A boltless reinforced concrete segmental lining structure for an assembled tunnel

Abstract

The application provides a boltless reinforced concrete segment structure for an assembled tunnel lining, and relates to the technical field of tunnel design and construction, which comprises a left haunch segment, a right haunch segment, a top wedge-shaped segment, and bottom segments, a left spring segment, and a right spring segment which are of the same structure, wherein the left side end surface one and the right side end surface one of the bottom segments, the left spring segment, and the right spring segment are straight surfaces parallel to the tunnel extension direction; a first main groove is formed in the middle position of the left side end surface one, and the middle position of the right side end surface one is provided with a first main tenon, wherein the cross sections of the first main groove and the first main tenon are both elliptical; a first groove and a first tenon are symmetrically arranged on the radial inner side and the radial outer side of the first main groove and the first main tenon, and the cross sections of the first groove and the first tenon are both concave. The application solves the problems of long assembly time, high labor intensity, and low construction efficiency in the prior art.

Description

Technical Field

[0001] This invention relates to the field of tunnel design and construction technology, and in particular to a boltless reinforced concrete segment structure for prefabricated tunnel lining. Background Technology

[0002] In existing tunnel precast lining construction technology, bolt holes need to be pre-drilled during the prefabrication of reinforced concrete segments to meet the installation requirements of fasteners. However, these bolt holes reduce the overall structural strength and load-bearing capacity of the segments, and also increase the risk of segment rupture along the bolt holes under ground loads, becoming a major weak point for groundwater infiltration into the tunnel. On the other hand, during actual assembly operations, the segments are easily displaced or misaligned due to the pressure of the surrounding soil and rock mass and the pressure of groundwater, making it impossible to accurately align the longitudinal and circumferential bolt holes between segments. This not only significantly increases the assembly difficulty and labor intensity for on-site workers, but also directly leads to low construction efficiency and increased construction period risks. In addition, tunnel segment linings assembled with bolts and nuts are prone to corrosion in the long-term humid underground environment. Corroded bolts and nuts can squeeze the surrounding concrete, causing damage to the segments and affecting their safety and durability.

[0003] Therefore, there is an urgent need to provide a precast reinforced concrete segment that has a shorter assembly time, lower labor intensity, higher construction efficiency, and is free from the effects of bolt corrosion. Summary of the Invention

[0004] The purpose of this invention is to provide a boltless reinforced concrete segment structure for prefabricated tunnel lining, which solves the problems of long assembly time, high labor intensity, low construction efficiency, and easy corrosion of fasteners such as segment bolts and nuts, which affect the tunnel's load-bearing capacity and durability in the prior art.

[0005] The technical solution of the present invention: This invention provides a boltless reinforced concrete segment structure for prefabricated tunnel lining, comprising: a left shoulder segment, a right shoulder segment, a top wedge-shaped segment, and bottom segments, left arch foot segments, and right arch foot segments with identical structures. The left and right end faces of the bottom segment, the left arch foot segment, and the right arch foot segment are all straight and parallel to the tunnel extension direction. A first main groove is formed in the middle of the left end face, and a first main tenon is formed in the middle of the right end face. The cross-sections of the first main groove and the first main tenon are both elliptical. A first groove and a first tenon are symmetrically arranged on the radially inner and radially outer sides of the first main groove and the first main tenon. The cross-sections of the first groove and the first tenon are both concave.

[0006] Furthermore, the left end face of the left shoulder segment is a straight surface parallel to the tunnel extension direction, the right end face of the left shoulder segment is an inclined surface intersecting the tunnel extension direction, a fourth main tenon is provided in the middle of the left end face, and a fourth main groove is provided in the middle of the right end face; a fourth secondary groove and a fourth secondary tenon are symmetrically provided on the radially inner and radially outer sides of the fourth main groove and the fourth main tenon.

[0007] Furthermore, the right end face five of the right shoulder segment is a straight surface and parallel to the tunnel extension direction, the left end face five of the right shoulder segment is an inclined surface and intersects with the tunnel extension direction, and a fifth main groove is provided in the middle position of both the left end face five and the right end face five; a fifth secondary groove and a fifth secondary tenon are symmetrically arranged on the radial inner side and the radial outer side of the fifth main groove.

[0008] Furthermore, the left end face six and the right end face six of the top wedge-shaped tube are both inclined surfaces and intersect with the tunnel extension direction. A sixth main tenon is provided at the middle position of the left end face six and the right end face six. A sixth secondary groove and a sixth secondary tenon are symmetrically provided on the radial inner side and the radial outer side of the sixth main tenon.

[0009] Furthermore, the central angles of the bottom segment, the left arch foot segment, and the right arch foot segment are equal, the central angles of the left arch shoulder segment and the right arch shoulder segment are equal, and the central angle corresponding to the rear end face of the top wedge-shaped segment is greater than the central angle corresponding to its front end face.

[0010] Furthermore, the front and rear faces of the bottom segment, left arch foot segment, right arch foot segment, left arch shoulder segment, right arch shoulder segment, and top wedge segment are all perpendicular to the tunnel extension direction; the cross-section of the front face is an inverted step structure, the inner side of the inverted step structure has a seventh arc surface, and the outer edge adjacent to the seventh arc surface has a longitudinal seventh tenon; the cross-section of the rear face is a normal step structure, the outer edge of the normal step structure has an eighth arc surface, and the inner side adjacent to the eighth arc surface has a longitudinal eighth groove; both sides of the inverted step structure have a first secondary groove and a second secondary groove; both sides of the normal step structure have a third groove and an eighth tenon.

[0011] Furthermore, the cross-sectional area of ​​the first main groove is greater than the cross-sectional area of ​​the first main tenon; the cross-sectional areas of the first groove and the first tenon are both smaller than the cross-sectional area of ​​the first main tenon; the cross-sections of the fourth main tenon, the sixth main tenon, the fourth main groove, and the fifth main groove are all elliptical; the cross-sections of the first secondary groove and the third tenon are both concave; and the cross-sections of the second secondary groove and the eighth tenon are both semi-circular.

[0012] Furthermore, hoisting through holes are provided at the center of gravity of the bottom segment, the left arch foot segment, the right arch foot segment, the left arch shoulder segment, the right arch shoulder segment, and the top wedge segment.

[0013] Furthermore, water-slow-expansion sealing strips are affixed to the first, fourth, fifth, sixth, first secondary, and third grooves.

[0014] Furthermore, along the radial direction of the tunnel, the bottom segment, left arch foot segment, right arch foot segment, left arch shoulder segment, right arch shoulder segment, and top wedge segment have equal thicknesses of 200~500mm; along the tunnel extension direction, the lengths of the bottom segment, left arch foot segment, right arch foot segment, left arch shoulder segment, right arch shoulder segment, and top wedge segment are equal and range from 1.2 to 1.8m.

[0015] Based on the above technical features, the beneficial effects of the present invention are as follows: (1) The boltless reinforced concrete segment structure for assembled tunnel lining provided by the present invention replaces traditional metal fasteners with a completely boltless tenon and groove and stepped structure, which can eliminate the stress concentration area of ​​bolt holes on the segment and thus improve the overall structural strength of the segment.

[0016] (2) The boltless reinforced concrete segment structure for assembled tunnel lining provided by the present invention can simplify the alignment process and reduce the labor intensity during construction by sliding the elliptical main tenon and the main groove.

[0017] (3) The boltless reinforced concrete segment structure for assembled tunnel lining provided by the present invention improves the resistance to groundwater seepage at the joints between segments by using the expansion pressure of the waterstop material and the complex geometric path of the main and secondary multiple tenons and grooves in conjunction with the waterstop strip.

[0018] (4) The boltless reinforced concrete segment structure for assembled tunnel lining provided by the present invention, through the longitudinal self-locking of the top wedge structure and the positive and negative step hinges of the front and rear rings, can not only transmit tensile, compressive and shear stress at the segment joints, but also restrict the lining structure’s degrees of freedom in the circumferential, longitudinal and radial directions, thereby maintaining the geometric stability of the tunnel lining during operation, and can eliminate the impact of corrosion of metal fasteners in existing segments on the durability of the tunnel lining structure. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the tunnel assembly lining structure of the present invention; Figure 2 This is a front view of the bottom segment, the left arch segment, and the right arch segment in this invention; Figure 3This is a top view of the bottom segment, the left arch segment, and the right arch segment in this invention; Figure 4 for Figure 2 and Figure 3 Cross-sectional view of AA in the middle; Figure 5 This is a front view of the left shoulder segment in this invention; Figure 6 for Figure 5 Top view; Figure 7 This is a front view of the right shoulder segment in this invention; Figure 8 for Figure 7 Top view; Figure 9 This is a front view of the top wedge-shaped tube segment in this invention; Figure 10 for Figure 9 Top view; Figure 11 This is a schematic diagram of the assembly process according to an embodiment of the present invention; Figure 12 This is a schematic diagram of the splicing process of two adjacent circumferential tunnel segments along the tunnel extension direction in an embodiment of the present invention; Figure 13 This is a schematic diagram of the splicing process of two adjacent tunnel segments along the tunnel extension direction in an embodiment of the present invention; Figure 14 This is a plan view of the tunnel lining after adjacent two ring segments are assembled in a through-joint manner in an embodiment of the present invention. Figure 15 This is a plan view of the tunnel lining after adjacent two ring segments are assembled in a staggered manner in an embodiment of the present invention.

[0020] In the diagram: 1. Bottom segment; 2. Left arch foot segment; 3. Right arch foot segment; 12301. Left end face one; 12302. Right end face one; 12303. First main groove; 12304. First main tenon; 12313. First groove; 12314. First tenon; 4. Left arch shoulder segment; 401. Left end face four; 402. Right end face four; 403. Fourth main groove; 404. Fourth main tenon; 413. Fourth groove; 414. Fourth tenon; 5. Right arch shoulder segment; 501. Left end face five; 502. Right end face five; 503. Fifth main groove; 51 3. Fifth groove; 514. Fifth tenon; 6. Top wedge-shaped tube; 601. Left end face six; 602. Right end face six; 604. Sixth main tenon; 613. Sixth groove; 614. Sixth tenon; 1606. Front end face; 1605. Rear end face; 7. Inverted step structure; 701. Seventh arc surface; 714. Seventh tenon; 713. First secondary groove; 723. Second secondary groove; 8. Positive step structure; 801. Eighth arc surface; 813. Eighth groove; 823. Third groove; 824. Eighth tenon; 9. Lifting through hole; 10. Waterstop strip. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] In the description of this invention, it should be understood that the terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0023] Furthermore, 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 with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] To better understand the spatial structural relationships of this invention, the extension direction of the tunnel is predefined as the front-to-back direction. Using the vertical center axis of the tunnel segment lining as a reference, the entire ring lining is divided into a left-side region and a right-side region. Simultaneously, using the vertical centerline of each precast segment as a reference, each individual segment is divided into a left-side and a right-side region. It should be noted that this spatial division method is used to assist in illustrating the geometric characteristics of the end faces of each segment and does not constitute a substantial limitation on the scope of protection of this invention.

[0026] It should be noted that prefabricated tunnel lining, also known as modular lining, is a common lining structure used in the construction of railway tunnels, highway tunnels, urban subway tunnels, municipal tunnels, water conveyance tunnels, and river-crossing tunnels for long-distance oil and gas pipelines using the TBM (tunnel boring machine) method and shield tunneling machine method. It is usually assembled on the construction site by prefabricated reinforced concrete segments using fasteners such as bolts and nuts or pins and sleeves.

[0027] In existing technologies, tunnel segment linings assembled with fasteners such as bolts and nuts are prone to corrosion during long-term operation due to electrochemical reactions in the humid underground environment. The corrosion of steel bolts and nuts will undoubtedly affect the long-term safety and durability of the tunnel segment lining.

[0028] Example

[0029] Please refer to the above as well. Figures 1-15This invention provides a boltless reinforced concrete segment structure for prefabricated tunnel lining, relating to the field of tunnel design and construction technology. The structure includes: a left shoulder segment 4, a right shoulder segment 5, a top wedge-shaped segment 6, and identical bottom segments 1, left arch foot segments 2, and right arch foot segments 3. The left end face -12301 and right end face -12302 of the bottom segment 1, left arch foot segment 2, and right arch foot segment 3 are both straight faces parallel to the tunnel extension direction; the left end face -12301... A first main groove 12303 is provided in the middle position of the first main groove 12303, and a first main tenon 12304 is provided in the middle position of the right end face 12302. The cross-sections of the first main groove 12303 and the first main tenon 12304 are both elliptical. A first groove 12313 and a first tenon 12314 are symmetrically arranged on the radial inner and radial outer sides of the first main groove 12303 and the first main tenon 12304. The cross-sections of the first groove 12313 and the first tenon 12314 are both concave.

[0030] It is worth noting that, in the embodiments of the present invention, the bottom segment 1, left arch foot segment 2, right arch foot segment 3, left arch shoulder segment 4, right arch shoulder segment 5, and top wedge-shaped segment 6 are connected end to end to form a ring structure. The present invention provides a segment structure without bolts, eliminating the need for bolts and nuts and other fasteners. Therefore, bolt holes in the segments are eliminated. Furthermore, the tunnel lining assembled with boltless segments solves the technical problems of segment cracking and water leakage caused by easy corrosion of bolts when fastening segments with bolts and nuts in existing prefabricated tunnel linings. It also enables rapid assembly of prefabricated segments and solves the prominent problems of difficult alignment of bolt holes, high labor intensity for assembly personnel, and low construction efficiency in the construction of tunnels using the TBM method and shield tunneling method when assembling segment linings with existing bolts and nuts and other fasteners.

[0031] It is worth noting that, in terms of stress characteristics, traditional bolted connections are "point connections," and stress concentration is easily generated around the bolt holes on the segments, leading to cracks in the concrete. In contrast, the tenon and groove structure of this invention is a "surface connection," where the hydrostatic pressure of the stratum and groundwater is transmitted through the large-area contact interface of the primary and secondary tenons. The elliptical primary tenon not only facilitates sliding and alignment during construction but also, when subjected to circumferential pressure, can evenly distribute the compressive stress to the segment matrix through curved surface contact.

[0032] Preferably, the cross-section of the first main groove 12303 is an unclosed ellipse; the first main groove 12303 corresponds to the first main tenon 12304, and the cross-sections of the first groove 12313 and the first tenon 12314 are both concave, specifically in the shape of a "︺". In detail, by setting the first main groove 12303, the first main tenon 12304, the first groove 12313, and the first tenon 12314, a multi-level tenon-groove structure is constructed. This not only provides circumferential positioning constraints for the pipe segments but also greatly extends the seepage path of groundwater by increasing the complexity of the contact interface, thereby improving the self-waterproofing performance of the pipe segment joints.

[0033] Further, please refer to Figure 5 and Figure 6 The left end face 401 of the left shoulder segment 4 is a straight surface and parallel to the tunnel extension direction. The right end face 402 of the left shoulder segment 4 is an inclined surface and intersects with the tunnel extension direction. A fourth main tenon 404 is provided in the middle of the left end face 401. A fourth main groove 403 is provided in the middle of the right end face 402. A fourth secondary groove 413 and a fourth secondary tenon 414 are symmetrically provided on the radial inner and radial outer sides of the fourth main groove 403 and the fourth main tenon 404.

[0034] It should be noted that the arrangement of the straight left end face 401 and the inclined right end face 402, with one side straight and the other inclined, provides the necessary geometric space for the final capping of the top wedge-shaped tube segment 6. Specifically, the cross-sections of the fourth groove 413 and the fourth tenon 414 are “︺” shaped.

[0035] Further, please refer to Figure 7 and Figure 8 The right end face 502 of the right shoulder segment 5 is a straight surface and parallel to the tunnel extension direction. The left end face 501 of the right shoulder segment 5 is an inclined surface and intersects with the tunnel extension direction. A fifth main groove 503 is provided in the middle position of both the left end face 501 and the right end face 502. A fifth secondary groove 513 and a fifth secondary tenon 514 are symmetrically arranged on the radial inner and radial outer sides of the fifth main groove 503.

[0036] It should be noted that the fifth secondary grooves 513 provided on both sides of the fifth main groove 503, in conjunction with the first main tenon 12304 on the right end face 12302 of the right arch foot tube 3 and the sixth main tenon 604 on the right end face 602 of the top wedge-shaped tube 6, can achieve a stable locking of the right arch shoulder. The cross-section of the fifth main groove 503 is preferably an unclosed ellipse, while the cross-sections of the fifth secondary groove 513 and the fifth secondary tenon 514 are specifically “︺” shaped.

[0037] Further, please refer to Figure 9 and Figure 10 The left end face 601 and the right end face 602 of the top wedge-shaped tube 6 are both inclined and intersect with the tunnel extension direction. The middle position of the left end face 601 and the right end face 602 is provided with a sixth main tenon 604. The radial inner side and the radial outer side of the sixth main tenon 604 are symmetrically provided with a sixth groove 613 and a sixth tenon 614.

[0038] It should be noted that both the left end face 601 and the right end face 602 are outwardly expanding slopes, making the whole structure a longitudinal wedge shape. The geometric dimensions of the top wedge tube 6 can meet the longitudinal self-locking requirements. In addition, the slopes of the right end face 402 of the left shoulder tube 4 and the left end face 501 of the right shoulder tube 5, as well as the long axis directions of the fourth main groove 403 and the fifth main groove 503, can be corrected according to the inclination angle of the slopes, thereby ensuring that the top wedge tube 6 can slide in smoothly when inserted.

[0039] It should be noted that during the assembly of the tunnel segments, each segment is pushed into the grooves along the tunnel extension direction using the tenons on the left and right ends, namely, the first main groove 12303, the first main tenon 12304, the fourth main groove 403, the fourth main tenon 404, the fifth main groove 503, the sixth main tenon 604, the first groove 12313, the first tenon 12314, the fourth secondary groove 413, the fourth secondary tenon 414, the fifth secondary groove 513, the fifth secondary tenon 514, the sixth secondary groove 613, and the sixth secondary tenon 614. This solves the problem of segments easily falling off along the tunnel circumference after boltless segment assembly. Furthermore, the hinged connection of the main and secondary tenons and grooves can provide shear stress generated at the joints of the segments, increasing the shear resistance of the segment joints.

[0040] The technical problem of boltless segments easily falling off along the tunnel extension direction is solved by hinged joints of the inverted step on the front end face 1606 of the preceding segment and the positive step on the rear end face 1605 of the following segment, as well as the secondary grooves and secondary tenons on the steps. At the same time, the shear resistance between the segment rings along the tunnel extension direction is increased.

[0041] Furthermore, the central angles of the bottom segment 1, the left arch segment 2, and the right arch segment 3... α The central angles β of the left shoulder segment 4 and the right shoulder segment 5 are equal, passing through the central angles. αThe angle distribution with the central angle β can ensure the geometric symmetry and stress balance of the lining ring. During long-term operation, if the tunnel experiences minor uneven settlement, the semi-circular longitudinal hinge structure has a certain rotational adaptation space. It can release shear stress through local minor rotation, thereby avoiding the collapse of the segment edges due to stress concentration. Compared with rigid bolt connections, it has better disaster prevention and damage resistance performance.

[0042] Furthermore, such as Figure 9 As shown, the central angle γ corresponding to the rear end face 1605 of the top wedge-shaped tube 6 is greater than the central angle corresponding to its front end face 1606. δ By γ and δ By setting unequal values, the thickness or width of the segments varies in the longitudinal direction, which in turn generates compressive force during shield assembly, making the entire ring of segments tend to be tighter.

[0043] It should be noted that the central angle α Central angle β , central angle γ, central angle δ Satisfy the calculation expression And as a preferred option: and The wedge-shaped structure, which is narrow at the front and wide at the back, allows the segments to be pushed into the tunnel longitudinally, generating strong lateral compression with the left shoulder segments 4 and right shoulder segments 5 on both sides. Through friction and geometric constraints, the lining ring is finally locked in the circumferential direction, thereby completely eliminating the risk of segment misalignment caused by radial load.

[0044] It should be noted that the concrete strength grade of the bottom segment 1, left arch foot segment 2, right arch foot segment 3, left arch shoulder segment 4, right arch shoulder segment 5, and top wedge segment 6 shall not be lower than C50.

[0045] Further, please refer to Figure 4 The front end face 1606 and rear end face 1605 of the bottom segment 1, left arch foot segment 2, right arch foot segment 3, left arch shoulder segment 4, right arch shoulder segment 5, and top wedge-shaped segment 6 are all perpendicular to the tunnel extension direction. The cross-section of the front end face 1606 is an inverted step structure 7. The inner side of the inverted step structure 7 has a seventh arc surface 701, which can be used to withstand the shear force between the rings, and the outer edge adjacent to the seventh arc surface 701 has a longitudinal seventh tenon 714.

[0046] Furthermore, the cross-section of the rear end face 1605 is a positive step structure 8, the outer edge of the positive step structure 8 has an eighth arc surface 801, the radius of the eighth arc surface 801 matches the radius of the seventh arc surface 701, and there is a longitudinal eighth groove 813 on the inner side adjacent to the eighth arc surface 801.

[0047] It should be noted that when the next ring lining is assembled, the inverted step structure 7 and the upright step structure 8 form a force-bearing mode similar to a hinge through the fit between the eighth arc surface 801 and the seventh arc surface 701.

[0048] Furthermore, both sides of the inverted step structure 7 have a first secondary groove 713 and a second secondary groove 723. Specifically, both sides of the upright step structure 8 have a third groove 823 and an eighth tenon 824. The cross-sections of the second secondary groove 723 and the eighth tenon 824 are semi-circular; the cross-sections of the first secondary groove 713 and the third tenon 823 are concave.

[0049] It should be noted that by embedding the eighth tenon 824 into the second secondary groove 723, additional longitudinal shear resistance can be provided. In turn, the multi-level interlocking structure enables the tunnel lining to maintain the integrity of the structure when subjected to uneven settlement or longitudinal tensile stress. This solves the technical problem of boltless segments being prone to falling off along the tunnel extension direction, ensuring that no misalignment or detachment occurs.

[0050] It should be noted that by setting the inverted step structure 7 and the positive step structure 8, the stability of the connection between adjacent segment lining rings along the tunnel extension direction can be enhanced. The inverted step structure 7 and the positive step structure 8 are set on the front end face 1606 and the rear end face 1605, and secondary grooves and secondary tenons are set on the steps, namely the seventh secondary tenon 714, the first secondary groove 713, the second secondary groove 723, the eighth groove 813, the third groove 823, and the eighth secondary tenon 824. This can form a longitudinal self-locking mechanism, so that after the thrust of the shield machine jack is removed, the steps between adjacent rings can be kept in a tight fit by the self-weight of the segment and the friction of the surrounding rock. This improves the shear resistance of the segment rings in the longitudinal direction and effectively prevents the segment rings from falling off or shifting due to uneven longitudinal stress.

[0051] Furthermore, the cross-sectional area of ​​the first main groove 12303 is larger than that of the first main tenon 12304, and the cross-sectional areas of the first groove 12313 and the first tenon 12314 are both smaller than that of the first main tenon 12304. This provides the necessary installation gap and sliding allowance during the assembly process, allowing the first tenon 12314 to slide smoothly into the first groove 12313 of the adjacent segment along the tunnel axis under the action of the tunnel boring machine propulsion system, and achieve automatic alignment by using the guiding effect of the elliptical arc surface.

[0052] Furthermore, the cross-sections of the fourth main tenon 404, the sixth main tenon 604, the fourth main groove 403, and the fifth main groove 503 are all elliptical. Through the guiding function of the elliptical interface, the tube segment will automatically correct the radial deviation according to the force during the advancement process.

[0053] Preferably, the cross-section of the secondary groove on the left and right end faces of each segment is “︺” shaped, and the cross-section of the secondary tenon and secondary groove on the front and rear end faces of each segment is semi-circular and “︺” shaped.

[0054] Furthermore, the cross-sections of the first secondary groove 713 and the eighth tenon 824 are both semi-circular. The semi-circular tenon and groove can form a longitudinal hinge structure, which can increase the shear area of ​​the joint surface and limit the shear displacement between adjacent rings through physical geometric constraints. When faced with earthquakes or vibrations caused by the passage of large heavy vehicles, it exhibits excellent dynamic stability, thereby effectively solving the problem of ring joint opening or misalignment that may occur in boltless segments in soft soil strata.

[0055] Furthermore, the bottom segment 1, the left arch foot segment 2, the right arch foot segment 3, the left arch shoulder segment 4, the right arch shoulder segment 5, and the top wedge-shaped segment 6 are all provided with lifting through holes 9 at their center of gravity. The lifting through holes 9 penetrate the thickness of the segments and serve as the access points for suction cups or lifting devices during the assembly stage.

[0056] It should be noted that after the entire ring lining is assembled and the tunnel boring machine advances forward, the hoisting through hole 9 also serves as a grouting hole. This facilitates the hoisting of the tunnel segments during assembly. Furthermore, after the tunnel segment lining is assembled, cement grout or cement mortar can be injected into the back of the tunnel segments through this grouting hole, forming a solid filling layer between the outer wall of the tunnel segments and the ground, thereby improving the waterproof, seepage-resistant, and seismic performance of the tunnel lining.

[0057] Furthermore, water-resistant, slow-expansion sealing strips 10 are affixed to the first groove 12313, the fourth groove 413, the fifth groove 513, the sixth groove 613, the first secondary groove 713, and the third groove 823.

[0058] It should be noted that when the bottom segment 1, left arch foot segment 2, right arch foot segment 3, left arch shoulder segment 4, right arch shoulder segment 5, and top wedge-shaped segment 6 are assembled and placed in place, and encounter groundwater during tunnel operation, the waterstop strip 10 will expand after absorbing water and block the joints between the segments along the circumferential and longitudinal directions. This can improve the waterproofing ability of the prefabricated segment lining at the segment joints, thereby helping to maintain a dry environment inside the prefabricated segment lining and extending the service life of the tunnel.

[0059] It should be noted that water-swellable sealing strips 10 are installed in all the "︺"-shaped grooves on the bottom tube segment 1, left arch foot tube segment 2, right arch foot tube segment 3, left arch shoulder tube segment 4, right arch shoulder tube segment 5, and top wedge-shaped tube segment 6.

[0060] It is worth noting that this embodiment features multiple layers of defense: the first line of defense is the waterstop strip 10 adhered to the groove. When the tenon is embedded in the groove, the waterstop strip 10 is confined within the closed cavity. The rebound force generated by the pressure adheres tightly to the concrete surface, forming a circumferential and longitudinally interwoven sealing net. Furthermore, the waterstop strip 10 absorbs water and expands upon contact with groundwater, blocking the gaps between the segment rings and improving the anti-seepage capacity between the segment rings. The second line of defense is the joint between the complex inverted step structure 7 and the upright step structure 8. If groundwater is to seep into the tunnel, it must bypass the arc surface, cross the longitudinal tenon, and pass through the semi-circular tenon groove, among other barriers. The significant hydraulic damping minimizes the risk of leakage. The third line of defense is the solidified grout injected through the grouting hole (i.e., the hoisting through hole 9). The grout fills the gap between the segment and the surrounding rock, thereby isolating the water source from direct contact with the segment joint from the source.

[0061] Furthermore, along the radial direction of the tunnel, the bottom segment 1, the left arch foot segment 2, the right arch foot segment 3, the left arch shoulder segment 4, the right arch shoulder segment 5, and the top wedge-shaped segment 6 have equal thicknesses of 200~500mm. Along the tunnel extension direction, the bottom segment 1, left arch foot segment 2, right arch foot segment 3, left arch shoulder segment 4, right arch shoulder segment 5, and top wedge-shaped segment 6 are all of equal length and have a length of 1.2~1.8m.

[0062] It should be noted that the “︺” shape is specifically a groove structure with a gradually widening opening. The geometric features of this shape can facilitate the limiting installation of the waterstop strip 10.

[0063] It is worth noting that the assembly process of the boltless reinforced concrete segment structure for prefabricated tunnel lining provided in this embodiment of the invention is as follows: Step 1: Adhere the waterstop strip 10 in the secondary grooves of each segment. Specifically, adhere the waterstop strip 10 in the "︺"-shaped secondary grooves of the precast bottom segment 1, left arch foot segment 2, right arch foot segment 3, left arch shoulder segment 4, right arch shoulder segment 5, and top wedge-shaped segment 6 that have reached the designed concrete strength grade. That is, adhere the water-slow-expansion waterstop strip 10 in the first groove 12313, the fourth groove 413, the fifth groove 513, the sixth groove 613, the first secondary groove 713, and the eighth groove 813.

[0064] Step 2: First, the bottom segment 1 is hoisted to the bottom of the tunnel at the assembly site through the hoisting through hole 9.

[0065] Step 3: The left arch foot segment 2, the right arch foot segment 3, the left arch shoulder segment 4, and the right arch shoulder segment 5 are sequentially hoisted into position, allowing the main tenon on the end face of the segment to be assembled to slide into the main groove on the end face of the already positioned segment along the tunnel extension direction, forming a circumferential connection; Details: First: The left arch foot segment 2 is hoisted and assembled on the left side of the already positioned bottom segment 1. Specifically, the first main tenon 12304 on the right end face of the left arch foot segment 2 (12302) is inserted along the tunnel extension direction into the first main groove 12303 in the middle position of the left end face of the already assembled bottom segment 1 (12301), and the left arch foot segment 2 is pushed forward along the tunnel extension direction. Figure 11 As shown, the right end face 12302 of the left arch foot segment 2 is then aligned with the left end face 12301 of the bottom segment 1, and the first groove 12313 and the first tenon 12314 are aligned, thus completing the assembly of the left arch foot segment 2. Next, the right arch foot segment 3 is hoisted and assembled on the right side of the already hoisted bottom segment 1. The specific process is as follows: the first main tenon 12304 at the middle position of the right end face 12302 of the bottom segment 1 is inserted into the first main groove 12303 of the left end face 12301 of the right arch foot segment 3 along the tunnel extension direction, and the right arch foot segment 3 is pushed forward along the tunnel extension direction so that the left end face 12301 of the right arch foot segment 3 is aligned with the right end face 12302 of the bottom segment 1, and at the same time, the first main groove 12303 of the left end face 12301 of the right arch foot segment 3 is aligned with the first main tenon 12304 of the right end face 12302 of the bottom segment 1, thus completing the assembly of the right arch foot segment 3. Then, the left arch shoulder segment 4 is hoisted. The specific process is as follows: the fourth main tenon 404 on the left end face 401 of the left arch shoulder segment 4 is inserted into the first main tenon 12304 on the left end face 12301 of the left arch foot segment 2 along the tunnel extension direction, and the left arch shoulder segment 4 is pushed forward along the tunnel extension direction so that the left end face 401 of the left arch shoulder segment 4 is aligned with the left end face 12301 of the left arch foot segment 2. At the same time, the fourth groove 413 and the fourth tenon 414 are aligned to complete the assembly of the left arch shoulder segment 4. Finally, the right arch shoulder segment 5 is hoisted. The specific process is as follows: the first main tenon 12304 at the middle position of the right end face 12302 of the right arch foot segment 3 is inserted into the fifth main groove 503 of the right end face 502 of the right arch shoulder segment 5 along the tunnel extension direction, and the right arch shoulder segment 5 is pushed forward along the tunnel extension direction so that the right end face 502 of the right arch shoulder segment 5 is aligned with the right end face 12302 of the right arch foot segment 3. At the same time, the fifth groove 513 and the fifth tenon 514 are aligned to complete the assembly of the right arch shoulder segment 5. At this time, a wedge-shaped opening is formed between the assembled left arch shoulder segment 4 and the right arch shoulder segment 5 along the tunnel extension direction. Step four: Hoist the top wedge-shaped segment 6 at the wedge-shaped opening, so that the main tenons on both sides of its inclined end face simultaneously slide into the main grooves on the inclined end faces of the two shoulder segments, forming a complete closed ring structure; in detail, the hoisting process of the top wedge-shaped segment 6 is as follows: insert the sixth main tenon 604 of the inclined surface of the left end face of the top wedge-shaped segment 6 601 upward along the tunnel direction into the fourth main groove 403 of the inclined surface of the right end face of the left shoulder segment 4 402, and at the same time insert the sixth main tenon 604 of the inclined surface of the right end face of the top wedge-shaped segment 6 602 into the fifth main groove 5 of the inclined surface of the left end face of the right shoulder segment 5 501 along the tunnel extension direction. Within section 03, the top wedge-shaped segment 6 is advanced along the tunnel's extension direction, causing the inclined surface of its left end face 601 to align with the inclined surface of its right end face 402 on the left shoulder segment 4, and the inclined surface of its right end face 602 to align with the inclined surface of its left end face 501 on the right shoulder segment 5. This creates continuous contact stress between the wedge-shaped side of the top wedge-shaped segment 6 and the segments on both sides. Simultaneously, the sixth groove 613 and the sixth tenon 614 are joined, completing the assembly of the top wedge-shaped segment 6. The normal component force generated by the longitudinal advancement tightens the entire lining ring outwards, ensuring it adheres tightly to the surrounding rock or the shield shell. This completes the assembly of a tunnel lining ring.

[0066] Step 5: After the entire ring assembly is completed, the tunnel boring machine continues to advance forward to assemble the next ring segment. The inverted step structure 7 of the front face 1606 of the segment to be assembled engages with the positive step structure 8 of the rear face 1605 of the corresponding segment from the previous ring through the seventh arc surface 701, the eighth arc surface 801, and the longitudinal seventh tenon 714, eighth groove 813, first secondary groove 713, second secondary groove 723, third groove 823, and eighth tenon 824, thereby forming a large-area force-transfer surface. (Details follow.) First, repeat steps one and two to continue assembling the bottom segment 1 of the next ring of tunnel lining. The inner seventh arc surface 701 and the outer seventh tenon 714 of the inverted step structure 7 on the front end face 1606 of the bottom segment 1 are engaged and hinged with the outer eighth arc surface 801 and the inner eighth groove 813 of the positive step structure 8 on the rear end face 1605 of the bottom segment 1 of the previous ring of tunnel lining. Through the layered interlocking of the front and rear, the assembly of the bottom segment 1 in the next ring of lining is completed, so that the entire tunnel lining forms a continuous tubular structure with uniform rigidity. Next, repeat steps three and four to continue assembling the remaining left arch foot segment 2, right arch foot segment 3, left arch shoulder segment 4, right arch shoulder segment 5, and top wedge segment 6 in the next ring of lining. During the assembly process, the inner seventh arc surface 701 and outer seventh tenon 714 of the inverted step structure 7 on the front end face 1606 of the left arch foot segment 2 to be assembled are made to mate and hinge with the outer eighth arc surface 801 and inner eighth groove 813 of the positive step structure 8 on the rear end face 1605 of the left arch foot segment 2, right arch foot segment 3, left arch shoulder segment 4, right arch shoulder segment 5, and top wedge segment 6 that have already been assembled in the previous ring. Figure 12 and Figure 13 As shown, this creates a multi-level labyrinthine sealing path between the segments to be assembled and the segments already assembled in the previous ring, which can greatly extend the infiltration path of groundwater. Combined with the expansion effect of multiple water-stop strips 10, better overall waterproof performance can still be achieved without the use of bolts for fastening, and the assembly of the next ring of segments can be completed. This process of assembling segments is repeated until the predetermined tunnel length is reached. Figure 12 for Figure 1 Cross-sectional view of BB in the middle.

[0067] Step 6: Inject grout into the gaps on the back of the segment through the lifting through hole 9.

[0068] It should be noted that the appendix Figure 11 The assembly process between adjacent circumferential segments along the tunnel extension direction is shown using only the bottom segment 1 and the left arch foot segment 2 as examples. The assembly process between the remaining circumferential segments along the tunnel extension direction is the same.

[0069] It should be noted that, during the actual assembly process using the boltless tunnel segments of this invention, two assembly modes are possible: continuous joint assembly and staggered joint assembly. When facing hard rock strata with favorable geological conditions, the continuous joint assembly mode can be used to simplify the construction logic and increase the tunneling speed. When facing complex strata such as soft soil or fault fracture zones, the staggered joint assembly mode can be used. Through the physical misalignment between the lining rings, the tenons and grooves of each segment mutually reinforce each other, enhancing the overall rigidity and deformation resistance of the lining rings and preventing local displacement of the segments due to uneven ground pressure. Furthermore, the hinged connection of the main tenon, main groove, secondary tenon, and secondary groove, all with curved cross-sections, allows for the transmission of tensile, compressive, and shear stresses at the segment joints. Simultaneously, it allows for limited rotation of the segments at the joints, eliminating stress concentration at the joints caused by earthquakes or excessive vehicle dynamic loads during operation, thus mitigating damage to the segment lining and extending the tunnel's service life. Figure 13 This is a plan view of the tunnel lining of the present invention, using a continuous joint pattern for the boltless segment. Figure 14 This is a plan view of the tunnel lining formed by assembling the boltless segments of the present invention in a staggered pattern.

[0070] It should be noted that the reinforced concrete segments of this invention no longer include bolts and nuts, thus eliminating bolt holes in the segments. Furthermore, the boltless segment assembly method solves the technical problems of segment cracking and water leakage caused by the easy corrosion of bolts and nuts when using bolts and nuts to fasten segments in existing prefabricated tunnel linings. Further, by eliminating the cumbersome processes of bolt drilling, washer installation, and electric torque wrench tightening, the positioning and placement of individual segments are almost simultaneous. The self-guiding features of the primary and secondary tenons reduce the need for manual hole correction, enabling rapid assembly of prefabricated segments. This not only reduces the labor intensity of construction workers but also eliminates the quality risks caused by forced assembly due to difficulties in bolt hole alignment. Moreover, since the all-concrete segment structure does not involve the corrosion of metal parts, the tunnel does not require bolt rust removal or replacement during its long operational life of up to 100 years, greatly reducing later maintenance costs and ensuring the long-term safety of the tunnel structure.

[0071] In summary, the boltless reinforced concrete segment structure for prefabricated tunnel lining provided by this invention achieves circumferential alignment and initial positioning through an elliptical main tenon, seals the structure by installing water-stopping material through a "︺"-shaped secondary tenon, achieves circumferential self-locking through the wedge design of the top segment, and finally achieves a stable longitudinal connection through the hinged joint of the inverted steps of the front and rear rings and the semi-circular secondary tenon. This invention's fully mechanical physical locking scheme completely solves the technical bottlenecks caused by traditional segment bolt holes, such as strength weakening, construction alignment difficulties, and metal corrosion failure. During assembly, the cumbersome processes of manually inserting bolts, installing washers, and tightening nuts are eliminated, greatly shortening the assembly time for each segment ring. Furthermore, since a large number of bolt hole molds are no longer needed inside the segments, the structural integrity of the prefabricated segments can be maximized, thereby effectively enhancing the long-term durability and safety of the tunnel structure.

[0072] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0073] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A boltless reinforced concrete segment structure for prefabricated tunnel lining, characterized in that, include: The left shoulder segment (4), the right shoulder segment (5), the top wedge segment (6), and the bottom segment (1), the left arch foot segment (2), and the right arch foot segment (3) with the same structure, the left end face (12301) and the right end face (12302) of the bottom segment (1), the left arch foot segment (2), and the right arch foot segment (3) are all straight and parallel to the tunnel extension direction; A first main groove (12303) is provided in the middle of the left end face (12301), and a first main tenon (12304) is provided in the middle of the right end face (12302). The cross-sections of the first main groove (12303) and the first main tenon (12304) are both elliptical. A first groove (12313) and a first tenon (12314) are symmetrically arranged on the radial inner and radial outer sides of the first main groove (12303) and the first main tenon (12304). The cross-sections of the first groove (12313) and the first tenon (12314) are both concave.

2. The boltless reinforced concrete segment structure according to claim 1, characterized in that, The left end face (401) of the left shoulder segment (4) is a straight face and parallel to the tunnel extension direction. The right end face (402) of the left shoulder segment (4) is an inclined plane and intersects with the tunnel extension direction. A fourth main tenon (404) is provided in the middle position of the left end face four (401), and a fourth main groove (403) is provided in the middle position of the right end face four (402). The fourth main groove (403) and the fourth main tenon (404) are symmetrically provided with a fourth secondary groove (413) and a fourth secondary tenon (414) on their radial inner and radial outer sides.

3. The boltless reinforced concrete segment structure according to claim 1, characterized in that, The right end face (502) of the right shoulder segment (5) is a straight face and parallel to the tunnel extension direction. The left end face (501) of the right shoulder segment (5) is an inclined surface and intersects with the tunnel extension direction. A fifth main groove (503) is provided at the middle position of both the left end face five (501) and the right end face five (502). The fifth main groove (503) is symmetrically provided with a fifth secondary groove (513) and a fifth secondary tenon (514) on its radial inner and radial outer sides.

4. The boltless reinforced concrete segment structure according to claim 1, characterized in that, The left end face 6 (601) and the right end face 6 (602) of the top wedge-shaped segment (6) are both inclined surfaces and intersect with the tunnel extension direction. The left end face six (601) and the right end face six (602) each have a sixth main tenon (604) at the middle position. The sixth main tenon (604) has a sixth groove (613) and a sixth tenon (614) symmetrically arranged on its radial inner and radial outer sides.

5. The boltless reinforced concrete segment structure according to claim 1, characterized in that, The central angles of the bottom segment (1), the left arch foot segment (2), and the right arch foot segment (3) are equal. The central angles of the left shoulder segment (4) and the right shoulder segment (5) are equal. The central angle corresponding to the rear end face of the top wedge-shaped tube (6) is greater than the central angle corresponding to its front end face.

6. The boltless reinforced concrete segment structure according to claim 4, characterized in that, The front end face (1606) and rear end face (1605) of the bottom segment (1), left arch foot segment (2), right arch foot segment (3), left arch shoulder segment (4), right arch shoulder segment (5), and top wedge segment (6) are all perpendicular to the tunnel extension direction. The cross-section of the front end face (1606) is an inverted step structure (7), the inner side of the inverted step structure (7) has a seventh arc surface (701), and the outer edge adjacent to the seventh arc surface (701) has a longitudinal seventh tenon (714). The cross-section of the rear end face (1605) is a positive step structure (8), the outer edge of the positive step structure (8) has an eighth arc surface (801), and there is a longitudinal eighth groove (813) on the inner side adjacent to the eighth arc surface (801). The inverted step structure (7) has a first secondary groove (713) and a second secondary groove (723) on both sides. The positive step structure (8) has a third groove (823) and an eighth tenon (824) on both sides.

7. The boltless reinforced concrete segment structure according to claim 6, characterized in that, The cross-sectional area of ​​the first main groove (12303) is larger than the cross-sectional area of ​​the first main tenon (12304); The cross-sectional areas of the first groove (12313) and the first tenon (12314) are both smaller than the cross-sectional area of ​​the first main tenon (12304); The cross-sections of the fourth main tenon (404), the sixth main tenon (604), the fourth main groove (403), and the fifth main groove (503) are all elliptical. The cross-sections of the first secondary groove (713) and the third protruding tenon (823) are both concave; The cross-sections of the second secondary groove (723) and the eighth protrusion (824) are both semi-circular.

8. The boltless reinforced concrete segment structure according to claim 1, characterized in that, Lifting through holes (9) are provided at the center of gravity of the bottom segment (1), left arch foot segment (2), right arch foot segment (3), left arch shoulder segment (4), right arch shoulder segment (5), and top wedge segment (6).

9. The boltless reinforced concrete segment structure according to claim 1, characterized in that, Water-resistant, slow-expansion sealing strips (10) are affixed to the first groove (12313), the fourth groove (413), the fifth groove (513), the sixth groove (613), the first secondary groove (713), and the third groove (823).

10. The boltless reinforced concrete segment structure according to claim 1, characterized in that, Along the radial direction of the tunnel, the bottom segment (1), left arch foot segment (2), right arch foot segment (3), left arch shoulder segment (4), right arch shoulder segment (5), and top wedge segment (6) have equal thicknesses and are 200~500mm thick; Along the tunnel extension direction, the bottom segment (1), left arch foot segment (2), right arch foot segment (3), left arch shoulder segment (4), right arch shoulder segment (5), and top wedge segment (6) are all of equal length and have a length of 1.2~1.8m.

Images