External pre-stress supplementary tensioning device for bridge and working method of external pre-stress supplementary tensioning device

Abstract

The invention provides an external pre-stress supplementary tensioning device for a bridge and a working method, relates to the field of bridges, and aims to solve the problem that bending or slipping is caused by unbalance loading when a single supporting rod is adopted for pre-stress tensioning at present. Synchronous tensioning of double prestressing tendons is achieved, single-side bending moment is eliminated, uniform distribution of tensioning force is ensured, the contact plate directly pushes and pulls the prestressing tendons in the horizontal direction, the situation that a vertical supporting structure is pressed to be unstable is avoided, stable axial position constraint can be provided through thread transmission in the screw locking state, and rebounding is prevented through cooperation with screw locking. And the reliability and the stability of bridge external pre-stress supplementary tensioning are improved.

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. 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 purpose of the present invention is to address the defects of the prior art and provide a device and a working method for tensioning external prestressed bridges. Two screws are arranged in parallel, and form staggered screw-optical axis cooperation with regulating splints respectively, so as to realize the synchronous tensioning of double prestressed bundles, eliminate unilateral bending moment, ensure uniform distribution of tensioning force, and directly push and pull the prestressed bundle in the horizontal direction of the contact plate to avoid compressive instability of the vertical supporting structure. The threaded transmission can provide stable axial position constraint when the screw is locked, and cooperate with the screw locking to prevent rebound, so as to improve the reliability and stability of the external prestressing of the bridge during the tensioning operation.

[0005] The first object of the present invention is to provide an external prestressing tensioning device for a bridge, which adopts the following scheme: 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 plates are installed with contact plates, and the contact plates are provided with a contact portion matching the prestressed bundle. The transmission mechanism cooperates with the screw rod and is acted upon by an external driving element to adjust the distance between the two regulating splints.

[0006] Furthermore, the fixing plate is connected to 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.

[0007] Furthermore, the regulating splint is located between the side plate and the force transmission plate, and the two regulating splints are located on opposite sides of the force transmission plate.

[0008] Furthermore, the regulating clamp is provided with a ball nut that matches the threaded section and a sliding hole that matches the optical axis section, and the sliding fit of the axis hole serves as a guide for the regulating clamp to move along the screw rod.

[0009] Furthermore, the contact plate is slidably matched with the regulating clamping plate, and the contact plate is connected with an anchor to constrain or release the movement of the contact plate relative to the regulating clamping plate.

[0010] Furthermore, the contact parts of the contact plates installed on the two regulating splints are arranged relatively, and the contact parts are grooves that conform to the distribution direction of the prestressed beam. The contact parts move closer or farther away synchronously under the drive of the regulating splints, and a pressure sensor is installed in the groove.

[0011] The contact area between the contact part and the prestressed tendon is chamfered.

[0012] Furthermore, the regulating splint cooperates with the screw 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 are jointly cooperated with a pull rod, combined with the screw to form a rectangular closed frame, and the prestressed bundle passes through the rectangular closed frame.

[0013] Furthermore, the transmission mechanism includes a gear set matched with two screw rods, the gear set is provided with a driving end for receiving external force, and is matched with a locking member for locking or unlocking its rotation.

[0014] The second object of the present invention is to provide a working method for the external prestressed tensioning device for a bridge as described in the first object, comprising: 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.

[0015] Furthermore, the relative positions of the contact plate and the regulating clamping plate are adjusted so that the contact portion of the contact plate cooperates with the prestressed bundle.

[0016] Compared with the prior art, the present invention has the following advantages and positive effects: In order to address the problem of bending or slipping caused by off-center load when using a single support rod for prestressing, two screws are arranged in parallel, which form an interlaced screw-optical axis cooperation with the regulating clamping plate to achieve synchronous tensioning of the two prestressed beams and eliminate unilateral bending moment. This ensures uniform distribution of tensioning force. The contact plate directly pushes and pulls the prestressed beam in the horizontal direction to avoid compressive instability of the vertical supporting structure. The threaded transmission can provide stable axial position constraints when the screw is locked, and cooperate with the screw locking to prevent rebound, thereby improving the reliability and stability of the external prestressing of the bridge.

[0017] The fixed plate is connected to the force transmission plate, and the screw passes through the force transmission plate and rotates to match, which solves the problem of the stability of the force transmission of the screw during the tensioning process, avoids the shaking or displacement of the screw due to uneven force, and ensures the stability of the tensioning process. At the same time, the regulating splint cooperates with the threaded section through the ball nut, the sliding hole cooperates with the smooth shaft section, and the shaft hole slides as a guide, which solves the accuracy problem of the regulating splint during movement, making the movement of the regulating splint more accurate, thereby more accurately controlling the tensioning degree of the prestressed tendons.

[0018] The contact plate and the regulating splint are slidably matched and the movement is constrained or released by the anchor, which solves the flexibility problem of the contact mode between the contact plate and the prestressed beam. The contact part is a groove body and a pressure sensor is installed to measure the stress condition of the prestressed beam to meet the needs of precise control, and the position of the contact plate can be adjusted according to actual construction needs to achieve the required contact state between the contact plate and the prestressed beam, thereby improving the applicability of the device. All edge parts of the contact part that contact the prestressed beam are chamfered with arcs to eliminate stress concentration at the contact interface and prevent shear damage to the prestressed beam due to sharp edge angles during tensioning or use.

[0019] The regulating splint cooperates with the screw to form a cantilever structure, and the end is connected with a pull rod through the reinforcement hole, combined with the screw to form a rectangular closed frame, which solves the stability problem of the overall structure of the device after tensioning, prevents structural deformation or loosening due to long-term stress, and ensures the long-term effect of bridge reinforcement.

[0020] The gear set cooperates with the locking piece to solve the safety problem of screw rotation control and locking, prevents the screw from accidentally rotating during or after tensioning, and ensures the safety and reliability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 It is a schematic diagram of an external prestressing tensioning device for a bridge in one or more embodiments of the present invention.

[0023] Figure 2 It is a front view schematic diagram of an external prestressing tensioning device for a bridge in one or more embodiments of the present invention.

[0024] Figure 3 This is a schematic diagram of installing an external prestressed tensioning device for a bridge on a longitudinal beam in one or more embodiments of the present invention.

[0025] Figure 4 It is a schematic diagram of the locking member cooperating with the adjusting gear in one or more embodiments of the present invention.

[0026] Figure 5 It is a side view schematic diagram of an external prestressing tensioning device for a bridge in one or more embodiments of the present invention.

[0027] Among them, 1. fixed frame; 101. side plate; 2. screw; 201. ball nut; 3. force transmission plate; 4. adjusting gear; 5. regulating splint; 6. contact plate; 7. anchor screw; 8. locking piece; 9. pressure sensor; 10. anchor bolt; 11. prestressed beam; 12. bridge deck; 13. longitudinal beam; 14. steering gear; 15. pull rod. DETAILED DESCRIPTION

[0028] Example 1 In a typical embodiment of the present invention, Figure 1-Figure 5 As shown, a device for external prestressing tensioning of bridges is provided.

[0029] The present embodiment provides a device for tensioning an external prestressed bridge, which is mainly composed of a fixing frame 1, a tensioning mechanism and a transmission mechanism. It is used to solve the problems existing in the existing external prestressed bridge tensioning technology, such as uneven force, poor stability and reliance on heavy machinery, and aims to improve the reliability and stability of bridge reinforcement and facilitate operation and implementation.

[0030] like Figure 1 As shown, the fixing frame 1 serves as the basic support part of the device, and its two side plates 101 are spaced and connected by the fixing plate to form an H-shaped structure, which provides a stable framework for the installation of the subsequent tensioning mechanism and the transmission mechanism. When it is used, 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 mounting holes reserved on the side plate 101, thereby improving the stability of the entire device after installation at the bottom of the bridge longitudinal beam 13, so that it can withstand the force generated during the tensioning process of the prestressed beam 11, and ensure the normal operation of the device in a complex bridge environment.

[0031] In this embodiment, for concrete bridges, the anchor bolt 10 can be connected to the device using a chemical anchor bolt. The chemical anchor bolt connection method has a strong connection reliability, which can enable the fixing frame 1 to be firmly installed on the longitudinal beam 13, providing a stable support foundation for subsequent prestressing tensioning operations, ensuring that the entire device can effectively play a role during the use of the bridge, maintaining the stability of the prestress, and ensuring the safety of the bridge structure. For other forms of bridges, such as steel structure bridges, the anchor bolt 10 can be connected to the device using a mechanical anchor bolt.

[0032] The tensioning mechanism includes a screw rod 2 , an adjusting clamp plate 5 and a contact plate 6 , wherein the screw rod 2 , the adjusting clamp plate 5 and the contact plate 6 work in coordination to achieve effective tensioning of the prestressed tendon 11 .

[0033] The threaded segments and optical axis segments of the screw rod 2 are arranged axially, and the threaded segments and optical axis segments of the two parallel screw rods 2 are staggered, wherein one side of the threaded segment of the first screw rod 2 is the optical axis segment of the second screw rod 2, and the other side of the optical axis segment of the first screw rod 2 is the threaded segment of the second screw rod 2, and they are staggered, so that the optical axis segment of one screw rod 2 serves as a guide structure for the regulating clamping plate 5 matched with the threaded segment of the other screw rod 2. The two parallel screw rods 2 are respectively rotatably connected to the side plates 101, such as Figure 2 As shown, one end of the screw rod 2 is rotatably connected to a side plate 101, and the other end of the screw rod 2 is rotatably connected to the other side plate 101. The two regulating clamps 5 form a lead screw slider mechanism with the threaded segments of different screw rods 2, and form an axial hole sliding fit with the optical axis segments, respectively. An interlaced lead screw-optical axis fit is adopted, so that when the screw rod 2 rotates, the regulating clamps 5 can achieve stable and precise movement in the horizontal direction.

[0034] like Figure 1 As shown, one regulating splint 5 forms a lead screw slider mechanism with the threaded section of one of the screws 2, and forms an axial hole sliding fit with the optical axis section of the other screw 2; another regulating splint 5 forms an axial hole sliding fit with the optical axis section of one screw 2, and forms a lead screw slider mechanism with the threaded section of the other screw 2.

[0035] The contact plate 6 installed on the regulating clamp 5 has a contact portion that closely matches the prestressed bundle 11. During the tensioning process, the contact plate 6 directly acts on the prestressed bundle 11, and performs a push-pull operation in the horizontal direction. Compared with the traditional vertical support tensioning method, the application of force in the horizontal direction avoids the safety hazard caused by the vertical support structure being instable due to compression, ensures the stability of the prestressed bundle 11 during the tensioning process, and effectively improves the reliability of the supplementary tensioning.

[0036] The transmission mechanism plays the role of connecting the external drive element and the screw 2 in the whole device. It can receive external drive and transmit it to the screw 2. The screw 2 can accurately adjust the spacing between the two regulating clamps 5 when rotating. Through the reasonably designed transmission ratio and connection method, the transmission mechanism can stably transmit the power of the external drive to the screw 2 to achieve the synchronous rotation of the screw 2. In actual operation, the operator can conveniently use external drive equipment such as hydraulic motors, electric motors, etc. to cooperate with the transmission mechanism, drive the screw 2 to rotate through the transmission mechanism, and then control the movement of the regulating clamp 5 to achieve precise tensioning operation of the prestressed beam 11.

[0037] During the tensioning process, due to the symmetrical arrangement and special matching of the two screws 2, the unilateral bending moment is effectively eliminated, ensuring that the tensioning force is evenly distributed on the prestressed bundle 11. The combination of threaded transmission and the locking mechanism of the screw 2 further prevents the rebound phenomenon after tensioning and ensures the long-term stability of the prestress. In actual bridge reinforcement projects, the device has broad application prospects. It has a compact structure and is easy to install. It does not require the assistance of large heavy machinery, which can effectively reduce the difficulty and cost of construction. At the same time, its high reliability and stability can significantly improve the quality of bridge reinforcement, extend the service life of the bridge, and provide strong guarantees for the safe operation of the bridge, which is of great significance to ensuring the safety and stability of transportation infrastructure.

[0038] like Figure 2 and Figure 1 As shown, a force transmission plate 3 located between the two side plates 101 is added to the fixed plate, and the screw 2 passes through the force transmission plate 3, and the screw 2 and the force transmission plate 3 form a rotational fit. After the rotational fit is formed, the middle part of the screw 2 can be supported and guided, the force transmission path of the screw 2 is optimized, and the operating stability of the screw 2 is improved. The force transmission plate 3 can effectively disperse and transmit the force borne by the screw 2 during the rotation process, and avoid stress concentration at the connection between the side plate 101 and the screw 2. During the long-term use of the bridge, the tension of the prestressed beam 11 will continue to change. The existence 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.

[0039] like Figure 1 and Figure 2 As shown, the regulating splint 5 is located between the side plate 101 and the force transmission plate 3, one regulating splint 5 is located between the force transmission plate 3 and a side plate 101, and the other regulating splint 5 is located between the force transmission plate 3 and the other side plate 101, so that the two regulating splints 5 are distributed on different sides of the force transmission plate 3. Under this relative position distribution, the regulating splint 5 can make full use of the space between the side plate 101 and the force transmission plate 3 to ensure that it is stably constrained during movement.

[0040] like 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 lead 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] like Figure 2 As shown, the regulating splint 5 cooperates with the screw rod 2 to form a cantilever structure, and a reinforcement hole is set at the end and connected by the pull rod 15 to form a rectangular closed frame, which significantly enhances the overall stability of the device. During the tensioning process of the prestressed bundle 11, the device will be subjected to a large tensile force, and the cantilever structure and the rectangular closed frame can effectively resist the deformation and displacement tendency caused by these tensile forces. The rectangular closed frame connects the screw rod 2 and the regulating splint 5 into a whole, so that the various components restrain each other and cooperate in force, which improves the structural strength of the device, ensures that it can maintain stable working performance during long-term use, provides reliable prestressing supplement for the bridge, and extends the service life of the bridge.

[0046] like Figure 3 As shown, under the longitudinal beam 13 of the bridge, there are spaced diverters 14, and between the diverters 14, a prestressing tensioning device for the bridge is installed. One end of the prestressed bundle 11 is anchored to the bridge beam, and the other end passes through the diverter 14 and cooperates with the prestressing tensioning device for the bridge beam, and continues to extend to another diverter 14 and passes over, and then is tensioned and anchored at the other end of the bridge beam. The diverter 14 can constrain the horizontal position and vertical position of the prestressed bundle 11 it contacts, and a tensioning section is initially formed between the diverters 14 at both ends. The prestressing tensioning device for the bridge pushes the tensioning section to bend the tensioning section, thereby realizing the tensioning of the prestressed bundle 11, so that the prestress value of the prestressed bundle is restored to the original design prestress value.

[0047] like Figure 4 and Figure 5 As shown, the transmission mechanism includes a gear set, the gear set includes an adjusting gear 4, and the two screw rods 2 are respectively connected with regulating gears, and cooperate with other regulating gears of the gear set to form a synchronous transmission, so that the two screw rods 2 can rotate synchronously and at the same speed in opposite directions.

[0048] The two screw rods 2 cooperate with the gear set, and are provided with a driving end receiving external force and a locking member 8, so as to realize 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 regulating clamping plate 5, ensuring the symmetrical tensioning of the prestressed bundle 11, and avoiding the problem of unbalanced force on the bridge structure caused by uneven tensioning.

[0049] The existence of the locking member 8 provides an important guarantee for the safety of the device. After the prestressed bundle 11 is tensioned to a predetermined value, the locking member 8 can lock the rotation of the gear set to prevent the screw 2 from accidentally rotating due to external interference or its own structural characteristics, ensuring that the tension of the prestressed bundle 11 remains stable, avoiding the influence of the reinforcement effect of the bridge due to the change of tension, and ensuring the safe operation of the bridge after reinforcement.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] Example 2 In another typical embodiment of the present invention, Figure 1-Figure 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.

[0056] A working method for an external prestressed tensioning device for a bridge, comprising: The fixing frame 1 is installed at the bottom of the longitudinal beam 13, and two prestressed beams 11 are tensioned at both ends of the beam body and anchored to the sides of the beam body respectively. The two prestressed beams 11 contact the contact plates 6 in the horizontal sections between the diverters 14 respectively. When the prestressed bundle 11 cooperates with the contact plate 6, the relative positions of the contact plate 6 and the regulating clamping plate 5 are adjusted so that the contact portion of the contact plate 6 cooperates with the prestressed bundle 11; the two screws 2 are rotated synchronously so that the two regulating clamping plates 5 are close to each other, and the two prestressed bundles 11 are tensioned in the horizontal direction through the contact plate 6 to perform the supplementary tensioning process; After the tensioning is completed, the screw rod 2 is locked, and the ends of the two regulating splints 5 are connected by the pull rod 15.

[0057] In the early preparation stage, the fixing frame 1 is installed 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 tensioning device. The prestressed beams 11 are pre-tensioned at both ends of the beam, and when they come into contact with the contact plate 6, a complete force transmission link is formed. The two prestressed beams 11 correspond to the contact plates 6 respectively, ensuring that the tensioning force can act accurately and effectively on the prestressed beams 11. The symmetrical arrangement is conducive to balancing the force on the beam body and avoiding the risk of structural deformation or imbalance due to unilateral force.

[0058] The synchronous rotation of the two screws 2 is achieved by acting on the gear set through an external driving device. During the rotation of the screw 2, the two regulating splints 5 are brought close to each other due to the special matching structure of the regulating splint 5 and the screw 2. The contact plate 6 on the regulating splint 5 tensions the prestressed beam 11 in the horizontal direction. The horizontal tensioning method has significant advantages over the traditional vertical tensioning. It avoids the instability problem that may occur in the vertical support structure during the compression process, ensures the stability and reliability of the prestressing, and can more accurately control the stretching direction and strength of the prestressed beam 11, so that the prestress is evenly distributed on the beam body, effectively compensates for the relaxation of the prestress, and improves the strength and rigidity of the beam body structure.

[0059] The locking screw 2 can prevent it from rotating due to external interference or changes in internal stress, ensuring that the prestressed bundle 11 remains in a predetermined tension state. The ends of the two regulating splints 5 are connected by a tie rod 15, which further enhances the integrity and stability of the device. The tie rod 15, the screw 2 and the regulating splint 5 together form a stable force-bearing frame, which effectively resists the reaction force of the prestress and the dynamic load of the bridge during use. The torque formed by tensioning is opposite to the torque of the bridge deck 12 on the longitudinal beam 13, thereby reinforcing the bridge deck 12, preventing the displacement of the regulating splint 5 or the loosening of the structure, and ensuring a long-term reinforcement effect.

[0060] Adjusting the relative position of the contact plate 6 and the regulating splint 5 to adapt to the prestressed bundle 11 reflects the flexibility and adaptability of the device. In actual engineering, the position and direction of the prestressed bundle 11 may vary due to differences in bridge structure or errors in early construction. By adjusting the relative position of the contact plate 6 and the regulating splint 5, the contact part is tightly fitted to the prestressed bundle 11, ensuring effective force transmission, avoiding stress concentration or tensioning failure caused by poor contact, and ensuring that the device can achieve efficient and accurate prestressing tensioning operations under different working conditions, providing reliable protection for the safety of bridge structures.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in 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 plates are installed with contact plates, and the contact plates are provided with a contact portion matching the prestressed bundle. The transmission mechanism cooperates with the screw rod and is acted upon by an external driving element to adjust the distance between the two 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: The contact parts of the contact plates installed on the two regulating splints are arranged relatively, and the contact parts are grooves that conform to the distribution direction of the prestressed bundles. The contact parts are synchronously approached or moved away under the drive of the regulating splints, and a pressure sensor is installed in the groove.

7. The external prestressing tensioning device for bridges according to claim 1, characterized in that: 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 are cooperated with a pull rod together, and combined with the screw rod to form a rectangular closed frame, and the prestressed bundle passes through the rectangular closed frame.

8. 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.

9. A working method for an external prestressed bridge tensioning device, using the external prestressed bridge tensioning device as claimed in any one of claims 1 to 8, 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.

10. The working method for the external prestressing tensioning device for bridges according to claim 9, 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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