Limiting structure for prestressed tendon tensioning

Abstract

The utility model discloses a limiting structure for tensioning a prestressed tendon, and aims to effectively solve the problem of prestress loss caused by outward loosening stroke generated when an anchorage device clamping piece is tensioned in the background technology. Therefore, the limiting structure for tensioning the prestressed tendon comprises a rigid pressure-bearing body, a containing cavity for containing a permanent anchor in a matched mode is formed in the front end of the rigid pressure-bearing body, a sliding cavity is formed in the bottom of the containing cavity, and a sliding push plate is installed in the sliding cavity in a matched and sliding mode. A hydraulic oil cylinder for driving the sliding push plate to move front and back is arranged in the tail end of the sliding cavity, first through holes allowing prestressed tendons to penetrate through are formed in the positions, corresponding to anchorage device clamping pieces of the permanent anchor, of the sliding push plate, and the diameter of the first through holes is smaller than that of the anchorage device clamping pieces. The tail end of the rigid pressure-bearing body is provided with a second through hole for a prestressed tendon to penetrate through.

Description

Technical Field

[0001] This utility model belongs to the field of prestressed tendon tensioning technology, and in particular relates to a limiting structure for prestressed tendon tensioning. Background Technology

[0002] Traditional prestressing tendon tensioning uses an integrated fixed limiting plate. During prestressing tendon tensioning, the permanent anchor clamps release tension in the outward direction. The traditional limiting plate only controls the maximum displacement of the permanent anchor clamps during the release tension. Therefore, after the prestressing tendon tensioning is completed and the tensioning jack is released, the permanent anchor clamps will retract inward to complete the anchoring and locking of the prestressing tendon. At this time, the outward release tension generated by the anchor clamps during tensioning will lead to a reduction in the stress length of the prestressing tendon during anchoring, resulting in a significant prestress loss during anchoring and locking. Summary of the Invention

[0003] The main purpose of this utility model is to provide a limiting structure for tensioning prestressed tendons, which aims to effectively solve the problem of prestress loss caused by the outward relaxation stroke of the anchor wedges during tensioning in the prior art.

[0004] To address this, the present invention provides a limiting structure for prestressed tendon tensioning, comprising a rigid bearing body. The front end of the rigid bearing body is provided with a receiving cavity for accommodating a permanent anchor. The bottom of the receiving cavity is provided with a sliding cavity. A sliding push plate is slidably installed in the sliding cavity. A hydraulic cylinder for driving the sliding push plate to move back and forth is provided at the rear end of the sliding cavity. The sliding push plate is provided with a first through hole for the prestressed tendon to pass through at each anchor clamp position of the permanent anchor. The diameter of the first through hole is smaller than the diameter of the anchor clamp. The rear end of the rigid bearing body is provided with a second through hole for the prestressed tendon to pass through.

[0005] Specifically, multiple hydraulic cylinders are evenly arranged around the anchor clamp, with one end of the hydraulic cylinder fixed to the rigid pressure body and the other end fixed to the sliding push plate.

[0006] Specifically, the rigid pressure-bearing body is designed as a frustum shape that is narrower at the front and wider at the back.

[0007] Specifically, the cross-section of the sliding cavity is circular.

[0008] Specifically, the central axis of the accommodating cavity coincides with that of the sliding cavity.

[0009] Compared with the prior art, the present invention has the following advantages: by adding a sliding cavity at the tail end of the permanent anchor accommodating cavity, and installing a hydraulic cylinder and a sliding push plate in the sliding cavity, the hydraulic cylinder drives the sliding push plate to move back and forth, thereby realizing the relaxation and retraction of the permanent anchor clamp, so as to effectively solve the problem of serious prestress loss caused by the large amount of retraction of the anchor clamp. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the prestressing tendon tensioning limiting structure provided in this embodiment of the utility model;

[0012] Figure 2 This is a schematic diagram of a permanent anchor provided in an embodiment of this utility model;

[0013] Figure 3 This is a schematic diagram of the sliding push plate provided in an embodiment of the present utility model;

[0014] The components are: 1. Rigid bearing body; 2. Permanent anchor; 3. Receptacle cavity; 4. Prestressed tendon; 5. Anchor wedge; 6. Sliding cavity; 7. Sliding push plate; 8. Hydraulic cylinder; 9. First through hole; 10. Second through hole; 11. Anchor pad steel plate. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0017] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0018] See Figures 1-3 A prestressing tendon tensioning limiting structure is characterized by comprising a rigid bearing body 1, the front end of which is provided with a receiving cavity 3 for accommodating a permanent anchor 2, the permanent anchor 2 having multiple tapered holes for prestressing tendons 4 to pass through and anchor clamps 5 that cooperate with the tapered holes, the bottom of the receiving cavity 3 having a sliding cavity 6, the sliding cavity 6 being slightly smaller than the receiving cavity 3 and coaxial, a sliding push plate 7 being slidably installed inside the sliding cavity 6, and a mechanism for driving the sliding push plate 7 to move back and forth inside the tail end of the sliding cavity 6. The hydraulic cylinder 8 and the sliding push plate 7 are provided with first through holes 9 at the positions of the anchor clamps 5 corresponding to the permanent anchor 2, through which the prestressing tendons 4 pass. The diameter of the first through hole 9 is smaller than the diameter of the anchor clamp 5, so that when the sliding push plate 7 moves forward, it can contact the anchor clamp 5, thereby pushing the anchor clamp 5 forward. The tail end of the rigid bearing body 1 is provided with a second through hole 10 for the prestressing tendons 4 to pass through. The front end of the permanent anchor 2 abuts against the anchor pad steel plate, and the tail end is inserted into the receiving cavity 3 and abuts against its bottom step surface.

[0019] When tensioning the prestressed tendon 4 using the aforementioned prestressed tendon tensioning limiting structure, the corrugated pipe, spiral reinforcement, and anchor plate 11 are installed at the designated positions on the bridge structure. After the bridge structure has been poured with concrete and cured for a period of time, the prestressed tendon 4 is installed at the designated positions on the bridge structure, and permanent anchors 2 and anchor wedges are installed at the anchorage and tensioning ends of the prestressed tendon 4.

[0020] Based on the number, arrangement, and tensioning tonnage of the prestressing tendons 4, the factory custom-produces matching rigid bearing bodies 1 and sliding push plates 7. Align each bundle of prestressing tendons 4 so that it passes through the first through hole 9 on the sliding push plate 7 and the second through hole 10 at the tail end of the rigid bearing body 1. Align the front end of the rigid bearing body 1 with the permanent anchor 2 and insert the permanent anchor 2 into the rigid bearing body 1. The front end of the permanent anchor 2 abuts against the anchor pad steel plate, and the tail end abuts against the stepped surface of the front end receiving cavity 3 of the rigid bearing body 1. The tensioning jack for tensioning the prestressing tendons 4 is supported on the rear end face of the rigid bearing body 1.

[0021] Before tensioning the prestressed tendon 4, the hydraulic cylinder 8 drives the sliding push plate 7 to move to the rear end. The sliding push plate 7 retracts to the rear of the sliding cavity 6, leaving space for the tensioning and relaxation stroke of the anchor wedge of the permanent anchor 2, thereby ensuring the smooth progress of the tensioning process of the prestressed tendon 4.

[0022] After the prestressing tendon 4 is tensioned and before the tensioning jack device is unloaded, the hydraulic cylinder 8 drives the sliding push plate 7 to move forward. The sliding push plate 7 pushes back the anchor wedge, effectively reducing the retraction stroke of the anchor wedge when the prestressing tendon 4 is anchored, thereby greatly reducing the prestress loss caused by the retraction of the anchor wedge.

[0023] After the tensioning jack is unloaded, the rigid bearing body 1 is removed, the excess exposed prestressing tendons 4 are cut, and the concrete inside the corrugated pipe is poured and the prestressing tendons 4 are sealed and anchored.

[0024] In this embodiment, the loosening and retraction of the anchor wedge of the permanent anchor 2 is achieved by moving the sliding push plate 7 back and forth driven by the hydraulic cylinder 8. This not only saves time and effort, but also effectively solves the problem of serious prestress loss caused by the large amount of retraction of the anchor wedge.

[0025] See Figure 1 Understandably, in the actual design, multiple hydraulic cylinders 8 are evenly arranged around the anchor clamp 5. One end of the hydraulic cylinder 8 is fixedly connected to the rigid bearing body 1, and the other end is fixedly connected to the sliding push plate 7. In addition, to prevent the rigid bearing body 1 from squeezing the concrete, the rigid bearing body 1 is designed as a frustum shape that is narrow at the front and wide at the back. The cross-section of the sliding cavity 6 is circular, that is, the sliding cavity 6 is a cylindrical cavity. Of course, it can also be designed into other shapes.

[0026] Unless otherwise stated, if any of the technical solutions disclosed in this utility model discloses a numerical range, then the disclosed numerical range is a preferred numerical range. Anyone skilled in the art should understand that the preferred numerical range is merely one among many feasible numerical values ​​that has a more obvious or representative technical effect. Because there are many numerical values, it is impossible to list them all. Therefore, this utility model discloses only some numerical values ​​to illustrate the technical solutions of the invention. Furthermore, the numerical values ​​listed above should not constitute a limitation on the scope of protection of this invention.

[0027] Meanwhile, if the present invention discloses or relates to mutually fixedly connected parts or structural components, then unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured by casting) (except where it is obviously impossible to use an integral forming process).

[0028] Furthermore, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model include states or shapes that are similar to, analogous to, or close to those states or shapes. Any component provided by this utility model can be assembled from multiple individual components or can be a single component manufactured using a one-piece molding process.

[0029] The above embodiments are merely illustrative examples to clearly illustrate the present invention, and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A limiting structure for tensioning prestressed tendons, characterized in that: The device includes a rigid bearing body (1), the front end of which is provided with a receiving cavity (3) for accommodating a permanent anchor (2), the bottom of which is provided with a sliding cavity (6), a sliding push plate (7) is slidably installed in the sliding cavity (6), and a hydraulic cylinder (8) for driving the sliding push plate (7) to move back and forth is provided in the tail end of the sliding cavity (6). The sliding push plate (7) is provided with a first through hole (9) for prestressing tendons (4) to pass through at the position of each anchor clamp (5) of the permanent anchor (2). The diameter of the first through hole (9) is smaller than the diameter of the anchor clamp (5). The tail end of the rigid bearing body (1) is provided with a second through hole (10) for prestressing tendons (4) to pass through.

2. The prestressed tendon tensioning limiting structure according to claim 1, characterized in that: Multiple hydraulic cylinders (8) are evenly arranged around the anchor clamp (5). One end of the hydraulic cylinder (8) is fixed to the rigid pressure body (1), and the other end is fixed to the sliding push plate (7).

3. The prestressed tendon tensioning limiting structure according to claim 1, characterized in that: The rigid bearing body (1) is designed as a frustum shape that is narrow at the front and wide at the back.

4. The prestressed tendon tensioning limiting structure according to claim 1, characterized in that: The cross-section of the sliding cavity (6) is circular.

5. The prestressed tendon tensioning limiting structure according to claim 1, characterized in that: The central axis of the accommodating cavity (3) coincides with that of the sliding cavity (6).

Images