CN116289509B - Multistage limiting-self-resetting element for full-assembled bridge of swinging bearing platform - Google Patents

Abstract

The multistage limiting-self-resetting element for the full-assembled bridge of the swinging bearing platform comprises a lower box body and an upper box body, wherein the top surface of the lower box body is transparent, the bottom surface of the upper box body is transparent, and the bottom end of the upper box body is inserted into the lower box body; an inner box body is arranged in the lower box body, the inner box body is transparent up and down, the bottom end of the inner box body is fixedly connected with the bottom surface of the inner cavity of the lower box body, a containing groove is formed between the side wall of the lower box body and the side wall of the inner box body, and the side wall of the upper box body extends into the containing groove; a plurality of breakable bearing pieces are arranged in the accommodating groove along the circumferential direction, and the bottom end surface of the upper box body is abutted to the top surfaces of the breakable bearing pieces; the inner box body is internally provided with a multistage elastic mechanism, the top end of the multistage elastic mechanism is fixedly connected with the top surface of the inner cavity of the upper box body, and the bottom end of the multistage elastic mechanism is fixedly connected with the bottom surface of the inner cavity of the lower box body. The invention fully utilizes the structural characteristics of the fully assembled bridge of the swinging bearing platform, organically combines a plurality of breakable bearing pieces with the elastic structure, further realizes the limit and self-resetting requirements of the swinging bridge under different earthquake grades, and improves the earthquake-resistant toughness.

Description

A multi-level limit-self-returning component for fully assembled bridges with swing caps

Technical field

The invention relates to the technical fields of bridge engineering and earthquake engineering, and in particular to a multi-level limiting-self-returning element for a fully assembled bridge with a swing cap.

Background technique

In recent years, the international community has proposed the concept of urban seismic resilience to reduce post-earthquake repair costs in response to problems such as the difficulty, long time, and huge social costs of urban post-earthquake reconstruction. As an important node of urban transportation, bridges are an important part of the city's earthquake resilience. Therefore, the development of bridge seismic resilience technology is crucial to improving the seismic resilience of the entire urban system. The seismic performance of prefabricated bridges is the key to restricting their promotion and use in strong earthquake areas. In this regard, some experts and scholars have proposed a rocking bridge system that achieves low post-earthquake damage and rapid repair through rocking self-returning to improve the seismic toughness of prefabricated bridges. The existing swing bridge system mainly includes two forms: swing foundation and swing pier. The swing foundation structure will cause post-earthquake residual deformation of the bridge structure due to soil deformation, affecting the post-earthquake recovery performance of the bridge; the swing pier structure has opening and closing interface dimensions. Smaller, it affects the layout and deformation of energy-consuming components, resulting in lower energy-consuming efficiency.

In order to solve the problem that the form of the existing swing bridge system is difficult to meet the major demand for seismic toughness of urban bridges, as well as the shortcomings of the swing cap being large and overweight, a swing bridge structural system based on a separate swing cap was developed. This system The swing bearing platform is divided into upper and lower bearing platforms to reduce the weight of the overall bearing platform and facilitate transportation and assembly. The bridge structure system with separate rocking caps can achieve self-returning of the rocking under earthquake action through the rocking of the caps, reducing seismic damage and improving seismic toughness. The bridge structure system with separate swing caps has a larger swing space between the upper and lower caps, and a larger allowable swing amplitude under earthquake action. The existing self-resetting method based on prestressed steel bars or other single reset elements cannot meet the corresponding self-returning requirements. Reset required. Moreover, the existing swing bridge structure realizes the self-reset function through a single self-reset element, which cannot meet the different self-reset requirements of the swing bridge under different earthquake levels. In addition, excessive sway of the bridge piers may lead to bridge damage such as falling beams and overturning. It is necessary to take into account the maximum allowable sway angle while giving full play to the role of the sway bridge system, and impose necessary restrictions on the sway process.

Contents of the invention

The purpose of the present invention is to provide a multi-level limiting-self-returning element for a fully assembled bridge with a swing bearing platform, so as to solve the above-mentioned problems existing in the prior art.

A multi-level limiting-self-returning element for a fully assembled bridge with a swinging platform, which is installed between the upper and lower supporting platforms of the swinging platform and includes a lower box body and an upper box body. The top surface of the lower box body Transparent, the bottom surface of the upper box is transparent, the height of the lower box is smaller than the height of the upper box, and the length and width of the upper box are smaller than the length and width of the lower box; The bottom end of the upper box body is inserted into the lower box body from top to bottom; the lower box body is also provided with an inner box body, the inner box body is transparent up and down, and the bottom end surface is in contact with the lower box body The bottom surface of the inner cavity is fixedly connected, the top surface of the inner box body is flush with the top surface of the lower box body, and a receiving groove is formed between the side wall of the lower box body and the side wall of the inner box body. , the side wall of the upper box extends into the accommodating groove; a plurality of breakable bearing members are provided in the accommodating groove along the circumferential direction, and the bottom end surface of the upper box abuts on several of the breakable bearing members. The top surface of the broken bearing member; the inner box body is also provided with a multi-level elastic mechanism, the top end of the multi-level elastic mechanism is fixedly connected to the top surface of the inner cavity of the upper box body, and the bottom surface is connected to the inner cavity top surface of the lower box body. The bottom surface of the inner cavity is fixed.

Preferably, the breakable bearing member includes a shear key arranged horizontally in the receiving groove, the shear key is perpendicular to the side of the lower box, and the side wall of the lower box is in contact with the shear key. A first rectangular pin hole is provided at a position corresponding to the force key, and a second rectangular pin hole is provided on the side wall of the inner box at a position corresponding to the shear key, and the second rectangular pin hole is in contact with the corresponding The first rectangular pin hole is arranged coaxially; the shear force key is disposed in the first rectangular pin hole and the second rectangular pin hole; the bottom end surface of the upper box body abuts on a plurality of the shear force keys; The top surface of the force key.

Preferably, the multi-level elastic mechanism includes a rubber block fixed in the middle of the bottom surface of the inner cavity of the lower box. Several first-level self-returning springs are vertically penetrated in the rubber block. The springs are arranged at equal intervals along the long central axis of the rubber block. The top end of the first-level self-returning spring is fixedly connected to the top surface of the inner cavity of the upper box body. The bottom end of the first-level self-returning spring is connected to the top surface of the inner cavity of the upper box body. The bottom surface of the inner cavity of the lower box body is fixed; several secondary self-returning springs are symmetrically and vertically penetrated in the rubber block on both sides of the long central axis; the bottom end of the secondary self-returning spring is connected to the The bottom surface of the inner cavity of the lower box is fixed and the top is suspended; the height of the secondary self-returning spring is smaller than the height of the primary self-returning spring, and the height of the rubber block is smaller than the height of the secondary self-returning spring. , the height of the upper box body is smaller than the height of the rubber block.

Preferably, the bottom end surface of the upper box body is symmetrically extended to both sides to form a first flange, the top end of the lower box body is extended toward the direction of the receiving groove and is formed with a second flange, and the inner box is The top end of the body extends in the direction of the receiving groove and is formed with a third flange. The distance from the second flange to the third flange is greater than the thickness of the side wall of the upper box body. The width of a flange is smaller than the width of the receiving groove and larger than the distance between the second flange and the third flange.

Preferably, the top surface of the upper box body is provided with several top peg holes, and the bottom surface of the lower box body is provided with several bottom peg holes.

The invention discloses the following technical effects:

1. The present invention can cooperate with prestressed tendons to provide self-returning performance for the separated swing cap bridge structural system; through the effective combination of different components, step limiting and self-returning elements are formed; multi-level limiting elements-self-returning elements are both It can limit the swing amplitude of the bridge under different earthquake levels, and can provide different self-returning forces for bridge piers with different swing amplitudes; the organic combination of multi-level limiting and self-resetting can realize the separation of the swing cap bridge structural system in different Multi-level self-resetting requirements under earthquake levels.

2. The present invention is an independent body and has little impact on the main structure of the bridge during operation. By providing self-resetting capabilities for the swing bridge, it can reduce the damage and residual displacement of the bridge structure under earthquakes and improve the seismic toughness of the bridge; and Compared with the traditional limiting form, the present invention can also achieve graded damage targets of the bridge structure under different earthquakes, ensuring that the bridge structure reaches corresponding toughness levels under different earthquake fortification targets.

3. The present invention innovatively integrates the two functions of providing multi-level self-returning force and multi-level limiting into one, which is conducive to simplifying the design, saving space, thereby reducing the difficulty of construction and reducing the cost; at the same time, the layout of this component can also It restrains the lateral sliding of the separated platform and improves the lateral stability of the swing platform; in addition, the box structure of the present invention can provide better protection for the internal multi-level elastic mechanism to avoid premature failure of components during normal use, such as Aging of rubber, corrosion of steel, etc.

4. The present invention can be prefabricated in the factory and installed at the construction site, and is simply connected to the separate swing cap, easy to construct, and can achieve rapid installation, meeting the major demand for "quick construction" in urban bridge construction; in addition, this invention The invention is easy to monitor and replace. Generally, it can be quickly replaced after an earthquake and the replacement cost is low. It ensures the rapid repair of bridges after earthquakes, greatly reduces the total cost of post-earthquake repairs, and improves the overall seismic resilience of the transportation network.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the drawings of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic diagram of the connection between the present invention and the upper platform and the lower platform;

Figure 2 is a schematic diagram of the three-dimensional structure of the present invention;

Figure 3 is a three-dimensional cross-sectional schematic diagram of the present invention;

Figure 4 is a schematic cross-sectional view of the present invention;

Figure 5 is a schematic structural diagram of the upper box body of the present invention;

Figure 6 is a schematic structural diagram of the lower box body of the present invention;

Figure 7 is a schematic diagram of the working state changes of the present invention when it is pressed under earthquake action;

Figure 8 is a schematic diagram of the working state of the present invention under tension under earthquake action;

Figure 9 is a schematic diagram of the mechanical model of the present invention;

Figure 10 is a schematic diagram of the multi-stage failure mode and toughness guarantee mechanism provided by the present invention for a fully assembled bridge with a swing cap.

in:

1. Shear key; 2. Primary self-returning spring; 3. Secondary self-returning spring; 4. Rubber block; 5. Lower box; 6. Upper box; 7. Inner box; 8. Accommodating groove; 9. First rectangular pin hole; 10. Second rectangular pin hole; 11. First flange; 12. Second flange; 13. Third flange; 14. Top peg hole; 15. Bottom peg hole ; 16. Upper platform; 17. Lower platform.

Implementation

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Referring to Figures 1-10, a multi-level limiting-self-returning element for a fully assembled bridge with a swinging platform is installed between the upper and lower supporting platforms of the swinging platform, including a lower box body 5 and an upper box body 6 , the top surface of the lower box 5 is transparent, the bottom surface of the upper box 6 is transparent, the height of the lower box 5 is smaller than the height of the upper box 6, and the length and width of the upper box 6 are both smaller than the length of the lower box 5 and width; the bottom end of the upper box body 6 is inserted into the lower box body 5 from top to bottom; the lower box body 5 is also provided with an inner box body 7, the inner box body 7 is transparent up and down, and the bottom end surface is in contact with the lower box body 5 The bottom surface of the inner cavity is fixedly connected. The top surface of the inner box 7 is flush with the top surface of the lower box 5. A receiving groove 8 is formed between the side wall of the lower box 5 and the side wall of the inner box 7. The upper box The side walls of the body 6 extend into the accommodating groove 8; a number of breakable load-bearing parts are arranged in the accommodating groove 8 along the circumferential direction, and the bottom end surface of the upper box body 6 abuts against the top surfaces of several breakable load-bearing parts; the inner box The body 7 is also provided with a multi-level elastic mechanism. The top end of the multi-level elastic mechanism is fixed to the top surface of the inner cavity of the upper box body 6 and the bottom surface is fixed to the bottom surface of the inner cavity of the lower box body 5 .

The swing platform includes two parts: an upper platform 16 and a lower platform 17. The present invention is installed between the upper platform 16 and the lower platform 17; the lengths of the lower box 5 and the upper box 6 can be determined according to the actual platform 16 The bottom surface of the lower box body 5 is fixedly connected to the top surface of the lower platform 17, and the top surface of the upper box body 6 is fixedly connected to the bottom surface of the upper platform 16; the inner box The bottom end surface of the body 7 can be welded to the bottom surface of the inner cavity of the lower box body 5. The four sides of the inner box body 7 are parallel to the four sides of the lower box body 5. The four sides of the upper box body 6 are also parallel to the lower box. The four sides of the body 5; the bottom end of the upper box body 6 extends into the receiving groove 8 from top to bottom, and the breakable bearing member is arranged at half the height of the side wall of the lower box body 5.

The breakable load-bearing part can withstand a certain weight, and will break when the weight it bears exceeds a certain value; the upper platform 16 and part of the weight above it are pressed on several breakable load-bearing parts through the upper box body 6, and several breakable load-bearing parts The breakable load-bearing members can withstand a certain load. When an earthquake occurs, the entire bridge will sway, resulting in uneven stress on the breakable load-bearing members, or the maximum load acting on the breakable load-bearing members exceeds the limit that they can withstand, resulting in The breakable load-bearing member breaks, and the breakable load-bearing member stops working, so the upper box body 6 will continue to move downward, and the multi-level elastic mechanism continues to work. The multi-level elastic force mechanism can provide elastic support to the upper box body 6 in levels, and the upper box body 6 will continue to move downward. The further the body 6 moves downward, the greater the elastic force provided by the multi-level elastic mechanism, realizing the step-by-step limiting function under the action of earthquakes, thereby allowing the upper cap platform 16 to quickly reset under the action of elastic force, so as to achieve the multi-stage structure of the bridge structure system. The purpose of damage and graded protection; if the swing amplitude is relatively large and the multi-level elastic mechanism is not enough to support it, the bottom end surface of the upper box body 6 will contact the bottom surface of the inner cavity of the lower box body 5. At this time, it is the limit limit, and the upper The box body 6 will no longer slide downward, preventing the bridge from collapsing due to excessive swing; when under tension, the multi-level elastic mechanism can also provide tension for self-resetting.

To further optimize the solution, the breakable load-bearing member includes a shear key 1 arranged horizontally in the receiving groove 8. The shear key 1 is perpendicular to the side of the lower box 5. The side wall of the lower box 5 is at a position corresponding to the shear key 1. A first rectangular pin hole 9 is opened, and a second rectangular pin hole 10 is opened on the side wall of the inner box 7 at a position corresponding to the shear key 1. The second rectangular pin hole 10 is coaxial with the corresponding first rectangular pin hole 9. The shear key 1 is installed in the first rectangular pin hole 9 and the second rectangular pin hole 10; the bottom end surface of the upper box 6 is in contact with the top surface of several shear keys 1.

The shear key 1 is located at half the height of the side wall of the lower box 5. The shear key 1 has a rectangular parallelepiped structure and can be just inserted into the first rectangular pin hole 9 and the second rectangular pin hole 10. The shear key 1 The length is greater than the distance between the side wall of the lower box 5 and the side wall of the inner box 7. The first rectangular pin hole 9 and the second rectangular pin hole 10 have the same size and shape and are adapted to the cross-sectional shape of the shear key 1. The force key 1 is supported by the side walls of the lower box 5 and the inner box 7. The downward pressure of the upper box 6 acts on the top surface of the shear key 1. When the pressure exceeds the limit that the shear key 1 can withstand, , the shear key 1 breaks, and the upper box body 6 continues to move downward. At this time, the multi-level elastic mechanism provides elastic force for reset.

To further optimize the solution, the multi-level elastic mechanism includes a rubber block 4 fixed in the middle of the bottom surface of the inner cavity of the lower box body 5. There are several first-level self-returning springs 2 vertically penetrated in the rubber block 4. Several first-level self-returning springs 2 are installed along the The long central axes of the rubber blocks 4 are arranged at equal intervals. The top end of the first-level self-returning spring 2 is fixedly connected to the top surface of the inner cavity of the upper box body 6. The bottom end of the first-level self-returning spring 2 is connected to the inner cavity of the lower box body 5. The bottom surface is fixed; several secondary self-returning springs 3 are provided symmetrically and vertically in the rubber block 4 on both sides of the long central axis; the bottom end of the secondary self-returning spring 3 is fixed to the bottom surface of the inner cavity of the lower box body 5 connected and the top is suspended; the height of the secondary self-returning spring 3 is less than the height of the primary self-returning spring 2, the height of the rubber block 4 is less than the height of the secondary self-returning spring 3, the height of the upper box body 6 is less than the height of the rubber block 4 .

The rubber block 4 can be bonded to the bottom surface of the inner cavity of the lower box body 5 and is located in the inner box body 7; the bottom end of the primary self-returning spring 2 is welded to the bottom surface of the inner cavity of the lower box body 5, and the top end is welded to the top surface of the inner cavity of the upper box body 6 Welding, the axes of all primary self-returning springs 2 are located in the same vertical plane, several secondary self-returning springs 3 are symmetrically arranged on both sides of the vertical plane, and the secondary self-returning springs 3 on the same side are also located in the same vertical plane The bottom end of the secondary self-returning spring 3 is welded to the bottom surface of the inner cavity of the lower box body 5; when the bottom end surface of the upper box body 6 is in contact with the top surface of the shear key 1 , the first-level self-returning spring 2 is exactly at its original length. When the shear key 1 breaks, the upper box body 6 slides downward. First, the first-level self-returning spring 2 is compressed. The first-level self-returning spring 2 provides upward elastic force, and the upper box body 6 slides downward. The body 6 continues to slide downward and contacts the secondary self-returning spring 3 and compresses it. At this time, the primary self-returning spring 2 and the secondary self-returning spring 3 provide upward elastic force at the same time, and the upper box body 6 continues When it slides down, it will come into contact with the rubber block 4 and compress it. At this time, the first-level self-returning spring 2, the second-level self-returning spring 3 and the rubber block 4 jointly provide upward elastic force to reset the upper box body 6, and then Reset the upper platform 16; if the upper box body 6 still slides downward, then the bottom end surface of the upper box body 6 will finally contact the bottom surface of the inner cavity of the lower box body 5, reaching the extreme sliding position, and the upper box body 6 will It will no longer slide down to prevent the bridge body from swinging too much and causing collapse; when the bridge body swings, the upper box body 6 will not only slide downwards, but also slide upwards in a reciprocating motion, so when the bottom end surface of the upper box body 6 moves When it is above the shear key 1, the first-level self-returning spring 2 will provide downward pulling force to achieve quick reset.

In a further optimized solution, the bottom end of the upper box 6 is symmetrically formed with first flanges 11 extending to both sides, the top of the lower box 5 is extended in the direction of the receiving groove 8 and is formed with a second flange 12, and the inner box 7 The top end of the top extends in the direction of the receiving groove 8 and is formed with a third flange 13. The distance between the second flange 12 and the third flange 13 is greater than the thickness of the side wall of the upper box 6, and the width of the first flange 11 It is smaller than the width of the receiving groove 8 and larger than the distance between the second flange 12 and the third flange 13 .

Under normal circumstances, the bottom end surface of the upper box body 6 will move up and down in the accommodating groove 8. If the vibration amplitude is too large, the bottom end surface of the upper box body 6 may be separated from the accommodating groove 8. In order to prevent this from happening, the second The first flange 11, the second flange 12, and the third flange 13 provide a good guarantee. When the upper box body 6 continues to move upward, the first flange 11 will interact with the second flange 12 and the third flange 13. The flanges 13 are in contact. Since the width of the first flange 11 is greater than the distance between the second flange 12 and the third flange 13, the first flange 11 will be limited to the second flange 12 and the third flange. 13 below, and will not slide out of the accommodating groove 8, ensuring that the bottom end surface of the upper box body 6 is in the accommodating groove 8 and will not break away from the lower box body 5; because the trajectory of the first flange 11 when swinging is in the plane. Line-based complex spatial curves, therefore in this embodiment, the width of the accommodation groove 8 can be determined by analytical geometry based on the relevant dimensions of the separate platform and the maximum allowable swing angle.

To further optimize the solution, the top surface of the upper box body 6 is provided with several top peg holes 14 , and the bottom surface of the lower box body 5 is provided with several bottom peg holes 15 .

The function of the top bolt hole 14 is to securely connect the upper box body 6 to the steel plate embedded in the bottom surface of the upper platform 16 through anchor bolts. The function of the bottom bolt hole 15 is to connect the lower box body 5 to the lower platform through anchor bolts. The pre-embedded steel plate on the top surface of platform 17 is fixedly connected.

The working principle is: in normal use or when swaying under small earthquakes, the shear key 1 is used to limit the position, and the elastic deformation of the shear key 1 is used to meet the force requirements; as the earthquake intensifies, the sway amplitude increases, and the compression side The limiting shear key 1 is cut off, and the first-level self-returning spring 2, the second-level self-returning spring 3 and the rubber block 4 are gradually compressed to provide self-returning force; under the action of a huge earthquake, the bottom end surface of the upper box 6 and the lower box The bottom surface of the inner cavity of body 5 contacts the limit limit to prevent collapse caused by excessive swing; when under tension, the first-level self-returning spring 2 stretches to provide self-returning force for the structure. In Figure 7, F ₂ is the first-level self-returning spring 2 F ₃ is the upward elastic force of the secondary self-returning spring 3 to the upper box 6 , F ₄ is the upward elastic force of the rubber block 4 to the upper box 6 , and F ₅ is the upward elastic force of the lower box 6 The supporting force of the upper box body 6. In Figure 8, T ₂ is the downward pulling force of the first-level self-returning spring 2 on the upper box body 6. Based on the stress and failure sequence of each component, a mechanical model of multi-level limiting-self-returning elements can be constructed using a combination of series-parallel springs and failure units, as shown in Figure 9; through the step-by-step limiting of multi-level limiting-self-resetting elements The position and self-resetting realize the toughness requirements of the swing bridge under different earthquake levels, see Figure 10.

In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientations or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or It is implied that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation and is therefore not to be construed as a limitation of the invention.

The above-described embodiments only describe preferred modes of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, those of ordinary skill in the art can make various modifications to the technical solutions of the present invention. All modifications and improvements shall fall within the protection scope determined by the claims of the present invention.

Claims (2)

1. A multistage limiting-self-resetting element for a rocking platform fully assembled bridge, mounted between an upper and a lower platform of the rocking platform, characterized by comprising: the upper box body (5) and the lower box body (6), wherein the top surface of the lower box body (5) is transparent, the bottom surface of the upper box body (6) is transparent, the height of the lower box body (5) is smaller than that of the upper box body (6), and the length and the width of the upper box body (6) are smaller than those of the lower box body (5); the bottom end of the upper box body (6) is inserted into the lower box body (5) from top to bottom; an inner box body (7) is further arranged in the lower box body (5), the inner box body (7) is transparent up and down, the bottom end face of the inner box body is fixedly connected with the bottom face of the inner cavity of the lower box body (5), the top end face of the inner box body (7) is flush with the top end face of the lower box body (5), a containing groove (8) is formed between the side wall of the lower box body (5) and the side wall of the inner box body (7), and the side wall of the upper box body (6) stretches into the containing groove (8); a plurality of breakable bearing pieces are arranged in the accommodating groove (8) along the circumferential direction, and the bottom end surface of the upper box body (6) is abutted to the top surfaces of the breakable bearing pieces; the inner box body (7) is internally provided with a multi-stage elastic mechanism, the top end of the multi-stage elastic mechanism is fixedly connected with the top surface of the inner cavity of the upper box body (6), and the bottom surface of the multi-stage elastic mechanism is fixedly connected with the bottom surface of the inner cavity of the lower box body (5);

the breakable bearing piece comprises a shear key (1) horizontally arranged in the accommodating groove (8), the shear key (1) is perpendicular to the side face of the lower box body (5), a first rectangular pin hole (9) is formed in the position, corresponding to the shear key (1), of the side wall of the lower box body (5), a second rectangular pin hole (10) is formed in the position, corresponding to the shear key (1), of the side wall of the inner box body (7), and the second rectangular pin hole (10) and the corresponding first rectangular pin hole (9) are coaxially arranged; the shear key (1) is arranged in the first rectangular pin hole (9) and the second rectangular pin hole (10) in a penetrating mode; the bottom end surface of the upper box body (6) is abutted against the top surfaces of the shear keys (1);

the multistage elastic mechanism comprises a rubber block (4) fixedly connected to the middle of the bottom surface of the inner cavity of the lower box body (5), a plurality of primary self-resetting springs (2) vertically penetrate through the rubber block (4), the primary self-resetting springs (2) are distributed at equal intervals along the long central axis of the rubber block (4), the top end of each primary self-resetting spring (2) is fixedly connected with the top surface of the inner cavity of the upper box body (6), and the bottom end of each primary self-resetting spring (2) is fixedly connected with the bottom surface of the inner cavity of the lower box body (5); a plurality of secondary self-resetting springs (3) are symmetrically and vertically arranged on two sides of the long central axis in the rubber block (4) in a penetrating way; the bottom end of the secondary self-resetting spring (3) is fixedly connected with the bottom surface of the inner cavity of the lower box body (5) and the top end of the secondary self-resetting spring is suspended in the air; the height of the secondary self-resetting spring (3) is smaller than that of the primary self-resetting spring (2), the height of the rubber block (4) is smaller than that of the secondary self-resetting spring (3), and the height of the upper box body (6) is smaller than that of the rubber block (4);

the bottom end face symmetry of last box body (6) extends to both sides and is formed with first edge of a wing (11), the top of lower box body (5) is towards the direction extension of holding tank (8) and is formed with second edge of a wing (12), the top of interior box body (7) is towards the direction extension of holding tank (8) and is formed with third edge of a wing (13), second edge of a wing (12) to distance between third edge of a wing (13) is greater than the lateral wall thickness of last box body (6), the width of first edge of a wing (11) is less than the width of holding tank (8) and is greater than second edge of a wing (12) to distance between third edge of a wing (13).

2. A multistage limit-self-resetting element for a rocking platform fully assembled bridge according to claim 1, characterized in that: the top surface of the upper box body (6) is provided with a plurality of top bolt holes (14), and the bottom surface of the lower box body (5) is provided with a plurality of bottom bolt holes (15).