouting ports, exhaust ports, trusses, T-plate holes, and screw holes.

[0005] The concrete shell is the outermost layer of the pipe segment, which is composed of 5 identical connecting blocks connected by two bent screws. Due to the presence of the inner steel honeycomb beam-longitudinal beam and cross beam, the thickness of the concrete shell is half of the existing pipe segment thickness while meeting the use requirements.

[0006] The connection blocks are provided with bent bolt holes for easy installation later. The main material of the connection blocks is concrete, with prefabricated steel mesh, reserved bars and reserved steel plates inside. The other ends of the reserved bars and reserved steel plates are welded to the top surface of the longitudinal beams, so that the bottom surface of each connection block is connected to the longitudinal beams of the two spans.

[0007] The longitudinal beams and cross beams are made of steel, aluminum alloy, carbon fiber, and fiberglass. The holes on the beams are hexagonal, octagonal, circular, and rectangular. Right-angle connecting plates are set in four directions at the overlap of the longitudinal beams and cross beams. 14 straight bolts are arranged on each connecting plate to connect the longitudinal beams and cross beams. In addition, an intelligent monitoring device is set in the steel honeycomb beam structure.

[0008] The connecting seam is an interface connecting two connecting blocks, and the connecting seam can be made flat or in the form of mortise and tenon joints.

[0009] The steel mesh is mainly composed of longitudinal steel bars, transverse steel bars and stirrups, and is prefabricated in the connection block.

[0010] The trusses are welded on the truss-type floor decking, and T-plate holes are reserved at both ends. The lower end of each T-shaped steel plate passes through two adjacent truss-type floor decking plates, and the exposed part is wrapped with a U-shaped bracket and finally fixed with two welding screws.

[0011] 2. According to claim 1, a shield segment based on the concept of secondary service life is characterized in that it is 20 cm larger than the inner diameter of the existing segment (segment deformation 15 cm + protective layer thickness 5 cm). When the segment is deformed too much in the later stage and ordinary reinforcement technology cannot achieve good results, the steel honeycomb beam-longitudinal beam and cross beam can be cast into a concrete lining to reinforce the tunnel as a whole.

[0012] 3. According to claim 1, a shield segment based on the concept of secondary service life, the method of cast-in-place concrete lining to reinforce the tunnel can also be used for existing subway segments and large-diameter segments.

[0013] 4. According to claim 1, a shield segment based on the concept of secondary service life is characterized in that the longitudinal beams and transverse beams are made of steel, aluminum alloy, carbon fiber, and fiberglass, and the holes on the beams are hexagonal, octagonal, circular, or rectangular.

[0014] 5. According to the shield segment based on the concept of secondary service life as described in claim 1, intelligent monitoring devices are arranged in the steel honeycomb beams-longitudinal beams and transverse beams.

[0015] 6. A shield segment based on the concept of secondary service life according to claim 1, characterized in that the thickness of the concrete shell 1 is half the thickness of existing concrete segments.

[0016] 7. A shield segment based on the concept of secondary service life according to claim 1, characterized in that the longitudinal beams and transverse beams have hexagonal hole design features, and the internal pipelines of the tunnel can pass through the holes.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention is a new shield segment structure, which utilizes a steel and concrete composite structure to replace the conventional concrete shield segments, thereby combining the tensile strength of steel and the compressive strength of concrete. The combined effect of the two has a better bearing effect than conventional concrete shield segments.

[0019] 2. The present invention not only provides a shield segment with a new structure, but also provides a good reinforcement method. Conventional reinforcement methods are mostly emergency measures, which have defects in stability, integrity, durability, and green environmental protection. A method of reinforcing the entire tunnel with a cast-in-place concrete lining is proposed, which not only solves the problems of conventional reinforcement methods in terms of fit, durability, and integrity, but also extends the service life of the segment to a great extent. In addition, it also avoids the double losses in economy and environment caused by the reconstruction of the tunnel when the life of the segment ends.

[0020] 3. Steel honeycomb beams have strong rigidity, high bending bearing capacity, light weight, beautiful appearance, practicality and economy, which improve the strength of the pipe segment as a whole. While meeting the design requirements, the thickness of the concrete part is smaller than that of the previous pipe segment, reducing the dead weight of the concrete piece.

[0021] 4. The present invention adopts an assembled type, and the thickness of the concrete part of the pipe segment is reduced by half compared with the previous pipe segments, so the dead weight is reduced, which brings convenience to transportation and reduces transportation costs.

[0022] 5. The present invention utilizes the characteristics of simple steel honeycomb beam structure, low assembly difficulty and multiple holes to increase the space utilization rate in the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 : Overall schematic diagram of the segment;

[0024] Figure 2 : Schematic diagram of segment connection block;

[0025] Figure 3 : Schematic diagram of steel mesh;

[0026] Figure 4 : Schematic diagram of longitudinal beam connection;

[0027] Figure 5 : Schematic diagram of the connection between longitudinal and transverse beams;

[0028] Figure 6 : Schematic diagram of truss type floor deck;

[0029] Figure 7 : Schematic diagram of bent bolt;

[0030] Figure 8 : Schematic diagram of straight bolt;

[0031] Fig. 9 : Schematic diagram of U-shaped support. DETAILED DESCRIPTION

[0032] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0033] like Figure 1 one Fig. 9 As shown, the present invention provides a shield segment based on the concept of secondary service life and a processing method thereof. The segment in this case is characterized in that it is 20 cm larger than the inner diameter of the existing segment (segment deformation 15 cm + protective layer thickness 5 cm), and space is reserved for the cast-in-place concrete lining in case the segment deforms too much in the later stage. The segment mainly includes a concrete shell 1, a connecting block 2, a longitudinal beam 3, a transverse beam 4, a connecting seam 5, a bent bolt hole 6, a steel mesh 7, a longitudinal steel bar 8, a transverse steel bar 9, stirrups 10, a reserved bar 11, a reserved steel plate 12, a right-angle connecting plate 13, a straight bolt 14, a bent bolt 15, a thread 16, a nut 17, a truss-type floor deck 18, a T-shaped steel plate 19, a U-shaped support 20, a welding screw 21, a grouting port 22, an exhaust port 23, a truss 24, a T-plate hole 25, and a screw hole 26.

[0034] The concrete shell 1 is the outermost layer of the pipe segment, and is formed by five identical connecting blocks 2 connected in pairs by two bent bolts 15 .

[0035] The connection block 2 is provided with bent bolt holes 6 for later installation. The connection block 2 is mainly made of concrete, and a steel mesh 7 is arranged inside, which is mainly composed of longitudinal steel bars 8, transverse steel bars 9 and stirrups 10.

[0036] The longitudinal beam 3 and the cross beam 4 are made of steel, aluminum alloy, carbon fiber, and fiberglass. The holes on the beams are hexagonal, octagonal, circular, and rectangular. Right-angle connecting plates 13 are arranged in four directions at the overlap of the longitudinal beam 3 and the cross beam 4. 14 straight bolts 14 are arranged on each connecting plate to connect the longitudinal beam 3 and the cross beam 4. In addition, an intelligent monitoring device can be set in the steel honeycomb beam structure.

[0037] The truss 24 is welded on the truss type floor decking plate 18, and T-plate holes 25 are reserved at both ends. The lower end of each T-shaped steel plate 19 passes through two adjacent truss type floor decking plates 18, and the exposed part is wrapped with a U-shaped bracket 20 and finally fixed with two welding screws 21.

[0038] The specific steps of shield segment construction based on the concept of secondary service life are as follows:

[0039] Step 1: Position and arrange the steel mesh 7, reserved reinforcement 11, and reserved steel plate 12 according to design requirements, and cast concrete in situ;

[0040] Step 2: transport the prefabricated concrete blocks to the site, weld the top of the longitudinal beam 3 to the tail of the reserved reinforcement 11 and the reserved steel plate 12, and weld the T-shaped steel plate 19 at the bottom of the longitudinal beam 3. The screw holes are reserved on the T-shaped steel plate. Figure 2 As shown;

[0041] Step 3: Connect five concrete blocks 2 into a concrete ring 1 by means of bent bolts 15;

[0042] Step 4: Arrange the cross beam 4 between every two longitudinal beams 3, and connect and fix the two through the right-angle connecting plate 13 and the straight bolt 14;

[0043] Step 5: Pass each T-shaped plate 19 on the lower surface of the longitudinal beam 3 through two adjacent truss-type floor decking plates 18, wrap the bottom surface of the T-shaped plate 19 with a U-shaped bracket 20, and fix it with welding screws 21 passing through the U-shaped bracket 20, so that the truss-type floor decking plate 18 fits on the lower surface of the cross beam 4;

[0044] Step 6: When the service life of the pipe segment reaches its limit, the damaged part is first replaced, and then grouting is injected into the interior through the grouting port 22 reserved on the truss-type floor deck 18, and a second lining of cast-in-place concrete is used to reinforce the lining as a whole, thereby making up for the deficiencies of the existing reinforcement methods in terms of structure, integrity and durability.

Claims

1. A shield segment and a processing method thereof based on the concept of secondary service life, characterized in that: The diameter of the pipe segment is 20 cm larger than the inner diameter of the existing pipe segment because the pipe segment is deformed too much in the later stage. The cast-in-place concrete lining reserves space, and mainly includes a concrete shell (1), a connecting block (2), a longitudinal beam (3), a transverse beam (4), a connecting seam (5), a bent bolt hole (6), a steel mesh (7), a longitudinal steel bar (8), a transverse steel bar (9), a stirrup (10), a reserved steel bar (11), a reserved steel plate (12), a right-angle connecting plate (13), a straight bolt (14), a bent bolt (15), a thread (16), a nut (17), a truss-type floor deck (18), a T-shaped steel plate (19), a U-shaped bracket (20), a welding screw (21), a grouting port (22), an exhaust port (23), a truss (24), a T-plate hole (25), and a screw hole (26); The concrete shell (1) is the outermost layer of the pipe segment, and is formed by connecting five identical connection blocks (2) in pairs through two bent bolts (15). Due to the presence of the inner steel honeycomb beam-longitudinal beam (3) and cross beam (4), the thickness of the concrete shell (1) is half of the thickness of the existing pipe segment while meeting the use requirements; The connection block (2) is provided with a bent bolt hole (6) for easy installation at a later stage. The main material of the connection block (2) is concrete, and a prefabricated steel mesh (7) is provided inside, as well as reserved ribs (11) and reserved steel plates (12). The other ends of the reserved ribs (11) and reserved steel plates (12) are welded to the top surface of the longitudinal beam (3), so that the bottom surface of each connection block (2) is connected to the longitudinal beams (3) of two spans. The longitudinal beam (3) and the cross beam (4) are made of steel, aluminum alloy, carbon fiber, or fiberglass. The holes on the beams are hexagonal, octagonal, circular, or rectangular. Right-angle connecting plates (13) are arranged in four directions at the overlap of the longitudinal beam (3) and the cross beam (4). 14 straight bolts (14) are arranged on each connecting plate. The longitudinal beam (3) and the cross beam (4) are connected by the straight bolts (14). In addition, an intelligent monitoring device is arranged in the steel honeycomb beam structure. The connecting seam (5) is an interface connecting two connecting blocks (2), and the connecting seam (5) is in the form of mortise and tenon joints; The steel mesh (7) is mainly composed of longitudinal steel bars (8), transverse steel bars (9) and stirrups (10), and is prefabricated in the connection block (2); A truss (24) is welded on the truss-type floor deck (18), and T-plate holes (25) are reserved at both ends. The lower end of each T-shaped steel plate (19) passes through two adjacent truss-type floor decks (18), and the exposed part is wrapped with a U-shaped bracket (20), and finally fixed with two welding screws (21).

2. A shield segment based on the concept of secondary service life according to claim 1, characterized in that: The diameter of the segment is 20 cm larger than that of the existing segment. When the segment is deformed too much in the later stage and the common reinforcement technology cannot achieve a good effect, the steel honeycomb beam-longitudinal beam (3) and cross beam (4) can be cast into a concrete lining to reinforce the tunnel as a whole.

3. According to claim 1, a shield segment based on the concept of secondary service life, the method of cast-in-place concrete lining to reinforce the tunnel can also be used for existing subway segments and large-diameter segments.

4. According to claim 1, a shield segment based on the concept of secondary service life is characterized in that the longitudinal beam (3) and the cross beam (4) are made of material, aluminum alloy, carbon fiber, fiberglass, and the holes on the beam are hexagonal, octagonal, circular, or rectangular.

5. According to the shield segment based on the concept of secondary service life as described in claim 1, intelligent monitoring devices are arranged in the steel honeycomb beam-longitudinal beam (3) and cross beam (4).

6. The shield segment based on the concept of secondary service life according to claim 1 is characterized in that: The thickness of the concrete shell 1 is half of the thickness of the existing concrete segments.

7. The shield segment based on the concept of secondary service life according to claim 1 is characterized in that: The longitudinal beam (3) and the cross beam (4) have a hexagonal hole design feature, and the pipelines inside the tunnel can pass through the holes.

8. A shield segment based on the concept of secondary service life and its processing method. The specific manufacturing steps are as follows: Step 1: Position and arrange the steel mesh (7), reserved reinforcement (11), and reserved steel plate (12) according to design requirements, and cast concrete in situ; Step 2: transport the prefabricated concrete blocks to the site, weld the top of the longitudinal beam (3) to the tail of the reserved reinforcement (11) and the reserved steel plate (12), and weld a T-shaped steel plate (19) at the bottom of the longitudinal beam (3), with screw holes reserved on the T-shaped steel plate. Step 3: Connect five concrete blocks (2) into a concrete ring (1) by using bent bolts (15); Step 4: Arrange a cross beam (4) between every two longitudinal beams (3), and connect and fix the two by a right-angle connecting plate (13) and a straight bolt (14); Step 5: Pass each T-shaped plate (19) on the lower bottom surface of the longitudinal beam (3) through two adjacent truss-type floor decking plates (18), wrap the bottom surface of the T-shaped plate (19) with a U-shaped bracket (20), and fix it with welding screws (21) passing through the U-shaped bracket (20), so that the truss-type floor decking plate (18) is attached to the lower bottom surface of the cross beam (4); Step 6: When the service life of the pipe segment reaches its limit, the damaged part is first replaced, and then grouting is injected into the interior through the grouting port (22) reserved on the truss type floor deck (18), and a second lining of cast-in-place concrete is used to reinforce the lining as a whole, thereby making up for the deficiencies of the existing reinforcement method in terms of structure, integrity and durability.

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