Tensioning pedestal suitable for prefabricating pi beam through long-line platform pre-tensioning method

Abstract

The utility model belongs to the technical field of tensioning pedestals, and particularly relates to a tensioning pedestal suitable for prefabricating a pi beam through a long-line platform pre-tensioning method, which comprises a fixed end reaction wall and a tensioning end reaction wall, and a fixed end cross beam is fixedly connected to one side, far away from the tensioning end reaction wall, of the fixed end reaction wall. A movable cross beam is installed on the side, away from the fixed end reaction wall, of the tensioning end reaction wall through a thrust applying set, round through holes are formed in the fixed end reaction wall, the tensioning end reaction wall, the fixed end cross beam and the movable cross beam, and steel strands are inserted into the round through holes. Threaded sleeves are installed on the outer sides of the steel strands and located on the sides, away from each other, of the fixed end cross beam and the movable cross beam, and a locking rod and a position adjusting set are assembled on the movable cross beam. According to the tensioning device, the force borne by the tensioning end sleeve in the steel strand tensioning process can be reduced, so that the deformation amplitude of the tensioning end sleeve is reduced, and the possibility that the tensioning end sleeve is locked on the outer side of the steel strand after being stressed and deformed is reduced.

Description

Technical Field

[0001] This invention belongs to the technical field of tensioning platform, specifically relating to a tensioning platform suitable for pre-tensioning π beams using the long-line platform pre-tensioning method. Background Technology

[0002] Precast concrete components are widely used in modern construction engineering, especially in bridge construction, precast building slabs, and other large structures. The π-beam, a special type of precast concrete beam, is named for its cross-sectional shape resembling the Greek letter "π." It boasts advantages such as light weight, large span, and convenient construction, and is widely used in bridge and building engineering.

[0003] In the production of π-beams, the long-line pretensioning method is a highly efficient prestressed concrete production method, widely used due to its ability to improve production efficiency and product quality. In this method, steel strands are pre-tensioned before concrete pouring to provide prestress, thereby improving the crack resistance and durability of the member.

[0004] Existing tensioning platforms, such as the Chinese patent with authorization announcement number CN205735486U, disclose a pre-tensioning and release structure for precast hollow slab steel strands. This structure involves installing sleeves and two crossbeams at both ends of the prestressed steel strands for anchoring. Then, the crossbeams apply forces that move away from each other to the two sleeves, thereby tensioning both ends of the steel strands through the two sleeves. During the tensioning process, due to the relatively long length of the steel strands in the π-beam, a larger tensioning force is required to complete the tensioning process. However, excessive force can easily cause deformation of the sleeves. When the deformation of the sleeves is large, they may lock onto the outside of the steel strands and cannot be effectively removed. Utility Model Content

[0005] The purpose of this invention is to provide a tensioning platform suitable for precast π beams using the long-line pre-tensioning method, which can reduce the force on the tensioning end sleeve during the tensioning of the steel strands, thereby reducing the deformation amplitude of the tensioning end sleeve and lowering the possibility that the tensioning end sleeve will lock onto the outside of the steel strands after being subjected to stress and deformation.

[0006] The specific technical solution adopted in this utility model is as follows:

[0007] A tensioning platform suitable for pre-tensioning π-beams using the long-line platform pre-tensioning method includes a fixed-end reaction wall and a tensioning-end reaction wall. A fixed-end crossbeam is fixedly connected to the side of the fixed-end reaction wall away from the tensioning-end reaction wall. A movable crossbeam is installed on the side of the tensioning-end reaction wall away from the fixed-end reaction wall via a thrust application assembly. Circular through holes are provided on the fixed-end reaction wall, the tensioning-end reaction wall, the fixed-end crossbeam, and the movable crossbeam. Steel strands are inserted into the circular through holes. Threaded sleeves are installed on the outer side of the steel strands and on the side of the fixed-end crossbeam and the movable crossbeam that are far apart from each other.

[0008] The movable crossbeam is equipped with a locking rod that can be moved into the circular through hole and a position adjustment assembly connected to the locking rod.

[0009] Furthermore, the position adjustment assembly includes a connected rotary drive and a threaded drum. A working hole is provided on the movable crossbeam. The rotary drive is installed inside the working hole. The threaded drum is rotatably connected to the inside of the movable crossbeam. An external thread is provided on the outer side of the locking rod. The locking rod is threadedly connected to the inside of the threaded drum through the external thread. A support plate is fixedly connected inside the working hole. A guide rib extending into the inside of the threaded drum is fixedly connected to the support plate. The locking rod is slidably connected inside the guide rib.

[0010] Furthermore, the rotary drive component includes a rotating rod rotatably connected inside the working hole, a bevel gear one fixedly connected to the rotating rod, and a bevel gear two fixedly connected to the threaded drum.

[0011] Furthermore, the thrust application assembly includes a jack fixedly connected to the reaction wall at the tensioning end, and the output end of the jack is fixedly connected to the movable crossbeam.

[0012] Furthermore, the tensioning end reaction wall is provided with two tracks located under the movable crossbeam on the side away from the fixed end reaction wall, and the movable crossbeam is slidably connected to the upper side of the tracks.

[0013] Furthermore, the fixed-end reaction wall and the tensioning-end reaction wall are made of concrete, and a fixed crossbeam is fixedly connected between the tensioning-end reaction wall and the jack. The fixed-end crossbeam, the fixed crossbeam, and the movable crossbeam are all made of steel.

[0014] The technical effects achieved by this utility model are as follows:

[0015] This utility model discloses a tensioning platform for precast π-beams using the long-line pre-tensioning method. By adding a locking rod inside the movable crossbeam, the platform can apply an auxiliary fixing force to the steel strand during the tensioning process, thereby sharing the force on the tensioning end sleeve during the tensioning process. This reduces the deformation amplitude of the threaded sleeve and lowers the possibility of the threaded sleeve locking onto the outside of the steel strand after deformation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this practical application;

[0017] Figure 2 This is a schematic diagram of the cross-sectional structure of this practical book;

[0018] Figure 3 This is a practical book Figure 2 A partial enlarged view of point A in the middle;

[0019] Figure 4 This is a cross-sectional structural diagram of this practical threaded rotary drum.

[0020] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0021] 1. Fixed end reaction wall; 2. Tensioning end reaction wall; 3. Fixed end crossbeam; 4. Fixed crossbeam; 5. Jack; 6. Movable crossbeam; 7. Track; 8. Steel strand; 9. Threaded sleeve; 10. Circular through hole; 11. Working hole; 12. Rotating rod; 13. Bevel gear one; 14. Bevel gear two; 15. Threaded rotating drum; 16. Locking rod; 17. Guide rib; 18. Support plate. Detailed Implementation

[0022] To make the purpose and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the following text is merely used to describe one or more specific implementations of this utility model and does not strictly limit the scope of protection specifically claimed by this utility model.

[0023] like Figure 1 As shown, a tensioning platform suitable for pre-tensioning π beams using the long-line pre-tensioning method includes a fixed-end reaction wall 1 and a tensioning-end reaction wall 2 arranged opposite to each other. A fixed-end crossbeam 3 is fixedly connected to the side of the fixed-end reaction wall 1 away from the tensioning-end reaction wall 2. A movable crossbeam 6 is installed on the side of the tensioning-end reaction wall 2 away from the fixed-end reaction wall 1 through a thrust application group. Circular through holes 10 are opened on the fixed-end reaction wall 1, tensioning-end reaction wall 2, fixed-end crossbeam 3, and movable crossbeam 6. The opposing circular through holes 10 on the fixed-end reaction wall 1, tensioning-end reaction wall 2, fixed-end crossbeam 3, and movable crossbeam 6 form a group. The same steel strand 8 is inserted into the group of circular through holes 10. Threaded sleeves 9 are installed on the outer side of the steel strand 8 and on the side of the fixed-end crossbeam 3 and movable crossbeam 6 that are far from each other. The threaded sleeve 9 located near the movable crossbeam 6 is the tensioning-end sleeve.

[0024] At this time, the steel strand 8 located between the fixed end reaction wall 1 and the tensioning end reaction wall 2 is the effective segment of the precast π beam. When precasting the π beam, the corresponding steel strand 8 is first inserted into the circular through hole 10. Then, the threaded sleeve 9 is used to limit the two ends of the steel strand 8. Then, by starting the thrust application group, the movable crossbeam 6 is moved away from the fixed end crossbeam 3, which can apply thrust to the threaded sleeve 9. Through the two threaded sleeves 9, the two ends of the steel strand 8 are applied with forces that move away from each other, thereby completing the tensioning of the effective segment of the steel strand 8. After tensioning, binding and concrete pouring are carried out to complete the precast π beam.

[0025] Because tensioning a long steel strand 8 requires applying a large thrust to the threaded sleeve 9, which can easily cause deformation of the threaded sleeve 9, this technical solution improves the movable crossbeam 6 to reduce the phenomenon of the threaded sleeve 9 locking onto the outside of the steel strand 8 after deformation. Specifically, the improvements are as follows: Figure 2-3 As shown, the movable crossbeam 6 is equipped with multiple locking rods 16 that can move into the circular through hole 10 and a position adjustment group connected to the locking rods 16. At this time, the locking rods 16 are moved along their axis by the position adjustment group, so that the locking rods 16 enter the interior of the circular through hole 10 until the end of the locking rods 16 abuts against the steel strand 8 inside the circular through hole 10. During the tensioning process of the steel strand 8, the locking rods 16 can apply an auxiliary fixing force to the steel strand 8, share the force on the tensioning end sleeve during the tensioning process of the steel strand 8, thereby reducing the deformation amplitude of the tensioning end sleeve and reducing the possibility that the tensioning end sleeve will lock on the outside of the steel strand 8 after being deformed by force.

[0026] One method of moving the locking rod 16 involves an external thread on the outer side of the locking rod 16, and a threaded hole connected to the circular through hole 10 inside the movable crossbeam 6. The locking rod 16 is threaded into the threaded hole through the external thread, and a pivot rod is slidably connected to the axis of the locking rod 16. The pivot rod extends to the outer side of the movable crossbeam 6 and is fixedly connected to a knob or nut. At this time, rotating the pivot rod can drive the locking rod 16 to rotate and move. The pivot rod is the position adjustment assembly.

[0027] Another way to move the locking lever 16 is as follows: Figure 3-4 As shown, the position adjustment assembly includes a connected rotary drive and a threaded drum 15. A working hole 11 is provided on the movable crossbeam 6. The rotary drive is installed inside the working hole 11. The threaded drum 15 is rotatably connected to the inside of the movable crossbeam 6. The locking rod 16 is provided with an external thread on its outer side. The locking rod 16 is threadedly connected to the inside of the threaded drum 15 through the external thread. A support plate 18 is fixedly connected inside the working hole 11. A guide rib 17 extending into the inside of the threaded drum 15 is fixedly connected to the support plate 18. The locking rod 16 is slidably connected inside the guide rib 17, so that the rotation of the locking rod 16 can be restricted by the guide rib 17. This allows the position of the locking rod 16 to be adjusted when the threaded drum 15 rotates. Due to the threaded design, the stability after adjustment is good.

[0028] The rotary drive component includes a rotating rod 12 rotatably connected inside the working hole 11. A bevel gear 13 is fixedly connected to the rotating rod 12. The bevel gear 13 meshes with a bevel gear 14 fixedly connected to the threaded drum 15. At this time, by rotating the working hole 11, the multiple threaded drums 15 can be synchronously driven to rotate through the transmission of the bevel gear 13 and the bevel gear 14. The adjustment method is relatively simple.

[0029] Among them, such as Figure 1 As shown, the thrust application group includes a jack 5 fixedly connected to the reaction wall 2 at the tensioning end. The output end of the jack 5 is fixedly connected to the movable crossbeam 6, which can apply thrust to the movable crossbeam 6 relatively stably.

[0030] To reduce the impact of the gravity of the movable beam 6 on the jack 5, two tracks 7 are provided on the side of the tensioning end reaction wall 2 away from the fixed end reaction wall 1, located below the movable beam 6. The movable beam 6 is slidably connected to the upper side of the tracks 7, so that the tracks 7 can bear the gravity of the movable beam 6 and reduce the impact of the gravity of the movable beam 6 on the jack 5.

[0031] Furthermore, the fixed end reaction wall 1 and the tensioning end reaction wall 2 are made of concrete. In order to reduce the damage caused by the jack 5 to the tensioning end reaction wall 2, a fixed crossbeam 4 is fixedly connected between the tensioning end reaction wall 2 and the jack 5. The fixed end crossbeam 3, the fixed crossbeam 4 and the movable crossbeam 6 are all made of steel.

[0032] The working principle of this utility model is as follows: the corresponding steel strand 8 is inserted into the circular through hole 10, and then the threaded sleeve 9 is used to limit the two ends of the steel strand 8. Then, by starting the jack 5, the movable crossbeam 6 is moved away from the fixed end crossbeam 3. The movable crossbeam 6 applies a pushing force to the threaded sleeve 9, and the two threaded sleeves 9 apply a force that moves away from each other to the two ends of the steel strand 8, thereby completing the tensioning of the effective section of the steel strand 8.

[0033] During the tensioning process, the locking rod 16 is moved along its axis to enter the interior of the circular through hole 10 until the end of the locking rod 16 abuts against the steel strand 8 inside the circular through hole 10. This allows the locking rod 16 to apply an auxiliary fixing force to the steel strand 8 during the tensioning process, sharing the force on the tensioning end sleeve during the tensioning process of the steel strand 8. This reduces the deformation amplitude of the tensioning end sleeve and lowers the possibility of the tensioning end sleeve locking onto the outside of the steel strand 8 after deformation.

[0034] The above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. Structures, devices, and operating methods not specifically described or explained in this utility model, unless otherwise specified or limited, shall be implemented using conventional methods in the art.

Claims

1. A tensioning platform suitable for pre-tensioning π-beams using the long-line pre-tensioning method, characterized in that: It includes a fixed end reaction wall (1) and a tensioning end reaction wall (2). A fixed end crossbeam (3) is fixedly connected to the side of the fixed end reaction wall (1) away from the tensioning end reaction wall (2). A movable crossbeam (6) is installed on the side of the tensioning end reaction wall (2) away from the fixed end reaction wall (1) through a thrust application group. A circular through hole (10) is opened on the fixed end reaction wall (1), the tensioning end reaction wall (2), the fixed end crossbeam (3), and the movable crossbeam (6). A steel strand (8) is inserted into the circular through hole (10). A threaded sleeve (9) is installed on the outside of the steel strand (8) and on the side of the fixed end crossbeam (3) and the movable crossbeam (6) away from each other. The movable crossbeam (6) is equipped with a locking rod (16) that can be moved into the circular through hole (10) and a position adjustment group connected to the locking rod (16).

2. A tensioning platform for pre-tensioned π-beams using the long-line pre-tensioning method according to claim 1, characterized in that: The position adjustment assembly includes a connected rotary drive and a threaded drum (15). A working hole (11) is provided on the movable crossbeam (6). The rotary drive is installed inside the working hole (11). The threaded drum (15) is rotatably connected to the inside of the movable crossbeam (6). An external thread is provided on the outer side of the locking rod (16). The locking rod (16) is threadedly connected to the inside of the threaded drum (15) through the external thread. A support plate (18) is fixedly connected inside the working hole (11). A guide rib (17) extending into the inside of the threaded drum (15) is fixedly connected on the support plate (18). The locking rod (16) is slidably connected inside the guide rib (17).

3. A tensioning platform for pre-tensioned π-beams using the long-line pre-tensioning method according to claim 2, characterized in that: The rotary drive includes a rotating rod (12) rotatably connected inside the working hole (11), a bevel gear (13) fixedly connected to the rotating rod (12), and a bevel gear (14) fixedly connected to the bevel gear (14) on the threaded drum (15).

4. A tensioning platform for pre-tensioned π-beams using the long-line pre-tensioning method as described in claim 1, characterized in that: The thrust application group includes a jack (5) fixedly connected to the reaction wall (2) at the tensioning end, and the output end of the jack (5) is fixedly connected to the movable crossbeam (6).

5. A tensioning platform for pre-tensioned π-beams using the long-line pre-tensioning method according to claim 4, characterized in that: Two tracks (7) are provided on the side of the tension end reaction wall (2) away from the fixed end reaction wall (1), located below the movable crossbeam (6), and the movable crossbeam (6) is slidably connected to the upper side of the tracks (7).

6. A tensioning platform for pre-tensioned π-beams using the long-line pre-tensioning method according to claim 5, characterized in that: The fixed end reaction wall (1) and the tensioning end reaction wall (2) are made of concrete. The tensioning end reaction wall (2) and the jack (5) are fixedly connected by a fixed crossbeam (4). The fixed end crossbeam (3), the fixed crossbeam (4) and the movable crossbeam (6) are all made of steel.

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