Bridge damping device and construction method thereof

Abstract

The invention discloses a bridge damping device and a construction method thereof, and the device comprises a steel bar, the top end of which is hinged to an upper main beam through an embedded connecting piece, and the bottom end of which is connected to a bridge pier; the damping box is connected to the steel bar in a sleeved mode, and the steel bar is connected with the damping box through a damping spring. Horizontal and vertical displacement, caused by earthquakes or other vibration, of the main beam of the upper structure of the bridge is limited, so that the vibration response of the main beam is reduced, the main beam is prevented from falling, and the damping and falling-preventing effects are achieved.

Description

Technical Field

[0001] The invention belongs to the field of structural shock absorption of bridges, and in particular relates to a bridge shock absorption device and a construction method thereof. Background Art

[0002] my country is located between the two major seismic belts in the world, namely the Pacific Rim and the Eurasian seismic belt, and is a country prone to strong earthquakes. The characteristics of earthquakes in my country are high frequency, high intensity, wide distribution, large casualties, and serious disasters. Almost all provinces, cities, and autonomous regions have experienced destructive earthquakes of magnitude 6 or above. Urban transportation and highways are important channels for disaster relief and mitigation of secondary disasters. The seismic safety of urban and highway bridges is particularly necessary. In the seismic design specifications for bridges, different fortification standards and fortification targets are determined according to the importance and role in earthquake relief and disaster relief, and according to the seismic fortification category of bridges. The seismic fortification target can be summarized as follows: under the action of E1 earthquake, the overall response of the bridge structure is within the elastic range, with basically no damage; under the action of E2 earthquake, the bridge structure will not collapse or cause serious structural damage. Bridges with high seismic fortification categories are allowed to have local damage or limited damage, and can be used to maintain emergency traffic after temporary reinforcement. At the same time, the seismic design specifications for bridges stipulate that seismic measures must be set according to the seismic fortification category.

[0003] There are two main types of structural earthquake-resistant systems currently used at home and abroad.

[0004] One type is a bridge designed for ductile earthquake resistance. By designing reasonable elastic-plastic energy dissipation parts and deformation components, the structural period is extended, the mechanism of dissipating earthquake energy is exerted, and the seismic response of the bridge is reduced. The elastic-plastic energy dissipation parts of this type of earthquake-resistant system are often set on components that are easy to inspect and repair. For example, bridge piers and tie beams are designed as ductile components that allow plastic deformation and energy dissipation. The superstructure, cap beam, support, and foundation are designed as capacity protection components to remain within the elastic range without damage. Figure 1 and Figure 2 As shown in the figure, the shaded area is the appropriate energy dissipation position of the pier column. The plastic hinge should be located at the top or bottom of the pier column, which is the main load-bearing component, and enters plasticity under the action of E2 earthquake.

[0005] However, this type of earthquake-resistant system has the following technical problems: not only can it not effectively reduce the reinforcement ratio of the lower structure, but in order to meet the requirements of the ductility design of the lower structure, the reinforcement ratio is usually relatively high; at the same time, under the action of an E2 earthquake (or an earthquake greater than an E1 earthquake), the pier structure will suffer plastic damage. Although it can prevent collapse in a major earthquake, it is not conducive to rapid post-earthquake repair. In the event of frequent aftershocks after a major earthquake, it is not conducive to the development of earthquake resistance and disaster relief work, and it also causes permanent damage to the bridge structure, reduces the structural durability, and shortens the service life of the bridge.

[0006] The other type is a bridge designed for seismic isolation, which controls displacement and energy consumption by setting seismic isolation bearings or energy dissipation devices, thereby reducing the seismic response of the bridge and keeping the main structure of the bridge within the elastic deformation range under the action of an E2 earthquake. This type of seismic system is mostly used for bridges with special structures, large pier height differences, large slopes and curvatures, and uneven stiffness and strength distribution, and uses seismic isolation bearings, shock absorbers, dampers and other devices.

[0007] However, bridges designed for seismic isolation also have technical problems: currently common seismic isolation bearings, shock absorbers, dampers and other devices are relatively expensive, require regular inspection and maintenance, have high manufacturing costs, are less economical, and require special designs based on the specific parameters of the seismic isolation devices, resulting in large differences in seismic isolation performance.

[0008] my country's current "Urban Bridge Seismic Code" and "Highway Bridge Seismic Design Code" both require measures to prevent beams from falling. The damage caused by previous major earthquakes has shown that some structural measures summarized from earthquake damage experience or inspired by basic mechanical concepts have been proven to be effective in reducing bridge damage. The stronger the earthquake, the more likely it is that beams will fall. Bridge structures in high-intensity areas need to pay special attention to the use of structural measures to prevent beams from falling. For example, limiting the minimum distance between the beam end and the edge of the pier, setting blocks, setting connection measures between the main beam and the main beam or between the main beam and the pier, etc. However, these seismic measures usually cannot replace the seismic isolation and energy dissipation devices to play a role in seismic isolation. If they are not set up properly, they may also have an adverse effect on the structural stress and seismic resistance.

[0009] In summary, the prior art lacks a device that can reduce the seismic response of the bridge structure, improve the seismic performance of the bridge structure, prevent the main beam from falling off, reduce the project cost, and reduce the difficulty of design and construction. Summary of the invention

[0010] The present invention aims to provide a bridge shock-absorbing device and a construction method thereof, which can simultaneously serve as a shock-absorbing device and a beam-falling prevention measure, combining the shock-absorbing function and the beam-falling prevention function into one, thereby reducing the seismic response of the bridge structure and improving the seismic resistance of the bridge structure.

[0011] According to one aspect of the present invention, there is provided a bridge shock absorbing device, comprising: a steel rod, the top end of which is hingedly connected to an upper main beam via an embedded connector, and the bottom end of which is connected to a bridge pier; a damping box, which is sleeved on the steel rod and connected to the damping box via a damping spring.

[0012] Preferably, the device further comprises: a connecting sleeve, which is sleeved on the steel rod; the damping spring is vertically connected to the connecting sleeve, and there are multiple of them, which are used to provide constraint stiffness and absorb and dissipate seismic energy through elastic deformation.

[0013] Preferably, the equivalent horizontal constraint stiffness K0 of the device is expressed as: K0=f(k,L1,L2,E,I) Wherein, k is the equivalent stiffness of the damping box, L1 is the length from point A at the bottom of the steel rod to point B, the constraint point of the damping box, L2 is the length from point B to point C, the connection between the steel rod and the main beam, E is the elastic modulus of the material of the steel rod, and I is the section moment of inertia of the steel rod.

[0014] Preferably, the total rotation angle θ of point C is C for: The total horizontal displacement y of point C C for: in: d is the diameter of the steel rod; The equivalent horizontal constraint stiffness K0 is: K0=P / y C , P is the force acting on the steel rod at point C.

[0015] Preferably, the embedded connection piece is used to constrain horizontal displacement; the device also includes a bolt nut, which is used in conjunction with the embedded connection piece to fix the steel rod and constrain its vertical displacement.

[0016] Preferably, the device further comprises: a vertical shock-absorbing buffer block, which is arranged on the upper part of the steel rod and is used to absorb and alleviate vertical impacts to prevent the main beam from falling out.

[0017] Preferably, the device further comprises: a filler located in the damping box and used for dissipating earthquake energy through viscoelastic properties.

[0018] Preferably, the device also includes: a reserved hole, which is arranged on the top surface of the pier and is used to install the steel rod, and the reserved hole is filled with polysulfide sealing paste to ensure sealing; the aperture D of the reserved hole is calculated according to the following formula: D=d+S, wherein d is the diameter of the steel rod and S is the reserved displacement; a reserved steel plate is used to support and fix the steel rod.

[0019] According to another aspect of the present invention, a construction method for a bridge shock-absorbing device is provided, comprising the following steps: hingedly connecting the top end of a steel rod to an embedded connecting piece embedded in an upper main beam; sleeved with a damping box on the steel rod; fixing the bottom end of the steel rod on a bridge pier; and connecting the steel rod with an adjustable damping spring to provide a shock-absorbing function.

[0020] Preferably, the construction method further comprises the following steps: sleeve a connecting sleeve on the steel rod; vertically connect a plurality of damping springs to the connecting sleeve to provide constraint stiffness and absorb and dissipate seismic energy through elastic deformation.

[0021] The present invention discloses a bridge shock-absorbing device and a construction method thereof, the device comprising: a steel rod, the top end of which is hingedly connected to the upper main beam through a pre-embedded connector, and the bottom end of which is connected to the bridge pier; a damping box, which is sleeved on the steel rod and connected to the damping box through a damping spring. The present invention reduces the vibration response of the main beam and prevents the main beam from falling by limiting the horizontal and vertical displacement of the main beam caused by earthquakes or other vibrations of the bridge superstructure, thereby achieving a shock-absorbing and anti-falling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 A schematic diagram of suitable energy dissipation positions of piers in the prior art;

[0024] Figure 2 A schematic diagram of another suitable energy dissipation position of a pier column in the prior art;

[0025] Figure 3 This is a schematic diagram of a shock-absorbing and anti-falling beam device after installation according to an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of parts of a shock-absorbing and anti-falling beam device according to an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of the structure of the shock-absorbing and anti-falling beam device according to an embodiment of the present invention;

[0028] Figure 6 Schematic diagram of an implementation case according to an embodiment of the present invention.

[0029] In the figure: 1. Embedded connecting parts; 2. Bolt nuts; 3. Vertical shock-absorbing buffer pads; 4. Connecting sleeves; 5. Damping springs; 6. Steel rods; 7. Fillers; 8. Steel box shell; 9. Reserved hole limit cover; 10. Reserved holes; A. Constraint points of steel rods on piers; B. Constraint points of steel rods in damping box; C. Constraint points of steel rods on superstructure; k. Equivalent stiffness of damping springs in damping box; L1. Length of AB section from bottom of steel rod to constraint point of damping box; L2. Length of BC section from constraint point of damping box to connection point with main beam; P is the force acting on the steel rod at point C. DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] Reference will now be made in detail to various embodiments of the present invention, examples of which are shown in the accompanying drawings and described below. For ease of interpretation and precise definition in the appended claims, the terms "upper", "lower", "inner" and "outer" are used to describe features of the exemplary embodiments shown in the drawings with reference to their positions.

[0032] Figure 3 , 4 A schematic diagram of the shock-absorbing and anti-falling beam device after installation and a schematic diagram of parts according to an embodiment of the present invention are shown. As shown in the figure, the embodiment of the present invention provides a bridge shock-absorbing device, including: a steel rod 6, the top end of which is hingedly connected to the upper main beam through a pre-embedded connecting piece 1, and the bottom end is connected to the bridge pier; a damping box, which is sleeved on the steel rod 6, and the steel rod 6 is connected to the damping box through a damping spring 5.

[0033] The invention discloses a bridge shock-absorbing and anti-falling beam device, which simultaneously plays the role of a shock-absorbing device and an anti-falling beam measure, combines the shock-absorbing function and the anti-falling beam function into one, thereby reducing the seismic response of the bridge structure and improving the seismic performance of the bridge structure.

[0034] In the embodiment of the present invention, the steel rod connects the pier column-damping box and the upper structure beam in series to form a continuous beam structure supported at two ends and three points in the middle. The bending stiffness of the steel rod is much smaller than its shear stiffness, which avoids increasing the overall stiffness of the structure due to the limited deformation of the steel rod. At the same time, the damping spring can effectively dissipate energy. In rare earthquakes (earthquakes exceeding E2), the damping spring reaches the maximum stroke, and the steel rod reaches the yield bending and enters the plastic deformation stage. Before the steel rod breaks, it continues to play a limiting and energy dissipation role, thereby realizing the shock absorption function and the limiting and anti-falling beam function.

[0035] According to an embodiment of the present invention, the device also includes: a connecting sleeve 4, which is sleeved on the steel rod 6; the damping spring 5 is vertically connected to the connecting sleeve 4, and there are multiple damping springs 5 ​​for providing constraint stiffness and absorbing and dissipating seismic energy through elastic deformation.

[0036] In the embodiment of the present invention, the damping box is composed of a steel rod connector 4, a spring 5, a viscoelastic damping material filler 7 and a steel box shell 8, wherein the connector is an annular sleeve connected to the steel rod, and the spring (disc spring) and the viscoelastic damping material provide constraint stiffness, and the equivalent support stiffness k of the damping box can be adjusted by adjusting the spring stiffness and the physical and mechanical indicators of the filler. The filler in the box is a viscoelastic damping material with a large loss factor such as rubber, polyurethane and other high molecular polymers. According to the loss factor g of the viscoelastic material, the damping ratio ζ is calculated by the formula g=2ζ.

[0037] Figure 5A structural force diagram of a shock-absorbing and anti-falling beam device according to an embodiment of the present invention is shown. As shown in the figure, according to an embodiment of the present invention, the equivalent horizontal constraint stiffness K0 of the device is expressed as: K0=f(k,L1,L2,E,I) Wherein, k is the equivalent stiffness of the damping box, L1 is the length from point A at the bottom of the steel rod 6 to point B, the constraint point of the damping box, L2 is the length from point B to point C, the connection between the steel rod 6 and the main beam, E is the elastic modulus of the material of the steel rod 6, and I is the section moment of inertia of the steel rod 6.

[0038] In the embodiment of the present invention, the horizontal constraint stiffness of the connection structure is mainly composed of the stiffness of the steel rod and the stiffness of the damping spring. When subjected to horizontal force, the steel rod is bent and deformed, and the damping spring is deformed. The present invention obtains different constraint stiffness, damping coefficient and limit displacement values ​​by adjusting parameters such as the cross-sectional size and length of the steel rod and the stiffness and damping material index of the damping spring. Thus, a series of models with different mechanical properties can be formed to adapt to bridges with different spans and different structural forms, making them widely available.

[0039] According to an embodiment of the present invention, the total rotation angle θ of point C is C for: The total horizontal displacement y of point C C for: in: d is the diameter of the steel rod 6; The equivalent horizontal constraint stiffness K0 is: K0=P / y C , P is the force acting on the steel rod 6 at point C.

[0040] In the embodiment of the present invention, according to the required stiffness, the parameters such as the diameter of the steel rod, the lengths of L1 and L2, and the equivalent support stiffness k of the damping box in the device are adjusted according to the theoretical calculation formula described above, and the corresponding device model is selected. When horizontal ground vibration occurs, relative horizontal displacement and relative velocity are generated between the pier column and the main beam. The device constrains the displacement through the steel rod and dissipates energy and reduces vibration through the viscoelastic damping material in the damping box.

[0041] According to an embodiment of the present invention, the embedded connector 1 is used to constrain horizontal displacement; the device also includes a bolt nut 2, which is used in conjunction with the embedded connector 1 to fix the steel rod 6 and constrain its vertical displacement.

[0042] According to an embodiment of the present invention, the device further comprises: a vertical shock-absorbing buffer block 3, which is arranged on the upper part of the steel rod 6 and is used to absorb and alleviate vertical impacts to prevent the main beam from falling out.

[0043] In the embodiment of the present invention, a shock-absorbing cushion block is installed on the top of the steel rod, and the bolt nut is screwed on, and a vertical gap is reserved between the nut and the connecting piece. After installation, the device provides the ability to adjust the horizontal rigidity of the structure, shock absorption and anti-falling beam.

[0044] According to an embodiment of the present invention, the device further comprises: a filler 7, located in the damping box, for dissipating earthquake energy through viscoelastic properties.

[0045] According to an embodiment of the present invention, the device further comprises: a reserved hole limiting cover plate 9 for positioning the steel rod. A reserved steel plate and a reserved hole 10 are arranged on the top surface of the pier for installing the steel rod 6. The reserved hole 10 is filled with polysulfide sealing paste to ensure sealing. The aperture D of the reserved hole 10 is calculated according to the following formula: D=d+S, where d is the diameter of the steel rod and S is the reserved displacement.

[0046] In the embodiment of the present invention, a reserved hole for installing a steel rod is reserved on the top surface of the pier, and the hole diameter is reserved according to the horizontal displacement required when the steel rod is displaced, and its value is diameter D = (steel rod diameter d + reserved displacement S).

[0047] According to another embodiment of the present invention, a construction method for a bridge shock-absorbing device is provided, comprising the following steps: hingedly connecting the top end of a steel rod 6 to an embedded connecting piece 1 embedded in an upper main beam; sleeved with a damping box on the steel rod 6; fixing the bottom end of the steel rod 6 on a bridge pier; and connecting the steel rod 6 with an adjusting damping spring 5 to provide a shock-absorbing function.

[0048] According to an embodiment of the present invention, the construction method also includes the following steps: sleeve a connecting sleeve 4 on the steel rod 6; vertically connect a plurality of damping springs 5 ​​to the connecting sleeve 4 to provide constraint stiffness and absorb and dissipate seismic energy through elastic deformation.

[0049] The total stiffness of the bridge structure is mainly composed of the foundation stiffness, the lower structure stiffness, the upper structure stiffness and the upper and lower connection stiffness. During an earthquake, the ground motion drives the bridge foundation to move together. In this process, the various parts of the bridge structure will try to maintain their original static or moving state due to inertia, causing inertial force in the bridge structure. The horizontal vibration of the ground surface will cause shear force V and bending moment M at the bottom or top of the bridge pier. Taking the bridge pier simplified into a single degree of freedom system as an example, the vibration equation is satisfied. The magnitude of the structural internal force caused by an earthquake is related to mass m, damping c and stiffness k. The larger the structural damping c, the smaller the structural internal force caused by the earthquake; when the structural stiffness is appropriate and evenly distributed, the seismic effect is small, which is conducive to the earthquake resistance of the structure. Therefore, earthquake reduction measures are generally taken from two aspects: adjusting the structural stiffness and increasing the structural damping.

[0050] like Figure 3The bridge shock-absorbing and anti-falling beam device shown has vertical circular holes on the top surfaces of piers, cap beams or cap beams, on which reserved steel plates and reserved holes 10 are arranged, and high-toughness, high-elongation alloy steel rods 6 are built in. The middle of the steel rods passes through the damping box and is connected to the damping spring 5 in the damping box; a connecting piece 1 (which can be exposed to the outside or embedded in the main beam structure) is arranged on the main beam of the upper structure, and the top of the steel rod is connected to the main beam through the connecting piece. Thus, the steel rod connects the pier-damping box and the upper structure beam in series, and its simplified force model is a continuous beam supported at two ends and three points in the middle. The horizontal constraint stiffness of this connection structure is mainly composed of the stiffness of the steel rod and the stiffness of the damping spring. When subjected to horizontal force, the steel rod is bent and deformed, and the damping spring is deformed. Then the equivalent overall stiffness of this device can be expressed as: K0=f(k,L1,L2,E,I)

[0051] Among them: point A is the constraint point of the steel rod on the pier; point B is the constraint point of the steel rod in the damping box; point C is the constraint point of the steel rod on the superstructure; k is the equivalent stiffness of the damping box; L1 is the length of the AB section from the bottom of the steel rod to the constraint point of the damping box; L2 is the length of the BC section from the constraint point of the damping box to the connection point with the main beam; E is the elastic modulus of the steel rod material; I is the section moment of inertia of the steel rod.

[0052] When the steel rod is subjected to force P at point C, the rotation angle and vertical displacement of point C are:

[0053] The total rotation angle of point C:

[0054] The total horizontal displacement of point C: in:

[0055] The equivalent horizontal constraint stiffness K0 of the device is: K0=P / y C (Formula 6) Wherein, P is the force acting on the steel rod 6 at the point C.

[0056] The damping box is composed of a steel rod connector 4, a spring (disc spring) 5, a viscoelastic damping material filler 7 and a steel box shell 8, wherein the connector is an annular sleeve connected to the steel rod, and the spring (disc spring) and the viscoelastic damping material provide constraint stiffness. The equivalent support stiffness k of the damping box can be adjusted by adjusting the spring stiffness and the physical and mechanical indicators of the filler. The filler in the box is a viscoelastic damping material with a large loss factor such as rubber, polyurethane and other high molecular polymers. The damping ratio ζ is calculated based on the loss factor g of the viscoelastic material by the formula g=2ζ.

[0057] The bending stiffness of the steel rod is much smaller than its shear stiffness, which avoids increasing the overall stiffness of the structure due to the restricted deformation of the steel rod. At the same time, the damping spring can effectively dissipate energy. In rare earthquakes (earthquake effects exceeding E2), the damping spring reaches its maximum stroke, and the steel rod reaches yield bending and enters the plastic deformation stage. Before the steel rod breaks, it continues to play a limiting and energy dissipation role, thereby realizing the shock absorption function and the limiting and anti-falling beam function.

[0058] By adjusting the cross-sectional dimensions and length of the steel rod and the stiffness and damping material index of the damping spring, different constraint stiffness, damping coefficient and limit displacement values ​​can be obtained. Thus, a series of models with different mechanical characteristics can be formed to adapt to bridges with different spans and different structural forms, making them widely available. In addition to the anti-seismic and anti-falling beam function, this device can also be used in conjunction with plate bearings or sliding bearings to adjust the horizontal constraint stiffness of the bearings during normal use, thereby adjusting the stiffness of the bridge structure to make it more evenly distributed and improve the seismic performance of the structure.

[0059] In this device, the bottom of the steel rod is connected to the bridge pier through a nut, and the upper part of the steel rod is hingedly connected to the main beam through a pre-embedded connector (to constrain horizontal displacement), and a bolt head nut 2 and a vertical shock-absorbing buffer pad 3 are provided to prevent the main beam from falling out (to constrain vertical displacement), thereby realizing the seismic limiting function. When setting up this device, a reserved hole with a diameter D = (steel rod diameter d + reserved displacement S) is required on the top surface of the pier (or cap beam) structure, and the hole is filled with polysulfide sealing paste. This device is a replaceable component, assembled with prefabricated parts to meet the requirements of rapid construction. It can be installed during or after the construction of the bridge, and can be quickly replaced when necessary. Therefore, this device can be used for new bridges, as well as for bridge maintenance and reinforcement and rapid recovery after an earthquake.

[0060] The device is ductile when it is destroyed, which is beneficial to the safety of the structure. Conventional seismic pins only rely on their shear resistance to provide restraint and limit, and a gap needs to be reserved in the direction of movement of the upper structure relative to the lower structure. The limit function can only be exerted when the displacement exceeds the gap, and there is no function to adjust the structural stiffness. In addition, stress concentration will occur at the contact surface between the steel rod and the structure, which will cause shear failure of the steel rod and local damage to the structure. The shear failure of the steel rod is a brittle failure, which is not conducive to the seismic safety of the structure.

[0061] Figure 6 A schematic diagram of an implementation case according to an embodiment of the present invention is shown. As shown in the figure, the device is used for structural shock absorption and anti-falling. It can be used alone or in combination with a support, and can be combined in various ways.

[0062] The lower structure of the bridge is connected to the upper structure through a movable support, and the shock-absorbing and anti-falling beam device is set at the same time. In this example, the construction sequence is as follows: (1) A reserved hole for installing a steel rod is reserved on the top surface of the pier. The hole diameter is reserved according to the horizontal displacement required when the steel rod is displaced, and its value is diameter D = (steel rod diameter d + reserved displacement S). (2) A damping box is installed above the reserved hole. The damping box is arranged based on the center of the steel rod sleeve in the box and the center of the reserved hole, and is fixed to the top surface of the pier by anchor bolts. (3) During the construction of the upper structure, the connecting parts are embedded, and the center of the reserved hole of the connecting parts is arranged in the center of the steel rod. (4) After the upper and lower structures are installed, the steel rod is passed through the sleeve in the damping box, and its bottom is extended into the reserved hole of the pier, and fixed in the hole by a fixing nut; if the construction space is limited, the steel rod can be pre-placed in the reserved hole of the pier or a short steel rod can be used for extension. When the steel rod needs to be extended, a sleeve connection or welding method is used for strength connection. The top of the steel rod is inserted into the embedded connector of the upper structure. (5) Install the shock-absorbing buffer block on the top of the steel rod, screw on the bolt head nut, and reserve a vertical gap between the nut and the connector. After installation, the device provides the ability to adjust the horizontal stiffness of the structure, shock absorption and prevent beams from falling.

[0063] For bridges with large height differences between adjacent piers and large differences in horizontal stiffness of piers, setting fixed bearings will lead to uneven distribution of horizontal forces on piers, with short piers receiving much greater forces than tall piers. Therefore, movable bearings are generally set on short piers to prevent them from bearing horizontal forces, but this will increase the internal forces of other fixed piers. After installing this device, the bridge piers with movable bearings will change from not participating in the distribution of horizontal forces to distributing horizontal forces according to the total equivalent horizontal stiffness after the device is connected in series with the piers. According to the required stiffness, the parameters such as the steel rod diameter, L1 and L2 lengths, and the equivalent support stiffness k of the damping box in this device are adjusted according to the theoretical calculation formulas (Formulas 1 to 5) described above, and the corresponding device model is selected. When horizontal earthquake motion occurs, relative horizontal displacement and relative velocity are generated between the pier and the main beam. This device constrains displacement through steel rods and dissipates energy and reduces vibration through viscoelastic damping materials in the damping box. As shown in the figure, the 01# pier and the 03# pier are shorter, have greater pier stiffness, and are subject to greater seismic forces; the 02# pier is taller, has less pier stiffness, and is subject to less seismic forces. In order to make the three piers evenly stressed, the 02# pier uses a fixed support, and the 01# pier and the 03# pier use movable supports in conjunction with the device of the present invention. The stiffness of the entire bridge can be adjusted and improved, so that the equivalent stiffness of the three piers 01# to 03# tends to be balanced, and the seismic force is better distributed, achieving a shock-absorbing effect.

[0064] In summary, the present invention has the following advantages:

[0065] (1) Taking into account both shock absorption and anti-beam drop functions: The present invention is provided with a damping shock absorption module, which includes a specially designed viscoelastic damping device to dissipate energy to achieve the shock absorption function; at the same time, it is provided with an anti-beam drop module, which includes a specially designed anti-seismic pin and a connecting device, which can achieve horizontal and vertical limit under large deformation conditions to achieve the anti-beam drop function. In this way, the shock absorption function and the anti-beam drop function are combined into one, thereby reducing the impact of earthquakes on the bridge structure and improving its seismic performance.

[0066] (2) Improve the breadth of application scenarios: The present invention obtains different constraint stiffness, damping coefficient and limit displacement values ​​by adjusting parameters such as the cross-sectional size and length of the steel rod and the stiffness and damping material index of the damping spring, thereby forming a series of models with different mechanical properties, which can be used to adapt to bridges with different spans and different structural forms, making them widely available. The present invention can adjust the horizontal constraint stiffness of the bearing during normal use to make the stiffness distribution of the bridge structure more uniform; in the event of an earthquake, it can increase the shock absorption effect of damping dissipation energy and limit the horizontal and vertical displacement of the bridge superstructure to prevent the beam from falling, and can be applied to a wide range of application scenarios.

[0067] (3) Reduce construction costs and improve construction efficiency: The bridge shock-absorbing device of the present invention is assembled using prefabricated parts, which significantly improves construction efficiency and can meet the needs of rapid construction. At the same time, the use of prefabricated parts can ensure the quality and consistency of components, shorten on-site construction time and reduce construction difficulty, and has significant application potential in bridge maintenance and reinforcement and rapid recovery after earthquakes.

[0068] The above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications may be made based on the following description, and these various changes, modifications, substitutions and deformations derived from the principles and spirit of the present invention still fall within the scope of protection of the present invention.

Claims

1. A bridge shock absorbing device, characterized in that: include: The top end of the steel rod (6) is hingedly connected to the upper main beam through the embedded connector (1), and the bottom end is connected to the bridge pier; The steel rod (6) is made of high-toughness, high-performance steel. The damping box is sleeved on the steel rod (6), and the steel rod (6) is connected to the damping box via a damping spring (5).

2. The device according to claim 1, characterized in that The device also includes: A connecting sleeve (4) is sleeved on the steel rod (6); The damping spring (5) is vertically connected to the connecting sleeve (4), there are a plurality of them, and they are used to provide restraint stiffness and absorb and dissipate earthquake energy through elastic deformation.

3. The device according to claim 2, characterized in that The equivalent horizontal constraint stiffness K0 of the device is expressed as: K0=f(k,L1,L2,E,I) Wherein, k is the equivalent stiffness of the damping box, L1 is the length from the bottom point A of the steel rod (6) to the damping box constraint point B, L2 is the length of the steel rod (6) from the point B to the connection point C between the steel rod (6) and the main beam, E is the elastic modulus of the material of the steel rod (6), and I is the section moment of inertia of the steel rod (6).

4. The device according to claim 3, characterized in that The total rotation angle θ of point C C for: The total horizontal displacement y of point C C for: in: d is the diameter of the steel rod (6); The equivalent horizontal constraint stiffness K0 is: K0=P / y C , P is the force acting on the steel rod (6) at the point C.

5. The device according to claim 1, characterized in that The embedded connection piece (1) is used to restrict horizontal displacement; The device also includes a bolt nut (2) which is used in conjunction with the embedded connecting piece (1) to fix the steel rod (6) and restrict its vertical displacement.

6. The device according to claim 6, characterized in that The device also includes: A vertical shock-absorbing buffer block (3) is arranged on the upper part of the steel rod (6) and is used to absorb and alleviate vertical impacts to prevent the main beam from falling out.

7. The device according to claim 6, characterized in that The device also includes: The filler (7) is located in the damping box and is used to dissipate earthquake energy through its own high viscoelastic properties.

8. The device according to any one of claims 1 to 7, characterized in that The device also includes: The reserved hole limiting cover plate (9) is used for positioning the steel rod. The reserved steel plate and the reserved hole (10) are arranged on the top surface of the pier and are used for installing the steel rod (6). The reserved hole (10) is filled with polysulfide sealing paste to ensure the sealing performance. The aperture D of the reserved hole (10) is calculated according to the following formula: D=d+S, wherein d is the diameter of the steel rod and S is the reserved displacement.

9. A construction method for a bridge shock absorbing device, characterized in that: The following steps are involved: The top end of the steel rod (6) is hingedly connected to a pre-embedded connecting piece (1) pre-embedded in the upper main beam; A damping box is sleeved on the steel rod (6); Fixing the bottom end of the steel rod (6) on the bridge pier; The damping spring (5) is connected to the steel rod (6) to provide a shock absorbing function.

10. The construction method according to claim 9, characterized in that: The following steps are also included: A connecting sleeve (4) is sleeved on the steel rod (6); A plurality of damping springs (5) are vertically connected to the connecting sleeve (4) to provide restraining rigidity and absorb and dissipate earthquake energy through elastic deformation.

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