Bridge prestress tensioning device and using method

Abstract

The invention relates to the technical field of bridge construction, and discloses a bridge prestress tensioning device which comprises a prefabricated box girder, a plurality of tensioning assemblies are arranged on the prefabricated box girder, and the tensioning assemblies are used for applying tensioning force to the prefabricated box girder. The tensioning assembly comprises a corrugated pipe, a fixing clamping block, a first limiting block, a conical clamping sleeve clamping piece, a steel strand, a protective outer cover, a hydraulic driving assembly, a spiral fixing strip, a grouting hole, a second limiting block and a protruding block, and the spiral fixing strip arranged on the conical clamping sleeve clamping piece is in a spiral shape matched with the twisting direction of the steel strand; in this way, when the hydraulic driving assembly abuts against the second limiting block, the conical clamping sleeve clamping piece can exert certain twisting acting force on the steel strand, and therefore the fixing stability of the steel strand is enhanced, and the situation that in a traditional mode, when a clamping piece sleeve with the smooth inner wall is used for fixing, the clamping piece sleeve cannot be fixed easily is avoided. And the problem that the steel strand is difficult to fix stably for a long time due to single clamping force is solved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a bridge prestressing tensioning device and a use method thereof. Background Art

[0002] In the field of bridge construction, prestressed technology is one of the key means to improve the strength and durability of bridge structures. As the core equipment for realizing this technology, the performance of prestressed tensioning devices is directly related to the overall quality and safety of bridges. Traditional prestressed tensioning devices usually use clip sleeves with smooth inner walls to fix steel strands. This fixing method mainly relies on the clamping force of the clip sleeves on the steel strands to achieve the fixing effect. However, in actual applications, this traditional fixing method has exposed some obvious problems.

[0003] Firstly, a single clamping force is difficult to ensure the long-term stability of the steel strands. The steel strands will be affected by various external forces during use, such as thermal expansion and contraction caused by temperature changes, vibration under wind force, etc. These may cause the steel strands to have slight displacements in the clip sleeves. With the passage of time, this slight displacement will gradually accumulate, eventually leading to unstable fixation of the steel strands and affecting the prestressing effect.

[0004] Secondly, the traditional clip sleeve design is prone to collapse. Since the inner wall of the clip sleeve is smooth and the friction between it and the steel strand is small, when subjected to a large external force, the clip sleeve is prone to damage or collapse, which will not only reduce the fixing effect, but also cause safety hazards to the bridge structure and is not conducive to ensuring the safety of the bridge. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a bridge prestressing tensioning device and a method of use, which solves the problem that the traditional clip sleeve design is prone to collapse, causing safety hazards to the bridge structure and being detrimental to ensuring the safety of the bridge.

[0007] (II) Technical solution

[0008] To achieve the above-mentioned object, the present invention provides the following technical solutions: a prestressed tensioning device for a bridge, comprising a prefabricated box girder, a plurality of tensioning assemblies are arranged on the prefabricated box girder, the tensioning assemblies are used to apply tensioning force to the prefabricated box girder, the tensioning assemblies include a corrugated pipe, a fixed block, a first limit block, a conical clamping piece, a steel strand, a protective cover, a hydraulic drive assembly, a spiral fixing strip, a grouting hole, a second limit block and a protruding block;

[0009] The outer surface of the conical ferrule clip in the tensioning assembly is provided with three movable grooves, which are all provided at the large end of the conical ferrule clip, and the three movable grooves are evenly arranged in a circular array;

[0010] The plurality of spiral fixing strips are all fixedly connected to the inner wall of the conical ferrule clip, the plurality of spiral fixing strips are evenly arranged in a circular array, and the spiral fixing strips are arranged in a spiral shape that matches the twisting direction of the steel strand.

[0011] Preferably, the corrugated pipe in the tensioning assembly is embedded in a designated position in the prefabricated box girder when the prefabricated box girder is cast, the corrugated pipe is arranged in a downwardly bent arc, and conical square grooves are provided at both ends of the prefabricated box girder.

[0012] Preferably, the conical square grooves are located at both ends of the corrugated pipe, the fixed blocks are respectively arranged in the corresponding conical square grooves, the opposite sides of the two fixed blocks are fixedly connected with connecting pipes, and the two connecting pipes are connected to both ends of the corrugated pipe.

[0013] Preferably, the outer surface of the spiral fixing strip is provided with a plurality of spacing grooves, the plurality of spacing grooves are evenly distributed at equal intervals, and a protrusion for increasing friction is formed between two adjacent spacing grooves.

[0014] Preferably, the first limit block is arranged on the fixed block, a plurality of conical holes are opened on the first limit block, conical ferrule clips are respectively arranged in the corresponding conical holes, a plurality of conical ferrule clips are respectively arranged between two corresponding conical ferrule clips, and grouting holes are provided on the fixed block.

[0015] Preferably, the conical ferrule clips are all located in the corrugated tube, pads are all provided on the first limit blocks, steel strand holes corresponding to the steel strands are all opened on the pads, and the steel strands extend out of the outer surfaces of the steel strand holes.

[0016] Preferably, the second limit block is arranged on the outer surface of multiple steel strands, the second limit block has the same structure as the first limit block, a protective cover is fixed on the second limit block, and the hydraulic drive component is arranged between the second limit block and the cushion block, and the hydraulic drive component is used to stretch the steel strands.

[0017] A method for using a bridge prestressing tensioning device:

[0018] S1: When in use, the fixed block is placed in the corresponding conical square groove and the steel strand is inserted into the corresponding steel strand. Then the corresponding first limit block and the conical clamping piece are sleeved on the plurality of steel strands, and then the cushion block is continued to be sleeved;

[0019] S2: After inserting the cushion block, the hydraulic drive assembly is installed on the multiple steel strands, and the second limit block and the conical ferrule clip thereon are continued to be installed on the steel strands. At this time, the hydraulic drive assembly is started, and the hydraulic drive assembly applies a force to the second limit block on the cushion block, so that the second limit block applies a force to the conical ferrule clip through the steel strand hole thereon, so that the large end of the conical ferrule clip can gradually shrink inwards;

[0020] S3: When the conical ferrule clamp is retracted to the specified position, the conical ferrule clamp can drive the protrusions on its inner wall to move inward and retract together. At this time, the moving protrusions will gradually get into the twisted gap of the steel strand, and the steel strand can be squeezed under the action of multiple protrusions. At this time, the steel strand is not only clamped by the contraction of the conical ferrule clamp, but also by the extrusion force of the spacing groove and the protrusions, so that the steel strand can be effectively restricted and clamped;

[0021] S4: As the hydraulic drive assembly slowly extends, the structure of the conical clamping piece causes the steel strand to move only outward, and the clamping piece at the tail end of the jack can clamp the steel strand and pull it outward. On the contrary, the steel strand on the first limit block can slide outward in the conical clamping piece. When the steel strand is pulled to the set tension by the hydraulic drive assembly, the hydraulic drive assembly releases the pressure. At this time, the steel strand will retract due to its own tension, but will be firmly clamped by the conical clamping piece on the first limit block.

[0022] S5: After the conical ferrule clip on the limit block firmly clamps the steel strand on the first limit block, remove the second limit block and the conical ferrule clip on it together with the hydraulic drive assembly, cut off the excess steel strand, inject high-strength concrete into the grouting hole reserved above the fixed block, and finally fill the conical square groove with concrete to complete the sealing.

[0023] (III) Beneficial effects

[0024] Compared with the prior art, the present invention provides a bridge prestressing tensioning device and a method of use, which have the following beneficial effects:

[0025] 1. The prestressed tensioning device for the bridge has a spiral fixing strip arranged on the conical ferrule clip in a spiral shape that matches the twisting direction of the steel strand. This enables the conical ferrule clip to apply a certain torsional force to the steel strand when the hydraulic drive assembly presses the second limit block, thereby enhancing the fixing stability of the steel strand and avoiding the problem that a single clamping force is difficult to fix the steel strand stably and permanently when a clip sleeve with a smooth inner wall is used for fixing in the traditional way.

[0026] 2. The prestressed tensioning device of the bridge is evenly arranged in a circular array through the three movable grooves, which can make the conical ferrule clip produce elastic deformation evenly, and the three movable grooves can also ensure that the conical ferrule clip can have sufficient strength under the premise of ensuring that the conical ferrule clip can deform evenly, which increases the service life of the conical ferrule clip, reduces the probability of damage and collapse of the conical ferrule clip and injuring people, and improves safety.

[0027] 3. The prestressed tensioning device of the bridge can effectively protect the conical ferrule clip on the second limit block when it is tightened by means of the protective outer cover, which further prevents the conical ferrule clip from being damaged by the tightening force and the fragments from breaking out and injuring people, thereby further improving safety.

[0028] 4. The method of using the prestressed tensioning device of the bridge is that when the prefabricated box girder is affected by its own gravity or the weight of the vehicles on the bridge deck, the bridge will bend downward, causing the lower part to be stretched or even cracked. The steel strands are generally located in the lower part or the bottom of the bridge. When we shrink the stressed steel strands at the bottom of the bridge, the lower part of the prefabricated box girder is compressed, resulting in an upward deformation. This effect is like an arch bridge, which can offset the deformation of the prefabricated box girder caused by gravity. Compared with traditional reinforced concrete bridges, prestressed bridges can withstand greater loads. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the bellows of the present invention;

[0031] Figure 3 This is a schematic diagram of the structure of the hydraulic drive assembly of the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of the tapered ferrule clip of the present invention;

[0033] Figure 5 For the present invention Figure 2 Enlarged view of point A in the middle;

[0034] Figure 6 This is a schematic diagram of the fixed card block structure of the present invention.

[0035] In the figure: 1. prefabricated box girder; 2. corrugated pipe; 3. conical square groove; 4. fixed block; 5. first limit block; 6. conical hole; 7. conical clamping clip; 8. steel strand; 9. protective cover; 10. hydraulic drive assembly; 11. movable groove; 12. spiral fixing strip; 13. spacing groove; 14. grouting hole; 15. second limit block; 16. steel strand hole; 17. raised block; 18. connecting pipe; 19. cushion block. DETAILED DESCRIPTION

[0036] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0037] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] In the description of the present invention, greater than, less than, exceed, etc. are understood as not including the number itself, and above, below, within, etc. are understood as including the number itself. If there is a description of first or second, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0039] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0040] See also Figure 1-6 The present invention provides a new technical solution: a prestressed tensioning device for a bridge, comprising a prefabricated box girder 1, a plurality of tensioning components are arranged on the prefabricated box girder 1, the tensioning components are used to apply tensioning force to the prefabricated box girder 1, the tensioning components include a bellows 2, a fixed block 4, a first limit block 5, a conical clamping piece 7, a steel strand 8, a protective cover 9, a hydraulic drive component 10, a spiral fixing strip 12, a grouting hole 14, a second limit block 15 and a protruding block 17;

[0041] The outer surface of the conical ferrule clip 7 in the tensioning assembly is provided with three movable grooves 11, and the movable grooves 11 are all provided at the large end of the conical ferrule clip 7, and the three movable grooves 11 are evenly arranged in a circular array;

[0042] The plurality of spiral fixing strips 12 are all fixedly connected to the inner wall of the conical ferrule clip 7 , and the plurality of spiral fixing strips 12 are evenly arranged in a circular array. The spiral fixing strips 12 are arranged in a spiral shape that matches the twisting direction of the steel strand 8 .

[0043] Furthermore, the corrugated pipe 2 in the tensioning assembly is embedded in a designated position in the prefabricated box girder 1 when the prefabricated box girder 1 is cast. The corrugated pipe 2 is arranged in a downwardly bent arc shape, and conical square grooves 3 are provided at both ends of the prefabricated box girder 1.

[0044] Furthermore, the conical square grooves 3 are located at both ends of the corrugated tube 2, and the fixed blocks 4 are respectively arranged in the corresponding conical square grooves 3. The opposite sides of the two fixed blocks 4 are fixedly connected with connecting pipes 18, and the two connecting pipes 18 are connected to both ends of the corrugated tube 2.

[0045] Furthermore, a plurality of spacing grooves 13 are formed on the outer surface of the spiral fixing strip 12 . The plurality of spacing grooves 13 are evenly distributed at equal intervals, and a protrusion 17 for increasing friction is formed between two adjacent spacing grooves 13 .

[0046] Furthermore, the first limit block 5 is arranged on the fixed block 4, and a plurality of conical holes 6 are opened on the first limit block 5. The conical ferrule clips 7 are respectively arranged in the corresponding conical holes 6, and the plurality of conical ferrule clips 7 are respectively arranged between two corresponding conical ferrule clips 7. The fixed block 4 is provided with grouting holes 14.

[0047] Furthermore, the conical ferrule clips 7 are all located in the corrugated tube 2 , the first limit blocks 5 are all provided with cushion blocks 19 , the cushion blocks 19 are all provided with steel strand holes 16 corresponding to the steel strands 8 , and the steel strands 8 extend out of the outer surface of the steel strand holes 16 .

[0048] Furthermore, a second limit block 15 is arranged on the outer surface of the plurality of steel strands 8. The second limit block 15 has the same structure as the first limit block 5. A protective outer cover 9 is fixedly sleeved on the second limit block 15. A hydraulic drive assembly 10 is arranged between the second limit block 15 and the cushion block 19. The hydraulic drive assembly 10 is used for stretching the steel strands 8. The hydraulic drive assembly 10 is a prior art and will not be described in detail herein.

[0049] Furthermore, by providing the spiral fixing strip 12 on the conical ferrule clamp 7 in a spiral shape that matches the twisting direction of the steel strand 8, the conical ferrule clamp 7 can apply a certain torsional force to the steel strand 8 when the hydraulic drive assembly 10 presses against the second limit block 15, thereby enhancing the fixing stability of the steel strand 8 and avoiding the problem that a single clamping force is difficult to fix the steel strand 8 stably and permanently when a clamp sleeve with a smooth inner wall is used for fixing in the traditional way.

[0050] Furthermore, by setting three movable grooves 11 evenly arranged in a circular array, the conical ferrule clip 7 can evenly produce elastic deformation, and the three movable grooves 11 can also ensure that the conical ferrule clip 7 can have sufficient strength when the deformation is unstable under the premise of ensuring that the conical ferrule clip 7 can be evenly deformed, which increases the service life of the conical ferrule clip 7, reduces the probability of the conical ferrule clip 7 being damaged and collapsing and injuring people, and improves safety.

[0051] Furthermore, the protective outer cover 9 can effectively protect the conical ferrule clip 7 on the second limit block 15 when it is tightened, which further prevents the conical ferrule clip 7 from being damaged by the tightening force and the fragments from breaking out and injuring people, thereby further improving safety.

[0052] Furthermore, the prefabricated box girder 1 is affected by its own gravity or the weight of the vehicles on the bridge deck, and the bridge will bend downward, causing the lower part to be stretched or even cracked. The steel strands 8 are generally located in the lower part or bottom of the bridge. When we shrink the stressed steel strands at the bottom of the bridge, the lower part of the prefabricated box girder 1 is compressed, resulting in an upward deformation. This effect is like an arch bridge, which can offset the downward deformation of the prefabricated box girder 1 caused by gravity. Compared with traditional reinforced concrete bridges, prestressed bridges can withstand greater loads.

[0053] A bridge How to use the beam prestressing tensioning device:

[0054] S1: When in use, the fixing block 4 is placed in the corresponding conical square groove 3 and the steel strand 8 is inserted into the corresponding first limit block 5 and the conical clamping piece 7 are sleeved on the plurality of steel strands 8, and then the cushion block 19 is continued to be sleeved;

[0055] S2: After inserting the cushion block 19, the hydraulic drive assembly 10 is installed and sleeved on the multiple steel strands 8, and the second limit block 15 and the conical ferrule clip 7 thereon are continued to be installed on the steel strands 8. At this time, the hydraulic drive assembly 10 is started, and the hydraulic drive assembly 10 applies a force to the second limit block 15 on the cushion block 19, so that the second limit block 15 applies a force to the conical ferrule clip 7 through the steel strand hole 16 thereon, so that the large end of the conical ferrule clip 7 can gradually shrink inward;

[0056] S3: When 7 is retracted to the specified position, the conical ferrule clip 7 can drive the protruding block 17 on its inner wall to move inward and retract together. At this time, the moving protruding block 17 will gradually get into the twisted gap of the steel strand 8, and can squeeze the steel strand 8 under the action of multiple protruding blocks 17. At this time, the steel strand 8 is not only subject to the clamping force of the conical ferrule clip 7, but also to the squeezing force of the spacing groove 13 and the protruding block 17, so that the steel strand 8 can be effectively restricted and clamped;

[0057] S4: As the hydraulic drive assembly 10 slowly extends, the structure of the conical clamping piece causes the steel strand to move only outward, and the clamping piece at the tail end of the jack can clamp the steel strand and pull it outward. On the contrary, the steel strand 8 on the first limit block 5 can slide outward in the conical clamping piece 7. When the steel strand 8 is pulled to the set tension by the hydraulic drive assembly 10, the hydraulic drive assembly 10 releases the pressure. At this time, the steel strand 8 will retract due to its own tension, but will be firmly clamped by the conical clamping piece 7 on the first limit block 5.

[0058] S5: After the conical ferrule clip 7 on the limit block 5 firmly clamps the steel strand 8 on the first limit block 5, the second limit block 15 and the conical ferrule clip 7 thereon are removed together with the hydraulic drive assembly 10, and then the excess steel strand 8 is cut off, and high-strength concrete is injected into the grouting hole 14 reserved above the fixed clamping block 4, and finally the conical square groove 3 is filled with concrete to complete the sealing.

[0059] Working principle: The spiral fixing strip 12 provided on the conical ferrule clamp 7 is in a spiral shape adapted to the twisting direction of the steel strand 8. This enables the conical ferrule clamp 7 to apply a certain torsional force to the steel strand 8 when the hydraulic drive assembly 10 presses against the second limit block 15, thereby enhancing the fixing stability of the steel strand 8.

[0060] Furthermore, by setting three movable grooves 11 evenly arranged in a circular array, the conical ferrule clip 7 can evenly produce elastic deformation, and the three movable grooves 11 can also ensure that the conical ferrule clip 7 has sufficient strength under the premise of even deformation to ensure unstable deformation.

[0061] Furthermore, the protective outer cover 9 can effectively protect the conical ferrule clip 7 on the second limiting block 15 when it is tightened.

[0062] Furthermore, the prefabricated box girder 1 is affected by its own gravity or the weight of the vehicles on the bridge deck, and the bridge will bend downward, causing the lower part to be stretched or even cracked. The steel strands 8 are generally located in the lower part or bottom of the bridge. When we shrink the stressed steel strands at the bottom of the bridge, the lower part of the prefabricated box girder 1 is compressed, resulting in an upward deformation. This effect is like an arch bridge, which can offset the downward deformation of the prefabricated box girder 1 caused by gravity.

[0063] 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 bridge prestressing tensioning device, characterized in that: The invention comprises a prefabricated box girder (1), wherein a plurality of tensioning components are arranged on the prefabricated box girder (1), and the tensioning components are used to apply tensioning force to the prefabricated box girder (1), and the tensioning components comprise a corrugated pipe (2), a fixing block (4), a first limiting block (5), a conical clamping piece (7), a steel strand (8), a protective cover (9), a hydraulic drive component (10), a spiral fixing strip (12), a grouting hole (14), a second limiting block (15) and a protruding block (17); The outer surface of the conical clamping piece (7) in the tensioning component is provided with three movable grooves (11), the movable grooves (11) are all provided at the large end of the conical clamping piece (7), and the three movable grooves (11) are evenly arranged in a circular array; The plurality of spiral fixing strips (12) are all fixedly connected to the inner wall of the conical ferrule clamp (7), the plurality of spiral fixing strips (12) are evenly arranged in a circular array, and the spiral fixing strips (12) are arranged in a spiral shape that matches the twisting direction of the steel strand (8).

2. A bridge prestressing tensioning device according to claim 1, characterized in that: The corrugated pipe (2) in the tensioning assembly is embedded in a designated position in the prefabricated box beam (1) when the prefabricated box beam (1) is cast. The corrugated pipe (2) is arranged in a downwardly bent arc shape. Conical square grooves (3) are provided at both ends of the prefabricated box beam (1).

3. A bridge prestressing tensioning device according to claim 2, characterized in that: The conical square grooves (3) are located at both ends of the corrugated tube (2); the fixed clamping blocks (4) are respectively arranged in the corresponding conical square grooves (3); the opposite sides of the two fixed clamping blocks (4) are fixedly connected with connecting pipes (18); and the two connecting pipes (18) are connected to both ends of the corrugated tube (2).

4. A bridge prestressing tensioning device according to claim 1, characterized in that: The outer surface of the spiral fixing strip (12) is provided with a plurality of spacing grooves (13), the plurality of spacing grooves (13) are evenly distributed at equal intervals, and a protrusion (17) for increasing friction force is formed between two adjacent spacing grooves (13).

5. The prestressed tensioning device for a bridge according to claim 1, characterized in that: The first limit block (5) is arranged on the fixed clamping block (4), a plurality of tapered holes (6) are provided on the first limit block (5), tapered clamping pieces (7) are respectively arranged in corresponding tapered holes (6), a plurality of tapered clamping pieces (7) are respectively arranged between two corresponding tapered clamping pieces (7), and grouting holes (14) are provided on the fixed clamping block (4).

6. A bridge prestressing tensioning device according to claim 5, characterized in that: The conical ferrule clips (7) are all located in the corrugated tube (2), the first limit blocks (5) are all provided with cushion blocks (19), the cushion blocks (19) are all provided with steel strand holes (16) corresponding to the steel strands (8), and the steel strands (8) extend out of the outer surface of the steel strand holes (16).

7. A bridge prestressing tensioning device according to claim 6, characterized in that: The second limit block (15) is arranged on the outer surface of the plurality of steel strands (8); the second limit block (15) has the same structure as the first limit block (5); a protective outer cover (9) is fixedly sleeved on the second limit block (15); a hydraulic drive assembly (10) is arranged between the second limit block (15) and the cushion block (19); and the hydraulic drive assembly (10) is used to stretch the steel strands (8).

8. A method for using a bridge prestressing tensioning device, characterized in that: S1: When in use, the fixing block (4) is placed in the corresponding conical square groove (3) and the steel strand (8) is inserted into the corresponding position, and then the corresponding first limit block (5) and the conical clamping piece (7) are sleeved on the plurality of steel strands (8), and then the cushion block (19) is continuously sleeved; S2: After inserting the cushion block (19), the hydraulic drive assembly (10) is installed and sleeved on the plurality of steel strands (8), and the second limit block (15) and the conical ferrule clip (7) thereon are further installed on the steel strands (8). At this time, the hydraulic drive assembly (10) is started, and the hydraulic drive assembly (10) applies a force to the second limit block (15) on the cushion block (19), so that the second limit block (15) applies a force to the conical ferrule clip (7) through the steel strand hole (16) thereon, so that the large end of the conical ferrule clip (7) can gradually shrink inward.

9. The method for using a bridge prestressing tensioning device according to claim 8, characterized in that: S3: When the conical clamping piece (7) contracts, it can drive the protruding block (17) on its inner wall to move inward and contract together. At this time, the moving protruding block (17) will gradually get stuck in the twisted gap of the steel strand (8), and under the action of multiple protruding blocks (17), the steel strand (8) can be squeezed. At this time, the steel strand (8) is not only subjected to the clamping force of the contraction of the conical clamping piece (7), but also to the squeezing force of the spacing groove (13) and the protruding block (17), so that the steel strand (8) can be effectively restricted and clamped; S4: As the hydraulic drive assembly (10) slowly extends, the structure of the conical clamp causes the steel strand to move only outward, so the clamp at the tail end of the jack can clamp the steel strand and pull it outward. Conversely, the steel strand (8) on the first limit block (5) can slide outward in the conical clamping clamp (7). When the steel strand (8) is pulled to the set tension by the hydraulic drive assembly (10), the hydraulic drive assembly (10) releases the pressure. At this time, the steel strand (8) will retract due to its own tension, but will be firmly clamped by the conical clamping clamp (7) on the first limit block (5).

10. The method for using the bridge prestressing tensioning device according to claim 9, characterized in that: S5: After the conical clamping piece (7) on the limit block (5) firmly clamps the steel strand (8) on the first limit block (5), the second limit block (15) and the conical clamping piece (7) thereon are removed together with the hydraulic drive assembly (10), and then the excess steel strand (8) is cut off, and high-strength concrete is injected into the grouting hole (14) reserved above the fixed clamping block (4), and finally the conical square groove (3) is filled with concrete to complete the sealing.

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