Prestressed concrete cable-stayed bridge girder hanging basket and construction process

Abstract

This application relates to a formwork for the main beam of a prestressed concrete cable-stayed bridge and its construction process, belonging to the technical field of formwork. It includes a support system and a traveling system erected on the main tower of the cable-stayed bridge. The traveling system includes a first hydraulic cylinder, a first air cylinder, a guide rail, and a hydraulic seat. The guide rail is fixed to the main tower, and the hydraulic seat is slidably mounted on the guide rail and slides along the length of the guide rail. The hydraulic seat is open at the top and hollow inside. A pressure plate and an adjusting screw are provided on the hydraulic seat. The pressure plate is located inside the hydraulic seat, and one end of the adjusting screw passes through the hydraulic seat and is rotatably connected to the pressure plate. The adjusting screw rotates relative to the pressure plate and is threadedly connected to the hydraulic seat. The piston end of the first air cylinder is connected to a pin on the outer wall of the hydraulic seat. The first air cylinder is horizontally positioned along the length of the guide rail and is used to push the hydraulic seat to slide relative to the guide rail. This application facilitates the replacement of the first hydraulic cylinder and improves the efficiency of installation and disassembly between the first hydraulic cylinder and the first air cylinder.

Description

Technical Field

[0001] This application relates to the technical field of hanging baskets, and in particular to a hanging basket for the main beam of a prestressed concrete cable-stayed bridge and its construction process. Background Technology

[0002] A cable-stayed bridge formwork is a construction device used in the construction of cable-stayed bridges. During the construction of a cable-stayed bridge, a supporting structure needs to be erected at the bridge towers, and then formwork and reinforcing steel are installed on it to complete the bridge deck construction. The cable-stayed bridge formwork is a specialized piece of equipment used for construction on this supporting structure.

[0003] Cable-stayed bridge formwork is typically made of steel, possessing high strength and stability, and capable of withstanding the weight and pressure during construction. The main structure of the formwork usually includes a formwork system, a support system, a hoisting system, and a traveling system.

[0004] The traveling system includes a guide rail fixed on the bridge tower, a first hydraulic cylinder for lifting the support system, and a first pneumatic cylinder for pushing the first hydraulic cylinder and the support system to slide on the guide rail. Different specifications of template systems correspond to different support system specifications, resulting in different models of the first hydraulic cylinder to be selected. Only the first hydraulic cylinder that meets the lifting requirements can be used on the corresponding support system. The replacement of the first hydraulic cylinder has the drawback of being cumbersome to install and disassemble the first hydraulic cylinder and the first pneumatic cylinder. Summary of the Invention

[0005] To facilitate the replacement of the first hydraulic cylinder and improve the efficiency of installation and disassembly between the first hydraulic cylinder and the first pneumatic cylinder, this application provides a formwork for the main beam of a prestressed concrete cable-stayed bridge and a construction process therefor.

[0006] Firstly, this application provides a formwork for the main girder of a prestressed concrete cable-stayed bridge, employing the following technical solution:

[0007] A prestressed concrete cable-stayed bridge main beam formwork includes a support system and a traveling system erected on the main tower of the cable-stayed bridge. The traveling system includes a first hydraulic cylinder, a first air cylinder, a guide rail, and a hydraulic seat. The guide rail is fixed to the main tower, and the hydraulic seat is slidably mounted on the guide rail and slides along the length of the guide rail. The hydraulic seat is open at the top and hollow inside. A pressure plate and an adjusting screw are provided on the hydraulic seat. The pressure plate is located inside the hydraulic seat, and one end of the adjusting screw passes through the hydraulic seat and is rotatably connected to the pressure plate. The adjusting screw rotates relative to the pressure plate and is threadedly connected to the hydraulic seat. The first hydraulic cylinder is placed vertically inside the hydraulic seat, and the pressure plate abuts against the outer wall of the first hydraulic cylinder. The piston end of the first air cylinder is detachably connected to the outer wall of the hydraulic seat. The length of the first air cylinder is horizontally arranged along the length of the guide rail, and the first cylinder is used to push the hydraulic seat to slide relative to the guide rail.

[0008] By adopting the above technical solution, different engineering projects require different specifications and dimensions of the support system, thus requiring first hydraulic cylinders with different lifting weights. After selecting a suitable first hydraulic cylinder, the first hydraulic cylinder is placed in the hydraulic seat, and then the adjusting screw is rotated to make the pressure plate press against the outer wall of the first hydraulic cylinder, thereby limiting and fixing the first hydraulic cylinder. The end of the first cylinder is detachably connected to the hydraulic seat, and can be installed and disassembled at any time, so as to facilitate the replacement of the first hydraulic cylinder and improve the efficiency of installation and disassembly between the first hydraulic cylinder and the first cylinder.

[0009] Optionally, a positioning seat is slidably mounted on the guide rail. The positioning seat slides along the length of the guide rail. The end of the positioning seat facing the hydraulic seat is open and the interior of the positioning seat is hollow. The positioning seat is provided with a locking strip and a positioning rod. A locking groove is opened on the outer wall of the body of the first cylinder. The locking strip is slidably mounted in the positioning seat. There are two locking strips. One end of the positioning rod passes through the positioning seat and through the two locking strips. The two locking strips slide on the positioning rod in a direction that approaches or moves away from each other. The positioning rod rotates relative to the positioning seat. The positioning rod and the two locking strips are threadedly connected. The first cylinder is inserted into the positioning seat, and the locking strip is inserted into the locking groove.

[0010] By adopting the above technical solution, when the first cylinder is installed on the positioning seat, one end of the first cylinder body is inserted into the positioning seat, and then the positioning rod is rotated. The positioning rod drives the two locking strips to move towards each other and finally inserts the locking strips into the slots. At this time, the two locking strips clamp the first cylinder, thereby achieving the limitation and fixation of the first cylinder. The operation is simple and convenient.

[0011] Optionally, the positioning seat is slidably provided with clamps, and there are two clamps symmetrically arranged on both sides of the guide rail. The two clamps slide in directions that are closer to or further away from each other.

[0012] By adopting the above technical solution, when the first cylinder needs to push the support system and the hydraulic seat to move along the length of the guide rail, the two clamping plates clamp the guide rail, the first cylinder is started, the first cylinder pushes the hydraulic seat forward, and then the two clamping plates move away from each other, releasing the clamping of the guide rail. The first cylinder is started again, the piston end of the first cylinder retracts, causing the positioning seat to slide closely behind the hydraulic seat. By repeating this process, the hydraulic seat can be pushed on the guide rail.

[0013] Optionally, the guide rail is provided with a positioning groove and a sliding groove, which are located at the top of the guide rail and are opened along the length of the guide rail; the sliding groove is located on the vertical groove wall of the positioning groove and is distributed on both vertical groove walls of the positioning groove; the guide rail is provided with a limit plate, a support rod and a spring, the limit plate is horizontally set and its end is located in the corresponding sliding groove, the support rod is located in the positioning groove, the support rod is vertically set and passes through the limit plate, the top end of the support rod is fixedly connected to the positioning seat, and the spring is fixed between the limit plate and the positioning seat and looped around the support rod; a steel ball is rotatably set on the end of the limit plate located in the sliding groove, the steel ball rotates relative to the limit plate and rolls in the sliding groove.

[0014] By adopting the above technical solution, when the positioning seat slides on the guide rail, the spring and the support rod push the positioning seat upward, so that the bottom of the positioning seat does not contact the top surface of the guide rail, reducing the friction between them. At the same time, the support rod is located in the positioning groove, which also plays a role in positioning the positioning seat. The steel ball rolls in the groove, further reducing the friction generated when the positioning seat slides on the guide rail, and extending the service life of the positioning seat.

[0015] Optionally, the connection between the limiting plate and the steel ball is located in the middle of the steel ball, and the steel ball abuts against the two groove walls in the vertical direction at the same time.

[0016] By adopting the above technical solution, the position of the steel ball is limited, which avoids the top of the limiting plate from contacting the groove wall, and further reduces the friction generated when the limiting plate moves in the groove.

[0017] Optionally, the edge of the guide rail near the clamping plate is inclined, with the inclination direction downward along the direction near the center line of the guide rail. A guide block is fixed to the side wall of the clamping plate near the guide rail. When the guide block slides on the inclined edge of the guide rail, it drives the positioning seat to move downward.

[0018] By adopting the above technical solution, when the guide block slides along the inclined edge of the guide rail to the center line of the guide rail, it drives the positioning seat to move downward. At this time, the spring is compressed, the two clamps clamp the guide rail, and the positioning seat also sits on the guide rail, contacting the friction between the positioning seat and the guide rail, thus ensuring the stability of the positioning seat at this time.

[0019] Optionally, the guide rail has positioning strip holes on its vertical sidewall. The positioning strip holes are opened along the length of the guide rail, and there are multiple positioning strip holes. Adjacent positioning strip holes are spaced apart along the length of the guide rail, and the end of the guide block is inserted into the positioning strip holes.

[0020] By adopting the above technical solution, after the two clamping plates hold the guide rail, the guide block is inserted into the corresponding positioning strip hole, which further enhances the stability of the positioning seat on the guide rail.

[0021] Optionally, the bottom of the hydraulic base is provided with a storage groove with the groove opening facing downwards. A second hydraulic cylinder and a roller are provided on the hydraulic base. The second hydraulic cylinder is fixed on the bottom of the storage groove, and the roller is located at the piston end of the second hydraulic cylinder. The second hydraulic cylinder is vertically arranged and is used to control the roller to move into or out of the storage groove.

[0022] By adopting the above technical solution, when the hydraulic seat does not need to move, the bottom of the hydraulic seat directly abuts against the top of the guide rail. When the hydraulic seat needs to move, the second hydraulic cylinder is activated to move the roller out of the storage groove. At this time, the roller rolls in the positioning groove, and there is a distance between the bottom of the hydraulic seat and the top of the guide rail, which reduces the friction generated when the hydraulic seat slides on the top of the guide rail.

[0023] Optionally, a second cylinder is fixed on the positioning seat, and a first rack is fixed to the piston end of the second cylinder. One clamping plate is fixedly connected to the piston rod of the second cylinder, and a second rack is fixed to the side wall of the other clamping plate near the first rack. A gear is rotatably arranged on the positioning seat. The gear rotates relative to the positioning seat and is located between the first rack and the second rack and meshes with both the first rack and the second rack.

[0024] By adopting the above technical solution, the second cylinder is started, and the second cylinder directly drives one clamping plate to move. The other clamping plate also begins to move through the transmission between the first rack, the second rack and the gear. Finally, the two clamping plates move in the direction of moving closer or further away from each other, achieving the effect that one second cylinder can drive the two clamping plates to move simultaneously.

[0025] Secondly, this application provides a construction process for the hanging basket of the main beam of a prestressed concrete cable-stayed bridge, adopting the following technical solution:

[0026] A construction process for the hanging basket of the main girder of a prestressed concrete cable-stayed bridge includes the following steps:

[0027] S1. Install the support system on the main tower using a hoisting system;

[0028] S2. Lay a walking system on the main tower;

[0029] S3. Select a suitable first hydraulic cylinder and install it in the hydraulic base;

[0030] S4. The support system works in conjunction with the formwork system to pour concrete for the cable-stayed bridge. After the pouring is completed, the first air cylinder and the first hydraulic cylinder work together to lift the support system and move it horizontally, so as to facilitate the pouring of concrete in the next area. This process is repeated until all areas are poured.

[0031] In summary, this application includes at least one of the following beneficial technical effects:

[0032] 1. Different projects require different specifications and dimensions of support systems, thus requiring first hydraulic cylinders with different lifting weights. After selecting a suitable first hydraulic cylinder, place it in the hydraulic seat, and then rotate the adjusting screw to make the pressure plate press against the outer wall of the first hydraulic cylinder, thereby limiting and fixing the first hydraulic cylinder, which facilitates the replacement of the first hydraulic cylinder and improves the efficiency of installation and disassembly between the first hydraulic cylinder and the first air cylinder.

[0033] 2. When the guide block slides along the inclined edge of the guide rail to the center line of the guide rail, it drives the positioning seat to move downward. At this time, the spring is compressed, the two clamps clamp the guide rail, and the positioning seat also sits on the guide rail, contacting the friction between the positioning seat and the guide rail, ensuring the stability of the positioning seat at this time.

[0034] 3. When the second cylinder is activated, it directly drives one clamping plate to move. The other clamping plate also begins to move through the transmission between the first rack, the second rack, and the gear. Ultimately, the two clamping plates move towards or away from each other, achieving the effect that one second cylinder can drive two clamping plates to move simultaneously. Attached Figure Description

[0035] Figure 1 This is a structural schematic diagram of an embodiment of this application;

[0036] Figure 2 This is a partial structural diagram of the first cylinder.

[0037] Figure 3 This is a partial structural cross-sectional view of the hydraulic seat;

[0038] Figure 4 This is a partial structural cross-sectional view of the positioning seat;

[0039] Figure 5 This is a partial structural cross-sectional view of the clamping plate area.

[0040] Explanation of reference numerals in the attached drawings: 1. Guide rail; 11. Positioning groove; 12. Slide groove; 13. Support rod; 14. Spring; 15. Limiting plate; 16. Steel ball; 17. Positioning strip hole; 2. First hydraulic cylinder; 3. First air cylinder; 31. Slot; 4. Hydraulic seat; 41. Pressure plate; 42. Adjusting screw; 43. Storage groove; 44. Second hydraulic cylinder; 45. Roller; 5. Positioning seat; 51. Slot; 52. Positioning rod; 53. Clamping plate; 531. Guide block; 54. Second air cylinder; 55. First rack; 56. Gear; 57. Second rack; 6. Support system. Detailed Implementation

[0041] The following is in conjunction with the appendix Figures 1-5 This application will be described in further detail.

[0042] This application discloses a formwork for the main beam of a prestressed concrete cable-stayed bridge.

[0043] refer to Figure 1 A prestressed concrete cable-stayed bridge main beam formwork includes a support system 6 and a walking system erected on the main tower of the cable-stayed bridge. A formwork system is installed on the support system 6, which provides an installation platform for the formwork system. The formwork system is a model for pouring concrete. In this embodiment, both the support system 6 and the formwork system are existing structures and will not be described in detail here.

[0044] refer to Figure 2 and Figure 3 The walking system includes a first hydraulic cylinder 2, a first air cylinder 3, a guide rail 1, and a hydraulic base 4. The guide rail 1 is fixed on the main tower, and its length is aligned with the length of the cable-stayed bridge. The hydraulic base 4 is slidably mounted on the guide rail 1 and slides along its length. The hydraulic base 4 can also move vertically relative to the guide rail 1. Specifically, the bottom of the hydraulic base 4 has a receiving groove 43 with its opening facing downwards. A second hydraulic cylinder 44 and a roller 45 are placed inside the receiving groove 43. The second hydraulic cylinder 44 is placed vertically, with one end of its body fixedly connected to the bottom of the receiving groove 43. The piston end of the second hydraulic cylinder 44 is connected to the roller 45. The second hydraulic cylinder 44 drives the roller 45 to retract into or out of the receiving groove 43. After the roller 45 is pushed out of the receiving groove 43 and abuts against the top of the guide rail 1, the bottom surface of the hydraulic base 4 separates from the top surface of the guide rail 1, reducing the friction between the hydraulic base 4 and the guide rail 1 during sliding.

[0045] refer to Figure 3 The hydraulic base 4 is open at the top and hollow inside. A pressure plate 41 and an adjusting screw 42 are mounted on the hydraulic base 4. The pressure plate 41 is located inside the hydraulic base 4. One end of the adjusting screw 42 passes through the hydraulic base 4 and is rotatably connected to the pressure plate 41. The adjusting screw 42 rotates relative to the pressure plate 41. The adjusting screw 42 is threadedly connected to the hydraulic base 4. A handwheel is fixed to the end of the adjusting screw 42 located outside the hydraulic base 4 for easy rotation by the operator. One pressure plate 41 and one adjusting screw 42 constitute a group. In this embodiment, multiple groups are spaced apart along the outer wall of the hydraulic base 4. The first hydraulic cylinder 2 is placed vertically inside the hydraulic base 4. Rotating the adjusting screw 42 causes the pressure plate 41 to abut against the outer wall of the first hydraulic cylinder 2.

[0046] refer to Figures 2 to 4 The first cylinder 3 is horizontally arranged along the length of the guide rail 1. The piston end of the first cylinder 3 is pin-connected to the outer wall of the hydraulic base 4. A groove 31 is provided on the outer wall of one end of the body of the first cylinder 3. The groove 31 is arranged around the outer wall of the body of the first cylinder 3. A positioning seat 5 is provided at one end of the body of the first cylinder 3. The positioning seat 5 is open at the end facing the first cylinder 3. The interior of the positioning seat 5 is hollow, and one end of the body of the first cylinder 3 is inserted into the positioning seat 5.

[0047] refer to Figure 3 and Figure 4 The positioning seat 5 is equipped with two locking strips 51 and two positioning rods 52. The two locking strips 51 are located on either side of the first cylinder 3. One end of the positioning rod 52 extends horizontally into the positioning seat 5 and is threadedly connected to both locking strips 51. The positioning rod 52 rotates relative to the positioning seat 5, and the two locking strips 51 move within the positioning seat 5 in directions that bring them closer together or further apart. That is, the ends of the locking strips 51 can only slide against the inner wall of the positioning seat 5; they cannot rotate relative to the positioning seat 5. This is achieved by the locking strip 51 having the same length as the inner diameter of the positioning seat 5, with its end abutting against the inner wall of the positioning seat 5, or by fixing a T-shaped block to the end of the locking strip 51, with a T-shaped slide rail on the inner wall of the positioning seat 5, allowing the T-shaped block to slide within the slide rail. The thread direction of the positioning rod 52 is symmetrically arranged on both sides of its midpoint. Rotating the positioning rod 52 causes the two locking strips 51 to move closer together, ultimately inserting the locking strips 51 into the locking slots 31.

[0048] refer to Figure 3 and Figure 5 The guide rail 1 has a positioning groove 11, a sliding groove 12, and positioning slots 17. Both the positioning groove 11 and the sliding groove 12 are formed along the length of the guide rail 1. The positioning groove 11 is located at the top of the guide rail 1 with its opening facing upwards. There are two sliding grooves 12, located on the vertical wall of the positioning groove 11, symmetrically distributed on the vertical wall of the positioning groove 11. Multiple positioning slots 17 are formed along the length of the guide rail 1, spaced apart from each other. The positioning slots 17 are located on the vertical sidewall of the guide rail 1 and do not penetrate through the guide rail 1; that is, positioning slots 17 are symmetrically distributed on the vertical sidewall of the guide rail 1. In this embodiment, the guide rail 1 is made of I-beam steel.

[0049] refer to Figure 3 and Figure 5 The guide rail 1 is provided with a limit plate 15, a support rod 13, and a spring 14. The limit plate 15 is horizontally positioned with its end located in the corresponding groove 12. The support rod 13 is located in the positioning groove 11, is vertically positioned, and passes through the limit plate 15. The support rod 13 slides vertically relative to the limit plate 15, and its top end is fixedly connected to the positioning seat 5. The spring 14 is located between the limit plate 15 and the positioning seat 5 and is looped around the support rod 13. One end of the spring 14 is fixedly connected to the limit plate 15, and the other end is fixedly connected to the positioning seat 5. A steel ball 16 is rotatably mounted on the end of the groove 12 of the limit plate 15. The steel ball 16 rotates relative to the limit plate 15, and the connection between the steel ball 16 and the limit plate 15 is located in the middle of the steel ball 16. The steel ball 16 rolls in the groove 12 and simultaneously abuts against the top and bottom of the groove 12.

[0050] refer to Figure 4 and Figure 5 The edge of the guide rail 1 near the clamping plate 53 is inclined, and the inclination direction is downward along the direction close to the center line of the guide rail 1. The positioning seat 5 is slidably provided with clamping plates 53. There are two clamping plates 53 and they are distributed on both sides of the guide rail 1. The two clamping plates 53 move in a direction that is closer to or further away from each other.

[0051] refer to Figure 4 The positioning seat 5 has a second cylinder 54, a first rack 55, a gear 56, and a second rack 57 on its top. The second cylinder 54 is fixedly connected to the positioning seat 5 and is positioned along the line connecting the two clamping plates 53. The piston end of the second cylinder 54 is fixedly connected to the first rack 55. The gear 56 is rotatably mounted on the top of the positioning seat 5, horizontally positioned and rotating relative to the positioning seat 5. One of the two retaining bars 51 is fixedly connected to the piston end of the second cylinder 54, which can be fixedly connected via a connecting rod. The other retaining bar 51 is fixedly connected to the second rack 57. The gear 56 is located between the first rack 55 and the second rack 57, and meshes with both the first rack 55 and the second rack 57. When the second cylinder 54 is activated, it moves one retaining bar 51 via the connecting rod, and moves the other retaining bar 51 via the first rack 55, the gear 56, and the second rack 57, ultimately achieving the effect of the two retaining bars 51 moving towards or away from each other.

[0052] refer to Figure 5 A guide block 531 is fixed to the side wall of the clamping plate 53 near the guide rail 1. When the guide block 531 slides on the inclined edge of the guide rail 1, it drives the positioning seat 5 to move downward. Finally, the guide block 531 is inserted into the corresponding positioning strip hole 17. At this time, the spring 14 is compressed and the bottom of the positioning seat 5 abuts against the top of the guide rail 1.

[0053] The implementation principle of a formwork for the main beam of a prestressed concrete cable-stayed bridge is as follows: Different projects require different specifications and dimensions of the support system 6, thus necessitating first hydraulic cylinders 2 with varying lifting weights. After selecting a suitable first hydraulic cylinder 2, it is placed inside the hydraulic seat 4. Then, the adjusting screw 42 is rotated to press the pressure plate 41 against the outer wall of the first hydraulic cylinder 2, thereby limiting and fixing the first hydraulic cylinder 2. The end of the first cylinder 3 is detachably connected to the hydraulic seat 4, allowing for easy installation and removal, facilitating the replacement of the first hydraulic cylinder 2 and lifting the first hydraulic cylinder. The efficiency of installation and disassembly between cylinder 2 and cylinder 3 is improved. When cylinder 3 needs to push support system 6 and hydraulic seat 4 to move along the length of guide rail 1, two clamping plates 53 clamp guide rail 1, start cylinder 3, cylinder 3 pushes hydraulic seat 4 forward, then the two clamping plates 53 move away from each other, release clamping guide rail 1, start cylinder 3 again, piston end of cylinder 3 retracts, driving positioning seat 5 to slide closely behind hydraulic seat 4, and so on, so that hydraulic seat 4 can be pushed on guide rail 1.

[0054] This application also discloses a construction process for the hanging basket of the main beam of a prestressed concrete cable-stayed bridge.

[0055] Includes the following steps:

[0056] S1. Install the support system 6 onto the main tower using a hoisting system;

[0057] S2. Lay a walking system on the main tower;

[0058] S3. Select a suitable first hydraulic cylinder 2 and install it in the hydraulic base 4;

[0059] S4. The support system 6 works in conjunction with the formwork system to pour concrete for the cable-stayed bridge. After the pouring is completed, the first cylinder 3 and the first hydraulic cylinder 2 work together to lift the support system 6 and move it horizontally, so as to facilitate the pouring of concrete for the next area. This process is repeated until all areas are poured.

[0060] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A formwork for the main girder of a prestressed concrete cable-stayed bridge, comprising a support system (6) and a traveling system erected on the main tower of the cable-stayed bridge, characterized in that: The walking system includes a first hydraulic cylinder (2), a first air cylinder (3), a guide rail (1), and a hydraulic base (4). The guide rail (1) is fixed on the main tower. The hydraulic base (4) is slidably mounted on the guide rail (1) and slides along the length of the guide rail (1). The hydraulic base (4) is open at the top and hollow inside. A pressure plate (41) and an adjusting screw (42) are provided on the hydraulic base (4). The pressure plate (41) is located inside the hydraulic base (4). One end of the adjusting screw (42) passes through the hydraulic base (4) and is rotatably connected to the pressure plate (41). The adjusting screw (42) rotates relative to the pressure plate (41). The adjusting screw (42) is threadedly connected to the hydraulic base (4). The first hydraulic cylinder (2) is placed vertically inside the hydraulic base (4). The pressure plate (41) is slidably mounted on the hydraulic base (4). 1) It abuts against the outer wall of the first hydraulic cylinder (2); the piston end of the first cylinder (3) is detachably connected to the outer wall of the hydraulic seat (4). The first cylinder (3) is horizontally arranged along the length direction of the guide rail (1). The first cylinder (3) is used to push the hydraulic seat (4) to slide relative to the guide rail (1); a positioning seat (5) is slidably arranged on the guide rail (1). The positioning seat (5) slides along the length direction of the guide rail (1). The end of the positioning seat (5) facing the hydraulic seat (4) is open and the interior of the positioning seat (5) is hollow. A locking strip (51) and a positioning rod (52) are provided on the positioning seat (5). A slot (31) is opened on the outer wall of the body of the first cylinder (3). The locking strip (51) is slidably arranged in the positioning seat (5). There are two positioning rods (52), one end of which passes through the positioning seat (5) and two retaining strips (51). The two retaining strips (51) slide on the positioning rod (52) in a direction that approaches or moves away from each other. The positioning rod (52) rotates relative to the positioning seat (5). The positioning rod (52) and the two retaining strips (51) are threadedly connected. The first cylinder (3) is inserted into the positioning seat (5), and the retaining strips (51) are inserted into the retaining grooves (31). The positioning seat (5) is slidably provided with clamping plates (53). There are two clamping plates (53) and they are symmetrically arranged on both sides of the guide rail (1). The two clamping plates (53) slide in a direction that approaches or moves away from each other. The guide rail (1) is provided with a positioning groove (11) and a sliding groove (12). The positioning groove (11) and the sliding groove (12) are located on the top of the guide rail (1) and are opened along the length of the guide rail (1); the sliding groove (12) is located on the vertical groove wall of the positioning groove (11) and is distributed on both vertical groove walls of the positioning groove (11); the guide rail (1) is provided with a limiting plate (15), a support rod (13) and a spring (14), the limiting plate (15) is set horizontally and its end is located in the corresponding sliding groove (12), the support rod (13) is located in the positioning groove (11), the support rod (13) is set vertically and passes through the limiting plate (15), the top of the support rod (13) is fixedly connected to the positioning seat (5), and the spring (14) is fixed between the limiting plate (15) and the positioning seat (5) and is looped on the support rod (13);A steel ball (16) is rotatably mounted on the end of the sliding groove (12) of the limiting plate (15). The steel ball (16) rotates relative to the limiting plate (15) and rolls within the sliding groove (12). The bottom of the hydraulic seat (4) is provided with a receiving groove (43), with the opening of the receiving groove (43) facing downwards. A second hydraulic cylinder (44) and a roller (45) are provided on the hydraulic seat (4). The second hydraulic cylinder (44) is fixed on the bottom of the receiving groove (43), and the roller (45) is located at the piston end of the second hydraulic cylinder (44). The second hydraulic cylinder (44) is vertically mounted and is used to control the roller (45) to move into or out of the receiving groove (43).

2. The formwork for the main beam of a prestressed concrete cable-stayed bridge according to claim 1, characterized in that: The connection between the limiting plate (15) and the steel ball (16) is located in the middle of the steel ball (16), and the steel ball (16) and the two groove walls of the slide (12) in the vertical direction abut against each other simultaneously.

3. The formwork for the main girder of a prestressed concrete cable-stayed bridge according to claim 1, characterized in that: The edge of the guide rail (1) near the clamping plate (53) is inclined, and the inclination direction is downward along the center line of the guide rail (1). A guide block (531) is fixed on the side wall of the clamping plate (53) near the guide rail (1). When the guide block (531) slides on the inclined edge of the guide rail (1), it drives the positioning seat (5) to move downward.

4. The formwork for the main beam of a prestressed concrete cable-stayed bridge according to claim 3, characterized in that: The guide rail (1) has a positioning strip hole (17) on its vertical side wall. The positioning strip hole (17) is opened along the length direction of the guide rail (1). There are multiple positioning strip holes (17). Adjacent positioning strip holes (17) are spaced apart along the length direction of the guide rail (1). The end of the guide block (531) is inserted into the positioning strip hole (17).

5. The formwork for the main girder of a prestressed concrete cable-stayed bridge according to claim 1, characterized in that: A second cylinder (54) is fixed on the positioning seat (5). A first rack (55) is fixed to the piston end of the second cylinder (54). One clamping plate (53) is fixedly connected to the piston rod of the second cylinder (54). A second rack (57) is fixed on the side wall of the other clamping plate (53) near the first rack (55). A gear (56) is rotatably arranged on the positioning seat (5). The gear (56) rotates relative to the positioning seat (5). The gear (56) is located between the first rack (55) and the second rack (57) and meshes with both the first rack (55) and the second rack (57).

6. A construction process using the formwork for the main beam of a prestressed concrete cable-stayed bridge as described in claim 1, characterized in that: Includes the following steps: S1. Install the support system (6) on the main tower using a hoisting system; S2. Lay a walking system on the main tower; S3. Select a suitable first hydraulic cylinder (2) and install it in the hydraulic base (4); S4. The support system (6) works with the formwork system to pour concrete for the cable-stayed bridge. After the pouring is completed, the support system (6) is lifted and moved horizontally by the cooperation of the first cylinder (3) and the first hydraulic cylinder (2), so as to facilitate the pouring of concrete in the next area. This process is repeated until all areas are poured.

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