Tensioning device for long-span large-section slow-bonding prestressed beam

Abstract

The utility model discloses a tensioning device for a long-span large-section slow-bonding prestressed beam, which relates to the technical field of bridge construction, and comprises an anchor backing plate and a steel strand, an anchor plate is clamped on the end face of the anchor backing plate, a through hole for the steel strand to pass through is formed in the anchor plate, two clamping pieces for clamping the steel strand are clamped in the through hole, and the steel strand is clamped in the clamping pieces. A limiting plate is clamped to the end face of the anchorage device plate, a contraction mechanism used for applying thrust to the clamping pieces is arranged in the limiting plate and comprises a push ring, a spring and a sliding pipe, a sliding groove is formed in the contraction mechanism, the sliding pipe is installed in the sliding groove in a sliding mode, the push ring is fixedly connected to one end of the sliding pipe, and the spring is connected to the outer side wall of the sliding pipe in a sleeving mode. The clamping pieces are pushed through the shrinking mechanism, the clamping pieces located in the same through hole are shrunk into the through hole, the shrunk clamping pieces make contact with the outer side wall of the steel strand, and the problem that part of the clamping pieces of an existing tensioning device cannot make contact with the outer side wall of a steel cable, and then the clamping pieces cannot fixedly clamp the steel cable after the steel cable is shrunk is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge construction, in particular to a tensioning device for slow-bonding prestressed beams with large spans and large cross-sections. Background Art

[0002] Prestressed beam tensioning device is an engineering device used to apply prestress to concrete beams. This process mainly uses stretched steel bars or cables (steel strands) and anchors the tension of the steel bars or cables in the concrete to enhance the bearing capacity and durability of the structure.

[0003] When stretching steel cables in a large-span and large-section bridge, in order to keep the cables in tension, the cables need to be fixed at both ends of the bridge to prevent them from bending and shrinking due to their own gravity. Most existing tensioning devices use two conical clamps to clamp and fix the two ends of the cables. The principle is that when the cables are tightened, the conical clamps separate. When the cables shrink, the cables contact the clamps, driving the clamps to shrink in the holes, thereby clamping and fixing the cables.

[0004] However, in order to ensure that the two clips contact the steel cable, most of the existing tensioning devices use rubber rings to be sleeved on the outer walls of the two clips to limit the position of the clips and ensure that the clips contact the steel cable. However, the rubber rings are affected by temperature (high or low temperature), mechanical damage (excessive stretching), material aging, etc. After the rubber rings are sleeved on the outer walls of the clips, the rubber rings cannot shrink to limit the position of the clips, so that some clips cannot contact the outer walls of the steel cable. Then, after the steel cable shrinks, the clips cannot fix and clamp the steel cable. In order to solve the above-mentioned problems, a tensioning device for large-span and large-section slow-bonding prestressed beams is provided. Utility Model Content

[0005] The purpose of the utility model is to provide a tensioning device for large-span and large-section slow-bonding prestressed beams, so as to solve the problem in the above-mentioned background technology that some clamps of the existing tensioning device cannot contact the outer wall of the steel cable, and then after the steel cable shrinks, the clamps cannot fix and clamp the steel cable.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a tensioning device for slow-bonding prestressed beams with large span and large cross-section, comprising an anchor plate and a steel strand, the end face of the anchor plate is clamped with an anchor plate, the anchor plate is provided with a plurality of through holes for the steel strands to pass through, two clips for clamping the steel strands are clamped in the through holes, the end face of the anchor plate is clamped with a limit plate, a contraction mechanism for applying thrust to the clip is arranged in the limit plate, the contraction mechanism pushes the clip, so that the clip located in the same through hole contracts into the through hole, and the contracted clip contacts the outer wall of the steel strand.

[0007] As a preferred technical solution of the utility model, the limiting plate is also provided with a through hole for the steel strand to pass through, and two clips located in the same through hole form a conical structure, and a through hole is also provided in the middle of the formed conical structure.

[0008] As a preferred technical solution of the utility model, a clip located in the same through hole is fixedly connected to an insert block, and adjacent clips are provided with insert holes matching the insert block.

[0009] As a preferred technical solution of the utility model, the retraction mechanism includes a push ring, a spring and a sliding tube. A sliding groove is opened inside the retraction mechanism. The sliding tube is slidably installed in the sliding groove. The push ring is fixedly connected to one end of the sliding tube. The spring is sleeved on the outer wall of the sliding tube. The spring applies an elastic force toward the clamp on the push ring.

[0010] As a preferred technical solution of the utility model, two anchor plates are buried at both ends of the bridge respectively, a corrugated pipe is buried in the bridge, and the two ends of the corrugated pipe are respectively connected to the two anchor plates, and the steel strand runs through the corrugated pipe and the two anchor plates.

[0011] As a preferred technical solution of the utility model, one end of the anchor plate is fixedly connected with a spiral reinforcement for increasing the tensile strength, and the spiral reinforcement is buried in the bridge.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] The utility model pushes the clamping piece through the contraction mechanism, so that the clamping piece located in the same through hole contracts into the through hole, and the contracted clamping piece contacts the outer wall of the steel strand, thereby solving the problem that some clamping pieces of the existing tensioning device cannot contact the outer wall of the steel cable, and further the clamping piece cannot fix and clamp the steel cable after the steel cable contracts. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the overall structure of the tensioning device of an embodiment of the utility model;

[0015] Figure 2 It is a partial structural schematic diagram of the tensioning device of an embodiment of the utility model;

[0016] Figure 3 This is a cross-sectional view of a limiting plate according to an embodiment of the utility model;

[0017] Figure 4 For the utility model embodiment Figure 3 Enlarged view of point A in the middle;

[0018] Figure 5 It is a partial exploded view of the tensioning device of the embodiment of the utility model;

[0019] Figure 6This is a schematic diagram of the clip structure of an embodiment of the utility model.

[0020] In the figure: 1. anchor plate; 11. spiral reinforcement; 2. steel strand; 3. anchor plate; 4. clip; 41. plug block; 5. limit plate; 6. retraction mechanism; 61. push ring; 62. spring; 63. sliding tube; 7. bellows. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] See also Figure 1-6 This embodiment provides a tensioning device for a large-span and large-section slow-bonding prestressed beam, including an anchor plate 1 and a steel strand 2, wherein two anchor plates 1 are provided, and a corrugated pipe 7 is fixedly connected between the two anchor plates 1, and the anchor plates 1 and the corrugated pipe 7 are both buried in the bridge. At this time, the two anchor plates 1 are respectively located at both ends of the bridge. That is, before the bridge is produced and cast, the anchor plate 1 and the corrugated pipe 7 are installed in the mold, and after concrete is poured into the mold, after the concrete solidifies into a bridge, the anchor plate 1 and the corrugated pipe 7 are buried in the bridge.

[0023] The anchor plate 1 is at risk of detaching from the bridge when subjected to tension. In order to increase the installation stability of the anchor plate 1, one end of the anchor plate 1 is fixedly connected with a spiral rib 11, which is also buried in the bridge. The spiral rib 11 increases the tensile strength of the anchor plate 1, thereby preventing the anchor plate 1 from detaching from the bridge.

[0024] The steel strand 2 is formed by twisting a plurality of steel wires. The steel strand 2 is provided with six strands. The six steel strands 2 all penetrate the corrugated tube 7 and the two anchor pads 1. Figure 1 As shown, two ends of the steel strand 2 extend through two anchor plates 1 respectively.

[0025] The end surface of the anchor plate 1 is clamped with an anchor plate 3, and the anchor plate 3 is provided with six through holes, through which the steel strand 2 extends, and two clips 4 are inserted into the through holes. Figure 4 and Figure 6As shown, two clips 4 form a conical structure, and a through hole is also provided in the middle of the conical structure. When the two clips 4 are inserted into the through hole of the anchor plate 3, the steel strand 2 is located in the through hole of the two clips 4. In order to prevent the clip 4 from being separated from the through hole of the anchor plate 3, a limiting plate 5 is engaged with the end face of the anchor plate 3. Among them, the limiting plate 5 is provided with a limiting groove, and one end of the clip 4 can be moved and fitted at the bottom of the limiting groove. At this time, one end of the clip 4 is still in the through hole of the anchor plate 3, and then the clip 4 is limited by the limiting plate 5 to prevent the clip 4 from being separated from the through hole of the anchor plate 3.

[0026] When in use, a hydraulic jack is installed on the end face of the limit plate 5 away from the anchor plate 3. Hydraulic jacks are installed at both ends of the bridge. The reference model of the hydraulic jack is a tensioning machine of CZB2 2-600A. Two hydraulic jacks are started synchronously to stretch the steel strand 2 to make the steel strand 2 tight. Of course, one hydraulic jack can also be used to fix one end of the steel strand 2, and the other hydraulic jack can be started to tighten the steel strand 2. After the pulling force of the hydraulic jack reaches the preset value, the steel strand 2 is released, and the steel strand 2 bends and contracts due to its own gravity. The contracted steel strand 2 contacts the two clamps 4, driving the two clamps 4 to contract into the through hole of the anchor plate 3. After the outer wall (arc-shaped surface) of the conical clamp 4 contacts the through hole of the anchor plate 3, the two clamps 4 will approach each other. The greater the contraction force of the steel strand 2, the closer the two clamps 4 are, and the two clamps 4 approaching each other can clamp and fix the steel strand 2, that is, the two clamps 4 form an anchoring unit for fixing the steel strand 2, to prevent the steel strand 2 from continuing to contract.

[0027] When installing the clip 4, the clip 4 needs to be kept in the through hole of the anchor plate 3, and then the limit plate 5 is installed. In order to stably install the clip 4, one clip 4 located in the same through hole is fixedly connected with an insert block 41, and another clip 4 in the same through hole is provided with an insertion hole. The insert block 41 is inserted into the through hole. At this time, the outer wall of the insert block 41 and the through hole form an interaction force, thereby forming a damping force to fix the insert block 41, and enter to fix the two clips 4, so that the conical structure composed of the two clips 4 remains sleeved on the outer wall of the steel strand 2. At this time, the conical structure composed of the two clips 4 can be slid into the through hole of the anchor plate 3. When the steel strand 2 is tightened, the contraction of the steel strand 2 drives the two clips 4 to approach each other. At this time, the pressure applied by the edge of the through hole of the anchor plate 3 on the clip 4 is greater than the damping force between the insert block 41 and the inner wall of the insertion hole, and then after the two clips 4 approach each other, the insert block 41 is driven to continue to move into the insertion hole.

[0028] When the steel strand 2 drives the two clips 4 to retract into the through hole of the anchor plate 3, it is necessary to ensure that the inner wall of the clip 4 contacts the outer wall of the steel strand 2. In order to ensure that the clip 4 maintains contact with the outer wall of the steel strand 2, a retracting mechanism 6 is provided in the limiting groove of the limiting plate 5. The retracting mechanism 6 includes a push ring 61, a spring 62 and a sliding tube 63. Figure 4As shown, a sliding groove is opened in the limiting groove of the limiting plate 5, and the sliding tube 63 is slidably installed in the sliding groove. The push ring 61 is fixedly connected to the end of the sliding tube 63 facing the clamping piece 4, and the steel strand 2 passes through the ring hole of the push ring 61 and the tube hole of the sliding tube 63. The spring 62 is sleeved on the outer wall of the sliding tube 63, and the two ends of the spring 62 are respectively connected to the end face of the push ring 61 and the bottom of the limiting groove. The spring 62 applies an elastic force toward the clamping piece 4 to the push ring 61, so that the push ring 61 contacts the clamping piece 4. The push ring 61 applies a thrust toward the through hole of the anchor plate 3 to the clamping piece 4 through the elastic force of the spring 62. The through hole of the anchor plate 3 contacts the outer wall (arc surface) of the clamping piece 4, which can drive the two clamping pieces 4 to approach each other, and the inner walls of the clamping pieces 4 approaching each other can contact the outer wall of the steel strand 2.

[0029] The two clips 4 are driven to retract into the through hole of the anchor plate 3 through the retraction mechanism 6, thereby ensuring that the clips 4 are always in contact with the steel strand 2. When the steel strand 2 retracts, the two clips 4 can be driven to approach, tighten, and clamp the anchor steel strand 2.

[0030] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A tensioning device for a large-span and large-section slow-bonding prestressed beam, comprising an anchor plate (1) and a steel strand (2), characterized in that: The end face of the anchor plate (1) is engaged with an anchor plate (3), the anchor plate (3) is provided with a plurality of through holes for the steel strands (2) to pass through, two clips (4) for clamping the steel strands (2) are engaged in the through holes, the end face of the anchor plate (3) is engaged with a limit plate (5), the limit plate (5) is provided with a retracting mechanism (6) for applying a thrust to the clip (4), the retracting mechanism (6) pushes the clip (4) so ​​that the clip (4) located in the same through hole is retracted into the through hole, and the retracted clip (4) contacts the outer wall of the steel strand (2).

2. The tensioning device for long-span and large-section slow-bonding prestressed beams according to claim 1 is characterized in that: The limiting plate (5) is also provided with a through hole for the steel strand (2) to pass through, and the two clips (4) located in the same through hole form a conical structure, and a through hole is also provided in the middle of the formed conical structure.

3. The tensioning device for long-span and large-section slow-bonding prestressed beams according to claim 2 is characterized in that: One of the clips (4) located in the same through hole is fixedly connected to an insert block (41), and an adjacent clip (4) is provided with an insert hole matching the insert block (41).

4. The tensioning device for slow-bonding prestressed beams with large span and large cross-section according to claim 3 is characterized in that: The retracting mechanism (6) comprises a push ring (61), a spring (62) and a sliding tube (63). A sliding groove is provided inside the retracting mechanism (6). The sliding tube (63) is slidably installed in the sliding groove. The push ring (61) is fixedly connected to one end of the sliding tube (63). The spring (62) is sleeved on the outer wall of the sliding tube (63). The spring (62) applies an elastic force to the push ring (61) toward the clamp (4).

5. The tensioning device for slow-bonding prestressed beams with large span and large cross-section according to claim 2 is characterized in that: The two anchor plates (1) are respectively buried at two ends of the bridge, a corrugated pipe (7) is buried in the bridge, and the two ends of the corrugated pipe (7) are respectively connected to the two anchor plates (1), and the steel strand (2) passes through the corrugated pipe (7) and the two anchor plates (1).

6. The tensioning device for slow-bonding prestressed beams with large span and large cross-section according to claim 5 is characterized in that: One end of the anchor plate (1) is fixedly connected to a spiral rib (11) for increasing tensile strength, and the spiral rib (11) is buried in the bridge.

Images