Multi-degree-of-freedom temporary limiting device for bridge structure water transportation

Abstract

The invention provides a multi-degree-of-freedom temporary limiting device for bridge structure water transportation, which comprises a steel cylindrical main support, four telescopic elastic main supports, four telescopic elastic inclined supports, a steel top plate, a steel base and a rubber pad, the steel cylindrical main support, the steel base and the steel top plate support a bridge structure; lateral displacement of the bridge structure in the horizontal direction is limited through the telescopic elastic inclined supports, the ship deck is tightly attached to the steel base through the steel base, the bridge structure is tightly connected with the steel top plate through the steel top plate, and buffering and damping of the bridge structure and lateral displacement of the bridge structure in the horizontal direction are achieved through the rubber pads. The fixing device has the beneficial effects that the requirement for firmly fixing the ultra-large bridge structure on a ship is met, meanwhile, the fixing device has the characteristic of being easy to mount and dismount, and a safety guarantee is provided for ship transportation of the ultra-large bridge structure.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering, and in particular relates to a multi-degree-of-freedom temporary limiting device for water transportation of bridge structures. Background Art

[0002] Temporary limiting devices are core equipment to ensure the safety of bridge structures in water transportation. During transportation, the bridge structure is affected by complex environmental factors such as water turbulence, wind and wave intensity, and tidal changes. It will continue to bear multi-directional dynamic loads, which can easily cause structural deformation and slippage. To address this technical problem, this device achieves double protection through innovative structural design: its main support adopts a spring-hydraulic composite mechanism, which can dynamically adjust the vertical elevation of the bridge structure according to the real-time ups and downs of the ship, effectively absorbing and buffering the vertical vibration energy generated by wave impact. Synchronously, the configured oblique support system can form a multi-directional constraint network in the horizontal plane through a preset angle tensioning mechanism, accurately suppressing the lateral displacement of the bridge structure. This collaborative working mechanism solves the problem of multi-directional slippage of the bridge structure during transportation, ensuring that large bridge components are within a controllable deformation range from departure to placement.

[0003] The current temporary limit devices used for water transportation of bridge structures have the following problems:

[0004] Current bridge structure fastening methods for water transport are generally subject to the risk of restraint failure. Conventional rope lashing schemes, for example, rely solely on multi-directional cables for basic connection and fixation between the bridge and the ship. During actual navigation, ships are subject to the combined effects of multiple factors, including crosswind disturbances, wave impacts, and tidal surges, resulting in complex motion patterns including sway and pitch. However, rope restraint systems are unable to offset the inertial forces caused by the multi-directional deformation of the hull, leading to continuous relative slip between the bridge and the supporting platform. This structural slip not only accelerates wear and aging of the connection nodes but also poses a risk of structural collision during sudden wind and wave events. Alternatively, arrays of rigid support blocks are currently used as bridge support foundations. While this rigid contact design provides static load support, it cannot adapt to the dynamic response of a ship heaving in waves. When the hull undergoes periodic vertical displacement due to slip motion, intermittent contact failure between the fixed support blocks and the bridge bottom surface occurs, forcing the structure to withstand impact forces under gravity loads. This dynamic impact load can cause hidden damage such as microcracks in local support areas due to sudden changes in stress amplitude, seriously threatening the transportation safety of long-span bridge components. Overall, there is an urgent need for a temporary limiter that can adapt to the complex environment on water and has multi-degree-of-freedom adjustment capabilities to ensure the safety and stability of bridge structures during water transportation. Summary of the Invention

[0005] In view of this, the present invention aims to propose a multi-degree-of-freedom temporary limiting device for water transportation of bridge structures, so as to solve the problem that the risk of constraint failure is prevalent in the current fixing process of water transportation of bridge structures.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A multi-degree-of-freedom temporary limiting device for water transportation of bridge structures, comprising a steel cylindrical main support, four telescopic elastic main supports, four telescopic elastic oblique supports, a steel top plate, a steel base and a rubber pad;

[0008] The steel top plate and the steel base are both rectangular parallelepipeds, and the steel top plate is located directly above the steel base. The top of the steel cylindrical main support is connected to the geometric center of the bottom of the steel top plate, and its bottom is connected to the geometric center of the top of the steel base. The steel cylindrical main support is perpendicular to the steel top plate and the steel base.

[0009] One end of the four telescopic elastic main supports is respectively connected to the four corners of the bottom of the steel top plate, and the other end is connected to the steel base. The four telescopic elastic main supports are perpendicular to the steel top plate and the steel base;

[0010] One end of the four telescopic elastic oblique supports is respectively connected to the four midpoints of the four sides of the rectangular bottom of the steel top plate, and the other end is connected to the steel base. The four telescopic elastic oblique supports are all at an obtuse angle to the steel top plate and an acute angle to the steel base.

[0011] A rubber pad is installed on the top of the steel top plate.

[0012] Furthermore, the top of the steel cylindrical main support is welded to the center of the bottom of the steel top plate, and is also welded to the center of the top of the steel base.

[0013] Furthermore, the telescopic elastic main support includes a telescopic rod, a telescopic sleeve, a spring, a connecting steel bottom plate, a connecting steel top plate, high-strength bolts for connecting the steel top plate and high-strength bolts for connecting the steel bottom plate. A spring is installed inside the telescopic sleeve, and the spring is connected to the telescopic rod. The telescopic rod is embedded in the telescopic sleeve. The top of the telescopic rod is welded to the connecting steel top plate, and the bottom of the telescopic sleeve is welded to the connecting steel bottom plate. The connecting steel top plate is installed with high-strength bolts for connecting the steel top plate, and the connecting steel bottom plate is installed with high-strength bolts for connecting the steel bottom plate.

[0014] Furthermore, the connecting steel top plate is connected to the steel top plate by connecting steel top plate high-strength bolts, and the connecting steel bottom plate is connected to the steel base by connecting steel bottom plate high-strength bolts.

[0015] Furthermore, the telescopic elastic oblique support includes a telescopic sleeve 2, a telescopic rod 2, a telescopic sleeve 3, a fixer, a pin, a spring 2 and a spring 3. The spring 2 is installed inside the telescopic sleeve 2, one end of the telescopic rod 2 is embedded in the telescopic sleeve 2, and one end of the telescopic rod 2 is connected to the spring 2. The spring 3 is installed inside the telescopic sleeve 3, the other end of the telescopic rod 2 is embedded in the telescopic sleeve 3, and the other end of the telescopic rod 2 is connected to the spring 3. The telescopic sleeve 2 and the telescopic sleeve 3 are both connected to the fixer through a pin.

[0016] Furthermore, the steel base is connected to the ship deck with bolts.

[0017] Furthermore, the steel top plate is connected to the bridge structure with bolts.

[0018] Furthermore, the rubber pad is made of rubber or polyurethane material and is located between the bridge structure and the steel top plate.

[0019] Compared with the prior art, the multi-degree-of-freedom temporary limiting device for water transportation of bridge structures described in the present invention has the following advantages:

[0020] (1) A multi-degree-of-freedom temporary limiter for bridge structure water transportation, which achieves flexible adjustment in multiple dimensions with its unique structural design, and fully considers the convenience and safety of operation in its design;

[0021] (2) The steel cylindrical main support, the telescopic elastic main support and the telescopic elastic diagonal support cooperate with each other to dynamically respond to the displacement and sway of the ship in real time, and use the elastic deformation of the spring to absorb impact energy and buffer shock. The bridge structure can be fully adjusted in the horizontal, longitudinal, vertical and rotational directions, significantly enhancing the protection of the bridge structure in harsh water environments;

[0022] (3) The telescopic elastic main support can accurately adjust the vertical position of the bridge structure according to the ups and downs of the ship through the internal spring and the hydraulic lifting column, while buffering the vertical impact force; the telescopic elastic diagonal support is symmetrically installed in the center of the four sides of the steel base, which can effectively limit the lateral displacement of the bridge structure in the horizontal direction, and the pin connection between its sleeve and the fixer allows rotation around the pin, which can flexibly adapt to different stress conditions and reduce the bending moment of the connection part;

[0023] (4) The surface of the steel base is equipped with numerous bolt holes, which fit tightly against the ship's deck by tightening the bolts, ensuring a secure installation of the device on the ship. At the same time, the large steel base combined with the anti-slip design effectively increases the friction with the deck, preventing the device from shifting when the ship shakes, greatly improving its adaptability to complex working conditions. Compared with traditional limit methods, the flexibility and accuracy of adjustment are greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 Shown is a schematic diagram of the overall structure of an embodiment of the present invention;

[0026] Figure 2 Shown are three schematic views of the overall structure according to an embodiment of the present invention;

[0027] Figure 3 FIG2 is a schematic diagram of the overall structure according to an embodiment of the present invention from another perspective;

[0028] Figure 4 The figure shows a schematic diagram of a telescopic elastic main support structure according to an embodiment of the present invention;

[0029] Figure 5 The figure shows a cross-sectional schematic diagram of the telescopic elastic main support according to an embodiment of the present invention;

[0030] Figure 6 Shown are three schematic views of the telescopic elastic main support according to an embodiment of the present invention;

[0031] Figure 7 FIG2 is a schematic diagram of a telescopic elastic oblique support structure according to an embodiment of the present invention;

[0032] Figure 8 FIG2 is a cross-sectional schematic diagram of a telescopic elastic oblique support according to an embodiment of the present invention;

[0033] Figure 9 Shown are three schematic views of the telescopic elastic oblique support according to an embodiment of the present invention.

[0034] Description of reference numerals:

[0035] 1. Steel cylindrical main support; 2. Telescopic elastic main support; 3. Telescopic elastic oblique support; 4. Steel base; 5. Steel top plate; 6. Rubber pad; 7. Telescopic rod one; 8. Telescopic sleeve one; 9. Spring one; 10. Connecting steel bottom plate; 11. Connecting steel top plate; 12. High-strength bolts connecting steel top plate; 13. High-strength bolts connecting steel bottom plate; 14. Telescopic sleeve two; 15. Telescopic rod two; 16. Telescopic sleeve three; 17. Fixer; 18. Pin; 19. Spring two; 20. Spring three. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0038] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0039] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0040] like Figures 1 to 9 As shown, a multi-degree-of-freedom temporary limiting device for water transportation of bridge structures includes a steel cylindrical main support 1, four telescopic elastic main supports 2, four telescopic elastic inclined supports 3, a steel top plate 5, a steel base 4 and a rubber pad 6.

[0041] The specific implementation is as follows:

[0042] In a preferred embodiment of the present invention, the steel top plate 5 and the steel base 4 are both rectangular parallelepipeds, and the steel top plate 5 is located directly above the steel base 4. The top of the steel cylindrical main support 1 is connected to the geometric center of the bottom of the steel top plate 5, and its bottom is connected to the geometric center of the top of the steel base 4. The steel cylindrical main support 1 is perpendicular to the steel top plate 5 and the steel base 4; one end of the four telescopic elastic main supports 2 is respectively connected to the four corners of the bottom of the steel top plate 5, and the other end is connected to the steel base 4. The four telescopic elastic main supports 2 are perpendicular to the Steel top plate 5 and steel base 4; one end of the four telescopic elastic oblique supports 3 are respectively connected to the four midpoints of the four sides of the bottom rectangle of the steel top plate 5, and the other end is connected to the steel base 4, the four telescopic elastic oblique supports 3 are all obtuse angles with the steel top plate 5, and acute angles with the steel base 4; a rubber pad 6 is installed on the top of the steel top plate 5; the rubber pad 6 is made of rubber or polyurethane material and is located between the bridge structure and the steel top plate 5; the top of the steel cylindrical main support 1 is welded to the center of the bottom of the steel top plate 5, and it is welded to the center of the top of the steel base 4. In this embodiment, the steel cylindrical main support 1, the steel base 4 and the steel top plate 5 are connected into one by welding to support the bridge structure. The four telescopic elastic main supports 2 include telescopic elastic main support 1 2a, telescopic elastic main support 2 2b, telescopic elastic main support 3 2c and telescopic elastic main support 4 2d. The four telescopic elastic main supports 2 provide stable and reliable vertical support for the bridge structure during the entire process of water transportation. The four telescopic elastic diagonal supports 3 include telescopic elastic diagonal support 1 3a, telescopic elastic diagonal support 2 3b, telescopic elastic diagonal support 3 3c and telescopic elastic diagonal support 4 3d. The four telescopic elastic diagonal supports 3 limit the horizontal lateral displacement of the bridge structure, and the rubber pad 6 buffers and dampens the bridge structure and its lateral displacement in the horizontal direction.

[0043] In a preferred embodiment of the present invention, the steel base 4 is bolted to the ship deck, and the steel top plate 5 is bolted to the bridge structure. In this embodiment, bolt holes are provided on the surface of the steel base 4, and the steel base 4 is tightly fitted to the ship deck by tightening the bolts, ensuring a stable installation of the device on the ship. At the same time, the large area of ​​the steel base 4 combined with the anti-slip design effectively increases the friction with the deck, preventing the device from shifting when the ship shakes. Bolt holes are provided on the surface of the steel top plate 5, and the tightening bolts pass through the bolt holes preset in the steel top plate 5 and the bottom of the bridge structure. The bridge structure and the steel top plate 5 are tightly connected by tightening the nuts.

[0044] In a preferred embodiment of the present invention, the telescopic elastic main support 2 includes a telescopic rod 7, a telescopic sleeve 8, a spring 9, a connecting steel bottom plate 10, a connecting steel top plate 11, a connecting steel top plate high-strength bolt 12 and a connecting steel bottom plate high-strength bolt 13. The spring 9 is installed inside the telescopic sleeve 8, and the spring 9 is connected to the telescopic rod 7. The telescopic rod 7 is embedded in the telescopic sleeve 8. The top of the telescopic rod 7 is welded to the connecting steel top plate 11, and the bottom of the telescopic sleeve 8 is welded to the connecting steel bottom plate 10. The connecting steel top plate 11 is installed with the connecting steel top plate high-strength bolt 12, and the connecting steel bottom plate 10 is installed with the connecting steel bottom plate high-strength bolt 13. The connecting steel top plate 11 is connected to the steel top plate 5 through the connecting steel top plate high-strength bolt 12, and the connecting steel bottom plate 10 is connected to the steel base 4 through the connecting steel bottom plate high-strength bolt 13. In this embodiment, the telescopic rod 7 and the spring 9 in the sleeve constitute the main limiting device in the vertical direction. A hollow cylindrical hole is provided inside the telescopic rod 7. The diameter of the cylindrical hole is similar to that of the spring 9. Its design purpose is to effectively limit the displacement of the spring 9 during operation, ensure that the spring 9 is always in the established working position, and stably exert its elastic properties. The telescopic elastic main support 2 cooperates with the hydraulic lifting column through the internal spring 9 to accurately adjust the vertical position of the bridge structure according to the ups and downs of the ship, while buffering the vertical impact force.

[0045] In a preferred embodiment of the present invention, the telescopic elastic oblique support 3 includes a telescopic sleeve 2 14, a telescopic rod 2 15, a telescopic sleeve 3 16, a fixer 17, a pin 18, a spring 2 19 and a spring 3 20. The spring 2 19 is installed inside the telescopic sleeve 2 14, one end of the telescopic rod 2 15 is embedded in the telescopic sleeve 2 14, and one end of the telescopic rod 2 15 is connected to the spring 2 19, the spring 3 20 is installed inside the telescopic sleeve 3 16, the other end of the telescopic rod 2 15 is embedded in the telescopic sleeve 3 16, and the other end of the telescopic rod 2 15 is connected to the spring 3 20, and the telescopic sleeve 2 14 and the telescopic sleeve 3 16 are both connected to the fixer 17 through the pin 18. In this embodiment, the two ends of the telescopic rod 2 15 are respectively combined with the spring 2 19 and the spring 3 20 to form a key limit device in the horizontal direction. The outer wall of the telescopic rod 2 15 is tightly fitted with the inner wall of the telescopic sleeve 2 14 and the telescopic sleeve 3 16. This tightly fitted structural design effectively limits the deviation of the telescopic rod 2 15 during operation, ensuring the stability of its motion trajectory. In addition, a corresponding buckle structure is provided inside the telescopic rod 2 15, the telescopic sleeve 2 14 and the telescopic sleeve 3 16. The buckle structure has been carefully designed to play a reliable locking role when the telescopic rod 2 15 performs telescopic movement, ensuring that the telescopic rod 2 15 will not fall off from the telescopic sleeve, thereby ensuring the stability of the entire The structural integrity and working reliability of the telescopic elastic diagonal support 3 during long-term use provide stable and lasting support for limiting the lateral displacement of the bridge structure in the horizontal direction. The telescopic elastic diagonal support 3 realizes tension and compression under the action of load. The telescopic sleeve 2 14 and telescopic sleeve 3 16 at both ends are tightly connected with the steel top plate 5 and the steel base 4 respectively through the fixer 17, and the sleeve and the fixer 17 are connected by a pin 18. Through this rotational movement around the pin 18, the corresponding bending moment borne by the connection between the sleeve and the fixer 17 can be effectively reduced. The telescopic elastic diagonal support 3 is symmetrically installed in the center of the four sides of the steel base 4 to limit the lateral displacement of the bridge structure in the horizontal direction.

[0046] Advantages and beneficial effects of the present invention:

[0047] (1) A multi-degree-of-freedom temporary limiter for bridge structure water transportation, which achieves flexible adjustment in multiple dimensions with its unique structural design, and fully considers the convenience and safety of operation in its design;

[0048] (2) The steel cylindrical main support, the telescopic elastic main support and the telescopic elastic diagonal support cooperate with each other to dynamically respond to the displacement and sway of the ship in real time, and use the elastic deformation of the spring to absorb impact energy and buffer shock. The bridge structure can be fully adjusted in the horizontal, longitudinal, vertical and rotational directions, significantly enhancing the protection of the bridge structure in harsh water environments;

[0049] (3) The telescopic elastic main support can accurately adjust the vertical position of the bridge structure according to the ups and downs of the ship through the internal spring and the hydraulic lifting column, while buffering the vertical impact force; the telescopic elastic diagonal support is symmetrically installed in the center of the four sides of the steel base, which can effectively limit the lateral displacement of the bridge structure in the horizontal direction, and the pin connection between its sleeve and the fixer allows rotation around the pin, which can flexibly adapt to different stress conditions and reduce the bending moment of the connection part;

[0050] (4) The surface of the steel base is equipped with numerous bolt holes, which fit tightly against the ship's deck by tightening the bolts, ensuring a secure installation of the device on the ship. At the same time, the large steel base combined with the anti-slip design effectively increases the friction with the deck, preventing the device from shifting when the ship shakes, greatly improving its adaptability to complex working conditions. Compared with traditional limit methods, the flexibility and accuracy of adjustment are greatly improved.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-degree-of-freedom temporary limiting device for water transportation of bridge structures, characterized by: It comprises a steel cylindrical main support (1), four telescopic elastic main supports (2), four telescopic elastic oblique supports (3), a steel top plate (5), a steel base (4) and a rubber pad (6); The steel top plate (5) and the steel base (4) are both rectangular parallelepipeds, and the steel top plate (5) is located directly above the steel base (4). The top of the steel cylindrical main support (1) is connected to the geometric center of the bottom of the steel top plate (5), and its bottom is connected to the geometric center of the top of the steel base (4). The steel cylindrical main support (1) is perpendicular to the steel top plate (5) and the steel base (4); One end of the four telescopic elastic main supports (2) is respectively connected to the four corners of the bottom of the steel top plate (5), and the other end is connected to the steel base (4), and the four telescopic elastic main supports (2) are perpendicular to the steel top plate (5) and the steel base (4); One end of the four telescopic elastic oblique supports (3) is respectively connected to the four midpoints of the four sides of the bottom rectangle of the steel top plate (5), and the other end is connected to the steel base (4). The four telescopic elastic oblique supports (3) are all at an obtuse angle with the steel top plate (5) and at an acute angle with the steel base (4); A rubber pad (6) is installed on the top of the steel top plate (5).

2. The multi-degree-of-freedom temporary limiting device for water transportation of bridge structures according to claim 1, characterized in that: The top of the steel cylindrical main support (1) is welded to the center of the bottom of the steel top plate (5), and is also welded to the center of the top of the steel base (4).

3. The multi-degree-of-freedom temporary limiting device for water transportation of bridge structures according to claim 1, characterized in that: The telescopic elastic main support (2) comprises a telescopic rod (7), a telescopic sleeve (8), a spring (9), a connecting steel bottom plate (10), a connecting steel top plate (11), a connecting steel top plate high-strength bolt (12) and a connecting steel bottom plate high-strength bolt (13); the telescopic sleeve (8) is internally installed with a spring (9); the spring (9) is connected to the telescopic rod (7); the telescopic rod (7) is embedded in the telescopic sleeve (8); the top of the telescopic rod (7) is welded to the connecting steel top plate (11); the bottom of the telescopic sleeve (8) is welded to the connecting steel bottom plate (10); the connecting steel top plate (11) is installed with the connecting steel top plate high-strength bolt (12); the connecting steel bottom plate (10) is installed with the connecting steel bottom plate high-strength bolt (13).

4. The multi-degree-of-freedom temporary limiting device for water transportation of bridge structures according to claim 3, characterized in that: The connecting steel top plate (11) is connected to the steel top plate (5) via connecting steel top plate high-strength bolts (12), and the connecting steel bottom plate (10) is connected to the steel base (4) via connecting steel bottom plate high-strength bolts (13).

5. The multi-degree-of-freedom temporary limiting device for water transportation of bridge structures according to claim 1, characterized in that: The telescopic elastic inclined support (3) comprises a telescopic sleeve 2 (14), a telescopic rod 2 (15), a telescopic sleeve 3 (16), a fixer (17), a pin (18), a spring 2 (19) and a spring 3 (20). The spring 2 (19) is installed inside the telescopic sleeve 2 (14). One end of the telescopic rod 2 (15) is embedded in the telescopic sleeve 2 (14), and one end of the telescopic rod 2 (15) is connected to the spring 2 (19). The spring 3 (20) is installed inside the telescopic sleeve 3 (16). The other end of the telescopic rod 2 (15) is embedded in the telescopic sleeve 3 (16), and the other end of the telescopic rod 2 (15) is connected to the spring 3 (20). The telescopic sleeve 2 (14) and the telescopic sleeve 3 (16) are both connected to the fixer (17) through the pin (18).

6. The multi-degree-of-freedom temporary limiting device for water transportation of bridge structures according to claim 1, characterized in that: The steel base (4) is connected to the ship deck with bolts.

7. The multi-degree-of-freedom temporary limiting device for water transportation of bridge structures according to claim 1, characterized in that: The steel top plate (5) is connected to the bridge structure by bolts.

8. The multi-degree-of-freedom temporary limiting device for water transportation of bridge structures according to claim 1, characterized in that: The rubber pad (6) is made of rubber or polyurethane material and is located between the bridge structure and the steel top plate (5).

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