Prestress corrugated plate hole body reinforcing structure and reinforcing method thereof

Abstract

The invention discloses a prestressed corrugated plate hole body reinforcing structure and a reinforcing method thereof.The reinforcing structure is composed of corrugated plate units, prestressed steel cables, end pouring locking bodies and a back concrete filling layer which are arranged in the circumferential direction of a hole body in a wall attaching mode, and a concrete inverted arch is arranged at the bottom of the hole body; the reinforcing method comprises the following steps: treating an inner side base surface of a newly built or existing hole body; the multiple corrugated plate units are assembled in a wall-attached mode in the circumferential direction, and prestressed steel cables are arranged along the wall-attached side wave troughs in a connecting and penetrating mode at the same time; a tensioning support is arranged to tension and anchor the two ends or the single side of the steel cable in a grading mode; an end locking body is poured in the reserved space of the support, and the tool is dismantled; pouring a back concrete filling layer between the plate body and the hole body from bottom to top; pouring an inverted arch as required to form a lower closed stress ring; under the working condition that the wall adhering side cannot be reached, the circumferential prestress wall adhering reinforcing structure is built in the circumferential direction of the hole body, seam opening is restrained, and the overall rigidity of the structure is improved; the method is suitable for supporting a newly-built hole body and reinforcing an existing hole body.

Description

Technical Field

[0001] This application relates to the field of tunnel support and reinforcement engineering, specifically to a prestressed corrugated plate tunnel reinforcement structure and its reinforcement method. Background Technology

[0002] A tunnel is an underground or semi-underground space structure enclosed by surrounding rock or artificial structures. Typical examples include highway and railway tunnels, urban utility tunnels, pipe jacking and culverts, shafts and connecting passages, etc. The cross-sectional shape can be circular, horseshoe-shaped, arched, rectangular, elliptical or other irregular shapes. Under the long-term effects of confining pressure, water pressure, vehicle dynamic loads, temperature and freeze-thaw cycles, seepage and chemical media, such structures often suffer from problems such as insufficient circumferential stiffness, cracks and leakage at the wall surface, poor coordination between the lining and the surrounding rock, and overall degradation. Existing tunnels also suffer from the additional adverse factors of material aging during the service life, disturbance during construction and the spread of defects.

[0003] Current reinforcement and repair practices can be broadly categorized into three types: First, using a combination of steel arch frames (or steel ribs) with shotcrete and steel mesh to form a secondary lining or thickened layer; second, adding a cast-in-place or prefabricated secondary lining (including inverted arch closure) to the inside of the original lining to improve circumferential load-bearing capacity and durability through thickening; and third, using lining plates for partial or full-section reinforcement, such as steel plate linings, fiberglass / carbon fiber reinforced composite panels, and corrugated steel linings, supplemented by anchor bolt connections and backfill grouting. While these methods are adaptable to situations where space is limited at the excavation face or in existing structures, they generally suffer from the following problems: long construction time, difficulty in establishing and maintaining controllable circumferential compressive stress in the ring direction, difficulty in achieving continuous fit of the backfill, and the tendency for joints and nodes to form weak rings.

[0004] Regarding the steel arch frame and shotcrete system, its stress path relies on the bond and frictional force transmission between the shotcrete layer and the original lining / surrounding rock, making it difficult to form a uniform circumferential compression state throughout the entire circumference. The shrinkage of the shotcrete layer and temperature effects can easily lead to secondary cracking, and local voids are difficult to identify and remedy in time when the wall is not tightly adhered. Although adding a secondary lining and closing the invert arch can improve the overall integrity, the installation of formwork, reinforcement binding and concrete pouring have high requirements for the width of the construction surface, traffic organization and ventilation and drainage. Moreover, in existing tunnels, it is often constrained by pipelines, track beds and existing equipment, resulting in complex construction organization and significant disruption to the construction period and traffic.

[0005] Traditional corrugated plate construction typically involves prefabricating arch segments at a specific center angle in a factory, then assembling them sequentially along the inner wall on-site to form an arch ring. Grouting is then used to fill the gaps between the arch ring and the surrounding rock to create a support layer. This process relies on bolted connections at the arch segment edge flanges. However, due to clearance and operational limitations, construction workers often place anchor bolts on the inner side of the arch ring (cavity side), making it difficult to achieve connections of equal strength and density on the side closest to the cave wall. This results in asymmetry in circumferential constraint. Under external loads, the support bears combined radial and tangential forces. When the cave undergoes minor deformation or displacement, the side closest to the wall is prone to joint opening or partial detachment due to insufficient constraint. Force flow concentrates at joints and transitions, increasing the risk of leakage and bolt failure, thus affecting overall stability. In areas with complex curvature or variable cross-sections, the difficulty of waveform matching, assembly tolerance control, and backfill continuity control further increases.

[0006] In summary, existing technologies urgently need to construct a reinforcement system that can achieve controllable circumferential action, continuous wall adhesion, and maintain integrity under conditions of unilateral operation and inaccessibility of the wall-adhering side.

[0007] Application content

[0008] This application proposes a prestressed corrugated slab cavity reinforcement structure and reinforcement method to solve the problems in the prior art.

[0009] To achieve the above objectives, the technical solution proposed in this application is as follows:

[0010] In the first aspect, this application provides a method for reinforcing prestressed corrugated slab cavities, comprising the following steps:

[0011] Step a: Construct the tunnel and repair the base surface; or clean, level, and treat the interface of the existing tunnel interior base surface.

[0012] Step b: Multiple corrugated plate units are sequentially installed along the circumference of the tunnel wall, and adjacent corrugated plate units are connected to the tunnel side by bolts through bolt holes on the connecting end plate; the crests and troughs of adjacent corrugated plate units continue sequentially in the connection direction, and multiple corrugated plate units form a continuous trough line along the circumference.

[0013] Step c: During the circumferential splicing process described in step b, prestressed steel cables are simultaneously threaded along the continuous trough line on the wall side until the prestressed steel cables penetrate all the corrugated plate units in the circumferential direction, and the prestressed steel cables extend beyond the connection range of multiple corrugated plate units to form exposed sections.

[0014] Step d: Use tensioning supports to tension the exposed section of the prestressed steel cable in stages to the design prestress value, and fix the exposed section of the prestressed steel cable with anchoring system;

[0015] Step e: Cast the anchoring system and the prestressed steel cable segment where the anchoring system is located within the formwork space reserved on the tensioning support to form an end casting locking body;

[0016] Step f: Cut off the prestressed steel cables other than the end-cast locking body and remove the tensioning support;

[0017] Step g: Pour a back concrete filling layer between the corrugated plate unit and the tunnel body. The back concrete filling layer is integrated with the corrugated plate unit, prestressed steel cable and the inner side of the tunnel body to form a continuous reinforced lining along the circumference of the tunnel body.

[0018] Further, in step h, after completing the pouring of the concrete filling layer behind, the formwork is erected and the concrete inverted arch is poured. The end casting locking body is poured into the concrete inverted arch and fixed together to form a closed force ring.

[0019] Furthermore, in step d, the graded tensioning is carried out in the form of symmetrical tensioning and zoned tensioning, and each grade of tensioning is controlled by two parameters: tension force and elongation. After each grade of tensioning, the pressure is stabilized and the elongation is remeasured. If the tension is insufficient, supplementary tensioning is performed.

[0020] Secondly, this application provides a prestressed corrugated plate tunnel reinforcement structure, which is installed along the circumference of the tunnel wall on the inner side of the tunnel, characterized in that it includes a prestressed corrugated plate system, a concrete system and an anchoring system;

[0021] The prestressed corrugated plate system includes multiple corrugated plate units connected in sequence. Each corrugated plate unit includes a corrugated plate body and at least two connecting end plates. The connecting end plates are fixed to the ends of the corrugated plate body and are perpendicular to the surface of the corrugated plate body.

[0022] The connecting end plate is provided with a first row of holes and a second row of holes along its length direction. The first row of holes and the second row of holes are arranged separately in the width direction of the same connecting end plate and are located on the upper and lower sides of the corrugated plate body respectively. The first row of holes are cable-passing holes, and the cable-passing holes correspond to the trough positions of the corrugated plate body on that side. The second row of holes are bolting holes, and the bolting holes are used to connect adjacent corrugated plate units with bolts.

[0023] The crests and troughs of adjacent corrugated plate units continue sequentially in the connection direction; prestressed steel cables are installed within the continuous trough lines of multiple corrugated plate units, and the prestressed steel cables pass through the corresponding cable holes in sequence and are in a tensile anchored state in the finished product state; the two ends of each prestressed steel cable extend beyond the connection range of multiple corrugated plate units to form exposed sections, and the exposed sections are fixed to the anchoring system after being prestressed by the tensioning support and are in a prestressed tensile state;

[0024] The concrete system includes a back concrete filling layer between the corrugated plate body and the cavity, and an end-cast locking body at the end of the prestressed steel cable, wherein the end-cast locking body is integrally fixed with the anchoring system.

[0025] Furthermore, the concrete system also includes a concrete inverted arch, and the end-cast locking body is integrally fixed to the concrete inverted arch.

[0026] Furthermore, guide cable limiting members are provided at intervals along the connection direction within the troughs of the corrugated plate body. The guide cable limiting members are fixedly connected to the corrugated plate body and are provided with circular or semi-circular grooves that match the shape of the prestressed steel cable.

[0027] Furthermore, the corrugated plate unit also includes a connecting side plate, which is perpendicular to the connecting end plate and fixed to both sides of the corrugated plate body, and the connecting side plate is provided with lateral connecting holes.

[0028] Furthermore, the anchoring system includes a nut anchor, a tapered anchor, or a tension-adjustable anchor.

[0029] Furthermore, the waveform of the corrugated plate body is a sinusoidal wave, a triangular zigzag, a trapezoidal zigzag, or a right-angled zigzag.

[0030] Furthermore, the prestressed steel cable includes reinforcing steel cable, steel strand, single high-strength steel wire, parallel steel wire bundle, or fiber-reinforced composite material cable.

[0031] Furthermore, the tensioning support includes a load-bearing frame, a tensioning mechanism, and a guiding mechanism disposed within the load-bearing frame;

[0032] The load-bearing frame includes a base plate, side plates, guide partition columns, and comb-shaped guide cable plates. The base plate is located at the lower end, and two side plates are erected along both ends of the base plate and are vertically fixed to the base plate. A number of guide partition columns are spaced apart between the two side plates. The guide partition columns are fixed to the base plate and extend upward. The comb-shaped guide cable plates are horizontally fixed to the upper ends of the side plates and the guide partition columns. A number of independent guide channels are formed between adjacent guide partition columns.

[0033] The tensioning mechanism includes a tensioning device mounting base, horizontal guide frames, jacks, and a reaction beam; the tensioning device mounting base is fixed to one side of the load-bearing frame, the two horizontal guide frames are fixed at both ends of the tensioning device mounting base and perpendicular to the load-bearing frame, the reaction beam is movably disposed between the two horizontal guide frames, and the bottom end and piston end of the jack are fixed to the tensioning device mounting base and the reaction beam, respectively.

[0034] The guiding mechanism includes a guide cable groove, a guide horizontal shaft, and a cable threading guide hole; multiple guide cable grooves are evenly opened on the upper edge of the comb-shaped guide cable plate; the guide horizontal shaft is horizontally arranged in the lower part of the load-bearing frame, passes through several guide channels, and is connected to the two side upright plates; multiple cable threading guide holes are opened on the tensioning device mounting base, and the guide cable groove, guide channel, and cable threading guide hole are aligned in sequence.

[0035] A formwork space for forming the end casting locking body is provided in the guide channel, and the formwork space can be used to arrange templates and pour concrete.

[0036] Compared with the prior art, the beneficial effects of this application are:

[0037] This reinforcement method addresses situations where the wall-adhering side is inaccessible or difficult to weld or bolt on. It employs a construction sequence of "wall-adhering assembly - simultaneous connection and threading - staged tensioning - end-casting and locking - backfilling," facilitating bolt tightening, cable threading, tensioning, and end-locking on the cavity side, avoiding reliance on wall-adhering construction. Staged tensioning is implemented symmetrically and in a zoned sequence, controlled by dual parameters of tension force and elongation, with pressure stabilization and retesting, and necessary supplementary tensioning, facilitating control of prestress level and circumferential internal force distribution. The tensioning support reserves end formwork space, allowing the anchor and end-casting locking body to be formed on the same working surface, followed by the removal of exposed sections other than the locking body and dismantling of the support. Backfilling with concrete on the cavity side facilitates air venting and grout overflow, promoting wall continuity and interface bonding. This method is suitable for confined spaces and single-sided operations in tunnels, culverts, and other similar scenarios.

[0038] The reinforcement structure of this application sets and tensions prestressed steel cables within the continuous trough lines on the wall-attached side. The prestressed steel cables are integrally fixed with the corrugated plate body and connecting end plates, forming a tensile constraint on the joints of adjacent connecting end plates along the connection direction of the corrugated plate. This compensates for the inability to implement bolted connections on the wall-attached side and restricts the opening of the joints of the connecting end plates on the wall-attached side. The prestressed steel cables, in conjunction with the cable-passing holes and guide cable limiting components, can connect the discretely assembled corrugated plate units into a continuous force path. The end-cast locking body is integrally fixed with the anchoring system, which is beneficial for maintaining the prestress over a long period and reducing losses caused by displacement, relaxation, etc. The concrete filling layer behind it forms a wall-attached surface contact force transmission with the corrugated plate and the cavity, reducing voids and leakage channels on the wall-attached side and improving circumferential stiffness and overall stability. If necessary, it forms a closed force ring with the concrete invert arch to further improve the reinforcement strength and control uneven deformation.

[0039] Of course, implementing the various technical solutions of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0041] Figures 1-5 This is a schematic diagram of the cavity reinforcement method according to an embodiment of this application;

[0042] Figure 6 yes Figure 2 Enlarged view of point A;

[0043] Figure 7 yes Figure 2 Enlarged view of point B;

[0044] Figure 8 yes Figure 2 Enlarged view of point C;

[0045] Figure 9 This is a schematic diagram of the structure of the corrugated plate unit according to an embodiment of this application;

[0046] Figure 10 and Figure 11 This is a schematic diagram of the overall structure of the tension support according to an embodiment of this application;

[0047] Figure 12 This is a schematic diagram of the tensioning process of the tensioning support according to an embodiment of this application;

[0048] Figure 13 This is a flowchart of the cavity reinforcement method according to an embodiment of this application;

[0049] In the figure, 1-corrugated plate unit, 101-corrugated plate body, 102-connecting end plate, 103-connecting side plate, 104-cable hole, 105-bolt hole, 106-guide cable limiting component, 107-end casting locking body;

[0050] 2-High-strength bolts;

[0051] 3-Prestressed steel cable;

[0052] 4-Tensioning support, 401-Comb-shaped guide plate, 402-Guide groove, 403-Side plate fixing hole, 404-Side upright plate, 405-Guide horizontal shaft, 406-Triangular stiffening plate, 407-Tensioning device mounting base, 408-Cable threading guide hole, 409-Jack, 410-Reaction beam, 411-Horizontal guide frame, 412-Guide partition column, 413-Base plate;

[0053] 5- Concrete filling layer behind;

[0054] 6- Concrete inverted arch. Detailed Implementation

[0055] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0056] In the description of this patent, it should be understood that the terms “center,” “upper,” “lower,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this patent 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 patent.

[0057] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0058] Example 1:

[0059] See Figure 13 This embodiment provides a method for reinforcing prestressed corrugated slab cavities, including the following steps:

[0060] Step a, Tunnel Construction and Repair: Newly excavated tunnels are constructed and the base surface is repaired; or the base surface inside existing tunnels is cleaned, leveled, and the interface is treated; before construction, seepage points, loose blocks, and residues are removed, and temporary drainage and local leveling are carried out if necessary to meet the flatness and cleanliness requirements of subsequent wall-mounted installation.

[0061] Step b, Corrugated plate unit wall-mounted assembly and cavity-side bolting: Multiple corrugated plate units 1 are sequentially mounted against the circumference of the cavity; adjacent corrugated plate units 1 are connected and fixed to the cavity side by high-strength bolts 2 through bolting holes 105 on the connecting end plate 102; the crests and troughs of adjacent corrugated plate units 1 continue sequentially in the connection direction, forming a continuous trough line along the circumference.

[0062] Step c, Synchronous Cable Insertion and Exposed Section Reservation on the Wall Side: During the circumferential splicing process of step b, prestressed steel cables 3 are synchronously inserted along the continuous trough line on the wall side, so that the prestressed steel cables 3 pass through the cable insertion holes 104 of each connecting end plate 102 in sequence, and are positioned and limited within the trough by the guide cable limiting member 106, until the prestressed steel cables 3 penetrate all the corrugated plate units 1 in the circumference; the two ends of the prestressed steel cables 3 extend beyond the connection range of multiple corrugated plate units 1 to form exposed sections, which are used for subsequent tensioning and locking. See [link to relevant documentation]. Figure 1 and Figure 2 Guide cable limiting members 106 are arranged at intervals along the arched connection direction within the troughs of the corrugated plate body 101. The guide cable limiting members 106 are provided with circular or semi-circular grooves that match the shape of the prestressed steel cable 3. The guide cable limiting members 106 are reliably connected to the corrugated plate body 101 by welding. The guide cable limiting members 106 are used to position, guide and limit the prestressed steel cable 3, constraining the cable body to a predetermined position within the trough and controlling lateral displacement.

[0063] Step d, tensioning and anchoring of tension supports: Tension supports 4 are installed, and the exposed sections of the prestressed cables 3 are tensioned in stages; tensioning is organized according to symmetrical and zoned tensioning procedures, see [link to procedure]. Figure 3 During tensioning, both tension force and elongation are controlled using dual parameters. After each stage of tensioning, the pressure is stabilized and retested, and supplementary tension is applied if under-tension is detected. After tensioning is completed, the exposed section of the prestressed cable 3 is fixed using an anchoring system. In other embodiments, the prestressed cable 3 can also be fixed on one side and then subjected to unilateral staged tensioning and anchoring.

[0064] Step e, End casting locking body formation: Using the formwork space reserved on the tension support 4, concrete is poured for the anchoring system and the prestressed steel cable section where it is located. After the concrete reaches the demolding strength, the formwork is removed to form the end casting locking body 107, which is integrally fixed with the anchoring system.

[0065] Step f, Cable Cutting and Removal of Tensioning Support: Cut off the prestressed steel cables 3 other than the end-cast locking body 107. After cutting the prestressed steel cables 3, remove the tensioning support 4 and other corresponding temporary fixtures. See [link to relevant documentation]. Figure 4 .

[0066] Step g, Concrete filling layer pouring and consolidation: Concrete filling layer 5 is poured from bottom to top between corrugated plate unit 1 and the tunnel body. Air is vented and overflow is observed in sections and compartments. It is cured to the design strength so that the concrete filling layer 5 is consolidated with the corrugated plate body 101, connecting end plate 102, prestressed steel cable 3 and the inside of the tunnel body, thereby forming a continuous reinforced lining along the circumference of the tunnel body.

[0067] Step h, Concrete Invert Arch Casting and Closed Load-Bearing Ring Formation: After completing the back concrete filling layer 5, formwork is erected and the concrete invert arch 6 is cast. The end-cast locking body 107 can be integrated with the invert arch 6 to form a closed load-bearing ring and improve overall stability. See [link to relevant documentation]. Figure 5 .

[0068] For long-distance support requirements, adjacent reinforcing structures can be connected in parallel through the lateral connection holes of the connecting side plates 103 using high-strength bolts 2, forming a continuous reinforcing unit along the line direction and ensuring the continuity of force and alignment. The construction of the concrete filling layer 5 behind can be carried out by either a single overall grouting or staged grouting, depending on the working conditions: when supporting new tunnel excavation, it is advisable to complete steps b-e in sections and then implement step g in sections to allow for air venting, observation of grout overflow, and control of relative displacement between sections; when there are limitations on the existing tunnel or construction surface, step g can be implemented uniformly after several sections are completed, and if necessary, it can be coordinated with the pouring of the concrete invert arch 6 in step h.

[0069] See Figures 10 to 12 In this embodiment, the tensioning support 4 is mainly composed of a load-bearing frame, a tensioning mechanism and a guiding mechanism, and is used to tension, guide and anchor the prestressed steel cable 3.

[0070] The load-bearing frame includes a base plate 413, side uprights 404, guide partition columns 412, and a comb-shaped guide cable plate 401. The base plate 413 is located at the lower end, and two side uprights 404 are vertically arranged along both ends of the base plate 413 and vertically fixed to the base plate 413. Several guide partition columns 412 are arranged laterally between the two side uprights 404. The bottom end of the partition column is fixed to the base plate 413, extends upward, and is fixedly connected to the lower surface of the comb-shaped guide cable plate 401, thereby connecting with the side uprights 404, the base plate 413, and the comb-shaped guide cable plate. 401 forms an integral rigid frame; the comb-shaped guide cable plate 401 is horizontally fixed to the upper end of the load-bearing frame, and the comb teeth are evenly distributed with guide cable grooves 402 along the horizontal direction, thus forming several independent guide channels between adjacent guide partition columns 412; this structure can achieve the separation and guidance of multiple parallel prestressed steel cables 3, avoid mutual interference, and maintain uniform force; the comb-shaped guide cable plate 401 is also provided with side plate positioning holes 403, which can be used to temporarily fix the side plate to the support by bolts when installing the corrugated plate unit 1.

[0071] The tensioning mechanism consists of a tensioning device mounting base 407, horizontal guide frames 411, a tensioning device 409, and a reaction beam 410. The tensioning device mounting base 407 is fixed to one side of the load-bearing frame and connected to the side upright plate 404. Two horizontal guide frames 411 are fixed to both ends of the mounting base 407 and extend horizontally, remaining perpendicular to the load-bearing frame. The reaction beam 410 is movably disposed between the two horizontal guide frames 411, and its two ends are connected to the guide frames via sliders, allowing it to move horizontally. In this embodiment, the tensioning device 409 is preferably a jack, and the bottom end of the tensioning device 409 is fixed to the mounting base 407. On the mounting base 407, its piston end is fixedly connected to the reaction beam 410, so that when the tensioning device 409 extends or retracts, it drives the reaction beam 410 to move, forming a tensioning effect on the prestressed steel cable 3; the reaction beam 410 has several cable-passing fixing holes arranged in the transverse direction, and these cable-passing fixing holes correspond one-to-one with the cable-passing guide holes 408 on the mounting base 407, ensuring that the prestressed steel cable 3 maintains a stable position during the tensioning process; in order to improve the stability of the frame, several triangular stiffening plates 406 are also arranged between the side upright plate 404 and the mounting base 407 to bear the local stress when the tensioning device 409 transmits thrust.

[0072] In this embodiment, the tensioning mechanism of the prestressed corrugated plate tensioning support is provided with two tensioning devices; the two tensioning devices 409 are symmetrically installed at both ends of the tensioning device mounting base 407 and are respectively connected to both ends of the reaction beam 410; through the arrangement of double jacks, the reaction beam 410 is subjected to more balanced forces during the tensioning process, and can simultaneously apply synchronous tensioning force to multiple prestressed steel cables 3; compared with the single jack drive, this structure can effectively reduce the eccentric force and tilting deformation of the reaction beam 410, and improve the tensioning accuracy and stability; for working conditions that require large-tonnage tensioning or multiple prestressed steel cables 3 to be arranged in parallel, the double jack configuration can significantly improve construction efficiency and force uniformity, ensuring that each prestressed steel cable 3 obtains a consistent tensioning effect.

[0073] The guiding mechanism includes guide grooves 402 on the comb-shaped guide plate 401, a guide horizontal shaft 405 at the bottom of the load-bearing frame, and cable-threading guide holes 08 on the tensioning device mounting base 7. Multiple guide grooves 402 are evenly opened on the upper edge of the comb-shaped guide plate 401 for initial separation and positioning of the prestressed steel cables 3. The guide horizontal shaft 405 is laterally installed through the bottom of the load-bearing frame and connected to two side upright plates 404 through a shaft seat. The guide horizontal shaft 405 is used to guide the prestressed steel cables 3 by turning and changing their running direction from longitudinal to transverse, so that the prestressed steel cables 3 can be tensioned in the horizontal direction. Several cable-threading guide holes 408 are opened on the tensioning device mounting base 407 and are aligned with the guide grooves 402 and the guide channel in sequence to form a through cable-threading path. To reduce friction and wear of the prestressed steel cables 3 during the tensioning process, replaceable wear-resistant bushings can be installed in the guide grooves 402 and the cable-threading guide holes 408.

[0074] During use, the prestressed steel cables 3 can sequentially pass through the guide cable groove 402, guide channel, guide horizontal shaft 405, and cable-passing guide hole 408, and be fixed in the cable-passing fixing hole of the reaction beam 410 by mechanical anchors; then, the tensioning device 409 applies a thrust to the reaction beam 410 to achieve synchronous tensioning of the prestressed steel cables 3; since the guide channel can separate and position multiple prestressed steel cables 3, and with the uniform distribution design of the comb-shaped guide plate 401, it can ensure that multiple prestressed steel cables 3 are subjected to uniform force, avoid mutual crossing or offset, and improve tensioning accuracy and construction efficiency; in addition, the entire support can be directly placed in the predetermined position on the construction site, and its base plate is fixed to the foundation or platform, ensuring the stability of the entire tensioning process.

[0075] In this embodiment, a formwork space is provided in the guide channel of the load-bearing frame for pouring the end casting locking body 107; during construction, the formwork is arranged in the guide channel, and concrete is poured directly into the formwork space after the cable is threaded.

[0076] Example 2:

[0077] This embodiment provides a prestressed corrugated plate tunnel reinforcement structure. This reinforcement structure is installed along the circumference of the tunnel wall on the inner side of the tunnel body and includes a prestressed corrugated plate system, a concrete system, and an anchoring system. The prestressed corrugated plate system uses corrugated plate units as basic units. High-strength bolts are used to connect the cables to the tunnel walls via cable-passing holes and bolting holes arranged on the connecting end plates, achieving continuous cable passage along the wall-mounted side. The prestressed cables are arranged along the continuous trough lines on the wall-mounted side and are positioned and guided by guide cable limiters, forming a tie constraint on the joints of the connecting end plates on the wall-mounted side. The prestressed cables are maintained at both ends by end-cast locking bodies fixed to the anchoring system. The corrugated plate units, prestressed cables, and the inner wall of the tunnel are integrally fixed through a backfill concrete layer, forming a continuous circumferential lining for surface contact force transmission. If necessary, a concrete invert arch can be configured to form a lower closed load-bearing ring. After the concrete filling layer behind it is solidified, the guide cable limiting component and the corrugated plate body together form a fixed guiding channel for the prestressed steel cable, and form a reinforcing rib structure at the trough position to improve the stability and buckling resistance of the wall side; the tensioning support is only used for tensioning during construction and forming support for the end casting locking body, and is not retained as a component in the final product.

[0078] For details, see Figures 1-9 The prestressed corrugated slab system comprises multiple corrugated slab units 1 connected sequentially along the inner wall of the tunnel; see also Figure 9 Each corrugated plate unit 1 includes a corrugated plate body 101, connecting end plates 102 fixedly welded to both ends of the corrugated plate body 101 and perpendicular to the surface of the corrugated plate body 101, and connecting side plates 103 fixedly welded to both sides of the corrugated plate body 101 and perpendicular to the surface of the corrugated plate body 101.

[0079] See Figure 9 Two sets of holes are arranged along the length of each corrugated plate unit 1 on the connecting end plate 102, namely the first hole row and the second hole row, as shown in the figure. Figure 6 The first row of holes consists of cable-passing holes 104, each cable-passing hole 104 corresponding one-to-one with the trough position of the corrugated plate body 101 on that side; see also Figure 8 The second hole is a bolt hole 105. Relative to the cable threading hole 104, the bolt hole 105 is located on the other side of the corrugated plate body 101. The bolt hole 105 is used for adjacent corrugated plate units 1 to realize the bolt connection of the connecting end plate 102 to the connecting end plate 102 through high-strength bolts 2.

[0080] See Figure 2 When two adjacent corrugated plate units 1 are assembled, their waveform phases are aligned so that the corresponding peaks and troughs continue continuously in the arching connection direction, forming multiple continuous peak and trough lines. On the outside of the arch ring, a prestressed steel cable 3 is set in each continuous trough line. The prestressed steel cable 3 passes through the cable holes 104 of the stacked connecting end plates 102 in sequence according to the arching connection direction, and extends continuously in the trough line until both ends protrude to form exposed sections. Tensioning supports 4 are set to apply pre-tension force to the exposed sections, so that the prestressed steel cable 3 is stretched to the design value and kept taut. The prestressed steel cable 3 forms a circumferential (connection direction) tie constraint in the trough line, which limits the relative opening displacement of the joint of the end plates of adjacent corrugated plate units, thereby suppressing the opening of the wall side and forming the cable and plate to share the force. Then, the exposed sections at both ends of each prestressed steel cable 3 are anchored to the anchoring system. In this embodiment, the anchoring system is a tapered anchor. In other embodiments, the anchoring system can also be a nut anchor, an adjustable anchor, etc., to adapt to different prestressed steel cables and construction conditions.

[0081] See Figure 7 In this embodiment, to ensure the guidance and positioning of the prestressed steel cable 3 within the corrugated plate unit 1, guide cable limiting members 106 are arranged at intervals along the arched connection direction within the troughs of the corrugated plate body 101. The guide cable limiting members 106 are provided with circular or semi-circular grooves that match the shape of the prestressed steel cable 3. The guide cable limiting members 106 are reliably connected to the corrugated plate body 101 by welding. The guide cable limiting members 106 are used to position, guide, and limit the prestressed steel cable 3, constraining the cable body within the corrugated plate unit 1. The prestressed cable 3 is positioned within the valley to control lateral displacement. A stable guiding channel is provided through a circular or semi-circular groove to reduce direct friction between the prestressed cable 3 and the corrugated plate body 101 during cable threading and tensioning. This avoids local scraping, additional bending, and cable force loss during tensioning of the prestressed cable 3, ensuring that the prestressed cable 3 is stressed along the designed trajectory and stably reaches the pretension. At the same time, the position of the prestressed cable 3 is kept stable during grouting, which facilitates the formation of a uniform filling layer and reliable force transmission.

[0082] The concrete system includes a backfill concrete layer 5 between the corrugated plate unit 1 and the tunnel body, and end-cast locking bodies 107 at the ends of the prestressed steel cables 3. The end-cast locking bodies 107 are integrally fixed with the anchoring system locking the ends of the prestressed steel cables 3. Concrete is poured in the anchoring system and the prestressed steel cable section therein, and a casting locking body 107 is formed at both ends of each tensioned prestressed steel cable 3. The casting locking bodies 107 are used to maintain the prestress of the prestressed steel cables 3 and reduce the prestress loss caused by displacement or relaxation.

[0083] See Figure 4 A back concrete filling layer 5 is set between the corrugated plate unit 1 and the inner wall of the tunnel. The back concrete filling layer 5 is integrated with the corrugated plate body 101, the connecting end plate 102, the prestressed steel cable 3 and the inner wall of the tunnel to form a surface contact force transmission path that adheres to the wall, fills the gap on the wall side, and improves the overall stiffness and stability of the tunnel reinforcement structure.

[0084] See Figure 5 A concrete inverted arch 6 is also installed at the bottom of the tunnel. The concrete inverted arch 6 is integrated with the end-cast locking body 107. The concrete inverted arch 6 works together with the concrete filling layer 5 behind it and the corrugated plate unit 1 to form a closed stress ring structure, which further improves the overall rigidity and stability of the tunnel reinforcement structure.

[0085] In this embodiment, the back concrete filling layer 5, the concrete invert arch 6, and the cast-in-place locking body 107 are made of fine aggregate concrete, which has good fluidity and pumpability, high bonding performance, low shrinkage, and good impermeability and durability. This facilitates filling the troughs and connecting voids, forming a reliable stress transfer path. In other embodiments, the concrete filling layer can be made of cement-based grouting material, ultrafine cement slurry, shotcrete, epoxy mortar, or polymer-modified mortar, depending on the construction method (pumping / shotcreting), layer thickness, early strength requirements, and environmental durability.

[0086] In this embodiment, the prestressed steel cable 3 is made of steel strand, which has the characteristics of high tensile strength, low relaxation, good flexibility, high efficiency in cable threading and tensioning, and mature compatibility with commonly used mechanical anchors; in other embodiments, the cable body can be made of materials such as steel bar cable, single high-strength steel wire, parallel steel wire bundle or fiber reinforced composite material cable.

[0087] In this embodiment, galvanized corrugated steel sheet is used as the corrugated plate, and the waveform of the corrugated plate body is sinusoidal wave, which has the characteristics of good corrosion resistance, high conformability to forming and arching, continuous and smooth stress transmission, no sharp corner stress concentration at the crests / troughs, high adhesion to the filler layer, and good fatigue adaptability. In other embodiments, the corrugated plate can also be made of weathering steel plate, stainless steel plate, aluminum-magnesium alloy plate, metal composite plate, non-metallic plate, etc.; its waveform includes, but is not limited to, triangular corrugated form, trapezoidal corrugated form, or right-angle corrugated form, to be selected according to the stress requirements, structural requirements, and processing technology.

[0088] For those skilled in the art, several improvements and modifications can be made without departing from the principles to which this application pertains, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for reinforcing prestressed corrugated slab cavities, characterized in that, Includes the following steps: Step a: Construct the tunnel and repair the base surface; or clean, level, and treat the interface of the existing tunnel interior base surface. Step b: Multiple corrugated plate units are sequentially installed along the circumference of the tunnel wall, and adjacent corrugated plate units are connected to the tunnel side by bolts through bolt holes on the connecting end plate; the crests and troughs of adjacent corrugated plate units continue sequentially in the connection direction, and multiple corrugated plate units form a continuous trough line along the circumference. Step c: During the circumferential splicing process described in step b, prestressed steel cables are simultaneously threaded along the continuous trough line on the wall side until the prestressed steel cables penetrate all the corrugated plate units in the circumferential direction, and the prestressed steel cables extend beyond the connection range of multiple corrugated plate units to form exposed sections. Step d: Use tensioning supports to tension the exposed section of the prestressed steel cable in stages to the design prestress value, and fix the exposed section of the prestressed steel cable with anchoring system; Step e: Cast the anchoring system and the prestressed steel cable segment where the anchoring system is located within the formwork space reserved on the tensioning support to form an end casting locking body; Step f: Cut off the prestressed steel cables other than the end-cast locking body and remove the tensioning support; Step g: Pour a back concrete filling layer between the corrugated plate unit and the tunnel body. The back concrete filling layer is integrated with the corrugated plate unit, prestressed steel cable and the inner side of the tunnel body to form a continuous reinforced lining along the circumference of the tunnel body.

2. The method for reinforcing prestressed corrugated slab cavities according to claim 1, characterized in that, Step h: After completing the pouring of the concrete filling layer behind the concrete, the formwork is erected and the concrete inverted arch is poured. The end casting locking body is poured into the concrete inverted arch and fixed together to form a closed force ring.

3. The method for reinforcing prestressed corrugated slab cavities according to claim 1, characterized in that, In step d, the graded tensioning is carried out in a symmetrical tensioning and zoned tensioning manner. Each level of tensioning is controlled by two parameters: tension force and elongation. After each level of tensioning, the pressure is stabilized and the elongation is remeasured. If the tension is insufficient, supplementary tensioning is performed.

4. A prestressed corrugated plate tunnel reinforcement structure, which is installed along the circumference of the tunnel wall on the inner side of the tunnel, characterized in that... Including prestressed corrugated slab systems, concrete systems, and anchorage systems; The prestressed corrugated plate system includes multiple corrugated plate units connected in sequence. Each corrugated plate unit includes a corrugated plate body and at least two connecting end plates. The connecting end plates are fixed to the ends of the corrugated plate body and are perpendicular to the surface of the corrugated plate body. The connecting end plate is provided with a first row of holes and a second row of holes along its length direction. The first row of holes and the second row of holes are arranged separately in the width direction of the same connecting end plate and are located on the upper and lower sides of the corrugated plate body respectively. The first row of holes are cable-passing holes, and the cable-passing holes correspond to the trough positions of the corrugated plate body on that side. The second row of holes are bolting holes, and the bolting holes are used to connect adjacent corrugated plate units with bolts. The crests and troughs of adjacent corrugated plate units continue sequentially in the connection direction; prestressed steel cables are installed within the continuous trough lines of multiple corrugated plate units, and the prestressed steel cables pass through the corresponding cable holes in sequence and are in a tensile anchored state in the finished product state; the two ends of each prestressed steel cable extend beyond the connection range of multiple corrugated plate units to form exposed sections, and the exposed sections of the prestressed steel cables are fixed by the anchoring system and are in a prestressed tensile state. The concrete system includes a back concrete filling layer between the corrugated plate body and the cavity, and an end-cast locking body at the end of the prestressed steel cable, wherein the end-cast locking body is integrally fixed with the anchoring system.

5. The prestressed corrugated slab cavity reinforcement structure according to claim 4, characterized in that, The concrete system also includes a concrete inverted arch, and the end-cast locking body is integrally fixed to the concrete inverted arch.

6. The prestressed corrugated slab cavity reinforcement structure according to claim 4, characterized in that, Guide cable limiting members are provided at intervals along the connection direction within the troughs of the corrugated plate body. The guide cable limiting members are fixedly connected to the corrugated plate body and are provided with circular or semi-circular grooves that match the shape of the prestressed steel cable.

7. The prestressed corrugated slab cavity reinforcement structure according to claim 4, characterized in that, The corrugated plate unit also includes a connecting side plate, which is perpendicular to the connecting end plate and fixed to both sides of the corrugated plate body. The connecting side plate is provided with lateral connecting holes.

8. The prestressed corrugated slab cavity reinforcement structure according to claim 4, characterized in that, The anchoring system includes nut anchors, tapered anchors, or tension-adjustable anchors.

9. The prestressed corrugated slab cavity reinforcement structure according to claim 4, characterized in that, The corrugated plate body has a waveform in the form of a sine wave, a triangular zigzag, a trapezoidal zigzag, or a right-angled zigzag.

10. The prestressed corrugated slab cavity reinforcement structure according to claim 4, characterized in that, The prestressed steel cable includes reinforcing steel cable, steel strand, single high-strength steel wire, parallel steel wire bundle or fiber-reinforced composite material cable.

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