Box girder damping reinforcement device and construction method

Abstract

The present application belongs to the technical field of box girder damping reinforcement, and discloses a box girder damping reinforcement device and a construction method, which comprises a damping pad, a reinforcing member, a supporting member and a connecting member. The damping pad comprises a top damping pad on the bottom surface of the top plate of the box girder and a bottom damping pad on the top surface of the bottom plate of the box girder. The top damping pad and the bottom damping pad are supported by the supporting member on both sides, the reinforcing member is arranged on the inner side of the supporting member, the number of the reinforcing member is N (N≥2), the height of the reinforcing member is adjustable, and both ends of the reinforcing member are hemispheres. Grooves corresponding to the hemispheres are formed on the top damping pad and the bottom damping pad, and the hemispheres are tightly arranged in the corresponding grooves. N connecting members are arranged between the supporting members (n≥2). The connecting member passes through the N reinforcing members and is fixedly connected with the supporting member at both ends. The present application not only shortens the transmission path of the load, but also can realize energy transmission, absorption and dissipation under the condition of high frequency and small amplitude vibration. The processing mode can shorten the construction period and facilitate quick disassembly and maintenance.

Description

Technical Field

[0001] This invention belongs to the field of box girder vibration reduction and reinforcement technology, specifically relating to a box girder vibration reduction and reinforcement device and construction method. Background Technology

[0002] Box girders are used in traffic bridges, where dynamic loads from vehicle traffic cause bridge vibrations. Existing vibration reduction and noise reduction methods include installing damping bearings or tuned mass dampers. Damping bearings can suppress the transmission of box girder vibrations to the lower piers, but lack the ability to reduce the vibration of the box girder itself; tuned mass dampers are only effective at reducing vibrations at the bridge's resonant frequency. Furthermore, neither damping bearings nor tuned mass dampers can strengthen the bridge.

[0003] The prior art discloses a bridge vibration reduction and reinforcement device, which is installed inside a box girder and includes a vertical expansion joint, a transmission assembly, and a lateral abutment joint. The vertical expansion joint abuts the transmission assembly against the inner bottom wall of the box girder. One end of the lateral abutment joint is connected to the transmission assembly, and the other end moves away from the transmission assembly along the width direction of the box girder and abuts against the inner side wall of the box girder. The transmission assembly can convert the downward pressure on the vertical expansion joint into a force that drives the lateral abutment joints to move away from each other.

[0004] The above solution distributes the vibration and pressure of the top wall through the side and bottom walls of the box girder, but it still has the following drawbacks: The vibration pressure on the top wall of the box girder is transmitted to the side wall of the box girder via the top plate, vertical piston rod, transmission piston rod, hydraulic medium, and transverse piston rod. The force transmission path is lengthy and has a delayed response. Moreover, it is essentially a load redistribution rather than vibration reduction and reinforcement. Under high-frequency, small-amplitude vibrations, the response is lagging and it cannot effectively absorb and dissipate vibration energy. Furthermore, the above-mentioned solution constructs the force transmission system by filling it with cement, hydraulic oil, and other media on-site, which also has the problems of long construction period, irreversibility, and difficulty in maintenance due to the inability to disassemble quickly. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a box girder vibration reduction and reinforcement device and construction method, which can solve the technical problems of existing technologies that cannot effectively absorb and dissipate vibration energy, and that the construction cycle is long, irreversible, and difficult to disassemble quickly, leading to maintenance difficulties.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In one aspect, a vibration reduction and reinforcement device for box girders is provided, including a damping pad, a reinforcement component, a support component, and a connecting component; The damping pads include a top damping pad disposed on the bottom surface of the box girder top plate and a bottom damping pad disposed on the top surface of the box girder bottom plate; the top and bottom damping pads are supported on both sides by support members, and reinforcing members are disposed inside the support members, the number of which is [number missing]. indivual, ≥2; The height of the reinforcing component is adjustable, and the upper and lower ends of the reinforcing component are hemispheres. The top and bottom damping pads are provided with grooves corresponding to the hemispheres, and the hemispheres are pressed tightly against the corresponding grooves. Setting between support components Connecting components of the channel ≥2; connecting components pass through A reinforcing component with both ends fixedly connected to the supporting component.

[0007] Furthermore, the depth of the groove is less than the radius of the hemisphere, and the depth of the groove is less than the thickness of the bottom damping pad or the top damping pad.

[0008] Furthermore, the reinforcing components include a reinforcing column and a telescopic rod, with the telescopic rod coaxially fixedly connected to the top of the reinforcing column, and the top of the telescopic rod coaxially fixedly connected to the center of the plane of the hemisphere; The reinforcing columns are evenly spaced along the longitudinal direction. There are one connecting hole, and the shape and size of the connecting hole are consistent with those of the connecting component.

[0009] Furthermore, the supporting component includes a support plate body and connecting plates at the upper and lower ends of the support plate body, the connecting plates being connected to the top damping pad or the bottom damping pad via... Fastener connection. ≥2, fasteners are embedded in damping pads.

[0010] Furthermore, both the top damping pad and the bottom damping pad are made of butyl rubber matrix with carbon black and flake mica powder filler added.

[0011] Secondly, a construction method for the aforementioned box girder vibration reduction and reinforcement device is provided, the specific steps of which include: Based on the frequency of the box girder, determine the energy dissipation of the vibration damping and strengthening device within one vibration cycle. The radius of the hemisphere and the length of the damping pad ,width ,thickness And prepare and process damping pads, reinforcing components, connecting components, and supporting components in advance; First, place the bottom damping pad on the top surface of the box girder bottom plate, place the bottom end of the reinforcing member on the bottom damping pad, and fasten the top damping pad on the top hemisphere of the reinforcing member; raise the telescopic rod to drive the top hemisphere of the reinforcing member to press against the top damping pad and lock the telescopic rod. Next, place a support member on one side on the bottom damping pad, and connect the upper and lower ends of the support member to the fasteners embedded in the bottom and top damping pads, so that the connecting member passes through N reinforcing members in sequence; then place the support member on the other side on the bottom damping pad and connect it to the bottom and top damping pads, and finally fix the two ends of the connecting member to the inside of the support members on both sides.

[0012] Furthermore, the energy dissipation of the vibration damping and reinforcement device within one vibration cycle for: ; In the formula: To add damping ratio to the vibration reduction and reinforcement device, it is set to... ; For the equivalent modal mass of the box girder, Take half of the total design mass of the box girder; The vibration amplitude of the box girder is set as follows: ; The natural frequency of the box girder.

[0013] Furthermore, the radius of the hemisphere for: ; In the formula: The minimum thickness of the groove bottom is set to [value]. ; The number of reinforcing components; This is the equivalent dynamic loss modulus of the damping pad; This is a size adjustment factor, set according to structural requirements. .

[0014] Furthermore, the thickness of the damping pad The following relationship must be satisfied: .

[0015] Furthermore, the lengths of the top damping pad and the bottom damping pad The lengths of the top damping pad and the bottom damping pad are the same. Determined by the following formula: ; In the formula: This refers to the span of the box girder; The top damping pad is fitted into the cavity on the bottom surface of the box girder top plate, and the bottom damping pad is fitted into the cavity on the top surface of the box girder bottom plate. The width of the top damping pad... and the width of the bottom damping pad Determined by the following formula: ; ; In the formula: The width of the top plate of the box girder cavity. This refers to the width of the bottom plate of the box girder cavity.

[0016] Compared with the prior art, the advantages and positive effects of this invention are: This invention establishes a series energy dissipation path of "absorption-conduction-reabsorption," which can cut off multiple reflection conditions within the box girder section, avoid the formation of standing waves by the reflection of vibration energy inside the box girder, eliminate the risk of amplification of local stress in the structure due to the superposition effect of standing waves, and improve the dynamic stability of the structure. In addition, the reinforcing components, under the constraints of the supporting and connecting components, work in conjunction with the damping pad to share the load. Compared with active or semi-active control devices that rely on hydraulic oil compression and throttle valve response time, this invention adopts a completely solid-state passive energy dissipation configuration, without the need for working medium filling and pressure build-up processes. This not only shortens the force transmission path but also avoids the response lag problems caused by pressure hysteresis, seal failure, and temperature sensitivity in hydraulic systems. It can achieve faster and more effective energy transfer, absorption, and dissipation even under high-frequency, small-amplitude vibration conditions. Furthermore, this invention uses a prefabricated component assembly method on-site, which avoids the complex construction process of filling cement, hydraulic oil, and other media on-site in existing technologies. This shortens the construction cycle and also makes the device reversible, facilitating rapid disassembly and maintenance. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a schematic diagram of the box girder vibration reduction and reinforcement device installed in the box girder according to Embodiment 1 or Embodiment 2 of the present invention; Figure 2 This is a structural schematic diagram of the box girder vibration reduction and reinforcement device according to Embodiment 1 or Embodiment 2 of the present invention; Figure 3 This is Embodiment 1 or Embodiment 2 of the present invention. Figure 2 Cross-sectional view of AA; Figure 4 This is a cross-sectional view of the top damping pad in Embodiment 1 or Embodiment 2 of the present invention; In the picture: 1. Top damping pad; 11. Groove; 2. Bottom damping pad; 3. First support member; 4. Second support member; 5. First reinforcing member; 51. Connecting hole; 6. Second reinforcing member; 7. First connecting member; 8. Second connecting member. Detailed Implementation

[0019] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] The present invention will now be described in detail with reference to the accompanying drawings.

[0021] Example 1 This embodiment discloses a vibration reduction and reinforcement device for box girders, such as... Figure 1 , Figure 2 As shown, it includes a damping pad, a reinforcing member, a supporting member, and a connecting member. The damping pad is used to absorb and dissipate vibration energy, the reinforcing member is used to improve the load-bearing capacity of the box girder and conduct vibration energy, the supporting member provides structural support for the damping pad, and the connecting member is used to connect the supporting member and the reinforcing member into a whole to enhance the overall stability of the box girder vibration reduction and isolation reinforcement device.

[0022] like Figure 2 As shown, the damping pad includes a top damping pad 1 disposed on the bottom surface of the top plate of the box girder and a bottom damping pad 2 disposed on the top surface of the bottom plate of the box girder. The top damping pad 1 and the bottom damping pad 2 are supported on both sides by support members. Specifically, the support members include a first support member 3 located on the left side of the top damping pad 1 and the bottom damping pad 2, and a second support member 4 located on the right side of the top damping pad 1 and the bottom damping pad 2. It should be noted that in this embodiment, "both sides" refers to both sides of the box girder axis. The support members mainly play a supporting role for the damping pad, so that the damping pad fits tightly against the top and bottom plates of the box girder, ensuring the stability of the damping pad.

[0023] like Figure 2 As shown, the reinforcing members are installed on the inner side of the two supporting members (here, "inner side" refers to the side facing the box girder axis), and the number of reinforcing members is [number missing]. indivual, ≥2. In this embodiment, two reinforcing components are provided, namely the first reinforcing component 5 and the second reinforcing component 6, which are evenly distributed along the width direction of the box girder. It can be understood that by providing multiple reinforcing components, the vibration energy of the top plate of the box girder can be transmitted and the supporting components can be used for support.

[0024] It is important to note that, such as Figure 3 , Figure 4As shown, the height of the reinforcing member is adjustable, and both the upper and lower ends of the reinforcing member are hemispherical. Grooves 11 corresponding to the hemispheres are formed on both the top damping pad 1 and the bottom damping pad 2. Adjusting the height of the reinforcing member allows the hemispheres to be tightly fitted into the corresponding grooves 11, establishing a path for the transmission of load and vibration energy. This design of the hemispheres tightly fitting into the grooves 11 can be seen as a combination of numerous arches, capable of converting the loads on the top plate of the box girder in all directions into pressure that is uniformly transmitted downwards along the axis of the reinforcing member. Simultaneously, it leverages the elastic material properties of the damping pads, maximizing their compressive strength and avoiding stress concentration. Furthermore, under the high-frequency, small-amplitude vibration conditions of vehicles passing over the box girder, the design of the hemispheres tightly fitting into the grooves 11 enables faster and more effective energy transfer, absorption, and dissipation.

[0025] Understandably, under the influence of traffic, the top plate of the box girder vibrates first, and the vibration energy is transmitted downwards to the top damping pad 1. The elastic properties of the top damping pad 1 dissipate the vibration energy, which is then transmitted downwards through the supporting and reinforcing components to the bottom damping pad 2, where it continues to dissipate the vibration energy. Furthermore, the load on the top plate of the box girder is transmitted through the top damping pad 1 to multiple reinforcing components, compressing the bottom damping pad 2. The bottom damping pad 2 generates a reaction force that supports the top plate of the box girder upwards, enabling the box girder vibration reduction and reinforcement device to achieve a self-balancing effect.

[0026] like Figure 2 As shown, a support structure is set between the two support members. Connecting components of the channel ≥2; connecting components pass through A reinforcing member is fixedly connected to the supporting member at both ends. In this embodiment, two connecting members are provided, namely a first connecting member 7 and a second connecting member 8. The first connecting member 7 and the second connecting member 8 are evenly arranged along the height direction of the box girder section, connecting the reinforcing member and the supporting member into a whole to prevent the reinforcing member from deflecting.

[0027] It should be noted that, compared to existing bridge vibration reduction and reinforcement devices that use hydraulic media and piston rods to construct a force transmission system, this device converts vertical pressure into lateral force through hydraulic media, achieving load redistribution rather than direct vibration reduction and reinforcement. This embodiment employs a collaborative working method involving damping pads, reinforcement components, support components, and connecting components. When the box girder vibrates due to traffic, the top damping pad 1 first receives the vibration energy and pressure from the top plate of the box girder. Part of the energy is absorbed and dissipated by the top damping pad 1. Through the tight fit between the hemisphere and the groove 11, the load and vibration are effectively transferred to the reinforcement component. The remaining energy is absorbed and dissipated by the bottom damping pad 2, preventing energy reflection and the formation of standing waves inside the box girder. The reinforcement component, constrained by the support and connecting components, works collaboratively with the damping pads and can also share the load. This collaborative working method not only shortens the load transmission path and avoids the response lag problem that may exist in hydraulic systems, but also achieves faster and more effective energy transfer, absorption, and dissipation under high-frequency, small-amplitude vibration conditions.

[0028] Under the combined action of the normal constraints of the supporting members and the tangential / rotational constraints of the connecting members, the reinforced member forms a statically determinate or statically indeterminate support system with well-defined boundary conditions. This system not only constrains the out-of-plane instability deformation of the reinforced member, but also achieves a controllable distribution of the load sharing ratio through the composite layered interface with the upper and lower damping pads. That is, part of the load is transferred through the compressive deformation of the damping pads, and part of the load is directly borne by the rigid members. The two work in parallel, so that the reinforced member is in a composite stress state of bending, shearing and local bearing, which can improve the local stiffness and fatigue life of the top plate-web connection area of ​​the box girder.

[0029] In addition, the damping pad, reinforcing component, supporting component and connecting component of this embodiment can be prefabricated and assembled on site. This avoids the complicated construction process of filling cement, hydraulic oil and other media on site in the prior art, shortens the construction cycle and also makes the device reversible, which is convenient for quick disassembly and maintenance, and solves the problem of difficult maintenance in the prior art.

[0030] like Figure 4As shown, the depth of groove 11 is less than the radius of the hemisphere, and the depth of groove 11 is less than the thickness of the top damping pad 1 or the bottom damping pad 2. It can be understood that the depth of groove 11 being less than the radius of the hemisphere means that the hemisphere cannot be completely embedded inside groove 11. Box girder vibration includes components in multiple directions, including vertical, horizontal, longitudinal, and torsional. Relative micro-slippage will occur between the hemisphere and the groove surface. The hemisphere always maintains a state of partial embedding and partial exposure, with continuous normal pressure at the contact interface. Coulomb frictional heat is generated during micro-slippage, converting vibrational mechanical energy into heat energy for dissipation. Furthermore, the initial contact area between the hemisphere and groove 11 is small, with low stiffness and high damping, resulting in good suppression of high-frequency, small-amplitude vibrations. As the damping pads accumulate creep, the contact area and stiffness between the hemisphere and groove 11 increase, and the contact stress decreases with increasing area, resulting in a more uniform load distribution. The vibration reduction effect will gradually decrease, but it will not suddenly lose its load-bearing capacity. Maintenance personnel can regularly check the aging of the damping pads and replace them before failure, avoiding sudden accidents. In addition, the depth of the groove 11 is less than the thickness of the damping pad, which means that the groove 11 will not penetrate the damping pad, thus preventing the hemisphere from contacting the top or bottom plate of the box girder and ensuring the buffering and vibration reduction effect of the damping pad.

[0031] It should be noted that this design takes into account the possibility of permanent, irreversible deformation of the damping pad during long-term operation. The depth of the groove 11 is less than the radius of the hemisphere, and also less than the thickness of the top damping pad 1 or the bottom damping pad 2. This is to provide a safety threshold. When the groove 11 deforms, the hemisphere sinks into it, further increasing the contact area between the hemisphere and the groove 11, resulting in a more uniform load distribution and allowing sufficient time for periodic maintenance. It also prevents the hemisphere from penetrating the damping pad and causing a rigid impact. Furthermore, the difference between the depth of the groove 11 and the radius of the hemisphere serves as a deformation allowance. During periodic inspections, operators can measure this allowance to determine whether the damping pad has reached its service limit and needs replacement, enabling quantitative management.

[0032] In this embodiment, the reinforcing components include a reinforcing column and a telescopic rod. The top of the reinforcing column is coaxially and fixedly connected to the telescopic rod, and the top of the telescopic rod is coaxially and fixedly connected to the center of the plane of the hemisphere. The coaxiality of the reinforcing column, telescopic rod, and hemisphere ensures uniform force transmission and structural stability. Figure 3 As shown, the reinforcing column has n connecting holes 51 evenly opened along the longitudinal direction. The shape and size of the connecting holes are consistent with those of the connecting components. These connecting holes provide a passage for the connecting components to pass through, ensuring that the connecting components can stably fix the reinforcing components.

[0033] It should be noted that the reinforcing components, connecting components, and supporting components are all made of high-strength metal materials, such as steel or alloy materials. The cross-sectional shape is designed to be circular or square according to load-bearing requirements to optimize their compressive and bending resistance. The telescopic rod is used to adjust the height of the reinforcing component during installation, ensuring that the hemispheres at the top and bottom of the reinforcing component can be engaged in the grooves during installation and can tighten the top damping pad 1 and bottom damping pad 2 after installation. In some embodiments, the telescopic rod can adopt a sleeve structure, locked by inserting pins or tightening bolts.

[0034] like Figure 2 As shown, the supporting component includes a support plate body and connecting plates at the upper and lower ends of the support plate body. The connecting plates are connected to the top damping pad 1 or the bottom damping pad 2 via... Fastener connection. ≥2, fasteners are embedded in damping pads. For example... Figure 1 As shown, the connecting plates are the bottom connecting plate connecting to the bottom damping pad 2 and the top connecting plate connecting to the top damping pad 1, wherein the width of the top connecting plate is greater than the width of the bottom connecting plate. This design fits the characteristic of the box girder cross-section being larger at the top and smaller at the bottom, facilitating the transfer of loads from the top plate of the box girder.

[0035] In this embodiment, unlike the flexible connection of the reinforcing member, the supporting member is firmly fixed to the top damping pad and the bottom damping pad through multiple pre-embedded fasteners, forming an integral supporting frame with the damping pad, which can resist horizontal lateral displacement and prevent large rotation or slippage between the reinforcing member and the damping pad.

[0036] Understandably, fasteners are general-purpose components used for mechanical connections. They can be bolts or screws, and M fasteners are used for connection to provide multi-point fixation, improving the stability and load-bearing capacity of the connection. To enhance the reliability and durability of the connection, the fasteners are placed in a predetermined position before the damping pad material (such as butyl rubber matrix) is molded or cured, so that the fasteners and damping pad material form a tight mechanical interlock.

[0037] In this embodiment, both the top damping pad 1 and the bottom damping pad 2 are made of butyl rubber matrix with carbon black and flake mica powder fillers. It should be noted that the butyl rubber matrix has excellent airtightness, aging resistance, and vibration damping performance. Carbon black, as a reinforcing filler, is used to improve the tensile strength, tear strength, and abrasion resistance of the rubber. Flake mica powder, as a functional filler, improves the interlaminar shear damping, tear resistance, and aging resistance of the material. This design enables the damping pads to have unidirectional and bidirectional deformation capabilities. When the box girder is subjected to vertical vibration, the damping pads can effectively absorb and dissipate energy through their unidirectional compressive deformation capability. When the box girder is subjected to horizontal shear vibration or torsional vibration, the damping pads, with their bidirectional deformation capability, especially shear deformation capability, effectively absorb and convert this lateral vibration energy.

[0038] Example 2 This embodiment discloses a method for vibration reduction and reinforcement of box girders, which utilizes a box girder vibration reduction and reinforcement device disclosed in Embodiment 1. The specific steps include: Based on the frequency of the box girder, determine the energy dissipation of the vibration damping and strengthening device within one vibration cycle. The radius of the hemisphere and the length of the damping pad ,width ,thickness And prepare and process damping pads, reinforcing components, connecting components, and supporting components in advance; First, place the bottom damping pad on the top surface of the box girder bottom plate, place the bottom end of the reinforcing member on the bottom damping pad, and fasten the top damping pad on the top hemisphere of the reinforcing member; raise the telescopic rod to drive the top hemisphere of the reinforcing member to press against the top damping pad and lock the telescopic rod. Next, place a support member on one side on the bottom damping pad, and connect the upper and lower ends of the support member to the fasteners embedded in the bottom and top damping pads, so that the connecting member passes through N reinforcing members in sequence; then place the support member on the other side on the bottom damping pad and connect it to the bottom and top damping pads, and finally fix the two ends of the connecting member to the inside of the support members on both sides.

[0039] It should be noted that the box girder vibration reduction and reinforcement device in this embodiment is placed at the splice of adjacent box girders. The top damping pad 1 is first subjected to the vibration of the bridge body and the vibration is transmitted to the bottom damping pad 2 through the reinforcement component. The two damping pads absorb and dissipate energy at the same time. The load borne by the bridge body is also transmitted to the reinforcement component and the support component through the top damping pad 1, so that the reinforcement component and the damping pad are loaded at the same time, achieving a self-balancing effect.

[0040] Understandably, this embodiment, by setting a bottom damping pad, reinforcing components, and a top damping pad inside the box girder, can establish a series energy dissipation path of absorption, conduction, and re-absorption, thereby cutting off multiple reflection conditions within the box girder section, preventing vibration energy from reflecting inside the box girder to form standing waves, eliminating the risk of amplification of local stress in the structure due to the superposition effect of standing waves, and improving the dynamic stability of the structure. Furthermore, the reinforcing components, under the constraints of the supporting and connecting components, work in conjunction with the damping pads to share the load. This embodiment uses a prefabricated component assembly method on-site, which also avoids the complex construction process of filling cement, hydraulic oil, and other media on-site, shortening the construction cycle and making the device reversible, facilitating rapid disassembly and maintenance.

[0041] Specifically, the energy dissipation of the vibration damping and strengthening device within one vibration cycle. for: ; In the formula: To add damping ratio to the vibration reduction and reinforcement device, reference was made to experience in similar vibration reduction projects (such as the requirements in GB50463-2019, "Engineering Vibration Isolation Design Standard," and sample values ​​from the article "Experimental Study on Mechanical Properties of High Damping Vibration Reduction (Seismic) Rubber Materials"). Considering that the vibration reduction device in this embodiment is not entirely rubber damping and needs to maintain continuous energy dissipation, the damping ratio was set based on experience in bridge engineering. ; This represents the maximum energy storage capacity for the box girder vibration. The maximum energy storage of box girder vibration when using the single-degree-of-freedom approximation for: ; In the formula: The equivalent modal mass of the box girder is given; box girders are mostly simply supported beams. Take half of the total design mass of the box girder; The vibration amplitude of the box girder was set based on dynamic load tests and engineering experience. It should be explained that the dynamic load test here is based on the dynamic load test method specified in the "Specifications for Load Testing of Highway Bridges" (JTG / T J21-01-2015). After measuring the vertical acceleration, the vibration amplitude is calculated through the simple harmonic vibration displacement-acceleration relationship. Engineering experience can be referenced in the "Specifications for Wind-Resistant Design of Highway Bridges" (JTG / T 3360-01—2018), which states that the peak vertical acceleration caused by bridge flutter under wind should not exceed 1.1 m / s². 2At a frequency of 3Hz, the vibration amplitude should not exceed 3.09mm; furthermore, the paper "Integrated Management Method of Line-Bridge for Long-Span Railway Suspension Bridges Based on Traffic Performance" mentions that the vertical acceleration should not exceed 1.3m / s². 2 The calculated vibration amplitude should not exceed 3.65 mm.

[0042] , where is the angular frequency of the box girder's vibration. Let be the natural frequency of the box girder. The natural frequency of a box girder as a simply supported beam can be determined through design conditions in structural mechanics. It can be determined based on the design mass, elastic modulus, and moment of inertia of the box girder.

[0043] Combining the above equations, we can see the energy dissipation of the vibration damping and reinforcement device within one vibration cycle. for: .

[0044] In this embodiment, the energy dissipation of the vibration damping and reinforcement device within one vibration cycle is determined. Afterwards, it can be determined that the vibration damping and reinforcement device contains... The total energy dissipation of the bottom damping pad and top damping pad corresponding to each reinforcing component in one vibration cycle. ≥ .

[0045] Vibration damping and reinforcement devices The total energy dissipation of the bottom damping pad and top damping pad corresponding to each reinforcing component in one vibration cycle for: ; ; In the formula: The energy dissipation of the bottom damping pad and top damping pad corresponding to a reinforcing component in one vibration cycle; The energy dissipation of a single damping pad in one vibration cycle; In this embodiment, the energy dissipation of a single damping pad in one vibration cycle for: ; ; ; ; In the formula: Energy density per unit volume of a single damping pad during one vibration cycle; The equivalent dynamic loss modulus of the damping pad can be determined by compression mode dynamic mechanical testing in accordance with GB / T 9870.1-2006, "Determination of dynamic properties of vulcanized rubber or thermoplastic rubber - Part 1 - General rules". The test conditions are set as room temperature, design operating frequency, and small strain amplitude, which are consistent with the working conditions of the vehicle vibrating when passing over the box girder in this embodiment.

[0046] This represents the compressive displacement amplitude of a single damping pad. It should be explained that the axial stiffness of the reinforcing member in this embodiment is much greater than the compressive stiffness of the damping pad, and its own axial deformation can be ignored; and the top and bottom damping pads are the same, so it is assumed that the compressive stiffness of the top and bottom damping pads is the same, so the total vibration amplitude is borne equally by the top and bottom. This is the minimum thickness of the groove bottom, to prevent the hemisphere from penetrating the damping pad and causing a rigid collision with the box girder. ; The energy dissipation volume of a single damping pad under localized pressure. Let be the projected area of ​​the hemispherical contact damping pad. , Let the radius of the contact area between the hemisphere and the damping pad be the projected radius. , The depth of the groove. , This is the size adjustment factor. The radius of the hemisphere; In this embodiment, Defined as the depth of the damping pad groove With the radius of the hemisphere The ratio is set according to the construction requirements. This is because when When the depth is less than 0.3, the hemisphere is embedded too shallowly in the groove, the contact area between the hemisphere surface and the groove is too small, and the local contact compressive stress may exceed the allowable bearing capacity of the damping pad. Furthermore, insufficient embedding depth of the hemisphere increases the difficulty of installation and alignment, making it impossible to guarantee stable force transmission and energy dissipation. When the value is greater than 0.6, the depth of the hemisphere embedded in the groove is too large. Under long-term vibration, the hemisphere may penetrate the damping pad and have a rigid collision with the bottom plate of the box girder.

[0047] Therefore ; Therefore ; Therefore ; To meet the energy dissipation target for vibration reduction of box girders, i.e. The radius of the hemisphere can be solved by combining the equations. for: .

[0048] It is understandable that after calculating the radius of the hemisphere... Afterwards, according to It can be known that the groove of the damping pad is ; The thickness of the damping pad The following relationship must be satisfied: ; Damping pad thickness The depth of the groove needs to be greater than the sum of the minimum depth of the groove bottom to ensure that the damping pad can meet the energy dissipation requirements. .

[0049] In this embodiment, since the vibration damping and reinforcement device is not arranged along the entire length of the box girder, and the box girder is a simply supported beam with its two ends being areas prone to vibration, the vibration damping and reinforcement device is mainly installed at both ends of the box girder. To ensure the continuity of load transfer and energy dissipation, the lengths of the top damping pad and the bottom damping pad are... If they are the same, then the lengths of the top damping pad and the bottom damping pad are... Determined by the following formula: ; In the formula: The span of the box girder (i.e., the length of a single box girder). In this embodiment, the length of the damping pad is... Setting the span to 1 / 9-1 / 6 of the box girder can meet the requirements of the vibration reduction and strengthening device to cover the areas of frequent vibration at both ends of the box girder, realize the structural requirements of vibration reduction and energy dissipation and local strengthening, and ensure convenient construction and installation when installed at both ends of the box girder.

[0050] It is understood that in this embodiment, the top damping pad is fitted into the cavity on the bottom surface of the box girder top plate, and the bottom damping pad is fitted into the cavity on the top surface of the box girder bottom plate. Therefore, the width of the top damping pad... and the width of the bottom damping pad Determined by the following formula: ; ; In the formula: The width of the top plate of the box girder cavity. This refers to the width of the bottom plate of the box girder cavity.

[0051] In one specific implementation, the known parameters of the box girder include: the equivalent modal mass of the box girder. span The width of the top plate of the box girder cavity The width of the box girder cavity bottom plate The frequency of the box girder Vibration amplitude of box girder .

[0052] The known parameters of the vibration damping and strengthening device are: the additional damping ratio of the vibration damping and strengthening device. The equivalent dynamic loss modulus of the damping pad Number of reinforcing components Then the energy dissipation of the vibration damping and reinforcement device within one vibration cycle is determined. The radius of the hemisphere and the length of the damping pad ,width ,thickness The following can be calculated: Determine the energy dissipation of the vibration damping and reinforcement device within one vibration cycle. : =

[0053] J; Determine the radius of the hemisphere : Based on the structural requirements, the size adjustment factor is taken. To prevent the hemisphere from penetrating the damping pad and causing a rigid collision with the box girder, the minimum thickness of the groove bottom is taken. ,but: ; Pick ; Determine the length of the damping pad: Length of top damping pad and the length of the bottom damping pad ; Determine the width of the damping pad: Width of top damping pad ; Width of bottom damping pad ; Determine the thickness of the damping pad based on the geometric dimensions. : m; Pick .

[0054] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A vibration reduction and reinforcement device for box girders, characterized in that, Includes damping pads, reinforcing components, supporting components, and connecting components; The damping pads include a top damping pad disposed on the bottom surface of the box girder top plate and a bottom damping pad disposed on the top surface of the box girder bottom plate; the top and bottom damping pads are supported on both sides by support members, and reinforcing members are disposed inside the support members, the number of which is [number missing]. indivual, ≥2; The height of the reinforcing member is adjustable, and the upper and lower ends of the reinforcing member are hemispheres. The top damping pad and the bottom damping pad are both provided with grooves corresponding to the hemispheres, and the hemispheres are pressed tightly against the corresponding grooves. The support components are arranged between Connecting components of the channel ≥2; connecting components pass through A reinforcing component with both ends fixedly connected to the supporting component.

2. The box girder vibration reduction and reinforcement device as described in claim 1, characterized in that, The depth of the groove is less than the radius of the hemisphere, and the depth of the groove is less than the thickness of the top damping pad or the bottom damping pad.

3. The box girder vibration reduction and reinforcement device as described in claim 1, characterized in that, The reinforcing component includes a reinforcing column and a telescopic rod. The top of the reinforcing column is coaxially and fixedly connected to the telescopic rod, and the top of the telescopic rod is coaxially and fixedly connected to the center of the plane of the hemisphere. The reinforcing columns are evenly spaced along the longitudinal direction. There are one connecting hole, and the shape and size of the connecting hole are consistent with those of the connecting component.

4. The box girder vibration reduction and reinforcement device as described in claim 1, characterized in that, The supporting component includes a support plate body and connecting plates at the upper and lower ends, the connecting plates being connected to the top damping pad or the bottom damping pad via... Fastener connection. ≥2, fasteners are embedded in damping pads.

5. The box girder vibration reduction and reinforcement device as described in claim 1, characterized in that, Both the top and bottom damping pads are made of butyl rubber matrix with carbon black and flake mica powder filler.

6. A construction method for a box girder vibration reduction and reinforcement device as described in any one of claims 1-5, characterized in that, The specific steps include: Based on the frequency of the box girder, determine the energy dissipation of the vibration damping and strengthening device within one vibration cycle. radius of the hemisphere and the length of the damping pad ,width ,thickness And prepare and process damping pads, reinforcing components, connecting components, and supporting components in advance; First, place the bottom damping pad on the top surface of the box girder bottom plate, place the bottom end of the reinforcing member on the bottom damping pad, and fasten the top damping pad on the top hemisphere of the reinforcing member; raise the telescopic rod to drive the top hemisphere of the reinforcing member to press against the top damping pad and lock the telescopic rod. Next, place a support member on one side on the bottom damping pad, and connect the upper and lower ends of the support member to the fasteners embedded in the bottom and top damping pads, so that the connecting member passes through N reinforcing members in sequence; then place the support member on the other side on the bottom damping pad and connect it to the bottom and top damping pads, and finally fix the two ends of the connecting member to the inside of the support members on both sides.

7. The construction method of the box girder vibration reduction and reinforcement device as described in claim 6, characterized in that, The vibration damping and reinforcement device consumes energy during one vibration cycle. for: ； In the formula: To add damping ratio to the vibration reduction and reinforcement device, it is set to... ; For the equivalent modal mass of the box girder, Take half of the total design mass of the box girder; The vibration amplitude of the box girder is set as follows: ; The natural frequency of the box girder.

8. The construction method of the box girder vibration reduction and reinforcement device as described in claim 6, characterized in that, The radius R of the hemisphere is: ； In the formula: The minimum thickness of the groove bottom is set to [value]. ; The number of reinforcing components; The equivalent dynamic loss modulus of the damping pad; This is a size adjustment factor, set according to structural requirements. .

9. The construction method of the box girder vibration reduction and reinforcement device as described in claim 6, characterized in that, The thickness of the damping pad The following relationship must be satisfied: 。 10. The construction method of the box girder vibration reduction and reinforcement device as described in claim 6, characterized in that, The lengths of the top damping pad and the bottom damping pad The lengths of the top damping pad and the bottom damping pad are the same. Determined by the following formula: ； In the formula: This refers to the span of the box girder; The top damping pad is fitted into the cavity on the bottom surface of the box girder top plate, and the bottom damping pad is fitted into the cavity on the top surface of the box girder bottom plate. The width of the top damping pad... and the width of the bottom damping pad Determined by the following formula: ； ； In the formula: The width of the top plate of the box girder cavity. This refers to the width of the bottom plate of the box girder cavity.

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