Bridge damping device and construction method thereof

Abstract

The application discloses a bridge damping device and a construction method thereof. The device comprises a steel rod, a top end of which is hingedly connected with an upper main beam through a pre-buried connecting piece, and a bottom end of which is connected with a pier; and a damping box, which is sleeved on the steel rod and connected with the steel rod through a damping spring. The application limits the horizontal and vertical displacement of the main beam of the upper structure of the bridge caused by the earthquake or other vibration, so as to reduce the vibration response of the main beam and prevent the main beam from falling, thereby realizing the damping and falling prevention effect.

Description

Technical Field

[0001] This invention belongs to the field of structural vibration reduction of bridges, specifically relating to a bridge vibration reduction device and its construction method. Background Technology

[0002] Located between two major global seismic belts—the Circum-Pacific Seismic Belt and the Eurasian Seismic Belt—my country is a country prone to strong earthquakes. Earthquakes in my country are characterized by high frequency, high intensity, wide distribution, high casualties, and severe damage. Almost all provinces, municipalities, and autonomous regions have experienced destructive earthquakes of magnitude 6 or higher. Urban transportation and highways are crucial channels for disaster relief and mitigation of secondary disasters, making the seismic safety of urban and highway bridges particularly essential. In bridge seismic design codes, different fortification standards and objectives are determined according to the bridge's importance and role in earthquake relief and disaster mitigation, based on the bridge's seismic fortification category. The seismic fortification objectives can be summarized as follows: under E1 earthquake action, the overall response of the bridge structure remains within the elastic range with minimal damage; under E2 earthquake action, the bridge structure will not collapse or suffer severe structural damage; bridges with higher seismic fortification categories are allowed to experience localized or limited damage, which can be temporarily reinforced to maintain emergency traffic use. Furthermore, bridge seismic design codes stipulate that seismic measures must be implemented according to the seismic fortification category.

[0003] Currently, there are two main types of seismic-resistant structural systems used both domestically and internationally.

[0004] One type is bridges designed for ductile seismic resistance. By designing appropriately elasto-plastic energy-dissipating components and deformable members, the structural period is extended, utilizing seismic energy dissipation mechanisms to reduce the bridge's seismic response. In this type of seismic system, the elasto-plastic energy-dissipating components are often located in easily inspected and repaired members. For example, piers and tie beams are designed as ductile members that allow plastic deformation and energy dissipation, while the superstructure, cap beams, supports, and foundations act as capacity-protecting components, remaining within their elastic range to prevent damage. Figure 1 and Figure 2 As shown, the shaded area represents the suitable energy dissipation part of the pier. The plastic hinge should be located at the top or bottom of the main load-bearing component, the pier, and enter the plastic phase under E2 seismic action.

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

[0006] Another type is a bridge designed according to a seismic mitigation design, which controls displacement and energy dissipation by setting a seismic mitigation support or a damping device, thereby reducing the seismic response of the bridge and keeping the main structure of the bridge in the elastic deformation range under the action of an E2 earthquake. Such an anti-seismic system is mostly used for special structure bridges, bridges with large differences in the height of piers, large slopes and large curvatures, and bridges with uneven distribution of stiffness and strength, and uses a seismic mitigation support, a damper, a shock absorber and other devices.

[0007] However, the bridge designed according to the seismic mitigation design also has technical problems: the commonly used seismic mitigation support, damper, shock absorber and other devices are relatively high in price, need to be regularly inspected and maintained, are high in manufacturing cost and poor in economy, and need to be specially designed according to the specific parameters of the seismic mitigation device, and the seismic mitigation performance has large differences.

[0008] The current Urban Bridge Seismic Code and Highway Bridge Seismic Design Code of China both require setting a fall prevention measure for a beam, and the damage in previous earthquakes shows that some structural measures summarized from the experience of earthquake damage or inspired by basic mechanics concepts can effectively reduce the damage of a bridge. The more intense the earthquake is, the more likely the beam is to fall, and the bridge structure in a high intensity area needs to pay special attention to the use of the fall prevention structural measure for the beam. For example, limiting the minimum distance of the beam end from the edge of the pier, setting a stopper, and setting a connecting measure between the main beam and the main beam or the main beam and the pier, but these anti-seismic measures usually cannot replace the seismic mitigation and energy dissipation device to play a role in seismic mitigation, and when improperly set, can also have an adverse effect on the stress and anti-seismic performance of the structure.

[0009] In summary, the prior art lacks a device capable of reducing the seismic response of a bridge structure, improving the anti-seismic performance of the bridge structure, preventing the main beam from falling, reducing the engineering cost, and reducing the design and construction difficulty. SUMMARY

[0010] The present application aims to provide a bridge seismic mitigation device and a construction method thereof, which can simultaneously play the roles of a seismic mitigation device and a fall prevention measure for a beam, and combine the seismic mitigation function and the fall prevention function for the beam, thereby reducing the seismic response of a bridge structure and improving the anti-seismic performance of the bridge structure.

[0011] According to one aspect of the present application, a bridge seismic mitigation device is provided, which comprises: a steel rod, the top end of which is hingedly connected to an upper main beam through a pre-buried connecting piece, and the bottom end of which is connected to a pier; and a damping box, which is sleeved on the steel rod, and the steel rod is connected to the damping box through a damping spring.

[0012] Preferably, the device further comprises: a connecting sleeve, which is sleeved on the steel rod; and the damping spring is vertically connected to the connecting sleeve and is in a plurality in number, for providing a constraint stiffness and absorbing and dissipating seismic energy through elastic deformation.

[0013] Preferably, the equivalent horizontal constraint stiffness K0 of the device is expressed as:

[0014] K0 = f(k, L1, L2, E, I)

[0015] wherein k is the equivalent stiffness of the damper box, L1 is the length of the steel bar from the point A to the point B, L2 is the length of the steel bar from the point B to the point C, E is the elastic modulus of the material of the steel bar, and I is the sectional moment of inertia of the steel bar.

[0016] Preferably, the total rotation angle θ of the point C is C

[0017]

[0018] The total horizontal displacement y of the point C is C

[0019]

[0020] wherein:

[0021] d is the diameter of the steel bar;

[0022] The equivalent horizontal constraint stiffness K0 is:

[0023] K0 = P / y C , P is the force acting on the steel bar at the point C.

[0024] Preferably, the embedded connector is used to constrain the horizontal displacement; the device further comprises a nut, which is used in cooperation with the embedded connector to fix the steel bar and constrain the vertical displacement thereof.

[0025] Preferably, the device further comprises a vertical shock-absorbing cushion block arranged at the upper portion of the steel bar, which is used to absorb and relieve the vertical impact and prevent the main beam from being pulled out.

[0026] Preferably, the device further comprises a filler located in the damper box, which is used to dissipate the seismic energy through the viscoelastic properties.

[0027] Preferably, the device further comprises a reserved hole arranged at the top surface of the pier, which is used to install the steel bar, and a polysulfide sealing paste is filled in the reserved hole to ensure the sealing property; the diameter D of the reserved hole is calculated according to the formula: D = d + S, wherein d is the diameter of the steel bar, and S is the reserved displacement amount; a reserved steel plate is used to support and fix the steel bar.

[0028] According to another aspect of the present application, a construction method of a bridge shock-absorbing device is provided, which comprises the following steps: hingedly connecting the top end of a steel bar with an embedded connector embedded in an upper main beam; sleeving a damper box on the steel bar; fixing the bottom end of the steel bar on a pier; and adjusting a damper spring connected with the steel bar to provide a shock-absorbing function.​​

[0029] Preferably, the construction method further comprises the steps of: sleeving a connecting sleeve on the steel rod; and connecting a plurality of damping springs to the connecting sleeve vertically for providing constraint stiffness and absorbing and dissipating seismic energy through elastic deformation.

[0030] The application discloses a bridge damping device and a construction method thereof. The device comprises a steel rod, a top end of which is hingedly connected to an upper main beam through a pre-buried connecting piece, and a bottom end of which is connected to a pier; and a damping box, which is sleeved on the steel rod and connected to the steel rod through damping springs. The application limits the horizontal and vertical displacement of the upper structure of the bridge caused by earthquakes or other vibrations, so as to reduce the vibration response of the main beam and prevent the main beam from falling, thereby achieving the damping and falling prevention effect. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and serve to explain the principles of the application. In the drawings:

[0032] Figure 1 Schematic diagram of a suitable energy dissipation site of a pier column in the prior art;

[0033] Figure 2 Schematic diagram of another suitable energy dissipation site of a pier column in the prior art;

[0034] Figure 3 Schematic diagram of the damping and falling prevention beam device after installation according to the embodiment of the application;

[0035] Figure 4 Schematic diagram of parts of the damping and falling prevention beam device according to the embodiment of the application;

[0036] Figure 5 Schematic diagram of the force on the structure of the damping and falling prevention beam device according to the embodiment of the application;

[0037] Figure 6 Schematic diagram of an implementation case according to the embodiment of the application.

[0038] In the drawings: 1, pre-buried connecting piece; 2, bolt head nut; 3, vertical damping and buffering pad block; 4, connecting sleeve; 5, damping spring; 6, steel rod; 7, filler; 8, steel box shell; 9, preformed hole limiting cover plate; 10, preformed hole; A, constraint point of the steel rod on the pier column; B, constraint point of the steel rod in the damping box; C, constraint point of the steel rod on the upper structure; k, equivalent stiffness of the damping spring of the damping box; L1, length of the AB section of the steel rod from the bottom to the constraint point of the damping box; L2, length of the BC section of the steel rod from the constraint point of the damping box to the connecting point with the main beam; P is the force acting on the steel rod at the C point. DETAILED DESCRIPTION

[0039] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0040] Reference will now be made in detail to various embodiments of the present application, examples of which are illustrated in the accompanying drawings and described below. For the purpose of explanation and definition, the terms "upper", "lower", "inner" and "outer" are used to describe the features of the example embodiments shown in the figures with reference to the positions of the features.

[0041] Figure 3 、 4 The schematic diagram of the shock-absorbing anti-falling beam device after installation and the schematic diagram of the parts are shown according to the embodiment of the present application, as shown in the figure, the embodiment of the present application provides a bridge shock-absorbing device, which comprises a steel rod 6, the top end is hingedly connected with the upper main beam through a pre-buried connecting piece 1, and the bottom end is connected with a pier; a damping box is sleeved on the steel rod 6, and the steel rod 6 is connected with the damping box through a damping spring 5.

[0042] The present application discloses a bridge shock-absorbing anti-falling beam device, which simultaneously plays the roles of a shock-absorbing device and an anti-falling beam measure. The shock-absorbing function and the anti-falling beam function are combined together, so as to reduce the seismic response of the bridge structure and improve the seismic performance of the bridge structure.

[0043] In the embodiment of the present application, the steel rod connects the pier-damping box and the upper structure beam together to form a continuous beam structure with three-point support at both ends and in the middle. The bending stiffness of the steel rod is much smaller than the shear stiffness, which avoids increasing the overall stiffness of the structure due to the deformation restriction of the steel rod, and the damping spring can effectively dissipate energy. When a rare earthquake (earthquake action exceeding E2) occurs, the damping spring reaches the maximum stroke, the steel rod reaches the yield bending and enters the plastic deformation stage, and the steel rod continues to play the roles of limiting and energy dissipation before the steel rod breaks, so as to realize the shock-absorbing function and the limiting anti-falling beam function.

[0044] According to the embodiment of the present application, the device further comprises a connecting sleeve 4 sleeved on the steel rod 6; the damping spring 5 is vertically connected to the connecting sleeve 4, and the number of the damping springs 5 is multiple, which are used to provide constraint stiffness and absorb and dissipate seismic energy through elastic deformation.

[0045] In the embodiment of the present application, the damping box is composed of a steel rod connector 4, a spring 5, a viscoelastic damping material filling 7 and a steel box shell 8, wherein the connector is connected with the steel rod through a ring sleeve, 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 indexes of the filling. The filling in the box adopts a viscoelastic damping material with a large loss factor, such as rubber, polyurethane and other high molecular polymers, and the damping ratio ζ is calculated according to the loss factor g of the viscoelastic material by the formula g = 2ζ.

[0046] Figure 5 The stress diagram of the shock-absorbing and anti-falling beam device structure according to the embodiment of the present application is shown, and the equivalent horizontal constraint stiffness K0 of the device is represented as:

[0047] K0 = f (k, L1, L2, E, I)

[0048] Wherein, k is the equivalent stiffness of the damping box, L1 is the length from the bottom A point of the steel rod 6 to the constraint point B point of the damping box, L2 is the length from the B point of the steel rod 6 to the connection point C point of 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 sectional moment of inertia of the steel rod 6.

[0049] In the embodiment of the present application, 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, and the steel rod produces bending deformation and the damping spring produces deformation under the action of the horizontal force. The present application obtains different constraint stiffness, damping coefficient and limit displacement value by adjusting the sectional size, length of the steel rod and the stiffness of the damping spring and the damping material indexes and other parameters. Thus, a series of models with different mechanical properties can be formed, which are used for bridges with different spans and different structural forms, so as to be widely used.

[0050] According to the embodiment of the present application, the total rotation angle θ of the C point C is:

[0051]

[0052] The total horizontal displacement y of the C point C is:

[0053]

[0054] Wherein:

[0055] d is the diameter of the steel rod 6;

[0056] The equivalent horizontal constraint stiffness K0 is:

[0057] K0 = P / y C , P is the force acting on the C point of the steel rod 6.

[0058] In the embodiment of the present application, according to the required rigidity, the parameters such as the diameter of the steel bar, the lengths of L1 and L2, and the equivalent support rigidity k of the damping box are adjusted according to the theoretical calculation formula described above, and the corresponding device model is selected. When horizontal seismic motion occurs, relative horizontal displacement and relative velocity are generated between the pier column and the main beam, and the device restrains the displacement through the steel bar and dissipates energy through the viscoelastic damping material in the damping box.

[0059] According to the embodiment of the present application, the embedded connecting piece 1 is used to constrain horizontal displacement; the device further comprises a bolt head nut 2 used in cooperation with the embedded connecting piece 1 for fixing the steel bar 6 and restraining the vertical displacement thereof.

[0060] According to the embodiment of the present application, the device further comprises a vertical shock-absorbing cushion block 3 arranged at the upper portion of the steel bar 6 for absorbing and relieving vertical impact and preventing the main beam from falling out.

[0061] In the embodiment of the present application, the shock-absorbing cushion block is installed at the top of the steel bar, the bolt head nut is screwed, and a vertical gap is reserved between the nut and the connecting piece. After installation is completed, the device provides the ability of adjusting structural horizontal rigidity, shock absorption, and fall beam prevention.

[0062] According to the embodiment of the present application, the device further comprises a filler 7 located in the damping box for dissipating seismic energy through viscoelastic properties.

[0063] According to the embodiment of the present application, the device further comprises a reserved hole limiting cover plate 9 for steel bar positioning. A reserved steel plate and a reserved hole 10 are arranged at the top surface of the bridge pier for installing the steel bar 6, and poly-sulfur sealing paste is filled in the reserved hole 10 to ensure sealing. The hole diameter D of the reserved hole 10 is calculated according to the following formula: D = d + S, wherein d is the diameter of the steel bar, and S is the reserved displacement amount.

[0064] In the embodiment of the present application, a reserved hole for installing the steel bar is reserved at the top surface of the bridge pier, and the hole diameter is reserved according to the required horizontal displacement amount when the steel bar is displaced, and the value is the diameter D = (steel bar diameter d + reserved displacement amount S).

[0065] According to another embodiment of the present application, a construction method of a bridge shock-absorbing device is provided, comprising the following steps: hingedly connecting the top end of the steel bar 6 with the embedded connecting piece 1 embedded in the upper main beam; sleeving the damping box on the steel bar 6; fixing the bottom end of the steel bar 6 on the bridge pier; and adjusting the damping spring 5 connected with the steel bar 6 to provide shock-absorbing function.

[0066] According to the embodiment of the present application, the construction method further comprises the following steps: sleeving the connecting sleeve 4 on the steel bar 6; and vertically connecting a plurality of damping springs 5 to the connecting sleeve 4 for providing constraint rigidity and absorbing and dissipating seismic energy through elastic deformation.

[0067] The total stiffness of the bridge structure is mainly composed of the foundation stiffness, the substructure stiffness, the superstructure stiffness and the connection stiffness between the substructure and the superstructure. During an earthquake, the ground motion drives the bridge foundation to move, in the process, the parts of the bridge structure try to keep their original static or moving state due to inertia, which causes the inertia force in the bridge structure. The horizontal ground motion causes the shear force V and the bending moment M at the bottom or the top of the pier column. Taking the pier simplified as a single degree of freedom system as an example, the vibration equation is satisfied The internal force caused by the earthquake is related to the mass m, the damping c and the stiffness k. The greater the damping c of the structure is, the smaller the internal force caused by the earthquake is. When the stiffness of the structure is appropriate and uniformly distributed, the earthquake effect is small, which is beneficial to the seismic resistance of the structure. Therefore, the damping measures are generally taken from two aspects of adjusting the stiffness of the structure and increasing the damping of the structure.

[0068] As shown in the bridge damping and anti-falling beam device shown in Figure 3 The vertical circular hole is opened on the top surface of the pier column, the cap beam or the hat beam, the reserved steel plate and the reserved hole 10 are arranged on the hole, the high-toughness and high-elongation alloy steel bar 6 is arranged in the hole, the middle part of the steel bar penetrates through the damping box and is connected with the damping spring 5 in the damping box, the connecting piece 1 is arranged on the main beam of the superstructure (which can be exposed outside or pre-buried in the main beam structure), and the top end of the steel bar is connected with the main beam through the connecting piece. Therefore, the steel bar connects the pier column-damping box and the main beam of the superstructure in series, and the simplified stress model is a continuous beam supported at three points at both ends and the middle. The horizontal constraint stiffness of the connecting structure is mainly composed of the stiffness of the steel bar and the stiffness of the damping spring. When the steel bar is subjected to the horizontal force, the steel bar is bent and deformed, and the damping spring is deformed. Therefore, the equivalent total stiffness of the device can be expressed as:

[0069] K0=f(k,L1,L2,E,I)

[0070] Wherein, A point is the constraint point of the steel bar on the pier column, B point is the constraint point of the steel bar in the damping box, C point is the constraint point of the steel bar on the superstructure, k is the equivalent stiffness of the damping box, L1 is the length of the AB section of the steel bar from the bottom to the constraint point of the damping box, L2 is the length of the BC section of the steel bar from the constraint point of the damping box to the connecting point with the main beam, E is the elastic modulus of the material of the steel bar, and I is the sectional moment of inertia of the steel bar.

[0071] When the steel bar is subjected to the force P at C point, the rotation angle and the vertical displacement of C point are:

[0072] The total rotation angle of C point is:

[0073]

[0074] The total horizontal displacement of C point is:

[0075]

[0076] Wherein:

[0077]

[0078] The equivalent horizontal constraint stiffness K0 of the device is:

[0079] K0 = P / y C (Formula 6)

[0080] Wherein, P is the force acting on the steel bar 6 at the C point.

[0081] The damping box is composed of a steel bar connector 4, a spring (disc spring) 5, a viscoelastic damping material filler 7, and a steel box shell 8, wherein the connector is a ring sleeve connected with the steel bar, 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 indexes of the filler. The filler in the box adopts viscoelastic damping materials such as rubber, polyurethane, and other high molecular polymers with large loss factors, and the damping ratio ζ is calculated according to the loss factor g of the viscoelastic material from the formula g = 2ζ.

[0082] The bending stiffness of the steel bar is much smaller than its shear stiffness, which avoids increasing the overall stiffness of the structure due to the deformation of the steel bar, and the damping spring can effectively dissipate energy. When a rare earthquake (earthquake action exceeding E2) occurs, the damping spring reaches the maximum stroke, the steel bar reaches the yield bending and enters the plastic deformation stage, and the steel bar continues to play a limiting and energy dissipation role before it breaks, thereby realizing the functions of shock absorption and limiting and preventing beam falling.

[0083] By adjusting the section size, length of the steel bar, and the stiffness and damping material indexes of the damping spring, different constraint stiffness, damping coefficients, and limit displacement values can be obtained. Thus, a series of models with different mechanical properties can be formed, which can be used for bridges with different spans and different structural forms, making them widely available. In addition to the anti-seismic and beam-falling-preventing functions, the device can also be used in combination with plate supports or sliding supports to realize the function of adjusting the horizontal constraint stiffness of the support in the normal use stage, thereby adjusting the structural stiffness of the bridge and making it more evenly distributed, and improving the seismic performance of the structure.

[0084] The bottom of the steel rod in the device is connected with the pier through a nut, the upper part of the steel rod is hinged connected with the main beam through a pre-buried connecting piece (horizontal displacement is restricted), and a bolt head nut 2 and a vertical shock absorption cushion block 3 are arranged to prevent the main beam from falling out (vertical displacement is restricted), so that the anti-seismic limiting function is realized. When the device is arranged, a reserved hole with a diameter D = (steel rod diameter d + reserved displacement S) is arranged on the top surface of the pier (or the bent cap) structure, and the hole is filled with polysulfide sealing paste. The device is a replaceable component and is assembled by using a prefabricated part to meet the requirement of rapid construction, and can be installed during the bridge construction process or after the construction is completed, and can be quickly replaced when necessary. Therefore, the device can be used for newly-built bridges, and can also be used for bridge maintenance and reinforcement and rapid recovery after an earthquake.

[0085] When the device is damaged, ductile damage occurs, which is beneficial to the safety of the structure. The conventional anti-seismic pin rod mainly relies on its shear to provide restraint and limiting, a gap needs to be reserved in the direction of movement of the upper structure relative to the lower structure, and the limiting function can be played only when the displacement exceeds the gap amount, the function of adjusting the stiffness of the structure cannot be realized, and stress concentration will occur at the contact surface between the steel rod and the structure, which will lead to shear fracture of the steel rod and local damage of the structure. The shear fracture of the steel rod belongs to brittle fracture, which is not conducive to the safety of the structure in resisting earthquakes.

[0086] Figure 6 An implementation case diagram according to an embodiment of the present application is shown, as shown in the figure, the device is used for structure shock absorption and anti-falling. It can be used alone or in combination with a support, and can be combined in various ways.

[0087] In the example, the lower structure of the bridge and the upper structure are connected through a movable support, and the anti-shock and anti-falling beam device is arranged. In this example, the construction sequence is as follows: (1) a reserved hole for installing the steel rod is reserved on the top surface of the pier, the diameter of the hole is reserved according to the horizontal displacement required when the steel rod is displaced, and the 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 in the center of the steel rod sleeve in the box and the center of the reserved hole, and is fixed on the top surface of the pier through foundation bolts.(3) The connecting piece is pre-buried when the upper structure is constructed, and the center of the connecting piece is arranged in the center of the steel rod.(4) After the upper and lower structures are installed, the steel rod is inserted through the sleeve in the damping box, the bottom of the steel rod is inserted into the reserved hole of the pier, and is fixed in the hole through the fixing nut; if the space is limited, the steel rod can also be pre-placed in the reserved hole of the pier or used by connecting long steel rods, and the steel rod needs to be connected when the strength connection is adopted by using a sleeve connection or welding.(5) The top shock absorption cushion block of the steel rod is installed, the bolt head nut is screwed, and a vertical gap is reserved between the nut and the connecting piece. After the installation is completed, the device provides the functions of adjusting the horizontal stiffness of the structure, shock absorption and anti-falling beam capacity.

[0088] For the bridge with large height difference between adjacent piers and large difference in horizontal stiffness of the piers, setting fixed bearings will result in uneven distribution of horizontal forces on the piers, and the low piers will bear much larger forces than the high piers. Therefore, movable bearings are generally set on the low piers so that they do not bear horizontal forces, but this will result in larger internal forces in the other fixed piers. After the installation of the device, the pier with movable bearings will no longer participate in the distribution of horizontal forces, but will distribute the horizontal forces according to the total equivalent horizontal stiffness of the device and the pier in series. 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 (formula 1-5) described above, and the corresponding device model is selected. When horizontal seismic motion occurs, relative horizontal displacement and relative velocity occur between the pier and the main beam, and the device restrains displacement through the steel rod and dissipates energy through the viscoelastic damping material in the damping box. As shown in the figure, the 01# pier and the 03# pier are relatively low, the pier stiffness is large, and the seismic force received is large; the 02# pier is relatively high, the pier stiffness is small, and the seismic force received is small. In order to make the three piers bear forces uniformly, the 02# pier adopts a fixed bearing, and the 01# pier and the 03# pier adopt movable bearings and the device of the application in combination. The stiffness of the whole bridge can be adjusted and improved, the equivalent stiffness of the three piers 01#-03# tends to be balanced, the seismic force is better distributed, and the effect of seismic mitigation is achieved.

[0089] In summary, the application has the following advantages:

[0090] (1) Considering both damping function and anti-falling beam function: the application is provided with a damping module containing a specially designed viscoelastic damping device to dissipate energy and achieve the damping function; and is also provided with an anti-falling beam module containing specially designed anti-seismic pins and connecting devices to achieve horizontal and vertical limiting under large deformation conditions and achieve the anti-falling beam function. Thus, the damping function and the anti-falling beam function are combined, thereby reducing the impact of earthquakes on the bridge structure and improving the seismic performance.

[0091] (2) Improving the universality of application scenarios: the application can obtain different constraint stiffness, damping coefficient and limit displacement value by adjusting the 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 for different span lengths and different structural forms of bridges, making them widely applicable. The application can adjust the horizontal constraint stiffness of the bearing during normal use to make the stiffness distribution of the bridge structure more uniform; and can play a role in increasing damping to dissipate energy and limiting the horizontal and vertical displacement of the bridge superstructure to prevent falling of the beam under seismic conditions, and can be applied to a wide range of application scenarios.

[0092] (3) Reduce the engineering cost, improve the construction efficiency: the bridge damping device of the application is assembled by using prefabricated parts, which significantly improves the construction efficiency and can meet the demand of rapid construction. At the same time, the use of prefabricated parts can ensure the quality and consistency of the components, shorten the on-site construction time and reduce the construction difficulty, and has significant application potential in bridge maintenance and reinforcement and post-earthquake rapid recovery.

[0093] The above examples are only examples for clearly illustrating the present application, and do not limit the embodiments of the application. For those skilled in the art, on the basis of the description, other different forms of changes or changes can also be made, and these belong to the changes, modifications, replacements and changes of the principles and spirits of the present application, which still fall within the protection scope of the present application.

Claims

1. A bridge vibration damping device, characterized in that, include: The steel bar (6) is hinged to the upper main beam at the top end through a pre-embedded connector (1) and connected to the pier at the bottom end. The steel bar (6) is made of high toughness and high performance steel. A connecting sleeve (4) is fitted onto the steel rod (6); Damping springs (5) are vertically connected to the connecting sleeves (4), and there are multiple of them. They are used to provide constraint stiffness and absorb and dissipate seismic energy through elastic deformation. as well as A damping box is fitted onto the steel rod (6), and the steel rod (6) is connected to the damping box via the damping spring (5). 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 bar (6) to point B at the constraint point of the damping box, L2 is the length of the steel bar (6) from point B to point C at the connection between the steel bar (6) and the main beam, E is the elastic modulus of the material of the steel bar (6), and I is the moment of inertia of the section of the steel bar (6). Wherein, the total rotation angle of point C for: ， The total horizontal displacement at point C for: ， in: , , d is the diameter of the steel rod (6); The equivalent horizontal constraint stiffness K0 is: K0 = P / , The force exerted on the steel bar (6) at point C is denoted as .

2. The apparatus according to claim 1, characterized in that, The pre-embedded connector (1) is used to constrain horizontal displacement; The device also includes a bolt head nut (2), which is used in conjunction with the pre-embedded connector (1) to fix the steel rod (6) and constrain its vertical displacement.

3. The apparatus according to claim 2, characterized in that, The device further includes: Vertical shock-absorbing buffer pads (3) are set on the upper part of the steel bar (6) to absorb and mitigate vertical impacts and prevent the main beam from coming off.

4. The apparatus according to claim 3, characterized in that, The device further includes: The filler (7), located inside the damping box, is used to dissipate seismic energy through its own high viscoelastic properties.

5. The apparatus according to any one of claims 1 to 4, characterized in that, The device further includes: A pre-drilled hole limiting cover plate (9) is used for positioning the steel bar; a pre-drilled steel plate and a pre-drilled hole (10) are set on the top surface of the pier for installing the steel bar (6). The pre-drilled hole (10) is filled with polysulfide sealant to ensure sealing. The diameter D of the pre-drilled hole (10) is calculated according to the following formula: D = d + S, where d is the diameter of the steel bar and S is the pre-drilled displacement.

6. A construction method for a bridge vibration damping device as described in claim 5, characterized in that, Includes the following steps: The top of the steel bar (6) is hinged to the pre-embedded connector (1) embedded in the upper main beam; A damping box is fitted onto the steel rod (6); The bottom end of the steel bar (6) is fixed to the bridge pier; The damping function is provided by adjusting the connection between the damping spring (5) and the steel rod (6); 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 bar (6) to point B at the constraint point of the damping box, L2 is the length of the steel bar (6) from point B to point C at the connection between the steel bar (6) and the main beam, E is the elastic modulus of the material of the steel bar (6), and I is the moment of inertia of the section of the steel bar (6). Wherein, the total rotation angle of point C for: ， The total horizontal displacement at point C for: ， in: , , d is the diameter of the steel rod (6); The equivalent horizontal constraint stiffness K0 is: K0 = P / , The force exerted on the steel bar (6) at point C is denoted as .

7. The construction method according to claim 6, characterized in that, It also includes the following steps: A connecting sleeve (4) is fitted onto the steel rod (6); Multiple damping springs (5) are vertically connected to the connecting sleeve (4) to provide constraint stiffness and absorb and dissipate seismic energy through elastic deformation.

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