Supporting structure for expanding process of shield tunneling machine and construction method of supporting structure

Abstract

The invention relates to the technical field of tunnel construction, and discloses a supporting structure for the expanding process of a shield tunneling machine and a construction method thereof.The supporting structure comprises a limiting connecting piece and a plurality of closed segment units, and the multiple closed segment units are sequentially connected end to end in the circumferential direction to define a closed ring; the limiting connecting pieces are arranged between the two adjacent sealing segment units in a penetrating mode in the radial direction, the limiting connecting pieces are connected with the two adjacent sealing segment units in a clamped mode, and the sealing ring is arranged on the periphery of the shield body in a sleeving mode and located behind the cutter head in the axial direction. And the closed ring is provided with a supporting surface which is axially arranged away from the shield body and is used for abutting against a soil body. The variable-diameter shield supporting device can adapt to the variable-diameter shield construction process, supporting is timely, splicing can be achieved in a narrow space, mechanical stability is achieved, and meanwhile mounting is convenient and fast.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction, in particular to a supporting structure for the expansion process of a shield machine and a construction method thereof. BACKGROUND

[0002] In urban rail transit construction, in order to solve the problems of large occupation area, strong interference, long cycle and high risk of mine method in open cut construction of core area station, the variable diameter shield technology has become a key means to realize the construction of "station-tunnel integration". This technology uses the same shield machine to maintain small diameter tunneling in the interval tunnel, expands to large diameter tunneling at the station position, and then shrinks to continue the construction of the next interval, thereby directly completing the continuous construction of "tunnel-station" underground. This method does not need the traditional step-by-step disassembly operation, greatly improves the construction efficiency, and significantly reduces the interference to the ground environment.

[0003] However, the expansion process of the variable diameter shield machine usually needs to be carried out in stages in the order of "cutter head-shield body-shield tail", the cutter head needs to be expanded and excavated first, and then the shield body and the shield tail are expanded and excavated, which leads to the formation of a ring-shaped "soil free surface" between the cutter head after expansion and excavation and the shield body which has not followed up (see FIG. 1). Figure 1 Under the combined action of self-weight, overlying soil pressure and surrounding water and soil pressure, the soil free surface is prone to collapse, deformation or water leakage, which not only directly threatens the safety of construction and equipment, but also may cause deviation of the assembly precision of the subsequent shield body, seriously affecting the overall reliability of the station-tunnel integrated structure.

[0004] The existing tunnel supporting technology cannot adapt to this special variable diameter working condition. On the one hand, the traditional segment assembly needs to be carried out after the shield tail is pulled out, which cannot realize "immediate support" after the cutter head is expanded, resulting in long exposure time of the free surface; on the other hand, the space for soil bin operation behind the cutter head is extremely small, and it is impossible to implement cast-in-place lining or steel bar binding operation, and the bolt connection of the traditional segment depends on manual warehouse operation, which poses a high safety risk to personnel. Therefore, it is urgent to develop a soil supporting structure which can adapt to the variable diameter shield process, realize rapid mechanized assembly in a small space, and has stable mechanical properties, to provide safety protection for the construction of station-tunnel integration. SUMMARY

[0005] The purpose of the present application is to provide a supporting structure for the expansion process of a shield machine which can adapt to the variable diameter shield construction process, support in time, assemble in a small space, has stable mechanics and is easy to install, and a construction method thereof.

[0006] To achieve the above object, the application provides a supporting structure for a shield machine diameter expansion process, comprising: a limiting connector and a plurality of closed segment units, the plurality of closed segment units are sequentially connected end to end in a circumferential direction to define a closed ring, the limiting connector is radially arranged between two adjacent closed segment units, and the limiting connector is respectively connected with the two adjacent closed segment units, the closed ring is arranged on the outer periphery of a shield body of the shield machine and located at the rear of the cutter head in the axial direction of the shield machine, and the closed ring has a supporting surface arranged axially away from the shield body of the shield machine and abutting against the soil.

[0007] Further, a plurality of supporting segment units are sequentially connected end to end in a circumferential direction to define a supporting ring, two adjacent supporting segment units are connected, the supporting ring is arranged on the shield body, one end of the supporting ring in the axial direction is connected with the side of the closed ring axially away from the supporting surface, and the outer peripheral wall of the supporting ring is arranged to abut against the soil.

[0008] Further, the closed segment unit has a first side edge and a second side edge arranged opposite in the circumferential direction, the first side edge is provided with a first connecting groove extending in the axial direction and at least one-way through, and the second side edge is provided with a first sliding connecting part extending in the axial direction, the first connecting groove and the first sliding connecting part are slidingly connected to realize the limiting connection of two adjacent closed segment units.

[0009] Further, the closed segment unit has an inner side surface arranged radially towards the shield body, the first side edge and the second side edge are both provided with a second connecting groove extending in the radial direction, the second connecting groove is one-way through to the inner side surface, and the opposite sides of the limiting connector are respectively provided with a second sliding connecting part, the limiting connector is connected with the closed segment unit by the second sliding connecting part arranged in the second connecting groove from the inner side surface.

[0010] Further, an anchor rod is arranged, the closed segment unit is provided with an anchor rod hole extending in the axial direction, and / or the supporting segment unit is provided with an anchor rod hole extending in the radial direction; the anchor rod is arranged in the anchor rod hole and connected with the soil.

[0011] Further, the supporting segment unit has two connecting side surfaces arranged opposite in the circumferential direction, the connecting side surfaces are provided with a third connecting groove extending in the axial direction and one-way through, and the connecting side surfaces are further provided with a third sliding connecting part extending in the axial direction, the third sliding connecting part and the third connecting groove are arranged opposite in the axial direction, and two adjacent supporting segment units are connected by the third sliding connecting part and the third connecting groove.

[0012] Further, a fixing connecting piece is further included, the closed pipe piece unit is connected with a first fixing connecting hole on a side axially away from the supporting surface, the supporting pipe piece unit is connected with the fixing connecting piece on a side axially towards the closed ring, and the fixing connecting piece is arranged in the first fixing connecting hole to connect the supporting pipe piece unit and the closed pipe piece unit.

[0013] Further, a plurality of the supporting rings are included, the plurality of the supporting rings are connected in sequence along the axial direction, the closed pipe piece unit is provided with a second fixing connecting hole on a side axially away from the closed ring, and the fixing connecting piece and the second fixing connecting hole are connected between the two adjacent supporting rings.

[0014] Further, a limiting slot extending along the extending direction of the first clamping slot is arranged on the slot wall of the first clamping slot, a limiting part extending along the extending direction of the first sliding clamping part is protruded on the first sliding clamping part, and the limiting part is limitedly matched with the limiting slot.

[0015] The application further provides a construction method of a supporting structure for a diameter expansion process of a shield machine. S1, the cutter head is expanded in diameter: when the variable-diameter shield machine is excavated to a preset expansion point position, the cutter head is controlled to expand and excavate in a radial direction until the diameter of the cutter head reaches a designed expansion diameter; S2, an operation space is formed: after the cutter head is expanded in diameter, the shield machine is controlled to excavate forward by a preset distance, and an operation space is reserved between the cutter head and the shield body; S3, the closed ring is installed: the closed pipe piece unit is transported to the operation space, the closed pipe piece unit is installed by a mechanical hand on the shield machine, and after every two adjacent closed pipe piece units are assembled in place, a limiting connecting piece is inserted into a connecting position for fixation, and the installation of the whole closed ring is completed; S4, the closed ring is anchored and grouted: after the installation of the closed ring is completed, an anchor rod is punched into the surrounding rock along the axial direction through an anchor rod hole on the closed pipe piece unit, and grouting is performed; S5, the supporting ring is installed: the shield machine is controlled to excavate forward by a size of an axial direction of a supporting ring, the supporting pipe piece unit is transported to the operation space, and the supporting pipe piece unit is installed by the mechanical hand; S6, the supporting ring is anchored and grouted: after the installation of the supporting ring is completed, an anchor rod is punched into the surrounding rock along the radial direction through an anchor rod hole on the supporting pipe piece unit, and grouting is performed; S7, the construction is repeated: the shield machine is controlled to continue to excavate forward, and S5 and S6 are repeated until the construction of a subsequent supporting structure is completed.

[0016] Compared with the prior art, the supporting structure for the diameter expansion process of the shield machine and the construction method thereof have the following beneficial effects: The supporting structure for the expansion process of the shield machine and the construction method thereof provided by the embodiment of the present application can timely fill the soil free face formed after the expansion of the variable-diameter shield machine, provide effective support for the surrounding rock, and prevent collapse and instability, by arranging a closed ring formed by connecting the closed segment units in sequence at the rear of the cutter head; wherein, the block type segment unit has small size and light weight, is suitable for the narrow operation space behind the cutter head and meets the small mechanical grabbing demand; in particular, the connecting mode of arranging the limiting connecting piece along the radial direction and connecting with the segment unit, discards the complex bolt connection, so that the automatic and rapid locking and assembling can be realized by the machine without manual warehouse entry, so that the "supporting while digging" in the expansion process is realized, the overall stress stability of the structure is ensured, and the construction risk is significantly reduced and the operation efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of a soil free face generated by a variable-diameter shield machine; Figure 2 is a schematic diagram of the supporting structure for the expansion process of the shield machine according to the embodiment of the present application; Figure 3 is a structural schematic diagram of the closed segment unit in the embodiment of the present application; Figure 4 is a connection schematic diagram of the first clamping groove and the first sliding clamping part in the adjacent closed segment units in the embodiment of the present application; Figure 5 is a plane schematic diagram of the inner side of the closed segment unit in the embodiment of the present application; Figure 6 is an installation schematic diagram of the closed segment unit in the embodiment of the present application; Figure 7 is a structural schematic diagram of the closed ring in the embodiment of the present application; Figure 8 is an axonometric view of the closed segment unit in the embodiment of the present application; Figure 9 is a structural schematic diagram of the supporting segment unit in the embodiment of the present application; Figure 10 is an installation schematic diagram of the supporting segment unit in the embodiment of the present application; Figure 11 is a connection schematic diagram of the fixed connecting piece and the second fixed connecting hole in the embodiment of the present application; Figure 12 is a structural schematic diagram of the third clamping groove and the third sliding clamping part on the connecting side surface in the supporting segment unit in the embodiment of the present application; Figure 13 is a structural schematic diagram of the supporting ring in the embodiment of the present application; Figure 14 is an axonometric view of the supporting segment unit in the embodiment of the present application.

[0018] In the figure, 10, soil body free surface; 11, cutter head; 12, shield body; 13, surrounding rock; 2, closed ring; 20, supporting surface; 3, closed segment unit; 31, first side edge; 32, second side edge; 33, first clamping groove; 331, limiting groove; 34, first sliding clamping part; 341, limiting part; 35, inner side surface; 36, second clamping groove; 37, first fixed connecting hole; 4, limiting connecting piece; 41, second sliding clamping part; 5, support ring; 6, support segment unit; 61, connecting side surface; 62, third clamping groove; 63, third sliding clamping part; 64, second fixed connecting hole; 7, anchor rod; 70, anchor rod hole; 8, fixed connecting piece; x, axial direction. DETAILED DESCRIPTION

[0019] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0020] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like in the present application are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0021] In the description of the present application, it should be understood that the terms "connected", "connected", "fixed" and the like in the present application should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or welding connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specified. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0022] The terms "first", "second", and the like are used to describe various information, but the information should not be limited to these terms, and the terms are only used to distinguish the same type of information from each other. For example, the "first" information can also be referred to as "second" information without departing from the scope of the present application, and similarly, the "second" information can also be referred to as "first" information.

[0023] The shield machine in the embodiment of the present application comprises a cutter head 11 and a shield body 12, the cutter head 11 is arranged at the front end of the shield body 12 in the axial direction x, and the cutter head 11 can expand its outer diameter in the radial direction, and the outer diameter of the cutter head 11 is greater than the outer diameter of the shield body 12 during the expansion process.

[0024] Referring to Figure 2 and Figure 3 , the supporting structure for the expansion process of the shield machine in the embodiment of the present application comprises a limiting connecting piece 4 and a plurality of closed segment units 3, the plurality of closed segment units 3 are sequentially connected in a head-to-tail manner in the circumferential direction to define a closed ring 2, the limiting connecting piece 4 is arranged in the radial direction between two adjacent closed segment units 3, and the limiting connecting piece 4 is respectively clamped with the two adjacent closed segment units 3, the closed ring 2 is sleeved on the outer periphery of the shield body 12 and located at the rear of the cutter head 11 in the axial direction x, and the closed ring 2 has a supporting surface 20 arranged away from the shield body 12 in the axial direction x and used for abutting against the soil body.

[0025] In the embodiment, the plurality of closed segment units 3 are prefabricated fan-shaped components, and the material is preferably high-strength steel structure or ductile cast iron to meet the requirements of "small volume, light weight" and convenient mechanical grabbing. The plurality of closed segment units 3 are sequentially connected in a head-to-tail manner in the circumferential direction to define a complete circular ring structure, i.e. the closed ring 2. The closed ring 2 is sleeved on the outer periphery of the shield body 12 and located at the rear of the cutter head 11 in the axial direction x. Specifically, after the cutter head 11 completes the expansion and advances a distance, the closed ring 2 is assembled in the space left by the cutter head 11 and the outer periphery of the shield body 12. The closed ring 2 has a supporting surface 20 arranged away from the shield body 12 in the axial direction x and used for abutting against the soil body. The supporting surface 20 directly faces the exposed surrounding rock 13 step surface after the expansion or serves as the starting bearing surface of the subsequent supporting structure, and plays a role of closing the soil body and preventing longitudinal collapse.

[0026] In order to realize rapid and unmanned connection in a small space, the two adjacent closed segment units 3 are fixed by the limiting connecting piece 4. Specifically, the limiting connecting piece 4 is radially arranged between the two adjacent closed segment units 3. That is, during the assembly process, the manipulator does not need to perform complex circumferential movement or axial x screwing of the bolt, but only needs to insert the limiting connecting piece 4 radially from the center to the outside or from the outside to the center, preferably from the shield 12 to the outside in the radial direction, into the joint of the adjacent segment units.

[0027] In the variable-diameter shield construction, the light-weight closed segment unit 3 is transported to the rear of the cutter head 11 by the manipulator of the shield machine or an additional manipulator. The manipulator first positions the assembled segment unit, and then inserts the limiting connecting piece 4 radially into the joint. Due to the radial clamping mode, the assembly action is simple and the path is short, avoiding manual bolt insertion operation in a narrow and muddy soil chamber, greatly improving the assembly efficiency and safety. The completed closed ring 2 quickly supports the soil body free surface 10 after the diameter expansion, ensuring the safety of subsequent construction.

[0028] Referring to Figure 9 and Figure 14 In some improved schemes of the present application, a plurality of supporting segment units 6 are further included, the plurality of supporting segment units 6 are sequentially connected in a circumferential direction to define a supporting ring 5, the two adjacent supporting segment units 6 are clamped, the supporting ring 5 is sleeved on the shield 12, and the supporting ring 5 is located between the cutter head 11 and the closed ring 2. One end of the supporting ring 5 in the axial direction x is connected to the side of the closed ring 2 in the axial direction x away from the support surface 20, and the outer peripheral wall of the supporting ring 5 is used to abut against the soil body. When the cutter head 11 of the variable-diameter shield machine completes the preliminary expansion and installs the first closed ring 2, as the shield machine continues to excavate forward, the distance between the cutter head 11 and the fixed closed ring 2 is enlarged, forming a new working space. The supporting ring 5 is installed in the space between the cutter head 11 and the closed ring 2. One end (usually the rear end) of the supporting ring 5 in the axial direction x is connected to the side of the closed ring 2 in the axial direction x away from the support surface 20 (i.e. the front end surface of the closed ring 2). This connection can be achieved by a reserved bolt, a fixed connecting piece 8 or a concave-convex matching structure. Through this connection, the supporting ring 5 is anchored on the closed ring 2, preventing it from moving forward with the shield machine or tilting. After installation, the outer peripheral wall of the supporting ring 5 directly contacts the expanded soil body. According to the geological conditions, grouting can be performed behind the supporting ring 5 to make the supporting ring 5 closely fit the surrounding rock 13, and jointly bear the ground pressure.

[0029] When the installation of the closed ring 2 is completed, the shield machine advances by a width of a support ring 5. At this time, the manipulator grabs the support segment unit 6 and assembles it in sequence in front of the closed ring 2. Each time a segment is assembled, it is clamped with the adjacent support segment unit 6 and fixed with the rear closed ring 2 or the complete support ring 5 that has been assembled. In this way, as the shield machine continuously advances, the support rings 5 are installed one after another until the entire tunnel support of the enlarged section is completed.

[0030] With reference to Figure 8 In some improved schemes of the present application, the closed segment unit 3 has a first side edge 31 and a second side edge 32 oppositely arranged in the circumferential direction, the first side edge 31 is provided with a first clamping groove 33 extending in the axial direction x and at least one-way through, and the second side edge 32 is provided with a first sliding clamping part 34 extending in the axial direction x, and the first clamping groove 33 and the first sliding clamping part 34 are in sliding connection to realize the limiting connection of the adjacent two closed segment units 3.

[0031] The cooperation of the first clamping groove 33 and the first sliding clamping part 34 provides a natural guide for the assembly of the closed segment unit 3. In the narrow and poor visibility environment behind the cutterhead 11, the manipulator only needs to align the first sliding clamping part 34 of the closed segment unit 3 with the first clamping groove 33 of the previous closed segment unit 3 and slide it into the groove, and the subsequent installation process can be automatically aligned in the circumferential direction. This self-guiding function significantly reduces the stringent requirements for the control accuracy of the manipulator and reduces the assembly adjustment time. Once the first sliding clamping part 34 is slid into the first clamping groove 33, the relative displacement of the adjacent two closed segment units 3 in the radial direction (perpendicular to the ring surface direction) and the circumferential direction (ring tangential direction) is limited, leaving only the axial x degree of freedom. The segments will not be radially misaligned or fall off during assembly, providing a stable geometric state for the subsequent insertion of the radial limiting connector 4 for final locking, ensuring the safety of the construction process.

[0032] The closed segment unit 3 structure of the above embodiment is the standard closed segment of the present application, and the present application can also have other closed segment units 3 with different structures, such as the first installed closed segment unit 3, referred to as C block; the last installed closed segment unit, referred to as F block, and the left and right adjacent closed segment units 3 of the F block, referred to as L1 block and L2 block respectively. Among them, the first side edge 31 and the second side edge 32 of the C block are provided with the clamping groove, and the first sliding clamping part is not provided.

[0033] With reference to Figure 5In some improved schemes of the present application, the closed pipe piece unit 3 has an inner side 35 arranged radially towards the shield body 12, the first side edge 31 and the second side edge 32 are both provided with a radially extending second clamping groove 36, the second clamping groove 36 is unidirectionally penetrated to the inner side 35, and the opposite sides of the limiting connecting piece 4 are respectively provided with a second sliding clamping part 41, and the limiting connecting piece 4 is clamped with the closed pipe piece unit 3 by penetrating the second sliding clamping part 41 from the inner side 35 to the second clamping groove 36.

[0034] Specifically, two adjacent closed pipe piece units 3 are provided with half-opened second clamping grooves 36 at the butted side edges, i.e. the first side edge 31 and the second side edge 32, and when the two closed pipe piece units 3 are butted, the two adjacent second clamping grooves 36 are combined at the joint to form a complete accommodating groove which is opened towards the inner side 35; and the opposite sides of the limiting connecting piece 4 are respectively provided with second sliding clamping parts 41. For example, the second clamping groove 36 is a T-shaped groove, and then the limiting connecting piece 4 can be in the shape of H or dumbbell, and the size is designed so that the limiting connecting piece 4 can be slid into the groove from the opening of the inner side 35, but cannot be pulled out in the axial direction x, thereby realizing the fixing and locking of the two adjacent closed pipe piece units 3 in the axial direction x. Through the simple radial pushing action, the traditional multi-bolt fastening action is replaced, and the quick and high-strength connection is realized.

[0035] In some improved schemes of the present application, an anchor rod 7 is further included, the closed pipe piece unit 3 is provided with an anchor rod hole 70 which is penetrated in the axial direction x, and / or the supporting pipe piece unit 6 is provided with an anchor rod hole 70 which is penetrated in the radial direction, and the anchor rod 7 is penetrated to the anchor rod hole 70 to be connected with the soil body. By arranging the anchor rod 7, the prefabricated closed pipe piece unit 3 or supporting pipe piece unit 6 structure is tightly connected with the surrounding deep stable rock-soil body. The anchoring force of the anchor rod 7 can firmly nail the pipe piece unit on the surrounding rock 13, so that the supporting structure is no longer loosely placed on the expanded excavation surface, but forms a composite ring protection structure which is jointly stressed with the surrounding rock 13, thereby significantly improving the ability of the supporting system to resist the deformation, collapse and vibration of the surrounding rock 13.

[0036] With reference to Figure 12 In some improved schemes of the present application, the supporting pipe piece unit 6 has two connecting sides 61 which are oppositely arranged in the circumferential direction, the connecting side 61 is provided with a third clamping groove 62 which is extended in the axial direction x and unidirectionally penetrated, and the connecting side 61 is further provided with a third sliding clamping part 63 which is extended in the axial direction x, the third sliding clamping part 63 is oppositely arranged with the third clamping groove 62 in the axial direction x, and the two adjacent supporting pipe piece units 6 are clamped by the third sliding clamping part 63 and the third clamping groove 62.

[0037] The cooperation of the third clamping groove 62 and the third sliding clamping part 63 forms a set of high-precision guide rails. During sliding, the structure forces the adjacent two support pipe piece units 6 to be flush in the radial direction, effectively preventing the misalignment phenomenon caused by the self-weight or assembly error. This not only ensures the roundness of the outer surface of the support ring 5, so that it can uniformly support the soil, but also provides a flat inner wall for the equipment passing through the internal space. When the third sliding clamping part 63 enters the third clamping groove 62, the freedom of the adjacent support pipe piece units 6 in the circumferential direction is limited. This geometric interlocking structure can directly bear the circumferential tension or shear force caused by the pressure from the surrounding rock 13, preventing the support ring 5 from collapsing under the action of soil pressure.

[0038] Referring to Figure 11 In some improved schemes of the present application, a fixing connector 8 is further included, the closed pipe piece unit 3 is connected with a first fixing connector hole 37 on the side away from the support surface 20 in the axial direction x, the support pipe piece unit 6 is connected with the fixing connector 8 on the side facing the closed ring 2 in the axial direction x, and the fixing connector 8 is arranged in the first fixing connector hole 37 to connect the support pipe piece unit 6 and the closed pipe piece unit 3. Through the cooperation of the fixing connector 8 and the first fixing connector hole 37, the newly assembled support ring 5 is firmly anchored on the already stably installed closed ring 2. When the manipulator grabs the support pipe piece unit 6 for installation, the process of inserting the fixing connector 8 into the first fixing connector hole 37 completes the centering and alignment of the pipe piece.

[0039] In some improved schemes of the present application, a plurality of support rings 5 are included, and the plurality of support rings 5 are connected in sequence along the axial direction x. The closed pipe piece unit 3 is provided with a second fixing connector hole 64 on the side away from the closed ring 2 in the axial direction x, and the fixing connector 8 and the second fixing connector hole 64 are arranged between the adjacent two support rings 5. Through the arrangement of the fixing connector 8 and the fixing connector hole on the support pipe piece unit 6, the support rings 5 on the support structure can be continuously extended one by one as the variable-diameter shield tunneling machine continuously advances forward, solving the support problem when the length of the expansion section is not fixed and realizing full coverage and closure of the entire expansion excavation section.

[0040] Specifically, the outer peripheral wall of the fixing connector 8 is provided with a first stepped structure with a stepped surface facing inwards, the first fixing connector hole 37 is provided with a second stepped structure with a stepped surface facing outwards matched with the first stepped structure, and the fixing connector 8 and the fixing connector hole are made of toughened modified polyamide material and have a certain elasticity. After the fixing connector 8 is inserted into the hole wall of the fixing connector hole, the first stepped structure and the second stepped structure are engaged to form self-locking, so that the fixing connector 8 and the fixing connector hole are fixedly connected.

[0041] Referring to Figure 4In some improved schemes of the present application, the slot wall of the first clamping slot 33 is provided with a limiting slot 331 extending along the extension direction of the first clamping slot 33, and the first sliding clamping part 34 is provided with a limiting part 341 extending along the extension direction of the first sliding clamping part 34, and the limiting part 341 is in limiting cooperation with the limiting slot 331. After the first sliding clamping part 34 is slid into the first clamping slot 33, the mechanical interlocking is formed between the limiting part 341 and the limiting slot 331, so that the adjacent two closed pipe piece units 3 can be limited to separate in the radial direction and the circumferential direction before the final limiting connecting piece 4 is inserted. Even after the mechanical hand is released, or before the limiting connecting piece 4 is inserted, the two closed pipe piece units 3 will not fall inward or collapse outward due to the dead weight or local earth pressure, which greatly improves the construction safety. The composite cross-section design further increases the contact area, which helps to disperse stress and improve the service life of the joint. The specific structures and cooperation modes of the other sliding clamping parts and clamping slots in the present application can be referred to the first sliding clamping part 34 and the first clamping slot 33.

[0042] The present application also provides an embodiment of a construction method of a supporting structure for a shield expansion process, comprising the following steps: S1: Expanding the cutter head 11: When the variable-diameter shield machine excavates to a preset expansion point position, the cutter head 11 is controlled to expand radially and break rock to excavate until the outer diameter of the cutter head 11 reaches the designed expansion diameter. At this time, the diameter of the cutter head 11 is larger than the diameter of the shield body 12.

[0043] S2: Forming a working space: After the cutter head 11 is expanded, the shield machine is controlled to excavate forward by a preset distance. In this embodiment, the preset distance is equal to the width of the shield machine cutout ring. The cutout ring refers to a section of shield shell structure located behind the cutter head 11 and at the front end of the shield body 12, which is a removable shield shell section specially designed for the shield machine without affecting the normal operation of the shield machine. When the shield machine excavates to the position, the cutout ring shield shell is removed or cut off by a mechanical method. After the cutout ring is cut off, an annular working space is exposed and formed between the expanded cutter head 11 and the remaining shield body 12, providing a place for subsequent pipe piece assembly.

[0044] S3: Installing the closed ring 2: Referring to Figure 6 and Figure 7The closed segment unit 3 is transported to the working space, and the robotic arm on the tunnel boring machine (TBM) grabs and installs the closed segment unit 3 piece by piece with the help of hydraulic cylinders. The specific assembly sequence is as follows: First, install the first closed segment unit 3 at the bottom as block C. After block C is in place, immediately perform bottom grouting to ensure that the bottom of block C is densely filled with soil, providing a stable base for the entire ring; then, with block C as the center, alternately assemble the standard blocks on the left and right sides of block C. That is, assemble them alternately upwards in the order of left block and right block. Whenever an adjacent closed segment unit 3 is assembled, a limiting connector 4 is inserted radially at the joint of the two segments, i.e., the aforementioned second locking groove 36, using a robotic arm or auxiliary device. In this embodiment, the limiting connector 4 is specifically made of H-beam. After the H-beam is inserted, it firmly locks the two adjacent closed segment units 3. Repeat the above process until the top sealing installation of the entire closed ring 2 is completed.

[0045] S4 Closed Ring 2 Anchoring Grouting: After the closed ring 2 is installed and locked, the tunnel boring machine drives anchor bolts 7 into the surrounding rock 13 formed by the excavation step surface through the axial x-anchor bolt holes 70 reserved on each closed segment unit 3. Grouting is then carried out, and the grout fills the pores and wraps the anchor bolts 7, firmly anchoring the closed ring 2 to the original soil and preventing axial x-displacement.

[0046] S5 Installation Support Ring 5: Refer to Figure 10 and Figure 13 After the completion of the closed ring 2, continuous support construction begins. The tunnel boring machine is controlled to advance one stroke, which is equal to the axial x dimension of one support ring 5. The support segment unit 6 is transported to the working space and picked up by a robotic arm.

[0047] The specific assembly sequence is as follows: First, install the first support segment unit 6 located at the bottom, and connect it to the corresponding closed segment unit 3 using the fixing connector 8. After installation, perform bottom grouting to ensure the bottom is filled densely. Subsequently, alternately use a robotic arm and hydraulic cylinders to assemble the standard blocks on the left and right sides of the support segment unit 6. During the assembly process, the third sliding locking part 63 on the side and the third locking groove 62 are used to achieve interlocking within the ring, and at the same time, axial x-connection is made with the corresponding closed segment unit 3 behind. Repeat the above steps until the installation of a complete support ring 5 is completed.

[0048] S6 Support Ring 5 Anchoring Grouting: After the support ring 5 is installed, anchor rods 7 are driven radially into the surrounding rock 13 through the pre-reserved radial anchor bolt holes 70 on the support segment unit 6, and grouting is performed. S7: continue the construction of the shield machine, repeat S5 and S6 until the construction of the subsequent supporting structure is completed. The shield machine continues to excavate for a ring distance, and steps S5 and S6 are repeated. That is, after each ring is excavated, the bottom closed management piece unit, grouting, both sides of the standard block, the radial anchor rod 7, and grouting are sequentially installed. This cycle is repeated until the shield machine completes the expansion process section.

[0049] In the specific embodiments of the present application, the engineering parameters are as follows: The original outer diameter of the variable-diameter tunnel is 8.5 m, and the outer diameter after variable-diameter is 11.6 m; the outer diameter of the shield body 12 of the shield machine before expansion is 8.8 m, and the outer diameter after variable-diameter is 11.9 m, and the cutout ring width behind the cutter head 11 is 1 m; the cutter head 11 expands the diameter to 12.4 m.

[0050] The supporting structure parameters are as follows: The outer diameter of the closed ring 2 is 12.4 m, the inner diameter is 8.9 m, and the thickness is 0.4 m; it is divided into 25 blocks in the ring direction, including the first block C at the bottom, 10 standard blocks B2 on the left side of C, and 11 standard blocks B1 on the right side of C; there is one sealing block F and its left and right adjacent blocks L1 and L2.

[0051] The supporting steel ring has an outer diameter of 12.4 m, an inner diameter of 12.0 m, a ring width of 0.625 m, and a thickness of 0.2 m. The block division method is the same as that of the closed ring 2. The assembly implementation method is the same as the above embodiment.

[0052] In summary, the embodiment of the present application provides a supporting structure for the expansion process of a shield machine and a construction method thereof, which has the following advantages: 1) Solving the problem of supporting the free surface, ensuring construction safety: The present application sets the closed ring 2 and the supporting ring 5 extending with the excavation between the cutter head 11 and the shield body 12, which realizes the immediate closure and support of the free surface 10 of the variable-diameter expansion, effectively prevents the collapse, block falling and instability deformation of the surrounding rock 13, and fills the gap of the lack of effective supporting means in the variable-diameter transition section in the prior art.

[0053] 2) Adapt to narrow space and realize unmanned rapid assembly: The supporting member adopts lightweight block design, which perfectly adapts to the narrow and complex working space behind the cutter head 11; the connecting method of limiting connecting piece 4 along the radial direction is innovatively used to connect and interlock the pipe pieces in the axial direction x, which discards the traditional bolt connection, and the mechanical hand can realize automatic and efficient grabbing and locking without manual operation, which significantly reduces the risk of personnel operation.

[0054] 3) Strong structural integrity, good synergistic stress effect: the radial clamping structure gives strong constraint force in the ring direction, preventing the separation of the pipe piece unit; combined with the axial x and radial anchor rod 7 grouting process, the closed ring 2 is anchored to the expanded diameter step, and the supporting ring 5 is rooted in the stable rock stratum, and a pipe piece-surrounding rock 13 integrated bearing system is constructed, which effectively controls the stratum deformation.

[0055] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled persons in the art, without departing from the technical principles of the present application, several improvements and replacements can be made, and these improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. A support structure for a shield machine reaming process, characterized in that, The application relates to a shield tunneling machine, which comprises a shield body and a cutter head. The shield tunneling machine further comprises a plurality of closed pipe units and a plurality of supporting pipe units.

2. The support structure for a shield machine reaming process of claim 1, wherein, The closed pipe units are provided with a first side edge and a second side edge arranged oppositely in the circumferential direction.

3. The support structure for a shield machine reaming process of claim 1, wherein, The first side edge is provided with a first clamping groove extending in the axial direction and penetrating in at least one direction.

4. The support structure for a shield machine reaming process of claim 3, wherein, The second side edge is provided with a first sliding clamping part extending in the axial direction.

5. The support structure for a shield machine reaming process of claim 2, wherein, The closed pipe units are provided with an inner side surface arranged towards the shield body in the radial direction.

6. The support structure for a shield machine reaming process of claim 2, wherein, The first side edge and the second side edge are both provided with a second clamping groove extending in the radial direction.

7. The support structure for a shield machine reaming process of claim 2, wherein, The second clamping groove penetrates to the inner side surface in one direction.

8. The support structure for a shield machine reaming process of claim 7, wherein, The limiting connecting piece is provided with a second sliding clamping part on opposite sides. The closed pipe units are provided with an anchor rod hole penetrating in the axial direction and / or the supporting pipe units are provided with an anchor rod hole penetrating in the radial direction. The anchor rod is connected with the soil through the anchor rod hole. The supporting pipe units are provided with two connecting side edges arranged oppositely in the circumferential direction. The connecting side edges are provided with a third clamping groove extending in the axial direction and penetrating in one direction. The connecting side edges are further provided with a third sliding clamping part extending in the axial direction. The third sliding clamping part is arranged oppositely to the third clamping groove in the axial direction. The supporting pipe units are connected through the third sliding clamping part and the third clamping groove. The closed pipe units are provided with a first fixing connecting hole on the side away from the support surface in the axial direction. The supporting pipe units are provided with the fixing connecting piece on the side towards the closed pipe units in the axial direction. The fixing connecting piece is arranged in the first fixing connecting hole to connect the supporting pipe units and the closed pipe units. The closed pipe units are provided with a second fixing connecting hole on the side away from the closed pipe units in the axial direction. The fixing connecting piece and the second fixing connecting hole are arranged between the adjacent supporting pipe units.

9. The support structure for a shield machine reaming process of claim 3, wherein, The slot wall of the first clamping slot is provided with a limiting slot extending along the extension direction of the first clamping slot, and the first sliding clamping part is provided with a limiting part extending along the extension direction of the first sliding clamping part, and the limiting part is limited and matched with the limiting slot.

10. A method for constructing a support structure for a shield machine diameter expansion process, for a support structure according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: S1: Expanding the diameter of the cutter head: when the variable-diameter shield tunneling machine reaches the preset expanding point, the cutter head is controlled to expand radially to break the rock until the diameter of the cutter head reaches the designed expanding diameter; S2: Forming a working space: after the cutter head expanding is completed, the shield tunneling machine is controlled to tunnel forward by a preset distance, and a working space is reserved between the cutter head and the shield body; S3: Installing the closed ring: the closed segment units are transported to the working space, the mechanical arm on the shield tunneling machine is used to grab and install the closed segment units one by one, after every two adjacent closed segment units are assembled in place, a limiting connecting piece is inserted into the connecting position for fixation, and the installation of the whole closed ring is completed; S4: Anchoring and grouting of the closed ring: after the installation of the closed ring is completed, the anchor rods are punched into the surrounding rock along the axial direction through the anchor rod holes on the closed segment units, and grouting is performed; S5: Installing the support ring: the shield tunneling machine is controlled to tunnel forward by a distance along the axial direction of the support ring, the support segment units are transported to the working space, and the mechanical arm is used to grab and install the support segment units one by one; S6: Anchoring and grouting of the support ring: after the installation of the support ring is completed, the anchor rods are punched into the surrounding rock along the radial direction through the anchor rod holes on the support segment units, and grouting is performed; S7: Circulating construction: the shield tunneling machine is controlled to continue tunneling forward, and S5 and S6 are repeated until the construction of the subsequent support structure is completed.

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