Shield tunnel expandable adjustable segment structure and construction method thereof

Abstract

The application belongs to the technical field of shield tunnel engineering, and specifically discloses a shield tunnel expandable adjustable segment structure and a construction method thereof. The segment structure comprises a plurality of annular segments, an adjusting piece, a sealing piece and a connecting piece. The annular segments are spliced by a plurality of ring segments, one of which is provided with a cavity. The adjusting piece is composed of an adjusting segment sliding in the cavity and a driving piece, and can realize radial adjustment of the diameter of the segment. The sealing piece is divided into inter-ring sealing and inter-ring segment sealing, and can adapt to the change of the diameter of the segment to maintain the sealing effect. The connecting piece realizes the annular fastening between the ring segments and the axial connection between the annular segments. The application replaces the traditional passive grouting with the active expansion of the segment, effectively reduces the grouting cost, avoids the loss and uneven filling of the slurry, improves the adhesion of the segment to the stratum and the structural stress safety, and is reliable in sealing and controllable in construction, and is suitable for various shield tunnel lining engineering.

Description

Technical Field

[0001] This invention belongs to the field of shield tunnel engineering technology, and specifically relates to a shield tunnel expandable adjustable segment structure and its construction method. Background Technology

[0002] In existing shield tunneling technology, the core construction process can be summarized as: "shield machine excavation—segment assembly—shield tail disengagement—synchronous grouting." During this process, to ensure that the shield machine does not interfere with the assembled segments during excavation, the diameter of its main casing must be designed to be larger than the outer diameter of the segments, thus forming a ring-shaped "shield tail gap" between the segment's outer wall and the soil. Therefore, synchronous grouting is necessary to fill the voids between the segments and the ground, thereby stabilizing the segments and controlling ground settlement. Synchronous grouting is currently the core method for filling the shield tail gap, but it inherently has significant uncertainties, and its limitations are becoming increasingly apparent, presenting three major problems: First, the economic cost is high. Filling the ring-shaped gap requires a large amount of grout, directly increasing the costs of raw materials, mixing, transportation, and equipment energy consumption, accounting for a significant proportion of the total project cost. Second, the grouting effect is difficult to predict. The diffusion pattern of the grout in the ground is complex, influenced by factors such as ground permeability and grouting pressure, easily leading to uneven filling, voids, and potential leakage and stress concentration hazards. Third, grout leakage is prone to occur. Grout in water-rich or fractured strata is easily wasted and changes hydrological conditions. Excessive pressure can also disturb the soil or affect surrounding buildings and structures, making it difficult to ensure the consistency of project quality.

[0003] After traditional tunnel lining segments are assembled, their geometry and spatial position are fixed, making them a static, passively pressure-bearing structure. At the moment the shield tail brush disengages from the segment, the surrounding soil undergoes a brief stress release and loosening process due to the sudden release of the shield's outer shell constraints. This is the golden window for establishing an ideal soil-structure interaction relationship. However, traditional tunnel lining segments are powerless in this regard, passively waiting for the flowing grout to fill this loosened space. The resulting support reaction force is indirect and delayed. This passive waiting means that the initial contact state between the segment and the stratum is entirely determined by the grouting effect. If the grouting is not dense, a "virtual contact" will exist between the segment and the stratum for a long time, leading to uneven soil pressure distribution, a significant deviation between the actual stress state of the segment and the design model, and easily causing problems such as localized damage and excessive joint opening. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a shield tunnel expandable adjustable segment structure and its construction method.

[0005] The technical solution of the present invention is: a shield tunnel expandable adjustable segment structure, comprising multiple annular pipes, adjusting components, sealing components, and connecting components.

[0006] Multiple ring-shaped pipes are distributed sequentially along the length of the tunnel. Each ring-shaped pipe consists of multiple sequentially spliced ​​ring pieces forming a tubular structure, with one of the ring pieces having a cavity inside.

[0007] The adjusting component includes an adjusting plate and a driving component. The adjusting plate is slidably disposed in the cavity and forms a telescopic structure with the ring plate. The driving component is connected to the adjusting plate and is used to drive the adjusting plate to slide in the cavity to adjust the diameter of the tubular structure.

[0008] The sealing element includes a first sealing element and a second sealing element. The first sealing element is disposed between two adjacent ring plates in each annular tube section. It adapts to the change in the gap between the two adjacent ring plates by its own deformation. The change in the gap between the two adjacent ring plates is caused by the change in the diameter of the tubular structure. The second sealing element is disposed between the ring plates corresponding to the positions of two adjacent annular tube sections.

[0009] The connector includes a first connector and a second connector. The first connector is fixedly connected to two adjacent ring plates of each annular tube section. The second connector is fixedly connected to two ring plates corresponding to the positions of two adjacent annular tube sections.

[0010] Furthermore, the driving component is a hydraulic telescopic component, which is fixed inside the cavity, and its telescopic end is connected to the adjusting plate.

[0011] Furthermore, the annular piece with the cavity is also provided with a guide member, which includes a guide rail and a slider. The guide rail is fixed on the annular piece and located on the side wall of the cavity; the slider is disposed on the side wall of the adjusting piece and is slidably disposed on the guide rail.

[0012] Furthermore, the adjusting plate is also provided with a spring pin, and the guide rail is provided with a slot corresponding to the spring pin. When the adjusting plate slides on the guide rail with the slider until the spring pin corresponds to the slot, the spring pin is inserted into the slot to limit the position of the adjusting plate.

[0013] Furthermore, the ring plate with the cavity is also provided with a constraint member, which is a constraint band, one end of which is fixed to the ring plate and the other end of which is fixed to the adjusting plate. The constraint band is used to constrain the sliding distance of the adjusting plate.

[0014] Furthermore, the first sealing element is a rubber strip fixed between two adjacent ring plates in each annular tube section.

[0015] Furthermore, the second seal is an expansion sealing ring, and the side wall of the ring has a placement cavity, in which the second seal is placed.

[0016] Furthermore, the first connector uses an arc bolt, and the connection between two adjacent ring plates of the same annular tube has a first screw hole corresponding to the arc bolt.

[0017] Furthermore, the second connector uses a straight bolt, and each of the two ring plates corresponding to the positions of two adjacent annular tube sections has a second threaded hole corresponding to the straight bolt.

[0018] A construction method for an expandable and adjustable segment structure for a shield tunnel, comprising the following steps: Inside the shield tail, ring plates are assembled into an annular tube. During assembly, the first sealing element is naturally compressed as the tube plates are squeezed, forming a preliminary seal. During the removal of the shield tail, the second sealing element is installed onto the end face of the ring plate of the previous annular tube that is already in place.

[0019] After the tube segment detaches from the shield tail, the driving component drives the adjusting plate to slide out of the cavity, completing the radial expansion; the first connecting component fixes two adjacent ring segments of each annular tube, and the second connecting component fixes two ring segments corresponding to the positions of two adjacent annular tube segments.

[0020] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention utilizes the coordinated work of multiple annular pipe sections, adjusting components, sealing components, and connecting components. It relies on a radially adjustable main body composed of a cavity-filled annular plate and a sliding, telescopic adjusting plate, and works in conjunction with a driving component to achieve active pipe diameter expansion. This allows for direct compaction of the surrounding strata after the shield tail exits, significantly reducing the need for synchronous grouting and solving the defects of traditional grouting processes, such as high cost, uneven filling, and grout leakage. The use of deformable sealing components that adapt to changes in gaps ensures continuous sealing of circumferential and axial joints during pipe diameter changes, preventing leakage risks. The connecting components rigidly fix the annular plate and the annular pipe, enabling the expanded pipe segments to form a stable integral lining. This transforms the pipe segments from passive pressure bearing to active support, eliminating the virtual contact between the pipe segments and the strata, improving uneven soil pressure distribution, and enhancing structural stress safety and long-term tunnel stability. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the structure of the present invention; Figure 2 This is a diagram showing the structural changes of the adjusting plate before and after the present invention is extended and retracted; Figure 3 This is a schematic diagram of the external structure of the present invention; Figure 4 This is a schematic diagram of the structure of the annular piece with a cavity according to the present invention.

[0022] Among them, 1-ring tube, 10-ring piece, 11-guide rail, 12-constraint, 2-adjusting piece, 21-adjusting piece, 22-driving piece, 3-seal, 31-first seal, 32-second seal, 4-connector, 41-first connector, 42-second connector. Detailed Implementation

[0023] The following is combined with Figures 1 to 4 The specific embodiments of the present invention will be described in detail below. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to 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 of the present invention.

[0024] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] Example like Figure 1 , Figure 2 , Figure 3 The shield tunnel expandable adjustable segment structure shown includes multiple annular pipes 1, adjusting components 2, sealing components 3, and connecting components 4.

[0026] The multiple ring pipes 1 are distributed sequentially along the length of the tunnel. Each ring pipe 1 is composed of multiple sequentially spliced ​​ring pieces 10 forming a tubular structure, and one of the ring pieces 10 has a cavity inside.

[0027] The adjusting component 2 includes an adjusting plate 21 and a driving component 22. The adjusting plate 21 is slidably disposed in the cavity and forms a telescopic structure with the ring plate 10. The driving component 22 is connected to the adjusting plate 21 and is used to drive the adjusting plate 21 to slide in the cavity to adjust the diameter of the tubular structure.

[0028] The sealing element 3 includes a first sealing element 31 and a second sealing element 32. The first sealing element 31 is disposed between two adjacent ring plates 10 in each section of the annular tube 1. It adapts to the change in the gap between the two adjacent ring plates 10 by its own deformation. The change in the gap between the two adjacent ring plates 10 is caused by the change in the diameter of the tubular structure. The second sealing element 32 is disposed between the ring plates 10 corresponding to the positions of two adjacent sections of the annular tube 1.

[0029] The connector 4 includes a first connector 41 and a second connector 42. The first connector 41 is fixedly connected to two adjacent ring pieces 10 of each annular tube 1. The second connector 42 is fixedly connected to two ring pieces 10 corresponding to the positions of two adjacent annular tubes 1.

[0030] Preferably, the drive component 22 is a hydraulic telescopic component, which is fixed in the cavity and its telescopic end is connected to the adjusting plate 21.

[0031] Preferred, such as Figure 4 As shown, the annular plate 10 with a cavity is also provided with a guide member, which includes a guide rail 11 and a slider. The guide rail 11 is fixed on the annular plate 10 and located on the side wall of the cavity; the slider is provided on the side wall of the adjusting plate 21 and is slidably disposed on the guide rail 11.

[0032] Preferably, the adjusting piece 21 is also provided with a spring pin, and the guide rail 11 is provided with a slot corresponding to the spring pin. When the adjusting piece 21 slides on the guide rail 11 with the slider until the spring pin corresponds to the slot, the spring pin is inserted into the slot to limit the adjusting piece 21.

[0033] Preferred, such as Figure 4 As shown, the ring plate 10 with a cavity is also provided with a constraint member 12. The constraint member 12 is a constraint band, one end of which is fixed on the ring plate 10 and the other end is fixed on the adjusting plate 21. The constraint band is used to constrain the sliding distance of the adjusting plate 21.

[0034] Preferably, the first sealing element 31 is a rubber strip fixed between two adjacent ring plates 10 in each section of the annular tube 1. In this embodiment, the rubber strip is made of EPDM rubber. During the prefabrication of the ring plates 10 in the factory, the rubber strip is embedded in the pre-set groove on the joint surface of each ring plate 10 by means of adhesive or pre-reserved slots. When two adjacent ring plates 10 in the same section of the annular tube 1 are assembled and squeezed together, the corresponding rubber strip is compressed to form the first continuous waterproof line that relies on elastic recovery force for sealing.

[0035] Preferably, the second sealing element 32 is an expansion sealing ring, and the side wall of the annular plate 10 has a placement cavity, in which the second sealing element 32 is placed. In this embodiment, the expansion sealing ring is a sealing ring made of water-swellable rubber. At the construction site, it is placed in the placement cavity of the annular plate 10 of the assembled previous section of the annular pipe 1. After the subsequent section of the annular pipe 1 is assembled and radial expansion is completed, the end faces of the two annular plates 10 face each other, and the second sealing element 32 is wrapped in the annular space formed by the two placement cavities. After being activated by subsequent grouting, it expands and tightly fills and presses itself into the annular space, thus achieving a seal.

[0036] Preferably, the first connector 41 is an arc bolt, and the connection between two adjacent ring pieces 10 of the same annular tube 1 has a first screw hole corresponding to the arc bolt.

[0037] Preferably, the second connector 42 is a straight bolt, and the two ring plates 10 corresponding to the positions of the two adjacent annular tube sections 1 each have a second screw hole corresponding to the straight bolt.

[0038] In this embodiment, both the arc-shaped bolts and straight bolts are made of high-strength alloy steel and require the use of nuts and washers. The arc-shaped bolt's threaded portion has an arc-shaped bend that matches the curvature of the tunnel segment, facilitating installation and tightening within the annular tunnel space. After the arc-shaped bolt passes through the first threaded holes of two adjacent ring segments 10 in the same annular tube 1, pre-tightening force is applied to both ends to ensure the ring becomes a solid whole in the circumferential direction. When using the straight bolt, after passing through the pre-drilled bolt holes at the ends of the ring segments 10 of the preceding annular tube 1, the annular gap, and the pre-drilled bolt holes at the ends of the ring segments 10 of the following annular tube 1, both ends are tightened with nuts, applying a large pre-tightening force to pull the two ring segments 10 together as a whole.

[0039] A construction method for an expandable and adjustable segment structure for shield tunnels, comprising the following steps: Step 1: Segment assembly and initial positioning in the contracted state Inside the tail section of the tunnel boring machine (TBM), the ring segments 10 of the annular tube 1, initially in their initial state, are transported to the assembly position. At this time, the adjusting component 2 is in its initial state, i.e., the adjusting piece 21 is inside the cavity and not protruding. Using the TBM's own segment assembly machine, the segments are assembled in a conventional sequence to form a section of the annular tube 1. This section of the annular tube 1 has one ring segment 10 with the adjusting component 2 installed. During assembly, the first sealing element 31 is fixed between two adjacent ring segments 10 of the same annular tube section 1. The first sealing element 31 is compressed by the assembly pressure, forming a first continuous elastic seal at all longitudinal seams within the ring. Before assembling the next ring, the second sealing element 32 is placed in the placement cavity of the already assembled end face of the previous ring.

[0040] Step 2: Shield tail disengagement and expansion system triggering The tunnel boring machine continued to advance, causing the newly assembled annular pipe 1 to completely leave the protection range of the tunnel boring machine's tail shield and be exposed to the strata.

[0041] The driving component 22 drives the adjusting plate 21 to slide out of the cavity, completing radial expansion. Specifically, the driving component 22 generates thrust, which acts on the adjusting plate 21, causing the sliding block on the side of the adjusting plate 21 to slide radially outward along the guide rail 11. During the sliding process, the constraint component 12 gradually tightens, ensuring that all wedge units move outward synchronously and uniformly. Furthermore, when the adjusting plate 21 reaches its maximum designed outer diameter D, it is straightened and tightened, forming a rigid mechanical limit to prevent over-expansion. When the wedge unit slides to the designed position, the spring pin automatically springs into the slot without external obstruction, instantly completing the anti-reverse locking of the wedge unit relative to the base segment. At this time, the outer diameter of the segment ring expands from the initial value d to the designed value D, actively compacting the surrounding strata.

[0042] Step 3, final rigid connection within the ring After passing the arc bolts sequentially through the first threaded holes of two adjacent ring plates 10 of the same annular pipe section 1 from the inside of the tunnel, tighten all the arc bolts 18 using a torque wrench according to the designed preload torque value. This step pulls all the ring plates 10 of the same annular pipe section 1 into a single rigid ring in the circumferential direction, which can bear the long-term circumferential load.

[0043] Step 4: Inter-ring sealing and final connection Specific expanding grout or water-swellable resin is injected into the placement cavity through grouting pipes pre-embedded in the tunnel lining segments. The second seal 32 expands in volume within minutes to hours, actively and tightly filling the circumferential gap between adjacent rings, forming a reliable second waterproof seal. After the second seal 32 has basically stabilized, construction workers apply the designed torque to the bolts along the tunnel axis, connecting the bolt holes pre-drilled at the ends of the ring plates 10 of the preceding and following annular pipe sections 1, the circumferential gap, and the pre-drilled bolt holes at the ends of the ring plates 10 of the following annular pipe section 1, tightening them. This step rigidly connects the adjacent annular pipes 1 into a single unit in the axial direction, forming a continuous tunnel lining structure.

[0044] Step 5: Quality Inspection and Process Iteration Check the compaction contact between the outer wall of the ring segment and the formation, and inspect the sealing appearance of all longitudinal and circumferential joints.

[0045] Step Six: Continue Construction The tunnel boring machine continues to excavate, repeating steps one through five to assemble, expand, and connect the next ring pipe 1, and so on, until the tunnel is completed.

[0046] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A shield tunnel expandable adjustable segment structure, characterized in that, include: Multiple ring-shaped pipes are distributed sequentially along the length of the tunnel. Each ring-shaped pipe consists of multiple sequentially spliced ​​ring pieces forming a tubular structure, with one of the ring pieces having an internal cavity. The adjusting component includes: an adjusting plate, which is slidably disposed in the cavity and forms a telescopic structure with the ring plate; and a driving component, which is connected to the adjusting plate and is used to drive the adjusting plate to slide in the cavity to adjust the diameter of the tubular structure. The sealing element includes: a first sealing element disposed between two adjacent ring plates in each annular tube section, which adapts to the change in the gap between the two adjacent ring plates by its own deformation, the change in the gap between the two adjacent ring plates being caused by the change in the diameter of the tubular structure; and a second sealing element disposed between the ring plates corresponding to the positions of two adjacent annular tube sections. The connector includes: a first connector, which is fixedly connected to two adjacent ring pieces on the same annular tube; and a second connector, which is fixedly connected to two ring pieces corresponding to the positions of two adjacent annular tube sections.

2. The adjustable segment structure for shield tunnels with expandable diameter as described in claim 1, characterized in that, The driving component is a hydraulic telescopic component, which is fixed in the cavity and its telescopic end is connected to the adjusting plate.

3. The adjustable segment structure for shield tunnels with expandable diameter as described in claim 1, characterized in that, The annular piece with a cavity is further provided with a guide, the guide comprising: The guide rail is fixed on the ring plate and located on the side wall of the cavity; The slider is located on the side wall of the adjustment plate and slides on the guide rail.

4. The adjustable segment structure for expandable tunnel as described in claim 3, characterized in that, The adjusting plate is also provided with a spring pin, and the guide rail is provided with a slot corresponding to the spring pin. When the adjusting plate slides on the guide rail with the slider until the spring pin corresponds to the slot, the spring pin is inserted into the slot to limit the adjustment plate.

5. The adjustable segment structure for expandable tunnel as described in claim 1, characterized in that, The ring plate with the cavity is also provided with a constraint member, which is a constraint band, one end of which is fixed to the ring plate and the other end of which is fixed to the adjusting plate. The constraint band is used to constrain the sliding distance of the adjusting plate.

6. The adjustable segment structure for expandable tunnel as described in claim 1, characterized in that, The first sealing element is a rubber strip fixed between two adjacent ring plates in each section of the annular tube.

7. The adjustable segment structure for expandable tunnel as described in claim 1, characterized in that, The second seal is an expansion sealing ring, and the side wall of the ring has a placement cavity, in which the second seal is placed.

8. The adjustable segment structure for expandable tunnel as described in claim 1, characterized in that, The first connector uses an arc bolt, and the connection between two adjacent ring plates of the same annular tube has a first screw hole corresponding to the arc bolt.

9. A shield tunnel expandable adjustable segment structure as described in claim 1, characterized in that, The second connector uses a straight bolt, and each of the two ring plates corresponding to the positions of two adjacent annular tube sections has a second threaded hole corresponding to the straight bolt.

10. A construction method for an expandable adjustable segment structure for shield tunnels, characterized in that, Construction of the segment structure according to any one of claims 1-9 specifically includes: Inside the shield tail, ring plates are assembled into an annular tube. During assembly, the first sealing element is naturally compressed as the tube plates are squeezed, forming a preliminary seal. During the removal of the shield tail, the second sealing element is installed onto the end face of the ring plate of the previous annular tube that is already in place. After the tube segment detaches from the shield tail, the driving component drives the adjusting plate to slide out of the cavity, completing the radial expansion; the first connecting component fixes two adjacent ring segments of each annular tube, and the second connecting component fixes two ring segments corresponding to the positions of two adjacent annular tube segments.

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