Anchorage structure for reducing prestress loss caused by anchorage retraction

Abstract

The application discloses an anchor structure for reducing prestress loss caused by anchor retraction, and belongs to the technical field of building anchor structures. The elastic supporting member compensates for the retraction of the anchor structure. When the prefabricated and assembled pier is subjected to earthquake action, the displacement between the joints is compensated by compression of the elastic supporting member, thereby avoiding the situation that the prestress is greatly increased due to the overstretching of the prestressed tendon, and the retraction of the clamping piece is avoided. That is, the deformation near the anchor is replaced by the compression of the elastic supporting member, and the irreversible prestress loss caused by the retraction of the clamping piece is avoided. Compared with the conventional anchor, the prestress loss caused by the stretching of the prestressed tendon of the unbonded prestressed prefabricated and assembled pier under the action of earthquake is solved, and the behavior of the clamping piece retraction is avoided. The patent mechanism is clear, the structure is simple, and the processing and installation are convenient.

Description

Technical Field

[0001] This invention belongs to the field of building anchorage structure technology, specifically relating to an anchorage structure that reduces prestress loss caused by anchorage retraction. Background Technology

[0002] When conventional anchorages are used in unbonded prestressed precast piers, the segments open and close during earthquakes. This stretches the prestressing tendons, increasing the prestress and causing the wedges to retract. After the earthquake, the pier self-resets due to the prestress, but the wedges cannot return to their original positions, resulting in a loss of prestress and adversely affecting the seismic performance of the precast piers. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide an anchor structure that reduces the loss of prestress caused by anchor retraction and avoids the failure of the wedges after an earthquake.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] This invention includes an anchor plate with several prestressing tendon holes in its center and several positioning holes through its edge. It also includes a base plate with several prestressing tendon holes in its center and several tie rods fixed to the top surface of its edge. Each tie rod passes through a positioning hole and is threaded with a locking nut. Prestressing tendons pass sequentially through the base plate and the anchor plate, with their ends fixed to the prestressing tendon holes on the anchor plate. An elastic support is provided between the anchor plate and the base plate.

[0006] Furthermore, it also includes a cylindrical clamping piece, which surrounds the end of the prestressing tendon. The clamping piece includes two semi-cylindrical pieces, both ends of which are tapered. The two semi-cylindrical pieces are joined together to form the clamping piece with tapered ends. An internally threaded cylinder extends upward from the top surface of the anchor plate. A positioning ring is threaded onto the internally threaded cylinder. A pressure plate is coaxially rotatable inside the positioning ring. The pressure plate has several prestressing tendon holes. The pressure plate moves toward the anchor plate as the positioning ring rotates, so that the tapered ends of the clamping piece are inserted into the prestressing tendon holes of the anchor plate and the pressure plate, respectively.

[0007] Furthermore, a pin extends from one end face of the closing surface of one of the semi-cylindrical pieces, and a hinged joint with a shaft extends from the other end face. A pin hole is provided on one end face of the closing surface of the other semi-cylindrical piece, and a hinged joint with a hole extends from the other end face. The shaft of the hinged joint with a shaft is inserted into the hole of the hinged joint with a hole, so that the two semi-cylindrical pieces are hinged together. When the two semi-cylindrical pieces are closed, the pin is inserted into the pin hole.

[0008] Furthermore, the anchor plate has a threaded hole at its center, and a fixed-length threaded post is threadedly connected to the threaded hole. The fixed-length threaded post has a hexagonal hole at its top and its bottom end abuts against the end face of the base plate, thereby fixing the shortest distance between the pressure plate and the anchor plate. The top end of the fixed-length threaded post is recessed below the end face of the anchor plate.

[0009] Furthermore, a countersunk hole is also formed at the positioning hole of the anchor plate, and the locking nut is located in the countersunk hole. Each of the tie rods is threaded with two locking nuts.

[0010] Furthermore, the chassis extends upwards with a ring of baffles, and the anchor plate slides inside the top of the baffles.

[0011] Furthermore, the elastic support is a disc spring, which overlaps between the anchor plate and the base plate, and the disc spring surrounds the outside of each prestressed tendon.

[0012] Furthermore, the elastic support is a spring, which rests between the anchor plate and the base plate, and the spring surrounds the outer side of all the prestressed tendons.

[0013] The beneficial effects of this invention are as follows:

[0014] In this invention, the elastic support structure compensates for shrinkage. Under seismic conditions, the displacement between the joints of precast precast piers is compensated by the compression of the elastic support, preventing excessive stretching of the prestressing tendons and thus avoiding the retraction of the wedges. In other words, deformation near the anchor is replaced by the compression of the elastic support, preventing irreversible prestress loss due to retraction at the wedge location. Compared to conventional anchors, this invention solves the problem of wedge retraction caused by stretching of prestressing tendons in unbonded precast precast piers under seismic action, which leads to prestress loss. The patented mechanism is clear, the structure is simple, and it is easy to process and install.

[0015] Other advantages, objectives, and features of the invention will be set forth in the following description and will be apparent to those skilled in the art in some respects, or may be learned by practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0016] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0017] Figure 1 This is a schematic diagram of the overall structure of the anchorage according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the internal structure of the anchorage structure in Embodiment 1 of the present invention;

[0019] Figure 3 This is a schematic diagram of vibration simulation of the anchor structure according to an embodiment of the present invention;

[0020] Figure 4 This is a cross-sectional view of the anchor structure in Embodiment 1 of the present invention;

[0021] Figure 5 This is a schematic diagram of the structure of the clip component according to an embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of the structure of the hinged joint with shaft and the hinged joint with hole according to embodiments of the present invention;

[0023] Figure 7 This is a cross-sectional view of the clip component according to an embodiment of the present invention;

[0024] Figure 8 This is a cross-sectional view of the anchor structure in Embodiment 2 of the present invention;

[0025] The following labels are used in the attached diagram: 1. Anchor plate; 11. Internal threaded cylinder; 12. Threaded hole; 13. Countersunk hole; 2. Base plate; 21. Tie rod; 22. Locking nut; 23. Stop cylinder; 3. Elastic support; 31. Disc spring; 32. Spring; 4. Clamping piece; 41. Semi-cylindrical piece; 411. Pin; 412. Pin hole; 413. Hinge joint with shaft; 414. Hinge joint with hole; 5. Positioning ring; 51. Pressure plate; 6. Fixed-length threaded post; 61. Hexagonal hole. Detailed Implementation

[0026] like Figures 1-8 As shown, this invention discloses an anchor structure that reduces prestress loss caused by anchor retraction, such as... Figure 3 As shown, this structure is used to fix unbonded prestressed precast bridge piers. One end of the prestressing tendon is fixed to the pier base, and the prestressing tendons pass through the assembled pier sequentially. Finally, this anchorage structure provides compression fixation to the assembled pier, restricting directional movement of the pier components. (Refer to...) Figure 1 and Figure 2This anchor structure includes an anchor plate 1, which is a disc-shaped metal entity. Several prestressing tendon holes are formed in the center of the anchor plate 1. The number of prestressing tendon holes is determined by the number of prestressing tendons in the prestressing tendon bundles to be prestressed. The prestressing tendon holes should be evenly distributed on the anchor plate 1 in a circular pattern. Then, several positioning holes are formed through the edge of the anchor plate 1, evenly distributed around the axis of the anchor plate 1. Approximately four to eight positioning holes can be provided. A countersunk hole 13, coaxial with the positioning holes, is also formed on the top surface of the anchor plate 1. It also includes a base plate 2, which is also a disc-shaped metal entity. Several prestressing tendon holes are formed in the center of the base plate 2. The position and number of the tie rods correspond to the anchor plate 1. Several tie rods 21 are fixed to the top surface of the edge of the base plate 2. The number and position of the tie rods 21 correspond to the positioning holes. The tie rods 21 can be fixed to the base plate 2 by pre-embedding. Each tie rod 21 passes through the positioning hole and is threaded with a locking nut 22. Each tie rod 21 is threaded with two or more locking nuts, which are located within the countersunk hole 13. The prestressing tendons pass sequentially through the base plate 2 and the anchor plate 1. The ends of the prestressing tendons are fixed to the prestressing tendon holes on the anchor plate 1 by tapered clips, thus fixing the ends of the prestressing tendons to the anchor plate 1. An elastic support 3 supports the anchor plate 1 and the base plate 2. (Reference) Figure 4 and Figure 8 The elastic support 3 can be a disc spring 31, which overlaps between the anchor plate 1 and the base plate 2 and surrounds the outside of each prestressing tendon. Alternatively, the elastic support 3 can be a spring 32, which abuts between the anchor plate 1 and the base plate 2 and surrounds the outside of all the prestressing tendons. After confirming the relative distance between the anchor plate 1 and the base plate 2 by the tie rod 21 and the locking nut, the elastic support 3 abuts between the anchor plate 1 and the base plate 2. Further elastic support can also be a ring spring, wherein the ring spring, disc spring, or spring can surround a single prestressing tendon or the entire bundle of prestressing tendons as needed.

[0027] The installation method of this anchor structure is as follows: Based on the designed prestress, determine the compression amount of the elastic support 3 (designed prestress / elastic support 3 stiffness), apply pressure to the anchor plate 1, stop applying pressure when the elastic pre-compression amount is reached, and lock the tie rod 21 by locking the lock nut to fix the relative position of the anchor plate 1 and the base plate 2. Next, install this anchor structure on the pier structure: one end of the prestressing tendon is fixed at the base position of the body to be connected, the bodies to be installed are stacked side by side on the base, the prestressing tendon passes through the body to be connected in sequence, extends out of the end face of the body to be connected, passes through the base plate 2 and the anchor plate 1 in sequence, a conical clamp is installed on the end of the prestressing tendon, the prestressing tendon is pulled by the equipment through the hydraulic cylinder, and the anchor plate 1 is pressed towards the body to be connected. The installation of the anchor is completed by tensioning the prestress.

[0028] This anchor structure, such as Figure 3The elastic support 3, a shrinkage-compensating anchorage structure, compensates for the displacement between the joints of precast precast piers under seismic action. This avoids a significant increase in prestress caused by excessive stretching of the prestressing tendons, thus preventing the wedges from shrinking back. In other words, the deformation near the anchorage is replaced by the compression of the elastic support 3, preventing irreversible prestress loss due to shrinkage at the wedge location. Compared to conventional anchorages, this solves the problem of wedge shrinkage caused by the stretching of prestressing tendons in unbonded precast precast piers under seismic action, which leads to prestress loss. The patented mechanism is clear, the structure is simple, and it is easy to process and install.

[0029] In a further refinement, to prevent the clips from detaching due to stronger deformation, this structure is further optimized by setting up as follows: Figure 5 The cylindrical clamping member 4 shown is wrapped around the end of the prestressing tendon. The clamping member 4 includes two semi-cylindrical pieces 41, both ends of which are tapered. The two semi-cylindrical pieces 41 are joined together to form the clamping member 4 with tapered ends, thus enabling the clamping member 4 to both surround and clamp the prestressing tendon. It should be noted that, like ordinary tapered clamping members 4, this clamping member 4 has serrated edges on its inner side to ensure a strong clamping effect on the prestressing tendon. Figure 2 and Figure 4 As shown, an internally threaded cylinder 11 extends upward from the top surface of the anchor plate 1. A positioning ring 5 is threaded onto the internally threaded cylinder 11. A pressure plate 51 is coaxially rotatably mounted inside the positioning ring 5. The pressure plate 51 has a protruding ridge on its outer side and a ring rail on the inner side of the positioning ring 5. The protruding ridge is rotatably mounted inside the ring rail, so that the pressure plate 51 is rotatably mounted inside the positioning ring 5 and its axial movement is restricted. Several prestressing tendon holes are opened on the pressure plate 51. The pressure plate 51 moves toward the anchor plate 1 as the positioning ring 5 rotates, so that the two conical surfaces of the clamping piece 4 are respectively inserted into the prestressing tendon holes of the anchor plate 1 and the pressure plate 51.

[0030] This structure further avoids clamp failure caused by clamp detachment. After prestressing tensioning, one end of the clamp 4 is inserted into the prestressing tendon hole of the anchor plate 1. At this time, by rotating the positioning ring 5, the pressure plate 51 is pressed against the other end of the clamp 4, so that the two conical surfaces of the clamp 4 are respectively inserted into the prestressing tendon holes of the anchor plate 1 and the pressure plate 51. When the prestressing tendon is subjected to vibration and expands or contracts, the movement of the clamp 4 is prevented. The movement of the clamp 4 in both directions is restricted by the prestressing tendon holes of the anchor plate 1 and the pressure plate 51, respectively. Regardless of the relative movement of the clamp 4 in both directions driven by the prestressing tendon, the clamp 4 can be retracted to clamp the prestressing tendon, preventing the clamp 4 from detaching from the prestressing tendon. This structure further strengthens the fixation between the end of the prestressing tendon and the anchor plate 1, and improves the anchor's resistance to vibration failure.

[0031] In further proposals, such as Figure 5 , Figure 6 and Figure 7 As shown, the clamping piece 4 is a prefabricated structural component. One end face of the closing surface of one of the semi-cylindrical pieces 41 has a pin 411 fixedly extending out, and the other end face has a hinge joint 413 with a shaft sliding out. One end face of the closing surface of the other semi-cylindrical piece 41 has a pin hole 412, and the other end face has a hinge joint 414 with a hole sliding out. The shaft of the hinge joint 413 is inserted into the hole of the hinge joint 414, so that the two semi-cylindrical pieces 41 are hinged together. When the two semi-cylindrical pieces 41 are closed, the pin 411 is inserted into the pin hole 412.

[0032] The clamping piece 4 of this structure, through the hinge of the perforated hinge joint 414 and the shaft hinge joint 413, and the connection of the pin 411 and the pin hole 412, allows the clamping piece 4 to easily and quickly surround the outside of the prestressing tendon without falling off. The hinge joint, which moves inside the semi-cylindrical piece 41, can also ensure the contraction and clamping function of the two semi-cylindrical pieces 41 while completing the connection structure. The pin 411 and the pin hole 412 restrict the axial separation of the two semi-cylindrical pieces 41. The installed clamping piece 4, through the cooperation of the perforated hinge joint 414, the shaft hinge joint 413, the pin 411, and the pin hole 412, can be temporarily hung on the prestressing tendon without falling off. The clamping piece 4 is simple and quick to assemble, further improving the installation efficiency of this anchor structure and ensuring the functionality of the anchor structure.

[0033] In further proposals, such as Figure 4 As shown, the anchor plate 1 has a threaded hole 12 in the center, and a fixed-length threaded post 6 is threadedly connected to the threaded hole 12. The top of the fixed-length threaded post 6 has a hexagonal hole 61, and the bottom of the fixed-length threaded post 6 abuts against the end face of the base plate 2, so that the shortest distance between the pressure plate 51 and the anchor plate 1 is fixed. The top of the fixed-length threaded post 6 is sunk below the end face of the anchor plate 1.

[0034] The fixed-length threaded column 6 is used to predetermine the relative distance between the anchor plate 1 and the base plate 2 in the normal state of the anchor structure. Rotating the fixed-length threaded column 6 allows it to protrude a certain distance from the bottom surface of the anchor plate 1, preventing excessive compression when compressing the elastic support 3. After the prestressing is completed, the fixed-length threaded column 6 is retracted. The fixed-length threaded column 6 also serves to limit the extreme compression of the elastic support 3, preventing it from failing due to excessive compression.

[0035] In further proposals, such as Figure 2 As shown, the chassis 2 extends upwards with a ring of baffles 23, and the anchor plate 1 slides inside the top of the baffles 23. In this structure, the baffles 23 both guide the anchor plate 1 to its position and protect the elastic support 3.

[0036] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. An anchorage structure to reduce loss of prestress due to anchorage retraction, characterized by: The utility model provides an anchor plate (1) in which a plurality of prestressed tendon holes are arranged in the middle, a plurality of positioning holes are arranged through the edge of the anchor plate (1), a base plate (2) in which a plurality of prestressed tendon holes are arranged in the middle, a plurality of pull rods (21) are fixedly arranged on the top surface of the edge of the base plate (2), the pull rods (21) pass through the positioning holes and are threadedly connected with locking nuts (22), prestressed tendons pass through the base plate (2) and the anchor plate (1) in sequence, the end of the prestressed tendons is fixed at the prestressed tendon hole on the anchor plate (1), and an elastic supporting piece (3) is arranged between the anchor plate (1) and the base plate (2); a clamping piece (4) in the shape of a cylinder is arranged around the end of the prestressed tendons, the clamping piece (4) comprises two half-cylinder pieces (41), the two ends of the half-cylinder pieces (41) are all conical, the two half-cylinder pieces (41) are folded to form the clamping piece (4) with conical ends, the anchor plate (1) is upwardly extended by an inner threaded cylinder (11) in the shape of a ring, the inner threaded cylinder (11) is threadedly connected with a positioning ring (5) in the shape of a ring, the positioning ring (5) is coaxially arranged with a pressing plate (51) inside, a plurality of prestressed tendon holes are arranged in the pressing plate (51), and the pressing plate (51) is moved towards the anchor plate (1) by rotating the positioning ring (5) so that the two ends of the clamping piece (4) are respectively inserted into the prestressed tendon holes of the anchor plate (1) and the pressing plate (51).

2. An anchor structure that reduces loss of pre-stress due to anchor retraction according to claim 1, wherein: One end of the folded surface of one of the half-cylinder pieces (41) is fixedly extended by a pin shaft (411), the other end is slidably extended by a shaft hinged joint (413), one end of the folded surface of the other half-cylinder piece (41) is arranged with a pin hole (412), and the other end is slidably extended by a hole hinged joint (414), the shaft of the shaft hinged joint (413) is inserted into the hole of the hole hinged joint (414) so that the two half-cylinder pieces (41) are hinged, and when the two half-cylinder pieces (41) are folded, the pin shaft (411) is inserted into the pin hole (412).

3. An anchor structure that reduces the loss of pre-stress due to anchor retraction according to claim 1, wherein: A threaded hole (12) is arranged in the center of the anchor plate (1), a fixed-length threaded column (6) is threadedly connected at the threaded hole (12), the fixed-length threaded column (6) is provided with a hexagonal hole (61) at the top end, the bottom end of the fixed-length threaded column (6) abuts against the end surface of the base plate (2) so that the shortest distance between the pressing plate (51) and the anchor plate (1) is fixed, and the top end of the fixed-length threaded column (6) is sunken below the end surface of the anchor plate (1).

4. The anchorage structure that reduces loss of pre-stress due to anchorage retraction according to claim 1, wherein: A counterbore (13) is further arranged downwardly at the positioning hole of the anchor plate (1), and the locking nuts (22) are arranged in the counterbore (13), and each pull rod (21) is threadedly connected with two locking nuts (22).

5. An anchor structure that reduces loss of pre-stress due to anchor retraction according to claim 1, wherein: The base plate (2) is upwardly extended by a blocking cylinder (23) in the shape of a ring, and the anchor plate (1) is slidably arranged inside the top end of the blocking cylinder (23).

6. An anchor structure that reduces loss of pre-stress due to anchor retraction according to claim 1, wherein: The elastic supporting piece (3) is a disc spring (31), the disc spring (31) is overlapped between the anchor plate (1) and the base plate (2), and the disc spring (31) is arranged around the outside of each prestressed tendon.

7. An anchor structure that reduces loss of pre-stress due to anchor retraction according to claim 1, wherein: The elastic support (3) is a spring (32) which is arranged between the anchor disc (1) and the base disc (2) and surrounds the outer side of all the prestressed tendons.

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