Steel box girder pushing device

Abstract

The application discloses a steel box girder pushing device, which comprises a fixing base, a base and a pushing mechanism, a plurality of profiled guide grooves are arranged on the inner walls of the two sides of the base, and a first pushing oil cylinder is arranged at one end of the base; the pushing mechanism comprises a pushing box, a sliding base and a jacking base; inner support plates are arranged on the two sides of the sliding base, and at least one support shaft is arranged on one side of the inner support plate; a plurality of guide columns are fixedly connected to the lower part of the jacking base, the lower ends of the plurality of guide columns are connected through a connecting plate, guide rods are fixedly connected to the two sides of the connecting plate, the guide rods pass through the straight guide grooves and are located in the profiled guide grooves; a fixing plate is arranged at the lower part of the jacking base, and at least one inclined guide groove is arranged on the fixing plate. The steel box girder pushing device realizes the jacking and pushing of the steel box girder by using one pushing oil cylinder, eliminates the time interval of switching, waiting and reconfirming between the jacking and pushing, makes each working cycle more compact and smooth, and improves the efficiency of the steel box girder pushing operation.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction technology, and specifically relates to a steel box girder jacking device. Background Technology

[0002] Steel box girders are widely used in the construction of long-span bridges due to their advantages such as high load-bearing capacity, light weight, and short construction period. During the erection of steel box girders, the incremental launching technique is a commonly used and important method. This technique uses a launching device to gradually push the steel box girder to the designed position. It is particularly suitable for steel box girder installation operations in complex conditions such as crossing existing lines (such as railways and highways) and rivers, effectively reducing interference with surrounding traffic and the environment.

[0003] Currently, existing steel box girder jacking devices typically follow a step-by-step "jacking-pushing" operation mode. Their core components include a hydraulic mechanism for jacking the steel box girder and a drive mechanism for propelling it forward. Specifically, when jacking the steel box girder, the hydraulic mechanism is first activated. Using the immense jacking force generated by hydraulic jacks and other components, the steel box girder is lifted from the temporary support structure, creating a gap between the girder and the temporary support structure to prevent friction and damage during subsequent forward movement. Once the girder has been lifted to a preset height and stabilized, the drive mechanism is activated, propelling the girder forward a predetermined distance along the jacking direction. After the girder has traveled this distance, the hydraulic mechanism is retracted, allowing the girder to fall back onto the temporary support structure. The drive mechanism then resets, preparing for the next "jacking-pushing" cycle. This process is repeated until the steel box girder is pushed to its final installation position.

[0004] However, in existing steel box girder jacking devices, the hydraulic mechanism and the drive mechanism are mostly two independent mechanisms. During the jacking operation, each cycle of "jacking up-pushing forward-lowering and resetting" requires operators to perform multiple operations on both the hydraulic and drive mechanisms. This frequent and repetitive manual operation not only makes each cycle time-consuming but also affects the overall efficiency of the jacking construction. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a steel box girder jacking device to solve the problem of low construction efficiency of existing steel box girder jacking devices.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A steel box girder jacking device, comprising:

[0008] The fixed base is fixedly installed on the jacking platform;

[0009] The base is installed on the upper part of the fixed seat. The base is a box-type structure with an open top. Several contoured guide grooves are provided on the inner walls on both sides of the base. A first push cylinder is provided at one end of the base, and a first guide rail is provided at the bottom of the base.

[0010] The jacking mechanism, located inside the base, includes a jacking box, a sliding seat, and a lifting seat. The lower part of the jacking box is provided with a first slider that is slidably connected to a first guide rail, and the two sides of the jacking box are provided with several straight guide grooves. The upper part of the jacking box is provided with a second guide rail. The sliding seat is slidably connected to the second guide rail via a second slider. The two sides of the sliding seat are provided with inner support plates, which are connected by stiffeners. The piston rod end of the first jacking cylinder is connected to the stiffeners. At least one support shaft is provided on one side of the inner support plate.

[0011] The lower part of the lifting seat is fixedly connected to several guide columns. The lower end of the guide columns extends into the interior of the pushing box and is clearance-fitted with the pushing box. The lower ends of the multiple guide columns are connected by a connecting plate. Guide rods are fixedly connected to both sides of the connecting plate. The guide rods pass through the straight guide groove and are located in the contour guide groove. In the initial state, the guide rods are located in the middle of the vertical section on the left side of the contour guide groove. The lower part of the lifting seat is provided with a fixing plate, and the fixing plate is provided with at least one inclined guide groove.

[0012] Furthermore, the upper part of the lifting seat is provided with several pads for adjusting the height between the lifting seat and the bottom of the steel box girder, so that the vertical lifting height of the lifting seat is greater than the height between it and the bottom of the steel box girder; the upper part of the lifting seat and the pads are provided with several positioning grooves, and the lower part of the pads is provided with positioning posts that engage with the positioning grooves.

[0013] Furthermore, a level is provided on both sides of the fixed base.

[0014] Furthermore, an outer support plate is fixedly connected to each side of the sliding seat, the fixed plate is located between the inner support plate and the outer support plate, one end of the support shaft is installed on the inner support plate, and the other end is installed on the outer support plate.

[0015] Furthermore, the contour guide groove is a loop-shaped structure or an isosceles trapezoidal structure with an upper base length greater than the lower base length.

[0016] Furthermore, a spring is sleeved on the outside of the guide column. The lower end of the spring is connected to the connecting plate, and the upper end of the spring is connected to the upper wall of the push box. When the guide rod is located in the middle of the vertical section of the contour guide groove, the spring is in a balanced state. When the guide rod is located in the lower horizontal section of the contour guide groove, the spring is in a stretched state. When the guide rod is located in the upper horizontal section of the contour guide groove, the spring is in a compressed state.

[0017] Furthermore, a limiting mechanism is provided on one side of the base. The limiting mechanism includes guide sleeves fixedly installed at both ends of the base. A limiting arm is slidably connected inside the guide sleeve. The upper end of the limiting arm abuts against the outer wall of the steel box girder to limit the movement direction of the steel box girder. Each end of the guide sleeve is provided with a threaded hole. A locking screw is threadedly connected to the threaded hole near the end of the limiting arm to lock the limiting arm after the position of the limiting arm is adjusted. A handwheel is provided at one end of the locking screw.

[0018] Furthermore, a first guide wheel is rotatably connected to the end of the guide rod, a second guide wheel is rotatably connected to the support shaft, and a third guide wheel is rotatably connected to the end of the limiting arm.

[0019] Furthermore, the fixed base has side plates on both sides, and the side plates are equipped with a correction mechanism. The correction mechanism includes a correction cylinder, the cylinder seat of which is pivotally connected to the side plate, and the piston rod of which is pivotally connected to the base. A rotating shaft is rotatably connected to the fixed base, and the upper end of the rotating shaft is fixedly connected to the base through a flange. Two sets of arc-shaped guide rails are symmetrically installed on both sides of the fixed base, and an arc-shaped slider that slides with the arc-shaped guide rails is fixedly connected to the lower part of the base.

[0020] Furthermore, the jacking mechanism is provided in two sets, which are arranged in a straight line along the jacking direction within the base. A second jacking cylinder is provided at the other end of the base. The piston rod end of the second jacking cylinder is connected to the stiffening plate of another sliding seat. The first and second jacking cylinders extend or retract synchronously. In the initial state, the guide rod of the left jacking mechanism is located in the middle of the left vertical section of the contour guide groove, and the guide rod of the right jacking mechanism is located in the middle of the right vertical section of the contour guide groove. The two sets of jacking mechanisms alternately jack the steel box girder.

[0021] The beneficial effects of this invention are:

[0022] (1) The present invention utilizes a jacking cylinder to realize the two actions of jacking and pushing the steel box girder, eliminating the time interval between switching, waiting and reconfirmation between the two actions of jacking and pushing, making each work cycle more compact and smooth, and improving the efficiency of the jacking operation of the steel box girder.

[0023] (2) Based on the construction height of the jacking platform, the height between the jacking seat and the bottom of the steel box girder is adjusted by using pads, which improves the flexibility and adaptability of the jacking device and reduces the impact of the construction height of the jacking platform on the jacking device.

[0024] (3) External support plates are provided on both sides of the sliding seat. One end of the support shaft is installed on the inner support plate and the other end is installed on the outer support plate, so that the support shaft is transformed into a simply supported beam structure, which enhances the shear resistance of the support shaft.

[0025] (4) By setting a spring outside the guide column, and when the guide rod is located in the middle of the vertical section of the contour guide groove, the spring is in a balanced state, which ensures that the guide rod moves along the preset route in the contour guide groove.

[0026] (5) A limiting mechanism is set on one side of the base to limit the side wall of the steel box girder, so as to avoid the steel box girder from shifting during the jacking process and ensure the accuracy of the jacking of the steel box girder.

[0027] (6) By setting a correction mechanism inside the side plate of the fixed seat, when the steel box girder deviates during the jacking, the correction cylinder extends or retracts to drive the base to rotate a certain angle inside the fixed seat, so as to correct the deviation of the jacking of the steel box girder and ensure that the steel box girder is jacked according to the design route.

[0028] (7) By setting two sets of parallel jacking mechanisms in the base and having the two sets of jacking mechanisms work alternately, the waiting time for the jacking device to return and reset is further shortened, and the efficiency of jacking the steel box girder is improved. Attached Figure Description

[0029] Figure 1 This is a diagram showing the usage status of a steel box girder jacking device according to the present invention.

[0030] Figure 2 This is a schematic diagram of a steel box girder jacking device according to the present invention.

[0031] Figure 3 This is a schematic diagram of the fixed base structure.

[0032] Figure 4 This is a schematic diagram of the interior of the base.

[0033] Figure 5 This is a schematic diagram of the base structure.

[0034] Figure 6 This is a schematic diagram of the jacking mechanism.

[0035] Figure 7 This is a cross-sectional view of the jacking mechanism.

[0036] Figure 8 This is a schematic diagram of the sliding seat.

[0037] Figure 9 This is a schematic diagram of the pad structure.

[0038] In the diagram, 1. Steel box girder; 2. Fixed seat; 21. Side plate; 22. Rotating shaft; 23. Flange; 24. Arc-shaped guide rail; 25. Arc-shaped slider; 26. Level; 27. Correction cylinder; 3. Base; 31. Contouring guide groove; 32. First guide rail; 33. First slider; 34. First jacking cylinder; 35. Guide sleeve; 36. Handwheel; 37. Limiting arm; 38. Third guide wheel; 39. Second jacking cylinder; 4. Top Pushing mechanism; 41. Lifting seat; 42. Guide column; 43. Fixing plate; 44. Inclined guide groove; 45. Connecting plate; 46. Spring; 47. First guide wheel; 48. Second guide rail; 49. Pushing box; 410. Straight guide groove; 5. Sliding seat; 51. Inner support plate; 52. Outer support plate; 53. Support shaft; 54. Second guide wheel; 55. Second slider; 56. Rib plate; 6. Pad plate; 61. Positioning groove; 62. Positioning column. Detailed Implementation

[0039] The following will be combined with the appendix Figures 1-9 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0041] like Figure 1 The steel box girder jacking device includes a fixed base 2, a base 3, and a jacking mechanism 4. The fixed base 2 is fixedly installed on the jacking platform to support the jacking device; the base 3 is installed on the upper part of the fixed base 2, such as... Figure 5 As shown, the base 3 is a box-type structure with an open top. Several contoured guide grooves 31 are provided on the inner walls on both sides of the base 3. A first push cylinder 34 is provided at one end of the base 3, and a first guide rail 32 is provided at the bottom of the base 3.

[0042] like Figure 2 , Figure 4 As shown, the jacking mechanism 4 is located inside the base 3 and includes a pushing box 49, a sliding seat 5, and a lifting seat 41. Figure 7 As shown, the lower part of the push box 49 is provided with a first slider 33 that is slidably connected to the first guide rail 32, such as... Figure 6As shown, the push box 49 has several straight guide grooves 410 on both sides; the upper part of the push box 49 has a second guide rail 48; the sliding seat 5 is slidably connected to the second guide rail 48 through the second slider 55, as shown. Figure 8 As shown, the sliding seat 5 has inner support plates 51 on both sides, such as Figure 7 As shown, the inner support plates 51 on both sides are connected by stiffeners 56, the piston rod end of the first push cylinder 34 is connected to the stiffeners 56, and at least one support shaft 53 is provided on one side of the inner support plate 51. In this embodiment, there are two support shafts 53.

[0043] like Figures 6-8 As shown, a number of guide columns 42 are fixedly connected to the lower part of the lifting seat 41. The lower ends of the guide columns 42 extend into the push box 49 and are clearance-fitted with the push box 49. The lower ends of the multiple guide columns 42 are connected by connecting plates 45, as shown. Figure 4 As shown, guide rods are fixedly connected to both sides of the connecting plate 45. The guide rods pass through the straight guide groove 410 and are located in the contour guide groove 31. In the initial state, the guide rods are located in the middle of the vertical section on the left side of the contour guide groove 31. A fixing plate 43 is provided at the lower part of the lifting seat 41. At least one inclined guide groove 44 is provided on the fixing plate 43. In this embodiment, two inclined guide grooves 44 are provided on the fixing plate 43, and the support shaft 53 is located inside the inclined guide groove 44.

[0044] like Figure 8 , Figure 9 As shown, the upper part of the lifting seat 41 is provided with several pads 6, which are used to adjust the height between the lifting seat 41 and the bottom of the steel box girder 1, so that the vertical lifting height of the lifting seat 41 is greater than the height between it and the bottom of the steel box girder 1, so that the lifting seat 41 can smoothly lift the steel box girder and enhance the flexibility of the jacking device. The upper part of the lifting seat 41 and the pads 6 are provided with several positioning grooves 61, and the lower part of the pads 6 is provided with positioning posts 62 that engage with the positioning grooves 61, ensuring the stability of the connection between the lifting seat 41 and the pads 6 and between the pads 6, and preventing the pads 6 from slipping and misaligning during the jacking process.

[0045] like Figure 3 As shown, both sides of the fixed base 2 are equipped with a level 26, which is used to quickly determine the installation angle of the jacking device on the jacking platform to ensure the accurate docking of the steel box girder.

[0046] like Figure 8 As shown, an outer support plate 52 is fixedly connected to each side of the sliding seat 5. The fixing plate 43 is located between the inner support plate 51 and the outer support plate 52. One end of the support shaft 53 is installed on the inner support plate 51, and the other end is installed on the outer support plate 52. Compared with the cantilever beam structure that is only installed on the inner support plate 51, the addition of the outer support plate 52 makes the support shaft 53 a simply supported beam structure, which enhances the rigidity and stability of the sliding seat 5.

[0047] The contour guide groove 31 is a loop-shaped structure or an isosceles trapezoidal structure with an upper base length greater than the lower base length. In this embodiment, for example... Figure 4 As shown, the contour guide groove 31 adopts a spiral structure.

[0048] like Figure 7 , Figure 8 As shown, a spring 46 is sleeved on the outside of the guide column 42. The lower end of the spring 46 is connected to the connecting plate 45, and the upper end of the spring 46 is connected to the upper wall of the push box 49. When the guide rod is located in the middle of the vertical section of the contour guide groove 31, the spring 46 is in a balanced state. That is, when the guide rod is located in the lower horizontal section of the contour guide groove 31, the spring 46 is in a stretched state, and when the guide rod is located in the upper horizontal section of the contour guide groove 31, the spring 46 is in a compressed state.

[0049] When the first jacking cylinder 34 pushes the lifting seat 41 to its maximum stroke, the guide rod moves to the rightmost end of the upper horizontal section. When the first jacking cylinder 34 retracts, the spring 46 pushes the guide rod downward along the vertical section on the right side of the contour guide groove 31. When the guide rod moves to the bottom of the vertical section on the right side of the contour guide groove 31, the spring 46 is in a stretched state and continues to move to the left along the lower horizontal section of the contour guide groove 31. The guide rod moves to the leftmost end of the lower horizontal section of the contour guide groove 31. When the first jacking cylinder 34 pushes again, the spring 46 will pull the guide rod upward along the vertical section on the left side of the contour guide groove 31 to continue the next jacking process. During the overall jacking process, the spring 46 ensures that the guide rod moves along the preset route within the contour guide groove 31.

[0050] like Figure 1 As shown, a limiting mechanism is provided on one side of the base 3, such as... Figure 2 , Figure 5 As shown, the limiting mechanism includes guide sleeves 35 fixedly installed at both ends of the base 3. A limiting arm 37 is slidably connected inside the guide sleeve 35. The upper end of the limiting arm 37 abuts against the outer wall of the steel box girder 1 to limit the movement direction of the steel box girder and prevent the steel box girder from shifting during the pushing process. Each end of the guide sleeve 35 is provided with a threaded hole. A locking screw is threadedly connected to the threaded hole near the end of the limiting arm 37 to lock the limiting arm 37 after the position of the limiting arm 37 is adjusted. A handwheel 36 is provided at one end of the locking screw.

[0051] like Figure 8 As shown, a first guide wheel 47 is rotatably connected to the end of the guide rod, and a second guide wheel 54 is rotatably connected to the support shaft 53, as follows. Figure 2 As shown, a third guide wheel 38 is rotatably connected to the end of the limiting arm 37. The first guide wheel 47, the second guide wheel 54 and the third guide wheel 38 reduce the frictional resistance during the operation of the jacking device and improve the smoothness of the jacking device.

[0052] like Figure 2 , Figure 3As shown, the fixed base 2 has side plates 21 on both sides, and a correction mechanism is provided on the side plates 21. The correction mechanism includes a correction cylinder 27. The cylinder seat of the correction cylinder 27 is pivotally connected to the side plate 21, and the piston rod of the correction cylinder 27 is pivotally connected to the base 3. A rotating shaft 22 is rotatably connected to the fixed base 2. The upper end of the rotating shaft 22 is fixedly connected to the base 3 through a flange 23. Two sets of arc-shaped guide rails 24 are symmetrically installed on both sides of the fixed base 2. An arc-shaped slider 25 that slides with the arc-shaped guide rails 24 is fixedly connected to the lower part of the base 3. When the steel box girder is pushed out of deviation, the correction cylinder 27 extends or retracts, causing the base 3 to rotate a certain angle within the fixed base 2, so as to realize the correction of the steel box girder pushing and ensure that the steel box girder is pushed out according to the design route.

[0053] like Figure 2 , Figure 4 As shown, the jacking mechanism 4 has two sets, which are arranged in a straight line along the jacking direction inside the base 3. The other end of the base 3 is provided with a second jacking cylinder 39. The piston rod end of the second jacking cylinder 39 is connected to the stiffener 56 of another sliding seat 5. The first jacking cylinder 34 and the second jacking cylinder 39 extend or retract synchronously. In the initial state, the guide rod of the left jacking mechanism 4 is located in the middle of the left vertical section of the contour guide groove 31, and the guide rod of the right jacking mechanism 4 is located in the middle of the right vertical section of the contour guide groove 31. The two sets of jacking mechanisms 4 alternately jack the steel box girder 1, which further improves the efficiency of jacking the steel box girder.

[0054] When the steel box girder 1 is being pushed, the first pushing cylinder 34 extends, pushing the sliding seat 5 on the left to move to the right. When the support shaft 53 moves to the right, the guide column 42 can only move vertically on the pushing box 49. Under the combined action of the inclined guide groove 44, the lifting seat 41 moves upward. At this time, the guide rod at the lower end of the guide column 42 is located in the middle of the vertical section on the left side of the contour guide groove 31. Therefore, the pushing box 49 cannot move within the base 3.

[0055] When the guide rod moves to the top of the vertical section on the left side of the contour guide groove 31, the lifting seat 41 has already lifted the steel box girder 1. When the first pushing cylinder 34 continues to extend, it pushes the guide rod to move to the right in the upper horizontal section of the contour guide groove 31, thereby driving the steel box girder 1 forward.

[0056] When the guide rod moves to the rightmost end of the horizontal section of the contour guide groove 31, the first jacking cylinder 34 retracts, and the guide rod returns to its original position along the contour guide groove 31, preparing for the next jacking.

[0057] When the first jacking cylinder 34 extends, the second jacking cylinder 39 extends simultaneously. Since the inclined guide grooves 44 of the fixed plate 43 in the two jacking mechanisms 4 are in the same direction, and when the second jacking cylinder 39 extends, the moving direction of the right sliding seat 5 is opposite to that of the left sliding seat 5, the right jacking mechanism 4 is in the return motion state when the second jacking cylinder 39 extends. After the left jacking mechanism 4 returns to its original position, the right jacking mechanism 4 continues to jack the steel box girder 1, realizing the alternating jacking operation of the two jacking mechanisms 4 and improving the efficiency of the steel box girder jacking operation.

[0058] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the scope defined by the structure of the invention, and all such modifications and additions should fall within the protection scope of the present invention.

Claims

1. A steel box girder jacking device, characterized in that, include: The fixed base is fixedly installed on the jacking platform; The base is installed on the upper part of the fixed seat. The base is a box-type structure with an open top. Several contoured guide grooves are provided on the inner walls on both sides of the base. A first push cylinder is provided at one end of the base, and a first guide rail is provided at the bottom of the base. A jacking mechanism, located inside the base, includes a jacking box, a sliding seat, and a lifting seat. The lower part of the jacking box has a first slider slidably connected to a first guide rail, and several vertical straight guide grooves are provided on both sides of the jacking box. The upper part of the jacking box has a second guide rail. The sliding seat is slidably connected to the second guide rail via a second slider. The sliding seat has inner support plates on both sides, connected by ribs. The piston rod end of the first jacking cylinder is connected to the ribs. At least one support shaft is provided on one side of each inner support plate. An outer support plate is fixedly connected to each side of the sliding seat, with the fixed plate located between the inner and outer support plates. One end of the support shaft is mounted on the inner support plate, and the other end is mounted on the outer support plate. The lower part of the lifting seat is fixedly connected to several guide columns. The lower end of the guide columns extends into the push box and is clearance-fitted with the push box. The lower ends of the multiple guide columns are connected by a connecting plate. Guide rods are fixedly connected to both sides of the connecting plate. The guide rods pass through the straight guide groove and are located in the contour guide groove. In the initial state, the guide rods are located in the middle of the vertical section on the side where the first push cylinder of the contour guide groove is located. The lower part of the lifting seat is provided with a fixing plate. The fixing plate is provided with at least one inclined guide groove, and the support shaft is located inside the inclined guide groove.

2. The steel box girder jacking device according to claim 1, characterized in that, The upper part of the lifting seat is provided with several pads for adjusting the height between the lifting seat and the bottom of the steel box girder, so that the vertical lifting height of the lifting seat is greater than the height between it and the bottom of the steel box girder; the upper part of the lifting seat and the pads are provided with several positioning grooves, and the lower part of the pads is provided with positioning columns that engage with the positioning grooves.

3. The steel box girder jacking device according to claim 1, characterized in that, A level is provided on both sides of the fixed base.

4. A steel box girder jacking device according to claim 1, characterized in that, The contour guide groove is a spiral structure or an isosceles trapezoidal structure with an upper base length greater than the lower base length.

5. A steel box girder jacking device according to claim 1, characterized in that, A spring is fitted around the outside of the guide column. The lower end of the spring is connected to the connecting plate, and the upper end of the spring is connected to the upper wall of the push box. When the guide rod is located in the middle of the vertical section of the contour guide groove, the spring is in a balanced state. When the guide rod is located in the lower horizontal section of the contour guide groove, the spring is in a stretched state. When the guide rod is located in the upper horizontal section of the contour guide groove, the spring is in a compressed state.

6. A steel box girder jacking device according to claim 1, characterized in that, A limiting mechanism is provided on one side of the base. The limiting mechanism includes guide sleeves fixedly installed at both ends of the base. A limiting arm is slidably connected inside the guide sleeve. The upper end of the limiting arm abuts against the outer wall of the steel box girder to limit the movement direction of the steel box girder. Each end of the guide sleeve is provided with a threaded hole. A locking screw is threadedly connected to the threaded hole near the end of the limiting arm to lock the limiting arm after the position of the limiting arm is adjusted. A handwheel is provided at one end of the locking screw.

7. A steel box girder jacking device according to claim 6, characterized in that, The end of the guide rod is rotatably connected to a first guide wheel, the support shaft is rotatably connected to a second guide wheel, and the end of the limiting arm is rotatably connected to a third guide wheel.

8. A steel box girder jacking device according to claim 1, characterized in that, The fixed base has side plates on both sides, and a correction mechanism is provided on the side plates. The correction mechanism includes a correction cylinder, the cylinder seat of the correction cylinder is pivotally connected to the side plate, and the piston rod of the correction cylinder is pivotally connected to the base. A rotating shaft is rotatably connected to the fixed base, and the upper end of the rotating shaft is fixedly connected to the base through a flange. Two sets of arc-shaped guide rails are symmetrically installed on both sides of the fixed base, and an arc-shaped slider that slides with the arc-shaped guide rails is fixedly connected to the lower part of the base.

9. A steel box girder jacking device according to any one of claims 1-8, characterized in that, The jacking mechanism is provided in two sets, which are arranged in a straight line along the jacking direction within the base. A second jacking cylinder is provided at the other end of the base. The piston rod end of the second jacking cylinder is connected to the stiffening plate of another sliding seat. The first and second jacking cylinders extend or retract synchronously. In the initial state, the guide rod of the left jacking mechanism is located in the middle of the left vertical section of the contour guide groove, and the guide rod of the right jacking mechanism is located in the middle of the right vertical section of the contour guide groove. The two sets of jacking mechanisms alternately jack the steel box girder.

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