Pipe joint retreat prevention device for tunnel construction and retreat prevention method thereof

Abstract

This invention discloses a pipe section anti-reverse device and its method for tunnel construction, relating to the field of tunnel construction technology. The pipe section anti-reverse device includes several tensioning blocks sequentially hinged to form a ring-shaped clamping structure, a tensioning cylinder driving the clamping structure to contract, an elastic protective block that adaptively conforms to the pipe segment, and a tie rod transmitting the anti-reverse force. The number of tensioning blocks can be adjusted according to the pipe section diameter. Adjacent tensioning blocks form a two-force transmission structure through hinges. The tensioning cylinder is hinged to the tensioning blocks through a nested connecting block assembly. The anti-reverse method employs the aforementioned pipe section anti-reverse device. This invention achieves anti-reverse force through clamping friction, eliminating the need for pre-drilled anti-reverse holes in the pipe segment, thus avoiding damage to the pipe segment structure and sealing failure. The nested connecting block optimizes the cylinder force transmission path, and the modular design significantly improves the adaptability of large-diameter pipe sections. It can be used individually or in series with staggered placement, offering a wide adjustable range of anti-reverse force, and significantly improving construction efficiency and structural reliability.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and in particular to a pipe section anti-reverse device and method for tunnel construction. Background Technology

[0002] The pipe section anti-reverse device is a key piece of equipment in the pipe jacking tunnel construction process. It is mainly used to prevent the pipe jacking machine from retreating and to prevent axial displacement of the jacked pipe sections, thus ensuring construction safety and tunnel forming quality. During pipe jacking construction, when the jacking cylinder retracts to assemble the next pipe section, the jacked pipe section will be subject to the reaction force of the strata and will tend to retreat. If this displacement cannot be effectively limited, it will lead to serious problems such as cracking of pipe section joints and excessive axial deviation.

[0003] Currently, most mainstream pipe section anti-reverse devices use a connection method where anti-reverse pins mate with pre-drilled holes in the pipe segments, transmitting the anti-reverse force through the anti-reverse pins. Existing technologies, such as the invention patent application CN223577930U ("An anti-reverse structure for pipe sections in pipe jacking construction") and CN113374489B ("An anti-reverse device for starting a pipe jacking machine"), both share the following common technical defects:

[0004] Damage to the structural integrity of tunnel segments: Pre-fabrication of anti-backflow holes during the segment production stage not only increases the production process and cost of segments, but also damages the overall stress structure of the segments, leading to a reduction in local strength of the segments; at the same time, the pre-fabricated holes are difficult to seal in the later stage, which can easily cause tunnel leakage problems and seriously affect the service life of the tunnel.

[0005] Low construction efficiency: The anti-lock pins need to be manually inserted and removed. This process needs to be repeated for each pipe section assembly, which is time-consuming and poses safety risks for working at heights. This problem is particularly prominent in the construction of large-diameter tunnels.

[0006] Poor adaptability of large-diameter pipe segments: The clamping structure of existing devices is mostly fixed or semi-fixed, which cannot flexibly adapt to pipe segments of different diameters. Especially for large-diameter pipe segments with a diameter greater than 3 meters, the fit is insufficient, the anti-reverse force is unevenly distributed, and it is easy to cause local crushing damage to the pipe segments.

[0007] Therefore, developing a pipe section anti-reverse device that does not require a backlash pin, has strong adaptability, reasonable force transmission, and good anti-reverse effect is of great engineering significance for improving the efficiency of pipe jacking construction, ensuring construction safety, and project quality.

[0008] It should be noted that the above technical information is the result of the applicant's inventive analysis. This description is only intended to deepen the understanding of the general background technology of the present invention by those skilled in the art, and should not be regarded as an admission or implication in any form that the following technical information constitutes prior art known to those skilled in the art. Summary of the Invention

[0009] To address the shortcomings in the aforementioned background technology, this invention proposes a pipe segment anti-reverse device and its anti-reverse method for tunnel construction. The technical problem to be solved is that existing pipe segment anti-reverse devices rely on anti-reverse pins connected to precast holes, which poses risks of damage to the pipe segment structure and subsequent sealing failure, resulting in low construction efficiency and poor adaptability to large-diameter pipe segments.

[0010] The technical solution of this invention is as follows:

[0011] A tunnel segment anti-reverse device for tunnel construction includes several tensioning blocks, adjacent tensioning blocks are hinged together to form an annular clamping structure that can surround the outer circumference of the tunnel segment. The number of tensioning blocks can be adjusted according to the diameter of the tunnel segment; at least one tensioning cylinder, with its two ends hinged to two adjacent tensioning blocks respectively, is used to drive the annular clamping structure to contract and clamp the tunnel segment; a segment protection block is disposed on the inner surface of each tensioning block, the segment protection block is elastic and can adaptively deform under the clamping force to conform to the outer wall of the tunnel segment; several tie rods, one end of which is connected to the tensioning block, and the other end is used to connect to the starting tunnel wall to transfer the axial force on the tunnel segment to the starting tunnel wall. It should be noted that the tie rods can be connected to the starting tunnel wall directly or indirectly, for example, indirectly connected to the starting tunnel wall through a tunnel portal sealing structure.

[0012] Beneficial effects:

[0013] Completely abandoning the traditional anti-reverse pin structure, it adopts the principle of clamping friction to prevent reversal, eliminating the need for any pre-drilled holes on the segments, fundamentally avoiding the risk of reduced segment structural strength and later sealing failure, and extending the service life of the segments; adopting a modular hinged tensioning block design, the number of tensioning blocks can be flexibly increased or decreased according to the diameter of the segment, and the ring clamping structure has a high degree of fit with the outer wall of the segment, perfectly adapting to various specifications of segments, especially solving the industry pain point of anti-reversal for large-diameter segments; the elastic segment protection block can adapt to the slight curvature deviation and surface unevenness of the outer wall of the segment, evenly distributing the clamping force to the segment surface, avoiding segment damage caused by local stress concentration; the construction process is greatly simplified, eliminating the manual insertion and removal of anti-reverse pins, shortening the anti-reversal time of a single segment, improving construction efficiency, and eliminating the safety risks of high-altitude operations.

[0014] Based on the above technical solutions, as a preferred technical solution for the pipe section anti-reverse device used in tunnel construction, the inner surface of the tensioning block is an arc-shaped surface, and the two ends of the tensioning cylinder are hinged to the connected tensioning block through mutually nested connecting block assemblies.

[0015] Further beneficial effects of this technical solution: The inner side of the tensioning block adopts an arc-shaped surface design that matches the curvature of the outer wall of the segment, increasing the initial contact area with the segment and further improving the uniformity of the clamping force; The use of nested connecting block assemblies to connect the tensioning cylinder and the tensioning block allows the cylinder thrust to be transmitted along the tangential direction of the annular clamping structure, avoiding the additional bending moment generated by the cylinder force acting directly on the hinge node, thus improving the force transmission efficiency; The nested structure has a guiding function, ensuring the stability of the cylinder extension and retraction process and preventing the clamping structure from twisting and deforming.

[0016] Based on the above technical solution, as a preferred technical solution for the pipe section anti-reverse device used in tunnel construction, the connecting block assembly includes an inner connecting block and an outer connecting frame that are slidably fitted. The front and rear sides of one end of the inner connecting block are slidably fitted with the inner wall of the outer connecting frame, and the other end is hinged to the adjacent tensioning block. One end of the outer connecting frame is hinged to the adjacent tensioning block, and the other end is located outside the annular clamping structure. The two ends of the tensioning cylinder are respectively hinged to the inner connecting block and the end of the outer connecting frame away from the tensioning block.

[0017] Further beneficial effects of this technical solution: The inner connecting block and the outer connecting frame adopt a sliding fit structure, which can convert the linear thrust of the hydraulic cylinder into the circumferential contraction force of the annular clamping structure, with a force conversion efficiency of over 95%; The hydraulic cylinder is arranged outside the annular clamping structure, avoiding interference between the hydraulic cylinder and the pipe section, and facilitating the installation, maintenance and repair of the hydraulic cylinder; The structure is simple and compact, easy to process and manufacture, low in cost, and has a strong load-bearing capacity, capable of withstanding the thrust of large-tonnage hydraulic cylinders.

[0018] Based on the above technical solutions, as a preferred technical solution for the pipe section anti-reverse device used in tunnel construction, the inner surface of the inner connecting block is an arc-shaped surface and is provided with the segment protection block.

[0019] Further beneficial effects of this technical solution: The inner side of the inner connecting block is also provided with an arc-shaped surface and a segment protection block, so that the position of the connecting block assembly can also be closely fitted with the outer wall of the segment, eliminating the contact blind zone of the clamping structure, further increasing the effective friction area, and improving the anti-retraction force; ensuring the continuity and uniformity of the contact between the entire annular clamping structure and the segment, and avoiding stress concentration at the position of the connecting block.

[0020] Based on the above technical solution, as a preferred technical solution for the pipe section anti-reverse device used in tunnel construction, it further includes a base for fixing and connecting the foundation, wherein the tensioning block located at the bottom is supported above the base during use.

[0021] Further beneficial effects of this technical solution: The base provides stable bottom support for the entire anti-reverse device, preventing the device from sinking or shifting during the clamping and anti-reverse process, thus ensuring the working stability of the device; The base is fixedly connected to the foundation and can bear part of the vertical load, reducing the stress on the tensioning block and tie rod; The base can be flexibly adjusted according to the site foundation conditions, making it highly adaptable.

[0022] Based on the above technical solutions, as a preferred technical solution for the pipe section anti-reverse device used in tunnel construction, adjacent tensioning blocks are hinged by pins, so that each tensioning block forms a two-force bar structure, avoiding excessive bending moment in the local structure.

[0023] Further beneficial effects of this technical solution: The pin-hinged structure is simple and reliable, easy to assemble and disassemble, and flexible in rotation, ensuring the smooth contraction and opening of the ring-shaped clamping structure; each tensioning block forms a pure two-force bar structure, bearing only axial tension or compression, without bearing any bending moment, thus improving the utilization rate of structural strength and increasing the overall load-bearing capacity of the device with the same amount of material; it avoids plastic deformation or fracture of local structures due to excessive bending moment, significantly improving the service life and reliability of the device.

[0024] Based on the above technical solution, as a preferred technical solution for the pipe section anti-reverse device used in tunnel construction, each tensioning block is provided with a tie rod connection hole near the hinge position at both ends, and the tie rod is connected to the tensioning block through the tie rod connection hole.

[0025] Further beneficial effects of this technical solution: By placing the tie rod connection hole near the hinge position, the line of action of the tie rod's tension is basically coincident with the axis of the tension block, further eliminating additional bending moment and optimizing the force transmission path; each tension block has tie rod connection holes at both ends, allowing for flexible selection of the tie rod connection position according to the force conditions, achieving uniform distribution of anti-reverse force; the standardized tie rod connection hole design facilitates quick installation and disassembly of the tie rod, improving construction efficiency.

[0026] Based on the above technical solutions, as a preferred technical solution for the pipe section anti-reverse device used in tunnel construction, the pipe section anti-reverse device is used individually; or several are used in series along the axial direction of the pipe section, with the tie rods of each pipe section anti-reverse device arranged in a staggered manner in the circumferential direction.

[0027] Further beneficial effects of this technical solution: the usage method can be flexibly selected according to construction needs; a single set of devices can provide a wide range of anti-backlash force to meet the construction needs of small and medium diameter pipe jacking; when the anti-backlash force of a single set of devices is insufficient, multiple sets of devices can be connected in series along the pipe section axis, and the anti-backlash force is linearly superimposed with the number of devices, theoretically providing an infinitely large anti-backlash force to meet the construction needs of ultra-large thrust pipe jacking; the circumferentially staggered arrangement of the tie rods of the series devices avoids interference between the tie rods, and at the same time makes the circumferential force of the pipe section more uniform, preventing the pipe section from twisting.

[0028] A method for preventing pipe section backlash in tunnel construction, employing any of the pipe section backlash prevention devices described above, comprises the following steps:

[0029] S1: Determine the number of tensioning blocks according to the diameter of the pipe section to be constructed, hinge each tensioning block in sequence to form a ring clamping structure, and fix the base to the foundation.

[0030] S2: Fit the annular clamping structure onto the outer circumference of the pipe section, and adjust the initial angle of the tensioning cylinder so that the radial component of the cylinder force is within the preset range;

[0031] S3: Start the tensioning cylinder to drive the annular clamping structure to contract, so that the segment protection block is deformed by pressure and evenly adheres to the outer wall of the segment until the preset clamping force is reached;

[0032] S4: Connect one end of each of the multiple tie rods to the tie rod connection hole of each tensioning block, and fix the other end to the starting hole wall;

[0033] S5: When the pipe section is subjected to axial backward force, the frictional force generated between the segment protection block and the outer wall of the pipe section is transmitted to the starting tunnel wall through the tension block and the anti-pull rod, thereby stopping the pipe section from moving backward.

[0034] Beneficial effects: The construction steps are standardized and streamlined, the operation is simple and convenient, no professional skills training is required, and ordinary workers can quickly get started; by adjusting the initial angle of the tensioning cylinder, the radial force is precisely controlled, ensuring sufficient clamping friction while minimizing the radial pressure on the tunnel segments, achieving the optimal balance between anti-backlash force and segment protection; the preset clamping force can be flexibly adjusted according to different geological conditions and jacking thrust, with a wide range of applications and strong adaptability; the anti-backlash process is fully automatic, requiring no manual intervention, greatly improving construction safety and reliability.

[0035] Based on the above technical solutions, as a preferred technical solution for the pipe section anti-reverse method used in tunnel construction, in step S1, when the pipe section diameter is greater than 3 meters, the number of tensioning blocks is increased to increase the fitting degree between the annular clamping structure and the outer wall of the pipe section; in step S1, S3, or S5, when the anti-reverse force provided by a single anti-reverse device is insufficient or the preset clamping force is insufficient, the number of anti-reverse devices installed in series along the pipe section axis is increased.

[0036] Further beneficial effects of this technical solution: For large-diameter pipe sections, increasing the number of tensioning blocks improves the fitting degree, ensuring a uniform distribution of clamping force and effectively protecting the structural safety of large-diameter pipe segments; the number of devices can be added in series at any time before, during, or during the backlash prevention process, flexibly adjusting the backlash prevention force without interrupting construction, thus ensuring construction continuity; there is no need to redesign and manufacture larger-specification backlash prevention devices, as different backlash prevention force requirements can be met through modular combination, significantly reducing equipment costs.

[0037] Compared with the prior art, the beneficial effects of the present invention include:

[0038] Zero damage to segments: The pre-fabricated anti-reverse holes in the segments are completely eliminated, avoiding damage to the segment structure and sealing failure, thus fundamentally ensuring the integrity and durability of the segments.

[0039] Full diameter compatibility: The modular tensioning block design can be adapted to all series of pipe sections, especially solving the industry problem of preventing large-diameter pipe sections from slipping, and the device has extremely strong versatility.

[0040] High construction efficiency: It eliminates the need for manual insertion of anti-reverse pins, shortens the anti-reverse time of a single pipe section, greatly improves construction efficiency, and eliminates the safety risks of working at height.

[0041] Highly efficient force transmission structure: The force transmission design of two-force bar tensioning blocks + nested connecting blocks increases the structural strength utilization rate to over 90% and the load-bearing capacity by 50%, which can meet the needs of high-thrust pipe jacking construction.

[0042] Stepless adjustment of anti-reverse force: By adjusting the cylinder pressure and the number of series devices, the anti-reverse force can be steplessly adjusted, making it suitable for various complex geological conditions and construction conditions.

[0043] Low cost and high reliability: The structure is simple and compact, easy to process and manufacture, reusable, and reduces the overall construction cost by more than 30%; it also has no vulnerable parts, long service life, and low maintenance cost. Attached Figure Description

[0044] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the overall structure of a pipe section anti-reverse device for tunnel construction according to the present invention;

[0046] Figure 2 This is a schematic diagram of the hinged structure of adjacent tensioning blocks according to the present invention;

[0047] Figure 3 This is a detailed structural diagram of the tensioning block of the present invention;

[0048] Figure 4 This is a schematic diagram of the connection between the nested connecting block assembly and the tensioning cylinder of the present invention;

[0049] Figure 5 This is a detailed structural diagram of the outer connecting frame of the present invention;

[0050] Figure 6 This is a detailed structural diagram of the internal connecting block of the present invention;

[0051] Figure 7 This is a schematic diagram of an embodiment of the present invention that simplifies the number of tensioning blocks and omits the connecting block assembly;

[0052] Figure 8 This is a schematic diagram of the structure of the present invention, in which multiple sets of devices are used in series and the tie rods are misaligned circumferentially.

[0053] Explanation of reference numerals in the attached figures:

[0054] 1-Tightening block, 1-1-Pin hole, 1-2-Tie rod connecting hole, 2-Outer connecting frame, 2-1-Tie rod connecting hole, 2-2-Connecting block side plate one, 2-3-Oil cylinder connecting seat one, 3-Inner connecting block, 3-1-Tie rod connecting hole, 3-2-Connecting block side plate two, 3-3-Oil cylinder connecting seat two, 4-Segment protection block, 5-Base, 6-Tightening cylinder, 7-Tie rod, 8-Pin. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the core concept of the present invention and the following embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] These embodiments are provided to make the application thorough and complete, and to fully express the scope of the application to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​illustrated in these embodiments should be interpreted as merely exemplary and not as limiting.

[0057] It should be noted that, in the description of this application, unless otherwise stated, "several" means greater than or equal to one; the terms "upper," "lower," "left," "right," "inner," "outer," "axial," "radial," etc., indicating orientation or positional relationships are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0058] Furthermore, the terms "first," "second," and similar words used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0059] It should also be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0060] All terms used in this application have the same meaning as understood by one of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0061] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0062] The two-force bar structure described in this invention refers to a component that is in equilibrium under the action of only two forces along its axis, and only axial tensile or compressive stress is generated inside the component, with no bending stress. The "fit degree" refers to the percentage of the actual contact area between the annular clamping structure and the outer wall of the pipe section to the total circumferential area of ​​the pipe section. The nested connecting block assembly refers to a force transmission structure composed of a relatively sliding inner connecting block and an outer connecting frame.

[0063] Basic Implementation

[0064] This embodiment provides a pipe section anti-reverse device for tunnel construction, referenced. Figure 1 and Figure 7 , Figure 1 It includes 6 identical tensioning blocks 1, 2 tensioning cylinders 6, 6 segment protection blocks 4, 12 tie rods 7, and two connecting block assemblies; Figure 7 It includes two tensioning blocks 1, two tensioning cylinders 6, two segment protection blocks 4, and four tie rods 7.

[0065] The tensioning blocks 1 are all made of Q355B low-alloy high-strength steel, with a cross-sectional dimension of 160mm × 120mm and a length of 850mm. For example... Figure 2 As shown, adjacent tensioning blocks 1 are hinged together by hinges 8, forming an annular clamping structure around the outer circumference of the pipe section. The hinges 8 can be in various forms such as pins or bolts; in this embodiment, pins 8 are used. The pins 8 have a diameter of 45mm, are made of 40Cr, and have undergone surface quenching treatment to a hardness of HRC42-45. The number of tensioning blocks 1 can be flexibly adjusted according to the pipe section diameter; this embodiment is suitable for pipe sections with a diameter of 3m.

[0066] The tensioning cylinder 6 is a double-acting hydraulic cylinder with a cylinder diameter of 140mm, a rod diameter of 80mm, a rated working pressure of 20MPa, and a maximum stroke of 250mm. Figure 1 In the middle, the upper and lower sets of tensioning blocks 1 are hinged to the tensioning cylinder 6 through two connecting block assemblies, which are used to drive the annular clamping structure formed by the six identical tensioning blocks 1 to contract and generate clamping force. Figure 7 In the middle, the two ends of the tensioning cylinder 6 are respectively hinged to two adjacent tensioning blocks 1, which are used to drive the annular clamping structure formed by the two identical tensioning blocks 1 to contract and generate clamping force.

[0067] Each tensioning block 1 has a segment protection block 4 fixedly installed on its inner surface. The segment protection block 4 is elastic and can adapt to deformation under clamping force, tightly fitting the outer wall of the pipe section. In this embodiment, the segment protection block 4 is made of natural rubber and is bonded to the inner surface of the tensioning block 1 with high-strength structural adhesive.

[0068] All six tie rods 7 are made of φ36mm 40Cr round steel. One end is connected to the tensioning block 1, and the other end is fixed to the starting tunnel wall through embedded parts. The embedded parts are made of 20mm thick Q235 steel plates and are welded and fixed to the main reinforcement in the tunnel wall. Each embedded part can withstand a tensile force of not less than 200kN.

[0069] Preferred embodiment 1

[0070] This embodiment optimizes the inner surface of the tensioning block based on the basic embodiment.

[0071] The inner surface of the tensioning block 1 is machined into an arc shape, and the radius of curvature of the arc shape is the same as the outer radius of the pipe section to be constructed, which is 1500 mm in this embodiment. The arc shape design increases the initial contact area between the tensioning block 1 and the pipe segment, making the clamping force distribution more uniform.

[0072] Preferred embodiment 2

[0073] This embodiment optimizes the connection method of the tensioning cylinder based on the basic embodiment.

[0074] like Figure 1 and Figure 4 As shown, the two ends of the tensioning cylinder 6 are hinged to the connected tensioning block 1 via nested connecting block assemblies. Figure 4 As shown, the connecting block assembly includes an inner connecting block 3 and an outer connecting frame 2 that are in sliding engagement. The front and rear sides of one end of the inner connecting block 3 are in sliding engagement with the inner wall of the outer connecting frame 2, with a sliding clearance of 0.5mm-1mm. The other end is hinged to the left-side tensioning block 1 via a pin 8. One end of the outer connecting frame 2 is hinged to the right-side tensioning block 1 via a pin 8, and the other end extends to the outside of the annular clamping structure. The piston rod end of the tensioning cylinder 6 is hinged to the cylinder connecting seat 2-3 of the inner connecting block 3 via a pin, and the cylinder barrel end is hinged to the cylinder connecting seat 2-3 of the outer connecting frame 2 via a pin.

[0075] Preferably, such as Figures 4 to 6 As shown, both the inner connecting block 3 and the outer connecting frame 2 are frame structures. The connecting block side plates 3-2 on both sides of the inner connecting block 3 and the connecting block side plates 2-2 on both sides of the outer connecting frame 2 are in sliding fit.

[0076] Preferably, such as Figure 1 and Figure 6 As shown, the inner surface of the inner connecting block 3 is also machined into an arc-shaped surface that matches the curvature of the tube segment, and the tube segment protection block 4 is bonded to it with structural adhesive. In this way, the position of the connecting block assembly can also fit tightly against the outer wall of the tube segment, eliminating contact blind spots and increasing the effective friction area of ​​the entire annular clamping structure.

[0077] When the tensioning cylinder 6 extends, it pushes the inner connecting block 3 to slide outward along the inner wall of the outer connecting frame 2, while simultaneously causing the tensioning blocks 1 on both sides to rotate around the hinge point, thus contracting the annular clamping structure. This nested force transmission structure ensures that the cylinder thrust is transmitted entirely along the tangential direction of the annular structure, avoiding the generation of additional bending moments and achieving high force transmission efficiency.

[0078] Preferably, such as Figure 1 As shown, when six tension blocks 1 are used, the three upper tension blocks 1 are hinged together to form a set of components, and the three lower tension blocks 1 are hinged together to form a set of components. The two sets of components are hinged together by two connecting block assemblies.

[0079] Preferred Example 3

[0080] This embodiment adds a base 5 and optimizes the hinge method based on the basic embodiment.

[0081] This embodiment also includes a base 5 for fixing the foundation. In use, the tensioning block 1 located at the bottom is supported above the base 5.

[0082] Preferably, the base 5 is welded from a 25mm thick Q235 steel plate, and is U-shaped, with a length of 1200mm, a width of 600mm, and a height of 200mm. The bottom of the base 5 is fixedly connected to the foundation by M27 expansion bolts or a pre-embedded anchoring structure, and the top is provided with a support groove that matches the shape of the bottom tension block 1. In use, the bottom tension block 1 is embedded in the support groove to achieve stable support.

[0083] Preferably, adjacent tension blocks 1 are hinged together by pins 8, which pass through pin holes 1-1 at the ends of adjacent tension blocks 1 and are locked at both ends with cotter pins. This hinged connection ensures that each tension block 1 only bears tension along the axial direction when under stress, forming a pure two-force bar structure. Finite element analysis verifies that by adopting the two-force bar structure, the maximum stress of the tension block 1 is reduced, the structural strength utilization rate is improved, and the overall load-bearing capacity of the device is increased.

[0084] Preferred embodiment 4

[0085] This embodiment optimizes the position of the tie rod connecting hole based on the basic embodiment.

[0086] like Figure 3 As shown, each tensioning block 1 has a tie rod connecting hole 1-2 near the pin hole 1-1 at both ends, and the center distance between the tie rod connecting hole 1-2 and the center of the pin hole 1-1 is 100-500mm. Placing the tie rod connecting hole near the hinge position further eliminates the additional bending moment generated by the tie rod tension.

[0087] In this embodiment, each tensioning block 1 has a tie rod connecting hole 1-2 at each end, with a hole diameter of 38mm, which is compatible with a φ36mm tie rod 7. The tie rod 7 is connected to the tie rod connecting hole 1-2 via a pin, making installation and disassembly convenient and quick. Depending on construction needs, multiple tie rod connecting holes can also be provided on each tensioning block 1 to achieve greater anti-reverse force.

[0088] Preferred Example 5

[0089] This embodiment provides two ways of using the pipe section anti-reverse device.

[0090] Method 1: Use individually

[0091] Suitable for small and medium diameter pipe jacking construction with a diameter ≤3m and a jacking thrust ≤800kN. A single unit can provide a maximum anti-backlash force of 800kN, fully meeting construction requirements.

[0092] Method 2: Use in series

[0093] When the pipe section diameter is >3m or the jacking thrust is >800kN, multiple sets of anti-backlash devices should be installed in series along the pipe section axis. For example... Figure 8 As shown, in this embodiment, three sets of anti-reverse devices are installed in series, with axial clearance fit between the three sets. The tie rods 7 of the two sets of devices are staggered by 30° in the circumferential direction to avoid interference between the tie rods and to make the circumferential force on the pipe section more uniform.

[0094] When used in series, the anti-reverse force can be linearly superimposed. In this embodiment, the maximum anti-reverse force of a single device is 800kN, and the maximum anti-reverse force after two devices are connected in series can reach 1600kN. Depending on construction requirements, three or more devices can be installed in series, theoretically providing an infinitely large anti-reverse force.

[0095] Preferred Example 6

[0096] This embodiment provides two specific implementations of the segment protection block 4, both of which are flexible.

[0097] Implementation Method 1: Rubber Protective Block

[0098] Made of neoprene rubber, it is 25mm thick, with a Shore A65 hardness, tensile strength ≥15MPa, and elongation at break ≥500%. Neoprene rubber has good weather resistance, oil resistance, and abrasion resistance, making it suitable for damp underground environments with a service life of over 5 years. This protective block has strong deformation capacity, which can adapt well to minor deviations in the outer wall of the tunnel lining segment, making it suitable for construction scenarios with poor surface flatness of the tunnel lining segment.

[0099] Implementation Method 2: Polyurethane Protective Block

[0100] Made of cast polyurethane elastomer (CPU), it is 40mm thick, with a Shore A75 hardness, tensile strength ≥30MPa, and elongation at break ≥400%. Polyurethane material exhibits excellent abrasion resistance and tear resistance, with a service life more than three times that of rubber materials. This protective block provides greater friction, making it suitable for large-diameter pipe jacking construction scenarios requiring significant anti-rolling force.

[0101] Both types of protective blocks are connected to tension block 1 using a composite connection method of structural adhesive and countersunk bolts to ensure that they will not fall off under high friction.

[0102] Alternative implementation methods

[0103] The technical solution of the present invention also includes the following alternative embodiments, all of which are within the protection scope of the present invention:

[0104] Adjustment of the number of tensioning blocks: The number of tensioning blocks 1 is not limited to 6 and can be flexibly adjusted according to the pipe section diameter. For example... Figure 7 As shown, when the pipe section diameter is 2m, two tensioning blocks 1 can be hinged to form a ring-shaped clamping structure, and the ends of the two tensioning blocks 1 are inserted and slidably fitted. At this time, the widths of the two tensioning blocks 1 are different, so the two ends of one tensioning block 1 can be inserted into the two ends of the other tensioning block 1. When the pipe section diameter is 4m, eight tensioning blocks 1 can be used; when the pipe section diameter is 6m, twelve tensioning blocks 1 can be used.

[0105] Hinges can be replaced by other types of hinges, such as high-strength bolts or rivets, in addition to pins, as long as they can enable relative rotation between adjacent tensioning blocks 1.

[0106] Alternative drive methods: In addition to hydraulic cylinders, tensioning cylinder 6 can also use other drive devices such as pneumatic cylinders or electric push rods, as long as they can provide sufficient clamping force.

[0107] Alternative methods for connecting the base: In addition to using expansion bolts, the base 5 can also be connected to the foundation by pre-embedded bolts, chemical anchors, or by pouring concrete foundations, as long as the base 5 can be firmly fixed.

[0108] Alternatives to tie rod fixing methods: In addition to welding pre-embedded parts, tie rod 7 can also be fixed to the starting tunnel wall by anchoring with anchor bolts, tensioning with steel strands, etc., as long as it can withstand sufficient tension. Preferred embodiment

[0109] This embodiment is the optimal implementation method that covers all the technical features of the present invention, and is applicable to the construction of large-diameter pipe jacking with a diameter of 4m and a jacking thrust of 2000kN.

[0110] The pipe section anti-reverse device includes 8 modular tensioning blocks 1, 2 sets of nested connecting block assemblies, 2 tensioning cylinders 6, 10 segment protection blocks 4, 10 tie rods 7 and 1 base 5.

[0111] All eight tension blocks 1 are made of Q355B steel, with a cross-sectional dimension of 180mm × 140mm and a length of 1000mm. The inner surface is machined into an arc surface with a radius of curvature of 2000mm. Adjacent tension blocks 1 are hinged together by φ50mm 40Cr pins 8, forming a two-force bar structure. Each tension block 1 has a φ40mm tie rod connecting hole 1-2 near the pin holes at both ends.

[0112] Two sets of nested connecting block assemblies are symmetrically arranged on the left and right sides of the annular clamping structure. Each connecting block assembly includes an inner connecting block 3 and an outer connecting frame 2 with a sliding fit. The inner surfaces of both the inner connecting block 3 and the outer connecting frame 2 are machined into arc surfaces and are bonded with segment protection blocks 4.

[0113] Both tensioning cylinders 6 are bidirectional hydraulic cylinders with a cylinder diameter of 160mm and a rod diameter of 90mm, and a rated working pressure of 25MPa. The two ends of each tensioning cylinder 6 are hinged to the corresponding inner connecting block 3 and outer connecting frame 2, respectively. The initial working angle is adjusted to 12°, at which time the radial component of the cylinder force is about 21% of the total thrust.

[0114] The segment protection block 4 is made of cast polyurethane elastomer with a thickness of 35mm and a hardness of Shore A72. The surface is provided with a grid-like anti-slip texture with a depth of 2mm and a spacing of 5mm to further increase the friction.

[0115] The base 5 is welded from a 30mm thick Q235 steel plate and is fixedly connected to the foundation by 8 M30 expansion bolts. The bottom tension block 1 is stably supported in the support groove of the base 5.

[0116] This embodiment uses two sets of devices connected in series, with an axial distance of 2.5m between the two sets and the tie rods 7 staggered by 22.5° in the circumferential direction. The maximum anti-backlash force of a single set of devices is 1100kN, and the total anti-backlash force of the two sets connected in series can reach 2200kN, which meets the construction requirements of 2000kN jacking thrust.

[0117] The pipe section anti-retraction method of this embodiment includes the following steps:

[0118] S1: The diameter of the pipe section to be constructed is measured to be 4m. It is determined that each set of equipment uses 8 tension blocks 1 and 2 connecting block assemblies. The 8 tension blocks 1 and 2 connecting block assemblies are hinged together by pin 8 to form a ring clamping structure with a fitting degree of 97%. The base 5 is fixed on the foundation below the pipe section.

[0119] S2: Hoist the first set of annular clamping structures to the outer circumference of the pipe section and adjust the initial angle of the two tensioning cylinders 6. Install the second set of annular clamping structures in the same way, with the two sets of devices axially spaced and the tie rod connecting holes circumferentially offset by 30°.

[0120] S3: Simultaneously start the four tensioning cylinders 6 of the two sets of devices, slowly pressurize to 15MPa, hold the pressure for 5 minutes, so that the segment protection block 4 is evenly attached to the outer wall of the segment, and the clamping force of a single set of devices reaches 900kN.

[0121] S4: Connect the 10 tie rods 7 to the tie rod connection holes of the two sets of devices respectively, and fix the other end to the starting hole wall. Note that the tie rods of the two sets of devices are arranged in a staggered manner to avoid interference.

[0122] S5: Start pipe jacking construction. When the backlash force of the pipe section exceeds 1800kN, immediately install a third set of anti-backlash devices in series along the axial direction of the pipe section to increase the total anti-backlash force to 3300kN and ensure construction safety.

[0123] The device in this embodiment does not require pre-fabricated anti-backlash holes in the pipe segments, resulting in high construction efficiency, strong adaptability, efficient force transmission, and large anti-backlash force. It can perfectly solve the problem of pipe segment anti-backlash in large-diameter, high-thrust pipe jacking construction.

[0124] All aspects not detailed in this invention are conventional technical means known to those skilled in the art.

[0125] The above content shows and describes the basic principles, main features, and beneficial effects of the present invention. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A pipe section anti-reverse device for tunnel construction, characterized in that, include: Several tensioning blocks are connected by hinges to form a ring-shaped clamping structure that can surround the outer circumference of the pipe section. The number of tensioning blocks can be adjusted according to the diameter of the pipe section. At least one tensioning cylinder, with its two ends respectively hinged to two adjacent tensioning blocks, is used to drive the annular clamping structure to contract and clamp the pipe section; Segment protection blocks are disposed on the inner surface of each tensioning block. The segment protection blocks are elastic and can adaptively deform under the action of clamping force to fit the outer wall of the segment. Several tie rods, one end of which is connected to the tensioning block and the other end of which is connected to the starting hole wall, are used to transmit the axial force on the pipe section to the starting hole wall.

2. The pipe section anti-reverse device for tunnel construction according to claim 1, characterized in that, The inner surface of the tensioning block is an arc-shaped surface, and the two ends of the tensioning cylinder are hinged to the connected tensioning block through nested connecting block assemblies.

3. The pipe section anti-reverse device for tunnel construction according to claim 2, characterized in that, The connecting block assembly includes an inner connecting block and an outer connecting frame that slide together. The front and rear sides of one end of the inner connecting block slide together with the inner wall of the outer connecting frame, and the other end is hinged to an adjacent tensioning block. One end of the outer connecting frame is hinged to an adjacent tensioning block, and the other end is located outside the annular clamping structure. The two ends of the tensioning cylinder are respectively hinged to the inner connecting block and the end of the outer connecting frame away from the tensioning block.

4. The pipe section anti-reverse device for tunnel construction according to claim 3, characterized in that, The inner surface of the inner connecting block is arc-shaped and is provided with the segment protection block.

5. The pipe section anti-reverse device for tunnel construction according to any one of claims 1-4, characterized in that, It also includes a base for securing the foundation, wherein, in use, the tension block located at the bottom is supported above the base.

6. The pipe section anti-reverse device for tunnel construction according to claim 5, characterized in that, The adjacent tensioning blocks are hinged by pins, so that each tensioning block forms a two-force bar structure, avoiding excessive bending moment in the local structure.

7. The pipe section anti-reverse device for tunnel construction according to any one of claims 1-4 and 6, characterized in that, Each of the tensioning blocks has a tie rod connection hole near the hinge position at both ends, and the tie rod is connected to the tensioning block through the tie rod connection hole.

8. The pipe section anti-reverse device for tunnel construction according to any one of claims 1-4 and 6, characterized in that, The pipe section anti-reverse device can be used individually or in series along the pipe section axis, with the tie rods of each pipe section anti-reverse device arranged in a staggered manner in the circumferential direction.

9. A method for preventing pipe section backlash in tunnel construction, characterized in that, Using the pipe section anti-reverse device for tunnel construction as described in any one of claims 1-8, the following steps are performed: S1: Determine the number of tensioning blocks according to the diameter of the pipe section to be constructed, hinge each tensioning block in sequence to form a ring clamping structure, and fix the base to the foundation. S2: Fit the annular clamping structure onto the outer circumference of the pipe section, and adjust the initial angle of the tensioning cylinder so that the radial component of the cylinder force is within the preset range; S3: Start the tensioning cylinder to drive the annular clamping structure to contract, so that the segment protection block is deformed by pressure and evenly adheres to the outer wall of the segment until the preset clamping force is reached; S4: Connect one end of each of the multiple tie rods to the tie rod connection hole of each tensioning block, and fix the other end to the starting hole wall; S5: When the pipe section is subjected to axial backward force, the frictional force generated between the segment protection block and the outer wall of the pipe section is transmitted to the starting tunnel wall through the tension block and the anti-pull rod, thereby stopping the pipe section from moving backward.

10. The method for preventing pipe section backlash in tunnel construction according to claim 9, characterized in that, In step S1, when the pipe section diameter is greater than 3 meters, the number of tensioning blocks is increased to increase the fit between the annular clamping structure and the outer wall of the pipe section. In step S1, S3, or S5, when the anti-reverse force provided by a single anti-reverse device is insufficient or the preset clamping force is insufficient, the number of anti-reverse devices installed in series along the pipe section axis is increased.

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