Adjustable down-pressure anchor and pedestal for pre-tensioned broken-line prestressed tendons with adjustable bending point.

Abstract

This invention provides a downward anchor with an adjustable bending point for prestressed tendons in a pre-tensioned, multi-line prestressed concrete system. The anchor includes a positioning bracket, a connecting rod, an anchoring support, and a limiting block. The positioning bracket has several through holes. The anchoring support includes an anchoring rebar, a first base plate, a cover plate, a sliding bracket, a connecting shaft, and a support sleeve. The anchoring rebar is connected to the first base plate, and the first base plate and the cover plate together form a slide rail. One end of the sliding bracket is located within the slide rail, and the other end extends out of the slide rail. The connecting shaft passes through the support sleeve and the sliding bracket. The connecting rod is connected at both ends to the support sleeve and the second base plate, respectively. The limiting block is detachably fixed within the slide rail. This invention designs a downward anchor device integrating a slide rail, an adjustable connecting rod, and a limiting block, achieving precise adjustment of the bending point position of the multi-line prestressed tendons and improving the versatility, adaptability, and construction efficiency of the precast platform.

Description

Technical Field

[0001] This utility model relates to a bridge construction auxiliary device, and more particularly to a pressure anchor and pedestal with adjustable bending point of prestressed tendons in the pre-tensioned broken line method. Background Technology

[0002] Pre-tensioning is a construction method in which prestressing tendons are tensioned before concrete is poured. Compared to post-tensioning, it eliminates the need for anchorages, and the prestress is obtained through the bond between the prestressing tendons and the concrete. Concrete members constructed using the pre-tensioning method have the advantages of simple process, better cost control, and prestress applied to the steel strands that is closer to the design value. It is widely used in the construction of hollow slabs and T-beams for bridges, and is particularly suitable for factory production.

[0003] Early pre-tensioning methods were only suitable for hollow slab bridges with short spans, where the prestressing tendons were generally arranged in a straight line. With the advancement of construction methods and techniques, beams with prestressing tendons arranged in a zigzag pattern are also constructed using the pre-tensioning method. By designing a downward anchor, the straight prestressing tendons are adjusted to a zigzag pattern.

[0004] There is a double-T beam with a span of 20 meters, a beam height of 1.0 meter, a rib thickness of 0.35 meters, a flange width of 2.315 meters, and a "π" shaped cross-section (double-T beam). The beam's zigzag prestressed tendons are divided into straight sections and bent sections. The straight sections are symmetrical about the beam's centerline, but the lengths vary depending on the beam shape. The length of the straight sections of the zigzag prestressed tendons ranges from 374 to 414 cm, meaning the bending point of the zigzag prestressed tendons is variable. However, the current position of the lower anchor is fixed and cannot be adjusted according to the change in the bending point position. Utility Model Content

[0005] Based on this, the present invention mainly provides a downward anchor with an adjustable bending point for prestressed tendons in the pre-tensioned zigzag method. Using this device, not only can the prestressed tendons be arranged along a zigzag line, but the anchorage point position can also be adjusted within a certain range, greatly improving the adaptability of the platform, increasing efficiency, accelerating progress, saving costs, and effectively ensuring construction safety.

[0006] Part One:

[0007] A prestressed tendon with adjustable bending point in the pre-tensioned broken line method includes a positioning bracket, a connecting rod, an anchoring support, and a limiting block.

[0008] The positioning bracket is provided with several through holes, which are used to constrain the steel strands.

[0009] The anchoring support includes a reaction plate and embedded parts; the embedded parts include anchoring steel bars, a first base plate and a cover plate; the anchoring steel bars are fixedly connected to the first base plate, and the first base plate and the cover plate enclose a sliding track.

[0010] The reaction plate includes a sliding bracket and a support sleeve; one end of the sliding bracket is located inside the slide rail and can slide along the slide rail, and the other end extends out above the slide rail; the support sleeve is detachably connected to the sliding bracket.

[0011] The connecting rod is detachably connected to the support sleeve and the positioning bracket at both ends, and its relative height to the support sleeve can be adjusted when connected.

[0012] The limiting block is detachably fixed inside the slide rail to restrict the sliding of the reaction plate.

[0013] This utility model designs a downward anchoring device that integrates a slide rail, an adjustable connecting rod, and a limiting block. By adjusting the relative height between the connecting rod and the support sleeve, or by adjusting the position of the slide rail bracket, the continuous and precise adjustment of the bending start position of the zigzag prestressed tendon can be achieved.

[0014] As a preferred embodiment, the positioning bracket includes a second base plate, a plurality of first intermediate partitions and second intermediate partitions; the plurality of first intermediate partitions are fixed to the second base plate, the plurality of first intermediate partitions are arranged in parallel, any two adjacent first intermediate partitions are provided with at least one second intermediate partition, and a plurality of through holes are formed between the second base plate, the first intermediate partitions and the second intermediate partitions.

[0015] As a preferred embodiment, the first intermediate partition is arranged perpendicularly to the second base plate, and the second intermediate partition is arranged parallel to the second base plate.

[0016] As a preferred embodiment, the second base plate has a first connecting hole at its center, the support sleeve has a second connecting hole, the first and second connecting holes have internal threads in opposite directions, and both ends of the connecting rod have external threads. By providing internal threads in opposite directions in the first and second connecting holes, when one end of the connecting rod is screwed in, the other end is simultaneously screwed out.

[0017] As a preferred embodiment, the bottom of the second intermediate partition is grooved. A grooved bottom on the second intermediate partition increases the contact area with the steel strand, resulting in stronger constraint on the steel strand and better positioning of it.

[0018] As a preferred embodiment, the connecting rod has a hexagonal body. The hexagonal body facilitates turning with a wrench.

[0019] As a preferred embodiment, the reaction plate further includes a connecting shaft, and the support sleeve is rotatably connected to the sliding bracket via the connecting shaft. The support sleeve is rotatably connected relative to the sliding bracket, allowing it to rotate at a small angle to adapt to the tensioning direction when the steel strand is tensioned.

[0020] As a preferred embodiment, the anchoring depth of the anchoring steel bar to the concrete is not less than 40cm, and the diameter of the anchoring steel bar is not less than 12mm.

[0021] Part Two:

[0022] A type of precast pedestal includes a pedestal base and an adjustable downward anchor for the bend point of the pre-tensioned, broken-line prestressed tendons described in the first part. The pedestal base has a groove, and the anchor support is fixed in the groove. This design solves the key problem of using the same precast pedestal for different beam types (with different bend point positions), and eliminates the drawback of traditional fixed downward anchors requiring customized or modified pedestals for each beam type. This improves the versatility, adaptability, and construction efficiency of the precast pedestal, and significantly reduces construction costs. Attached Figure Description

[0023] Figure 1 A front perspective view of the concrete pedestal, beam, and adjustable down-pressure anchor;

[0024] Figure 2 This is a cross-sectional view of the beam;

[0025] Figure 3 A front perspective view of the adjustable pressure anchor;

[0026] Figure 4 Left view of the adjustable pressure anchor;

[0027] Among them: 1-positioning bracket, 2-connecting rod, 3-anchoring support, 4-limiting block, 5-beam body, 6-base body, 11-second base plate, 12-first intermediate partition plate, 13-second intermediate partition plate, 14-through hole, 15-first connecting hole, 16-bend starting point, 31-anchoring steel bar, 32-first base plate, 33-L-shaped plate, 34-sliding bracket, 341-bracket seat, 342-bracket body, 35-connecting shaft, 36-support sleeve, 37-second connecting hole, 51-steel strand. Detailed Implementation

[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0031] Secondly, this utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In addition, actual manufacturing should include the three-dimensional spatial dimensions of length, width, and depth.

[0032] Example 1

[0033] Reference Figure 1-4 A prestressed tendon with adjustable bending point in the prestressing process includes a positioning bracket 1, a connecting rod 2, an anchoring support 3, and a limiting block 4.

[0034] The concrete platform includes a platform base 6, which has a groove. The pre-tensioned zigzag prestressed tendons are adjustable and anchored in the groove. The beam 5 is placed on the platform base 6, and the beam 5 has steel strands 51 inside.

[0035] The positioning bracket 1 includes a second base plate 11, four first intermediate partition plates 12, and nine second intermediate partition plates 13. The four first intermediate partition plates 12 are arranged parallel to each other at equal intervals and perpendicular to the second base plate 11. Three second intermediate partition plates 13 are arranged at equal vertical distances between adjacent first intermediate partition plates 12. The second intermediate partition plates 13 are parallel to the second base plate 11, and the bottom of the second intermediate partition plates 13 is grooved. Nine through holes 14 are formed between the second base plate 11, the first intermediate partition plates 12, and the second intermediate partition plates 13 for constraining the steel strands 51. A first connecting hole 15 is provided at the center of the second base plate 11, and the first connecting hole 15 has an internal thread.

[0036] The anchorage support 3 includes a reaction plate and embedded parts. The embedded parts include anchoring steel bars 31, a first base plate 32, and two L-shaped plates 33. The anchoring steel bars 31 are 12mm threaded steel bars, one end of which is anchored in the concrete to a depth of 40cm, and the other end is welded to the bottom of the first base plate 32. The L-shaped plates 33 are welded to the first base plate 32 and are symmetrically arranged, forming a slide together with the first base plate 32 to enclose a slide. The cross-section of the slide is convex, with the bottom cross-sectional area being larger than the top cross-sectional area. The bottom surface is the first base plate 32, the side surface is the L-shaped plate 33, and the top part is connected to the outside.

[0037] The reaction plate includes a sliding bracket 34, a connecting shaft 35, and a support sleeve 36. The sliding bracket 34 includes a bracket base 341 and a bracket body 342. The bracket base 341 is located at the bottom of the slide, and the bracket body 342 extends out of the slide from the top of the slide. The slide bracket 34 can only move in the direction of adjustment at the bend point 16 and cannot move in the vertical direction. The connecting shaft 35 is located above the slide and passes through the support sleeve 36 and the bracket body 342. One end of the support sleeve 36 is rotatably connected to the connecting shaft 35, and the other end is provided with a second connecting hole 37. The second connecting hole 37 is provided with an internal thread, and the internal thread of the second connecting hole 37 is opposite to that of the first connecting hole 15.

[0038] The connecting rod 2 has external threads at both ends and the rod body is hexagonal. The two ends of the connecting rod 2 are respectively connected to the second connecting hole 37 of the support sleeve 36 and the first connecting hole 15 of the second base plate 11. The limiting block 4 is detachably fixed in the slide and is detachably connected to the sliding bracket 34 to limit the sliding of the reaction plate.

[0039] Example 2

[0040] Reference Figure 1-4 The application of a pre-tensioned, broken-line prestressed tendon with an adjustable bending point as a pressure anchor includes the following steps:

[0041] The steel strand 51 is passed through the through hole 14. The position of the reaction plate is adjusted to the projection point of the bending point 16 in the vertical direction by the sliding bracket 34. Then, the limiting block 4 is placed in the slide. The limiting block 4 is fixed in the slide and is detachably connected to the first base plate 32 and the bracket seat 341 respectively, restricting the sliding of the sliding bracket 34.

[0042] Install connecting rod 2, connecting one end to the second base plate 11 and the other end to the support sleeve 36. Use connecting shaft 35 to connect the support sleeve 36 and the sliding bracket 34, so that the positioning bracket 1 and the anchor support 3 are integrated. At the same time, use PVC plastic sleeve to cover the body of connecting rod 2 to prevent connecting rod 2 from solidifying with concrete when the beam 5 is poured.

[0043] After tensioning the steel strand 51 and the beam 5 has been cured and meets the conditions for release, rotate the connecting rod 2 so that the connecting rod 2 is screwed out of the positioning bracket 1 and screwed in of the anchor support 3, so that the connecting rod 2 is separated from the positioning bracket 1. At this time, the cast beam 5 can be removed from the platform.

[0044] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. For those skilled in the art, various modifications and improvements can be made without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. A pre-tensioning method of a pre-stressed tendon with adjustable bending point of a folded line, characterized in that, Includes positioning brackets, connecting rods, anchor supports, and limit blocks; The positioning bracket is provided with several through holes, which are used to constrain the steel strands. The anchoring support includes a reaction plate and embedded parts; the embedded parts include anchoring steel bars, a first base plate and a cover plate; the anchoring steel bars are fixedly connected to the first base plate, and the first base plate and the cover plate enclose a sliding track. The reaction plate includes a sliding bracket and a support sleeve; one end of the sliding bracket is located inside the slide rail and can slide along the slide rail, and the other end extends out above the slide rail; the support sleeve is detachably connected to the sliding bracket. The connecting rod is detachably connected to the support sleeve and the positioning bracket at both ends, and its relative height to the support sleeve can be adjusted when connected. The limiting block is detachably fixed inside the slide rail to restrict the sliding of the reaction plate.

2. The down-pressing anchor for the pre-stressed tendon with adjustable bending-up point in the pre-stressed tendon according to the pre-tensioning method as claimed in claim 1, characterized in that, The positioning bracket includes a second base plate, several first intermediate partitions and second intermediate partitions; several first intermediate partitions are fixed to the second base plate, several first intermediate partitions are arranged in parallel, any two adjacent first intermediate partitions are provided with at least one second intermediate partition, and several through holes are formed between the second base plate, the first intermediate partitions and the second intermediate partitions.

3. The down-pressing anchor for the pre-stressed tendon with adjustable bending-up point in the pre-stressed tendon according to the pre-tensioning method as claimed in claim 2, characterized in that, The first intermediate partition is perpendicular to the second base plate, and the second intermediate partition is parallel to the second base plate.

4. The down-pressing anchor for the pre-stressed tendon with adjustable bending-up point in the pre-stressed tendon according to the pre-tensioning method as claimed in claim 2, characterized in that, The second base plate has a first connecting hole at its center, the support sleeve has a second connecting hole, the first connecting hole and the second connecting hole have internal threads in opposite directions, and the two ends of the connecting rod have external threads.

5. The down-pressing anchor for the pre-stressed tendon with adjustable bending-up point in the pre-stressed tendon according to the pre-tensioning method as claimed in claim 2, characterized in that, The bottom of the second intermediate partition is grooved.

6. The down-pressing anchor for the pre-stressed tendon with adjustable bending-up point in pre-stressed tendon according to the pre-tensioning method of claim 1, characterized in that, The connecting rod has a hexagonal body.

7. The down-pressing anchor for the pre-stressed tendon with adjustable bending-up point in pre-stressed tendon according to the pre-tensioning method of claim 1, characterized in that, The reaction plate also includes a connecting shaft, and the support sleeve is rotatably connected to the sliding bracket through the connecting shaft.

8. The down-pressing anchor for the pre-stressed tendon with adjustable bending-up point in the pre-stressed tendon according to the pre-tensioning method as claimed in claim 1, characterized in that, The anchoring depth of the anchoring steel bar to the concrete is not less than 40cm, and the diameter of the anchoring steel bar is not less than 12mm.

9. A pedestal, characterized by The device includes a base and a downward anchor with an adjustable bending point of the prestressed tendon as described in any one of claims 1-8. The base has a groove, and the anchor support is fixed in the groove.

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