Prestressed tendon tensioning limiting block with clamping piece back-jacking function

Abstract

The utility model discloses a prestressed tendon tensioning limiting block with a clamping piece back-jacking function, which can effectively restrain a movable limiting plate and control the movable limiting plate to move, and solves the problem of obvious prestress loss during anchoring and locking of a prestressed tendon mentioned in the background technology. Therefore, the limiting block for tensioning the prestressed tendon comprises a rigid pressure-bearing body, the front end of the rigid pressure-bearing body is provided with a counter bore for accommodating a permanent anchor in a matched mode, the bottom of the counter bore is provided with a sliding cavity, a sliding block is installed in the sliding cavity in a matched and sliding mode, and a pushing mechanism for driving the sliding block to move front and back is arranged in 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 block, the diameter of the first through holes is smaller than that of the anchorage device clamping pieces, and second through holes allowing the prestressed tendons to penetrate through are formed in the tail end of the rigid pressure bearing body.

Description

TECHNICAL FIELD

[0001] The utility model belongs to prestressed tendon tensioning technical field especially relates to a prestressed tendon tensioning limiting block with clamping piece back top function. BACKGROUND

[0002] The traditional prestressed tendon tensioning limiting plate is integrated fixed, when prestressed tendon tensioning, permanent anchor fixed clamping piece produces relaxation travel in the outward tension direction, the traditional limiting plate only controls the maximum displacement of permanent anchor anchorage clamping piece relaxation travel, therefore, after prestressed tendon tensioning is completed, permanent anchor anchorage clamping piece will retract inwards to complete the anchoring locking of prestressed tendon, at this time, the relaxation travel of anchorage clamping piece tensioning in the outward direction will cause the decrease of prestressed tendon anchoring stress length, thereby making prestressed tendon anchoring locking produce significant prestress loss. SUMMARY

[0003] The utility model discloses a prestressed tendon tensioning limiting block with clamping piece back top function, which can effectively constrain the movable limiting plate and control the movement of the movable limiting plate, and solves the problem of significant prestress loss during prestressed tendon anchoring locking mentioned in the background technology.

[0004] Therefore, the prestressed tendon tensioning limiting block with clamping piece back top function provided by the utility model comprises a rigid pressure-bearing body, the front end of the rigid pressure-bearing body is provided with a counterbore matched with a permanent anchor, the bottom of the counterbore is provided with a sliding cavity, a sliding block is slidably installed in the sliding cavity, a pushing mechanism for driving the sliding block to move forward and backward is arranged in the sliding cavity, a first through hole for the prestressed tendon to pass through is arranged at the position of each anchorage clamping piece of the permanent anchor on the sliding block, the diameter of the first through hole is smaller than the diameter of the anchorage clamping piece, and the tail end of the rigid pressure-bearing body is provided with a second through hole for the prestressed tendon to pass through.

[0005] Specifically, the pushing mechanism comprises an annular inflatable bag body, the annular inflatable bag body is connected between the bottom of the sliding cavity and the sliding block, and an inflation pipe connected with an inflation port on the annular inflatable bag body is arranged on the rigid pressure-bearing body.

[0006] Specifically, the rigid pressure-bearing body is designed in the shape of a circular truncated cone with a narrow front end and a wide rear end.

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

[0008] Compared with the prior art, the utility model has the beneficial effects that the relaxation and back top of the anchorage clamping piece of the permanent anchor are realized by the method that the sliding block is driven to move forward and backward by the pushing mechanism, which not only saves time and effort, but also effectively solves the problem of serious prestress loss caused by the large retraction amount of the anchorage clamping piece. BRIEF DESCRIPTION OF DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0010] Figure 1 is a schematic diagram of a limiting block for prestressed tendon tensioning provided by the embodiments of the present application;

[0011] Figure 2 is a schematic diagram of a permanent anchor provided by the embodiments of the present application;

[0012] Figure 3 is a schematic diagram of a sliding block provided by the embodiments of the present application;

[0013] 1, rigid pressure body; 2, permanent anchor; 3, counterbore; 4, prestressed tendon; 5, anchor clamp; 6, sliding cavity; 7, sliding block; 8, pushing mechanism; 9, first through hole; 10, second through hole; 11, anchor pad steel plate. DETAILED DESCRIPTION

[0014] The technical solutions of the embodiments of the present application will be described clearly and completely in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0015] In the description of the present application, it should be understood that the orientations or positional relationships indicated by 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" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0016] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and should not be construed as implying or suggesting relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0017] Referring to Figures 1-3 A prestressed tendon tensioning limiting block with a clamping piece back-up function, comprising a rigid pressure-bearing body 1, the front end of the rigid pressure-bearing body 1 is provided with a counterbore 3 matching a permanent anchor 2, the permanent anchor 2 is provided with a plurality of conical hole bodies for the prestressed tendon 4 to pass through and anchor clamping pieces 5 matched with the conical hole bodies, the bottom of the counterbore 3 is provided with a sliding cavity 6, the size of the sliding cavity 6 is slightly smaller than that of the counterbore 3, and they are coaxial, a sliding block 7 is matched and slidingly installed in the sliding cavity 6, the sliding cavity 6 is provided with a pushing mechanism 8 driving the sliding block 7 to move forward and backward, the sliding block 7 is provided with a first through hole 9 for the prestressed tendon 4 to pass through at a position corresponding to each anchor clamping piece 5 of the permanent anchor 2, the diameter of the first through hole 9 is smaller than that of the anchor clamping piece 5, so that when the sliding block 7 moves forward, the sliding block 7 can contact the anchor clamping piece 5, thereby pushing the anchor clamping piece 5 to move forward, the tail end of the rigid pressure-bearing body 1 is provided with a second through hole 10 for the prestressed tendon 4 to pass through, the front end of the permanent anchor 2 abuts against an anchor pad steel plate, and the tail end is inserted into the counterbore 3 and abuts against the stepped surface of the counterbore 3.

[0018] When the prestressed tendon 4 is tensioned by using the prestressed tendon tensioning limiting block, the corrugated pipe, the spiral tendon and the anchor pad steel plate 11 are installed at the specified position of the bridge structure, the prestressed tendon 4 is installed at the specified position of the bridge structure after the bridge structure is poured with concrete and maintained for a period of time, and the permanent anchor 2 and the anchor clamping piece are installed at the prestressed tendon 4 anchoring end and the tensioning end.

[0019] According to the number of steel strands of the prestressed tendon 4, the arrangement mode and the tensioning tonnage, the rigid pressure-bearing body 1 and the sliding block 7 matched are produced in the factory, each bundle of steel strands of the prestressed tendon 4 is aligned to pass through the first through hole 9 on the sliding block 7 and the second through hole 10 at the tail end of the rigid pressure-bearing body 1, the front end of the rigid pressure-bearing body 1 is aligned to the permanent anchor 2, the permanent anchor 2 is matched and inserted into the rigid pressure-bearing body 1, the front end anchor pad steel plate of the permanent anchor 2 abuts against, and the tail end abuts against the stepped surface of the counterbore 3 at the front end of the rigid pressure-bearing body 1, and the tensioning jack for tensioning the prestressed tendon 4 is supported at the rear end surface of the rigid pressure-bearing body 1.

[0020] Before the prestressed tendon 4 is tensioned, the pushing mechanism 8 drives the sliding block 7 to move to the rear end, the sliding block 7 is retracted to the rear part of the sliding cavity 6, and the anchor clamping piece of the permanent anchor 2 is left with a tensioning and relaxing stroke space, thereby ensuring the smooth progress of the prestressed tendon 4 tensioning process.

[0021] After the tensioning of the prestressed tendon 4 is completed and before the tensioning jack device is unloaded, the pushing mechanism 8 drives the sliding block 7 to move forward, and the sliding block 7 pushes back the anchor clamp, effectively reducing the retraction stroke of the anchor clamp during anchoring of the prestressed tendon 4, thereby greatly reducing the prestress loss caused by the retraction of the anchor clamp.

[0022] After the tensioning jack is unloaded, the rigid pressure body 1 is removed, the excess exposed prestressed tendon 4 is cut off, and the concrete inside the corrugated pipe is poured and the prestressed tendon 4 is anchored.

[0023] The embodiment realizes the loosening and pushing back of the anchor clamp of the permanent anchor 2 by the method of moving the sliding block 7 forward and backward by the pushing mechanism 8, which not only saves time and effort, but also effectively solves the problem of serious prestress loss caused by the large retraction amount of the anchor clamp.

[0024] Referring to Figure 1 It can be understood that in actual design, the pushing mechanism 8 includes a ring-shaped inflatable bag body connected between the bottom of the sliding cavity 6 and the sliding block 7, each steel strand passes through the middle of the ring-shaped inflatable bag body, and the rigid pressure body 1 is provided with an inflation pipe (not shown in the figure) connected with the inflation port of the ring-shaped inflatable bag body. When the clamp needs to be pushed back, the ring-shaped inflatable bag body is inflated through the inflation pipe to expand and drive the sliding block 7 to move, so as to achieve the purpose of pushing back the anchor clamp. During the prestress tendon pre-tensioning process, the ring-shaped inflatable bag body is not inflated. Of course, the pushing mechanism 8 can also use other mechanisms such as linear motors.

[0025] In addition, in order to prevent the rigid pressure body 1 from extruding the concrete, the rigid pressure body 1 is designed as a circular truncated cone with a narrow front and a wide back, and 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 in other shapes.

[0026] Unless otherwise stated, if the above-mentioned any technical solution of the utility model discloses a numerical range, the disclosed numerical range is a preferred numerical range, and any person skilled in the art should understand that the preferred numerical range is only one of the many implementable values with more obvious technical effects or representative values. Since there are too many values, it is impossible to enumerate them all, so the utility model only discloses part of the values to illustrate the technical solutions of the application, and the above-mentioned enumerated values should not constitute a limitation on the protection scope of the application.

[0027] Meanwhile, if the above-mentioned utility model discloses or involves mutually fixedly connected parts or structural members, then, except for another declaration, the fixed connection can be understood as: detachably fixedly connected (for example, connected by using bolts or screws), and can also be understood as: non-detachably fixedly connected (for example, riveted, welded), of course, the mutually fixed connection can also be replaced by an integral structure (for example, integrally formed by using a casting process) (except for obviously unable to use an integral forming process).

[0028] In addition, the meaning of the term used for indicating the position relationship or shape in any of the above-mentioned utility model disclosed technical solutions includes the approximate, similar or close state or shape, except for another declaration. Any component provided by the utility model can be assembled by a plurality of separate components, or can be a separate component manufactured by an integral forming process.

[0029] The above-mentioned embodiments are only examples for clearly illustrating the utility model, and are not limited to the implementation modes. For ordinary skilled persons in the art, other different forms of changes or variations can be made on the basis of the above-mentioned description. Here, all the embodiments need not be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the utility model.

Claims

1. A prestressed tendon tensioning limiting block with a clamping backstop function, characterized in that: The utility model relates to a rigid pressure-bearing body (1) provided with a counterbore (3) matching a permanent anchor (2) at the front end, the bottom of the counterbore (3) is provided with a sliding cavity (6), a sliding block (7) is matched and slidably installed in the sliding cavity (6), a pushing mechanism (8) is arranged in the sliding cavity (6) to drive the sliding block (7) to move forward and backward, a first through hole (9) for a prestressed tendon (4) to pass through is arranged on the sliding block (7) corresponding to 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), and the tail end of the rigid pressure-bearing body (1) is provided with a second through hole (10) for the prestressed tendon (4) to pass through.

2. The limiting block for tensioning of a prestressed tendon according to claim 1, characterized in that: The pushing mechanism (8) comprises an annular inflatable bag body connected between the bottom of the sliding cavity (6) and the sliding block (7), and the rigid pressure-bearing body (1) is provided with an inflation pipe connected with an inflation port on the annular inflatable bag body.

3. The prestressed tendon tensioning spacer block of claim 1, wherein: The rigid pressure-bearing body (1) is designed as a circular truncated cone with a narrow front end and a wide tail end.

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

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