Coordinated seismic mitigation system of high-speed railway bridge considering multiple performance requirements

Abstract

The application discloses a high-speed railway bridge collaborative seismic mitigation and isolation system considering multiple performance requirements, which comprises a single-pin performance controllable isolation bearing and a multidirectional shear type damper, the single-pin performance controllable isolation bearing comprises a top plate, a sliding layer, a shear pin, an intermediate steel plate, a rubber plate, a dust cover, a steel basin and a bottom plate, the shear pin of the single-pin performance controllable isolation bearing is arranged at the center of the bearing and is made of high-strength and high-brittle steel, the top plate of the single-pin performance controllable isolation bearing is provided with a reserved clamping groove, and the intermediate steel plate is provided with a reserved hole, the multidirectional shear type damper comprises a driving plate, a fixed plate, a top plate, a base, a gasket, a long bolt, a cushion block and a driving column, and the fixed plate of the multidirectional shear type damper is fixed through the long bolt fixedly connected with the base and the top plate. The application can effectively guarantee the safety of high-speed running trains and the seismic safety of bridge structures during earthquakes, and can guarantee the large rigidity requirement of high-speed railway bridges during normal operation.

Description

Technical Field

[0001] This invention belongs to the field of bridge vibration reduction and isolation technology, and specifically relates to a combined vibration reduction system for high-speed railway bridges that takes into account the safety of train operation at high speeds, for energy dissipation vibration reduction and vibration isolation of high-speed railway bridges. Background Technology

[0002] For high-speed railways, bridges constitute a large proportion of the entire line, and train intervals are short, making it highly likely that trains will run on bridges during an earthquake. Therefore, ensuring that trains do not suffer serious safety accidents during an earthquake has become a crucial performance requirement that must be considered in the design of high-speed railway bridges. And directly related to train safety are track deformation and dynamic response.

[0003] High-speed railway bridges differ significantly from ordinary highway bridges. To ensure the safety and comfort of trains during normal operation, the overall stiffness requirements of the bridge are extremely high, which is precisely what makes them unsuitable for earthquake resistance. The seismic design of high-speed railway bridges must consider both the stiffness requirements for normal operation and the safety of high-speed trains during an earthquake. Conventional seismic isolation and damping measures can reduce the bridge's seismic response, but they are highly detrimental to the safety of high-speed trains.

[0004] Traditional seismic isolation and damping measures are not suitable for high-speed railway bridges. Therefore, there is an urgent need for a seismic isolation and damping system for high-speed railway bridges that can simultaneously meet the requirements of high stiffness during normal operation, train safety during earthquakes, and bridge structural safety after an earthquake. After years of development, many seismic isolation and damping devices have emerged. The following section presents the advantages and disadvantages of some existing patents.

[0005] The existing patent "A Shear Force Controllable Seismic Isolation Bearing (CN208201626U)" contains multiple shear keys distributed on both sides of the bearing. This design suffers from several drawbacks: firstly, the failure time cannot be guaranteed to be consistent, leading to performance instability and the inability to achieve stable sliding; secondly, its complex construction results in high cost. In this design, the shear keys have a large slenderness ratio, potentially causing uncontrollable mechanical properties due to bending failure, thus hindering the successful achievement of shear failure. In CN208201626U, the shear keys are directly connected to the upper connecting plate and are subjected to both vertical and horizontal loads, resulting in a complex stress state. Furthermore, shear key breakage can easily cause jamming.

[0006] The existing patent, "Impact-Resistant Extra-Large Tonnage Multidirectional Energy Dissipating Damper (CN201611141938.0)," uses a fixed plate that is directly and rigidly connected to the side plate of the damper base. Adding and replacing the fixed plate is cumbersome, and the spacing between the fixed plates cannot be adjusted, resulting in a lack of flexibility and design adaptability, making it difficult to meet diverse seismic requirements. To meet different seismic requirements, this solution requires designing the number and spacing of fixed plates according to the damping force requirements, and then rigidly connecting the fixed plates to the base side plate, which is quite complicated. Otherwise, the damping force may exceed the requirements, resulting in waste; or the damping force may be insufficient, failing to guarantee traffic safety. Furthermore, achieving high damping force and high stiffness requires a large size, suitable for large-span bridges such as suspension bridges and cable-stayed bridges, but not for high-speed railway bridges with limited pier installation space. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies and the aforementioned urgent needs by proposing a combined vibration reduction system for high-speed railway bridges that takes into account the safety of high-speed train operation. This system can effectively ensure the safety of high-speed trains during earthquakes, the seismic safety of bridge structures, and the high stiffness requirements of high-speed railway bridges during normal operation.

[0008] The technical solution adopted in this invention is as follows: a high-speed railway bridge synergistic seismic isolation system considering multiple performance requirements, including a single-pin performance controllable seismic isolation bearing and a multi-directional shear damper; the single-pin performance controllable seismic isolation bearing and the multi-directional shear damper are both set between the main beam and the pier, and the single-pin performance controllable seismic isolation bearing is set on both sides of the multi-directional shear damper.

[0009] The single-pin performance controllable seismic isolation bearing includes a top plate, a slot, a shear pin, a horizontal sliding layer, an intermediate steel plate, a rubber plate, a dust cover, a steel basin, and a bottom plate. The bottom plate is connected to the pier at the bottom and to the steel basin at the top. The top plate is connected to the main beam at the top. A horizontal sliding layer capable of free sliding in all directions is provided below the top plate. A dust cover is provided around the horizontal sliding layer. An intermediate steel plate is provided below the horizontal sliding layer. The lower half of the intermediate steel plate is embedded in the steel basin. A rubber plate is provided between the steel basin and the intermediate steel plate. A shear pin is provided at the center of the single-pin performance controllable seismic isolation bearing. The top end of the shear pin extends into the top plate. A slot is provided in the connection area between the top plate and the shear pin. The size of the slot needs to be determined according to the temperature deformation of the main beam and the allowable deformation of the bearing during an earthquake. A reserved hole of the same size as the shear pin is provided on the intermediate steel plate. The bottom of the shear pin is embedded in the reserved hole.

[0010] The multi-directional shear damper includes a drive plate, a fixed plate, a second top plate, a base, washers, long bolts, pads, and a drive column. One end of the multi-directional shear damper is rigidly connected to the main beam via the second top plate, and the other end is rigidly connected to the pier via the base. A drive column is provided between the second top plate and the base, and a drive plate is provided on the drive column. The long bolts are fixedly connected to the base and the second top plate, and the fixed plate is fixed by the long bolts. The multi-directional shear damper adopts a multi-layer structure with multiple drive plates and fixed plates stacked on top of each other to improve its energy dissipation capacity and achieve multi-directional energy dissipation. Washers and pads are provided between the drive plate and the fixed plate.

[0011] Preferably, the shear pin has a circular or square cross-section, and is made of steel with high shear strength, high brittleness, and a smooth shear surface. The horizontal sliding layer is made of polytetrafluoroethylene (PTFE).

[0012] Preferably, a certain gap, such as 5mm, is left between the top surface of the slot and the end of the shear pin. This ensures that the shear pin does not bear vertical loads, and that under the action of earthquakes E2 and E3, after the shear pin is sheared, the upper part will not be jammed when it enters the slot.

[0013] Preferably, the shear pin is provided with a V-groove, the top of the V-groove being at the same height as the top of the horizontal sliding layer. The top cut of the V-groove is triangular.

[0014] Preferably, the shear gap of the multi-directional shear damper can be adjusted by the height of the pad.

[0015] The working principle of the multi-directional shear damper of this invention is that the damping fluid slides against the fixed plate and the driving plate, converting kinetic energy into heat energy.

[0016] Under normal use, the vertical bearing capacity of this invention is borne by the support, and the horizontal shear force is borne by the shear pin. Under E1 earthquake action, the horizontal shear force is borne by the shear pin. Under E2 and E3 earthquake action, the shear pin of the support is sheared off, playing a seismic isolation role. The impact force at the moment of shearing is borne by the damper, which at the same time provides high stiffness to control track deformation, preventing excessive deformation of the track and thus avoiding catastrophic consequences such as high-speed train derailment. Subsequently, the damper plays an energy dissipation role. The two work together to achieve seismic safety.

[0017] The key innovation of this invention lies in the synergistic effect of the two components, forming a unified whole that works together to meet multiple performance requirements. The single-pin performance controllable seismic isolation bearing, compared to the bearing described in CN208201626U, only has a shear pin in the middle position, and only one of them. This structure effectively prevents the performance instability and inability to achieve stable sliding that may be caused by the inconsistent failure times of multiple shear keys in CN208201626U, while also simplifying the structure and reducing costs. The single-pin performance controllable seismic isolation bearing has a slot in the connection area between the shear pin and the top plate, with a 5mm gap between the top surface of the slot and the end of the shear pin. This ensures that the shear pin only bears horizontal shear force and not vertical pressure, avoiding the complex stress state of the shear key under vertical and horizontal loads as in CN208201626U. Furthermore, after the shear pin is sheared, the upper half can be squeezed into the gap in the middle of the slot, avoiding jamming. Furthermore, the shear pins are made of brittle materials, which cause brittle failure directly when they reach their shear strength. This makes the impact force transmitted to the damper clear and controllable, allowing for precise design based on actual seismic requirements, and making them more suitable for practical engineering applications.

[0018] The damper of this invention features fixed plates connected in series with long bolts to the base and top plate, allowing for flexible adjustment of the number and spacing of the fixed plates as needed, thus offering strong design flexibility. The shear area can be easily changed by increasing or decreasing the number of fixed plate layers; the shear gap can be adjusted by easily increasing or decreasing the spacing of the fixed plates, thereby changing the damping coefficient to adapt to different seismic requirements. This simplifies the design of the damper; it only requires designing the corresponding number and spacing of fixed plates for different seismic requirements, and then easily fixing and adjusting the shear gap using long bolts.

[0019] The beneficial effects of this invention are:

[0020] This invention comprehensively considers the multiple performance requirements of high-speed railway bridges, including the high stiffness requirements for normal operation, the safety requirements for train operation during earthquakes, and the structural safety requirements after an earthquake. It connects a performance-controllable seismic isolation bearing in parallel with a multi-directional shear damper, allowing them to work synergistically. The vertical load of the high-speed railway bridge is borne by the bearings, while the horizontal load during normal operation and under the E1 earthquake is borne by the shear pin in the middle of the bearing. During E2 and E3 earthquakes, the shear pin is sheared, and the impact force at the moment of shearing is borne by the shear damper. This damper provides the high stiffness required to control track deformation at the moment of shear pin shearing, giving high-speed trains sufficient deceleration time to rapidly reduce speed and prevent catastrophic consequences such as derailment. Afterward, the bearings perform seismic isolation, and the damper performs energy dissipation; their synergistic action reduces the seismic response of the bridge structure and ensures its seismic safety. In summary, this invention achieves multiple performance requirements for the seismic resistance of high-speed railway bridges. Attached Figure Description

[0021] Figure 1 A plan view of the combined vibration reduction system for high-speed railway bridges provided by the present invention;

[0022] Figure 2 A schematic diagram illustrating the structural design of the single-pin performance controllable seismic isolation bearing provided by the present invention;

[0023] Figure 3 A cross-sectional view of the single-pin performance controllable seismic isolation bearing provided by the present invention;

[0024] Figure 4 This is a schematic diagram of the structural design of the multi-directional shear damper provided by the present invention. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the drawings described are only some embodiments of the present invention, and not all embodiments.

[0026] like Figures 1 to 4 As shown, the high-speed railway bridge collaborative seismic isolation system considering multiple performance requirements includes a single-pin performance controllable seismic isolation bearing 2 and a multi-directional shear damper 4. The single-pin performance controllable seismic isolation bearing 2 and the multi-directional shear damper 4 are both installed between the main beam 1 and the pier 3. The single-pin performance controllable seismic isolation bearing 2 is installed on both sides of the multi-directional shear damper 4.

[0027] The single-pin performance controllable seismic isolation bearing 2 includes a top plate 5, a slot, a shear pin 6, a horizontal sliding layer 7, a middle steel plate 9, a rubber sheet 10, a dust cover 8, a steel basin 11, and a bottom plate 12. The bottom plate 12 is connected to the pier 3 at the bottom and to the steel basin 11 at the top. The top plate 5 is connected to the main beam 1 at the top. The bottom of the top plate 5 is provided with a horizontal sliding layer 7 that can slide freely in all directions. A dust cover 8 is provided around the horizontal sliding layer 7. A middle steel plate 9 is provided below the sliding layer 7. The lower half of the middle steel plate 9 is embedded in the steel basin 11. A rubber plate 10 is provided between the steel basin 11 and the middle steel plate 9. A shear pin 6 is provided at the center of the single-pin performance controllable seismic isolation bearing 2. The top end of the shear pin 6 extends into the top plate 5. A groove is provided in the connection area between the top plate 5 and the shear pin 6. A reserved hole is provided on the middle steel plate 9, which is the same size as the shear pin 6. The bottom of the shear pin 6 is embedded in the reserved hole.

[0028] The single-pin performance controllable seismic isolation bearing has a shear pin 6 with a cross-sectional shape that can be circular or square, or other shapes as needed. The material is steel with high shear strength and high brittleness. The horizontal sliding layer 7 is made of polytetrafluoroethylene. The position of the shear surface is precisely set on the shear pin 6, that is, a weak layer is set, so that the shear pin 6 will shear at the specified position, thereby reducing the uncertainty of the shear position when the shear pin 6 shears and preventing the bearing from being jammed.

[0029] The multi-directional shear damper 4 includes a drive plate 15, a fixed plate 17, a second top plate 13, a base 20, washers 19, long bolts 18, pads 16, and a drive column 14. One end of the multi-directional shear damper 4 is rigidly connected to the main beam 1 via the second top plate 13, and the other end is rigidly connected to the pier 3 via the base 20. A drive column 14 is provided between the second top plate 13 and the base 20, and a drive plate 15 is provided on the drive column 14. The long bolts 18 are fixedly connected to the base 20 and the second top plate 13, and the fixed plate 17 is fixed by the long bolts 18. The multi-directional shear damper 4 adopts a multi-layer structure with multiple layers of drive plates 15 and fixed plates 17 stacked together to improve its energy dissipation capacity and achieve multi-directional energy dissipation. Washers 19 and pads 16 are provided between the drive plate 15 and the fixed plate 17. The shear gap of the multi-directional shear damper 4 can be adjusted by the height of the pads 16.

[0030] The working principle of this invention is as follows: During normal operation, the vertical bearing capacity is borne by the intermediate steel plate 9 and the rubber plate 10, and the horizontal shear force is borne by the shear pin 6; under the action of E1 earthquake, the horizontal shear force is borne by the shear pin 6; under the action of E2 and E3 earthquake, the shear pin 6 is sheared along the weak surface, and the support slides freely along the horizontal sliding surface, playing a seismic isolation role. The large impact force at the moment of shearing of the shear pin 6 is borne by the multi-directional shear damper 4, which at the same time provides greater stiffness, realizes the stable transformation of the structural system, controls the track from undergoing excessive deformation, avoids catastrophic consequences such as high-speed train derailment, and then plays an energy dissipation role.

[0031] The embodiments of this invention have been described in detail above with reference to the accompanying drawings, but this invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations of these embodiments within the principles and technical concept of this invention will still fall within the protection scope of this invention.

Claims

1. A high-speed railway bridge synergistic seismic isolation and damping system considering multiple performance requirements, characterized in that: It includes a single-pin performance controllable seismic isolation bearing and a multi-directional shear damper; both the single-pin performance controllable seismic isolation bearing and the multi-directional shear damper are installed between the main beam and the pier, with the single-pin performance controllable seismic isolation bearing installed on both sides of the multi-directional shear damper. The single-pin performance controllable seismic isolation bearing includes a top plate, a slot, a shear pin, a horizontal sliding layer, a middle steel plate, a rubber plate, a dust cover, a steel basin, and a bottom plate. The bottom plate is connected to the bridge pier at the bottom and to the steel basin at the top. The top plate is connected to the main beam at the top. A horizontal sliding layer capable of free sliding in all directions is provided below the top plate. A dust cover is provided around the horizontal sliding layer. A middle steel plate is provided below the horizontal sliding layer. The lower half of the middle steel plate is embedded in the steel basin. A rubber plate is provided between the steel basin and the middle steel plate. A shear pin is provided at the center of the single-pin performance controllable seismic isolation bearing. The top end of the shear pin extends into the top plate. A slot is provided in the connection area between the top plate and the shear pin. A reserved hole of the same size as the shear pin is provided on the middle steel plate. The bottom of the shear pin is embedded in the reserved hole. The multi-directional shear damper includes a drive plate, a fixed plate, a second top plate, a base, washers, long bolts, pads, and a drive column. One end of the multi-directional shear damper is rigidly connected to the main beam via the second top plate, and the other end is rigidly connected to the pier via the base. A drive column is provided between the second top plate and the base, and a drive plate is provided on the drive column. The long bolts are fixedly connected to the base and the second top plate, and the fixed plate is fixed by the long bolts. The multi-directional shear damper adopts a multi-layer structure with multiple drive plates and fixed plates stacked on top of each other, and washers and pads are provided between the drive plates and the fixed plates. The shear pin has a circular or square cross-section and is made of steel with high shear strength, high brittleness, and a smooth shear surface; a 5mm gap is left between the top surface of the slot and the end of the shear pin. The shear pin is provided with a V-shaped groove, the top of the V-shaped groove is at the same height as the top of the horizontal sliding layer, and the top cut of the V-shaped groove is triangular.

2. The high-speed railway bridge synergistic seismic isolation and damping system considering multiple performance requirements as described in claim 1, characterized in that: The horizontal slip layer is made of polytetrafluoroethylene.

3. The high-speed railway bridge synergistic seismic isolation and damping system considering multiple performance requirements as described in claim 1, characterized in that: The shear gap of the multi-directional shear damper is adjusted by the height of the pad.

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