Fabricated pre-tensioning method prestress pedestal tensioning counter-force system and construction method

Abstract

The invention provides an assembly type pre-tensioning method prestress pedestal tensioning counter-force system and a construction method. The tension counterforce system comprises two groups of force transmission columns which are arranged on the ground in parallel at intervals in the extension direction of a precast beam; the beam end fixing cross beams are fixedly connected to the ends of the two sets of force transmission columns correspondingly, and the side walls, away from the force transmission columns, of the beam end fixing cross beams comprise inclined faces and vertical faces in the height direction; the first power structure is installed on the inclined face and used for tensioning inclined prestressed tendons of the precast beam, and the second power structure is installed on the vertical face and used for tensioning horizontal prestressed tendons of the precast beam. The two ends of each beam bottom anchoring cross beam are correspondingly and fixedly connected with the two sets of force transmission columns respectively. According to the tensioning counterforce system, tensioning of the sectional type prestressed tendons can be achieved, the tensioning counterforce system is good in strength, rigidity and stability, meanwhile, an assembly type structure is adopted, and reutilization can be achieved.

Description

Technical Field

[0001] This invention generally relates to the field of bridge construction technology, and specifically to a prefabricated prestressed pedestal tensioning reaction system and construction method. Background Technology

[0002] Pre-tensioning pedestals in related technologies are divided into pier type and channel type. Pier type pedestals rely on their own weight to resist the overturning moment generated by the tension force, while channel type pedestals use a frame system composed of end columns and force-transfer columns to bear the tension force, which is suitable for large components with large tension tonnage. However, pre-tensioning pedestals in related technologies are not suitable for tensioning pre-tensioned linear segmented prestressed tendons, and they are all cast as a whole using reinforced concrete structures, occupying relatively large space, and are not recyclable or reusable, requiring temporary structures to be disposed of after completion. Summary of the Invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a prefabricated prestressed pedestal tensioning reaction system that can realize the tensioning of segmented prestressed tendons. The tensioning reaction system has good strength, stiffness and stability, and adopts a prefabricated structure that can be reused.

[0004] In a first aspect, the present invention provides a prefabricated prestressed pedestal tensioning reaction system, comprising: Two sets of force transmission columns are set on the ground at intervals and parallel to each other along the extension direction of the precast beam. The beam end fixed crossbeam is set along the direction perpendicular to the extension of the precast beam, and the beam end fixed crossbeam is fixedly connected to the ends of the two sets of force transmission columns respectively. The side wall of the beam end fixed crossbeam away from the force transmission column includes an inclined surface and a vertical surface in the height direction. The power structure includes a first power structure and a second power structure. The first power structure is installed on the inclined surface and is used to tension the inclined prestressing tendons of the precast beam. The second power structure is installed on the vertical surface and is used to tension the horizontal prestressing tendons of the precast beam. Multiple bottom anchor beams are arranged at intervals between two sets of force transmission columns, perpendicular to the extension direction of the precast beam. Each bottom anchor beam has two ends fixedly connected to the two sets of force transmission columns respectively. Each bottom anchor beam is equipped with an anchor, which is used to anchor the inclined prestressing tendons of the precast beam.

[0005] As an optional solution, the first power structure includes a first jack and a first beam end movable crossbeam. The first jack is installed on an inclined surface, and the first beam end movable crossbeam is located on one side of the first jack. During the tensioning process of the first jack, the first beam end movable crossbeam is moved. The second power structure includes a second jack and a second beam end movable crossbeam. The second jack is installed on a vertical surface, and the second beam end movable crossbeam is located on one side of the second jack. During the tensioning process of the second jack, the second beam end movable crossbeam is moved.

[0006] As an optional solution, after the first jack tensions and pushes the movable crossbeam at the first beam end to complete one tensioning stroke, the position of the movable crossbeam at the first beam end is fixed by a nut.

[0007] As an optional solution, a platform is also included. The platform is formed by casting reinforced concrete or splicing I-beams. The platform is set along the extension direction of the precast beam and is located between two sets of force transmission columns. The surface of the platform is higher than the ground and is used to support the installation of the precast beam.

[0008] As an optional solution, each set of force-transmitting columns includes multiple prefabricated steel truss components, which are sequentially and detachably connected along the extension direction of the prefabricated beam.

[0009] As an optional solution, the bottom of each set of force-transfer columns is anchored to the concrete enlarged foundation via U-shaped fixing bars.

[0010] As an optional solution, the beam-end fixed crossbeam is a lattice steel box structure formed by welding steel plates, and the bottom of the beam-end fixed crossbeam is fixed in the concrete spread foundation by welding pre-embedded bars.

[0011] As an optional solution, the bottom anchoring beam is a steel box structure formed by welding steel sections and stiffening ribs or steel plates. The bottom of the bottom anchoring beam is anchored in the concrete spread foundation by pre-embedded bars to resist the upward pull-out force generated by tension.

[0012] As an optional option, the embedded reinforcement is a U-shaped anchor bar made of JL32 precision rolled threaded steel.

[0013] Secondly, the present invention provides a construction method for a pre-tensioned prestressed platform tensioning reaction system as described in the first aspect, specifically including the following steps: Constructing a tension reaction system includes: Two sets of force-transmitting columns are placed parallel to each other on the ground along the extension direction of the precast beam; The beam end is fixed with a crossbeam, which is then fixedly connected to the ends of the two sets of force transmission columns. The first power structure and the second power structure are respectively installed on the fixed crossbeam at the beam end; The bottom anchor beams are spaced between the two sets of force transmission columns, and the two ends of the bottom anchor beams are fixedly connected to the two sets of force transmission columns respectively. Anchors are installed on the bottom anchor beams. The inclined prestressing tendons and the horizontal prestressing tendons are installed at the construction position of the precast beam in a predetermined manner. One end of the inclined prestressing tendon is anchored to the anchor and the other end is connected to the first power structure. The two ends of the horizontal prestressing tendon are respectively connected to the second power structure on the fixed crossbeams at both ends of the beam. The first power structure tensions the oblique prestressing tendons multiple times, and the second power structure tensions the horizontal prestressing tendons from both ends multiple times, until the elastic elongation of the oblique and horizontal prestressing tendons reaches the preset threshold. Precast beams are obtained by pouring concrete at the construction location of the precast beams; Dismantle the tensioning reaction system.

[0014] The prefabricated prestressed beam tensioning reaction system of this invention features force transfer columns positioned on the ground, avoiding the difficulties of excavation and dismantling required for embedded force transfer beam construction. It is easy to operate and can be reused after dismantling. Beam-end fixing beams are fixed to both ends of the force transfer columns, forming inclined and vertical surfaces, reliably enabling the tensioning of both diagonal and horizontal prestressing tendons in the precast beam. Multiple beam-bottom anchoring beams are positioned between the force transfer columns, with anchorages on each beam-bottom anchoring beam for anchoring the diagonal prestressing tendons. This allows for the construction of linear segmented prestressed beams. Furthermore, the bottom anchor beam can gather and anchor the diagonal prestressing tendons, thus directly and effectively transferring the enormous tension force to the bottom anchor beam, and then to the force transmission columns on both sides and the entire reaction system, improving the stability of the entire reaction system. At the same time, it allows the entire reaction system to be set entirely on the ground, avoiding the cumbersome process of excavating deep trenches and burying the force transmission columns underground, which is required for traditional trough-type platforms. This facilitates the rapid installation, dismantling, and turnover of the reaction system, and can also adapt to beam designs with different spans or different angles of diagonal prestressing tendons. Attached Figure Description

[0015] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic elevation view of the prefabricated prestressed platform tensioning reaction system, which is an embodiment of this application. Figure 2 This is a schematic diagram of the planar structure of the prefabricated prestressed platform tensioning reaction system according to an embodiment of this application. Figure 3 for Figure 2 Cross-sectional view of the AA plane.

[0016] In the picture, 100. Reaction system; 1. Precast beam; 11. Diagonal prestressing tendon; 12. Horizontal prestressing tendon; 10. Force transmission column; 20. Beam end fixed crossbeam; A1. Inclined surface; A2. Vertical surface; 30. First jack; 31. First beam end movable crossbeam; 32. Second jack; 33. Second beam end movable crossbeam; 40. Beam bottom anchoring crossbeam; 41. Anchor; 50. Platform; 60. Concrete spread foundation; 70. Embedded reinforcement; 80. U-shaped fixing reinforcement. Detailed Implementation

[0017] The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present application will now be described in detail with reference to embodiments.

[0018] To address the aforementioned problems, embodiments of this application provide a pre-tensioned prestressed platform tensioning reaction system 100, such as... Figure 1 , Figure 2 and Figure 3 As shown, it includes: Two sets of force transmission columns 10 are set on the ground at intervals and parallel to each other along the extension direction of the precast beam 1. A beam end fixed crossbeam 20 is provided along the extension direction perpendicular to the precast beam 1, and the beam end fixed crossbeam 20 is fixedly connected to the ends of two sets of force transmission columns 10 respectively. The side wall of the beam end fixed crossbeam 20 away from the force transmission column 10 includes an inclined surface A1 and a vertical surface A2 in the height direction. The power structure includes a first power structure and a second power structure. The first power structure is installed on the inclined surface A1 and is used to tension the inclined prestressing tendons 11 of the precast beam 1. The second power structure is installed on the vertical surface A2 and is used to tension the horizontal prestressing tendons 12 of the precast beam 1. Multiple bottom anchor beams 40 are arranged at intervals between two sets of force transmission columns 10, perpendicular to the extension direction of the precast beam 1. The two ends of each bottom anchor beam 40 are fixedly connected to the two sets of force transmission columns 10 respectively. Each bottom anchor beam 40 is provided with an anchor 41, which is used to anchor the inclined prestressing tendons 11 of the precast beam 1.

[0019] Understandably, the fixed crossbeam 20 at the beam end includes an inclined surface A1 and a vertical surface A2. This allows the first dynamic structure (inclined direction) and the second dynamic structure (in horizontal direction) of the prestressing tendons 12 to be arranged on the same operating plane, enabling synchronous or sequential tensioning of prestressing tendons in different directions. This reduces equipment movement and adjustment time, significantly improving the efficiency and accuracy of tensioning operations. Furthermore, the inclined surface A1, targeting the inclined prestressing tendons 11, ensures that the direction of the tension force coincides with the tendon axis, reducing secondary stress and guaranteeing the accuracy of prestress establishment. The vertical surface A2, targeting the horizontal prestressing tendons 12, can adapt to new beam structures with complex three-dimensional prestressing tendon arrangements, such as linear segmented beams.

[0020] Multiple bottom anchor beams 40 are spaced apart, providing multiple intermediate anchor points for the inclined prestressing tendons 11. This allows the prestress to be transferred more evenly to different sections of the precast beam 1, effectively improving the stress distribution in the web and bottom plate of the precast beam 1, and enhancing the shear resistance, bending resistance, and overall stiffness of the precast beam 1. Furthermore, the multiple bottom anchor beams 40 tightly connect the two rows of force transmission columns 10, forming a rigid frame with multiple lateral connections. This greatly enhances the lateral stability, torsional stiffness, and integrity of the entire reaction system when subjected to huge unbalanced tension forces, preventing buckling instability of the slender force transmission columns 10, and ensuring the safety and reliability of ultra-tonnage tensioning operations.

[0021] It is also understandable that the force transmission column 10, the beam end fixed crossbeam 20 and the beam bottom anchoring crossbeam 40 are all set above the ground, which helps to avoid the heavy earthwork excavation, cast-in-place concrete and subsequent demolition work of the traditional underground platform 50, and realizes rapid installation, convenient disassembly and reuse.

[0022] The prefabricated prestressed beam pedestal 50 tensioning reaction system of this application solves the problems in related technologies where the prestressed beam pedestal 50 is not suitable for tensioning prestressed straight segmented prestressing tendons, and all are cast as a whole using reinforced concrete structures, occupying relatively large space and being non-recyclable and non-reusable. This application's embodiment avoids the difficulties of excavation and dismantling required for the construction of embedded force-transfer beams by placing the force-transfer column 10 on the ground, making operation simple and reusable after dismantling; the beam end fixing crossbeam 20 is fixed to both ends of the force-transfer column 10, forming an inclined surface A1 and a vertical surface A2, which can reliably realize the tensioning of the oblique prestressing tendons 11 and the horizontal prestressing tendons 12 of the precast beam 1; multiple beam bottom anchoring crossbeams 40 are arranged between the force-transfer columns 10, and each beam bottom anchoring crossbeam 40 is provided with an anchor 41, which is used to anchor the oblique prestressing tendons 11, thus making the construction of straight segmented prestressed beams feasible. Furthermore, the bottom anchor beam 40 can gather and anchor the inclined prestressing tendons 11, thus allowing the huge tension force to be directly and effectively transferred to the bottom anchor beam 40, and then transferred to the force transmission columns 10 on both sides and the entire reaction system through the bottom anchor beam 40, improving the stability of the entire reaction system. At the same time, it allows the entire reaction system to be set on the ground, avoiding the cumbersome process of excavating deep trenches and burying the force transmission columns 10 underground, which is required by the traditional trough-type platform 50. This facilitates the rapid installation, dismantling and turnover of the reaction system, and can also adapt to beam designs with different spans or different angles of inclined prestressing tendons 11.

[0023] In some embodiments, the first power structure includes a first jack 30 and a first beam end movable crossbeam 31. The first jack 30 is installed on the inclined surface A1, and the first beam end movable crossbeam 31 is located on one side of the first jack 30. During the tensioning process, the first jack 30 pushes the first beam end movable crossbeam 31 to move. The second power structure includes a second jack 32 and a second beam end movable crossbeam 33. The second jack 32 is installed on the vertical plane A2, and the second beam end movable crossbeam 33 is located on one side of the second jack 32. During the tensioning process of the second jack 32, the second beam end movable crossbeam 33 is moved.

[0024] In this system, the front end of the first jack 30 or the second jack 32 rests on the fixed crossbeam 20 at the beam end as a reaction point, while the rear end pushes the movable crossbeam 31 or the movable crossbeam 33 at the beam end (and the prestressing tendons temporarily anchored thereto) forward a distance of one stroke. When this stroke ends, the prestressing tendons are immediately locked onto the movable crossbeam 31 or the movable crossbeam 33 at the beam end using a tool anchor (e.g., a nut). The tension force is transmitted from the movable crossbeam 31 or the movable crossbeam 33 at the beam end to the fixed crossbeam 20 at the beam end, and then borne by the entire reaction system. The first jack 30 or the second jack 32 can then safely return to its original position to prepare for the next stroke. After the first jack 30 or the second jack 32 returns to its original position, its rear end rests again on the movable crossbeam 31 or the movable crossbeam 33 at the beam end that has moved forward, and the next stroke begins. This cycle continues until the prestressing tendons are stretched to the total length required by the design.

[0025] The movable crossbeam 31 at the first beam end or the movable crossbeam 33 at the second beam end in this application is beneficial for enabling jacks with normal strokes to complete tensioning operations with ultra-long strokes, reducing the equipment requirements for jacks, and improving operational safety.

[0026] In a preferred embodiment, after the first jack 30 tensions and pushes the movable crossbeam 31 at the first beam end to complete one tensioning stroke, the position of the movable crossbeam 31 at the first beam end is fixed by a nut.

[0027] In some embodiments, a pedestal 50 is also included. The pedestal 50 is formed by casting reinforced concrete or splicing I-beams. The pedestal 50 is arranged along the extension direction of the precast beam 1 and is located between the two sets of force transmission columns 10. The surface of the pedestal 50 is higher than the ground and is used to support the installation of the precast beam 1.

[0028] In this embodiment, the pedestal 50 is mainly used to support the installation of the precast beam 1. Throughout the construction process, it directly bears and distributes the entire weight of the precast beam 1 formwork, reinforcing steel cage, and newly poured concrete. Its design, above ground level, provides the necessary working space and convenience for operations such as the installation and sealing of the bottom formwork and the application of release agent, ensuring the accuracy of the beam's bottom dimensions and appearance quality. Whether the reinforced concrete is poured monolithically or the I-beams are precisely assembled, it forms a flat, strong, and non-deformable support surface, thus helping to ensure the stability of the precast beam 1's linearity and geometric dimensions during tensioning, pouring, and curing, effectively preventing beam distortion or cracking caused by uneven foundation settlement or deformation.

[0029] In a preferred embodiment, each set of force transmission columns 10 includes multiple prefabricated steel truss components, which are sequentially and detachably connected along the extension direction of the prefabricated beam 1.

[0030] Two adjacent precast steel truss components can be connected by flanges.

[0031] The force transmission column 10 in this embodiment has good strength, stiffness and stability, and the structure is safe and reliable under stress. The prefabricated structure can be installed on site, and the longitudinal length of the force transmission column 10 can be arbitrarily combined. It is suitable for the prefabrication of pre-tensioned beams with different spans, which helps to improve work efficiency, share costs, and facilitate secondary reuse.

[0032] In a preferred embodiment, the bottom of each set of force transmission columns 10 is anchored to the concrete enlarged foundation 60 by U-shaped fixing bars 80.

[0033] In some embodiments, the beam-end fixed crossbeam 20 is a lattice steel box structure formed by welding steel plates, and the bottom of the beam-end fixed crossbeam 20 is welded and fixed in the concrete enlarged foundation 60 by pre-embedded reinforcing bars 70.

[0034] The concrete spread foundation 60 is made of C25 concrete and its top is flush with the ground.

[0035] The beam-end fixed crossbeam 20 of this embodiment has a simple structure, is easy to process, is convenient to construct, and has high construction efficiency. Furthermore, it is fixed in the enlarged foundation by the pre-embedded reinforcement 70, which is conducive to the stability of the entire reaction system structure and facilitates dismantling and recycling.

[0036] In some embodiments, the bottom anchoring beam 40 is a steel box structure formed by welding steel sections and stiffening ribs or steel plates. The bottom of the bottom anchoring beam 40 is anchored in the concrete enlarged foundation 60 by pre-embedded reinforcement bars 70 to resist the upward pull-out force generated by tension.

[0037] In this embodiment, the bottom anchoring beam 40 is not only used to anchor the inclined prestressing tendons 11 of the web of the precast beam 1, but also serves as a transverse tie beam for the force transmission columns 10 on both sides, effectively ensuring the overall stability of the force transmission columns 10.

[0038] In a preferred embodiment, the embedded bar 70 is a U-shaped anchor bar made of JL32 precision rolled threaded steel.

[0039] In summary, the prefabricated prestressed pedestal 50 tension reaction system of this application adopts a prefabricated modular steel truss structure, which has good strength, stiffness and stability, and the structure is safe and reliable under stress. The force transmission column 10 is set above the ground, avoiding the problem of excavation and dismantling difficulties required for the construction of buried force transmission columns 10, making the operation simple and reusable after dismantling. The longitudinal length of the force transmission beam can be arbitrarily combined, which is suitable for the prefabrication of prestressed beams with different spans, which helps to improve work efficiency and share costs. The transverse side can be designed as a short-line pedestal 50, with adjacent pedestals 50 sharing the force transmission beam, resulting in a reasonable structural layout and compact site planning.

[0040] Secondly, the present invention provides a construction method for a prefabricated prestressed pedestal tension reaction system of the first aspect, specifically including the following steps: S10. Construct a tension reaction system, including: Two sets of force transmission columns 10 are set on the ground at intervals and parallel to each other along the extension direction of the precast beam 1; The beam end fixed crossbeam 20 is fixedly connected to the ends of the two sets of force transmission columns 10 respectively. The first power structure and the second power structure are respectively installed on the fixed crossbeam 20 at the beam end; Anchor beams 40 are spaced between two sets of force transmission columns 10, and the two ends of anchor beams 40 are fixedly connected to the two sets of force transmission columns 10 respectively. Anchors 41 are installed on anchor beams 40. S20. The inclined prestressing tendons 11 and the horizontal prestressing tendons 12 are installed at the construction position of the precast beam 1 according to the preset method. One end of the inclined prestressing tendon 11 is anchored on the anchor 41, and the other end is connected to the first power structure. The two ends of the horizontal prestressing tendon 12 are respectively connected to the second power structure on the fixed crossbeam 20 on both sides of the beam end. S30. The inclined prestressing tendon 11 is tensioned multiple times by the first power structure, and the horizontal prestressing tendon 12 is tensioned multiple times from both ends by the second power structure until the elastic elongation of the inclined prestressing tendon 11 and the horizontal prestressing tendon 12 reaches the preset threshold. S40. Concrete is poured at the construction location of the precast beam to obtain precast beam 1; S50, Remove the tensioning reaction system.

[0041] The following specific embodiment illustrates the 50-tension reaction system of the prefabricated prestressed pedestal of the present invention.

[0042] like Figure 1 , Figure 2 and Figure 3 As shown, the prefabricated pre-tensioning platform 50 tensioning reaction system is mainly composed of force transmission column 10, beam end fixed crossbeam 20, beam end movable crossbeam, and beam bottom anchoring crossbeam 40, forming an integral frame force system. All the above components are made of Q355 steel.

[0043] The force transmission column 10 is designed as an eccentrically compressed member, installed above ground, and adopts a prefabricated modular steel truss structure. Each module segment is welded from steel pipes in the factory, and each segment is 3 meters long. The module segments are transported to the site and connected using flanges. The force transmission column 10 is mainly used to support the fixed crossbeam 20 at the beam end and bear the tension force of the prestressed tendons at both ends of the precast beam 1. To prevent the force transmission column 10 from slipping on the ground, every 3 meters, a steel plate is welded to the two steel pipes at the bottom of the force transmission column 10 using U-shaped fixing bars 80 and anchored to the concrete spread foundation 60.

[0044] The fixed crossbeam 20 at the beam end is constructed from welded steel plates to form a lattice-type steel box structure, which is welded to the end of the steel pipe of the force transmission column 10 with padding steel plates to form an integral whole. The upper outer end of the crossbeam is set as an inclined surface A1, used to arrange a set of jacks to tension the inclined prestressing tendons 11 of the web of the precast beam 1; the lower end of the crossbeam remains a vertical surface A2, used to arrange a set of jacks to tension the horizontal prestressing tendons 12 of the bottom slab of the precast beam 1. The bottom of the crossbeam is welded to the embedded reinforcement 70, which is anchored in the concrete enlarged foundation 60 using JL32 precision-rolled threaded steel U-shaped anchor bars.

[0045] The movable crossbeam at the beam end is made of steel sections and stiffening ribs or steel plates welded into a steel box structure and is arranged at the rear end of the jack. When the jack is tensioned, it pushes the movable crossbeam to move. After completing one tensioning stroke, the movable crossbeam is held in place by a nut. This process is repeated until the tensioning is completed.

[0046] The bottom anchoring beam 40 passes transversely through the middle of the precast beam 1 platform 50. It is constructed of steel sections and stiffening ribs or steel plates welded into a steel box structure, with anchors 41 on its sides to anchor the diagonal prestressing tendons 11 of the web of the precast beam 1. The bottom of the beam is welded to the embedded reinforcement 70, which is anchored in the concrete enlarged foundation 60 using JL32 precision-rolled threaded steel U-shaped anchor bars to resist the pull-out force of the prestressing tendons. The two ends of the bottom anchoring beam 40 are welded to the steel pipes of the force transmission columns 10 with steel plates to form a whole. It not only anchors the diagonal prestressing tendons 11 of the web of the precast beam 1, but also serves as a transverse tie beam for the force transmission columns 10 on both sides, effectively ensuring the overall stability of the force transmission columns 10.

[0047] The pedestal 50 for the precast beam is generally made of reinforced concrete or assembled from I-beams, and is 30cm above the ground to provide operating space for installing the formwork of the precast beam 1. The enlarged foundation is made of C25 concrete, and its top is flush with the ground.

[0048] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A prefabricated prestressed concrete platform tensioning reaction system, characterized in that, include: Two sets of force transmission columns are arranged parallel to each other on the ground along the extension direction of the precast beam. A beam-end fixed crossbeam is provided, which is arranged perpendicular to the extension direction of the precast beam, and the beam-end fixed crossbeam is fixedly connected to the ends of the two sets of force transmission columns respectively, and the side wall of the beam-end fixed crossbeam away from the force transmission column includes an inclined surface and a vertical surface in the height direction. The power structure includes a first power structure and a second power structure. The first power structure is installed on the inclined surface and is used to tension the inclined prestressing tendons of the precast beam. The second power structure is installed on the vertical surface and is used to tension the horizontal prestressing tendons of the precast beam. Multiple bottom anchoring beams are provided, which are spaced apart between two sets of force transmission columns perpendicular to the extension direction of the precast beam. Each bottom anchoring beam has two ends fixedly connected to the two sets of force transmission columns respectively. Each bottom anchoring beam is provided with an anchor, which is used to anchor the inclined prestressing tendons of the precast beam.

2. The prefabricated prestressed platform tensioning reaction system according to claim 1, characterized in that, The first power structure includes a first jack and a first beam-end movable crossbeam. The first jack is installed on the inclined surface, and the first beam-end movable crossbeam is located on one side of the first jack. During the tensioning process of the first jack, the first beam-end movable crossbeam is pushed to move. The second power structure includes a second jack and a second beam end movable crossbeam. The second jack is installed on the vertical surface, and the second beam end movable crossbeam is located on one side of the second jack. During the tensioning process of the second jack, the second beam end movable crossbeam is pushed to move.

3. The prefabricated prestressed platform tensioning reaction system according to claim 2, characterized in that, After the first jack tensions and pushes the movable crossbeam at the first beam end to complete one tensioning stroke, the position of the movable crossbeam at the first beam end is fixed by a nut.

4. The prefabricated prestressed platform tensioning reaction system according to claim 1, characterized in that, It also includes a pedestal, which is formed by casting reinforced concrete or splicing I-beams. The pedestal is set along the extension direction of the precast beam and is located between the two sets of force transmission columns. The surface of the pedestal is higher than the ground and is used to support the installation of the precast beam.

5. The prefabricated prestressed pedestal tensioning reaction system according to any one of claims 1-4, characterized in that, Each set of force-transmitting columns includes multiple prefabricated steel truss components, which are sequentially and detachably connected along the extension direction of the prefabricated beam.

6. The prefabricated prestressed pedestal tensioning reaction system according to any one of claims 1-4, characterized in that, The bottom of each set of force-transmitting columns is anchored to the concrete enlarged foundation via U-shaped fixing bars.

7. The prefabricated prestressed pedestal tensioning reaction system according to any one of claims 1-4, characterized in that, The beam-end fixed crossbeam is a lattice steel box structure formed by welding steel plates, and the bottom of the beam-end fixed crossbeam is fixed in the concrete enlarged foundation by pre-embedded reinforcement.

8. The prefabricated prestressed pedestal tensioning reaction system according to any one of claims 1-4, characterized in that, The bottom anchoring beam is a steel box structure formed by welding steel sections and stiffening ribs or steel plates. The bottom of the bottom anchoring beam is anchored in the concrete spread foundation by pre-embedded bars to resist the upward pull-out force generated by tension.

9. The prefabricated prestressed platform tensioning reaction system according to claim 7 or 8, characterized in that, The embedded reinforcement is a U-shaped anchor bar made of JL32 precision rolled threaded steel.

10. A construction method for a prefabricated prestressed platform tensioning reaction system as described in any one of claims 1-9, characterized in that, Specifically, the steps include the following: Constructing the tension reaction system includes: The two sets of force transmission columns are arranged parallel to each other on the ground along the extension direction of the precast beam; The beam end fixing crossbeam is fixedly connected to the ends of the two sets of force transmission columns respectively. The first power structure and the second power structure are respectively installed on the fixed crossbeam at the beam end; The bottom anchoring beams are spaced between the two sets of force transmission columns, and the two ends of the bottom anchoring beams are respectively fixedly connected to the two sets of force transmission columns. Anchors are installed on the bottom anchoring beams. The inclined prestressing tendons and the horizontal prestressing tendons are threaded through the construction position of the precast beam in a preset manner, and one end of the inclined prestressing tendon is anchored to the anchor and the other end is connected to the first power structure. The two ends of the horizontal prestressing tendon are respectively connected to the second power structure on the beam end fixed crossbeam on both sides. The inclined prestressing tendon is tensioned multiple times by the first power structure, and the horizontal prestressing tendon is tensioned multiple times from both ends by the second power structure until the elastic elongation of the inclined prestressing tendon and the horizontal prestressing tendon reaches a preset threshold. The precast beam is obtained by pouring concrete at the construction location of the precast beam. Dismantle the tension reaction system.

Images