Prestress cambered surface tensioning device for repairing shield segment

Abstract

The invention discloses a prestress cambered surface tensioning device for repairing a shield segment. Relates to the technical field of civil engineering, and comprises two fixed hollow anchor bearing plates, the two fixed hollow anchor bearing plates are symmetrically arranged on the two sides of a CFRP rib, the ends, away from each other, of the fixed hollow anchor bearing plates are each provided with an annular cambered surface single-hole anchorage device, and the ends, away from each other, of the fixed hollow anchor bearing plates are each provided with an annular cambered surface single-hole anchorage device; the end, away from the fixed type hollow anchor bearing plate, of each annular cambered surface single-hole anchorage device is provided with a jacking and pressing bearing plate. The front clamping type jack is detachably arranged at the end, away from the annular cambered-surface single-hole anchorage device, of the jacking and pressing base plate, the fixed type hollow anchor base plate is arranged and matched with the front clamping type jack, and the influence of radian change of an arc-shaped structure on the shear performance of the CFRP rib in the tensioning process can be eliminated, so that the tensile strength of the CFRP rib is improved, and the tensile strength of the CFRP rib is improved. And the performance of the material is fully exerted.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and more particularly to a prestressed arc surface tensioning device for repairing shield segments. Background Art

[0002] In the context of rapid urbanization, land reclamation has become an important strategy to increase the available space in coastal cities, and subways play an important role as a key connection between old and new urban areas. Among the many construction methods, shield tunneling is favored due to its flexibility, cost-effectiveness and low environmental impact. Typically, the shield tunnel structure consists of precast concrete segments connected by multiple joints. These joints are the weakest part of the tunnel structure and are easily affected by differential settlement of soft foundations and excessive ground loads, which in turn cause leakage and affect the structural integrity.

[0003] Traditional steel and concrete reinforcement methods face the problems of steel corrosion and concrete reinforcement taking up large space, which may interfere with the layout of shield tunnel pipelines. Carbon fiber reinforced polymer (CFRP) is an ideal reinforcement material due to its corrosion resistance and high strength. Prestressed carbon fiber reinforcement technology brings significant advantages by actively enhancing the mechanical properties and functionality of the structure, including significantly improving the load-bearing capacity, reducing cracks, deformations, and stiffness reduction under external loads.

[0004] Although prestressed CFRP tendon technology has been effective in the application of flat structures (such as the bottom of a bridge), there are still many challenges in its application in special curved structures such as shield segments. Since the curvature of the curved structure changes during the tensioning process, the existing prestressed CFRP tendon tensioning device cannot eliminate the impact of this change on the shear performance of the CFRP tendon, resulting in the material's performance not being fully utilized.

[0005] The patent with the announcement number CN117449608B discloses an automatic leveling carbon fiber plate prestressing tensioning device for curved surface structures. The device includes a fixed end device and a tensioning end device. One end of the CFRP plate is connected to the fixed end device, and the other end is connected to the tensioning end device. The curved surface is reinforced by the cooperation of the fixed end device and the tensioning end device. A clamp is designed in the device, and the clamp can rotate in the slide groove of the fixed end bottom plate. Through the hinge structure, the clamp can automatically level the CFRP plate during the tensioning process.

[0006] Since the tensioning device disclosed in the above patent can only rotate up and down, it cannot overcome the torsion problem caused by the left and right deviation of the device during use, causing the CFRP plate at the end of the clamp to be sheared and damaged.

[0007] Therefore, how to provide a prestressed arc surface tensioning device for repairing shield segments that can eliminate the influence of the change in the curvature of the arc structure during the tensioning process on the shear performance of the CFRP tendons and fully utilize the performance of the material is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0008] In view of this, the present invention provides a prestressed arc surface tensioning device for repairing shield segments, which aims to solve one of the problems in the above-mentioned background technology, and can eliminate the influence of the change in the curvature of the arc structure during the tensioning process on the shear performance of the CFRP tendons, so that the performance of the material can be fully utilized.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] A prestressed curved surface tensioning device for repairing shield segments, comprising:

[0011] A fixed hollow anchor pad, wherein two fixed hollow anchor pads are provided, and the two fixed hollow anchor pads are symmetrically arranged on both sides of the CFRP tendons, and each of the fixed hollow anchor pads is provided with a circular arc surface single hole anchor at one end away from each other, and each of the circular arc surface single hole anchors is provided with a top pressure pad at one end away from the fixed hollow anchor pad;

[0012] A front cardanic jack is detachably arranged on an end of the top pressure pad away from the circular arc surface single-hole anchor.

[0013] Furthermore, each of the fixed hollow anchor pads includes a fixed top plate and a reaction front plate, one end of the fixed top plate is connected to the top of the reaction front plate, and diagonal braces are provided between the two sides of the other end of the fixed top plate and the two sides of the bottom of the reaction front plate.

[0014] Furthermore, each of the reaction front plates is provided with a through hole in the middle, the CFRP rib passes through the through hole, the inner diameter of the through hole is much larger than the diameter of the CFRP rib, and an arc-shaped sliding groove is provided on the circumferential side of the through hole.

[0015] Furthermore, one side of the circular arc surface single-hole anchor close to the top pressure pad is set as an arc surface, and a quasi-conical hole is provided in the middle of the circular arc surface single-hole anchor. The quasi-conical hole and the through hole are located on the same axis, and the CFRP rib passes through the quasi-conical hole.

[0016] Furthermore, a cylindrical groove is provided at one end of the top pressure plate close to the circular arc surface single-hole anchor, and the cylindrical groove is adapted to the arc surface of the top pressure plate. A socket is provided in the middle of the top pressure plate, and the socket and the conical hole are located on the same axis, and the CFRP rib passes through the socket.

[0017] Furthermore, it also includes a wedge-shaped clip, which is arranged between the circular arc surface single-hole anchor and the fixed hollow anchor plate, and the wedge-shaped clip is adapted to the conical hole, and the CFRP reinforcement passes through the through hole, the conical hole, the wedge-shaped clip and the plug hole in sequence.

[0018] Furthermore, a plurality of capsule-shaped bolt holes are arranged on the fixed top plate, and the plurality of capsule-shaped bolt holes are arranged in two rows at equal intervals on both sides of the top of the fixed top plate. The fixed top plate is connected to the reinforced curved surface structure by high-strength bolts.

[0019] It can be seen from the above technical scheme that, compared with the prior art, the present invention discloses a prestressed arc surface tensioning device for repairing shield segments, wherein the inner diameter of the perforation arranged in the middle of the reaction front plate is much larger than the diameter of the CFRP tendons, so that the CFRP tendons can pass through and have sufficient rotation space during the tensioning process, thereby reducing the overall deadweight of the structure while ensuring that the structure does not undergo large deformation during the tensioning process; two diagonal braces are arranged between the fixed top plate and the reaction front plate, which are used to share the thrust exerted on the reaction front plate, reduce the thickness and height of the reaction front plate, reduce the overall size, and increase the operable space; the arc-shaped slide groove of the reaction front plate is connected to the arc-shaped surface of the circular arc surface single-hole anchor, and during the tensioning process, as the curvature changes, the two slide against each other to always keep the two relatively fixed and concentric in the final position, thereby preventing eccentricity during tensioning and preventing disturbance after the tensioning is completed. Moreover, it is an all-round sliding, which overcomes the shear force of the CFRP reinforcement caused by the installation error of the device, prevents it from being damaged by shearing, and gives full play to the tensile properties of the material; the top pressure pad is provided with a deep cylindrical groove, which covers the circular arc surface single-hole anchor. The deep groove avoids the problem of the rear end of the wedge-shaped clip protruding when it is not tensioned. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0021] Figure 1 A schematic structural diagram of a prestressed curved surface tensioning device for repairing shield segments provided by the present invention;

[0022] Figure 2 An exploded schematic diagram of a prestressed arc surface tensioning device for repairing shield segments provided by the present invention;

[0023] Figure 3 A schematic diagram of the structure of a fixed hollow anchor pad provided by the present invention;

[0024] Figure 4 A front view of the fixed hollow anchor pad provided by the present invention;

[0025] Figure 5 A right side view of the fixed hollow anchor pad provided by the present invention;

[0026] Figure 6 A top view of the fixed hollow anchor pad provided by the present invention;

[0027] Figure 7 A schematic diagram of a circular arc surface single hole anchor provided by the present invention;

[0028] Figure 8 A front view of the circular arc surface single hole anchor provided by the present invention;

[0029] Fig. 9 A right side view of the circular arc surface single hole anchor provided by the present invention;

[0030] Fig.10 A top view of the circular arc surface single hole anchor provided by the present invention;

[0031] Fig.11 A schematic diagram of a top pressure pad provided by the present invention;

[0032] Fig.12 A front view of the top pressure pad provided by the present invention;

[0033] Fig.13 A right side view of the top pressure pad provided by the present invention;

[0034] Fig.14 A top view of the top pressure pad provided by the present invention;

[0035] Fig.15 A finite element stress cloud diagram of the overall structure of the prestressed curved surface tensioning device for repairing shield segments provided by the present invention;

[0036] Among them: 1 is a fixed hollow anchor plate; 11 is a fixed top plate; 12 is a reaction front plate; 13 is a diagonal brace; 121 is a through hole; 122 is an arc-shaped slide groove; 2 is a circular arc surface single-hole anchor; 21 is an arc surface; 22 is a conical hole; 3 is a top pressure pad; 31 is a cylindrical groove; 32 is a socket; 4 is a front card jack; 5 is a wedge-shaped clip; 6 is a CFRP rib. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] See also Figure 1-15 The embodiment of the present invention discloses a prestressed arc surface tensioning device for repairing shield segments, comprising:

[0039] A fixed hollow anchor pad 1, two fixed hollow anchor pads 1 are provided, and the two fixed hollow anchor pads 1 are symmetrically arranged on both sides of the CFRP rib 6, and a circular arc surface single hole anchor 2 is provided at one end of each fixed hollow anchor pad 1 away from each other, and a top pressure pad 3 is provided at one end of each circular arc surface single hole anchor 2 away from the fixed hollow anchor pad 1;

[0040] The front cardan jack 4 is detachably arranged at one end of the top pressure pad 3 away from the circular arc surface single hole anchor 2.

[0041] In this embodiment, each fixed hollow anchor pad 1 includes a fixed top plate 11 and a reaction front plate 12, one end of the fixed top plate 11 is connected to the top of the reaction front plate 12, and diagonal braces 13 are arranged between the two sides of the other end of the fixed top plate 11 and the two sides of the bottom of the reaction front plate 12; the two diagonal braces 13 are used to share the thrust exerted on the reaction front plate 12, reduce the thickness and height of the reaction front plate 12, reduce the overall size, and increase the operable space; at the same time, due to the presence of the top pressure pad 3, when the tensioning stroke is insufficient, the tensioning head of the front cardan jack 4 can be disassembled for use.

[0042] In this embodiment, a through hole 121 is provided in the middle of each reaction front plate 12, and the CFRP tendon 6 passes through the through hole 121. The inner diameter of the through hole 121 is much larger than the diameter of the CFRP tendon 6, and an arc-shaped groove 122 is provided on the circumferential side of the through hole 121; the arc-shaped groove 122 is used to dock with the circular arc surface single-hole anchor 2. The inner diameter of the through hole 121 provided in the middle of the reaction front plate 12 is much larger than the diameter of the CFRP tendon 6, so that the CFRP tendon 6 can pass through and have sufficient rotation space during the tensioning process, thereby reducing the overall self-weight of the structure while ensuring that the structure does not undergo large deformation during the tensioning process.

[0043] In the present embodiment, one side of the annular arc surface single-hole anchor 2 close to the top pressure pad 3 is set as an arc surface 21, and a quasi-conical hole 22 is provided in the middle of the annular arc surface single-hole anchor 2. The quasi-conical hole 22 and the through hole 121 are located on the same axis, and the CFRP rib 6 passes through the quasi-conical hole 22; the quasi-conical hole 22 limits the sliding of the wedge-shaped clip 5 during the tensioning process, and provides annular clamping force; the arc-shaped slide groove 122 of the reaction front plate 12 is connected to the arc-shaped surface 21 of the annular arc surface single-hole anchor 2, and during the tensioning process, as the curvature changes, the two slide against each other, and always keep the two relatively fixed and concentric in the final position, thereby achieving the effect of preventing eccentricity during tensioning and preventing disturbance after the tensioning is completed; and it is an all-round sliding, which overcomes the shear force of the CFRP rib 6 caused by the installation error of the device, prevents it from being sheared, and gives full play to the tensile properties of the material.

[0044] In this embodiment, a cylindrical groove 31 is provided at one end of the top pressure pad 3 close to the circular arc surface single-hole anchor 2, and the cylindrical groove 31 is adapted to the arc surface 21 of the top pressure pad 3. A plug hole 32 is provided in the middle of the top pressure pad 3, and the plug hole 32 and the conical hole 22 are located on the same axis, and the CFRP rib 6 passes through the plug hole 32; the cylindrical groove 31 on the top pressure pad 3 is deeper, and covers the circular arc surface single-hole anchor 2. The deeper depth of the cylindrical groove 31 can avoid the problem of the rear end of the wedge-shaped clip 5 protruding when not tensioned.

[0045] In this embodiment, a wedge-shaped clip 5 is also included. The wedge-shaped clip 5 is arranged between the circular arc surface single-hole anchor 2 and the fixed hollow anchor plate 1. The wedge-shaped clip 5 is adapted to the conical hole 22, and the CFRP rib 6 passes through the through hole 121, the conical hole 22, the wedge-shaped clip 5 and the insertion hole 32 in sequence.

[0046] In this embodiment, a plurality of capsule-shaped bolt holes are arranged on the fixed top plate 11 , and the plurality of capsule-shaped bolt holes are arranged in two rows at equal intervals on both sides of the top of the fixed top plate 11 . The fixed top plate 11 is connected to the reinforced curved surface structure through high-strength bolts.

[0047] In addition, in this embodiment, two rows of 8 capsule-shaped bolt holes with equal spacing are formed on the fixed top plate 11 .

[0048] The specific implementation steps are as follows:

[0049] Step 1: Drill holes on the pipe segment to be repaired, clean it, and then inject the rebar glue. Use screws to pass through the 8 screw holes on the fixed top plate 11, insert them into the pipe segment, and connect them to the reinforced curved surface structure through high-strength bolts;

[0050] Step 2: Apply engine oil on the arc-shaped chute 122 of the fixed top plate 11, and place the annular arc surface single hole anchor 2 so that the arc surface 21 and the arc-shaped chute 122 correspond to each other;

[0051] Step 3: insert the CFRP tendon 6 from the non-tensioned end side, insert the CFRP tendon 6 into the wedge-shaped clip 5, and then insert them together into the conical hole 22 corresponding to the circular arc surface single hole anchor 2 for fixing;

[0052] Step 4: Fix the CFRP rib 6 at the tensioning end in the same way, then cover it with the top pressure pad 3, and install the front card jack 4 for tensioning;

[0053] Step 5: After the crack is closed, remove the front cassette jack 4.

[0054] Safety performance analysis

[0055] like Figure 6 As shown, the finite element stress cloud diagram of the tensioning device shows the stress distribution when 20 tons of prestress is applied and Q355 steel is used; the stress cloud diagram represents the stress from low to high through colors from blue to red, which is used to observe the stress distribution in the finite element analysis; the results show that during the tensioning process of CFRP tendon 6, the device is always in the elastic stage and there is no risk of damage.

[0056] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0057] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A prestressed arc surface tensioning device for repairing shield segments, characterized in that: include: A fixed hollow anchor pad, wherein two fixed hollow anchor pads are provided, and the two fixed hollow anchor pads are symmetrically arranged on both sides of the CFRP tendons, and each of the fixed hollow anchor pads is provided with a circular arc surface single hole anchor at one end away from each other, and each of the circular arc surface single hole anchors is provided with a top pressure pad at one end away from the fixed hollow anchor pad; A front cardanic jack is detachably arranged on an end of the top pressure pad away from the circular arc surface single-hole anchor.

2. A prestressed curved surface tensioning device for repairing shield segments according to claim 1, characterized in that: Each of the fixed hollow anchor pads includes a fixed top plate and a reaction front plate, one end of the fixed top plate is connected to the top of the reaction front plate, and diagonal braces are provided between the two sides of the other end of the fixed top plate and the two sides of the bottom of the reaction front plate.

3. The prestressed curved surface tensioning device for repairing shield segments according to claim 2 is characterized in that: A through hole is provided in the middle of each reaction front plate, and the CFRP rib passes through the through hole. The inner diameter of the through hole is much larger than the diameter of the CFRP rib, and an arc-shaped sliding groove is provided on the circumference of the through hole.

4. A prestressed arc surface tensioning device for repairing shield segments according to claim 3, characterized in that: The side of the circular arc surface single-hole anchor close to the top pressure pad is set as an arc surface, and a conical hole is provided in the middle of the circular arc surface single-hole anchor. The conical hole and the through hole are located on the same axis, and the CFRP rib passes through the conical hole.

5. The prestressed curved surface tensioning device for repairing shield segments according to claim 4 is characterized in that: A cylindrical groove is provided at one end of the top pressure pad close to the circular arc surface single-hole anchor, and the cylindrical groove is adapted to the arc surface of the top pressure pad. A socket is provided in the middle of the top pressure pad, and the socket and the conical hole are located on the same axis, and the CFRP rib passes through the socket.

6. A prestressed curved surface tensioning device for repairing shield segments according to claim 5, characterized in that: It also includes a wedge-shaped clip, which is arranged between the circular arc surface single-hole anchor and the fixed hollow anchor plate. The wedge-shaped clip is adapted to the conical hole, and the CFRP reinforcement passes through the through hole, the conical hole, the wedge-shaped clip and the plug hole in sequence.

7. The prestressed curved surface tensioning device for repairing shield segments according to claim 2 is characterized in that: The fixed top plate is provided with a plurality of capsule-shaped bolt holes, and the plurality of capsule-shaped bolt holes are arranged in two rows at equal intervals on both sides of the top of the fixed top plate. The fixed top plate is connected to the reinforced curved surface structure through high-strength bolts.

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