An external prestress supplementary tensioning device for bridges and its working method

Abstract

The present invention provides a device and working method for supplementary tensioning of external prestress of bridges, which relates to the field of bridges. Aiming at the problems of bending or slipping caused by eccentric load when single struts are currently used for prestress tensioning, two screws are arranged in parallel and respectively form an interleaved lead screw - optical axis cooperation with the regulating splints to achieve synchronous tensioning of double prestress bundles, eliminate the unilateral bending moment, ensure uniform distribution of the tensile force, the contact plate directly pushes and pulls the prestress bundle in the horizontal direction to avoid compressive instability of the vertical support structure, and the screw drive can provide stable axial position constraint in the locked state of the screw, cooperate with the screw locking to prevent rebound, and improve the reliability and stability of the supplementary tensioning of external prestress of bridges.

Description

Technical Field

[0001] The invention relates to the field of bridges, and in particular to an external prestressed tensioning device for bridges and a working method. Background Art

[0002] The external prestressing technology of bridges is an engineering technology that arranges prestressed bundles (such as steel strands, carbon fiber bundles, etc.) outside the main structure of the bridge and applies tension to them, thereby improving the internal stress state of the bridge to offset part of the external load effect. It can be used for both new bridges and existing bridge reinforcement. Its core purpose is to enhance the bearing capacity of the bridge, control deformation, inhibit the development of cracks, and extend the service life of the bridge. However, after long-term use, the stress of the prestressed bundle will gradually decrease due to factors such as prestress relaxation, which is called prestress loss, thereby weakening the external prestressing effect, resulting in reduced structural stiffness and stability, increased deformation, and increased risk of safety accidents, especially under extreme external forces such as typhoons and earthquakes, and may even cause structural damage. Therefore, in order to solve the problem that the prestressed bundles in the external prestressing technology relax after long-term use and cause the prestress to decrease, it is necessary to design a device that can perform a supplementary tensioning operation on the prestressed bundles when the prestress decreases, so that it can be restored to the original design prestress value.

[0003] A Chinese patent (publication number CN116201041A, publication date 20230602) discloses a rotatable external prestressed reinforcement device and its tensioning method, including 2 sets of fixed anchor frames, 2 sets of anchors, a carbon fiber plate and a support assembly; the 2 sets of fixed anchor frames and the support assembly are respectively fixed to the two ends and the mid-span of the structure to be reinforced, the 2 sets of anchors respectively clamp the two ends of the carbon fiber plate, and are rotatably connected to the 2 sets of fixed anchor frames; the support assembly presses the carbon fiber plate tightly to form a transverse tension on the carbon fiber plate, and the use of the support device to transversely tension the carbon fiber plate can get rid of the dependence on heavy mechanical devices such as jacks. However, the device has certain shortcomings. The tensioning action of the device relies on the support assembly to push the prestressed beam vertically. In this process, a single strut needs to bear the reaction force of the prestressed beams on both sides, which is prone to force deviation, which leads to bending or slipping of the strut, making the reliability of the device poor and difficult to play a stable role in the long-term service of the bridge. Moreover, after completing the external prestressing, the external prestressing tendons will relax over time, resulting in a decrease in prestress, and it is difficult to continue using the device for supplementary tensioning, and the reliability of a single strut cannot meet the requirements of supplementary tensioning. Summary of the invention

[0004] The object of the present invention is to provide a device and working method for supplementary tensioning of external prestress of bridges aiming at the defects existing in the prior art. Two screws are arranged in parallel and respectively form a staggered screw - optical axis cooperation with the regulating clamping plates to realize the synchronous tensioning of double prestressed tendons, eliminate the unilateral bending moment, ensure the uniform distribution of the tensile force, the contact plate directly pushes and pulls the prestressed tendon in the horizontal direction to avoid the compression instability of the vertical support structure, and the screw drive can provide stable axial position constraint in the locked state of the screw, cooperate with the screw locking to prevent rebound, and improve the reliability and stability of the external prestress of the bridge during the supplementary tensioning operation.

[0005] The first object of the present invention is to provide a device for supplementary tensioning of external prestress of bridges, adopting the following scheme:

[0006] It includes:

[0007] A fixing frame, provided with two side plates spaced apart and connected by a fixing plate;

[0008] A tensioning mechanism, including screws, regulating clamping plates and contact plates. Two parallel screws are respectively rotatably connected to the side plates. The screws are provided with threaded sections and optical axis sections along the axial direction. Two regulating clamping plates respectively form a screw - slider mechanism with the threaded sections of different screws and form a sliding fit of the shaft hole with the optical axis sections of different screws. A contact plate is installed on the regulating clamping plate, and a contact part for cooperating with the prestressed tendon is provided on the contact plate;

[0009] A transmission mechanism, cooperating with the screws and receiving the action of an external driving element to adjust the distance between the two regulating clamping plates.

[0010] Further, a force - transmitting plate located between the two side plates is connected to the fixing plate, and the screw passes through the force - transmitting plate and forms a rotational fit.

[0011] Further, the regulating clamping plates are located between the side plates and the force - transmitting plate, and the two regulating clamping plates are on different sides of the force - transmitting plate.

[0012] Further, the regulating clamping plates are provided with ball nuts for cooperating with the threaded sections and sliding holes for cooperating with the optical axis sections. The sliding fit of the shaft hole serves as the guide for the regulating clamping plate to move along the screw.

[0013] Further, the contact plate is slidably fitted with the regulating clamping plate, and the contact plate is connected with an anchor to restrain or release the movement of the contact plate relative to the regulating clamping plate.

[0014] Further, the contact parts of the contact plates installed on the two regulating clamping plates are arranged oppositely. The contact part is a groove body conforming to the distribution direction of the prestressed tendon. The contact parts approach or move away synchronously under the drive of the regulating clamping plates, and a pressure sensor is installed in the groove body.

[0015] The contact area between the contact part and the prestressed tendon is chamfered.

[0016] Furthermore, the regulating clamping plate and the screw rod form a cantilever structure. A reinforcement hole is provided at the end of the cantilever structure. The reinforcement holes on the two regulating clamping plates are jointly cooperated with a pull rod, and together with the screw rod, a rectangular closed frame is formed. The prestressed tendon passes through the rectangular closed frame.

[0017] Furthermore, the transmission mechanism includes a gear set that cooperates with two screw rods. The gear set is provided with a driving end that receives an external force, and is cooperated with a locking member that locks or unlocks its rotation.

[0018] The second object of the present invention is to provide a working method for the external prestress supplementary tensioning device for bridges as described in the first object, including:

[0019] The fixing frame is installed at the bottom of the longitudinal beam. Two prestressed tendons are tensioned at both ends of the beam body and are respectively anchored on the side surface of the beam body. The horizontal sections of the two prestressed tendons between the deflectors respectively correspond to and contact the contact plates.

[0020] Rotate the two screw rods synchronously to make the two regulating clamping plates approach each other, and push and pull the prestressed tendon in the horizontal direction through the contact plate to perform the supplementary tensioning process.

[0021] After the supplementary tensioning is completed, lock the screw rod, and connect the ends of the two regulating clamping plates through a pull rod.

[0022] Furthermore, adjust the relative positions of the contact plate and the regulating clamping plate so that the contact part of the contact plate cooperates with the prestressed tendon.

[0023] Compared with the prior art, the advantages and positive effects of the present invention are:

[0024] Aiming at the problems of bending or slipping caused by eccentric loading when using a single strut for prestress tensioning at present, two screw rods are arranged in parallel, and respectively form an interleaved lead screw - optical axis cooperation with the regulating clamping plate to realize the synchronous tensioning of the two prestressed tendons, eliminate the unilateral bending moment, ensure the uniform distribution of the tensile force, the contact plate directly pushes and pulls the prestressed tendon in the horizontal direction, avoid the compression instability of the vertical support structure, and the screw drive can provide stable axial position constraint in the locked state of the screw rod, cooperate with the screw rod locking to prevent rebound, and improve the reliability and stability of the external prestress supplementary tensioning of the bridge.

[0025] The force - transmitting plate is connected to the fixing plate, and the screw rod passes through the force - transmitting plate and is rotationally cooperated, which solves the problem of the stability of the force transmission of the screw rod during the tensioning process, avoids the screw rod from shaking or displacing due to uneven force, and ensures the smoothness of the tensioning process. At the same time, the regulating clamping plate is cooperated with the threaded section through a ball nut, the sliding hole is cooperated with the optical axis section, and the shaft hole sliding cooperation is used as a guide, which solves the problem of the accuracy of the regulating clamping plate during the moving process, makes the movement of the regulating clamping plate more accurate, and thus more precisely controls the tensioning degree of the prestressed tendon.

[0026] The contact plate is in sliding fit with the regulating clamping plate and is constrained or released to move through the anchor, which solves the flexibility problem of the contact mode between the contact plate and the prestressed tendon. The contact part is a groove body and is equipped with a pressure sensor to measure the force condition of the prestressed tendon to meet the requirement of precise control. Moreover, the position of the contact plate can be adjusted according to the actual construction requirements to achieve the desired contact state between the contact plate and the prestressed tendon, improving the applicability of the device. And all the edge parts where the contact part contacts the prestressed tendon are chamfered with arcs to eliminate the stress concentration phenomenon at the contact interface and prevent the prestressed tendon from being sheared due to the sharp edges during tensioning or use.

[0027] The regulating clamping plate cooperates with the screw rod to form a cantilever structure, and the end is connected by a pull rod through the reinforcement hole, combined with the screw rod to form a rectangular closed frame, which solves the stability problem of the overall structure of the device after tensioning, prevents the structure from deforming or loosening due to long-term stress, and ensures the long-term effect of bridge reinforcement.

[0028] The gear set cooperates with the locking part, which solves the safety problem of the rotation control and locking of the screw rod, prevents the screw rod from accidentally rotating during or after tensioning, and ensures the safety and reliability of the device. Brief Description of the Drawings

[0029] The schematic drawings of the specification forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0030] Figure 1 It is a schematic diagram of the device for the external prestressed supplementary tensioning of a bridge in one or more embodiments of the present invention.

[0031] Figure 2 It is a front view schematic diagram of the device for the external prestressed supplementary tensioning of a bridge in one or more embodiments of the present invention.

[0032] Figure 3 It is a schematic diagram of the device for the external prestressed supplementary tensioning of a bridge installed on a longitudinal beam in one or more embodiments of the present invention.

[0033] Figure 4 It is a schematic diagram of the locking part cooperating with the adjusting gear in one or more embodiments of the present invention.

[0034] Figure 5 It is a side view schematic diagram of the device for the external prestressed supplementary tensioning of a bridge in one or more embodiments of the present invention.

[0035] Among them, 1. Fixed frame; 101. Side plate; 2. Screw rod; 201. Ball nut; 3. Force transmission plate; 4. Adjusting gear; 5. Regulation clamping plate; 6. Contact plate; 7. Anchor screw rod; 8. Locking piece; 9. Pressure sensor; 10. Anchor bolt; 11. Prestressed tendon; 12. Bridge deck; 13. Longitudinal beam; 14. Steering gear; 15. Tie rod. Specific implementation manner

[0036] Embodiment 1

[0037] In a typical embodiment of the present invention, as Figures 1 - 5 shown, a device for post-tensioning of external prestress of a bridge is given.

[0038] This embodiment provides a device for post-tensioning of external prestress of a bridge, which mainly consists of a fixed frame 1, a tensioning mechanism and a transmission mechanism, and is used to solve problems existing in the existing post-tensioning technology of external prestress of bridges, such as uneven stress, poor stability and dependence on heavy machinery, aiming to improve the reliability and stability of bridge reinforcement and facilitate operation and implementation.

[0039] As Figure 1 shown, the fixed frame 1 serves as the basic support part of the device. Its two side plates 101 that are spaced apart and connected by fixing plates form an H-shaped structure, providing a stable framework for the subsequent installation of the tensioning mechanism and the transmission mechanism. When in use, the groove formed by the fixing plate and the side plate 101 above it can match the bottom of the longitudinal beam 13 and can be fixed on the longitudinal beam 13 through the installation holes reserved on the side plate 101, improving the stability of the entire device after installation at the bottom of the bridge longitudinal beam 13, enabling it to withstand the acting force generated during the tensioning process of the prestressed tendon 11, and ensuring the normal operation of the device in a complex bridge environment.

[0040] In this embodiment, for a concrete bridge, chemical anchor bolts can be used for the connection of the device by the anchor bolts 10. The chemical anchor bolt connection method has strong connection reliability, enabling the fixed frame 1 to be firmly installed on the longitudinal beam 13, providing a stable support foundation for the subsequent post-tensioning operation of prestress, ensuring that the entire device can effectively play its role during the use of the bridge, maintaining the stability of the prestress, and guaranteeing the safety of the bridge structure. For other forms of bridges, such as steel structure bridges, mechanical anchor bolts can be used as the form of the anchor bolts 10 for the connection of the device.

[0041] The tensioning mechanism includes a screw rod 2, a regulation clamping plate 5 and a contact plate 6, among which the screw rod 2, the regulation clamping plate 5 and the contact plate 6 work together to effectively tension the prestressed tendon 11.

[0042] The threaded section and the smooth shaft section of the screw rod 2 are arranged axially. The threaded sections and the smooth shaft sections of the two parallel screw rods 2 are arranged in a staggered manner. One side of the threaded section of the first screw rod 2 is the smooth shaft section of the second screw rod 2, and one side of the smooth shaft section of the first screw rod 2 is the threaded section of the second screw rod 2, showing an alternating distribution. In this way, the smooth shaft section of one screw rod 2 serves as the guiding structure for the adjusting clamping plate 5 that cooperates with the threaded section of the other screw rod 2. The two parallel screw rods 2 are respectively rotatably connected to the side plates 101. As Figure 2 shown, one end of the screw rod 2 is rotatably connected to one side plate 101, and the other end of the screw rod 2 is rotatably connected to the other side plate 101. The two adjusting clamping plates 5 respectively form a lead screw-slider mechanism with the threaded sections of different screw rods 2 and form a shaft-hole sliding fit with the smooth shaft sections respectively. By adopting an interleaved lead screw-smooth shaft matching method, when the screw rod 2 rotates, the adjusting clamping plate 5 can achieve stable and precise movement in the horizontal direction.

[0043] As Figure 1 shown, one adjusting clamping plate 5 forms a lead screw-slider mechanism with the threaded section of one screw rod 2 and forms a shaft-hole sliding fit with the smooth shaft section of the other screw rod 2; the other adjusting clamping plate 5 forms a shaft-hole sliding fit with the smooth shaft section of one screw rod 2 and forms a lead screw-slider mechanism with the threaded section of the other screw rod 2.

[0044] The contact plate 6 installed on the adjusting clamping plate 5 has its contact part closely cooperate with the prestressed tendon 11. During the tensioning process, the contact plate 6 directly acts on the prestressed tendon 11 and performs push-pull operations in the horizontal direction. Compared with the traditional vertical support tensioning method, the application of the horizontal force avoids the safety hazards caused by the compression instability of the vertical support structure, ensures the stability of the prestressed tendon 11 during the tensioning process, and effectively improves the reliability of the supplementary tensioning.

[0045] The transmission mechanism plays a role in connecting the external driving element and the screw rod 2 in the whole device. It can receive the external drive and transmit it to the screw rod 2. When the screw rod 2 rotates, it can precisely adjust the distance between the two adjusting clamping plates 5. Through a reasonably designed transmission ratio and connection method, the transmission mechanism can stably transmit the power of the external drive to the screw rod 2 to realize the synchronous rotation of the screw rod 2. In actual operation, the operator can conveniently use external drive devices such as hydraulic motors and electric motors to cooperate with the transmission mechanism, drive the screw rod 2 to rotate through the transmission mechanism, and then control the movement of the adjusting clamping plate 5 to realize the precise tensioning operation of the prestressed tendon 11.

[0046] During the tensioning process, due to the symmetrical arrangement and special cooperation mode of the two screws 2, the unilateral bending moment is effectively eliminated, ensuring that the tension force is evenly distributed on the prestressed tendon 11. The cooperation of the screw drive and the locking mechanism of the screw 2 further prevents the rebound phenomenon after tensioning, ensuring the long-term stability of the prestress. In actual bridge reinforcement projects, this device has broad application prospects. Its structure is compact and easy to install, without the assistance of large and heavy machinery, which can effectively reduce the construction difficulty and cost. At the same time, its high reliability and stability can significantly improve the quality of bridge reinforcement, extend the service life of the bridge, provide a strong guarantee for the safe operation of the bridge, and is of great significance for ensuring the safety and stability of traffic infrastructure.

[0047] As Figure 2 and Figure 1 shown, a force transmission plate 3 is added to the fixed plate between the two side plates 101. The screw 2 passes through the force transmission plate 3, and a rotational fit is formed between the screw 2 and the force transmission plate 3. After the rotational fit is formed, it can support and guide the middle part of the screw 2, optimize the force transmission path of the screw 2, and improve the running stability of the screw 2. The force transmission plate 3 can effectively disperse and transmit the force borne by the screw 2 during rotation, avoiding stress concentration at the connection part between the side plate 101 and the screw 2. During the long-term use of the bridge, the tension force of the prestressed tendon 11 will constantly change. The presence of the force transmission plate 3 ensures that these forces can be stably transmitted to the entire device structure, enhancing the durability and reliability of the device, enabling it to better adapt to the complex bridge stress environment and maintain a stable working state.

[0048] As Figure 1 and Figure 2 shown, the regulating clamping plates 5 are located between the side plates 101 and the force transmission plate 3. One regulating clamping plate 5 is located between the force transmission plate 3 and one side plate 101, and the other regulating clamping plate 5 is located between the force transmission plate 3 and the other side plate 101, such that the two regulating clamping plates 5 are distributed on the opposite sides of the force transmission plate 3. Under this relative position distribution, the regulating clamping plates 5 can make full use of the space between the side plates 101 and the force transmission plate 3, ensuring that they are stably constrained during movement.

[0049] As Figure 2As shown, the regulating splint 5 is installed with a ball nut 201 and provided with a sliding hole. The ball nut 201 and the sliding hole are arranged at intervals. The ball nut 201 cooperates with the threaded section to form a screw slider mechanism. The sliding hole and the optical axis section form a shaft hole sliding fit. When the threaded section drives the ball nut 201 to move along its axis, it drives the regulating splint 5 to move horizontally. At the same time, the shaft hole sliding fit serves as a guide for the translation of the regulating splint 5, thereby improving the precision and stability of the movement of the regulating splint 5. The ball nut 201 reduces the friction between the threads, so that the regulating splint 5 can move smoothly when the screw 2 rotates; the sliding fit between the sliding hole and the shaft hole of the optical axis section provides a precise guide for the regulating splint 5 to prevent it from deflecting during the movement, thereby ensuring the accurate action of the contact plate 6 on the prestressed beam 11, improving the precision of the prestressing tensioning, and ensuring that the bridge reinforcement effect meets the design requirements.

[0050] In the bridge external prestressing tensioning device, the ball nut 201 installed on the regulating splint 5 and the opened sliding hole cooperate with the threaded section and the optical axis section of the screw rod 2 to build a stable movement.

[0051] The sliding hole and the axial hole of the optical axis segment slide together to achieve precise guidance of the movement of the regulating clamping plate 5. During the translation of the regulating clamping plate 5, the sliding hole fits tightly against the optical axis segment, constraining its movement trajectory, ensuring that the regulating clamping plate 5 always moves precisely along the preset path, thereby ensuring that the contact plate 6 can always accurately interact with the prestressed beam 11 in a stable posture, maintaining the uniformity and accuracy of the prestress transmission, and fundamentally improving the accuracy and stability of the prestress tensioning.

[0052] The contact plate 6 is slidably matched with the regulating clamp plate 5. The contact plate 6 can adjust the relative position with the regulating clamp plate 5 by moving, so that the position of the contact plate 6 is adapted to the distribution position of the prestressed bundle 11, and the movement is constrained or released by the anchor, which brings good flexibility to the device. In actual engineering, according to different construction stages and the specific conditions of the prestressed bundle 11, the position of the contact plate 6 can be easily adjusted to better adapt to the shape and position changes of the prestressed bundle 11, ensure close and uniform contact, and effectively transmit the tension force.

[0053] like Figure 1 and Figure 2 As shown, the contact part is designed as a groove body that conforms to the distribution direction of the prestressed bundle 11, and a pressure sensor 9 is installed in the groove body to realize real-time monitoring of the stress of the prestressed bundle 11. During the use of the bridge, the stress of the prestressed bundle 11 may change due to various factors (such as temperature changes, bridge load changes, etc.). The pressure sensor 9 can capture these changes in time and feedback to the operator. When the stress changes abnormally, the operator can take timely measures to adjust it to ensure the safety and stability of the bridge structure, and realize the intelligent management of bridge reinforcement.

[0054] As Figure 2 shown, the adjusting splint 5 and the screw rod 2 form a cantilever structure. Reinforcement holes are provided at the end and connected by a tie rod 15 to form a rectangular closed frame, significantly enhancing the overall stability of the device. During the tensioning process of the prestressed tendon 11, the device will bear a large tensile force, and the cantilever structure and the rectangular closed frame can effectively resist the deformation and displacement trends caused by these tensile forces. The rectangular closed frame connects the screw rod 2 and the adjusting splint 5 into a whole, enabling the components to restrict each other and cooperate in force, improving the structural strength of the device, ensuring its stable working performance during long-term use, providing reliable prestress supplement for the bridge, and extending the service life of the bridge.

[0055] As Figure 3 shown, deviators 14 are arranged at intervals below the longitudinal beam 13 of the bridge. An external prestressed supplementary tensioning device for the bridge is installed between the deviators 14. One end of the prestressed tendon 11 is anchored to the beam body of the bridge, and the other end passes through the deviator 14 and cooperates with the external prestressed supplementary tensioning device for the bridge, and continues to extend to another deviator 14 and then passes over it, and is tensioned and anchored at the other end of the bridge beam body. The deviator 14 can restrict the horizontal and vertical positions of the prestressed tendon 11 at the contact point. An initial supplementary tensioning section is formed between the two deviators 14 at both ends, and the external prestressed supplementary tensioning device for the bridge is used to push this supplementary tensioning section to bend the supplementary tensioning section, thereby realizing the supplementary tensioning of the prestressed tendon 11 and restoring the prestress value of the prestressed tendon to the original designed prestress value.

[0056] As Figure 4 and Figure 5 shown, the transmission mechanism includes a gear set. The gear set includes an adjusting gear 4. Adjusting gears are respectively connected to the two screw rods 2 and cooperate with other adjusting gears of the gear set to form a synchronous transmission, enabling the two screw rods 2 to rotate synchronously and at the same speed in opposite directions.

[0057] The two screw rods 2 cooperate with the gear set and are provided with a driving end and a locking member 8 that are subjected to external forces, achieving efficient transmission and reliable control. The gear set can evenly distribute the power of the external driving device to the two screw rods 2, ensuring their synchronous rotation, thereby realizing the synchronous movement of the adjusting splint 5, ensuring the symmetrical tensioning of the prestressed tendon 11, and avoiding the problem of uneven stress on the bridge structure caused by uneven tensioning.

[0058] The existence of the locking member 8 provides an important guarantee for the safety of the device. After the prestressed tendon 11 is tensioned to the predetermined value, the locking member 8 can lock the rotation of the gear set, prevent the screw rod 2 from rotating accidentally due to external interference or its own structural characteristics, ensure the stability of the tensile force of the prestressed tendon 11, avoid affecting the reinforcement effect of the bridge due to the change of the tensile force, and ensure the safe operation of the bridge after reinforcement.

[0059] In this embodiment, the external drive device can adopt a motor drive structure. The motor has the characteristics of stable output torque and easy control of speed, and can accurately provide power for the gear set. The motor can be connected to the driving end of the gear set through a coupling, and the rotational motion of the motor can be efficiently transmitted to the gear set. In terms of control, the motor controller can be connected to accurately adjust the speed, direction and start and stop of the motor according to the preset program and sensor feedback information (such as the prestressing condition monitored by the pressure sensor 9), so as to achieve precise control of the movement of the regulating splint 5, meet the needs of different bridge prestressing tensioning working conditions, and ensure stable and efficient operation of the entire device.

[0060] In addition, a hydraulic motor drive structure can also be used. The hydraulic system can generate a large output torque, which is suitable for large bridges with high power requirements or situations where the prestressed bundle 11 has a large pulling force. The speed and torque of the hydraulic motor can be flexibly adjusted through the hydraulic valve group. After its output shaft is connected to the driving end of the gear group, the pressure and flow adjustment function of the hydraulic control system can be used to achieve stable and powerful driving of the gear group, ensuring that the two screws 2 rotate synchronously, thereby effectively controlling the movement of the regulating splint 5, ensuring the accurate tensioning of the prestressed bundle 11, and maintaining the force balance and stability of the bridge structure.

[0061] It is understandable that the locking member 8 can adopt a latch-type structure. An adaptable socket is set at a key part of the gear set (such as a gear shaft or a component fixedly connected to the gear), and the locking member 8 is a latch with a positioning protrusion. When locking is required, the latch is inserted into the socket, and the positioning protrusion is tightly matched with the hole wall to prevent the gear from rotating. It has a simple structure, convenient operation and high reliability.

[0062] The locking member 8 can also adopt a brake-type structure. The friction force is applied to the rotating parts of the gear set by a clamping device (such as a brake pad and a brake caliper), and the clamping force can be provided by hydraulic, pneumatic or mechanical springs. In the locked state, the clamping device fits tightly against the gear or its shaft, generating sufficient friction torque to hinder rotation; when unlocked, the clamping force is released, allowing the gear set to rotate freely. The clamping device can provide sufficient locking force, which is suitable for occasions with high requirements for locking reliability.

[0063] In other optional implementations, the structure of the locking member 8 can be configured according to needs, such as using a ratchet structure to lock and unlock the gear set, using a block to lock the rotation of the adjustment gear 4, etc.

[0064] Example 2

[0065] In another typical embodiment of the present invention, Figures 1 - 5 As shown, a working method for an external prestressed tensioning device for a bridge is provided, using the external prestressed tensioning device for a bridge as in Example 1.

[0066] A working method for an external prestress supplementary tensioning device for a bridge, comprising:

[0067] The fixing frame 1 is installed at the bottom of the longitudinal beam 13. Two prestressed tendons 11 are tensioned at both ends of the beam body and are respectively anchored to the side surface of the beam body. The horizontal sections of the two prestressed tendons 11 between the deflectors 14 respectively correspond to and contact the contact plates 6;

[0068] When the prestressed tendon 11 cooperates with the contact plate 6, adjust the relative positions of the contact plate 6 and the regulating clamping plate 5 so that the contact part of the contact plate 6 cooperates with the prestressed tendon 11; Rotate the two screws 2 synchronously to make the two regulating clamping plates 5 approach each other, and tension the two prestressed tendons 11 in the horizontal direction through the contact plate 6 to perform the supplementary tensioning process;

[0069] After the supplementary tensioning is completed, lock the screws 2 and connect the ends of the two regulating clamping plates 5 through the tie rod 15.

[0070] In the preliminary preparation stage, install the fixing frame 1 at the bottom of the longitudinal beam 13. This step lays the foundation for subsequent operations. The longitudinal beam 13 is a key load-bearing component of the bridge, and its bottom provides a stable support platform for the supplementary tensioning device. The prestressed tendons 11 are pre-tensioned at both ends of the beam body. When contacting the contact plate 6, a complete force transmission link is formed. The two prestressed tendons 11 respectively correspond to and contact the contact plates 6, ensuring that the tensile force can act accurately and effectively on the prestressed tendons 11. The symmetrical layout is conducive to balancing the force on the beam body and avoiding the risk of structural deformation or imbalance caused by unilateral force.

[0071] Act on the gear set through an external driving device to realize the synchronous rotation of the two screws 2. During the rotation of the screws 2, due to the special matching structure between the regulating clamping plate 5 and the screws 2, the two regulating clamping plates 5 approach each other. The contact plate 6 on the regulating clamping plate 5 tensions the prestressed tendon 11 in the horizontal direction. The horizontal tensioning method has significant advantages compared with the traditional vertical tensioning. It avoids the instability problem that may occur in the vertical support structure during compression, ensures the stability and reliability of the prestress application, and can more accurately control the stretching direction and strength of the prestressed tendon 11, so that the prestress is evenly distributed on the beam body, effectively compensates for the prestress relaxation, and improves the strength and stiffness of the beam body structure.

[0072] The locking screw 2 can prevent it from rotating due to external force interference or internal stress changes, ensuring that the prestressed tendon 11 remains in a predetermined tension state. Connecting the ends of the two regulating clamping plates 5 through the tie rod 15 further enhances the integrity and stability of the device. The tie rod 15, the screw 2 and the regulating clamping plate 5 together form a solid force-bearing framework, effectively resisting the prestress reaction force and the dynamic load during the use of the bridge. The moment formed by tensioning is opposite to the moment borne by the bridge deck 12 on the longitudinal beam 13, thereby playing a role in strengthening the bridge deck 12, preventing the displacement of the regulating clamping plate 5 or the loosening of the structure, and ensuring the long-term strengthening effect.

[0073] Adjusting the relative positions of the adjusting contact plate 6 and the regulating clamping plate 5 to adapt to the prestressed tendon 11 reflects the flexibility and adaptability of the device. In actual engineering, the position and direction of the prestressed tendon 11 may vary due to differences in bridge structures or previous construction errors. By adjusting the relative positions of the contact plate 6 and the regulating clamping plate 5, the contact part is closely attached to the prestressed tendon 11, ensuring the effective transmission of force, avoiding problems such as stress concentration or tensioning failure caused by poor contact, and ensuring that the device can achieve efficient and accurate prestress supplementary tensioning operations under different working conditions, providing a reliable guarantee for the safety of the bridge structure.

[0074] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A prestressed tensioning device for bridges, characterized in that: include: A fixed frame, provided with two side plates spaced apart and connected by a fixed plate; The tensioning mechanism comprises a screw, a regulating clamping plate and a contact plate. Two parallel screws are rotatably connected to the side plates respectively. The screw is provided with a threaded section and an optical axis section along the axial direction. The two regulating clamping plates respectively form a lead screw slider mechanism with the threaded sections of different screws and form a shaft hole sliding fit with the optical axis sections of different screws respectively. The regulating clamping plate is provided with a contact portion for matching the prestressed bundle. The contact plate directly pushes and pulls the prestressed bundle in the horizontal direction to realize the synchronous tensioning of the double prestressed bundles. The transmission mechanism cooperates with the screw rod and receives the action of the external driving element to adjust the distance between the two regulating splints; The regulating splint cooperates with the screw rod to form a cantilever structure, a reinforcement hole is provided at the end of the cantilever structure, the reinforcement holes on the two regulating splints cooperate with a pull rod together, and the screw rod is combined to form a rectangular closed frame, and the prestressed bundle passes through the rectangular closed frame; The contact parts of the contact plates installed on the two regulating splints are arranged relatively to each other, the contact parts are grooves conforming to the distribution direction of the prestressed bundle, and the contact parts are synchronously approached or moved away under the driving of the regulating splints.

2. The external prestressing tensioning device for bridges according to claim 1, characterized in that: The fixing plate is connected with a force transmission plate located between the two side plates, and the screw rod passes through the force transmission plate to form a rotational fit.

3. The device for external prestressing of bridges as claimed in claim 2 is characterized in that: The regulating splint is located between the side plate and the force transmission plate, and the two regulating splints are located on the opposite sides of the force transmission plate.

4. The external prestressing tensioning device for bridges according to claim 1, characterized in that: The regulating clamping plate is provided with a ball nut matching the threaded section and a sliding hole matching the optical axis section, and the sliding matching of the axis hole serves as a guide for the regulating clamping plate to move along the screw rod.

5. The device for external prestressing tensioning of bridges according to claim 1, characterized in that: The contact plate is slidably matched with the regulating clamping plate, and the contact plate is connected with an anchor to restrict or release the movement of the contact plate relative to the regulating clamping plate.

6. The external prestressing tensioning device for bridges according to claim 5, characterized in that: A pressure sensor is installed in the tank.

7. The external prestressing tensioning device for bridges according to claim 1, characterized in that: The transmission mechanism comprises a gear set matched with two screw rods. The gear set is provided with a driving end for receiving external force and matched with a locking member for locking or unlocking its rotation.

8. A working method for an external prestressing tensioning device for a bridge, using the external prestressing tensioning device for a bridge as claimed in any one of claims 1 to 7, characterized in that: include: The fixing frame is installed at the bottom of the longitudinal beam, and two prestressed beams are tensioned at both ends of the beam body and anchored to the sides of the beam body respectively. The two prestressed beams contact the contact plates respectively in the horizontal section between the steering gears; The two screws are rotated synchronously to bring the two regulating clamps closer to each other, and the prestressed tendons are pushed and pulled in the horizontal direction through the contact plate to perform the tensioning process; After the tensioning is completed, the screw is locked and the ends of the two regulating splints are connected by a pull rod.

9. The working method for the external prestressing tensioning device for bridges according to claim 8, characterized in that: The relative positions of the contact plate and the regulating clamp are adjusted so that the contact portion of the contact plate matches the prestressed tendon.

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