Shield body structure and heading machine

Abstract

The utility model discloses a shield body structure and a heading machine, and solves the technical problems that the shield body structure in the prior art is a pure steel structure, and when a shell discarding mode is adopted, the shell cost is high, the durability cannot be guaranteed, the working procedure is complicated, the working environment is poor and the like. The shield body structure comprises an inner metal shield shell and a reinforced concrete shield shell connected outside the inner metal shield shell; the heading machine comprises the shield body structure. Compared with an existing shield body scheme, the combined shield body structure has the advantages of being low in manufacturing cost, high in prefabrication degree, high in structural strength and the like. The shield body structure can be used as a temporary structure in the tunneling period to support and protect internal components and can also be used as a tunnel permanent lining segment after tunneling is completed, concrete does not need to be cast in place in a discarded shield body, the working procedure is simple, the shield body structure is of an outer-concrete inner-steel structure, and compared with a traditional method that concrete is cast in place in the shield body, the shield body structure has the advantages that the construction cost is low, and the construction efficiency is high. The structure is more corrosion-resistant and better in durability.

Description

Technical Field

[0001] This utility model relates to the field of tunneling machine shield technology, and in particular to a shield structure and a tunneling machine. Background Technology

[0002] In recent years, my country's urbanization has steadily progressed, with most provincial capitals and developed coastal cities alleviating surface traffic pressure by constructing underground rail transit. As the siphon effect of central cities on surrounding smaller cities and rural areas becomes increasingly pronounced, a large influx of people into these cities exacerbates traffic congestion. Due to the increasing scarcity of urban surface space, subway construction requires the creation of new working shafts, occupying surface space for extended periods, extending construction time, and involving unfavorable factors such as demolition and disruption to the travel of surrounding residents, thus increasing costs throughout the construction period. In some mountainous areas with complex terrain, large-section tunnel boring machines also face difficulties in transporting and hoisting the shield structure. One approach is to use the tunnel boring machine's shield as a support and protective shell during the tunneling process. After tunneling is completed, the shell is discarded, serving as permanent tunnel segments. This avoids the need to hoist the large shield out of the tunnel, reducing the number of new working shafts, significantly shortening the construction period and increasing the utilization rate of existing working shafts.

[0003] For example, Chinese invention patent application publication number CN 114718586 A discloses a method for dismantling the shell of a double-shield TBM main unit inside a tunnel, including the following steps: dismantling the main unit, leaving the shield shell as initial support during the dismantling process, and after the main unit is dismantled, segment support is provided for the tunnel section surrounded by the shield shell. This invention does not set up lifting points or carry out any chamber expansion excavation, thus ensuring the integrity of the tunnel. Leaving the shield shell inside the tunnel as initial support reduces support costs, saves construction time, and meets the requirements for dismantling inside the tunnel when the end of the tunnel does not have the conditions for receiving.

[0004] For example, Chinese invention patent application CN 112610233 A discloses a "cicada shedding its shell" rectangular pipe jacking receiving construction method, proposing a method for shield shell disposal construction without setting up a receiving working shaft. After tunneling is completed, the shield is disassembled, retaining only the steel shield shell, and then the steel mesh, formwork, etc. are hoisted to the disposal site to reinforce the steel shell with cast-in-place concrete. Due to the limited space, the concrete used needs to be pumped from the existing working shaft to the work site. This method requires long-distance transportation of cement slurry, and the formwork curing time is long, which brings inconvenience to construction. The overall shell disposal will also greatly increase material costs.

[0005] For example, Chinese invention patent application CN 116163750 A discloses a double-layer shield shell structure suitable for disassembly inside large-diameter shield tunnels. The double-layer structure of the inner and outer shells facilitates the disassembly of the shield machine and reserves space for expansion and contraction modifications, improving the versatility of the shield machine. The middle shield and tail shield employ a movable sleeve design, combined with sealing airbags and connecting steel plates, ensuring sealing and flexibility, facilitating shield turning and disassembly. Power support is provided by articulated hydraulic cylinders, enhancing the shield machine's adaptability in curved sections and improving shield flexibility and construction efficiency. Its structure is relatively complex; the double-layer shell, movable sleeve, sealing airbags, and articulated hydraulic cylinders increase structural complexity and may increase the difficulty of manufacturing and maintenance.

[0006] For example, Chinese invention patent CN116398155 A discloses a prefabricated, dismantled shield machine main shield body and its installation and dismantling method. The shield body is designed as a front shield, middle shield, and tail shield, each part adopting a modular design. The assembled blocks are fixed together by flanges and connecting bolts, reducing welding workload and improving construction efficiency. The modular design eliminates the need for cutting during dismantling, reducing dismantling difficulty and workload, and facilitating disassembly and reassembly. However, the connections between the assembled blocks require high-precision manufacturing; otherwise, the stability and sealing of the overall structure will be affected. The reliability of the bolt connections requires regular inspection and maintenance, which may affect the structural stability. Although the dismantling sequence of the shield body is optimized, a certain amount of space is still required for dismantling operations, which may be restrictive, especially in confined construction environments.

[0007] For example, Chinese utility model patent CN219932169U discloses a modular and segmented shield tunneling machine that is easy to disassemble and reassemble. The main shield also adopts a modular and segmented design, making the disassembly and assembly of the main shield more convenient. By transferring the inner shield of the front shield to the open space inside the outer shell of the middle shield for disassembly, the problem of limited disassembly space caused by the main drive unit is avoided, thus improving disassembly efficiency. The addition of a cross-beam and an outer ring plate enhances structural stability and ensures construction safety.

[0008] The above existing technical solutions provide the shield structure of the tunneling machine in the case of no reserved exit. The shield structures mentioned above are all pure steel structures. When adopting the shell disposal method, it will face unfavorable factors such as high shell cost and inability to guarantee durability. These are technical problems that still need to be solved.

[0009] It should be noted that the above technical information is intended only to enhance the understanding of the overall background technology of this utility model, and should not be regarded as an admission or in any form implying that the above technical information constitutes prior art known to those skilled in the art. Summary of the Invention

[0010] In view of the shortcomings in the above-mentioned background technology, this utility model proposes a shield structure and a tunneling machine. The technical problem to be solved is that the shield structures in the prior art are all pure steel structures. When adopting the shell disposal method, it will face unfavorable factors such as high shell cost, inability to guarantee durability, complex process and poor working environment.

[0011] The technical solution of this utility model is as follows:

[0012] A shield structure includes an inner metal shield shell and a reinforced concrete shield shell connected to the outside of the inner metal shield shell.

[0013] Based on the above technical solutions, as a preferred technical solution for the shield structure, an outer metal shield shell is provided outside the reinforced concrete shield shell, and the thickness of the outer metal shield shell is less than the thickness of the inner metal shield shell.

[0014] Based on the above technical solutions, as a preferred technical solution for the shield structure, the reinforced concrete shield shell includes circumferential stirrups, longitudinal reinforcing bars and pins cast in concrete, with the ends of the pins connected to the inner metal shield shell.

[0015] Based on the above technical solutions, as a preferred technical solution for the shield structure, the shield structure is an integral structure, or the shield structure includes several blocks that are detachably connected along the axial direction and / or several blocks that are detachably connected along the circumferential direction.

[0016] Based on the above technical solutions, as a preferred technical solution for the shield structure, the shield structure is provided with a connecting structure for connecting adjacent blocks or for connecting existing buildings in the tunnel, and a water-stopping structure is provided at the joints between adjacent blocks and between blocks and existing buildings.

[0017] Based on the above technical solutions, as a preferred technical solution for the shield structure, the inner metal shield shell is fixedly connected to an outer ring plate, and the outer ring plate is detachably connected to an inner partition plate via partition bolts. The inner partition plate has cutter head holes and screw holes.

[0018] Based on the above technical solutions, as a preferred technical solution for the shield structure, the inner partition is a single plate, or the inner partition includes several sub-plates spliced ​​vertically and / or horizontally.

[0019] Based on the above technical solutions, as a preferred technical solution for the shield structure, a water-stopping structure is provided at the joints between the outer ring plate and the inner partition plate, and between adjacent partition plates.

[0020] Based on the above technical solutions, as a preferred technical solution for the shield structure, the outer contour of the shield structure is circular, horseshoe-shaped, rectangular, or elliptical.

[0021] A tunneling machine includes the shield structure described in any of the above technical solutions, wherein the cutterhead hole is connected to the main drive of the cutterhead, and the screw conveyor hole is for a screw conveyor to pass through.

[0022] This utility model proposes a shield structure and a tunneling machine using the shield structure, which has the following advantages compared with the prior art:

[0023] 1) Compared with existing shield body schemes, this utility model proposes a combined steel structure and concrete structure shield body structure, which has the advantages of low manufacturing cost, high degree of prefabrication and high structural strength.

[0024] 2) Compared with the existing shell disposal scheme, the new shield structure proposed in this utility model can serve as a temporary structure during tunneling to support and protect internal components, and can also serve as a permanent tunnel lining segment after tunneling is completed. It does not require the pouring of concrete inside the abandoned shield, and the process is simple. Moreover, this structure is a "concrete outside steel inside" structure. Compared with the traditional method of pouring concrete inside the shield, this structure is more corrosion resistant and has better structural durability.

[0025] 3) The modular shield body of this scheme can be divided into multiple rings at the front and back, or into multiple blocks at the top and bottom, which greatly reduces the difficulty and cost of transportation. Attached Figure Description

[0026] To more clearly illustrate the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a cross-sectional schematic diagram of the shield structure (including a partially enlarged schematic diagram in the upper right corner).

[0028] Figure 2 This is a schematic diagram of the longitudinal section of the shield structure.

[0029] Figure 3 Schematic diagram of the shield body partitions: a) outer ring plate; b) inner partition plate;

[0030] Figure 4 Three implementation methods for the internal partition of the shield: c. Divided into six sections in both directions; d. Divided into two sections in the top and bottom; e. Divided into three sections in the left and right.

[0031] Figure 5 Two modular implementation methods for the shield structure: f divides it into two blocks along the circumferential direction; g divides it into three blocks along the axial direction.

[0032] Figure 6This is another modular implementation of the shield structure;

[0033] Figure 7 Four implementation methods for the cross-sectional shape of the shield structure: the outer contour of section h is circular; the outer contour of section i is horseshoe-shaped; the outer contour of section j is rectangular; and the outer contour of section k is elliptical.

[0034] Explanation of icon numbers:

[0035] 1: Shield structure; 1-1: Reinforced concrete shield shell; 1-2: Circumferential stirrups; 1-3: Pins; 1-4: Longitudinal reinforcement; 1-51: Inner steel shield shell; 1-52: Outer steel shield shell; 1-6: Shield bolt holes; 1-7: Outer ring plate; 1-8: Diaphragm bolts; 1-9: Inner diaphragm; 1-10: Cutterhead hole; 1-11: Screw hole; 2-1: Cutterhead; 2-2: Shield bolts; 3-1: Upper shield block; 3-2: Lower shield block; 3-3: Front shield block; 3-4: Rear shield block. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the core concept of the present utility model and the following embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0037] These embodiments are provided to make the application thorough and complete, and to fully express the scope of the application to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​illustrated in these embodiments should be interpreted as merely exemplary and not as limiting.

[0038] It should be noted that, in the description of this application, unless otherwise stated, "several" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "axial," "radial," etc., indicating orientation or positional relationships are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0039] Furthermore, the terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well.

[0040] It should also be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0041] All terms used in this application have the same meaning as understood by one of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0042] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0043] This utility model proposes a combined shield structure, which serves as a shield shell to support and protect internal components during the tunneling process and as a permanent tunnel lining structure after tunneling is completed. The proposed structure can effectively solve the problems of high construction costs for discarding the shell of rectangular tunnel jacking machines and poor durability of the cast-in-place lining structure after shell disposal, thus expanding the application scenarios of rectangular and quasi-rectangular tunneling machines.

[0044] The core invention point 1 of this utility model is to provide a combined shield structure, whose shield shell structure is a steel-concrete-steel "sandwich" structure, which can be used as a temporary structure during tunneling to support and protect internal components, and can also be used as a permanent tunnel lining segment after tunneling is completed. Moreover, its structure has good durability and is not easily corroded. This structure has the advantages of low manufacturing cost and high degree of prefabrication.

[0045] The second core invention of this utility model is to provide a combined shield structure that can be divided into multiple rings in the front and back or into multiple blocks in the upper and lower parts, which facilitates transportation.

[0046] The specific implementation method is as follows:

[0047] A shield structure, such as Figure 1 As shown, the shield structure includes an inner metal shield shell and a reinforced concrete shield shell 1-1 connected to the inner metal shield shell, forming an "outer concrete, inner steel" structure. It should be noted that this embodiment does not include the outer metal shield shell outside the reinforced concrete shield shell 1-1. Compared to traditional methods, not only is the cost of discarding the shield shell lower, but this structure is also more corrosion-resistant and has better structural durability compared to casting concrete inside the shield. The main component of the shield structure is the reinforced concrete shield shell 1-1, while the inner metal shield shell is used for axial force transmission during tunneling, thus enabling the "concrete shield detachment" technology. That is, after tunnel excavation is completed, the shield structure remains underground as a permanent support structure, while the cutterhead system, drive system, muck removal system, and other structures connected to the shield structure can be "detached" from the concrete shield, "retreat" to the launching shaft, and transported out of the tunnel, thus achieving reuse.

[0048] Based on the above technical solutions, as a preferred technical solution for the shield structure, the shield structure includes an inner metal shield shell, an outer metal shield shell, and a reinforced concrete shield shell 1-1 located between the inner and outer metal shield shells. The inner metal shield shell, the outer metal shield shell, and the reinforced concrete shield shell 1-1 form an integral structure. That is, a three-layer sandwich structure is formed with a metal outer shell and an inner shell, and a reinforced concrete structure in the middle. The advantage of using a sandwich structure with an outer metal shield shell is that the outer metal shield shell can be used as a formwork support and can also play a role in reducing wear during tunneling.

[0049] Preferably, both the inner and outer metal shields are steel shields. The thickness of the outer metal shield is less than that of the inner metal shield, making the outer metal shield relatively thin. This outer metal shield serves to support the formwork and reduce wear during tunneling. After prolonged use, the outer metal shield will corrode, at which point the reinforced concrete shield will directly contact the soil, thus preventing corrosion of the inner metal shield.

[0050] Based on the above technical solutions, the preferred technical solution for the shield structure is as follows: Figure 1 As shown in the enlarged view, the reinforced concrete shield 1-1 includes circumferential stirrups 1-2, longitudinal reinforcing bars 1-4, and pins 1-3 cast in concrete. The end of the pin 1-3 is connected to the inner metal shield. Preferably, the pin 1-3 is welded to the inner metal shield.

[0051] Based on the above technical solutions, the preferred technical solution for the shield structure is as follows: Figure 1As shown, the shield structure 1 is a one-piece structure, meaning it is an integral structure and cannot be disassembled. Or as... Figure 5 and Figure 6 As shown, the shield structure 1 includes several sections that are detachably connected along the axial direction and / or several sections that are detachably connected along the circumferential direction, wherein... Figure 5 Figure f shows two detachable sections connected along the circumferential direction, with the two seams between the two sections located at different horizontal heights; Figure 5 Figure g shows three sections that can be detachably connected along the axial direction; Figure 6 It consists of two detachably connected sections along the circumferential direction, with the two seams between the two sections located at the same horizontal height.

[0052] Based on the above technical solutions, as a preferred technical solution for the shield structure, the shield structure 1 is provided with shield bolt holes 1-6 that are adapted to shield bolts 2-2. The shield bolt holes 1-6 are used to connect adjacent blocks or to connect existing buildings in the tunnel.

[0053] Based on the above technical solutions, as a preferred technical solution for the shield structure, waterstop strips are provided at the joints between adjacent blocks and between blocks and existing buildings.

[0054] Based on the above technical solutions, the preferred technical solution for the shield structure is as follows: Figure 3 As shown, the inner metal shield shell is fixedly connected to an outer ring plate 1-7. The outer ring plate 1-7 is detachably connected to an inner partition plate 1-9 via partition bolts 1-8. The inner partition plate 1-9 has a cutterhead hole 1-10 and a screwdriver hole 1-11. Figure 3 In Figure 'a', the positional relationship between the outer ring plates 1-7 and the inner metal shield is shown. Figure 3 b in the diagram illustrates the structural form of the inner partitions 1-9.

[0055] Based on the above technical solutions, the preferred technical solution for the shield structure is as follows: Figure 3 As shown in a, the inner partitions 1-9 are a single piece of material. Or as... Figure 4 As shown, the inner partitions 1-9 comprise several panels that are joined vertically and / or horizontally. Among them, Figure 4 c, d, and e represent the three forms of inner partitions 1-9. c shows six partitions that are joined in two rows vertically and three columns horizontally. d shows two partitions that are joined in two rows vertically. e shows three partitions that are joined in three columns horizontally.

[0056] Preferably, adjacent inner partitions 1-9 are connected by bolts or welded together. After use, the partitions can be reused in the next project. For example, if Project A uses six rectangular sections, Project B can also use the same partitions from Project A, combining them into four sections.

[0057] Based on the above technical solutions, as a preferred technical solution for the shield structure, waterstop strips are provided at the joints between the outer ring plate 1-7 and the inner partition plate 1-9, and between adjacent partition plates.

[0058] Based on the above technical solutions, as a preferred technical solution for the shield structure, the outer contour of the shield structure's cross-section is circular, horseshoe-shaped, rectangular, or elliptical. For example... Figure 7 As shown, Figure 7 h, i, j, and k in the figure respectively represent shield structures with circular, horseshoe, rectangular, and elliptical cross-sectional outlines.

[0059] As a preferred embodiment of the shield structure, such as Figure 1 As shown, the shield shell structure includes a reinforced concrete shield shell 1-1, with an inner steel mesh composed of circumferential stirrups 1-2 and longitudinal steel bars 1-4, which serves to bear the water and soil pressure and prevent corrosion; an inner steel shield shell 1-51, which serves to fix the partition and transmit the thrust; an outer steel shield shell 1-52, which serves to reduce friction with the soil; pins 1-3, which connect the steel shell and the concrete shell, making them a whole to bear the water and soil pressure, and at the same time transmit the thrust of the steel shell to the concrete shell, and the pins are fixed to the inner steel shield shell; and pre-drilled bolt holes 1-6, through which shield bolts 2-2 pass to connect the shield shell to the existing building, and enlarged ends are welded to the bolt ends to increase their pull-out resistance.

[0060] Preferably, such as Figure 5 As shown, alternative solutions for the shield structure can be adopted, such as dividing the shield structure into upper and lower sections or front and rear sections. The sections are connected by shield bolts 2-2, and water-stop strips are installed at the joints. In Figure f, the shield structure is divided into two sections along the circumferential direction, including an upper shield block 3-1 and a lower shield block 3-2, with the joints on both sides of the upper shield block 3-1 and the lower shield block 3-2 located at different horizontal heights. In Figure g, the shield structure is divided into three sections along the axial direction, including a front shield block 3-3 and a rear shield block 3-4. Preferably, as shown... Figure 6 As shown, the shield structure is divided into two sections along the circumferential direction, including the upper shield block 3-1 and the lower shield block 3-2, and the joints on both sides of the upper shield block 3-1 and the lower shield block 3-2 are at the same horizontal height.

[0061] like Figure 2As shown, the shield structure consists of a shield shell 1, which supports and protects the main drive system during tunneling and functions as a tunnel segment after tunneling is completed; an outer ring plate 1-7, which is fixedly connected to the inner steel shield shell; an inner partition plate 1-9, which isolates the soil and groundwater behind the cutterhead during construction to prevent ground collapse and debris from entering the shield and damaging the equipment; the outer ring plate 1-7 and the inner partition plate 1-9 are connected by partition bolts 1-8; and a cutterhead 2-1, whose size can be changed and which is transported out of the tunnel after tunneling is completed.

[0062] like Figure 3 As shown, the shield body diaphragm consists of an outer ring plate 1-7 and an inner diaphragm 1-9, which are connected by diaphragm bolts 1-8. The inner diaphragm has openings: a cutterhead hole 1-10 for connecting the cutterhead to the main drive, and a screw conveyor hole 1-11 for the screw conveyor to pass through. Alternative diaphragm options are attached. Figure 4 As shown, some designs include a single block, divided into two sections (top and bottom), three sections (left, center, and right), or six sections (top, bottom, left, center, and right), to accommodate different transport conditions. The partitions can be connected by bolts, with rubber waterstops installed at the joints, or by welding. For large-section tunneling machines, the shield sections can be vibrated separately, reducing the volume and mitigating the problem of insufficient concrete compaction.

[0063] A tunneling machine includes a shield structure as described in any of the above technical solutions, wherein the cutterhead hole 1-10 is used to connect the main drive of the cutterhead 2-1, and the screw conveyor hole 1-11 is used for the screw conveyor to pass through.

[0064] The reinforced concrete shield shell in the middle of the shield structure is durable enough to resist erosion from groundwater and stratum chemicals, extending the service life of the shield and tunnel. The concrete layer, through its rigidity and thickness, evenly distributes stratum pressure, preventing stratum collapse and protecting core components. It is welded to the inner steel shield shell with pins welded to the outer shell, forming a unified whole and enhancing the shield's integrity and deformation resistance. After tunneling is completed, it can be used directly as a permanent segment, achieving "dual-purpose use," reducing construction steps, shortening the construction period, lowering disposal costs, and significantly improving construction efficiency.

[0065] This utility model is applicable to subway construction in busy urban areas where there is insufficient ground space or where the cost of using ground space is too high to allow for new construction work. Based on the proposed project, the dimensions, thickness, and shape of the cross-section are determined. The shield shell is manufactured using prefabricated templates in a factory, and then installed and tested. After the shield is completed, the planned tunneling operation is carried out. Grouting reinforcement is performed in the area where the proposed tunnel is close to existing underground structures, extending the reinforcement range to 3 meters below the building foundation.

[0066] During construction, observe whether there is any groundwater seepage in the existing buildings. If groundwater seepage is found, drainage and dewatering treatment should be carried out in a timely manner, and the setting time of the grouting concrete should be adjusted. After the tunneling reaches the predetermined position, the side walls and retaining structures should be removed according to the diameter and position of the tunnel, with the dimensions slightly larger than the outer contour of the tunneling machine. After the tunneling machine reaches the predetermined position, the tunneling should be stopped, and then the following operations should be carried out.

[0067] like Figure 2 As shown, ① the screw conveyor, articulated cylinder, and cabinet pump station are dismantled; ② the hydraulic lock of the cutterhead is released, and the fan-shaped block is folded to a diameter smaller than the inner diameter of the tunnel; ③ the cutterhead, inner partition, and rear drive motor are retracted as a whole to the launching shaft and hoisted out. The above components are transported from the newly built tunnel using a winch and pulled to the launching shaft for removal; arc bolts are installed in the reserved holes in the shield shell, and steel plates are welded at the ends of the straight sections to anchor the reinforced ring beam concrete for pull-out resistance and fixation. Reinforced concrete reinforced ring beams are cast in place within the opening range of the side wall. The reinforced ring beams are fixed to the tunnel entrance by means of rebar installation, welding, and reserved rebar. Grouting steel pipes are pre-embedded in the reinforced ring beams; the gap between the reinforced ring beams and the shield shell is grouted through the pre-embedded grouting steel pipes to prevent groundwater seepage. The bolts are tightened to achieve the fixing effect between the shield body and the tunnel entrance.

[0068] Any aspects of this utility model that are not detailed herein are conventional technical means known to those skilled in the art.

[0069] The above content shows and describes the basic principles, main features, and beneficial effects of this utility model. The above description is merely a preferred embodiment of this utility model and is not intended to limit it. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A shield structure, characterized in that: It includes an inner metal shield and a reinforced concrete shield connected to the outside of the inner metal shield (1-1).

2. The shield structure according to claim 1, characterized in that: The reinforced concrete shield (1-1) is provided with an outer metal shield, the thickness of which is less than the thickness of the inner metal shield.

3. The shield structure according to claim 2, characterized in that: The reinforced concrete shield (1-1) includes circumferential stirrups (1-2), longitudinal reinforcing bars (1-4), and pins (1-3) cast in concrete. The end of the pins (1-3) is connected to the inner metal shield.

4. The shield structure according to any one of claims 1-3, characterized in that: The shield structure (1) is an integral structure, or the shield structure (1) includes several blocks that are detachably connected in the axial direction and / or several blocks that are detachably connected in the circumferential direction.

5. The shield structure according to claim 4, characterized in that: The shield structure (1) is provided with a connecting structure for connecting adjacent blocks or for connecting existing buildings in the tunnel. Water-stopping structures are provided at the joints between adjacent blocks and between blocks and existing buildings.

6. The shield structure according to any one of claims 1-3 and 5, characterized in that: The inner metal shield shell is fixedly connected to an outer ring plate (1-7), and the outer ring plate (1-7) is detachably connected to an inner partition plate (1-9) by a partition bolt (1-8). The inner partition plate (1-9) has a cutter head hole (1-10) and a screw machine hole (1-11).

7. The shield structure according to claim 6, characterized in that: The inner partition (1-9) is a single piece of board, or the inner partition (1-9) comprises several sub-boards that are spliced ​​together vertically and / or horizontally.

8. The shield structure according to claim 7, characterized in that: Water-stop structures are provided at the joints between the outer ring plate (1-7) and the inner partition plate (1-9), as well as at the joints between adjacent partition plates.

9. The shield structure according to any one of claims 1-3, 5, 7, and 8, characterized in that: The outer contour of the shield structure is circular, horseshoe-shaped, rectangular, or elliptical.

10. A tunneling machine, characterized in that: The shield structure includes any one of claims 1-9, wherein the inner metal shield shell is fixedly connected to an outer ring plate (1-7), and the outer ring plate (1-7) is detachably connected to an inner partition plate (1-9) by partition bolts (1-8). The inner partition plate (1-9) has a cutter head hole (1-10) and a screw conveyor hole (1-11). The cutter head hole (1-10) is connected to the main drive of the cutter head (2-1), and the screw conveyor hole (1-11) is used for the screw conveyor to pass through.

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